33 files changed, 4140 insertions, 258 deletions

diff --git a/lib/Makefile b/lib/Makefile
index 812f721c..f4ade9a6 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -1,7 +1,7 @@
-src := bitmap.c bitops.c blake2s.c blake2b.c checksum.c event.c flowspec.c idm.c ip.c lists.c mac.c md5.c mempool.c net.c patmatch.c printf.c resource.c sha1.c sha256.c sha512.c slab.c slists.c strtoul.c tbf.c timer.c xmalloc.c
+src := a-path.c a-set.c bitmap.c bitops.c blake2s.c blake2b.c checksum.c event.c flowspec.c idm.c ip.c lists.c mac.c md5.c mempool.c net.c patmatch.c printf.c rcu.c resource.c sha1.c sha256.c sha512.c slab.c slists.c strtoul.c tbf.c timer.c xmalloc.c
 obj := $(src-o-files)
 $(all-daemon)
 
-tests_src := bitmap_test.c heap_test.c buffer_test.c event_test.c flowspec_test.c bitops_test.c patmatch_test.c fletcher16_test.c slist_test.c checksum_test.c lists_test.c mac_test.c ip_test.c hash_test.c printf_test.c slab_test.c
+tests_src := a-set_test.c a-path_test.c bitmap_test.c heap_test.c buffer_test.c event_test.c flowspec_test.c bitops_test.c patmatch_test.c fletcher16_test.c slist_test.c checksum_test.c lists_test.c mac_test.c ip_test.c hash_test.c printf_test.c slab_test.c type_test.c
 tests_targets := $(tests_targets) $(tests-target-files)
 tests_objs := $(tests_objs) $(src-o-files)
diff --git a/lib/a-path.c b/lib/a-path.c
new file mode 100644
index 00000000..a7a22e40
--- /dev/null
+++ b/lib/a-path.c
@@ -0,0 +1,936 @@
+/*
+ *	BIRD -- Path Operations
+ *
+ *	(c) 2000 Martin Mares <mj@ucw.cz>
+ *	(c) 2000 Pavel Machek <pavel@ucw.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#include "nest/bird.h"
+#include "nest/rt.h"
+#include "lib/attrs.h"
+#include "lib/resource.h"
+#include "lib/unaligned.h"
+#include "lib/string.h"
+#include "filter/data.h"
+
+// static inline void put_as(byte *data, u32 as) { put_u32(data, as); }
+// static inline u32 get_as(byte *data) { return get_u32(data); }
+
+#define put_as put_u32
+#define get_as get_u32
+#define BS  4	/* Default block size of ASN (autonomous system number) */
+
+#define BAD(DSC, VAL) ({ err_dsc = DSC; err_val = VAL; goto bad; })
+
+int
+as_path_valid(byte *data, uint len, int bs, int sets, int confed, char *err, uint elen)
+{
+  byte *pos = data;
+  char *err_dsc = NULL;
+  uint err_val = 0;
+
+  while (len)
+  {
+    if (len < 2)
+      BAD("segment framing error", 0);
+
+    /* Process one AS path segment */
+    uint type = pos[0];
+    uint slen = 2 + bs * pos[1];
+
+    if (len < slen)
+      BAD("segment framing error", len);
+
+    switch (type)
+    {
+    case AS_PATH_SET:
+      if (!sets)
+	BAD("AS_SET segment", type);
+      break;
+
+    case AS_PATH_SEQUENCE:
+      break;
+
+    case AS_PATH_CONFED_SEQUENCE:
+      if (!confed)
+	BAD("AS_CONFED_SEQUENCE segment", type);
+      break;
+
+    case AS_PATH_CONFED_SET:
+      if (!sets || !confed)
+	BAD("AS_CONFED_SET segment", type);
+      break;
+
+    default:
+      BAD("unknown segment", type);
+    }
+
+    if (pos[1] == 0)
+      BAD("zero-length segment", type);
+
+    pos += slen;
+    len -= slen;
+  }
+
+  return 1;
+
+bad:
+  if (err)
+    if (bsnprintf(err, elen, "%s (%u) at %d", err_dsc, err_val, (int) (pos - data)) < 0)
+      err[0] = 0;
+
+  return 0;
+}
+
+int
+as_path_16to32(byte *dst, const byte *src, uint len)
+{
+  byte *dst0 = dst;
+  const byte *end = src + len;
+  uint i, n;
+
+  while (src < end)
+  {
+    n = src[1];
+    *dst++ = *src++;
+    *dst++ = *src++;
+
+    for (i = 0; i < n; i++)
+    {
+      put_u32(dst, get_u16(src));
+      src += 2;
+      dst += 4;
+    }
+  }
+
+  return dst - dst0;
+}
+
+int
+as_path_32to16(byte *dst, const byte *src, uint len)
+{
+  byte *dst0 = dst;
+  const byte *end = src + len;
+  uint i, n;
+
+  while (src < end)
+  {
+    n = src[1];
+    *dst++ = *src++;
+    *dst++ = *src++;
+
+    for (i = 0; i < n; i++)
+    {
+      put_u16(dst, get_u32(src));
+      src += 4;
+      dst += 2;
+    }
+  }
+
+  return dst - dst0;
+}
+
+int
+as_path_contains_as4(const struct adata *path)
+{
+  const byte *pos = path->data;
+  const byte *end = pos + path->length;
+  uint i, n;
+
+  while (pos < end)
+  {
+    n = pos[1];
+    pos += 2;
+
+    for (i = 0; i < n; i++)
+    {
+      if (get_as(pos) > 0xFFFF)
+	return 1;
+
+      pos += BS;
+    }
+  }
+
+  return 0;
+}
+
+int
+as_path_contains_confed(const struct adata *path)
+{
+  const byte *pos = path->data;
+  const byte *end = pos + path->length;
+
+  while (pos < end)
+  {
+    uint type = pos[0];
+    uint slen = 2 + BS * pos[1];
+
+    if ((type == AS_PATH_CONFED_SEQUENCE) ||
+	(type == AS_PATH_CONFED_SET))
+      return 1;
+
+    pos += slen;
+  }
+
+  return 0;
+}
+
+struct adata *
+as_path_strip_confed(struct linpool *pool, const struct adata *path)
+{
+  struct adata *res = lp_alloc_adata(pool, path->length);
+  const byte *src = path->data;
+  const byte *end = src + path->length;
+  byte *dst = res->data;
+
+  while (src < end)
+  {
+    uint type = src[0];
+    uint slen = 2 + BS * src[1];
+
+    /* Copy regular segments */
+    if ((type == AS_PATH_SET) || (type == AS_PATH_SEQUENCE))
+    {
+      memcpy(dst, src, slen);
+      dst += slen;
+    }
+
+    src += slen;
+  }
+
+  /* Fix the result length */
+  res->length = dst - res->data;
+
+  return res;
+}
+
+struct adata *
+as_path_prepend2(struct linpool *pool, const struct adata *op, int seq, u32 as)
+{
+  struct adata *np;
+  const byte *pos = op->data;
+  uint len = op->length;
+
+  if (len && (pos[0] == seq) && (pos[1] < 255))
+  {
+    /* Starting with matching segment => just prepend the AS number */
+    np = lp_alloc_adata(pool, len + BS);
+    np->data[0] = seq;
+    np->data[1] = pos[1] + 1;
+    put_as(np->data + 2, as);
+
+    uint dlen = BS * pos[1];
+    memcpy(np->data + 2 + BS, pos + 2, dlen);
+    ADVANCE(pos, len, 2 + dlen);
+  }
+  else
+  {
+    /* Create a new path segment */
+    np = lp_alloc_adata(pool, len + 2 + BS);
+    np->data[0] = seq;
+    np->data[1] = 1;
+    put_as(np->data + 2, as);
+  }
+
+  if (len)
+  {
+    byte *dst = np->data + 2 + BS * np->data[1];
+
+    memcpy(dst, pos, len);
+  }
+
+  return np;
+}
+
+
+struct adata *
+as_path_to_old(struct linpool *pool, const struct adata *path)
+{
+  struct adata *res = lp_alloc_adata(pool, path->length);
+  byte *pos = res->data;
+  byte *end = pos + res->length;
+  uint i, n;
+  u32 as;
+
+  /* Copy the whole path */
+  memcpy(res->data, path->data, path->length);
+
+  /* Replace 32-bit AS numbers with AS_TRANS */
+  while (pos < end)
+  {
+    n = pos[1];
+    pos += 2;
+
+    for (i = 0; i < n; i++)
+    {
+      as = get_as(pos);
+      if (as > 0xFFFF)
+	put_as(pos, AS_TRANS);
+
+      pos += BS;
+    }
+  }
+
+  return res;
+}
+
+/*
+ * Cut the path to the length @num, measured to the usual path metric. Note that
+ * AS_CONFED_* segments have zero length and must be added if they are on edge.
+ */
+struct adata *
+as_path_cut(struct linpool *pool, const struct adata *path, uint num)
+{
+  const byte *pos = path->data;
+  const byte *end = pos + path->length;
+
+  while (pos < end)
+  {
+    uint t = pos[0];
+    uint l = pos[1];
+    uint n = 0;
+
+    switch (t)
+    {
+    case AS_PATH_SET:			n = 1; break;
+    case AS_PATH_SEQUENCE:		n = l; break;
+    case AS_PATH_CONFED_SEQUENCE:	n = 0; break;
+    case AS_PATH_CONFED_SET:		n = 0; break;
+    default: bug("as_path_cut: Invalid path segment");
+    }
+
+    /* Cannot add whole segment, so try partial one and finish */
+    if (num < n)
+    {
+      const byte *nend = pos;
+      if (num)
+	nend += 2 + BS * num;
+
+      struct adata *res = lp_alloc_adata(pool, path->length);
+      res->length = nend - (const byte *) path->data;
+      memcpy(res->data, path->data, res->length);
+
+      if (num)
+      {
+	byte *dpos = ((byte *) res->data) + (pos - (const byte *) path->data);
+	dpos[1] = num;
+      }
+
+      return res;
+    }
+
+    num -= n;
+    pos += 2 + BS * l;
+  }
+
+  struct adata *res = lp_alloc_adata(pool, path->length);
+  res->length = path->length;
+  memcpy(res->data, path->data, res->length);
+  return res;
+}
+
+/*
+ * Merge (concatenate) paths @p1 and @p2 and return the result.
+ * In contrast to other as_path_* functions, @p1 and @p2 may be reused.
+ */
+const struct adata *
+as_path_merge(struct linpool *pool, const struct adata *p1, const struct adata *p2)
+{
+  if (p1->length == 0)
+    return p2;
+
+  if (p2->length == 0)
+    return p1;
+
+  struct adata *res = lp_alloc_adata(pool, p1->length + p2->length);
+  memcpy(res->data, p1->data, p1->length);
+  memcpy(res->data + p1->length, p2->data, p2->length);
+
+  return res;
+}
+
+void
+as_path_format(const struct adata *path, byte *bb, uint size)
+{
+  buffer buf = { .start = bb, .pos = bb, .end = bb + size }, *b = &buf;
+  const byte *pos = path->data;
+  const byte *end = pos + path->length;
+  const char *ops, *cls;
+
+  b->pos[0] = 0;
+
+  while (pos < end)
+  {
+    uint type = pos[0];
+    uint len  = pos[1];
+    pos += 2;
+
+    switch (type)
+    {
+    case AS_PATH_SET:			ops = "{";	cls = "}";	break;
+    case AS_PATH_SEQUENCE:		ops = NULL;	cls = NULL;	break;
+    case AS_PATH_CONFED_SEQUENCE:	ops = "(";	cls = ")";	break;
+    case AS_PATH_CONFED_SET:		ops = "({";	cls = "})";	break;
+    default: bug("Invalid path segment");
+    }
+
+    if (ops)
+      buffer_puts(b, ops);
+
+    while (len--)
+    {
+      buffer_print(b, len ? "%u " : "%u", get_as(pos));
+      pos += BS;
+    }
+
+    if (cls)
+      buffer_puts(b, cls);
+
+    if (pos < end)
+      buffer_puts(b, " ");
+  }
+
+  /* Handle overflow */
+  if (b->pos == b->end)
+    strcpy(b->end - 12, "...");
+}
+
+int
+as_path_getlen(const struct adata *path)
+{
+  const byte *pos = path->data;
+  const byte *end = pos + path->length;
+  uint res = 0;
+
+  while (pos < end)
+  {
+    uint t = pos[0];
+    uint l = pos[1];
+    uint n = 0;
+
+    switch (t)
+    {
+    case AS_PATH_SET:			n = 1; break;
+    case AS_PATH_SEQUENCE:		n = l; break;
+    case AS_PATH_CONFED_SEQUENCE:	n = 0; break;
+    case AS_PATH_CONFED_SET:		n = 0; break;
+    default: bug("as_path_getlen: Invalid path segment");
+    }
+
+    res += n;
+    pos += 2 + BS * l;
+  }
+
+  return res;
+}
+
+int
+as_path_get_last(const struct adata *path, u32 *orig_as)
+{
+  const byte *pos = path->data;
+  const byte *end = pos + path->length;
+  int found = 0;
+  u32 val = 0;
+
+  while (pos < end)
+  {
+    uint type = pos[0];
+    uint len  = pos[1];
+    pos += 2;
+
+    if (!len)
+      continue;
+
+    switch (type)
+    {
+    case AS_PATH_SET:
+    case AS_PATH_CONFED_SET:
+      found = 0;
+      break;
+
+    case AS_PATH_SEQUENCE:
+    case AS_PATH_CONFED_SEQUENCE:
+      val = get_as(pos + BS * (len - 1));
+      found = 1;
+      break;
+
+    default:
+      bug("Invalid path segment");
+    }
+
+    pos += BS * len;
+  }
+
+  if (found)
+    *orig_as = val;
+  return found;
+}
+
+u32
+as_path_get_last_nonaggregated(const struct adata *path)
+{
+  const byte *pos = path->data;
+  const byte *end = pos + path->length;
+  u32 val = 0;
+
+  while (pos < end)
+  {
+    uint type = pos[0];
+    uint len  = pos[1];
+    pos += 2;
+
+    if (!len)
+      continue;
+
+    switch (type)
+    {
+    case AS_PATH_SET:
+    case AS_PATH_CONFED_SET:
+      return val;
+
+    case AS_PATH_SEQUENCE:
+    case AS_PATH_CONFED_SEQUENCE:
+      val = get_as(pos + BS * (len - 1));
+      break;
+
+    default:
+      bug("Invalid path segment");
+    }
+
+    pos += BS * len;
+  }
+
+  return val;
+}
+
+int
+as_path_get_first(const struct adata *path, u32 *last_as)
+{
+  const u8 *p = path->data;
+
+  if ((path->length == 0) || (p[0] != AS_PATH_SEQUENCE) || (p[1] == 0))
+    return 0;
+
+  *last_as = get_as(p+2);
+  return 1;
+}
+
+int
+as_path_get_first_regular(const struct adata *path, u32 *last_as)
+{
+  const byte *pos = path->data;
+  const byte *end = pos + path->length;
+
+  while (pos < end)
+  {
+    uint type = pos[0];
+    uint len  = pos[1];
+    pos += 2;
+
+    switch (type)
+    {
+    case AS_PATH_SET:
+      return 0;
+
+    case AS_PATH_SEQUENCE:
+      if (len == 0)
+	return 0;
+
+      *last_as = get_as(pos);
+      return 1;
+
+    case AS_PATH_CONFED_SEQUENCE:
+    case AS_PATH_CONFED_SET:
+      break;
+
+    default:
+      bug("Invalid path segment");
+    }
+
+    pos += BS * len;
+  }
+
+  return 0;
+}
+
+int
+as_path_contains(const struct adata *path, u32 as, int min)
+{
+  const u8 *p = path->data;
+  const u8 *q = p+path->length;
+  int num = 0;
+  int i, n;
+
+  while (p<q)
+    {
+      n = p[1];
+      p += 2;
+      for(i=0; i<n; i++)
+	{
+	  if (get_as(p) == as)
+	    if (++num == min)
+	      return 1;
+	  p += BS;
+	}
+    }
+  return 0;
+}
+
+int
+as_path_match_set(const struct adata *path, const struct f_tree *set)
+{
+  const u8 *p = path->data;
+  const u8 *q = p+path->length;
+  int i, n;
+
+  while (p<q)
+    {
+      n = p[1];
+      p += 2;
+      for (i=0; i<n; i++)
+	{
+	  struct f_val v = { .type = T_INT, .val.i = get_as(p)};
+	  if (find_tree(set, &v))
+	    return 1;
+	  p += BS;
+	}
+    }
+
+  return 0;
+}
+
+const struct adata *
+as_path_filter(struct linpool *pool, const struct adata *path, const struct f_val *set, int pos)
+{
+  ASSERT((set->type == T_SET) || (set->type == T_INT));
+
+  if (!path)
+    return NULL;
+
+  int len = path->length;
+  const u8 *p = path->data;
+  const u8 *q = path->data + len;
+  u8 *d, *d2;
+  int i, bt, sn, dn;
+  u8 buf[len];
+
+  d = buf;
+  while (p<q)
+    {
+      /* Read block header (type and length) */
+      bt = p[0];
+      sn = p[1];
+      dn = 0;
+      p += 2;
+      d2 = d + 2;
+
+      for (i = 0; i < sn; i++)
+	{
+	  u32 as = get_as(p);
+	  int match;
+
+	  if (set->type == T_SET)
+	    {
+	      struct f_val v = { .type = T_INT, .val.i = as};
+	      match = !!find_tree(set->val.t, &v);
+	    }
+	  else /* T_INT */
+	    match = (as == set->val.i);
+
+	  if (match == pos)
+	    {
+	      put_as(d2, as);
+	      d2 += BS;
+	      dn++;
+	    }
+
+	  p += BS;
+	}
+
+      if (dn > 0)
+	{
+	  /* Nonempty block, set block header and advance */
+	  d[0] = bt;
+	  d[1] = dn;
+	  d = d2;
+	}
+  }
+
+  uint nl = d - buf;
+  if (nl == path->length)
+    return path;
+
+  struct adata *res = lp_alloc(pool, sizeof(struct adata) + nl);
+  res->length = nl;
+  memcpy(res->data, buf, nl);
+
+  return res;
+}
+
+int
+as_path_walk(const struct adata *path, uint *pos, uint *val)
+{
+  if (!path)
+    return 0;
+
+  const u8 *p = path->data;
+  const u8 *q = p + path->length;
+  uint n, x = *pos;
+
+  while (p < q)
+  {
+    n = p[1];
+    p += 2;
+
+    if (x < n)
+    {
+      *val = get_as(p + x * BS);
+      *pos += 1;
+      return 1;
+    }
+
+    p += n * BS;
+    x -= n;
+  }
+
+  return 0;
+}
+
+
+struct pm_pos
+{
+  u8 set;
+  u8 mark;
+  union
+  {
+    const char *sp;
+    u32 asn;
+  } val;
+};
+
+static int
+parse_path(const struct adata *path, struct pm_pos *pp)
+{
+  const byte *pos = path->data;
+  const byte *end = pos + path->length;
+  struct pm_pos *op = pp;
+  uint i;
+
+  while (pos < end)
+  {
+    uint type = pos[0];
+    uint len  = pos[1];
+    pos += 2;
+
+    switch (type)
+    {
+    case AS_PATH_SET:
+    case AS_PATH_CONFED_SET:
+      pp->set = 1;
+      pp->mark = 0;
+      pp->val.sp = pos - 1;
+      pp++;
+
+      pos += BS * len;
+      break;
+
+    case AS_PATH_SEQUENCE:
+    case AS_PATH_CONFED_SEQUENCE:
+      for (i = 0; i < len; i++)
+      {
+	pp->set = 0;
+	pp->mark = 0;
+	pp->val.asn = get_as(pos);
+	pp++;
+
+	pos += BS;
+      }
+      break;
+
+    default:
+      bug("Invalid path segment");
+    }
+  }
+
+  return pp - op;
+}
+
+static int
+pm_match_val(const struct pm_pos *pos, u32 asn, u32 asn2)
+{
+  u32 gas;
+  if (! pos->set)
+    return ((pos->val.asn >= asn) && (pos->val.asn <= asn2));
+
+  const u8 *p = pos->val.sp;
+  int len = *p++;
+  int i;
+
+  for (i = 0; i < len; i++)
+  {
+    gas = get_as(p + i * BS);
+
+    if ((gas >= asn) && (gas <= asn2))
+      return 1;
+  }
+
+  return 0;
+}
+
+static int
+pm_match_set(const struct pm_pos *pos, const struct f_tree *set)
+{
+  struct f_val asn = { .type = T_INT };
+
+  if (! pos->set)
+  {
+    asn.val.i = pos->val.asn;
+    return !!find_tree(set, &asn);
+  }
+
+  const u8 *p = pos->val.sp;
+  int len = *p++;
+  int i;
+
+  for (i = 0; i < len; i++)
+  {
+    asn.val.i = get_as(p + i * BS);
+    if (find_tree(set, &asn))
+      return 1;
+  }
+
+  return 0;
+}
+
+static inline int
+pm_match(const struct pm_pos *pos, const struct f_path_mask_item *mask, u32 asn, u32 asn2)
+{
+  return ((mask->kind == PM_QUESTION) ||
+	  ((mask->kind != PM_ASN_SET) ?
+	   pm_match_val(pos, asn, asn2) :
+	   pm_match_set(pos, mask->set)));
+}
+
+static void
+pm_mark(struct pm_pos *pos, int *i, int plen, int *nl, int *nh)
+{
+  int j = *i;
+
+  if (pos[j].set)
+    do { pos[j].mark = 1; j++; }
+    while ((j < plen) && pos[j].set);
+  else
+    j++;
+
+  pos[j].mark = 1;
+
+  /* Update low, high based on first and last marked pos */
+  int l = pos[*i].set ? *i : j;
+
+  *nl = (*nl < 0) ? l : MIN(*nl, l);
+  *nh = MAX(*nh, j);
+  *i = j;
+}
+
+/* AS path matching is nontrivial. Because AS path can
+ * contain sets, it is not a plain wildcard matching. A set
+ * in an AS path is interpreted as it might represent any
+ * sequence of AS numbers from that set (possibly with
+ * repetitions). So it is also a kind of a pattern,
+ * more complicated than a path mask.
+ *
+ * The algorithm for AS path matching is a variant
+ * of nondeterministic finite state machine, where
+ * positions in AS path are states, and items in
+ * path mask are input for that finite state machine.
+ * During execution of the algorithm we maintain a set
+ * of marked states - a state is marked if it can be
+ * reached by any walk through NFSM with regard to
+ * currently processed part of input. When we process
+ * next part of mask, we advance each marked state.
+ * We start with marked first position, when we
+ * run out of marked positions, we reject. When
+ * we process the whole mask, we accept if final position
+ * (auxiliary position after last real position in AS path)
+ * is marked.
+ */
+int
+as_path_match(const struct adata *path, const struct f_path_mask *mask)
+{
+  struct pm_pos pos[2048 + 1];
+  int plen = parse_path(path, pos);
+  int l, h, i, nh, nl, last, loop;
+  u32 val = 0;
+  u32 val2 = 0;
+
+  /* l and h are bound of interval of positions where
+     are marked states */
+
+  pos[plen].set = 0;
+  pos[plen].mark = 0;
+
+  l = h = loop = 0;
+  pos[0].mark = 1;
+
+  for (uint m=0; m < mask->len; m++)
+    {
+      /* We remove this mark to not step after pos[plen] */
+      pos[plen].mark = 0;
+
+      switch (mask->item[m].kind)
+	{
+	case PM_ASTERISK:
+	  for (i = l; i <= plen; i++)
+	    pos[i].mark = 1;
+	  h = plen;
+	  break;
+
+	case PM_LOOP:
+	  loop = 1;
+	  break;
+
+	case PM_ASN:	/* Define single ASN as ASN..ASN - very narrow interval */
+	  val2 = val = mask->item[m].asn;
+	  goto step;
+	case PM_ASN_EXPR:
+	  bug("Expressions should be evaluated on AS path mask construction.");
+	case PM_ASN_RANGE:
+	  val = mask->item[m].from;
+	  val2 = mask->item[m].to;
+	  goto step;
+	case PM_QUESTION:
+	case PM_ASN_SET:
+	step:
+	  nh = nl = -1;
+	  last = plen;
+	  for (i = h; i >= l; i--)
+	    if (pos[i].mark)
+	      {
+		pos[i].mark = 0;
+		int j = i;
+
+	      match:
+		if (pm_match(pos + j, &mask->item[m], val, val2))
+		{
+		  pm_mark(pos, &j, plen, &nl, &nh);
+		  if (loop && (j < last))
+		    goto match;
+		}
+
+		last = i;
+	      }
+
+	  if (nh < 0)
+	    return 0;
+
+	  h = nh;
+	  l = nl;
+	  loop = 0;
+	  break;
+	}
+    }
+
+  return pos[plen].mark;
+}
diff --git a/lib/a-path_test.c b/lib/a-path_test.c
new file mode 100644
index 00000000..08c6c96c
--- /dev/null
+++ b/lib/a-path_test.c
@@ -0,0 +1,208 @@
+/*
+ *	BIRD -- Path Operations Tests
+ *
+ *	(c) 2015 CZ.NIC z.s.p.o.
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#include "test/birdtest.h"
+#include "test/bt-utils.h"
+
+#include "nest/rt.h"
+#include "lib/attrs.h"
+#include "lib/resource.h"
+#include "filter/data.h"
+
+#define TESTS_NUM 30
+#define AS_PATH_LENGTH 1000
+
+#if AS_PATH_LENGTH > AS_PATH_MAXLEN
+#warning "AS_PATH_LENGTH should be <= AS_PATH_MAXLEN"
+#endif
+
+static int
+t_as_path_match(void)
+{
+  int round;
+  for (round = 0; round < TESTS_NUM; round++)
+  {
+    struct adata empty_as_path = {};
+    struct adata *as_path = &empty_as_path;
+    u32 first_prepended, last_prepended;
+    first_prepended = last_prepended = 0;
+
+    struct f_path_mask *mask = alloca(sizeof(struct f_path_mask) + AS_PATH_LENGTH * sizeof(struct f_path_mask_item));
+    mask->len = AS_PATH_LENGTH;
+    for (int i = AS_PATH_LENGTH - 1; i >= 0; i--)
+    {
+      u32 val = bt_random();
+      as_path = as_path_prepend(tmp_linpool, as_path, val);
+      bt_debug("Prepending ASN: %10u \n", val);
+
+      if (i == 0)
+	last_prepended = val;
+      if (i == AS_PATH_LENGTH-1)
+	first_prepended = val;
+
+      mask->item[i].kind = PM_ASN;
+      mask->item[i].asn  = val;
+    }
+
+    bt_assert_msg(as_path_match(as_path, mask), "Mask should match with AS path");
+
+    u32 asn;
+
+    bt_assert(as_path_get_first(as_path, &asn));
+    bt_assert_msg(asn == last_prepended, "as_path_get_first() should return the last prepended ASN");
+
+    bt_assert(as_path_get_last(as_path, &asn));
+    bt_assert_msg(asn == first_prepended, "as_path_get_last() should return the first prepended ASN");
+
+    tmp_flush();
+  }
+
+  return 1;
+}
+
+static int
+t_path_format(void)
+{
+  struct adata empty_as_path = {};
+  struct adata *as_path = &empty_as_path;
+
+  uint i;
+  for (i = 4294967285; i <= 4294967294; i++)
+  {
+    as_path = as_path_prepend(tmp_linpool, as_path, i);
+    bt_debug("Prepending ASN: %10u \n", i);
+  }
+
+#define T_BUFFER_SIZE 120
+  byte buf[T_BUFFER_SIZE] = {};
+
+  as_path_format(&empty_as_path, buf, T_BUFFER_SIZE);
+  bt_assert_msg(strcmp(buf, "") == 0, "Buffer(%zu): '%s'", strlen(buf), buf);
+
+  as_path_format(as_path, buf, T_BUFFER_SIZE);
+  bt_assert_msg(strcmp(buf, "4294967294 4294967293 4294967292 4294967291 4294967290 4294967289 4294967288 4294967287 4294967286 4294967285") == 0, "Buffer(%zu): '%s'", strlen(buf), buf);
+
+#define SMALL_BUFFER_SIZE 25
+  byte buf2[SMALL_BUFFER_SIZE] = {};
+  as_path_format(as_path, buf2, SMALL_BUFFER_SIZE);
+  bt_assert_msg(strcmp(buf2, "4294967294 42...") == 0, "Small Buffer(%zu): '%s'", strlen(buf2), buf2);
+
+  tmp_flush();
+
+  return 1;
+}
+
+static int
+count_asn_in_array(const u32 *array, u32 asn)
+{
+  int counts_of_contains = 0;
+  int u;
+  for (u = 0; u < AS_PATH_LENGTH; u++)
+    if (array[u] == asn)
+	counts_of_contains++;
+  return counts_of_contains;
+}
+
+static int
+t_path_include(void)
+{
+  struct adata empty_as_path = {};
+  struct adata *as_path = &empty_as_path;
+
+  u32 as_nums[AS_PATH_LENGTH] = {};
+  int i;
+  for (i = 0; i < AS_PATH_LENGTH; i++)
+  {
+    u32 val = bt_random();
+    as_nums[i] = val;
+    as_path = as_path_prepend(tmp_linpool, as_path, val);
+  }
+
+  for (i = 0; i < AS_PATH_LENGTH; i++)
+  {
+    int counts_of_contains = count_asn_in_array(as_nums, as_nums[i]);
+    bt_assert_msg(as_path_contains(as_path, as_nums[i], counts_of_contains), "AS Path should contains %d-times number %d", counts_of_contains, as_nums[i]);
+
+    struct f_val v = { .type = T_INT, .val.i = as_nums[i] };
+    bt_assert(as_path_filter(tmp_linpool, as_path, &v, 0) != NULL);
+    bt_assert(as_path_filter(tmp_linpool, as_path, &v, 1) != NULL);
+  }
+
+  for (i = 0; i < 10000; i++)
+  {
+    u32 test_val = bt_random();
+    int counts_of_contains = count_asn_in_array(as_nums, test_val);
+    int result = as_path_contains(as_path, test_val, (counts_of_contains == 0 ? 1 : counts_of_contains));
+
+    if (counts_of_contains)
+      bt_assert_msg(result, "As path should contain %d-times the number %u", counts_of_contains, test_val);
+    else
+      bt_assert_msg(result == 0, "As path should not contain the number %u", test_val);
+  }
+
+  tmp_flush();
+
+  return 1;
+}
+
+#if 0
+static int
+t_as_path_converting(void)
+{
+  struct adata empty_as_path = {};
+  struct adata *as_path = &empty_as_path;
+#define AS_PATH_LENGTH_FOR_CONVERTING_TEST 10
+
+  int i;
+  for (i = 0; i < AS_PATH_LENGTH_FOR_CONVERTING_TEST; i++)
+    as_path = as_path_prepend(tmp_linpool, as_path, i);
+
+  bt_debug("data length: %u \n", as_path->length);
+
+  byte buffer[100] = {};
+  int used_size = as_path_convert_to_new(as_path, buffer, AS_PATH_LENGTH_FOR_CONVERTING_TEST-1);
+  bt_debug("as_path_convert_to_new: len %d \n%s\n", used_size, buffer);
+  for (i = 0; i < used_size; i++)
+  {
+    bt_debug("\\03%d", buffer[i]);
+  }
+  bt_debug("\n");
+  bt_assert(memcmp(buffer,
+		   "\032\039\030\030\030\030\030\030\030\039\030\030\030\030\030\030\030\038\030\030\030\030\030\030"
+		   "\030\037\030\030\030\030\030\030\030\036\030\030\030\030",
+		   38));
+
+  bzero(buffer, sizeof(buffer));
+  int new_used;
+  used_size = as_path_convert_to_old(as_path, buffer, &new_used);
+  bt_debug("as_path_convert_to_old: len %d, new_used: %d \n", used_size, new_used);
+  for (i = 0; i < used_size; i++)
+  {
+    bt_debug("\\03%d", buffer[i]);
+  }
+  bt_debug("\n");
+  bt_assert(memcmp(buffer,
+		   "\032\0310\030\039\030\038\030\037\030\036\030\035\030\034\030\033\030\032\030\031\030\030",
+		   22));
+
+  return 1;
+}
+#endif
+
+int
+main(int argc, char *argv[])
+{
+  bt_init(argc, argv);
+
+  bt_test_suite(t_as_path_match, "Testing AS path matching and some a-path utilities.");
+  bt_test_suite(t_path_format, "Testing formating as path into byte buffer");
+  bt_test_suite(t_path_include, "Testing including a AS number in AS path");
+  // bt_test_suite(t_as_path_converting, "Testing as_path_convert_to_*() output constancy");
+
+  return bt_exit_value();
+}
diff --git a/lib/a-set.c b/lib/a-set.c
new file mode 100644
index 00000000..dcb86058
--- /dev/null
+++ b/lib/a-set.c
@@ -0,0 +1,743 @@
+/*
+ *	BIRD -- Set/Community-list Operations
+ *
+ *	(c) 2000 Martin Mares <mj@ucw.cz>
+ *	(c) 2000 Pavel Machek <pavel@ucw.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#include <stdlib.h>
+
+#include "nest/bird.h"
+#include "nest/rt.h"
+#include "lib/attrs.h"
+#include "lib/resource.h"
+#include "lib/string.h"
+
+/**
+ * int_set_format - format an &set for printing
+ * @set: set attribute to be formatted
+ * @way: style of format (0 for router ID list, 1 for community list)
+ * @from: starting position in set
+ * @buf: destination buffer
+ * @size: size of buffer
+ *
+ * This function takes a set attribute and formats it. @way specifies
+ * the style of format (router ID / community). @from argument can be
+ * used to specify the first printed value for the purpose of printing
+ * untruncated sets even with smaller buffers. If the output fits in
+ * the buffer, 0 is returned, otherwise the position of the first not
+ * printed item is returned. This value can be used as @from argument
+ * in subsequent calls. If truncated output suffices, -1 can be
+ * instead used as @from, in that case " ..." is eventually added at
+ * the buffer to indicate truncation.
+ */
+int
+int_set_format(const struct adata *set, int way, int from, byte *buf, uint size)
+{
+  u32 *z = (u32 *) set->data;
+  byte *end = buf + size - 24;
+  int from2 = MAX(from, 0);
+  int to = set->length / 4;
+  int i;
+
+  for (i = from2; i < to; i++)
+    {
+      if (buf > end)
+	{
+	  if (from < 0)
+	    strcpy(buf, " ...");
+	  else
+	    *buf = 0;
+	  return i;
+	}
+
+      if (i > from2)
+	*buf++ = ' ';
+
+      if (way)
+	buf += bsprintf(buf, "(%d,%d)", z[i] >> 16, z[i] & 0xffff);
+      else
+	buf += bsprintf(buf, "%R", z[i]);
+    }
+  *buf = 0;
+  return 0;
+}
+
+int
+ec_format(byte *buf, u64 ec)
+{
+  u32 type, key, val;
+  char tbuf[16];
+  const char *kind;
+
+  type = ec >> 48;
+  kind = ec_subtype_str(type & 0xf0ff);
+
+  if (!kind) {
+    bsprintf(tbuf, "unknown 0x%x", type);
+    kind = tbuf;
+  }
+
+  switch (ec >> 56)
+    {
+      /* RFC 4360 3.1.  Two-Octet AS Specific Extended Community */
+    case 0x00:
+    case 0x40:
+      key = (ec >> 32) & 0xFFFF;
+      val = ec;
+      return bsprintf(buf, "(%s, %u, %u)", kind, key, val);
+
+      /* RFC 4360 3.2.  IPv4 Address Specific Extended Community */
+    case 0x01:
+    case 0x41:
+      key = ec >> 16;
+      val = ec & 0xFFFF;
+      return bsprintf(buf, "(%s, %R, %u)", kind, key, val);
+
+      /* RFC 5668  4-Octet AS Specific BGP Extended Community */
+    case 0x02:
+    case 0x42:
+      key = ec >> 16;
+      val = ec & 0xFFFF;
+      return bsprintf(buf, "(%s, %u, %u)", kind, key, val);
+
+      /* Generic format for unknown kinds of extended communities */
+    default:
+      key = ec >> 32;
+      val = ec;
+      return bsprintf(buf, "(generic, 0x%x, 0x%x)", key, val);
+    }
+
+}
+
+int
+ec_set_format(const struct adata *set, int from, byte *buf, uint size)
+{
+  u32 *z = int_set_get_data(set);
+  byte *end = buf + size - 64;
+  int from2 = MAX(from, 0);
+  int to = int_set_get_size(set);
+  int i;
+
+  for (i = from2; i < to; i += 2)
+    {
+      if (buf > end)
+	{
+	  if (from < 0)
+	    strcpy(buf, " ...");
+	  else
+	    *buf = 0;
+	  return i;
+	}
+
+      if (i > from2)
+	*buf++ = ' ';
+
+      buf += ec_format(buf, ec_get(z, i));
+    }
+  *buf = 0;
+  return 0;
+}
+
+int
+lc_format(byte *buf, lcomm lc)
+{
+  return bsprintf(buf, "(%u, %u, %u)", lc.asn, lc.ldp1, lc.ldp2);
+}
+
+int
+lc_set_format(const struct adata *set, int from, byte *buf, uint bufsize)
+{
+  u32 *d = (u32 *) set->data;
+  byte *end = buf + bufsize - 64;
+  int from2 = MAX(from, 0);
+  int to = set->length / 4;
+  int i;
+
+  for (i = from2; i < to; i += 3)
+    {
+      if (buf > end)
+	{
+	  if (from < 0)
+	    strcpy(buf, "...");
+	  else
+	    buf[-1] = 0;
+	  return i;
+	}
+
+      buf += bsprintf(buf, "(%u, %u, %u)", d[i], d[i+1], d[i+2]);
+      *buf++ = ' ';
+    }
+
+  if (i != from2)
+    buf--;
+
+  *buf = 0;
+  return 0;
+}
+
+int
+int_set_contains(const struct adata *list, u32 val)
+{
+  if (!list)
+    return 0;
+
+  u32 *l = (u32 *) list->data;
+  int len = int_set_get_size(list);
+  int i;
+
+  for (i = 0; i < len; i++)
+    if (*l++ == val)
+      return 1;
+
+  return 0;
+}
+
+int
+ec_set_contains(const struct adata *list, u64 val)
+{
+  if (!list)
+    return 0;
+
+  u32 *l = int_set_get_data(list);
+  int len = int_set_get_size(list);
+  u32 eh = ec_hi(val);
+  u32 el = ec_lo(val);
+  int i;
+
+  for (i=0; i < len; i += 2)
+    if (l[i] == eh && l[i+1] == el)
+      return 1;
+
+  return 0;
+}
+
+int
+lc_set_contains(const struct adata *list, lcomm val)
+{
+  if (!list)
+    return 0;
+
+  u32 *l = int_set_get_data(list);
+  int len = int_set_get_size(list);
+  int i;
+
+  for (i = 0; i < len; i += 3)
+    if (lc_match(l, i, val))
+      return 1;
+
+  return 0;
+}
+
+const struct adata *
+int_set_prepend(struct linpool *pool, const struct adata *list, u32 val)
+{
+  struct adata *res;
+  int len;
+
+  if (int_set_contains(list, val))
+    return list;
+
+  len = list ? list->length : 0;
+  res = lp_alloc(pool, sizeof(struct adata) + len + 4);
+  res->length = len + 4;
+
+  if (list)
+    memcpy(res->data + 4, list->data, list->length);
+
+  * (u32 *) res->data = val;
+
+  return res;
+}
+
+const struct adata *
+int_set_add(struct linpool *pool, const struct adata *list, u32 val)
+{
+  struct adata *res;
+  int len;
+
+  if (int_set_contains(list, val))
+    return list;
+
+  len = list ? list->length : 0;
+  res = lp_alloc(pool, sizeof(struct adata) + len + 4);
+  res->length = len + 4;
+
+  if (list)
+    memcpy(res->data, list->data, list->length);
+
+  * (u32 *) (res->data + len) = val;
+
+  return res;
+}
+
+const struct adata *
+ec_set_add(struct linpool *pool, const struct adata *list, u64 val)
+{
+  if (ec_set_contains(list, val))
+    return list;
+
+  int olen = list ? list->length : 0;
+  struct adata *res = lp_alloc(pool, sizeof(struct adata) + olen + 8);
+  res->length = olen + 8;
+
+  if (list)
+    memcpy(res->data, list->data, list->length);
+
+  u32 *l = (u32 *) (res->data + olen);
+  l[0] = ec_hi(val);
+  l[1] = ec_lo(val);
+
+  return res;
+}
+
+const struct adata *
+lc_set_add(struct linpool *pool, const struct adata *list, lcomm val)
+{
+  if (lc_set_contains(list, val))
+    return list;
+
+  int olen = list ? list->length : 0;
+  struct adata *res = lp_alloc(pool, sizeof(struct adata) + olen + LCOMM_LENGTH);
+  res->length = olen + LCOMM_LENGTH;
+
+  if (list)
+    memcpy(res->data, list->data, list->length);
+
+  lc_put((u32 *) (res->data + olen), val);
+
+  return res;
+}
+
+const struct adata *
+int_set_del(struct linpool *pool, const struct adata *list, u32 val)
+{
+  if (!int_set_contains(list, val))
+    return list;
+
+  struct adata *res;
+  res = lp_alloc(pool, sizeof(struct adata) + list->length - 4);
+  res->length = list->length - 4;
+
+  u32 *l = int_set_get_data(list);
+  u32 *k = int_set_get_data(res);
+  int len = int_set_get_size(list);
+  int i;
+
+  for (i = 0; i < len; i++)
+    if (l[i] != val)
+      *k++ = l[i];
+
+  return res;
+}
+
+const struct adata *
+ec_set_del(struct linpool *pool, const struct adata *list, u64 val)
+{
+  if (!ec_set_contains(list, val))
+    return list;
+
+  struct adata *res;
+  res = lp_alloc(pool, sizeof(struct adata) + list->length - 8);
+  res->length = list->length - 8;
+
+  u32 *l = int_set_get_data(list);
+  u32 *k = int_set_get_data(res);
+  int len = int_set_get_size(list);
+  u32 eh = ec_hi(val);
+  u32 el = ec_lo(val);
+  int i;
+
+  for (i=0; i < len; i += 2)
+    if (! (l[i] == eh && l[i+1] == el))
+      {
+	*k++ = l[i];
+	*k++ = l[i+1];
+      }
+
+  return res;
+}
+
+const struct adata *
+lc_set_del(struct linpool *pool, const struct adata *list, lcomm val)
+{
+  if (!lc_set_contains(list, val))
+    return list;
+
+  struct adata *res;
+  res = lp_alloc(pool, sizeof(struct adata) + list->length - LCOMM_LENGTH);
+  res->length = list->length - LCOMM_LENGTH;
+
+  u32 *l = int_set_get_data(list);
+  u32 *k = int_set_get_data(res);
+  int len = int_set_get_size(list);
+  int i;
+
+  for (i=0; i < len; i += 3)
+    if (! lc_match(l, i, val))
+      k = lc_copy(k, l+i);
+
+  return res;
+}
+
+const struct adata *
+int_set_union(struct linpool *pool, const struct adata *l1, const struct adata *l2)
+{
+  if (!l1)
+    return l2;
+  if (!l2)
+    return l1;
+
+  struct adata *res;
+  int len = int_set_get_size(l2);
+  u32 *l = int_set_get_data(l2);
+  u32 tmp[len];
+  u32 *k = tmp;
+  int i;
+
+  for (i = 0; i < len; i++)
+    if (!int_set_contains(l1, l[i]))
+      *k++ = l[i];
+
+  if (k == tmp)
+    return l1;
+
+  len = (k - tmp) * 4;
+  res = lp_alloc(pool, sizeof(struct adata) + l1->length + len);
+  res->length = l1->length + len;
+  memcpy(res->data, l1->data, l1->length);
+  memcpy(res->data + l1->length, tmp, len);
+  return res;
+}
+
+const struct adata *
+ec_set_union(struct linpool *pool, const struct adata *l1, const struct adata *l2)
+{
+  if (!l1)
+    return l2;
+  if (!l2)
+    return l1;
+
+  struct adata *res;
+  int len = int_set_get_size(l2);
+  u32 *l = int_set_get_data(l2);
+  u32 tmp[len];
+  u32 *k = tmp;
+  int i;
+
+  for (i = 0; i < len; i += 2)
+    if (!ec_set_contains(l1, ec_get(l, i)))
+      {
+	*k++ = l[i];
+	*k++ = l[i+1];
+      }
+
+  if (k == tmp)
+    return l1;
+
+  len = (k - tmp) * 4;
+  res = lp_alloc(pool, sizeof(struct adata) + l1->length + len);
+  res->length = l1->length + len;
+  memcpy(res->data, l1->data, l1->length);
+  memcpy(res->data + l1->length, tmp, len);
+  return res;
+}
+
+const struct adata *
+lc_set_union(struct linpool *pool, const struct adata *l1, const struct adata *l2)
+{
+  if (!l1)
+    return l2;
+  if (!l2)
+    return l1;
+
+  struct adata *res;
+  int len = int_set_get_size(l2);
+  u32 *l = int_set_get_data(l2);
+  u32 tmp[len];
+  u32 *k = tmp;
+  int i;
+
+  for (i = 0; i < len; i += 3)
+    if (!lc_set_contains(l1, lc_get(l, i)))
+      k = lc_copy(k, l+i);
+
+  if (k == tmp)
+    return l1;
+
+  len = (k - tmp) * 4;
+  res = lp_alloc(pool, sizeof(struct adata) + l1->length + len);
+  res->length = l1->length + len;
+  memcpy(res->data, l1->data, l1->length);
+  memcpy(res->data + l1->length, tmp, len);
+  return res;
+}
+
+
+struct adata *
+ec_set_del_nontrans(struct linpool *pool, const struct adata *set)
+{
+  adata *res = lp_alloc_adata(pool, set->length);
+  u32 *src = int_set_get_data(set);
+  u32 *dst = int_set_get_data(res);
+  int len = int_set_get_size(set);
+  int i;
+
+  /* Remove non-transitive communities (EC_TBIT set) */
+  for (i = 0; i < len; i += 2)
+  {
+    if (src[i] & EC_TBIT)
+      continue;
+
+    *dst++ = src[i];
+    *dst++ = src[i+1];
+  }
+
+  res->length = ((byte *) dst) - res->data;
+
+  return res;
+}
+
+static int
+int_set_cmp(const void *X, const void *Y)
+{
+  const u32 *x = X, *y = Y;
+  return (*x < *y) ? -1 : (*x > *y) ? 1 : 0;
+}
+
+struct adata *
+int_set_sort(struct linpool *pool, const struct adata *src)
+{
+  struct adata *dst = lp_alloc_adata(pool, src->length);
+  memcpy(dst->data, src->data, src->length);
+  qsort(dst->data, dst->length / 4, 4, int_set_cmp);
+  return dst;
+}
+
+int
+int_set_min(const struct adata *list, u32 *val)
+{
+  if (!list)
+    return 0;
+
+  u32 *l = (u32 *) list->data;
+  int len = int_set_get_size(list);
+  int i;
+
+  if (len < 1)
+    return 0;
+
+  *val = *l++;
+  for (i = 1; i < len; i++, l++)
+    if (int_set_cmp(val, l) > 0)
+      *val = *l;
+
+  return 1;
+}
+
+int
+int_set_max(const struct adata *list, u32 *val)
+{
+  if (!list)
+    return 0;
+
+  u32 *l = (u32 *) list->data;
+  int len = int_set_get_size(list);
+  int i;
+
+  if (len < 1)
+    return 0;
+
+  *val = *l++;
+  for (i = 1; i < len; i++, l++)
+    if (int_set_cmp(val, l) < 0)
+      *val = *l;
+
+  return 1;
+}
+
+
+static int
+ec_set_cmp(const void *X, const void *Y)
+{
+  u64 x = ec_get(X, 0);
+  u64 y = ec_get(Y, 0);
+  return (x < y) ? -1 : (x > y) ? 1 : 0;
+}
+
+struct adata *
+ec_set_sort(struct linpool *pool, const struct adata *src)
+{
+  struct adata *dst = lp_alloc_adata(pool, src->length);
+  memcpy(dst->data, src->data, src->length);
+  qsort(dst->data, dst->length / 8, 8, ec_set_cmp);
+  return dst;
+}
+
+void
+ec_set_sort_x(struct adata *set)
+{
+  /* Sort in place */
+  qsort(set->data, set->length / 8, 8, ec_set_cmp);
+}
+
+int
+ec_set_min(const struct adata *list, u64 *val)
+{
+  if (!list)
+    return 0;
+
+  u32 *l = int_set_get_data(list);
+  int len = int_set_get_size(list);
+  int i;
+
+  if (len < 1)
+    return 0;
+
+  u32 *res = l; l += 2;
+  for (i = 2; i < len; i += 2, l += 2)
+    if (ec_set_cmp(res, l) > 0)
+      res = l;
+
+  *val = ec_generic(res[0], res[1]);
+  return 1;
+}
+
+int
+ec_set_max(const struct adata *list, u64 *val)
+{
+  if (!list)
+    return 0;
+
+  u32 *l = int_set_get_data(list);
+  int len = int_set_get_size(list);
+  int i;
+
+  if (len < 1)
+    return 0;
+
+  u32 *res = l; l += 2;
+  for (i = 2; i < len; i += 2, l += 2)
+    if (ec_set_cmp(res, l) < 0)
+      res = l;
+
+  *val = ec_generic(res[0], res[1]);
+  return 1;
+}
+
+
+static int
+lc_set_cmp(const void *X, const void *Y)
+{
+  const u32 *x = X, *y = Y;
+  if (x[0] != y[0])
+    return (x[0] > y[0]) ? 1 : -1;
+  if (x[1] != y[1])
+    return (x[1] > y[1]) ? 1 : -1;
+  if (x[2] != y[2])
+    return (x[2] > y[2]) ? 1 : -1;
+  return 0;
+}
+
+struct adata *
+lc_set_sort(struct linpool *pool, const struct adata *src)
+{
+  struct adata *dst = lp_alloc_adata(pool, src->length);
+  memcpy(dst->data, src->data, src->length);
+  qsort(dst->data, dst->length / LCOMM_LENGTH, LCOMM_LENGTH, lc_set_cmp);
+  return dst;
+}
+
+int
+lc_set_min(const struct adata *list, lcomm *val)
+{
+  if (!list)
+    return 0;
+
+  u32 *l = int_set_get_data(list);
+  int len = int_set_get_size(list);
+  int i;
+
+  if (len < 1)
+    return 0;
+
+  u32 *res = l; l += 3;
+  for (i = 3; i < len; i += 3, l += 3)
+    if (lc_set_cmp(res, l) > 0)
+      res = l;
+
+  *val = (lcomm) { res[0], res[1], res[2] };
+  return 1;
+}
+
+int
+lc_set_max(const struct adata *list, lcomm *val)
+{
+  if (!list)
+    return 0;
+
+  u32 *l = int_set_get_data(list);
+  int len = int_set_get_size(list);
+  int i;
+
+  if (len < 1)
+    return 0;
+
+  u32 *res = l; l += 3;
+  for (i = 3; i < len; i += 3, l += 3)
+    if (lc_set_cmp(res, l) < 0)
+      res = l;
+
+  *val = (lcomm) { res[0], res[1], res[2] };
+  return 1;
+}
+
+int
+int_set_walk(const struct adata *list, uint *pos, uint *val)
+{
+  if (!list)
+    return 0;
+
+  if (*pos >= (uint) int_set_get_size(list))
+    return 0;
+
+  u32 *res = int_set_get_data(list) + *pos;
+  *val = *res;
+  *pos += 1;
+
+  return 1;
+}
+
+int
+ec_set_walk(const struct adata *list, uint *pos, u64 *val)
+{
+  if (!list)
+    return 0;
+
+  if (*pos >= (uint) int_set_get_size(list))
+    return 0;
+
+  u32 *res = int_set_get_data(list) + *pos;
+  *val = ec_generic(res[0], res[1]);
+  *pos += 2;
+
+  return 1;
+}
+
+int
+lc_set_walk(const struct adata *list, uint *pos, lcomm *val)
+{
+  if (!list)
+    return 0;
+
+  if (*pos >= (uint) int_set_get_size(list))
+    return 0;
+
+  u32 *res = int_set_get_data(list) + *pos;
+  *val = (lcomm) { res[0], res[1], res[2] };
+  *pos += 3;
+
+  return 1;
+}
diff --git a/lib/a-set_test.c b/lib/a-set_test.c
new file mode 100644
index 00000000..79b5cf9a
--- /dev/null
+++ b/lib/a-set_test.c
@@ -0,0 +1,241 @@
+/*
+ *	BIRD -- Set/Community-list Operations Tests
+ *
+ *	(c) 2015 CZ.NIC z.s.p.o.
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#include "test/birdtest.h"
+#include "test/bt-utils.h"
+
+#include "lib/net.h"
+#include "nest/rt.h"
+#include "lib/attrs.h"
+#include "lib/resource.h"
+
+#define SET_SIZE 10
+static const struct adata *set_sequence;		/* <0; SET_SIZE) */
+static const struct adata *set_sequence_same;		/* <0; SET_SIZE) */
+static const struct adata *set_sequence_higher;	/* <SET_SIZE; 2*SET_SIZE) */
+static const struct adata *set_random;
+
+#define T_BUFFER_SIZE 1000
+static byte buf[T_BUFFER_SIZE] = {};
+
+#define SET_SIZE_FOR_FORMAT_OUTPUT 10
+
+enum set_type
+{
+  SET_TYPE_INT,
+  SET_TYPE_EC
+};
+
+static void
+generate_set_sequence(enum set_type type, int len)
+{
+  struct adata empty_as_path = {};
+  set_sequence = set_sequence_same = set_sequence_higher = set_random = &empty_as_path;
+
+  int i;
+  for (i = 0; i < len; i++)
+  {
+    if (type == SET_TYPE_INT)
+    {
+      set_sequence 	  = int_set_add(tmp_linpool, set_sequence, i);
+      set_sequence_same   = int_set_add(tmp_linpool, set_sequence_same, i);
+      set_sequence_higher = int_set_add(tmp_linpool, set_sequence_higher, i + SET_SIZE);
+      set_random   	  = int_set_add(tmp_linpool, set_random, bt_random());
+    }
+    else if (type == SET_TYPE_EC)
+    {
+      set_sequence 	  = ec_set_add(tmp_linpool, set_sequence, i);
+      set_sequence_same   = ec_set_add(tmp_linpool, set_sequence_same, i);
+      set_sequence_higher = ec_set_add(tmp_linpool, set_sequence_higher, i + SET_SIZE);
+      set_random   	  = ec_set_add(tmp_linpool, set_random, (bt_random() << 32 | bt_random()));
+    }
+    else
+      bt_abort_msg("This should be unreachable");
+  }
+}
+
+/*
+ * SET INT TESTS
+ */
+
+static int
+t_set_int_contains(void)
+{
+  int i;
+
+  generate_set_sequence(SET_TYPE_INT, SET_SIZE);
+
+  bt_assert(int_set_get_size(set_sequence) == SET_SIZE);
+
+  for (i = 0; i < SET_SIZE; i++)
+    bt_assert(int_set_contains(set_sequence, i));
+  bt_assert(int_set_contains(set_sequence, -1) == 0);
+  bt_assert(int_set_contains(set_sequence, SET_SIZE) == 0);
+
+  int *data = int_set_get_data(set_sequence);
+  for (i = 0; i < SET_SIZE; i++)
+    bt_assert_msg(data[i] == i, "(data[i] = %d) == i = %d)", data[i], i);
+
+  return 1;
+}
+
+static int
+t_set_int_union(void)
+{
+  generate_set_sequence(SET_TYPE_INT, SET_SIZE);
+
+  const struct adata *set_union;
+  set_union = int_set_union(tmp_linpool, set_sequence, set_sequence_same);
+  bt_assert(int_set_get_size(set_union) == SET_SIZE);
+  bt_assert(int_set_format(set_union, 0, 2, buf, T_BUFFER_SIZE) == 0);
+
+  set_union = int_set_union(tmp_linpool, set_sequence, set_sequence_higher);
+  bt_assert_msg(int_set_get_size(set_union) == SET_SIZE*2, "int_set_get_size(set_union) %d, SET_SIZE*2 %d", int_set_get_size(set_union), SET_SIZE*2);
+  bt_assert(int_set_format(set_union, 0, 2, buf, T_BUFFER_SIZE) == 0);
+
+  return 1;
+}
+
+static int
+t_set_int_format(void)
+{
+  generate_set_sequence(SET_TYPE_INT, SET_SIZE_FOR_FORMAT_OUTPUT);
+
+  bt_assert(int_set_format(set_sequence, 0, 0, buf, T_BUFFER_SIZE) == 0);
+  bt_assert(strcmp(buf, "0.0.0.0 0.0.0.1 0.0.0.2 0.0.0.3 0.0.0.4 0.0.0.5 0.0.0.6 0.0.0.7 0.0.0.8 0.0.0.9") == 0);
+
+  bzero(buf, T_BUFFER_SIZE);
+  bt_assert(int_set_format(set_sequence, 0, 2, buf, T_BUFFER_SIZE) == 0);
+  bt_assert(strcmp(buf, "0.0.0.2 0.0.0.3 0.0.0.4 0.0.0.5 0.0.0.6 0.0.0.7 0.0.0.8 0.0.0.9") == 0);
+
+  bzero(buf, T_BUFFER_SIZE);
+  bt_assert(int_set_format(set_sequence, 1, 0, buf, T_BUFFER_SIZE) == 0);
+  bt_assert(strcmp(buf, "(0,0) (0,1) (0,2) (0,3) (0,4) (0,5) (0,6) (0,7) (0,8) (0,9)") == 0);
+
+  return 1;
+}
+
+static int
+t_set_int_delete(void)
+{
+  generate_set_sequence(SET_TYPE_INT, SET_SIZE);
+
+  const struct adata *deleting_sequence = set_sequence;
+  u32 i;
+  for (i = 0; i < SET_SIZE; i++)
+  {
+    deleting_sequence = int_set_del(tmp_linpool, deleting_sequence, i);
+    bt_assert_msg(int_set_get_size(deleting_sequence) == (int) (SET_SIZE-1-i),
+		  "int_set_get_size(deleting_sequence) %d == SET_SIZE-1-i %d",
+		  int_set_get_size(deleting_sequence),
+		  SET_SIZE-1-i);
+  }
+
+  bt_assert(int_set_get_size(set_sequence) == SET_SIZE);
+
+  return 1;
+}
+
+/*
+ * SET EC TESTS
+ */
+
+static int
+t_set_ec_contains(void)
+{
+  u32 i;
+
+  generate_set_sequence(SET_TYPE_EC, SET_SIZE);
+
+  bt_assert(ec_set_get_size(set_sequence) == SET_SIZE);
+
+  for (i = 0; i < SET_SIZE; i++)
+    bt_assert(ec_set_contains(set_sequence, i));
+  bt_assert(ec_set_contains(set_sequence, -1) == 0);
+  bt_assert(ec_set_contains(set_sequence, SET_SIZE) == 0);
+
+//  int *data = ec_set_get_data(set_sequence);
+//  for (i = 0; i < SET_SIZE; i++)
+//    bt_assert_msg(data[i] == (SET_SIZE-1-i), "(data[i] = %d) == ((SET_SIZE-1-i) = %d)", data[i], SET_SIZE-1-i);
+
+  return 1;
+}
+
+static int
+t_set_ec_union(void)
+{
+  generate_set_sequence(SET_TYPE_EC, SET_SIZE);
+
+  const struct adata *set_union;
+  set_union = ec_set_union(tmp_linpool, set_sequence, set_sequence_same);
+  bt_assert(ec_set_get_size(set_union) == SET_SIZE);
+  bt_assert(ec_set_format(set_union, 0, buf, T_BUFFER_SIZE) == 0);
+
+  set_union = ec_set_union(tmp_linpool, set_sequence, set_sequence_higher);
+  bt_assert_msg(ec_set_get_size(set_union) == SET_SIZE*2, "ec_set_get_size(set_union) %d, SET_SIZE*2 %d", ec_set_get_size(set_union), SET_SIZE*2);
+  bt_assert(ec_set_format(set_union, 0, buf, T_BUFFER_SIZE) == 0);
+
+  return 1;
+}
+
+static int
+t_set_ec_format(void)
+{
+  const struct adata empty_as_path = {};
+  set_sequence = set_sequence_same = set_sequence_higher = set_random = &empty_as_path;
+
+  u64 i = 0;
+  set_sequence = ec_set_add(tmp_linpool, set_sequence, i);
+  for (i = 1; i < SET_SIZE_FOR_FORMAT_OUTPUT; i++)
+    set_sequence = ec_set_add(tmp_linpool, set_sequence, i + ((i%2) ? ((u64)EC_RO << 48) : ((u64)EC_RT << 48)));
+
+  bt_assert(ec_set_format(set_sequence, 0, buf, T_BUFFER_SIZE) == 0);
+  bt_assert_msg(strcmp(buf, "(unknown 0x0, 0, 0) (ro, 0, 1) (rt, 0, 2) (ro, 0, 3) (rt, 0, 4) (ro, 0, 5) (rt, 0, 6) (ro, 0, 7) (rt, 0, 8) (ro, 0, 9)") == 0,
+		"ec_set_format() returns '%s'", buf);
+
+  return 1;
+}
+
+static int
+t_set_ec_delete(void)
+{
+  generate_set_sequence(SET_TYPE_EC, SET_SIZE);
+
+  const struct adata *deleting_sequence = set_sequence;
+  u32 i;
+  for (i = 0; i < SET_SIZE; i++)
+  {
+    deleting_sequence = ec_set_del(tmp_linpool, deleting_sequence, i);
+    bt_assert_msg(ec_set_get_size(deleting_sequence) == (int) (SET_SIZE-1-i),
+		  "ec_set_get_size(deleting_sequence) %d  == SET_SIZE-1-i %d",
+		  ec_set_get_size(deleting_sequence), SET_SIZE-1-i);
+  }
+
+  bt_assert(ec_set_get_size(set_sequence) == SET_SIZE);
+
+  return 1;
+}
+
+
+int
+main(int argc, char *argv[])
+{
+  bt_init(argc, argv);
+
+  bt_test_suite(t_set_int_contains, "Testing sets of integers: contains, get_data");
+  bt_test_suite(t_set_int_format,   "Testing sets of integers: format");
+  bt_test_suite(t_set_int_union,    "Testing sets of integers: union");
+  bt_test_suite(t_set_int_delete,   "Testing sets of integers: delete");
+
+  bt_test_suite(t_set_ec_contains, "Testing sets of Extended Community values: contains, get_data");
+  bt_test_suite(t_set_ec_format,   "Testing sets of Extended Community values: format");
+  bt_test_suite(t_set_ec_union,    "Testing sets of Extended Community values: union");
+  bt_test_suite(t_set_ec_delete,   "Testing sets of Extended Community values: delete");
+
+  return bt_exit_value();
+}
diff --git a/lib/attrs.h b/lib/attrs.h
new file mode 100644
index 00000000..b4dd2e83
--- /dev/null
+++ b/lib/attrs.h
@@ -0,0 +1,276 @@
+/*
+ *	BIRD Internet Routing Daemon -- Attribute Operations
+ *
+ *	(c) 2000 Martin Mares <mj@ucw.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_ATTRS_H_
+#define _BIRD_ATTRS_H_
+
+#include <stdint.h>
+#include "lib/unaligned.h"
+
+typedef struct adata {
+  uint length;				/* Length of data */
+  byte data[0];
+} adata;
+
+#define ADATA_SIZE(s)	BIRD_CPU_ALIGN(sizeof(struct adata) + s)
+
+extern const adata null_adata;		/* adata of length 0 */
+
+static inline struct adata *
+lp_alloc_adata(struct linpool *pool, uint len)
+{
+  struct adata *ad = lp_alloc(pool, sizeof(struct adata) + len);
+  ad->length = len;
+  return ad;
+}
+
+static inline struct adata *
+lp_store_adata(struct linpool *pool, const void *buf, uint len)
+{
+  struct adata *ad = lp_alloc_adata(pool, len);
+  memcpy(ad->data, buf, len);
+  return ad;
+}
+
+#define tmp_alloc_adata(len)	  lp_alloc_adata(tmp_linpool, len)
+#define tmp_store_adata(buf, len) lp_store_adata(tmp_linpool, buf, len)
+#define tmp_copy_adata(ad)	  tmp_store_adata((ad)->data, (ad)->length)
+
+static inline int adata_same(const struct adata *a, const struct adata *b)
+{ return (!a && !b) || (a->length == b->length && !memcmp(a->data, b->data, a->length)); }
+
+
+
+/* a-path.c */
+
+#define AS_PATH_SET		1	/* Types of path segments */
+#define AS_PATH_SEQUENCE	2
+#define AS_PATH_CONFED_SEQUENCE	3
+#define AS_PATH_CONFED_SET	4
+
+#define AS_PATH_MAXLEN		10000
+
+#define AS_TRANS		23456
+/* AS_TRANS is used when we need to store 32bit ASN larger than 0xFFFF
+ * to 16bit slot (like in 16bit AS_PATH). See RFC 4893 for details
+ */
+
+struct f_val;
+struct f_tree;
+
+int as_path_valid(byte *data, uint len, int bs, int sets, int confed, char *err, uint elen);
+int as_path_16to32(byte *dst, const byte *src, uint len);
+int as_path_32to16(byte *dst, const byte *src, uint len);
+int as_path_contains_as4(const struct adata *path);
+int as_path_contains_confed(const struct adata *path);
+struct adata *as_path_strip_confed(struct linpool *pool, const struct adata *op);
+struct adata *as_path_prepend2(struct linpool *pool, const struct adata *op, int seq, u32 as);
+struct adata *as_path_to_old(struct linpool *pool, const struct adata *path);
+struct adata *as_path_cut(struct linpool *pool, const struct adata *path, uint num);
+const struct adata *as_path_merge(struct linpool *pool, const struct adata *p1, const struct adata *p2);
+void as_path_format(const struct adata *path, byte *buf, uint size);
+int as_path_getlen(const struct adata *path);
+int as_path_getlen_int(const struct adata *path, int bs);
+int as_path_get_first(const struct adata *path, u32 *orig_as);
+int as_path_get_first_regular(const struct adata *path, u32 *last_as);
+int as_path_get_last(const struct adata *path, u32 *last_as);
+u32 as_path_get_last_nonaggregated(const struct adata *path);
+int as_path_contains(const struct adata *path, u32 as, int min);
+int as_path_match_set(const struct adata *path, const struct f_tree *set);
+const struct adata *as_path_filter(struct linpool *pool, const struct adata *path, const struct f_val *set, int pos);
+int as_path_walk(const struct adata *path, uint *pos, uint *val);
+
+static inline struct adata *as_path_prepend(struct linpool *pool, const struct adata *path, u32 as)
+{ return as_path_prepend2(pool, path, AS_PATH_SEQUENCE, as); }
+
+
+#define PM_ASN		0
+#define PM_QUESTION	1
+#define PM_ASTERISK	2
+#define PM_ASN_EXPR	3
+#define PM_ASN_RANGE	4
+#define PM_ASN_SET	5
+#define PM_LOOP		6
+
+struct f_path_mask_item {
+  union {
+    u32 asn; /* PM_ASN */
+    const struct f_line *expr; /* PM_ASN_EXPR */
+    const struct f_tree *set; /* PM_ASN_SET */
+    struct { /* PM_ASN_RANGE */
+      u32 from;
+      u32 to;
+    };
+  };
+  int kind;
+};
+
+struct f_path_mask {
+  uint len;
+  struct f_path_mask_item item[0];
+};
+
+int as_path_match(const struct adata *path, const struct f_path_mask *mask);
+
+
+/* Counterparts to appropriate as_path_* functions */
+
+static inline int
+aggregator_16to32(byte *dst, const byte *src)
+{
+  put_u32(dst, get_u16(src));
+  memcpy(dst+4, src+2, 4);
+  return 8;
+}
+
+static inline int
+aggregator_32to16(byte *dst, const byte *src)
+{
+  put_u16(dst, get_u32(src));
+  memcpy(dst+2, src+4, 4);
+  return 6;
+}
+
+static inline int
+aggregator_contains_as4(const struct adata *a)
+{
+  return get_u32(a->data) > 0xFFFF;
+}
+
+static inline struct adata *
+aggregator_to_old(struct linpool *pool, const struct adata *a)
+{
+  struct adata *d = lp_alloc_adata(pool, 8);
+  put_u32(d->data, AS_TRANS);
+  memcpy(d->data + 4, a->data + 4, 4);
+  return d;
+}
+
+
+/* a-set.c */
+
+
+/* Extended Community subtypes (kinds) */
+enum ec_subtype {
+  EC_RT = 0x0002,
+  EC_RO = 0x0003,
+  EC_GENERIC = 0xFFFF,
+};
+
+static inline const char *ec_subtype_str(const enum ec_subtype ecs) {
+  switch (ecs) {
+    case EC_RT: return "rt";
+    case EC_RO: return "ro";
+    default: return NULL;
+  }
+}
+
+/* Check for EC_RT subtype within different types (0-2) */
+static inline int ec_type_is_rt(uint type)
+{ return (type == EC_RT) || (type == (0x0100 | EC_RT)) || (type == (0x0200 | EC_RT)); }
+
+
+/* Transitive bit (for first u32 half of EC) */
+#define EC_TBIT 0x40000000
+
+#define ECOMM_LENGTH 8
+
+static inline int int_set_get_size(const struct adata *list)
+{ return list->length / 4; }
+
+static inline int ec_set_get_size(const struct adata *list)
+{ return list->length / 8; }
+
+static inline int lc_set_get_size(const struct adata *list)
+{ return list->length / 12; }
+
+static inline u32 *int_set_get_data(const struct adata *list)
+{ return (u32 *) list->data; }
+
+static inline u32 ec_hi(u64 ec) { return ec >> 32; }
+static inline u32 ec_lo(u64 ec) { return ec; }
+
+static inline u64 ec_get(const u32 *l, int i)
+{ return (((u64) l[i]) << 32) | l[i+1]; }
+
+static inline void ec_put(u32 *l, int i, u64 val)
+{ l[i] = ec_hi(val); l[i+1] = ec_lo(val); }
+
+/* RFC 4360 3.1.  Two-Octet AS Specific Extended Community */
+static inline u64 ec_as2(enum ec_subtype kind, u64 key, u64 val)
+{ return (((u64) kind | 0x0000) << 48) | (key << 32) | val; }
+
+/* RFC 5668  4-Octet AS Specific BGP Extended Community */
+static inline u64 ec_as4(enum ec_subtype kind, u64 key, u64 val)
+{ return (((u64) kind | 0x0200) << 48) | (key << 16) | val; }
+
+/* RFC 4360 3.2.  IPv4 Address Specific Extended Community */
+static inline u64 ec_ip4(enum ec_subtype kind, u64 key, u64 val)
+{ return (((u64) kind | 0x0100) << 48) | (key << 16) | val; }
+
+static inline u64 ec_generic(u64 key, u64 val)
+{ return (key << 32) | val; }
+
+/* Large community value */
+typedef struct lcomm {
+  u32 asn;
+  u32 ldp1;
+  u32 ldp2;
+} lcomm;
+
+#define LCOMM_LENGTH 12
+
+static inline lcomm lc_get(const u32 *l, int i)
+{ return (lcomm) { l[i], l[i+1], l[i+2] }; }
+
+static inline void lc_put(u32 *l, lcomm v)
+{ l[0] = v.asn; l[1] = v.ldp1; l[2] = v.ldp2; }
+
+static inline int lc_match(const u32 *l, int i, lcomm v)
+{ return (l[i] == v.asn && l[i+1] == v.ldp1 && l[i+2] == v.ldp2); }
+
+static inline u32 *lc_copy(u32 *dst, const u32 *src)
+{ memcpy(dst, src, LCOMM_LENGTH); return dst + 3; }
+
+
+int int_set_format(const struct adata *set, int way, int from, byte *buf, uint size);
+int ec_format(byte *buf, u64 ec);
+int ec_set_format(const struct adata *set, int from, byte *buf, uint size);
+int lc_format(byte *buf, lcomm lc);
+int lc_set_format(const struct adata *set, int from, byte *buf, uint size);
+int int_set_contains(const struct adata *list, u32 val);
+int ec_set_contains(const struct adata *list, u64 val);
+int lc_set_contains(const struct adata *list, lcomm val);
+const struct adata *int_set_prepend(struct linpool *pool, const struct adata *list, u32 val);
+const struct adata *int_set_add(struct linpool *pool, const struct adata *list, u32 val);
+const struct adata *ec_set_add(struct linpool *pool, const struct adata *list, u64 val);
+const struct adata *lc_set_add(struct linpool *pool, const struct adata *list, lcomm val);
+const struct adata *int_set_del(struct linpool *pool, const struct adata *list, u32 val);
+const struct adata *ec_set_del(struct linpool *pool, const struct adata *list, u64 val);
+const struct adata *lc_set_del(struct linpool *pool, const struct adata *list, lcomm val);
+const struct adata *int_set_union(struct linpool *pool, const struct adata *l1, const struct adata *l2);
+const struct adata *ec_set_union(struct linpool *pool, const struct adata *l1, const struct adata *l2);
+const struct adata *lc_set_union(struct linpool *pool, const struct adata *l1, const struct adata *l2);
+
+struct adata *ec_set_del_nontrans(struct linpool *pool, const struct adata *set);
+struct adata *int_set_sort(struct linpool *pool, const struct adata *src);
+struct adata *ec_set_sort(struct linpool *pool, const struct adata *src);
+struct adata *lc_set_sort(struct linpool *pool, const struct adata *src);
+int int_set_min(const struct adata *list, u32 *val);
+int ec_set_min(const struct adata *list, u64 *val);
+int lc_set_min(const struct adata *list, lcomm *val);
+int int_set_max(const struct adata *list, u32 *val);
+int ec_set_max(const struct adata *list, u64 *val);
+int lc_set_max(const struct adata *list, lcomm *val);
+int int_set_walk(const struct adata *list, uint *pos, u32 *val);
+int ec_set_walk(const struct adata *list, uint *pos, u64 *val);
+int lc_set_walk(const struct adata *list, uint *pos, lcomm *val);
+
+void ec_set_sort_x(struct adata *set); /* Sort in place */
+
+#endif
diff --git a/lib/birdlib.h b/lib/birdlib.h
index e03bd0b2..3f65b8c2 100644
--- a/lib/birdlib.h
+++ b/lib/birdlib.h
@@ -9,16 +9,39 @@
 #ifndef _BIRD_BIRDLIB_H_
 #define _BIRD_BIRDLIB_H_
 
+#include <stddef.h>
+
+#include "sysdep/config.h"
 #include "lib/alloca.h"
 
 /* Ugly structure offset handling macros */
 
-struct align_probe { char x; long int y; };
+#define SAME_TYPE(a, b)	({ int _ = ((a) != (b)); !_; })
+#define TYPE_CAST(from, to, what) ( SAME_TYPE(((from) NULL), (what)), ((to) (what)))
 
+#ifdef offsetof
+#define OFFSETOF offsetof
+#else
 #define OFFSETOF(s, i) ((size_t) &((s *)0)->i)
-#define SKIP_BACK(s, i, p) ((s *)((char *)p - OFFSETOF(s, i)))
+#endif
+
+#define SKIP_BACK(s, i, p) ({ s *_ptr = ((s *)((char *)p - OFFSETOF(s, i))); SAME_TYPE(&_ptr->i, p); _ptr; })
 #define BIRD_ALIGN(s, a) (((s)+a-1)&~(a-1))
-#define CPU_STRUCT_ALIGN (sizeof(struct align_probe))
+#define CPU_STRUCT_ALIGN  (MAX_(_Alignof(void*), _Alignof(u64)))
+#define BIRD_CPU_ALIGN(s) BIRD_ALIGN((s), CPU_STRUCT_ALIGN)
+
+/* Structure item alignment macros */
+
+#define PADDING_NAME(id)	_padding_##id
+#define PADDING_(id, sz)	u8 PADDING_NAME(id)[sz]
+
+#if CPU_POINTER_ALIGNMENT == 4
+#define PADDING(id, n32, n64)	PADDING_(id, n32)
+#elif CPU_POINTER_ALIGNMENT == 8
+#define PADDING(id, n32, n64)	PADDING_(id, n64)
+#else
+#error "Strange CPU pointer alignment: " CPU_POINTER_ALIGNMENT
+#endif
 
 /* Utility macros */
 
@@ -73,6 +96,7 @@ static inline int u64_cmp(u64 i1, u64 i2)
 /* Macros for gcc attributes */
 
 #define NORET __attribute__((noreturn))
+#define USE_RESULT __atribute__((warn_unused_result))
 #define UNUSED __attribute__((unused))
 #define PACKED __attribute__((packed))
 #define NONNULL(...) __attribute__((nonnull((__VA_ARGS__))))
@@ -80,10 +104,6 @@ static inline int u64_cmp(u64 i1, u64 i2)
 #define STATIC_ASSERT(EXP) _Static_assert(EXP, #EXP)
 #define STATIC_ASSERT_MSG(EXP,MSG) _Static_assert(EXP, MSG)
 
-#ifndef HAVE_THREAD_LOCAL
-#define _Thread_local
-#endif
-
 /* Microsecond time */
 
 typedef s64 btime;
@@ -95,6 +115,7 @@ typedef s64 btime;
 #define TO_S	/1000000
 #define TO_MS	/1000
 #define TO_US	/1
+#define TO_NS	* (btime) 1000
 
 #ifndef PARSER
 #define S	S_
@@ -166,8 +187,13 @@ void debug_safe(const char *msg);	/* Printf to debug output, async-safe */
 
 #if defined(LOCAL_DEBUG) || defined(GLOBAL_DEBUG)
 #define DBG(x, y...) debug(x, ##y)
+#define DBGL(x, y...) debug(x "\n", ##y)
+#elif defined(DEBUG_TO_LOG)
+#define DBG(...) do { } while (0)
+#define DBGL(...) log(L_DEBUG __VA_ARGS__)
 #else
-#define DBG(x, y...) do { } while(0)
+#define DBG(...) do { } while(0)
+#define DBGL(...) do { } while (0)
 #endif
 
 #define ASSERT_DIE(x) do { if (!(x)) bug("Assertion '%s' failed at %s:%d", #x, __FILE__, __LINE__); } while(0)
diff --git a/lib/event.c b/lib/event.c
index 33dc00b0..68888a4c 100644
--- a/lib/event.c
+++ b/lib/event.c
@@ -19,31 +19,163 @@
  * events in them and explicitly ask to run them.
  */
 
+#undef LOCAL_DEBUG
+
 #include "nest/bird.h"
 #include "lib/event.h"
+#include "lib/io-loop.h"
 
 event_list global_event_list;
 event_list global_work_list;
 
-inline void
-ev_postpone(event *e)
+//#ifdef DEBUGGING
+#if 0
+#define EDL_MAX		16384
+enum edl_caller {
+  EDL_REMOVE_FROM = 1,
+  EDL_POSTPONE = 2,
+  EDL_RUN = 3,
+  EDL_SEND = 4, 
+  EDL_RUN_LIST = 5,
+} caller;
+static struct event_debug_log {
+  event_list *target_list;
+  event *event;
+  event *receiver;
+  uint pos;
+  uint prev_edl_pos;
+  uint thread;
+  enum edl_caller caller;
+} edl[EDL_MAX];
+static _Atomic uint edl_cnt;
+_Thread_local static uint edl_thread;
+_Thread_local static uint prev_edl_pos = ~0;
+static inline void edlog(event_list *list, event *e, event *receiver, uint pos, enum edl_caller caller)
+{
+  uint edl_pos = atomic_fetch_add_explicit(&edl_cnt, 1, memory_order_acq_rel);
+  if (!edl_thread)
+    edl_thread = edl_pos;
+
+  edl[edl_pos % EDL_MAX] = (struct event_debug_log) {
+    .target_list = list,
+    .event = e,
+    .receiver = receiver,
+    .pos = pos,
+    .prev_edl_pos = prev_edl_pos,
+    .thread = edl_thread,
+    .caller = caller,
+  };
+
+  prev_edl_pos = edl_pos;
+}
+#else
+#define edlog(...)
+#endif
+
+
+void
+ev_init_list(event_list *el, struct birdloop *loop, const char *name)
 {
-  if (ev_active(e))
+  el->name = name;
+  el->loop = loop;
+
+  atomic_store_explicit(&el->receiver, NULL, memory_order_release);
+  atomic_store_explicit(&el->_executor, NULL, memory_order_release);
+}
+
+/*
+ * The event list should work as a message passing point. Sending a message
+ * must be a fairly fast process with no locks and low waiting times. OTOH,
+ * processing messages always involves running the assigned code and the
+ * receiver is always a single one thread with no concurrency at all. There is
+ * also a postponing requirement to synchronously remove an event from a queue,
+ * yet we allow this only when the caller has its receiver event loop locked.
+ * It still means that the event may get postponed from other event in the same
+ * list, therefore we have to be careful.
+ */
+
+static inline int
+ev_remove_from(event *e, event * _Atomic * head)
+{
+  /* The head pointer stores where cur is pointed to from */
+  event * _Atomic *prev = head;
+
+  /* The current event in queue to check */
+  event *cur = atomic_load_explicit(prev, memory_order_acquire);
+
+  /* This part of queue is empty! */
+  if (!cur)
+    return 0;
+
+  edlog(NULL, e, cur, 1, EDL_REMOVE_FROM);
+  while (cur)
+  {
+    /* Pre-loaded next pointer */
+    event *next = atomic_load_explicit(&cur->next, memory_order_acquire);
+
+    if (e == cur)
     {
-      rem_node(&e->n);
-      e->n.next = NULL;
+      edlog(NULL, e, next, 3, EDL_REMOVE_FROM);
+
+      /* Check whether we have collided with somebody else
+       * adding an item to the queue. */
+      if (!atomic_compare_exchange_strong_explicit(
+	    prev, &cur, next,
+	    memory_order_acq_rel, memory_order_acquire))
+      {
+	/* This may happen only on list head */
+	ASSERT_DIE(prev == head);
+
+	/* Restart. The collision should never happen again. */
+	return ev_remove_from(e, head);
+      }
+
+      /* Successfully removed from the list; inactivate this event. */
+      atomic_store_explicit(&cur->next, NULL, memory_order_release);
+      return 1;
     }
+
+    edlog(NULL, e, next, 2, EDL_REMOVE_FROM);
+
+    /* Go to the next event. */
+    prev = &cur->next;
+    cur = next;
+  }
+
+  edlog(NULL, e, cur, 4, EDL_REMOVE_FROM);
+
+  return 0;
+}
+
+inline void
+ev_postpone(event *e)
+{
+  /* Find the list to remove the event from */
+  event_list *sl = ev_get_list(e);
+  edlog(sl, e, NULL, 1, EDL_POSTPONE);
+  if (!sl)
+    return;
+
+  /* Postponing allowed only from the target loop */
+  ASSERT_DIE(birdloop_inside(sl->loop));
+
+  /* Remove from one of these lists. */
+  ASSERT(ev_remove_from(e, &sl->_executor) || ev_remove_from(e, &sl->receiver));
+
+  /* Mark as inactive */
+  ASSERT_DIE(sl == atomic_exchange_explicit(&e->list, NULL, memory_order_acq_rel));
+  edlog(sl, e, NULL, 2, EDL_POSTPONE);
 }
 
 static void
-ev_dump(resource *r)
+ev_dump(resource *r, unsigned indent UNUSED)
 {
   event *e = (event *) r;
 
   debug("(code %p, data %p, %s)\n",
 	e->hook,
 	e->data,
-	e->n.next ? "scheduled" : "inactive");
+	atomic_load_explicit(&e->next, memory_order_relaxed) ? "scheduled" : "inactive");
 }
 
 static struct resclass ev_class = {
@@ -82,8 +214,10 @@ ev_new(pool *p)
 inline void
 ev_run(event *e)
 {
+  edlog(NULL, e, NULL, 1, EDL_RUN);
   ev_postpone(e);
   e->hook(e->data);
+  edlog(NULL, e, NULL, 2, EDL_RUN);
 }
 
 /**
@@ -95,40 +229,39 @@ ev_run(event *e)
  * list @l which can be run by calling ev_run_list().
  */
 inline void
-ev_enqueue(event_list *l, event *e)
+ev_send(event_list *l, event *e)
 {
-  ev_postpone(e);
-  add_tail(l, &e->n);
-}
+  edlog(l, e, NULL, 1, EDL_SEND);
+  /* Set the target list */
+  event_list *ol = NULL;
+  if (!atomic_compare_exchange_strong_explicit(
+	&e->list, &ol, l,
+	memory_order_acq_rel, memory_order_acquire))
+    if (ol == l)
+      return;
+    else
+      bug("Queuing an already queued event to another queue is not supported.");
 
-/**
- * ev_schedule - schedule an event
- * @e: an event
- *
- * This function schedules an event by enqueueing it to a system-wide
- * event list which is run by the platform dependent code whenever
- * appropriate.
- */
-void
-ev_schedule(event *e)
-{
-  ev_enqueue(&global_event_list, e);
-}
+  /* Here should be no concurrent senders */
+  event *next = atomic_load_explicit(&l->receiver, memory_order_acquire);
+  edlog(l, e, next, 2, EDL_SEND);
+  event *old_next = NULL;
+  do
+    if (!atomic_compare_exchange_strong_explicit(
+	  &e->next, &old_next, next,
+	  memory_order_acq_rel, memory_order_acquire))
+      bug("Event %p in inconsistent state");
+    else
+    {
+      old_next = next;
+      edlog(l, old_next, next, 3, EDL_SEND);
+    }
+  while (!atomic_compare_exchange_strong_explicit(
+	&l->receiver, &next, e,
+	memory_order_acq_rel, memory_order_acquire));
 
-/**
- * ev_schedule_work - schedule a work-event.
- * @e: an event
- *
- * This function schedules an event by enqueueing it to a system-wide work-event
- * list which is run by the platform dependent code whenever appropriate. This
- * is designated for work-events instead of regular events. They are executed
- * less often in order to not clog I/O loop.
- */
-void
-ev_schedule_work(event *e)
-{
-  if (!ev_active(e))
-    add_tail(&global_work_list, &e->n);
+  edlog(l, e, next, 4, EDL_SEND);
+  if (l->loop) birdloop_ping(l->loop);
 }
 
 void io_log_event(void *hook, void *data);
@@ -140,62 +273,66 @@ void io_log_event(void *hook, void *data);
  * This function calls ev_run() for all events enqueued in the list @l.
  */
 int
-ev_run_list(event_list *l)
+ev_run_list_limited(event_list *l, uint limit)
 {
-  node *n;
-  list tmp_list;
-
-  init_list(&tmp_list);
-  add_tail_list(&tmp_list, l);
-  init_list(l);
-  WALK_LIST_FIRST(n, tmp_list)
-    {
-      event *e = SKIP_BACK(event, n, n);
+  event * _Atomic *ep = &l->_executor;
+  edlog(l, NULL, NULL, 1, EDL_RUN_LIST);
 
-      /* This is ugly hack, we want to log just events executed from the main I/O loop */
-      if ((l == &global_event_list) || (l == &global_work_list))
-	io_log_event(e->hook, e->data);
+  /* No pending events, refill the queue. */
+  if (!atomic_load_explicit(ep, memory_order_acquire))
+  {
+    /* Move the current event list aside and create a new one. */
+    event *received = atomic_exchange_explicit(&l->receiver, NULL, memory_order_acq_rel);
+    edlog(l, NULL, received, 2, EDL_RUN_LIST);
 
-      ev_run(e);
-      tmp_flush();
-    }
+    /* No event to run. */
+    if (!received)
+      return 0;
 
-  return !EMPTY_LIST(*l);
-}
+    /* Setup the executor queue */
+    event *head = NULL;
 
-int
-ev_run_list_limited(event_list *l, uint limit)
-{
-  node *n;
-  list tmp_list;
+    /* Flip the order of the events by relinking them one by one (push-pop) */
+    while (received)
+    {
+      event *cur = received;
+      received = atomic_exchange_explicit(&cur->next, head, memory_order_acq_rel);
+      edlog(l, head, received, 3, EDL_RUN_LIST);
+      head = cur;
+    }
 
-  init_list(&tmp_list);
-  add_tail_list(&tmp_list, l);
-  init_list(l);
+    /* Store the executor queue to its designated place */
+    ASSERT_DIE(atomic_exchange_explicit(ep, head, memory_order_acq_rel) == NULL);
+    edlog(l, NULL, head, 4, EDL_RUN_LIST);
+  }
 
-  WALK_LIST_FIRST(n, tmp_list)
+  /* Run the events in order. */
+  event *e;
+  while (e = atomic_load_explicit(ep, memory_order_acquire))
     {
-      event *e = SKIP_BACK(event, n, n);
-
-      if (!limit)
-	break;
+      edlog(l, e, NULL, 5, EDL_RUN_LIST);
+      /* Check limit */
+      if (!--limit)
+	return 1;
 
       /* This is ugly hack, we want to log just events executed from the main I/O loop */
       if ((l == &global_event_list) || (l == &global_work_list))
 	io_log_event(e->hook, e->data);
 
-      ev_run(e);
+      edlog(l, e, NULL, 6, EDL_RUN_LIST);
+      /* Inactivate the event */
+      event *next = atomic_load_explicit(&e->next, memory_order_relaxed);
+      ASSERT_DIE(e == atomic_exchange_explicit(ep, next, memory_order_acq_rel));
+      ASSERT_DIE(next == atomic_exchange_explicit(&e->next, NULL, memory_order_acq_rel));
+      ASSERT_DIE(l == atomic_exchange_explicit(&e->list, NULL, memory_order_acq_rel));
+      edlog(l, e, next, 7, EDL_RUN_LIST);
+
+      /* Run the event */
+      e->hook(e->data);
       tmp_flush();
-      limit--;
-    }
 
-  if (!EMPTY_LIST(tmp_list))
-  {
-    /* Attach new items after the unprocessed old items */
-    add_tail_list(&tmp_list, l);
-    init_list(l);
-    add_tail_list(l, &tmp_list);
-  }
+      edlog(l, e, next, 8, EDL_RUN_LIST);
+    }
 
-  return !EMPTY_LIST(*l);
+  return !!atomic_load_explicit(&l->receiver, memory_order_acquire);
 }
diff --git a/lib/event.h b/lib/event.h
index 5f3b78d8..6fd9f31c 100644
--- a/lib/event.h
+++ b/lib/event.h
@@ -10,33 +10,56 @@
 #define _BIRD_EVENT_H_
 
 #include "lib/resource.h"
+#include "lib/locking.h"
+
+#include <stdatomic.h>
+
+struct birdloop;
 
 typedef struct event {
   resource r;
   void (*hook)(void *);
   void *data;
-  node n;				/* Internal link */
+  struct event * _Atomic next;
+  struct event_list * _Atomic list;
 } event;
 
-typedef list event_list;
+typedef struct event_list {
+  event * _Atomic receiver;	/* Event receive list */
+  event * _Atomic _executor;	/* Event execute list */
+  const char *name;
+  struct birdloop *loop;	/* The executor loop */
+} event_list;
 
 extern event_list global_event_list;
 extern event_list global_work_list;
 
 event *ev_new(pool *);
 void ev_run(event *);
-#define ev_init_list(el) init_list(el)
+void ev_init_list(event_list *, struct birdloop *loop, const char *name);
 void ev_enqueue(event_list *, event *);
-void ev_schedule(event *);
-void ev_schedule_work(event *);
+#define ev_send ev_enqueue
+#define ev_send_loop(l, e) ev_send(birdloop_event_list((l)), (e))
+
+#define ev_schedule(e) ({ ASSERT_THE_BIRD_LOCKED; if (!ev_active((e))) ev_send(&global_event_list, (e)); })
+#define ev_schedule_work(e) ({ ASSERT_THE_BIRD_LOCKED; if (!ev_active((e))) ev_send(&global_work_list, (e)); })
+
 void ev_postpone(event *);
-int ev_run_list(event_list *);
 int ev_run_list_limited(event_list *, uint);
+#define ev_run_list(l)	ev_run_list_limited((l), ~0)
+
+#define LEGACY_EVENT_LIST(l)  (((l) == &global_event_list) || ((l) == &global_work_list))
 
 static inline int
 ev_active(event *e)
 {
-  return e->n.next != NULL;
+  return atomic_load_explicit(&e->list, memory_order_acquire) != NULL;
+}
+
+static inline event_list *
+ev_get_list(event *e)
+{
+  return atomic_load_explicit(&e->list, memory_order_acquire);
 }
 
 static inline event*
diff --git a/lib/event_test.c b/lib/event_test.c
index e1fbea8f..612deb25 100644
--- a/lib/event_test.c
+++ b/lib/event_test.c
@@ -15,7 +15,7 @@
 #include "nest/locks.h"
 #include "sysdep/unix/unix.h"
 #include "nest/iface.h"
-#include "nest/route.h"
+#include "nest/rt.h"
 
 #define MAX_NUM 4
 
@@ -54,9 +54,8 @@ t_ev_run_list(void)
   int i;
 
   olock_init();
-  timer_init();
-  io_init();
   rt_init();
+  io_init();
   if_init();
 //  roa_init();
   config_init();
diff --git a/lib/fib.h b/lib/fib.h
new file mode 100644
index 00000000..bec2a8d4
--- /dev/null
+++ b/lib/fib.h
@@ -0,0 +1,119 @@
+/*
+ *	BIRD Internet Routing Daemon -- Network prefix storage
+ *
+ *	(c) 1998--2000 Martin Mares <mj@ucw.cz>
+ *	(c) 2022 Maria Matejka <mq@jmq.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_LIB_FIB_H_
+#define _BIRD_LIB_FIB_H_
+
+/*
+ *	BIRD FIBs are generic data structure for storing network prefixes.
+ *	Also used for the master routing table. Currently implemented as
+ *	a hash table.
+ *
+ *	Available operations:
+ *		- insertion of new entry
+ *		- deletion of entry
+ *		- searching for entry by network prefix
+ *		- asynchronous retrieval of fib contents
+ */
+
+struct fib;
+
+struct fib_node {
+  struct fib_node *next;		/* Next in hash chain */
+  struct fib_iterator *readers;		/* List of readers of this node */
+  net_addr addr[0];
+};
+
+struct fib_iterator {			/* See lib/slists.h for an explanation */
+  struct fib_iterator *prev, *next;	/* Must be synced with struct fib_node! */
+  byte efef;				/* 0xff to distinguish between iterator and node */
+  byte pad[3];
+  struct fib_node *node;		/* Or NULL if freshly merged */
+  uint hash;
+};
+
+typedef void (*fib_init_fn)(struct fib *, void *);
+
+struct fib {
+  pool *fib_pool;			/* Pool holding all our data */
+  slab *fib_slab;			/* Slab holding all fib nodes */
+  struct fib_node **hash_table;		/* Node hash table */
+  uint hash_size;			/* Number of hash table entries (a power of two) */
+  uint hash_order;			/* Binary logarithm of hash_size */
+  uint hash_shift;			/* 32 - hash_order */
+  uint addr_type;			/* Type of address data stored in fib (NET_*) */
+  uint node_size;			/* FIB node size, 0 for nonuniform */
+  uint node_offset;			/* Offset of fib_node struct inside of user data */
+  uint entries;				/* Number of entries */
+  uint entries_min, entries_max;	/* Entry count limits (else start rehashing) */
+  fib_init_fn init;			/* Constructor */
+};
+
+static inline void * fib_node_to_user(struct fib *f, struct fib_node *e)
+{ return e ? (void *) ((char *) e - f->node_offset) : NULL; }
+
+static inline struct fib_node * fib_user_to_node(struct fib *f, void *e)
+{ return e ? (void *) ((char *) e + f->node_offset) : NULL; }
+
+void fib_init(struct fib *f, pool *p, uint addr_type, uint node_size, uint node_offset, uint hash_order, fib_init_fn init);
+void *fib_find(struct fib *, const net_addr *);	/* Find or return NULL if doesn't exist */
+void *fib_get_chain(struct fib *f, const net_addr *a); /* Find first node in linked list from hash table */
+void *fib_get(struct fib *, const net_addr *);	/* Find or create new if nonexistent */
+void *fib_route(struct fib *, const net_addr *); /* Longest-match routing lookup */
+void fib_delete(struct fib *, void *);	/* Remove fib entry */
+void fib_free(struct fib *);		/* Destroy the fib */
+void fib_check(struct fib *);		/* Consistency check for debugging */
+
+void fit_init(struct fib_iterator *, struct fib *); /* Internal functions, don't call */
+struct fib_node *fit_get(struct fib *, struct fib_iterator *);
+void fit_put(struct fib_iterator *, struct fib_node *);
+void fit_put_next(struct fib *f, struct fib_iterator *i, struct fib_node *n, uint hpos);
+void fit_put_end(struct fib_iterator *i);
+void fit_copy(struct fib *f, struct fib_iterator *dst, struct fib_iterator *src);
+
+
+#define FIB_WALK(fib, type, z) do {				\
+	struct fib_node *fn_, **ff_ = (fib)->hash_table;	\
+	uint count_ = (fib)->hash_size;				\
+	type *z;						\
+	while (count_--)					\
+	  for (fn_ = *ff_++; z = fib_node_to_user(fib, fn_); fn_=fn_->next)
+
+#define FIB_WALK_END } while (0)
+
+#define FIB_ITERATE_INIT(it, fib) fit_init(it, fib)
+
+#define FIB_ITERATE_START(fib, it, type, z) do {		\
+	struct fib_node *fn_ = fit_get(fib, it);		\
+	uint count_ = (fib)->hash_size;				\
+	uint hpos_ = (it)->hash;				\
+	type *z;						\
+	for(;;) {						\
+	  if (!fn_)						\
+	    {							\
+	       if (++hpos_ >= count_)				\
+		 break;						\
+	       fn_ = (fib)->hash_table[hpos_];			\
+	       continue;					\
+	    }							\
+	  z = fib_node_to_user(fib, fn_);
+
+#define FIB_ITERATE_END fn_ = fn_->next; } } while(0)
+
+#define FIB_ITERATE_PUT(it) fit_put(it, fn_)
+
+#define FIB_ITERATE_PUT_NEXT(it, fib) fit_put_next(fib, it, fn_, hpos_)
+
+#define FIB_ITERATE_PUT_END(it) fit_put_end(it)
+
+#define FIB_ITERATE_UNLINK(it, fib) fit_get(fib, it)
+
+#define FIB_ITERATE_COPY(dst, src, fib) fit_copy(fib, dst, src)
+
+#endif
diff --git a/lib/hash.h b/lib/hash.h
index 8febb33f..ebb2857a 100644
--- a/lib/hash.h
+++ b/lib/hash.h
@@ -10,7 +10,7 @@
 #ifndef _BIRD_HASH_H_
 #define _BIRD_HASH_H_
 
-#define HASH(type)		struct { type **data; uint count, order; }
+#define HASH(type)		struct { type **data; uint count; u16 iterators; u8 order; u8 down_requested:1; }
 #define HASH_TYPE(v)		typeof(** (v).data)
 #define HASH_SIZE(v)		(1U << (v).order)
 
@@ -125,20 +125,26 @@
 
 #define HASH_MAY_STEP_DOWN_(v,pool,rehash_fn,args)			\
   ({                                                                    \
-    if (((v).count < (HASH_SIZE(v) REHASH_LO_MARK(args))) &&		\
-	((v).order > (REHASH_LO_BOUND(args))))				\
+    if ((v).iterators)							\
+      (v).down_requested = 1;						\
+    else if (((v).count < (HASH_SIZE(v) REHASH_LO_MARK(args))) &&	\
+	     ((v).order > (REHASH_LO_BOUND(args))))			\
       rehash_fn(&(v), pool, -(REHASH_LO_STEP(args)));			\
   })
 
 #define HASH_MAY_RESIZE_DOWN_(v,pool,rehash_fn,args)			\
   ({                                                                    \
-    uint _o = (v).order;							\
-    while (((v).count < ((1U << _o) REHASH_LO_MARK(args))) &&		\
-	   (_o > (REHASH_LO_BOUND(args))))				\
-      _o -= (REHASH_LO_STEP(args));					\
-    if (_o < (v).order)							\
-      rehash_fn(&(v), pool, _o - (v).order);				\
-  })
+    if ((v).iterators)							\
+      (v).down_requested = 1;						\
+    else {								\
+      uint _o = (v).order;						\
+      while (((v).count < ((1U << _o) REHASH_LO_MARK(args))) &&		\
+	     (_o > (REHASH_LO_BOUND(args))))				\
+	_o -= (REHASH_LO_STEP(args));					\
+      if (_o < (v).order)						\
+	rehash_fn(&(v), pool, _o - (v).order);				\
+    }									\
+   })
 
 
 #define HASH_INSERT2(v,id,pool,node)					\
@@ -195,6 +201,20 @@
 #define HASH_WALK_FILTER_END } while (0)
 
 
+#define HASH_WALK_ITER(v, id, n, iter)					\
+  do {									\
+    uint _hash_walk_iter_put = 0;					\
+    uint _shift = 32 - (v).order;					\
+    for ( ; !_hash_walk_iter_put; (iter) += (1U << _shift)) {		\
+      _hash_walk_iter_put = ((iter) + (1U << _shift) == 0);		\
+      for (HASH_TYPE(v) *n = (v).data[(iter) >> _shift]; n; n = id##_NEXT((n)))\
+	if (HASH_FN(v, id, id##_KEY(n)) >= ((iter) >> _shift))		\
+
+#define HASH_WALK_ITER_PUT	(_hash_walk_iter_put = 1)
+
+#define HASH_WALK_ITER_END } } while (0)
+
+
 static inline void
 mem_hash_init(u64 *h)
 {
diff --git a/lib/hash_test.c b/lib/hash_test.c
index 4bce7017..ecfcdd66 100644
--- a/lib/hash_test.c
+++ b/lib/hash_test.c
@@ -285,6 +285,46 @@ t_walk_filter(void)
   return 1;
 }
 
+static int
+t_walk_iter(void)
+{
+  init_hash();
+  fill_hash();
+
+  u32 hit = 0;
+
+  u32 prev_hash = ~0;
+  for (uint cnt = 0; cnt < MAX_NUM; )
+  {
+    u32 last_hash = ~0;
+//    printf("PUT!\n");
+    HASH_WALK_ITER(hash, TEST, n, hit)
+    {
+      cnt++;
+      u32 cur_hash = HASH_FN(hash, TEST, n->key);
+      /*
+      printf("C%08x L%08x P%08x K%08x H%08x N%p S%d I%ld\n",
+	  cur_hash, last_hash, prev_hash, n->key, hit, n, _shift, n - &nodes[0]);
+	  */
+
+      if (last_hash == ~0U)
+      {
+	if (prev_hash != ~0U)
+	  bt_assert(prev_hash < cur_hash);
+	last_hash = prev_hash = cur_hash;
+      }
+      else
+	bt_assert(last_hash == cur_hash);
+
+      if (cnt < MAX_NUM)
+	HASH_WALK_ITER_PUT;
+    }
+    HASH_WALK_ITER_END;
+  }
+
+  return 1;
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -299,6 +339,7 @@ main(int argc, char *argv[])
   bt_test_suite(t_walk_delsafe_remove, 	"HASH_WALK_DELSAFE and HASH_REMOVE");
   bt_test_suite(t_walk_delsafe_remove2,	"HASH_WALK_DELSAFE and HASH_REMOVE2. HASH_REMOVE2 is HASH_REMOVE and smart auto-resize function");
   bt_test_suite(t_walk_filter,		"HASH_WALK_FILTER");
+  bt_test_suite(t_walk_iter,		"HASH_WALK_ITER");
 
   return bt_exit_value();
 }
diff --git a/lib/io-loop.h b/lib/io-loop.h
new file mode 100644
index 00000000..502d77fc
--- /dev/null
+++ b/lib/io-loop.h
@@ -0,0 +1,66 @@
+/*
+ *	BIRD -- I/O and event loop
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_IO_LOOP_H_
+#define _BIRD_IO_LOOP_H_
+
+#include "nest/bird.h"
+#include "lib/lists.h"
+#include "lib/locking.h"
+#include "lib/resource.h"
+#include "lib/event.h"
+#include "lib/socket.h"
+
+extern struct birdloop main_birdloop;
+
+/* Start a new birdloop owned by given pool and domain */
+struct birdloop *birdloop_new(pool *p, uint order, const char *name);
+
+/* Stop the loop. At the end, the @stopped callback is called unlocked in tail
+ * position to finish cleanup. Run birdloop_free() from that callback to free
+ * the loop itself. */
+void birdloop_stop(struct birdloop *loop, void (*stopped)(void *data), void *data);
+void birdloop_stop_self(struct birdloop *loop, void (*stopped)(void *data), void *data);
+void birdloop_free(struct birdloop *loop);
+
+/* Get birdloop's event list */
+event_list *birdloop_event_list(struct birdloop *loop);
+
+/* Get birdloop's time heap */
+struct timeloop *birdloop_time_loop(struct birdloop *loop);
+
+/* Enter and exit the birdloop */
+void birdloop_enter(struct birdloop *loop);
+void birdloop_leave(struct birdloop *loop);
+
+_Bool birdloop_inside(struct birdloop *loop);
+
+void birdloop_mask_wakeups(struct birdloop *loop);
+void birdloop_unmask_wakeups(struct birdloop *loop);
+
+void birdloop_link(struct birdloop *loop);
+void birdloop_unlink(struct birdloop *loop);
+
+void birdloop_ping(struct birdloop *loop);
+
+struct birdloop_flag_handler {
+  void (*hook)(struct birdloop_flag_handler *, u32 flags);
+  void *data;
+};
+
+void birdloop_flag(struct birdloop *loop, u32 flag);
+void birdloop_flag_set_handler(struct birdloop *, struct birdloop_flag_handler *);
+
+/* Setup sockets */
+void birdloop_add_socket(struct birdloop *, struct birdsock *);
+void birdloop_remove_socket(struct birdloop *, struct birdsock *);
+
+void birdloop_init(void);
+
+/* Yield for a little while. Use only in special cases. */
+void birdloop_yield(void);
+
+#endif /* _BIRD_IO_LOOP_H_ */
diff --git a/lib/ip.h b/lib/ip.h
index 9eef2e16..20e7a336 100644
--- a/lib/ip.h
+++ b/lib/ip.h
@@ -362,11 +362,7 @@ static inline ip6_addr ip6_hton(ip6_addr a)
 static inline ip6_addr ip6_ntoh(ip6_addr a)
 { return _MI6(ntohl(_I0(a)), ntohl(_I1(a)), ntohl(_I2(a)), ntohl(_I3(a))); }
 
-#define MPLS_MAX_LABEL_STACK 8
-typedef struct mpls_label_stack {
-  uint len;
-  u32 stack[MPLS_MAX_LABEL_STACK];
-} mpls_label_stack;
+#define MPLS_MAX_LABEL_STACK 16
 
 static inline int
 mpls_get(const char *buf, int buflen, u32 *stack)
diff --git a/lib/lists.c b/lib/lists.c
index 200576cf..cabfddba 100644
--- a/lib/lists.c
+++ b/lib/lists.c
@@ -26,7 +26,7 @@
 
 #define _BIRD_LISTS_C_
 
-#include "nest/bird.h"
+#include "lib/birdlib.h"
 #include "lib/lists.h"
 
 LIST_INLINE int
@@ -37,9 +37,10 @@ check_list(list *l, node *n)
     ASSERT_DIE(n);
     ASSERT_DIE(n->prev);
 
-    do { n = n->prev; } while (n->prev);
+    node *nn = n;
+    do { nn = nn->prev; } while (nn->prev);
 
-    l = SKIP_BACK(list, head_node, n);
+    l = SKIP_BACK(list, head_node, nn);
   }
 
   int seen = 0;
@@ -120,7 +121,7 @@ add_head(list *l, node *n)
 LIST_INLINE void
 insert_node(node *n, node *after)
 {
-  EXPENSIVE_CHECK(check_list(l, after));
+  EXPENSIVE_CHECK((after->prev == NULL) || check_list(NULL, after));
   ASSUME(n->prev == NULL);
   ASSUME(n->next == NULL);
 
@@ -141,7 +142,7 @@ insert_node(node *n, node *after)
 LIST_INLINE void
 rem_node(node *n)
 {
-  EXPENSIVE_CHECK(check_list(NULL, n));
+  EXPENSIVE_CHECK((n->prev == n) && (n->next == n) || check_list(NULL, n));
 
   node *z = n->prev;
   node *x = n->next;
diff --git a/lib/lists.h b/lib/lists.h
index 7e6d5467..86ff59c9 100644
--- a/lib/lists.h
+++ b/lib/lists.h
@@ -69,6 +69,18 @@ typedef union list {			/* In fact two overlayed nodes */
 
 #define EMPTY_LIST(list) (!(list).head->next)
 
+static inline _Bool
+enlisted(node *n)
+{
+  switch ((!!n->next) + (!!n->prev))
+  {
+    case 0: return 0;
+    case 2: return 1;
+    case 1: bug("Garbled event list node");
+  }
+
+  bug("Maths is broken. And you should see a new heaven and a new earth: for the first heaven and the first earth had been passed away.");
+}
 
 #ifndef _BIRD_LISTS_C_
 #define LIST_INLINE static inline
diff --git a/lib/locking.h b/lib/locking.h
new file mode 100644
index 00000000..6bed14bf
--- /dev/null
+++ b/lib/locking.h
@@ -0,0 +1,70 @@
+/*
+ *	BIRD Library -- Locking
+ *
+ *	(c) 2020--2021 Maria Matejka <mq@jmq.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_LOCKING_H_
+#define _BIRD_LOCKING_H_
+
+struct domain_generic;
+
+/* Here define the global lock order; first to last. */
+struct lock_order {
+  struct domain_generic *meta;
+  struct domain_generic *the_bird;
+  struct domain_generic *control;
+  struct domain_generic *proto;
+  struct domain_generic *service;
+  struct domain_generic *rtable;
+  struct domain_generic *attrs;
+  struct domain_generic *resource;
+};
+
+extern _Thread_local struct lock_order locking_stack;
+extern _Thread_local struct domain_generic **last_locked;
+
+#define DOMAIN(type) struct domain__##type
+#define DEFINE_DOMAIN(type) DOMAIN(type) { struct domain_generic *type; }
+#define DOMAIN_ORDER(type)  OFFSETOF(struct lock_order, type)
+
+#define DOMAIN_NEW(type, name)  (DOMAIN(type)) { .type = domain_new(name, DOMAIN_ORDER(type)) }
+struct domain_generic *domain_new(const char *name, uint order);
+
+#define DOMAIN_FREE(type, d)	domain_free((d).type)
+void domain_free(struct domain_generic *);
+
+#define DOMAIN_NAME(type, d)	domain_name((d).type)
+const char *domain_name(struct domain_generic *);
+
+#define DOMAIN_NULL(type)   (DOMAIN(type)) {}
+
+#define LOCK_DOMAIN(type, d)	do_lock(((d).type), &(locking_stack.type))
+#define UNLOCK_DOMAIN(type, d)  do_unlock(((d).type), &(locking_stack.type))
+
+#define DOMAIN_IS_LOCKED(type, d) (((d).type) == (locking_stack.type))
+#define DG_IS_LOCKED(d)	((d) == *(DG_LSP(d)))
+
+/* Internal for locking */
+void do_lock(struct domain_generic *dg, struct domain_generic **lsp);
+void do_unlock(struct domain_generic *dg, struct domain_generic **lsp);
+
+uint dg_order(struct domain_generic *dg);
+
+#define DG_LSP(d)	((struct domain_generic **) (((void *) &locking_stack) + dg_order(d)))
+#define DG_LOCK(d)	do_lock(d, DG_LSP(d))
+#define DG_UNLOCK(d)	do_unlock(d, DG_LSP(d))
+
+/* Use with care. To be removed in near future. */
+DEFINE_DOMAIN(the_bird);
+extern DOMAIN(the_bird) the_bird_domain;
+
+#define the_bird_lock()		LOCK_DOMAIN(the_bird, the_bird_domain)
+#define the_bird_unlock()	UNLOCK_DOMAIN(the_bird, the_bird_domain)
+#define the_bird_locked()	DOMAIN_IS_LOCKED(the_bird, the_bird_domain)
+
+#define ASSERT_THE_BIRD_LOCKED	({ if (!the_bird_locked()) bug("The BIRD lock must be locked here: %s:%d", __FILE__, __LINE__); })
+
+#endif
diff --git a/lib/macro.h b/lib/macro.h
index 24fc3393..8f5d4b0e 100644
--- a/lib/macro.h
+++ b/lib/macro.h
@@ -26,6 +26,8 @@
 #define MACRO_DROP(...)
 #define MACRO_UNPAREN(...) __VA_ARGS__
 #define MACRO_SEP(a, b, sep)  a sep b
+#define MACRO_STR(a)  #a
+#define MACRO_STR_AFTER(a) MACRO_STR(a)
 
 /* Aliases for some special chars */
 #define MACRO_COMMA ,
diff --git a/lib/mempool.c b/lib/mempool.c
index 325b1ecf..5200f5e7 100644
--- a/lib/mempool.c
+++ b/lib/mempool.c
@@ -41,10 +41,8 @@ struct linpool {
   uint total, total_large;
 };
 
-_Thread_local linpool *tmp_linpool;
-
 static void lp_free(resource *);
-static void lp_dump(resource *);
+static void lp_dump(resource *, unsigned);
 static resource *lp_lookup(resource *, unsigned long);
 static struct resmem lp_memsize(resource *r);
 
@@ -233,9 +231,9 @@ lp_restore(linpool *m, lp_state *p)
   struct lp_chunk *c;
 
   /* Move ptr to the saved pos and free all newer large chunks */
-  m->current = c = p->current;
-  m->ptr = p->ptr;
-  m->end = c ? c->data + LP_DATA_SIZE : NULL;
+  m->current = c = p->current ?: m->first;
+  m->ptr = p->ptr ?: (c ? c->data : NULL);
+  m->end = c ? (c->data + LP_DATA_SIZE) : NULL;
   m->total_large = p->total_large;
 
   while ((c = m->first_large) && (c != p->large))
@@ -264,11 +262,12 @@ lp_free(resource *r)
 }
 
 static void
-lp_dump(resource *r)
+lp_dump(resource *r, unsigned indent)
 {
   linpool *m = (linpool *) r;
   struct lp_chunk *c;
   int cnt, cntl;
+  char x[32];
 
   for(cnt=0, c=m->first; c; c=c->next, cnt++)
     ;
@@ -279,6 +278,14 @@ lp_dump(resource *r)
 	cntl,
 	m->total,
 	m->total_large);
+
+  bsprintf(x, "%%%dschunk %%p\n", indent + 2);
+  for (c=m->first; c; c=c->next)
+    debug(x, "", c);
+
+  bsprintf(x, "%%%dslarge %%p\n", indent + 2);
+  for (c=m->first_large; c; c=c->next)
+    debug(x, "", c);
 }
 
 static struct resmem
diff --git a/lib/rcu.c b/lib/rcu.c
new file mode 100644
index 00000000..8ae4f2ab
--- /dev/null
+++ b/lib/rcu.c
@@ -0,0 +1,79 @@
+/*
+ *	BIRD Library -- Read-Copy-Update Basic Operations
+ *
+ *	(c) 2021 Maria Matejka <mq@jmq.cz>
+ *	(c) 2021 CZ.NIC z.s.p.o.
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ *	Note: all the relevant patents shall be expired.
+ *
+ *	Using the Supplementary Material for User-Level Implementations of Read-Copy-Update
+ *	by Matthieu Desnoyers, Paul E. McKenney, Alan S. Stern, Michel R. Dagenais and Jonathan Walpole
+ *	obtained from https://www.efficios.com/pub/rcu/urcu-supp-accepted.pdf
+ */
+
+#include "lib/rcu.h"
+#include "lib/io-loop.h"
+#include "lib/locking.h"
+
+_Atomic uint rcu_gp_ctl = RCU_NEST_CNT;
+_Thread_local struct rcu_thread *this_rcu_thread = NULL;
+
+static list rcu_thread_list;
+
+static struct rcu_thread main_rcu_thread;
+
+DEFINE_DOMAIN(resource);
+static DOMAIN(resource) rcu_domain;
+
+static int
+rcu_gp_ongoing(_Atomic uint *ctl)
+{
+  uint val = atomic_load(ctl);
+  return (val & RCU_NEST_CNT) && ((val ^ rcu_gp_ctl) & RCU_GP_PHASE);
+}
+
+static void
+update_counter_and_wait(void)
+{
+  atomic_fetch_xor(&rcu_gp_ctl, RCU_GP_PHASE);
+  struct rcu_thread *rc;
+  WALK_LIST(rc, rcu_thread_list)
+    while (rcu_gp_ongoing(&rc->ctl))
+      birdloop_yield();
+}
+
+void
+synchronize_rcu(void)
+{
+  LOCK_DOMAIN(resource, rcu_domain);
+  update_counter_and_wait();
+  update_counter_and_wait();
+  UNLOCK_DOMAIN(resource, rcu_domain);
+}
+
+void
+rcu_thread_start(struct rcu_thread *rc)
+{
+  LOCK_DOMAIN(resource, rcu_domain);
+  add_tail(&rcu_thread_list, &rc->n);
+  this_rcu_thread = rc;
+  UNLOCK_DOMAIN(resource, rcu_domain);
+}
+
+void
+rcu_thread_stop(struct rcu_thread *rc)
+{
+  LOCK_DOMAIN(resource, rcu_domain);
+  this_rcu_thread = NULL;
+  rem_node(&rc->n);
+  UNLOCK_DOMAIN(resource, rcu_domain);
+}
+
+void
+rcu_init(void)
+{
+  rcu_domain = DOMAIN_NEW(resource, "Read-Copy-Update");
+  init_list(&rcu_thread_list);
+  rcu_thread_start(&main_rcu_thread);
+}
diff --git a/lib/rcu.h b/lib/rcu.h
new file mode 100644
index 00000000..30eacc5b
--- /dev/null
+++ b/lib/rcu.h
@@ -0,0 +1,55 @@
+/*
+ *	BIRD Library -- Read-Copy-Update Basic Operations
+ *
+ *	(c) 2021 Maria Matejka <mq@jmq.cz>
+ *	(c) 2021 CZ.NIC z.s.p.o.
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ *	Note: all the relevant patents shall be expired.
+ */
+
+#ifndef _BIRD_RCU_H_
+#define _BIRD_RCU_H_
+
+#include "lib/birdlib.h"
+#include "lib/lists.h"
+#include <stdatomic.h>
+
+#define RCU_GP_PHASE  0x100000
+#define RCU_NEST_MASK 0x0fffff
+#define RCU_NEST_CNT  0x000001
+
+extern _Atomic uint rcu_gp_ctl;
+
+struct rcu_thread {
+  node n;
+  _Atomic uint ctl;
+};
+
+extern _Thread_local struct rcu_thread *this_rcu_thread;
+
+static inline void rcu_read_lock(void)
+{
+  uint cmp = atomic_load_explicit(&this_rcu_thread->ctl, memory_order_acquire);
+
+  if (cmp & RCU_NEST_MASK)
+    atomic_store_explicit(&this_rcu_thread->ctl, cmp + RCU_NEST_CNT, memory_order_relaxed);
+  else
+    atomic_store(&this_rcu_thread->ctl, atomic_load_explicit(&rcu_gp_ctl, memory_order_acquire));
+}
+
+static inline void rcu_read_unlock(void)
+{
+  atomic_fetch_sub(&this_rcu_thread->ctl, RCU_NEST_CNT);
+}
+
+void synchronize_rcu(void);
+
+/* Registering and unregistering a birdloop. To be called from birdloop implementation */
+void rcu_thread_start(struct rcu_thread *);
+void rcu_thread_stop(struct rcu_thread *);
+
+/* Run this from resource init */
+void rcu_init(void);
+
+#endif
diff --git a/lib/resource.c b/lib/resource.c
index 89e559b4..94b8d019 100644
--- a/lib/resource.c
+++ b/lib/resource.c
@@ -14,6 +14,7 @@
 #include "nest/bird.h"
 #include "lib/resource.h"
 #include "lib/string.h"
+#include "lib/rcu.h"
 
 /**
  * DOC: Resource pools
@@ -29,13 +30,7 @@
  * is freed upon shutdown of the module.
  */
 
-struct pool {
-  resource r;
-  list inside;
-  const char *name;
-};
-
-static void pool_dump(resource *);
+static void pool_dump(resource *, unsigned);
 static void pool_free(resource *);
 static resource *pool_lookup(resource *, unsigned long);
 static struct resmem pool_memsize(resource *P);
@@ -51,8 +46,6 @@ static struct resclass pool_class = {
 
 pool root_pool;
 
-static int indent;
-
 /**
  * rp_new - create a resource pool
  * @p: parent pool
@@ -100,16 +93,14 @@ pool_free(resource *P)
 }
 
 static void
-pool_dump(resource *P)
+pool_dump(resource *P, unsigned indent)
 {
   pool *p = (pool *) P;
   resource *r;
 
   debug("%s\n", p->name);
-  indent += 3;
   WALK_LIST(r, p->inside)
-    rdump(r);
-  indent -= 3;
+    rdump(r, indent + 3);
 }
 
 static struct resmem
@@ -199,7 +190,7 @@ rfree(void *res)
  * It works by calling a class-specific dump function.
  */
 void
-rdump(void *res)
+rdump(void *res, unsigned indent)
 {
   char x[16];
   resource *r = res;
@@ -209,7 +200,7 @@ rdump(void *res)
   if (r)
     {
       debug("%s ", r->class->name);
-      r->class->dump(r);
+      r->class->dump(r, indent);
     }
   else
     debug("NULL\n");
@@ -269,7 +260,7 @@ rlookup(unsigned long a)
 
   debug("Looking up %08lx\n", a);
   if (r = pool_lookup(&root_pool.r, a))
-    rdump(r);
+    rdump(r, 3);
   else
     debug("Not found.\n");
 }
@@ -284,6 +275,7 @@ rlookup(unsigned long a)
 void
 resource_init(void)
 {
+  rcu_init();
   resource_sys_init();
 
   root_pool.r.class = &pool_class;
@@ -292,6 +284,25 @@ resource_init(void)
   tmp_init(&root_pool);
 }
 
+_Thread_local struct tmp_resources tmp_res;
+
+void
+tmp_init(pool *p)
+{
+  tmp_res.lp = lp_new_default(p);
+  tmp_res.parent = p;
+  tmp_res.pool = rp_new(p, "TMP");
+}
+
+void
+tmp_flush(void)
+{
+  lp_flush(tmp_linpool);
+  rfree(tmp_res.pool);
+  tmp_res.pool = rp_new(tmp_res.parent, "TMP");
+}
+
+
 /**
  * DOC: Memory blocks
  *
@@ -316,7 +327,7 @@ static void mbl_free(resource *r UNUSED)
 {
 }
 
-static void mbl_debug(resource *r)
+static void mbl_debug(resource *r, unsigned indent UNUSED)
 {
   struct mblock *m = (struct mblock *) r;
 
diff --git a/lib/resource.h b/lib/resource.h
index a4e110a5..911b990d 100644
--- a/lib/resource.h
+++ b/lib/resource.h
@@ -30,7 +30,7 @@ struct resclass {
   char *name;				/* Resource class name */
   unsigned size;			/* Standard size of single resource */
   void (*free)(resource *);		/* Freeing function */
-  void (*dump)(resource *);		/* Dump to debug output */
+  void (*dump)(resource *, unsigned indent);		/* Dump to debug output */
   resource *(*lookup)(resource *, unsigned long);	/* Look up address (only for debugging) */
   struct resmem (*memsize)(resource *);	/* Return size of memory used by the resource, may be NULL */
 };
@@ -40,13 +40,18 @@ struct resclass {
 
 /* Generic resource manipulation */
 
-typedef struct pool pool;
+typedef struct pool {
+  resource r;
+  list inside;
+  const char *name;
+} pool;
+
 
 void resource_init(void);
 pool *rp_new(pool *, const char *);	/* Create new pool */
 pool *rp_newf(pool *, const char *, ...);	/* Create a new pool with a formatted string as its name */
 void rfree(void *);			/* Free single resource */
-void rdump(void *);			/* Dump to debug output */
+void rdump(void *, unsigned indent);	/* Dump to debug output */
 struct resmem rmemsize(void *res);		/* Return size of memory used by the resource */
 void rlookup(unsigned long);		/* Look up address (only for debugging) */
 void rmove(void *, pool *);		/* Move to a different pool */
@@ -80,14 +85,21 @@ void lp_flush(linpool *);			/* Free everything, but leave linpool */
 void lp_save(linpool *m, lp_state *p);		/* Save state */
 void lp_restore(linpool *m, lp_state *p);	/* Restore state */
 
-extern _Thread_local linpool *tmp_linpool;	/* Temporary linpool autoflushed regularily */
+struct tmp_resources {
+  pool *pool, *parent;
+  linpool *lp;
+};
+
+extern _Thread_local struct tmp_resources tmp_res;
 
+#define tmp_linpool	tmp_res.lp
 #define tmp_alloc(sz)	lp_alloc(tmp_linpool, sz)
 #define tmp_allocu(sz)	lp_allocu(tmp_linpool, sz)
 #define tmp_allocz(sz)	lp_allocz(tmp_linpool, sz)
 
-#define tmp_init(p)	tmp_linpool = lp_new_default(p)
-#define tmp_flush()	lp_flush(tmp_linpool)
+void tmp_init(pool *p);
+void tmp_flush(void);
+
 
 #define lp_new_default	lp_new
 
@@ -108,9 +120,13 @@ void sl_free(void *);
 void buffer_realloc(void **buf, unsigned *size, unsigned need, unsigned item_size);
 
 /* Allocator of whole pages; for use in slabs and other high-level allocators. */
+#define PAGE_HEAD(x)	((void *) (((uintptr_t) (x)) & ~(page_size-1)))
 extern long page_size;
+extern _Atomic int pages_kept;
+extern _Atomic int pages_kept_locally;
 void *alloc_page(void);
 void free_page(void *);
+void flush_local_pages(void);
 
 void resource_sys_init(void);
 
diff --git a/lib/route.h b/lib/route.h
new file mode 100644
index 00000000..6189895a
--- /dev/null
+++ b/lib/route.h
@@ -0,0 +1,560 @@
+/*
+ *	BIRD Internet Routing Daemon -- Routing data structures
+ *
+ *	(c) 1998--2000 Martin Mares <mj@ucw.cz>
+ *	(c) 2022 Maria Matejka <mq@jmq.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_LIB_ROUTE_H_
+#define _BIRD_LIB_ROUTE_H_
+
+#undef RT_SOURCE_DEBUG
+
+#include "lib/type.h"
+#include "lib/rcu.h"
+#include "lib/hash.h"
+#include "lib/event.h"
+
+struct network;
+struct proto;
+struct cli;
+struct rtable_private;
+
+typedef struct rte {
+  struct ea_list *attrs;		/* Attributes of this route */
+  const net_addr *net;			/* Network this RTE belongs to */
+  struct rte_src *src;			/* Route source that created the route */
+  struct rt_import_hook *sender;	/* Import hook used to send the route to the routing table */
+  btime lastmod;			/* Last modified (set by table) */
+  u32 id;				/* Table specific route id */
+  byte flags;				/* Table-specific flags */
+  byte pflags;				/* Protocol-specific flags */
+  u8 generation;			/* If this route import is based on other previously exported route,
+					   this value should be 1 + MAX(generation of the parent routes).
+					   Otherwise the route is independent and this value is zero. */
+  u8 stale_cycle;			/* Auxiliary value for route refresh */
+} rte;
+
+#define REF_FILTERED	2		/* Route is rejected by import filter */
+#define REF_PENDING	32		/* Route has not propagated completely yet */
+
+/* Route is valid for propagation (may depend on other flags in the future), accepts NULL */
+static inline int rte_is_valid(const rte *r) { return r && !(r->flags & REF_FILTERED); }
+
+/* Route just has REF_FILTERED flag */
+static inline int rte_is_filtered(const rte *r) { return !!(r->flags & REF_FILTERED); }
+
+/* Strip the route of the table-specific values */
+static inline rte rte_init_from(const rte *r)
+{
+  return (rte) {
+    .attrs = r->attrs,
+    .net = r->net,
+    .src = r->src,
+  };
+}
+
+struct rte_src {
+  struct rte_src *next;			/* Hash chain */
+  struct rte_owner *owner;		/* Route source owner */
+  u32 private_id;			/* Private ID, assigned by the protocol */
+  u32 global_id;			/* Globally unique ID of the source */
+  _Atomic u64 uc;			/* Use count */
+};
+
+struct rte_owner_class {
+  void (*get_route_info)(const rte *, byte *buf); /* Get route information (for `show route' command) */
+  int (*rte_better)(const rte *, const rte *);
+  int (*rte_mergable)(const rte *, const rte *);
+  u32 (*rte_igp_metric)(const rte *);
+};
+
+struct rte_owner {
+  struct rte_owner_class *class;
+  int (*rte_recalculate)(struct rtable_private *, struct network *, struct rte *, struct rte *, struct rte *);
+  HASH(struct rte_src) hash;
+  const char *name;
+  u32 hash_key;
+  u32 uc;
+  event_list *list;
+  event *prune;
+  event *stop;
+};
+
+DEFINE_DOMAIN(attrs);
+extern DOMAIN(attrs) attrs_domain;
+
+#define RTA_LOCK       LOCK_DOMAIN(attrs, attrs_domain)
+#define RTA_UNLOCK     UNLOCK_DOMAIN(attrs, attrs_domain)
+
+#define RTE_SRC_PU_SHIFT      44
+#define RTE_SRC_IN_PROGRESS   (1ULL << RTE_SRC_PU_SHIFT)
+
+/* Get a route source. This also locks the source, therefore the caller has to
+ * unlock the source after the route has been propagated. */
+struct rte_src *rt_get_source_o(struct rte_owner *o, u32 id);
+#define rt_get_source(p, id)  rt_get_source_o(&(p)->sources, (id))
+
+struct rte_src *rt_find_source_global(u32 id);
+
+#ifdef RT_SOURCE_DEBUG
+#define rt_lock_source _rt_lock_source_internal
+#define rt_unlock_source _rt_unlock_source_internal
+#endif
+
+static inline void rt_lock_source(struct rte_src *src)
+{
+  /* Locking a source is trivial; somebody already holds it so we just increase
+   * the use count. Nothing can be freed underneath our hands. */
+  u64 uc = atomic_fetch_add_explicit(&src->uc, 1, memory_order_acq_rel);
+  ASSERT_DIE(uc > 0);
+}
+
+static inline void rt_unlock_source(struct rte_src *src)
+{
+  /* Unlocking is tricky. We do it lockless so at the same time, the prune
+   * event may be running, therefore if the unlock gets us to zero, it must be
+   * the last thing in this routine, otherwise the prune routine may find the
+   * source's usecount zeroed, freeing it prematurely.
+   *
+   * The usecount is split into two parts:
+   * the top 20 bits are an in-progress indicator
+   * the bottom 44 bits keep the actual usecount.
+   *
+   * Therefore at most 1 million of writers can simultaneously unlock the same
+   * source, while at most ~17T different routes can reference it. Both limits
+   * are insanely high from the 2022 point of view. Let's suppose that when 17T
+   * routes or 1M writers get real, we get also 128bit atomic variables in the
+   * C norm. */
+
+  /* First, we push the in-progress indicator */
+  u64 uc = atomic_fetch_add_explicit(&src->uc, RTE_SRC_IN_PROGRESS, memory_order_acq_rel);
+
+  /* Then we split the indicator to its parts. Remember, we got the value before the operation happened. */
+  u64 pending = (uc >> RTE_SRC_PU_SHIFT) + 1;
+  uc &= RTE_SRC_IN_PROGRESS - 1;
+
+  /* We per-use the RCU critical section indicator to make the prune event wait
+   * until we finish here in the rare case we get preempted. */
+  rcu_read_lock();
+
+  /* Obviously, there can't be more pending unlocks than the usecount itself */
+  if (uc == pending)
+    /* If we're the last unlocker, schedule the owner's prune event */
+    ev_send(src->owner->list, src->owner->prune);
+  else
+    ASSERT_DIE(uc > pending);
+
+  /* And now, finally, simultaneously pop the in-progress indicator and the
+   * usecount, possibly allowing the source pruning routine to free this structure */
+  atomic_fetch_sub_explicit(&src->uc, RTE_SRC_IN_PROGRESS + 1, memory_order_acq_rel);
+
+  /* ... and to reduce the load a bit, the source pruning routine will better wait for
+   * RCU synchronization instead of a busy loop. */
+  rcu_read_unlock();
+}
+
+#ifdef RT_SOURCE_DEBUG
+#undef rt_lock_source
+#undef rt_unlock_source
+
+#define rt_lock_source(x) ( log(L_INFO "Lock source %uG at %s:%d", (x)->global_id, __FILE__, __LINE__), _rt_lock_source_internal(x) )
+#define rt_unlock_source(x) ( log(L_INFO "Unlock source %uG at %s:%d", (x)->global_id, __FILE__, __LINE__), _rt_unlock_source_internal(x) )
+#endif
+
+void rt_init_sources(struct rte_owner *, const char *name, event_list *list);
+void rt_destroy_sources(struct rte_owner *, event *);
+
+/*
+ *	Route Attributes
+ *
+ *	Beware: All standard BGP attributes must be represented here instead
+ *	of making them local to the route. This is needed to ensure proper
+ *	construction of BGP route attribute lists.
+ */
+
+/* Nexthop structure */
+struct nexthop {
+  ip_addr gw;				/* Next hop */
+  struct iface *iface;			/* Outgoing interface */
+  byte flags;
+  byte weight;
+  byte labels;				/* Number of all labels */
+  u32 label[0];
+};
+
+/* For packing one into eattrs */
+struct nexthop_adata {
+  struct adata ad;
+  /* There is either a set of nexthops or a special destination (RTD_*) */
+  union {
+    struct nexthop nh;
+    uint dest;
+  };
+};
+
+#define NEXTHOP_DEST_SIZE	(OFFSETOF(struct nexthop_adata, dest) + sizeof(uint) - OFFSETOF(struct adata, data))
+#define NEXTHOP_DEST_LITERAL(x)	((struct nexthop_adata) { \
+      .ad.length = NEXTHOP_DEST_SIZE, .dest = (x), })
+
+#define RNF_ONLINK		0x1	/* Gateway is onlink regardless of IP ranges */
+
+
+#define RTS_STATIC 1			/* Normal static route */
+#define RTS_INHERIT 2			/* Route inherited from kernel */
+#define RTS_DEVICE 3			/* Device route */
+#define RTS_STATIC_DEVICE 4		/* Static device route */
+#define RTS_REDIRECT 5			/* Learned via redirect */
+#define RTS_RIP 6			/* RIP route */
+#define RTS_OSPF 7			/* OSPF route */
+#define RTS_OSPF_IA 8			/* OSPF inter-area route */
+#define RTS_OSPF_EXT1 9			/* OSPF external route type 1 */
+#define RTS_OSPF_EXT2 10		/* OSPF external route type 2 */
+#define RTS_BGP 11			/* BGP route */
+#define RTS_PIPE 12			/* Inter-table wormhole */
+#define RTS_BABEL 13			/* Babel route */
+#define RTS_RPKI 14			/* Route Origin Authorization */
+#define RTS_PERF 15			/* Perf checker */
+#define RTS_MAX 16
+
+#define RTD_NONE 0			/* Undefined next hop */
+#define RTD_UNICAST 1			/* A standard next hop */
+#define RTD_BLACKHOLE 2			/* Silently drop packets */
+#define RTD_UNREACHABLE 3		/* Reject as unreachable */
+#define RTD_PROHIBIT 4			/* Administratively prohibited */
+#define RTD_MAX 5
+
+extern const char * rta_dest_names[RTD_MAX];
+
+static inline const char *rta_dest_name(uint n)
+{ return (n < RTD_MAX) ? rta_dest_names[n] : "???"; }
+
+
+/*
+ *	Extended Route Attributes
+ */
+
+typedef struct eattr {
+  word id;				/* EA_CODE(PROTOCOL_..., protocol-dependent ID) */
+  byte flags;				/* Protocol-dependent flags */
+  byte type;				/* Attribute type */
+  byte rfu:5;
+  byte originated:1;			/* The attribute has originated locally */
+  byte fresh:1;				/* An uncached attribute (e.g. modified in export filter) */
+  byte undef:1;				/* Explicitly undefined */
+
+  PADDING(unused, 3, 3);
+
+  union bval u;
+} eattr;
+
+
+#define EA_CODE_MASK 0xffff
+#define EA_ALLOW_UNDEF 0x10000		/* ea_find: allow EAF_TYPE_UNDEF */
+#define EA_BIT(n) ((n) << 24)		/* Used in bitfield accessors */
+#define EA_BIT_GET(ea) ((ea) >> 24)
+
+typedef struct ea_list {
+  struct ea_list *next;			/* In case we have an override list */
+  byte flags;				/* Flags: EALF_... */
+  byte rfu;
+  word count;				/* Number of attributes */
+  eattr attrs[0];			/* Attribute definitions themselves */
+} ea_list;
+
+struct ea_storage {
+  struct ea_storage *next_hash;		/* Next in hash chain */
+  struct ea_storage **pprev_hash;	/* Previous in hash chain */
+  _Atomic u32 uc;			/* Use count */
+  u32 hash_key;				/* List hash */
+  ea_list l[0];				/* The list itself */
+};
+
+#define EALF_SORTED 1			/* Attributes are sorted by code */
+#define EALF_BISECT 2			/* Use interval bisection for searching */
+#define EALF_CACHED 4			/* List is cached */
+#define EALF_HUGE   8			/* List is too big to fit into slab */
+
+struct ea_class {
+#define EA_CLASS_INSIDE \
+  const char *name;			/* Name (both print and filter) */ \
+  struct symbol *sym;			/* Symbol to export to configs */ \
+  uint id;				/* Autoassigned attribute ID */ \
+  uint uc;				/* Reference count */ \
+  btype type;				/* Data type ID */ \
+  uint readonly:1;			/* This attribute can't be changed by filters */ \
+  uint conf:1;				/* Requested by config */ \
+  uint hidden:1;			/* Technical attribute, do not show, do not expose to filters */ \
+  void (*format)(const eattr *ea, byte *buf, uint size); \
+  void (*stored)(const eattr *ea);	/* When stored into global hash */ \
+  void (*freed)(const eattr *ea);	/* When released from global hash */ \
+
+  EA_CLASS_INSIDE;
+};
+
+struct ea_class_ref {
+  resource r;
+  struct ea_class *class;
+};
+
+void ea_register_init(struct ea_class *);
+struct ea_class_ref *ea_register_alloc(pool *, struct ea_class);
+
+#define EA_REGISTER_ALL_HELPER(x)	ea_register_init(x);
+#define EA_REGISTER_ALL(...)		MACRO_FOREACH(EA_REGISTER_ALL_HELPER, __VA_ARGS__)
+
+struct ea_class *ea_class_find_by_id(uint id);
+struct ea_class *ea_class_find_by_name(const char *name);
+static inline struct ea_class *ea_class_self(struct ea_class *self) { return self; }
+#define ea_class_find(_arg)	_Generic((_arg), \
+  uint: ea_class_find_by_id, \
+  word: ea_class_find_by_id, \
+  char *: ea_class_find_by_name, \
+  const char *: ea_class_find_by_name, \
+  struct ea_class *: ea_class_self)(_arg)
+
+struct ea_walk_state {
+  ea_list *eattrs;			/* Ccurrent ea_list, initially set by caller */
+  eattr *ea;				/* Current eattr, initially NULL */
+  u32 visited[4];			/* Bitfield, limiting max to 128 */
+};
+
+#define ea_find(_l, _arg)	_Generic((_arg), uint: ea_find_by_id, struct ea_class *: ea_find_by_class, char *: ea_find_by_name)(_l, _arg)
+eattr *ea_find_by_id(ea_list *, unsigned ea);
+static inline eattr *ea_find_by_class(ea_list *l, const struct ea_class *def)
+{ return ea_find_by_id(l, def->id); }
+static inline eattr *ea_find_by_name(ea_list *l, const char *name)
+{
+  const struct ea_class *def = ea_class_find_by_name(name);
+  return def ? ea_find_by_class(l, def) : NULL;
+}
+
+#define ea_get_int(_l, _ident, _def)  ({ \
+    struct ea_class *cls = ea_class_find((_ident)); \
+    ASSERT_DIE(cls->type & EAF_EMBEDDED); \
+    const eattr *ea = ea_find((_l), cls->id); \
+    (ea ? ea->u.data : (_def)); \
+    })
+
+#define ea_get_ip(_l, _ident, _def)  ({ \
+    struct ea_class *cls = ea_class_find((_ident)); \
+    ASSERT_DIE(cls->type == T_IP); \
+    const eattr *ea = ea_find((_l), cls->id); \
+    (ea ? *((const ip_addr *) ea->u.ptr->data) : (_def)); \
+    })
+
+eattr *ea_walk(struct ea_walk_state *s, uint id, uint max);
+void ea_dump(ea_list *);
+int ea_same(ea_list *x, ea_list *y);	/* Test whether two ea_lists are identical */
+uint ea_hash(ea_list *e);	/* Calculate 16-bit hash value */
+ea_list *ea_append(ea_list *to, ea_list *what);
+void ea_format_bitfield(const struct eattr *a, byte *buf, int bufsize, const char **names, int min, int max);
+
+/* Normalize ea_list; allocates the result from tmp_linpool */
+ea_list *ea_normalize(ea_list *e, int overlay);
+
+uint ea_list_size(ea_list *);
+void ea_list_copy(ea_list *dest, ea_list *src, uint size);
+
+#define EA_LOCAL_LIST(N)  struct { ea_list l; eattr a[N]; }
+
+#define EA_LITERAL_EMBEDDED(_class, _flags, _val) ({ \
+    btype _type = (_class)->type; \
+    ASSERT_DIE(_type & EAF_EMBEDDED); \
+    EA_LITERAL_GENERIC((_class)->id, _type, _flags, .u.i = _val); \
+    })
+
+#define EA_LITERAL_STORE_ADATA(_class, _flags, _buf, _len) ({ \
+    btype _type = (_class)->type; \
+    ASSERT_DIE(!(_type & EAF_EMBEDDED)); \
+    EA_LITERAL_GENERIC((_class)->id, _type, _flags, .u.ad = tmp_store_adata((_buf), (_len))); \
+    })
+
+#define EA_LITERAL_DIRECT_ADATA(_class, _flags, _adata) ({ \
+    btype _type = (_class)->type; \
+    ASSERT_DIE(!(_type & EAF_EMBEDDED)); \
+    EA_LITERAL_GENERIC((_class)->id, _type, _flags, .u.ad = _adata); \
+    })
+
+#define EA_LITERAL_GENERIC(_id, _type, _flags, ...) \
+  ((eattr) { .id = _id, .type = _type, .flags = _flags, __VA_ARGS__ })
+
+static inline eattr *
+ea_set_attr(ea_list **to, eattr a)
+{
+  EA_LOCAL_LIST(1) *ea = tmp_alloc(sizeof(*ea));
+  *ea = (typeof(*ea)) {
+    .l.flags = EALF_SORTED,
+    .l.count = 1,
+    .l.next = *to,
+    .a[0] = a,
+  };
+
+  *to = &ea->l;
+  return &ea->a[0];
+}
+
+static inline void
+ea_unset_attr(ea_list **to, _Bool local, const struct ea_class *def)
+{
+  ea_set_attr(to, EA_LITERAL_GENERIC(def->id, 0, 0,
+	.fresh = local, .originated = local, .undef = 1));
+}
+
+static inline void
+ea_set_attr_u32(ea_list **to, const struct ea_class *def, uint flags, u64 data)
+{ ea_set_attr(to, EA_LITERAL_EMBEDDED(def, flags, data)); }
+
+static inline void
+ea_set_attr_data(ea_list **to, const struct ea_class *def, uint flags, const void *data, uint len)
+{ ea_set_attr(to, EA_LITERAL_STORE_ADATA(def, flags, data, len)); }
+
+static inline void
+ea_copy_attr(ea_list **to, ea_list *from, const struct ea_class *def)
+{
+  eattr *e = ea_find_by_class(from, def);
+  if (e)
+    if (e->type & EAF_EMBEDDED)
+      ea_set_attr_u32(to, def, e->flags, e->u.data);
+    else
+      ea_set_attr_data(to, def, e->flags, e->u.ptr->data, e->u.ptr->length);
+  else
+    ea_unset_attr(to, 0, def);
+}
+
+/*
+ *	Common route attributes
+ */
+
+/* Preference: first-order comparison */
+extern struct ea_class ea_gen_preference;
+static inline u32 rt_get_preference(const rte *rt)
+{ return ea_get_int(rt->attrs, &ea_gen_preference, 0); }
+
+/* IGP metric: second-order comparison */
+extern struct ea_class ea_gen_igp_metric;
+u32 rt_get_igp_metric(const rte *rt);
+#define IGP_METRIC_UNKNOWN 0x80000000	/* Default igp_metric used when no other
+					   protocol-specific metric is availabe */
+
+/* From: Advertising router */
+extern struct ea_class ea_gen_from;
+
+/* Source: An old method to devise the route source protocol and kind.
+ * To be superseded in a near future by something more informative. */
+extern struct ea_class ea_gen_source;
+static inline u32 rt_get_source_attr(const rte *rt)
+{ return ea_get_int(rt->attrs, &ea_gen_source, 0); }
+
+/* Flowspec validation result */
+enum flowspec_valid {
+  FLOWSPEC_UNKNOWN	= 0,
+  FLOWSPEC_VALID	= 1,
+  FLOWSPEC_INVALID	= 2,
+  FLOWSPEC__MAX,
+};
+
+extern const char * flowspec_valid_names[FLOWSPEC__MAX];
+static inline const char *flowspec_valid_name(enum flowspec_valid v)
+{ return (v < FLOWSPEC__MAX) ? flowspec_valid_names[v] : "???"; }
+
+extern struct ea_class ea_gen_flowspec_valid;
+static inline enum flowspec_valid rt_get_flowspec_valid(rte *rt)
+{ return ea_get_int(rt->attrs, &ea_gen_flowspec_valid, FLOWSPEC_UNKNOWN); }
+
+/* Next hop: For now, stored as adata */
+extern struct ea_class ea_gen_nexthop;
+
+static inline void ea_set_dest(struct ea_list **to, uint flags, uint dest)
+{
+  struct nexthop_adata nhad = NEXTHOP_DEST_LITERAL(dest);
+  ea_set_attr_data(to, &ea_gen_nexthop, flags, &nhad.ad.data, nhad.ad.length);
+}
+
+/* Next hop structures */
+
+#define NEXTHOP_ALIGNMENT	(_Alignof(struct nexthop))
+#define NEXTHOP_MAX_SIZE	(sizeof(struct nexthop) + sizeof(u32)*MPLS_MAX_LABEL_STACK)
+#define NEXTHOP_SIZE(_nh)	NEXTHOP_SIZE_CNT(((_nh)->labels))
+#define NEXTHOP_SIZE_CNT(cnt)	BIRD_ALIGN((sizeof(struct nexthop) + sizeof(u32) * (cnt)), NEXTHOP_ALIGNMENT)
+#define nexthop_size(nh)	NEXTHOP_SIZE((nh))
+
+#define NEXTHOP_NEXT(_nh)	((void *) (_nh) + NEXTHOP_SIZE(_nh))
+#define NEXTHOP_END(_nhad)	((_nhad)->ad.data + (_nhad)->ad.length)
+#define NEXTHOP_VALID(_nh, _nhad) ((void *) (_nh) < (void *) NEXTHOP_END(_nhad))
+#define NEXTHOP_ONE(_nhad)	(NEXTHOP_NEXT(&(_nhad)->nh) == NEXTHOP_END(_nhad))
+
+#define NEXTHOP_WALK(_iter, _nhad) for ( \
+    struct nexthop *_iter = &(_nhad)->nh; \
+    (void *) _iter < (void *) NEXTHOP_END(_nhad); \
+    _iter = NEXTHOP_NEXT(_iter))
+
+
+static inline int nexthop_same(struct nexthop_adata *x, struct nexthop_adata *y)
+{ return adata_same(&x->ad, &y->ad); }
+struct nexthop_adata *nexthop_merge(struct nexthop_adata *x, struct nexthop_adata *y, int max, linpool *lp);
+struct nexthop_adata *nexthop_sort(struct nexthop_adata *x, linpool *lp);
+int nexthop_is_sorted(struct nexthop_adata *x);
+
+#define NEXTHOP_IS_REACHABLE(nhad)	((nhad)->ad.length > NEXTHOP_DEST_SIZE)
+
+/* Route has regular, reachable nexthop (i.e. not RTD_UNREACHABLE and like) */
+static inline int rte_is_reachable(rte *r)
+{
+  eattr *nhea = ea_find(r->attrs, &ea_gen_nexthop);
+  if (!nhea)
+    return 0;
+
+  struct nexthop_adata *nhad = (void *) nhea->u.ptr;
+  return NEXTHOP_IS_REACHABLE(nhad);
+}
+
+static inline int nhea_dest(eattr *nhea)
+{
+  if (!nhea)
+    return RTD_NONE;
+
+  struct nexthop_adata *nhad = nhea ? (struct nexthop_adata *) nhea->u.ptr : NULL;
+  if (NEXTHOP_IS_REACHABLE(nhad))
+    return RTD_UNICAST;
+  else
+    return nhad->dest;
+}
+
+static inline int rte_dest(const rte *r)
+{
+  return nhea_dest(ea_find(r->attrs, &ea_gen_nexthop));
+}
+
+void rta_init(void);
+ea_list *ea_lookup(ea_list *, int overlay);		/* Get a cached (and normalized) variant of this attribute list */
+static inline int ea_is_cached(const ea_list *r) { return r->flags & EALF_CACHED; }
+static inline struct ea_storage *ea_get_storage(ea_list *r)
+{
+  ASSERT_DIE(ea_is_cached(r));
+  return SKIP_BACK(struct ea_storage, l[0], r);
+}
+
+static inline ea_list *ea_clone(ea_list *r) {
+  ASSERT_DIE(0 < atomic_fetch_add_explicit(&ea_get_storage(r)->uc, 1, memory_order_acq_rel));
+  return r;
+}
+void ea__free(struct ea_storage *r);
+static inline void ea_free(ea_list *l) {
+  if (!l) return;
+  struct ea_storage *r = ea_get_storage(l);
+  if (1 == atomic_fetch_sub_explicit(&r->uc, 1, memory_order_acq_rel)) ea__free(r);
+}
+
+void ea_dump(ea_list *);
+void ea_dump_all(void);
+void ea_show_list(struct cli *, ea_list *);
+
+#define rta_lookup	ea_lookup
+#define rta_is_cached	ea_is_cached
+#define rta_clone	ea_clone
+#define rta_free	ea_free
+
+#endif
diff --git a/lib/settle.h b/lib/settle.h
new file mode 100644
index 00000000..e721f21f
--- /dev/null
+++ b/lib/settle.h
@@ -0,0 +1,64 @@
+/*
+ *	BIRD -- Settle timer
+ *
+ *	(c) 2022 Maria Matejka <mq@jmq.cz>
+ *	(c) 2022 CZ.NIC z.s.p.o.
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_SETTLE_H_
+#define _BIRD_SETTLE_H_
+
+#include "lib/birdlib.h"
+#include "lib/timer.h"
+
+struct settle_config {
+  btime min, max;
+};
+
+struct settle {
+  union {
+    /* Timer hook polymorphism. */
+    struct {
+      resource _r;
+      void (*hook)(struct settle *);
+    };
+    timer tm;
+  };
+  struct settle_config cf;
+  btime started;
+};
+
+STATIC_ASSERT(OFFSETOF(struct settle, hook) == OFFSETOF(struct settle, tm) + OFFSETOF(timer, hook));
+
+#define SETTLE_INIT(_cfp, _hook, _data) (struct settle) { .tm = { .data = (_data), .hook = TYPE_CAST(void (*)(struct settle *), void (*)(struct timer *), (_hook)), }, .cf = ({ASSERT_DIE((_cfp)->min <= (_cfp)->max); *(_cfp); }), }
+
+
+static inline void settle_init(struct settle *s, struct settle_config *cf, void (*hook)(struct settle *), void *data)
+{
+  *s = SETTLE_INIT(cf, hook, data);
+}
+
+#define settle_active(s) tm_active(&(s)->tm)
+
+static inline void settle_kick(struct settle *s, struct birdloop *loop)
+{
+  if (!tm_active(&s->tm))
+  {
+    s->started = current_time();
+    tm_set_in(&s->tm, s->started + s->cf.min, loop);
+  }
+  else
+  {
+    btime now = current_time();
+    tm_set_in(&s->tm, MIN_(now + s->cf.min, s->started + s->cf.max), loop);
+  }
+}
+
+static inline void settle_cancel(struct settle *s)
+{
+  tm_stop(&s->tm);
+}
+
+#endif
diff --git a/lib/slab.c b/lib/slab.c
index 38d10626..23316e82 100644
--- a/lib/slab.c
+++ b/lib/slab.c
@@ -41,7 +41,7 @@
 #endif
 
 static void slab_free(resource *r);
-static void slab_dump(resource *r);
+static void slab_dump(resource *r, unsigned indent);
 static resource *slab_lookup(resource *r, unsigned long addr);
 static struct resmem slab_memsize(resource *r);
 
@@ -118,7 +118,7 @@ slab_free(resource *r)
 }
 
 static void
-slab_dump(resource *r)
+slab_dump(resource *r, unsigned indent UNUSED)
 {
   slab *s = (slab *) r;
   int cnt = 0;
@@ -197,7 +197,7 @@ static struct resclass sl_class = {
   slab_memsize
 };
 
-#define SL_GET_HEAD(x)	((struct sl_head *) (((uintptr_t) (x)) & ~(page_size-1)))
+#define SL_GET_HEAD(x)	PAGE_HEAD(x)
 
 #define SL_HEAD_CHANGE_STATE(_s, _h, _from, _to) ({ \
     ASSERT_DIE(_h->state == slh_##_from); \
@@ -236,7 +236,7 @@ sl_new(pool *p, uint size)
       + sizeof(u32) * s->head_bitfield_len
       + align - 1)
     / align * align;
-  } while (s->objs_per_slab * size + s->head_size > page_size);
+  } while (s->objs_per_slab * size + s->head_size > (size_t) page_size);
 
   if (!s->objs_per_slab)
     bug("Slab: object too large");
@@ -378,7 +378,7 @@ slab_free(resource *r)
 }
 
 static void
-slab_dump(resource *r)
+slab_dump(resource *r, unsigned indent UNUSED)
 {
   slab *s = (slab *) r;
   int ec=0, pc=0, fc=0;
@@ -390,6 +390,15 @@ slab_dump(resource *r)
   WALK_TLIST(sl_head, h, &s->full_heads)
     fc++;
   debug("(%de+%dp+%df blocks per %d objs per %d bytes)\n", ec, pc, fc, s->objs_per_slab, s->obj_size);
+
+  char x[16];
+  bsprintf(x, "%%%ds%%s %%p\n", indent + 2);
+  WALK_TLIST(sl_head, h, &s->full_heads)
+    debug(x, "", "full", h);
+  WALK_TLIST(sl_head, h, &s->partial_heads)
+    debug(x, "", "partial", h);
+  WALK_TLIST(sl_head, h, &s->empty_heads)
+    debug(x, "", "empty", h);
 }
 
 static struct resmem
diff --git a/lib/socket.h b/lib/socket.h
index 0b6ac589..4b169581 100644
--- a/lib/socket.h
+++ b/lib/socket.h
@@ -12,6 +12,7 @@
 #include <errno.h>
 
 #include "lib/resource.h"
+#include "lib/event.h"
 #ifdef HAVE_LIBSSH
 #define LIBSSH_LEGACY_0_4
 #include <libssh/libssh.h>
@@ -79,16 +80,22 @@ typedef struct birdsock {
   const char *password;			/* Password for MD5 authentication */
   const char *err;			/* Error message */
   struct ssh_sock *ssh;			/* Used in SK_SSH */
+  struct birdloop *loop;		/* BIRDLoop owning this socket */
 } sock;
 
 sock *sock_new(pool *);			/* Allocate new socket */
 #define sk_new(X) sock_new(X)		/* Wrapper to avoid name collision with OpenSSL */
 
-int sk_open(sock *);			/* Open socket */
+int sk_open(sock *, struct birdloop *);		/* Open socket */
+void sk_reloop(sock *, struct birdloop *);	/* Move socket to another loop. Both loops must be locked. */
+
 int sk_rx_ready(sock *s);
+_Bool sk_tx_pending(sock *s);
 int sk_send(sock *, uint len);		/* Send data, <0=err, >0=ok, 0=sleep */
 int sk_send_to(sock *, uint len, ip_addr to, uint port); /* sk_send to given destination */
 void sk_reallocate(sock *);		/* Free and allocate tbuf & rbuf */
+void sk_pause_rx(struct birdloop *loop, sock *s);
+void sk_resume_rx(struct birdloop *loop, sock *s, int (*hook)(sock *, uint));
 void sk_set_rbsize(sock *s, uint val);	/* Resize RX buffer */
 void sk_set_tbsize(sock *s, uint val);	/* Resize TX buffer, keeping content */
 void sk_set_tbuf(sock *s, void *tbuf);	/* Switch TX buffer, NULL-> return to internal */
@@ -112,6 +119,7 @@ int sk_set_icmp6_filter(sock *s, int p1, int p2);
 void sk_log_error(sock *s, const char *p);
 
 byte * sk_rx_buffer(sock *s, int *len);	/* Temporary */
+sock *sk_next(sock *s);
 
 extern int sk_priority_control;		/* Suggested priority for control traffic, should be sysdep define */
 
@@ -125,7 +133,6 @@ extern int sk_priority_control;		/* Suggested priority for control traffic, shou
 #define SKF_HIGH_PORT	0x20	/* Choose port from high range if possible */
 #define SKF_FREEBIND	0x40	/* Allow socket to bind to a nonlocal address */
 
-#define SKF_THREAD	0x100	/* Socked used in thread, Do not add to main loop */
 #define SKF_TRUNCATED	0x200	/* Received packet was truncated, set by IO layer */
 #define SKF_HDRINCL	0x400	/* Used internally */
 #define SKF_PKTINFO	0x800	/* Used internally */
diff --git a/lib/timer.c b/lib/timer.c
index c47e0bbc..4e4aa55e 100644
--- a/lib/timer.c
+++ b/lib/timer.c
@@ -36,57 +36,13 @@
 #include "lib/resource.h"
 #include "lib/timer.h"
 
-
-struct timeloop main_timeloop;
-
-
-#ifdef USE_PTHREADS
-
 #include <pthread.h>
 
-/* Data accessed and modified from proto/bfd/io.c */
-pthread_key_t current_time_key;
-
-static inline struct timeloop *
-timeloop_current(void)
-{
-  return pthread_getspecific(current_time_key);
-}
-
-static inline void
-timeloop_init_current(void)
-{
-  pthread_key_create(&current_time_key, NULL);
-  pthread_setspecific(current_time_key, &main_timeloop);
-}
+_Atomic btime last_time;
+_Atomic btime real_time;
 
 void wakeup_kick_current(void);
 
-#else
-
-/* Just use main timelooop */
-static inline struct timeloop * timeloop_current(void) { return &main_timeloop; }
-static inline void timeloop_init_current(void) { }
-
-#endif
-
-btime
-current_time(void)
-{
-  return timeloop_current()->last_time;
-}
-
-btime
-current_real_time(void)
-{
-  struct timeloop *loop = timeloop_current();
-
-  if (!loop->real_time)
-    times_update_real_time(loop);
-
-  return loop->real_time;
-}
-
 
 #define TIMER_LESS(a,b)		((a)->expires < (b)->expires)
 #define TIMER_SWAP(heap,a,b,t)	(t = heap[a], heap[a] = heap[b], heap[b] = t, \
@@ -102,7 +58,7 @@ tm_free(resource *r)
 }
 
 static void
-tm_dump(resource *r)
+tm_dump(resource *r, unsigned indent UNUSED)
 {
   timer *t = (void *) r;
 
@@ -112,7 +68,7 @@ tm_dump(resource *r)
   if (t->recurrent)
     debug("recur %d, ", t->recurrent);
   if (t->expires)
-    debug("expires in %d ms)\n", (t->expires - current_time()) TO_MS);
+    debug("in loop %p expires in %d ms)\n", t->loop, (t->expires - current_time()) TO_MS);
   else
     debug("inactive)\n");
 }
@@ -135,41 +91,40 @@ tm_new(pool *p)
   return t;
 }
 
-void
-tm_set(timer *t, btime when)
+static void
+tm_set_in_tl(timer *t, btime when, struct timeloop *local_timeloop)
 {
-  struct timeloop *loop = timeloop_current();
-  uint tc = timers_count(loop);
+  uint tc = timers_count(local_timeloop);
 
   if (!t->expires)
   {
     t->index = ++tc;
     t->expires = when;
-    BUFFER_PUSH(loop->timers) = t;
-    HEAP_INSERT(loop->timers.data, tc, timer *, TIMER_LESS, TIMER_SWAP);
+    BUFFER_PUSH(local_timeloop->timers) = t;
+    HEAP_INSERT(local_timeloop->timers.data, tc, timer *, TIMER_LESS, TIMER_SWAP);
   }
   else if (t->expires < when)
   {
     t->expires = when;
-    HEAP_INCREASE(loop->timers.data, tc, timer *, TIMER_LESS, TIMER_SWAP, t->index);
+    HEAP_INCREASE(local_timeloop->timers.data, tc, timer *, TIMER_LESS, TIMER_SWAP, t->index);
   }
   else if (t->expires > when)
   {
     t->expires = when;
-    HEAP_DECREASE(loop->timers.data, tc, timer *, TIMER_LESS, TIMER_SWAP, t->index);
+    HEAP_DECREASE(local_timeloop->timers.data, tc, timer *, TIMER_LESS, TIMER_SWAP, t->index);
   }
 
-#ifdef CONFIG_BFD
-  /* Hack to notify BFD loops */
-  if ((loop != &main_timeloop) && (t->index == 1))
-    wakeup_kick_current();
-#endif
+  t->loop = local_timeloop;
+
+  if (t->index == 1)
+    birdloop_ping(local_timeloop->loop);
 }
 
 void
-tm_start(timer *t, btime after)
+tm_set_in(timer *t, btime when, struct birdloop *loop)
 {
-  tm_set(t, current_time() + MAX(after, 0));
+  ASSERT_DIE(birdloop_inside(loop));
+  tm_set_in_tl(t, when, birdloop_time_loop(loop));
 }
 
 void
@@ -178,20 +133,22 @@ tm_stop(timer *t)
   if (!t->expires)
     return;
 
-  struct timeloop *loop = timeloop_current();
-  uint tc = timers_count(loop);
+  TLOCK_TIMER_ASSERT(t->loop);
 
-  HEAP_DELETE(loop->timers.data, tc, timer *, TIMER_LESS, TIMER_SWAP, t->index);
-  BUFFER_POP(loop->timers);
+  uint tc = timers_count(t->loop);
+
+  HEAP_DELETE(t->loop->timers.data, tc, timer *, TIMER_LESS, TIMER_SWAP, t->index);
+  BUFFER_POP(t->loop->timers);
 
   t->index = -1;
   t->expires = 0;
+  t->loop = NULL;
 }
 
 void
 timers_init(struct timeloop *loop, pool *p)
 {
-  times_init(loop);
+  TLOCK_TIMER_ASSERT(loop);
 
   BUFFER_INIT(loop->timers, p, 4);
   BUFFER_PUSH(loop->timers) = NULL;
@@ -200,13 +157,15 @@ timers_init(struct timeloop *loop, pool *p)
 void io_log_event(void *hook, void *data);
 
 void
-timers_fire(struct timeloop *loop)
+timers_fire(struct timeloop *loop, int io_log)
 {
+  TLOCK_TIMER_ASSERT(loop);
+
   btime base_time;
   timer *t;
 
-  times_update(loop);
-  base_time = loop->last_time;
+  times_update();
+  base_time = current_time();
 
   while (t = timers_first(loop))
   {
@@ -217,19 +176,19 @@ timers_fire(struct timeloop *loop)
     {
       btime when = t->expires + t->recurrent;
 
-      if (when <= loop->last_time)
-	when = loop->last_time + t->recurrent;
+      if (when <= base_time)
+	when = base_time + t->recurrent;
 
       if (t->randomize)
 	when += random() % (t->randomize + 1);
 
-      tm_set(t, when);
+      tm_set_in_tl(t, when, loop);
     }
     else
       tm_stop(t);
 
     /* This is ugly hack, we want to log just timers executed from the main I/O loop */
-    if (loop == &main_timeloop)
+    if (io_log)
       io_log_event(t->hook, t->data);
 
     t->hook(t);
@@ -237,13 +196,6 @@ timers_fire(struct timeloop *loop)
   }
 }
 
-void
-timer_init(void)
-{
-  timers_init(&main_timeloop, &root_pool);
-  timeloop_init_current();
-}
-
 
 /**
  * tm_parse_time - parse a date and time
diff --git a/lib/timer.h b/lib/timer.h
index c5ea430c..4a3a2108 100644
--- a/lib/timer.h
+++ b/lib/timer.h
@@ -12,8 +12,14 @@
 
 #include "nest/bird.h"
 #include "lib/buffer.h"
+#include "lib/io-loop.h"
+#include "lib/locking.h"
 #include "lib/resource.h"
 
+#include <stdatomic.h>
+
+extern _Atomic btime last_time;
+extern _Atomic btime real_time;
 
 typedef struct timer
 {
@@ -25,36 +31,42 @@ typedef struct timer
   uint randomize;			/* Amount of randomization */
   uint recurrent;			/* Timer recurrence */
 
+  struct timeloop *loop;		/* Loop where the timer is active */
+
   int index;
 } timer;
 
 struct timeloop
 {
   BUFFER_(timer *) timers;
-  btime last_time;
-  btime real_time;
+  struct domain_generic *domain;
+  struct birdloop *loop;
 };
 
+#define TLOCK_TIMER_ASSERT(loop) ASSERT_DIE((loop)->domain && DG_IS_LOCKED((loop)->domain))
+#define TLOCK_LOCAL_ASSERT(loop) ASSERT_DIE(!(loop)->domain || DG_IS_LOCKED((loop)->domain))
+
 static inline uint timers_count(struct timeloop *loop)
-{ return loop->timers.used - 1; }
+{ TLOCK_TIMER_ASSERT(loop); return loop->timers.used - 1; }
 
 static inline timer *timers_first(struct timeloop *loop)
-{ return (loop->timers.used > 1) ? loop->timers.data[1] : NULL; }
-
-extern struct timeloop main_timeloop;
+{ TLOCK_TIMER_ASSERT(loop); return (loop->timers.used > 1) ? loop->timers.data[1] : NULL; }
 
-btime current_time(void);
-btime current_real_time(void);
+#define current_time()		atomic_load_explicit(&last_time, memory_order_acquire)
+#define current_real_time()	atomic_load_explicit(&real_time, memory_order_acquire)
 
 //#define now (current_time() TO_S)
 //#define now_real (current_real_time() TO_S)
 extern btime boot_time;
 
 timer *tm_new(pool *p);
-void tm_set(timer *t, btime when);
-void tm_start(timer *t, btime after);
+#define tm_set(t, when) tm_set_in((t), (when), &main_birdloop)
+#define tm_start(t, after) tm_start_in((t), (after), &main_birdloop)
 void tm_stop(timer *t);
 
+void tm_set_in(timer *t, btime when, struct birdloop *loop);
+#define tm_start_in(t, after, loop) tm_set_in((t), (current_time() + MAX_((after), 0)), loop)
+
 static inline int
 tm_active(timer *t)
 {
@@ -87,22 +99,20 @@ tm_set_max(timer *t, btime when)
 }
 
 static inline void
-tm_start_max(timer *t, btime after)
+tm_start_max_in(timer *t, btime after, struct birdloop *loop)
 {
   btime rem = tm_remains(t);
-  tm_start(t, MAX_(rem, after));
+  tm_start_in(t, MAX_(rem, after), loop);
 }
 
+#define tm_start_max(t, after)	tm_start_max_in(t, after, &main_birdloop)
+
 /* In sysdep code */
-void times_init(struct timeloop *loop);
-void times_update(struct timeloop *loop);
-void times_update_real_time(struct timeloop *loop);
+void times_update(void);
 
 /* For I/O loop */
 void timers_init(struct timeloop *loop, pool *p);
-void timers_fire(struct timeloop *loop);
-
-void timer_init(void);
+void timers_fire(struct timeloop *loop, int io_log);
 
 
 struct timeformat {
diff --git a/lib/tlists.h b/lib/tlists.h
index e1ed79ea..1437e17e 100644
--- a/lib/tlists.h
+++ b/lib/tlists.h
@@ -147,9 +147,14 @@ static inline void TLIST_NAME(rem_node)(TLIST_LIST_STRUCT *list, TLIST_TYPE *nod
 #error "You should first include lib/tlists.h without requesting a TLIST"
 #endif
 
-#define TLIST_NODE(_name, _type)	struct _name##_node { _type *next; _type *prev; }
+#define TLIST_NODE_CONTENTS(_type)	{ _type *next; _type *prev; }
+#define TLIST_NODE(_name, _type)	struct _name##_node TLIST_NODE_CONTENTS(_type) 
+#define TLIST_DEFAULT_NODE		struct MACRO_CONCAT_AFTER(TLIST_PREFIX,_node) \
+					TLIST_NODE_CONTENTS(TLIST_TYPE) TLIST_ITEM
+
 #define TLIST_LIST(_name)		struct _name##_list 
 
+
 /* Use ->first and ->last to access HEAD and TAIL */
 #define THEAD(_name, _list)  (_list)->first
 #define TTAIL(_name, _list)  (_list)->last
diff --git a/lib/type.h b/lib/type.h
new file mode 100644
index 00000000..b54744c1
--- /dev/null
+++ b/lib/type.h
@@ -0,0 +1,112 @@
+/*
+ *     BIRD Internet Routing Daemon -- Internal Data Types
+ *
+ *     (c) 2022 Maria Matejka <mq@jmq.cz>
+ *
+ *     Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_TYPE_H_
+#define _BIRD_TYPE_H_
+
+#include "lib/birdlib.h"
+#include "lib/attrs.h"
+
+union bval {
+#define BVAL_ITEMS									\
+  struct {										\
+    u32 data;			/* Integer type inherited from eattrs */		\
+    PADDING(data, 0, 4);	/* Must be padded on 64-bits */				\
+  };											\
+  struct {										\
+    u32 i;			/* Integer type inherited from filters */		\
+    PADDING(i, 0, 4);		/* Must be padded on 64-bits */				\
+  };											\
+  const struct adata *ptr;	/* Generic attribute data inherited from eattrs */	\
+  const struct adata *ad;     	/* Generic attribute data inherited from filters */	\
+
+  BVAL_ITEMS;
+};
+
+union bval_long {
+  union bval bval;		/* For direct assignments */
+  BVAL_ITEMS;			/* For item-wise access */
+
+  u64 ec;
+  lcomm lc;
+  ip_addr ip;
+  const net_addr *net;
+  const char *s;
+  const struct f_tree *t;
+  const struct f_trie *ti;
+  const struct f_path_mask *path_mask;
+  struct f_path_mask_item pmi;
+};
+
+
+/* Internal types */
+enum btype {
+/* Nothing. Simply nothing. */
+  T_VOID = 0,
+
+/* Something but inaccessible. */
+  T_OPAQUE = 0x02,		/* Opaque byte string (not filterable) */
+  T_IFACE = 0x0c,		/* Pointer to an interface (inside adata) */
+  T_NEXTHOP_LIST = 0x2c,	/* The whole nexthop block */
+  T_HOSTENTRY = 0x2e,		/* Hostentry with possible MPLS labels */
+
+/* Types shared with eattrs */
+  T_INT = 0x01,			/* 32-bit unsigned integer number */
+  T_IP = 0x04,			/* IP address */
+  T_QUAD = 0x05,		/* Router ID (IPv4 address) */
+  T_PATH = 0x06,		/* BGP AS path (encoding per RFC 1771:4.3) */
+  T_CLIST = 0x0a,		/* Set of u32's (e.g., a community list) */
+  T_ECLIST = 0x0e,		/* Set of pairs of u32's - ext. community list */
+  T_LCLIST = 0x08,		/* Set of triplets of u32's - large community list */
+
+  T_ENUM_BGP_ORIGIN = 0x11,	/* BGP Origin enum */
+  T_ENUM_RA_PREFERENCE = 0x13,	/* RA Preference enum */
+  T_ENUM_FLOWSPEC_VALID = 0x15,	/* Flowspec validation result */
+
+#define EAF_TYPE__MAX 0x1f
+#define EAF_EMBEDDED 0x01		/* Data stored in eattr.u.data (part of type spec) */
+					/* Otherwise, attribute data is adata */
+
+/* Other user visible types which fit in int */
+  T_BOOL = 0xa0,
+  T_PAIR = 0xa4,  /*	Notice that pair is stored as integer: first << 16 | second */
+
+/* Put enumerational types in 0x20..0x3f range */
+  T_ENUM_LO = 0x10,
+  T_ENUM_HI = 0x3f,
+
+  T_ENUM_RTS = 0x31,
+  T_ENUM_SCOPE = 0x33,
+  T_ENUM_RTD = 0x37,
+  T_ENUM_ROA = 0x39,
+  T_ENUM_NETTYPE = 0x3b,
+  T_ENUM_AF = 0x3d,
+
+/* new enums go here */
+
+#define T_ENUM T_ENUM_LO ... T_ENUM_HI
+
+/* Bigger ones */
+  T_NET = 0xb0,
+  T_STRING = 0xb4,
+  T_PATH_MASK = 0xb8,	/* mask for BGP path */
+  T_EC = 0xbc,		/* Extended community value, u64 */
+  T_LC = 0xc0,		/* Large community value, lcomm */
+  T_RD = 0xc4,		/* Route distinguisher for VPN addresses */
+  T_PATH_MASK_ITEM = 0xc8,	/* Path mask item for path mask constructors */
+
+  T_SET = 0x80,
+  T_PREFIX_SET = 0x84,
+} PACKED;
+
+typedef enum btype btype;
+
+STATIC_ASSERT(sizeof(btype) == sizeof(byte));
+
+
+#endif
diff --git a/lib/type_test.c b/lib/type_test.c
new file mode 100644
index 00000000..b526db69
--- /dev/null
+++ b/lib/type_test.c
@@ -0,0 +1,79 @@
+/*
+ *	BIRD Library -- Data Type Alignment Tests
+ *
+ *	(c) 2022 Maria Matejka <mq@jmq.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#include "test/birdtest.h"
+#include "lib/type.h"
+#include "lib/route.h"
+
+#define CHECK_ONE(val)	\
+  for (uint i=0; i<sizeof(val); i++) \
+    bt_assert(((const u8 *) &val)[i] == (u8) ~0);
+
+#define SET_PADDING(val, name)	\
+  for (uint i=0; i<sizeof(val.PADDING_NAME(name)); i++) \
+    val.PADDING_NAME(name)[i] = ~0;
+
+
+static int
+t_bval(void)
+{
+  union bval v;
+
+  memset(&v, 0, sizeof(v));
+  v.data = ~0;
+  SET_PADDING(v, data);
+  CHECK_ONE(v);
+
+  memset(&v, 0, sizeof(v));
+  v.i = ~0;
+  SET_PADDING(v, i);
+  CHECK_ONE(v);
+
+  memset(&v, 0, sizeof(v));
+  v.ptr = (void *) ~0;
+  CHECK_ONE(v);
+
+  memset(&v, 0, sizeof(v));
+  v.ad = (void *) ~0;
+  CHECK_ONE(v);
+
+  return 1;
+}
+
+static int
+t_eattr(void)
+{
+  struct eattr e;
+  memset(&e, 0, sizeof(e));
+
+  e.id = ~0;
+  e.flags = ~0;
+  e.type = ~0;
+  e.rfu = ~0;
+  e.originated = ~0;
+  e.fresh = ~0;
+  e.undef = ~0;
+  memset(&e.u, ~0, sizeof(e.u));  /* Assumes t_bval passed */
+
+  SET_PADDING(e, unused);
+
+  CHECK_ONE(e);
+
+  return 1;
+}
+
+
+int main(int argc, char *argv[])
+{
+  bt_init(argc, argv);
+
+  bt_test_suite(t_bval,	  "Structure alignment test: bval");
+  bt_test_suite(t_eattr,  "Structure alignment test: eattr");
+
+  return bt_exit_value();
+}