Merge commit '977b82fb' into wireguard-next-tmp7-1

6 files changed, 1074 insertions, 0 deletions

diff --git a/proto/aggregator/Doc b/proto/aggregator/Doc
new file mode 100644
index 00000000..6111f2f1
--- /dev/null
+++ b/proto/aggregator/Doc
@@ -0,0 +1 @@
+S aggregator.c
diff --git a/proto/aggregator/Makefile b/proto/aggregator/Makefile
new file mode 100644
index 00000000..d1dae8dd
--- /dev/null
+++ b/proto/aggregator/Makefile
@@ -0,0 +1,6 @@
+src := aggregator.c
+obj := $(src-o-files)
+$(all-daemon)
+$(cf-local)
+
+tests_objs := $(tests_objs) $(src-o-files)
diff --git a/proto/aggregator/aggregator.c b/proto/aggregator/aggregator.c
new file mode 100644
index 00000000..9d95c7db
--- /dev/null
+++ b/proto/aggregator/aggregator.c
@@ -0,0 +1,731 @@
+/*
+ *	BIRD Internet Routing Daemon -- Route aggregation
+ *
+ *	(c) 2023--2023 Igor Putovny <igor.putovny@nic.cz>
+ *	(c) 2023       CZ.NIC, z.s.p.o.
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+/**
+ * DOC: Route aggregation
+ *
+ * This is an implementation of route aggregation functionality.
+ * It enables user to specify a set of route attributes in the configuarion file
+ * and then, for a given destination (net), aggregate routes with the same
+ * values of these attributes into a single multi-path route.
+ *
+ * Structure &channel contains pointer to aggregation list which is represented
+ * by &aggr_list_linearized. In rt_notify_aggregated(), attributes from this
+ * list are evaluated for every route of a given net and results are stored
+ * in &rte_val_list which contains pointer to this route and array of &f_val.
+ * Array of pointers to &rte_val_list entries is sorted using
+ * sort_rte_val_list(). For comparison of &f_val structures, val_compare()
+ * is used. Comparator function is written so that sorting is stable. If all
+ * attributes have the same values, routes are compared by their global IDs.
+ *
+ * After sorting, &rte_val_list entries containing equivalent routes will be
+ * adjacent to each other. Function process_rte_list() iterates through these
+ * entries to identify sequences of equivalent routes. New route will be
+ * created for each such sequence, even if only from a single route.
+ * Only attributes from the aggreagation list will be set for the new route.
+ * New &rta is created and prepare_rta() is used to copy static and dynamic
+ * attributes to new &rta from &rta of the original route. New route is created
+ * by create_merged_rte() from new &rta and exported to the routing table.
+ */
+
+#undef LOCAL_DEBUG
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include "nest/bird.h"
+#include "nest/iface.h"
+#include "filter/filter.h"
+#include "aggregator.h"
+
+#include <stdlib.h>
+/*
+#include "nest/route.h"
+#include "nest/iface.h"
+#include "lib/resource.h"
+#include "lib/event.h"
+#include "lib/timer.h"
+#include "lib/string.h"
+#include "conf/conf.h"
+#include "filter/filter.h"
+#include "filter/data.h"
+#include "lib/hash.h"
+#include "lib/string.h"
+#include "lib/alloca.h"
+#include "lib/flowspec.h"
+*/
+
+/* Context of &f_val comparison. */
+struct cmp_ctx {
+  const struct aggregator_proto *p;
+  const struct network *net;
+  const int val_count;
+  u32 failed:1;
+};
+
+extern linpool *rte_update_pool;
+
+/*
+ * Set static attribute in @rta from static attribute in @old according to @sa.
+ */
+static void
+rta_set_static_attr(struct rta *rta, const struct rta *old, struct f_static_attr sa)
+{
+  switch (sa.sa_code)
+  {
+    case SA_NET:
+      break;
+
+    case SA_FROM:
+      rta->from = old->from;
+      break;
+
+    case SA_GW:
+      rta->dest = RTD_UNICAST;
+      rta->nh.gw = old->nh.gw;
+      rta->nh.iface = old->nh.iface;
+      rta->nh.next = NULL;
+      rta->hostentry = NULL;
+      rta->nh.labels = 0;
+      break;
+
+    case SA_SCOPE:
+      rta->scope = old->scope;
+      break;
+
+    case SA_DEST:
+      rta->dest = old->dest;
+      rta->nh.gw = IPA_NONE;
+      rta->nh.iface = NULL;
+      rta->nh.next = NULL;
+      rta->hostentry = NULL;
+      rta->nh.labels = 0;
+      break;
+
+    case SA_IFNAME:
+      rta->dest = RTD_UNICAST;
+      rta->nh.gw = IPA_NONE;
+      rta->nh.iface = old->nh.iface;
+      rta->nh.next = NULL;
+      rta->hostentry = NULL;
+      rta->nh.labels = 0;
+      break;
+
+    case SA_GW_MPLS:
+      rta->nh.labels = old->nh.labels;
+      memcpy(&rta->nh.label, &old->nh.label, sizeof(u32) * old->nh.labels);
+      break;
+
+    case SA_WEIGHT:
+      rta->nh.weight = old->nh.weight;
+      break;
+
+    case SA_PREF:
+      rta->pref = old->pref;
+      break;
+
+    default:
+      bug("Invalid static attribute access (%u/%u)", sa.f_type, sa.sa_code);
+  }
+}
+
+/*
+ * Compare list of &f_val entries.
+ * @count: number of &f_val entries
+ */
+static int
+same_val_list(const struct f_val *v1, const struct f_val *v2, uint len)
+{
+  for (uint i = 0; i < len; i++)
+    if (!val_same(&v1[i], &v2[i]))
+      return 0;
+
+  return 1;
+}
+
+/*
+ * Create and export new merged route.
+ * @old: first route in a sequence of equivalent routes that are to be merged
+ * @rte_val: first element in a sequence of equivalent rte_val_list entries
+ * @length: number of equivalent routes that are to be merged (at least 1)
+ * @ail: aggregation list
+ */
+static void
+aggregator_bucket_update(struct aggregator_proto *p, struct aggregator_bucket *bucket, struct network *net)
+{
+  /* Empty bucket */
+  if (!bucket->rte)
+  {
+    rte_update2(p->dst, net->n.addr, NULL, bucket->last_src);
+    bucket->last_src = NULL;
+    return;
+  }
+
+  /* Allocate RTA and EA list */
+  struct rta *rta = allocz(rta_size(bucket->rte->attrs));
+  rta->dest = RTD_UNREACHABLE;
+  rta->source = RTS_AGGREGATED;
+  rta->scope = SCOPE_UNIVERSE;
+
+  struct ea_list *eal = allocz(sizeof(struct ea_list) + sizeof(struct eattr) * p->aggr_on_da_count);
+  eal->next = NULL;
+  eal->count = 0;
+  rta->eattrs = eal;
+
+  /* Seed the attributes from aggregator rule */
+  for (uint i = 0; i < p->aggr_on_count; i++)
+  {
+    if (p->aggr_on[i].type == AGGR_ITEM_DYNAMIC_ATTR)
+    {
+      u32 ea_code = p->aggr_on[i].da.ea_code;
+      const struct eattr *e = ea_find(bucket->rte->attrs->eattrs, ea_code);
+
+      if (e)
+        eal->attrs[eal->count++] = *e;
+    }
+    else if (p->aggr_on[i].type == AGGR_ITEM_STATIC_ATTR)
+      rta_set_static_attr(rta, bucket->rte->attrs, p->aggr_on[i].sa);
+  }
+
+  struct rte *new = rte_get_temp(rta, bucket->rte->src);
+  new->net = net;
+
+  /*
+  log("=============== CREATE MERGED ROUTE ===============");
+  log("New route created: id = %d, protocol: %s", new->src->global_id, new->src->proto->name);
+  log("===================================================");
+  */
+
+  /* merge filter needs one argument called "routes" */
+  struct f_val val = {
+    .type = T_ROUTES_BLOCK,
+    .val.rte = bucket->rte,
+  };
+
+  /* Actually run the filter */
+  enum filter_return fret = f_eval_rte(p->merge_by, &new, rte_update_pool, 1, &val, 0);
+
+  /* Src must be stored now, rte_update2() may return new */
+  struct rte_src *new_src = new ? new->src : NULL;
+
+  /* Finally import the route */
+  switch (fret)
+  {
+    /* Pass the route to the protocol */
+    case F_ACCEPT:
+      rte_update2(p->dst, net->n.addr, new, bucket->last_src ?: new->src);
+      break;
+
+    /* Something bad happened */
+    default:
+      ASSERT_DIE(fret == F_ERROR);
+      /* fall through */
+
+    /* We actually don't want this route */
+    case F_REJECT:
+      if (bucket->last_src)
+	rte_update2(p->dst, net->n.addr, NULL, bucket->last_src);
+      break;
+  }
+
+  /* Switch source lock for bucket->last_src */
+  if (bucket->last_src != new_src)
+  {
+    if (new_src)
+      rt_lock_source(new_src);
+    if (bucket->last_src)
+      rt_unlock_source(bucket->last_src);
+
+    bucket->last_src = new_src;
+  }
+}
+
+/*
+ * Reload all the buckets on reconfiguration if merge filter has changed.
+ * TODO: make this splitted
+ */
+static void
+aggregator_reload_buckets(void *data)
+{
+  struct aggregator_proto *p = data;
+
+  HASH_WALK(p->buckets, next_hash, b)
+    if (b->rte)
+      aggregator_bucket_update(p, b, b->rte->net);
+  HASH_WALK_END;
+}
+
+
+/*
+ * Evaluate static attribute of @rt1 according to @sa
+ * and store result in @pos.
+ */
+static void
+eval_static_attr(const struct rte *rt1, struct f_static_attr sa, struct f_val *pos)
+{
+  const struct rta *rta = rt1->attrs;
+
+#define RESULT(_type, value, result)    \
+  do {                                  \
+    pos->type = _type;                  \
+    pos->val.value = result;            \
+  } while (0)
+
+  switch (sa.sa_code)
+  {
+    case SA_NET:	RESULT(sa.f_type, net, rt1->net->n.addr); break;
+    case SA_FROM:       RESULT(sa.f_type, ip, rta->from); break;
+    case SA_GW:	        RESULT(sa.f_type, ip, rta->nh.gw); break;
+    case SA_PROTO:	    RESULT(sa.f_type, s, rt1->src->proto->name); break;
+    case SA_SOURCE:	    RESULT(sa.f_type, i, rta->source); break;
+    case SA_SCOPE:	    RESULT(sa.f_type, i, rta->scope); break;
+    case SA_DEST:	    RESULT(sa.f_type, i, rta->dest); break;
+    case SA_IFNAME:	    RESULT(sa.f_type, s, rta->nh.iface ? rta->nh.iface->name : ""); break;
+    case SA_IFINDEX:	RESULT(sa.f_type, i, rta->nh.iface ? rta->nh.iface->index : 0); break;
+    case SA_WEIGHT:	    RESULT(sa.f_type, i, rta->nh.weight + 1); break;
+    case SA_PREF:	    RESULT(sa.f_type, i, rta->pref); break;
+    case SA_GW_MPLS:    RESULT(sa.f_type, i, rta->nh.labels ? rta->nh.label[0] : MPLS_NULL); break;
+    default:
+      bug("Invalid static attribute access (%u/%u)", sa.f_type, sa.sa_code);
+  }
+
+#undef RESULT
+}
+
+/*
+ * Evaluate dynamic attribute of @rt1 according to @da
+ * and store result in @pos.
+ */
+static void
+eval_dynamic_attr(const struct rte *rt1, struct f_dynamic_attr da, struct f_val *pos)
+{
+  const struct rta *rta = rt1->attrs;
+  const struct eattr *e = ea_find(rta->eattrs, da.ea_code);
+
+#define RESULT(_type, value, result)    \
+  do {                                  \
+    pos->type = _type;                  \
+    pos->val.value = result;            \
+  } while (0)
+
+#define RESULT_VOID         \
+  do {                      \
+    pos->type = T_VOID;     \
+  } while (0)
+
+  if (!e)
+  {
+    /* A special case: undefined as_path looks like empty as_path */
+    if (da.type == EAF_TYPE_AS_PATH)
+    {
+      RESULT(T_PATH, ad, &null_adata);
+      return;
+    }
+
+    /* The same special case for int_set */
+    if (da.type == EAF_TYPE_INT_SET)
+    {
+      RESULT(T_CLIST, ad, &null_adata);
+      return;
+    }
+
+    /* The same special case for ec_set */
+    if (da.type == EAF_TYPE_EC_SET)
+    {
+      RESULT(T_ECLIST, ad, &null_adata);
+      return;
+    }
+
+    /* The same special case for lc_set */
+    if (da.type == EAF_TYPE_LC_SET)
+    {
+      RESULT(T_LCLIST, ad, &null_adata);
+      return;
+    }
+
+    /* Undefined value */
+    RESULT_VOID;
+    return;
+  }
+
+  switch (e->type & EAF_TYPE_MASK)
+  {
+    case EAF_TYPE_INT:
+      RESULT(da.f_type, i, e->u.data);
+      break;
+    case EAF_TYPE_ROUTER_ID:
+      RESULT(T_QUAD, i, e->u.data);
+      break;
+    case EAF_TYPE_OPAQUE:
+      RESULT(T_ENUM_EMPTY, i, 0);
+      break;
+    case EAF_TYPE_IP_ADDRESS:
+      RESULT(T_IP, ip, *((ip_addr *) e->u.ptr->data));
+      break;
+    case EAF_TYPE_AS_PATH:
+      RESULT(T_PATH, ad, e->u.ptr);
+      break;
+    case EAF_TYPE_BITFIELD:
+      RESULT(T_BOOL, i, !!(e->u.data & (1u << da.bit)));
+      break;
+    case EAF_TYPE_INT_SET:
+      RESULT(T_CLIST, ad, e->u.ptr);
+      break;
+    case EAF_TYPE_EC_SET:
+      RESULT(T_ECLIST, ad, e->u.ptr);
+      break;
+    case EAF_TYPE_LC_SET:
+      RESULT(T_LCLIST, ad, e->u.ptr);
+      break;
+    default:
+      bug("Unknown dynamic attribute type");
+  }
+
+#undef RESULT
+#undef RESULT_VOID
+}
+
+static inline u32 aggr_route_hash(const rte *e)
+{
+  struct {
+    net *net;
+    struct rte_src *src;
+  } obj = {
+    .net = e->net,
+    .src = e->src,
+  };
+
+  return mem_hash(&obj, sizeof obj);
+}
+
+#define AGGR_RTE_KEY(n)			(&(n)->rte)
+#define AGGR_RTE_NEXT(n)		((n)->next_hash)
+#define AGGR_RTE_EQ(a,b)		(((a)->src == (b)->src) && ((a)->net == (b)->net))
+#define AGGR_RTE_FN(_n)			aggr_route_hash(_n)
+#define AGGR_RTE_ORDER			4 /* Initial */
+
+#define AGGR_RTE_REHASH			aggr_rte_rehash
+#define AGGR_RTE_PARAMS			/8, *2, 2, 2, 4, 24
+
+HASH_DEFINE_REHASH_FN(AGGR_RTE, struct aggregator_route);
+
+
+#define AGGR_BUCK_KEY(n)		(n)
+#define AGGR_BUCK_NEXT(n)		((n)->next_hash)
+#define AGGR_BUCK_EQ(a,b)		(((a)->hash == (b)->hash) && (same_val_list((a)->aggr_data, (b)->aggr_data, p->aggr_on_count)))
+#define AGGR_BUCK_FN(n)			((n)->hash)
+#define AGGR_BUCK_ORDER			4 /* Initial */
+
+#define AGGR_BUCK_REHASH		aggr_buck_rehash
+#define AGGR_BUCK_PARAMS		/8, *2, 2, 2, 4, 24
+
+HASH_DEFINE_REHASH_FN(AGGR_BUCK, struct aggregator_bucket);
+
+
+#define AGGR_DATA_MEMSIZE	(sizeof(struct f_val) * p->aggr_on_count)
+
+static void
+aggregator_rt_notify(struct proto *P, struct channel *src_ch, net *net, rte *new, rte *old)
+{
+  struct aggregator_proto *p = SKIP_BACK(struct aggregator_proto, p, P);
+  ASSERT_DIE(src_ch == p->src);
+  struct aggregator_bucket *new_bucket = NULL, *old_bucket = NULL;
+  struct aggregator_route *old_route = NULL;
+
+  /* Find the objects for the old route */
+  if (old)
+    old_route = HASH_FIND(p->routes, AGGR_RTE, old);
+
+  if (old_route)
+    old_bucket = old_route->bucket;
+
+  /* Find the bucket for the new route */
+  if (new)
+  {
+    /* Routes are identical, do nothing */
+    if (old_route && rte_same(&old_route->rte, new))
+      return;
+
+    /* Evaluate route attributes. */
+    struct aggregator_bucket *tmp_bucket = sl_allocz(p->bucket_slab);
+
+    for (uint val_idx = 0; val_idx < p->aggr_on_count; val_idx++)
+    {
+      int type = p->aggr_on[val_idx].type;
+
+      switch (type)
+      {
+        case AGGR_ITEM_TERM: {
+          const struct f_line *line = p->aggr_on[val_idx].line;
+          struct rte *rt1 = new;
+          enum filter_return fret = f_eval_rte(line, &new, rte_update_pool, 0, NULL, &tmp_bucket->aggr_data[val_idx]);
+
+          if (rt1 != new)
+          {
+            rte_free(rt1);
+            log(L_WARN "Aggregator rule modifies the route, reverting");
+          }
+
+          if (fret > F_RETURN)
+            log(L_WARN "%s.%s: Wrong number of items left on stack after evaluation of aggregation list", rt1->src->proto->name, rt1->sender);
+
+          break;
+        }
+
+        case AGGR_ITEM_STATIC_ATTR: {
+          struct f_val *pos = &tmp_bucket->aggr_data[val_idx];
+          eval_static_attr(new, p->aggr_on[val_idx].sa, pos);
+          break;
+        }
+
+        case AGGR_ITEM_DYNAMIC_ATTR: {
+          struct f_val *pos = &tmp_bucket->aggr_data[val_idx];
+          eval_dynamic_attr(new, p->aggr_on[val_idx].da, pos);
+          break;
+        }
+
+        default:
+          break;
+      }
+    }
+
+    /* Compute the hash */
+    tmp_bucket->hash = mem_hash(tmp_bucket->aggr_data, AGGR_DATA_MEMSIZE);
+
+    /* Find the existing bucket */
+    if (new_bucket = HASH_FIND(p->buckets, AGGR_BUCK, tmp_bucket))
+      sl_free(tmp_bucket);
+    else
+    {
+      new_bucket = tmp_bucket;
+      HASH_INSERT2(p->buckets, AGGR_BUCK, p->p.pool, new_bucket);
+    }
+
+    /* Store the route attributes */
+    if (rta_is_cached(new->attrs))
+      rta_clone(new->attrs);
+    else
+      new->attrs = rta_lookup(new->attrs);
+
+    /* Insert the new route into the bucket */
+    struct aggregator_route *arte = sl_alloc(p->route_slab);
+    *arte = (struct aggregator_route) {
+      .bucket = new_bucket,
+      .rte = *new,
+    };
+    arte->rte.next = new_bucket->rte,
+    new_bucket->rte = &arte->rte;
+    new_bucket->count++;
+    HASH_INSERT2(p->routes, AGGR_RTE, p->p.pool, arte);
+  }
+
+  /* Remove the old route from its bucket */
+  if (old_bucket)
+  {
+    for (struct rte **k = &old_bucket->rte; *k; k = &(*k)->next)
+      if (*k == &old_route->rte)
+      {
+	*k = (*k)->next;
+	break;
+      }
+
+    old_bucket->count--;
+    HASH_REMOVE2(p->routes, AGGR_RTE, p->p.pool, old_route);
+    rta_free(old_route->rte.attrs);
+    sl_free(old_route);
+  }
+
+  /* Announce changes */
+  if (old_bucket)
+    aggregator_bucket_update(p, old_bucket, net);
+
+  if (new_bucket && (new_bucket != old_bucket))
+    aggregator_bucket_update(p, new_bucket, net);
+
+  /* Cleanup the old bucket if empty */
+  if (old_bucket && (!old_bucket->rte || !old_bucket->count))
+  {
+    ASSERT_DIE(!old_bucket->rte && !old_bucket->count);
+    HASH_REMOVE2(p->buckets, AGGR_BUCK, p->p.pool, old_bucket);
+    sl_free(old_bucket);
+  }
+}
+
+static int
+aggregator_preexport(struct channel *C, struct rte *new)
+{
+  struct aggregator_proto *p = SKIP_BACK(struct aggregator_proto, p, C->proto);
+  /* Reject our own routes */
+  if (new->sender == p->dst)
+    return -1;
+
+  /* Disallow aggregating already aggregated routes */
+  if (new->attrs->source == RTS_AGGREGATED)
+  {
+    log(L_ERR "Multiple aggregations of the same route not supported in BIRD 2.");
+    return -1;
+  }
+
+  return 0;
+}
+
+static void
+aggregator_postconfig(struct proto_config *CF)
+{
+  struct aggregator_config *cf = SKIP_BACK(struct aggregator_config, c, CF);
+
+  if (!cf->dst->table)
+    cf_error("Source table not specified");
+
+  if (!cf->src->table)
+    cf_error("Destination table not specified");
+
+  if (cf->dst->table->addr_type != cf->src->table->addr_type)
+    cf_error("Both tables must be of the same type");
+
+  cf->dst->in_filter = cf->src->in_filter;
+
+  cf->src->in_filter = FILTER_REJECT;
+  cf->dst->out_filter = FILTER_REJECT;
+
+  cf->dst->debug = cf->src->debug;
+}
+
+static struct proto *
+aggregator_init(struct proto_config *CF)
+{
+  struct proto *P = proto_new(CF);
+  struct aggregator_proto *p = SKIP_BACK(struct aggregator_proto, p, P);
+  struct aggregator_config *cf = SKIP_BACK(struct aggregator_config, c, CF);
+
+  proto_configure_channel(P, &p->src, cf->src);
+  proto_configure_channel(P, &p->dst, cf->dst);
+
+  p->aggr_on_count = cf->aggr_on_count;
+  p->aggr_on_da_count = cf->aggr_on_da_count;
+  p->aggr_on = cf->aggr_on;
+  p->merge_by = cf->merge_by;
+
+  P->rt_notify = aggregator_rt_notify;
+  P->preexport = aggregator_preexport;
+
+  return P;
+}
+
+static int
+aggregator_start(struct proto *P)
+{
+  struct aggregator_proto *p = SKIP_BACK(struct aggregator_proto, p, P);
+
+  p->bucket_slab = sl_new(P->pool, sizeof(struct aggregator_bucket) + AGGR_DATA_MEMSIZE);
+  HASH_INIT(p->buckets, P->pool, AGGR_BUCK_ORDER);
+
+  p->route_slab = sl_new(P->pool, sizeof(struct aggregator_route));
+  HASH_INIT(p->routes, P->pool, AGGR_RTE_ORDER);
+
+  p->reload_buckets = (event) {
+    .hook = aggregator_reload_buckets,
+    .data = p,
+  };
+
+  return PS_UP;
+}
+
+static int
+aggregator_shutdown(struct proto *P)
+{
+  struct aggregator_proto *p = SKIP_BACK(struct aggregator_proto, p, P);
+
+  HASH_WALK_DELSAFE(p->buckets, next_hash, b)
+  {
+    while (b->rte)
+    {
+      struct aggregator_route *arte = SKIP_BACK(struct aggregator_route, rte, b->rte);
+      b->rte = arte->rte.next;
+      b->count--;
+      HASH_REMOVE(p->routes, AGGR_RTE, arte);
+      rta_free(arte->rte.attrs);
+      sl_free(arte);
+    }
+
+    ASSERT_DIE(b->count == 0);
+    HASH_REMOVE(p->buckets, AGGR_BUCK, b);
+    sl_free(b);
+  }
+  HASH_WALK_END;
+
+  return PS_DOWN;
+}
+
+static int
+aggregator_reconfigure(struct proto *P, struct proto_config *CF)
+{
+  struct aggregator_proto *p = SKIP_BACK(struct aggregator_proto, p, P);
+  struct aggregator_config *cf = SKIP_BACK(struct aggregator_config, c, CF);
+
+  TRACE(D_EVENTS, "Reconfiguring");
+
+  /* Compare numeric values (shortcut) */
+  if (cf->aggr_on_count != p->aggr_on_count)
+    return 0;
+
+  if (cf->aggr_on_da_count != p->aggr_on_da_count)
+    return 0;
+
+  /* Compare aggregator rule */
+  for (uint i = 0; i < p->aggr_on_count; i++)
+    switch (cf->aggr_on[i].type)
+    {
+      case AGGR_ITEM_TERM:
+	if (!f_same(cf->aggr_on[i].line, p->aggr_on[i].line))
+	  return 0;
+	break;
+      case AGGR_ITEM_STATIC_ATTR:
+	if (memcmp(&cf->aggr_on[i].sa, &p->aggr_on[i].sa, sizeof(struct f_static_attr)) != 0)
+	  return 0;
+	break;
+      case AGGR_ITEM_DYNAMIC_ATTR:
+	if (memcmp(&cf->aggr_on[i].da, &p->aggr_on[i].da, sizeof(struct f_dynamic_attr)) != 0)
+	  return 0;
+	break;
+      default:
+	bug("Broken aggregator rule");
+    }
+
+  /* Compare merge filter */
+  if (!f_same(cf->merge_by, p->merge_by))
+    ev_schedule(&p->reload_buckets);
+
+  p->aggr_on = cf->aggr_on;
+  p->merge_by = cf->merge_by;
+
+  return 1;
+}
+
+struct protocol proto_aggregator = {
+  .name =		"Aggregator",
+  .template =		"aggregator%d",
+  .class =		PROTOCOL_AGGREGATOR,
+  .preference =		1,
+  .channel_mask =	NB_ANY,
+  .proto_size =		sizeof(struct aggregator_proto),
+  .config_size =	sizeof(struct aggregator_config),
+  .postconfig =		aggregator_postconfig,
+  .init =		aggregator_init,
+  .start =		aggregator_start,
+  .shutdown =		aggregator_shutdown,
+  .reconfigure =	aggregator_reconfigure,
+};
+
+void
+aggregator_build(void)
+{
+  proto_build(&proto_aggregator);
+}
diff --git a/proto/aggregator/aggregator.h b/proto/aggregator/aggregator.h
new file mode 100644
index 00000000..19459b1d
--- /dev/null
+++ b/proto/aggregator/aggregator.h
@@ -0,0 +1,86 @@
+/*
+ *	BIRD -- Aggregator Pseudoprotocol
+ *
+ *	(c) 2023       Igor Putovny <igor.putovny@nic.cz>
+ *	(c) 2023       Maria Matejka <mq@ucw.cz>
+ *	(c) 2023       CZ.NIC z.s.p.o.
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ *
+ *	This file contains the data structures used by Babel.
+ */
+
+#ifndef _BIRD_AGGREGATOR_H_
+#define _BIRD_AGGREGATOR_H_
+
+#include "nest/bird.h"
+#include "nest/protocol.h"
+#include "lib/hash.h"
+
+struct aggregator_config {
+  struct proto_config c;
+  struct channel_config *src, *dst;
+  uint aggr_on_count;
+  uint aggr_on_da_count;
+  struct aggr_item *aggr_on;
+  const struct f_line *merge_by;
+};
+
+struct aggregator_route {
+  struct aggregator_route *next_hash;
+  struct aggregator_bucket *bucket;
+  struct rte rte;
+};
+
+struct aggregator_bucket {
+  struct aggregator_bucket *next_hash;
+  struct rte *rte;			/* Pointer to struct aggregator_route.rte */
+  struct rte_src *last_src;		/* Which src we announced the bucket last with */
+  u32 count;
+  u32 hash;
+  struct f_val aggr_data[0];
+};
+
+struct aggregator_proto {
+  struct proto p;
+  struct channel *src, *dst;
+
+  /* Buckets by aggregator rule */
+  HASH(struct aggregator_bucket) buckets;
+  slab *bucket_slab;
+
+  /* Routes by net and src */
+  HASH(struct aggregator_route) routes;
+  slab *route_slab;
+
+  /* Aggregator rule */
+  uint aggr_on_count;
+  uint aggr_on_da_count;
+  struct aggr_item *aggr_on;
+
+  /* Merge filter */
+  const struct f_line *merge_by;
+  event reload_buckets;
+};
+
+enum aggr_item_type {
+  AGGR_ITEM_TERM,
+  AGGR_ITEM_STATIC_ATTR,
+  AGGR_ITEM_DYNAMIC_ATTR,
+};
+
+struct aggr_item {
+  enum aggr_item_type type;
+  union {
+    struct f_static_attr sa;
+    struct f_dynamic_attr da;
+    const struct f_line *line;
+  };
+};
+
+struct aggr_item_node {
+  const struct aggr_item_node *next;
+  struct aggr_item i;
+};
+
+#endif
diff --git a/proto/aggregator/config.Y b/proto/aggregator/config.Y
new file mode 100644
index 00000000..44b7752f
--- /dev/null
+++ b/proto/aggregator/config.Y
@@ -0,0 +1,134 @@
+/*
+ *	BIRD -- Aggregator configuration
+ *
+ *	(c) 2023       Igor Putovny <igor.putovny@nic.cz>
+ *	(c) 2023       Maria Matejka <mq@ucw.cz>
+ *	(c) 2023       CZ.NIC z.s.p.o.
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+CF_HDR
+
+#include "proto/aggregator/aggregator.h"
+
+CF_DEFINES
+
+#define AGGREGATOR_CFG ((struct aggregator_config *) this_proto)
+#define AGGR_ITEM_ALLOC ((struct aggr_item_node *) cfg_allocz(sizeof(struct aggr_item_node)))
+
+
+CF_DECLS
+
+CF_KEYWORDS(AGGREGATOR, AGGREGATE, ON, MERGE, BY)
+
+%type <ai> aggr_item aggr_list
+
+CF_GRAMMAR
+
+proto: aggregator_proto ;
+
+aggregator_proto_start: proto_start AGGREGATOR
+{
+  this_proto = proto_config_new(&proto_aggregator, $1);
+  this_channel = AGGREGATOR_CFG->src = channel_config_new(NULL, "source", 0, this_proto);
+  AGGREGATOR_CFG->dst = channel_config_new(NULL, "destination", 0, this_proto);
+
+  AGGREGATOR_CFG->src->ra_mode = AGGREGATOR_CFG->dst->ra_mode = RA_ANY;
+};
+
+aggregator_proto_item:
+   proto_item
+ | channel_item_
+ | PEER TABLE rtable { AGGREGATOR_CFG->dst->table = $3; }
+ | AGGREGATE ON aggr_list {
+    if (AGGREGATOR_CFG->aggr_on)
+      cf_error("Only one aggregate on clause allowed");
+
+    _Bool net_present = 0;
+    int count = 0;
+
+    for (const struct aggr_item_node *item = $3; item; item = item->next) {
+//      log(L_WARN "type %d sacode %d", item->i.type, item->i.sa.sa_code);
+      if (item->i.type == AGGR_ITEM_STATIC_ATTR && item->i.sa.sa_code == SA_NET)
+	net_present = 1;
+
+      count++;
+    }
+
+   if (!net_present)
+     cf_error("'NET' must be present");
+
+   AGGREGATOR_CFG->aggr_on = cfg_alloc(sizeof(struct aggr_item) * count);
+
+   int pos = 0;
+   for (const struct aggr_item_node *item = $3; item; item = item->next) {
+     if (item->i.type == AGGR_ITEM_DYNAMIC_ATTR)
+       AGGREGATOR_CFG->aggr_on_da_count++;
+
+     AGGREGATOR_CFG->aggr_on[pos++] = item->i;
+   }
+
+   AGGREGATOR_CFG->aggr_on_count = pos;
+ }
+ | MERGE BY {
+   cf_push_block_scope(new_config);
+   cf_create_symbol(new_config, "routes", SYM_VARIABLE | T_ROUTES_BLOCK, offset, f_new_var(sym_->scope));
+ } function_body {
+   cf_pop_block_scope(new_config);
+   $4->args++;
+   AGGREGATOR_CFG->merge_by = $4;
+ }
+;
+
+aggregator_proto_opts: /* empty */ | aggregator_proto_opts aggregator_proto_item ';' ;
+aggregator_proto: aggregator_proto_start proto_name '{' aggregator_proto_opts '}' ;
+
+
+aggr_list:
+   aggr_item
+ | aggr_list ',' aggr_item {
+       if ($3 == NULL) {
+         $$ = $1;
+       } else {
+         $$ = $3;
+         $$->next = $1;
+       }
+   }
+ ;
+
+aggr_item:
+   '(' term ')' {
+       $$ = AGGR_ITEM_ALLOC;
+       $$->i.type = AGGR_ITEM_TERM;
+       $$->i.line = f_linearize($2, 1);
+    }
+  | CF_SYM_KNOWN {
+      switch ($1->class) {
+        case SYM_ATTRIBUTE:
+          $$ = AGGR_ITEM_ALLOC;
+          $$->i.type = AGGR_ITEM_DYNAMIC_ATTR;
+          $$->i.da = *$1->attribute;
+          break;
+        case SYM_CONSTANT_RANGE:
+          $$ = NULL;
+          break;
+        default:
+          cf_error("Can't aggregate on symbol type %s.", cf_symbol_class_name($1));
+      }
+    }
+  | dynamic_attr {
+      $$ = AGGR_ITEM_ALLOC;
+      $$->i.type = AGGR_ITEM_DYNAMIC_ATTR;
+      $$->i.da = $1;
+    }
+  | static_attr {
+      $$ = AGGR_ITEM_ALLOC;
+      $$->i.type = AGGR_ITEM_STATIC_ATTR;
+      $$->i.sa = $1;
+    }
+  ;
+
+CF_CODE
+
+CF_END
diff --git a/proto/aggregator/test.conf b/proto/aggregator/test.conf
new file mode 100644
index 00000000..e5e1e267
--- /dev/null
+++ b/proto/aggregator/test.conf
@@ -0,0 +1,116 @@
+log "bird.log" all;
+
+protocol device {}
+
+protocol static {
+  ipv6;
+  route 2001:db8:0::/48 unreachable { bgp_path.prepend(65432); bgp_path.prepend(4200000000); };
+  route 2001:db8:1::/48 unreachable;
+  route 2001:db8:2::/48 unreachable;
+  route 2001:db8:3::/48 unreachable;
+  route 2001:db8:4::/48 unreachable;
+  route 2001:db8:5::/48 unreachable;
+  route 2001:db8:6::/48 unreachable;
+  route 2001:db8:7::/48 unreachable;
+  route 2001:db8:8::/48 unreachable;
+  route 2001:db8:9::/48 unreachable;
+  route 2001:db8:a::/48 unreachable;
+  route 2001:db8:b::/48 unreachable;
+  route 2001:db8:c::/48 unreachable;
+  route 2001:db8:d::/48 unreachable;
+  route 2001:db8:e::/48 unreachable;
+  route 2001:db8:f::/48 unreachable;
+}
+
+protocol static {
+  ipv6 {
+    import filter {
+      bgp_med = 1;
+      bgp_community = -empty-.add((65533,1)).add((65500,0xe));
+      accept;
+    };
+  };
+  route 2001:db8:1::/48 unreachable;
+  route 2001:db8:3::/48 unreachable;
+  route 2001:db8:5::/48 unreachable;
+  route 2001:db8:7::/48 unreachable;
+  route 2001:db8:9::/48 unreachable;
+  route 2001:db8:b::/48 unreachable;
+  route 2001:db8:d::/48 unreachable;
+  route 2001:db8:f::/48 unreachable;
+}
+
+protocol static {
+  ipv6 {
+    import filter {
+      bgp_med = 2;
+      bgp_community = -empty-.add((65533,2)).add((65500,0xd));
+      accept;
+    };
+  };
+  route 2001:db8:2::/48 unreachable;
+  route 2001:db8:3::/48 unreachable;
+  route 2001:db8:6::/48 unreachable;
+  route 2001:db8:7::/48 unreachable;
+  route 2001:db8:a::/48 unreachable;
+  route 2001:db8:b::/48 unreachable;
+  route 2001:db8:e::/48 unreachable;
+  route 2001:db8:f::/48 unreachable;
+}
+
+protocol static {
+  ipv6 {
+    import filter {
+      bgp_med = 4;
+      bgp_community = -empty-.add((65533,4)).add((65500,0xb));
+      accept;
+    };
+  };
+  route 2001:db8:4::/48 unreachable;
+  route 2001:db8:5::/48 unreachable;
+  route 2001:db8:6::/48 unreachable;
+  route 2001:db8:7::/48 unreachable;
+  route 2001:db8:c::/48 unreachable;
+  route 2001:db8:d::/48 unreachable;
+  route 2001:db8:e::/48 unreachable;
+  route 2001:db8:f::/48 unreachable;
+}
+
+protocol static {
+  ipv6 {
+    import filter {
+      bgp_med = 8;
+      bgp_community = -empty-.add((65533,8)).add((65500,0x7));
+      accept;
+    };
+  };
+  route 2001:db8:8::/48 unreachable;
+  route 2001:db8:9::/48 unreachable;
+  route 2001:db8:a::/48 unreachable;
+  route 2001:db8:b::/48 unreachable;
+  route 2001:db8:c::/48 unreachable;
+  route 2001:db8:d::/48 unreachable;
+  route 2001:db8:e::/48 unreachable;
+  route 2001:db8:f::/48 unreachable;
+}
+
+ipv6 table agr_result;
+
+protocol aggregator {
+  table master6;
+  peer table agr_result;
+  export all;
+  aggregate on net,(defined(bgp_med));
+  merge by {
+    print "Merging all these: ", routes;
+    bgp_med = 0;
+    for route r in routes do {
+      if ! defined(r.bgp_med) then { unset(bgp_med); accept; }
+
+      print r, " bgp_med: ", r.bgp_med;
+      bgp_med = bgp_med + r.bgp_med;
+      bgp_community = bgp_community.add(r.bgp_community);
+    }
+    accept;
+  };
+}