Implements Router Advertisement protocol.

6 files changed, 892 insertions, 0 deletions

diff --git a/proto/radv/Doc b/proto/radv/Doc
new file mode 100644
index 00000000..d051692a
--- /dev/null
+++ b/proto/radv/Doc
@@ -0,0 +1,2 @@
+S radv.c
+S packets.c
diff --git a/proto/radv/Makefile b/proto/radv/Makefile
new file mode 100644
index 00000000..efc4d4af
--- /dev/null
+++ b/proto/radv/Makefile
@@ -0,0 +1,5 @@
+source=radv.c packets.c
+root-rel=../../
+dir-name=proto/radv
+
+include ../../Rules
diff --git a/proto/radv/config.Y b/proto/radv/config.Y
new file mode 100644
index 00000000..78a09551
--- /dev/null
+++ b/proto/radv/config.Y
@@ -0,0 +1,157 @@
+/*
+ *	BIRD -- Router Advertisement Configuration
+ *
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+CF_HDR
+
+#include "proto/radv/radv.h"
+
+CF_DEFINES
+
+#define RADV_CFG ((struct radv_config *) this_proto)
+#define RADV_IFACE ((struct radv_iface_config *) this_ipatt)
+#define RADV_PREFIX this_radv_prefix
+
+static struct radv_prefix_config *this_radv_prefix;
+
+CF_DECLS
+
+CF_KEYWORDS(RADV, PREFIX, INTERFACE, MIN, MAX, RA, DELAY, INTERVAL,
+	MANAGED, OTHER, CONFIG, LINK, MTU, REACHABLE, TIME, RETRANS,
+	TIMER, CURRENT, HOP, LIMIT, DEFAULT, VALID, PREFERRED,
+	LIFETIME, SKIP, ONLINK, AUTONOMOUS)
+
+
+CF_GRAMMAR
+
+CF_ADDTO(proto, radv_proto '}')
+
+radv_proto_start: proto_start RADV
+{
+  this_proto = proto_config_new(&proto_radv, sizeof(struct radv_config));
+  init_list(&RADV_CFG->patt_list);
+  init_list(&RADV_CFG->pref_list);
+};
+
+radv_proto_item:
+   proto_item
+ | PREFIX radv_prefix { add_tail(&RADV_CFG->pref_list, NODE this_radv_prefix); }
+ | INTERFACE radv_iface
+ ;
+
+radv_proto_opts:
+   /* empty */
+ | radv_proto_opts radv_proto_item ';'
+ ;
+
+radv_proto:
+   radv_proto_start proto_name '{' radv_proto_opts;
+
+
+radv_iface_start:
+{
+  this_ipatt = cfg_allocz(sizeof(struct radv_iface_config));
+  add_tail(&RADV_CFG->patt_list, NODE this_ipatt);
+  init_list(&this_ipatt->ipn_list);
+  init_list(&RADV_IFACE->pref_list);
+
+  RADV_IFACE->min_ra_int = -1; /* undefined */
+  RADV_IFACE->max_ra_int = DEFAULT_MAX_RA_INT;
+  RADV_IFACE->min_delay = DEFAULT_MIN_DELAY;
+  RADV_IFACE->current_hop_limit = DEFAULT_CURRENT_HOP_LIMIT;
+  RADV_IFACE->default_lifetime = -1;
+};
+
+radv_iface_item:
+   MIN RA INTERVAL expr { RADV_IFACE->min_ra_int = $4; if ($4 < 3) cf_error("Min RA interval must be at least 3"); }
+ | MAX RA INTERVAL expr { RADV_IFACE->max_ra_int = $4; if (($4 < 4) || ($4 > 1800)) cf_error("Max RA interval must be in range 4-1800"); }
+ | MIN DELAY expr { RADV_IFACE->min_delay = $3; if ($3 <= 0) cf_error("Min delay must be positive"); }
+ | MANAGED bool { RADV_IFACE->managed = $2; }
+ | OTHER CONFIG bool { RADV_IFACE->other_config = $3; }
+ | LINK MTU expr { RADV_IFACE->link_mtu = $3; if ($3 < 0) cf_error("Link MTU must be 0 or positive"); }
+ | REACHABLE TIME expr { RADV_IFACE->reachable_time = $3; if (($3 < 0) || ($3 > 3600000)) cf_error("Reachable time must be in range 0-3600000"); }
+ | RETRANS TIMER expr { RADV_IFACE->retrans_timer = $3; if ($3 < 0) cf_error("Retrans timer must be 0 or positive"); }
+ | CURRENT HOP LIMIT expr { RADV_IFACE->current_hop_limit = $4; if (($4 < 0) || ($4 > 255))  cf_error("Current hop limit must be in range 0-255"); }
+ | DEFAULT LIFETIME expr { RADV_IFACE->default_lifetime = $3; if (($3 < 0) || ($3 > 9000))  cf_error("Default lifetime must be in range 0-9000"); }
+ | PREFIX radv_prefix { add_tail(&RADV_IFACE->pref_list, NODE this_radv_prefix); }
+ ;
+
+radv_iface_finish:
+{
+  struct radv_iface_config *ic = RADV_IFACE;
+
+  if (ic->min_ra_int == (u32) -1)
+    ic->min_ra_int = _MAX(ic->max_ra_int / 3, 3);
+
+  if (ic->default_lifetime == (u32) -1)
+    ic->default_lifetime = 3 * ic->max_ra_int;
+
+  if ((ic->min_ra_int > 3) &&
+      (ic->min_ra_int > (ic->max_ra_int * 3 / 4)))
+    cf_error("Min RA interval must be at most 3/4 * Max RA interval %d %d", ic->min_ra_int, ic->max_ra_int);
+
+  if ((ic->default_lifetime > 0) && (ic->default_lifetime < ic->max_ra_int))
+    cf_error("Default lifetime must be either 0 or at least Max RA interval");
+};
+
+
+radv_iface_opts:
+   /* empty */
+ | radv_iface_opts radv_iface_item ';'
+ ;
+
+radv_iface_opt_list:
+   /* empty */
+ | '{' radv_iface_opts '}'
+ ;
+
+radv_iface:
+  radv_iface_start iface_patt_list radv_iface_opt_list radv_iface_finish;
+
+
+radv_prefix_start: prefix
+{
+  this_radv_prefix = cfg_allocz(sizeof(struct radv_prefix_config));
+  RADV_PREFIX->prefix = $1.addr;
+  RADV_PREFIX->pxlen = $1.len;
+
+  RADV_PREFIX->onlink = 1;
+  RADV_PREFIX->autonomous = 1;
+  RADV_PREFIX->valid_lifetime = DEFAULT_VALID_LIFETIME;
+  RADV_PREFIX->preferred_lifetime = DEFAULT_PREFERRED_LIFETIME;
+};
+
+radv_prefix_item:
+   SKIP bool { RADV_PREFIX->skip = $2; }
+ | ONLINK bool { RADV_PREFIX->onlink = $2; }
+ | AUTONOMOUS bool { RADV_PREFIX->autonomous = $2; }
+ | VALID LIFETIME expr { RADV_PREFIX->valid_lifetime = $3; if ($3 < 0) cf_error("Valid lifetime must be 0 or positive"); }
+ | PREFERRED LIFETIME expr { RADV_PREFIX->preferred_lifetime = $3; if ($3 < 0) cf_error("Preferred lifetime must be 0 or positive"); }
+ ;
+
+radv_prefix_finish:
+{
+  if (RADV_PREFIX->preferred_lifetime > RADV_PREFIX->valid_lifetime)
+    cf_error("Preferred lifetime must be at most Valid lifetime");
+};
+
+radv_prefix_opts:
+   /* empty */
+ | radv_prefix_opts radv_prefix_item ';'
+ ;
+
+radv_prefix_opt_list:
+   /* empty */
+ | '{' radv_prefix_opts '}'
+ ;
+
+radv_prefix:
+  radv_prefix_start radv_prefix_opt_list radv_prefix_finish;
+
+
+CF_CODE
+
+CF_END
diff --git a/proto/radv/packets.c b/proto/radv/packets.c
new file mode 100644
index 00000000..8aa487b0
--- /dev/null
+++ b/proto/radv/packets.c
@@ -0,0 +1,268 @@
+/*
+ *	BIRD -- RAdv Packet Processing
+ *
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+
+#include <stdlib.h>
+#include "radv.h"
+
+struct radv_ra_packet
+{
+  u8 type;
+  u8 code;
+  u16 checksum;
+  u8 current_hop_limit;
+  u8 flags;
+  u16 router_lifetime;
+  u32 reachable_time;
+  u32 retrans_timer;
+};
+
+#define OPT_RA_MANAGED 0x80
+#define OPT_RA_OTHER_CFG 0x40
+
+#define OPT_PREFIX 3
+#define OPT_MTU 5
+
+struct radv_opt_prefix
+{
+  u8 type;
+  u8 length;
+  u8 pxlen;
+  u8 flags;
+  u32 valid_lifetime;
+  u32 preferred_lifetime;
+  u32 reserved;
+  ip_addr prefix;
+};
+
+#define OPT_PX_ONLINK 0x80
+#define OPT_PX_AUTONOMOUS 0x40
+
+struct radv_opt_mtu
+{
+  u8 type;
+  u8 length;
+  u16 reserved;
+  u32 mtu;
+};
+
+static struct radv_prefix_config default_prefix = {
+  .onlink = 1,
+  .autonomous = 1,
+  .valid_lifetime = DEFAULT_VALID_LIFETIME,
+  .preferred_lifetime = DEFAULT_PREFERRED_LIFETIME
+};
+
+static struct radv_prefix_config *
+radv_prefix_match(struct radv_iface *ifa, struct ifa *a)
+{
+  struct proto *p = &ifa->ra->p;
+  struct radv_config *cf = (struct radv_config *) (p->cf);
+  struct radv_prefix_config *pc;
+
+  if (a->scope <= SCOPE_LINK)
+    return NULL;
+
+  WALK_LIST(pc, ifa->cf->pref_list)
+    if ((a->pxlen >= pc->pxlen) && ipa_in_net(a->prefix, pc->prefix, pc->pxlen))
+      return pc;
+
+  WALK_LIST(pc, cf->pref_list)
+    if ((a->pxlen >= pc->pxlen) && ipa_in_net(a->prefix, pc->prefix, pc->pxlen))
+      return pc;
+
+  return &default_prefix;
+}
+
+static void
+radv_prepare_ra(struct radv_iface *ifa)
+{
+  struct proto_radv *ra = ifa->ra;
+
+  char *buf = ifa->sk->tbuf;
+  char *bufstart = buf;
+  char *bufend = buf + ifa->sk->tbsize;
+
+  struct radv_ra_packet *pkt = (void *) buf;
+  pkt->type = ICMPV6_RA;
+  pkt->code = 0;
+  pkt->checksum = 0;
+  pkt->current_hop_limit = ifa->cf->current_hop_limit;
+  pkt->flags = (ifa->cf->managed ? OPT_RA_MANAGED : 0) |
+    (ifa->cf->other_config ? OPT_RA_OTHER_CFG : 0);
+  pkt->router_lifetime = htons(ifa->cf->default_lifetime);
+  pkt->reachable_time = htonl(ifa->cf->reachable_time);
+  pkt->retrans_timer = htonl(ifa->cf->retrans_timer);
+  buf += sizeof(*pkt);
+
+  if (ifa->cf->link_mtu)
+  {
+    struct radv_opt_mtu *om = (void *) buf;
+    om->type = OPT_MTU;
+    om->length = 1;
+    om->reserved = 0;
+    om->mtu = htonl(ifa->cf->link_mtu);
+    buf += sizeof (*om);
+  }
+
+  struct ifa *addr;
+  WALK_LIST(addr, ifa->iface->addrs)
+  {
+    struct radv_prefix_config *pc;
+    pc = radv_prefix_match(ifa, addr);
+
+    if (!pc || pc->skip)
+      continue;
+
+    if (buf + sizeof(struct radv_opt_prefix) > bufend)
+    {
+      log(L_WARN "%s: Too many prefixes on interface %s", ra->p.name, ifa->iface->name);
+      break;
+    }
+
+    struct radv_opt_prefix *op = (void *) buf;
+    op->type = OPT_PREFIX;
+    op->length = 4;
+    op->pxlen = addr->pxlen;
+    op->flags = (pc->onlink ? OPT_PX_ONLINK : 0) |
+      (pc->autonomous ? OPT_PX_AUTONOMOUS : 0);
+    op->valid_lifetime = htonl(pc->valid_lifetime);
+    op->preferred_lifetime = htonl(pc->preferred_lifetime);
+    op->reserved = 0;
+    op->prefix = addr->prefix;
+    ipa_hton(op->prefix);
+    buf += sizeof(*op);
+  }
+  
+  ifa->plen = buf - bufstart;
+}
+
+
+void
+radv_send_ra(struct radv_iface *ifa, int shutdown)
+{
+  struct proto_radv *ra = ifa->ra;
+
+  /* We store prepared RA in tbuf */
+  if (!ifa->plen)
+    radv_prepare_ra(ifa);
+
+  if (shutdown)
+  {
+    /* Modify router lifetime to 0, it is not restored because
+       we suppose that the iface will be removed */
+    struct radv_ra_packet *pkt = (void *) ifa->sk->tbuf;
+    pkt->router_lifetime = 0;
+  }
+
+  RADV_TRACE(D_PACKETS, "Sending RA via %s", ifa->iface->name);
+  sk_send_to(ifa->sk, ifa->plen, AllNodes, 0);
+}
+
+
+static int
+radv_rx_hook(sock *sk, int size)
+{
+  struct radv_iface *ifa = sk->data;
+  struct proto_radv *ra = ifa->ra;
+
+  /* We want just packets from sk->iface */
+  if (sk->lifindex != sk->iface->index)
+    return 1;
+
+  if (ipa_equal(sk->faddr, ifa->addr->ip))
+    return 1;
+
+  if (size < 8)
+    return 1;
+
+  byte *buf = sk->rbuf;
+
+  if (buf[1] != 0)
+    return 1;
+
+  /* Validation is a bit sloppy - Hop Limit is not checked and
+     length of options is ignored for RS and left to later for RA */
+
+  switch (buf[0])
+  {
+  case ICMPV6_RS:
+    RADV_TRACE(D_PACKETS, "Received RS from %I via %s",
+	       sk->faddr, ifa->iface->name);
+    radv_iface_notify(ifa, RA_EV_RS);
+    return 1;
+
+  case ICMPV6_RA:
+    RADV_TRACE(D_PACKETS, "Received RA from %I via %s",
+	       sk->faddr, ifa->iface->name);
+    /* FIXME - there should be some checking of received RAs, but we just ignore them */
+    return 1;
+
+  default:
+    return 1;
+  }
+}
+
+static void
+radv_tx_hook(sock *sk)
+{
+  struct radv_iface *ifa = sk->data;
+  log(L_WARN "%s: TX hook called", ifa->ra->p.name);
+}
+
+static void
+radv_err_hook(sock *sk, int err)
+{
+  struct radv_iface *ifa = sk->data;
+  log(L_ERR "%s: Socket error: %m", ifa->ra->p.name, err);
+}
+
+int
+radv_sk_open(struct radv_iface *ifa)
+{
+  sock *sk = sk_new(ifa->ra->p.pool);
+  sk->type = SK_IP;
+  sk->dport = ICMPV6_PROTO;
+  sk->saddr = IPA_NONE;
+
+  sk->ttl = 255; /* Mandatory for Neighbor Discovery packets */
+  sk->rx_hook = radv_rx_hook;
+  sk->tx_hook = radv_tx_hook;
+  sk->err_hook = radv_err_hook;
+  sk->iface = ifa->iface;
+  sk->rbsize = 1024; // bufsize(ifa);
+  sk->tbsize = 1024; // bufsize(ifa);
+  sk->data = ifa;
+  sk->flags = SKF_LADDR_RX;
+
+  if (sk_open(sk) != 0)
+    goto err;
+
+  sk->saddr = ifa->addr->ip;
+
+  /* 2 is an offset of the checksum in an ICMPv6 packet */
+  if (sk_set_ipv6_checksum(sk, 2) < 0)
+    goto err;
+
+  /* We want listen just to ICMPv6 messages of type RS and RA */
+  if (sk_set_icmp_filter(sk, ICMPV6_RS, ICMPV6_RA) < 0)
+    goto err;
+
+  if (sk_setup_multicast(sk) < 0)
+    goto err;
+
+  if (sk_join_group(sk, AllRouters) < 0)
+    goto err;
+
+  ifa->sk = sk;
+  return 1;
+
+ err:
+  rfree(sk);
+  return 0;
+}
+
diff --git a/proto/radv/radv.c b/proto/radv/radv.c
new file mode 100644
index 00000000..01cb6899
--- /dev/null
+++ b/proto/radv/radv.c
@@ -0,0 +1,329 @@
+/*
+ *	BIRD -- Router Advertisement
+ *
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+
+#include <stdlib.h>
+#include "radv.h"
+
+/**
+ * DOC: Router Advertisements
+ *
+ * The RAdv protocol is implemented in two files: |radv.c| containing
+ * the interface with BIRD core and the protocol logic and |packets.c|
+ * handling low level protocol stuff (RX, TX and packet formats).
+ * The protocol does not import or export any routes.
+ *
+ * The RAdv is structured in the usual way - for each handled interface
+ * there is a structure &radv_iface that contains a state related to
+ * that interface together with its resources (a socket, a timer).
+ * There is also a prepared RA stored in a TX buffer of the socket
+ * associated with an iface. These iface structures are created
+ * and removed according to iface events from BIRD core handled by
+ * radv_if_notify() callback.
+ *
+ * The main logic of RAdv consists of two functions:
+ * radv_iface_notify(), which processes asynchronous events (specified
+ * by RA_EV_* codes), and radv_timer(), which triggers sending RAs and
+ * computes the next timeout.
+ */
+
+static void
+radv_timer(timer *tm)
+{
+  struct radv_iface *ifa = tm->data;
+  struct proto_radv *ra = ifa->ra;
+
+  RADV_TRACE(D_EVENTS, "Timer fired on %s", ifa->iface->name);
+
+  radv_send_ra(ifa, 0);
+
+  /* Update timer */
+  ifa->last = now;
+  unsigned after = ifa->cf->min_ra_int;
+  after += random() % (ifa->cf->max_ra_int - ifa->cf->min_ra_int + 1);
+
+  if (ifa->initial)
+    ifa->initial--;
+
+  if (ifa->initial)
+    after = MIN(after, MAX_INITIAL_RTR_ADVERT_INTERVAL);
+
+  tm_start(ifa->timer, after);
+}
+
+static char* ev_name[] = { NULL, "Init", "Change", "RS" };
+
+void
+radv_iface_notify(struct radv_iface *ifa, int event)
+{
+  struct proto_radv *ra = ifa->ra;
+
+  if (!ifa->sk)
+    return;
+
+  RADV_TRACE(D_EVENTS, "Event %s on %s", ev_name[event], ifa->iface->name);
+
+  switch (event)
+  {
+  case RA_EV_CHANGE:
+    ifa->plen = 0;
+  case RA_EV_INIT:
+    ifa->initial = MAX_INITIAL_RTR_ADVERTISEMENTS;
+    break;
+
+  case RA_EV_RS:
+    break;
+  }
+
+  /* Update timer */
+  unsigned delta = now - ifa->last;
+  unsigned after = 0;
+
+  if (delta < ifa->cf->min_delay)
+    after = ifa->cf->min_delay - delta;
+
+  tm_start(ifa->timer, after);
+}
+
+static struct radv_iface *
+radv_iface_find(struct proto_radv *ra, struct iface *what)
+{
+  struct radv_iface *ifa;
+
+  WALK_LIST(ifa, ra->iface_list)
+    if (ifa->iface == what)
+      return ifa;
+
+  return NULL;
+}
+
+static void
+radv_iface_add(struct object_lock *lock)
+{
+  struct radv_iface *ifa = lock->data;
+  struct proto_radv *ra = ifa->ra;
+
+  if (! radv_sk_open(ifa))
+  {
+    log(L_ERR "%s: Socket open failed on interface %s", ra->p.name, ifa->iface->name);
+    return;
+  }
+
+  radv_iface_notify(ifa, RA_EV_INIT);
+}
+
+static inline struct ifa *
+find_lladdr(struct iface *iface)
+{
+  struct ifa *a;
+  WALK_LIST(a, iface->addrs)
+    if (a->scope == SCOPE_LINK)
+      return a;
+
+  return NULL;
+}
+
+static void
+radv_iface_new(struct proto_radv *ra, struct iface *iface, struct radv_iface_config *cf)
+{
+  pool *pool = ra->p.pool;
+  struct radv_iface *ifa;
+
+  RADV_TRACE(D_EVENTS, "Adding interface %s", iface->name);
+
+  ifa = mb_allocz(pool, sizeof(struct radv_iface));
+  ifa->ra = ra;
+  ifa->cf = cf;
+  ifa->iface = iface;
+
+  add_tail(&ra->iface_list, NODE ifa);
+
+  ifa->addr = find_lladdr(iface);
+  if (!ifa->addr)
+  {
+    log(L_ERR "%s: Cannot find link-locad addr on interface %s", ra->p.name, iface->name);
+    return;
+  }
+
+  timer *tm = tm_new(pool);
+  tm->hook = radv_timer;
+  tm->data = ifa;
+  tm->randomize = 0;
+  tm->recurrent = 0;
+  ifa->timer = tm;
+
+  struct object_lock *lock = olock_new(pool);
+  lock->addr = IPA_NONE;
+  lock->type = OBJLOCK_IP;
+  lock->port = ICMPV6_PROTO;
+  lock->iface = iface;
+  lock->data = ifa;
+  lock->hook = radv_iface_add;
+  ifa->lock = lock;
+
+  olock_acquire(lock);
+}
+
+static void
+radv_iface_remove(struct radv_iface *ifa)
+{
+  struct proto_radv *ra = ifa->ra;
+  RADV_TRACE(D_EVENTS, "Removing interface %s", ifa->iface->name);
+
+  rem_node(NODE ifa);
+
+  rfree(ifa->sk);
+  rfree(ifa->timer);
+  rfree(ifa->lock);
+
+  mb_free(ifa);
+}
+
+static void
+radv_if_notify(struct proto *p, unsigned flags, struct iface *iface)
+{ 
+  struct proto_radv *ra = (struct proto_radv *) p;
+  struct radv_config *cf = (struct radv_config *) (p->cf);
+
+  if (iface->flags & IF_IGNORE)
+    return;
+
+  if (flags & IF_CHANGE_UP)
+  {
+    struct radv_iface_config *ic = (struct radv_iface_config *)
+      iface_patt_find(&cf->patt_list, iface, NULL);
+
+    if (ic)
+      radv_iface_new(ra, iface, ic);
+
+    return;
+  }
+
+  struct radv_iface *ifa = radv_iface_find(ra, iface);
+  if (!ifa)
+    return;
+
+  if (flags & IF_CHANGE_DOWN)
+  {
+    radv_iface_remove(ifa);
+    return;
+  }
+
+  if ((flags & IF_CHANGE_LINK) && (iface->flags & IF_LINK_UP))
+    radv_iface_notify(ifa, RA_EV_INIT);
+}
+
+static void
+radv_ifa_notify(struct proto *p, unsigned flags, struct ifa *a)
+{
+  struct proto_radv *ra = (struct proto_radv *) p;
+
+  if (a->flags & IA_SECONDARY)
+    return;
+
+  if (a->scope <= SCOPE_LINK)
+    return;
+
+  struct radv_iface *ifa = radv_iface_find(ra, a->iface);
+
+  if (ifa)
+    radv_iface_notify(ifa, RA_EV_CHANGE);
+}
+
+static struct proto *
+radv_init(struct proto_config *c)
+{
+  struct proto *p = proto_new(c, sizeof(struct proto_radv));
+
+  p->if_notify = radv_if_notify;
+  p->ifa_notify = radv_ifa_notify;
+  return p;
+}
+
+static int
+radv_start(struct proto *p)
+{
+  struct proto_radv *ra = (struct proto_radv *) p;
+  // struct radv_config *cf = (struct radv_config *) (p->cf);
+
+  init_list(&(ra->iface_list));
+
+  return PS_UP;
+}
+
+static inline void
+radv_iface_shutdown(struct radv_iface *ifa)
+{
+  if (ifa->sk)
+    radv_send_ra(ifa, 1);
+}
+
+static int
+radv_shutdown(struct proto *p)
+{
+  struct proto_radv *ra = (struct proto_radv *) p;
+
+  struct radv_iface *ifa;
+  WALK_LIST(ifa, ra->iface_list)
+    radv_iface_shutdown(ifa);
+
+  return PS_DOWN;
+}
+
+static int
+radv_reconfigure(struct proto *p, struct proto_config *c)
+{
+  struct proto_radv *ra = (struct proto_radv *) p;
+  // struct radv_config *old = (struct radv_config *) (p->cf);
+  struct radv_config *new = (struct radv_config *) c;
+
+  /* 
+   * The question is why there is a reconfigure function for RAdv if
+   * it has almost none internal state so restarting the protocol
+   * would probably suffice. One small reason is that restarting the
+   * protocol would lead to sending a RA with Router Lifetime 0
+   * causing nodes to temporary remove their default routes.
+   */
+
+  struct iface *iface;
+  WALK_LIST(iface, iface_list)
+  {
+    struct radv_iface *ifa = radv_iface_find(ra, iface);
+    struct radv_iface_config *ic = (struct radv_iface_config *)
+      iface_patt_find(&new->patt_list, iface, NULL);
+
+    if (ifa && ic)
+    {
+      ifa->cf = ic;
+
+      /* We cheat here - always notify the change even if there isn't
+	 any. That would leads just to a few unnecessary RAs. */
+      radv_iface_notify(ifa, RA_EV_CHANGE);
+    }
+
+    if (ifa && !ic)
+    {
+      radv_iface_shutdown(ifa);
+      radv_iface_remove(ifa);
+    }
+
+    if (!ifa && ic)
+      radv_iface_new(ra, iface, ic);
+  }
+
+  return 1;
+}
+
+
+struct protocol proto_radv = {
+  .name =		"RAdv",
+  .template =		"radv%d",
+  .init =		radv_init,
+  .start =		radv_start,
+  .shutdown =		radv_shutdown,
+  .reconfigure =	radv_reconfigure
+};
diff --git a/proto/radv/radv.h b/proto/radv/radv.h
new file mode 100644
index 00000000..fe121f26
--- /dev/null
+++ b/proto/radv/radv.h
@@ -0,0 +1,131 @@
+/*
+ *	BIRD -- Router Advertisement
+ *
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_RADV_H_
+#define _BIRD_RADV_H_
+
+#include "nest/bird.h"
+
+#include "lib/ip.h"
+#include "lib/lists.h"
+#include "lib/socket.h"
+#include "lib/timer.h"
+#include "lib/resource.h"
+#include "nest/protocol.h"
+#include "nest/iface.h"
+#include "nest/route.h"
+#include "nest/cli.h"
+#include "nest/locks.h"
+#include "conf/conf.h"
+#include "lib/string.h"
+
+
+#define ICMPV6_PROTO 58
+
+#define AllNodes   _MI(0xFF020000, 0, 0, 1)	/* FF02::1 */
+#define AllRouters _MI(0xFF020000, 0, 0, 2)	/* FF02::2 */
+
+#define ICMPV6_RS 133
+#define ICMPV6_RA 134
+
+#define MAX_INITIAL_RTR_ADVERTISEMENTS 3
+#define MAX_INITIAL_RTR_ADVERT_INTERVAL 16
+
+#define DEFAULT_MAX_RA_INT 600
+#define DEFAULT_MIN_DELAY 3
+#define DEFAULT_CURRENT_HOP_LIMIT 64
+
+#define DEFAULT_VALID_LIFETIME 86400
+#define DEFAULT_PREFERRED_LIFETIME 14400
+
+
+struct radv_config
+{
+  struct proto_config c;
+  list patt_list;		/* List of iface configs */
+  list pref_list;		/* Global list of prefix configs */
+};
+
+struct radv_iface_config
+{
+  struct iface_patt i;
+  list pref_list;		/* Local list of prefix configs */
+
+  u32 min_ra_int;		/* Standard options from RFC 4261 */
+  u32 max_ra_int;
+  u32 min_delay;
+
+  u8 managed;
+  u8 other_config;
+  u32 link_mtu;
+  u32 reachable_time;
+  u32 retrans_timer;
+  u32 current_hop_limit;               
+  u32 default_lifetime;
+};
+
+struct radv_prefix_config
+{
+  node n;
+  ip_addr prefix;
+  int pxlen;
+
+  u8 skip;			/* Do not include this prefix to RA */
+  u8 onlink;			/* Standard options from RFC 4261 */
+  u8 autonomous;
+  u32 valid_lifetime;
+  u32 preferred_lifetime;
+};
+
+struct proto_radv
+{
+  struct proto p;
+  list iface_list;		/* List of active ifaces */
+};
+
+struct radv_iface
+{
+  node n;
+  struct proto_radv *ra;
+  struct radv_iface_config *cf;	/* Related config, must be updated in reconfigure */
+  struct iface *iface;
+  struct ifa *addr;		/* Link-local address of iface */
+
+  timer *timer;
+  struct object_lock *lock;
+  sock *sk;
+
+  bird_clock_t last;		/* Time of last sending of RA */
+  u16 plen;			/* Length of prepared RA in tbuf, or 0 if not valid */
+  byte initial;			/* List of active ifaces */
+};
+
+#define RA_EV_INIT 1		/* Switch to initial mode */
+#define RA_EV_CHANGE 2		/* Change of options or prefixes */
+#define RA_EV_RS 3		/* Received RS */
+
+
+
+#ifdef LOCAL_DEBUG
+#define RADV_FORCE_DEBUG 1
+#else
+#define RADV_FORCE_DEBUG 0
+#endif
+#define RADV_TRACE(flags, msg, args...) do { if ((ra->p.debug & flags) || RADV_FORCE_DEBUG) \
+	log(L_TRACE "%s: " msg, ra->p.name , ## args ); } while(0)
+
+
+/* radv.c */
+void radv_iface_notify(struct radv_iface *ifa, int event);
+
+/* packets.c */
+void radv_send_ra(struct radv_iface *ifa, int shutdown);
+int radv_sk_open(struct radv_iface *ifa);
+
+
+
+#endif /* _BIRD_RADV_H_ */