1 files changed, 288 insertions, 261 deletions

diff --git a/proto/ospf/hello.c b/proto/ospf/hello.c
index e8bce09f..3aeb9f9a 100644
--- a/proto/ospf/hello.c
+++ b/proto/ospf/hello.c
@@ -2,6 +2,8 @@
  *	BIRD -- OSPF
  *
  *	(c) 1999--2004 Ondrej Filip <feela@network.cz>
+ *	(c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
+ *	(c) 2009--2014 CZ.NIC z.s.p.o.
  *
  *	Can be freely distributed and used under the terms of the GNU GPL.
  */
@@ -9,25 +11,26 @@
 #include "ospf.h"
 
 
-#ifdef OSPFv2
-struct ospf_hello_packet
+struct ospf_hello2_packet
 {
-  struct ospf_packet ospf_packet;
-  ip_addr netmask;
+  struct ospf_packet hdr;
+  union ospf_auth auth;
+
+  u32 netmask;
   u16 helloint;
   u8 options;
   u8 priority;
   u32 deadint;
   u32 dr;
   u32 bdr;
-};
-#endif
 
+  u32 neighbors[];
+};
 
-#ifdef OSPFv3
-struct ospf_hello_packet
+struct ospf_hello3_packet
 {
-  struct ospf_packet ospf_packet;
+  struct ospf_packet hdr;
+
   u32 iface_id;
   u8 priority;
   u8 options3;
@@ -37,286 +40,92 @@ struct ospf_hello_packet
   u16 deadint;
   u32 dr;
   u32 bdr;
-};
-#endif
-
-
-void
-ospf_hello_receive(struct ospf_packet *ps_i, struct ospf_iface *ifa,
-		   struct ospf_neighbor *n, ip_addr faddr)
-{
-  struct proto_ospf *po = ifa->oa->po;
-  struct proto *p = &po->proto;
-  char *beg = "OSPF: Bad HELLO packet from ";
-  unsigned int size, i, twoway, peers;
-  u32 tmp;
-  u32 *pnrid;
-
-  size = ntohs(ps_i->length);
-  if (size < sizeof(struct ospf_hello_packet))
-  {
-    log(L_ERR "%s%I - too short (%u B)", beg, faddr, size);
-    return;
-  }
-
-  struct ospf_hello_packet *ps = (void *) ps_i;
-
-  OSPF_TRACE(D_PACKETS, "HELLO packet received from %I via %s", faddr, ifa->ifname);
-
-#ifdef OSPFv2
-  ip_addr mask = ps->netmask;
-  ipa_ntoh(mask);
-  if ((ifa->type != OSPF_IT_VLINK) &&
-      (ifa->type != OSPF_IT_PTP) &&
-      !ipa_equal(mask, ipa_mkmask(ifa->addr->pxlen)))
-  {
-    log(L_ERR "%s%I - netmask mismatch (%I)", beg, faddr, mask);
-    return;
-  }
-#endif
-
-  tmp = ntohs(ps->helloint);
-  if (tmp != ifa->helloint)
-  {
-    log(L_ERR "%s%I - hello interval mismatch (%d)", beg, faddr, tmp);
-    return;
-  }
-
-#ifdef OSPFv2
-  tmp = ntohl(ps->deadint);
-#else /* OSPFv3 */
-  tmp = ntohs(ps->deadint);
-#endif
-  if (tmp != ifa->deadint)
-  {
-    log(L_ERR "%s%I - dead interval mismatch (%d)", beg, faddr, tmp);
-    return;
-  }
-
-  /* Check whether bits E, N match */
-  if ((ps->options ^ ifa->oa->options) & (OPT_E | OPT_N))
-  {
-    log(L_ERR "%s%I - area type mismatch (%x)", beg, faddr, ps->options);
-    return;
-  }
-
-#ifdef OSPFv2
-  if (n && (n->rid != ntohl(ps_i->routerid)))
-  {
-    OSPF_TRACE(D_EVENTS,
-	"Neighbor %I has changed router id from %R to %R.",
-	     n->ip, n->rid, ntohl(ps_i->routerid));
-    ospf_neigh_remove(n);
-    n = NULL;
-  }
-#endif
-
-  if (!n)
-  {
-    if ((ifa->type == OSPF_IT_NBMA) || (ifa->type == OSPF_IT_PTMP))
-    {
-      struct nbma_node *nn = find_nbma_node(ifa, faddr);
 
-      if (!nn && ifa->strictnbma)
-      {
-	log(L_WARN "Ignoring new neighbor: %I on %s", faddr, ifa->ifname);
-	return;
-      }
-
-      if (nn && (ifa->type == OSPF_IT_NBMA) &&
-	  (((ps->priority == 0) && nn->eligible) ||
-	   ((ps->priority > 0) && !nn->eligible)))
-      {
-	log(L_ERR "Eligibility mismatch for neighbor: %I on %s", faddr, ifa->ifname);
-	return;
-      }
-
-      if (nn)
-	nn->found = 1;
-    }
-
-    OSPF_TRACE(D_EVENTS, "New neighbor found: %I on %s", faddr, ifa->ifname);
-
-    n = ospf_neighbor_new(ifa);
-
-    n->rid = ntohl(ps_i->routerid);
-    n->ip = faddr;
-    n->dr = ntohl(ps->dr);
-    n->bdr = ntohl(ps->bdr);
-    n->priority = ps->priority;
-#ifdef OSPFv3
-    n->iface_id = ntohl(ps->iface_id);
-#endif
-
-    if (n->ifa->cf->bfd)
-      ospf_neigh_update_bfd(n, n->ifa->bfd);
-  }
-#ifdef OSPFv3	/* NOTE: this could also be relevant for OSPFv2 on PtP ifaces */
-  else if (!ipa_equal(faddr, n->ip))
-  {
-    OSPF_TRACE(D_EVENTS, "Neighbor address changed from %I to %I", n->ip, faddr);
-    n->ip = faddr;
-  }
-#endif
-
-  ospf_neigh_sm(n, INM_HELLOREC);
-
-  pnrid = (u32 *) ((struct ospf_hello_packet *) (ps + 1));
-
-  peers = (size - sizeof(struct ospf_hello_packet))/ sizeof(u32);
-
-  twoway = 0;
-  for (i = 0; i < peers; i++)
-  {
-    if (ntohl(pnrid[i]) == po->router_id)
-    {
-      DBG("%s: Twoway received from %I\n", p->name, faddr);
-      ospf_neigh_sm(n, INM_2WAYREC);
-      twoway = 1;
-      break;
-    }
-  }
-
-  if (!twoway)
-    ospf_neigh_sm(n, INM_1WAYREC);
-
-  u32 olddr = n->dr;
-  u32 oldbdr = n->bdr;
-  u32 oldpriority = n->priority;
-#ifdef OSPFv3
-  u32 oldiface_id = n->iface_id;
-#endif
-
-  n->dr = ntohl(ps->dr);
-  n->bdr = ntohl(ps->bdr);
-  n->priority = ps->priority;
-#ifdef OSPFv3
-  n->iface_id = ntohl(ps->iface_id);
-#endif
-
-
-  /* Check priority change */
-  if (n->state >= NEIGHBOR_2WAY)
-  {
-#ifdef OSPFv2
-    u32 neigh = ipa_to_u32(n->ip);
-#else /* OSPFv3 */
-    u32 neigh = n->rid;
-#endif
-
-    if (n->priority != oldpriority)
-      ospf_iface_sm(ifa, ISM_NEICH);
-
-#ifdef OSPFv3
-    if (n->iface_id != oldiface_id)
-      ospf_iface_sm(ifa, ISM_NEICH);
-#endif
-
-    /* Neighbor is declaring itself ad DR and there is no BDR */
-    if ((n->dr == neigh) && (n->bdr == 0)
-	&& (n->state != NEIGHBOR_FULL))
-      ospf_iface_sm(ifa, ISM_BACKS);
-
-    /* Neighbor is declaring itself as BDR */
-    if ((n->bdr == neigh) && (n->state != NEIGHBOR_FULL))
-      ospf_iface_sm(ifa, ISM_BACKS);
-
-    /* Neighbor is newly declaring itself as DR or BDR */
-    if (((n->dr == neigh) && (n->dr != olddr))
-	|| ((n->bdr == neigh) && (n->bdr != oldbdr)))
-      ospf_iface_sm(ifa, ISM_NEICH);
-
-    /* Neighbor is no more declaring itself as DR or BDR */
-    if (((olddr == neigh) && (n->dr != olddr))
-	|| ((oldbdr == neigh) && (n->bdr != oldbdr)))
-      ospf_iface_sm(ifa, ISM_NEICH);
-  }
+  u32 neighbors[];
+};
 
-  if (ifa->type == OSPF_IT_NBMA)
-  {
-    if ((ifa->priority == 0) && (n->priority > 0))
-      ospf_hello_send(n->ifa, OHS_HELLO, n);
-  }
-  ospf_neigh_sm(n, INM_HELLOREC);
-}
 
 void
-ospf_hello_send(struct ospf_iface *ifa, int kind, struct ospf_neighbor *dirn)
+ospf_send_hello(struct ospf_iface *ifa, int kind, struct ospf_neighbor *dirn)
 {
-  struct ospf_hello_packet *pkt;
-  struct ospf_packet *op;
-  struct proto *p;
+  struct ospf_proto *p = ifa->oa->po;
+  struct ospf_packet *pkt;
   struct ospf_neighbor *neigh, *n1;
-  u16 length;
-  int i;
   struct nbma_node *nb;
+  u32 *neighbors;
+  uint length;
+  int i, max;
 
   if (ifa->state <= OSPF_IS_LOOP)
     return;
 
   if (ifa->stub)
-    return;			/* Don't send any packet on stub iface */
+    return;
 
-  p = (struct proto *) (ifa->oa->po);
-  DBG("%s: Hello/Poll timer fired on interface %s with IP %I\n",
-      p->name, ifa->ifname, ifa->addr->ip);
 
-  /* Now we should send a hello packet */
   pkt = ospf_tx_buffer(ifa);
-  op = &pkt->ospf_packet;
-
-  /* Now fill ospf_hello header */
   ospf_pkt_fill_hdr(ifa, pkt, HELLO_P);
 
-#ifdef OSPFv2
-  pkt->netmask = ipa_mkmask(ifa->addr->pxlen);
-  ipa_hton(pkt->netmask);
-  if ((ifa->type == OSPF_IT_VLINK) ||
-      ((ifa->type == OSPF_IT_PTP) && !ifa->ptp_netmask))
-    pkt->netmask = IPA_NONE;
-#endif
-
-  pkt->helloint = ntohs(ifa->helloint);
-  pkt->priority = ifa->priority;
-
-#ifdef OSPFv3
-  pkt->iface_id = htonl(ifa->iface_id);
-
-  pkt->options3 = ifa->oa->options >> 16;
-  pkt->options2 = ifa->oa->options >> 8;
-#endif
-  pkt->options = ifa->oa->options;
-
-#ifdef OSPFv2
-  pkt->deadint = htonl(ifa->deadint);
-  pkt->dr = htonl(ipa_to_u32(ifa->drip));
-  pkt->bdr = htonl(ipa_to_u32(ifa->bdrip));
-#else /* OSPFv3 */
-  pkt->deadint = htons(ifa->deadint);
-  pkt->dr = htonl(ifa->drid);
-  pkt->bdr = htonl(ifa->bdrid);
-#endif
+  if (ospf_is_v2(p))
+  {
+    struct ospf_hello2_packet *ps = (void *) pkt;
+
+    if ((ifa->type == OSPF_IT_VLINK) ||
+	((ifa->type == OSPF_IT_PTP) && !ifa->ptp_netmask))
+      ps->netmask = 0;
+    else
+      ps->netmask = htonl(u32_mkmask(ifa->addr->pxlen));
+
+    ps->helloint = ntohs(ifa->helloint);
+    ps->options = ifa->oa->options;
+    ps->priority = ifa->priority;
+    ps->deadint = htonl(ifa->deadint);
+    ps->dr = htonl(ipa_to_u32(ifa->drip));
+    ps->bdr = htonl(ipa_to_u32(ifa->bdrip));
+
+    length = sizeof(struct ospf_hello2_packet);
+    neighbors = ps->neighbors;
+  }
+  else
+  {
+    struct ospf_hello3_packet *ps = (void *) pkt;
+
+    ps->iface_id = htonl(ifa->iface_id);
+    ps->priority = ifa->priority;
+    ps->options3 = ifa->oa->options >> 16;
+    ps->options2 = ifa->oa->options >> 8;
+    ps->options = ifa->oa->options;
+    ps->helloint = ntohs(ifa->helloint);
+    ps->deadint = htons(ifa->deadint);
+    ps->dr = htonl(ifa->drid);
+    ps->bdr = htonl(ifa->bdrid);
+
+    length = sizeof(struct ospf_hello3_packet);
+    neighbors = ps->neighbors;
+  }
 
-  /* Fill all neighbors */
   i = 0;
+  max = (ospf_pkt_maxsize(ifa) - length) / sizeof(u32);
 
+  /* Fill all neighbors */
   if (kind != OHS_SHUTDOWN)
   {
-    u32 *pp = (u32 *) (((u8 *) pkt) + sizeof(struct ospf_hello_packet));
     WALK_LIST(neigh, ifa->neigh_list)
     {
-      if ((i+1) * sizeof(u32) + sizeof(struct ospf_hello_packet) > ospf_pkt_maxsize(ifa))
+      if (i == max)
       {
-	log(L_WARN "%s: Too many neighbors on interface %s", p->name, ifa->ifname);
+	log(L_WARN "%s: Too many neighbors on interface %s", p->p.name, ifa->ifname);
 	break;
       }
-      *(pp + i) = htonl(neigh->rid);
+      neighbors[i] = htonl(neigh->rid);
       i++;
     }
   }
 
-  length = sizeof(struct ospf_hello_packet) + i * sizeof(u32);
-  op->length = htons(length);
+  length += i * sizeof(u32);
+  pkt->length = htons(length);
+
+  OSPF_TRACE(D_PACKETS, "HELLO packet sent via %s", ifa->ifname);
 
   switch(ifa->type)
   {
@@ -334,7 +143,7 @@ ospf_hello_send(struct ospf_iface *ifa, int kind, struct ospf_neighbor *dirn)
 
     int to_all = ifa->state > OSPF_IS_DROTHER;
     int me_elig = ifa->priority > 0;
- 
+
     if (kind == OHS_POLL)	/* Poll timer */
     {
       WALK_LIST(nb, ifa->nbma_list)
@@ -369,8 +178,226 @@ ospf_hello_send(struct ospf_iface *ifa, int kind, struct ospf_neighbor *dirn)
     break;
 
   default:
-    bug("Bug in ospf_hello_send()");
+    bug("Bug in ospf_send_hello()");
   }
+}
 
-  OSPF_TRACE(D_PACKETS, "HELLO packet sent via %s", ifa->ifname);
+
+void
+ospf_receive_hello(struct ospf_packet *pkt, struct ospf_iface *ifa,
+		   struct ospf_neighbor *n, ip_addr faddr)
+{
+  struct ospf_proto *p = ifa->oa->po;
+  char *beg = "OSPF: Bad HELLO packet from ";
+  u32 rcv_iface_id, rcv_helloint, rcv_deadint, rcv_dr, rcv_bdr;
+  u8 rcv_options, rcv_priority;
+  u32 *neighbors;
+  u32 neigh_count;
+  uint plen, i;
+
+  /* RFC 2328 10.5 */
+
+  OSPF_TRACE(D_PACKETS, "HELLO packet received from %I via %s", faddr, ifa->ifname);
+
+  plen = ntohs(pkt->length);
+
+  if (ospf_is_v2(p))
+  {
+    struct ospf_hello2_packet *ps = (void *) pkt;
+
+    if (plen < sizeof(struct ospf_hello2_packet))
+    {
+      log(L_ERR "%s%I - too short (%u B)", beg, faddr, plen);
+      return;
+    }
+
+    rcv_iface_id = 0;
+    rcv_helloint = ntohs(ps->helloint);
+    rcv_deadint = ntohl(ps->deadint);
+    rcv_dr = ntohl(ps->dr);
+    rcv_bdr = ntohl(ps->bdr);
+    rcv_options = ps->options;
+    rcv_priority = ps->priority;
+
+    int pxlen = u32_masklen(ntohl(ps->netmask));
+    if ((ifa->type != OSPF_IT_VLINK) &&
+	(ifa->type != OSPF_IT_PTP) &&
+	(pxlen != ifa->addr->pxlen))
+    {
+      log(L_ERR "%s%I - prefix length mismatch (%d)", beg, faddr, pxlen);
+      return;
+    }
+
+    neighbors = ps->neighbors;
+    neigh_count = (plen - sizeof(struct ospf_hello2_packet)) / sizeof(u32);
+  }
+  else /* OSPFv3 */
+  {
+    struct ospf_hello3_packet *ps = (void *) pkt;
+
+    if (plen < sizeof(struct ospf_hello3_packet))
+    {
+      log(L_ERR "%s%I - too short (%u B)", beg, faddr, plen);
+      return;
+    }
+
+    rcv_iface_id = ntohl(ps->iface_id);
+    rcv_helloint = ntohs(ps->helloint);
+    rcv_deadint = ntohs(ps->deadint);
+    rcv_dr = ntohl(ps->dr);
+    rcv_bdr = ntohl(ps->bdr);
+    rcv_options = ps->options;
+    rcv_priority = ps->priority;
+
+    neighbors = ps->neighbors;
+    neigh_count = (plen - sizeof(struct ospf_hello3_packet)) / sizeof(u32);
+  }
+
+  if (rcv_helloint != ifa->helloint)
+  {
+    log(L_ERR "%s%I - hello interval mismatch (%d)", beg, faddr, rcv_helloint);
+    return;
+  }
+
+  if (rcv_deadint != ifa->deadint)
+  {
+    log(L_ERR "%s%I - dead interval mismatch (%d)", beg, faddr, rcv_deadint);
+    return;
+  }
+
+  /* Check whether bits E, N match */
+  if ((rcv_options ^ ifa->oa->options) & (OPT_E | OPT_N))
+  {
+    log(L_ERR "%s%I - area type mismatch (%x)", beg, faddr, rcv_options);
+    return;
+  }
+
+  /* Check consistency of existing neighbor entry */
+  if (n)
+  {
+    uint t = ifa->type;
+    if (ospf_is_v2(p) && ((t == OSPF_IT_BCAST) || (t == OSPF_IT_NBMA) || (t == OSPF_IT_PTMP)))
+    {
+      /* Neighbor identified by IP address; Router ID may change */
+      if (n->rid != ntohl(pkt->routerid))
+      {
+	OSPF_TRACE(D_EVENTS, "Neighbor %I has changed Router ID from %R to %R",
+		   n->ip, n->rid, ntohl(pkt->routerid));
+	ospf_neigh_remove(n);
+	n = NULL;
+      }
+    }
+    else /* OSPFv3 or OSPFv2/PtP */
+    {
+      /* Neighbor identified by Router ID; IP address may change */
+      if (!ipa_equal(faddr, n->ip))
+      {
+	OSPF_TRACE(D_EVENTS, "Neighbor address changed from %I to %I", n->ip, faddr);
+	n->ip = faddr;
+      }
+    }
+  }
+
+  if (!n)
+  {
+    if ((ifa->type == OSPF_IT_NBMA) || (ifa->type == OSPF_IT_PTMP))
+    {
+      struct nbma_node *nn = find_nbma_node(ifa, faddr);
+
+      if (!nn && ifa->strictnbma)
+      {
+	log(L_WARN "Ignoring new neighbor: %I on %s", faddr, ifa->ifname);
+	return;
+      }
+
+      if (nn && (ifa->type == OSPF_IT_NBMA) &&
+	  (((rcv_priority == 0) && nn->eligible) ||
+	   ((rcv_priority > 0) && !nn->eligible)))
+      {
+	log(L_ERR "Eligibility mismatch for neighbor: %I on %s", faddr, ifa->ifname);
+	return;
+      }
+
+      if (nn)
+	nn->found = 1;
+    }
+
+    OSPF_TRACE(D_EVENTS, "New neighbor found: %I on %s", faddr, ifa->ifname);
+
+    n = ospf_neighbor_new(ifa);
+
+    n->rid = ntohl(pkt->routerid);
+    n->ip = faddr;
+    n->dr = rcv_dr;
+    n->bdr = rcv_bdr;
+    n->priority = rcv_priority;
+    n->iface_id = rcv_iface_id;
+
+    if (n->ifa->cf->bfd)
+      ospf_neigh_update_bfd(n, n->ifa->bfd);
+  }
+
+  u32 n_id = ospf_is_v2(p) ? ipa_to_u32(n->ip) : n->rid;
+
+  u32 old_dr = n->dr;
+  u32 old_bdr = n->bdr;
+  u32 old_priority = n->priority;
+  u32 old_iface_id = n->iface_id;
+
+  n->dr = rcv_dr;
+  n->bdr = rcv_bdr;
+  n->priority = rcv_priority;
+  n->iface_id = rcv_iface_id;
+
+
+  /* Update inactivity timer */
+  ospf_neigh_sm(n, INM_HELLOREC);
+
+  /* RFC 2328 9.5.1 - non-eligible routers reply to hello on NBMA nets */
+  if (ifa->type == OSPF_IT_NBMA)
+    if ((ifa->priority == 0) && (n->priority > 0))
+      ospf_send_hello(n->ifa, OHS_HELLO, n);
+
+
+  /* Examine list of neighbors */
+  for (i = 0; i < neigh_count; i++)
+    if (neighbors[i] == htonl(p->router_id))
+      goto found_self;
+
+  ospf_neigh_sm(n, INM_1WAYREC);
+  return;
+
+ found_self:
+  ospf_neigh_sm(n, INM_2WAYREC);
+
+
+  if (n->iface_id != old_iface_id)
+  {
+    /* If neighbor is DR, also update cached DR interface ID */
+    if (ifa->drid == n->rid)
+      ifa->dr_iface_id = n->iface_id;
+
+    /* RFC 5340 4.4.3 Event 4 - change of neighbor's interface ID */
+    ospf_notify_rt_lsa(ifa->oa);
+
+    /* Missed in RFC 5340 4.4.3 Event 4 - (Px-)Net-LSA uses iface_id to ref Link-LSAs */
+    ospf_notify_net_lsa(ifa);
+  }
+
+  if (ifa->state == OSPF_IS_WAITING)
+  {
+    /* Neighbor is declaring itself DR (and there is no BDR) or as BDR */
+    if (((n->dr == n_id) && (n->bdr == 0)) || (n->bdr == n_id))
+      ospf_iface_sm(ifa, ISM_BACKS);
+  }
+  else if (ifa->state >= OSPF_IS_DROTHER)
+  {
+    /* Neighbor changed priority or started/stopped declaring itself as DR/BDR */
+    if ((n->priority != old_priority) ||
+	((n->dr == n_id) && (old_dr != n_id)) ||
+	((n->dr != n_id) && (old_dr == n_id)) ||
+	((n->bdr == n_id) && (old_bdr != n_id)) ||
+	((n->bdr != n_id) && (old_bdr == n_id)))
+      ospf_iface_sm(ifa, ISM_NEICH);
+  }
 }