[thirdparty/bird.git] / proto / ospf / hello.c

/*
 *	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.
 */

#include "ospf.h"


struct ospf_hello2_packet
{
  struct ospf_packet hdr;
  union ospf_auth auth;

  u32 netmask;
  u16 helloint;
  u8 options;
  u8 priority;
  u32 deadint;
  u32 dr;
  u32 bdr;

  u32 neighbors[];
};

struct ospf_hello3_packet
{
  struct ospf_packet hdr;

  u32 iface_id;
  u8 priority;
  u8 options3;
  u8 options2;
  u8 options;
  u16 helloint;
  u16 deadint;
  u32 dr;
  u32 bdr;

  u32 neighbors[];
};


void
ospf_send_hello(struct ospf_iface *ifa, int kind, struct ospf_neighbor *dirn)
{
  struct ospf_proto *p = ifa->oa->po;
  struct ospf_packet *pkt;
  struct ospf_neighbor *neigh, *n1;
  struct nbma_node *nb;
  u32 *neighbors;
  uint length;
  int i, max;

  if (ifa->state <= OSPF_IS_LOOP)
    return;

  if (ifa->stub)
    return;


  pkt = ospf_tx_buffer(ifa);
  ospf_pkt_fill_hdr(ifa, pkt, HELLO_P);

  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->prefix.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;
  }

  i = 0;
  max = (ospf_pkt_maxsize(p, ifa) - length) / sizeof(u32);

  /* Fill all neighbors */
  if (kind != OHS_SHUTDOWN)
  {
    WALK_LIST(neigh, ifa->neigh_list)
    {
      if (i == max)
      {
	log(L_WARN "%s: Too many neighbors on %s", p->p.name, ifa->ifname);
	break;
      }
      neighbors[i] = htonl(neigh->rid);
      i++;
    }
  }

  length += i * sizeof(u32);
  pkt->length = htons(length);

  OSPF_TRACE(D_PACKETS, "HELLO packet sent via %s", ifa->ifname);

  switch(ifa->type)
  {
  case OSPF_IT_BCAST:
  case OSPF_IT_PTP:
    ospf_send_to_all(ifa);
    break;

  case OSPF_IT_NBMA:
    if (dirn)		/* Response to received hello */
    {
      ospf_send_to(ifa, dirn->ip);
      break;
    }

    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)
	if (!nb->found && (to_all || (me_elig && nb->eligible)))
	  ospf_send_to(ifa, nb->ip);
    }
    else			/* Hello timer */
    {
      WALK_LIST(n1, ifa->neigh_list)
	if (to_all || (me_elig && (n1->priority > 0)) ||
	    (n1->rid == ifa->drid) || (n1->rid == ifa->bdrid))
	  ospf_send_to(ifa, n1->ip);
    }
    break;

  case OSPF_IT_PTMP:
    WALK_LIST(n1, ifa->neigh_list)
      ospf_send_to(ifa, n1->ip);

    WALK_LIST(nb, ifa->nbma_list)
      if (!nb->found)
	ospf_send_to(ifa, nb->ip);

    /* If there is no other target, we also send HELLO packet to the other end */
    if (ipa_nonzero(ifa->addr->opposite) && !ifa->strictnbma &&
	EMPTY_LIST(ifa->neigh_list) && EMPTY_LIST(ifa->nbma_list))
      ospf_send_to(ifa, ifa->addr->opposite);
    break;

  case OSPF_IT_VLINK:
    ospf_send_to(ifa, ifa->vip);
    break;

  default:
    bug("Bug in ospf_send_hello()");
  }
}


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;
  const char *err_dsc = NULL;
  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, err_val = 0;

  /* RFC 2328 10.5 */

  /*
   * We may not yet have the associate neighbor, so we use Router ID from the
   * packet instead of one from the neighbor structure for log messages.
   */
  u32 rcv_rid = ntohl(pkt->routerid);
  OSPF_TRACE(D_PACKETS, "HELLO packet received from nbr %R on %s", rcv_rid, 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))
      DROP("too short", plen);

    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->prefix.pxlen))
      DROP("prefix length mismatch", pxlen);

    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))
      DROP("too short", plen);

    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)
    DROP("hello interval mismatch", rcv_helloint);

  if (rcv_deadint != ifa->deadint)
    DROP("dead interval mismatch", rcv_deadint);

  /* Check whether bits E, N match */
  if ((rcv_options ^ ifa->oa->options) & (OPT_E | OPT_N))
    DROP("area type mismatch", rcv_options);

  /* 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 != rcv_rid)
      {
	OSPF_TRACE(D_EVENTS, "Neighbor %R on %s changed Router ID to %R",
		   n->rid, ifa->ifname, rcv_rid);
	ospf_neigh_sm(n, INM_KILLNBR);
	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 %R on %s changed IP address to %I",
		   n->rid, ifa->ifname, 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)
	DROP1("new neighbor denied");

      if (nn && (ifa->type == OSPF_IT_NBMA) &&
	  (((rcv_priority == 0) && nn->eligible) ||
	   ((rcv_priority > 0) && !nn->eligible)))
	DROP("eligibility mismatch", rcv_priority);

      if (nn)
	nn->found = 1;
    }

    OSPF_TRACE(D_EVENTS, "New neighbor %R on %s, IP address %I",
	       rcv_rid, ifa->ifname, faddr);

    n = ospf_neighbor_new(ifa);

    n->rid = rcv_rid;
    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);
  }

  return;

drop:
  LOG_PKT("Bad HELLO packet from nbr %R on %s - %s (%u)",
	  rcv_rid, ifa->ifname, err_dsc, err_val);
}
Commit	Line	Data
4364b47e OF	1	/*
	2	* BIRD -- OSPF
	3	*
bc4ea680	4	* (c) 1999--2004 Ondrej Filip <feela@network.cz>
70945cb6 OZ	5	* (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
70945cb6 OZ	6	* (c) 2009--2014 CZ.NIC z.s.p.o.
4364b47e OF	7	*
	8	* Can be freely distributed and used under the terms of the GNU GPL.
	9	*/
	10
	11	#include "ospf.h"
	12
c3226991	13
70945cb6	14	struct ospf_hello2_packet
c3226991	15	{
70945cb6 OZ	16	struct ospf_packet hdr;
	17	union ospf_auth auth;
	18
	19	u32 netmask;
c3226991 OZ	20	u16 helloint;
	21	u8 options;
	22	u8 priority;
	23	u32 deadint;
	24	u32 dr;
	25	u32 bdr;
c3226991	26
70945cb6 OZ	27	u32 neighbors[];
70945cb6 OZ	28	};
c3226991	29
70945cb6	30	struct ospf_hello3_packet
c3226991	31	{
70945cb6 OZ	32	struct ospf_packet hdr;
70945cb6 OZ	33
c3226991 OZ	34	u32 iface_id;
	35	u8 priority;
	36	u8 options3;
	37	u8 options2;
	38	u8 options;
	39	u16 helloint;
	40	u16 deadint;
	41	u32 dr;
	42	u32 bdr;
c3226991	43
70945cb6 OZ	44	u32 neighbors[];
70945cb6 OZ	45	};
b29c620f	46
4364b47e	47
a190e720	48	void
70945cb6	49	ospf_send_hello(struct ospf_iface ifa, int kind, struct ospf_neighbor dirn)
4364b47e	50	{
70945cb6 OZ	51	struct ospf_proto *p = ifa->oa->po;
70945cb6 OZ	52	struct ospf_packet *pkt;
98ac6176	53	struct ospf_neighbor neigh, n1;
98ac6176	54	struct nbma_node *nb;
70945cb6 OZ	55	u32 *neighbors;
	56	uint length;
	57	int i, max;
86c84d76	58
391931d4	59	if (ifa->state <= OSPF_IS_LOOP)
98ac6176 OF	60	return;
98ac6176 OF	61
77539c44	62	if (ifa->stub)
70945cb6	63	return;
e3bc10fd	64
4364b47e	65
e7b76b97	66	pkt = ospf_tx_buffer(ifa);
3e2bd0f1	67	ospf_pkt_fill_hdr(ifa, pkt, HELLO_P);
e5b5d18c	68
70945cb6 OZ	69	if (ospf_is_v2(p))
	70	{
	71	struct ospf_hello2_packet ps = (void ) pkt;
	72
	73	if ((ifa->type == OSPF_IT_VLINK) \|\|
	74	((ifa->type == OSPF_IT_PTP) && !ifa->ptp_netmask))
	75	ps->netmask = 0;
	76	else
d44e686e	77	ps->netmask = htonl(u32_mkmask(ifa->addr->prefix.pxlen));
70945cb6 OZ	78
	79	ps->helloint = ntohs(ifa->helloint);
	80	ps->options = ifa->oa->options;
	81	ps->priority = ifa->priority;
	82	ps->deadint = htonl(ifa->deadint);
	83	ps->dr = htonl(ipa_to_u32(ifa->drip));
	84	ps->bdr = htonl(ipa_to_u32(ifa->bdrip));
	85
	86	length = sizeof(struct ospf_hello2_packet);
	87	neighbors = ps->neighbors;
	88	}
	89	else
	90	{
	91	struct ospf_hello3_packet ps = (void ) pkt;
	92
	93	ps->iface_id = htonl(ifa->iface_id);
	94	ps->priority = ifa->priority;
	95	ps->options3 = ifa->oa->options >> 16;
	96	ps->options2 = ifa->oa->options >> 8;
	97	ps->options = ifa->oa->options;
	98	ps->helloint = ntohs(ifa->helloint);
	99	ps->deadint = htons(ifa->deadint);
	100	ps->dr = htonl(ifa->drid);
	101	ps->bdr = htonl(ifa->bdrid);
	102
	103	length = sizeof(struct ospf_hello3_packet);
	104	neighbors = ps->neighbors;
	105	}
e5b5d18c	106
77539c44	107	i = 0;
fe9f1a6d	108	max = (ospf_pkt_maxsize(p, ifa) - length) / sizeof(u32);
8e48831a	109
70945cb6	110	/* Fill all neighbors */
8e48831a	111	if (kind != OHS_SHUTDOWN)
e5b5d18c	112	{
8e48831a	113	WALK_LIST(neigh, ifa->neigh_list)
3e2bd0f1	114	{
70945cb6	115	if (i == max)
8e48831a	116	{
f8fefde3	117	log(L_WARN "%s: Too many neighbors on %s", p->p.name, ifa->ifname);
8e48831a OZ	118	break;
8e48831a OZ	119	}
70945cb6	120	neighbors[i] = htonl(neigh->rid);
8e48831a	121	i++;
3e2bd0f1	122	}
e5b5d18c OF	123	}
e5b5d18c OF	124
70945cb6 OZ	125	length += i * sizeof(u32);
	126	pkt->length = htons(length);
	127
	128	OSPF_TRACE(D_PACKETS, "HELLO packet sent via %s", ifa->ifname);
e5b5d18c	129
98ac6176	130	switch(ifa->type)
e5b5d18c	131	{
919f5411 OZ	132	case OSPF_IT_BCAST:
919f5411 OZ	133	case OSPF_IT_PTP:
95127cbb	134	ospf_send_to_all(ifa);
919f5411 OZ	135	break;
	136
	137	case OSPF_IT_NBMA:
beeda6af	138	if (dirn) /* Response to received hello */
919f5411 OZ	139	{
919f5411 OZ	140	ospf_send_to(ifa, dirn->ip);
98ac6176	141	break;
919f5411 OZ	142	}
	143
	144	int to_all = ifa->state > OSPF_IS_DROTHER;
	145	int me_elig = ifa->priority > 0;
742029eb	146
8e48831a	147	if (kind == OHS_POLL) /* Poll timer */
919f5411 OZ	148	{
	149	WALK_LIST(nb, ifa->nbma_list)
	150	if (!nb->found && (to_all \|\| (me_elig && nb->eligible)))
	151	ospf_send_to(ifa, nb->ip);
	152	}
	153	else /* Hello timer */
	154	{
	155	WALK_LIST(n1, ifa->neigh_list)
	156	if (to_all \|\| (me_elig && (n1->priority > 0)) \|\|
	157	(n1->rid == ifa->drid) \|\| (n1->rid == ifa->bdrid))
	158	ospf_send_to(ifa, n1->ip);
	159	}
	160	break;
	161
	162	case OSPF_IT_PTMP:
	163	WALK_LIST(n1, ifa->neigh_list)
	164	ospf_send_to(ifa, n1->ip);
	165
	166	WALK_LIST(nb, ifa->nbma_list)
	167	if (!nb->found)
	168	ospf_send_to(ifa, nb->ip);
	169
	170	/* If there is no other target, we also send HELLO packet to the other end */
	171	if (ipa_nonzero(ifa->addr->opposite) && !ifa->strictnbma &&
	172	EMPTY_LIST(ifa->neigh_list) && EMPTY_LIST(ifa->nbma_list))
	173	ospf_send_to(ifa, ifa->addr->opposite);
	174	break;
	175
	176	case OSPF_IT_VLINK:
	177	ospf_send_to(ifa, ifa->vip);
	178	break;
	179
	180	default:
70945cb6	181	bug("Bug in ospf_send_hello()");
e5b5d18c	182	}
70945cb6	183	}
8298d780	184
70945cb6 OZ	185
	186	void
	187	ospf_receive_hello(struct ospf_packet pkt, struct ospf_iface ifa,
	188	struct ospf_neighbor *n, ip_addr faddr)
	189	{
	190	struct ospf_proto *p = ifa->oa->po;
f8fefde3	191	const char *err_dsc = NULL;
70945cb6 OZ	192	u32 rcv_iface_id, rcv_helloint, rcv_deadint, rcv_dr, rcv_bdr;
	193	u8 rcv_options, rcv_priority;
	194	u32 *neighbors;
	195	u32 neigh_count;
f8fefde3	196	uint plen, i, err_val = 0;
70945cb6 OZ	197
	198	/* RFC 2328 10.5 */
	199
f8fefde3	200	/*
d44e686e	201	* We may not yet have the associate neighbor, so we use Router ID from the
f8fefde3 OZ	202	* packet instead of one from the neighbor structure for log messages.
	203	*/
	204	u32 rcv_rid = ntohl(pkt->routerid);
	205	OSPF_TRACE(D_PACKETS, "HELLO packet received from nbr %R on %s", rcv_rid, ifa->ifname);
70945cb6 OZ	206
	207	plen = ntohs(pkt->length);
	208
	209	if (ospf_is_v2(p))
	210	{
	211	struct ospf_hello2_packet ps = (void ) pkt;
	212
	213	if (plen < sizeof(struct ospf_hello2_packet))
f8fefde3	214	DROP("too short", plen);
70945cb6 OZ	215
	216	rcv_iface_id = 0;
	217	rcv_helloint = ntohs(ps->helloint);
	218	rcv_deadint = ntohl(ps->deadint);
	219	rcv_dr = ntohl(ps->dr);
	220	rcv_bdr = ntohl(ps->bdr);
	221	rcv_options = ps->options;
	222	rcv_priority = ps->priority;
	223
	224	int pxlen = u32_masklen(ntohl(ps->netmask));
	225	if ((ifa->type != OSPF_IT_VLINK) &&
	226	(ifa->type != OSPF_IT_PTP) &&
d44e686e	227	(pxlen != ifa->addr->prefix.pxlen))
f8fefde3	228	DROP("prefix length mismatch", pxlen);
70945cb6 OZ	229
	230	neighbors = ps->neighbors;
	231	neigh_count = (plen - sizeof(struct ospf_hello2_packet)) / sizeof(u32);
	232	}
	233	else /* OSPFv3 */
	234	{
	235	struct ospf_hello3_packet ps = (void ) pkt;
	236
	237	if (plen < sizeof(struct ospf_hello3_packet))
f8fefde3	238	DROP("too short", plen);
70945cb6 OZ	239
	240	rcv_iface_id = ntohl(ps->iface_id);
	241	rcv_helloint = ntohs(ps->helloint);
	242	rcv_deadint = ntohs(ps->deadint);
	243	rcv_dr = ntohl(ps->dr);
	244	rcv_bdr = ntohl(ps->bdr);
	245	rcv_options = ps->options;
	246	rcv_priority = ps->priority;
	247
	248	neighbors = ps->neighbors;
	249	neigh_count = (plen - sizeof(struct ospf_hello3_packet)) / sizeof(u32);
	250	}
	251
	252	if (rcv_helloint != ifa->helloint)
f8fefde3	253	DROP("hello interval mismatch", rcv_helloint);
70945cb6 OZ	254
70945cb6 OZ	255	if (rcv_deadint != ifa->deadint)
f8fefde3	256	DROP("dead interval mismatch", rcv_deadint);
70945cb6 OZ	257
	258	/* Check whether bits E, N match */
	259	if ((rcv_options ^ ifa->oa->options) & (OPT_E \| OPT_N))
f8fefde3	260	DROP("area type mismatch", rcv_options);
70945cb6 OZ	261
	262	/* Check consistency of existing neighbor entry */
	263	if (n)
	264	{
a7a7372a	265	uint t = ifa->type;
70945cb6 OZ	266	if (ospf_is_v2(p) && ((t == OSPF_IT_BCAST) \|\| (t == OSPF_IT_NBMA) \|\| (t == OSPF_IT_PTMP)))
	267	{
	268	/* Neighbor identified by IP address; Router ID may change */
f8fefde3	269	if (n->rid != rcv_rid)
70945cb6	270	{
f8fefde3 OZ	271	OSPF_TRACE(D_EVENTS, "Neighbor %R on %s changed Router ID to %R",
	272	n->rid, ifa->ifname, rcv_rid);
	273	ospf_neigh_sm(n, INM_KILLNBR);
70945cb6 OZ	274	n = NULL;
	275	}
	276	}
	277	else /* OSPFv3 or OSPFv2/PtP */
	278	{
	279	/* Neighbor identified by Router ID; IP address may change */
	280	if (!ipa_equal(faddr, n->ip))
	281	{
f8fefde3 OZ	282	OSPF_TRACE(D_EVENTS, "Neighbor %R on %s changed IP address to %I",
f8fefde3 OZ	283	n->rid, ifa->ifname, n->ip, faddr);
70945cb6 OZ	284	n->ip = faddr;
	285	}
	286	}
	287	}
	288
	289	if (!n)
	290	{
	291	if ((ifa->type == OSPF_IT_NBMA) \|\| (ifa->type == OSPF_IT_PTMP))
	292	{
	293	struct nbma_node *nn = find_nbma_node(ifa, faddr);
	294
	295	if (!nn && ifa->strictnbma)
f8fefde3	296	DROP1("new neighbor denied");
70945cb6 OZ	297
	298	if (nn && (ifa->type == OSPF_IT_NBMA) &&
	299	(((rcv_priority == 0) && nn->eligible) \|\|
	300	((rcv_priority > 0) && !nn->eligible)))
f8fefde3	301	DROP("eligibility mismatch", rcv_priority);
70945cb6 OZ	302
	303	if (nn)
	304	nn->found = 1;
	305	}
	306
6f8bbaa1 OZ	307	OSPF_TRACE(D_EVENTS, "New neighbor %R on %s, IP address %I",
6f8bbaa1 OZ	308	rcv_rid, ifa->ifname, faddr);
70945cb6 OZ	309
	310	n = ospf_neighbor_new(ifa);
	311
f8fefde3	312	n->rid = rcv_rid;
70945cb6 OZ	313	n->ip = faddr;
	314	n->dr = rcv_dr;
	315	n->bdr = rcv_bdr;
	316	n->priority = rcv_priority;
	317	n->iface_id = rcv_iface_id;
	318
	319	if (n->ifa->cf->bfd)
	320	ospf_neigh_update_bfd(n, n->ifa->bfd);
	321	}
	322
	323	u32 n_id = ospf_is_v2(p) ? ipa_to_u32(n->ip) : n->rid;
	324
	325	u32 old_dr = n->dr;
	326	u32 old_bdr = n->bdr;
	327	u32 old_priority = n->priority;
	328	u32 old_iface_id = n->iface_id;
	329
	330	n->dr = rcv_dr;
	331	n->bdr = rcv_bdr;
	332	n->priority = rcv_priority;
	333	n->iface_id = rcv_iface_id;
	334
	335
	336	/* Update inactivity timer */
	337	ospf_neigh_sm(n, INM_HELLOREC);
	338
	339	/* RFC 2328 9.5.1 - non-eligible routers reply to hello on NBMA nets */
	340	if (ifa->type == OSPF_IT_NBMA)
	341	if ((ifa->priority == 0) && (n->priority > 0))
	342	ospf_send_hello(n->ifa, OHS_HELLO, n);
742029eb	343
70945cb6 OZ	344
	345	/* Examine list of neighbors */
	346	for (i = 0; i < neigh_count; i++)
	347	if (neighbors[i] == htonl(p->router_id))
	348	goto found_self;
	349
	350	ospf_neigh_sm(n, INM_1WAYREC);
	351	return;
	352
f8fefde3	353	found_self:
70945cb6 OZ	354	ospf_neigh_sm(n, INM_2WAYREC);
	355
	356
	357	if (n->iface_id != old_iface_id)
	358	{
	359	/* If neighbor is DR, also update cached DR interface ID */
	360	if (ifa->drid == n->rid)
	361	ifa->dr_iface_id = n->iface_id;
	362
	363	/* RFC 5340 4.4.3 Event 4 - change of neighbor's interface ID */
	364	ospf_notify_rt_lsa(ifa->oa);
	365
	366	/* Missed in RFC 5340 4.4.3 Event 4 - (Px-)Net-LSA uses iface_id to ref Link-LSAs */
	367	ospf_notify_net_lsa(ifa);
	368	}
	369
	370	if (ifa->state == OSPF_IS_WAITING)
	371	{
	372	/* Neighbor is declaring itself DR (and there is no BDR) or as BDR */
	373	if (((n->dr == n_id) && (n->bdr == 0)) \|\| (n->bdr == n_id))
	374	ospf_iface_sm(ifa, ISM_BACKS);
	375	}
	376	else if (ifa->state >= OSPF_IS_DROTHER)
	377	{
	378	/* Neighbor changed priority or started/stopped declaring itself as DR/BDR */
	379	if ((n->priority != old_priority) \|\|
	380	((n->dr == n_id) && (old_dr != n_id)) \|\|
	381	((n->dr != n_id) && (old_dr == n_id)) \|\|
	382	((n->bdr == n_id) && (old_bdr != n_id)) \|\|
	383	((n->bdr != n_id) && (old_bdr == n_id)))
	384	ospf_iface_sm(ifa, ISM_NEICH);
	385	}
f8fefde3 OZ	386
	387	return;
	388
	389	drop:
	390	LOG_PKT("Bad HELLO packet from nbr %R on %s - %s (%u)",
	391	rcv_rid, ifa->ifname, err_dsc, err_val);
4364b47e	392	}