mirror of
https://gitlab.nic.cz/labs/bird.git
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366 lines
8.1 KiB
C
366 lines
8.1 KiB
C
/*
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* BIRD -- OSPF
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*
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* (c) 1999--2004 Ondrej Filip <feela@network.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*/
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#include "ospf.h"
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#ifdef OSPFv2
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struct ospf_hello_packet
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{
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struct ospf_packet ospf_packet;
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ip_addr netmask;
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u16 helloint;
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u8 options;
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u8 priority;
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u32 deadint;
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u32 dr;
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u32 bdr;
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};
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#endif
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#ifdef OSPFv3
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struct ospf_hello_packet
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{
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struct ospf_packet ospf_packet;
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u32 iface_id;
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u8 priority;
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u8 options3;
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u8 options2;
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u8 options;
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u16 helloint;
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u16 deadint;
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u32 dr;
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u32 bdr;
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};
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#endif
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void
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ospf_hello_receive(struct ospf_packet *ps_i, struct ospf_iface *ifa,
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struct ospf_neighbor *n, ip_addr faddr)
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{
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struct proto_ospf *po = ifa->oa->po;
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struct proto *p = &po->proto;
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char *beg = "OSPF: Bad HELLO packet from ";
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unsigned int size, i, twoway, eligible, peers;
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u32 tmp;
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u32 *pnrid;
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size = ntohs(ps_i->length);
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if (size < sizeof(struct ospf_hello_packet))
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{
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log(L_ERR "%s%I - too short (%u B)", beg, faddr, size);
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return;
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}
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struct ospf_hello_packet *ps = (void *) ps_i;
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OSPF_TRACE(D_PACKETS, "HELLO packet received from %I via %s%s", faddr,
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(ifa->type == OSPF_IT_VLINK ? "vlink-" : ""), ifa->iface->name);
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#ifdef OSPFv2
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ip_addr mask = ps->netmask;
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ipa_ntoh(mask);
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if ((ifa->type != OSPF_IT_VLINK) &&
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(ifa->type != OSPF_IT_PTP) &&
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!ipa_equal(mask, ipa_mkmask(ifa->addr->pxlen)))
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{
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log(L_ERR "%s%I - netmask mismatch (%I)", beg, faddr, mask);
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return;
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}
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#endif
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tmp = ntohs(ps->helloint);
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if (tmp != ifa->helloint)
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{
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log(L_ERR "%s%I - hello interval mismatch (%d)", beg, faddr, tmp);
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return;
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}
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#ifdef OSPFv2
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tmp = ntohl(ps->deadint);
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#else /* OSPFv3 */
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tmp = ntohs(ps->deadint);
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#endif
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if (tmp != ifa->dead)
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{
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log(L_ERR "%s%I - dead interval mismatch (%d)", beg, faddr, tmp);
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return;
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}
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tmp = !(ps->options & OPT_E);
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if (tmp != ifa->oa->stub)
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{
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log(L_ERR "%s%I - stub area flag mismatch (%d)", beg, faddr, tmp);
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return;
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}
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if (!n)
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{
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if ((ifa->type == OSPF_IT_NBMA))
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{
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struct nbma_node *nn;
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int found = 0;
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WALK_LIST(nn, ifa->nbma_list)
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{
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if (ipa_equal(faddr, nn->ip))
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{
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found = 1;
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break;
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}
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}
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if ((found == 0) && (ifa->strictnbma))
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{
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log(L_WARN "Ignoring new neighbor: %I on %s", faddr,
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ifa->iface->name);
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return;
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}
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if (found)
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{
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eligible = nn->eligible;
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if (((ps->priority == 0) && eligible)
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|| ((ps->priority > 0) && (eligible == 0)))
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{
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log(L_ERR "Eligibility mismatch for neighbor: %I on %s",
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faddr, ifa->iface->name);
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return;
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}
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}
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}
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OSPF_TRACE(D_EVENTS, "New neighbor found: %I on %s", faddr,
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ifa->iface->name);
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n = ospf_neighbor_new(ifa);
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n->rid = ntohl(((struct ospf_packet *) ps)->routerid);
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n->ip = faddr;
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n->dr = ntohl(ps->dr);
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n->bdr = ntohl(ps->bdr);
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n->priority = ps->priority;
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#ifdef OSPFv3
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n->iface_id = ntohl(ps->iface_id);
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#endif
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}
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ospf_neigh_sm(n, INM_HELLOREC);
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pnrid = (u32 *) ((struct ospf_hello_packet *) (ps + 1));
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peers = (size - sizeof(struct ospf_hello_packet))/ sizeof(u32);
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twoway = 0;
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for (i = 0; i < peers; i++)
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{
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if (ntohl(pnrid[i]) == po->router_id)
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{
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DBG("%s: Twoway received from %I\n", p->name, faddr);
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ospf_neigh_sm(n, INM_2WAYREC);
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twoway = 1;
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break;
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}
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}
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if (!twoway)
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ospf_neigh_sm(n, INM_1WAYREC);
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u32 olddr = n->dr;
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u32 oldbdr = n->bdr;
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u32 oldpriority = n->priority;
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#ifdef OSPFv3
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u32 oldiface_id = n->iface_id;
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#endif
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n->dr = ntohl(ps->dr);
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n->bdr = ntohl(ps->bdr);
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n->priority = ps->priority;
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#ifdef OSPFv3
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n->iface_id = ntohl(ps->iface_id);
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#endif
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/* Check priority change */
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if (n->state >= NEIGHBOR_2WAY)
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{
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#ifdef OSPFv2
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u32 neigh = ipa_to_u32(n->ip);
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#else /* OSPFv3 */
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u32 neigh = n->rid;
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#endif
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if (n->priority != oldpriority)
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ospf_iface_sm(ifa, ISM_NEICH);
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#ifdef OSPFv3
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if (n->iface_id != oldiface_id)
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ospf_iface_sm(ifa, ISM_NEICH);
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#endif
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/* Neighbor is declaring itself ad DR and there is no BDR */
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if ((n->dr == neigh) && (n->bdr == 0)
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&& (n->state != NEIGHBOR_FULL))
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ospf_iface_sm(ifa, ISM_BACKS);
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/* Neighbor is declaring itself as BDR */
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if ((n->bdr == neigh) && (n->state != NEIGHBOR_FULL))
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ospf_iface_sm(ifa, ISM_BACKS);
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/* Neighbor is newly declaring itself as DR or BDR */
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if (((n->dr == neigh) && (n->dr != olddr))
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|| ((n->bdr == neigh) && (n->bdr != oldbdr)))
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ospf_iface_sm(ifa, ISM_NEICH);
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/* Neighbor is no more declaring itself as DR or BDR */
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if (((olddr == neigh) && (n->dr != olddr))
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|| ((oldbdr == neigh) && (n->bdr != oldbdr)))
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ospf_iface_sm(ifa, ISM_NEICH);
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}
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if (ifa->type == OSPF_IT_NBMA)
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{
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if ((ifa->priority == 0) && (n->priority > 0))
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ospf_hello_send(NULL, 0, n);
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}
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ospf_neigh_sm(n, INM_HELLOREC);
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}
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void
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ospf_hello_send(timer *timer, int poll, struct ospf_neighbor *dirn)
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{
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struct ospf_iface *ifa;
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struct ospf_hello_packet *pkt;
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struct ospf_packet *op;
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struct proto *p;
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struct ospf_neighbor *neigh, *n1;
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u16 length;
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u32 *pp;
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int i, send;
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struct nbma_node *nb;
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if (timer == NULL)
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ifa = dirn->ifa;
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else
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ifa = (struct ospf_iface *) timer->data;
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if (ifa->state == OSPF_IS_DOWN)
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return;
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if (ifa->stub)
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return; /* Don't send any packet on stub iface */
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p = (struct proto *) (ifa->oa->po);
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DBG("%s: Hello/Poll timer fired on interface %s with IP %I\n",
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p->name, ifa->iface->name, ifa->addr->ip);
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/* Now we should send a hello packet */
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pkt = ospf_tx_buffer(ifa);
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op = &pkt->ospf_packet;
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/* Now fill ospf_hello header */
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ospf_pkt_fill_hdr(ifa, pkt, HELLO_P);
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#ifdef OSPFv2
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pkt->netmask = ipa_mkmask(ifa->addr->pxlen);
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ipa_hton(pkt->netmask);
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if ((ifa->type == OSPF_IT_VLINK) || (ifa->type == OSPF_IT_PTP))
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pkt->netmask = IPA_NONE;
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#endif
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pkt->helloint = ntohs(ifa->helloint);
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pkt->priority = ifa->priority;
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#ifdef OSPFv3
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pkt->iface_id = htonl(ifa->iface->index);
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pkt->options3 = ifa->oa->options >> 16;
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pkt->options2 = ifa->oa->options >> 8;
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#endif
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pkt->options = ifa->oa->options;
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#ifdef OSPFv2
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pkt->deadint = htonl(ifa->dead);
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pkt->dr = htonl(ipa_to_u32(ifa->drip));
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pkt->bdr = htonl(ipa_to_u32(ifa->bdrip));
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#else /* OSPFv3 */
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pkt->deadint = htons(ifa->dead);
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pkt->dr = htonl(ifa->drid);
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pkt->bdr = htonl(ifa->bdrid);
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#endif
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/* Fill all neighbors */
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i = 0;
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pp = (u32 *) (((u8 *) pkt) + sizeof(struct ospf_hello_packet));
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WALK_LIST(neigh, ifa->neigh_list)
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{
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if ((i+1) * sizeof(u32) + sizeof(struct ospf_hello_packet) > ospf_pkt_maxsize(ifa))
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{
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OSPF_TRACE(D_PACKETS, "Too many neighbors on the interface!");
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break;
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}
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*(pp + i) = htonl(neigh->rid);
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i++;
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}
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length = sizeof(struct ospf_hello_packet) + i * sizeof(u32);
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op->length = htons(length);
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switch(ifa->type)
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{
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case OSPF_IT_NBMA:
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if (timer == NULL) /* Response to received hello */
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{
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ospf_send_to(ifa, dirn->ip);
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}
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else
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{
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int toall = 0;
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int meeli = 0;
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if (ifa->state > OSPF_IS_DROTHER)
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toall = 1;
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if (ifa->priority > 0)
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meeli = 1;
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WALK_LIST(nb, ifa->nbma_list)
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{
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send = 1;
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WALK_LIST(n1, ifa->neigh_list)
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{
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if (ipa_equal(nb->ip, n1->ip))
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{
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send = 0;
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break;
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}
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}
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if ((poll == 1) && (send))
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{
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if (toall || (meeli && nb->eligible))
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ospf_send_to(ifa, nb->ip);
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}
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}
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if (poll == 0)
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{
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WALK_LIST(n1, ifa->neigh_list)
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{
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if (toall || (n1->rid == ifa->drid) || (n1->rid == ifa->bdrid) ||
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(meeli && (n1->priority > 0)))
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ospf_send_to(ifa, n1->ip);
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}
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}
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}
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break;
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case OSPF_IT_VLINK:
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ospf_send_to(ifa, ifa->vip);
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break;
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default:
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ospf_send_to(ifa, AllSPFRouters);
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}
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OSPF_TRACE(D_PACKETS, "HELLO packet sent via %s%s",
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(ifa->type == OSPF_IT_VLINK ? "vlink-" : ""), ifa->iface->name);
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}
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