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https://gitlab.nic.cz/labs/bird.git
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1aec7112f7
Per RFC 3101, N-bit signalling NSSA support should be used only in Hello packets, not in DBDES packets. BIRD since 2.0.4 verifies N-bit in neighbor structure, which is learned from DBDES packets, therefore NSSA-LSAs are not propagated to proper implementations of RFC 3101. This patch fixes that. Both removing the check and removing N-bit from DBDES packet. This will fix compatibility issues with proper implementations, but causes compatibility issues with BIRD 2.0.4.
402 lines
9.8 KiB
C
402 lines
9.8 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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* (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
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* (c) 2009--2014 CZ.NIC z.s.p.o.
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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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struct ospf_hello2_packet
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{
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struct ospf_packet hdr;
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union ospf_auth2 auth;
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u32 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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u32 neighbors[];
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};
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struct ospf_hello3_packet
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{
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struct ospf_packet hdr;
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u32 iface_id;
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u32 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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u32 neighbors[];
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};
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uint
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ospf_hello3_options(struct ospf_packet *pkt)
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{
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struct ospf_hello3_packet *ps = (void *) pkt;
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return ntohl(ps->options) & 0x00FFFFFF;
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}
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void
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ospf_send_hello(struct ospf_iface *ifa, int kind, struct ospf_neighbor *dirn)
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{
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struct ospf_proto *p = ifa->oa->po;
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struct ospf_packet *pkt;
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struct ospf_neighbor *neigh, *n1;
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struct nbma_node *nb;
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u32 *neighbors;
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uint length;
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int i, max;
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if (ifa->state <= OSPF_IS_LOOP)
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return;
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if (ifa->stub)
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return;
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pkt = ospf_tx_buffer(ifa);
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ospf_pkt_fill_hdr(ifa, pkt, HELLO_P);
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if (ospf_is_v2(p))
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{
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struct ospf_hello2_packet *ps = (void *) pkt;
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if ((ifa->type == OSPF_IT_VLINK) ||
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((ifa->type == OSPF_IT_PTP) && !ifa->ptp_netmask))
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ps->netmask = 0;
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else
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ps->netmask = htonl(u32_mkmask(ifa->addr->prefix.pxlen));
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ps->helloint = ntohs(ifa->helloint);
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ps->options = ifa->oa->options & HELLO2_OPT_MASK;
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ps->priority = ifa->priority;
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ps->deadint = htonl(ifa->deadint);
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ps->dr = htonl(ipa_to_u32(ifa->drip));
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ps->bdr = htonl(ipa_to_u32(ifa->bdrip));
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length = sizeof(struct ospf_hello2_packet);
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neighbors = ps->neighbors;
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}
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else
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{
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struct ospf_hello3_packet *ps = (void *) pkt;
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u32 options = ifa->oa->options | (ifa->autype == OSPF_AUTH_CRYPT ? OPT_AT : 0);
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ps->iface_id = htonl(ifa->iface_id);
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ps->options = ntohl((options & HELLO3_OPT_MASK) | (ifa->priority << 24));
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ps->helloint = ntohs(ifa->helloint);
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ps->deadint = htons(ifa->deadint);
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ps->dr = htonl(ifa->drid);
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ps->bdr = htonl(ifa->bdrid);
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length = sizeof(struct ospf_hello3_packet);
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neighbors = ps->neighbors;
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}
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i = 0;
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max = (ospf_pkt_maxsize(ifa) - length) / sizeof(u32);
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/* Fill all neighbors */
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if (kind != OHS_SHUTDOWN)
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{
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WALK_LIST(neigh, ifa->neigh_list)
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{
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if (i == max)
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{
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log(L_WARN "%s: Too many neighbors on %s", p->p.name, ifa->ifname);
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break;
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}
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neighbors[i] = htonl(neigh->rid);
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i++;
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}
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}
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length += i * sizeof(u32);
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pkt->length = htons(length);
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OSPF_TRACE(D_PACKETS, "HELLO packet sent via %s", ifa->ifname);
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switch(ifa->type)
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{
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case OSPF_IT_BCAST:
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case OSPF_IT_PTP:
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ospf_send_to_all(ifa);
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break;
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case OSPF_IT_NBMA:
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if (dirn) /* Response to received hello */
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{
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ospf_send_to(ifa, dirn->ip);
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break;
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}
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int to_all = ifa->state > OSPF_IS_DROTHER;
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int me_elig = ifa->priority > 0;
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if (kind == OHS_POLL) /* Poll timer */
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{
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WALK_LIST(nb, ifa->nbma_list)
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if (!nb->found && (to_all || (me_elig && nb->eligible)))
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ospf_send_to(ifa, nb->ip);
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}
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else /* Hello timer */
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{
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WALK_LIST(n1, ifa->neigh_list)
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if (to_all || (me_elig && (n1->priority > 0)) ||
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(n1->rid == ifa->drid) || (n1->rid == ifa->bdrid))
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ospf_send_to(ifa, n1->ip);
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}
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break;
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case OSPF_IT_PTMP:
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WALK_LIST(n1, ifa->neigh_list)
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ospf_send_to(ifa, n1->ip);
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WALK_LIST(nb, ifa->nbma_list)
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if (!nb->found)
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ospf_send_to(ifa, nb->ip);
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/* If there is no other target, we also send HELLO packet to the other end */
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if (ipa_nonzero(ifa->addr->opposite) && !ifa->strictnbma &&
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EMPTY_LIST(ifa->neigh_list) && EMPTY_LIST(ifa->nbma_list))
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ospf_send_to(ifa, ifa->addr->opposite);
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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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bug("Bug in ospf_send_hello()");
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}
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}
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void
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ospf_receive_hello(struct ospf_packet *pkt, struct ospf_iface *ifa,
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struct ospf_neighbor *n, ip_addr faddr)
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{
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struct ospf_proto *p = ifa->oa->po;
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const char *err_dsc = NULL;
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u32 rcv_iface_id, rcv_helloint, rcv_deadint, rcv_dr, rcv_bdr;
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uint rcv_options, rcv_priority;
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uint loc_options = ifa->oa->options;
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u32 *neighbors;
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u32 neigh_count;
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uint plen, i, err_val = 0;
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/* RFC 2328 10.5 */
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/*
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* We may not yet have the associate neighbor, so we use Router ID from the
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* packet instead of one from the neighbor structure for log messages.
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*/
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u32 rcv_rid = ntohl(pkt->routerid);
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OSPF_TRACE(D_PACKETS, "HELLO packet received from nbr %R on %s", rcv_rid, ifa->ifname);
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plen = ntohs(pkt->length);
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if (ospf_is_v2(p))
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{
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struct ospf_hello2_packet *ps = (void *) pkt;
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if (plen < sizeof(struct ospf_hello2_packet))
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DROP("too short", plen);
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rcv_iface_id = 0;
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rcv_helloint = ntohs(ps->helloint);
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rcv_deadint = ntohl(ps->deadint);
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rcv_dr = ntohl(ps->dr);
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rcv_bdr = ntohl(ps->bdr);
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rcv_options = ps->options;
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rcv_priority = ps->priority;
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int pxlen = u32_masklen(ntohl(ps->netmask));
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if (pxlen < 0)
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DROP("prefix garbled", ntohl(ps->netmask));
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if ((ifa->type != OSPF_IT_VLINK) &&
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(ifa->type != OSPF_IT_PTP) &&
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((uint) pxlen != ifa->addr->prefix.pxlen))
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DROP("prefix length mismatch", pxlen);
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neighbors = ps->neighbors;
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neigh_count = (plen - sizeof(struct ospf_hello2_packet)) / sizeof(u32);
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}
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else /* OSPFv3 */
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{
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struct ospf_hello3_packet *ps = (void *) pkt;
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if (plen < sizeof(struct ospf_hello3_packet))
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DROP("too short", plen);
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rcv_iface_id = ntohl(ps->iface_id);
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rcv_helloint = ntohs(ps->helloint);
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rcv_deadint = ntohs(ps->deadint);
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rcv_dr = ntohl(ps->dr);
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rcv_bdr = ntohl(ps->bdr);
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rcv_options = ntohl(ps->options) & 0x00FFFFFF;
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rcv_priority = ntohl(ps->options) >> 24;
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neighbors = ps->neighbors;
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neigh_count = (plen - sizeof(struct ospf_hello3_packet)) / sizeof(u32);
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}
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if (rcv_helloint != ifa->helloint)
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DROP("hello interval mismatch", rcv_helloint);
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if (rcv_deadint != ifa->deadint)
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DROP("dead interval mismatch", rcv_deadint);
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/* Check whether bits E, N match */
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if ((rcv_options ^ loc_options) & (OPT_E | OPT_N))
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DROP("area type mismatch", rcv_options);
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/* RFC 5838 2.4 - AF-bit check unless on IPv6 unicast */
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if ((loc_options & OPT_AF) && !(loc_options & OPT_V6) && !(rcv_options & OPT_AF))
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DROP("AF-bit mismatch", rcv_options);
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/* Check consistency of existing neighbor entry */
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if (n)
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{
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uint t = ifa->type;
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if (ospf_is_v2(p) && ((t == OSPF_IT_BCAST) || (t == OSPF_IT_NBMA) || (t == OSPF_IT_PTMP)))
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{
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/* Neighbor identified by IP address; Router ID may change */
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if (n->rid != rcv_rid)
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{
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OSPF_TRACE(D_EVENTS, "Neighbor %R on %s changed Router ID to %R",
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n->rid, ifa->ifname, rcv_rid);
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ospf_neigh_sm(n, INM_KILLNBR);
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n = NULL;
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}
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}
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else /* OSPFv3 or OSPFv2/PtP */
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{
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/* Neighbor identified by Router ID; IP address may change */
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if (!ipa_equal(faddr, n->ip))
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{
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OSPF_TRACE(D_EVENTS, "Neighbor %R on %s changed IP address to %I",
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n->rid, ifa->ifname, faddr);
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n->ip = faddr;
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}
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}
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}
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if (!n)
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{
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if ((ifa->type == OSPF_IT_NBMA) || (ifa->type == OSPF_IT_PTMP))
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{
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struct nbma_node *nn = find_nbma_node(ifa, faddr);
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if (!nn && ifa->strictnbma)
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DROP1("new neighbor denied");
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if (nn && (ifa->type == OSPF_IT_NBMA) &&
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(((rcv_priority == 0) && nn->eligible) ||
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((rcv_priority > 0) && !nn->eligible)))
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DROP("eligibility mismatch", rcv_priority);
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if (nn)
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nn->found = 1;
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}
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OSPF_TRACE(D_EVENTS, "New neighbor %R on %s, IP address %I",
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rcv_rid, ifa->ifname, faddr);
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n = ospf_neighbor_new(ifa);
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n->rid = rcv_rid;
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n->ip = faddr;
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n->dr = rcv_dr;
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n->bdr = rcv_bdr;
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n->priority = rcv_priority;
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n->iface_id = rcv_iface_id;
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if (n->ifa->cf->bfd)
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ospf_neigh_update_bfd(n, n->ifa->bfd);
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}
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u32 n_id = ospf_is_v2(p) ? ipa_to_u32(n->ip) : n->rid;
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u32 old_dr = n->dr;
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u32 old_bdr = n->bdr;
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u32 old_priority = n->priority;
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u32 old_iface_id = n->iface_id;
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n->dr = rcv_dr;
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n->bdr = rcv_bdr;
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n->priority = rcv_priority;
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n->iface_id = rcv_iface_id;
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/* Update inactivity timer */
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ospf_neigh_sm(n, INM_HELLOREC);
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/* RFC 2328 9.5.1 - non-eligible routers reply to hello on NBMA nets */
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if (ifa->type == OSPF_IT_NBMA)
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if ((ifa->priority == 0) && (n->priority > 0))
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ospf_send_hello(n->ifa, OHS_HELLO, n);
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/* Examine list of neighbors */
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for (i = 0; i < neigh_count; i++)
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if (neighbors[i] == htonl(p->router_id))
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goto found_self;
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ospf_neigh_sm(n, INM_1WAYREC);
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return;
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found_self:
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ospf_neigh_sm(n, INM_2WAYREC);
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if (n->iface_id != old_iface_id)
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{
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/* If neighbor is DR, also update cached DR interface ID */
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if (ifa->drid == n->rid)
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ifa->dr_iface_id = n->iface_id;
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/* RFC 5340 4.4.3 Event 4 - change of neighbor's interface ID */
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ospf_notify_rt_lsa(ifa->oa);
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/* Missed in RFC 5340 4.4.3 Event 4 - (Px-)Net-LSA uses iface_id to ref Link-LSAs */
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ospf_notify_net_lsa(ifa);
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}
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if (ifa->state == OSPF_IS_WAITING)
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{
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/* Neighbor is declaring itself DR (and there is no BDR) or as BDR */
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if (((n->dr == n_id) && (n->bdr == 0)) || (n->bdr == n_id))
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ospf_iface_sm(ifa, ISM_BACKS);
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}
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else if (ifa->state >= OSPF_IS_DROTHER)
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{
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/* Neighbor changed priority or started/stopped declaring itself as DR/BDR */
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if ((n->priority != old_priority) ||
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((n->dr == n_id) && (old_dr != n_id)) ||
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((n->dr != n_id) && (old_dr == n_id)) ||
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((n->bdr == n_id) && (old_bdr != n_id)) ||
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((n->bdr != n_id) && (old_bdr == n_id)))
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ospf_iface_sm(ifa, ISM_NEICH);
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}
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return;
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drop:
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LOG_PKT("Bad HELLO packet from nbr %R on %s - %s (%u)",
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rcv_rid, ifa->ifname, err_dsc, err_val);
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}
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