proto/ospf/lsreq.c

   1 /*
   2  *      BIRD -- OSPF
   3  *
   4  *      (c) 2000--2004 Ondrej Filip <feela@network.cz>
   5  *      (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
   6  *      (c) 2009--2014 CZ.NIC z.s.p.o.
   7  *
   8  *      Can be freely distributed and used under the terms of the GNU GPL.
   9  */
  10
  11 #include "ospf.h"
  12
  13
  14 /*
  15 struct ospf_lsreq_packet
  16 {
  17   struct ospf_packet hdr;
  18   // union ospf_auth auth;
  19
  20   struct ospf_lsreq_header lsrs[];
  21 };
  22 */
  23
  24
  25 static inline void
  26 ospf_lsreq_body(struct ospf_proto *p, struct ospf_packet *pkt,
  27                 struct ospf_lsreq_header **body, uint *count)
  28 {
  29   uint plen = ntohs(pkt->length);
  30   uint hlen = ospf_pkt_hdrlen(p);
  31
  32   *body = ((void *) pkt) + hlen;
  33   *count = (plen - hlen) / sizeof(struct ospf_lsreq_header);
  34 }
  35
  36 static void
  37 ospf_dump_lsreq(struct ospf_proto *p, struct ospf_packet *pkt)
  38 {
  39   struct ospf_lsreq_header *lsrs;
  40   uint i, lsr_count;
  41
  42   ASSERT(pkt->type == LSREQ_P);
  43   ospf_dump_common(p, pkt);
  44
  45   ospf_lsreq_body(p, pkt, &lsrs, &lsr_count);
  46   for (i = 0; i < lsr_count; i++)
  47     log(L_TRACE "%s:     LSR      Type: %04x, Id: %R, Rt: %R", p->p.name,
  48         ntohl(lsrs[i].type), ntohl(lsrs[i].id), ntohl(lsrs[i].rt));
  49 }
  50
  51
  52 void
  53 ospf_send_lsreq(struct ospf_proto *p, struct ospf_neighbor *n)
  54 {
  55   struct ospf_iface *ifa = n->ifa;
  56   struct ospf_lsreq_header *lsrs;
  57   struct top_hash_entry *en;
  58   struct ospf_packet *pkt;
  59   uint i, lsr_max, length;
  60
  61   /* RFC 2328 10.9 */
  62
  63   if (EMPTY_SLIST(n->lsrql))
  64   {
  65     if (n->state == NEIGHBOR_LOADING)
  66       ospf_neigh_sm(n, INM_LOADDONE);
  67     return;
  68   }
  69
  70   pkt = ospf_tx_buffer(ifa);
  71   ospf_pkt_fill_hdr(ifa, pkt, LSREQ_P);
  72   ospf_lsreq_body(p, pkt, &lsrs, &lsr_max);
  73
  74   /* We send smaller LSREQ to prevent multiple LSACKs as answer */
  75   lsr_max = lsr_max / 4;
  76
  77   i = 0;
  78   WALK_SLIST(en, n->lsrql)
  79   {
  80     if (i == lsr_max)
  81       break;
  82
  83     DBG("Requesting %uth LSA: Type: %04u, ID: %R, RT: %R, SN: 0x%x, Age %u\n",
  84         i, en->lsa_type, en->lsa.id, en->lsa.rt, en->lsa.sn, en->lsa.age);
  85
  86     u32 etype = lsa_get_etype(&en->lsa, p);
  87     lsrs[i].type = htonl(etype);
  88     lsrs[i].rt = htonl(en->lsa.rt);
  89     lsrs[i].id = htonl(en->lsa.id);
  90     i++;
  91   }
  92
  93   length = ospf_pkt_hdrlen(p) + i * sizeof(struct ospf_lsreq_header);
  94   pkt->length = htons(length);
  95
  96   OSPF_PACKET(ospf_dump_lsreq, pkt, "LSREQ packet sent to %I via %s", n->ip, ifa->ifname);
  97   ospf_send_to(ifa, n->ip);
  98 }
  99
 100
 101 void
 102 ospf_receive_lsreq(struct ospf_packet *pkt, struct ospf_iface *ifa,
 103                    struct ospf_neighbor *n)
 104 {
 105   struct ospf_proto *p = ifa->oa->po;
 106   struct ospf_lsreq_header *lsrs;
 107   uint i, lsr_count;
 108
 109   /* RFC 2328 10.7 */
 110
 111   /* No need to check length, lsreq has only basic header */
 112
 113   OSPF_PACKET(ospf_dump_lsreq, pkt, "LSREQ packet received from %I via %s", n->ip, ifa->ifname);
 114
 115   if (n->state < NEIGHBOR_EXCHANGE)
 116     return;
 117
 118   ospf_neigh_sm(n, INM_HELLOREC);       /* Not in RFC */
 119
 120   ospf_lsreq_body(p, pkt, &lsrs, &lsr_count);
 121
 122   struct top_hash_entry *en, *entries[lsr_count];
 123
 124   for (i = 0; i < lsr_count; i++)
 125   {
 126     u32 id, rt, type, domain;
 127
 128     id = ntohl(lsrs[i].id);
 129     rt = ntohl(lsrs[i].rt);
 130     lsa_get_type_domain_(ntohl(lsrs[i].type), ifa, &type, &domain);
 131
 132     DBG("Processing requested LSA: Type: %04x, Id: %R, Rt: %R\n", type, id, rt);
 133
 134     en = ospf_hash_find(p->gr, domain, id, rt, type);
 135     if (!en)
 136     {
 137       log(L_WARN "%s: Received LSREQ from %I for missing LSA (Type: %04x, Id: %R, Rt: %R)",
 138           p->p.name, n->ip, type, id, rt);
 139       ospf_neigh_sm(n, INM_BADLSREQ);
 140       return;
 141     }
 142
 143     entries[i] = en;
 144   }
 145
 146   ospf_send_lsupd(p, entries, lsr_count, n);
 147 }