Annotation of embedaddon/bird/proto/ospf/dbdes.c, revision 1.1.1.1

1.1       misho       1: /*
                      2:  *     BIRD -- OSPF
                      3:  *
                      4:  *     (c) 1999--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: struct ospf_dbdes2_packet
                     15: {
                     16:   struct ospf_packet hdr;
                     17:   union ospf_auth auth;
                     18: 
                     19:   u16 iface_mtu;
                     20:   u8 options;
                     21:   u8 imms;                     /* I, M, MS bits */
                     22:   u32 ddseq;
                     23: 
                     24:   struct ospf_lsa_header lsas[];
                     25: };
                     26: 
                     27: struct ospf_dbdes3_packet
                     28: {
                     29:   struct ospf_packet hdr;
                     30: 
                     31:   u32 options;
                     32:   u16 iface_mtu;
                     33:   u8 padding;
                     34:   u8 imms;                     /* I, M, MS bits */
                     35:   u32 ddseq;
                     36: 
                     37:   struct ospf_lsa_header lsas[];
                     38: };
                     39: 
                     40: 
                     41: static inline uint
                     42: ospf_dbdes_hdrlen(struct ospf_proto *p UNUSED4 UNUSED6)
                     43: {
                     44:   return ospf_is_v2(p) ?
                     45:     sizeof(struct ospf_dbdes2_packet) : sizeof(struct ospf_dbdes3_packet);
                     46: }
                     47: 
                     48: 
                     49: static void
                     50: ospf_dbdes_body(struct ospf_proto *p, struct ospf_packet *pkt,
                     51:                struct ospf_lsa_header **body, uint *count)
                     52: {
                     53:   uint plen = ntohs(pkt->length);
                     54:   uint hlen = ospf_dbdes_hdrlen(p);
                     55: 
                     56:   *body = ((void *) pkt) + hlen;
                     57:   *count = (plen - hlen) / sizeof(struct ospf_lsa_header);
                     58: }
                     59: 
                     60: static void
                     61: ospf_dump_dbdes(struct ospf_proto *p, struct ospf_packet *pkt)
                     62: {
                     63:   struct ospf_lsa_header *lsas;
                     64:   uint i, lsa_count;
                     65:   u32 pkt_ddseq;
                     66:   u16 pkt_iface_mtu;
                     67:   u8 pkt_imms;
                     68: 
                     69:   ASSERT(pkt->type == DBDES_P);
                     70:   ospf_dump_common(p, pkt);
                     71: 
                     72:   if (ospf_is_v2(p))
                     73:   {
                     74:     struct ospf_dbdes2_packet *ps = (void *) pkt;
                     75:     pkt_iface_mtu = ntohs(ps->iface_mtu);
                     76:     pkt_imms = ps->imms;
                     77:     pkt_ddseq = ntohl(ps->ddseq);
                     78:   }
                     79:   else /* OSPFv3 */
                     80:   {
                     81:     struct ospf_dbdes3_packet *ps = (void *) pkt;
                     82:     pkt_iface_mtu = ntohs(ps->iface_mtu);
                     83:     pkt_imms = ps->imms;
                     84:     pkt_ddseq = ntohl(ps->ddseq);
                     85:   }
                     86: 
                     87:   log(L_TRACE "%s:     mtu      %u", p->p.name, pkt_iface_mtu);
                     88:   log(L_TRACE "%s:     imms     %s%s%s", p->p.name,
                     89:       (pkt_imms & DBDES_I) ? "I " : "",
                     90:       (pkt_imms & DBDES_M) ? "M " : "",
                     91:       (pkt_imms & DBDES_MS) ? "MS" : "");
                     92:   log(L_TRACE "%s:     ddseq    %u", p->p.name, pkt_ddseq);
                     93: 
                     94:   ospf_dbdes_body(p, pkt, &lsas, &lsa_count);
                     95:   for (i = 0; i < lsa_count; i++)
                     96:     ospf_dump_lsahdr(p, lsas + i);
                     97: }
                     98: 
                     99: 
                    100: static void
                    101: ospf_prepare_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
                    102: {
                    103:   struct ospf_iface *ifa = n->ifa;
                    104:   struct ospf_packet *pkt;
                    105:   uint length;
                    106: 
                    107:   u16 iface_mtu = (ifa->type == OSPF_IT_VLINK) ? 0 : ifa->iface->mtu;
                    108: 
                    109:   /* Update DBDES buffer */
                    110:   if (n->ldd_bsize != ifa->tx_length)
                    111:   {
                    112:     mb_free(n->ldd_buffer);
                    113:     n->ldd_buffer = mb_allocz(n->pool, ifa->tx_length);
                    114:     n->ldd_bsize = ifa->tx_length;
                    115:   }
                    116: 
                    117:   pkt = n->ldd_buffer;
                    118:   ospf_pkt_fill_hdr(ifa, pkt, DBDES_P);
                    119: 
                    120:   if (ospf_is_v2(p))
                    121:   {
                    122:     struct ospf_dbdes2_packet *ps = (void *) pkt;
                    123:     ps->iface_mtu = htons(iface_mtu);
                    124:     ps->options = ifa->oa->options;
                    125:     ps->imms = 0;      /* Will be set later */
                    126:     ps->ddseq = htonl(n->dds);
                    127:     length = sizeof(struct ospf_dbdes2_packet);
                    128:   }
                    129:   else /* OSPFv3 */
                    130:   {
                    131:     struct ospf_dbdes3_packet *ps = (void *) pkt;
                    132:     ps->options = htonl(ifa->oa->options);
                    133:     ps->iface_mtu = htons(iface_mtu);
                    134:     ps->padding = 0;
                    135:     ps->imms = 0;      /* Will be set later */
                    136:     ps->ddseq = htonl(n->dds);
                    137:     length = sizeof(struct ospf_dbdes3_packet);
                    138:   }
                    139: 
                    140:   /* Prepare DBDES body */
                    141:   if (!(n->myimms & DBDES_I) && (n->myimms & DBDES_M))
                    142:   {
                    143:     struct ospf_lsa_header *lsas;
                    144:     struct top_hash_entry *en;
                    145:     uint i = 0, lsa_max;
                    146: 
                    147:     ospf_dbdes_body(p, pkt, &lsas, &lsa_max);
                    148:     en = (void *) s_get(&(n->dbsi));
                    149: 
                    150:     while (i < lsa_max)
                    151:     {
                    152:       if (!SNODE_VALID(en))
                    153:       {
                    154:        n->myimms &= ~DBDES_M;  /* Unset More bit */
                    155:        break;
                    156:       }
                    157: 
                    158:       if ((en->lsa.age < LSA_MAXAGE) &&
                    159:          lsa_flooding_allowed(en->lsa_type, en->domain, ifa))
                    160:       {
                    161:        lsa_hton_hdr(&(en->lsa), lsas + i);
                    162:        i++;
                    163:       }
                    164: 
                    165:       en = SNODE_NEXT(en);
                    166:     }
                    167: 
                    168:     s_put(&(n->dbsi), SNODE en);
                    169: 
                    170:     length += i * sizeof(struct ospf_lsa_header);
                    171:   }
                    172: 
                    173:   if (ospf_is_v2(p))
                    174:     ((struct ospf_dbdes2_packet *) pkt)->imms = n->myimms;
                    175:   else
                    176:     ((struct ospf_dbdes3_packet *) pkt)->imms = n->myimms;
                    177: 
                    178:   pkt->length = htons(length);
                    179: }
                    180: 
                    181: static void
                    182: ospf_do_send_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
                    183: {
                    184:   struct ospf_iface *ifa = n->ifa;
                    185: 
                    186:   OSPF_PACKET(ospf_dump_dbdes, n->ldd_buffer,
                    187:              "DBDES packet sent to nbr %R on %s", n->rid, ifa->ifname);
                    188:   sk_set_tbuf(ifa->sk, n->ldd_buffer);
                    189:   ospf_send_to(ifa, n->ip);
                    190:   sk_set_tbuf(ifa->sk, NULL);
                    191: }
                    192: 
                    193: /**
                    194:  * ospf_send_dbdes - transmit database description packet
                    195:  * @p: OSPF protocol instance
                    196:  * @n: neighbor
                    197:  *
                    198:  * Sending of a database description packet is described in 10.8 of RFC 2328.
                    199:  * Reception of each packet is acknowledged in the sequence number of another.
                    200:  * When I send a packet to a neighbor I keep a copy in a buffer. If the neighbor
                    201:  * does not reply, I don't create a new packet but just send the content
                    202:  * of the buffer.
                    203:  */
                    204: void
                    205: ospf_send_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
                    206: {
                    207:   /* RFC 2328 10.8 */
                    208: 
                    209:   ASSERT((n->state == NEIGHBOR_EXSTART) || (n->state == NEIGHBOR_EXCHANGE));
                    210: 
                    211:   if (n->ifa->oa->rt == NULL)
                    212:     return;
                    213: 
                    214:   ospf_prepare_dbdes(p, n);
                    215:   ospf_do_send_dbdes(p, n);
                    216: }
                    217: 
                    218: void
                    219: ospf_rxmt_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
                    220: {
                    221:   ASSERT(n->state > NEIGHBOR_EXSTART);
                    222: 
                    223:   if (!n->ldd_buffer)
                    224:   {
                    225:     log(L_WARN "%s: No DBDES packet for retransmit", p->p.name);
                    226:     ospf_neigh_sm(n, INM_SEQMIS);
                    227:     return;
                    228:   }
                    229: 
                    230:   /* Send last packet */
                    231:   ospf_do_send_dbdes(p, n);
                    232: }
                    233: 
                    234: static int
                    235: ospf_process_dbdes(struct ospf_proto *p, struct ospf_packet *pkt, struct ospf_neighbor *n)
                    236: {
                    237:   struct ospf_iface *ifa = n->ifa;
                    238:   struct ospf_lsa_header *lsas, lsa;
                    239:   struct top_hash_entry *en, *req;
                    240:   const char *err_dsc = NULL;
                    241:   u32 lsa_type, lsa_domain;
                    242:   uint i, lsa_count;
                    243: 
                    244:   ospf_dbdes_body(p, pkt, &lsas, &lsa_count);
                    245: 
                    246:   for (i = 0; i < lsa_count; i++)
                    247:   {
                    248:     lsa_ntoh_hdr(lsas + i, &lsa);
                    249:     lsa_get_type_domain(&lsa, ifa, &lsa_type, &lsa_domain);
                    250: 
                    251:     /* RFC 2328 10.6 and RFC 5340 4.2.2 */
                    252: 
                    253:     if (!lsa_type)
                    254:       DROP1("LSA of unknown type");
                    255: 
                    256:     if (!oa_is_ext(ifa->oa) && (LSA_SCOPE(lsa_type) == LSA_SCOPE_AS))
                    257:       DROP1("LSA with AS scope in stub area");
                    258: 
                    259:     /* Errata 3746 to RFC 2328 - rt-summary-LSAs forbidden in stub areas */
                    260:     if (!oa_is_ext(ifa->oa) && (lsa_type == LSA_T_SUM_RT))
                    261:       DROP1("rt-summary-LSA in stub area");
                    262: 
                    263:     /* Not explicitly mentioned in RFC 5340 4.2.2 but makes sense */
                    264:     if (LSA_SCOPE(lsa_type) == LSA_SCOPE_RES)
                    265:       DROP1("LSA with invalid scope");
                    266: 
                    267:     en = ospf_hash_find(p->gr, lsa_domain, lsa.id, lsa.rt, lsa_type);
                    268:     if (!en || (lsa_comp(&lsa, &(en->lsa)) == CMP_NEWER))
                    269:     {
                    270:       /* This should be splitted to ospf_lsa_lsrq_up() */
                    271:       req = ospf_hash_get(n->lsrqh, lsa_domain, lsa.id, lsa.rt, lsa_type);
                    272: 
                    273:       if (!SNODE_VALID(req))
                    274:        s_add_tail(&n->lsrql, SNODE req);
                    275: 
                    276:       if (!SNODE_VALID(n->lsrqi))
                    277:        n->lsrqi = req;
                    278: 
                    279:       req->lsa = lsa;
                    280:       req->lsa_body = LSA_BODY_DUMMY;
                    281: 
                    282:       if (!tm_active(n->lsrq_timer))
                    283:        tm_start(n->lsrq_timer, 0);
                    284:     }
                    285:   }
                    286: 
                    287:   return 0;
                    288: 
                    289: drop:
                    290:   LOG_LSA1("Bad LSA (Type: %04x, Id: %R, Rt: %R) in DBDES", lsa_type, lsa.id, lsa.rt);
                    291:   LOG_LSA2("  received from nbr %R on %s - %s", n->rid, ifa->ifname, err_dsc);
                    292: 
                    293:   ospf_neigh_sm(n, INM_SEQMIS);
                    294:   return -1;
                    295: }
                    296: 
                    297: void
                    298: ospf_receive_dbdes(struct ospf_packet *pkt, struct ospf_iface *ifa,
                    299:                   struct ospf_neighbor *n)
                    300: {
                    301:   struct ospf_proto *p = ifa->oa->po;
                    302:   const char *err_dsc = NULL;
                    303:   u32 rcv_ddseq, rcv_options;
                    304:   u16 rcv_iface_mtu;
                    305:   u8 rcv_imms;
                    306:   uint plen, err_val = 0;
                    307: 
                    308:   /* RFC 2328 10.6 */
                    309: 
                    310:   plen = ntohs(pkt->length);
                    311:   if (plen < ospf_dbdes_hdrlen(p))
                    312:   {
                    313:     LOG_PKT("Bad DBDES packet from nbr %R on %s - %s (%u)", n->rid, ifa->ifname, "too short", plen);
                    314:     return;
                    315:   }
                    316: 
                    317:   OSPF_PACKET(ospf_dump_dbdes, pkt, "DBDES packet received from nbr %R on %s", n->rid, ifa->ifname);
                    318: 
                    319:   ospf_neigh_sm(n, INM_HELLOREC);
                    320: 
                    321:   if (ospf_is_v2(p))
                    322:   {
                    323:     struct ospf_dbdes2_packet *ps = (void *) pkt;
                    324:     rcv_iface_mtu = ntohs(ps->iface_mtu);
                    325:     rcv_options = ps->options;
                    326:     rcv_imms = ps->imms;
                    327:     rcv_ddseq = ntohl(ps->ddseq);
                    328:   }
                    329:   else /* OSPFv3 */
                    330:   {
                    331:     struct ospf_dbdes3_packet *ps = (void *) pkt;
                    332:     rcv_options = ntohl(ps->options);
                    333:     rcv_iface_mtu = ntohs(ps->iface_mtu);
                    334:     rcv_imms = ps->imms;
                    335:     rcv_ddseq = ntohl(ps->ddseq);
                    336:   }
                    337: 
                    338:   switch (n->state)
                    339:   {
                    340:   case NEIGHBOR_DOWN:
                    341:   case NEIGHBOR_ATTEMPT:
                    342:   case NEIGHBOR_2WAY:
                    343:     OSPF_TRACE(D_PACKETS, "DBDES packet ignored - lesser state than ExStart");
                    344:     return;
                    345: 
                    346:   case NEIGHBOR_INIT:
                    347:     ospf_neigh_sm(n, INM_2WAYREC);
                    348:     if (n->state != NEIGHBOR_EXSTART)
                    349:       return;
                    350: 
                    351:   case NEIGHBOR_EXSTART:
                    352:     if ((ifa->type != OSPF_IT_VLINK) &&
                    353:        (rcv_iface_mtu != ifa->iface->mtu) &&
                    354:        (rcv_iface_mtu != 0) &&
                    355:        (ifa->iface->mtu != 0))
                    356:       LOG_PKT_WARN("MTU mismatch with nbr %R on %s (remote %d, local %d)",
                    357:                   n->rid, ifa->ifname, rcv_iface_mtu, ifa->iface->mtu);
                    358: 
                    359:     if ((rcv_imms == DBDES_IMMS) &&
                    360:        (n->rid > p->router_id) &&
                    361:        (plen == ospf_dbdes_hdrlen(p)))
                    362:     {
                    363:       /* I'm slave! */
                    364:       n->dds = rcv_ddseq;
                    365:       n->ddr = rcv_ddseq;
                    366:       n->options = rcv_options;
                    367:       n->myimms &= ~DBDES_MS;
                    368:       n->imms = rcv_imms;
                    369:       tm_stop(n->dbdes_timer);
                    370:       ospf_neigh_sm(n, INM_NEGDONE);
                    371:       ospf_send_dbdes(p, n);
                    372:       break;
                    373:     }
                    374: 
                    375:     if (!(rcv_imms & DBDES_I) &&
                    376:        !(rcv_imms & DBDES_MS) &&
                    377:        (n->rid < p->router_id) &&
                    378:        (n->dds == rcv_ddseq))
                    379:     {
                    380:       /* I'm master! */
                    381:       n->options = rcv_options;
                    382:       n->ddr = rcv_ddseq - 1;  /* It will be set corectly a few lines down */
                    383:       n->imms = rcv_imms;
                    384:       ospf_neigh_sm(n, INM_NEGDONE);
                    385:       /* Continue to the NEIGHBOR_EXCHANGE case */
                    386:     }
                    387:     else
                    388:     {
                    389:       DBG("%s: Nothing happend to %I (imms=%d)\n", p->name, n->ip, rcv_imms);
                    390:       break;
                    391:     }
                    392: 
                    393:   case NEIGHBOR_EXCHANGE:
                    394:     if ((rcv_imms == n->imms) &&
                    395:        (rcv_options == n->options) &&
                    396:        (rcv_ddseq == n->ddr))
                    397:       goto duplicate;
                    398: 
                    399:     if ((rcv_imms & DBDES_MS) != (n->imms & DBDES_MS))
                    400:       DROP("MS-bit mismatch", rcv_imms);
                    401: 
                    402:     if (rcv_imms & DBDES_I)
                    403:       DROP("I-bit mismatch", rcv_imms);
                    404: 
                    405:     if (rcv_options != n->options)
                    406:       DROP("options mismatch", rcv_options);
                    407: 
                    408:     n->ddr = rcv_ddseq;
                    409:     n->imms = rcv_imms;
                    410: 
                    411:     if (n->myimms & DBDES_MS)
                    412:     {
                    413:       /* MASTER */
                    414: 
                    415:       if (rcv_ddseq != n->dds)
                    416:        DROP("DD sequence number mismatch", rcv_ddseq);
                    417: 
                    418:       n->dds++;
                    419: 
                    420:       if (ospf_process_dbdes(p, pkt, n) < 0)
                    421:        return;
                    422: 
                    423:       if (!(n->myimms & DBDES_M) && !(n->imms & DBDES_M))
                    424:       {
                    425:        tm_stop(n->dbdes_timer);
                    426:        ospf_neigh_sm(n, INM_EXDONE);
                    427:        break;
                    428:       }
                    429: 
                    430:       ospf_send_dbdes(p, n);
                    431:       tm_start(n->dbdes_timer, n->ifa->rxmtint);
                    432:     }
                    433:     else
                    434:     {
                    435:       /* SLAVE */
                    436: 
                    437:       if (rcv_ddseq != (n->dds + 1))
                    438:        DROP("DD sequence number mismatch", rcv_ddseq);
                    439: 
                    440:       n->ddr = rcv_ddseq;
                    441:       n->dds = rcv_ddseq;
                    442: 
                    443:       if (ospf_process_dbdes(p, pkt, n) < 0)
                    444:        return;
                    445: 
                    446:       ospf_send_dbdes(p, n);
                    447: 
                    448:       if (!(n->myimms & DBDES_M) && !(n->imms & DBDES_M))
                    449:        ospf_neigh_sm(n, INM_EXDONE);
                    450:     }
                    451:     break;
                    452: 
                    453:   case NEIGHBOR_LOADING:
                    454:   case NEIGHBOR_FULL:
                    455:     if ((rcv_imms == n->imms) &&
                    456:        (rcv_options == n->options) &&
                    457:        (rcv_ddseq == n->ddr))
                    458:       goto duplicate;
                    459: 
                    460:     DROP("too late for DD exchange", n->state);
                    461: 
                    462:   default:
                    463:     bug("Undefined interface state");
                    464:   }
                    465:   return;
                    466: 
                    467: duplicate:
                    468:   OSPF_TRACE(D_PACKETS, "DBDES packet is duplicate");
                    469: 
                    470:   /* Slave should retransmit DBDES packet */
                    471:   if (!(n->myimms & DBDES_MS))
                    472:     ospf_rxmt_dbdes(p, n);
                    473:   return;
                    474: 
                    475: drop:
                    476:   LOG_PKT("Bad DBDES packet from nbr %R on %s - %s (%u)",
                    477:          n->rid, ifa->ifname, err_dsc, err_val);
                    478: 
                    479:   ospf_neigh_sm(n, INM_SEQMIS);
                    480:   return;
                    481: }

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