Annotation of embedaddon/quagga/bgpd/bgp_network.c, revision 1.1.1.4

1.1       misho       1: /* BGP network related fucntions
                      2:    Copyright (C) 1999 Kunihiro Ishiguro
                      3: 
                      4: This file is part of GNU Zebra.
                      5: 
                      6: GNU Zebra is free software; you can redistribute it and/or modify it
                      7: under the terms of the GNU General Public License as published by the
                      8: Free Software Foundation; either version 2, or (at your option) any
                      9: later version.
                     10: 
                     11: GNU Zebra is distributed in the hope that it will be useful, but
                     12: WITHOUT ANY WARRANTY; without even the implied warranty of
                     13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
                     14: General Public License for more details.
                     15: 
                     16: You should have received a copy of the GNU General Public License
                     17: along with GNU Zebra; see the file COPYING.  If not, write to the Free
                     18: Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
                     19: 02111-1307, USA.  */
                     20: 
                     21: #include <zebra.h>
                     22: 
                     23: #include "thread.h"
                     24: #include "sockunion.h"
                     25: #include "sockopt.h"
                     26: #include "memory.h"
                     27: #include "log.h"
                     28: #include "if.h"
                     29: #include "prefix.h"
                     30: #include "command.h"
                     31: #include "privs.h"
                     32: #include "linklist.h"
                     33: #include "network.h"
1.1.1.4 ! misho      34: #include "filter.h"
1.1       misho      35: 
                     36: #include "bgpd/bgpd.h"
                     37: #include "bgpd/bgp_fsm.h"
                     38: #include "bgpd/bgp_attr.h"
                     39: #include "bgpd/bgp_debug.h"
                     40: #include "bgpd/bgp_network.h"
                     41: 
                     42: extern struct zebra_privs_t bgpd_privs;
                     43: 
                     44: /* BGP listening socket. */
                     45: struct bgp_listener
                     46: {
                     47:   int fd;
                     48:   union sockunion su;
                     49:   struct thread *thread;
                     50: };
1.1.1.4 ! misho      51: 
1.1       misho      52: /*
                     53:  * Set MD5 key for the socket, for the given IPv4 peer address.
                     54:  * If the password is NULL or zero-length, the option will be disabled.
                     55:  */
                     56: static int
                     57: bgp_md5_set_socket (int socket, union sockunion *su, const char *password)
                     58: {
                     59:   int ret = -1;
                     60:   int en = ENOSYS;
                     61:   
                     62:   assert (socket >= 0);
                     63:   
                     64: #if HAVE_DECL_TCP_MD5SIG  
                     65:   ret = sockopt_tcp_signature (socket, su, password);
                     66:   en  = errno;
                     67: #endif /* HAVE_TCP_MD5SIG */
                     68:   
                     69:   if (ret < 0)
                     70:     zlog (NULL, LOG_WARNING, "can't set TCP_MD5SIG option on socket %d: %s",
                     71:           socket, safe_strerror (en));
                     72: 
                     73:   return ret;
                     74: }
                     75: 
                     76: /* Helper for bgp_connect */
                     77: static int
                     78: bgp_md5_set_connect (int socket, union sockunion *su, const char *password)
                     79: {
                     80:   int ret = -1;
                     81: 
                     82: #if HAVE_DECL_TCP_MD5SIG  
                     83:   if ( bgpd_privs.change (ZPRIVS_RAISE) )
                     84:     {
                     85:       zlog_err ("%s: could not raise privs", __func__);
                     86:       return ret;
                     87:     }
                     88:   
                     89:   ret = bgp_md5_set_socket (socket, su, password);
                     90: 
                     91:   if (bgpd_privs.change (ZPRIVS_LOWER) )
                     92:     zlog_err ("%s: could not lower privs", __func__);
                     93: #endif /* HAVE_TCP_MD5SIG */
                     94:   
                     95:   return ret;
                     96: }
                     97: 
                     98: int
                     99: bgp_md5_set (struct peer *peer)
                    100: {
                    101:   struct listnode *node;
                    102:   int ret = 0;
                    103:   struct bgp_listener *listener;
                    104: 
                    105:   if ( bgpd_privs.change (ZPRIVS_RAISE) )
                    106:     {
                    107:       zlog_err ("%s: could not raise privs", __func__);
                    108:       return -1;
                    109:     }
                    110:   
                    111:   /* Just set the password on the listen socket(s). Outbound connections
                    112:    * are taken care of in bgp_connect() below.
                    113:    */
                    114:   for (ALL_LIST_ELEMENTS_RO(bm->listen_sockets, node, listener))
                    115:     if (listener->su.sa.sa_family == peer->su.sa.sa_family)
                    116:       {
                    117:        ret = bgp_md5_set_socket (listener->fd, &peer->su, peer->password);
                    118:        break;
                    119:       }
                    120: 
                    121:   if (bgpd_privs.change (ZPRIVS_LOWER) )
                    122:     zlog_err ("%s: could not lower privs", __func__);
                    123:   
                    124:   return ret;
                    125: }
1.1.1.4 ! misho     126: 
        !           127: /* Update BGP socket send buffer size */
        !           128: static void
        !           129: bgp_update_sock_send_buffer_size (int fd)
        !           130: {
        !           131:   int size = BGP_SOCKET_SNDBUF_SIZE;
        !           132:   int optval;
        !           133:   socklen_t optlen = sizeof(optval);
        !           134: 
        !           135:   if (getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &optval, &optlen) < 0)
        !           136:     {
        !           137:       zlog_err("getsockopt of SO_SNDBUF failed %s\n", safe_strerror(errno));
        !           138:       return;
        !           139:     }
        !           140:   if (optval < size)
        !           141:     {
        !           142:       if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size)) < 0)
        !           143:         {
        !           144:           zlog_err("Couldn't increase send buffer: %s\n", safe_strerror(errno));
        !           145:         }
        !           146:     }
        !           147: }
        !           148: 
        !           149: static void
        !           150: bgp_set_socket_ttl (struct peer *peer, int bgp_sock)
        !           151: {
        !           152:   char buf[INET_ADDRSTRLEN];
        !           153:   int ret;
        !           154: 
        !           155:   /* In case of peer is EBGP, we should set TTL for this connection.  */
        !           156:   if (!peer->gtsm_hops && (peer_sort (peer) == BGP_PEER_EBGP))
        !           157:     {
        !           158:       ret = sockopt_ttl (peer->su.sa.sa_family, bgp_sock, peer->ttl);
        !           159:       if (ret)
        !           160:        {
        !           161:          zlog_err ("%s: Can't set TxTTL on peer (rtrid %s) socket, err = %d",
        !           162:                    __func__,
        !           163:                    inet_ntop (AF_INET, &peer->remote_id, buf, sizeof(buf)),
        !           164:                    errno);
        !           165:        }
        !           166:     }
        !           167:   else if (peer->gtsm_hops)
        !           168:     {
        !           169:       /* On Linux, setting minttl without setting ttl seems to mess with the
        !           170:         outgoing ttl. Therefore setting both.
        !           171:       */
        !           172:       ret = sockopt_ttl (peer->su.sa.sa_family, bgp_sock, MAXTTL);
        !           173:       if (ret)
        !           174:        {
        !           175:          zlog_err ("%s: Can't set TxTTL on peer (rtrid %s) socket, err = %d",
        !           176:                    __func__,
        !           177:                    inet_ntop (AF_INET, &peer->remote_id, buf, sizeof(buf)),
        !           178:                    errno);
        !           179:        }
        !           180:       ret = sockopt_minttl (peer->su.sa.sa_family, bgp_sock,
        !           181:                            MAXTTL + 1 - peer->gtsm_hops);
        !           182:       if (ret)
        !           183:        {
        !           184:          zlog_err ("%s: Can't set MinTTL on peer (rtrid %s) socket, err = %d",
        !           185:                    __func__,
        !           186:                    inet_ntop (AF_INET, &peer->remote_id, buf, sizeof(buf)),
        !           187:                    errno);
        !           188:        }
        !           189:     }
        !           190: }
        !           191: 
1.1       misho     192: /* Accept bgp connection. */
                    193: static int
                    194: bgp_accept (struct thread *thread)
                    195: {
                    196:   int bgp_sock;
                    197:   int accept_sock;
                    198:   union sockunion su;
                    199:   struct bgp_listener *listener = THREAD_ARG(thread);
                    200:   struct peer *peer;
                    201:   struct peer *peer1;
                    202:   char buf[SU_ADDRSTRLEN];
                    203: 
                    204:   /* Register accept thread. */
                    205:   accept_sock = THREAD_FD (thread);
                    206:   if (accept_sock < 0)
                    207:     {
                    208:       zlog_err ("accept_sock is nevative value %d", accept_sock);
                    209:       return -1;
                    210:     }
1.1.1.4 ! misho     211:   listener->thread = thread_add_read (bm->master, bgp_accept, listener, accept_sock);
1.1       misho     212: 
                    213:   /* Accept client connection. */
                    214:   bgp_sock = sockunion_accept (accept_sock, &su);
                    215:   if (bgp_sock < 0)
                    216:     {
                    217:       zlog_err ("[Error] BGP socket accept failed (%s)", safe_strerror (errno));
                    218:       return -1;
                    219:     }
                    220:   set_nonblocking (bgp_sock);
                    221: 
1.1.1.4 ! misho     222:   /* Set socket send buffer size */
        !           223:   bgp_update_sock_send_buffer_size(bgp_sock);
        !           224: 
1.1       misho     225:   if (BGP_DEBUG (events, EVENTS))
                    226:     zlog_debug ("[Event] BGP connection from host %s", inet_sutop (&su, buf));
                    227:   
                    228:   /* Check remote IP address */
                    229:   peer1 = peer_lookup (NULL, &su);
                    230:   if (! peer1 || peer1->status == Idle)
                    231:     {
                    232:       if (BGP_DEBUG (events, EVENTS))
                    233:        {
                    234:          if (! peer1)
                    235:            zlog_debug ("[Event] BGP connection IP address %s is not configured",
                    236:                       inet_sutop (&su, buf));
                    237:          else
                    238:            zlog_debug ("[Event] BGP connection IP address %s is Idle state",
                    239:                       inet_sutop (&su, buf));
                    240:        }
                    241:       close (bgp_sock);
                    242:       return -1;
                    243:     }
                    244: 
1.1.1.4 ! misho     245:   bgp_set_socket_ttl (peer1, bgp_sock);
1.1       misho     246: 
                    247:   /* Make dummy peer until read Open packet. */
                    248:   if (BGP_DEBUG (events, EVENTS))
                    249:     zlog_debug ("[Event] Make dummy peer structure until read Open packet");
                    250: 
                    251:   {
1.1.1.3   misho     252:     char buf[SU_ADDRSTRLEN];
1.1       misho     253: 
                    254:     peer = peer_create_accept (peer1->bgp);
                    255:     SET_FLAG (peer->sflags, PEER_STATUS_ACCEPT_PEER);
                    256:     peer->su = su;
                    257:     peer->fd = bgp_sock;
                    258:     peer->status = Active;
                    259:     peer->local_id = peer1->local_id;
                    260:     peer->v_holdtime = peer1->v_holdtime;
                    261:     peer->v_keepalive = peer1->v_keepalive;
                    262: 
                    263:     /* Make peer's address string. */
                    264:     sockunion2str (&su, buf, SU_ADDRSTRLEN);
                    265:     peer->host = XSTRDUP (MTYPE_BGP_PEER_HOST, buf);
                    266:   }
                    267: 
                    268:   BGP_EVENT_ADD (peer, TCP_connection_open);
                    269: 
                    270:   return 0;
                    271: }
                    272: 
                    273: /* BGP socket bind. */
                    274: static int
                    275: bgp_bind (struct peer *peer)
                    276: {
                    277: #ifdef SO_BINDTODEVICE
                    278:   int ret;
                    279:   struct ifreq ifreq;
1.1.1.4 ! misho     280:   int myerrno;
1.1       misho     281: 
                    282:   if (! peer->ifname)
                    283:     return 0;
                    284: 
                    285:   strncpy ((char *)&ifreq.ifr_name, peer->ifname, sizeof (ifreq.ifr_name));
                    286: 
                    287:   if ( bgpd_privs.change (ZPRIVS_RAISE) )
                    288:        zlog_err ("bgp_bind: could not raise privs");
                    289:   
                    290:   ret = setsockopt (peer->fd, SOL_SOCKET, SO_BINDTODEVICE, 
                    291:                    &ifreq, sizeof (ifreq));
1.1.1.4 ! misho     292:   myerrno = errno;
        !           293:   
1.1       misho     294:   if (bgpd_privs.change (ZPRIVS_LOWER) )
                    295:     zlog_err ("bgp_bind: could not lower privs");
                    296: 
                    297:   if (ret < 0)
                    298:     {
1.1.1.4 ! misho     299:       zlog (peer->log, LOG_INFO, "bind to interface %s failed, errno=%d",
        !           300:             peer->ifname, myerrno);
1.1       misho     301:       return ret;
                    302:     }
                    303: #endif /* SO_BINDTODEVICE */
                    304:   return 0;
                    305: }
                    306: 
                    307: static int
1.1.1.2   misho     308: bgp_update_address (struct interface *ifp, const union sockunion *dst,
                    309:                    union sockunion *addr)
1.1       misho     310: {
1.1.1.4 ! misho     311:   struct prefix *p, *sel, d;
1.1       misho     312:   struct connected *connected;
                    313:   struct listnode *node;
1.1.1.2   misho     314:   int common;
                    315: 
1.1.1.4 ! misho     316:   sockunion2hostprefix (dst, &d);
1.1.1.2   misho     317:   sel = NULL;
                    318:   common = -1;
1.1       misho     319: 
                    320:   for (ALL_LIST_ELEMENTS_RO (ifp->connected, node, connected))
                    321:     {
1.1.1.2   misho     322:       p = connected->address;
1.1.1.4 ! misho     323:       if (p->family != d.family)
1.1.1.2   misho     324:        continue;
1.1.1.4 ! misho     325:       if (prefix_common_bits (p, &d) > common)
1.1.1.2   misho     326:        {
                    327:          sel = p;
1.1.1.4 ! misho     328:          common = prefix_common_bits (sel, &d);
1.1.1.2   misho     329:        }
1.1       misho     330:     }
1.1.1.2   misho     331: 
                    332:   if (!sel)
                    333:     return 1;
                    334: 
                    335:   prefix2sockunion (sel, addr);
                    336:   return 0;
1.1       misho     337: }
                    338: 
                    339: /* Update source selection.  */
                    340: static void
                    341: bgp_update_source (struct peer *peer)
                    342: {
                    343:   struct interface *ifp;
1.1.1.2   misho     344:   union sockunion addr;
1.1       misho     345: 
                    346:   /* Source is specified with interface name.  */
                    347:   if (peer->update_if)
                    348:     {
                    349:       ifp = if_lookup_by_name (peer->update_if);
                    350:       if (! ifp)
                    351:        return;
                    352: 
1.1.1.2   misho     353:       if (bgp_update_address (ifp, &peer->su, &addr))
1.1       misho     354:        return;
                    355: 
1.1.1.2   misho     356:       sockunion_bind (peer->fd, &addr, 0, &addr);
1.1       misho     357:     }
                    358: 
                    359:   /* Source is specified with IP address.  */
                    360:   if (peer->update_source)
                    361:     sockunion_bind (peer->fd, peer->update_source, 0, peer->update_source);
                    362: }
                    363: 
                    364: /* BGP try to connect to the peer.  */
                    365: int
                    366: bgp_connect (struct peer *peer)
                    367: {
1.1.1.4 ! misho     368:   ifindex_t ifindex = 0;
1.1       misho     369: 
                    370:   /* Make socket for the peer. */
                    371:   peer->fd = sockunion_socket (&peer->su);
                    372:   if (peer->fd < 0)
                    373:     return -1;
                    374: 
1.1.1.4 ! misho     375:   set_nonblocking (peer->fd);
        !           376: 
        !           377:   /* Set socket send buffer size */
        !           378:   bgp_update_sock_send_buffer_size(peer->fd);
        !           379: 
        !           380:   bgp_set_socket_ttl (peer, peer->fd);
1.1       misho     381: 
                    382:   sockopt_reuseaddr (peer->fd);
                    383:   sockopt_reuseport (peer->fd);
                    384:   
                    385: #ifdef IPTOS_PREC_INTERNETCONTROL
1.1.1.2   misho     386:   if (bgpd_privs.change (ZPRIVS_RAISE))
                    387:     zlog_err ("%s: could not raise privs", __func__);
1.1       misho     388:   if (sockunion_family (&peer->su) == AF_INET)
                    389:     setsockopt_ipv4_tos (peer->fd, IPTOS_PREC_INTERNETCONTROL);
1.1.1.2   misho     390:   else if (sockunion_family (&peer->su) == AF_INET6)
                    391:     setsockopt_ipv6_tclass (peer->fd, IPTOS_PREC_INTERNETCONTROL);
                    392:   if (bgpd_privs.change (ZPRIVS_LOWER))
                    393:     zlog_err ("%s: could not lower privs", __func__);
1.1       misho     394: #endif
                    395: 
                    396:   if (peer->password)
                    397:     bgp_md5_set_connect (peer->fd, &peer->su, peer->password);
                    398: 
                    399:   /* Bind socket. */
                    400:   bgp_bind (peer);
                    401: 
                    402:   /* Update source bind. */
                    403:   bgp_update_source (peer);
                    404: 
                    405:   if (peer->ifname)
1.1.1.4 ! misho     406:     ifindex = ifname2ifindex (peer->ifname);
1.1       misho     407: 
                    408:   if (BGP_DEBUG (events, EVENTS))
                    409:     plog_debug (peer->log, "%s [Event] Connect start to %s fd %d",
                    410:               peer->host, peer->host, peer->fd);
                    411: 
                    412:   /* Connect to the remote peer. */
                    413:   return sockunion_connect (peer->fd, &peer->su, htons (peer->port), ifindex);
                    414: }
                    415: 
                    416: /* After TCP connection is established.  Get local address and port. */
                    417: void
                    418: bgp_getsockname (struct peer *peer)
                    419: {
                    420:   if (peer->su_local)
                    421:     {
                    422:       sockunion_free (peer->su_local);
                    423:       peer->su_local = NULL;
                    424:     }
                    425: 
                    426:   if (peer->su_remote)
                    427:     {
                    428:       sockunion_free (peer->su_remote);
                    429:       peer->su_remote = NULL;
                    430:     }
                    431: 
                    432:   peer->su_local = sockunion_getsockname (peer->fd);
                    433:   peer->su_remote = sockunion_getpeername (peer->fd);
                    434: 
                    435:   bgp_nexthop_set (peer->su_local, peer->su_remote, &peer->nexthop, peer);
                    436: }
                    437: 
                    438: 
                    439: static int
                    440: bgp_listener (int sock, struct sockaddr *sa, socklen_t salen)
                    441: {
                    442:   struct bgp_listener *listener;
                    443:   int ret, en;
                    444: 
                    445:   sockopt_reuseaddr (sock);
                    446:   sockopt_reuseport (sock);
                    447: 
1.1.1.2   misho     448:   if (bgpd_privs.change (ZPRIVS_RAISE))
                    449:     zlog_err ("%s: could not raise privs", __func__);
                    450: 
1.1       misho     451: #ifdef IPTOS_PREC_INTERNETCONTROL
                    452:   if (sa->sa_family == AF_INET)
                    453:     setsockopt_ipv4_tos (sock, IPTOS_PREC_INTERNETCONTROL);
1.1.1.2   misho     454:   else if (sa->sa_family == AF_INET6)
                    455:     setsockopt_ipv6_tclass (sock, IPTOS_PREC_INTERNETCONTROL);
1.1       misho     456: #endif
                    457: 
1.1.1.2   misho     458:   sockopt_v6only (sa->sa_family, sock);
1.1       misho     459: 
                    460:   ret = bind (sock, sa, salen);
                    461:   en = errno;
1.1.1.2   misho     462:   if (bgpd_privs.change (ZPRIVS_LOWER))
                    463:     zlog_err ("%s: could not lower privs", __func__);
1.1       misho     464: 
                    465:   if (ret < 0)
                    466:     {
                    467:       zlog_err ("bind: %s", safe_strerror (en));
                    468:       return ret;
                    469:     }
                    470: 
                    471:   ret = listen (sock, 3);
                    472:   if (ret < 0)
                    473:     {
                    474:       zlog_err ("listen: %s", safe_strerror (errno));
                    475:       return ret;
                    476:     }
                    477: 
                    478:   listener = XMALLOC (MTYPE_BGP_LISTENER, sizeof(*listener));
                    479:   listener->fd = sock;
                    480:   memcpy(&listener->su, sa, salen);
1.1.1.4 ! misho     481:   listener->thread = thread_add_read (bm->master, bgp_accept, listener, sock);
1.1       misho     482:   listnode_add (bm->listen_sockets, listener);
                    483: 
                    484:   return 0;
                    485: }
                    486: 
                    487: /* IPv6 supported version of BGP server socket setup.  */
                    488: int
                    489: bgp_socket (unsigned short port, const char *address)
                    490: {
                    491:   struct addrinfo *ainfo;
                    492:   struct addrinfo *ainfo_save;
                    493:   static const struct addrinfo req = {
                    494:     .ai_family = AF_UNSPEC,
                    495:     .ai_flags = AI_PASSIVE,
                    496:     .ai_socktype = SOCK_STREAM,
                    497:   };
                    498:   int ret, count;
                    499:   char port_str[BUFSIZ];
                    500: 
                    501:   snprintf (port_str, sizeof(port_str), "%d", port);
                    502:   port_str[sizeof (port_str) - 1] = '\0';
                    503: 
                    504:   ret = getaddrinfo (address, port_str, &req, &ainfo_save);
                    505:   if (ret != 0)
                    506:     {
                    507:       zlog_err ("getaddrinfo: %s", gai_strerror (ret));
                    508:       return -1;
                    509:     }
                    510: 
                    511:   count = 0;
                    512:   for (ainfo = ainfo_save; ainfo; ainfo = ainfo->ai_next)
                    513:     {
                    514:       int sock;
                    515: 
                    516:       if (ainfo->ai_family != AF_INET && ainfo->ai_family != AF_INET6)
                    517:        continue;
                    518:      
                    519:       sock = socket (ainfo->ai_family, ainfo->ai_socktype, ainfo->ai_protocol);
                    520:       if (sock < 0)
                    521:        {
                    522:          zlog_err ("socket: %s", safe_strerror (errno));
                    523:          continue;
                    524:        }
                    525:        
                    526:       /* if we intend to implement ttl-security, this socket needs ttl=255 */
                    527:       sockopt_ttl (ainfo->ai_family, sock, MAXTTL);
                    528:       
                    529:       ret = bgp_listener (sock, ainfo->ai_addr, ainfo->ai_addrlen);
                    530:       if (ret == 0)
                    531:        ++count;
                    532:       else
                    533:        close(sock);
                    534:     }
                    535:   freeaddrinfo (ainfo_save);
                    536:   if (count == 0)
                    537:     {
                    538:       zlog_err ("%s: no usable addresses", __func__);
                    539:       return -1;
                    540:     }
                    541: 
                    542:   return 0;
                    543: }
                    544: 
                    545: void
                    546: bgp_close (void)
                    547: {
                    548:   struct listnode *node, *next;
                    549:   struct bgp_listener *listener;
                    550: 
                    551:   for (ALL_LIST_ELEMENTS (bm->listen_sockets, node, next, listener))
                    552:     {
                    553:       thread_cancel (listener->thread);
                    554:       close (listener->fd);
                    555:       listnode_delete (bm->listen_sockets, listener);
                    556:       XFREE (MTYPE_BGP_LISTENER, listener);
                    557:     }
                    558: }

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