pimd/pim_msdp_socket.c

   1 /*
   2  * IP MSDP socket management
   3  * Copyright (C) 2016 Cumulus Networks, Inc.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; see the file COPYING; if not, write to the
  17  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  18  * MA 02110-1301 USA
  19  */
  20
  21 #include <zebra.h>
  22
  23 #include <lib/log.h>
  24 #include <lib/network.h>
  25 #include <lib/sockunion.h>
  26 #include <lib/thread.h>
  27 #include <lib/vty.h>
  28
  29 #include "pimd.h"
  30
  31 #include "pim_msdp.h"
  32 #include "pim_msdp_socket.h"
  33
  34 /* increase socket send buffer size */
  35 static void
  36 pim_msdp_update_sock_send_buffer_size (int fd)
  37 {
  38   int size = PIM_MSDP_SOCKET_SNDBUF_SIZE;
  39   int optval;
  40   socklen_t optlen = sizeof(optval);
  41
  42   if (getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &optval, &optlen) < 0) {
  43     zlog_err("getsockopt of SO_SNDBUF failed %s\n", safe_strerror(errno));
  44     return;
  45   }
  46
  47   if (optval < size) {
  48     if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size)) < 0) {
  49       zlog_err("Couldn't increase send buffer: %s\n", safe_strerror(errno));
  50     }
  51   }
  52 }
  53
  54 /* passive peer socket accept */
  55 static int
  56 pim_msdp_sock_accept(struct thread *thread)
  57 {
  58   union sockunion su;
  59   struct pim_msdp_listener *listener = THREAD_ARG(thread);
  60   int accept_sock;
  61   int msdp_sock;
  62   struct pim_msdp_peer *mp;
  63   char buf[SU_ADDRSTRLEN];
  64
  65   sockunion_init(&su);
  66
  67   /* re-register accept thread */
  68   accept_sock = THREAD_FD(thread);
  69   if (accept_sock < 0) {
  70     zlog_err ("accept_sock is negative value %d", accept_sock);
  71     return -1;
  72   }
  73   listener->thread = NULL;
  74   thread_add_read(master, pim_msdp_sock_accept, listener, accept_sock,
  75                   &listener->thread);
  76
  77   /* accept client connection. */
  78   msdp_sock = sockunion_accept(accept_sock, &su);
  79   if (msdp_sock < 0) {
  80     zlog_err ("pim_msdp_sock_accept failed (%s)", safe_strerror (errno));
  81     return -1;
  82   }
  83
  84   /* see if have peer config for this */
  85   mp = pim_msdp_peer_find(su.sin.sin_addr);
  86   if (!mp || !PIM_MSDP_PEER_IS_LISTENER(mp)) {
  87     ++msdp->rejected_accepts;
  88     if (PIM_DEBUG_MSDP_EVENTS) {
  89       zlog_err("msdp peer connection refused from %s",
  90           sockunion2str(&su, buf, SU_ADDRSTRLEN));
  91     }
  92     close(msdp_sock);
  93     return -1;
  94   }
  95
  96   if (PIM_DEBUG_MSDP_INTERNAL) {
  97     zlog_debug("MSDP peer %s accept success%s", mp->key_str, mp->fd>=0?"(dup)":"");
  98   }
  99
 100   /* if we have an existing connection we need to kill that one
 101    * with this one */
 102   if (mp->fd >= 0) {
 103     if (PIM_DEBUG_MSDP_EVENTS) {
 104       zlog_err("msdp peer new connection from %s stop old connection",
 105           sockunion2str(&su, buf, SU_ADDRSTRLEN));
 106     }
 107     pim_msdp_peer_stop_tcp_conn(mp, true /* chg_state */);
 108   }
 109   mp->fd = msdp_sock;
 110   set_nonblocking(mp->fd);
 111   pim_msdp_update_sock_send_buffer_size(mp->fd);
 112   pim_msdp_peer_established(mp);
 113   return 0;
 114 }
 115
 116 /* global listener for the MSDP well know TCP port */
 117 int
 118 pim_msdp_sock_listen(void)
 119 {
 120   int sock;
 121   int socklen;
 122   struct sockaddr_in sin;
 123   int rc;
 124   struct pim_msdp_listener *listener = &msdp->listener;
 125
 126   if (msdp->flags & PIM_MSDPF_LISTENER) {
 127     /* listener already setup */
 128     return 0;
 129   }
 130
 131   sock = socket(AF_INET, SOCK_STREAM, 0);
 132   if (sock < 0) {
 133     zlog_err ("socket: %s", safe_strerror (errno));
 134     return sock;
 135   }
 136
 137   memset(&sin, 0, sizeof(struct sockaddr_in));
 138   sin.sin_family = AF_INET;
 139   sin.sin_port = htons(PIM_MSDP_TCP_PORT);
 140   socklen = sizeof(struct sockaddr_in);
 141 #ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
 142   sin.sin_len = socklen;
 143 #endif /* HAVE_STRUCT_SOCKADDR_IN_SIN_LEN */
 144
 145   sockopt_reuseaddr(sock);
 146   sockopt_reuseport(sock);
 147
 148   if (pimd_privs.change(ZPRIVS_RAISE)) {
 149     zlog_err ("pim_msdp_socket: could not raise privs, %s",
 150         safe_strerror (errno));
 151   }
 152
 153   /* bind to well known TCP port */
 154   rc = bind(sock, (struct sockaddr *)&sin, socklen);
 155
 156   if (pimd_privs.change(ZPRIVS_LOWER)) {
 157     zlog_err ("pim_msdp_socket: could not lower privs, %s",
 158         safe_strerror (errno));
 159   }
 160
 161   if (rc < 0) {
 162     zlog_err ("pim_msdp_socket bind to port %d: %s", ntohs(sin.sin_port), safe_strerror (errno));
 163     close(sock);
 164     return rc;
 165   }
 166
 167   rc = listen(sock, 3 /* backlog */);
 168   if (rc < 0) {
 169     zlog_err ("pim_msdp_socket listen: %s", safe_strerror (errno));
 170     close(sock);
 171     return rc;
 172   }
 173
 174   /* add accept thread */
 175   listener->fd = sock;
 176   memcpy(&listener->su, &sin, socklen);
 177   listener->thread = NULL;
 178   thread_add_read(msdp->master, pim_msdp_sock_accept, listener, sock,
 179                   &listener->thread);
 180
 181   msdp->flags |= PIM_MSDPF_LISTENER;
 182   return 0;
 183 }
 184
 185 /* active peer socket setup */
 186 int
 187 pim_msdp_sock_connect(struct pim_msdp_peer *mp)
 188 {
 189   int rc;
 190
 191   if (PIM_DEBUG_MSDP_INTERNAL) {
 192     zlog_debug("MSDP peer %s attempt connect%s", mp->key_str, mp->fd<0?"":"(dup)");
 193   }
 194
 195   /* if we have an existing connection we need to kill that one
 196    * with this one */
 197   if (mp->fd >= 0) {
 198     if (PIM_DEBUG_MSDP_EVENTS) {
 199       zlog_err("msdp duplicate connect to %s nuke old connection", mp->key_str);
 200     }
 201     pim_msdp_peer_stop_tcp_conn(mp, false /* chg_state */);
 202   }
 203
 204   /* Make socket for the peer. */
 205   mp->fd = sockunion_socket(&mp->su_peer);
 206   if (mp->fd < 0) {
 207     zlog_err ("pim_msdp_socket socket failure: %s", safe_strerror (errno));
 208     return -1;
 209   }
 210
 211   set_nonblocking(mp->fd);
 212
 213   /* Set socket send buffer size */
 214   pim_msdp_update_sock_send_buffer_size(mp->fd);
 215   sockopt_reuseaddr(mp->fd);
 216   sockopt_reuseport(mp->fd);
 217
 218   /* source bind */
 219   rc = sockunion_bind(mp->fd, &mp->su_local, 0, &mp->su_local);
 220   if (rc < 0) {
 221     zlog_err ("pim_msdp_socket connect bind failure: %s", safe_strerror (errno));
 222     close(mp->fd);
 223     mp->fd = -1;
 224     return rc;
 225   }
 226
 227   /* Connect to the remote mp. */
 228   return (sockunion_connect(mp->fd, &mp->su_peer, htons(PIM_MSDP_TCP_PORT), 0));
 229 }
 230