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 along
  16  * with this program; see the file COPYING; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 #include <zebra.h>
  21
  22 #include <lib/log.h>
  23 #include <lib/network.h>
  24 #include <lib/sockunion.h>
  25 #include <lib/thread.h>
  26 #include <lib/vty.h>
  27 #include <lib/if.h>
  28 #include <lib/vrf.h>
  29 #include <lib/lib_errors.h>
  30
  31 #include "pimd.h"
  32 #include "pim_sock.h"
  33 #include "pim_errors.h"
  34
  35 #include "pim_msdp.h"
  36 #include "pim_msdp_socket.h"
  37
  38 /* increase socket send buffer size */
  39 static void pim_msdp_update_sock_send_buffer_size(int fd)
  40 {
  41         int size = PIM_MSDP_SOCKET_SNDBUF_SIZE;
  42         int optval;
  43         socklen_t optlen = sizeof(optval);
  44
  45         if (getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &optval, &optlen) < 0) {
  46                 flog_err_sys(EC_LIB_SOCKET,
  47                              "getsockopt of SO_SNDBUF failed %s",
  48                              safe_strerror(errno));
  49                 return;
  50         }
  51
  52         if (optval < size) {
  53                 if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size))
  54                     < 0) {
  55                         flog_err_sys(EC_LIB_SOCKET,
  56                                      "Couldn't increase send buffer: %s",
  57                                      safe_strerror(errno));
  58                 }
  59         }
  60 }
  61
  62 /* passive peer socket accept */
  63 static int pim_msdp_sock_accept(struct thread *thread)
  64 {
  65         union sockunion su;
  66         struct pim_instance *pim = THREAD_ARG(thread);
  67         int accept_sock;
  68         int msdp_sock;
  69         struct pim_msdp_peer *mp;
  70
  71         sockunion_init(&su);
  72
  73         /* re-register accept thread */
  74         accept_sock = THREAD_FD(thread);
  75         if (accept_sock < 0) {
  76                 flog_err(EC_LIB_DEVELOPMENT, "accept_sock is negative value %d",
  77                          accept_sock);
  78                 return -1;
  79         }
  80         pim->msdp.listener.thread = NULL;
  81         thread_add_read(router->master, pim_msdp_sock_accept, pim, accept_sock,
  82                         &pim->msdp.listener.thread);
  83
  84         /* accept client connection. */
  85         msdp_sock = sockunion_accept(accept_sock, &su);
  86         if (msdp_sock < 0) {
  87                 flog_err_sys(EC_LIB_SOCKET, "pim_msdp_sock_accept failed (%s)",
  88                              safe_strerror(errno));
  89                 return -1;
  90         }
  91
  92         /* see if have peer config for this */
  93         mp = pim_msdp_peer_find(pim, su.sin.sin_addr);
  94         if (!mp || !PIM_MSDP_PEER_IS_LISTENER(mp)) {
  95                 ++pim->msdp.rejected_accepts;
  96                 if (PIM_DEBUG_MSDP_EVENTS) {
  97                         flog_err(EC_PIM_MSDP_PACKET,
  98                                  "msdp peer connection refused from %pSU", &su);
  99                 }
 100                 close(msdp_sock);
 101                 return -1;
 102         }
 103
 104         if (PIM_DEBUG_MSDP_INTERNAL) {
 105                 zlog_debug("MSDP peer %s accept success%s", mp->key_str,
 106                            mp->fd >= 0 ? "(dup)" : "");
 107         }
 108
 109         /* if we have an existing connection we need to kill that one
 110          * with this one */
 111         if (mp->fd >= 0) {
 112                 if (PIM_DEBUG_MSDP_EVENTS) {
 113                         zlog_notice(
 114                                 "msdp peer new connection from %pSU stop old connection",
 115                                 &su);
 116                 }
 117                 pim_msdp_peer_stop_tcp_conn(mp, true /* chg_state */);
 118         }
 119         mp->fd = msdp_sock;
 120         set_nonblocking(mp->fd);
 121         pim_msdp_update_sock_send_buffer_size(mp->fd);
 122         pim_msdp_peer_established(mp);
 123         return 0;
 124 }
 125
 126 /* global listener for the MSDP well know TCP port */
 127 int pim_msdp_sock_listen(struct pim_instance *pim)
 128 {
 129         int sock;
 130         int socklen;
 131         struct sockaddr_in sin;
 132         int rc;
 133         struct pim_msdp_listener *listener = &pim->msdp.listener;
 134
 135         if (pim->msdp.flags & PIM_MSDPF_LISTENER) {
 136                 /* listener already setup */
 137                 return 0;
 138         }
 139
 140         sock = socket(AF_INET, SOCK_STREAM, 0);
 141         if (sock < 0) {
 142                 flog_err_sys(EC_LIB_SOCKET, "socket: %s", safe_strerror(errno));
 143                 return sock;
 144         }
 145
 146         memset(&sin, 0, sizeof(struct sockaddr_in));
 147         sin.sin_family = AF_INET;
 148         sin.sin_port = htons(PIM_MSDP_TCP_PORT);
 149         socklen = sizeof(struct sockaddr_in);
 150 #ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
 151         sin.sin_len = socklen;
 152 #endif /* HAVE_STRUCT_SOCKADDR_IN_SIN_LEN */
 153
 154         sockopt_reuseaddr(sock);
 155         sockopt_reuseport(sock);
 156
 157         if (pim->vrf_id != VRF_DEFAULT) {
 158                 struct interface *ifp =
 159                         if_lookup_by_name(pim->vrf->name, pim->vrf_id);
 160                 if (!ifp) {
 161                         flog_err(EC_LIB_INTERFACE,
 162                                  "%s: Unable to lookup vrf interface: %s",
 163                                  __func__, pim->vrf->name);
 164                         close(sock);
 165                         return -1;
 166                 }
 167                 if (pim_socket_bind(sock, ifp)) {
 168                         flog_err_sys(EC_LIB_SOCKET,
 169                                      "%s: Unable to bind to socket: %s",
 170                                      __func__, safe_strerror(errno));
 171                         close(sock);
 172                         return -1;
 173                 }
 174         }
 175
 176         frr_with_privs(&pimd_privs) {
 177                 /* bind to well known TCP port */
 178                 rc = bind(sock, (struct sockaddr *)&sin, socklen);
 179         }
 180
 181         if (rc < 0) {
 182                 flog_err_sys(EC_LIB_SOCKET,
 183                              "pim_msdp_socket bind to port %d: %s",
 184                              ntohs(sin.sin_port), safe_strerror(errno));
 185                 close(sock);
 186                 return rc;
 187         }
 188
 189         rc = listen(sock, 3 /* backlog */);
 190         if (rc < 0) {
 191                 flog_err_sys(EC_LIB_SOCKET, "pim_msdp_socket listen: %s",
 192                              safe_strerror(errno));
 193                 close(sock);
 194                 return rc;
 195         }
 196
 197         /* add accept thread */
 198         listener->fd = sock;
 199         memcpy(&listener->su, &sin, socklen);
 200         listener->thread = NULL;
 201         thread_add_read(pim->msdp.master, pim_msdp_sock_accept, pim, sock,
 202                         &listener->thread);
 203
 204         pim->msdp.flags |= PIM_MSDPF_LISTENER;
 205         return 0;
 206 }
 207
 208 /* active peer socket setup */
 209 int pim_msdp_sock_connect(struct pim_msdp_peer *mp)
 210 {
 211         int rc;
 212
 213         if (PIM_DEBUG_MSDP_INTERNAL) {
 214                 zlog_debug("MSDP peer %s attempt connect%s", mp->key_str,
 215                            mp->fd < 0 ? "" : "(dup)");
 216         }
 217
 218         /* if we have an existing connection we need to kill that one
 219          * with this one */
 220         if (mp->fd >= 0) {
 221                 if (PIM_DEBUG_MSDP_EVENTS) {
 222                         zlog_notice(
 223                                 "msdp duplicate connect to %s nuke old connection",
 224                                 mp->key_str);
 225                 }
 226                 pim_msdp_peer_stop_tcp_conn(mp, false /* chg_state */);
 227         }
 228
 229         /* Make socket for the peer. */
 230         mp->fd = sockunion_socket(&mp->su_peer);
 231         if (mp->fd < 0) {
 232                 flog_err_sys(EC_LIB_SOCKET,
 233                              "pim_msdp_socket socket failure: %s",
 234                              safe_strerror(errno));
 235                 return -1;
 236         }
 237
 238         if (mp->pim->vrf_id != VRF_DEFAULT) {
 239                 struct interface *ifp =
 240                         if_lookup_by_name(mp->pim->vrf->name, mp->pim->vrf_id);
 241                 if (!ifp) {
 242                         flog_err(EC_LIB_INTERFACE,
 243                                  "%s: Unable to lookup vrf interface: %s",
 244                                  __func__, mp->pim->vrf->name);
 245                         return -1;
 246                 }
 247                 if (pim_socket_bind(mp->fd, ifp)) {
 248                         flog_err_sys(EC_LIB_SOCKET,
 249                                      "%s: Unable to bind to socket: %s",
 250                                      __func__, safe_strerror(errno));
 251                         close(mp->fd);
 252                         mp->fd = -1;
 253                         return -1;
 254                 }
 255         }
 256
 257         set_nonblocking(mp->fd);
 258
 259         /* Set socket send buffer size */
 260         pim_msdp_update_sock_send_buffer_size(mp->fd);
 261         sockopt_reuseaddr(mp->fd);
 262         sockopt_reuseport(mp->fd);
 263
 264         /* source bind */
 265         rc = sockunion_bind(mp->fd, &mp->su_local, 0, &mp->su_local);
 266         if (rc < 0) {
 267                 flog_err_sys(EC_LIB_SOCKET,
 268                              "pim_msdp_socket connect bind failure: %s",
 269                              safe_strerror(errno));
 270                 close(mp->fd);
 271                 mp->fd = -1;
 272                 return rc;
 273         }
 274
 275         /* Connect to the remote mp. */
 276         return (sockunion_connect(mp->fd, &mp->su_peer,
 277                                   htons(PIM_MSDP_TCP_PORT), 0));
 278 }