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 #include "sockopt.h"
  39
  40 /* increase socket send buffer size */
  41 static void pim_msdp_update_sock_send_buffer_size(int fd)
  42 {
  43         int size = PIM_MSDP_SOCKET_SNDBUF_SIZE;
  44         int optval;
  45         socklen_t optlen = sizeof(optval);
  46
  47         if (getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &optval, &optlen) < 0) {
  48                 flog_err_sys(EC_LIB_SOCKET,
  49                              "getsockopt of SO_SNDBUF failed %s",
  50                              safe_strerror(errno));
  51                 return;
  52         }
  53
  54         if (optval < size) {
  55                 if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size))
  56                     < 0) {
  57                         flog_err_sys(EC_LIB_SOCKET,
  58                                      "Couldn't increase send buffer: %s",
  59                                      safe_strerror(errno));
  60                 }
  61         }
  62 }
  63
  64 /* passive peer socket accept */
  65 static void pim_msdp_sock_accept(struct thread *thread)
  66 {
  67         union sockunion su;
  68         struct pim_instance *pim = THREAD_ARG(thread);
  69         int accept_sock;
  70         int msdp_sock;
  71         struct pim_msdp_peer *mp;
  72
  73         sockunion_init(&su);
  74
  75         /* re-register accept thread */
  76         accept_sock = THREAD_FD(thread);
  77         if (accept_sock < 0) {
  78                 flog_err(EC_LIB_DEVELOPMENT, "accept_sock is negative value %d",
  79                          accept_sock);
  80                 return;
  81         }
  82         pim->msdp.listener.thread = NULL;
  83         thread_add_read(router->master, pim_msdp_sock_accept, pim, accept_sock,
  84                         &pim->msdp.listener.thread);
  85
  86         /* accept client connection. */
  87         msdp_sock = sockunion_accept(accept_sock, &su);
  88         if (msdp_sock < 0) {
  89                 flog_err_sys(EC_LIB_SOCKET, "pim_msdp_sock_accept failed (%s)",
  90                              safe_strerror(errno));
  91                 return;
  92         }
  93
  94         /* see if have peer config for this */
  95         mp = pim_msdp_peer_find(pim, su.sin.sin_addr);
  96         if (!mp || !PIM_MSDP_PEER_IS_LISTENER(mp)) {
  97                 ++pim->msdp.rejected_accepts;
  98                 if (PIM_DEBUG_MSDP_EVENTS) {
  99                         flog_err(EC_PIM_MSDP_PACKET,
 100                                  "msdp peer connection refused from %pSU", &su);
 101                 }
 102                 close(msdp_sock);
 103                 return;
 104         }
 105
 106         if (PIM_DEBUG_MSDP_INTERNAL) {
 107                 zlog_debug("MSDP peer %s accept success%s", mp->key_str,
 108                            mp->fd >= 0 ? "(dup)" : "");
 109         }
 110
 111         /* if we have an existing connection we need to kill that one
 112          * with this one */
 113         if (mp->fd >= 0) {
 114                 if (PIM_DEBUG_MSDP_EVENTS) {
 115                         zlog_notice(
 116                                 "msdp peer new connection from %pSU stop old connection",
 117                                 &su);
 118                 }
 119                 pim_msdp_peer_stop_tcp_conn(mp, true /* chg_state */);
 120         }
 121         mp->fd = msdp_sock;
 122         set_nonblocking(mp->fd);
 123         pim_msdp_update_sock_send_buffer_size(mp->fd);
 124         pim_msdp_peer_established(mp);
 125 }
 126
 127 /* global listener for the MSDP well know TCP port */
 128 int pim_msdp_sock_listen(struct pim_instance *pim)
 129 {
 130         int sock;
 131         int socklen;
 132         struct sockaddr_in sin;
 133         int rc;
 134         struct pim_msdp_listener *listener = &pim->msdp.listener;
 135
 136         if (pim->msdp.flags & PIM_MSDPF_LISTENER) {
 137                 /* listener already setup */
 138                 return 0;
 139         }
 140
 141         sock = socket(AF_INET, SOCK_STREAM, 0);
 142         if (sock < 0) {
 143                 flog_err_sys(EC_LIB_SOCKET, "socket: %s", safe_strerror(errno));
 144                 return sock;
 145         }
 146
 147         memset(&sin, 0, sizeof(struct sockaddr_in));
 148         sin.sin_family = AF_INET;
 149         sin.sin_port = htons(PIM_MSDP_TCP_PORT);
 150         socklen = sizeof(struct sockaddr_in);
 151 #ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
 152         sin.sin_len = socklen;
 153 #endif /* HAVE_STRUCT_SOCKADDR_IN_SIN_LEN */
 154
 155         sockopt_reuseaddr(sock);
 156         sockopt_reuseport(sock);
 157
 158         if (pim->vrf->vrf_id != VRF_DEFAULT) {
 159                 struct interface *ifp =
 160                         if_lookup_by_name(pim->vrf->name, pim->vrf->vrf_id);
 161                 if (!ifp) {
 162                         flog_err(EC_LIB_INTERFACE,
 163                                  "%s: Unable to lookup vrf interface: %s",
 164                                  __func__, pim->vrf->name);
 165                         close(sock);
 166                         return -1;
 167                 }
 168                 if (pim_socket_bind(sock, ifp)) {
 169                         flog_err_sys(EC_LIB_SOCKET,
 170                                      "%s: Unable to bind to socket: %s",
 171                                      __func__, safe_strerror(errno));
 172                         close(sock);
 173                         return -1;
 174                 }
 175         }
 176
 177         frr_with_privs(&pimd_privs) {
 178                 /* bind to well known TCP port */
 179                 rc = bind(sock, (struct sockaddr *)&sin, socklen);
 180         }
 181
 182         if (rc < 0) {
 183                 flog_err_sys(EC_LIB_SOCKET,
 184                              "pim_msdp_socket bind to port %d: %s",
 185                              ntohs(sin.sin_port), safe_strerror(errno));
 186                 close(sock);
 187                 return rc;
 188         }
 189
 190         rc = listen(sock, 3 /* backlog */);
 191         if (rc < 0) {
 192                 flog_err_sys(EC_LIB_SOCKET, "pim_msdp_socket listen: %s",
 193                              safe_strerror(errno));
 194                 close(sock);
 195                 return rc;
 196         }
 197
 198         /* Set socket DSCP byte */
 199         if (setsockopt_ipv4_tos(sock, IPTOS_PREC_INTERNETCONTROL)) {
 200                 zlog_warn("can't set sockopt IP_TOS to MSDP socket %d: %s",
 201                                 sock, safe_strerror(errno));
 202         }
 203
 204         /* add accept thread */
 205         listener->fd = sock;
 206         memcpy(&listener->su, &sin, socklen);
 207         thread_add_read(pim->msdp.master, pim_msdp_sock_accept, pim, sock,
 208                         &listener->thread);
 209
 210         pim->msdp.flags |= PIM_MSDPF_LISTENER;
 211         return 0;
 212 }
 213
 214 /* active peer socket setup */
 215 int pim_msdp_sock_connect(struct pim_msdp_peer *mp)
 216 {
 217         int rc;
 218
 219         if (PIM_DEBUG_MSDP_INTERNAL) {
 220                 zlog_debug("MSDP peer %s attempt connect%s", mp->key_str,
 221                            mp->fd < 0 ? "" : "(dup)");
 222         }
 223
 224         /* if we have an existing connection we need to kill that one
 225          * with this one */
 226         if (mp->fd >= 0) {
 227                 if (PIM_DEBUG_MSDP_EVENTS) {
 228                         zlog_notice(
 229                                 "msdp duplicate connect to %s nuke old connection",
 230                                 mp->key_str);
 231                 }
 232                 pim_msdp_peer_stop_tcp_conn(mp, false /* chg_state */);
 233         }
 234
 235         /* Make socket for the peer. */
 236         mp->fd = sockunion_socket(&mp->su_peer);
 237         if (mp->fd < 0) {
 238                 flog_err_sys(EC_LIB_SOCKET,
 239                              "pim_msdp_socket socket failure: %s",
 240                              safe_strerror(errno));
 241                 return -1;
 242         }
 243
 244         if (mp->pim->vrf->vrf_id != VRF_DEFAULT) {
 245                 struct interface *ifp = if_lookup_by_name(mp->pim->vrf->name,
 246                                                           mp->pim->vrf->vrf_id);
 247                 if (!ifp) {
 248                         flog_err(EC_LIB_INTERFACE,
 249                                  "%s: Unable to lookup vrf interface: %s",
 250                                  __func__, mp->pim->vrf->name);
 251                         return -1;
 252                 }
 253                 if (pim_socket_bind(mp->fd, ifp)) {
 254                         flog_err_sys(EC_LIB_SOCKET,
 255                                      "%s: Unable to bind to socket: %s",
 256                                      __func__, safe_strerror(errno));
 257                         close(mp->fd);
 258                         mp->fd = -1;
 259                         return -1;
 260                 }
 261         }
 262
 263         set_nonblocking(mp->fd);
 264
 265         /* Set socket send buffer size */
 266         pim_msdp_update_sock_send_buffer_size(mp->fd);
 267         sockopt_reuseaddr(mp->fd);
 268         sockopt_reuseport(mp->fd);
 269
 270         /* source bind */
 271         rc = sockunion_bind(mp->fd, &mp->su_local, 0, &mp->su_local);
 272         if (rc < 0) {
 273                 flog_err_sys(EC_LIB_SOCKET,
 274                              "pim_msdp_socket connect bind failure: %s",
 275                              safe_strerror(errno));
 276                 close(mp->fd);
 277                 mp->fd = -1;
 278                 return rc;
 279         }
 280
 281         /* Set socket DSCP byte */
 282         if (setsockopt_ipv4_tos(mp->fd, IPTOS_PREC_INTERNETCONTROL)) {
 283                 zlog_warn("can't set sockopt IP_TOS to MSDP socket %d: %s",
 284                                 mp->fd, safe_strerror(errno));
 285         }
 286
 287         /* Connect to the remote mp. */
 288         return (sockunion_connect(mp->fd, &mp->su_peer,
 289                                   htons(PIM_MSDP_TCP_PORT), 0));
 290 }