src/common/sessiond-comm/inet.c

   1 /*
   2  * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <assert.h>
  20 #include <limits.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/stat.h>
  25 #include <sys/types.h>
  26 #include <unistd.h>
  27 #include <errno.h>
  28
  29 #include <common/common.h>
  30
  31 #include "inet.h"
  32
  33 /*
  34  * INET protocol operations.
  35  */
  36 static const struct lttcomm_proto_ops inet_ops = {
  37         .bind = lttcomm_bind_inet_sock,
  38         .close = lttcomm_close_inet_sock,
  39         .connect = lttcomm_connect_inet_sock,
  40         .accept = lttcomm_accept_inet_sock,
  41         .listen = lttcomm_listen_inet_sock,
  42         .recvmsg = lttcomm_recvmsg_inet_sock,
  43         .sendmsg = lttcomm_sendmsg_inet_sock,
  44 };
  45
  46 /*
  47  * Creates an PF_INET socket.
  48  */
  49 LTTNG_HIDDEN
  50 int lttcomm_create_inet_sock(struct lttcomm_sock *sock, int type, int proto)
  51 {
  52         int val = 1, ret;
  53
  54         /* Create server socket */
  55         if ((sock->fd = socket(PF_INET, type, proto)) < 0) {
  56                 PERROR("socket inet");
  57                 goto error;
  58         }
  59
  60         sock->ops = &inet_ops;
  61
  62         /*
  63          * Set socket option to reuse the address.
  64          */
  65         ret = setsockopt(sock->fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(int));
  66         if (ret < 0) {
  67                 PERROR("setsockopt inet");
  68                 goto error;
  69         }
  70
  71         return 0;
  72
  73 error:
  74         return -1;
  75 }
  76
  77 /*
  78  * Bind socket and return.
  79  */
  80 LTTNG_HIDDEN
  81 int lttcomm_bind_inet_sock(struct lttcomm_sock *sock)
  82 {
  83         int ret;
  84
  85         ret = bind(sock->fd, &sock->sockaddr.addr.sin,
  86                         sizeof(sock->sockaddr.addr.sin));
  87         if (ret < 0) {
  88                 PERROR("bind inet");
  89         }
  90
  91         return ret;
  92 }
  93
  94 /*
  95  * Connect PF_INET socket.
  96  */
  97 LTTNG_HIDDEN
  98 int lttcomm_connect_inet_sock(struct lttcomm_sock *sock)
  99 {
 100         int ret, closeret;
 101
 102         ret = connect(sock->fd, (struct sockaddr *) &sock->sockaddr.addr.sin,
 103                         sizeof(sock->sockaddr.addr.sin));
 104         if (ret < 0) {
 105                 /*
 106                  * Don't print message on connect error, because connect is used in
 107                  * normal execution to detect if sessiond is alive.
 108                  */
 109                 goto error_connect;
 110         }
 111
 112         return ret;
 113
 114 error_connect:
 115         closeret = close(sock->fd);
 116         if (closeret) {
 117                 PERROR("close inet");
 118         }
 119
 120         return ret;
 121 }
 122
 123 /*
 124  * Do an accept(2) on the sock and return the new lttcomm socket. The socket
 125  * MUST be bind(2) before.
 126  */
 127 LTTNG_HIDDEN
 128 struct lttcomm_sock *lttcomm_accept_inet_sock(struct lttcomm_sock *sock)
 129 {
 130         int new_fd;
 131         socklen_t len;
 132         struct lttcomm_sock *new_sock;
 133
 134         if (sock->proto == LTTCOMM_SOCK_UDP) {
 135                 /*
 136                  * accept(2) does not exist for UDP so simply return the passed socket.
 137                  */
 138                 new_sock = sock;
 139                 goto end;
 140         }
 141
 142         new_sock = lttcomm_alloc_sock(sock->proto);
 143         if (new_sock == NULL) {
 144                 goto error;
 145         }
 146
 147         len = sizeof(new_sock->sockaddr.addr.sin);
 148
 149         /* Blocking call */
 150         new_fd = accept(sock->fd, (struct sockaddr *) &new_sock->sockaddr.addr.sin,
 151                         &len);
 152         if (new_fd < 0) {
 153                 PERROR("accept inet");
 154                 goto error;
 155         }
 156
 157         new_sock->fd = new_fd;
 158         new_sock->ops = &inet_ops;
 159
 160 end:
 161         return new_sock;
 162
 163 error:
 164         free(new_sock);
 165         return NULL;
 166 }
 167
 168 /*
 169  * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
 170  */
 171 LTTNG_HIDDEN
 172 int lttcomm_listen_inet_sock(struct lttcomm_sock *sock, int backlog)
 173 {
 174         int ret;
 175
 176         if (sock->proto == LTTCOMM_SOCK_UDP) {
 177                 /* listen(2) does not exist for UDP so simply return success. */
 178                 ret = 0;
 179                 goto end;
 180         }
 181
 182         /* Default listen backlog */
 183         if (backlog <= 0) {
 184                 backlog = LTTNG_SESSIOND_COMM_MAX_LISTEN;
 185         }
 186
 187         ret = listen(sock->fd, backlog);
 188         if (ret < 0) {
 189                 PERROR("listen inet");
 190         }
 191
 192 end:
 193         return ret;
 194 }
 195
 196 /*
 197  * Receive data of size len in put that data into the buf param. Using recvmsg
 198  * API.
 199  *
 200  * Return the size of received data.
 201  */
 202 LTTNG_HIDDEN
 203 ssize_t lttcomm_recvmsg_inet_sock(struct lttcomm_sock *sock, void *buf,
 204                 size_t len, int flags)
 205 {
 206         struct msghdr msg;
 207         struct iovec iov[1];
 208         ssize_t ret = -1;
 209         size_t len_last;
 210
 211         memset(&msg, 0, sizeof(msg));
 212
 213         iov[0].iov_base = buf;
 214         iov[0].iov_len = len;
 215         msg.msg_iov = iov;
 216         msg.msg_iovlen = 1;
 217
 218         msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin;
 219         msg.msg_namelen = sizeof(sock->sockaddr.addr.sin);
 220
 221         do {
 222                 len_last = iov[0].iov_len;
 223                 ret = recvmsg(sock->fd, &msg, flags);
 224                 if (ret > 0) {
 225                         iov[0].iov_base += ret;
 226                         iov[0].iov_len -= ret;
 227                         assert(ret <= len_last);
 228                 }
 229         } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
 230         if (ret < 0) {
 231                 PERROR("recvmsg inet");
 232         } else if (ret > 0) {
 233                 ret = len;
 234         }
 235         /* Else ret = 0 meaning an orderly shutdown. */
 236
 237         return ret;
 238 }
 239
 240 /*
 241  * Send buf data of size len. Using sendmsg API.
 242  *
 243  * Return the size of sent data.
 244  */
 245 LTTNG_HIDDEN
 246 ssize_t lttcomm_sendmsg_inet_sock(struct lttcomm_sock *sock, void *buf,
 247                 size_t len, int flags)
 248 {
 249         struct msghdr msg;
 250         struct iovec iov[1];
 251         ssize_t ret = -1;
 252
 253         memset(&msg, 0, sizeof(msg));
 254
 255         iov[0].iov_base = buf;
 256         iov[0].iov_len = len;
 257         msg.msg_iov = iov;
 258         msg.msg_iovlen = 1;
 259
 260         switch (sock->proto) {
 261         case LTTCOMM_SOCK_UDP:
 262                 msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin;
 263                 msg.msg_namelen = sizeof(sock->sockaddr.addr.sin);
 264                 break;
 265         default:
 266                 break;
 267         }
 268
 269         do {
 270                 ret = sendmsg(sock->fd, &msg, flags);
 271         } while (ret < 0 && errno == EINTR);
 272         if (ret < 0) {
 273                 /*
 274                  * Only warn about EPIPE when quiet mode is deactivated.
 275                  * We consider EPIPE as expected.
 276                  */
 277                 if (errno != EPIPE || !lttng_opt_quiet) {
 278                         PERROR("sendmsg inet");
 279                 }
 280         }
 281
 282         return ret;
 283 }
 284
 285 /*
 286  * Shutdown cleanly and close.
 287  */
 288 LTTNG_HIDDEN
 289 int lttcomm_close_inet_sock(struct lttcomm_sock *sock)
 290 {
 291         int ret;
 292
 293         /* Don't try to close an invalid marked socket */
 294         if (sock->fd == -1) {
 295                 return 0;
 296         }
 297
 298         ret = close(sock->fd);
 299         if (ret) {
 300                 PERROR("close inet");
 301         }
 302
 303         /* Mark socket */
 304         sock->fd = -1;
 305
 306         return ret;
 307 }