src/common/sessiond-comm/inet6.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 _LGPL_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 #include <fcntl.h>
  29 #include <time.h>
  30 #include <poll.h>
  31
  32 #include <common/common.h>
  33
  34 #include "inet6.h"
  35
  36 #define MSEC_PER_SEC    1000
  37 #define NSEC_PER_MSEC   1000000
  38 #define RECONNECT_DELAY 200     /* ms */
  39
  40 /*
  41  * INET protocol operations.
  42  */
  43 static const struct lttcomm_proto_ops inet6_ops = {
  44         .bind = lttcomm_bind_inet6_sock,
  45         .close = lttcomm_close_inet6_sock,
  46         .connect = lttcomm_connect_inet6_sock,
  47         .accept = lttcomm_accept_inet6_sock,
  48         .listen = lttcomm_listen_inet6_sock,
  49         .recvmsg = lttcomm_recvmsg_inet6_sock,
  50         .sendmsg = lttcomm_sendmsg_inet6_sock,
  51 };
  52
  53 /*
  54  * Creates an PF_INET socket.
  55  */
  56 LTTNG_HIDDEN
  57 int lttcomm_create_inet6_sock(struct lttcomm_sock *sock, int type, int proto)
  58 {
  59         int val = 1, ret;
  60         unsigned long timeout;
  61
  62         /* Create server socket */
  63         if ((sock->fd = socket(PF_INET6, type, proto)) < 0) {
  64                 PERROR("socket inet6");
  65                 goto error;
  66         }
  67
  68         sock->ops = &inet6_ops;
  69
  70         /*
  71          * Set socket option to reuse the address.
  72          */
  73         ret = setsockopt(sock->fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(int));
  74         if (ret < 0) {
  75                 PERROR("setsockopt inet6");
  76                 goto error;
  77         }
  78         timeout = lttcomm_get_network_timeout();
  79         if (timeout) {
  80                 ret = lttcomm_setsockopt_rcv_timeout(sock->fd, timeout);
  81                 if (ret) {
  82                         goto error;
  83                 }
  84                 ret = lttcomm_setsockopt_snd_timeout(sock->fd, timeout);
  85                 if (ret) {
  86                         goto error;
  87                 }
  88         }
  89
  90         return 0;
  91
  92 error:
  93         return -1;
  94 }
  95
  96 /*
  97  * Bind socket and return.
  98  */
  99 LTTNG_HIDDEN
 100 int lttcomm_bind_inet6_sock(struct lttcomm_sock *sock)
 101 {
 102         int ret;
 103
 104         ret = bind(sock->fd, (const struct sockaddr *) &sock->sockaddr.addr.sin6,
 105                         sizeof(sock->sockaddr.addr.sin6));
 106         if (ret < 0) {
 107                 PERROR("bind inet6");
 108         }
 109
 110         return ret;
 111 }
 112
 113 static
 114 int connect_no_timeout(struct lttcomm_sock *sock)
 115 {
 116         return connect(sock->fd, (struct sockaddr *) &sock->sockaddr.addr.sin6,
 117                         sizeof(sock->sockaddr.addr.sin6));
 118 }
 119
 120 /*
 121  * Return time_a - time_b  in milliseconds.
 122  */
 123 static
 124 unsigned long time_diff_ms(struct timespec *time_a,
 125                 struct timespec *time_b)
 126 {
 127         time_t sec_diff;
 128         long nsec_diff;
 129         unsigned long result_ms;
 130
 131         sec_diff = time_a->tv_sec - time_b->tv_sec;
 132         nsec_diff = time_a->tv_nsec - time_b->tv_nsec;
 133
 134         result_ms = sec_diff * MSEC_PER_SEC;
 135         result_ms += nsec_diff / NSEC_PER_MSEC;
 136         return result_ms;
 137 }
 138
 139 static
 140 int connect_with_timeout(struct lttcomm_sock *sock)
 141 {
 142         unsigned long timeout = lttcomm_get_network_timeout();
 143         int ret, flags, connect_ret;
 144         struct timespec orig_time, cur_time;
 145
 146         ret = fcntl(sock->fd, F_GETFL, 0);
 147         if (ret == -1) {
 148                 PERROR("fcntl");
 149                 return -1;
 150         }
 151         flags = ret;
 152
 153         /* Set socket to nonblock */
 154         ret = fcntl(sock->fd, F_SETFL, flags | O_NONBLOCK);
 155         if (ret == -1) {
 156                 PERROR("fcntl");
 157                 return -1;
 158         }
 159
 160         ret = clock_gettime(CLOCK_MONOTONIC, &orig_time);
 161         if (ret == -1) {
 162                 PERROR("clock_gettime");
 163                 return -1;
 164         }
 165
 166         connect_ret = connect(sock->fd,
 167                 (struct sockaddr *) &sock->sockaddr.addr.sin6,
 168                 sizeof(sock->sockaddr.addr.sin6));
 169         if (connect_ret == -1 && errno != EAGAIN
 170                         && errno != EWOULDBLOCK
 171                         && errno != EINPROGRESS) {
 172                 goto error;
 173         } else if (!connect_ret) {
 174                 /* Connect succeeded */
 175                 goto success;
 176         }
 177
 178         /*
 179          * Perform poll loop following EINPROGRESS recommendation from
 180          * connect(2) man page.
 181          */
 182         do {
 183                 struct pollfd fds;
 184
 185                 fds.fd = sock->fd;
 186                 fds.events = POLLOUT;
 187                 fds.revents = 0;
 188                 ret = poll(&fds, 1, RECONNECT_DELAY);
 189                 if (ret < 0) {
 190                         goto error;
 191                 } else if (ret > 0) {
 192                         int optval;
 193                         socklen_t optval_len = sizeof(optval);
 194
 195                         if (!(fds.revents & POLLOUT)) {
 196                                 /* Either hup or error */
 197                                 errno = EPIPE;
 198                                 goto error;
 199                         }
 200                         /* got something */
 201                         ret = getsockopt(sock->fd, SOL_SOCKET,
 202                                 SO_ERROR, &optval, &optval_len);
 203                         if (ret) {
 204                                 goto error;
 205                         }
 206                         if (!optval) {
 207                                 connect_ret = 0;
 208                                 goto success;
 209                         } else {
 210                                 goto error;
 211                         }
 212                 }
 213                 /* ret == 0: timeout */
 214                 ret = clock_gettime(CLOCK_MONOTONIC, &cur_time);
 215                 if (ret == -1) {
 216                         PERROR("clock_gettime");
 217                         connect_ret = ret;
 218                         goto error;
 219                 }
 220         } while (time_diff_ms(&cur_time, &orig_time) < timeout);
 221
 222         /* Timeout */
 223         errno = ETIMEDOUT;
 224         connect_ret = -1;
 225
 226 success:
 227         /* Restore initial flags */
 228         ret = fcntl(sock->fd, F_SETFL, flags);
 229         if (ret == -1) {
 230                 PERROR("fcntl");
 231                 /* Continue anyway */
 232         }
 233 error:
 234         return connect_ret;
 235 }
 236
 237 /*
 238  * Connect PF_INET socket.
 239  */
 240 LTTNG_HIDDEN
 241 int lttcomm_connect_inet6_sock(struct lttcomm_sock *sock)
 242 {
 243         int ret, closeret;
 244
 245         if (lttcomm_get_network_timeout()) {
 246                 ret = connect_with_timeout(sock);
 247         } else {
 248                 ret = connect_no_timeout(sock);
 249         }
 250         if (ret < 0) {
 251                 PERROR("connect inet6");
 252                 goto error_connect;
 253         }
 254
 255         return ret;
 256
 257 error_connect:
 258         closeret = close(sock->fd);
 259         if (closeret) {
 260                 PERROR("close inet6");
 261         }
 262
 263         return ret;
 264 }
 265
 266 /*
 267  * Do an accept(2) on the sock and return the new lttcomm socket. The socket
 268  * MUST be bind(2) before.
 269  */
 270 LTTNG_HIDDEN
 271 struct lttcomm_sock *lttcomm_accept_inet6_sock(struct lttcomm_sock *sock)
 272 {
 273         int new_fd;
 274         socklen_t len;
 275         struct lttcomm_sock *new_sock;
 276
 277         if (sock->proto == LTTCOMM_SOCK_UDP) {
 278                 /*
 279                  * accept(2) does not exist for UDP so simply return the passed socket.
 280                  */
 281                 new_sock = sock;
 282                 goto end;
 283         }
 284
 285         new_sock = lttcomm_alloc_sock(sock->proto);
 286         if (new_sock == NULL) {
 287                 goto error;
 288         }
 289
 290         len = sizeof(new_sock->sockaddr.addr.sin6);
 291
 292         /* Blocking call */
 293         new_fd = accept(sock->fd,
 294                         (struct sockaddr *) &new_sock->sockaddr.addr.sin6, &len);
 295         if (new_fd < 0) {
 296                 PERROR("accept inet6");
 297                 goto error;
 298         }
 299
 300         new_sock->fd = new_fd;
 301         new_sock->ops = &inet6_ops;
 302
 303 end:
 304         return new_sock;
 305
 306 error:
 307         free(new_sock);
 308         return NULL;
 309 }
 310
 311 /*
 312  * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
 313  */
 314 LTTNG_HIDDEN
 315 int lttcomm_listen_inet6_sock(struct lttcomm_sock *sock, int backlog)
 316 {
 317         int ret;
 318
 319         if (sock->proto == LTTCOMM_SOCK_UDP) {
 320                 /* listen(2) does not exist for UDP so simply return success. */
 321                 ret = 0;
 322                 goto end;
 323         }
 324
 325         /* Default listen backlog */
 326         if (backlog <= 0) {
 327                 backlog = LTTNG_SESSIOND_COMM_MAX_LISTEN;
 328         }
 329
 330         ret = listen(sock->fd, backlog);
 331         if (ret < 0) {
 332                 PERROR("listen inet6");
 333         }
 334
 335 end:
 336         return ret;
 337 }
 338
 339 /*
 340  * Receive data of size len in put that data into the buf param. Using recvmsg
 341  * API.
 342  *
 343  * Return the size of received data.
 344  */
 345 LTTNG_HIDDEN
 346 ssize_t lttcomm_recvmsg_inet6_sock(struct lttcomm_sock *sock, void *buf,
 347                 size_t len, int flags)
 348 {
 349         struct msghdr msg;
 350         struct iovec iov[1];
 351         ssize_t ret = -1;
 352         size_t len_last;
 353
 354         memset(&msg, 0, sizeof(msg));
 355
 356         iov[0].iov_base = buf;
 357         iov[0].iov_len = len;
 358         msg.msg_iov = iov;
 359         msg.msg_iovlen = 1;
 360
 361         msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin6;
 362         msg.msg_namelen = sizeof(sock->sockaddr.addr.sin6);
 363
 364         do {
 365                 len_last = iov[0].iov_len;
 366                 ret = recvmsg(sock->fd, &msg, flags);
 367                 if (ret > 0) {
 368                         iov[0].iov_base += ret;
 369                         iov[0].iov_len -= ret;
 370                         assert(ret <= len_last);
 371                 }
 372         } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
 373         if (ret < 0) {
 374                 PERROR("recvmsg inet");
 375         } else if (ret > 0) {
 376                 ret = len;
 377         }
 378         /* Else ret = 0 meaning an orderly shutdown. */
 379
 380         return ret;
 381 }
 382
 383 /*
 384  * Send buf data of size len. Using sendmsg API.
 385  *
 386  * Return the size of sent data.
 387  */
 388 LTTNG_HIDDEN
 389 ssize_t lttcomm_sendmsg_inet6_sock(struct lttcomm_sock *sock, const void *buf,
 390                 size_t len, int flags)
 391 {
 392         struct msghdr msg;
 393         struct iovec iov[1];
 394         ssize_t ret = -1;
 395
 396         memset(&msg, 0, sizeof(msg));
 397
 398         iov[0].iov_base = (void *) buf;
 399         iov[0].iov_len = len;
 400         msg.msg_iov = iov;
 401         msg.msg_iovlen = 1;
 402
 403         switch (sock->proto) {
 404         case LTTCOMM_SOCK_UDP:
 405                 msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin6;
 406                 msg.msg_namelen = sizeof(sock->sockaddr.addr.sin6);
 407                 break;
 408         default:
 409                 break;
 410         }
 411
 412         do {
 413                 ret = sendmsg(sock->fd, &msg, flags);
 414         } while (ret < 0 && errno == EINTR);
 415         if (ret < 0) {
 416                 /*
 417                  * Only warn about EPIPE when quiet mode is deactivated.
 418                  * We consider EPIPE as expected.
 419                  */
 420                 if (errno != EPIPE || !lttng_opt_quiet) {
 421                         PERROR("sendmsg inet6");
 422                 }
 423         }
 424
 425         return ret;
 426 }
 427
 428 /*
 429  * Shutdown cleanly and close.
 430  */
 431 LTTNG_HIDDEN
 432 int lttcomm_close_inet6_sock(struct lttcomm_sock *sock)
 433 {
 434         int ret;
 435
 436         /* Don't try to close an invalid marked socket */
 437         if (sock->fd == -1) {
 438                 return 0;
 439         }
 440
 441         ret = close(sock->fd);
 442         if (ret) {
 443                 PERROR("close inet6");
 444         }
 445
 446         /* Mark socket */
 447         sock->fd = -1;
 448
 449         return ret;
 450 }