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 <common/compat/time.h>
  30 #include <poll.h>
  31
  32 #include <common/common.h>
  33 #include <common/time.h>
  34
  35 #include "inet6.h"
  36
  37 #define RECONNECT_DELAY 200     /* ms */
  38
  39 /*
  40  * INET protocol operations.
  41  */
  42 static const struct lttcomm_proto_ops inet6_ops = {
  43         .bind = lttcomm_bind_inet6_sock,
  44         .close = lttcomm_close_inet6_sock,
  45         .connect = lttcomm_connect_inet6_sock,
  46         .accept = lttcomm_accept_inet6_sock,
  47         .listen = lttcomm_listen_inet6_sock,
  48         .recvmsg = lttcomm_recvmsg_inet6_sock,
  49         .sendmsg = lttcomm_sendmsg_inet6_sock,
  50 };
  51
  52 /*
  53  * Creates an PF_INET socket.
  54  */
  55 LTTNG_HIDDEN
  56 int lttcomm_create_inet6_sock(struct lttcomm_sock *sock, int type, int proto)
  57 {
  58         int val = 1, ret;
  59         unsigned long timeout;
  60
  61         /* Create server socket */
  62         if ((sock->fd = socket(PF_INET6, type, proto)) < 0) {
  63                 PERROR("socket inet6");
  64                 goto error;
  65         }
  66
  67         sock->ops = &inet6_ops;
  68
  69         /*
  70          * Set socket option to reuse the address.
  71          */
  72         ret = setsockopt(sock->fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(int));
  73         if (ret < 0) {
  74                 PERROR("setsockopt inet6");
  75                 goto error;
  76         }
  77         timeout = lttcomm_get_network_timeout();
  78         if (timeout) {
  79                 ret = lttcomm_setsockopt_rcv_timeout(sock->fd, timeout);
  80                 if (ret) {
  81                         goto error;
  82                 }
  83                 ret = lttcomm_setsockopt_snd_timeout(sock->fd, timeout);
  84                 if (ret) {
  85                         goto error;
  86                 }
  87         }
  88
  89         return 0;
  90
  91 error:
  92         return -1;
  93 }
  94
  95 /*
  96  * Bind socket and return.
  97  */
  98 LTTNG_HIDDEN
  99 int lttcomm_bind_inet6_sock(struct lttcomm_sock *sock)
 100 {
 101         return bind(sock->fd,
 102                         (const struct sockaddr *) &sock->sockaddr.addr.sin6,
 103                         sizeof(sock->sockaddr.addr.sin6));
 104 }
 105
 106 static
 107 int connect_no_timeout(struct lttcomm_sock *sock)
 108 {
 109         return connect(sock->fd, (struct sockaddr *) &sock->sockaddr.addr.sin6,
 110                         sizeof(sock->sockaddr.addr.sin6));
 111 }
 112
 113 /*
 114  * Return time_a - time_b  in milliseconds.
 115  */
 116 static
 117 unsigned long time_diff_ms(struct timespec *time_a,
 118                 struct timespec *time_b)
 119 {
 120         time_t sec_diff;
 121         long nsec_diff;
 122         unsigned long result_ms;
 123
 124         sec_diff = time_a->tv_sec - time_b->tv_sec;
 125         nsec_diff = time_a->tv_nsec - time_b->tv_nsec;
 126
 127         result_ms = sec_diff * MSEC_PER_SEC;
 128         result_ms += nsec_diff / NSEC_PER_MSEC;
 129         return result_ms;
 130 }
 131
 132 static
 133 int connect_with_timeout(struct lttcomm_sock *sock)
 134 {
 135         unsigned long timeout = lttcomm_get_network_timeout();
 136         int ret, flags, connect_ret;
 137         struct timespec orig_time, cur_time;
 138
 139         ret = fcntl(sock->fd, F_GETFL, 0);
 140         if (ret == -1) {
 141                 PERROR("fcntl");
 142                 return -1;
 143         }
 144         flags = ret;
 145
 146         /* Set socket to nonblock */
 147         ret = fcntl(sock->fd, F_SETFL, flags | O_NONBLOCK);
 148         if (ret == -1) {
 149                 PERROR("fcntl");
 150                 return -1;
 151         }
 152
 153         ret = lttng_clock_gettime(CLOCK_MONOTONIC, &orig_time);
 154         if (ret == -1) {
 155                 PERROR("clock_gettime");
 156                 return -1;
 157         }
 158
 159         connect_ret = connect(sock->fd,
 160                 (struct sockaddr *) &sock->sockaddr.addr.sin6,
 161                 sizeof(sock->sockaddr.addr.sin6));
 162         if (connect_ret == -1 && errno != EAGAIN
 163                         && errno != EWOULDBLOCK
 164                         && errno != EINPROGRESS) {
 165                 goto error;
 166         } else if (!connect_ret) {
 167                 /* Connect succeeded */
 168                 goto success;
 169         }
 170
 171         DBG("Asynchronous connect for sock %d, performing polling with"
 172                         " timeout: %lums", sock->fd, timeout);
 173
 174         /*
 175          * Perform poll loop following EINPROGRESS recommendation from
 176          * connect(2) man page.
 177          */
 178         do {
 179                 struct pollfd fds;
 180
 181                 fds.fd = sock->fd;
 182                 fds.events = POLLOUT;
 183                 fds.revents = 0;
 184                 ret = poll(&fds, 1, RECONNECT_DELAY);
 185                 if (ret < 0) {
 186                         goto error;
 187                 } else if (ret > 0) {
 188                         int optval;
 189                         socklen_t optval_len = sizeof(optval);
 190
 191                         if (!(fds.revents & POLLOUT)) {
 192                                 /* Either hup or error */
 193                                 errno = EPIPE;
 194                                 goto error;
 195                         }
 196                         /* got something */
 197                         ret = getsockopt(sock->fd, SOL_SOCKET,
 198                                 SO_ERROR, &optval, &optval_len);
 199                         if (ret) {
 200                                 PERROR("getsockopt");
 201                                 goto error;
 202                         }
 203                         if (!optval) {
 204                                 connect_ret = 0;
 205                                 goto success;
 206                         } else {
 207                                 /* Get actual connect() errno from opt_val */
 208                                 errno = optval;
 209                                 goto error;
 210                         }
 211                 }
 212                 /* ret == 0: timeout */
 213                 ret = lttng_clock_gettime(CLOCK_MONOTONIC, &cur_time);
 214                 if (ret == -1) {
 215                         PERROR("clock_gettime");
 216                         connect_ret = ret;
 217                         goto error;
 218                 }
 219         } while (time_diff_ms(&cur_time, &orig_time) < timeout);
 220
 221         /* Timeout */
 222         errno = ETIMEDOUT;
 223         connect_ret = -1;
 224
 225 success:
 226         /* Restore initial flags */
 227         ret = fcntl(sock->fd, F_SETFL, flags);
 228         if (ret == -1) {
 229                 PERROR("fcntl");
 230                 /* Continue anyway */
 231         }
 232 error:
 233         return connect_ret;
 234 }
 235
 236 /*
 237  * Connect PF_INET socket.
 238  */
 239 LTTNG_HIDDEN
 240 int lttcomm_connect_inet6_sock(struct lttcomm_sock *sock)
 241 {
 242         int ret, closeret;
 243
 244         if (lttcomm_get_network_timeout()) {
 245                 ret = connect_with_timeout(sock);
 246         } else {
 247                 ret = connect_no_timeout(sock);
 248         }
 249         if (ret < 0) {
 250                 PERROR("connect inet6");
 251                 goto error_connect;
 252         }
 253
 254         return ret;
 255
 256 error_connect:
 257         closeret = close(sock->fd);
 258         if (closeret) {
 259                 PERROR("close inet6");
 260         }
 261
 262         return ret;
 263 }
 264
 265 /*
 266  * Do an accept(2) on the sock and return the new lttcomm socket. The socket
 267  * MUST be bind(2) before.
 268  */
 269 LTTNG_HIDDEN
 270 struct lttcomm_sock *lttcomm_accept_inet6_sock(struct lttcomm_sock *sock)
 271 {
 272         int new_fd;
 273         socklen_t len;
 274         struct lttcomm_sock *new_sock;
 275
 276         if (sock->proto == LTTCOMM_SOCK_UDP) {
 277                 /*
 278                  * accept(2) does not exist for UDP so simply return the passed socket.
 279                  */
 280                 new_sock = sock;
 281                 goto end;
 282         }
 283
 284         new_sock = lttcomm_alloc_sock(sock->proto);
 285         if (new_sock == NULL) {
 286                 goto error;
 287         }
 288
 289         len = sizeof(new_sock->sockaddr.addr.sin6);
 290
 291         /* Blocking call */
 292         new_fd = accept(sock->fd,
 293                         (struct sockaddr *) &new_sock->sockaddr.addr.sin6, &len);
 294         if (new_fd < 0) {
 295                 PERROR("accept inet6");
 296                 goto error;
 297         }
 298
 299         new_sock->fd = new_fd;
 300         new_sock->ops = &inet6_ops;
 301
 302 end:
 303         return new_sock;
 304
 305 error:
 306         free(new_sock);
 307         return NULL;
 308 }
 309
 310 /*
 311  * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
 312  */
 313 LTTNG_HIDDEN
 314 int lttcomm_listen_inet6_sock(struct lttcomm_sock *sock, int backlog)
 315 {
 316         int ret;
 317
 318         if (sock->proto == LTTCOMM_SOCK_UDP) {
 319                 /* listen(2) does not exist for UDP so simply return success. */
 320                 ret = 0;
 321                 goto end;
 322         }
 323
 324         /* Default listen backlog */
 325         if (backlog <= 0) {
 326                 backlog = LTTNG_SESSIOND_COMM_MAX_LISTEN;
 327         }
 328
 329         ret = listen(sock->fd, backlog);
 330         if (ret < 0) {
 331                 PERROR("listen inet6");
 332         }
 333
 334 end:
 335         return ret;
 336 }
 337
 338 /*
 339  * Receive data of size len in put that data into the buf param. Using recvmsg
 340  * API.
 341  *
 342  * Return the size of received data.
 343  */
 344 LTTNG_HIDDEN
 345 ssize_t lttcomm_recvmsg_inet6_sock(struct lttcomm_sock *sock, void *buf,
 346                 size_t len, int flags)
 347 {
 348         struct msghdr msg;
 349         struct iovec iov[1];
 350         ssize_t ret = -1;
 351         size_t len_last;
 352
 353         memset(&msg, 0, sizeof(msg));
 354
 355         iov[0].iov_base = buf;
 356         iov[0].iov_len = len;
 357         msg.msg_iov = iov;
 358         msg.msg_iovlen = 1;
 359
 360         msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin6;
 361         msg.msg_namelen = sizeof(sock->sockaddr.addr.sin6);
 362
 363         do {
 364                 len_last = iov[0].iov_len;
 365                 ret = recvmsg(sock->fd, &msg, flags);
 366                 if (ret > 0) {
 367                         if (flags & MSG_DONTWAIT) {
 368                                 goto end;
 369                         }
 370                         iov[0].iov_base += ret;
 371                         iov[0].iov_len -= ret;
 372                         assert(ret <= len_last);
 373                 }
 374         } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
 375         if (ret < 0) {
 376                 PERROR("recvmsg inet");
 377         } else if (ret > 0) {
 378                 ret = len;
 379         }
 380         /* Else ret = 0 meaning an orderly shutdown. */
 381 end:
 382         return ret;
 383 }
 384
 385 /*
 386  * Send buf data of size len. Using sendmsg API.
 387  *
 388  * Return the size of sent data.
 389  */
 390 LTTNG_HIDDEN
 391 ssize_t lttcomm_sendmsg_inet6_sock(struct lttcomm_sock *sock, const void *buf,
 392                 size_t len, int flags)
 393 {
 394         struct msghdr msg;
 395         struct iovec iov[1];
 396         ssize_t ret = -1;
 397
 398         memset(&msg, 0, sizeof(msg));
 399
 400         iov[0].iov_base = (void *) buf;
 401         iov[0].iov_len = len;
 402         msg.msg_iov = iov;
 403         msg.msg_iovlen = 1;
 404
 405         switch (sock->proto) {
 406         case LTTCOMM_SOCK_UDP:
 407                 msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin6;
 408                 msg.msg_namelen = sizeof(sock->sockaddr.addr.sin6);
 409                 break;
 410         default:
 411                 break;
 412         }
 413
 414         do {
 415                 ret = sendmsg(sock->fd, &msg, flags);
 416         } while (ret < 0 && errno == EINTR);
 417         if (ret < 0) {
 418                 /*
 419                  * Only warn about EPIPE when quiet mode is deactivated.
 420                  * We consider EPIPE as expected.
 421                  */
 422                 if (errno != EPIPE || !lttng_opt_quiet) {
 423                         PERROR("sendmsg inet6");
 424                 }
 425         }
 426
 427         return ret;
 428 }
 429
 430 /*
 431  * Shutdown cleanly and close.
 432  */
 433 LTTNG_HIDDEN
 434 int lttcomm_close_inet6_sock(struct lttcomm_sock *sock)
 435 {
 436         int ret;
 437
 438         /* Don't try to close an invalid marked socket */
 439         if (sock->fd == -1) {
 440                 return 0;
 441         }
 442
 443         ret = close(sock->fd);
 444         if (ret) {
 445                 PERROR("close inet6");
 446         }
 447
 448         /* Mark socket */
 449         sock->fd = -1;
 450
 451         return ret;
 452 }