libustcomm/ustcomm.c

   1 /* Copyright (C) 2009  Pierre-Marc Fournier
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  16  */
  17
  18 /* API used by UST components to communicate with each other via sockets. */
  19
  20 #define _GNU_SOURCE
  21 #include <sys/types.h>
  22 #include <signal.h>
  23 #include <errno.h>
  24 #include <sys/socket.h>
  25 #include <sys/un.h>
  26 #include <unistd.h>
  27 #include <poll.h>
  28 #include <sys/epoll.h>
  29 #include <sys/stat.h>
  30
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <execinfo.h>
  35
  36 #include "ustcomm.h"
  37 #include "usterr.h"
  38 #include "share.h"
  39
  40 static int mkdir_p(const char *path, mode_t mode)
  41 {
  42         const char *path_p;
  43         char *tmp;
  44
  45         int retval = 0;
  46         int result;
  47         mode_t old_umask;
  48
  49         tmp = zmalloc(strlen(path) + 1);
  50         if (tmp == NULL)
  51                 return -1;
  52
  53         /* skip first / */
  54         path_p = path+1;
  55
  56         old_umask = umask(0);
  57         for(;;) {
  58                 while (*path_p != '/') {
  59                         if(*path_p == 0)
  60                                 break;
  61                         ++path_p;
  62                 }
  63                 if (*path_p == '/') {
  64                         strncpy(tmp, path, path_p - path);
  65                         tmp[path_p-path] = '\0';
  66                         if (tmp[path_p - path - 1] != '/') {
  67                                 result = mkdir(tmp, mode);
  68                                 if(result == -1) {
  69                                         if (!(errno == EEXIST || errno == EACCES || errno == EROFS)) {
  70                                                 /* Then this is a real error */
  71                                                 retval = -1;
  72                                                 break;
  73                                         }
  74                                 }
  75                         }
  76                         /* pass / */
  77                         path_p++;
  78                 } else {
  79                         /* last component */
  80                         result = mkdir(path, mode);
  81                         if (result == -1)
  82                                 retval = -1;
  83                         break;
  84                 }
  85         }
  86
  87         free(tmp);
  88         umask(old_umask);
  89         return retval;
  90 }
  91
  92 static struct sockaddr_un * create_sock_addr(const char *name,
  93                                              size_t *sock_addr_size)
  94 {
  95         struct sockaddr_un * addr;
  96         size_t alloc_size;
  97
  98         alloc_size = (size_t) (((struct sockaddr_un *) 0)->sun_path) +
  99                 strlen(name) + 1;
 100
 101         addr = malloc(alloc_size);
 102         if (addr < 0) {
 103                 ERR("allocating addr failed");
 104                 return NULL;
 105         }
 106
 107         addr->sun_family = AF_UNIX;
 108         strcpy(addr->sun_path, name);
 109
 110         *sock_addr_size = alloc_size;
 111
 112         return addr;
 113 }
 114
 115 struct ustcomm_sock * ustcomm_init_sock(int fd, int epoll_fd,
 116                                         struct list_head *list)
 117 {
 118         struct epoll_event ev;
 119         struct ustcomm_sock *sock;
 120
 121         sock = malloc(sizeof(struct ustcomm_sock));
 122         if (!sock) {
 123                 perror("malloc: couldn't allocate ustcomm_sock");
 124                 return NULL;
 125         }
 126
 127         ev.events = EPOLLIN;
 128         ev.data.ptr = sock;
 129         sock->fd = fd;
 130
 131         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock->fd, &ev) == -1) {
 132                 perror("epoll_ctl: failed to add socket\n");
 133                 free(sock);
 134                 return NULL;
 135         }
 136
 137         sock->epoll_fd = epoll_fd;
 138         if (list) {
 139                 list_add(&sock->list, list);
 140         } else {
 141                 INIT_LIST_HEAD(&sock->list);
 142         }
 143
 144         return sock;
 145 }
 146
 147 void ustcomm_del_sock(struct ustcomm_sock *sock, int keep_in_epoll)
 148 {
 149         list_del(&sock->list);
 150         if (!keep_in_epoll) {
 151                 if (epoll_ctl(sock->epoll_fd, EPOLL_CTL_DEL, sock->fd, NULL) == -1) {
 152                         PERROR("epoll_ctl: failed to delete socket");
 153                 }
 154         }
 155         close(sock->fd);
 156         free(sock);
 157 }
 158
 159 struct ustcomm_sock * ustcomm_init_named_socket(const char *name,
 160                                                 int epoll_fd)
 161 {
 162         int result;
 163         int fd;
 164         size_t sock_addr_size;
 165         struct sockaddr_un * addr;
 166         struct ustcomm_sock *sock;
 167
 168         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 169         if(fd == -1) {
 170                 PERROR("socket");
 171                 return NULL;
 172         }
 173
 174         addr = create_sock_addr(name, &sock_addr_size);
 175         if (addr == NULL) {
 176                 ERR("allocating addr, UST thread bailing");
 177                 goto close_sock;
 178         }
 179
 180         result = access(name, F_OK);
 181         if(result == 0) {
 182                 /* file exists */
 183                 result = unlink(name);
 184                 if(result == -1) {
 185                         PERROR("unlink of socket file");
 186                         goto free_addr;
 187                 }
 188                 DBG("socket already exists; overwriting");
 189         }
 190
 191         result = bind(fd, (struct sockaddr *)addr, sock_addr_size);
 192         if(result == -1) {
 193                 PERROR("bind");
 194                 goto free_addr;
 195         }
 196
 197         result = listen(fd, 1);
 198         if(result == -1) {
 199                 PERROR("listen");
 200                 goto free_addr;
 201         }
 202
 203         sock = ustcomm_init_sock(fd, epoll_fd,
 204                                  NULL);
 205         if (!sock) {
 206                 ERR("failed to create ustcomm_sock");
 207                 goto free_addr;
 208         }
 209
 210         free(addr);
 211
 212         return sock;
 213
 214 free_addr:
 215         free(addr);
 216 close_sock:
 217         close(fd);
 218
 219         return NULL;
 220 }
 221
 222 void ustcomm_del_named_sock(struct ustcomm_sock *sock,
 223                             int keep_socket_file)
 224 {
 225         int result, fd;
 226         struct stat st;
 227         struct sockaddr dummy;
 228         struct sockaddr_un *sockaddr = NULL;
 229         int alloc_size;
 230
 231         fd = sock->fd;
 232
 233         if(!keep_socket_file) {
 234
 235                 /* Get the socket name */
 236                 alloc_size = sizeof(dummy);
 237                 if (getsockname(fd, &dummy, (socklen_t *)&alloc_size) < 0) {
 238                         PERROR("getsockname failed");
 239                         goto del_sock;
 240                 }
 241
 242                 sockaddr = zmalloc(alloc_size);
 243                 if (!sockaddr) {
 244                         ERR("failed to allocate sockaddr");
 245                         goto del_sock;
 246                 }
 247
 248                 if (getsockname(fd, sockaddr, (socklen_t *)&alloc_size) < 0) {
 249                         PERROR("getsockname failed");
 250                         goto free_sockaddr;
 251                 }
 252
 253                 /* Destroy socket */
 254                 result = stat(sockaddr->sun_path, &st);
 255                 if(result < 0) {
 256                         PERROR("stat (%s)", sockaddr->sun_path);
 257                         goto free_sockaddr;
 258                 }
 259
 260                 /* Paranoid check before deleting. */
 261                 result = S_ISSOCK(st.st_mode);
 262                 if(!result) {
 263                         ERR("The socket we are about to delete is not a socket.");
 264                         goto free_sockaddr;
 265                 }
 266
 267                 result = unlink(sockaddr->sun_path);
 268                 if(result < 0) {
 269                         PERROR("unlink");
 270                 }
 271         }
 272
 273 free_sockaddr:
 274         free(sockaddr);
 275
 276 del_sock:
 277         ustcomm_del_sock(sock, keep_socket_file);
 278 }
 279
 280 int ustcomm_recv_alloc(int sock,
 281                        struct ustcomm_header *header,
 282                        char **data) {
 283         int result;
 284         struct ustcomm_header peek_header;
 285         struct iovec iov[2];
 286         struct msghdr msg;
 287
 288         /* Just to make the caller fail hard */
 289         *data = NULL;
 290
 291         result = recv(sock, &peek_header, sizeof(peek_header),
 292                       MSG_PEEK | MSG_WAITALL);
 293         if (result <= 0) {
 294                 if(errno == ECONNRESET) {
 295                         return 0;
 296                 } else if (errno == EINTR) {
 297                         return -1;
 298                 } else if (result < 0) {
 299                         PERROR("recv");
 300                         return -1;
 301                 }
 302                 return 0;
 303         }
 304
 305         memset(&msg, 0, sizeof(msg));
 306
 307         iov[0].iov_base = (char *)header;
 308         iov[0].iov_len = sizeof(struct ustcomm_header);
 309
 310         msg.msg_iov = iov;
 311         msg.msg_iovlen = 1;
 312
 313         if (peek_header.size) {
 314                 *data = zmalloc(peek_header.size);
 315                 if (!*data) {
 316                         return -ENOMEM;
 317                 }
 318
 319                 iov[1].iov_base = *data;
 320                 iov[1].iov_len = peek_header.size;
 321
 322                 msg.msg_iovlen++;
 323         }
 324
 325         result = recvmsg(sock, &msg, MSG_WAITALL);
 326         if (result < 0) {
 327                 free(*data);
 328                 PERROR("recvmsg failed");
 329         }
 330
 331         return result;
 332 }
 333
 334 /* returns 1 to indicate a message was received
 335  * returns 0 to indicate no message was received (end of stream)
 336  * returns -1 to indicate an error
 337  */
 338 int ustcomm_recv_fd(int sock,
 339                     struct ustcomm_header *header,
 340                     char *data, int *fd)
 341 {
 342         int result;
 343         struct ustcomm_header peek_header;
 344         struct iovec iov[2];
 345         struct msghdr msg;
 346         struct cmsghdr *cmsg;
 347         char buf[CMSG_SPACE(sizeof(int))];
 348
 349         result = recv(sock, &peek_header, sizeof(peek_header),
 350                       MSG_PEEK | MSG_WAITALL);
 351         if (result <= 0) {
 352                 if(errno == ECONNRESET) {
 353                         return 0;
 354                 } else if (errno == EINTR) {
 355                         return -1;
 356                 } else if (result < 0) {
 357                         PERROR("recv");
 358                         return -1;
 359                 }
 360                 return 0;
 361         }
 362
 363         memset(&msg, 0, sizeof(msg));
 364
 365         iov[0].iov_base = (char *)header;
 366         iov[0].iov_len = sizeof(struct ustcomm_header);
 367
 368         msg.msg_iov = iov;
 369         msg.msg_iovlen = 1;
 370
 371         if (peek_header.size && data) {
 372                 if (peek_header.size < 0 ||
 373                     peek_header.size > USTCOMM_DATA_SIZE) {
 374                         ERR("big peek header! %d", peek_header.size);
 375                         return 0;
 376                 }
 377
 378                 iov[1].iov_base = data;
 379                 iov[1].iov_len = peek_header.size;
 380
 381                 msg.msg_iovlen++;
 382         }
 383
 384         if (fd && peek_header.fd_included) {
 385                 msg.msg_control = buf;
 386                 msg.msg_controllen = sizeof(buf);
 387         }
 388
 389         result = recvmsg(sock, &msg, MSG_WAITALL);
 390         if (result <= 0) {
 391                 if (result < 0) {
 392                         PERROR("recvmsg failed");
 393                 }
 394                 return result;
 395         }
 396
 397         if (fd && peek_header.fd_included) {
 398                 cmsg = CMSG_FIRSTHDR(&msg);
 399                 result = 0;
 400                 while (cmsg != NULL) {
 401                         if (cmsg->cmsg_level == SOL_SOCKET
 402                             && cmsg->cmsg_type  == SCM_RIGHTS) {
 403                                 *fd = *(int *) CMSG_DATA(cmsg);
 404                                 result = 1;
 405                                 break;
 406                         }
 407                         cmsg = CMSG_NXTHDR(&msg, cmsg);
 408                 }
 409                 if (!result) {
 410                         ERR("Failed to receive file descriptor\n");
 411                 }
 412         }
 413
 414         return 1;
 415 }
 416
 417 int ustcomm_recv(int sock,
 418                  struct ustcomm_header *header,
 419                  char *data)
 420 {
 421         return ustcomm_recv_fd(sock, header, data, NULL);
 422 }
 423
 424
 425 int ustcomm_send_fd(int sock,
 426                     const struct ustcomm_header *header,
 427                     const char *data,
 428                     int *fd)
 429 {
 430         struct iovec iov[2];
 431         struct msghdr msg;
 432         int result;
 433         struct cmsghdr *cmsg;
 434         char buf[CMSG_SPACE(sizeof(int))];
 435
 436         memset(&msg, 0, sizeof(msg));
 437
 438         iov[0].iov_base = (char *)header;
 439         iov[0].iov_len = sizeof(struct ustcomm_header);
 440
 441         msg.msg_iov = iov;
 442         msg.msg_iovlen = 1;
 443
 444         if (header->size && data) {
 445                 iov[1].iov_base = (char *)data;
 446                 iov[1].iov_len = header->size;
 447
 448                 msg.msg_iovlen++;
 449
 450         }
 451
 452         if (fd && header->fd_included) {
 453                 msg.msg_control = buf;
 454                 msg.msg_controllen = sizeof(buf);
 455                 cmsg = CMSG_FIRSTHDR(&msg);
 456                 cmsg->cmsg_level = SOL_SOCKET;
 457                 cmsg->cmsg_type = SCM_RIGHTS;
 458                 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
 459                 *(int *) CMSG_DATA(cmsg) = *fd;
 460                 msg.msg_controllen = cmsg->cmsg_len;
 461         }
 462
 463         result = sendmsg(sock, &msg, MSG_NOSIGNAL);
 464         if (result < 0 && errno != EPIPE) {
 465                 PERROR("sendmsg failed");
 466         }
 467         return result;
 468 }
 469
 470 int ustcomm_send(int sock,
 471                  const struct ustcomm_header *header,
 472                  const char *data)
 473 {
 474         return ustcomm_send_fd(sock, header, data, NULL);
 475 }
 476
 477 int ustcomm_req(int sock,
 478                 const struct ustcomm_header *req_header,
 479                 const char *req_data,
 480                 struct ustcomm_header *res_header,
 481                 char *res_data)
 482 {
 483         int result;
 484
 485         result = ustcomm_send(sock, req_header, req_data);
 486         if ( result <= 0) {
 487                 return result;
 488         }
 489
 490         return ustcomm_recv(sock, res_header, res_data);
 491 }
 492
 493 /* Return value:
 494  *  0: success
 495  * -1: error
 496  */
 497
 498 int ustcomm_connect_path(const char *name, int *connection_fd)
 499 {
 500         int result, fd;
 501         size_t sock_addr_size;
 502         struct sockaddr_un *addr;
 503
 504         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 505         if(fd == -1) {
 506                 PERROR("socket");
 507                 return -1;
 508         }
 509
 510         addr = create_sock_addr(name, &sock_addr_size);
 511         if (addr == NULL) {
 512                 ERR("allocating addr failed");
 513                 goto close_sock;
 514         }
 515
 516         result = connect(fd, (struct sockaddr *)addr, sock_addr_size);
 517         if(result == -1) {
 518                 PERROR("connect (path=%s)", name);
 519                 goto free_sock_addr;
 520         }
 521
 522         *connection_fd = fd;
 523
 524         free(addr);
 525
 526         return 0;
 527
 528 free_sock_addr:
 529         free(addr);
 530 close_sock:
 531         close(fd);
 532
 533         return -1;
 534 }
 535
 536
 537 /* Open a connection to a traceable app.
 538  *
 539  * Return value:
 540  *  0: success
 541  * -1: error
 542  */
 543
 544 int ustcomm_connect_app(pid_t pid, int *app_fd)
 545 {
 546         int result;
 547         int retval = 0;
 548         char *name;
 549
 550         result = asprintf(&name, "%s/%d", SOCK_DIR, pid);
 551         if (result < 0) {
 552                 ERR("failed to allocate socket name");
 553                 return -1;
 554         }
 555
 556         result = ustcomm_connect_path(name, app_fd);
 557         if (result < 0) {
 558                 ERR("failed to connect to app");
 559                 retval = -1;
 560         }
 561
 562         free(name);
 563
 564         return retval;
 565 }
 566
 567 int ensure_dir_exists(const char *dir)
 568 {
 569         struct stat st;
 570         int result;
 571
 572         if(!strcmp(dir, ""))
 573                 return -1;
 574
 575         result = stat(dir, &st);
 576         if(result == -1 && errno != ENOENT) {
 577                 return -1;
 578         }
 579         else if(result == -1) {
 580                 /* ENOENT */
 581                 int result;
 582
 583                 /* mkdir mode to 0777 */
 584                 result = mkdir_p(dir, S_IRWXU | S_IRWXG | S_IRWXO);
 585                 if(result != 0) {
 586                         ERR("executing in recursive creation of directory %s", dir);
 587                         return -1;
 588                 }
 589         }
 590
 591         return 0;
 592 }
 593
 594 char * ustcomm_print_data(char *data_field, int field_size,
 595                           int *offset, const char *format, ...)
 596 {
 597         va_list args;
 598         int count, limit;
 599         char *ptr = USTCOMM_POISON_PTR;
 600
 601         limit = field_size - *offset;
 602         va_start(args, format);
 603         count = vsnprintf(&data_field[*offset], limit, format, args);
 604         va_end(args);
 605
 606         if (count < limit && count > -1) {
 607                 ptr = NULL + *offset;
 608                 *offset = *offset + count + 1;
 609         }
 610
 611         return ptr;
 612 }
 613
 614 char * ustcomm_restore_ptr(char *ptr, char *data_field, int data_field_size)
 615 {
 616         if ((unsigned long)ptr > data_field_size ||
 617             ptr == USTCOMM_POISON_PTR) {
 618                 return NULL;
 619         }
 620
 621         return data_field + (long)ptr;
 622 }
 623
 624
 625 int ustcomm_pack_channel_info(struct ustcomm_header *header,
 626                               struct ustcomm_channel_info *ch_inf,
 627                               const char *channel)
 628 {
 629         int offset = 0;
 630
 631         ch_inf->channel = ustcomm_print_data(ch_inf->data,
 632                                              sizeof(ch_inf->data),
 633                                              &offset,
 634                                              channel);
 635
 636         if (ch_inf->channel == USTCOMM_POISON_PTR) {
 637                 return -ENOMEM;
 638         }
 639
 640         header->size = COMPUTE_MSG_SIZE(ch_inf, offset);
 641
 642         return 0;
 643 }
 644
 645
 646 int ustcomm_unpack_channel_info(struct ustcomm_channel_info *ch_inf)
 647 {
 648         ch_inf->channel = ustcomm_restore_ptr(ch_inf->channel,
 649                                               ch_inf->data,
 650                                               sizeof(ch_inf->data));
 651         if (!ch_inf->channel) {
 652                 return -EINVAL;
 653         }
 654
 655         return 0;
 656 }
 657
 658 int ustcomm_pack_buffer_info(struct ustcomm_header *header,
 659                              struct ustcomm_buffer_info *buf_inf,
 660                              const char *channel,
 661                              int channel_cpu)
 662 {
 663         int offset = 0;
 664
 665         buf_inf->channel = ustcomm_print_data(buf_inf->data,
 666                                               sizeof(buf_inf->data),
 667                                               &offset,
 668                                               channel);
 669
 670         if (buf_inf->channel == USTCOMM_POISON_PTR) {
 671                 return -ENOMEM;
 672         }
 673
 674         buf_inf->ch_cpu = channel_cpu;
 675
 676         header->size = COMPUTE_MSG_SIZE(buf_inf, offset);
 677
 678         return 0;
 679 }
 680
 681
 682 int ustcomm_unpack_buffer_info(struct ustcomm_buffer_info *buf_inf)
 683 {
 684         buf_inf->channel = ustcomm_restore_ptr(buf_inf->channel,
 685                                                buf_inf->data,
 686                                                sizeof(buf_inf->data));
 687         if (!buf_inf->channel) {
 688                 return -EINVAL;
 689         }
 690
 691         return 0;
 692 }
 693
 694 int ustcomm_pack_marker_info(struct ustcomm_header *header,
 695                              struct ustcomm_marker_info *marker_inf,
 696                              const char *channel,
 697                              const char *marker)
 698 {
 699         int offset = 0;
 700
 701         marker_inf->channel = ustcomm_print_data(marker_inf->data,
 702                                                  sizeof(marker_inf->data),
 703                                                  &offset,
 704                                                  channel);
 705
 706         if (marker_inf->channel == USTCOMM_POISON_PTR) {
 707                 return -ENOMEM;
 708         }
 709
 710
 711         marker_inf->marker = ustcomm_print_data(marker_inf->data,
 712                                                  sizeof(marker_inf->data),
 713                                                  &offset,
 714                                                  marker);
 715
 716         if (marker_inf->marker == USTCOMM_POISON_PTR) {
 717                 return -ENOMEM;
 718         }
 719
 720         header->size = COMPUTE_MSG_SIZE(marker_inf, offset);
 721
 722         return 0;
 723 }
 724
 725 int ustcomm_unpack_marker_info(struct ustcomm_marker_info *marker_inf)
 726 {
 727         marker_inf->channel = ustcomm_restore_ptr(marker_inf->channel,
 728                                                   marker_inf->data,
 729                                                   sizeof(marker_inf->data));
 730         if (!marker_inf->channel) {
 731                 return -EINVAL;
 732         }
 733
 734         marker_inf->marker = ustcomm_restore_ptr(marker_inf->marker,
 735                                                  marker_inf->data,
 736                                                  sizeof(marker_inf->data));
 737         if (!marker_inf->marker) {
 738                 return -EINVAL;
 739         }
 740
 741         return 0;
 742 }
 743
 744 int ustcomm_pack_sock_path(struct ustcomm_header *header,
 745                            struct ustcomm_sock_path *sock_path_inf,
 746                            const char *socket_path)
 747 {
 748         int offset = 0;
 749
 750         sock_path_inf->sock_path =
 751                 ustcomm_print_data(sock_path_inf->data,
 752                                    sizeof(sock_path_inf->data),
 753                                    &offset,
 754                                    socket_path);
 755
 756         if (sock_path_inf->sock_path == USTCOMM_POISON_PTR) {
 757                 return -ENOMEM;
 758         }
 759
 760         header->size = COMPUTE_MSG_SIZE(sock_path_inf, offset);
 761
 762         return 0;
 763 }
 764
 765 int ustcomm_unpack_sock_path(struct ustcomm_sock_path *sock_path_inf)
 766 {
 767         sock_path_inf->sock_path =
 768                 ustcomm_restore_ptr(sock_path_inf->sock_path,
 769                                     sock_path_inf->data,
 770                                     sizeof(sock_path_inf->data));
 771         if (!sock_path_inf->sock_path) {
 772                 return -EINVAL;
 773         }
 774
 775         return 0;
 776 }
 777