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 <dirent.h>
  22 #include <sys/types.h>
  23 #include <signal.h>
  24 #include <errno.h>
  25 #include <limits.h>
  26 #include <sys/socket.h>
  27 #include <sys/un.h>
  28 #include <unistd.h>
  29 #include <poll.h>
  30 #include <sys/epoll.h>
  31 #include <sys/stat.h>
  32
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <execinfo.h>
  37
  38 #include "ustcomm.h"
  39 #include "usterr.h"
  40 #include "share.h"
  41
  42 static int mkdir_p(const char *path, mode_t mode)
  43 {
  44         const char *path_p;
  45         char *tmp;
  46
  47         int retval = 0;
  48         int result;
  49         mode_t old_umask;
  50
  51         tmp = zmalloc(strlen(path) + 1);
  52         if (tmp == NULL)
  53                 return -1;
  54
  55         /* skip first / */
  56         path_p = path+1;
  57
  58         old_umask = umask(0);
  59         for(;;) {
  60                 while (*path_p != '/') {
  61                         if(*path_p == 0)
  62                                 break;
  63                         ++path_p;
  64                 }
  65                 if (*path_p == '/') {
  66                         strncpy(tmp, path, path_p - path);
  67                         tmp[path_p-path] = '\0';
  68                         if (tmp[path_p - path - 1] != '/') {
  69                                 result = mkdir(tmp, mode);
  70                                 if(result == -1) {
  71                                         if (!(errno == EEXIST || errno == EACCES || errno == EROFS)) {
  72                                                 /* Then this is a real error */
  73                                                 retval = -1;
  74                                                 break;
  75                                         }
  76                                 }
  77                         }
  78                         /* pass / */
  79                         path_p++;
  80                 } else {
  81                         /* last component */
  82                         result = mkdir(path, mode);
  83                         if (result == -1)
  84                                 retval = -1;
  85                         break;
  86                 }
  87         }
  88
  89         free(tmp);
  90         umask(old_umask);
  91         return retval;
  92 }
  93
  94 static struct sockaddr_un * create_sock_addr(const char *name,
  95                                              size_t *sock_addr_size)
  96 {
  97         struct sockaddr_un * addr;
  98         size_t alloc_size;
  99
 100         alloc_size = (size_t) (((struct sockaddr_un *) 0)->sun_path) +
 101                 strlen(name) + 1;
 102
 103         addr = malloc(alloc_size);
 104         if (addr < 0) {
 105                 ERR("allocating addr failed");
 106                 return NULL;
 107         }
 108
 109         addr->sun_family = AF_UNIX;
 110         strcpy(addr->sun_path, name);
 111
 112         *sock_addr_size = alloc_size;
 113
 114         return addr;
 115 }
 116
 117 struct ustcomm_sock * ustcomm_init_sock(int fd, int epoll_fd,
 118                                         struct cds_list_head *list)
 119 {
 120         struct epoll_event ev;
 121         struct ustcomm_sock *sock;
 122
 123         sock = malloc(sizeof(struct ustcomm_sock));
 124         if (!sock) {
 125                 perror("malloc: couldn't allocate ustcomm_sock");
 126                 return NULL;
 127         }
 128
 129         ev.events = EPOLLIN;
 130         ev.data.ptr = sock;
 131         sock->fd = fd;
 132
 133         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock->fd, &ev) == -1) {
 134                 perror("epoll_ctl: failed to add socket\n");
 135                 free(sock);
 136                 return NULL;
 137         }
 138
 139         sock->epoll_fd = epoll_fd;
 140         if (list) {
 141                 cds_list_add(&sock->list, list);
 142         } else {
 143                 CDS_INIT_LIST_HEAD(&sock->list);
 144         }
 145
 146         return sock;
 147 }
 148
 149 void ustcomm_del_sock(struct ustcomm_sock *sock, int keep_in_epoll)
 150 {
 151         cds_list_del(&sock->list);
 152         if (!keep_in_epoll) {
 153                 if (epoll_ctl(sock->epoll_fd, EPOLL_CTL_DEL, sock->fd, NULL) == -1) {
 154                         PERROR("epoll_ctl: failed to delete socket");
 155                 }
 156         }
 157         close(sock->fd);
 158         free(sock);
 159 }
 160
 161 struct ustcomm_sock * ustcomm_init_named_socket(const char *name,
 162                                                 int epoll_fd)
 163 {
 164         int result;
 165         int fd;
 166         size_t sock_addr_size;
 167         struct sockaddr_un * addr;
 168         struct ustcomm_sock *sock;
 169
 170         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 171         if(fd == -1) {
 172                 PERROR("socket");
 173                 return NULL;
 174         }
 175
 176         addr = create_sock_addr(name, &sock_addr_size);
 177         if (addr == NULL) {
 178                 ERR("allocating addr, UST thread bailing");
 179                 goto close_sock;
 180         }
 181
 182         result = access(name, F_OK);
 183         if(result == 0) {
 184                 /* file exists */
 185                 result = unlink(name);
 186                 if(result == -1) {
 187                         PERROR("unlink of socket file");
 188                         goto free_addr;
 189                 }
 190                 DBG("socket already exists; overwriting");
 191         }
 192
 193         result = bind(fd, (struct sockaddr *)addr, sock_addr_size);
 194         if(result == -1) {
 195                 PERROR("bind");
 196                 goto free_addr;
 197         }
 198
 199         result = listen(fd, 1);
 200         if(result == -1) {
 201                 PERROR("listen");
 202                 goto free_addr;
 203         }
 204
 205         sock = ustcomm_init_sock(fd, epoll_fd,
 206                                  NULL);
 207         if (!sock) {
 208                 ERR("failed to create ustcomm_sock");
 209                 goto free_addr;
 210         }
 211
 212         free(addr);
 213
 214         return sock;
 215
 216 free_addr:
 217         free(addr);
 218 close_sock:
 219         close(fd);
 220
 221         return NULL;
 222 }
 223
 224 void ustcomm_del_named_sock(struct ustcomm_sock *sock,
 225                             int keep_socket_file)
 226 {
 227         int result, fd;
 228         struct stat st;
 229         struct sockaddr dummy;
 230         struct sockaddr_un *sockaddr = NULL;
 231         int alloc_size;
 232
 233         fd = sock->fd;
 234
 235         if(!keep_socket_file) {
 236
 237                 /* Get the socket name */
 238                 alloc_size = sizeof(dummy);
 239                 if (getsockname(fd, &dummy, (socklen_t *)&alloc_size) < 0) {
 240                         PERROR("getsockname failed");
 241                         goto del_sock;
 242                 }
 243
 244                 sockaddr = zmalloc(alloc_size);
 245                 if (!sockaddr) {
 246                         ERR("failed to allocate sockaddr");
 247                         goto del_sock;
 248                 }
 249
 250                 if (getsockname(fd, sockaddr, (socklen_t *)&alloc_size) < 0) {
 251                         PERROR("getsockname failed");
 252                         goto free_sockaddr;
 253                 }
 254
 255                 /* Destroy socket */
 256                 result = stat(sockaddr->sun_path, &st);
 257                 if(result < 0) {
 258                         PERROR("stat (%s)", sockaddr->sun_path);
 259                         goto free_sockaddr;
 260                 }
 261
 262                 /* Paranoid check before deleting. */
 263                 result = S_ISSOCK(st.st_mode);
 264                 if(!result) {
 265                         ERR("The socket we are about to delete is not a socket.");
 266                         goto free_sockaddr;
 267                 }
 268
 269                 result = unlink(sockaddr->sun_path);
 270                 if(result < 0) {
 271                         PERROR("unlink");
 272                 }
 273         }
 274
 275 free_sockaddr:
 276         free(sockaddr);
 277
 278 del_sock:
 279         ustcomm_del_sock(sock, keep_socket_file);
 280 }
 281
 282 int ustcomm_recv_alloc(int sock,
 283                        struct ustcomm_header *header,
 284                        char **data) {
 285         int result;
 286         struct ustcomm_header peek_header;
 287         struct iovec iov[2];
 288         struct msghdr msg;
 289
 290         /* Just to make the caller fail hard */
 291         *data = NULL;
 292
 293         result = recv(sock, &peek_header, sizeof(peek_header),
 294                       MSG_PEEK | MSG_WAITALL);
 295         if (result <= 0) {
 296                 if(errno == ECONNRESET) {
 297                         return 0;
 298                 } else if (errno == EINTR) {
 299                         return -1;
 300                 } else if (result < 0) {
 301                         PERROR("recv");
 302                         return -1;
 303                 }
 304                 return 0;
 305         }
 306
 307         memset(&msg, 0, sizeof(msg));
 308
 309         iov[0].iov_base = (char *)header;
 310         iov[0].iov_len = sizeof(struct ustcomm_header);
 311
 312         msg.msg_iov = iov;
 313         msg.msg_iovlen = 1;
 314
 315         if (peek_header.size) {
 316                 *data = zmalloc(peek_header.size);
 317                 if (!*data) {
 318                         return -ENOMEM;
 319                 }
 320
 321                 iov[1].iov_base = *data;
 322                 iov[1].iov_len = peek_header.size;
 323
 324                 msg.msg_iovlen++;
 325         }
 326
 327         result = recvmsg(sock, &msg, MSG_WAITALL);
 328         if (result < 0) {
 329                 free(*data);
 330                 PERROR("recvmsg failed");
 331         }
 332
 333         return result;
 334 }
 335
 336 /* returns 1 to indicate a message was received
 337  * returns 0 to indicate no message was received (end of stream)
 338  * returns -1 to indicate an error
 339  */
 340 int ustcomm_recv_fd(int sock,
 341                     struct ustcomm_header *header,
 342                     char *data, int *fd)
 343 {
 344         int result;
 345         struct ustcomm_header peek_header;
 346         struct iovec iov[2];
 347         struct msghdr msg;
 348         struct cmsghdr *cmsg;
 349         char buf[CMSG_SPACE(sizeof(int))];
 350
 351         result = recv(sock, &peek_header, sizeof(peek_header),
 352                       MSG_PEEK | MSG_WAITALL);
 353         if (result <= 0) {
 354                 if(errno == ECONNRESET) {
 355                         return 0;
 356                 } else if (errno == EINTR) {
 357                         return -1;
 358                 } else if (result < 0) {
 359                         PERROR("recv");
 360                         return -1;
 361                 }
 362                 return 0;
 363         }
 364
 365         memset(&msg, 0, sizeof(msg));
 366
 367         iov[0].iov_base = (char *)header;
 368         iov[0].iov_len = sizeof(struct ustcomm_header);
 369
 370         msg.msg_iov = iov;
 371         msg.msg_iovlen = 1;
 372
 373         if (peek_header.size && data) {
 374                 if (peek_header.size < 0 ||
 375                     peek_header.size > USTCOMM_DATA_SIZE) {
 376                         ERR("big peek header! %ld", peek_header.size);
 377                         return 0;
 378                 }
 379
 380                 iov[1].iov_base = data;
 381                 iov[1].iov_len = peek_header.size;
 382
 383                 msg.msg_iovlen++;
 384         }
 385
 386         if (fd && peek_header.fd_included) {
 387                 msg.msg_control = buf;
 388                 msg.msg_controllen = sizeof(buf);
 389         }
 390
 391         result = recvmsg(sock, &msg, MSG_WAITALL);
 392         if (result <= 0) {
 393                 if (result < 0) {
 394                         PERROR("recvmsg failed");
 395                 }
 396                 return result;
 397         }
 398
 399         if (fd && peek_header.fd_included) {
 400                 cmsg = CMSG_FIRSTHDR(&msg);
 401                 result = 0;
 402                 while (cmsg != NULL) {
 403                         if (cmsg->cmsg_level == SOL_SOCKET
 404                             && cmsg->cmsg_type  == SCM_RIGHTS) {
 405                                 *fd = *(int *) CMSG_DATA(cmsg);
 406                                 result = 1;
 407                                 break;
 408                         }
 409                         cmsg = CMSG_NXTHDR(&msg, cmsg);
 410                 }
 411                 if (!result) {
 412                         ERR("Failed to receive file descriptor\n");
 413                 }
 414         }
 415
 416         return 1;
 417 }
 418
 419 int ustcomm_recv(int sock,
 420                  struct ustcomm_header *header,
 421                  char *data)
 422 {
 423         return ustcomm_recv_fd(sock, header, data, NULL);
 424 }
 425
 426
 427 int ustcomm_send_fd(int sock,
 428                     const struct ustcomm_header *header,
 429                     const char *data,
 430                     int *fd)
 431 {
 432         struct iovec iov[2];
 433         struct msghdr msg;
 434         int result;
 435         struct cmsghdr *cmsg;
 436         char buf[CMSG_SPACE(sizeof(int))];
 437
 438         memset(&msg, 0, sizeof(msg));
 439
 440         iov[0].iov_base = (char *)header;
 441         iov[0].iov_len = sizeof(struct ustcomm_header);
 442
 443         msg.msg_iov = iov;
 444         msg.msg_iovlen = 1;
 445
 446         if (header->size && data) {
 447                 iov[1].iov_base = (char *)data;
 448                 iov[1].iov_len = header->size;
 449
 450                 msg.msg_iovlen++;
 451
 452         }
 453
 454         if (fd && header->fd_included) {
 455                 msg.msg_control = buf;
 456                 msg.msg_controllen = sizeof(buf);
 457                 cmsg = CMSG_FIRSTHDR(&msg);
 458                 cmsg->cmsg_level = SOL_SOCKET;
 459                 cmsg->cmsg_type = SCM_RIGHTS;
 460                 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
 461                 *(int *) CMSG_DATA(cmsg) = *fd;
 462                 msg.msg_controllen = cmsg->cmsg_len;
 463         }
 464
 465         result = sendmsg(sock, &msg, MSG_NOSIGNAL);
 466         if (result < 0 && errno != EPIPE) {
 467                 PERROR("sendmsg failed");
 468         }
 469         return result;
 470 }
 471
 472 int ustcomm_send(int sock,
 473                  const struct ustcomm_header *header,
 474                  const char *data)
 475 {
 476         return ustcomm_send_fd(sock, header, data, NULL);
 477 }
 478
 479 int ustcomm_req(int sock,
 480                 const struct ustcomm_header *req_header,
 481                 const char *req_data,
 482                 struct ustcomm_header *res_header,
 483                 char *res_data)
 484 {
 485         int result;
 486
 487         result = ustcomm_send(sock, req_header, req_data);
 488         if ( result <= 0) {
 489                 return result;
 490         }
 491
 492         return ustcomm_recv(sock, res_header, res_data);
 493 }
 494
 495 /* Return value:
 496  *  0: success
 497  * -1: error
 498  */
 499
 500 int ustcomm_connect_path(const char *name, int *connection_fd)
 501 {
 502         int result, fd;
 503         size_t sock_addr_size;
 504         struct sockaddr_un *addr;
 505
 506         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 507         if(fd == -1) {
 508                 PERROR("socket");
 509                 return -1;
 510         }
 511
 512         addr = create_sock_addr(name, &sock_addr_size);
 513         if (addr == NULL) {
 514                 ERR("allocating addr failed");
 515                 goto close_sock;
 516         }
 517
 518         result = connect(fd, (struct sockaddr *)addr, sock_addr_size);
 519         if(result == -1) {
 520                 PERROR("connect (path=%s)", name);
 521                 goto free_sock_addr;
 522         }
 523
 524         *connection_fd = fd;
 525
 526         free(addr);
 527
 528         return 0;
 529
 530 free_sock_addr:
 531         free(addr);
 532 close_sock:
 533         close(fd);
 534
 535         return -1;
 536 }
 537
 538 /* Returns the current users socket directory, must be freed */
 539 char *ustcomm_user_sock_dir(void)
 540 {
 541         int result;
 542         char *sock_dir = NULL;
 543
 544         result = asprintf(&sock_dir, "%s%s", USER_SOCK_DIR,
 545                           cuserid(NULL));
 546         if (result < 0) {
 547                 ERR("string overflow allocating directory name");
 548                 return NULL;
 549         }
 550
 551         return sock_dir;
 552 }
 553
 554 static int time_and_pid_from_socket_name(char *sock_name, unsigned long *time,
 555                                          pid_t *pid)
 556 {
 557         char *saveptr, *pid_m_time_str;
 558         char *sock_basename = strdup(basename(sock_name));
 559
 560         if (!sock_basename) {
 561                 return -1;
 562         }
 563
 564         /* This is the pid */
 565         pid_m_time_str = strtok_r(sock_basename, ".", &saveptr);
 566         if (!pid_m_time_str) {
 567                 goto out_err;
 568         }
 569
 570         errno = 0;
 571         *pid = (pid_t)strtoul(pid_m_time_str, NULL, 10);
 572         if (errno) {
 573                 goto out_err;
 574         }
 575
 576         /* This should be the time-stamp */
 577         pid_m_time_str = strtok_r(NULL, ".", &saveptr);
 578         if (!pid_m_time_str) {
 579                 goto out_err;
 580         }
 581
 582         errno = 0;
 583         *time = strtoul(pid_m_time_str, NULL, 10);
 584         if (errno) {
 585                 goto out_err;
 586         }
 587
 588         return 0;
 589
 590 out_err:
 591         free(sock_basename);
 592         return -1;
 593 }
 594
 595 time_t ustcomm_pid_st_mtime(pid_t pid)
 596 {
 597         struct stat proc_stat;
 598         char proc_name[PATH_MAX];
 599
 600         if (snprintf(proc_name, PATH_MAX - 1, "/proc/%ld", (long) pid) < 0) {
 601                 return 0;
 602         }
 603
 604         if (stat(proc_name, &proc_stat)) {
 605                 return 0;
 606         }
 607
 608         return proc_stat.st_mtime;
 609 }
 610
 611 int ustcomm_is_socket_live(char *sock_name, pid_t *read_pid)
 612 {
 613         time_t time_from_pid;
 614         unsigned long time_from_sock;
 615         pid_t pid;
 616
 617         if (time_and_pid_from_socket_name(sock_name, &time_from_sock, &pid)) {
 618                 return 0;
 619         }
 620
 621         if (read_pid) {
 622                 *read_pid = pid;
 623         }
 624
 625         time_from_pid = ustcomm_pid_st_mtime(pid);
 626         if (!time_from_pid) {
 627                 return 0;
 628         }
 629
 630         if ((unsigned long) time_from_pid == time_from_sock) {
 631                 return 1;
 632         }
 633
 634         return 0;
 635 }
 636
 637 #define MAX_SOCK_PATH_BASE_LEN 100
 638
 639 static int ustcomm_get_sock_name(char *dir_name, pid_t pid, char *sock_name)
 640 {
 641         struct dirent *dirent;
 642         char sock_path_base[MAX_SOCK_PATH_BASE_LEN];
 643         int len;
 644         DIR *dir = opendir(dir_name);
 645
 646         snprintf(sock_path_base, MAX_SOCK_PATH_BASE_LEN - 1,
 647                  "%ld.", (long) pid);
 648         len = strlen(sock_path_base);
 649
 650         while ((dirent = readdir(dir))) {
 651                 if (!strcmp(dirent->d_name, ".") ||
 652                     !strcmp(dirent->d_name, "..") ||
 653                     !strcmp(dirent->d_name, "ust-consumer") ||
 654                     dirent->d_type == DT_DIR ||
 655                     strncmp(dirent->d_name, sock_path_base, len)) {
 656                         continue;
 657                 }
 658
 659                 if (ustcomm_is_socket_live(dirent->d_name, NULL)) {
 660                         if (snprintf(sock_name, PATH_MAX - 1, "%s/%s",
 661                                      dir_name, dirent->d_name) < 0) {
 662                                 PERROR("path longer than PATH_MAX?");
 663                                 goto out_err;
 664                         }
 665                         closedir(dir);
 666                         return 0;
 667                 }
 668         }
 669
 670 out_err:
 671         closedir(dir);
 672         return -1;
 673 }
 674
 675 /* Open a connection to a traceable app.
 676  *
 677  * Return value:
 678  *  0: success
 679  * -1: error
 680  */
 681
 682 static int connect_app_non_root(pid_t pid, int *app_fd)
 683 {
 684         int result;
 685         int retval = 0;
 686         char *dir_name;
 687         char sock_name[PATH_MAX];
 688
 689         dir_name = ustcomm_user_sock_dir();
 690         if (!dir_name)
 691                 return -ENOMEM;
 692
 693         if (ustcomm_get_sock_name(dir_name, pid, sock_name)) {
 694                 retval = -ENOENT;
 695                 goto free_dir_name;
 696         }
 697
 698         result = ustcomm_connect_path(sock_name, app_fd);
 699         if (result < 0) {
 700                 ERR("failed to connect to app");
 701                 retval = -1;
 702                 goto free_dir_name;
 703         }
 704
 705 free_dir_name:
 706         free(dir_name);
 707
 708         return retval;
 709 }
 710
 711
 712
 713 static int connect_app_root(pid_t pid, int *app_fd)
 714 {
 715         DIR *tmp_dir;
 716         struct dirent *dirent;
 717         char dir_name[PATH_MAX], sock_name[PATH_MAX];
 718         int result = -1;
 719
 720         tmp_dir = opendir(USER_TMP_DIR);
 721         if (!tmp_dir) {
 722                 return -1;
 723         }
 724
 725         while ((dirent = readdir(tmp_dir))) {
 726                 if (!strncmp(dirent->d_name, USER_SOCK_DIR_BASE,
 727                              strlen(USER_SOCK_DIR_BASE))) {
 728
 729                         if (snprintf(dir_name, PATH_MAX - 1, "%s/%s", USER_TMP_DIR,
 730                                      dirent->d_name) < 0) {
 731                                 continue;
 732                         }
 733
 734                         if (ustcomm_get_sock_name(dir_name, pid, sock_name)) {
 735                                 continue;
 736                         }
 737
 738                         result = ustcomm_connect_path(sock_name, app_fd);
 739
 740                         if (result == 0) {
 741                                 goto close_tmp_dir;
 742                         }
 743                 }
 744         }
 745
 746 close_tmp_dir:
 747         closedir(tmp_dir);
 748
 749         return result;
 750 }
 751
 752 int ustcomm_connect_app(pid_t pid, int *app_fd)
 753 {
 754         *app_fd = 0;
 755
 756         if (geteuid()) {
 757                 return connect_app_non_root(pid, app_fd);
 758         } else {
 759                 return connect_app_root(pid, app_fd);
 760         }
 761
 762 }
 763
 764 int ensure_dir_exists(const char *dir, mode_t mode)
 765 {
 766         struct stat st;
 767         int result;
 768
 769         if (!strcmp(dir, ""))
 770                 return -1;
 771
 772         result = stat(dir, &st);
 773         if (result < 0 && errno != ENOENT) {
 774                 return -1;
 775         } else if (result < 0) {
 776                 /* ENOENT */
 777                 int result;
 778
 779                 result = mkdir_p(dir, mode);
 780                 if(result != 0) {
 781                         ERR("executing in recursive creation of directory %s", dir);
 782                         return -1;
 783                 }
 784         } else {
 785                 if (st.st_mode != mode) {
 786                         result = chmod(dir, mode);
 787                         if (result < 0) {
 788                                 ERR("couldn't set directory mode on %s", dir);
 789                                 return -1;
 790                         }
 791                 }
 792         }
 793
 794         return 0;
 795 }
 796
 797 char * ustcomm_print_data(char *data_field, int field_size,
 798                           int *offset, const char *format, ...)
 799 {
 800         va_list args;
 801         int count, limit;
 802         char *ptr = USTCOMM_POISON_PTR;
 803
 804         limit = field_size - *offset;
 805         va_start(args, format);
 806         count = vsnprintf(&data_field[*offset], limit, format, args);
 807         va_end(args);
 808
 809         if (count < limit && count > -1) {
 810                 ptr = NULL + *offset;
 811                 *offset = *offset + count + 1;
 812         }
 813
 814         return ptr;
 815 }
 816
 817 char * ustcomm_restore_ptr(char *ptr, char *data_field, int data_field_size)
 818 {
 819         if ((unsigned long)ptr > data_field_size ||
 820             ptr == USTCOMM_POISON_PTR) {
 821                 return NULL;
 822         }
 823
 824         return data_field + (long)ptr;
 825 }
 826
 827 int ustcomm_pack_single_field(struct ustcomm_header *header,
 828                               struct ustcomm_single_field *single_field,
 829                               const char *string)
 830 {
 831         int offset = 0;
 832
 833         single_field->field = ustcomm_print_data(single_field->data,
 834                                                  sizeof(single_field->data),
 835                                                  &offset,
 836                                                  string);
 837
 838         if (single_field->field == USTCOMM_POISON_PTR) {
 839                 return -ENOMEM;
 840         }
 841
 842         header->size = COMPUTE_MSG_SIZE(single_field, offset);
 843
 844         return 0;
 845 }
 846
 847 int ustcomm_unpack_single_field(struct ustcomm_single_field *single_field)
 848 {
 849         single_field->field = ustcomm_restore_ptr(single_field->field,
 850                                                   single_field->data,
 851                                                   sizeof(single_field->data));
 852         if (!single_field->field) {
 853                 return -EINVAL;
 854         }
 855
 856         return 0;
 857 }
 858
 859 int ustcomm_pack_channel_info(struct ustcomm_header *header,
 860                               struct ustcomm_channel_info *ch_inf,
 861                               const char *trace,
 862                               const char *channel)
 863 {
 864         int offset = 0;
 865
 866         ch_inf->trace = ustcomm_print_data(ch_inf->data,
 867                                            sizeof(ch_inf->data),
 868                                            &offset,
 869                                            trace);
 870
 871         if (ch_inf->trace == USTCOMM_POISON_PTR) {
 872                 return -ENOMEM;
 873         }
 874
 875         ch_inf->channel = ustcomm_print_data(ch_inf->data,
 876                                              sizeof(ch_inf->data),
 877                                              &offset,
 878                                              channel);
 879
 880         if (ch_inf->channel == USTCOMM_POISON_PTR) {
 881                 return -ENOMEM;
 882         }
 883
 884         header->size = COMPUTE_MSG_SIZE(ch_inf, offset);
 885
 886         return 0;
 887 }
 888
 889
 890 int ustcomm_unpack_channel_info(struct ustcomm_channel_info *ch_inf)
 891 {
 892         ch_inf->trace = ustcomm_restore_ptr(ch_inf->trace,
 893                                             ch_inf->data,
 894                                             sizeof(ch_inf->data));
 895         if (!ch_inf->trace) {
 896                 return -EINVAL;
 897         }
 898
 899         ch_inf->channel = ustcomm_restore_ptr(ch_inf->channel,
 900                                               ch_inf->data,
 901                                               sizeof(ch_inf->data));
 902         if (!ch_inf->channel) {
 903                 return -EINVAL;
 904         }
 905
 906         return 0;
 907 }
 908
 909 int ustcomm_pack_buffer_info(struct ustcomm_header *header,
 910                              struct ustcomm_buffer_info *buf_inf,
 911                              const char *trace,
 912                              const char *channel,
 913                              int channel_cpu)
 914 {
 915         int offset = 0;
 916
 917         buf_inf->trace = ustcomm_print_data(buf_inf->data,
 918                                             sizeof(buf_inf->data),
 919                                             &offset,
 920                                             trace);
 921
 922         if (buf_inf->trace == USTCOMM_POISON_PTR) {
 923                 return -ENOMEM;
 924         }
 925
 926         buf_inf->channel = ustcomm_print_data(buf_inf->data,
 927                                               sizeof(buf_inf->data),
 928                                               &offset,
 929                                               channel);
 930
 931         if (buf_inf->channel == USTCOMM_POISON_PTR) {
 932                 return -ENOMEM;
 933         }
 934
 935         buf_inf->ch_cpu = channel_cpu;
 936
 937         header->size = COMPUTE_MSG_SIZE(buf_inf, offset);
 938
 939         return 0;
 940 }
 941
 942
 943 int ustcomm_unpack_buffer_info(struct ustcomm_buffer_info *buf_inf)
 944 {
 945         buf_inf->trace = ustcomm_restore_ptr(buf_inf->trace,
 946                                              buf_inf->data,
 947                                              sizeof(buf_inf->data));
 948         if (!buf_inf->trace) {
 949                 return -EINVAL;
 950         }
 951
 952         buf_inf->channel = ustcomm_restore_ptr(buf_inf->channel,
 953                                                buf_inf->data,
 954                                                sizeof(buf_inf->data));
 955         if (!buf_inf->channel) {
 956                 return -EINVAL;
 957         }
 958
 959         return 0;
 960 }
 961
 962 int ustcomm_pack_ust_marker_info(struct ustcomm_header *header,
 963                              struct ustcomm_ust_marker_info *ust_marker_inf,
 964                              const char *trace,
 965                              const char *channel,
 966                              const char *ust_marker)
 967 {
 968         int offset = 0;
 969
 970         ust_marker_inf->trace = ustcomm_print_data(ust_marker_inf->data,
 971                                                sizeof(ust_marker_inf->data),
 972                                                &offset,
 973                                                trace);
 974
 975         if (ust_marker_inf->trace == USTCOMM_POISON_PTR) {
 976                 return -ENOMEM;
 977         }
 978
 979
 980         ust_marker_inf->channel = ustcomm_print_data(ust_marker_inf->data,
 981                                                  sizeof(ust_marker_inf->data),
 982                                                  &offset,
 983                                                  channel);
 984
 985         if (ust_marker_inf->channel == USTCOMM_POISON_PTR) {
 986                 return -ENOMEM;
 987         }
 988
 989
 990         ust_marker_inf->ust_marker = ustcomm_print_data(ust_marker_inf->data,
 991                                                  sizeof(ust_marker_inf->data),
 992                                                  &offset,
 993                                                  ust_marker);
 994
 995         if (ust_marker_inf->ust_marker == USTCOMM_POISON_PTR) {
 996                 return -ENOMEM;
 997         }
 998
 999         header->size = COMPUTE_MSG_SIZE(ust_marker_inf, offset);
1000
1001         return 0;
1002 }
1003
1004 int ustcomm_unpack_ust_marker_info(struct ustcomm_ust_marker_info *ust_marker_inf)
1005 {
1006         ust_marker_inf->trace = ustcomm_restore_ptr(ust_marker_inf->trace,
1007                                                 ust_marker_inf->data,
1008                                                 sizeof(ust_marker_inf->data));
1009         if (!ust_marker_inf->trace) {
1010                 return -EINVAL;
1011         }
1012
1013         ust_marker_inf->channel = ustcomm_restore_ptr(ust_marker_inf->channel,
1014                                                   ust_marker_inf->data,
1015                                                   sizeof(ust_marker_inf->data));
1016         if (!ust_marker_inf->channel) {
1017                 return -EINVAL;
1018         }
1019
1020         ust_marker_inf->ust_marker = ustcomm_restore_ptr(ust_marker_inf->ust_marker,
1021                                                  ust_marker_inf->data,
1022                                                  sizeof(ust_marker_inf->data));
1023         if (!ust_marker_inf->ust_marker) {
1024                 return -EINVAL;
1025         }
1026
1027         return 0;
1028 }
1029