| 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 | |
| 281 | /* Called by an app to ask the consumer daemon to connect to it. */ |
| 282 | |
| 283 | int ustcomm_request_consumer(pid_t pid, const char *channel) |
| 284 | { |
| 285 | int result, daemon_fd; |
| 286 | int retval = 0; |
| 287 | char *msg=NULL; |
| 288 | char *explicit_daemon_socket_path, *daemon_path; |
| 289 | |
| 290 | explicit_daemon_socket_path = getenv("UST_DAEMON_SOCKET"); |
| 291 | if (explicit_daemon_socket_path) { |
| 292 | /* user specified explicitly a socket path */ |
| 293 | result = asprintf(&daemon_path, "%s", explicit_daemon_socket_path); |
| 294 | } else { |
| 295 | /* just use the default path */ |
| 296 | result = asprintf(&daemon_path, "%s/ustd", SOCK_DIR); |
| 297 | } |
| 298 | if (result < 0) { |
| 299 | ERR("string overflow allocating socket name"); |
| 300 | return -1; |
| 301 | } |
| 302 | |
| 303 | if (asprintf(&msg, "collect %d %s", pid, channel) < 0) { |
| 304 | ERR("ustcomm_request_consumer : asprintf failed (collect %d/%s)", |
| 305 | pid, channel); |
| 306 | retval = -1; |
| 307 | goto free_daemon_path; |
| 308 | } |
| 309 | |
| 310 | result = ustcomm_connect_path(daemon_path, &daemon_fd); |
| 311 | if (result < 0) { |
| 312 | WARN("ustcomm_connect_path failed, daemon_path: %s", |
| 313 | daemon_path); |
| 314 | retval = -1; |
| 315 | goto del_string; |
| 316 | } |
| 317 | |
| 318 | result = ustcomm_send_request(daemon_fd, msg, NULL); |
| 319 | if (result < 0) { |
| 320 | WARN("ustcomm_send_request failed, daemon path: %s", |
| 321 | daemon_path); |
| 322 | retval = -1; |
| 323 | } |
| 324 | |
| 325 | close(daemon_fd); |
| 326 | del_string: |
| 327 | free(msg); |
| 328 | free_daemon_path: |
| 329 | free(daemon_path); |
| 330 | |
| 331 | return retval; |
| 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 | int retval; |
| 344 | struct ustcomm_header peek_header; |
| 345 | struct iovec iov[2]; |
| 346 | struct msghdr msg; |
| 347 | struct cmsghdr *cmsg; |
| 348 | char buf[CMSG_SPACE(sizeof(int))]; |
| 349 | |
| 350 | result = recv(sock, &peek_header, sizeof(peek_header), |
| 351 | MSG_PEEK | MSG_WAITALL); |
| 352 | if (result <= 0) { |
| 353 | if(errno == ECONNRESET) { |
| 354 | return 0; |
| 355 | } else if (errno == EINTR) { |
| 356 | return -1; |
| 357 | } else if (result < 0) { |
| 358 | PERROR("recv"); |
| 359 | return -1; |
| 360 | } |
| 361 | return 0; |
| 362 | } |
| 363 | |
| 364 | memset(&msg, 0, sizeof(msg)); |
| 365 | |
| 366 | iov[0].iov_base = (char *)header; |
| 367 | iov[0].iov_len = sizeof(struct ustcomm_header); |
| 368 | |
| 369 | msg.msg_iov = iov; |
| 370 | msg.msg_iovlen = 1; |
| 371 | |
| 372 | if (peek_header.size) { |
| 373 | if (peek_header.size < 0 || peek_header.size > 100) { |
| 374 | WARN("big peek header! %d", peek_header.size); |
| 375 | } |
| 376 | *data = malloc(peek_header.size); |
| 377 | if (!*data) { |
| 378 | ERR("failed to allocate space for message"); |
| 379 | } |
| 380 | |
| 381 | iov[1].iov_base = (char *)*data; |
| 382 | iov[1].iov_len = peek_header.size; |
| 383 | |
| 384 | msg.msg_iovlen++; |
| 385 | } |
| 386 | |
| 387 | if (fd && peek_header.fd_included) { |
| 388 | msg.msg_control = buf; |
| 389 | msg.msg_controllen = sizeof(buf); |
| 390 | } |
| 391 | |
| 392 | result = recvmsg(sock, &msg, |
| 393 | MSG_WAITALL); |
| 394 | |
| 395 | if (result <= 0) { |
| 396 | if(errno == ECONNRESET) { |
| 397 | retval = 0; |
| 398 | } else if (errno == EINTR) { |
| 399 | retval = -1; |
| 400 | } else if (result < 0) { |
| 401 | PERROR("recv"); |
| 402 | retval = -1; |
| 403 | } else { |
| 404 | retval = 0; |
| 405 | } |
| 406 | free(*data); |
| 407 | return retval; |
| 408 | } |
| 409 | |
| 410 | if (fd && peek_header.fd_included) { |
| 411 | cmsg = CMSG_FIRSTHDR(&msg); |
| 412 | result = 0; |
| 413 | while (cmsg != NULL) { |
| 414 | if (cmsg->cmsg_level == SOL_SOCKET |
| 415 | && cmsg->cmsg_type == SCM_RIGHTS) { |
| 416 | *fd = *(int *) CMSG_DATA(cmsg); |
| 417 | result = 1; |
| 418 | break; |
| 419 | } |
| 420 | cmsg = CMSG_NXTHDR(&msg, cmsg); |
| 421 | } |
| 422 | if (!result) { |
| 423 | ERR("Failed to receive file descriptor\n"); |
| 424 | } |
| 425 | } |
| 426 | |
| 427 | return 1; |
| 428 | } |
| 429 | |
| 430 | int ustcomm_recv(int sock, |
| 431 | struct ustcomm_header *header, |
| 432 | char **data) |
| 433 | { |
| 434 | return ustcomm_recv_fd(sock, header, data, NULL); |
| 435 | } |
| 436 | |
| 437 | |
| 438 | int recv_message_conn(int sock, char **msg) |
| 439 | { |
| 440 | struct ustcomm_header header; |
| 441 | |
| 442 | return ustcomm_recv(sock, &header, msg); |
| 443 | } |
| 444 | |
| 445 | int ustcomm_send_fd(int sock, |
| 446 | const struct ustcomm_header *header, |
| 447 | const char *data, |
| 448 | int *fd) |
| 449 | { |
| 450 | struct iovec iov[2]; |
| 451 | struct msghdr msg; |
| 452 | int result; |
| 453 | struct cmsghdr *cmsg; |
| 454 | char buf[CMSG_SPACE(sizeof(int))]; |
| 455 | |
| 456 | memset(&msg, 0, sizeof(msg)); |
| 457 | |
| 458 | iov[0].iov_base = (char *)header; |
| 459 | iov[0].iov_len = sizeof(struct ustcomm_header); |
| 460 | |
| 461 | msg.msg_iov = iov; |
| 462 | msg.msg_iovlen = 1; |
| 463 | |
| 464 | if (header->size) { |
| 465 | iov[1].iov_base = (char *)data; |
| 466 | iov[1].iov_len = header->size; |
| 467 | |
| 468 | msg.msg_iovlen++; |
| 469 | |
| 470 | } |
| 471 | |
| 472 | if (fd && header->fd_included) { |
| 473 | msg.msg_control = buf; |
| 474 | msg.msg_controllen = sizeof(buf); |
| 475 | cmsg = CMSG_FIRSTHDR(&msg); |
| 476 | cmsg->cmsg_level = SOL_SOCKET; |
| 477 | cmsg->cmsg_type = SCM_RIGHTS; |
| 478 | cmsg->cmsg_len = CMSG_LEN(sizeof(int)); |
| 479 | *(int *) CMSG_DATA(cmsg) = *fd; |
| 480 | msg.msg_controllen = cmsg->cmsg_len; |
| 481 | } |
| 482 | |
| 483 | result = sendmsg(sock, &msg, MSG_NOSIGNAL); |
| 484 | if (result < 0 && errno != EPIPE) { |
| 485 | PERROR("sendmsg failed"); |
| 486 | } |
| 487 | return result; |
| 488 | } |
| 489 | |
| 490 | int ustcomm_send(int sock, |
| 491 | const struct ustcomm_header *header, |
| 492 | const char *data) |
| 493 | { |
| 494 | return ustcomm_send_fd(sock, header, data, NULL); |
| 495 | } |
| 496 | |
| 497 | int ustcomm_send_reply(char *msg, int sock) |
| 498 | { |
| 499 | int result; |
| 500 | struct ustcomm_header header; |
| 501 | |
| 502 | memset(&header, 0, sizeof(header)); |
| 503 | |
| 504 | header.size = strlen(msg) + 1; |
| 505 | |
| 506 | result = ustcomm_send(sock, &header, msg); |
| 507 | if(result < 0) { |
| 508 | ERR("error in ustcomm_send"); |
| 509 | return result; |
| 510 | } |
| 511 | |
| 512 | return 0; |
| 513 | } |
| 514 | |
| 515 | int ustcomm_send_req(int sock, |
| 516 | const struct ustcomm_header *req_header, |
| 517 | const char *data, |
| 518 | char **response) |
| 519 | { |
| 520 | int result; |
| 521 | struct ustcomm_header res_header; |
| 522 | |
| 523 | result = ustcomm_send(sock, req_header, data); |
| 524 | if ( result <= 0) { |
| 525 | return result; |
| 526 | } |
| 527 | |
| 528 | if (!response) { |
| 529 | return 1; |
| 530 | } |
| 531 | |
| 532 | return ustcomm_recv(sock, |
| 533 | &res_header, |
| 534 | response); |
| 535 | |
| 536 | } |
| 537 | |
| 538 | /* |
| 539 | * Return value: |
| 540 | * 0: Success, but no reply because recv() returned 0 |
| 541 | * 1: Success |
| 542 | * -1: Error |
| 543 | * |
| 544 | * On error, the error message is printed, except on |
| 545 | * ECONNRESET, which is normal when the application dies. |
| 546 | */ |
| 547 | |
| 548 | int ustcomm_send_request(int sock, const char *req, char **reply) |
| 549 | { |
| 550 | struct ustcomm_header req_header; |
| 551 | |
| 552 | req_header.size = strlen(req) + 1; |
| 553 | |
| 554 | return ustcomm_send_req(sock, |
| 555 | &req_header, |
| 556 | req, |
| 557 | reply); |
| 558 | |
| 559 | } |
| 560 | |
| 561 | /* Return value: |
| 562 | * 0: success |
| 563 | * -1: error |
| 564 | */ |
| 565 | |
| 566 | int ustcomm_connect_path(const char *name, int *connection_fd) |
| 567 | { |
| 568 | int result, fd; |
| 569 | size_t sock_addr_size; |
| 570 | struct sockaddr_un *addr; |
| 571 | |
| 572 | fd = socket(PF_UNIX, SOCK_STREAM, 0); |
| 573 | if(fd == -1) { |
| 574 | PERROR("socket"); |
| 575 | return -1; |
| 576 | } |
| 577 | |
| 578 | addr = create_sock_addr(name, &sock_addr_size); |
| 579 | if (addr == NULL) { |
| 580 | ERR("allocating addr failed"); |
| 581 | goto close_sock; |
| 582 | } |
| 583 | |
| 584 | result = connect(fd, (struct sockaddr *)addr, sock_addr_size); |
| 585 | if(result == -1) { |
| 586 | PERROR("connect (path=%s)", name); |
| 587 | goto free_sock_addr; |
| 588 | } |
| 589 | |
| 590 | *connection_fd = fd; |
| 591 | |
| 592 | free(addr); |
| 593 | |
| 594 | return 0; |
| 595 | |
| 596 | free_sock_addr: |
| 597 | free(addr); |
| 598 | close_sock: |
| 599 | close(fd); |
| 600 | |
| 601 | return -1; |
| 602 | } |
| 603 | |
| 604 | |
| 605 | /* Open a connection to a traceable app. |
| 606 | * |
| 607 | * Return value: |
| 608 | * 0: success |
| 609 | * -1: error |
| 610 | */ |
| 611 | |
| 612 | int ustcomm_connect_app(pid_t pid, int *app_fd) |
| 613 | { |
| 614 | int result; |
| 615 | int retval = 0; |
| 616 | char *name; |
| 617 | |
| 618 | result = asprintf(&name, "%s/%d", SOCK_DIR, pid); |
| 619 | if (result < 0) { |
| 620 | ERR("failed to allocate socket name"); |
| 621 | return -1; |
| 622 | } |
| 623 | |
| 624 | result = ustcomm_connect_path(name, app_fd); |
| 625 | if (result < 0) { |
| 626 | ERR("failed to connect to app"); |
| 627 | retval = -1; |
| 628 | } |
| 629 | |
| 630 | free(name); |
| 631 | |
| 632 | return retval; |
| 633 | } |
| 634 | |
| 635 | int ensure_dir_exists(const char *dir) |
| 636 | { |
| 637 | struct stat st; |
| 638 | int result; |
| 639 | |
| 640 | if(!strcmp(dir, "")) |
| 641 | return -1; |
| 642 | |
| 643 | result = stat(dir, &st); |
| 644 | if(result == -1 && errno != ENOENT) { |
| 645 | return -1; |
| 646 | } |
| 647 | else if(result == -1) { |
| 648 | /* ENOENT */ |
| 649 | int result; |
| 650 | |
| 651 | /* mkdir mode to 0777 */ |
| 652 | result = mkdir_p(dir, S_IRWXU | S_IRWXG | S_IRWXO); |
| 653 | if(result != 0) { |
| 654 | ERR("executing in recursive creation of directory %s", dir); |
| 655 | return -1; |
| 656 | } |
| 657 | } |
| 658 | |
| 659 | return 0; |
| 660 | } |
| 661 | |
| 662 | /* Used by the daemon to initialize its server so applications |
| 663 | * can connect to it. |
| 664 | */ |
| 665 | |
| 666 | |
| 667 | static const char *find_tok(const char *str) |
| 668 | { |
| 669 | while(*str == ' ') { |
| 670 | str++; |
| 671 | |
| 672 | if(*str == 0) |
| 673 | return NULL; |
| 674 | } |
| 675 | |
| 676 | return str; |
| 677 | } |
| 678 | |
| 679 | static const char *find_sep(const char *str) |
| 680 | { |
| 681 | while(*str != ' ') { |
| 682 | str++; |
| 683 | |
| 684 | if(*str == 0) |
| 685 | break; |
| 686 | } |
| 687 | |
| 688 | return str; |
| 689 | } |
| 690 | |
| 691 | int nth_token_is(const char *str, const char *token, int tok_no) |
| 692 | { |
| 693 | int i; |
| 694 | const char *start; |
| 695 | const char *end; |
| 696 | |
| 697 | for(i=0; i<=tok_no; i++) { |
| 698 | str = find_tok(str); |
| 699 | if(str == NULL) |
| 700 | return -1; |
| 701 | |
| 702 | start = str; |
| 703 | |
| 704 | str = find_sep(str); |
| 705 | if(str == NULL) |
| 706 | return -1; |
| 707 | |
| 708 | end = str; |
| 709 | } |
| 710 | |
| 711 | if(end-start != strlen(token)) |
| 712 | return 0; |
| 713 | |
| 714 | if(strncmp(start, token, end-start)) |
| 715 | return 0; |
| 716 | |
| 717 | return 1; |
| 718 | } |
| 719 | |
| 720 | char *nth_token(const char *str, int tok_no) |
| 721 | { |
| 722 | static char *retval = NULL; |
| 723 | int i; |
| 724 | const char *start; |
| 725 | const char *end; |
| 726 | |
| 727 | for(i=0; i<=tok_no; i++) { |
| 728 | str = find_tok(str); |
| 729 | if(str == NULL) |
| 730 | return NULL; |
| 731 | |
| 732 | start = str; |
| 733 | |
| 734 | str = find_sep(str); |
| 735 | if(str == NULL) |
| 736 | return NULL; |
| 737 | |
| 738 | end = str; |
| 739 | } |
| 740 | |
| 741 | if(retval) { |
| 742 | free(retval); |
| 743 | retval = NULL; |
| 744 | } |
| 745 | |
| 746 | if (asprintf(&retval, "%.*s", (int)(end-start), start) < 0) { |
| 747 | ERR("nth_token : asprintf failed (%.*s)", |
| 748 | (int)(end-start), start); |
| 749 | return NULL; |
| 750 | } |
| 751 | |
| 752 | return retval; |
| 753 | } |