Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 1 | /* xwrap.c - wrappers around existing library functions. |
| 2 | * |
| 3 | * Functions with the x prefix are wrappers that either succeed or kill the |
| 4 | * program with an error message, but never return failure. They usually have |
| 5 | * the same arguments and return value as the function they wrap. |
| 6 | * |
| 7 | * Copyright 2006 Rob Landley <rob@landley.net> |
| 8 | */ |
| 9 | |
| 10 | #include "toys.h" |
| 11 | |
| 12 | // Strcpy with size checking: exit if there's not enough space for the string. |
| 13 | void xstrncpy(char *dest, char *src, size_t size) |
| 14 | { |
Rob Landley | 3704f82 | 2013-11-02 14:24:54 -0500 | [diff] [blame] | 15 | if (strlen(src)+1 > size) error_exit("'%s' > %ld bytes", src, (long)size); |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 16 | strcpy(dest, src); |
| 17 | } |
| 18 | |
| 19 | void xexit(void) |
| 20 | { |
| 21 | if (toys.rebound) longjmp(*toys.rebound, 1); |
| 22 | else exit(toys.exitval); |
| 23 | } |
| 24 | |
| 25 | // Die unless we can allocate memory. |
| 26 | void *xmalloc(size_t size) |
| 27 | { |
| 28 | void *ret = malloc(size); |
| 29 | if (!ret) error_exit("xmalloc"); |
| 30 | |
| 31 | return ret; |
| 32 | } |
| 33 | |
| 34 | // Die unless we can allocate prezeroed memory. |
| 35 | void *xzalloc(size_t size) |
| 36 | { |
| 37 | void *ret = xmalloc(size); |
| 38 | memset(ret, 0, size); |
| 39 | return ret; |
| 40 | } |
| 41 | |
| 42 | // Die unless we can change the size of an existing allocation, possibly |
| 43 | // moving it. (Notice different arguments from libc function.) |
| 44 | void *xrealloc(void *ptr, size_t size) |
| 45 | { |
| 46 | ptr = realloc(ptr, size); |
| 47 | if (!ptr) error_exit("xrealloc"); |
| 48 | |
| 49 | return ptr; |
| 50 | } |
| 51 | |
| 52 | // Die unless we can allocate a copy of this many bytes of string. |
| 53 | char *xstrndup(char *s, size_t n) |
| 54 | { |
| 55 | char *ret = xmalloc(++n); |
| 56 | strncpy(ret, s, n); |
| 57 | ret[--n]=0; |
| 58 | |
| 59 | return ret; |
| 60 | } |
| 61 | |
| 62 | // Die unless we can allocate a copy of this string. |
| 63 | char *xstrdup(char *s) |
| 64 | { |
| 65 | return xstrndup(s, strlen(s)); |
| 66 | } |
| 67 | |
| 68 | // Die unless we can allocate enough space to sprintf() into. |
Rob Landley | 59d85e2 | 2014-01-16 09:26:50 -0600 | [diff] [blame] | 69 | char *xmprintf(char *format, ...) |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 70 | { |
| 71 | va_list va, va2; |
| 72 | int len; |
| 73 | char *ret; |
| 74 | |
| 75 | va_start(va, format); |
| 76 | va_copy(va2, va); |
| 77 | |
| 78 | // How long is it? |
| 79 | len = vsnprintf(0, 0, format, va); |
| 80 | len++; |
| 81 | va_end(va); |
| 82 | |
| 83 | // Allocate and do the sprintf() |
| 84 | ret = xmalloc(len); |
| 85 | vsnprintf(ret, len, format, va2); |
| 86 | va_end(va2); |
| 87 | |
| 88 | return ret; |
| 89 | } |
| 90 | |
| 91 | void xprintf(char *format, ...) |
| 92 | { |
| 93 | va_list va; |
| 94 | va_start(va, format); |
| 95 | |
| 96 | vprintf(format, va); |
Rob Landley | ddbaa71 | 2014-05-26 12:25:47 -0500 | [diff] [blame] | 97 | if (fflush(stdout) || ferror(stdout)) perror_exit("write"); |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 98 | } |
| 99 | |
| 100 | void xputs(char *s) |
| 101 | { |
Rob Landley | ddbaa71 | 2014-05-26 12:25:47 -0500 | [diff] [blame] | 102 | if (EOF == puts(s) || fflush(stdout) || ferror(stdout)) perror_exit("write"); |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 103 | } |
| 104 | |
| 105 | void xputc(char c) |
| 106 | { |
Rob Landley | ddbaa71 | 2014-05-26 12:25:47 -0500 | [diff] [blame] | 107 | if (EOF == fputc(c, stdout) || fflush(stdout) || ferror(stdout)) |
| 108 | perror_exit("write"); |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 109 | } |
| 110 | |
| 111 | void xflush(void) |
| 112 | { |
Rob Landley | ddbaa71 | 2014-05-26 12:25:47 -0500 | [diff] [blame] | 113 | if (fflush(stdout) || ferror(stdout)) perror_exit("write");; |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 114 | } |
| 115 | |
Rob Landley | d8872c4 | 2014-05-31 12:33:24 -0500 | [diff] [blame] | 116 | pid_t xfork(void) |
| 117 | { |
| 118 | pid_t pid = fork(); |
| 119 | |
| 120 | if (pid < 0) perror_exit("fork"); |
| 121 | |
| 122 | return pid; |
| 123 | } |
| 124 | |
Rob Landley | 7275667 | 2013-07-17 17:22:46 -0500 | [diff] [blame] | 125 | // Call xexec with a chunk of optargs, starting at skip. (You can't just |
| 126 | // call xexec() directly because toy_init() frees optargs.) |
| 127 | void xexec_optargs(int skip) |
| 128 | { |
| 129 | char **s = toys.optargs; |
| 130 | |
| 131 | toys.optargs = 0; |
| 132 | xexec(s+skip); |
| 133 | } |
| 134 | |
| 135 | |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 136 | // Die unless we can exec argv[] (or run builtin command). Note that anything |
| 137 | // with a path isn't a builtin, so /bin/sh won't match the builtin sh. |
| 138 | void xexec(char **argv) |
| 139 | { |
Rob Landley | 977e48e | 2014-10-20 19:52:29 -0500 | [diff] [blame^] | 140 | if (CFG_TOYBOX && !CFG_TOYBOX_NORECURSE) toy_exec(argv); |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 141 | execvp(argv[0], argv); |
| 142 | |
| 143 | perror_exit("exec %s", argv[0]); |
| 144 | } |
| 145 | |
Rob Landley | 44e68a1 | 2014-06-03 06:27:24 -0500 | [diff] [blame] | 146 | // Spawn child process, capturing stdin/stdout. |
| 147 | // argv[]: command to exec. If null, child returns to original program. |
Rob Landley | 360d57f | 2014-09-14 12:29:44 -0500 | [diff] [blame] | 148 | // pipes[2]: stdin, stdout of new process. If -1 will not have pipe allocated. |
Rob Landley | 44e68a1 | 2014-06-03 06:27:24 -0500 | [diff] [blame] | 149 | // return: pid of child process |
Rob Landley | 360d57f | 2014-09-14 12:29:44 -0500 | [diff] [blame] | 150 | pid_t xpopen_both(char **argv, int *pipes) |
Rob Landley | 44e68a1 | 2014-06-03 06:27:24 -0500 | [diff] [blame] | 151 | { |
| 152 | int cestnepasun[4], pid; |
| 153 | |
Rob Landley | 360d57f | 2014-09-14 12:29:44 -0500 | [diff] [blame] | 154 | // Make the pipes? Not this won't set either pipe to 0 because if fds are |
| 155 | // allocated in order and if fd0 was free it would go to cestnepasun[0] |
Rob Landley | 44e68a1 | 2014-06-03 06:27:24 -0500 | [diff] [blame] | 156 | if (pipes) { |
Rob Landley | 360d57f | 2014-09-14 12:29:44 -0500 | [diff] [blame] | 157 | for (pid = 0; pid < 2; pid++) { |
| 158 | if (pipes[pid] == -1) continue; |
| 159 | if (pipe(cestnepasun+(2*pid))) perror_exit("pipe"); |
| 160 | pipes[pid] = cestnepasun[pid+1]; |
| 161 | } |
Rob Landley | 44e68a1 | 2014-06-03 06:27:24 -0500 | [diff] [blame] | 162 | } |
| 163 | |
| 164 | // Child process |
| 165 | if (!(pid = xfork())) { |
| 166 | // Dance of the stdin/stdout redirection. |
| 167 | if (pipes) { |
Rob Landley | 360d57f | 2014-09-14 12:29:44 -0500 | [diff] [blame] | 168 | // if we had no stdin/out, pipe handles could overlap, so test for it |
| 169 | // and free up potentially overlapping pipe handles before reuse |
| 170 | if (pipes[1] != -1) close(cestnepasun[2]); |
| 171 | if (pipes[0] != -1) { |
| 172 | close(cestnepasun[1]); |
| 173 | if (cestnepasun[0]) { |
| 174 | dup2(cestnepasun[0], 0); |
| 175 | close(cestnepasun[0]); |
| 176 | } |
Rob Landley | 44e68a1 | 2014-06-03 06:27:24 -0500 | [diff] [blame] | 177 | } |
Rob Landley | 360d57f | 2014-09-14 12:29:44 -0500 | [diff] [blame] | 178 | if (pipes[1] != -1) { |
| 179 | dup2(cestnepasun[3], 1); |
| 180 | dup2(cestnepasun[3], 2); |
| 181 | if (cestnepasun[3] > 2 || !cestnepasun[3]) close(cestnepasun[3]); |
| 182 | } |
Rob Landley | 44e68a1 | 2014-06-03 06:27:24 -0500 | [diff] [blame] | 183 | } |
| 184 | if (argv) { |
| 185 | if (CFG_TOYBOX) toy_exec(argv); |
| 186 | execvp(argv[0], argv); |
| 187 | _exit(127); |
| 188 | } |
| 189 | return 0; |
| 190 | |
Rob Landley | 44e68a1 | 2014-06-03 06:27:24 -0500 | [diff] [blame] | 191 | } |
Rob Landley | 360d57f | 2014-09-14 12:29:44 -0500 | [diff] [blame] | 192 | |
| 193 | // Parent process |
| 194 | if (pipes) { |
| 195 | if (pipes[0] != -1) close(cestnepasun[0]); |
| 196 | if (pipes[1] != -1) close(cestnepasun[3]); |
| 197 | } |
| 198 | |
| 199 | return pid; |
Rob Landley | 44e68a1 | 2014-06-03 06:27:24 -0500 | [diff] [blame] | 200 | } |
| 201 | |
Rob Landley | 360d57f | 2014-09-14 12:29:44 -0500 | [diff] [blame] | 202 | int xpclose_both(pid_t pid, int *pipes) |
Rob Landley | 44e68a1 | 2014-06-03 06:27:24 -0500 | [diff] [blame] | 203 | { |
| 204 | int rc = 127; |
| 205 | |
| 206 | if (pipes) { |
| 207 | close(pipes[0]); |
| 208 | close(pipes[1]); |
| 209 | } |
| 210 | waitpid(pid, &rc, 0); |
| 211 | |
| 212 | return WIFEXITED(rc) ? WEXITSTATUS(rc) : WTERMSIG(rc) + 127; |
| 213 | } |
| 214 | |
Rob Landley | 360d57f | 2014-09-14 12:29:44 -0500 | [diff] [blame] | 215 | // Wrapper to xpopen with a pipe for just one of stdin/stdout |
| 216 | pid_t xpopen(char **argv, int *pipe, int stdout) |
| 217 | { |
Rob Landley | 8a99071 | 2014-09-14 19:54:19 -0500 | [diff] [blame] | 218 | int pipes[2], pid; |
Rob Landley | 360d57f | 2014-09-14 12:29:44 -0500 | [diff] [blame] | 219 | |
Rob Landley | 8a99071 | 2014-09-14 19:54:19 -0500 | [diff] [blame] | 220 | pipes[!stdout] = -1; |
| 221 | pipes[!!stdout] = 0; |
| 222 | pid = xpopen_both(argv, pipes); |
| 223 | *pipe = pid ? pipes[!!stdout] : -1; |
Rob Landley | 360d57f | 2014-09-14 12:29:44 -0500 | [diff] [blame] | 224 | |
Rob Landley | 8a99071 | 2014-09-14 19:54:19 -0500 | [diff] [blame] | 225 | return pid; |
Rob Landley | 360d57f | 2014-09-14 12:29:44 -0500 | [diff] [blame] | 226 | } |
| 227 | |
| 228 | int xpclose(pid_t pid, int pipe) |
| 229 | { |
| 230 | close(pipe); |
| 231 | |
| 232 | return xpclose_both(pid, 0); |
| 233 | } |
| 234 | |
| 235 | // Call xpopen and wait for it to finish, keeping existing stdin/stdout. |
| 236 | int xrun(char **argv) |
| 237 | { |
| 238 | return xpclose_both(xpopen_both(argv, 0), 0); |
| 239 | } |
| 240 | |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 241 | void xaccess(char *path, int flags) |
| 242 | { |
| 243 | if (access(path, flags)) perror_exit("Can't access '%s'", path); |
| 244 | } |
| 245 | |
| 246 | // Die unless we can delete a file. (File must exist to be deleted.) |
| 247 | void xunlink(char *path) |
| 248 | { |
| 249 | if (unlink(path)) perror_exit("unlink '%s'", path); |
| 250 | } |
| 251 | |
| 252 | // Die unless we can open/create a file, returning file descriptor. |
| 253 | int xcreate(char *path, int flags, int mode) |
| 254 | { |
Rob Landley | ccb73f8 | 2014-07-26 13:27:07 -0500 | [diff] [blame] | 255 | int fd = open(path, flags^O_CLOEXEC, mode); |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 256 | if (fd == -1) perror_exit("%s", path); |
| 257 | return fd; |
| 258 | } |
| 259 | |
| 260 | // Die unless we can open a file, returning file descriptor. |
| 261 | int xopen(char *path, int flags) |
| 262 | { |
| 263 | return xcreate(path, flags, 0); |
| 264 | } |
| 265 | |
| 266 | void xclose(int fd) |
| 267 | { |
| 268 | if (close(fd)) perror_exit("xclose"); |
| 269 | } |
| 270 | |
| 271 | int xdup(int fd) |
| 272 | { |
| 273 | if (fd != -1) { |
| 274 | fd = dup(fd); |
| 275 | if (fd == -1) perror_exit("xdup"); |
| 276 | } |
| 277 | return fd; |
| 278 | } |
| 279 | |
Rob Landley | 1aa7511 | 2013-08-07 12:19:51 -0500 | [diff] [blame] | 280 | FILE *xfdopen(int fd, char *mode) |
| 281 | { |
| 282 | FILE *f = fdopen(fd, mode); |
| 283 | |
| 284 | if (!f) perror_exit("xfdopen"); |
| 285 | |
| 286 | return f; |
| 287 | } |
| 288 | |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 289 | // Die unless we can open/create a file, returning FILE *. |
| 290 | FILE *xfopen(char *path, char *mode) |
| 291 | { |
| 292 | FILE *f = fopen(path, mode); |
| 293 | if (!f) perror_exit("No file %s", path); |
| 294 | return f; |
| 295 | } |
| 296 | |
| 297 | // Die if there's an error other than EOF. |
| 298 | size_t xread(int fd, void *buf, size_t len) |
| 299 | { |
| 300 | ssize_t ret = read(fd, buf, len); |
| 301 | if (ret < 0) perror_exit("xread"); |
| 302 | |
| 303 | return ret; |
| 304 | } |
| 305 | |
| 306 | void xreadall(int fd, void *buf, size_t len) |
| 307 | { |
| 308 | if (len != readall(fd, buf, len)) perror_exit("xreadall"); |
| 309 | } |
| 310 | |
| 311 | // There's no xwriteall(), just xwrite(). When we read, there may or may not |
| 312 | // be more data waiting. When we write, there is data and it had better go |
| 313 | // somewhere. |
| 314 | |
| 315 | void xwrite(int fd, void *buf, size_t len) |
| 316 | { |
| 317 | if (len != writeall(fd, buf, len)) perror_exit("xwrite"); |
| 318 | } |
| 319 | |
| 320 | // Die if lseek fails, probably due to being called on a pipe. |
| 321 | |
| 322 | off_t xlseek(int fd, off_t offset, int whence) |
| 323 | { |
| 324 | offset = lseek(fd, offset, whence); |
| 325 | if (offset<0) perror_exit("lseek"); |
| 326 | |
| 327 | return offset; |
| 328 | } |
| 329 | |
| 330 | char *xgetcwd(void) |
| 331 | { |
| 332 | char *buf = getcwd(NULL, 0); |
| 333 | if (!buf) perror_exit("xgetcwd"); |
| 334 | |
| 335 | return buf; |
| 336 | } |
| 337 | |
| 338 | void xstat(char *path, struct stat *st) |
| 339 | { |
| 340 | if(stat(path, st)) perror_exit("Can't stat %s", path); |
| 341 | } |
| 342 | |
| 343 | // Cannonicalize path, even to file with one or more missing components at end. |
| 344 | // if exact, require last path component to exist |
| 345 | char *xabspath(char *path, int exact) |
| 346 | { |
| 347 | struct string_list *todo, *done = 0; |
| 348 | int try = 9999, dirfd = open("/", 0);; |
| 349 | char buf[4096], *ret; |
| 350 | |
| 351 | // If this isn't an absolute path, start with cwd. |
| 352 | if (*path != '/') { |
| 353 | char *temp = xgetcwd(); |
| 354 | |
| 355 | splitpath(path, splitpath(temp, &todo)); |
| 356 | free(temp); |
| 357 | } else splitpath(path, &todo); |
| 358 | |
| 359 | // Iterate through path components |
| 360 | while (todo) { |
| 361 | struct string_list *new = llist_pop(&todo), **tail; |
| 362 | ssize_t len; |
| 363 | |
| 364 | if (!try--) { |
| 365 | errno = ELOOP; |
| 366 | goto error; |
| 367 | } |
| 368 | |
| 369 | // Removable path componenents. |
| 370 | if (!strcmp(new->str, ".") || !strcmp(new->str, "..")) { |
| 371 | int x = new->str[1]; |
| 372 | |
| 373 | free(new); |
| 374 | if (x) { |
| 375 | if (done) free(llist_pop(&done)); |
| 376 | len = 0; |
| 377 | } else continue; |
| 378 | |
| 379 | // Is this a symlink? |
| 380 | } else len=readlinkat(dirfd, new->str, buf, 4096); |
| 381 | |
| 382 | if (len>4095) goto error; |
| 383 | if (len<1) { |
| 384 | int fd; |
| 385 | char *s = ".."; |
| 386 | |
| 387 | // For .. just move dirfd |
| 388 | if (len) { |
| 389 | // Not a symlink: add to linked list, move dirfd, fail if error |
| 390 | if ((exact || todo) && errno != EINVAL) goto error; |
| 391 | new->next = done; |
| 392 | done = new; |
| 393 | if (errno == EINVAL && !todo) break; |
| 394 | s = new->str; |
| 395 | } |
| 396 | fd = openat(dirfd, s, 0); |
| 397 | if (fd == -1 && (exact || todo || errno != ENOENT)) goto error; |
| 398 | close(dirfd); |
| 399 | dirfd = fd; |
| 400 | continue; |
| 401 | } |
| 402 | |
| 403 | // If this symlink is to an absolute path, discard existing resolved path |
| 404 | buf[len] = 0; |
| 405 | if (*buf == '/') { |
| 406 | llist_traverse(done, free); |
| 407 | done=0; |
| 408 | close(dirfd); |
| 409 | dirfd = open("/", 0); |
| 410 | } |
| 411 | free(new); |
| 412 | |
| 413 | // prepend components of new path. Note symlink to "/" will leave new NULL |
| 414 | tail = splitpath(buf, &new); |
| 415 | |
| 416 | // symlink to "/" will return null and leave tail alone |
| 417 | if (new) { |
| 418 | *tail = todo; |
| 419 | todo = new; |
| 420 | } |
| 421 | } |
| 422 | close(dirfd); |
| 423 | |
| 424 | // At this point done has the path, in reverse order. Reverse list while |
| 425 | // calculating buffer length. |
| 426 | |
| 427 | try = 2; |
| 428 | while (done) { |
| 429 | struct string_list *temp = llist_pop(&done);; |
| 430 | |
| 431 | if (todo) try++; |
| 432 | try += strlen(temp->str); |
| 433 | temp->next = todo; |
| 434 | todo = temp; |
| 435 | } |
| 436 | |
| 437 | // Assemble return buffer |
| 438 | |
| 439 | ret = xmalloc(try); |
| 440 | *ret = '/'; |
| 441 | ret [try = 1] = 0; |
| 442 | while (todo) { |
| 443 | if (try>1) ret[try++] = '/'; |
| 444 | try = stpcpy(ret+try, todo->str) - ret; |
| 445 | free(llist_pop(&todo)); |
| 446 | } |
| 447 | |
| 448 | return ret; |
| 449 | |
| 450 | error: |
| 451 | close(dirfd); |
| 452 | llist_traverse(todo, free); |
| 453 | llist_traverse(done, free); |
| 454 | |
| 455 | return NULL; |
| 456 | } |
| 457 | |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 458 | void xchdir(char *path) |
| 459 | { |
| 460 | if (chdir(path)) error_exit("chdir '%s'", path); |
| 461 | } |
| 462 | |
Rob Landley | afba5b8 | 2013-12-23 06:49:38 -0600 | [diff] [blame] | 463 | void xchroot(char *path) |
| 464 | { |
| 465 | if (chroot(path)) error_exit("chroot '%s'", path); |
| 466 | xchdir("/"); |
| 467 | } |
| 468 | |
Rob Landley | 9e44a58 | 2013-11-28 20:18:04 -0600 | [diff] [blame] | 469 | struct passwd *xgetpwuid(uid_t uid) |
| 470 | { |
| 471 | struct passwd *pwd = getpwuid(uid); |
Rob Landley | 5ec4ab3 | 2013-11-28 21:06:15 -0600 | [diff] [blame] | 472 | if (!pwd) error_exit("bad uid %ld", (long)uid); |
Rob Landley | 9e44a58 | 2013-11-28 20:18:04 -0600 | [diff] [blame] | 473 | return pwd; |
| 474 | } |
| 475 | |
| 476 | struct group *xgetgrgid(gid_t gid) |
| 477 | { |
| 478 | struct group *group = getgrgid(gid); |
Rob Landley | 4fd07e0 | 2014-07-21 19:57:36 -0500 | [diff] [blame] | 479 | |
| 480 | if (!group) perror_exit("gid %ld", (long)gid); |
Rob Landley | 9e44a58 | 2013-11-28 20:18:04 -0600 | [diff] [blame] | 481 | return group; |
| 482 | } |
| 483 | |
Rob Landley | 5ec4ab3 | 2013-11-28 21:06:15 -0600 | [diff] [blame] | 484 | struct passwd *xgetpwnam(char *name) |
| 485 | { |
| 486 | struct passwd *up = getpwnam(name); |
Rob Landley | 4fd07e0 | 2014-07-21 19:57:36 -0500 | [diff] [blame] | 487 | |
| 488 | if (!up) perror_exit("user '%s'", name); |
Rob Landley | 5ec4ab3 | 2013-11-28 21:06:15 -0600 | [diff] [blame] | 489 | return up; |
| 490 | } |
| 491 | |
Rob Landley | 60c35c4 | 2014-08-03 15:50:10 -0500 | [diff] [blame] | 492 | struct group *xgetgrnam(char *name) |
| 493 | { |
| 494 | struct group *gr = getgrnam(name); |
| 495 | |
| 496 | if (!gr) perror_exit("group '%s'", name); |
| 497 | return gr; |
| 498 | } |
| 499 | |
Rob Landley | afba5b8 | 2013-12-23 06:49:38 -0600 | [diff] [blame] | 500 | // setuid() can fail (for example, too many processes belonging to that user), |
| 501 | // which opens a security hole if the process continues as the original user. |
| 502 | |
| 503 | void xsetuser(struct passwd *pwd) |
| 504 | { |
| 505 | if (initgroups(pwd->pw_name, pwd->pw_gid) || setgid(pwd->pw_uid) |
| 506 | || setuid(pwd->pw_uid)) perror_exit("xsetuser '%s'", pwd->pw_name); |
| 507 | } |
| 508 | |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 509 | // This can return null (meaning file not found). It just won't return null |
| 510 | // for memory allocation reasons. |
| 511 | char *xreadlink(char *name) |
| 512 | { |
| 513 | int len, size = 0; |
| 514 | char *buf = 0; |
| 515 | |
| 516 | // Grow by 64 byte chunks until it's big enough. |
| 517 | for(;;) { |
| 518 | size +=64; |
| 519 | buf = xrealloc(buf, size); |
| 520 | len = readlink(name, buf, size); |
| 521 | |
| 522 | if (len<0) { |
| 523 | free(buf); |
| 524 | return 0; |
| 525 | } |
| 526 | if (len<size) { |
| 527 | buf[len]=0; |
| 528 | return buf; |
| 529 | } |
| 530 | } |
| 531 | } |
| 532 | |
Rob Landley | dc37317 | 2013-12-27 18:45:01 -0600 | [diff] [blame] | 533 | char *xreadfile(char *name, char *buf, off_t len) |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 534 | { |
Rob Landley | dc37317 | 2013-12-27 18:45:01 -0600 | [diff] [blame] | 535 | if (!(buf = readfile(name, buf, len))) perror_exit("Bad '%s'", name); |
| 536 | |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 537 | return buf; |
| 538 | } |
| 539 | |
| 540 | int xioctl(int fd, int request, void *data) |
| 541 | { |
| 542 | int rc; |
| 543 | |
| 544 | errno = 0; |
| 545 | rc = ioctl(fd, request, data); |
| 546 | if (rc == -1 && errno) perror_exit("ioctl %x", request); |
| 547 | |
| 548 | return rc; |
| 549 | } |
| 550 | |
| 551 | // Open a /var/run/NAME.pid file, dying if we can't write it or if it currently |
| 552 | // exists and is this executable. |
| 553 | void xpidfile(char *name) |
| 554 | { |
| 555 | char pidfile[256], spid[32]; |
| 556 | int i, fd; |
| 557 | pid_t pid; |
| 558 | |
| 559 | sprintf(pidfile, "/var/run/%s.pid", name); |
| 560 | // Try three times to open the sucker. |
| 561 | for (i=0; i<3; i++) { |
Felix Janda | dccfb2a | 2013-08-26 21:55:33 +0200 | [diff] [blame] | 562 | fd = open(pidfile, O_CREAT|O_EXCL|O_WRONLY, 0644); |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 563 | if (fd != -1) break; |
| 564 | |
| 565 | // If it already existed, read it. Loop for race condition. |
| 566 | fd = open(pidfile, O_RDONLY); |
| 567 | if (fd == -1) continue; |
| 568 | |
| 569 | // Is the old program still there? |
| 570 | spid[xread(fd, spid, sizeof(spid)-1)] = 0; |
| 571 | close(fd); |
| 572 | pid = atoi(spid); |
Rob Landley | 46e8e1d | 2013-09-06 04:45:36 -0500 | [diff] [blame] | 573 | if (pid < 1 || (kill(pid, 0) && errno == ESRCH)) unlink(pidfile); |
Rob Landley | d390493 | 2013-07-16 00:04:56 -0500 | [diff] [blame] | 574 | |
| 575 | // An else with more sanity checking might be nice here. |
| 576 | } |
| 577 | |
| 578 | if (i == 3) error_exit("xpidfile %s", name); |
| 579 | |
| 580 | xwrite(fd, spid, sprintf(spid, "%ld\n", (long)getpid())); |
| 581 | close(fd); |
| 582 | } |
| 583 | |
| 584 | // Copy the rest of in to out and close both files. |
| 585 | |
| 586 | void xsendfile(int in, int out) |
| 587 | { |
| 588 | long len; |
| 589 | char buf[4096]; |
| 590 | |
| 591 | if (in<0) return; |
| 592 | for (;;) { |
| 593 | len = xread(in, buf, 4096); |
| 594 | if (len<1) break; |
| 595 | xwrite(out, buf, len); |
| 596 | } |
| 597 | } |
Rob Landley | 7275667 | 2013-07-17 17:22:46 -0500 | [diff] [blame] | 598 | |
| 599 | // parse fractional seconds with optional s/m/h/d suffix |
| 600 | long xparsetime(char *arg, long units, long *fraction) |
| 601 | { |
| 602 | double d; |
| 603 | long l; |
| 604 | |
| 605 | if (CFG_TOYBOX_FLOAT) d = strtod(arg, &arg); |
| 606 | else l = strtoul(arg, &arg, 10); |
| 607 | |
| 608 | // Parse suffix |
| 609 | if (*arg) { |
| 610 | int ismhd[]={1,60,3600,86400}, i = stridx("smhd", *arg); |
| 611 | |
| 612 | if (i == -1) error_exit("Unknown suffix '%c'", *arg); |
| 613 | if (CFG_TOYBOX_FLOAT) d *= ismhd[i]; |
| 614 | else l *= ismhd[i]; |
| 615 | } |
| 616 | |
| 617 | if (CFG_TOYBOX_FLOAT) { |
| 618 | l = (long)d; |
| 619 | if (fraction) *fraction = units*(d-l); |
| 620 | } else if (fraction) *fraction = 0; |
| 621 | |
| 622 | return l; |
| 623 | } |
Rob Landley | 5b40582 | 2014-03-29 18:11:00 -0500 | [diff] [blame] | 624 | |
| 625 | // Compile a regular expression into a regex_t |
| 626 | void xregcomp(regex_t *preg, char *regex, int cflags) |
| 627 | { |
| 628 | int rc = regcomp(preg, regex, cflags); |
| 629 | |
| 630 | if (rc) { |
| 631 | regerror(rc, preg, libbuf, sizeof(libbuf)); |
| 632 | error_exit("xregcomp: %s", libbuf); |
| 633 | } |
| 634 | } |