1/* vi: set sw=4 ts=4: */ 2/* 3 * Utility routines. 4 * 5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> 6 * Copyright (C) 2006 Rob Landley 7 * Copyright (C) 2006 Denys Vlasenko 8 * 9 * Licensed under GPL version 2, see file LICENSE in this tarball for details. 10 */ 11 12/* We need to have separate xfuncs.c and xfuncs_printf.c because 13 * with current linkers, even with section garbage collection, 14 * if *.o module references any of XXXprintf functions, you pull in 15 * entire printf machinery. Even if you do not use the function 16 * which uses XXXprintf. 17 * 18 * xfuncs.c contains functions (not necessarily xfuncs) 19 * which do not pull in printf, directly or indirectly. 20 * xfunc_printf.c contains those which do. 21 */ 22 23#include "libbb.h" 24 25 26/* All the functions starting with "x" call bb_error_msg_and_die() if they 27 * fail, so callers never need to check for errors. If it returned, it 28 * succeeded. */ 29 30#ifndef DMALLOC 31/* dmalloc provides variants of these that do abort() on failure. 32 * Since dmalloc's prototypes overwrite the impls here as they are 33 * included after these prototypes in libbb.h, all is well. 34 */ 35// Warn if we can't allocate size bytes of memory. 36void* FAST_FUNC malloc_or_warn(size_t size) 37{ 38 void *ptr = malloc(size); 39 if (ptr == NULL && size != 0) 40 bb_error_msg(bb_msg_memory_exhausted); 41 return ptr; 42} 43 44// Die if we can't allocate size bytes of memory. 45void* FAST_FUNC xmalloc(size_t size) 46{ 47 void *ptr = malloc(size); 48 if (ptr == NULL && size != 0) 49 bb_error_msg_and_die(bb_msg_memory_exhausted); 50 return ptr; 51} 52 53// Die if we can't resize previously allocated memory. (This returns a pointer 54// to the new memory, which may or may not be the same as the old memory. 55// It'll copy the contents to a new chunk and free the old one if necessary.) 56void* FAST_FUNC xrealloc(void *ptr, size_t size) 57{ 58 ptr = realloc(ptr, size); 59 if (ptr == NULL && size != 0) 60 bb_error_msg_and_die(bb_msg_memory_exhausted); 61 return ptr; 62} 63#endif /* DMALLOC */ 64 65// Die if we can't allocate and zero size bytes of memory. 66void* FAST_FUNC xzalloc(size_t size) 67{ 68 void *ptr = xmalloc(size); 69 memset(ptr, 0, size); 70 return ptr; 71} 72 73// Die if we can't copy a string to freshly allocated memory. 74char* FAST_FUNC xstrdup(const char *s) 75{ 76 char *t; 77 78 if (s == NULL) 79 return NULL; 80 81 t = strdup(s); 82 83 if (t == NULL) 84 bb_error_msg_and_die(bb_msg_memory_exhausted); 85 86 return t; 87} 88 89// Die if we can't allocate n+1 bytes (space for the null terminator) and copy 90// the (possibly truncated to length n) string into it. 91char* FAST_FUNC xstrndup(const char *s, int n) 92{ 93 int m; 94 char *t; 95 96 if (ENABLE_DEBUG && s == NULL) 97 bb_error_msg_and_die("xstrndup bug"); 98 99 /* We can just xmalloc(n+1) and strncpy into it, */ 100 /* but think about xstrndup("abc", 10000) wastage! */ 101 m = n; 102 t = (char*) s; 103 while (m) { 104 if (!*t) break; 105 m--; 106 t++; 107 } 108 n -= m; 109 t = xmalloc(n + 1); 110 t[n] = '\0'; 111 112 return memcpy(t, s, n); 113} 114 115// Die if we can't open a file and return a FILE* to it. 116// Notice we haven't got xfread(), This is for use with fscanf() and friends. 117FILE* FAST_FUNC xfopen(const char *path, const char *mode) 118{ 119 FILE *fp = fopen(path, mode); 120 if (fp == NULL) 121 bb_perror_msg_and_die("can't open '%s'", path); 122 return fp; 123} 124 125// Die if we can't open a file and return a fd. 126int FAST_FUNC xopen3(const char *pathname, int flags, int mode) 127{ 128 int ret; 129 130 ret = open(pathname, flags, mode); 131 if (ret < 0) { 132 bb_perror_msg_and_die("can't open '%s'", pathname); 133 } 134 return ret; 135} 136 137// Die if we can't open an existing file and return a fd. 138int FAST_FUNC xopen(const char *pathname, int flags) 139{ 140 return xopen3(pathname, flags, 0666); 141} 142 143/* Die if we can't open an existing file readonly with O_NONBLOCK 144 * and return the fd. 145 * Note that for ioctl O_RDONLY is sufficient. 146 */ 147int FAST_FUNC xopen_nonblocking(const char *pathname) 148{ 149 return xopen(pathname, O_RDONLY | O_NONBLOCK); 150} 151 152// Warn if we can't open a file and return a fd. 153int FAST_FUNC open3_or_warn(const char *pathname, int flags, int mode) 154{ 155 int ret; 156 157 ret = open(pathname, flags, mode); 158 if (ret < 0) { 159 bb_perror_msg("can't open '%s'", pathname); 160 } 161 return ret; 162} 163 164// Warn if we can't open a file and return a fd. 165int FAST_FUNC open_or_warn(const char *pathname, int flags) 166{ 167 return open3_or_warn(pathname, flags, 0666); 168} 169 170void FAST_FUNC xunlink(const char *pathname) 171{ 172 if (unlink(pathname)) 173 bb_perror_msg_and_die("can't remove file '%s'", pathname); 174} 175 176void FAST_FUNC xrename(const char *oldpath, const char *newpath) 177{ 178 if (rename(oldpath, newpath)) 179 bb_perror_msg_and_die("can't move '%s' to '%s'", oldpath, newpath); 180} 181 182int FAST_FUNC rename_or_warn(const char *oldpath, const char *newpath) 183{ 184 int n = rename(oldpath, newpath); 185 if (n) 186 bb_perror_msg("can't move '%s' to '%s'", oldpath, newpath); 187 return n; 188} 189 190void FAST_FUNC xpipe(int filedes[2]) 191{ 192 if (pipe(filedes)) 193 bb_perror_msg_and_die("can't create pipe"); 194} 195 196void FAST_FUNC xdup2(int from, int to) 197{ 198 if (dup2(from, to) != to) 199 bb_perror_msg_and_die("can't duplicate file descriptor"); 200} 201 202// "Renumber" opened fd 203void FAST_FUNC xmove_fd(int from, int to) 204{ 205 if (from == to) 206 return; 207 xdup2(from, to); 208 close(from); 209} 210 211// Die with an error message if we can't write the entire buffer. 212void FAST_FUNC xwrite(int fd, const void *buf, size_t count) 213{ 214 if (count) { 215 ssize_t size = full_write(fd, buf, count); 216 if ((size_t)size != count) 217 bb_error_msg_and_die("short write"); 218 } 219} 220void FAST_FUNC xwrite_str(int fd, const char *str) 221{ 222 xwrite(fd, str, strlen(str)); 223} 224 225void FAST_FUNC xclose(int fd) 226{ 227 if (close(fd)) 228 bb_perror_msg_and_die("close failed"); 229} 230 231// Die with an error message if we can't lseek to the right spot. 232off_t FAST_FUNC xlseek(int fd, off_t offset, int whence) 233{ 234 off_t off = lseek(fd, offset, whence); 235 if (off == (off_t)-1) { 236 if (whence == SEEK_SET) 237 bb_perror_msg_and_die("lseek(%"OFF_FMT"u)", offset); 238 bb_perror_msg_and_die("lseek"); 239 } 240 return off; 241} 242 243// Die with supplied filename if this FILE* has ferror set. 244void FAST_FUNC die_if_ferror(FILE *fp, const char *fn) 245{ 246 if (ferror(fp)) { 247 /* ferror doesn't set useful errno */ 248 bb_error_msg_and_die("%s: I/O error", fn); 249 } 250} 251 252// Die with an error message if stdout has ferror set. 253void FAST_FUNC die_if_ferror_stdout(void) 254{ 255 die_if_ferror(stdout, bb_msg_standard_output); 256} 257 258int FAST_FUNC fflush_all(void) 259{ 260 return fflush(NULL); 261} 262 263 264int FAST_FUNC bb_putchar(int ch) 265{ 266 return putchar(ch); 267} 268 269/* Die with an error message if we can't copy an entire FILE* to stdout, 270 * then close that file. */ 271void FAST_FUNC xprint_and_close_file(FILE *file) 272{ 273 fflush_all(); 274 // copyfd outputs error messages for us. 275 if (bb_copyfd_eof(fileno(file), STDOUT_FILENO) == -1) 276 xfunc_die(); 277 278 fclose(file); 279} 280 281// Die with an error message if we can't malloc() enough space and do an 282// sprintf() into that space. 283char* FAST_FUNC xasprintf(const char *format, ...) 284{ 285 va_list p; 286 int r; 287 char *string_ptr; 288 289 va_start(p, format); 290 r = vasprintf(&string_ptr, format, p); 291 va_end(p); 292 293 if (r < 0) 294 bb_error_msg_and_die(bb_msg_memory_exhausted); 295 return string_ptr; 296} 297 298void FAST_FUNC xsetenv(const char *key, const char *value) 299{ 300 if (setenv(key, value, 1)) 301 bb_error_msg_and_die(bb_msg_memory_exhausted); 302} 303 304/* Handles "VAR=VAL" strings, even those which are part of environ 305 * _right now_ 306 */ 307void FAST_FUNC bb_unsetenv(const char *var) 308{ 309 char *tp = strchr(var, '='); 310 311 if (!tp) { 312 unsetenv(var); 313 return; 314 } 315 316 /* In case var was putenv'ed, we can't replace '=' 317 * with NUL and unsetenv(var) - it won't work, 318 * env is modified by the replacement, unsetenv 319 * sees "VAR" instead of "VAR=VAL" and does not remove it! 320 * horror :( */ 321 tp = xstrndup(var, tp - var); 322 unsetenv(tp); 323 free(tp); 324} 325 326void FAST_FUNC bb_unsetenv_and_free(char *var) 327{ 328 bb_unsetenv(var); 329 free(var); 330} 331 332// Die with an error message if we can't set gid. (Because resource limits may 333// limit this user to a given number of processes, and if that fills up the 334// setgid() will fail and we'll _still_be_root_, which is bad.) 335void FAST_FUNC xsetgid(gid_t gid) 336{ 337 if (setgid(gid)) bb_perror_msg_and_die("setgid"); 338} 339 340// Die with an error message if we can't set uid. (See xsetgid() for why.) 341void FAST_FUNC xsetuid(uid_t uid) 342{ 343 if (setuid(uid)) bb_perror_msg_and_die("setuid"); 344} 345 346// Die if we can't chdir to a new path. 347void FAST_FUNC xchdir(const char *path) 348{ 349 if (chdir(path)) 350 bb_perror_msg_and_die("chdir(%s)", path); 351} 352 353void FAST_FUNC xchroot(const char *path) 354{ 355 if (chroot(path)) 356 bb_perror_msg_and_die("can't change root directory to %s", path); 357} 358 359// Print a warning message if opendir() fails, but don't die. 360DIR* FAST_FUNC warn_opendir(const char *path) 361{ 362 DIR *dp; 363 364 dp = opendir(path); 365 if (!dp) 366 bb_perror_msg("can't open '%s'", path); 367 return dp; 368} 369 370// Die with an error message if opendir() fails. 371DIR* FAST_FUNC xopendir(const char *path) 372{ 373 DIR *dp; 374 375 dp = opendir(path); 376 if (!dp) 377 bb_perror_msg_and_die("can't open '%s'", path); 378 return dp; 379} 380 381// Die with an error message if we can't open a new socket. 382int FAST_FUNC xsocket(int domain, int type, int protocol) 383{ 384 int r = socket(domain, type, protocol); 385 386 if (r < 0) { 387 /* Hijack vaguely related config option */ 388#if ENABLE_VERBOSE_RESOLUTION_ERRORS 389 const char *s = "INET"; 390 if (domain == AF_PACKET) s = "PACKET"; 391 if (domain == AF_NETLINK) s = "NETLINK"; 392IF_FEATURE_IPV6(if (domain == AF_INET6) s = "INET6";) 393 bb_perror_msg_and_die("socket(AF_%s,%d,%d)", s, type, protocol); 394#else 395 bb_perror_msg_and_die("socket"); 396#endif 397 } 398 399 return r; 400} 401 402// Die with an error message if we can't bind a socket to an address. 403void FAST_FUNC xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen) 404{ 405 if (bind(sockfd, my_addr, addrlen)) bb_perror_msg_and_die("bind"); 406} 407 408// Die with an error message if we can't listen for connections on a socket. 409void FAST_FUNC xlisten(int s, int backlog) 410{ 411 if (listen(s, backlog)) bb_perror_msg_and_die("listen"); 412} 413 414/* Die with an error message if sendto failed. 415 * Return bytes sent otherwise */ 416ssize_t FAST_FUNC xsendto(int s, const void *buf, size_t len, const struct sockaddr *to, 417 socklen_t tolen) 418{ 419 ssize_t ret = sendto(s, buf, len, 0, to, tolen); 420 if (ret < 0) { 421 if (ENABLE_FEATURE_CLEAN_UP) 422 close(s); 423 bb_perror_msg_and_die("sendto"); 424 } 425 return ret; 426} 427 428// xstat() - a stat() which dies on failure with meaningful error message 429void FAST_FUNC xstat(const char *name, struct stat *stat_buf) 430{ 431 if (stat(name, stat_buf)) 432 bb_perror_msg_and_die("can't stat '%s'", name); 433} 434 435// selinux_or_die() - die if SELinux is disabled. 436void FAST_FUNC selinux_or_die(void) 437{ 438#if ENABLE_SELINUX 439 int rc = is_selinux_enabled(); 440 if (rc == 0) { 441 bb_error_msg_and_die("SELinux is disabled"); 442 } else if (rc < 0) { 443 bb_error_msg_and_die("is_selinux_enabled() failed"); 444 } 445#else 446 bb_error_msg_and_die("SELinux support is disabled"); 447#endif 448} 449 450int FAST_FUNC ioctl_or_perror_and_die(int fd, unsigned request, void *argp, const char *fmt,...) 451{ 452 int ret; 453 va_list p; 454 455 ret = ioctl(fd, request, argp); 456 if (ret < 0) { 457 va_start(p, fmt); 458 bb_verror_msg(fmt, p, strerror(errno)); 459 /* xfunc_die can actually longjmp, so be nice */ 460 va_end(p); 461 xfunc_die(); 462 } 463 return ret; 464} 465 466int FAST_FUNC ioctl_or_perror(int fd, unsigned request, void *argp, const char *fmt,...) 467{ 468 va_list p; 469 int ret = ioctl(fd, request, argp); 470 471 if (ret < 0) { 472 va_start(p, fmt); 473 bb_verror_msg(fmt, p, strerror(errno)); 474 va_end(p); 475 } 476 return ret; 477} 478 479#if ENABLE_IOCTL_HEX2STR_ERROR 480int FAST_FUNC bb_ioctl_or_warn(int fd, unsigned request, void *argp, const char *ioctl_name) 481{ 482 int ret; 483 484 ret = ioctl(fd, request, argp); 485 if (ret < 0) 486 bb_simple_perror_msg(ioctl_name); 487 return ret; 488} 489int FAST_FUNC bb_xioctl(int fd, unsigned request, void *argp, const char *ioctl_name) 490{ 491 int ret; 492 493 ret = ioctl(fd, request, argp); 494 if (ret < 0) 495 bb_simple_perror_msg_and_die(ioctl_name); 496 return ret; 497} 498#else 499int FAST_FUNC bb_ioctl_or_warn(int fd, unsigned request, void *argp) 500{ 501 int ret; 502 503 ret = ioctl(fd, request, argp); 504 if (ret < 0) 505 bb_perror_msg("ioctl %#x failed", request); 506 return ret; 507} 508int FAST_FUNC bb_xioctl(int fd, unsigned request, void *argp) 509{ 510 int ret; 511 512 ret = ioctl(fd, request, argp); 513 if (ret < 0) 514 bb_perror_msg_and_die("ioctl %#x failed", request); 515 return ret; 516} 517#endif 518 519char* FAST_FUNC xmalloc_ttyname(int fd) 520{ 521 char *buf = xzalloc(128); 522 int r = ttyname_r(fd, buf, 127); 523 if (r) { 524 free(buf); 525 buf = NULL; 526 } 527 return buf; 528} 529 530void FAST_FUNC generate_uuid(uint8_t *buf) 531{ 532 /* http://www.ietf.org/rfc/rfc4122.txt 533 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 534 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 535 * | time_low | 536 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 537 * | time_mid | time_hi_and_version | 538 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 539 * |clk_seq_and_variant | node (0-1) | 540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 541 * | node (2-5) | 542 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 543 * IOW, uuid has this layout: 544 * uint32_t time_low (big endian) 545 * uint16_t time_mid (big endian) 546 * uint16_t time_hi_and_version (big endian) 547 * version is a 4-bit field: 548 * 1 Time-based 549 * 2 DCE Security, with embedded POSIX UIDs 550 * 3 Name-based (MD5) 551 * 4 Randomly generated 552 * 5 Name-based (SHA-1) 553 * uint16_t clk_seq_and_variant (big endian) 554 * variant is a 3-bit field: 555 * 0xx Reserved, NCS backward compatibility 556 * 10x The variant specified in rfc4122 557 * 110 Reserved, Microsoft backward compatibility 558 * 111 Reserved for future definition 559 * uint8_t node[6] 560 * 561 * For version 4, these bits are set/cleared: 562 * time_hi_and_version & 0x0fff | 0x4000 563 * clk_seq_and_variant & 0x3fff | 0x8000 564 */ 565 pid_t pid; 566 int i; 567 568 i = open("/dev/urandom", O_RDONLY); 569 if (i >= 0) { 570 read(i, buf, 16); 571 close(i); 572 } 573 /* Paranoia. /dev/urandom may be missing. 574 * rand() is guaranteed to generate at least [0, 2^15) range, 575 * but lowest bits in some libc are not so "random". */ 576 srand(monotonic_us()); /* pulls in printf */ 577 pid = getpid(); 578 while (1) { 579 for (i = 0; i < 16; i++) 580 buf[i] ^= rand() >> 5; 581 if (pid == 0) 582 break; 583 srand(pid); 584 pid = 0; 585 } 586 587 /* version = 4 */ 588 buf[4 + 2 ] = (buf[4 + 2 ] & 0x0f) | 0x40; 589 /* variant = 10x */ 590 buf[4 + 2 + 2] = (buf[4 + 2 + 2] & 0x3f) | 0x80; 591} 592 593#if BB_MMU 594pid_t FAST_FUNC xfork(void) 595{ 596 pid_t pid; 597 pid = fork(); 598 if (pid < 0) /* wtf? */ 599 bb_perror_msg_and_die("vfork"+1); 600 return pid; 601} 602#endif 603