blob: 2a20d5339a057c0114fff12bca7f490e5cc55dc9
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 GPLv2, see file LICENSE in this source tree. |
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. |
36 | void* FAST_FUNC malloc_or_warn(size_t size) |
37 | { |
38 | void *ptr = malloc(size); |
39 | if (ptr == NULL && size != 0) |
40 | bb_error_msg("%s", bb_msg_memory_exhausted); |
41 | return ptr; |
42 | } |
43 | |
44 | // Die if we can't allocate size bytes of memory. |
45 | void* FAST_FUNC xmalloc(size_t size) |
46 | { |
47 | void *ptr = malloc(size); |
48 | if (ptr == NULL && size != 0) |
49 | bb_error_msg_and_die("%s", 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.) |
56 | void* 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("%s", 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. |
66 | void* 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. |
74 | char* 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("%s", 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. |
91 | char* 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 | void* FAST_FUNC xmemdup(const void *s, int n) |
116 | { |
117 | return memcpy(xmalloc(n), s, n); |
118 | } |
119 | |
120 | // Die if we can't open a file and return a FILE* to it. |
121 | // Notice we haven't got xfread(), This is for use with fscanf() and friends. |
122 | FILE* FAST_FUNC xfopen(const char *path, const char *mode) |
123 | { |
124 | FILE *fp = fopen(path, mode); |
125 | if (fp == NULL) |
126 | bb_perror_msg_and_die("can't open '%s'", path); |
127 | return fp; |
128 | } |
129 | |
130 | // Die if we can't open a file and return a fd. |
131 | int FAST_FUNC xopen3(const char *pathname, int flags, int mode) |
132 | { |
133 | int ret; |
134 | |
135 | ret = open(pathname, flags, mode); |
136 | if (ret < 0) { |
137 | bb_perror_msg_and_die("can't open '%s'", pathname); |
138 | } |
139 | return ret; |
140 | } |
141 | |
142 | // Die if we can't open a file and return a fd. |
143 | int FAST_FUNC xopen(const char *pathname, int flags) |
144 | { |
145 | return xopen3(pathname, flags, 0666); |
146 | } |
147 | |
148 | // Warn if we can't open a file and return a fd. |
149 | int FAST_FUNC open3_or_warn(const char *pathname, int flags, int mode) |
150 | { |
151 | int ret; |
152 | |
153 | ret = open(pathname, flags, mode); |
154 | if (ret < 0) { |
155 | bb_perror_msg("can't open '%s'", pathname); |
156 | } |
157 | return ret; |
158 | } |
159 | |
160 | // Warn if we can't open a file and return a fd. |
161 | int FAST_FUNC open_or_warn(const char *pathname, int flags) |
162 | { |
163 | return open3_or_warn(pathname, flags, 0666); |
164 | } |
165 | |
166 | /* Die if we can't open an existing file readonly with O_NONBLOCK |
167 | * and return the fd. |
168 | * Note that for ioctl O_RDONLY is sufficient. |
169 | */ |
170 | int FAST_FUNC xopen_nonblocking(const char *pathname) |
171 | { |
172 | return xopen(pathname, O_RDONLY | O_NONBLOCK); |
173 | } |
174 | |
175 | int FAST_FUNC xopen_as_uid_gid(const char *pathname, int flags, uid_t u, gid_t g) |
176 | { |
177 | int fd; |
178 | uid_t old_euid = geteuid(); |
179 | gid_t old_egid = getegid(); |
180 | |
181 | xsetegid(g); |
182 | xseteuid(u); |
183 | |
184 | fd = xopen(pathname, flags); |
185 | |
186 | xseteuid(old_euid); |
187 | xsetegid(old_egid); |
188 | |
189 | return fd; |
190 | } |
191 | |
192 | void FAST_FUNC xunlink(const char *pathname) |
193 | { |
194 | if (unlink(pathname)) |
195 | bb_perror_msg_and_die("can't remove file '%s'", pathname); |
196 | } |
197 | |
198 | void FAST_FUNC xrename(const char *oldpath, const char *newpath) |
199 | { |
200 | if (rename(oldpath, newpath)) |
201 | bb_perror_msg_and_die("can't move '%s' to '%s'", oldpath, newpath); |
202 | } |
203 | |
204 | int FAST_FUNC rename_or_warn(const char *oldpath, const char *newpath) |
205 | { |
206 | int n = rename(oldpath, newpath); |
207 | if (n) |
208 | bb_perror_msg("can't move '%s' to '%s'", oldpath, newpath); |
209 | return n; |
210 | } |
211 | |
212 | void FAST_FUNC xpipe(int filedes[2]) |
213 | { |
214 | if (pipe(filedes)) |
215 | bb_perror_msg_and_die("can't create pipe"); |
216 | } |
217 | |
218 | void FAST_FUNC xdup2(int from, int to) |
219 | { |
220 | if (dup2(from, to) != to) |
221 | bb_perror_msg_and_die("can't duplicate file descriptor"); |
222 | } |
223 | |
224 | // "Renumber" opened fd |
225 | void FAST_FUNC xmove_fd(int from, int to) |
226 | { |
227 | if (from == to) |
228 | return; |
229 | xdup2(from, to); |
230 | close(from); |
231 | } |
232 | |
233 | // Die with an error message if we can't write the entire buffer. |
234 | void FAST_FUNC xwrite(int fd, const void *buf, size_t count) |
235 | { |
236 | if (count) { |
237 | ssize_t size = full_write(fd, buf, count); |
238 | if ((size_t)size != count) { |
239 | /* |
240 | * Two cases: write error immediately; |
241 | * or some writes succeeded, then we hit an error. |
242 | * In either case, errno is set. |
243 | */ |
244 | bb_perror_msg_and_die( |
245 | size >= 0 ? "short write" : "write error" |
246 | ); |
247 | } |
248 | } |
249 | } |
250 | void FAST_FUNC xwrite_str(int fd, const char *str) |
251 | { |
252 | xwrite(fd, str, strlen(str)); |
253 | } |
254 | |
255 | void FAST_FUNC xclose(int fd) |
256 | { |
257 | if (close(fd)) |
258 | bb_perror_msg_and_die("close failed"); |
259 | } |
260 | |
261 | // Die with an error message if we can't lseek to the right spot. |
262 | uoff_t FAST_FUNC xlseek(int fd, uoff_t offset, int whence) |
263 | { |
264 | uoff_t off = lseek(fd, offset, whence); |
265 | if (off == (uoff_t)-1) { |
266 | if (whence == SEEK_SET) |
267 | bb_perror_msg_and_die("lseek(%"OFF_FMT"u)", offset); |
268 | bb_perror_msg_and_die("lseek"); |
269 | } |
270 | return off; |
271 | } |
272 | |
273 | int FAST_FUNC xmkstemp(char *template) |
274 | { |
275 | int fd = mkstemp(template); |
276 | if (fd < 0) |
277 | bb_perror_msg_and_die("can't create temp file '%s'", template); |
278 | return fd; |
279 | } |
280 | |
281 | // Die with supplied filename if this FILE* has ferror set. |
282 | void FAST_FUNC die_if_ferror(FILE *fp, const char *fn) |
283 | { |
284 | if (ferror(fp)) { |
285 | /* ferror doesn't set useful errno */ |
286 | bb_error_msg_and_die("%s: I/O error", fn); |
287 | } |
288 | } |
289 | |
290 | // Die with an error message if stdout has ferror set. |
291 | void FAST_FUNC die_if_ferror_stdout(void) |
292 | { |
293 | die_if_ferror(stdout, bb_msg_standard_output); |
294 | } |
295 | |
296 | int FAST_FUNC fflush_all(void) |
297 | { |
298 | return fflush(NULL); |
299 | } |
300 | |
301 | |
302 | int FAST_FUNC bb_putchar(int ch) |
303 | { |
304 | return putchar(ch); |
305 | } |
306 | |
307 | /* Die with an error message if we can't copy an entire FILE* to stdout, |
308 | * then close that file. */ |
309 | void FAST_FUNC xprint_and_close_file(FILE *file) |
310 | { |
311 | fflush_all(); |
312 | // copyfd outputs error messages for us. |
313 | if (bb_copyfd_eof(fileno(file), STDOUT_FILENO) == -1) |
314 | xfunc_die(); |
315 | |
316 | fclose(file); |
317 | } |
318 | |
319 | // Die with an error message if we can't malloc() enough space and do an |
320 | // sprintf() into that space. |
321 | char* FAST_FUNC xasprintf(const char *format, ...) |
322 | { |
323 | va_list p; |
324 | int r; |
325 | char *string_ptr; |
326 | |
327 | va_start(p, format); |
328 | r = vasprintf(&string_ptr, format, p); |
329 | va_end(p); |
330 | |
331 | if (r < 0) |
332 | bb_error_msg_and_die("%s", bb_msg_memory_exhausted); |
333 | return string_ptr; |
334 | } |
335 | |
336 | void FAST_FUNC xsetenv(const char *key, const char *value) |
337 | { |
338 | #ifdef __BIONIC__ |
339 | /* on login, can be NULL, and should not be for bionic */ |
340 | if (environ == NULL) |
341 | bb_error_msg_and_die("environment is not initialized"); |
342 | #endif |
343 | if (setenv(key, value, 1)) |
344 | bb_error_msg_and_die("%s", bb_msg_memory_exhausted); |
345 | } |
346 | |
347 | /* Handles "VAR=VAL" strings, even those which are part of environ |
348 | * _right now_ |
349 | */ |
350 | void FAST_FUNC bb_unsetenv(const char *var) |
351 | { |
352 | char *tp = strchr(var, '='); |
353 | |
354 | if (!tp) { |
355 | unsetenv(var); |
356 | return; |
357 | } |
358 | |
359 | /* In case var was putenv'ed, we can't replace '=' |
360 | * with NUL and unsetenv(var) - it won't work, |
361 | * env is modified by the replacement, unsetenv |
362 | * sees "VAR" instead of "VAR=VAL" and does not remove it! |
363 | * horror :( */ |
364 | tp = xstrndup(var, tp - var); |
365 | unsetenv(tp); |
366 | free(tp); |
367 | } |
368 | |
369 | void FAST_FUNC bb_unsetenv_and_free(char *var) |
370 | { |
371 | bb_unsetenv(var); |
372 | free(var); |
373 | } |
374 | |
375 | // Die with an error message if we can't set gid. (Because resource limits may |
376 | // limit this user to a given number of processes, and if that fills up the |
377 | // setgid() will fail and we'll _still_be_root_, which is bad.) |
378 | void FAST_FUNC xsetgid(gid_t gid) |
379 | { |
380 | if (setgid(gid)) bb_perror_msg_and_die("setgid"); |
381 | } |
382 | |
383 | // Die with an error message if we can't set uid. (See xsetgid() for why.) |
384 | void FAST_FUNC xsetuid(uid_t uid) |
385 | { |
386 | if (setuid(uid)) bb_perror_msg_and_die("setuid"); |
387 | } |
388 | |
389 | void FAST_FUNC xsetegid(gid_t egid) |
390 | { |
391 | if (setegid(egid)) bb_perror_msg_and_die("setegid"); |
392 | } |
393 | |
394 | void FAST_FUNC xseteuid(uid_t euid) |
395 | { |
396 | if (seteuid(euid)) bb_perror_msg_and_die("seteuid"); |
397 | } |
398 | |
399 | // Die if we can't chdir to a new path. |
400 | void FAST_FUNC xchdir(const char *path) |
401 | { |
402 | if (chdir(path)) |
403 | bb_perror_msg_and_die("can't change directory to '%s'", path); |
404 | } |
405 | |
406 | void FAST_FUNC xfchdir(int fd) |
407 | { |
408 | if (fchdir(fd)) |
409 | bb_perror_msg_and_die("fchdir"); |
410 | } |
411 | |
412 | void FAST_FUNC xchroot(const char *path) |
413 | { |
414 | if (chroot(path)) |
415 | bb_perror_msg_and_die("can't change root directory to '%s'", path); |
416 | xchdir("/"); |
417 | } |
418 | |
419 | // Print a warning message if opendir() fails, but don't die. |
420 | DIR* FAST_FUNC warn_opendir(const char *path) |
421 | { |
422 | DIR *dp; |
423 | |
424 | dp = opendir(path); |
425 | if (!dp) |
426 | bb_perror_msg("can't open '%s'", path); |
427 | return dp; |
428 | } |
429 | |
430 | // Die with an error message if opendir() fails. |
431 | DIR* FAST_FUNC xopendir(const char *path) |
432 | { |
433 | DIR *dp; |
434 | |
435 | dp = opendir(path); |
436 | if (!dp) |
437 | bb_perror_msg_and_die("can't open '%s'", path); |
438 | return dp; |
439 | } |
440 | |
441 | // Die with an error message if we can't open a new socket. |
442 | int FAST_FUNC xsocket(int domain, int type, int protocol) |
443 | { |
444 | int r = socket(domain, type, protocol); |
445 | |
446 | if (r < 0) { |
447 | /* Hijack vaguely related config option */ |
448 | #if ENABLE_VERBOSE_RESOLUTION_ERRORS |
449 | const char *s = "INET"; |
450 | # ifdef AF_PACKET |
451 | if (domain == AF_PACKET) s = "PACKET"; |
452 | # endif |
453 | # ifdef AF_NETLINK |
454 | if (domain == AF_NETLINK) s = "NETLINK"; |
455 | # endif |
456 | IF_FEATURE_IPV6(if (domain == AF_INET6) s = "INET6";) |
457 | bb_perror_msg_and_die("socket(AF_%s,%d,%d)", s, type, protocol); |
458 | #else |
459 | bb_perror_msg_and_die("socket"); |
460 | #endif |
461 | } |
462 | |
463 | return r; |
464 | } |
465 | |
466 | // Die with an error message if we can't bind a socket to an address. |
467 | void FAST_FUNC xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen) |
468 | { |
469 | if (bind(sockfd, my_addr, addrlen)) bb_perror_msg_and_die("bind"); |
470 | } |
471 | |
472 | // Die with an error message if we can't listen for connections on a socket. |
473 | void FAST_FUNC xlisten(int s, int backlog) |
474 | { |
475 | if (listen(s, backlog)) bb_perror_msg_and_die("listen"); |
476 | } |
477 | |
478 | /* Die with an error message if sendto failed. |
479 | * Return bytes sent otherwise */ |
480 | ssize_t FAST_FUNC xsendto(int s, const void *buf, size_t len, const struct sockaddr *to, |
481 | socklen_t tolen) |
482 | { |
483 | ssize_t ret = sendto(s, buf, len, 0, to, tolen); |
484 | if (ret < 0) { |
485 | if (ENABLE_FEATURE_CLEAN_UP) |
486 | close(s); |
487 | bb_perror_msg_and_die("sendto"); |
488 | } |
489 | return ret; |
490 | } |
491 | |
492 | // xstat() - a stat() which dies on failure with meaningful error message |
493 | void FAST_FUNC xstat(const char *name, struct stat *stat_buf) |
494 | { |
495 | if (stat(name, stat_buf)) |
496 | bb_perror_msg_and_die("can't stat '%s'", name); |
497 | } |
498 | |
499 | void FAST_FUNC xfstat(int fd, struct stat *stat_buf, const char *errmsg) |
500 | { |
501 | /* errmsg is usually a file name, but not always: |
502 | * xfstat may be called in a spot where file name is no longer |
503 | * available, and caller may give e.g. "can't stat input file" string. |
504 | */ |
505 | if (fstat(fd, stat_buf)) |
506 | bb_simple_perror_msg_and_die(errmsg); |
507 | } |
508 | |
509 | // selinux_or_die() - die if SELinux is disabled. |
510 | void FAST_FUNC selinux_or_die(void) |
511 | { |
512 | #if ENABLE_SELINUX |
513 | int rc = is_selinux_enabled(); |
514 | if (rc == 0) { |
515 | bb_error_msg_and_die("SELinux is disabled"); |
516 | } else if (rc < 0) { |
517 | bb_error_msg_and_die("is_selinux_enabled() failed"); |
518 | } |
519 | #else |
520 | bb_error_msg_and_die("SELinux support is disabled"); |
521 | #endif |
522 | } |
523 | |
524 | int FAST_FUNC ioctl_or_perror_and_die(int fd, unsigned request, void *argp, const char *fmt,...) |
525 | { |
526 | int ret; |
527 | va_list p; |
528 | |
529 | ret = ioctl(fd, request, argp); |
530 | if (ret < 0) { |
531 | va_start(p, fmt); |
532 | bb_verror_msg(fmt, p, strerror(errno)); |
533 | /* xfunc_die can actually longjmp, so be nice */ |
534 | va_end(p); |
535 | xfunc_die(); |
536 | } |
537 | return ret; |
538 | } |
539 | |
540 | int FAST_FUNC ioctl_or_perror(int fd, unsigned request, void *argp, const char *fmt,...) |
541 | { |
542 | va_list p; |
543 | int ret = ioctl(fd, request, argp); |
544 | |
545 | if (ret < 0) { |
546 | va_start(p, fmt); |
547 | bb_verror_msg(fmt, p, strerror(errno)); |
548 | va_end(p); |
549 | } |
550 | return ret; |
551 | } |
552 | |
553 | #if ENABLE_IOCTL_HEX2STR_ERROR |
554 | int FAST_FUNC bb_ioctl_or_warn(int fd, unsigned request, void *argp, const char *ioctl_name) |
555 | { |
556 | int ret; |
557 | |
558 | ret = ioctl(fd, request, argp); |
559 | if (ret < 0) |
560 | bb_simple_perror_msg(ioctl_name); |
561 | return ret; |
562 | } |
563 | int FAST_FUNC bb_xioctl(int fd, unsigned request, void *argp, const char *ioctl_name) |
564 | { |
565 | int ret; |
566 | |
567 | ret = ioctl(fd, request, argp); |
568 | if (ret < 0) |
569 | bb_simple_perror_msg_and_die(ioctl_name); |
570 | return ret; |
571 | } |
572 | #else |
573 | int FAST_FUNC bb_ioctl_or_warn(int fd, unsigned request, void *argp) |
574 | { |
575 | int ret; |
576 | |
577 | ret = ioctl(fd, request, argp); |
578 | if (ret < 0) |
579 | bb_perror_msg("ioctl %#x failed", request); |
580 | return ret; |
581 | } |
582 | int FAST_FUNC bb_xioctl(int fd, unsigned request, void *argp) |
583 | { |
584 | int ret; |
585 | |
586 | ret = ioctl(fd, request, argp); |
587 | if (ret < 0) |
588 | bb_perror_msg_and_die("ioctl %#x failed", request); |
589 | return ret; |
590 | } |
591 | #endif |
592 | |
593 | char* FAST_FUNC xmalloc_ttyname(int fd) |
594 | { |
595 | char buf[128]; |
596 | int r = ttyname_r(fd, buf, sizeof(buf) - 1); |
597 | if (r) |
598 | return NULL; |
599 | return xstrdup(buf); |
600 | } |
601 | |
602 | void FAST_FUNC generate_uuid(uint8_t *buf) |
603 | { |
604 | /* http://www.ietf.org/rfc/rfc4122.txt |
605 | * 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 |
606 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
607 | * | time_low | |
608 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
609 | * | time_mid | time_hi_and_version | |
610 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
611 | * |clk_seq_and_variant | node (0-1) | |
612 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
613 | * | node (2-5) | |
614 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
615 | * IOW, uuid has this layout: |
616 | * uint32_t time_low (big endian) |
617 | * uint16_t time_mid (big endian) |
618 | * uint16_t time_hi_and_version (big endian) |
619 | * version is a 4-bit field: |
620 | * 1 Time-based |
621 | * 2 DCE Security, with embedded POSIX UIDs |
622 | * 3 Name-based (MD5) |
623 | * 4 Randomly generated |
624 | * 5 Name-based (SHA-1) |
625 | * uint16_t clk_seq_and_variant (big endian) |
626 | * variant is a 3-bit field: |
627 | * 0xx Reserved, NCS backward compatibility |
628 | * 10x The variant specified in rfc4122 |
629 | * 110 Reserved, Microsoft backward compatibility |
630 | * 111 Reserved for future definition |
631 | * uint8_t node[6] |
632 | * |
633 | * For version 4, these bits are set/cleared: |
634 | * time_hi_and_version & 0x0fff | 0x4000 |
635 | * clk_seq_and_variant & 0x3fff | 0x8000 |
636 | */ |
637 | pid_t pid; |
638 | int i; |
639 | |
640 | i = open("/dev/urandom", O_RDONLY); |
641 | if (i >= 0) { |
642 | read(i, buf, 16); |
643 | close(i); |
644 | } |
645 | /* Paranoia. /dev/urandom may be missing. |
646 | * rand() is guaranteed to generate at least [0, 2^15) range, |
647 | * but lowest bits in some libc are not so "random". */ |
648 | srand(monotonic_us()); /* pulls in printf */ |
649 | pid = getpid(); |
650 | while (1) { |
651 | for (i = 0; i < 16; i++) |
652 | buf[i] ^= rand() >> 5; |
653 | if (pid == 0) |
654 | break; |
655 | srand(pid); |
656 | pid = 0; |
657 | } |
658 | |
659 | /* version = 4 */ |
660 | buf[4 + 2 ] = (buf[4 + 2 ] & 0x0f) | 0x40; |
661 | /* variant = 10x */ |
662 | buf[4 + 2 + 2] = (buf[4 + 2 + 2] & 0x3f) | 0x80; |
663 | } |
664 | |
665 | #if BB_MMU |
666 | pid_t FAST_FUNC xfork(void) |
667 | { |
668 | pid_t pid; |
669 | pid = fork(); |
670 | if (pid < 0) /* wtf? */ |
671 | bb_perror_msg_and_die("%s", "vfork"+1); |
672 | return pid; |
673 | } |
674 | #endif |
675 | |
676 | void FAST_FUNC xvfork_parent_waits_and_exits(void) |
677 | { |
678 | pid_t pid; |
679 | |
680 | fflush_all(); |
681 | pid = xvfork(); |
682 | if (pid > 0) { |
683 | /* Parent */ |
684 | int exit_status = wait_for_exitstatus(pid); |
685 | if (WIFSIGNALED(exit_status)) |
686 | kill_myself_with_sig(WTERMSIG(exit_status)); |
687 | _exit(WEXITSTATUS(exit_status)); |
688 | } |
689 | /* Child continues */ |
690 | } |
691 |