1#include "cache.h"
2#include "run-command.h"
3#include "exec_cmd.h"
4#include "sigchain.h"
5#include "argv-array.h"
6#ifndef SHELL_PATH
8# define SHELL_PATH "/bin/sh"
9#endif
10struct child_to_clean {
12 pid_t pid;
13 struct child_to_clean *next;
14};
15static struct child_to_clean *children_to_clean;
16static int installed_child_cleanup_handler;
17static void cleanup_children(int sig)
19{
20 while (children_to_clean) {
21 struct child_to_clean *p = children_to_clean;
22 children_to_clean = p->next;
23 kill(p->pid, sig);
24 free(p);
25 }
26}
27static void cleanup_children_on_signal(int sig)
29{
30 cleanup_children(sig);
31 sigchain_pop(sig);
32 raise(sig);
33}
34static void cleanup_children_on_exit(void)
36{
37 cleanup_children(SIGTERM);
38}
39static void mark_child_for_cleanup(pid_t pid)
41{
42 struct child_to_clean *p = xmalloc(sizeof(*p));
43 p->pid = pid;
44 p->next = children_to_clean;
45 children_to_clean = p;
46 if (!installed_child_cleanup_handler) {
48 atexit(cleanup_children_on_exit);
49 sigchain_push_common(cleanup_children_on_signal);
50 installed_child_cleanup_handler = 1;
51 }
52}
53static void clear_child_for_cleanup(pid_t pid)
55{
56 struct child_to_clean **last, *p;
57 last = &children_to_clean;
59 for (p = children_to_clean; p; p = p->next) {
60 if (p->pid == pid) {
61 *last = p->next;
62 free(p);
63 return;
64 }
65 }
66}
67static inline void close_pair(int fd[2])
69{
70 close(fd[0]);
71 close(fd[1]);
72}
73#ifndef WIN32
75static inline void dup_devnull(int to)
76{
77 int fd = open("/dev/null", O_RDWR);
78 dup2(fd, to);
79 close(fd);
80}
81#endif
82static char *locate_in_PATH(const char *file)
84{
85 const char *p = getenv("PATH");
86 struct strbuf buf = STRBUF_INIT;
87 if (!p || !*p)
89 return NULL;
90 while (1) {
92 const char *end = strchrnul(p, ':');
93 strbuf_reset(&buf);
95 /* POSIX specifies an empty entry as the current directory. */
97 if (end != p) {
98 strbuf_add(&buf, p, end - p);
99 strbuf_addch(&buf, '/');
100 }
101 strbuf_addstr(&buf, file);
102 if (!access(buf.buf, F_OK))
104 return strbuf_detach(&buf, NULL);
105 if (!*end)
107 break;
108 p = end + 1;
109 }
110 strbuf_release(&buf);
112 return NULL;
113}
114static int exists_in_PATH(const char *file)
116{
117 char *r = locate_in_PATH(file);
118 free(r);
119 return r != NULL;
120}
121int sane_execvp(const char *file, char * const argv[])
123{
124 if (!execvp(file, argv))
125 return 0; /* cannot happen ;-) */
126 /*
128 * When a command can't be found because one of the directories
129 * listed in $PATH is unsearchable, execvp reports EACCES, but
130 * careful usability testing (read: analysis of occasional bug
131 * reports) reveals that "No such file or directory" is more
132 * intuitive.
133 *
134 * We avoid commands with "/", because execvp will not do $PATH
135 * lookups in that case.
136 *
137 * The reassignment of EACCES to errno looks like a no-op below,
138 * but we need to protect against exists_in_PATH overwriting errno.
139 */
140 if (errno == EACCES && !strchr(file, '/'))
141 errno = exists_in_PATH(file) ? EACCES : ENOENT;
142 return -1;
143}
144static const char **prepare_shell_cmd(const char **argv)
146{
147 int argc, nargc = 0;
148 const char **nargv;
149 for (argc = 0; argv[argc]; argc++)
151 ; /* just counting */
152 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
153 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
154 if (argc < 1)
156 die("BUG: shell command is empty");
157 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
159#ifndef WIN32
160 nargv[nargc++] = SHELL_PATH;
161#else
162 nargv[nargc++] = "sh";
163#endif
164 nargv[nargc++] = "-c";
165 if (argc < 2)
167 nargv[nargc++] = argv[0];
168 else {
169 struct strbuf arg0 = STRBUF_INIT;
170 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
171 nargv[nargc++] = strbuf_detach(&arg0, NULL);
172 }
173 }
174 for (argc = 0; argv[argc]; argc++)
176 nargv[nargc++] = argv[argc];
177 nargv[nargc] = NULL;
178 return nargv;
180}
181#ifndef WIN32
183static int execv_shell_cmd(const char **argv)
184{
185 const char **nargv = prepare_shell_cmd(argv);
186 trace_argv_printf(nargv, "trace: exec:");
187 sane_execvp(nargv[0], (char **)nargv);
188 free(nargv);
189 return -1;
190}
191#endif
192#ifndef WIN32
194static int child_err = 2;
195static int child_notifier = -1;
196static void notify_parent(void)
198{
199 /*
200 * execvp failed. If possible, we'd like to let start_command
201 * know, so failures like ENOENT can be handled right away; but
202 * otherwise, finish_command will still report the error.
203 */
204 xwrite(child_notifier, "", 1);
205}
206static NORETURN void die_child(const char *err, va_list params)
208{
209 vwritef(child_err, "fatal: ", err, params);
210 exit(128);
211}
212static void error_child(const char *err, va_list params)
214{
215 vwritef(child_err, "error: ", err, params);
216}
217#endif
218static inline void set_cloexec(int fd)
220{
221 int flags = fcntl(fd, F_GETFD);
222 if (flags >= 0)
223 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
224}
225static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
227{
228 int status, code = -1;
229 pid_t waiting;
230 int failed_errno = 0;
231 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
233 ; /* nothing */
234 if (waiting < 0) {
236 failed_errno = errno;
237 error("waitpid for %s failed: %s", argv0, strerror(errno));
238 } else if (waiting != pid) {
239 error("waitpid is confused (%s)", argv0);
240 } else if (WIFSIGNALED(status)) {
241 code = WTERMSIG(status);
242 error("%s died of signal %d", argv0, code);
243 /*
244 * This return value is chosen so that code & 0xff
245 * mimics the exit code that a POSIX shell would report for
246 * a program that died from this signal.
247 */
248 code -= 128;
249 } else if (WIFEXITED(status)) {
250 code = WEXITSTATUS(status);
251 /*
252 * Convert special exit code when execvp failed.
253 */
254 if (code == 127) {
255 code = -1;
256 failed_errno = ENOENT;
257 }
258 } else {
259 error("waitpid is confused (%s)", argv0);
260 }
261 clear_child_for_cleanup(pid);
263 errno = failed_errno;
265 return code;
266}
267int start_command(struct child_process *cmd)
269{
270 int need_in, need_out, need_err;
271 int fdin[2], fdout[2], fderr[2];
272 int failed_errno = failed_errno;
273 /*
275 * In case of errors we must keep the promise to close FDs
276 * that have been passed in via ->in and ->out.
277 */
278 need_in = !cmd->no_stdin && cmd->in < 0;
280 if (need_in) {
281 if (pipe(fdin) < 0) {
282 failed_errno = errno;
283 if (cmd->out > 0)
284 close(cmd->out);
285 goto fail_pipe;
286 }
287 cmd->in = fdin[1];
288 }
289 need_out = !cmd->no_stdout
291 && !cmd->stdout_to_stderr
292 && cmd->out < 0;
293 if (need_out) {
294 if (pipe(fdout) < 0) {
295 failed_errno = errno;
296 if (need_in)
297 close_pair(fdin);
298 else if (cmd->in)
299 close(cmd->in);
300 goto fail_pipe;
301 }
302 cmd->out = fdout[0];
303 }
304 need_err = !cmd->no_stderr && cmd->err < 0;
306 if (need_err) {
307 if (pipe(fderr) < 0) {
308 failed_errno = errno;
309 if (need_in)
310 close_pair(fdin);
311 else if (cmd->in)
312 close(cmd->in);
313 if (need_out)
314 close_pair(fdout);
315 else if (cmd->out)
316 close(cmd->out);
317fail_pipe:
318 error("cannot create pipe for %s: %s",
319 cmd->argv[0], strerror(failed_errno));
320 errno = failed_errno;
321 return -1;
322 }
323 cmd->err = fderr[0];
324 }
325 trace_argv_printf(cmd->argv, "trace: run_command:");
327 fflush(NULL);
328#ifndef WIN32
330{
331 int notify_pipe[2];
332 if (pipe(notify_pipe))
333 notify_pipe[0] = notify_pipe[1] = -1;
334 cmd->pid = fork();
336 if (!cmd->pid) {
337 /*
338 * Redirect the channel to write syscall error messages to
339 * before redirecting the process's stderr so that all die()
340 * in subsequent call paths use the parent's stderr.
341 */
342 if (cmd->no_stderr || need_err) {
343 child_err = dup(2);
344 set_cloexec(child_err);
345 }
346 set_die_routine(die_child);
347 set_error_routine(error_child);
348 close(notify_pipe[0]);
350 set_cloexec(notify_pipe[1]);
351 child_notifier = notify_pipe[1];
352 atexit(notify_parent);
353 if (cmd->no_stdin)
355 dup_devnull(0);
356 else if (need_in) {
357 dup2(fdin[0], 0);
358 close_pair(fdin);
359 } else if (cmd->in) {
360 dup2(cmd->in, 0);
361 close(cmd->in);
362 }
363 if (cmd->no_stderr)
365 dup_devnull(2);
366 else if (need_err) {
367 dup2(fderr[1], 2);
368 close_pair(fderr);
369 } else if (cmd->err > 1) {
370 dup2(cmd->err, 2);
371 close(cmd->err);
372 }
373 if (cmd->no_stdout)
375 dup_devnull(1);
376 else if (cmd->stdout_to_stderr)
377 dup2(2, 1);
378 else if (need_out) {
379 dup2(fdout[1], 1);
380 close_pair(fdout);
381 } else if (cmd->out > 1) {
382 dup2(cmd->out, 1);
383 close(cmd->out);
384 }
385 if (cmd->dir && chdir(cmd->dir))
387 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
388 cmd->dir);
389 if (cmd->env) {
390 for (; *cmd->env; cmd->env++) {
391 if (strchr(*cmd->env, '='))
392 putenv((char *)*cmd->env);
393 else
394 unsetenv(*cmd->env);
395 }
396 }
397 if (cmd->preexec_cb) {
398 /*
399 * We cannot predict what the pre-exec callback does.
400 * Forgo parent notification.
401 */
402 close(child_notifier);
403 child_notifier = -1;
404 cmd->preexec_cb();
406 }
407 if (cmd->git_cmd) {
408 execv_git_cmd(cmd->argv);
409 } else if (cmd->use_shell) {
410 execv_shell_cmd(cmd->argv);
411 } else {
412 sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
413 }
414 if (errno == ENOENT) {
415 if (!cmd->silent_exec_failure)
416 error("cannot run %s: %s", cmd->argv[0],
417 strerror(ENOENT));
418 exit(127);
419 } else {
420 die_errno("cannot exec '%s'", cmd->argv[0]);
421 }
422 }
423 if (cmd->pid < 0)
424 error("cannot fork() for %s: %s", cmd->argv[0],
425 strerror(failed_errno = errno));
426 else if (cmd->clean_on_exit)
427 mark_child_for_cleanup(cmd->pid);
428 /*
430 * Wait for child's execvp. If the execvp succeeds (or if fork()
431 * failed), EOF is seen immediately by the parent. Otherwise, the
432 * child process sends a single byte.
433 * Note that use of this infrastructure is completely advisory,
434 * therefore, we keep error checks minimal.
435 */
436 close(notify_pipe[1]);
437 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
438 /*
439 * At this point we know that fork() succeeded, but execvp()
440 * failed. Errors have been reported to our stderr.
441 */
442 wait_or_whine(cmd->pid, cmd->argv[0],
443 cmd->silent_exec_failure);
444 failed_errno = errno;
445 cmd->pid = -1;
446 }
447 close(notify_pipe[0]);
448}
450#else
451{
452 int fhin = 0, fhout = 1, fherr = 2;
453 const char **sargv = cmd->argv;
454 char **env = environ;
455 if (cmd->no_stdin)
457 fhin = open("/dev/null", O_RDWR);
458 else if (need_in)
459 fhin = dup(fdin[0]);
460 else if (cmd->in)
461 fhin = dup(cmd->in);
462 if (cmd->no_stderr)
464 fherr = open("/dev/null", O_RDWR);
465 else if (need_err)
466 fherr = dup(fderr[1]);
467 else if (cmd->err > 2)
468 fherr = dup(cmd->err);
469 if (cmd->no_stdout)
471 fhout = open("/dev/null", O_RDWR);
472 else if (cmd->stdout_to_stderr)
473 fhout = dup(fherr);
474 else if (need_out)
475 fhout = dup(fdout[1]);
476 else if (cmd->out > 1)
477 fhout = dup(cmd->out);
478 if (cmd->env)
480 env = make_augmented_environ(cmd->env);
481 if (cmd->git_cmd) {
483 cmd->argv = prepare_git_cmd(cmd->argv);
484 } else if (cmd->use_shell) {
485 cmd->argv = prepare_shell_cmd(cmd->argv);
486 }
487 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
489 fhin, fhout, fherr);
490 failed_errno = errno;
491 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
492 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
493 if (cmd->clean_on_exit && cmd->pid >= 0)
494 mark_child_for_cleanup(cmd->pid);
495 if (cmd->env)
497 free_environ(env);
498 if (cmd->git_cmd)
499 free(cmd->argv);
500 cmd->argv = sargv;
502 if (fhin != 0)
503 close(fhin);
504 if (fhout != 1)
505 close(fhout);
506 if (fherr != 2)
507 close(fherr);
508}
509#endif
510 if (cmd->pid < 0) {
512 if (need_in)
513 close_pair(fdin);
514 else if (cmd->in)
515 close(cmd->in);
516 if (need_out)
517 close_pair(fdout);
518 else if (cmd->out)
519 close(cmd->out);
520 if (need_err)
521 close_pair(fderr);
522 else if (cmd->err)
523 close(cmd->err);
524 errno = failed_errno;
525 return -1;
526 }
527 if (need_in)
529 close(fdin[0]);
530 else if (cmd->in)
531 close(cmd->in);
532 if (need_out)
534 close(fdout[1]);
535 else if (cmd->out)
536 close(cmd->out);
537 if (need_err)
539 close(fderr[1]);
540 else if (cmd->err)
541 close(cmd->err);
542 return 0;
544}
545int finish_command(struct child_process *cmd)
547{
548 return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
549}
550int run_command(struct child_process *cmd)
552{
553 int code = start_command(cmd);
554 if (code)
555 return code;
556 return finish_command(cmd);
557}
558static void prepare_run_command_v_opt(struct child_process *cmd,
560 const char **argv,
561 int opt)
562{
563 memset(cmd, 0, sizeof(*cmd));
564 cmd->argv = argv;
565 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
566 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
567 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
568 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
569 cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
570 cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
571}
572int run_command_v_opt(const char **argv, int opt)
574{
575 struct child_process cmd;
576 prepare_run_command_v_opt(&cmd, argv, opt);
577 return run_command(&cmd);
578}
579int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
581{
582 struct child_process cmd;
583 prepare_run_command_v_opt(&cmd, argv, opt);
584 cmd.dir = dir;
585 cmd.env = env;
586 return run_command(&cmd);
587}
588#ifndef NO_PTHREADS
590static pthread_t main_thread;
591static int main_thread_set;
592static pthread_key_t async_key;
593static void *run_thread(void *data)
595{
596 struct async *async = data;
597 intptr_t ret;
598 pthread_setspecific(async_key, async);
600 ret = async->proc(async->proc_in, async->proc_out, async->data);
601 return (void *)ret;
602}
603static NORETURN void die_async(const char *err, va_list params)
605{
606 vreportf("fatal: ", err, params);
607 if (!pthread_equal(main_thread, pthread_self())) {
609 struct async *async = pthread_getspecific(async_key);
610 if (async->proc_in >= 0)
611 close(async->proc_in);
612 if (async->proc_out >= 0)
613 close(async->proc_out);
614 pthread_exit((void *)128);
615 }
616 exit(128);
618}
619#endif
620int start_async(struct async *async)
622{
623 int need_in, need_out;
624 int fdin[2], fdout[2];
625 int proc_in, proc_out;
626 need_in = async->in < 0;
628 if (need_in) {
629 if (pipe(fdin) < 0) {
630 if (async->out > 0)
631 close(async->out);
632 return error("cannot create pipe: %s", strerror(errno));
633 }
634 async->in = fdin[1];
635 }
636 need_out = async->out < 0;
638 if (need_out) {
639 if (pipe(fdout) < 0) {
640 if (need_in)
641 close_pair(fdin);
642 else if (async->in)
643 close(async->in);
644 return error("cannot create pipe: %s", strerror(errno));
645 }
646 async->out = fdout[0];
647 }
648 if (need_in)
650 proc_in = fdin[0];
651 else if (async->in)
652 proc_in = async->in;
653 else
654 proc_in = -1;
655 if (need_out)
657 proc_out = fdout[1];
658 else if (async->out)
659 proc_out = async->out;
660 else
661 proc_out = -1;
662#ifdef NO_PTHREADS
664 /* Flush stdio before fork() to avoid cloning buffers */
665 fflush(NULL);
666 async->pid = fork();
668 if (async->pid < 0) {
669 error("fork (async) failed: %s", strerror(errno));
670 goto error;
671 }
672 if (!async->pid) {
673 if (need_in)
674 close(fdin[1]);
675 if (need_out)
676 close(fdout[0]);
677 exit(!!async->proc(proc_in, proc_out, async->data));
678 }
679 mark_child_for_cleanup(async->pid);
681 if (need_in)
683 close(fdin[0]);
684 else if (async->in)
685 close(async->in);
686 if (need_out)
688 close(fdout[1]);
689 else if (async->out)
690 close(async->out);
691#else
692 if (!main_thread_set) {
693 /*
694 * We assume that the first time that start_async is called
695 * it is from the main thread.
696 */
697 main_thread_set = 1;
698 main_thread = pthread_self();
699 pthread_key_create(&async_key, NULL);
700 set_die_routine(die_async);
701 }
702 if (proc_in >= 0)
704 set_cloexec(proc_in);
705 if (proc_out >= 0)
706 set_cloexec(proc_out);
707 async->proc_in = proc_in;
708 async->proc_out = proc_out;
709 {
710 int err = pthread_create(&async->tid, NULL, run_thread, async);
711 if (err) {
712 error("cannot create thread: %s", strerror(err));
713 goto error;
714 }
715 }
716#endif
717 return 0;
718error:
720 if (need_in)
721 close_pair(fdin);
722 else if (async->in)
723 close(async->in);
724 if (need_out)
726 close_pair(fdout);
727 else if (async->out)
728 close(async->out);
729 return -1;
730}
731int finish_async(struct async *async)
733{
734#ifdef NO_PTHREADS
735 return wait_or_whine(async->pid, "child process", 0);
736#else
737 void *ret = (void *)(intptr_t)(-1);
738 if (pthread_join(async->tid, &ret))
740 error("pthread_join failed");
741 return (int)(intptr_t)ret;
742#endif
743}
744int run_hook(const char *index_file, const char *name, ...)
746{
747 struct child_process hook;
748 struct argv_array argv = ARGV_ARRAY_INIT;
749 const char *p, *env[2];
750 char index[PATH_MAX];
751 va_list args;
752 int ret;
753 if (access(git_path("hooks/%s", name), X_OK) < 0)
755 return 0;
756 va_start(args, name);
758 argv_array_push(&argv, git_path("hooks/%s", name));
759 while ((p = va_arg(args, const char *)))
760 argv_array_push(&argv, p);
761 va_end(args);
762 memset(&hook, 0, sizeof(hook));
764 hook.argv = argv.argv;
765 hook.no_stdin = 1;
766 hook.stdout_to_stderr = 1;
767 if (index_file) {
768 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
769 env[0] = index;
770 env[1] = NULL;
771 hook.env = env;
772 }
773 ret = run_command(&hook);
775 argv_array_clear(&argv);
776 return ret;
777}