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
10void child_process_init(struct child_process *child)
12{
13 memset(child, 0, sizeof(*child));
14 argv_array_init(&child->args);
15}
16struct child_to_clean {
18 pid_t pid;
19 struct child_to_clean *next;
20};
21static struct child_to_clean *children_to_clean;
22static int installed_child_cleanup_handler;
23static void cleanup_children(int sig)
25{
26 while (children_to_clean) {
27 struct child_to_clean *p = children_to_clean;
28 children_to_clean = p->next;
29 kill(p->pid, sig);
30 free(p);
31 }
32}
33static void cleanup_children_on_signal(int sig)
35{
36 cleanup_children(sig);
37 sigchain_pop(sig);
38 raise(sig);
39}
40static void cleanup_children_on_exit(void)
42{
43 cleanup_children(SIGTERM);
44}
45static void mark_child_for_cleanup(pid_t pid)
47{
48 struct child_to_clean *p = xmalloc(sizeof(*p));
49 p->pid = pid;
50 p->next = children_to_clean;
51 children_to_clean = p;
52 if (!installed_child_cleanup_handler) {
54 atexit(cleanup_children_on_exit);
55 sigchain_push_common(cleanup_children_on_signal);
56 installed_child_cleanup_handler = 1;
57 }
58}
59static void clear_child_for_cleanup(pid_t pid)
61{
62 struct child_to_clean **pp;
63 for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
65 struct child_to_clean *clean_me = *pp;
66 if (clean_me->pid == pid) {
68 *pp = clean_me->next;
69 free(clean_me);
70 return;
71 }
72 }
73}
74static inline void close_pair(int fd[2])
76{
77 close(fd[0]);
78 close(fd[1]);
79}
80#ifndef GIT_WINDOWS_NATIVE
82static inline void dup_devnull(int to)
83{
84 int fd = open("/dev/null", O_RDWR);
85 if (fd < 0)
86 die_errno(_("open /dev/null failed"));
87 if (dup2(fd, to) < 0)
88 die_errno(_("dup2(%d,%d) failed"), fd, to);
89 close(fd);
90}
91#endif
92static char *locate_in_PATH(const char *file)
94{
95 const char *p = getenv("PATH");
96 struct strbuf buf = STRBUF_INIT;
97 if (!p || !*p)
99 return NULL;
100 while (1) {
102 const char *end = strchrnul(p, ':');
103 strbuf_reset(&buf);
105 /* POSIX specifies an empty entry as the current directory. */
107 if (end != p) {
108 strbuf_add(&buf, p, end - p);
109 strbuf_addch(&buf, '/');
110 }
111 strbuf_addstr(&buf, file);
112 if (!access(buf.buf, F_OK))
114 return strbuf_detach(&buf, NULL);
115 if (!*end)
117 break;
118 p = end + 1;
119 }
120 strbuf_release(&buf);
122 return NULL;
123}
124static int exists_in_PATH(const char *file)
126{
127 char *r = locate_in_PATH(file);
128 free(r);
129 return r != NULL;
130}
131int sane_execvp(const char *file, char * const argv[])
133{
134 if (!execvp(file, argv))
135 return 0; /* cannot happen ;-) */
136 /*
138 * When a command can't be found because one of the directories
139 * listed in $PATH is unsearchable, execvp reports EACCES, but
140 * careful usability testing (read: analysis of occasional bug
141 * reports) reveals that "No such file or directory" is more
142 * intuitive.
143 *
144 * We avoid commands with "/", because execvp will not do $PATH
145 * lookups in that case.
146 *
147 * The reassignment of EACCES to errno looks like a no-op below,
148 * but we need to protect against exists_in_PATH overwriting errno.
149 */
150 if (errno == EACCES && !strchr(file, '/'))
151 errno = exists_in_PATH(file) ? EACCES : ENOENT;
152 else if (errno == ENOTDIR && !strchr(file, '/'))
153 errno = ENOENT;
154 return -1;
155}
156static const char **prepare_shell_cmd(const char **argv)
158{
159 int argc, nargc = 0;
160 const char **nargv;
161 for (argc = 0; argv[argc]; argc++)
163 ; /* just counting */
164 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
165 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
166 if (argc < 1)
168 die("BUG: shell command is empty");
169 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
171#ifndef GIT_WINDOWS_NATIVE
172 nargv[nargc++] = SHELL_PATH;
173#else
174 nargv[nargc++] = "sh";
175#endif
176 nargv[nargc++] = "-c";
177 if (argc < 2)
179 nargv[nargc++] = argv[0];
180 else {
181 struct strbuf arg0 = STRBUF_INIT;
182 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
183 nargv[nargc++] = strbuf_detach(&arg0, NULL);
184 }
185 }
186 for (argc = 0; argv[argc]; argc++)
188 nargv[nargc++] = argv[argc];
189 nargv[nargc] = NULL;
190 return nargv;
192}
193#ifndef GIT_WINDOWS_NATIVE
195static int execv_shell_cmd(const char **argv)
196{
197 const char **nargv = prepare_shell_cmd(argv);
198 trace_argv_printf(nargv, "trace: exec:");
199 sane_execvp(nargv[0], (char **)nargv);
200 free(nargv);
201 return -1;
202}
203#endif
204#ifndef GIT_WINDOWS_NATIVE
206static int child_err = 2;
207static int child_notifier = -1;
208static void notify_parent(void)
210{
211 /*
212 * execvp failed. If possible, we'd like to let start_command
213 * know, so failures like ENOENT can be handled right away; but
214 * otherwise, finish_command will still report the error.
215 */
216 xwrite(child_notifier, "", 1);
217}
218static NORETURN void die_child(const char *err, va_list params)
220{
221 vwritef(child_err, "fatal: ", err, params);
222 exit(128);
223}
224static void error_child(const char *err, va_list params)
226{
227 vwritef(child_err, "error: ", err, params);
228}
229#endif
230static inline void set_cloexec(int fd)
232{
233 int flags = fcntl(fd, F_GETFD);
234 if (flags >= 0)
235 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
236}
237static int wait_or_whine(pid_t pid, const char *argv0)
239{
240 int status, code = -1;
241 pid_t waiting;
242 int failed_errno = 0;
243 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
245 ; /* nothing */
246 if (waiting < 0) {
248 failed_errno = errno;
249 error("waitpid for %s failed: %s", argv0, strerror(errno));
250 } else if (waiting != pid) {
251 error("waitpid is confused (%s)", argv0);
252 } else if (WIFSIGNALED(status)) {
253 code = WTERMSIG(status);
254 if (code != SIGINT && code != SIGQUIT)
255 error("%s died of signal %d", argv0, code);
256 /*
257 * This return value is chosen so that code & 0xff
258 * mimics the exit code that a POSIX shell would report for
259 * a program that died from this signal.
260 */
261 code += 128;
262 } else if (WIFEXITED(status)) {
263 code = WEXITSTATUS(status);
264 /*
265 * Convert special exit code when execvp failed.
266 */
267 if (code == 127) {
268 code = -1;
269 failed_errno = ENOENT;
270 }
271 } else {
272 error("waitpid is confused (%s)", argv0);
273 }
274 clear_child_for_cleanup(pid);
276 errno = failed_errno;
278 return code;
279}
280int start_command(struct child_process *cmd)
282{
283 int need_in, need_out, need_err;
284 int fdin[2], fdout[2], fderr[2];
285 int failed_errno;
286 char *str;
287 if (!cmd->argv)
289 cmd->argv = cmd->args.argv;
290 /*
292 * In case of errors we must keep the promise to close FDs
293 * that have been passed in via ->in and ->out.
294 */
295 need_in = !cmd->no_stdin && cmd->in < 0;
297 if (need_in) {
298 if (pipe(fdin) < 0) {
299 failed_errno = errno;
300 if (cmd->out > 0)
301 close(cmd->out);
302 str = "standard input";
303 goto fail_pipe;
304 }
305 cmd->in = fdin[1];
306 }
307 need_out = !cmd->no_stdout
309 && !cmd->stdout_to_stderr
310 && cmd->out < 0;
311 if (need_out) {
312 if (pipe(fdout) < 0) {
313 failed_errno = errno;
314 if (need_in)
315 close_pair(fdin);
316 else if (cmd->in)
317 close(cmd->in);
318 str = "standard output";
319 goto fail_pipe;
320 }
321 cmd->out = fdout[0];
322 }
323 need_err = !cmd->no_stderr && cmd->err < 0;
325 if (need_err) {
326 if (pipe(fderr) < 0) {
327 failed_errno = errno;
328 if (need_in)
329 close_pair(fdin);
330 else if (cmd->in)
331 close(cmd->in);
332 if (need_out)
333 close_pair(fdout);
334 else if (cmd->out)
335 close(cmd->out);
336 str = "standard error";
337fail_pipe:
338 error("cannot create %s pipe for %s: %s",
339 str, cmd->argv[0], strerror(failed_errno));
340 argv_array_clear(&cmd->args);
341 errno = failed_errno;
342 return -1;
343 }
344 cmd->err = fderr[0];
345 }
346 trace_argv_printf(cmd->argv, "trace: run_command:");
348 fflush(NULL);
349#ifndef GIT_WINDOWS_NATIVE
351{
352 int notify_pipe[2];
353 if (pipe(notify_pipe))
354 notify_pipe[0] = notify_pipe[1] = -1;
355 cmd->pid = fork();
357 failed_errno = errno;
358 if (!cmd->pid) {
359 /*
360 * Redirect the channel to write syscall error messages to
361 * before redirecting the process's stderr so that all die()
362 * in subsequent call paths use the parent's stderr.
363 */
364 if (cmd->no_stderr || need_err) {
365 child_err = dup(2);
366 set_cloexec(child_err);
367 }
368 set_die_routine(die_child);
369 set_error_routine(error_child);
370 close(notify_pipe[0]);
372 set_cloexec(notify_pipe[1]);
373 child_notifier = notify_pipe[1];
374 atexit(notify_parent);
375 if (cmd->no_stdin)
377 dup_devnull(0);
378 else if (need_in) {
379 dup2(fdin[0], 0);
380 close_pair(fdin);
381 } else if (cmd->in) {
382 dup2(cmd->in, 0);
383 close(cmd->in);
384 }
385 if (cmd->no_stderr)
387 dup_devnull(2);
388 else if (need_err) {
389 dup2(fderr[1], 2);
390 close_pair(fderr);
391 } else if (cmd->err > 1) {
392 dup2(cmd->err, 2);
393 close(cmd->err);
394 }
395 if (cmd->no_stdout)
397 dup_devnull(1);
398 else if (cmd->stdout_to_stderr)
399 dup2(2, 1);
400 else if (need_out) {
401 dup2(fdout[1], 1);
402 close_pair(fdout);
403 } else if (cmd->out > 1) {
404 dup2(cmd->out, 1);
405 close(cmd->out);
406 }
407 if (cmd->dir && chdir(cmd->dir))
409 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
410 cmd->dir);
411 if (cmd->env) {
412 for (; *cmd->env; cmd->env++) {
413 if (strchr(*cmd->env, '='))
414 putenv((char *)*cmd->env);
415 else
416 unsetenv(*cmd->env);
417 }
418 }
419 if (cmd->git_cmd)
420 execv_git_cmd(cmd->argv);
421 else if (cmd->use_shell)
422 execv_shell_cmd(cmd->argv);
423 else
424 sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
425 if (errno == ENOENT) {
426 if (!cmd->silent_exec_failure)
427 error("cannot run %s: %s", cmd->argv[0],
428 strerror(ENOENT));
429 exit(127);
430 } else {
431 die_errno("cannot exec '%s'", cmd->argv[0]);
432 }
433 }
434 if (cmd->pid < 0)
435 error("cannot fork() for %s: %s", cmd->argv[0],
436 strerror(errno));
437 else if (cmd->clean_on_exit)
438 mark_child_for_cleanup(cmd->pid);
439 /*
441 * Wait for child's execvp. If the execvp succeeds (or if fork()
442 * failed), EOF is seen immediately by the parent. Otherwise, the
443 * child process sends a single byte.
444 * Note that use of this infrastructure is completely advisory,
445 * therefore, we keep error checks minimal.
446 */
447 close(notify_pipe[1]);
448 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
449 /*
450 * At this point we know that fork() succeeded, but execvp()
451 * failed. Errors have been reported to our stderr.
452 */
453 wait_or_whine(cmd->pid, cmd->argv[0]);
454 failed_errno = errno;
455 cmd->pid = -1;
456 }
457 close(notify_pipe[0]);
458}
459#else
460{
461 int fhin = 0, fhout = 1, fherr = 2;
462 const char **sargv = cmd->argv;
463 if (cmd->no_stdin)
465 fhin = open("/dev/null", O_RDWR);
466 else if (need_in)
467 fhin = dup(fdin[0]);
468 else if (cmd->in)
469 fhin = dup(cmd->in);
470 if (cmd->no_stderr)
472 fherr = open("/dev/null", O_RDWR);
473 else if (need_err)
474 fherr = dup(fderr[1]);
475 else if (cmd->err > 2)
476 fherr = dup(cmd->err);
477 if (cmd->no_stdout)
479 fhout = open("/dev/null", O_RDWR);
480 else if (cmd->stdout_to_stderr)
481 fhout = dup(fherr);
482 else if (need_out)
483 fhout = dup(fdout[1]);
484 else if (cmd->out > 1)
485 fhout = dup(cmd->out);
486 if (cmd->git_cmd)
488 cmd->argv = prepare_git_cmd(cmd->argv);
489 else if (cmd->use_shell)
490 cmd->argv = prepare_shell_cmd(cmd->argv);
491 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, (char**) cmd->env,
493 cmd->dir, fhin, fhout, fherr);
494 failed_errno = errno;
495 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
496 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
497 if (cmd->clean_on_exit && cmd->pid >= 0)
498 mark_child_for_cleanup(cmd->pid);
499 if (cmd->git_cmd)
501 free(cmd->argv);
502 cmd->argv = sargv;
504 if (fhin != 0)
505 close(fhin);
506 if (fhout != 1)
507 close(fhout);
508 if (fherr != 2)
509 close(fherr);
510}
511#endif
512 if (cmd->pid < 0) {
514 if (need_in)
515 close_pair(fdin);
516 else if (cmd->in)
517 close(cmd->in);
518 if (need_out)
519 close_pair(fdout);
520 else if (cmd->out)
521 close(cmd->out);
522 if (need_err)
523 close_pair(fderr);
524 else if (cmd->err)
525 close(cmd->err);
526 argv_array_clear(&cmd->args);
527 errno = failed_errno;
528 return -1;
529 }
530 if (need_in)
532 close(fdin[0]);
533 else if (cmd->in)
534 close(cmd->in);
535 if (need_out)
537 close(fdout[1]);
538 else if (cmd->out)
539 close(cmd->out);
540 if (need_err)
542 close(fderr[1]);
543 else if (cmd->err)
544 close(cmd->err);
545 return 0;
547}
548int finish_command(struct child_process *cmd)
550{
551 int ret = wait_or_whine(cmd->pid, cmd->argv[0]);
552 argv_array_clear(&cmd->args);
553 return ret;
554}
555int run_command(struct child_process *cmd)
557{
558 int code = start_command(cmd);
559 if (code)
560 return code;
561 return finish_command(cmd);
562}
563int run_command_v_opt(const char **argv, int opt)
565{
566 return run_command_v_opt_cd_env(argv, opt, NULL, NULL);
567}
568int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
570{
571 struct child_process cmd = CHILD_PROCESS_INIT;
572 cmd.argv = argv;
573 cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
574 cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
575 cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
576 cmd.silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
577 cmd.use_shell = opt & RUN_USING_SHELL ? 1 : 0;
578 cmd.clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
579 cmd.dir = dir;
580 cmd.env = env;
581 return run_command(&cmd);
582}
583#ifndef NO_PTHREADS
585static pthread_t main_thread;
586static int main_thread_set;
587static pthread_key_t async_key;
588static pthread_key_t async_die_counter;
589static void *run_thread(void *data)
591{
592 struct async *async = data;
593 intptr_t ret;
594 pthread_setspecific(async_key, async);
596 ret = async->proc(async->proc_in, async->proc_out, async->data);
597 return (void *)ret;
598}
599static NORETURN void die_async(const char *err, va_list params)
601{
602 vreportf("fatal: ", err, params);
603 if (!pthread_equal(main_thread, pthread_self())) {
605 struct async *async = pthread_getspecific(async_key);
606 if (async->proc_in >= 0)
607 close(async->proc_in);
608 if (async->proc_out >= 0)
609 close(async->proc_out);
610 pthread_exit((void *)128);
611 }
612 exit(128);
614}
615static int async_die_is_recursing(void)
617{
618 void *ret = pthread_getspecific(async_die_counter);
619 pthread_setspecific(async_die_counter, (void *)1);
620 return ret != NULL;
621}
622#endif
624int start_async(struct async *async)
626{
627 int need_in, need_out;
628 int fdin[2], fdout[2];
629 int proc_in, proc_out;
630 need_in = async->in < 0;
632 if (need_in) {
633 if (pipe(fdin) < 0) {
634 if (async->out > 0)
635 close(async->out);
636 return error("cannot create pipe: %s", strerror(errno));
637 }
638 async->in = fdin[1];
639 }
640 need_out = async->out < 0;
642 if (need_out) {
643 if (pipe(fdout) < 0) {
644 if (need_in)
645 close_pair(fdin);
646 else if (async->in)
647 close(async->in);
648 return error("cannot create pipe: %s", strerror(errno));
649 }
650 async->out = fdout[0];
651 }
652 if (need_in)
654 proc_in = fdin[0];
655 else if (async->in)
656 proc_in = async->in;
657 else
658 proc_in = -1;
659 if (need_out)
661 proc_out = fdout[1];
662 else if (async->out)
663 proc_out = async->out;
664 else
665 proc_out = -1;
666#ifdef NO_PTHREADS
668 /* Flush stdio before fork() to avoid cloning buffers */
669 fflush(NULL);
670 async->pid = fork();
672 if (async->pid < 0) {
673 error("fork (async) failed: %s", strerror(errno));
674 goto error;
675 }
676 if (!async->pid) {
677 if (need_in)
678 close(fdin[1]);
679 if (need_out)
680 close(fdout[0]);
681 exit(!!async->proc(proc_in, proc_out, async->data));
682 }
683 mark_child_for_cleanup(async->pid);
685 if (need_in)
687 close(fdin[0]);
688 else if (async->in)
689 close(async->in);
690 if (need_out)
692 close(fdout[1]);
693 else if (async->out)
694 close(async->out);
695#else
696 if (!main_thread_set) {
697 /*
698 * We assume that the first time that start_async is called
699 * it is from the main thread.
700 */
701 main_thread_set = 1;
702 main_thread = pthread_self();
703 pthread_key_create(&async_key, NULL);
704 pthread_key_create(&async_die_counter, NULL);
705 set_die_routine(die_async);
706 set_die_is_recursing_routine(async_die_is_recursing);
707 }
708 if (proc_in >= 0)
710 set_cloexec(proc_in);
711 if (proc_out >= 0)
712 set_cloexec(proc_out);
713 async->proc_in = proc_in;
714 async->proc_out = proc_out;
715 {
716 int err = pthread_create(&async->tid, NULL, run_thread, async);
717 if (err) {
718 error("cannot create thread: %s", strerror(err));
719 goto error;
720 }
721 }
722#endif
723 return 0;
724error:
726 if (need_in)
727 close_pair(fdin);
728 else if (async->in)
729 close(async->in);
730 if (need_out)
732 close_pair(fdout);
733 else if (async->out)
734 close(async->out);
735 return -1;
736}
737int finish_async(struct async *async)
739{
740#ifdef NO_PTHREADS
741 return wait_or_whine(async->pid, "child process");
742#else
743 void *ret = (void *)(intptr_t)(-1);
744 if (pthread_join(async->tid, &ret))
746 error("pthread_join failed");
747 return (int)(intptr_t)ret;
748#endif
749}
750char *find_hook(const char *name)
752{
753 char *path = git_path("hooks/%s", name);
754 if (access(path, X_OK) < 0)
755 path = NULL;
756 return path;
758}
759int run_hook_ve(const char *const *env, const char *name, va_list args)
761{
762 struct child_process hook = CHILD_PROCESS_INIT;
763 const char *p;
764 p = find_hook(name);
766 if (!p)
767 return 0;
768 argv_array_push(&hook.args, p);
770 while ((p = va_arg(args, const char *)))
771 argv_array_push(&hook.args, p);
772 hook.env = env;
773 hook.no_stdin = 1;
774 hook.stdout_to_stderr = 1;
775 return run_command(&hook);
777}
778int run_hook_le(const char *const *env, const char *name, ...)
780{
781 va_list args;
782 int ret;
783 va_start(args, name);
785 ret = run_hook_ve(env, name, args);
786 va_end(args);
787 return ret;
789}
790int run_hook_with_custom_index(const char *index_file, const char *name, ...)
792{
793 const char *hook_env[3] = { NULL };
794 char index[PATH_MAX];
795 va_list args;
796 int ret;
797 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
799 hook_env[0] = index;
800 va_start(args, name);
802 ret = run_hook_ve(hook_env, name, args);
803 va_end(args);
804 return ret;
806}