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 argv_array_init(&child->env_array);
16}
17struct child_to_clean {
19 pid_t pid;
20 struct child_to_clean *next;
21};
22static struct child_to_clean *children_to_clean;
23static int installed_child_cleanup_handler;
24static void cleanup_children(int sig)
26{
27 while (children_to_clean) {
28 struct child_to_clean *p = children_to_clean;
29 children_to_clean = p->next;
30 kill(p->pid, sig);
31 free(p);
32 }
33}
34static void cleanup_children_on_signal(int sig)
36{
37 cleanup_children(sig);
38 sigchain_pop(sig);
39 raise(sig);
40}
41static void cleanup_children_on_exit(void)
43{
44 cleanup_children(SIGTERM);
45}
46static void mark_child_for_cleanup(pid_t pid)
48{
49 struct child_to_clean *p = xmalloc(sizeof(*p));
50 p->pid = pid;
51 p->next = children_to_clean;
52 children_to_clean = p;
53 if (!installed_child_cleanup_handler) {
55 atexit(cleanup_children_on_exit);
56 sigchain_push_common(cleanup_children_on_signal);
57 installed_child_cleanup_handler = 1;
58 }
59}
60static void clear_child_for_cleanup(pid_t pid)
62{
63 struct child_to_clean **pp;
64 for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
66 struct child_to_clean *clean_me = *pp;
67 if (clean_me->pid == pid) {
69 *pp = clean_me->next;
70 free(clean_me);
71 return;
72 }
73 }
74}
75static inline void close_pair(int fd[2])
77{
78 close(fd[0]);
79 close(fd[1]);
80}
81#ifndef GIT_WINDOWS_NATIVE
83static inline void dup_devnull(int to)
84{
85 int fd = open("/dev/null", O_RDWR);
86 if (fd < 0)
87 die_errno(_("open /dev/null failed"));
88 if (dup2(fd, to) < 0)
89 die_errno(_("dup2(%d,%d) failed"), fd, to);
90 close(fd);
91}
92#endif
93static char *locate_in_PATH(const char *file)
95{
96 const char *p = getenv("PATH");
97 struct strbuf buf = STRBUF_INIT;
98 if (!p || !*p)
100 return NULL;
101 while (1) {
103 const char *end = strchrnul(p, ':');
104 strbuf_reset(&buf);
106 /* POSIX specifies an empty entry as the current directory. */
108 if (end != p) {
109 strbuf_add(&buf, p, end - p);
110 strbuf_addch(&buf, '/');
111 }
112 strbuf_addstr(&buf, file);
113 if (!access(buf.buf, F_OK))
115 return strbuf_detach(&buf, NULL);
116 if (!*end)
118 break;
119 p = end + 1;
120 }
121 strbuf_release(&buf);
123 return NULL;
124}
125static int exists_in_PATH(const char *file)
127{
128 char *r = locate_in_PATH(file);
129 free(r);
130 return r != NULL;
131}
132int sane_execvp(const char *file, char * const argv[])
134{
135 if (!execvp(file, argv))
136 return 0; /* cannot happen ;-) */
137 /*
139 * When a command can't be found because one of the directories
140 * listed in $PATH is unsearchable, execvp reports EACCES, but
141 * careful usability testing (read: analysis of occasional bug
142 * reports) reveals that "No such file or directory" is more
143 * intuitive.
144 *
145 * We avoid commands with "/", because execvp will not do $PATH
146 * lookups in that case.
147 *
148 * The reassignment of EACCES to errno looks like a no-op below,
149 * but we need to protect against exists_in_PATH overwriting errno.
150 */
151 if (errno == EACCES && !strchr(file, '/'))
152 errno = exists_in_PATH(file) ? EACCES : ENOENT;
153 else if (errno == ENOTDIR && !strchr(file, '/'))
154 errno = ENOENT;
155 return -1;
156}
157static const char **prepare_shell_cmd(const char **argv)
159{
160 int argc, nargc = 0;
161 const char **nargv;
162 for (argc = 0; argv[argc]; argc++)
164 ; /* just counting */
165 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
166 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
167 if (argc < 1)
169 die("BUG: shell command is empty");
170 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
172#ifndef GIT_WINDOWS_NATIVE
173 nargv[nargc++] = SHELL_PATH;
174#else
175 nargv[nargc++] = "sh";
176#endif
177 nargv[nargc++] = "-c";
178 if (argc < 2)
180 nargv[nargc++] = argv[0];
181 else {
182 struct strbuf arg0 = STRBUF_INIT;
183 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
184 nargv[nargc++] = strbuf_detach(&arg0, NULL);
185 }
186 }
187 for (argc = 0; argv[argc]; argc++)
189 nargv[nargc++] = argv[argc];
190 nargv[nargc] = NULL;
191 return nargv;
193}
194#ifndef GIT_WINDOWS_NATIVE
196static int execv_shell_cmd(const char **argv)
197{
198 const char **nargv = prepare_shell_cmd(argv);
199 trace_argv_printf(nargv, "trace: exec:");
200 sane_execvp(nargv[0], (char **)nargv);
201 free(nargv);
202 return -1;
203}
204#endif
205#ifndef GIT_WINDOWS_NATIVE
207static int child_err = 2;
208static int child_notifier = -1;
209static void notify_parent(void)
211{
212 /*
213 * execvp failed. If possible, we'd like to let start_command
214 * know, so failures like ENOENT can be handled right away; but
215 * otherwise, finish_command will still report the error.
216 */
217 xwrite(child_notifier, "", 1);
218}
219static NORETURN void die_child(const char *err, va_list params)
221{
222 vwritef(child_err, "fatal: ", err, params);
223 exit(128);
224}
225static void error_child(const char *err, va_list params)
227{
228 vwritef(child_err, "error: ", err, params);
229}
230#endif
231static inline void set_cloexec(int fd)
233{
234 int flags = fcntl(fd, F_GETFD);
235 if (flags >= 0)
236 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
237}
238static int wait_or_whine(pid_t pid, const char *argv0)
240{
241 int status, code = -1;
242 pid_t waiting;
243 int failed_errno = 0;
244 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
246 ; /* nothing */
247 if (waiting < 0) {
249 failed_errno = errno;
250 error("waitpid for %s failed: %s", argv0, strerror(errno));
251 } else if (waiting != pid) {
252 error("waitpid is confused (%s)", argv0);
253 } else if (WIFSIGNALED(status)) {
254 code = WTERMSIG(status);
255 if (code != SIGINT && code != SIGQUIT)
256 error("%s died of signal %d", argv0, code);
257 /*
258 * This return value is chosen so that code & 0xff
259 * mimics the exit code that a POSIX shell would report for
260 * a program that died from this signal.
261 */
262 code += 128;
263 } else if (WIFEXITED(status)) {
264 code = WEXITSTATUS(status);
265 /*
266 * Convert special exit code when execvp failed.
267 */
268 if (code == 127) {
269 code = -1;
270 failed_errno = ENOENT;
271 }
272 } else {
273 error("waitpid is confused (%s)", argv0);
274 }
275 clear_child_for_cleanup(pid);
277 errno = failed_errno;
279 return code;
280}
281int start_command(struct child_process *cmd)
283{
284 int need_in, need_out, need_err;
285 int fdin[2], fdout[2], fderr[2];
286 int failed_errno;
287 char *str;
288 if (!cmd->argv)
290 cmd->argv = cmd->args.argv;
291 if (!cmd->env)
292 cmd->env = cmd->env_array.argv;
293 /*
295 * In case of errors we must keep the promise to close FDs
296 * that have been passed in via ->in and ->out.
297 */
298 need_in = !cmd->no_stdin && cmd->in < 0;
300 if (need_in) {
301 if (pipe(fdin) < 0) {
302 failed_errno = errno;
303 if (cmd->out > 0)
304 close(cmd->out);
305 str = "standard input";
306 goto fail_pipe;
307 }
308 cmd->in = fdin[1];
309 }
310 need_out = !cmd->no_stdout
312 && !cmd->stdout_to_stderr
313 && cmd->out < 0;
314 if (need_out) {
315 if (pipe(fdout) < 0) {
316 failed_errno = errno;
317 if (need_in)
318 close_pair(fdin);
319 else if (cmd->in)
320 close(cmd->in);
321 str = "standard output";
322 goto fail_pipe;
323 }
324 cmd->out = fdout[0];
325 }
326 need_err = !cmd->no_stderr && cmd->err < 0;
328 if (need_err) {
329 if (pipe(fderr) < 0) {
330 failed_errno = errno;
331 if (need_in)
332 close_pair(fdin);
333 else if (cmd->in)
334 close(cmd->in);
335 if (need_out)
336 close_pair(fdout);
337 else if (cmd->out)
338 close(cmd->out);
339 str = "standard error";
340fail_pipe:
341 error("cannot create %s pipe for %s: %s",
342 str, cmd->argv[0], strerror(failed_errno));
343 argv_array_clear(&cmd->args);
344 argv_array_clear(&cmd->env_array);
345 errno = failed_errno;
346 return -1;
347 }
348 cmd->err = fderr[0];
349 }
350 trace_argv_printf(cmd->argv, "trace: run_command:");
352 fflush(NULL);
353#ifndef GIT_WINDOWS_NATIVE
355{
356 int notify_pipe[2];
357 if (pipe(notify_pipe))
358 notify_pipe[0] = notify_pipe[1] = -1;
359 cmd->pid = fork();
361 failed_errno = errno;
362 if (!cmd->pid) {
363 /*
364 * Redirect the channel to write syscall error messages to
365 * before redirecting the process's stderr so that all die()
366 * in subsequent call paths use the parent's stderr.
367 */
368 if (cmd->no_stderr || need_err) {
369 child_err = dup(2);
370 set_cloexec(child_err);
371 }
372 set_die_routine(die_child);
373 set_error_routine(error_child);
374 close(notify_pipe[0]);
376 set_cloexec(notify_pipe[1]);
377 child_notifier = notify_pipe[1];
378 atexit(notify_parent);
379 if (cmd->no_stdin)
381 dup_devnull(0);
382 else if (need_in) {
383 dup2(fdin[0], 0);
384 close_pair(fdin);
385 } else if (cmd->in) {
386 dup2(cmd->in, 0);
387 close(cmd->in);
388 }
389 if (cmd->no_stderr)
391 dup_devnull(2);
392 else if (need_err) {
393 dup2(fderr[1], 2);
394 close_pair(fderr);
395 } else if (cmd->err > 1) {
396 dup2(cmd->err, 2);
397 close(cmd->err);
398 }
399 if (cmd->no_stdout)
401 dup_devnull(1);
402 else if (cmd->stdout_to_stderr)
403 dup2(2, 1);
404 else if (need_out) {
405 dup2(fdout[1], 1);
406 close_pair(fdout);
407 } else if (cmd->out > 1) {
408 dup2(cmd->out, 1);
409 close(cmd->out);
410 }
411 if (cmd->dir && chdir(cmd->dir))
413 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
414 cmd->dir);
415 if (cmd->env) {
416 for (; *cmd->env; cmd->env++) {
417 if (strchr(*cmd->env, '='))
418 putenv((char *)*cmd->env);
419 else
420 unsetenv(*cmd->env);
421 }
422 }
423 if (cmd->git_cmd)
424 execv_git_cmd(cmd->argv);
425 else if (cmd->use_shell)
426 execv_shell_cmd(cmd->argv);
427 else
428 sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
429 if (errno == ENOENT) {
430 if (!cmd->silent_exec_failure)
431 error("cannot run %s: %s", cmd->argv[0],
432 strerror(ENOENT));
433 exit(127);
434 } else {
435 die_errno("cannot exec '%s'", cmd->argv[0]);
436 }
437 }
438 if (cmd->pid < 0)
439 error("cannot fork() for %s: %s", cmd->argv[0],
440 strerror(errno));
441 else if (cmd->clean_on_exit)
442 mark_child_for_cleanup(cmd->pid);
443 /*
445 * Wait for child's execvp. If the execvp succeeds (or if fork()
446 * failed), EOF is seen immediately by the parent. Otherwise, the
447 * child process sends a single byte.
448 * Note that use of this infrastructure is completely advisory,
449 * therefore, we keep error checks minimal.
450 */
451 close(notify_pipe[1]);
452 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
453 /*
454 * At this point we know that fork() succeeded, but execvp()
455 * failed. Errors have been reported to our stderr.
456 */
457 wait_or_whine(cmd->pid, cmd->argv[0]);
458 failed_errno = errno;
459 cmd->pid = -1;
460 }
461 close(notify_pipe[0]);
462}
463#else
464{
465 int fhin = 0, fhout = 1, fherr = 2;
466 const char **sargv = cmd->argv;
467 if (cmd->no_stdin)
469 fhin = open("/dev/null", O_RDWR);
470 else if (need_in)
471 fhin = dup(fdin[0]);
472 else if (cmd->in)
473 fhin = dup(cmd->in);
474 if (cmd->no_stderr)
476 fherr = open("/dev/null", O_RDWR);
477 else if (need_err)
478 fherr = dup(fderr[1]);
479 else if (cmd->err > 2)
480 fherr = dup(cmd->err);
481 if (cmd->no_stdout)
483 fhout = open("/dev/null", O_RDWR);
484 else if (cmd->stdout_to_stderr)
485 fhout = dup(fherr);
486 else if (need_out)
487 fhout = dup(fdout[1]);
488 else if (cmd->out > 1)
489 fhout = dup(cmd->out);
490 if (cmd->git_cmd)
492 cmd->argv = prepare_git_cmd(cmd->argv);
493 else if (cmd->use_shell)
494 cmd->argv = prepare_shell_cmd(cmd->argv);
495 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, (char**) cmd->env,
497 cmd->dir, fhin, fhout, fherr);
498 failed_errno = errno;
499 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
500 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
501 if (cmd->clean_on_exit && cmd->pid >= 0)
502 mark_child_for_cleanup(cmd->pid);
503 if (cmd->git_cmd)
505 free(cmd->argv);
506 cmd->argv = sargv;
508 if (fhin != 0)
509 close(fhin);
510 if (fhout != 1)
511 close(fhout);
512 if (fherr != 2)
513 close(fherr);
514}
515#endif
516 if (cmd->pid < 0) {
518 if (need_in)
519 close_pair(fdin);
520 else if (cmd->in)
521 close(cmd->in);
522 if (need_out)
523 close_pair(fdout);
524 else if (cmd->out)
525 close(cmd->out);
526 if (need_err)
527 close_pair(fderr);
528 else if (cmd->err)
529 close(cmd->err);
530 argv_array_clear(&cmd->args);
531 argv_array_clear(&cmd->env_array);
532 errno = failed_errno;
533 return -1;
534 }
535 if (need_in)
537 close(fdin[0]);
538 else if (cmd->in)
539 close(cmd->in);
540 if (need_out)
542 close(fdout[1]);
543 else if (cmd->out)
544 close(cmd->out);
545 if (need_err)
547 close(fderr[1]);
548 else if (cmd->err)
549 close(cmd->err);
550 return 0;
552}
553int finish_command(struct child_process *cmd)
555{
556 int ret = wait_or_whine(cmd->pid, cmd->argv[0]);
557 argv_array_clear(&cmd->args);
558 argv_array_clear(&cmd->env_array);
559 return ret;
560}
561int run_command(struct child_process *cmd)
563{
564 int code = start_command(cmd);
565 if (code)
566 return code;
567 return finish_command(cmd);
568}
569int run_command_v_opt(const char **argv, int opt)
571{
572 return run_command_v_opt_cd_env(argv, opt, NULL, NULL);
573}
574int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
576{
577 struct child_process cmd = CHILD_PROCESS_INIT;
578 cmd.argv = argv;
579 cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
580 cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
581 cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
582 cmd.silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
583 cmd.use_shell = opt & RUN_USING_SHELL ? 1 : 0;
584 cmd.clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
585 cmd.dir = dir;
586 cmd.env = env;
587 return run_command(&cmd);
588}
589#ifndef NO_PTHREADS
591static pthread_t main_thread;
592static int main_thread_set;
593static pthread_key_t async_key;
594static pthread_key_t async_die_counter;
595static void *run_thread(void *data)
597{
598 struct async *async = data;
599 intptr_t ret;
600 pthread_setspecific(async_key, async);
602 ret = async->proc(async->proc_in, async->proc_out, async->data);
603 return (void *)ret;
604}
605static NORETURN void die_async(const char *err, va_list params)
607{
608 vreportf("fatal: ", err, params);
609 if (!pthread_equal(main_thread, pthread_self())) {
611 struct async *async = pthread_getspecific(async_key);
612 if (async->proc_in >= 0)
613 close(async->proc_in);
614 if (async->proc_out >= 0)
615 close(async->proc_out);
616 pthread_exit((void *)128);
617 }
618 exit(128);
620}
621static int async_die_is_recursing(void)
623{
624 void *ret = pthread_getspecific(async_die_counter);
625 pthread_setspecific(async_die_counter, (void *)1);
626 return ret != NULL;
627}
628#else
630static struct {
632 void (**handlers)(void);
633 size_t nr;
634 size_t alloc;
635} git_atexit_hdlrs;
636static int git_atexit_installed;
638static void git_atexit_dispatch(void)
640{
641 size_t i;
642 for (i=git_atexit_hdlrs.nr ; i ; i--)
644 git_atexit_hdlrs.handlers[i-1]();
645}
646static void git_atexit_clear(void)
648{
649 free(git_atexit_hdlrs.handlers);
650 memset(&git_atexit_hdlrs, 0, sizeof(git_atexit_hdlrs));
651 git_atexit_installed = 0;
652}
653#undef atexit
655int git_atexit(void (*handler)(void))
656{
657 ALLOC_GROW(git_atexit_hdlrs.handlers, git_atexit_hdlrs.nr + 1, git_atexit_hdlrs.alloc);
658 git_atexit_hdlrs.handlers[git_atexit_hdlrs.nr++] = handler;
659 if (!git_atexit_installed) {
660 if (atexit(&git_atexit_dispatch))
661 return -1;
662 git_atexit_installed = 1;
663 }
664 return 0;
665}
666#define atexit git_atexit
667#endif
669int start_async(struct async *async)
671{
672 int need_in, need_out;
673 int fdin[2], fdout[2];
674 int proc_in, proc_out;
675 need_in = async->in < 0;
677 if (need_in) {
678 if (pipe(fdin) < 0) {
679 if (async->out > 0)
680 close(async->out);
681 return error("cannot create pipe: %s", strerror(errno));
682 }
683 async->in = fdin[1];
684 }
685 need_out = async->out < 0;
687 if (need_out) {
688 if (pipe(fdout) < 0) {
689 if (need_in)
690 close_pair(fdin);
691 else if (async->in)
692 close(async->in);
693 return error("cannot create pipe: %s", strerror(errno));
694 }
695 async->out = fdout[0];
696 }
697 if (need_in)
699 proc_in = fdin[0];
700 else if (async->in)
701 proc_in = async->in;
702 else
703 proc_in = -1;
704 if (need_out)
706 proc_out = fdout[1];
707 else if (async->out)
708 proc_out = async->out;
709 else
710 proc_out = -1;
711#ifdef NO_PTHREADS
713 /* Flush stdio before fork() to avoid cloning buffers */
714 fflush(NULL);
715 async->pid = fork();
717 if (async->pid < 0) {
718 error("fork (async) failed: %s", strerror(errno));
719 goto error;
720 }
721 if (!async->pid) {
722 if (need_in)
723 close(fdin[1]);
724 if (need_out)
725 close(fdout[0]);
726 git_atexit_clear();
727 exit(!!async->proc(proc_in, proc_out, async->data));
728 }
729 mark_child_for_cleanup(async->pid);
731 if (need_in)
733 close(fdin[0]);
734 else if (async->in)
735 close(async->in);
736 if (need_out)
738 close(fdout[1]);
739 else if (async->out)
740 close(async->out);
741#else
742 if (!main_thread_set) {
743 /*
744 * We assume that the first time that start_async is called
745 * it is from the main thread.
746 */
747 main_thread_set = 1;
748 main_thread = pthread_self();
749 pthread_key_create(&async_key, NULL);
750 pthread_key_create(&async_die_counter, NULL);
751 set_die_routine(die_async);
752 set_die_is_recursing_routine(async_die_is_recursing);
753 }
754 if (proc_in >= 0)
756 set_cloexec(proc_in);
757 if (proc_out >= 0)
758 set_cloexec(proc_out);
759 async->proc_in = proc_in;
760 async->proc_out = proc_out;
761 {
762 int err = pthread_create(&async->tid, NULL, run_thread, async);
763 if (err) {
764 error("cannot create thread: %s", strerror(err));
765 goto error;
766 }
767 }
768#endif
769 return 0;
770error:
772 if (need_in)
773 close_pair(fdin);
774 else if (async->in)
775 close(async->in);
776 if (need_out)
778 close_pair(fdout);
779 else if (async->out)
780 close(async->out);
781 return -1;
782}
783int finish_async(struct async *async)
785{
786#ifdef NO_PTHREADS
787 return wait_or_whine(async->pid, "child process");
788#else
789 void *ret = (void *)(intptr_t)(-1);
790 if (pthread_join(async->tid, &ret))
792 error("pthread_join failed");
793 return (int)(intptr_t)ret;
794#endif
795}
796char *find_hook(const char *name)
798{
799 char *path = git_path("hooks/%s", name);
800 if (access(path, X_OK) < 0)
801 path = NULL;
802 return path;
804}
805int run_hook_ve(const char *const *env, const char *name, va_list args)
807{
808 struct child_process hook = CHILD_PROCESS_INIT;
809 const char *p;
810 p = find_hook(name);
812 if (!p)
813 return 0;
814 argv_array_push(&hook.args, p);
816 while ((p = va_arg(args, const char *)))
817 argv_array_push(&hook.args, p);
818 hook.env = env;
819 hook.no_stdin = 1;
820 hook.stdout_to_stderr = 1;
821 return run_command(&hook);
823}
824int run_hook_le(const char *const *env, const char *name, ...)
826{
827 va_list args;
828 int ret;
829 va_start(args, name);
831 ret = run_hook_ve(env, name, args);
832 va_end(args);
833 return ret;
835}