run-command: use internal argv_array of struct child_process in run_hook_ve()
[git/git.git] / run-command.c
1 #include "cache.h"
2 #include "run-command.h"
3 #include "exec_cmd.h"
4 #include "sigchain.h"
5 #include "argv-array.h"
6
7 #ifndef SHELL_PATH
8 # define SHELL_PATH "/bin/sh"
9 #endif
10
11 struct child_to_clean {
12 pid_t pid;
13 struct child_to_clean *next;
14 };
15 static struct child_to_clean *children_to_clean;
16 static int installed_child_cleanup_handler;
17
18 static 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 }
27
28 static void cleanup_children_on_signal(int sig)
29 {
30 cleanup_children(sig);
31 sigchain_pop(sig);
32 raise(sig);
33 }
34
35 static void cleanup_children_on_exit(void)
36 {
37 cleanup_children(SIGTERM);
38 }
39
40 static 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
47 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 }
53
54 static void clear_child_for_cleanup(pid_t pid)
55 {
56 struct child_to_clean **pp;
57
58 for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
59 struct child_to_clean *clean_me = *pp;
60
61 if (clean_me->pid == pid) {
62 *pp = clean_me->next;
63 free(clean_me);
64 return;
65 }
66 }
67 }
68
69 static inline void close_pair(int fd[2])
70 {
71 close(fd[0]);
72 close(fd[1]);
73 }
74
75 #ifndef GIT_WINDOWS_NATIVE
76 static inline void dup_devnull(int to)
77 {
78 int fd = open("/dev/null", O_RDWR);
79 if (fd < 0)
80 die_errno(_("open /dev/null failed"));
81 if (dup2(fd, to) < 0)
82 die_errno(_("dup2(%d,%d) failed"), fd, to);
83 close(fd);
84 }
85 #endif
86
87 static char *locate_in_PATH(const char *file)
88 {
89 const char *p = getenv("PATH");
90 struct strbuf buf = STRBUF_INIT;
91
92 if (!p || !*p)
93 return NULL;
94
95 while (1) {
96 const char *end = strchrnul(p, ':');
97
98 strbuf_reset(&buf);
99
100 /* POSIX specifies an empty entry as the current directory. */
101 if (end != p) {
102 strbuf_add(&buf, p, end - p);
103 strbuf_addch(&buf, '/');
104 }
105 strbuf_addstr(&buf, file);
106
107 if (!access(buf.buf, F_OK))
108 return strbuf_detach(&buf, NULL);
109
110 if (!*end)
111 break;
112 p = end + 1;
113 }
114
115 strbuf_release(&buf);
116 return NULL;
117 }
118
119 static int exists_in_PATH(const char *file)
120 {
121 char *r = locate_in_PATH(file);
122 free(r);
123 return r != NULL;
124 }
125
126 int sane_execvp(const char *file, char * const argv[])
127 {
128 if (!execvp(file, argv))
129 return 0; /* cannot happen ;-) */
130
131 /*
132 * When a command can't be found because one of the directories
133 * listed in $PATH is unsearchable, execvp reports EACCES, but
134 * careful usability testing (read: analysis of occasional bug
135 * reports) reveals that "No such file or directory" is more
136 * intuitive.
137 *
138 * We avoid commands with "/", because execvp will not do $PATH
139 * lookups in that case.
140 *
141 * The reassignment of EACCES to errno looks like a no-op below,
142 * but we need to protect against exists_in_PATH overwriting errno.
143 */
144 if (errno == EACCES && !strchr(file, '/'))
145 errno = exists_in_PATH(file) ? EACCES : ENOENT;
146 else if (errno == ENOTDIR && !strchr(file, '/'))
147 errno = ENOENT;
148 return -1;
149 }
150
151 static const char **prepare_shell_cmd(const char **argv)
152 {
153 int argc, nargc = 0;
154 const char **nargv;
155
156 for (argc = 0; argv[argc]; argc++)
157 ; /* just counting */
158 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
159 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
160
161 if (argc < 1)
162 die("BUG: shell command is empty");
163
164 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
165 #ifndef GIT_WINDOWS_NATIVE
166 nargv[nargc++] = SHELL_PATH;
167 #else
168 nargv[nargc++] = "sh";
169 #endif
170 nargv[nargc++] = "-c";
171
172 if (argc < 2)
173 nargv[nargc++] = argv[0];
174 else {
175 struct strbuf arg0 = STRBUF_INIT;
176 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
177 nargv[nargc++] = strbuf_detach(&arg0, NULL);
178 }
179 }
180
181 for (argc = 0; argv[argc]; argc++)
182 nargv[nargc++] = argv[argc];
183 nargv[nargc] = NULL;
184
185 return nargv;
186 }
187
188 #ifndef GIT_WINDOWS_NATIVE
189 static int execv_shell_cmd(const char **argv)
190 {
191 const char **nargv = prepare_shell_cmd(argv);
192 trace_argv_printf(nargv, "trace: exec:");
193 sane_execvp(nargv[0], (char **)nargv);
194 free(nargv);
195 return -1;
196 }
197 #endif
198
199 #ifndef GIT_WINDOWS_NATIVE
200 static int child_err = 2;
201 static int child_notifier = -1;
202
203 static void notify_parent(void)
204 {
205 /*
206 * execvp failed. If possible, we'd like to let start_command
207 * know, so failures like ENOENT can be handled right away; but
208 * otherwise, finish_command will still report the error.
209 */
210 xwrite(child_notifier, "", 1);
211 }
212
213 static NORETURN void die_child(const char *err, va_list params)
214 {
215 vwritef(child_err, "fatal: ", err, params);
216 exit(128);
217 }
218
219 static void error_child(const char *err, va_list params)
220 {
221 vwritef(child_err, "error: ", err, params);
222 }
223 #endif
224
225 static inline void set_cloexec(int fd)
226 {
227 int flags = fcntl(fd, F_GETFD);
228 if (flags >= 0)
229 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
230 }
231
232 static int wait_or_whine(pid_t pid, const char *argv0)
233 {
234 int status, code = -1;
235 pid_t waiting;
236 int failed_errno = 0;
237
238 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
239 ; /* nothing */
240
241 if (waiting < 0) {
242 failed_errno = errno;
243 error("waitpid for %s failed: %s", argv0, strerror(errno));
244 } else if (waiting != pid) {
245 error("waitpid is confused (%s)", argv0);
246 } else if (WIFSIGNALED(status)) {
247 code = WTERMSIG(status);
248 if (code != SIGINT && code != SIGQUIT)
249 error("%s died of signal %d", argv0, code);
250 /*
251 * This return value is chosen so that code & 0xff
252 * mimics the exit code that a POSIX shell would report for
253 * a program that died from this signal.
254 */
255 code += 128;
256 } else if (WIFEXITED(status)) {
257 code = WEXITSTATUS(status);
258 /*
259 * Convert special exit code when execvp failed.
260 */
261 if (code == 127) {
262 code = -1;
263 failed_errno = ENOENT;
264 }
265 } else {
266 error("waitpid is confused (%s)", argv0);
267 }
268
269 clear_child_for_cleanup(pid);
270
271 errno = failed_errno;
272 return code;
273 }
274
275 int start_command(struct child_process *cmd)
276 {
277 int need_in, need_out, need_err;
278 int fdin[2], fdout[2], fderr[2];
279 int failed_errno;
280 char *str;
281
282 if (!cmd->argv)
283 cmd->argv = cmd->args.argv;
284
285 /*
286 * In case of errors we must keep the promise to close FDs
287 * that have been passed in via ->in and ->out.
288 */
289
290 need_in = !cmd->no_stdin && cmd->in < 0;
291 if (need_in) {
292 if (pipe(fdin) < 0) {
293 failed_errno = errno;
294 if (cmd->out > 0)
295 close(cmd->out);
296 str = "standard input";
297 goto fail_pipe;
298 }
299 cmd->in = fdin[1];
300 }
301
302 need_out = !cmd->no_stdout
303 && !cmd->stdout_to_stderr
304 && cmd->out < 0;
305 if (need_out) {
306 if (pipe(fdout) < 0) {
307 failed_errno = errno;
308 if (need_in)
309 close_pair(fdin);
310 else if (cmd->in)
311 close(cmd->in);
312 str = "standard output";
313 goto fail_pipe;
314 }
315 cmd->out = fdout[0];
316 }
317
318 need_err = !cmd->no_stderr && cmd->err < 0;
319 if (need_err) {
320 if (pipe(fderr) < 0) {
321 failed_errno = errno;
322 if (need_in)
323 close_pair(fdin);
324 else if (cmd->in)
325 close(cmd->in);
326 if (need_out)
327 close_pair(fdout);
328 else if (cmd->out)
329 close(cmd->out);
330 str = "standard error";
331 fail_pipe:
332 error("cannot create %s pipe for %s: %s",
333 str, cmd->argv[0], strerror(failed_errno));
334 argv_array_clear(&cmd->args);
335 errno = failed_errno;
336 return -1;
337 }
338 cmd->err = fderr[0];
339 }
340
341 trace_argv_printf(cmd->argv, "trace: run_command:");
342 fflush(NULL);
343
344 #ifndef GIT_WINDOWS_NATIVE
345 {
346 int notify_pipe[2];
347 if (pipe(notify_pipe))
348 notify_pipe[0] = notify_pipe[1] = -1;
349
350 cmd->pid = fork();
351 failed_errno = errno;
352 if (!cmd->pid) {
353 /*
354 * Redirect the channel to write syscall error messages to
355 * before redirecting the process's stderr so that all die()
356 * in subsequent call paths use the parent's stderr.
357 */
358 if (cmd->no_stderr || need_err) {
359 child_err = dup(2);
360 set_cloexec(child_err);
361 }
362 set_die_routine(die_child);
363 set_error_routine(error_child);
364
365 close(notify_pipe[0]);
366 set_cloexec(notify_pipe[1]);
367 child_notifier = notify_pipe[1];
368 atexit(notify_parent);
369
370 if (cmd->no_stdin)
371 dup_devnull(0);
372 else if (need_in) {
373 dup2(fdin[0], 0);
374 close_pair(fdin);
375 } else if (cmd->in) {
376 dup2(cmd->in, 0);
377 close(cmd->in);
378 }
379
380 if (cmd->no_stderr)
381 dup_devnull(2);
382 else if (need_err) {
383 dup2(fderr[1], 2);
384 close_pair(fderr);
385 } else if (cmd->err > 1) {
386 dup2(cmd->err, 2);
387 close(cmd->err);
388 }
389
390 if (cmd->no_stdout)
391 dup_devnull(1);
392 else if (cmd->stdout_to_stderr)
393 dup2(2, 1);
394 else if (need_out) {
395 dup2(fdout[1], 1);
396 close_pair(fdout);
397 } else if (cmd->out > 1) {
398 dup2(cmd->out, 1);
399 close(cmd->out);
400 }
401
402 if (cmd->dir && chdir(cmd->dir))
403 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
404 cmd->dir);
405 if (cmd->env) {
406 for (; *cmd->env; cmd->env++) {
407 if (strchr(*cmd->env, '='))
408 putenv((char *)*cmd->env);
409 else
410 unsetenv(*cmd->env);
411 }
412 }
413 if (cmd->git_cmd)
414 execv_git_cmd(cmd->argv);
415 else if (cmd->use_shell)
416 execv_shell_cmd(cmd->argv);
417 else
418 sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
419 if (errno == ENOENT) {
420 if (!cmd->silent_exec_failure)
421 error("cannot run %s: %s", cmd->argv[0],
422 strerror(ENOENT));
423 exit(127);
424 } else {
425 die_errno("cannot exec '%s'", cmd->argv[0]);
426 }
427 }
428 if (cmd->pid < 0)
429 error("cannot fork() for %s: %s", cmd->argv[0],
430 strerror(errno));
431 else if (cmd->clean_on_exit)
432 mark_child_for_cleanup(cmd->pid);
433
434 /*
435 * Wait for child's execvp. If the execvp succeeds (or if fork()
436 * failed), EOF is seen immediately by the parent. Otherwise, the
437 * child process sends a single byte.
438 * Note that use of this infrastructure is completely advisory,
439 * therefore, we keep error checks minimal.
440 */
441 close(notify_pipe[1]);
442 if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
443 /*
444 * At this point we know that fork() succeeded, but execvp()
445 * failed. Errors have been reported to our stderr.
446 */
447 wait_or_whine(cmd->pid, cmd->argv[0]);
448 failed_errno = errno;
449 cmd->pid = -1;
450 }
451 close(notify_pipe[0]);
452 }
453 #else
454 {
455 int fhin = 0, fhout = 1, fherr = 2;
456 const char **sargv = cmd->argv;
457 char **env = environ;
458
459 if (cmd->no_stdin)
460 fhin = open("/dev/null", O_RDWR);
461 else if (need_in)
462 fhin = dup(fdin[0]);
463 else if (cmd->in)
464 fhin = dup(cmd->in);
465
466 if (cmd->no_stderr)
467 fherr = open("/dev/null", O_RDWR);
468 else if (need_err)
469 fherr = dup(fderr[1]);
470 else if (cmd->err > 2)
471 fherr = dup(cmd->err);
472
473 if (cmd->no_stdout)
474 fhout = open("/dev/null", O_RDWR);
475 else if (cmd->stdout_to_stderr)
476 fhout = dup(fherr);
477 else if (need_out)
478 fhout = dup(fdout[1]);
479 else if (cmd->out > 1)
480 fhout = dup(cmd->out);
481
482 if (cmd->env)
483 env = make_augmented_environ(cmd->env);
484
485 if (cmd->git_cmd)
486 cmd->argv = prepare_git_cmd(cmd->argv);
487 else if (cmd->use_shell)
488 cmd->argv = prepare_shell_cmd(cmd->argv);
489
490 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
491 fhin, fhout, fherr);
492 failed_errno = errno;
493 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
494 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
495 if (cmd->clean_on_exit && cmd->pid >= 0)
496 mark_child_for_cleanup(cmd->pid);
497
498 if (cmd->env)
499 free_environ(env);
500 if (cmd->git_cmd)
501 free(cmd->argv);
502
503 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
513 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
531 if (need_in)
532 close(fdin[0]);
533 else if (cmd->in)
534 close(cmd->in);
535
536 if (need_out)
537 close(fdout[1]);
538 else if (cmd->out)
539 close(cmd->out);
540
541 if (need_err)
542 close(fderr[1]);
543 else if (cmd->err)
544 close(cmd->err);
545
546 return 0;
547 }
548
549 int 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 }
555
556 int 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 }
563
564 static void prepare_run_command_v_opt(struct child_process *cmd,
565 const char **argv,
566 int opt)
567 {
568 memset(cmd, 0, sizeof(*cmd));
569 cmd->argv = argv;
570 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
571 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
572 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
573 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
574 cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
575 cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
576 }
577
578 int run_command_v_opt(const char **argv, int opt)
579 {
580 struct child_process cmd;
581 prepare_run_command_v_opt(&cmd, argv, opt);
582 return run_command(&cmd);
583 }
584
585 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
586 {
587 struct child_process cmd;
588 prepare_run_command_v_opt(&cmd, argv, opt);
589 cmd.dir = dir;
590 cmd.env = env;
591 return run_command(&cmd);
592 }
593
594 #ifndef NO_PTHREADS
595 static pthread_t main_thread;
596 static int main_thread_set;
597 static pthread_key_t async_key;
598 static pthread_key_t async_die_counter;
599
600 static void *run_thread(void *data)
601 {
602 struct async *async = data;
603 intptr_t ret;
604
605 pthread_setspecific(async_key, async);
606 ret = async->proc(async->proc_in, async->proc_out, async->data);
607 return (void *)ret;
608 }
609
610 static NORETURN void die_async(const char *err, va_list params)
611 {
612 vreportf("fatal: ", err, params);
613
614 if (!pthread_equal(main_thread, pthread_self())) {
615 struct async *async = pthread_getspecific(async_key);
616 if (async->proc_in >= 0)
617 close(async->proc_in);
618 if (async->proc_out >= 0)
619 close(async->proc_out);
620 pthread_exit((void *)128);
621 }
622
623 exit(128);
624 }
625
626 static int async_die_is_recursing(void)
627 {
628 void *ret = pthread_getspecific(async_die_counter);
629 pthread_setspecific(async_die_counter, (void *)1);
630 return ret != NULL;
631 }
632
633 #endif
634
635 int start_async(struct async *async)
636 {
637 int need_in, need_out;
638 int fdin[2], fdout[2];
639 int proc_in, proc_out;
640
641 need_in = async->in < 0;
642 if (need_in) {
643 if (pipe(fdin) < 0) {
644 if (async->out > 0)
645 close(async->out);
646 return error("cannot create pipe: %s", strerror(errno));
647 }
648 async->in = fdin[1];
649 }
650
651 need_out = async->out < 0;
652 if (need_out) {
653 if (pipe(fdout) < 0) {
654 if (need_in)
655 close_pair(fdin);
656 else if (async->in)
657 close(async->in);
658 return error("cannot create pipe: %s", strerror(errno));
659 }
660 async->out = fdout[0];
661 }
662
663 if (need_in)
664 proc_in = fdin[0];
665 else if (async->in)
666 proc_in = async->in;
667 else
668 proc_in = -1;
669
670 if (need_out)
671 proc_out = fdout[1];
672 else if (async->out)
673 proc_out = async->out;
674 else
675 proc_out = -1;
676
677 #ifdef NO_PTHREADS
678 /* Flush stdio before fork() to avoid cloning buffers */
679 fflush(NULL);
680
681 async->pid = fork();
682 if (async->pid < 0) {
683 error("fork (async) failed: %s", strerror(errno));
684 goto error;
685 }
686 if (!async->pid) {
687 if (need_in)
688 close(fdin[1]);
689 if (need_out)
690 close(fdout[0]);
691 exit(!!async->proc(proc_in, proc_out, async->data));
692 }
693
694 mark_child_for_cleanup(async->pid);
695
696 if (need_in)
697 close(fdin[0]);
698 else if (async->in)
699 close(async->in);
700
701 if (need_out)
702 close(fdout[1]);
703 else if (async->out)
704 close(async->out);
705 #else
706 if (!main_thread_set) {
707 /*
708 * We assume that the first time that start_async is called
709 * it is from the main thread.
710 */
711 main_thread_set = 1;
712 main_thread = pthread_self();
713 pthread_key_create(&async_key, NULL);
714 pthread_key_create(&async_die_counter, NULL);
715 set_die_routine(die_async);
716 set_die_is_recursing_routine(async_die_is_recursing);
717 }
718
719 if (proc_in >= 0)
720 set_cloexec(proc_in);
721 if (proc_out >= 0)
722 set_cloexec(proc_out);
723 async->proc_in = proc_in;
724 async->proc_out = proc_out;
725 {
726 int err = pthread_create(&async->tid, NULL, run_thread, async);
727 if (err) {
728 error("cannot create thread: %s", strerror(err));
729 goto error;
730 }
731 }
732 #endif
733 return 0;
734
735 error:
736 if (need_in)
737 close_pair(fdin);
738 else if (async->in)
739 close(async->in);
740
741 if (need_out)
742 close_pair(fdout);
743 else if (async->out)
744 close(async->out);
745 return -1;
746 }
747
748 int finish_async(struct async *async)
749 {
750 #ifdef NO_PTHREADS
751 return wait_or_whine(async->pid, "child process");
752 #else
753 void *ret = (void *)(intptr_t)(-1);
754
755 if (pthread_join(async->tid, &ret))
756 error("pthread_join failed");
757 return (int)(intptr_t)ret;
758 #endif
759 }
760
761 char *find_hook(const char *name)
762 {
763 char *path = git_path("hooks/%s", name);
764 if (access(path, X_OK) < 0)
765 path = NULL;
766
767 return path;
768 }
769
770 int run_hook_ve(const char *const *env, const char *name, va_list args)
771 {
772 struct child_process hook;
773 const char *p;
774
775 p = find_hook(name);
776 if (!p)
777 return 0;
778
779 memset(&hook, 0, sizeof(hook));
780 argv_array_push(&hook.args, p);
781 while ((p = va_arg(args, const char *)))
782 argv_array_push(&hook.args, p);
783 hook.env = env;
784 hook.no_stdin = 1;
785 hook.stdout_to_stderr = 1;
786
787 return run_command(&hook);
788 }
789
790 int run_hook_le(const char *const *env, const char *name, ...)
791 {
792 va_list args;
793 int ret;
794
795 va_start(args, name);
796 ret = run_hook_ve(env, name, args);
797 va_end(args);
798
799 return ret;
800 }
801
802 int run_hook_with_custom_index(const char *index_file, const char *name, ...)
803 {
804 const char *hook_env[3] = { NULL };
805 char index[PATH_MAX];
806 va_list args;
807 int ret;
808
809 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
810 hook_env[0] = index;
811
812 va_start(args, name);
813 ret = run_hook_ve(hook_env, name, args);
814 va_end(args);
815
816 return ret;
817 }