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 **pp;
57 for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
59 struct child_to_clean *clean_me = *pp;
60 if (clean_me->pid == pid) {
62 *pp = clean_me->next;
63 free(clean_me);
64 return;
65 }
66 }
67}
68static inline void close_pair(int fd[2])
70{
71 close(fd[0]);
72 close(fd[1]);
73}
74#ifndef GIT_WINDOWS_NATIVE
76static 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
86static char *locate_in_PATH(const char *file)
88{
89 const char *p = getenv("PATH");
90 struct strbuf buf = STRBUF_INIT;
91 if (!p || !*p)
93 return NULL;
94 while (1) {
96 const char *end = strchrnul(p, ':');
97 strbuf_reset(&buf);
99 /* 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 if (!access(buf.buf, F_OK))
108 return strbuf_detach(&buf, NULL);
109 if (!*end)
111 break;
112 p = end + 1;
113 }
114 strbuf_release(&buf);
116 return NULL;
117}
118static int exists_in_PATH(const char *file)
120{
121 char *r = locate_in_PATH(file);
122 free(r);
123 return r != NULL;
124}
125int sane_execvp(const char *file, char * const argv[])
127{
128 if (!execvp(file, argv))
129 return 0; /* cannot happen ;-) */
130 /*
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}
150static const char **prepare_shell_cmd(const char **argv)
152{
153 int argc, nargc = 0;
154 const char **nargv;
155 for (argc = 0; argv[argc]; argc++)
157 ; /* just counting */
158 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
159 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
160 if (argc < 1)
162 die("BUG: shell command is empty");
163 if (strcspn(argv[0], "|&;<>()$`\\\"' \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 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 for (argc = 0; argv[argc]; argc++)
182 nargv[nargc++] = argv[argc];
183 nargv[nargc] = NULL;
184 return nargv;
186}
187#ifndef GIT_WINDOWS_NATIVE
189static 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#ifndef GIT_WINDOWS_NATIVE
200static int child_err = 2;
201static int child_notifier = -1;
202static 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}
212static NORETURN void die_child(const char *err, va_list params)
214{
215 vwritef(child_err, "fatal: ", err, params);
216 exit(128);
217}
218static void error_child(const char *err, va_list params)
220{
221 vwritef(child_err, "error: ", err, params);
222}
223#endif
224static 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}
231static 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 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
239 ; /* nothing */
240 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 clear_child_for_cleanup(pid);
270 errno = failed_errno;
272 return code;
273}
274int 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 if (!cmd->argv)
283 cmd->argv = cmd->args.argv;
284 /*
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 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 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 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";
331fail_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 trace_argv_printf(cmd->argv, "trace: run_command:");
342 fflush(NULL);
343#ifndef GIT_WINDOWS_NATIVE
345{
346 int notify_pipe[2];
347 if (pipe(notify_pipe))
348 notify_pipe[0] = notify_pipe[1] = -1;
349 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 close(notify_pipe[0]);
366 set_cloexec(notify_pipe[1]);
367 child_notifier = notify_pipe[1];
368 atexit(notify_parent);
369 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 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 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 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 /*
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], ¬ify_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 if (cmd->no_stdin)
459 fhin = open("/dev/null", O_RDWR);
460 else if (need_in)
461 fhin = dup(fdin[0]);
462 else if (cmd->in)
463 fhin = dup(cmd->in);
464 if (cmd->no_stderr)
466 fherr = open("/dev/null", O_RDWR);
467 else if (need_err)
468 fherr = dup(fderr[1]);
469 else if (cmd->err > 2)
470 fherr = dup(cmd->err);
471 if (cmd->no_stdout)
473 fhout = open("/dev/null", O_RDWR);
474 else if (cmd->stdout_to_stderr)
475 fhout = dup(fherr);
476 else if (need_out)
477 fhout = dup(fdout[1]);
478 else if (cmd->out > 1)
479 fhout = dup(cmd->out);
480 if (cmd->git_cmd)
482 cmd->argv = prepare_git_cmd(cmd->argv);
483 else if (cmd->use_shell)
484 cmd->argv = prepare_shell_cmd(cmd->argv);
485 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, (char**) cmd->env,
487 cmd->dir, fhin, fhout, fherr);
488 failed_errno = errno;
489 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
490 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
491 if (cmd->clean_on_exit && cmd->pid >= 0)
492 mark_child_for_cleanup(cmd->pid);
493 if (cmd->git_cmd)
495 free(cmd->argv);
496 cmd->argv = sargv;
498 if (fhin != 0)
499 close(fhin);
500 if (fhout != 1)
501 close(fhout);
502 if (fherr != 2)
503 close(fherr);
504}
505#endif
506 if (cmd->pid < 0) {
508 if (need_in)
509 close_pair(fdin);
510 else if (cmd->in)
511 close(cmd->in);
512 if (need_out)
513 close_pair(fdout);
514 else if (cmd->out)
515 close(cmd->out);
516 if (need_err)
517 close_pair(fderr);
518 else if (cmd->err)
519 close(cmd->err);
520 argv_array_clear(&cmd->args);
521 errno = failed_errno;
522 return -1;
523 }
524 if (need_in)
526 close(fdin[0]);
527 else if (cmd->in)
528 close(cmd->in);
529 if (need_out)
531 close(fdout[1]);
532 else if (cmd->out)
533 close(cmd->out);
534 if (need_err)
536 close(fderr[1]);
537 else if (cmd->err)
538 close(cmd->err);
539 return 0;
541}
542int finish_command(struct child_process *cmd)
544{
545 int ret = wait_or_whine(cmd->pid, cmd->argv[0]);
546 argv_array_clear(&cmd->args);
547 return ret;
548}
549int run_command(struct child_process *cmd)
551{
552 int code = start_command(cmd);
553 if (code)
554 return code;
555 return finish_command(cmd);
556}
557static void prepare_run_command_v_opt(struct child_process *cmd,
559 const char **argv,
560 int opt)
561{
562 memset(cmd, 0, sizeof(*cmd));
563 cmd->argv = argv;
564 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
565 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
566 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
567 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
568 cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
569 cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
570}
571int run_command_v_opt(const char **argv, int opt)
573{
574 struct child_process cmd;
575 prepare_run_command_v_opt(&cmd, argv, opt);
576 return run_command(&cmd);
577}
578int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
580{
581 struct child_process cmd;
582 prepare_run_command_v_opt(&cmd, argv, opt);
583 cmd.dir = dir;
584 cmd.env = env;
585 return run_command(&cmd);
586}
587#ifndef NO_PTHREADS
589static pthread_t main_thread;
590static int main_thread_set;
591static pthread_key_t async_key;
592static pthread_key_t async_die_counter;
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}
619static int async_die_is_recursing(void)
621{
622 void *ret = pthread_getspecific(async_die_counter);
623 pthread_setspecific(async_die_counter, (void *)1);
624 return ret != NULL;
625}
626#endif
628int start_async(struct async *async)
630{
631 int need_in, need_out;
632 int fdin[2], fdout[2];
633 int proc_in, proc_out;
634 need_in = async->in < 0;
636 if (need_in) {
637 if (pipe(fdin) < 0) {
638 if (async->out > 0)
639 close(async->out);
640 return error("cannot create pipe: %s", strerror(errno));
641 }
642 async->in = fdin[1];
643 }
644 need_out = async->out < 0;
646 if (need_out) {
647 if (pipe(fdout) < 0) {
648 if (need_in)
649 close_pair(fdin);
650 else if (async->in)
651 close(async->in);
652 return error("cannot create pipe: %s", strerror(errno));
653 }
654 async->out = fdout[0];
655 }
656 if (need_in)
658 proc_in = fdin[0];
659 else if (async->in)
660 proc_in = async->in;
661 else
662 proc_in = -1;
663 if (need_out)
665 proc_out = fdout[1];
666 else if (async->out)
667 proc_out = async->out;
668 else
669 proc_out = -1;
670#ifdef NO_PTHREADS
672 /* Flush stdio before fork() to avoid cloning buffers */
673 fflush(NULL);
674 async->pid = fork();
676 if (async->pid < 0) {
677 error("fork (async) failed: %s", strerror(errno));
678 goto error;
679 }
680 if (!async->pid) {
681 if (need_in)
682 close(fdin[1]);
683 if (need_out)
684 close(fdout[0]);
685 exit(!!async->proc(proc_in, proc_out, async->data));
686 }
687 mark_child_for_cleanup(async->pid);
689 if (need_in)
691 close(fdin[0]);
692 else if (async->in)
693 close(async->in);
694 if (need_out)
696 close(fdout[1]);
697 else if (async->out)
698 close(async->out);
699#else
700 if (!main_thread_set) {
701 /*
702 * We assume that the first time that start_async is called
703 * it is from the main thread.
704 */
705 main_thread_set = 1;
706 main_thread = pthread_self();
707 pthread_key_create(&async_key, NULL);
708 pthread_key_create(&async_die_counter, NULL);
709 set_die_routine(die_async);
710 set_die_is_recursing_routine(async_die_is_recursing);
711 }
712 if (proc_in >= 0)
714 set_cloexec(proc_in);
715 if (proc_out >= 0)
716 set_cloexec(proc_out);
717 async->proc_in = proc_in;
718 async->proc_out = proc_out;
719 {
720 int err = pthread_create(&async->tid, NULL, run_thread, async);
721 if (err) {
722 error("cannot create thread: %s", strerror(err));
723 goto error;
724 }
725 }
726#endif
727 return 0;
728error:
730 if (need_in)
731 close_pair(fdin);
732 else if (async->in)
733 close(async->in);
734 if (need_out)
736 close_pair(fdout);
737 else if (async->out)
738 close(async->out);
739 return -1;
740}
741int finish_async(struct async *async)
743{
744#ifdef NO_PTHREADS
745 return wait_or_whine(async->pid, "child process");
746#else
747 void *ret = (void *)(intptr_t)(-1);
748 if (pthread_join(async->tid, &ret))
750 error("pthread_join failed");
751 return (int)(intptr_t)ret;
752#endif
753}
754char *find_hook(const char *name)
756{
757 char *path = git_path("hooks/%s", name);
758 if (access(path, X_OK) < 0)
759 path = NULL;
760 return path;
762}
763int run_hook_ve(const char *const *env, const char *name, va_list args)
765{
766 struct child_process hook;
767 const char *p;
768 p = find_hook(name);
770 if (!p)
771 return 0;
772 memset(&hook, 0, sizeof(hook));
774 argv_array_push(&hook.args, p);
775 while ((p = va_arg(args, const char *)))
776 argv_array_push(&hook.args, p);
777 hook.env = env;
778 hook.no_stdin = 1;
779 hook.stdout_to_stderr = 1;
780 return run_command(&hook);
782}
783int run_hook_le(const char *const *env, const char *name, ...)
785{
786 va_list args;
787 int ret;
788 va_start(args, name);
790 ret = run_hook_ve(env, name, args);
791 va_end(args);
792 return ret;
794}
795int run_hook_with_custom_index(const char *index_file, const char *name, ...)
797{
798 const char *hook_env[3] = { NULL };
799 char index[PATH_MAX];
800 va_list args;
801 int ret;
802 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
804 hook_env[0] = index;
805 va_start(args, name);
807 ret = run_hook_ve(hook_env, name, args);
808 va_end(args);
809 return ret;
811}