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 WIN32
76static inline void dup_devnull(int to)
77{
78 int fd = open("/dev/null", O_RDWR);
79 dup2(fd, to);
80 close(fd);
81}
82#endif
83static char *locate_in_PATH(const char *file)
85{
86 const char *p = getenv("PATH");
87 struct strbuf buf = STRBUF_INIT;
88 if (!p || !*p)
90 return NULL;
91 while (1) {
93 const char *end = strchrnul(p, ':');
94 strbuf_reset(&buf);
96 /* POSIX specifies an empty entry as the current directory. */
98 if (end != p) {
99 strbuf_add(&buf, p, end - p);
100 strbuf_addch(&buf, '/');
101 }
102 strbuf_addstr(&buf, file);
103 if (!access(buf.buf, F_OK))
105 return strbuf_detach(&buf, NULL);
106 if (!*end)
108 break;
109 p = end + 1;
110 }
111 strbuf_release(&buf);
113 return NULL;
114}
115static int exists_in_PATH(const char *file)
117{
118 char *r = locate_in_PATH(file);
119 free(r);
120 return r != NULL;
121}
122int sane_execvp(const char *file, char * const argv[])
124{
125 if (!execvp(file, argv))
126 return 0; /* cannot happen ;-) */
127 /*
129 * When a command can't be found because one of the directories
130 * listed in $PATH is unsearchable, execvp reports EACCES, but
131 * careful usability testing (read: analysis of occasional bug
132 * reports) reveals that "No such file or directory" is more
133 * intuitive.
134 *
135 * We avoid commands with "/", because execvp will not do $PATH
136 * lookups in that case.
137 *
138 * The reassignment of EACCES to errno looks like a no-op below,
139 * but we need to protect against exists_in_PATH overwriting errno.
140 */
141 if (errno == EACCES && !strchr(file, '/'))
142 errno = exists_in_PATH(file) ? EACCES : ENOENT;
143 else if (errno == ENOTDIR && !strchr(file, '/'))
144 errno = ENOENT;
145 return -1;
146}
147static const char **prepare_shell_cmd(const char **argv)
149{
150 int argc, nargc = 0;
151 const char **nargv;
152 for (argc = 0; argv[argc]; argc++)
154 ; /* just counting */
155 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
156 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
157 if (argc < 1)
159 die("BUG: shell command is empty");
160 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
162#ifndef WIN32
163 nargv[nargc++] = SHELL_PATH;
164#else
165 nargv[nargc++] = "sh";
166#endif
167 nargv[nargc++] = "-c";
168 if (argc < 2)
170 nargv[nargc++] = argv[0];
171 else {
172 struct strbuf arg0 = STRBUF_INIT;
173 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
174 nargv[nargc++] = strbuf_detach(&arg0, NULL);
175 }
176 }
177 for (argc = 0; argv[argc]; argc++)
179 nargv[nargc++] = argv[argc];
180 nargv[nargc] = NULL;
181 return nargv;
183}
184#ifndef WIN32
186static int execv_shell_cmd(const char **argv)
187{
188 const char **nargv = prepare_shell_cmd(argv);
189 trace_argv_printf(nargv, "trace: exec:");
190 sane_execvp(nargv[0], (char **)nargv);
191 free(nargv);
192 return -1;
193}
194#endif
195#ifndef WIN32
197static int child_err = 2;
198static int child_notifier = -1;
199static void notify_parent(void)
201{
202 /*
203 * execvp failed. If possible, we'd like to let start_command
204 * know, so failures like ENOENT can be handled right away; but
205 * otherwise, finish_command will still report the error.
206 */
207 xwrite(child_notifier, "", 1);
208}
209static NORETURN void die_child(const char *err, va_list params)
211{
212 vwritef(child_err, "fatal: ", err, params);
213 exit(128);
214}
215static void error_child(const char *err, va_list params)
217{
218 vwritef(child_err, "error: ", err, params);
219}
220#endif
221static inline void set_cloexec(int fd)
223{
224 int flags = fcntl(fd, F_GETFD);
225 if (flags >= 0)
226 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
227}
228static int wait_or_whine(pid_t pid, const char *argv0)
230{
231 int status, code = -1;
232 pid_t waiting;
233 int failed_errno = 0;
234 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
236 ; /* nothing */
237 if (waiting < 0) {
239 failed_errno = errno;
240 error("waitpid for %s failed: %s", argv0, strerror(errno));
241 } else if (waiting != pid) {
242 error("waitpid is confused (%s)", argv0);
243 } else if (WIFSIGNALED(status)) {
244 code = WTERMSIG(status);
245 if (code != SIGINT && code != SIGQUIT)
246 error("%s died of signal %d", argv0, code);
247 /*
248 * This return value is chosen so that code & 0xff
249 * mimics the exit code that a POSIX shell would report for
250 * a program that died from this signal.
251 */
252 code += 128;
253 } else if (WIFEXITED(status)) {
254 code = WEXITSTATUS(status);
255 /*
256 * Convert special exit code when execvp failed.
257 */
258 if (code == 127) {
259 code = -1;
260 failed_errno = ENOENT;
261 }
262 } else {
263 error("waitpid is confused (%s)", argv0);
264 }
265 clear_child_for_cleanup(pid);
267 errno = failed_errno;
269 return code;
270}
271int start_command(struct child_process *cmd)
273{
274 int need_in, need_out, need_err;
275 int fdin[2], fdout[2], fderr[2];
276 int failed_errno = failed_errno;
277 char *str;
278 /*
280 * In case of errors we must keep the promise to close FDs
281 * that have been passed in via ->in and ->out.
282 */
283 need_in = !cmd->no_stdin && cmd->in < 0;
285 if (need_in) {
286 if (pipe(fdin) < 0) {
287 failed_errno = errno;
288 if (cmd->out > 0)
289 close(cmd->out);
290 str = "standard input";
291 goto fail_pipe;
292 }
293 cmd->in = fdin[1];
294 }
295 need_out = !cmd->no_stdout
297 && !cmd->stdout_to_stderr
298 && cmd->out < 0;
299 if (need_out) {
300 if (pipe(fdout) < 0) {
301 failed_errno = errno;
302 if (need_in)
303 close_pair(fdin);
304 else if (cmd->in)
305 close(cmd->in);
306 str = "standard output";
307 goto fail_pipe;
308 }
309 cmd->out = fdout[0];
310 }
311 need_err = !cmd->no_stderr && cmd->err < 0;
313 if (need_err) {
314 if (pipe(fderr) < 0) {
315 failed_errno = errno;
316 if (need_in)
317 close_pair(fdin);
318 else if (cmd->in)
319 close(cmd->in);
320 if (need_out)
321 close_pair(fdout);
322 else if (cmd->out)
323 close(cmd->out);
324 str = "standard error";
325fail_pipe:
326 error("cannot create %s pipe for %s: %s",
327 str, cmd->argv[0], strerror(failed_errno));
328 errno = failed_errno;
329 return -1;
330 }
331 cmd->err = fderr[0];
332 }
333 trace_argv_printf(cmd->argv, "trace: run_command:");
335 fflush(NULL);
336#ifndef WIN32
338{
339 int notify_pipe[2];
340 if (pipe(notify_pipe))
341 notify_pipe[0] = notify_pipe[1] = -1;
342 cmd->pid = fork();
344 if (!cmd->pid) {
345 /*
346 * Redirect the channel to write syscall error messages to
347 * before redirecting the process's stderr so that all die()
348 * in subsequent call paths use the parent's stderr.
349 */
350 if (cmd->no_stderr || need_err) {
351 child_err = dup(2);
352 set_cloexec(child_err);
353 }
354 set_die_routine(die_child);
355 set_error_routine(error_child);
356 close(notify_pipe[0]);
358 set_cloexec(notify_pipe[1]);
359 child_notifier = notify_pipe[1];
360 atexit(notify_parent);
361 if (cmd->no_stdin)
363 dup_devnull(0);
364 else if (need_in) {
365 dup2(fdin[0], 0);
366 close_pair(fdin);
367 } else if (cmd->in) {
368 dup2(cmd->in, 0);
369 close(cmd->in);
370 }
371 if (cmd->no_stderr)
373 dup_devnull(2);
374 else if (need_err) {
375 dup2(fderr[1], 2);
376 close_pair(fderr);
377 } else if (cmd->err > 1) {
378 dup2(cmd->err, 2);
379 close(cmd->err);
380 }
381 if (cmd->no_stdout)
383 dup_devnull(1);
384 else if (cmd->stdout_to_stderr)
385 dup2(2, 1);
386 else if (need_out) {
387 dup2(fdout[1], 1);
388 close_pair(fdout);
389 } else if (cmd->out > 1) {
390 dup2(cmd->out, 1);
391 close(cmd->out);
392 }
393 if (cmd->dir && chdir(cmd->dir))
395 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
396 cmd->dir);
397 if (cmd->env) {
398 for (; *cmd->env; cmd->env++) {
399 if (strchr(*cmd->env, '='))
400 putenv((char *)*cmd->env);
401 else
402 unsetenv(*cmd->env);
403 }
404 }
405 if (cmd->git_cmd) {
406 execv_git_cmd(cmd->argv);
407 } else if (cmd->use_shell) {
408 execv_shell_cmd(cmd->argv);
409 } else {
410 sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
411 }
412 if (errno == ENOENT) {
413 if (!cmd->silent_exec_failure)
414 error("cannot run %s: %s", cmd->argv[0],
415 strerror(ENOENT));
416 exit(127);
417 } else {
418 die_errno("cannot exec '%s'", cmd->argv[0]);
419 }
420 }
421 if (cmd->pid < 0)
422 error("cannot fork() for %s: %s", cmd->argv[0],
423 strerror(failed_errno = errno));
424 else if (cmd->clean_on_exit)
425 mark_child_for_cleanup(cmd->pid);
426 /*
428 * Wait for child's execvp. If the execvp succeeds (or if fork()
429 * failed), EOF is seen immediately by the parent. Otherwise, the
430 * child process sends a single byte.
431 * Note that use of this infrastructure is completely advisory,
432 * therefore, we keep error checks minimal.
433 */
434 close(notify_pipe[1]);
435 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
436 /*
437 * At this point we know that fork() succeeded, but execvp()
438 * failed. Errors have been reported to our stderr.
439 */
440 wait_or_whine(cmd->pid, cmd->argv[0]);
441 failed_errno = errno;
442 cmd->pid = -1;
443 }
444 close(notify_pipe[0]);
445}
447#else
448{
449 int fhin = 0, fhout = 1, fherr = 2;
450 const char **sargv = cmd->argv;
451 char **env = environ;
452 if (cmd->no_stdin)
454 fhin = open("/dev/null", O_RDWR);
455 else if (need_in)
456 fhin = dup(fdin[0]);
457 else if (cmd->in)
458 fhin = dup(cmd->in);
459 if (cmd->no_stderr)
461 fherr = open("/dev/null", O_RDWR);
462 else if (need_err)
463 fherr = dup(fderr[1]);
464 else if (cmd->err > 2)
465 fherr = dup(cmd->err);
466 if (cmd->no_stdout)
468 fhout = open("/dev/null", O_RDWR);
469 else if (cmd->stdout_to_stderr)
470 fhout = dup(fherr);
471 else if (need_out)
472 fhout = dup(fdout[1]);
473 else if (cmd->out > 1)
474 fhout = dup(cmd->out);
475 if (cmd->env)
477 env = make_augmented_environ(cmd->env);
478 if (cmd->git_cmd) {
480 cmd->argv = prepare_git_cmd(cmd->argv);
481 } else if (cmd->use_shell) {
482 cmd->argv = prepare_shell_cmd(cmd->argv);
483 }
484 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
486 fhin, fhout, fherr);
487 failed_errno = errno;
488 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
489 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
490 if (cmd->clean_on_exit && cmd->pid >= 0)
491 mark_child_for_cleanup(cmd->pid);
492 if (cmd->env)
494 free_environ(env);
495 if (cmd->git_cmd)
496 free(cmd->argv);
497 cmd->argv = sargv;
499 if (fhin != 0)
500 close(fhin);
501 if (fhout != 1)
502 close(fhout);
503 if (fherr != 2)
504 close(fherr);
505}
506#endif
507 if (cmd->pid < 0) {
509 if (need_in)
510 close_pair(fdin);
511 else if (cmd->in)
512 close(cmd->in);
513 if (need_out)
514 close_pair(fdout);
515 else if (cmd->out)
516 close(cmd->out);
517 if (need_err)
518 close_pair(fderr);
519 else if (cmd->err)
520 close(cmd->err);
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 return wait_or_whine(cmd->pid, cmd->argv[0]);
546}
547int run_command(struct child_process *cmd)
549{
550 int code = start_command(cmd);
551 if (code)
552 return code;
553 return finish_command(cmd);
554}
555static void prepare_run_command_v_opt(struct child_process *cmd,
557 const char **argv,
558 int opt)
559{
560 memset(cmd, 0, sizeof(*cmd));
561 cmd->argv = argv;
562 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
563 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
564 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
565 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
566 cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
567 cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
568}
569int run_command_v_opt(const char **argv, int opt)
571{
572 struct child_process cmd;
573 prepare_run_command_v_opt(&cmd, argv, opt);
574 return run_command(&cmd);
575}
576int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
578{
579 struct child_process cmd;
580 prepare_run_command_v_opt(&cmd, argv, opt);
581 cmd.dir = dir;
582 cmd.env = env;
583 return run_command(&cmd);
584}
585#ifndef NO_PTHREADS
587static pthread_t main_thread;
588static int main_thread_set;
589static pthread_key_t async_key;
590static void *run_thread(void *data)
592{
593 struct async *async = data;
594 intptr_t ret;
595 pthread_setspecific(async_key, async);
597 ret = async->proc(async->proc_in, async->proc_out, async->data);
598 return (void *)ret;
599}
600static NORETURN void die_async(const char *err, va_list params)
602{
603 vreportf("fatal: ", err, params);
604 if (!pthread_equal(main_thread, pthread_self())) {
606 struct async *async = pthread_getspecific(async_key);
607 if (async->proc_in >= 0)
608 close(async->proc_in);
609 if (async->proc_out >= 0)
610 close(async->proc_out);
611 pthread_exit((void *)128);
612 }
613 exit(128);
615}
616#endif
617int start_async(struct async *async)
619{
620 int need_in, need_out;
621 int fdin[2], fdout[2];
622 int proc_in, proc_out;
623 need_in = async->in < 0;
625 if (need_in) {
626 if (pipe(fdin) < 0) {
627 if (async->out > 0)
628 close(async->out);
629 return error("cannot create pipe: %s", strerror(errno));
630 }
631 async->in = fdin[1];
632 }
633 need_out = async->out < 0;
635 if (need_out) {
636 if (pipe(fdout) < 0) {
637 if (need_in)
638 close_pair(fdin);
639 else if (async->in)
640 close(async->in);
641 return error("cannot create pipe: %s", strerror(errno));
642 }
643 async->out = fdout[0];
644 }
645 if (need_in)
647 proc_in = fdin[0];
648 else if (async->in)
649 proc_in = async->in;
650 else
651 proc_in = -1;
652 if (need_out)
654 proc_out = fdout[1];
655 else if (async->out)
656 proc_out = async->out;
657 else
658 proc_out = -1;
659#ifdef NO_PTHREADS
661 /* Flush stdio before fork() to avoid cloning buffers */
662 fflush(NULL);
663 async->pid = fork();
665 if (async->pid < 0) {
666 error("fork (async) failed: %s", strerror(errno));
667 goto error;
668 }
669 if (!async->pid) {
670 if (need_in)
671 close(fdin[1]);
672 if (need_out)
673 close(fdout[0]);
674 exit(!!async->proc(proc_in, proc_out, async->data));
675 }
676 mark_child_for_cleanup(async->pid);
678 if (need_in)
680 close(fdin[0]);
681 else if (async->in)
682 close(async->in);
683 if (need_out)
685 close(fdout[1]);
686 else if (async->out)
687 close(async->out);
688#else
689 if (!main_thread_set) {
690 /*
691 * We assume that the first time that start_async is called
692 * it is from the main thread.
693 */
694 main_thread_set = 1;
695 main_thread = pthread_self();
696 pthread_key_create(&async_key, NULL);
697 set_die_routine(die_async);
698 }
699 if (proc_in >= 0)
701 set_cloexec(proc_in);
702 if (proc_out >= 0)
703 set_cloexec(proc_out);
704 async->proc_in = proc_in;
705 async->proc_out = proc_out;
706 {
707 int err = pthread_create(&async->tid, NULL, run_thread, async);
708 if (err) {
709 error("cannot create thread: %s", strerror(err));
710 goto error;
711 }
712 }
713#endif
714 return 0;
715error:
717 if (need_in)
718 close_pair(fdin);
719 else if (async->in)
720 close(async->in);
721 if (need_out)
723 close_pair(fdout);
724 else if (async->out)
725 close(async->out);
726 return -1;
727}
728int finish_async(struct async *async)
730{
731#ifdef NO_PTHREADS
732 return wait_or_whine(async->pid, "child process");
733#else
734 void *ret = (void *)(intptr_t)(-1);
735 if (pthread_join(async->tid, &ret))
737 error("pthread_join failed");
738 return (int)(intptr_t)ret;
739#endif
740}
741char *find_hook(const char *name)
743{
744 char *path = git_path("hooks/%s", name);
745 if (access(path, X_OK) < 0)
746 path = NULL;
747 return path;
749}
750int run_hook(const char *index_file, const char *name, ...)
752{
753 struct child_process hook;
754 struct argv_array argv = ARGV_ARRAY_INIT;
755 const char *p, *env[2];
756 char index[PATH_MAX];
757 va_list args;
758 int ret;
759 p = find_hook(name);
761 if (!p)
762 return 0;
763 argv_array_push(&argv, p);
765 va_start(args, name);
767 while ((p = va_arg(args, const char *)))
768 argv_array_push(&argv, p);
769 va_end(args);
770 memset(&hook, 0, sizeof(hook));
772 hook.argv = argv.argv;
773 hook.no_stdin = 1;
774 hook.stdout_to_stderr = 1;
775 if (index_file) {
776 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
777 env[0] = index;
778 env[1] = NULL;
779 hook.env = env;
780 }
781 ret = run_command(&hook);
783 argv_array_clear(&argv);
784 return ret;
785}