1#include "cache.h"
2#include "run-command.h"
3#include "exec_cmd.h"
4static inline void close_pair(int fd[2])
6{
7 close(fd[0]);
8 close(fd[1]);
9}
10#ifndef WIN32
12static inline void dup_devnull(int to)
13{
14 int fd = open("/dev/null", O_RDWR);
15 dup2(fd, to);
16 close(fd);
17}
18#endif
19static const char **prepare_shell_cmd(const char **argv)
21{
22 int argc, nargc = 0;
23 const char **nargv;
24 for (argc = 0; argv[argc]; argc++)
26 ; /* just counting */
27 /* +1 for NULL, +3 for "sh -c" plus extra $0 */
28 nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
29 if (argc < 1)
31 die("BUG: shell command is empty");
32 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
34 nargv[nargc++] = "sh";
35 nargv[nargc++] = "-c";
36 if (argc < 2)
38 nargv[nargc++] = argv[0];
39 else {
40 struct strbuf arg0 = STRBUF_INIT;
41 strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
42 nargv[nargc++] = strbuf_detach(&arg0, NULL);
43 }
44 }
45 for (argc = 0; argv[argc]; argc++)
47 nargv[nargc++] = argv[argc];
48 nargv[nargc] = NULL;
49 return nargv;
51}
52#ifndef WIN32
54static int execv_shell_cmd(const char **argv)
55{
56 const char **nargv = prepare_shell_cmd(argv);
57 trace_argv_printf(nargv, "trace: exec:");
58 execvp(nargv[0], (char **)nargv);
59 free(nargv);
60 return -1;
61}
62#endif
63#ifndef WIN32
65static int child_err = 2;
66static int child_notifier = -1;
67static void notify_parent(void)
69{
70 /*
71 * execvp failed. If possible, we'd like to let start_command
72 * know, so failures like ENOENT can be handled right away; but
73 * otherwise, finish_command will still report the error.
74 */
75 xwrite(child_notifier, "", 1);
76}
77static NORETURN void die_child(const char *err, va_list params)
79{
80 char msg[4096];
81 int len = vsnprintf(msg, sizeof(msg), err, params);
82 if (len > sizeof(msg))
83 len = sizeof(msg);
84 write_in_full(child_err, "fatal: ", 7);
86 write_in_full(child_err, msg, len);
87 write_in_full(child_err, "\n", 1);
88 exit(128);
89}
90#endif
91static inline void set_cloexec(int fd)
93{
94 int flags = fcntl(fd, F_GETFD);
95 if (flags >= 0)
96 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
97}
98static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
100{
101 int status, code = -1;
102 pid_t waiting;
103 int failed_errno = 0;
104 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
106 ; /* nothing */
107 if (waiting < 0) {
109 failed_errno = errno;
110 error("waitpid for %s failed: %s", argv0, strerror(errno));
111 } else if (waiting != pid) {
112 error("waitpid is confused (%s)", argv0);
113 } else if (WIFSIGNALED(status)) {
114 code = WTERMSIG(status);
115 error("%s died of signal %d", argv0, code);
116 /*
117 * This return value is chosen so that code & 0xff
118 * mimics the exit code that a POSIX shell would report for
119 * a program that died from this signal.
120 */
121 code -= 128;
122 } else if (WIFEXITED(status)) {
123 code = WEXITSTATUS(status);
124 /*
125 * Convert special exit code when execvp failed.
126 */
127 if (code == 127) {
128 code = -1;
129 failed_errno = ENOENT;
130 if (!silent_exec_failure)
131 error("cannot run %s: %s", argv0,
132 strerror(ENOENT));
133 }
134 } else {
135 error("waitpid is confused (%s)", argv0);
136 }
137 errno = failed_errno;
138 return code;
139}
140int start_command(struct child_process *cmd)
142{
143 int need_in, need_out, need_err;
144 int fdin[2], fdout[2], fderr[2];
145 int failed_errno = failed_errno;
146 /*
148 * In case of errors we must keep the promise to close FDs
149 * that have been passed in via ->in and ->out.
150 */
151 need_in = !cmd->no_stdin && cmd->in < 0;
153 if (need_in) {
154 if (pipe(fdin) < 0) {
155 failed_errno = errno;
156 if (cmd->out > 0)
157 close(cmd->out);
158 goto fail_pipe;
159 }
160 cmd->in = fdin[1];
161 }
162 need_out = !cmd->no_stdout
164 && !cmd->stdout_to_stderr
165 && cmd->out < 0;
166 if (need_out) {
167 if (pipe(fdout) < 0) {
168 failed_errno = errno;
169 if (need_in)
170 close_pair(fdin);
171 else if (cmd->in)
172 close(cmd->in);
173 goto fail_pipe;
174 }
175 cmd->out = fdout[0];
176 }
177 need_err = !cmd->no_stderr && cmd->err < 0;
179 if (need_err) {
180 if (pipe(fderr) < 0) {
181 failed_errno = errno;
182 if (need_in)
183 close_pair(fdin);
184 else if (cmd->in)
185 close(cmd->in);
186 if (need_out)
187 close_pair(fdout);
188 else if (cmd->out)
189 close(cmd->out);
190fail_pipe:
191 error("cannot create pipe for %s: %s",
192 cmd->argv[0], strerror(failed_errno));
193 errno = failed_errno;
194 return -1;
195 }
196 cmd->err = fderr[0];
197 }
198 trace_argv_printf(cmd->argv, "trace: run_command:");
200 fflush(NULL);
201#ifndef WIN32
203{
204 int notify_pipe[2];
205 if (pipe(notify_pipe))
206 notify_pipe[0] = notify_pipe[1] = -1;
207 cmd->pid = fork();
209 if (!cmd->pid) {
210 /*
211 * Redirect the channel to write syscall error messages to
212 * before redirecting the process's stderr so that all die()
213 * in subsequent call paths use the parent's stderr.
214 */
215 if (cmd->no_stderr || need_err) {
216 child_err = dup(2);
217 set_cloexec(child_err);
218 }
219 set_die_routine(die_child);
220 close(notify_pipe[0]);
222 set_cloexec(notify_pipe[1]);
223 child_notifier = notify_pipe[1];
224 atexit(notify_parent);
225 if (cmd->no_stdin)
227 dup_devnull(0);
228 else if (need_in) {
229 dup2(fdin[0], 0);
230 close_pair(fdin);
231 } else if (cmd->in) {
232 dup2(cmd->in, 0);
233 close(cmd->in);
234 }
235 if (cmd->no_stderr)
237 dup_devnull(2);
238 else if (need_err) {
239 dup2(fderr[1], 2);
240 close_pair(fderr);
241 } else if (cmd->err > 1) {
242 dup2(cmd->err, 2);
243 close(cmd->err);
244 }
245 if (cmd->no_stdout)
247 dup_devnull(1);
248 else if (cmd->stdout_to_stderr)
249 dup2(2, 1);
250 else if (need_out) {
251 dup2(fdout[1], 1);
252 close_pair(fdout);
253 } else if (cmd->out > 1) {
254 dup2(cmd->out, 1);
255 close(cmd->out);
256 }
257 if (cmd->dir && chdir(cmd->dir))
259 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
260 cmd->dir);
261 if (cmd->env) {
262 for (; *cmd->env; cmd->env++) {
263 if (strchr(*cmd->env, '='))
264 putenv((char *)*cmd->env);
265 else
266 unsetenv(*cmd->env);
267 }
268 }
269 if (cmd->preexec_cb) {
270 /*
271 * We cannot predict what the pre-exec callback does.
272 * Forgo parent notification.
273 */
274 close(child_notifier);
275 child_notifier = -1;
276 cmd->preexec_cb();
278 }
279 if (cmd->git_cmd) {
280 execv_git_cmd(cmd->argv);
281 } else if (cmd->use_shell) {
282 execv_shell_cmd(cmd->argv);
283 } else {
284 execvp(cmd->argv[0], (char *const*) cmd->argv);
285 }
286 /*
287 * Do not check for cmd->silent_exec_failure; the parent
288 * process will check it when it sees this exit code.
289 */
290 if (errno == ENOENT)
291 exit(127);
292 else
293 die_errno("cannot exec '%s'", cmd->argv[0]);
294 }
295 if (cmd->pid < 0)
296 error("cannot fork() for %s: %s", cmd->argv[0],
297 strerror(failed_errno = errno));
298 /*
300 * Wait for child's execvp. If the execvp succeeds (or if fork()
301 * failed), EOF is seen immediately by the parent. Otherwise, the
302 * child process sends a single byte.
303 * Note that use of this infrastructure is completely advisory,
304 * therefore, we keep error checks minimal.
305 */
306 close(notify_pipe[1]);
307 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
308 /*
309 * At this point we know that fork() succeeded, but execvp()
310 * failed. Errors have been reported to our stderr.
311 */
312 wait_or_whine(cmd->pid, cmd->argv[0],
313 cmd->silent_exec_failure);
314 failed_errno = errno;
315 cmd->pid = -1;
316 }
317 close(notify_pipe[0]);
318}
319#else
320{
321 int fhin = 0, fhout = 1, fherr = 2;
322 const char **sargv = cmd->argv;
323 char **env = environ;
324 if (cmd->no_stdin)
326 fhin = open("/dev/null", O_RDWR);
327 else if (need_in)
328 fhin = dup(fdin[0]);
329 else if (cmd->in)
330 fhin = dup(cmd->in);
331 if (cmd->no_stderr)
333 fherr = open("/dev/null", O_RDWR);
334 else if (need_err)
335 fherr = dup(fderr[1]);
336 else if (cmd->err > 2)
337 fherr = dup(cmd->err);
338 if (cmd->no_stdout)
340 fhout = open("/dev/null", O_RDWR);
341 else if (cmd->stdout_to_stderr)
342 fhout = dup(fherr);
343 else if (need_out)
344 fhout = dup(fdout[1]);
345 else if (cmd->out > 1)
346 fhout = dup(cmd->out);
347 if (cmd->env)
349 env = make_augmented_environ(cmd->env);
350 if (cmd->git_cmd) {
352 cmd->argv = prepare_git_cmd(cmd->argv);
353 } else if (cmd->use_shell) {
354 cmd->argv = prepare_shell_cmd(cmd->argv);
355 }
356 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
358 fhin, fhout, fherr);
359 failed_errno = errno;
360 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
361 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
362 if (cmd->env)
364 free_environ(env);
365 if (cmd->git_cmd)
366 free(cmd->argv);
367 cmd->argv = sargv;
369 if (fhin != 0)
370 close(fhin);
371 if (fhout != 1)
372 close(fhout);
373 if (fherr != 2)
374 close(fherr);
375}
376#endif
377 if (cmd->pid < 0) {
379 if (need_in)
380 close_pair(fdin);
381 else if (cmd->in)
382 close(cmd->in);
383 if (need_out)
384 close_pair(fdout);
385 else if (cmd->out)
386 close(cmd->out);
387 if (need_err)
388 close_pair(fderr);
389 else if (cmd->err)
390 close(cmd->err);
391 errno = failed_errno;
392 return -1;
393 }
394 if (need_in)
396 close(fdin[0]);
397 else if (cmd->in)
398 close(cmd->in);
399 if (need_out)
401 close(fdout[1]);
402 else if (cmd->out)
403 close(cmd->out);
404 if (need_err)
406 close(fderr[1]);
407 else if (cmd->err)
408 close(cmd->err);
409 return 0;
411}
412int finish_command(struct child_process *cmd)
414{
415 return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
416}
417int run_command(struct child_process *cmd)
419{
420 int code = start_command(cmd);
421 if (code)
422 return code;
423 return finish_command(cmd);
424}
425static void prepare_run_command_v_opt(struct child_process *cmd,
427 const char **argv,
428 int opt)
429{
430 memset(cmd, 0, sizeof(*cmd));
431 cmd->argv = argv;
432 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
433 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
434 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
435 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
436 cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
437}
438int run_command_v_opt(const char **argv, int opt)
440{
441 struct child_process cmd;
442 prepare_run_command_v_opt(&cmd, argv, opt);
443 return run_command(&cmd);
444}
445int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
447{
448 struct child_process cmd;
449 prepare_run_command_v_opt(&cmd, argv, opt);
450 cmd.dir = dir;
451 cmd.env = env;
452 return run_command(&cmd);
453}
454#ifndef NO_PTHREADS
456static pthread_t main_thread;
457static int main_thread_set;
458static pthread_key_t async_key;
459static void *run_thread(void *data)
461{
462 struct async *async = data;
463 intptr_t ret;
464 pthread_setspecific(async_key, async);
466 ret = async->proc(async->proc_in, async->proc_out, async->data);
467 return (void *)ret;
468}
469static NORETURN void die_async(const char *err, va_list params)
471{
472 vreportf("fatal: ", err, params);
473 if (!pthread_equal(main_thread, pthread_self())) {
475 struct async *async = pthread_getspecific(async_key);
476 if (async->proc_in >= 0)
477 close(async->proc_in);
478 if (async->proc_out >= 0)
479 close(async->proc_out);
480 pthread_exit((void *)128);
481 }
482 exit(128);
484}
485#endif
486int start_async(struct async *async)
488{
489 int need_in, need_out;
490 int fdin[2], fdout[2];
491 int proc_in, proc_out;
492 need_in = async->in < 0;
494 if (need_in) {
495 if (pipe(fdin) < 0) {
496 if (async->out > 0)
497 close(async->out);
498 return error("cannot create pipe: %s", strerror(errno));
499 }
500 async->in = fdin[1];
501 }
502 need_out = async->out < 0;
504 if (need_out) {
505 if (pipe(fdout) < 0) {
506 if (need_in)
507 close_pair(fdin);
508 else if (async->in)
509 close(async->in);
510 return error("cannot create pipe: %s", strerror(errno));
511 }
512 async->out = fdout[0];
513 }
514 if (need_in)
516 proc_in = fdin[0];
517 else if (async->in)
518 proc_in = async->in;
519 else
520 proc_in = -1;
521 if (need_out)
523 proc_out = fdout[1];
524 else if (async->out)
525 proc_out = async->out;
526 else
527 proc_out = -1;
528#ifdef NO_PTHREADS
530 /* Flush stdio before fork() to avoid cloning buffers */
531 fflush(NULL);
532 async->pid = fork();
534 if (async->pid < 0) {
535 error("fork (async) failed: %s", strerror(errno));
536 goto error;
537 }
538 if (!async->pid) {
539 if (need_in)
540 close(fdin[1]);
541 if (need_out)
542 close(fdout[0]);
543 exit(!!async->proc(proc_in, proc_out, async->data));
544 }
545 if (need_in)
547 close(fdin[0]);
548 else if (async->in)
549 close(async->in);
550 if (need_out)
552 close(fdout[1]);
553 else if (async->out)
554 close(async->out);
555#else
556 if (!main_thread_set) {
557 /*
558 * We assume that the first time that start_async is called
559 * it is from the main thread.
560 */
561 main_thread_set = 1;
562 main_thread = pthread_self();
563 pthread_key_create(&async_key, NULL);
564 set_die_routine(die_async);
565 }
566 if (proc_in >= 0)
568 set_cloexec(proc_in);
569 if (proc_out >= 0)
570 set_cloexec(proc_out);
571 async->proc_in = proc_in;
572 async->proc_out = proc_out;
573 {
574 int err = pthread_create(&async->tid, NULL, run_thread, async);
575 if (err) {
576 error("cannot create thread: %s", strerror(err));
577 goto error;
578 }
579 }
580#endif
581 return 0;
582error:
584 if (need_in)
585 close_pair(fdin);
586 else if (async->in)
587 close(async->in);
588 if (need_out)
590 close_pair(fdout);
591 else if (async->out)
592 close(async->out);
593 return -1;
594}
595int finish_async(struct async *async)
597{
598#ifdef NO_PTHREADS
599 return wait_or_whine(async->pid, "child process", 0);
600#else
601 void *ret = (void *)(intptr_t)(-1);
602 if (pthread_join(async->tid, &ret))
604 error("pthread_join failed");
605 return (int)(intptr_t)ret;
606#endif
607}
608int run_hook(const char *index_file, const char *name, ...)
610{
611 struct child_process hook;
612 const char **argv = NULL, *env[2];
613 char index[PATH_MAX];
614 va_list args;
615 int ret;
616 size_t i = 0, alloc = 0;
617 if (access(git_path("hooks/%s", name), X_OK) < 0)
619 return 0;
620 va_start(args, name);
622 ALLOC_GROW(argv, i + 1, alloc);
623 argv[i++] = git_path("hooks/%s", name);
624 while (argv[i-1]) {
625 ALLOC_GROW(argv, i + 1, alloc);
626 argv[i++] = va_arg(args, const char *);
627 }
628 va_end(args);
629 memset(&hook, 0, sizeof(hook));
631 hook.argv = argv;
632 hook.no_stdin = 1;
633 hook.stdout_to_stderr = 1;
634 if (index_file) {
635 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
636 env[0] = index;
637 env[1] = NULL;
638 hook.env = env;
639 }
640 ret = run_command(&hook);
642 free(argv);
643 return ret;
644}