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 if (write(child_notifier, "", 1))
76 ; /* yes, dear gcc -D_FORTIFY_SOURCE, there was an error. */
77}
78static NORETURN void die_child(const char *err, va_list params)
80{
81 char msg[4096];
82 int len = vsnprintf(msg, sizeof(msg), err, params);
83 if (len > sizeof(msg))
84 len = sizeof(msg);
85 if (write(child_err, "fatal: ", 7) ||
87 write(child_err, msg, len) ||
88 write(child_err, "\n", 1))
89 ; /* yes, gcc -D_FORTIFY_SOURCE, we know there was an error. */
90 exit(128);
91}
92#endif
93static inline void set_cloexec(int fd)
95{
96 int flags = fcntl(fd, F_GETFD);
97 if (flags >= 0)
98 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
99}
100static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
102{
103 int status, code = -1;
104 pid_t waiting;
105 int failed_errno = 0;
106 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
108 ; /* nothing */
109 if (waiting < 0) {
111 failed_errno = errno;
112 error("waitpid for %s failed: %s", argv0, strerror(errno));
113 } else if (waiting != pid) {
114 error("waitpid is confused (%s)", argv0);
115 } else if (WIFSIGNALED(status)) {
116 code = WTERMSIG(status);
117 error("%s died of signal %d", argv0, code);
118 /*
119 * This return value is chosen so that code & 0xff
120 * mimics the exit code that a POSIX shell would report for
121 * a program that died from this signal.
122 */
123 code -= 128;
124 } else if (WIFEXITED(status)) {
125 code = WEXITSTATUS(status);
126 /*
127 * Convert special exit code when execvp failed.
128 */
129 if (code == 127) {
130 code = -1;
131 failed_errno = ENOENT;
132 if (!silent_exec_failure)
133 error("cannot run %s: %s", argv0,
134 strerror(ENOENT));
135 }
136 } else {
137 error("waitpid is confused (%s)", argv0);
138 }
139 errno = failed_errno;
140 return code;
141}
142int start_command(struct child_process *cmd)
144{
145 int need_in, need_out, need_err;
146 int fdin[2], fdout[2], fderr[2];
147 int failed_errno = failed_errno;
148 /*
150 * In case of errors we must keep the promise to close FDs
151 * that have been passed in via ->in and ->out.
152 */
153 need_in = !cmd->no_stdin && cmd->in < 0;
155 if (need_in) {
156 if (pipe(fdin) < 0) {
157 failed_errno = errno;
158 if (cmd->out > 0)
159 close(cmd->out);
160 goto fail_pipe;
161 }
162 cmd->in = fdin[1];
163 }
164 need_out = !cmd->no_stdout
166 && !cmd->stdout_to_stderr
167 && cmd->out < 0;
168 if (need_out) {
169 if (pipe(fdout) < 0) {
170 failed_errno = errno;
171 if (need_in)
172 close_pair(fdin);
173 else if (cmd->in)
174 close(cmd->in);
175 goto fail_pipe;
176 }
177 cmd->out = fdout[0];
178 }
179 need_err = !cmd->no_stderr && cmd->err < 0;
181 if (need_err) {
182 if (pipe(fderr) < 0) {
183 failed_errno = errno;
184 if (need_in)
185 close_pair(fdin);
186 else if (cmd->in)
187 close(cmd->in);
188 if (need_out)
189 close_pair(fdout);
190 else if (cmd->out)
191 close(cmd->out);
192fail_pipe:
193 error("cannot create pipe for %s: %s",
194 cmd->argv[0], strerror(failed_errno));
195 errno = failed_errno;
196 return -1;
197 }
198 cmd->err = fderr[0];
199 }
200 trace_argv_printf(cmd->argv, "trace: run_command:");
202 fflush(NULL);
203#ifndef WIN32
205{
206 int notify_pipe[2];
207 if (pipe(notify_pipe))
208 notify_pipe[0] = notify_pipe[1] = -1;
209 cmd->pid = fork();
211 if (!cmd->pid) {
212 /*
213 * Redirect the channel to write syscall error messages to
214 * before redirecting the process's stderr so that all die()
215 * in subsequent call paths use the parent's stderr.
216 */
217 if (cmd->no_stderr || need_err) {
218 child_err = dup(2);
219 set_cloexec(child_err);
220 }
221 set_die_routine(die_child);
222 close(notify_pipe[0]);
224 set_cloexec(notify_pipe[1]);
225 child_notifier = notify_pipe[1];
226 atexit(notify_parent);
227 if (cmd->no_stdin)
229 dup_devnull(0);
230 else if (need_in) {
231 dup2(fdin[0], 0);
232 close_pair(fdin);
233 } else if (cmd->in) {
234 dup2(cmd->in, 0);
235 close(cmd->in);
236 }
237 if (cmd->no_stderr)
239 dup_devnull(2);
240 else if (need_err) {
241 dup2(fderr[1], 2);
242 close_pair(fderr);
243 } else if (cmd->err > 1) {
244 dup2(cmd->err, 2);
245 close(cmd->err);
246 }
247 if (cmd->no_stdout)
249 dup_devnull(1);
250 else if (cmd->stdout_to_stderr)
251 dup2(2, 1);
252 else if (need_out) {
253 dup2(fdout[1], 1);
254 close_pair(fdout);
255 } else if (cmd->out > 1) {
256 dup2(cmd->out, 1);
257 close(cmd->out);
258 }
259 if (cmd->dir && chdir(cmd->dir))
261 die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
262 cmd->dir);
263 if (cmd->env) {
264 for (; *cmd->env; cmd->env++) {
265 if (strchr(*cmd->env, '='))
266 putenv((char *)*cmd->env);
267 else
268 unsetenv(*cmd->env);
269 }
270 }
271 if (cmd->preexec_cb) {
272 /*
273 * We cannot predict what the pre-exec callback does.
274 * Forgo parent notification.
275 */
276 close(child_notifier);
277 child_notifier = -1;
278 cmd->preexec_cb();
280 }
281 if (cmd->git_cmd) {
282 execv_git_cmd(cmd->argv);
283 } else if (cmd->use_shell) {
284 execv_shell_cmd(cmd->argv);
285 } else {
286 execvp(cmd->argv[0], (char *const*) cmd->argv);
287 }
288 /*
289 * Do not check for cmd->silent_exec_failure; the parent
290 * process will check it when it sees this exit code.
291 */
292 if (errno == ENOENT)
293 exit(127);
294 else
295 die_errno("cannot exec '%s'", cmd->argv[0]);
296 }
297 if (cmd->pid < 0)
298 error("cannot fork() for %s: %s", cmd->argv[0],
299 strerror(failed_errno = errno));
300 /*
302 * Wait for child's execvp. If the execvp succeeds (or if fork()
303 * failed), EOF is seen immediately by the parent. Otherwise, the
304 * child process sends a single byte.
305 * Note that use of this infrastructure is completely advisory,
306 * therefore, we keep error checks minimal.
307 */
308 close(notify_pipe[1]);
309 if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) {
310 /*
311 * At this point we know that fork() succeeded, but execvp()
312 * failed. Errors have been reported to our stderr.
313 */
314 wait_or_whine(cmd->pid, cmd->argv[0],
315 cmd->silent_exec_failure);
316 failed_errno = errno;
317 cmd->pid = -1;
318 }
319 close(notify_pipe[0]);
320}
321#else
322{
323 int fhin = 0, fhout = 1, fherr = 2;
324 const char **sargv = cmd->argv;
325 char **env = environ;
326 if (cmd->no_stdin)
328 fhin = open("/dev/null", O_RDWR);
329 else if (need_in)
330 fhin = dup(fdin[0]);
331 else if (cmd->in)
332 fhin = dup(cmd->in);
333 if (cmd->no_stderr)
335 fherr = open("/dev/null", O_RDWR);
336 else if (need_err)
337 fherr = dup(fderr[1]);
338 else if (cmd->err > 2)
339 fherr = dup(cmd->err);
340 if (cmd->no_stdout)
342 fhout = open("/dev/null", O_RDWR);
343 else if (cmd->stdout_to_stderr)
344 fhout = dup(fherr);
345 else if (need_out)
346 fhout = dup(fdout[1]);
347 else if (cmd->out > 1)
348 fhout = dup(cmd->out);
349 if (cmd->env)
351 env = make_augmented_environ(cmd->env);
352 if (cmd->git_cmd) {
354 cmd->argv = prepare_git_cmd(cmd->argv);
355 } else if (cmd->use_shell) {
356 cmd->argv = prepare_shell_cmd(cmd->argv);
357 }
358 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
360 fhin, fhout, fherr);
361 failed_errno = errno;
362 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
363 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
364 if (cmd->env)
366 free_environ(env);
367 if (cmd->git_cmd)
368 free(cmd->argv);
369 cmd->argv = sargv;
371 if (fhin != 0)
372 close(fhin);
373 if (fhout != 1)
374 close(fhout);
375 if (fherr != 2)
376 close(fherr);
377}
378#endif
379 if (cmd->pid < 0) {
381 if (need_in)
382 close_pair(fdin);
383 else if (cmd->in)
384 close(cmd->in);
385 if (need_out)
386 close_pair(fdout);
387 else if (cmd->out)
388 close(cmd->out);
389 if (need_err)
390 close_pair(fderr);
391 else if (cmd->err)
392 close(cmd->err);
393 errno = failed_errno;
394 return -1;
395 }
396 if (need_in)
398 close(fdin[0]);
399 else if (cmd->in)
400 close(cmd->in);
401 if (need_out)
403 close(fdout[1]);
404 else if (cmd->out)
405 close(cmd->out);
406 if (need_err)
408 close(fderr[1]);
409 else if (cmd->err)
410 close(cmd->err);
411 return 0;
413}
414int finish_command(struct child_process *cmd)
416{
417 return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
418}
419int run_command(struct child_process *cmd)
421{
422 int code = start_command(cmd);
423 if (code)
424 return code;
425 return finish_command(cmd);
426}
427static void prepare_run_command_v_opt(struct child_process *cmd,
429 const char **argv,
430 int opt)
431{
432 memset(cmd, 0, sizeof(*cmd));
433 cmd->argv = argv;
434 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
435 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
436 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
437 cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
438 cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
439}
440int run_command_v_opt(const char **argv, int opt)
442{
443 struct child_process cmd;
444 prepare_run_command_v_opt(&cmd, argv, opt);
445 return run_command(&cmd);
446}
447int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
449{
450 struct child_process cmd;
451 prepare_run_command_v_opt(&cmd, argv, opt);
452 cmd.dir = dir;
453 cmd.env = env;
454 return run_command(&cmd);
455}
456#ifndef NO_PTHREADS
458static pthread_t main_thread;
459static int main_thread_set;
460static pthread_key_t async_key;
461static void *run_thread(void *data)
463{
464 struct async *async = data;
465 intptr_t ret;
466 pthread_setspecific(async_key, async);
468 ret = async->proc(async->proc_in, async->proc_out, async->data);
469 return (void *)ret;
470}
471static NORETURN void die_async(const char *err, va_list params)
473{
474 vreportf("fatal: ", err, params);
475 if (!pthread_equal(main_thread, pthread_self())) {
477 struct async *async = pthread_getspecific(async_key);
478 if (async->proc_in >= 0)
479 close(async->proc_in);
480 if (async->proc_out >= 0)
481 close(async->proc_out);
482 pthread_exit((void *)128);
483 }
484 exit(128);
486}
487#endif
488int start_async(struct async *async)
490{
491 int need_in, need_out;
492 int fdin[2], fdout[2];
493 int proc_in, proc_out;
494 need_in = async->in < 0;
496 if (need_in) {
497 if (pipe(fdin) < 0) {
498 if (async->out > 0)
499 close(async->out);
500 return error("cannot create pipe: %s", strerror(errno));
501 }
502 async->in = fdin[1];
503 }
504 need_out = async->out < 0;
506 if (need_out) {
507 if (pipe(fdout) < 0) {
508 if (need_in)
509 close_pair(fdin);
510 else if (async->in)
511 close(async->in);
512 return error("cannot create pipe: %s", strerror(errno));
513 }
514 async->out = fdout[0];
515 }
516 if (need_in)
518 proc_in = fdin[0];
519 else if (async->in)
520 proc_in = async->in;
521 else
522 proc_in = -1;
523 if (need_out)
525 proc_out = fdout[1];
526 else if (async->out)
527 proc_out = async->out;
528 else
529 proc_out = -1;
530#ifdef NO_PTHREADS
532 /* Flush stdio before fork() to avoid cloning buffers */
533 fflush(NULL);
534 async->pid = fork();
536 if (async->pid < 0) {
537 error("fork (async) failed: %s", strerror(errno));
538 goto error;
539 }
540 if (!async->pid) {
541 if (need_in)
542 close(fdin[1]);
543 if (need_out)
544 close(fdout[0]);
545 exit(!!async->proc(proc_in, proc_out, async->data));
546 }
547 if (need_in)
549 close(fdin[0]);
550 else if (async->in)
551 close(async->in);
552 if (need_out)
554 close(fdout[1]);
555 else if (async->out)
556 close(async->out);
557#else
558 if (!main_thread_set) {
559 /*
560 * We assume that the first time that start_async is called
561 * it is from the main thread.
562 */
563 main_thread_set = 1;
564 main_thread = pthread_self();
565 pthread_key_create(&async_key, NULL);
566 set_die_routine(die_async);
567 }
568 if (proc_in >= 0)
570 set_cloexec(proc_in);
571 if (proc_out >= 0)
572 set_cloexec(proc_out);
573 async->proc_in = proc_in;
574 async->proc_out = proc_out;
575 {
576 int err = pthread_create(&async->tid, NULL, run_thread, async);
577 if (err) {
578 error("cannot create thread: %s", strerror(err));
579 goto error;
580 }
581 }
582#endif
583 return 0;
584error:
586 if (need_in)
587 close_pair(fdin);
588 else if (async->in)
589 close(async->in);
590 if (need_out)
592 close_pair(fdout);
593 else if (async->out)
594 close(async->out);
595 return -1;
596}
597int finish_async(struct async *async)
599{
600#ifdef NO_PTHREADS
601 return wait_or_whine(async->pid, "child process", 0);
602#else
603 void *ret = (void *)(intptr_t)(-1);
604 if (pthread_join(async->tid, &ret))
606 error("pthread_join failed");
607 return (int)(intptr_t)ret;
608#endif
609}
610int run_hook(const char *index_file, const char *name, ...)
612{
613 struct child_process hook;
614 const char **argv = NULL, *env[2];
615 char index[PATH_MAX];
616 va_list args;
617 int ret;
618 size_t i = 0, alloc = 0;
619 if (access(git_path("hooks/%s", name), X_OK) < 0)
621 return 0;
622 va_start(args, name);
624 ALLOC_GROW(argv, i + 1, alloc);
625 argv[i++] = git_path("hooks/%s", name);
626 while (argv[i-1]) {
627 ALLOC_GROW(argv, i + 1, alloc);
628 argv[i++] = va_arg(args, const char *);
629 }
630 va_end(args);
631 memset(&hook, 0, sizeof(hook));
633 hook.argv = argv;
634 hook.no_stdin = 1;
635 hook.stdout_to_stderr = 1;
636 if (index_file) {
637 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
638 env[0] = index;
639 env[1] = NULL;
640 hook.env = env;
641 }
642 ret = run_command(&hook);
644 free(argv);
645 return ret;
646}