diff options
Diffstat (limited to 'run-command.c')
| -rw-r--r-- | run-command.c | 797 |
1 files changed, 797 insertions, 0 deletions
diff --git a/run-command.c b/run-command.c new file mode 100644 index 0000000000..1b32a12a29 --- /dev/null +++ b/run-command.c @@ -0,0 +1,797 @@ +#include "cache.h" +#include "run-command.h" +#include "exec_cmd.h" +#include "sigchain.h" +#include "argv-array.h" + +#ifndef SHELL_PATH +# define SHELL_PATH "/bin/sh" +#endif + +struct child_to_clean { + pid_t pid; + struct child_to_clean *next; +}; +static struct child_to_clean *children_to_clean; +static int installed_child_cleanup_handler; + +static void cleanup_children(int sig) +{ + while (children_to_clean) { + struct child_to_clean *p = children_to_clean; + children_to_clean = p->next; + kill(p->pid, sig); + free(p); + } +} + +static void cleanup_children_on_signal(int sig) +{ + cleanup_children(sig); + sigchain_pop(sig); + raise(sig); +} + +static void cleanup_children_on_exit(void) +{ + cleanup_children(SIGTERM); +} + +static void mark_child_for_cleanup(pid_t pid) +{ + struct child_to_clean *p = xmalloc(sizeof(*p)); + p->pid = pid; + p->next = children_to_clean; + children_to_clean = p; + + if (!installed_child_cleanup_handler) { + atexit(cleanup_children_on_exit); + sigchain_push_common(cleanup_children_on_signal); + installed_child_cleanup_handler = 1; + } +} + +static void clear_child_for_cleanup(pid_t pid) +{ + struct child_to_clean **pp; + + for (pp = &children_to_clean; *pp; pp = &(*pp)->next) { + struct child_to_clean *clean_me = *pp; + + if (clean_me->pid == pid) { + *pp = clean_me->next; + free(clean_me); + return; + } + } +} + +static inline void close_pair(int fd[2]) +{ + close(fd[0]); + close(fd[1]); +} + +#ifndef WIN32 +static inline void dup_devnull(int to) +{ + int fd = open("/dev/null", O_RDWR); + dup2(fd, to); + close(fd); +} +#endif + +static char *locate_in_PATH(const char *file) +{ + const char *p = getenv("PATH"); + struct strbuf buf = STRBUF_INIT; + + if (!p || !*p) + return NULL; + + while (1) { + const char *end = strchrnul(p, ':'); + + strbuf_reset(&buf); + + /* POSIX specifies an empty entry as the current directory. */ + if (end != p) { + strbuf_add(&buf, p, end - p); + strbuf_addch(&buf, '/'); + } + strbuf_addstr(&buf, file); + + if (!access(buf.buf, F_OK)) + return strbuf_detach(&buf, NULL); + + if (!*end) + break; + p = end + 1; + } + + strbuf_release(&buf); + return NULL; +} + +static int exists_in_PATH(const char *file) +{ + char *r = locate_in_PATH(file); + free(r); + return r != NULL; +} + +int sane_execvp(const char *file, char * const argv[]) +{ + if (!execvp(file, argv)) + return 0; /* cannot happen ;-) */ + + /* + * When a command can't be found because one of the directories + * listed in $PATH is unsearchable, execvp reports EACCES, but + * careful usability testing (read: analysis of occasional bug + * reports) reveals that "No such file or directory" is more + * intuitive. + * + * We avoid commands with "/", because execvp will not do $PATH + * lookups in that case. + * + * The reassignment of EACCES to errno looks like a no-op below, + * but we need to protect against exists_in_PATH overwriting errno. + */ + if (errno == EACCES && !strchr(file, '/')) + errno = exists_in_PATH(file) ? EACCES : ENOENT; + else if (errno == ENOTDIR && !strchr(file, '/')) + errno = ENOENT; + return -1; +} + +static const char **prepare_shell_cmd(const char **argv) +{ + int argc, nargc = 0; + const char **nargv; + + for (argc = 0; argv[argc]; argc++) + ; /* just counting */ + /* +1 for NULL, +3 for "sh -c" plus extra $0 */ + nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3)); + + if (argc < 1) + die("BUG: shell command is empty"); + + if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) { +#ifndef WIN32 + nargv[nargc++] = SHELL_PATH; +#else + nargv[nargc++] = "sh"; +#endif + nargv[nargc++] = "-c"; + + if (argc < 2) + nargv[nargc++] = argv[0]; + else { + struct strbuf arg0 = STRBUF_INIT; + strbuf_addf(&arg0, "%s \"$@\"", argv[0]); + nargv[nargc++] = strbuf_detach(&arg0, NULL); + } + } + + for (argc = 0; argv[argc]; argc++) + nargv[nargc++] = argv[argc]; + nargv[nargc] = NULL; + + return nargv; +} + +#ifndef WIN32 +static int execv_shell_cmd(const char **argv) +{ + const char **nargv = prepare_shell_cmd(argv); + trace_argv_printf(nargv, "trace: exec:"); + sane_execvp(nargv[0], (char **)nargv); + free(nargv); + return -1; +} +#endif + +#ifndef WIN32 +static int child_err = 2; +static int child_notifier = -1; + +static void notify_parent(void) +{ + /* + * execvp failed. If possible, we'd like to let start_command + * know, so failures like ENOENT can be handled right away; but + * otherwise, finish_command will still report the error. + */ + xwrite(child_notifier, "", 1); +} + +static NORETURN void die_child(const char *err, va_list params) +{ + vwritef(child_err, "fatal: ", err, params); + exit(128); +} + +static void error_child(const char *err, va_list params) +{ + vwritef(child_err, "error: ", err, params); +} +#endif + +static inline void set_cloexec(int fd) +{ + int flags = fcntl(fd, F_GETFD); + if (flags >= 0) + fcntl(fd, F_SETFD, flags | FD_CLOEXEC); +} + +static int wait_or_whine(pid_t pid, const char *argv0) +{ + int status, code = -1; + pid_t waiting; + int failed_errno = 0; + + while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR) + ; /* nothing */ + + if (waiting < 0) { + failed_errno = errno; + error("waitpid for %s failed: %s", argv0, strerror(errno)); + } else if (waiting != pid) { + error("waitpid is confused (%s)", argv0); + } else if (WIFSIGNALED(status)) { + code = WTERMSIG(status); + if (code != SIGINT && code != SIGQUIT) + error("%s died of signal %d", argv0, code); + /* + * This return value is chosen so that code & 0xff + * mimics the exit code that a POSIX shell would report for + * a program that died from this signal. + */ + code += 128; + } else if (WIFEXITED(status)) { + code = WEXITSTATUS(status); + /* + * Convert special exit code when execvp failed. + */ + if (code == 127) { + code = -1; + failed_errno = ENOENT; + } + } else { + error("waitpid is confused (%s)", argv0); + } + + clear_child_for_cleanup(pid); + + errno = failed_errno; + return code; +} + +int start_command(struct child_process *cmd) +{ + int need_in, need_out, need_err; + int fdin[2], fdout[2], fderr[2]; + int failed_errno; + char *str; + + /* + * In case of errors we must keep the promise to close FDs + * that have been passed in via ->in and ->out. + */ + + need_in = !cmd->no_stdin && cmd->in < 0; + if (need_in) { + if (pipe(fdin) < 0) { + failed_errno = errno; + if (cmd->out > 0) + close(cmd->out); + str = "standard input"; + goto fail_pipe; + } + cmd->in = fdin[1]; + } + + need_out = !cmd->no_stdout + && !cmd->stdout_to_stderr + && cmd->out < 0; + if (need_out) { + if (pipe(fdout) < 0) { + failed_errno = errno; + if (need_in) + close_pair(fdin); + else if (cmd->in) + close(cmd->in); + str = "standard output"; + goto fail_pipe; + } + cmd->out = fdout[0]; + } + + need_err = !cmd->no_stderr && cmd->err < 0; + if (need_err) { + if (pipe(fderr) < 0) { + failed_errno = errno; + if (need_in) + close_pair(fdin); + else if (cmd->in) + close(cmd->in); + if (need_out) + close_pair(fdout); + else if (cmd->out) + close(cmd->out); + str = "standard error"; +fail_pipe: + error("cannot create %s pipe for %s: %s", + str, cmd->argv[0], strerror(failed_errno)); + errno = failed_errno; + return -1; + } + cmd->err = fderr[0]; + } + + trace_argv_printf(cmd->argv, "trace: run_command:"); + fflush(NULL); + +#ifndef WIN32 +{ + int notify_pipe[2]; + if (pipe(notify_pipe)) + notify_pipe[0] = notify_pipe[1] = -1; + + cmd->pid = fork(); + failed_errno = errno; + if (!cmd->pid) { + /* + * Redirect the channel to write syscall error messages to + * before redirecting the process's stderr so that all die() + * in subsequent call paths use the parent's stderr. + */ + if (cmd->no_stderr || need_err) { + child_err = dup(2); + set_cloexec(child_err); + } + set_die_routine(die_child); + set_error_routine(error_child); + + close(notify_pipe[0]); + set_cloexec(notify_pipe[1]); + child_notifier = notify_pipe[1]; + atexit(notify_parent); + + if (cmd->no_stdin) + dup_devnull(0); + else if (need_in) { + dup2(fdin[0], 0); + close_pair(fdin); + } else if (cmd->in) { + dup2(cmd->in, 0); + close(cmd->in); + } + + if (cmd->no_stderr) + dup_devnull(2); + else if (need_err) { + dup2(fderr[1], 2); + close_pair(fderr); + } else if (cmd->err > 1) { + dup2(cmd->err, 2); + close(cmd->err); + } + + if (cmd->no_stdout) + dup_devnull(1); + else if (cmd->stdout_to_stderr) + dup2(2, 1); + else if (need_out) { + dup2(fdout[1], 1); + close_pair(fdout); + } else if (cmd->out > 1) { + dup2(cmd->out, 1); + close(cmd->out); + } + + if (cmd->dir && chdir(cmd->dir)) + die_errno("exec '%s': cd to '%s' failed", cmd->argv[0], + cmd->dir); + if (cmd->env) { + for (; *cmd->env; cmd->env++) { + if (strchr(*cmd->env, '=')) + putenv((char *)*cmd->env); + else + unsetenv(*cmd->env); + } + } + if (cmd->git_cmd) { + execv_git_cmd(cmd->argv); + } else if (cmd->use_shell) { + execv_shell_cmd(cmd->argv); + } else { + sane_execvp(cmd->argv[0], (char *const*) cmd->argv); + } + if (errno == ENOENT) { + if (!cmd->silent_exec_failure) + error("cannot run %s: %s", cmd->argv[0], + strerror(ENOENT)); + exit(127); + } else { + die_errno("cannot exec '%s'", cmd->argv[0]); + } + } + if (cmd->pid < 0) + error("cannot fork() for %s: %s", cmd->argv[0], + strerror(errno)); + else if (cmd->clean_on_exit) + mark_child_for_cleanup(cmd->pid); + + /* + * Wait for child's execvp. If the execvp succeeds (or if fork() + * failed), EOF is seen immediately by the parent. Otherwise, the + * child process sends a single byte. + * Note that use of this infrastructure is completely advisory, + * therefore, we keep error checks minimal. + */ + close(notify_pipe[1]); + if (read(notify_pipe[0], ¬ify_pipe[1], 1) == 1) { + /* + * At this point we know that fork() succeeded, but execvp() + * failed. Errors have been reported to our stderr. + */ + wait_or_whine(cmd->pid, cmd->argv[0]); + failed_errno = errno; + cmd->pid = -1; + } + close(notify_pipe[0]); + +} +#else +{ + int fhin = 0, fhout = 1, fherr = 2; + const char **sargv = cmd->argv; + char **env = environ; + + if (cmd->no_stdin) + fhin = open("/dev/null", O_RDWR); + else if (need_in) + fhin = dup(fdin[0]); + else if (cmd->in) + fhin = dup(cmd->in); + + if (cmd->no_stderr) + fherr = open("/dev/null", O_RDWR); + else if (need_err) + fherr = dup(fderr[1]); + else if (cmd->err > 2) + fherr = dup(cmd->err); + + if (cmd->no_stdout) + fhout = open("/dev/null", O_RDWR); + else if (cmd->stdout_to_stderr) + fhout = dup(fherr); + else if (need_out) + fhout = dup(fdout[1]); + else if (cmd->out > 1) + fhout = dup(cmd->out); + + if (cmd->env) + env = make_augmented_environ(cmd->env); + + if (cmd->git_cmd) { + cmd->argv = prepare_git_cmd(cmd->argv); + } else if (cmd->use_shell) { + cmd->argv = prepare_shell_cmd(cmd->argv); + } + + cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir, + fhin, fhout, fherr); + failed_errno = errno; + if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT)) + error("cannot spawn %s: %s", cmd->argv[0], strerror(errno)); + if (cmd->clean_on_exit && cmd->pid >= 0) + mark_child_for_cleanup(cmd->pid); + + if (cmd->env) + free_environ(env); + if (cmd->git_cmd) + free(cmd->argv); + + cmd->argv = sargv; + if (fhin != 0) + close(fhin); + if (fhout != 1) + close(fhout); + if (fherr != 2) + close(fherr); +} +#endif + + if (cmd->pid < 0) { + if (need_in) + close_pair(fdin); + else if (cmd->in) + close(cmd->in); + if (need_out) + close_pair(fdout); + else if (cmd->out) + close(cmd->out); + if (need_err) + close_pair(fderr); + else if (cmd->err) + close(cmd->err); + errno = failed_errno; + return -1; + } + + if (need_in) + close(fdin[0]); + else if (cmd->in) + close(cmd->in); + + if (need_out) + close(fdout[1]); + else if (cmd->out) + close(cmd->out); + + if (need_err) + close(fderr[1]); + else if (cmd->err) + close(cmd->err); + + return 0; +} + +int finish_command(struct child_process *cmd) +{ + return wait_or_whine(cmd->pid, cmd->argv[0]); +} + +int run_command(struct child_process *cmd) +{ + int code = start_command(cmd); + if (code) + return code; + return finish_command(cmd); +} + +static void prepare_run_command_v_opt(struct child_process *cmd, + const char **argv, + int opt) +{ + memset(cmd, 0, sizeof(*cmd)); + cmd->argv = argv; + cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0; + cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0; + cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0; + cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0; + cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0; + cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0; +} + +int run_command_v_opt(const char **argv, int opt) +{ + struct child_process cmd; + prepare_run_command_v_opt(&cmd, argv, opt); + return run_command(&cmd); +} + +int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env) +{ + struct child_process cmd; + prepare_run_command_v_opt(&cmd, argv, opt); + cmd.dir = dir; + cmd.env = env; + return run_command(&cmd); +} + +#ifndef NO_PTHREADS +static pthread_t main_thread; +static int main_thread_set; +static pthread_key_t async_key; +static pthread_key_t async_die_counter; + +static void *run_thread(void *data) +{ + struct async *async = data; + intptr_t ret; + + pthread_setspecific(async_key, async); + ret = async->proc(async->proc_in, async->proc_out, async->data); + return (void *)ret; +} + +static NORETURN void die_async(const char *err, va_list params) +{ + vreportf("fatal: ", err, params); + + if (!pthread_equal(main_thread, pthread_self())) { + struct async *async = pthread_getspecific(async_key); + if (async->proc_in >= 0) + close(async->proc_in); + if (async->proc_out >= 0) + close(async->proc_out); + pthread_exit((void *)128); + } + + exit(128); +} + +static int async_die_is_recursing(void) +{ + void *ret = pthread_getspecific(async_die_counter); + pthread_setspecific(async_die_counter, (void *)1); + return ret != NULL; +} + +#endif + +int start_async(struct async *async) +{ + int need_in, need_out; + int fdin[2], fdout[2]; + int proc_in, proc_out; + + need_in = async->in < 0; + if (need_in) { + if (pipe(fdin) < 0) { + if (async->out > 0) + close(async->out); + return error("cannot create pipe: %s", strerror(errno)); + } + async->in = fdin[1]; + } + + need_out = async->out < 0; + if (need_out) { + if (pipe(fdout) < 0) { + if (need_in) + close_pair(fdin); + else if (async->in) + close(async->in); + return error("cannot create pipe: %s", strerror(errno)); + } + async->out = fdout[0]; + } + + if (need_in) + proc_in = fdin[0]; + else if (async->in) + proc_in = async->in; + else + proc_in = -1; + + if (need_out) + proc_out = fdout[1]; + else if (async->out) + proc_out = async->out; + else + proc_out = -1; + +#ifdef NO_PTHREADS + /* Flush stdio before fork() to avoid cloning buffers */ + fflush(NULL); + + async->pid = fork(); + if (async->pid < 0) { + error("fork (async) failed: %s", strerror(errno)); + goto error; + } + if (!async->pid) { + if (need_in) + close(fdin[1]); + if (need_out) + close(fdout[0]); + exit(!!async->proc(proc_in, proc_out, async->data)); + } + + mark_child_for_cleanup(async->pid); + + if (need_in) + close(fdin[0]); + else if (async->in) + close(async->in); + + if (need_out) + close(fdout[1]); + else if (async->out) + close(async->out); +#else + if (!main_thread_set) { + /* + * We assume that the first time that start_async is called + * it is from the main thread. + */ + main_thread_set = 1; + main_thread = pthread_self(); + pthread_key_create(&async_key, NULL); + pthread_key_create(&async_die_counter, NULL); + set_die_routine(die_async); + set_die_is_recursing_routine(async_die_is_recursing); + } + + if (proc_in >= 0) + set_cloexec(proc_in); + if (proc_out >= 0) + set_cloexec(proc_out); + async->proc_in = proc_in; + async->proc_out = proc_out; + { + int err = pthread_create(&async->tid, NULL, run_thread, async); + if (err) { + error("cannot create thread: %s", strerror(err)); + goto error; + } + } +#endif + return 0; + +error: + if (need_in) + close_pair(fdin); + else if (async->in) + close(async->in); + + if (need_out) + close_pair(fdout); + else if (async->out) + close(async->out); + return -1; +} + +int finish_async(struct async *async) +{ +#ifdef NO_PTHREADS + return wait_or_whine(async->pid, "child process"); +#else + void *ret = (void *)(intptr_t)(-1); + + if (pthread_join(async->tid, &ret)) + error("pthread_join failed"); + return (int)(intptr_t)ret; +#endif +} + +char *find_hook(const char *name) +{ + char *path = git_path("hooks/%s", name); + if (access(path, X_OK) < 0) + path = NULL; + + return path; +} + +int run_hook(const char *index_file, const char *name, ...) +{ + struct child_process hook; + struct argv_array argv = ARGV_ARRAY_INIT; + const char *p, *env[2]; + char index[PATH_MAX]; + va_list args; + int ret; + + p = find_hook(name); + if (!p) + return 0; + + argv_array_push(&argv, p); + + va_start(args, name); + while ((p = va_arg(args, const char *))) + argv_array_push(&argv, p); + va_end(args); + + memset(&hook, 0, sizeof(hook)); + hook.argv = argv.argv; + hook.no_stdin = 1; + hook.stdout_to_stderr = 1; + if (index_file) { + snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file); + env[0] = index; + env[1] = NULL; + hook.env = env; + } + + ret = run_command(&hook); + argv_array_clear(&argv); + return ret; +} |