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-rw-r--r--src/basic/exec-util.c360
1 files changed, 360 insertions, 0 deletions
diff --git a/src/basic/exec-util.c b/src/basic/exec-util.c
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index 000000000..aced9e8e3
--- /dev/null
+++ b/src/basic/exec-util.c
@@ -0,0 +1,360 @@
+/***
+ This file is part of systemd.
+
+ Copyright 2010 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <dirent.h>
+#include <errno.h>
+#include <sys/prctl.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#include "alloc-util.h"
+#include "conf-files.h"
+#include "env-util.h"
+#include "exec-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "hashmap.h"
+#include "macro.h"
+#include "process-util.h"
+#include "set.h"
+#include "signal-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "terminal-util.h"
+#include "util.h"
+
+/* Put this test here for a lack of better place */
+assert_cc(EAGAIN == EWOULDBLOCK);
+
+static int do_spawn(const char *path, char *argv[], int stdout_fd, pid_t *pid) {
+
+ pid_t _pid;
+
+ if (null_or_empty_path(path)) {
+ log_debug("%s is empty (a mask).", path);
+ return 0;
+ }
+
+ _pid = fork();
+ if (_pid < 0)
+ return log_error_errno(errno, "Failed to fork: %m");
+ if (_pid == 0) {
+ char *_argv[2];
+
+ assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
+
+ if (stdout_fd >= 0) {
+ /* If the fd happens to be in the right place, go along with that */
+ if (stdout_fd != STDOUT_FILENO &&
+ dup2(stdout_fd, STDOUT_FILENO) < 0)
+ return -errno;
+
+ fd_cloexec(STDOUT_FILENO, false);
+ }
+
+ if (!argv) {
+ _argv[0] = (char*) path;
+ _argv[1] = NULL;
+ argv = _argv;
+ } else
+ argv[0] = (char*) path;
+
+ execv(path, argv);
+ log_error_errno(errno, "Failed to execute %s: %m", path);
+ _exit(EXIT_FAILURE);
+ }
+
+ log_debug("Spawned %s as " PID_FMT ".", path, _pid);
+ *pid = _pid;
+ return 1;
+}
+
+static int do_execute(
+ char **directories,
+ usec_t timeout,
+ gather_stdout_callback_t const callbacks[_STDOUT_CONSUME_MAX],
+ void* const callback_args[_STDOUT_CONSUME_MAX],
+ int output_fd,
+ char *argv[]) {
+
+ _cleanup_hashmap_free_free_ Hashmap *pids = NULL;
+ _cleanup_strv_free_ char **paths = NULL;
+ char **path;
+ int r;
+
+ /* We fork this all off from a child process so that we can somewhat cleanly make
+ * use of SIGALRM to set a time limit.
+ *
+ * If callbacks is nonnull, execution is serial. Otherwise, we default to parallel.
+ */
+
+ (void) reset_all_signal_handlers();
+ (void) reset_signal_mask();
+
+ assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
+
+ r = conf_files_list_strv(&paths, NULL, NULL, (const char* const*) directories);
+ if (r < 0)
+ return r;
+
+ if (!callbacks) {
+ pids = hashmap_new(NULL);
+ if (!pids)
+ return log_oom();
+ }
+
+ /* Abort execution of this process after the timout. We simply rely on SIGALRM as
+ * default action terminating the process, and turn on alarm(). */
+
+ if (timeout != USEC_INFINITY)
+ alarm((timeout + USEC_PER_SEC - 1) / USEC_PER_SEC);
+
+ STRV_FOREACH(path, paths) {
+ _cleanup_free_ char *t = NULL;
+ _cleanup_close_ int fd = -1;
+ pid_t pid;
+
+ t = strdup(*path);
+ if (!t)
+ return log_oom();
+
+ if (callbacks) {
+ fd = open_serialization_fd(basename(*path));
+ if (fd < 0)
+ return log_error_errno(fd, "Failed to open serialization file: %m");
+ }
+
+ r = do_spawn(t, argv, fd, &pid);
+ if (r <= 0)
+ continue;
+
+ if (pids) {
+ r = hashmap_put(pids, PID_TO_PTR(pid), t);
+ if (r < 0)
+ return log_oom();
+ t = NULL;
+ } else {
+ r = wait_for_terminate_and_warn(t, pid, true);
+ if (r < 0)
+ continue;
+
+ if (lseek(fd, 0, SEEK_SET) < 0)
+ return log_error_errno(errno, "Failed to seek on serialization fd: %m");
+
+ r = callbacks[STDOUT_GENERATE](fd, callback_args[STDOUT_GENERATE]);
+ fd = -1;
+ if (r < 0)
+ return log_error_errno(r, "Failed to process output from %s: %m", *path);
+ }
+ }
+
+ if (callbacks) {
+ r = callbacks[STDOUT_COLLECT](output_fd, callback_args[STDOUT_COLLECT]);
+ if (r < 0)
+ return log_error_errno(r, "Callback two failed: %m");
+ }
+
+ while (!hashmap_isempty(pids)) {
+ _cleanup_free_ char *t = NULL;
+ pid_t pid;
+
+ pid = PTR_TO_PID(hashmap_first_key(pids));
+ assert(pid > 0);
+
+ t = hashmap_remove(pids, PID_TO_PTR(pid));
+ assert(t);
+
+ wait_for_terminate_and_warn(t, pid, true);
+ }
+
+ return 0;
+}
+
+int execute_directories(
+ const char* const* directories,
+ usec_t timeout,
+ gather_stdout_callback_t const callbacks[_STDOUT_CONSUME_MAX],
+ void* const callback_args[_STDOUT_CONSUME_MAX],
+ char *argv[]) {
+
+ pid_t executor_pid;
+ char *name;
+ char **dirs = (char**) directories;
+ _cleanup_close_ int fd = -1;
+ int r;
+
+ assert(!strv_isempty(dirs));
+
+ name = basename(dirs[0]);
+ assert(!isempty(name));
+
+ if (callbacks) {
+ assert(callback_args);
+ assert(callbacks[STDOUT_GENERATE]);
+ assert(callbacks[STDOUT_COLLECT]);
+ assert(callbacks[STDOUT_CONSUME]);
+
+ fd = open_serialization_fd(name);
+ if (fd < 0)
+ return log_error_errno(fd, "Failed to open serialization file: %m");
+ }
+
+ /* Executes all binaries in the directories serially or in parallel and waits for
+ * them to finish. Optionally a timeout is applied. If a file with the same name
+ * exists in more than one directory, the earliest one wins. */
+
+ executor_pid = fork();
+ if (executor_pid < 0)
+ return log_error_errno(errno, "Failed to fork: %m");
+
+ if (executor_pid == 0) {
+ r = do_execute(dirs, timeout, callbacks, callback_args, fd, argv);
+ _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
+ }
+
+ r = wait_for_terminate_and_warn(name, executor_pid, true);
+ if (r < 0)
+ return log_error_errno(r, "Execution failed: %m");
+ if (r > 0) {
+ /* non-zero return code from child */
+ log_error("Forker process failed.");
+ return -EREMOTEIO;
+ }
+
+ if (!callbacks)
+ return 0;
+
+ if (lseek(fd, 0, SEEK_SET) < 0)
+ return log_error_errno(errno, "Failed to rewind serialization fd: %m");
+
+ r = callbacks[STDOUT_CONSUME](fd, callback_args[STDOUT_CONSUME]);
+ fd = -1;
+ if (r < 0)
+ return log_error_errno(r, "Failed to parse returned data: %m");
+ return 0;
+}
+
+static int gather_environment_generate(int fd, void *arg) {
+ char ***env = arg, **x, **y;
+ _cleanup_fclose_ FILE *f = NULL;
+ _cleanup_strv_free_ char **new;
+ int r;
+
+ /* Read a series of VAR=value assignments from fd, use them to update the list of
+ * variables in env. Also update the exported environment.
+ *
+ * fd is always consumed, even on error.
+ */
+
+ assert(env);
+
+ f = fdopen(fd, "r");
+ if (!f) {
+ safe_close(fd);
+ return -errno;
+ }
+
+ r = load_env_file_pairs(f, NULL, NULL, &new);
+ if (r < 0)
+ return r;
+
+ STRV_FOREACH_PAIR(x, y, new) {
+ char *p;
+
+ if (!env_name_is_valid(*x)) {
+ log_warning("Invalid variable assignment \"%s=...\", ignoring.", *x);
+ continue;
+ }
+
+ p = strjoin(*x, "=", *y);
+ if (!p)
+ return -ENOMEM;
+
+ r = strv_env_replace(env, p);
+ if (r < 0)
+ return r;
+
+ if (setenv(*x, *y, true) < 0)
+ return -errno;
+ }
+
+ return r;
+}
+
+static int gather_environment_collect(int fd, void *arg) {
+ char ***env = arg;
+ _cleanup_fclose_ FILE *f = NULL;
+ int r;
+
+ /* Write out a series of env=cescape(VAR=value) assignments to fd. */
+
+ assert(env);
+
+ f = fdopen(fd, "w");
+ if (!f) {
+ safe_close(fd);
+ return -errno;
+ }
+
+ r = serialize_environment(f, *env);
+ if (r < 0)
+ return r;
+
+ if (ferror(f))
+ return errno > 0 ? -errno : -EIO;
+
+ return 0;
+}
+
+static int gather_environment_consume(int fd, void *arg) {
+ char ***env = arg;
+ _cleanup_fclose_ FILE *f = NULL;
+ char line[LINE_MAX];
+ int r = 0, k;
+
+ /* Read a series of env=cescape(VAR=value) assignments from fd into env. */
+
+ assert(env);
+
+ f = fdopen(fd, "r");
+ if (!f) {
+ safe_close(fd);
+ return -errno;
+ }
+
+ FOREACH_LINE(line, f, return -EIO) {
+ truncate_nl(line);
+
+ k = deserialize_environment(env, line);
+ if (k < 0)
+ log_error_errno(k, "Invalid line \"%s\": %m", line);
+ if (k < 0 && r == 0)
+ r = k;
+ }
+
+ return r;
+}
+
+const gather_stdout_callback_t gather_environment[] = {
+ gather_environment_generate,
+ gather_environment_collect,
+ gather_environment_consume,
+};