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author | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2017-01-22 12:35:08 -0500 |
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committer | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2017-02-11 18:21:06 -0500 |
commit | 89711996b3f561522508306e0b5ecf34f6016638 (patch) | |
tree | 1a677a8a00c4a00fb6f9fb8ad3264175003793bb /src/basic/exec-util.c | |
parent | 8367fea557cffaa6e870ccf1b94a063f560a922f (diff) | |
download | systemd-89711996b3f561522508306e0b5ecf34f6016638.tar.gz |
basic/util: move execute_directory() to separate file
It's a fairly specialized function. Let's make new files for it and the tests.
Diffstat (limited to 'src/basic/exec-util.c')
-rw-r--r-- | src/basic/exec-util.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/src/basic/exec-util.c b/src/basic/exec-util.c new file mode 100644 index 0000000000..757cd3b4ff --- /dev/null +++ b/src/basic/exec-util.c @@ -0,0 +1,181 @@ +/*** + 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 "alloc-util.h" +#include "dirent-util.h" +#include "exec-util.h" +#include "fd-util.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 "util.h" + +/* Put this test here for a lack of better place */ +assert_cc(EAGAIN == EWOULDBLOCK); + +static int do_execute(char **directories, usec_t timeout, char *argv[]) { + _cleanup_hashmap_free_free_ Hashmap *pids = NULL; + _cleanup_set_free_free_ Set *seen = NULL; + char **directory; + + /* We fork this all off from a child process so that we can + * somewhat cleanly make use of SIGALRM to set a time limit */ + + (void) reset_all_signal_handlers(); + (void) reset_signal_mask(); + + assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0); + + pids = hashmap_new(NULL); + if (!pids) + return log_oom(); + + seen = set_new(&string_hash_ops); + if (!seen) + return log_oom(); + + STRV_FOREACH(directory, directories) { + _cleanup_closedir_ DIR *d; + struct dirent *de; + + d = opendir(*directory); + if (!d) { + if (errno == ENOENT) + continue; + + return log_error_errno(errno, "Failed to open directory %s: %m", *directory); + } + + FOREACH_DIRENT(de, d, break) { + _cleanup_free_ char *path = NULL; + pid_t pid; + int r; + + if (!dirent_is_file(de)) + continue; + + if (set_contains(seen, de->d_name)) { + log_debug("%1$s/%2$s skipped (%2$s was already seen).", *directory, de->d_name); + continue; + } + + r = set_put_strdup(seen, de->d_name); + if (r < 0) + return log_oom(); + + path = strjoin(*directory, "/", de->d_name); + if (!path) + return log_oom(); + + if (null_or_empty_path(path)) { + log_debug("%s is empty (a mask).", path); + continue; + } + + pid = fork(); + if (pid < 0) { + log_error_errno(errno, "Failed to fork: %m"); + continue; + } else if (pid == 0) { + char *_argv[2]; + + assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0); + + if (!argv) { + _argv[0] = path; + _argv[1] = NULL; + argv = _argv; + } else + argv[0] = path; + + execv(path, argv); + return log_error_errno(errno, "Failed to execute %s: %m", path); + } + + log_debug("Spawned %s as " PID_FMT ".", path, pid); + + r = hashmap_put(pids, PID_TO_PTR(pid), path); + if (r < 0) + return log_oom(); + path = NULL; + } + } + + /* 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); + + while (!hashmap_isempty(pids)) { + _cleanup_free_ char *path = NULL; + pid_t pid; + + pid = PTR_TO_PID(hashmap_first_key(pids)); + assert(pid > 0); + + path = hashmap_remove(pids, PID_TO_PTR(pid)); + assert(path); + + wait_for_terminate_and_warn(path, pid, true); + } + + return 0; +} + +void execute_directories(const char* const* directories, usec_t timeout, char *argv[]) { + pid_t executor_pid; + int r; + char *name; + char **dirs = (char**) directories; + + assert(!strv_isempty(dirs)); + + name = basename(dirs[0]); + assert(!isempty(name)); + + /* Executes all binaries in the directories 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) { + log_error_errno(errno, "Failed to fork: %m"); + return; + + } else if (executor_pid == 0) { + r = do_execute(dirs, timeout, argv); + _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS); + } + + wait_for_terminate_and_warn(name, executor_pid, true); +} |