Files
systemd/src/core/executor.c
Daan De Meyer 836e4e7ea8 core: Clean up includes
Split out of #37344.
2025-05-22 09:37:20 +02:00

287 lines
11 KiB
C

/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <getopt.h>
#include <stdlib.h>
#include "sd-messages.h"
#include "alloc-util.h"
#include "argv-util.h"
#include "build.h"
#include "capability-util.h"
#include "cgroup.h"
#include "dynamic-user.h"
#include "exec-invoke.h"
#include "execute.h"
#include "execute-serialize.h"
#include "exit-status.h"
#include "fd-util.h"
#include "fdset.h"
#include "fileio.h"
#include "getopt-defs.h"
#include "label-util.h"
#include "log.h"
#include "parse-util.h"
#include "pretty-print.h"
#include "selinux-util.h"
#include "static-destruct.h"
static FILE *arg_serialization = NULL;
STATIC_DESTRUCTOR_REGISTER(arg_serialization, fclosep);
static int help(void) {
_cleanup_free_ char *link = NULL;
int r;
r = terminal_urlify_man("systemd", "1", &link);
if (r < 0)
return log_oom();
printf("%s [OPTIONS...]\n\n"
"%sSandbox and execute processes.%s\n\n"
" -h --help Show this help and exit\n"
" --version Print version string and exit\n"
" --log-target=TARGET Set log target (console, journal,\n"
" journal-or-kmsg,\n"
" kmsg, null)\n"
" --log-level=LEVEL Set log level (debug, info, notice,\n"
" warning, err, crit,\n"
" alert, emerg)\n"
" --log-color=BOOL Highlight important messages\n"
" --log-location=BOOL Include code location in messages\n"
" --log-time=BOOL Prefix messages with current time\n"
" --deserialize=FD Deserialize process config from FD\n"
"\nSee the %s for details.\n",
program_invocation_short_name,
ansi_highlight(),
ansi_normal(),
link);
return 0;
}
static int parse_argv(int argc, char *argv[]) {
enum {
COMMON_GETOPT_ARGS,
ARG_VERSION,
ARG_DESERIALIZE,
};
static const struct option options[] = {
{ "log-level", required_argument, NULL, ARG_LOG_LEVEL },
{ "log-target", required_argument, NULL, ARG_LOG_TARGET },
{ "log-color", required_argument, NULL, ARG_LOG_COLOR },
{ "log-location", required_argument, NULL, ARG_LOG_LOCATION },
{ "log-time", required_argument, NULL, ARG_LOG_TIME },
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, ARG_VERSION },
{ "deserialize", required_argument, NULL, ARG_DESERIALIZE },
{}
};
int c, r;
assert(argc >= 0);
assert(argv);
while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
switch (c) {
case 'h':
return help();
case ARG_VERSION:
return version();
case ARG_LOG_LEVEL:
r = log_set_max_level_from_string(optarg);
if (r < 0)
return log_error_errno(r, "Failed to parse log level \"%s\": %m", optarg);
break;
case ARG_LOG_TARGET:
r = log_set_target_from_string(optarg);
if (r < 0)
return log_error_errno(r, "Failed to parse log target \"%s\": %m", optarg);
break;
case ARG_LOG_COLOR:
r = log_show_color_from_string(optarg);
if (r < 0)
return log_error_errno(
r,
"Failed to parse log color setting \"%s\": %m",
optarg);
break;
case ARG_LOG_LOCATION:
r = log_show_location_from_string(optarg);
if (r < 0)
return log_error_errno(
r,
"Failed to parse log location setting \"%s\": %m",
optarg);
break;
case ARG_LOG_TIME:
r = log_show_time_from_string(optarg);
if (r < 0)
return log_error_errno(
r,
"Failed to parse log time setting \"%s\": %m",
optarg);
break;
case ARG_DESERIALIZE: {
_cleanup_close_ int fd = -EBADF;
FILE *f;
fd = parse_fd(optarg);
if (fd < 0)
return log_error_errno(fd,
"Failed to parse serialization fd \"%s\": %m",
optarg);
r = fd_cloexec(fd, /* cloexec= */ true);
if (r < 0)
return log_error_errno(r,
"Failed to set serialization fd %d to close-on-exec: %m",
fd);
f = take_fdopen(&fd, "r");
if (!f)
return log_error_errno(errno, "Failed to open serialization fd %d: %m", fd);
safe_fclose(arg_serialization);
arg_serialization = f;
break;
}
case '?':
return -EINVAL;
default:
assert_not_reached();
}
if (!arg_serialization)
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "No serialization fd specified.");
return 1 /* work to do */;
}
static int run(int argc, char *argv[]) {
_cleanup_fdset_free_ FDSet *fdset = NULL;
_cleanup_(cgroup_context_done) CGroupContext cgroup_context = {};
_cleanup_(exec_context_done) ExecContext context = {};
_cleanup_(exec_command_done) ExecCommand command = {};
_cleanup_(exec_params_deep_clear) ExecParameters params = EXEC_PARAMETERS_INIT(/* flags= */ 0);
_cleanup_(exec_shared_runtime_done) ExecSharedRuntime shared = {
.netns_storage_socket = EBADF_PAIR,
.ipcns_storage_socket = EBADF_PAIR,
};
_cleanup_(dynamic_creds_done) DynamicCreds dynamic_creds = {};
_cleanup_(exec_runtime_clear) ExecRuntime runtime = {
.ephemeral_storage_socket = EBADF_PAIR,
.shared = &shared,
.dynamic_creds = &dynamic_creds,
};
int exit_status = EXIT_SUCCESS, r;
exec_context_init(&context);
cgroup_context_init(&cgroup_context);
/* We might be starting the journal itself, we'll be told by the caller what to do */
log_set_always_reopen_console(true);
log_set_prohibit_ipc(true);
log_setup();
r = parse_argv(argc, argv);
if (r <= 0)
return r;
/* Now that we know the intended log target, allow IPC and open the final log target. */
log_set_prohibit_ipc(false);
log_open();
/* Clear ambient capabilities, so services do not inherit them implicitly. Dropping them does
* not affect the permitted and effective sets which are important for the executor itself to
* operate. */
r = capability_ambient_set_apply(0, /* also_inherit= */ false);
if (r < 0)
log_warning_errno(r, "Failed to clear ambient capabilities, ignoring: %m");
/* This call would collect all passed fds and enable CLOEXEC. We'll unset it in exec_invoke (flag_fds)
* for fds that shall be passed to the child.
* The serialization fd is set to CLOEXEC in parse_argv, so it's also filtered. */
r = fdset_new_fill(/* filter_cloexec= */ 0, &fdset);
if (r < 0)
return log_error_errno(r, "Failed to create fd set: %m");
/* Initialize lazily. SMACK is just a few operations, but the SELinux is very slow as it requires
* loading the entire database in memory, so we will do it lazily only if it is actually needed, to
* avoid wasting 2ms-10ms for each sd-executor that gets spawned. */
r = mac_init_lazy();
if (r < 0)
return log_error_errno(r, "Failed to initialize MAC layer: %m");
r = exec_deserialize_invocation(arg_serialization,
fdset,
&context,
&command,
&params,
&runtime,
&cgroup_context);
if (r < 0)
return log_error_errno(r, "Failed to deserialize: %m");
LOG_CONTEXT_PUSH_EXEC(&context, &params);
arg_serialization = safe_fclose(arg_serialization);
fdset = fdset_free(fdset);
r = exec_invoke(&command,
&context,
&params,
&runtime,
&cgroup_context,
&exit_status);
if (r < 0) {
const char *status = ASSERT_PTR(
exit_status_to_string(exit_status, EXIT_STATUS_LIBC | EXIT_STATUS_SYSTEMD));
log_struct_errno(LOG_ERR, r,
LOG_MESSAGE_ID(SD_MESSAGE_SPAWN_FAILED_STR),
LOG_EXEC_MESSAGE(&params, "Failed at step %s spawning %s: %m",
status, command.path),
LOG_ITEM("EXECUTABLE=%s", command.path));
} else
/* r == 0: 'skip' is chosen in the confirm spawn prompt
* r > 0: expected/ignored failure, do not log at error level */
assert((r == 0) == (exit_status == EXIT_SUCCESS));
return exit_status;
}
int main(int argc, char *argv[]) {
int r;
/* We use safe_fork() for spawning sd-pam helper process, which internally calls rename_process().
* As the last step of renaming, all saved argvs are memzero()-ed. Hence, we need to save the argv
* first to prevent showing "intense" cmdline. See #30352. */
save_argc_argv(argc, argv);
r = run(argc, argv);
mac_selinux_finish();
static_destruct();
return r < 0 ? EXIT_FAILURE : r;
}