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-rw-r--r--src/udev/udev-spawn.c355
1 files changed, 355 insertions, 0 deletions
diff --git a/src/udev/udev-spawn.c b/src/udev/udev-spawn.c
new file mode 100644
index 0000000..67a3005
--- /dev/null
+++ b/src/udev/udev-spawn.c
@@ -0,0 +1,355 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "sd-event.h"
+
+#include "device-private.h"
+#include "device-util.h"
+#include "fd-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "signal-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "udev-builtin.h"
+#include "udev-event.h"
+#include "udev-spawn.h"
+#include "udev-trace.h"
+
+typedef struct Spawn {
+ sd_device *device;
+ const char *cmd;
+ pid_t pid;
+ usec_t timeout_warn_usec;
+ usec_t timeout_usec;
+ int timeout_signal;
+ usec_t event_birth_usec;
+ bool accept_failure;
+ int fd_stdout;
+ int fd_stderr;
+ char *result;
+ size_t result_size;
+ size_t result_len;
+ bool truncated;
+} Spawn;
+
+static int on_spawn_io(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+ Spawn *spawn = ASSERT_PTR(userdata);
+ char buf[4096], *p;
+ size_t size;
+ ssize_t l;
+ int r;
+
+ assert(fd == spawn->fd_stdout || fd == spawn->fd_stderr);
+ assert(!spawn->result || spawn->result_len < spawn->result_size);
+
+ if (fd == spawn->fd_stdout && spawn->result) {
+ p = spawn->result + spawn->result_len;
+ size = spawn->result_size - spawn->result_len;
+ } else {
+ p = buf;
+ size = sizeof(buf);
+ }
+
+ l = read(fd, p, size - (p == buf));
+ if (l < 0) {
+ if (errno == EAGAIN)
+ goto reenable;
+
+ log_device_error_errno(spawn->device, errno,
+ "Failed to read stdout of '%s': %m", spawn->cmd);
+
+ return 0;
+ }
+
+ if ((size_t) l == size) {
+ log_device_warning(spawn->device, "Truncating stdout of '%s' up to %zu byte.",
+ spawn->cmd, spawn->result_size);
+ l--;
+ spawn->truncated = true;
+ }
+
+ p[l] = '\0';
+ if (fd == spawn->fd_stdout && spawn->result)
+ spawn->result_len += l;
+
+ /* Log output only if we watch stderr. */
+ if (l > 0 && spawn->fd_stderr >= 0) {
+ _cleanup_strv_free_ char **v = NULL;
+
+ r = strv_split_newlines_full(&v, p, EXTRACT_RETAIN_ESCAPE);
+ if (r < 0)
+ log_device_debug(spawn->device,
+ "Failed to split output from '%s'(%s), ignoring: %m",
+ spawn->cmd, fd == spawn->fd_stdout ? "out" : "err");
+
+ STRV_FOREACH(q, v)
+ log_device_debug(spawn->device, "'%s'(%s) '%s'", spawn->cmd,
+ fd == spawn->fd_stdout ? "out" : "err", *q);
+ }
+
+ if (l == 0 || spawn->truncated)
+ return 0;
+
+reenable:
+ /* Re-enable the event source if we did not encounter EOF */
+
+ r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT);
+ if (r < 0)
+ log_device_error_errno(spawn->device, r,
+ "Failed to reactivate IO source of '%s'", spawn->cmd);
+ return 0;
+}
+
+static int on_spawn_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
+ Spawn *spawn = ASSERT_PTR(userdata);
+
+ DEVICE_TRACE_POINT(spawn_timeout, spawn->device, spawn->cmd);
+
+ kill_and_sigcont(spawn->pid, spawn->timeout_signal);
+
+ log_device_error(spawn->device, "Spawned process '%s' ["PID_FMT"] timed out after %s, killing",
+ spawn->cmd, spawn->pid,
+ FORMAT_TIMESPAN(spawn->timeout_usec, USEC_PER_SEC));
+
+ return 1;
+}
+
+static int on_spawn_timeout_warning(sd_event_source *s, uint64_t usec, void *userdata) {
+ Spawn *spawn = ASSERT_PTR(userdata);
+
+ log_device_warning(spawn->device, "Spawned process '%s' ["PID_FMT"] is taking longer than %s to complete",
+ spawn->cmd, spawn->pid,
+ FORMAT_TIMESPAN(spawn->timeout_warn_usec, USEC_PER_SEC));
+
+ return 1;
+}
+
+static int on_spawn_sigchld(sd_event_source *s, const siginfo_t *si, void *userdata) {
+ Spawn *spawn = ASSERT_PTR(userdata);
+ int ret = -EIO;
+
+ switch (si->si_code) {
+ case CLD_EXITED:
+ if (si->si_status == 0)
+ log_device_debug(spawn->device, "Process '%s' succeeded.", spawn->cmd);
+ else
+ log_device_full(spawn->device, spawn->accept_failure ? LOG_DEBUG : LOG_WARNING,
+ "Process '%s' failed with exit code %i.", spawn->cmd, si->si_status);
+ ret = si->si_status;
+ break;
+ case CLD_KILLED:
+ case CLD_DUMPED:
+ log_device_error(spawn->device, "Process '%s' terminated by signal %s.", spawn->cmd, signal_to_string(si->si_status));
+ break;
+ default:
+ log_device_error(spawn->device, "Process '%s' failed due to unknown reason.", spawn->cmd);
+ }
+
+ DEVICE_TRACE_POINT(spawn_exit, spawn->device, spawn->cmd);
+
+ sd_event_exit(sd_event_source_get_event(s), ret);
+ return 1;
+}
+
+static int spawn_wait(Spawn *spawn) {
+ _cleanup_(sd_event_unrefp) sd_event *e = NULL;
+ _cleanup_(sd_event_source_disable_unrefp) sd_event_source *sigchld_source = NULL;
+ _cleanup_(sd_event_source_disable_unrefp) sd_event_source *stdout_source = NULL;
+ _cleanup_(sd_event_source_disable_unrefp) sd_event_source *stderr_source = NULL;
+ int r;
+
+ assert(spawn);
+
+ r = sd_event_new(&e);
+ if (r < 0)
+ return log_device_debug_errno(spawn->device, r, "Failed to allocate sd-event object: %m");
+
+ if (spawn->timeout_usec > 0) {
+ usec_t usec, age_usec;
+
+ usec = now(CLOCK_MONOTONIC);
+ age_usec = usec - spawn->event_birth_usec;
+ if (age_usec < spawn->timeout_usec) {
+ if (spawn->timeout_warn_usec > 0 &&
+ spawn->timeout_warn_usec < spawn->timeout_usec &&
+ spawn->timeout_warn_usec > age_usec) {
+ spawn->timeout_warn_usec -= age_usec;
+
+ r = sd_event_add_time(e, NULL, CLOCK_MONOTONIC,
+ usec + spawn->timeout_warn_usec, USEC_PER_SEC,
+ on_spawn_timeout_warning, spawn);
+ if (r < 0)
+ return log_device_debug_errno(spawn->device, r, "Failed to create timeout warning event source: %m");
+ }
+
+ spawn->timeout_usec -= age_usec;
+
+ r = sd_event_add_time(e, NULL, CLOCK_MONOTONIC,
+ usec + spawn->timeout_usec, USEC_PER_SEC, on_spawn_timeout, spawn);
+ if (r < 0)
+ return log_device_debug_errno(spawn->device, r, "Failed to create timeout event source: %m");
+ }
+ }
+
+ if (spawn->fd_stdout >= 0) {
+ r = sd_event_add_io(e, &stdout_source, spawn->fd_stdout, EPOLLIN, on_spawn_io, spawn);
+ if (r < 0)
+ return log_device_debug_errno(spawn->device, r, "Failed to create stdio event source: %m");
+ r = sd_event_source_set_enabled(stdout_source, SD_EVENT_ONESHOT);
+ if (r < 0)
+ return log_device_debug_errno(spawn->device, r, "Failed to enable stdio event source: %m");
+ }
+
+ if (spawn->fd_stderr >= 0) {
+ r = sd_event_add_io(e, &stderr_source, spawn->fd_stderr, EPOLLIN, on_spawn_io, spawn);
+ if (r < 0)
+ return log_device_debug_errno(spawn->device, r, "Failed to create stderr event source: %m");
+ r = sd_event_source_set_enabled(stderr_source, SD_EVENT_ONESHOT);
+ if (r < 0)
+ return log_device_debug_errno(spawn->device, r, "Failed to enable stderr event source: %m");
+ }
+
+ r = sd_event_add_child(e, &sigchld_source, spawn->pid, WEXITED, on_spawn_sigchld, spawn);
+ if (r < 0)
+ return log_device_debug_errno(spawn->device, r, "Failed to create sigchild event source: %m");
+ /* SIGCHLD should be processed after IO is complete */
+ r = sd_event_source_set_priority(sigchld_source, SD_EVENT_PRIORITY_NORMAL + 1);
+ if (r < 0)
+ return log_device_debug_errno(spawn->device, r, "Failed to set priority to sigchild event source: %m");
+
+ return sd_event_loop(e);
+}
+
+int udev_event_spawn(
+ UdevEvent *event,
+ usec_t timeout_usec,
+ int timeout_signal,
+ bool accept_failure,
+ const char *cmd,
+ char *result,
+ size_t result_size,
+ bool *ret_truncated) {
+
+ _cleanup_close_pair_ int outpipe[2] = EBADF_PAIR, errpipe[2] = EBADF_PAIR;
+ _cleanup_strv_free_ char **argv = NULL;
+ char **envp = NULL;
+ Spawn spawn;
+ pid_t pid;
+ int r;
+
+ assert(event);
+ assert(event->dev);
+ assert(result || result_size == 0);
+
+ /* pipes from child to parent */
+ if (result || log_get_max_level() >= LOG_INFO)
+ if (pipe2(outpipe, O_NONBLOCK|O_CLOEXEC) != 0)
+ return log_device_error_errno(event->dev, errno,
+ "Failed to create pipe for command '%s': %m", cmd);
+
+ if (log_get_max_level() >= LOG_INFO)
+ if (pipe2(errpipe, O_NONBLOCK|O_CLOEXEC) != 0)
+ return log_device_error_errno(event->dev, errno,
+ "Failed to create pipe for command '%s': %m", cmd);
+
+ r = strv_split_full(&argv, cmd, NULL, EXTRACT_UNQUOTE | EXTRACT_RELAX | EXTRACT_RETAIN_ESCAPE);
+ if (r < 0)
+ return log_device_error_errno(event->dev, r, "Failed to split command: %m");
+
+ if (isempty(argv[0]))
+ return log_device_error_errno(event->dev, SYNTHETIC_ERRNO(EINVAL),
+ "Invalid command '%s'", cmd);
+
+ /* allow programs in /usr/lib/udev/ to be called without the path */
+ if (!path_is_absolute(argv[0])) {
+ char *program;
+
+ program = path_join(UDEVLIBEXECDIR, argv[0]);
+ if (!program)
+ return log_oom();
+
+ free_and_replace(argv[0], program);
+ }
+
+ r = device_get_properties_strv(event->dev, &envp);
+ if (r < 0)
+ return log_device_error_errno(event->dev, r, "Failed to get device properties");
+
+ log_device_debug(event->dev, "Starting '%s'", cmd);
+
+ r = safe_fork_full("(spawn)",
+ (int[]) { -EBADF, outpipe[WRITE_END], errpipe[WRITE_END] },
+ NULL, 0,
+ FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_DEATHSIG_SIGTERM|FORK_REARRANGE_STDIO|FORK_LOG|FORK_RLIMIT_NOFILE_SAFE,
+ &pid);
+ if (r < 0)
+ return log_device_error_errno(event->dev, r,
+ "Failed to fork() to execute command '%s': %m", cmd);
+ if (r == 0) {
+ DEVICE_TRACE_POINT(spawn_exec, event->dev, cmd);
+ execve(argv[0], argv, envp);
+ _exit(EXIT_FAILURE);
+ }
+
+ /* parent closed child's ends of pipes */
+ outpipe[WRITE_END] = safe_close(outpipe[WRITE_END]);
+ errpipe[WRITE_END] = safe_close(errpipe[WRITE_END]);
+
+ spawn = (Spawn) {
+ .device = event->dev,
+ .cmd = cmd,
+ .pid = pid,
+ .accept_failure = accept_failure,
+ .timeout_warn_usec = udev_warn_timeout(timeout_usec),
+ .timeout_usec = timeout_usec,
+ .timeout_signal = timeout_signal,
+ .event_birth_usec = event->birth_usec,
+ .fd_stdout = outpipe[READ_END],
+ .fd_stderr = errpipe[READ_END],
+ .result = result,
+ .result_size = result_size,
+ };
+ r = spawn_wait(&spawn);
+ if (r < 0)
+ return log_device_error_errno(event->dev, r,
+ "Failed to wait for spawned command '%s': %m", cmd);
+
+ if (result)
+ result[spawn.result_len] = '\0';
+
+ if (ret_truncated)
+ *ret_truncated = spawn.truncated;
+
+ return r; /* 0 for success, and positive if the program failed */
+}
+
+void udev_event_execute_run(UdevEvent *event, usec_t timeout_usec, int timeout_signal) {
+ const char *command;
+ void *val;
+ int r;
+
+ ORDERED_HASHMAP_FOREACH_KEY(val, command, event->run_list) {
+ UdevBuiltinCommand builtin_cmd = PTR_TO_UDEV_BUILTIN_CMD(val);
+
+ if (builtin_cmd != _UDEV_BUILTIN_INVALID) {
+ log_device_debug(event->dev, "Running built-in command \"%s\"", command);
+ r = udev_builtin_run(event, builtin_cmd, command, false);
+ if (r < 0)
+ log_device_debug_errno(event->dev, r, "Failed to run built-in command \"%s\", ignoring: %m", command);
+ } else {
+ if (event->exec_delay_usec > 0) {
+ log_device_debug(event->dev, "Delaying execution of \"%s\" for %s.",
+ command, FORMAT_TIMESPAN(event->exec_delay_usec, USEC_PER_SEC));
+ (void) usleep_safe(event->exec_delay_usec);
+ }
+
+ log_device_debug(event->dev, "Running command \"%s\"", command);
+
+ r = udev_event_spawn(event, timeout_usec, timeout_signal, false, command, NULL, 0, NULL);
+ if (r < 0)
+ log_device_warning_errno(event->dev, r, "Failed to execute '%s', ignoring: %m", command);
+ else if (r > 0) /* returned value is positive when program fails */
+ log_device_debug(event->dev, "Command \"%s\" returned %d (error), ignoring.", command, r);
+ }
+ }
+}