+static int spawn_exec(struct udev_event *event,
+ const char *cmd, char *const argv[], char **envp, const sigset_t *sigmask,
+ int fd_stdout, int fd_stderr)
+{
+ struct udev *udev = event->udev;
+ int err;
+ int fd;
+
+ /* discard child output or connect to pipe */
+ fd = open("/dev/null", O_RDWR);
+ if (fd >= 0) {
+ dup2(fd, STDIN_FILENO);
+ if (fd_stdout < 0)
+ dup2(fd, STDOUT_FILENO);
+ if (fd_stderr < 0)
+ dup2(fd, STDERR_FILENO);
+ close(fd);
+ } else {
+ err(udev, "open /dev/null failed: %m\n");
+ }
+
+ /* connect pipes to std{out,err} */
+ if (fd_stdout >= 0) {
+ dup2(fd_stdout, STDOUT_FILENO);
+ close(fd_stdout);
+ }
+ if (fd_stderr >= 0) {
+ dup2(fd_stderr, STDERR_FILENO);
+ close(fd_stderr);
+ }
+
+ /* terminate child in case parent goes away */
+ prctl(PR_SET_PDEATHSIG, SIGTERM);
+
+ /* restore original udev sigmask before exec */
+ if (sigmask)
+ sigprocmask(SIG_SETMASK, sigmask, NULL);
+
+ execve(argv[0], argv, envp);
+
+ /* exec failed */
+ err = -errno;
+ err(udev, "failed to execute '%s' '%s': %m\n", argv[0], cmd);
+ return err;
+}
+
+static int spawn_read(struct udev_event *event,
+ const char *cmd,
+ int fd_stdout, int fd_stderr,
+ char *result, size_t ressize)
+{
+ struct udev *udev = event->udev;
+ size_t respos = 0;
+ int fd_ep = -1;
+ struct epoll_event ep_outpipe, ep_errpipe;
+ int err = 0;
+
+ /* read from child if requested */
+ if (fd_stdout < 0 && fd_stderr < 0)
+ return 0;
+
+ fd_ep = epoll_create1(EPOLL_CLOEXEC);
+ if (fd_ep < 0) {
+ err = -errno;
+ err(udev, "error creating epoll fd: %m\n");
+ goto out;
+ }
+
+ if (fd_stdout >= 0) {
+ memset(&ep_outpipe, 0, sizeof(struct epoll_event));
+ ep_outpipe.events = EPOLLIN;
+ ep_outpipe.data.ptr = &fd_stdout;
+ if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stdout, &ep_outpipe) < 0) {
+ err(udev, "fail to add fd to epoll: %m\n");
+ goto out;
+ }
+ }
+
+ if (fd_stderr >= 0) {
+ memset(&ep_errpipe, 0, sizeof(struct epoll_event));
+ ep_errpipe.events = EPOLLIN;
+ ep_errpipe.data.ptr = &fd_stderr;
+ if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stderr, &ep_errpipe) < 0) {
+ err(udev, "fail to add fd to epoll: %m\n");
+ goto out;
+ }
+ }
+
+ /* read child output */
+ while (fd_stdout >= 0 || fd_stderr >= 0) {
+ int timeout;
+ int fdcount;
+ struct epoll_event ev[4];
+ int i;
+
+ if (event->timeout_usec > 0) {
+ unsigned long long age_usec;
+
+ age_usec = now_usec() - event->birth_usec;
+ if (age_usec >= event->timeout_usec) {
+ err = -ETIMEDOUT;
+ err(udev, "timeout '%s'\n", cmd);
+ goto out;
+ }
+ timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
+ } else {
+ timeout = -1;
+ }
+
+ fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout);
+ if (fdcount < 0) {
+ if (errno == EINTR)
+ continue;
+ err = -errno;
+ err(udev, "failed to poll: %m\n");
+ goto out;
+ }
+ if (fdcount == 0) {
+ err = -ETIMEDOUT;
+ err(udev, "timeout '%s'\n", cmd);
+ goto out;
+ }
+
+ for (i = 0; i < fdcount; i++) {
+ int *fd = (int *)ev[i].data.ptr;
+
+ if (ev[i].events & EPOLLIN) {
+ ssize_t count;
+ char buf[4096];
+
+ count = read(*fd, buf, sizeof(buf)-1);
+ if (count <= 0)
+ continue;
+ buf[count] = '\0';
+
+ /* store stdout result */
+ if (result != NULL && *fd == fd_stdout) {
+ if (respos + count < ressize) {
+ memcpy(&result[respos], buf, count);
+ respos += count;
+ } else {
+ err(udev, "'%s' ressize %zd too short\n", cmd, ressize);
+ err = -ENOBUFS;
+ }
+ }
+
+ /* log debug output only if we watch stderr */
+ if (fd_stderr >= 0) {
+ char *pos;
+ char *line;
+
+ pos = buf;
+ while ((line = strsep(&pos, "\n"))) {
+ if (pos != NULL || line[0] != '\0')
+ info(udev, "'%s'(%s) '%s'\n", cmd, *fd == fd_stdout ? "out" : "err" , line);
+ }
+ }
+ } else if (ev[i].events & EPOLLHUP) {
+ if (epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL) < 0) {
+ err = -errno;
+ err(udev, "failed to remove fd from epoll: %m\n");
+ goto out;
+ }
+ *fd = -1;
+ }
+ }
+ }
+
+ /* return the child's stdout string */
+ if (result != NULL) {
+ result[respos] = '\0';
+ dbg(udev, "result='%s'\n", result);
+ }
+out:
+ if (fd_ep >= 0)
+ close(fd_ep);
+ return err;
+}
+
+static int spawn_wait(struct udev_event *event, const char *cmd, pid_t pid)
+{
+ struct udev *udev = event->udev;
+ struct pollfd pfd[1];
+ int err = 0;
+
+ pfd[0].events = POLLIN;
+ pfd[0].fd = event->fd_signal;
+
+ while (pid > 0) {
+ int timeout;
+ int fdcount;
+
+ if (event->timeout_usec > 0) {
+ unsigned long long age_usec;
+
+ age_usec = now_usec() - event->birth_usec;
+ if (age_usec >= event->timeout_usec)
+ timeout = 1000;
+ else
+ timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
+ } else {
+ timeout = -1;
+ }
+
+ fdcount = poll(pfd, 1, timeout);
+ if (fdcount < 0) {
+ if (errno == EINTR)
+ continue;
+ err = -errno;
+ err(udev, "failed to poll: %m\n");
+ goto out;
+ }
+ if (fdcount == 0) {
+ err(udev, "timeout: killing '%s' [%u]\n", cmd, pid);
+ kill(pid, SIGKILL);
+ }
+
+ if (pfd[0].revents & POLLIN) {
+ struct signalfd_siginfo fdsi;
+ int status;
+ ssize_t size;
+
+ size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
+ if (size != sizeof(struct signalfd_siginfo))
+ continue;
+
+ switch (fdsi.ssi_signo) {
+ case SIGTERM:
+ event->sigterm = true;
+ break;
+ case SIGCHLD:
+ if (waitpid(pid, &status, WNOHANG) < 0)
+ break;
+ if (WIFEXITED(status)) {
+ info(udev, "'%s' [%u] exit with return code %i\n", cmd, pid, WEXITSTATUS(status));
+ if (WEXITSTATUS(status) != 0)
+ err = -1;
+ } else if (WIFSIGNALED(status)) {
+ err(udev, "'%s' [%u] terminated by signal %i (%s)\n", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
+ err = -1;
+ } else if (WIFSTOPPED(status)) {
+ err(udev, "'%s' [%u] stopped\n", cmd, pid);
+ err = -1;
+ } else if (WIFCONTINUED(status)) {
+ err(udev, "'%s' [%u] continued\n", cmd, pid);
+ err = -1;
+ } else {
+ err(udev, "'%s' [%u] exit with status 0x%04x\n", cmd, pid, status);
+ err = -1;
+ }
+ pid = 0;
+ break;
+ }
+ }
+ }
+out:
+ return err;
+}
+
+int udev_event_spawn(struct udev_event *event,
+ const char *cmd, char **envp, const sigset_t *sigmask,
+ char *result, size_t ressize)
+{
+ struct udev *udev = event->udev;
+ int outpipe[2] = {-1, -1};
+ int errpipe[2] = {-1, -1};
+ pid_t pid;
+ char arg[UTIL_PATH_SIZE];
+ char program[UTIL_PATH_SIZE];
+ char *argv[((sizeof(arg) + 1) / 2) + 1];
+ int i;
+ int err = 0;
+
+ /* build argv from command */
+ util_strscpy(arg, sizeof(arg), cmd);
+ i = 0;
+ if (strchr(arg, ' ') != NULL) {
+ char *pos = arg;
+
+ while (pos != NULL && pos[0] != '\0') {
+ if (pos[0] == '\'') {
+ /* do not separate quotes */
+ pos++;
+ argv[i] = strsep(&pos, "\'");
+ if (pos != NULL)
+ while (pos[0] == ' ')
+ pos++;
+ } else {
+ argv[i] = strsep(&pos, " ");
+ if (pos != NULL)
+ while (pos[0] == ' ')
+ pos++;
+ }
+ dbg(udev, "arg[%i] '%s'\n", i, argv[i]);
+ i++;
+ }
+ argv[i] = NULL;
+ } else {
+ argv[0] = arg;
+ argv[1] = NULL;
+ }
+
+ /* pipes from child to parent */
+ if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
+ if (pipe2(outpipe, O_NONBLOCK) != 0) {
+ err = -errno;
+ err(udev, "pipe failed: %m\n");
+ goto out;
+ }
+ }
+ if (udev_get_log_priority(udev) >= LOG_INFO) {
+ if (pipe2(errpipe, O_NONBLOCK) != 0) {
+ err = -errno;
+ err(udev, "pipe failed: %m\n");
+ goto out;
+ }
+ }
+
+ /* allow programs in /lib/udev/ to be called without the path */
+ if (argv[0][0] != '/') {
+ util_strscpyl(program, sizeof(program), LIBEXECDIR "/", argv[0], NULL);
+ argv[0] = program;
+ }
+
+ pid = fork();
+ switch(pid) {
+ case 0:
+ /* child closes parent's ends of pipes */
+ if (outpipe[READ_END] >= 0) {
+ close(outpipe[READ_END]);
+ outpipe[READ_END] = -1;
+ }
+ if (errpipe[READ_END] >= 0) {
+ close(errpipe[READ_END]);
+ errpipe[READ_END] = -1;
+ }
+
+ info(udev, "starting '%s'\n", cmd);
+
+ err = spawn_exec(event, cmd, argv, envp, sigmask,
+ outpipe[WRITE_END], errpipe[WRITE_END]);
+
+ _exit(2 );
+ case -1:
+ err(udev, "fork of '%s' failed: %m\n", cmd);
+ err = -1;
+ goto out;
+ default:
+ /* parent closed child's ends of pipes */
+ if (outpipe[WRITE_END] >= 0) {
+ close(outpipe[WRITE_END]);
+ outpipe[WRITE_END] = -1;
+ }
+ if (errpipe[WRITE_END] >= 0) {
+ close(errpipe[WRITE_END]);
+ errpipe[WRITE_END] = -1;
+ }
+
+ err = spawn_read(event, cmd,
+ outpipe[READ_END], errpipe[READ_END],
+ result, ressize);
+
+ err = spawn_wait(event, cmd, pid);
+ }
+
+out:
+ if (outpipe[READ_END] >= 0)
+ close(outpipe[READ_END]);
+ if (outpipe[WRITE_END] >= 0)
+ close(outpipe[WRITE_END]);
+ if (errpipe[READ_END] >= 0)
+ close(errpipe[READ_END]);
+ if (errpipe[WRITE_END] >= 0)
+ close(errpipe[WRITE_END]);
+ return err;
+}
+