+static int run_program_exec(struct udev *udev, int fd_stdout, int fd_stderr,
+ char *const argv[], char **envp, const sigset_t *sigmask)
+{
+ 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;
+ if (err == -ENOENT || err == -ENOTDIR) {
+ /* may be on a filesystem which is not mounted right now */
+ info(udev, "program '%s' not found\n", argv[0]);
+ } else {
+ /* other problems */
+ err(udev, "exec of program '%s' failed\n", argv[0]);
+ }
+ return err;
+}
+
+static int run_program_read(struct udev *udev, int fd_stdout, int fd_stderr,
+ char *const argv[], char *result, size_t ressize, size_t *reslen)
+{
+ size_t respos = 0;
+ int fd_ep = -1;
+ struct epoll_event ep_outpipe;
+ struct epoll_event 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 fdcount;
+ struct epoll_event ev[4];
+ int i;
+
+ fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), -1);
+ if (fdcount < 0) {
+ if (errno == EINTR)
+ continue;
+ err(udev, "failed to poll: %m\n");
+ err = -errno;
+ 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, "ressize %zd too short\n", 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", argv[0], *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);
+ if (reslen != NULL)
+ *reslen = respos;
+ }
+out:
+ if (fd_ep >= 0)
+ close(fd_ep);
+ return err;
+}
+