Function start_pre_exec

clientserver.c:500–562

Used for "early exec", "pre-xfer exec", and the "name converter" script. */

/* Used for "early exec", "pre-xfer exec", and the "name converter" script. */
static pid_t start_pre_exec(const char *cmd, int *arg_fd_ptr, int *error_fd_ptr)
{
	int arg_fds[2], error_fds[2], arg_fd;
	pid_t pid;

	if ((error_fd_ptr && pipe(error_fds) < 0) || pipe(arg_fds) < 0 || (pid = fork()) < 0)
		return (pid_t)-1;

	if (pid == 0) {
		char buf[BIGPATHBUFLEN];
		int j, len, status;

		if (error_fd_ptr) {
			close(error_fds[0]);
			set_blocking(error_fds[1]);
		}

		close(arg_fds[1]);
		arg_fd = arg_fds[0];
		set_blocking(arg_fd);

		len = read_arg_from_pipe(arg_fd, buf, BIGPATHBUFLEN);
		if (len <= 0)
			_exit(1);
		set_env_str("RSYNC_REQUEST", buf);

		for (j = 0; ; j++) {
			len = read_arg_from_pipe(arg_fd, buf, BIGPATHBUFLEN);
			if (len <= 0) {
				if (!len)
					break;
				_exit(1);
			}
			set_envN_str("RSYNC_ARG", j, buf);
		}

		dup2(arg_fd, STDIN_FILENO);
		close(arg_fd);

		if (error_fd_ptr) {
			dup2(error_fds[1], STDOUT_FILENO);
			close(error_fds[1]);
		}

		status = shell_exec(cmd);

		if (!WIFEXITED(status))
			_exit(1);
		_exit(WEXITSTATUS(status));
	}

	if (error_fd_ptr) {
		close(error_fds[1]);
		*error_fd_ptr = error_fds[0];
		set_blocking(error_fds[0]);
	}

	close(arg_fds[0]);