conf: move file descriptor synchronization with child into single function

src/lxc/conf.c

@@ -1635,7 +1635,7 @@ static const struct id_map *find_mapped_nsid_entry(const struct lxc_conf *conf,
 	return retmap;
 }
 
-int lxc_setup_devpts_parent(struct lxc_handler *handler)
+static int lxc_setup_devpts_parent(struct lxc_handler *handler)
 {
 	int ret;
 
@@ -4013,6 +4013,71 @@ int lxc_idmapped_mounts_parent(struct lxc_handler *handler)
 	}
 }
 
+static int lxc_recv_ttys_from_child(struct lxc_handler *handler)
+{
+	int i;
+	struct lxc_terminal_info *tty;
+	int ret = -1;
+	int sock = handler->data_sock[1];
+	struct lxc_conf *conf = handler->conf;
+	struct lxc_tty_info *ttys = &conf->ttys;
+
+	if (!conf->ttys.max)
+		return 0;
+
+	ttys->tty = malloc(sizeof(*ttys->tty) * ttys->max);
+	if (!ttys->tty)
+		return -1;
+
+	for (i = 0; i < conf->ttys.max; i++) {
+		int ttyx = -EBADF, ttyy = -EBADF;
+
+		ret = lxc_abstract_unix_recv_two_fds(sock, &ttyx, &ttyy);
+		if (ret < 0)
+			break;
+
+		tty = &ttys->tty[i];
+		tty->busy = -1;
+		tty->ptx = ttyx;
+		tty->pty = ttyy;
+		TRACE("Received pty with ptx fd %d and pty fd %d from child", tty->ptx, tty->pty);
+	}
+
+	if (ret < 0)
+		SYSERROR("Failed to receive %zu ttys from child", ttys->max);
+	else
+		TRACE("Received %zu ttys from child", ttys->max);
+
+	return ret;
+}
+
+int lxc_sync_fds_parent(struct lxc_handler *handler)
+{
+	int ret;
+
+	ret = lxc_seccomp_recv_notifier_fd(&handler->conf->seccomp, handler->data_sock[1]);
+	if (ret < 0)
+		return syserror_ret(ret, "Failed to receive seccomp notify fd from child");
+
+	ret = lxc_setup_devpts_parent(handler);
+	if (ret < 0)
+		return syserror_ret(ret, "Failed to receive devpts fd from child");
+
+	/* Read tty fds allocated by child. */
+	ret = lxc_recv_ttys_from_child(handler);
+	if (ret < 0)
+		return syserror_ret(ret, "Failed to receive tty info from child process");
+
+	if (handler->ns_clone_flags & CLONE_NEWNET) {
+		ret = lxc_network_recv_name_and_ifindex_from_child(handler);
+		if (ret < 0)
+			return syserror_ret(ret, "Failed to receive names and ifindices for network devices from child");
+	}
+
+	TRACE("Finished syncing file descriptors with child");
+	return 0;
+}
+
 int lxc_setup(struct lxc_handler *handler)
 {
 	int ret;

src/lxc/conf.h

@@ -582,7 +582,7 @@ static inline int chown_mapped_root(const char *path, const struct lxc_conf *con
 	return userns_exec_mapped_root(path, -EBADF, conf);
 }
 
-__hidden int lxc_setup_devpts_parent(struct lxc_handler *handler);
+__hidden extern int lxc_sync_fds_parent(struct lxc_handler *handler);
 
 static inline const char *get_rootfs_mnt(const struct lxc_rootfs *rootfs)
 {

src/lxc/start.c

@@ -1464,44 +1464,6 @@ out_error:
 	return -1;
 }
 
-static int lxc_recv_ttys_from_child(struct lxc_handler *handler)
-{
-	int i;
-	struct lxc_terminal_info *tty;
-	int ret = -1;
-	int sock = handler->data_sock[1];
-	struct lxc_conf *conf = handler->conf;
-	struct lxc_tty_info *ttys = &conf->ttys;
-
-	if (!conf->ttys.max)
-		return 0;
-
-	ttys->tty = malloc(sizeof(*ttys->tty) * ttys->max);
-	if (!ttys->tty)
-		return -1;
-
-	for (i = 0; i < conf->ttys.max; i++) {
-		int ttyx = -EBADF, ttyy = -EBADF;
-
-		ret = lxc_abstract_unix_recv_two_fds(sock, &ttyx, &ttyy);
-		if (ret < 0)
-			break;
-
-		tty = &ttys->tty[i];
-		tty->busy = -1;
-		tty->ptx = ttyx;
-		tty->pty = ttyy;
-		TRACE("Received pty with ptx fd %d and pty fd %d from child", tty->ptx, tty->pty);
-	}
-
-	if (ret < 0)
-		SYSERROR("Failed to receive %zu ttys from child", ttys->max);
-	else
-		TRACE("Received %zu ttys from child", ttys->max);
-
-	return ret;
-}
-
 int resolve_clone_flags(struct lxc_handler *handler)
 {
 	int i;
@@ -1959,33 +1921,12 @@ static int lxc_spawn(struct lxc_handler *handler)
 	if (!lxc_sync_wake_child(handler, START_SYNC_FDS))
 		goto out_delete_net;
 
-	ret = lxc_seccomp_recv_notifier_fd(&handler->conf->seccomp, data_sock1);
+	ret = lxc_sync_fds_parent(handler);
 	if (ret < 0) {
-		SYSERROR("Failed to receive seccomp notify fd from child");
+		SYSERROR("Failed to sync file descriptors with child");
 		goto out_delete_net;
 	}
 
-	ret = lxc_setup_devpts_parent(handler);
-	if (ret < 0) {
-		SYSERROR("Failed to receive devpts fd from child");
-		goto out_delete_net;
-	}
-
-	/* Read tty fds allocated by child. */
-	ret = lxc_recv_ttys_from_child(handler);
-	if (ret < 0) {
-		ERROR("Failed to receive tty info from child process");
-		goto out_delete_net;
-	}
-
-	if (handler->ns_clone_flags & CLONE_NEWNET) {
-		ret = lxc_network_recv_name_and_ifindex_from_child(handler);
-		if (ret < 0) {
-			ERROR("Failed to receive names and ifindices for network devices from child");
-			goto out_delete_net;
-		}
-	}
-
 	/*
 	 * Tell the child to complete its initialization and wait for it to
 	 * exec or return an error. (The child will never return