+/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
Copyright 2015 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <linux/veth.h>
#include <net/if.h>
+#include <sys/file.h>
#include "libudev.h"
#include "sd-id128.h"
#include "alloc-util.h"
#include "ether-addr-util.h"
+#include "lockfile-util.h"
#include "netlink-util.h"
#include "nspawn-network.h"
#include "siphash24.h"
+#include "socket-util.h"
+#include "stat-util.h"
#include "string-util.h"
#include "udev-util.h"
#include "util.h"
#define VETH_EXTRA_CONTAINER_HASH_KEY SD_ID128_MAKE(af,50,17,61,ce,f9,4d,35,84,0d,2b,20,54,be,ce,59)
#define MACVLAN_HASH_KEY SD_ID128_MAKE(00,13,6d,bc,66,83,44,81,bb,0c,f9,51,1f,24,a6,6f)
+static int remove_one_link(sd_netlink *rtnl, const char *name) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+ int r;
+
+ if (isempty(name))
+ return 0;
+
+ r = sd_rtnl_message_new_link(rtnl, &m, RTM_DELLINK, 0);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate netlink message: %m");
+
+ r = sd_netlink_message_append_string(m, IFLA_IFNAME, name);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add netlink interface name: %m");
+
+ r = sd_netlink_call(rtnl, m, 0, NULL);
+ if (r == -ENODEV) /* Already gone */
+ return 0;
+ if (r < 0)
+ return log_error_errno(r, "Failed to remove interface %s: %m", name);
+
+ return 1;
+}
+
static int generate_mac(
const char *machine_name,
struct ether_addr *mac,
return 0;
}
-int setup_bridge(const char *veth_name, const char *bridge_name) {
+static int join_bridge(sd_netlink *rtnl, const char *veth_name, const char *bridge_name) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
- _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
int r, bridge_ifi;
+ assert(rtnl);
assert(veth_name);
assert(bridge_name);
bridge_ifi = (int) if_nametoindex(bridge_name);
if (bridge_ifi <= 0)
- return log_error_errno(errno, "Failed to resolve interface %s: %m", bridge_name);
-
- r = sd_netlink_open(&rtnl);
- if (r < 0)
- return log_error_errno(r, "Failed to connect to netlink: %m");
+ return -errno;
r = sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, 0);
if (r < 0)
- return log_error_errno(r, "Failed to allocate netlink message: %m");
+ return r;
r = sd_rtnl_message_link_set_flags(m, IFF_UP, IFF_UP);
if (r < 0)
- return log_error_errno(r, "Failed to set IFF_UP flag: %m");
+ return r;
r = sd_netlink_message_append_string(m, IFLA_IFNAME, veth_name);
if (r < 0)
- return log_error_errno(r, "Failed to add netlink interface name field: %m");
+ return r;
r = sd_netlink_message_append_u32(m, IFLA_MASTER, bridge_ifi);
if (r < 0)
- return log_error_errno(r, "Failed to add netlink master field: %m");
+ return r;
r = sd_netlink_call(rtnl, m, 0, NULL);
if (r < 0)
- return log_error_errno(r, "Failed to add veth interface to bridge: %m");
+ return r;
return bridge_ifi;
}
+static int create_bridge(sd_netlink *rtnl, const char *bridge_name) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+ int r;
+
+ r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_append_string(m, IFLA_IFNAME, bridge_name);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_open_container(m, IFLA_LINKINFO);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, "bridge");
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_close_container(m);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_call(rtnl, m, 0, NULL);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+int setup_bridge(const char *veth_name, const char *bridge_name, bool create) {
+ _cleanup_release_lock_file_ LockFile bridge_lock = LOCK_FILE_INIT;
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ int r, bridge_ifi;
+ unsigned n = 0;
+
+ assert(veth_name);
+ assert(bridge_name);
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ if (create) {
+ /* We take a system-wide lock here, so that we can safely check whether there's still a member in the
+ * bridge before removing it, without risking interference from other nspawn instances. */
+
+ r = make_lock_file("/run/systemd/nspawn-network-zone", LOCK_EX, &bridge_lock);
+ if (r < 0)
+ return log_error_errno(r, "Failed to take network zone lock: %m");
+ }
+
+ for (;;) {
+ bridge_ifi = join_bridge(rtnl, veth_name, bridge_name);
+ if (bridge_ifi >= 0)
+ return bridge_ifi;
+ if (bridge_ifi != -ENODEV || !create || n > 10)
+ return log_error_errno(bridge_ifi, "Failed to add interface %s to bridge %s: %m", veth_name, bridge_name);
+
+ /* Count attempts, so that we don't enter an endless loop here. */
+ n++;
+
+ /* The bridge doesn't exist yet. Let's create it */
+ r = create_bridge(rtnl, bridge_name);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create bridge interface %s: %m", bridge_name);
+
+ /* Try again, now that the bridge exists */
+ }
+}
+
+int remove_bridge(const char *bridge_name) {
+ _cleanup_release_lock_file_ LockFile bridge_lock = LOCK_FILE_INIT;
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ const char *path;
+ int r;
+
+ /* Removes the specified bridge, but only if it is currently empty */
+
+ if (isempty(bridge_name))
+ return 0;
+
+ r = make_lock_file("/run/systemd/nspawn-network-zone", LOCK_EX, &bridge_lock);
+ if (r < 0)
+ return log_error_errno(r, "Failed to take network zone lock: %m");
+
+ path = strjoina("/sys/class/net/", bridge_name, "/brif");
+
+ r = dir_is_empty(path);
+ if (r == -ENOENT) /* Already gone? */
+ return 0;
+ if (r < 0)
+ return log_error_errno(r, "Can't detect if bridge %s is empty: %m", bridge_name);
+ if (r == 0) /* Still populated, leave it around */
+ return 0;
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ return remove_one_link(rtnl, bridge_name);
+}
+
static int parse_interface(struct udev *udev, const char *name) {
_cleanup_udev_device_unref_ struct udev_device *d = NULL;
char ifi_str[2 + DECIMAL_STR_MAX(int)];
r = extract_first_word(&p, &a, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
if (r < 0)
return r;
- if (r == 0 || isempty(a))
+ if (r == 0 || !ifname_valid(a))
return -EINVAL;
r = extract_first_word(&p, &b, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
if (r < 0)
return r;
- if (r == 0 || isempty(b)) {
+ if (r == 0 || !ifname_valid(b)) {
free(b);
b = strdup(a);
if (!b)
a = b = NULL;
return 0;
}
+
+int remove_veth_links(const char *primary, char **pairs) {
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ char **a, **b;
+ int r;
+
+ /* In some cases the kernel might pin the veth links between host and container even after the namespace
+ * died. Hence, let's better remove them explicitly too. */
+
+ if (isempty(primary) && strv_isempty(pairs))
+ return 0;
+
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to connect to netlink: %m");
+
+ remove_one_link(rtnl, primary);
+
+ STRV_FOREACH_PAIR(a, b, pairs)
+ remove_one_link(rtnl, *a);
+
+ return 0;
+}
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