Merge pull request #2973 from tomponline/tp-gw-dev

doc/api-extensions.md

@@ -84,3 +84,10 @@ For IPv6 addresses it will check the following sysctl values and fail with an er
 net.ipv6.conf.[link].proxy_ndp=1
 net.ipv6.conf.[link].forwarding=1
 ```
+
+## network\_gateway\_device\_route
+
+This introduces the ability to specify `lxc.net.[i].ipv4.gateway` and/or
+`lxc.net.[i].ipv6.gateway` with a value of `dev` which will cause the default gateway
+inside the container to be created as a device route without destination gateway IP needed.
+This is primarily intended for use with layer 3 networking devices, such as IPVLAN.

doc/lxc.container.conf.sgml.in

@@ -665,6 +665,9 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
               the gateway. <option>auto</option> is only available when
               using the <option>veth</option>,
               <option>macvlan</option> and <option>ipvlan</option> network types.
+              Can also have the special value of <option>dev</option>,
+              which means to set the default gateway as a device route.
+              This is primarily for use with layer 3 network modes, such as IPVLAN.
             </para>
           </listitem>
         </varlistentry>
@@ -699,6 +702,9 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
               the gateway. <option>auto</option> is only available when
               using the <option>veth</option>,
               <option>macvlan</option> and <option>ipvlan</option> network types.
+              Can also have the special value of <option>dev</option>,
+              which means to set the default gateway as a device route.
+              This is primarily for use with layer 3 network modes, such as IPVLAN.
             </para>
           </listitem>
         </varlistentry>

src/lxc/api_extensions.h

@@ -47,6 +47,7 @@ static char *api_extensions[] = {
 	"network_veth_routes",
 	"network_ipvlan",
 	"network_l2proxy",
+	"network_gateway_device_route",
 };
 
 static size_t nr_api_extensions = sizeof(api_extensions) / sizeof(*api_extensions);

src/lxc/confile.c

@@ -686,9 +686,13 @@ static int set_config_net_ipv4_gateway(const char *key, const char *value,
 
 	free(netdev->ipv4_gateway);
 
-	if (!strcmp(value, "auto")) {
+	if (strcmp(value, "auto") == 0) {
 		netdev->ipv4_gateway = NULL;
 		netdev->ipv4_gateway_auto = true;
+	} else if (strcmp(value, "dev") == 0) {
+		netdev->ipv4_gateway = NULL;
+		netdev->ipv4_gateway_auto = false;
+		netdev->ipv4_gateway_dev = true;
 	} else {
 		int ret;
 		struct in_addr *gw;
@@ -853,9 +857,13 @@ static int set_config_net_ipv6_gateway(const char *key, const char *value,
 
 	free(netdev->ipv6_gateway);
 
-	if (!strcmp(value, "auto")) {
+	if (strcmp(value, "auto") == 0) {
 		netdev->ipv6_gateway = NULL;
 		netdev->ipv6_gateway_auto = true;
+	} else if (strcmp(value, "dev") == 0) {
+		netdev->ipv6_gateway = NULL;
+		netdev->ipv6_gateway_auto = false;
+		netdev->ipv6_gateway_dev = true;
 	} else {
 		int ret;
 		struct in6_addr *gw;
@@ -5625,6 +5633,8 @@ static int get_config_net_ipv4_gateway(const char *key, char *retv, int inlen,
 
 	if (netdev->ipv4_gateway_auto) {
 		strprint(retv, inlen, "auto");
+	} else if (netdev->ipv4_gateway_dev) {
+		strprint(retv, inlen, "dev");
 	} else if (netdev->ipv4_gateway) {
 		inet_ntop(AF_INET, netdev->ipv4_gateway, buf, sizeof(buf));
 		strprint(retv, inlen, "%s", buf);
@@ -5714,6 +5724,8 @@ static int get_config_net_ipv6_gateway(const char *key, char *retv, int inlen,
 
 	if (netdev->ipv6_gateway_auto) {
 		strprint(retv, inlen, "auto");
+	} else if (netdev->ipv6_gateway_dev) {
+		strprint(retv, inlen, "dev");
 	} else if (netdev->ipv6_gateway) {
 		inet_ntop(AF_INET6, netdev->ipv6_gateway, buf, sizeof(buf));
 		strprint(retv, inlen, "%s", buf);

src/lxc/confile_utils.c

@@ -361,6 +361,9 @@ void lxc_log_configured_netdevs(const struct lxc_conf *conf)
 			TRACE("ipv4 gateway auto: %s",
 			      netdev->ipv4_gateway_auto ? "true" : "false");
 
+			TRACE("ipv4 gateway dev: %s",
+			      netdev->ipv4_gateway_dev ? "true" : "false");
+
 			if (netdev->ipv4_gateway) {
 				inet_ntop(AF_INET, netdev->ipv4_gateway,
 					  bufinet4, sizeof(bufinet4));
@@ -377,6 +380,9 @@ void lxc_log_configured_netdevs(const struct lxc_conf *conf)
 			TRACE("ipv6 gateway auto: %s",
 			      netdev->ipv6_gateway_auto ? "true" : "false");
 
+			TRACE("ipv6 gateway dev: %s",
+			      netdev->ipv6_gateway_dev ? "true" : "false");
+
 			if (netdev->ipv6_gateway) {
 				inet_ntop(AF_INET6, netdev->ipv6_gateway,
 					  bufinet6, sizeof(bufinet6));

src/lxc/network.c

@@ -2074,8 +2074,12 @@ static int ip_gateway_add(int family, int ifindex, void *gw)
 	rt->rtm_dst_len = 0;
 
 	err = -EINVAL;
+
+	/* If gateway address not supplied, then a device route will be created instead */
+	if (gw != NULL) {
 		if (nla_put_buffer(nlmsg, RTA_GATEWAY, gw, addrlen))
 			goto out;
+	}
 
 	/* Adding the interface index enables the use of link-local
 	 * addresses for the gateway.
@@ -3480,12 +3484,12 @@ static int lxc_setup_netdev_in_child_namespaces(struct lxc_netdev *netdev)
 	}
 
 	/* We can only set up the default routes after bringing
-	 * up the interface, sine bringing up the interface adds
+	 * up the interface, since bringing up the interface adds
 	 * the link-local routes and we can't add a default
 	 * route if the gateway is not reachable. */
 
 	/* setup ipv4 gateway on the interface */
-	if (netdev->ipv4_gateway) {
+	if (netdev->ipv4_gateway || netdev->ipv4_gateway_dev) {
 		if (!(netdev->flags & IFF_UP)) {
 			ERROR("Cannot add ipv4 gateway for network device "
 			      "\"%s\" when not bringing up the interface", ifname);
@@ -3498,6 +3502,15 @@ static int lxc_setup_netdev_in_child_namespaces(struct lxc_netdev *netdev)
 			return -1;
 		}
 
+		/* Setup device route if ipv4_gateway_dev is enabled */
+		if (netdev->ipv4_gateway_dev) {
+			err = lxc_ipv4_gateway_add(netdev->ifindex, NULL);
+			if (err < 0) {
+				SYSERROR("Failed to setup ipv4 gateway to network device \"%s\"",
+				         ifname);
+				return minus_one_set_errno(-err);
+			}
+		} else {
 			err = lxc_ipv4_gateway_add(netdev->ifindex, netdev->ipv4_gateway);
 			if (err) {
 				err = lxc_ipv4_dest_add(netdev->ifindex, netdev->ipv4_gateway, 32);
@@ -3522,9 +3535,10 @@ static int lxc_setup_netdev_in_child_namespaces(struct lxc_netdev *netdev)
 				}
 			}
 		}
+	}
 
 	/* setup ipv6 gateway on the interface */
-	if (netdev->ipv6_gateway) {
+	if (netdev->ipv6_gateway || netdev->ipv6_gateway_dev) {
 		if (!(netdev->flags & IFF_UP)) {
 			ERROR("Cannot add ipv6 gateway for network device "
 			      "\"%s\" when not bringing up the interface", ifname);
@@ -3537,6 +3551,15 @@ static int lxc_setup_netdev_in_child_namespaces(struct lxc_netdev *netdev)
 			return -1;
 		}
 
+		/* Setup device route if ipv6_gateway_dev is enabled */
+		if (netdev->ipv6_gateway_dev) {
+			err = lxc_ipv6_gateway_add(netdev->ifindex, NULL);
+			if (err < 0) {
+				SYSERROR("Failed to setup ipv6 gateway to network device \"%s\"",
+				         ifname);
+				return minus_one_set_errno(-err);
+			}
+		} else {
 			err = lxc_ipv6_gateway_add(netdev->ifindex, netdev->ipv6_gateway);
 			if (err) {
 				err = lxc_ipv6_dest_add(netdev->ifindex, netdev->ipv6_gateway, 128);
@@ -3563,6 +3586,7 @@ static int lxc_setup_netdev_in_child_namespaces(struct lxc_netdev *netdev)
 				}
 			}
 		}
+	}
 
 	DEBUG("Network device \"%s\" has been setup", current_ifname);
 

src/lxc/network.h

@@ -156,9 +156,11 @@ union netdev_p {
  * @ipv6              : a list of ipv6 addresses to be set on the network device
  * @ipv4_gateway_auto : whether the ipv4 gateway is to be automatically gathered
  *                      from the associated @link
+ * @ipv4_gateway_dev  : whether the ipv4 gateway is to be set as a device route
  * @ipv4_gateway      : ipv4 gateway
  * @ipv6_gateway_auto : whether the ipv6 gateway is to be automatically gathered
  *                      from the associated @link
+ * @ipv6_gateway_dev  : whether the ipv6 gateway is to be set as a device route
  * @ipv6_gateway      : ipv6 gateway
  * @upscript          : a script filename to be executed during interface
  *                      configuration
@@ -179,8 +181,10 @@ struct lxc_netdev {
 	struct lxc_list ipv4;
 	struct lxc_list ipv6;
 	bool ipv4_gateway_auto;
+	bool ipv4_gateway_dev;
 	struct in_addr *ipv4_gateway;
 	bool ipv6_gateway_auto;
+	bool ipv6_gateway_dev;
 	struct in6_addr *ipv6_gateway;
 	char *upscript;
 	char *downscript;

src/tests/parse_config_file.c

@@ -108,6 +108,16 @@ static int set_and_clear_complete_netdev(struct lxc_container *c)
 		return -1;
 	}
 
+	if (!c->set_config_item(c, "lxc.net.1.ipv4.gateway", "auto")) {
+		lxc_error("%s\n", "lxc.net.1.ipv4.gateway");
+		return -1;
+	}
+
+	if (!c->set_config_item(c, "lxc.net.1.ipv4.gateway", "dev")) {
+		lxc_error("%s\n", "lxc.net.1.ipv4.gateway");
+		return -1;
+	}
+
 	if (!c->set_config_item(c, "lxc.net.1.ipv6.address",
 				"2003:db8:1:0:214:1234:fe0b:3596/64")) {
 		lxc_error("%s\n", "lxc.net.1.ipv6.address");
@@ -120,6 +130,16 @@ static int set_and_clear_complete_netdev(struct lxc_container *c)
 		return -1;
 	}
 
+	if (!c->set_config_item(c, "lxc.net.1.ipv6.gateway", "auto")) {
+		lxc_error("%s\n", "lxc.net.1.ipv6.gateway");
+		return -1;
+	}
+
+	if (!c->set_config_item(c, "lxc.net.1.ipv6.gateway", "dev")) {
+		lxc_error("%s\n", "lxc.net.1.ipv6.gateway");
+		return -1;
+	}
+
 	if (!c->set_config_item(c, "lxc.net.1.flags", "up")) {
 		lxc_error("%s\n", "lxc.net.1.flags");
 		return -1;
@@ -781,11 +801,31 @@ int main(int argc, char *argv[])
 		goto non_test_error;
 	}
 
+	if (set_get_compare_clear_save_load(c, "lxc.net.0.ipv4.gateway", "auto", tmpf, true)) {
+		lxc_error("%s\n", "lxc.net.0.ipv4.gateway");
+		goto non_test_error;
+	}
+
+	if (set_get_compare_clear_save_load(c, "lxc.net.0.ipv4.gateway", "dev", tmpf, true)) {
+		lxc_error("%s\n", "lxc.net.0.ipv4.gateway");
+		goto non_test_error;
+	}
+
 	if (set_get_compare_clear_save_load(c, "lxc.net.0.ipv6.gateway", "2003:db8:1::1", tmpf, true)) {
 		lxc_error("%s\n", "lxc.net.0.ipv6.gateway");
 		goto non_test_error;
 	}
 
+	if (set_get_compare_clear_save_load(c, "lxc.net.0.ipv6.gateway", "auto", tmpf, true)) {
+		lxc_error("%s\n", "lxc.net.0.ipv6.gateway");
+		goto non_test_error;
+	}
+
+	if (set_get_compare_clear_save_load(c, "lxc.net.0.ipv6.gateway", "dev", tmpf, true)) {
+		lxc_error("%s\n", "lxc.net.0.ipv6.gateway");
+		goto non_test_error;
+	}
+
 	if (set_get_compare_clear_save_load(c, "lxc.net.0.ipv4.address", "10.0.2.3/24", tmpf, true)) {
 		lxc_error("%s\n", "lxc.net.0.ipv4.address");
 		goto non_test_error;