Add option to define target routing table for protocol routes.

This unifies source-routing for both IPv6 and IPv4 (default off).

Based on a patch by Kristian Evensen

diff --git a/interface-ip.c b/interface-ip.c
index e2655632c285baf76a9d0c034b1db47d3784b498..2444cda2128e4505b67186bd1ea85d9839fad17c 100644 (file)
--- a/interface-ip.c
+++ b/interface-ip.c
@@ -90,28 +90,41 @@ match_if_addr(union if_addr *a1, union if_addr *a2, int mask)
        return !memcmp(p1, p2, sizeof(*p1));
 }
 
-static int set_ipv6_source_policy(bool add, const union if_addr *addr, uint8_t mask, int ifindex)
+static int set_ip_source_policy(bool add, bool v6, unsigned int priority,
+               const union if_addr *addr, uint8_t mask, struct interface *iface)
 {
+
+
        struct iprule rule = {
-               .flags = IPRULE_INET6 | IPRULE_SRC | IPRULE_LOOKUP | IPRULE_PRIORITY,
-               .priority = 65535,
-               .lookup = interface_ip_resolve_v6_rtable(ifindex),
+               .flags = IPRULE_SRC | IPRULE_LOOKUP | IPRULE_PRIORITY,
+               .priority = priority,
+               .lookup = (v6) ? iface->ip6table : iface->ip4table,
                .src_addr = *addr,
                .src_mask = mask,
        };
 
+       if (!rule.lookup)
+               return 0;
+
+       rule.flags |= (v6) ? IPRULE_INET6 : IPRULE_INET4;
+
        return (add) ? system_add_iprule(&rule) : system_del_iprule(&rule);
 }
 
-static int set_ipv6_lo_policy(bool add, int ifindex)
+static int set_ip_lo_policy(bool add, bool v6, struct interface *iface)
 {
        struct iprule rule = {
-               .flags = IPRULE_INET6 | IPRULE_IN | IPRULE_LOOKUP | IPRULE_PRIORITY,
-               .priority = 65535,
-               .lookup = interface_ip_resolve_v6_rtable(ifindex),
+               .flags = IPRULE_IN | IPRULE_LOOKUP | IPRULE_PRIORITY,
+               .priority = IPRULE_PRIORITY_NW + iface->l3_dev.dev->ifindex,
+               .lookup = (v6) ? iface->ip6table : iface->ip4table,
                .in_dev = "lo"
        };
 
+       if (!rule.lookup)
+               return 0;
+
+       rule.flags |= (v6) ? IPRULE_INET6 : IPRULE_INET4;
+
        return (add) ? system_add_iprule(&rule) : system_del_iprule(&rule);
 }
 
@@ -246,7 +259,7 @@ interface_ip_add_route(struct interface *iface, struct blob_attr *attr, bool v6)
        struct blob_attr *tb[__ROUTE_MAX], *cur;
        struct device_route *route;
        int af = v6 ? AF_INET6 : AF_INET;
-       bool is_v6_proto_route = v6 && iface;
+       bool is_proto_route = !!iface;
 
        blobmsg_parse(route_attr, __ROUTE_MAX, tb, blobmsg_data(attr), blobmsg_data_len(attr));
 
@@ -300,8 +313,8 @@ interface_ip_add_route(struct interface *iface, struct blob_attr *attr, bool v6)
        }
 
        // Use source-based routing
-       if (is_v6_proto_route) {
-               route->table = interface_ip_resolve_v6_rtable(iface->l3_dev.dev->ifindex);
+       if (is_proto_route) {
+               route->table = (v6) ? iface->ip6table : iface->ip4table;
                route->flags |= DEVROUTE_SRCTABLE;
        }
 
@@ -394,6 +407,7 @@ interface_update_proto_addr(struct vlist_tree *tree,
        struct device *dev;
        struct device_addr *a_new = NULL, *a_old = NULL;
        bool keep = false;
+       bool v6 = false;
 
        ip = container_of(tree, struct interface_ip_settings, addr);
        iface = ip->iface;
@@ -434,7 +448,16 @@ interface_update_proto_addr(struct vlist_tree *tree,
                        interface_handle_subnet_route(iface, a_old, false);
 
                        if ((a_old->flags & DEVADDR_FAMILY) == DEVADDR_INET6)
-                               set_ipv6_source_policy(false, &a_old->addr, a_old->mask, dev->ifindex);
+                               v6 = true;
+
+                       //This is needed for source routing to work correctly. If a device
+                       //has two connections to a network using the same subnet, adding
+                       //only the network-rule will cause packets to be routed through the
+                       //first matching network (source IP matches both masks).
+                       set_ip_source_policy(false, v6, IPRULE_PRIORITY_ADDR, &a_old->addr,
+                               (v6) ? 128 : 32, iface);
+                       set_ip_source_policy(false, v6, IPRULE_PRIORITY_NW, &a_old->addr,
+                               a_old->mask, iface);
 
                        system_del_address(dev, a_old);
                }
@@ -447,7 +470,12 @@ interface_update_proto_addr(struct vlist_tree *tree,
                        system_add_address(dev, a_new);
 
                        if ((a_new->flags & DEVADDR_FAMILY) == DEVADDR_INET6)
-                               set_ipv6_source_policy(true, &a_new->addr, a_new->mask, dev->ifindex);
+                               v6 = true;
+
+                       set_ip_source_policy(true, v6, IPRULE_PRIORITY_ADDR, &a_new->addr,
+                               (v6) ? 128 : 32, iface);
+                       set_ip_source_policy(true, v6, IPRULE_PRIORITY_NW, &a_new->addr,
+                               a_new->mask, iface);
 
                        if ((a_new->flags & DEVADDR_OFFLINK) || iface->metric)
                                interface_handle_subnet_route(iface, a_new, true);
@@ -758,8 +786,8 @@ interface_update_prefix(struct vlist_tree *tree,
                // Set null-route to avoid routing loops and set routing policy
                system_add_route(NULL, &route);
                if (prefix_new->iface)
-                       set_ipv6_source_policy(true, &route.addr, route.mask,
-                                       prefix_new->iface->l3_dev.dev->ifindex);
+                       set_ip_source_policy(true, true, IPRULE_PRIORITY_NW, &route.addr,
+                                       route.mask, prefix_new->iface);
 
 
                interface_update_prefix_assignments(prefix_new, true);
@@ -768,8 +796,8 @@ interface_update_prefix(struct vlist_tree *tree,
 
                // Remove null-route
                if (prefix_old->iface)
-                       set_ipv6_source_policy(false, &route.addr, route.mask,
-                                       prefix_old->iface->l3_dev.dev->ifindex);
+                       set_ip_source_policy(false, true, IPRULE_PRIORITY_NW, &route.addr,
+                                       route.mask, prefix_old->iface);
                system_del_route(NULL, &route);
        }
 
@@ -841,11 +869,6 @@ interface_ip_set_ula_prefix(const char *prefix)
        }
 }
 
-int interface_ip_resolve_v6_rtable(int ifindex)
-{
-       return ifindex + 1000;
-}
-
 void
 interface_add_dns_server(struct interface_ip_settings *ip, const char *str)
 {
@@ -1041,7 +1064,8 @@ void interface_ip_set_enabled(struct interface_ip_settings *ip, bool enabled)
                        if (!strcmp(a->name, ip->iface->name))
                                interface_set_prefix_address(a, c, ip->iface, enabled);
 
-       set_ipv6_lo_policy(enabled, dev->ifindex);
+       set_ip_lo_policy(enabled, true, ip->iface);
+       set_ip_lo_policy(enabled, false, ip->iface);
 }
 
 void

diff --git a/interface-ip.h b/interface-ip.h
index c2213fda62106fe4ece96fc8dbd19fa41aafb076..4be97f2824b3b599ebc5f3646cf61dfc799e2ef7 100644 (file)
--- a/interface-ip.h
+++ b/interface-ip.h
@@ -144,6 +144,5 @@ struct device_prefix* interface_ip_add_device_prefix(struct interface *iface,
                struct in6_addr *excl_addr, uint8_t excl_length);
 void interface_ip_set_ula_prefix(const char *prefix);
 void interface_refresh_assignments(bool hint);
-int interface_ip_resolve_v6_rtable(int ifindex);
 
 #endif

diff --git a/interface.c b/interface.c
index a2c3f44fb6c84b57953e58f2c58ef2b4d10f9adc..42e5a8248c6d37b9382fb8a30c57411e34ccc0a1 100644 (file)
--- a/interface.c
+++ b/interface.c
@@ -26,6 +26,7 @@
 
 struct vlist_tree interfaces;
 static LIST_HEAD(iface_all_users);
+static unsigned int interface_serial = 0;
 
 enum {
        IFACE_ATTR_IFNAME,
@@ -39,6 +40,8 @@ enum {
        IFACE_ATTR_INTERFACE,
        IFACE_ATTR_IP6ASSIGN,
        IFACE_ATTR_IP6HINT,
+       IFACE_ATTR_IP4TABLE,
+       IFACE_ATTR_IP6TABLE,
        IFACE_ATTR_MAX
 };
 
@@ -54,6 +57,8 @@ static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = {
        [IFACE_ATTR_INTERFACE] = { .name = "interface", .type = BLOBMSG_TYPE_STRING },
        [IFACE_ATTR_IP6ASSIGN] = { .name = "ip6assign", .type = BLOBMSG_TYPE_INT32 },
        [IFACE_ATTR_IP6HINT] = { .name = "ip6hint", .type = BLOBMSG_TYPE_STRING },
+       [IFACE_ATTR_IP4TABLE] = { .name = "ip4table", .type = BLOBMSG_TYPE_STRING },
+       [IFACE_ATTR_IP6TABLE] = { .name = "ip6table", .type = BLOBMSG_TYPE_STRING },
 };
 
 static const union config_param_info iface_attr_info[IFACE_ATTR_MAX] = {
@@ -497,6 +502,18 @@ interface_init(struct interface *iface, const char *name,
                iface->config_ip.assignment_hint = strtol(blobmsg_get_string(cur), NULL, 16) &
                                ~((1 << (64 - iface->config_ip.assignment_length)) - 1);
 
+       if ((cur = tb[IFACE_ATTR_IP4TABLE])) {
+               if (!system_resolve_rt_table(blobmsg_data(cur), &iface->ip4table))
+                       DPRINTF("Failed to resolve routing table: %s\n", (char *) blobmsg_data(cur));
+       }
+
+       // Set a default exteranl routing table for IPv6 to do source-based-filtering
+       iface->ip6table = 1000 + ++interface_serial;
+       if ((cur = tb[IFACE_ATTR_IP6TABLE])) {
+               if (!system_resolve_rt_table(blobmsg_data(cur), &iface->ip6table))
+                       DPRINTF("Failed to resolve routing table: %s\n", (char *) blobmsg_data(cur));
+       }
+
        iface->config_autostart = iface->autostart;
 }
 

diff --git a/interface.h b/interface.h
index 0c56b3640c30376857173d1fede1785316d2375c..d1869030c279cb928b428ac7f2630edd32f075c4 100644 (file)
--- a/interface.h
+++ b/interface.h
@@ -118,6 +118,8 @@ struct interface {
        struct vlist_tree host_routes;
 
        int metric;
+       unsigned int ip4table;
+       unsigned int ip6table;
 
        /* errors/warnings while trying to bring up the interface */
        struct list_head errors;

diff --git a/iprule.h b/iprule.h
index 4b10760c9096f687f269264e6f2f28cdda8b4d73..2ac01b93e24f7de13d8dbcf5a52598bd3307bd00 100644 (file)
--- a/iprule.h
+++ b/iprule.h
@@ -17,6 +17,9 @@
 
 #include "interface-ip.h"
 
+#define IPRULE_PRIORITY_ADDR 80000
+#define IPRULE_PRIORITY_NW 90000
+
 enum iprule_flags {
        /* address family for rule */
        IPRULE_INET4            = (0 << 0),

diff --git a/proto.c b/proto.c
index 676852d8b05239cb76175e4f88857161868ac971..dff5bbb736f684e369aec8661256fe6a6bca61f9 100644 (file)
--- a/proto.c
+++ b/proto.c
@@ -252,8 +252,9 @@ parse_gateway_option(struct interface *iface, struct blob_attr *attr, bool v6)
        route->mask = 0;
        route->flags = (v6 ? DEVADDR_INET6 : DEVADDR_INET4);
 
-       if (v6) {
-               route->table = interface_ip_resolve_v6_rtable(iface->l3_dev.dev->ifindex);
+       unsigned int table = (v6) ? iface->ip6table : iface->ip4table;
+       if (table) {
+               route->table = table;
                route->flags |= DEVROUTE_SRCTABLE;
        }