From 587655b45085fcfc9c575792640c21c6ffb24f42 Mon Sep 17 00:00:00 2001 From: Steven Barth Date: Sat, 11 May 2013 12:56:02 +0200 Subject: [PATCH] IPv6: Use source-routing to allow multi-wan --- interface-ip.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++-- interface-ip.h | 4 ++++ proto.c | 6 ++++++ system-linux.c | 3 ++- 4 files changed, 62 insertions(+), 3 deletions(-) diff --git a/interface-ip.c b/interface-ip.c index afdf67b..e0bcdc0 100644 --- a/interface-ip.c +++ b/interface-ip.c @@ -90,6 +90,19 @@ 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) +{ + struct iprule rule = { + .flags = IPRULE_INET6 | IPRULE_SRC | IPRULE_LOOKUP | IPRULE_PRIORITY, + .priority = 65535, + .lookup = interface_ip_resolve_v6_rtable(ifindex), + .src_addr = *addr, + .src_mask = mask, + }; + + return (add) ? system_add_iprule(&rule) : system_del_iprule(&rule); +} + static bool __find_ip_addr_target(struct interface_ip_settings *ip, union if_addr *a, bool v6) { @@ -102,7 +115,13 @@ __find_ip_addr_target(struct interface_ip_settings *ip, union if_addr *a, bool v if (v6 != ((addr->flags & DEVADDR_FAMILY) == DEVADDR_INET6)) continue; - if (!match_if_addr(&addr->addr, a, addr->mask)) + // Handle offlink addresses correctly + unsigned int mask = addr->mask; + if ((addr->flags & DEVADDR_FAMILY) == DEVADDR_INET6 && + (addr->flags & DEVADDR_OFFLINK)) + mask = 128; + + if (!match_if_addr(&addr->addr, a, mask)) continue; return true; @@ -188,6 +207,7 @@ interface_ip_add_target_route(union if_addr *addr, bool v6) memcpy(&route->nexthop, &r_next->nexthop, sizeof(route->nexthop)); route->mtu = r_next->mtu; route->metric = r_next->metric; + route->table = r_next->table; done: route->iface = iface; @@ -205,6 +225,7 @@ 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; blobmsg_parse(route_attr, __ROUTE_MAX, tb, blobmsg_data(attr), blobmsg_data_len(attr)); @@ -257,6 +278,12 @@ interface_ip_add_route(struct interface *iface, struct blob_attr *attr, bool v6) route->flags |= DEVROUTE_MTU; } + // Use source-based routing + if (is_v6_proto_route) { + route->table = interface_ip_resolve_v6_rtable(iface->l3_dev.dev->ifindex); + route->flags |= DEVROUTE_SRCTABLE; + } + if ((cur = tb[ROUTE_TABLE]) != NULL) { if (!system_resolve_rt_table(blobmsg_data(cur), &route->table)) { DPRINTF("Failed to resolve routing table: %s\n", (char *) blobmsg_data(cur)); @@ -384,6 +411,10 @@ interface_update_proto_addr(struct vlist_tree *tree, if (node_old) { if (!(a_old->flags & DEVADDR_EXTERNAL) && a_old->enabled && !keep) { 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); + system_del_address(dev, a_old); } free(a_old); @@ -393,6 +424,10 @@ interface_update_proto_addr(struct vlist_tree *tree, a_new->enabled = true; if (!(a_new->flags & DEVADDR_EXTERNAL) && !keep) { 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); + if ((a_new->flags & DEVADDR_OFFLINK) || iface->metric) interface_handle_subnet_route(iface, a_new, true); } @@ -687,6 +722,7 @@ interface_update_prefix(struct vlist_tree *tree, route.mask = (node_new) ? prefix_new->length : prefix_old->length; route.addr.in6 = (node_new) ? prefix_new->addr : prefix_old->addr; + struct device_prefix_assignment *c; struct interface *iface; @@ -698,14 +734,21 @@ interface_update_prefix(struct vlist_tree *tree, if ((iface = vlist_find(&interfaces, c->name, iface, node))) interface_set_prefix_address(c, prefix_new, iface, true); } else if (node_new) { - // Set null-route to avoid routing loops + // 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); + interface_update_prefix_assignments(prefix_new, true); } else if (node_old) { interface_update_prefix_assignments(prefix_old, false); // Remove null-route + if (prefix_old->iface) + set_ipv6_source_policy(false, &route.addr, route.mask, + prefix_old->iface->l3_dev.dev->ifindex); system_del_route(NULL, &route); } @@ -777,6 +820,11 @@ 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) { diff --git a/interface-ip.h b/interface-ip.h index 607999e..cd6ec84 100644 --- a/interface-ip.h +++ b/interface-ip.h @@ -39,6 +39,9 @@ enum device_addr_flags { /* route resides in different table */ DEVROUTE_TABLE = (1 << 7), + + /* route resides in default source-route table */ + DEVROUTE_SRCTABLE = (1 << 8), }; union if_addr { @@ -141,5 +144,6 @@ 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/proto.c b/proto.c index 83c6345..676852d 100644 --- a/proto.c +++ b/proto.c @@ -251,6 +251,12 @@ 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); + route->flags |= DEVROUTE_SRCTABLE; + } + vlist_add(&iface->proto_ip.route, &route->node, route); return true; diff --git a/system-linux.c b/system-linux.c index 9d2e92f..4401f78 100644 --- a/system-linux.c +++ b/system-linux.c @@ -965,7 +965,8 @@ static int system_rt(struct device *dev, struct device_route *route, int cmd) unsigned char scope = (cmd == RTM_DELROUTE) ? RT_SCOPE_NOWHERE : (have_gw) ? RT_SCOPE_UNIVERSE : RT_SCOPE_LINK; - unsigned int table = (route->flags & DEVROUTE_TABLE) ? route->table : RT_TABLE_MAIN; + unsigned int table = (route->flags & (DEVROUTE_TABLE | DEVROUTE_SRCTABLE)) + ? route->table : RT_TABLE_MAIN; struct rtmsg rtm = { .rtm_family = (alen == 4) ? AF_INET : AF_INET6, -- 2.25.1