From 2f31bff38d4dc2f36006ded6b8a7d039cb569eaa Mon Sep 17 00:00:00 2001 From: Steven Barth Date: Fri, 17 May 2013 16:24:37 +0200 Subject: [PATCH] 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 --- interface-ip.c | 70 +++++++++++++++++++++++++++++++++----------------- interface-ip.h | 1 - interface.c | 17 ++++++++++++ interface.h | 2 ++ iprule.h | 3 +++ proto.c | 5 ++-- 6 files changed, 72 insertions(+), 26 deletions(-) diff --git a/interface-ip.c b/interface-ip.c index e265563..2444cda 100644 --- 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 c2213fd..4be97f2 100644 --- 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 a2c3f44..42e5a82 100644 --- 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 0c56b36..d186903 100644 --- 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 4b10760..2ac01b9 100644 --- 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 676852d..dff5bbb 100644 --- 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; } -- 2.30.2