From dc7ba66de87c2f624e906238e5a74b03da7c3b46 Mon Sep 17 00:00:00 2001 From: Steven Barth Date: Mon, 3 Jun 2013 18:42:10 +0200 Subject: [PATCH] IPv6: Improve source-routing policies * Set a default policy-failed rule per prefix (based on a patch by Jonas Gorski) * Use input interface in addition to source for filtering * Avoid duplicate routing policies --- interface-ip.c | 80 +++++++++++++++++++++++++++++++++----------------- iprule.h | 1 + system-linux.c | 6 ++++ 3 files changed, 60 insertions(+), 27 deletions(-) diff --git a/interface-ip.c b/interface-ip.c index 165d4a8..a945147 100644 --- a/interface-ip.c +++ b/interface-ip.c @@ -92,20 +92,35 @@ match_if_addr(union if_addr *a1, union if_addr *a2, int mask) } static int set_ip_source_policy(bool add, bool v6, unsigned int priority, - const union if_addr *addr, uint8_t mask, struct interface *iface) + const union if_addr *addr, uint8_t mask, struct interface *iface, + struct interface *in_iface, const char *action) { - - struct iprule rule = { - .flags = IPRULE_SRC | IPRULE_LOOKUP | IPRULE_PRIORITY, - .priority = priority, - .lookup = (v6) ? iface->ip6table : iface->ip4table, - .src_addr = *addr, - .src_mask = mask, + .flags = IPRULE_PRIORITY, + .priority = priority }; - if (!rule.lookup) - return 0; + if (addr) { + rule.flags |= IPRULE_SRC; + rule.src_addr = *addr; + rule.src_mask = mask; + } + + if (iface) { + rule.flags |= IPRULE_LOOKUP; + rule.lookup = (v6) ? iface->ip6table : iface->ip4table; + + if (!rule.lookup) + return 0; + } else if (action) { + rule.flags |= IPRULE_ACTION; + system_resolve_iprule_action(action, &rule.action); + } + + if (in_iface && in_iface->l3_dev.dev) { + rule.flags |= IPRULE_IN; + strcpy(rule.in_dev, in_iface->l3_dev.dev->ifname); + } rule.flags |= (v6) ? IPRULE_INET6 : IPRULE_INET4; @@ -460,9 +475,9 @@ interface_update_proto_addr(struct vlist_tree *tree, //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); + (v6) ? 128 : 32, iface, NULL, NULL); set_ip_source_policy(false, v6, IPRULE_PRIORITY_NW, &a_old->addr, - a_old->mask, iface); + a_old->mask, iface, NULL, NULL); system_del_address(dev, a_old); } @@ -478,9 +493,9 @@ interface_update_proto_addr(struct vlist_tree *tree, v6 = true; set_ip_source_policy(true, v6, IPRULE_PRIORITY_ADDR, &a_new->addr, - (v6) ? 128 : 32, iface); + (v6) ? 128 : 32, iface, NULL, NULL); set_ip_source_policy(true, v6, IPRULE_PRIORITY_NW, &a_new->addr, - a_new->mask, iface); + a_new->mask, iface, NULL, NULL); if ((a_new->flags & DEVADDR_OFFLINK) || iface->metric) interface_handle_subnet_route(iface, a_new, true); @@ -589,9 +604,24 @@ interface_set_prefix_address(struct device_prefix_assignment *assignment, if (!addr.valid_until || addr.valid_until - now > 7200) addr.valid_until = now + 7200; system_add_address(l3_downlink, &addr); + if (prefix->iface) { + set_ip_source_policy(false, true, IPRULE_PRIORITY_NW, &addr.addr, + addr.mask, prefix->iface, iface, NULL); + + set_ip_source_policy(false, true, IPRULE_PRIORITY_REJECT, &addr.addr, + addr.mask, NULL, iface, "unreachable"); + } + assignment->enabled = false; } else if (add && (iface->state == IFS_UP || iface->state == IFS_SETUP)) { system_add_address(l3_downlink, &addr); + if (prefix->iface && !assignment->enabled) { + set_ip_source_policy(true, true, IPRULE_PRIORITY_REJECT, &addr.addr, + addr.mask, NULL, iface, "unreachable"); + + set_ip_source_policy(true, true, IPRULE_PRIORITY_NW, &addr.addr, + addr.mask, prefix->iface, iface, NULL); + } if (uplink && uplink->l3_dev.dev) { int mtu = system_update_ipv6_mtu( uplink->l3_dev.dev, 0); @@ -775,21 +805,12 @@ 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 and set routing policy + // Set null-route to avoid routing loops system_add_route(NULL, &route); - if (prefix_new->iface) - set_ip_source_policy(true, true, IPRULE_PRIORITY_NW, &route.addr, - route.mask, prefix_new->iface); - - 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_ip_source_policy(false, true, IPRULE_PRIORITY_NW, &route.addr, - route.mask, prefix_old->iface); + interface_update_prefix_assignments(prefix_old, false); system_del_route(NULL, &route); } @@ -1061,8 +1082,13 @@ 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_ip_lo_policy(enabled, true, ip->iface); - set_ip_lo_policy(enabled, false, ip->iface); + if (ip->iface && ip->iface->l3_dev.dev) { + set_ip_lo_policy(enabled, true, ip->iface); + set_ip_lo_policy(enabled, false, ip->iface); + + set_ip_source_policy(enabled, true, IPRULE_PRIORITY_REJECT + ip->iface->l3_dev.dev->ifindex, + NULL, 0, NULL, ip->iface, "failed_policy"); + } } void diff --git a/iprule.h b/iprule.h index 2ac01b9..e4ceee0 100644 --- a/iprule.h +++ b/iprule.h @@ -19,6 +19,7 @@ #define IPRULE_PRIORITY_ADDR 80000 #define IPRULE_PRIORITY_NW 90000 +#define IPRULE_PRIORITY_REJECT 2000000000 enum iprule_flags { /* address family for rule */ diff --git a/system-linux.c b/system-linux.c index c6d81e6..4299a61 100644 --- a/system-linux.c +++ b/system-linux.c @@ -36,6 +36,10 @@ #include #include +#ifndef RTN_FAILED_POLICY +#define RTN_FAILED_POLICY 12 +#endif + #include #include #include @@ -1255,6 +1259,8 @@ bool system_resolve_iprule_action(const char *action, unsigned int *id) n = RTN_UNICAST; else if (!strcmp(action, "throw")) n = RTN_THROW; + else if (!strcmp(action, "failed_policy")) + n = RTN_FAILED_POLICY; else { n = strtoul(action, &e, 0); if (!e || *e || e == action || n > 255) -- 2.30.2