IPv6: fix wrap-arounds in address lifetimes

[project/netifd.git] / interface-ip.c

diff --git a/interface-ip.c b/interface-ip.c
index e265563..47747cb 100644 (file)
--- a/interface-ip.c
+++ b/interface-ip.c
@@ -17,6 +17,7 @@
 #include <stdio.h>
 #include <unistd.h>
 
+#include <limits.h>
 #include <arpa/inet.h>
 
 #include "netifd.h"
@@ -90,28 +91,41 @@ 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 +260,7 @@ 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 +314,8 @@ 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;
        }
 
@@ -315,8 +329,12 @@ interface_ip_add_route(struct interface *iface, struct blob_attr *attr, bool v6)
                        route->flags |= DEVROUTE_TABLE;
        }
 
-       if ((cur = tb[ROUTE_VALID]) != NULL)
-               route->valid_until = system_get_rtime() + blobmsg_get_u32(cur);
+       if ((cur = tb[ROUTE_VALID]) != NULL) {
+               int64_t valid = blobmsg_get_u32(cur);
+               int64_t valid_until = valid + (int64_t)system_get_rtime();
+               if (valid_until <= LONG_MAX && valid != 0xffffffffLL) // Catch overflow
+                       route->valid_until = valid_until;
+       }
 
        vlist_add(&ip->route, &route->node, route);
        return;
@@ -394,6 +412,7 @@ 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 +453,16 @@ 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 +475,12 @@ 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 +791,8 @@ 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 +801,8 @@ 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 +874,6 @@ 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 +1069,8 @@ 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