1 files changed, 103 insertions, 37 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index aa4411c81e7e..fe3966a9c999 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2440,7 +2440,8 @@ static int ip6_convert_metrics(struct mx6_config *mxc,
 
 static struct rt6_info *ip6_nh_lookup_table(struct net *net,
                                             struct fib6_config *cfg,
-                                            const struct in6_addr *gw_addr)
+                                            const struct in6_addr *gw_addr,
+                                            u32 tbid, int flags)
 {
         struct flowi6 fl6 = {
                 .flowi6_oif = cfg->fc_ifindex,
@@ -2449,15 +2450,15 @@ static struct rt6_info *ip6_nh_lookup_table(struct net *net,
         };
         struct fib6_table *table;
         struct rt6_info *rt;
-        int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_IGNORE_LINKSTATE;
 
-        table = fib6_get_table(net, cfg->fc_table);
+        table = fib6_get_table(net, tbid);
         if (!table)
                 return NULL;
 
         if (!ipv6_addr_any(&cfg->fc_prefsrc))
                 flags |= RT6_LOOKUP_F_HAS_SADDR;
 
+        flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
         rt = ip6_pol_route(net, table, cfg->fc_ifindex, &fl6, flags);
 
         /* if table lookup failed, fall back to full lookup */
@@ -2469,6 +2470,82 @@ static struct rt6_info *ip6_nh_lookup_table(struct net *net,
         return rt;
 }
 
+static int ip6_route_check_nh_onlink(struct net *net,
+                                     struct fib6_config *cfg,
+                                     struct net_device *dev,
+                                     struct netlink_ext_ack *extack)
+{
+        u32 tbid = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
+        const struct in6_addr *gw_addr = &cfg->fc_gateway;
+        u32 flags = RTF_LOCAL | RTF_ANYCAST | RTF_REJECT;
+        struct rt6_info *grt;
+        int err;
+
+        err = 0;
+        grt = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0);
+        if (grt) {
+                if (grt->rt6i_flags & flags || dev != grt->dst.dev) {
+                        NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway");
+                        err = -EINVAL;
+                }
+
+                ip6_rt_put(grt);
+        }
+
+        return err;
+}
+
+static int ip6_route_check_nh(struct net *net,
+                              struct fib6_config *cfg,
+                              struct net_device **_dev,
+                              struct inet6_dev **idev)
+{
+        const struct in6_addr *gw_addr = &cfg->fc_gateway;
+        struct net_device *dev = _dev ? *_dev : NULL;
+        struct rt6_info *grt = NULL;
+        int err = -EHOSTUNREACH;
+
+        if (cfg->fc_table) {
+                int flags = RT6_LOOKUP_F_IFACE;
+
+                grt = ip6_nh_lookup_table(net, cfg, gw_addr,
+                                          cfg->fc_table, flags);
+                if (grt) {
+                        if (grt->rt6i_flags & RTF_GATEWAY ||
+                            (dev && dev != grt->dst.dev)) {
+                                ip6_rt_put(grt);
+                                grt = NULL;
+                        }
+                }
+        }
+
+        if (!grt)
+                grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1);
+
+        if (!grt)
+                goto out;
+
+        if (dev) {
+                if (dev != grt->dst.dev) {
+                        ip6_rt_put(grt);
+                        goto out;
+                }
+        } else {
+                *_dev = dev = grt->dst.dev;
+                *idev = grt->rt6i_idev;
+                dev_hold(dev);
+                in6_dev_hold(grt->rt6i_idev);
+        }
+
+        if (!(grt->rt6i_flags & RTF_GATEWAY))
+                err = 0;
+
+        ip6_rt_put(grt);
+
+out:
+        return err;
+}
+
 static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg,
                                               struct netlink_ext_ack *extack)
 {
@@ -2520,6 +2597,21 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg,
         if (cfg->fc_metric == 0)
                 cfg->fc_metric = IP6_RT_PRIO_USER;
 
+        if (cfg->fc_flags & RTNH_F_ONLINK) {
+                if (!dev) {
+                        NL_SET_ERR_MSG(extack,
+                                       "Nexthop device required for onlink");
+                        err = -ENODEV;
+                        goto out;
+                }
+
+                if (!(dev->flags & IFF_UP)) {
+                        NL_SET_ERR_MSG(extack, "Nexthop device is not up");
+                        err = -ENETDOWN;
+                        goto out;
+                }
+        }
+
         err = -ENOBUFS;
         if (cfg->fc_nlinfo.nlh &&
             !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
@@ -2664,8 +2756,6 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg,
                 rt->rt6i_gateway = *gw_addr;
 
                 if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {
-                        struct rt6_info *grt = NULL;
-
                         /* IPv6 strictly inhibits using not link-local
                            addresses as nexthop address.
                            Otherwise, router will not able to send redirects.
@@ -2682,40 +2772,12 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg,
                                 goto out;
                         }
 
-                        if (cfg->fc_table) {
-                                grt = ip6_nh_lookup_table(net, cfg, gw_addr);
-
-                                if (grt) {
-                                        if (grt->rt6i_flags & RTF_GATEWAY ||
-                                            (dev && dev != grt->dst.dev)) {
-                                                ip6_rt_put(grt);
-                                                grt = NULL;
-                                        }
-                                }
-                        }
-
-                        if (!grt)
-                                grt = rt6_lookup(net, gw_addr, NULL,
-                                                 cfg->fc_ifindex, 1);
-
-                        err = -EHOSTUNREACH;
-                        if (!grt)
-                                goto out;
-                        if (dev) {
-                                if (dev != grt->dst.dev) {
-                                        ip6_rt_put(grt);
-                                        goto out;
-                                }
+                        if (cfg->fc_flags & RTNH_F_ONLINK) {
+                                err = ip6_route_check_nh_onlink(net, cfg, dev,
+                                                                extack);
                         } else {
-                                dev = grt->dst.dev;
-                                idev = grt->rt6i_idev;
-                                dev_hold(dev);
-                                in6_dev_hold(grt->rt6i_idev);
+                                err = ip6_route_check_nh(net, cfg, &dev, &idev);
                         }
-                        if (!(grt->rt6i_flags & RTF_GATEWAY))
-                                err = 0;
-                        ip6_rt_put(grt);
-
                         if (err)
                                 goto out;
                 }
@@ -2757,6 +2819,7 @@ install_route:
         if (!(rt->rt6i_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
             !netif_carrier_ok(dev))
                 rt->rt6i_nh_flags |= RTNH_F_LINKDOWN;
+        rt->rt6i_nh_flags |= (cfg->fc_flags & RTNH_F_ONLINK);
         rt->dst.dev = dev;
         rt->rt6i_idev = idev;
         rt->rt6i_table = table;
@@ -3826,6 +3889,8 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
         if (rtm->rtm_flags & RTM_F_CLONED)
                 cfg->fc_flags |= RTF_CACHE;
 
+        cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
+
         cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
         cfg->fc_nlinfo.nlh = nlh;
         cfg->fc_nlinfo.nl_net = sock_net(skb->sk);
@@ -4231,6 +4296,7 @@ static int rt6_nexthop_info(struct sk_buff *skb, struct rt6_info *rt,
                         goto nla_put_failure;
         }
 
+        *flags |= (rt->rt6i_nh_flags & RTNH_F_ONLINK);
         if (rt->rt6i_nh_flags & RTNH_F_OFFLOAD)
                 *flags |= RTNH_F_OFFLOAD;