1 files changed, 154 insertions, 43 deletions

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 1f93a5978f2a..8c5707db53c5 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -15,6 +15,10 @@
 #include <net/ip_fib.h>
 #include <net/netevent.h>
 #include <net/netns/generic.h>
+#if IS_ENABLED(CONFIG_IPV6)
+#include <net/ipv6.h>
+#include <net/addrconf.h>
+#endif
 #include "internal.h"
 
 #define LABEL_NOT_SPECIFIED (1<<20)
@@ -23,11 +27,23 @@
 /* This maximum ha length copied from the definition of struct neighbour */
 #define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, sizeof(unsigned long)))
 
+enum mpls_payload_type {
+        MPT_UNSPEC, /* IPv4 or IPv6 */
+        MPT_IPV4 = 4,
+        MPT_IPV6 = 6,
+
+        /* Other types not implemented:
+         *  - Pseudo-wire with or without control word (RFC4385)
+         *  - GAL (RFC5586)
+         */
+};
+
 struct mpls_route { /* next hop label forwarding entry */
         struct net_device __rcu *rt_dev;
         struct rcu_head         rt_rcu;
         u32                     rt_label[MAX_NEW_LABELS];
         u8                      rt_protocol; /* routing protocol that set this entry */
+        u8                      rt_payload_type;
         u8                      rt_labels;
         u8                      rt_via_alen;
         u8                      rt_via_table;
@@ -58,10 +74,11 @@ static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
         return rcu_dereference_rtnl(dev->mpls_ptr);
 }
 
-static bool mpls_output_possible(const struct net_device *dev)
+bool mpls_output_possible(const struct net_device *dev)
 {
         return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
 }
+EXPORT_SYMBOL_GPL(mpls_output_possible);
 
 static unsigned int mpls_rt_header_size(const struct mpls_route *rt)
 {
@@ -69,13 +86,14 @@ static unsigned int mpls_rt_header_size(const struct mpls_route *rt)
         return rt->rt_labels * sizeof(struct mpls_shim_hdr);
 }
 
-static unsigned int mpls_dev_mtu(const struct net_device *dev)
+unsigned int mpls_dev_mtu(const struct net_device *dev)
 {
         /* The amount of data the layer 2 frame can hold */
         return dev->mtu;
 }
+EXPORT_SYMBOL_GPL(mpls_dev_mtu);
 
-static bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
+bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
 {
         if (skb->len <= mtu)
                 return false;
@@ -85,20 +103,13 @@ static bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
 
         return true;
 }
+EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
 
 static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb,
                         struct mpls_entry_decoded dec)
 {
-        /* RFC4385 and RFC5586 encode other packets in mpls such that
-         * they don't conflict with the ip version number, making
-         * decoding by examining the ip version correct in everything
-         * except for the strangest cases.
-         *
-         * The strange cases if we choose to support them will require
-         * manual configuration.
-         */
-        struct iphdr *hdr4;
-        bool success = true;
+        enum mpls_payload_type payload_type;
+        bool success = false;
 
         /* The IPv4 code below accesses through the IPv4 header
          * checksum, which is 12 bytes into the packet.
@@ -113,23 +124,32 @@ static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb,
         if (!pskb_may_pull(skb, 12))
                 return false;
 
-        /* Use ip_hdr to find the ip protocol version */
-        hdr4 = ip_hdr(skb);
-        if (hdr4->version == 4) {
+        payload_type = rt->rt_payload_type;
+        if (payload_type == MPT_UNSPEC)
+                payload_type = ip_hdr(skb)->version;
+
+        switch (payload_type) {
+        case MPT_IPV4: {
+                struct iphdr *hdr4 = ip_hdr(skb);
                 skb->protocol = htons(ETH_P_IP);
                 csum_replace2(&hdr4->check,
                               htons(hdr4->ttl << 8),
                               htons(dec.ttl << 8));
                 hdr4->ttl = dec.ttl;
+                success = true;
+                break;
         }
-        else if (hdr4->version == 6) {
+        case MPT_IPV6: {
                 struct ipv6hdr *hdr6 = ipv6_hdr(skb);
                 skb->protocol = htons(ETH_P_IPV6);
                 hdr6->hop_limit = dec.ttl;
+                success = true;
+                break;
+        }
+        case MPT_UNSPEC:
+                break;
         }
-        else
-                /* version 0 and version 1 are used by pseudo wires */
-                success = false;
+
         return success;
 }
 
@@ -248,16 +268,17 @@ static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
 };
 
 struct mpls_route_config {
-        u32             rc_protocol;
-        u32             rc_ifindex;
-        u16             rc_via_table;
-        u16             rc_via_alen;
-        u8              rc_via[MAX_VIA_ALEN];
-        u32             rc_label;
-        u32             rc_output_labels;
-        u32             rc_output_label[MAX_NEW_LABELS];
-        u32             rc_nlflags;
-        struct nl_info  rc_nlinfo;
+        u32                     rc_protocol;
+        u32                     rc_ifindex;
+        u16                     rc_via_table;
+        u16                     rc_via_alen;
+        u8                      rc_via[MAX_VIA_ALEN];
+        u32                     rc_label;
+        u32                     rc_output_labels;
+        u32                     rc_output_label[MAX_NEW_LABELS];
+        u32                     rc_nlflags;
+        enum mpls_payload_type  rc_payload_type;
+        struct nl_info          rc_nlinfo;
 };
 
 static struct mpls_route *mpls_rt_alloc(size_t alen)
@@ -286,7 +307,7 @@ static void mpls_notify_route(struct net *net, unsigned index,
         struct mpls_route *rt = new ? new : old;
         unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
         /* Ignore reserved labels for now */
-        if (rt && (index >= 16))
+        if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED))
                 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
 }
 
@@ -320,13 +341,96 @@ static unsigned find_free_label(struct net *net)
 
         platform_label = rtnl_dereference(net->mpls.platform_label);
         platform_labels = net->mpls.platform_labels;
-        for (index = 16; index < platform_labels; index++) {
+        for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels;
+             index++) {
                 if (!rtnl_dereference(platform_label[index]))
                         return index;
         }
         return LABEL_NOT_SPECIFIED;
 }
 
+#if IS_ENABLED(CONFIG_INET)
+static struct net_device *inet_fib_lookup_dev(struct net *net, void *addr)
+{
+        struct net_device *dev;
+        struct rtable *rt;
+        struct in_addr daddr;
+
+        memcpy(&daddr, addr, sizeof(struct in_addr));
+        rt = ip_route_output(net, daddr.s_addr, 0, 0, 0);
+        if (IS_ERR(rt))
+                return ERR_CAST(rt);
+
+        dev = rt->dst.dev;
+        dev_hold(dev);
+
+        ip_rt_put(rt);
+
+        return dev;
+}
+#else
+static struct net_device *inet_fib_lookup_dev(struct net *net, void *addr)
+{
+        return ERR_PTR(-EAFNOSUPPORT);
+}
+#endif
+
+#if IS_ENABLED(CONFIG_IPV6)
+static struct net_device *inet6_fib_lookup_dev(struct net *net, void *addr)
+{
+        struct net_device *dev;
+        struct dst_entry *dst;
+        struct flowi6 fl6;
+        int err;
+
+        if (!ipv6_stub)
+                return ERR_PTR(-EAFNOSUPPORT);
+
+        memset(&fl6, 0, sizeof(fl6));
+        memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
+        err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6);
+        if (err)
+                return ERR_PTR(err);
+
+        dev = dst->dev;
+        dev_hold(dev);
+        dst_release(dst);
+
+        return dev;
+}
+#else
+static struct net_device *inet6_fib_lookup_dev(struct net *net, void *addr)
+{
+        return ERR_PTR(-EAFNOSUPPORT);
+}
+#endif
+
+static struct net_device *find_outdev(struct net *net,
+                                      struct mpls_route_config *cfg)
+{
+        struct net_device *dev = NULL;
+
+        if (!cfg->rc_ifindex) {
+                switch (cfg->rc_via_table) {
+                case NEIGH_ARP_TABLE:
+                        dev = inet_fib_lookup_dev(net, cfg->rc_via);
+                        break;
+                case NEIGH_ND_TABLE:
+                        dev = inet6_fib_lookup_dev(net, cfg->rc_via);
+                        break;
+                case NEIGH_LINK_TABLE:
+                        break;
+                }
+        } else {
+                dev = dev_get_by_index(net, cfg->rc_ifindex);
+        }
+
+        if (!dev)
+                return ERR_PTR(-ENODEV);
+
+        return dev;
+}
+
 static int mpls_route_add(struct mpls_route_config *cfg)
 {
         struct mpls_route __rcu **platform_label;
@@ -345,8 +449,8 @@ static int mpls_route_add(struct mpls_route_config *cfg)
                 index = find_free_label(net);
         }
 
-        /* The first 16 labels are reserved, and may not be set */
-        if (index < 16)
+        /* Reserved labels may not be set */
+        if (index < MPLS_LABEL_FIRST_UNRESERVED)
                 goto errout;
 
         /* The full 20 bit range may not be supported. */
@@ -357,10 +461,12 @@ static int mpls_route_add(struct mpls_route_config *cfg)
         if (cfg->rc_output_labels > MAX_NEW_LABELS)
                 goto errout;
 
-        err = -ENODEV;
-        dev = dev_get_by_index(net, cfg->rc_ifindex);
-        if (!dev)
+        dev = find_outdev(net, cfg);
+        if (IS_ERR(dev)) {
+                err = PTR_ERR(dev);
+                dev = NULL;
                 goto errout;
+        }
 
         /* Ensure this is a supported device */
         err = -EINVAL;
@@ -401,6 +507,7 @@ static int mpls_route_add(struct mpls_route_config *cfg)
                 rt->rt_label[i] = cfg->rc_output_label[i];
         rt->rt_protocol = cfg->rc_protocol;
         RCU_INIT_POINTER(rt->rt_dev, dev);
+        rt->rt_payload_type = cfg->rc_payload_type;
         rt->rt_via_table = cfg->rc_via_table;
         memcpy(rt->rt_via, cfg->rc_via, cfg->rc_via_alen);
 
@@ -423,8 +530,8 @@ static int mpls_route_del(struct mpls_route_config *cfg)
 
         index = cfg->rc_label;
 
-        /* The first 16 labels are reserved, and may not be removed */
-        if (index < 16)
+        /* Reserved labels may not be removed */
+        if (index < MPLS_LABEL_FIRST_UNRESERVED)
                 goto errout;
 
         /* The full 20 bit range may not be supported */
@@ -626,6 +733,7 @@ int nla_put_labels(struct sk_buff *skb, int attrtype,
 
         return 0;
 }
+EXPORT_SYMBOL_GPL(nla_put_labels);
 
 int nla_get_labels(const struct nlattr *nla,
                    u32 max_labels, u32 *labels, u32 label[])
@@ -671,6 +779,7 @@ int nla_get_labels(const struct nlattr *nla,
         *labels = nla_labels;
         return 0;
 }
+EXPORT_SYMBOL_GPL(nla_get_labels);
 
 static int rtm_to_route_config(struct sk_buff *skb,  struct nlmsghdr *nlh,
                                struct mpls_route_config *cfg)
@@ -740,8 +849,8 @@ static int rtm_to_route_config(struct sk_buff *skb,  struct nlmsghdr *nlh,
                                            &cfg->rc_label))
                                 goto errout;
 
-                        /* The first 16 labels are reserved, and may not be set */
-                        if (cfg->rc_label < 16)
+                        /* Reserved labels may not be set */
+                        if (cfg->rc_label < MPLS_LABEL_FIRST_UNRESERVED)
                                 goto errout;
 
                         break;
@@ -866,8 +975,8 @@ static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
         ASSERT_RTNL();
 
         index = cb->args[0];
-        if (index < 16)
-                index = 16;
+        if (index < MPLS_LABEL_FIRST_UNRESERVED)
+                index = MPLS_LABEL_FIRST_UNRESERVED;
 
         platform_label = rtnl_dereference(net->mpls.platform_label);
         platform_labels = net->mpls.platform_labels;
@@ -953,6 +1062,7 @@ static int resize_platform_label_table(struct net *net, size_t limit)
                         goto nort0;
                 RCU_INIT_POINTER(rt0->rt_dev, lo);
                 rt0->rt_protocol = RTPROT_KERNEL;
+                rt0->rt_payload_type = MPT_IPV4;
                 rt0->rt_via_table = NEIGH_LINK_TABLE;
                 memcpy(rt0->rt_via, lo->dev_addr, lo->addr_len);
         }
@@ -963,6 +1073,7 @@ static int resize_platform_label_table(struct net *net, size_t limit)
                         goto nort2;
                 RCU_INIT_POINTER(rt2->rt_dev, lo);
                 rt2->rt_protocol = RTPROT_KERNEL;
+                rt2->rt_payload_type = MPT_IPV6;
                 rt2->rt_via_table = NEIGH_LINK_TABLE;
                 memcpy(rt2->rt_via, lo->dev_addr, lo->addr_len);
         }