1 files changed, 157 insertions, 44 deletions

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 1f93a59..bb185a2 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);
 	}
@@ -1066,8 +1177,10 @@ static int mpls_net_init(struct net *net)
 
 	table[0].data = net;
 	net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
-	if (net->mpls.ctl == NULL)
+	if (net->mpls.ctl == NULL) {
+		kfree(table);
 		return -ENOMEM;
+	}
 
 	return 0;
 }