Commit c75fc0b9 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

gtp: identify tunnel via GTP device + GTP version + TEID + family 



This allows to define a GTP tunnel for dual stack MS/UE with both IPv4
and IPv6 addresses while using the same TEID via two PDP context
objects.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent e30ea48b

drivers/net/gtp.c

+63 −22
Original line number Diff line number Diff line
@@ -141,7 +141,7 @@ static u32 ipv6_hashfn(const struct in6_addr *ip6) 
}



/* Resolve a PDP context structure based on the 64bit TID. */

static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)

static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid, u16 family)

{

	struct hlist_head *head;

	struct pdp_ctx *pdp;
@@ -149,7 +149,8 @@ static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid) 
	head = &gtp->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];



	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {

		if (pdp->gtp_version == GTP_V0 &&

		if (pdp->af == family &&

		    pdp->gtp_version == GTP_V0 &&

		    pdp->u.v0.tid == tid)

			return pdp;

	}
@@ -157,7 +158,7 @@ static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid) 
}



/* Resolve a PDP context structure based on the 32bit TEI. */

static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)

static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid, u16 family)

{

	struct hlist_head *head;

	struct pdp_ctx *pdp;
@@ -165,7 +166,8 @@ static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid) 
	head = &gtp->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];



	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {

		if (pdp->gtp_version == GTP_V1 &&

		if (pdp->af == family &&

		    pdp->gtp_version == GTP_V1 &&

		    pdp->u.v1.i_tei == tid)

			return pdp;

	}
@@ -305,15 +307,8 @@ static int gtp_inner_proto(struct sk_buff *skb, unsigned int hdrlen, 
}



static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,

		  unsigned int hdrlen, unsigned int role)

		  unsigned int hdrlen, unsigned int role, __u16 inner_proto)

{

	__u16 inner_proto;



	if (gtp_inner_proto(skb, hdrlen, &inner_proto) < 0) {

		netdev_dbg(pctx->dev, "GTP packet does not encapsulate an IP packet\n");

		return -1;

	}



	if (!gtp_check_ms(skb, pctx, hdrlen, role, inner_proto)) {

		netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");

		return 1;
@@ -562,6 +557,21 @@ static int gtp0_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) 
				       msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);

}



static int gtp_proto_to_family(__u16 proto)

{

	switch (proto) {

	case ETH_P_IP:

		return AF_INET;

	case ETH_P_IPV6:

		return AF_INET6;

	default:

		WARN_ON_ONCE(1);

		break;

	}



	return AF_UNSPEC;

}



/* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */

static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)

{
@@ -569,6 +579,7 @@ static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) 
			      sizeof(struct gtp0_header);

	struct gtp0_header *gtp0;

	struct pdp_ctx *pctx;

	__u16 inner_proto;



	if (!pskb_may_pull(skb, hdrlen))

		return -1;
@@ -591,13 +602,19 @@ static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) 
	if (gtp0->type != GTP_TPDU)

		return 1;



	pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));

	if (gtp_inner_proto(skb, hdrlen, &inner_proto) < 0) {

		netdev_dbg(gtp->dev, "GTP packet does not encapsulate an IP packet\n");

		return -1;

	}



	pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid),

			     gtp_proto_to_family(inner_proto));

	if (!pctx) {

		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);

		return 1;

	}



	return gtp_rx(pctx, skb, hdrlen, gtp->role);

	return gtp_rx(pctx, skb, hdrlen, gtp->role, inner_proto);

}



/* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */
@@ -768,6 +785,7 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) 
			      sizeof(struct gtp1_header);

	struct gtp1_header *gtp1;

	struct pdp_ctx *pctx;

	__u16 inner_proto;



	if (!pskb_may_pull(skb, hdrlen))

		return -1;
@@ -803,9 +821,15 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) 
	if (!pskb_may_pull(skb, hdrlen))

		return -1;



	if (gtp_inner_proto(skb, hdrlen, &inner_proto) < 0) {

		netdev_dbg(gtp->dev, "GTP packet does not encapsulate an IP packet\n");

		return -1;

	}



	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));



	pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));

	pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid),

			     gtp_proto_to_family(inner_proto));

	if (!pctx) {

		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);

		return 1;
@@ -815,7 +839,7 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) 
	    gtp_parse_exthdrs(skb, &hdrlen) < 0)

		return -1;



	return gtp_rx(pctx, skb, hdrlen, gtp->role);

	return gtp_rx(pctx, skb, hdrlen, gtp->role, inner_proto);

}



static void __gtp_encap_destroy(struct sock *sk)
@@ -1843,10 +1867,12 @@ static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk, 
		found = true;

	if (version == GTP_V0)

		pctx_tid = gtp0_pdp_find(gtp,

					 nla_get_u64(info->attrs[GTPA_TID]));

					 nla_get_u64(info->attrs[GTPA_TID]),

					 family);

	else if (version == GTP_V1)

		pctx_tid = gtp1_pdp_find(gtp,

					 nla_get_u32(info->attrs[GTPA_I_TEI]));

					 nla_get_u32(info->attrs[GTPA_I_TEI]),

					 family);

	if (pctx_tid)

		found = true;
@@ -2034,6 +2060,12 @@ static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net, 
					    struct nlattr *nla[])

{

	struct gtp_dev *gtp;

	int family;



	if (nla[GTPA_FAMILY])

		family = nla_get_u8(nla[GTPA_FAMILY]);

	else

		family = AF_INET;



	gtp = gtp_find_dev(net, nla);

	if (!gtp)
@@ -2042,10 +2074,16 @@ static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net, 
	if (nla[GTPA_MS_ADDRESS]) {

		__be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);



		if (family != AF_INET)

			return ERR_PTR(-EINVAL);



		return ipv4_pdp_find(gtp, ip);

	} else if (nla[GTPA_MS_ADDR6]) {

		struct in6_addr addr = nla_get_in6_addr(nla[GTPA_MS_ADDR6]);



		if (family != AF_INET6)

			return ERR_PTR(-EINVAL);



		if (addr.s6_addr32[2] ||

		    addr.s6_addr32[3])

			return ERR_PTR(-EADDRNOTAVAIL);
@@ -2054,10 +2092,13 @@ static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net, 
	} else if (nla[GTPA_VERSION]) {

		u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);



		if (gtp_version == GTP_V0 && nla[GTPA_TID])

			return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));

		else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])

			return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));

		if (gtp_version == GTP_V0 && nla[GTPA_TID]) {

			return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]),

					     family);

		} else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI]) {

			return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]),

					     family);

		}

	}



	return ERR_PTR(-EINVAL);