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authorSteffen Klassert <steffen.klassert@secunet.com>2014-02-21 08:41:09 +0100
committerSteffen Klassert <steffen.klassert@secunet.com>2014-02-25 07:04:17 +0100
commit70be6c91c86596ad2b60c73587880b47df170a41 (patch)
treef1728dd87ed10e66916277f89caef5a261b5a70f
parentd099160e029391de857464d987b141f30434052b (diff)
xfrm: Add xfrm_tunnel_skb_cb to the skb common buffer
IPsec vti_rcv needs to remind the tunnel pointer to check it later at the vti_rcv_cb callback. So add this pointer to the IPsec common buffer, initialize it and check it to avoid transport state matching of a tunneled packet. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
-rw-r--r--include/net/xfrm.h50
-rw-r--r--net/ipv4/xfrm4_protocol.c7
-rw-r--r--net/xfrm/xfrm_input.c5
3 files changed, 50 insertions, 12 deletions
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 345a15084557..33112599fa47 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -599,16 +599,27 @@ struct xfrm_mgr {
int xfrm_register_km(struct xfrm_mgr *km);
int xfrm_unregister_km(struct xfrm_mgr *km);
+struct xfrm_tunnel_skb_cb {
+ union {
+ struct inet_skb_parm h4;
+ struct inet6_skb_parm h6;
+ } header;
+
+ union {
+ struct ip_tunnel *ip4;
+ struct ip6_tnl *ip6;
+ } tunnel;
+};
+
+#define XFRM_TUNNEL_SKB_CB(__skb) ((struct xfrm_tunnel_skb_cb *)&((__skb)->cb[0]))
+
/*
* This structure is used for the duration where packets are being
* transformed by IPsec. As soon as the packet leaves IPsec the
* area beyond the generic IP part may be overwritten.
*/
struct xfrm_skb_cb {
- union {
- struct inet_skb_parm h4;
- struct inet6_skb_parm h6;
- } header;
+ struct xfrm_tunnel_skb_cb header;
/* Sequence number for replay protection. */
union {
@@ -630,10 +641,7 @@ struct xfrm_skb_cb {
* to transmit header information to the mode input/output functions.
*/
struct xfrm_mode_skb_cb {
- union {
- struct inet_skb_parm h4;
- struct inet6_skb_parm h6;
- } header;
+ struct xfrm_tunnel_skb_cb header;
/* Copied from header for IPv4, always set to zero and DF for IPv6. */
__be16 id;
@@ -665,10 +673,7 @@ struct xfrm_mode_skb_cb {
* related information.
*/
struct xfrm_spi_skb_cb {
- union {
- struct inet_skb_parm h4;
- struct inet6_skb_parm h6;
- } header;
+ struct xfrm_tunnel_skb_cb header;
unsigned int daddroff;
unsigned int family;
@@ -1510,6 +1515,7 @@ int xfrm4_rcv(struct sk_buff *skb);
static inline int xfrm4_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
{
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
XFRM_SPI_SKB_CB(skb)->family = AF_INET;
XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
return xfrm_input(skb, nexthdr, spi, 0);
@@ -1781,4 +1787,24 @@ static inline int xfrm_rcv_cb(struct sk_buff *skb, unsigned int family,
return 0;
}
+static inline int xfrm_tunnel_check(struct sk_buff *skb, struct xfrm_state *x,
+ unsigned int family)
+{
+ bool tunnel = false;
+
+ switch(family) {
+ case AF_INET:
+ if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4)
+ tunnel = true;
+ break;
+ case AF_INET6:
+ if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6)
+ tunnel = true;
+ break;
+ }
+ if (tunnel && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL))
+ return -EINVAL;
+
+ return 0;
+}
#endif /* _NET_XFRM_H */
diff --git a/net/ipv4/xfrm4_protocol.c b/net/ipv4/xfrm4_protocol.c
index 862a26c2014f..cdc09efca442 100644
--- a/net/ipv4/xfrm4_protocol.c
+++ b/net/ipv4/xfrm4_protocol.c
@@ -65,6 +65,7 @@ int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
int ret;
struct xfrm4_protocol *handler;
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
XFRM_SPI_SKB_CB(skb)->family = AF_INET;
XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
@@ -84,6 +85,8 @@ static int xfrm4_esp_rcv(struct sk_buff *skb)
int ret;
struct xfrm4_protocol *handler;
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
+
for_each_protocol_rcu(esp4_handlers, handler)
if ((ret = handler->handler(skb)) != -EINVAL)
return ret;
@@ -108,6 +111,8 @@ static int xfrm4_ah_rcv(struct sk_buff *skb)
int ret;
struct xfrm4_protocol *handler;
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
+
for_each_protocol_rcu(ah4_handlers, handler)
if ((ret = handler->handler(skb)) != -EINVAL)
return ret;;
@@ -132,6 +137,8 @@ static int xfrm4_ipcomp_rcv(struct sk_buff *skb)
int ret;
struct xfrm4_protocol *handler;
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
+
for_each_protocol_rcu(ipcomp4_handlers, handler)
if ((ret = handler->handler(skb)) != -EINVAL)
return ret;
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 99e3a9e5285e..4218164f4f5e 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -163,6 +163,11 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
skb->sp->xvec[skb->sp->len++] = x;
+ if (xfrm_tunnel_check(skb, x, family)) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
+ goto drop;
+ }
+
spin_lock(&x->lock);
if (unlikely(x->km.state == XFRM_STATE_ACQ)) {
XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);