vrf: make sure skb->data contains ip header to make routing

vrf_process_v4_outbound() and vrf_process_v6_outbound() do routing
using ip/ipv6 addresses, but don't make sure the header is available
in skb->data[] (skb_headlen() is less then header size).

Case:

1) igb driver from intel.
2) Packet size is greater then 255.
3) MPLS forwards to VRF device.

So, patch adds pskb_may_pull() calls in vrf_process_v4/v6_outbound()
functions.

Signed-off-by: Peter Kosyh <p.kosyh@gmail.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 54edf8956a254cd718b4329e57ed2c8884e5ff1e..6e84328bdd402f0b66b71a92e7f894765e20dc1b 100644 (file)
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -165,23 +165,29 @@ static int vrf_ip6_local_out(struct net *net, struct sock *sk,
 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
                                           struct net_device *dev)
 {
-       const struct ipv6hdr *iph = ipv6_hdr(skb);
+       const struct ipv6hdr *iph;
        struct net *net = dev_net(skb->dev);
-       struct flowi6 fl6 = {
-               /* needed to match OIF rule */
-               .flowi6_oif = dev->ifindex,
-               .flowi6_iif = LOOPBACK_IFINDEX,
-               .daddr = iph->daddr,
-               .saddr = iph->saddr,
-               .flowlabel = ip6_flowinfo(iph),
-               .flowi6_mark = skb->mark,
-               .flowi6_proto = iph->nexthdr,
-               .flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF,
-       };
+       struct flowi6 fl6;
        int ret = NET_XMIT_DROP;
        struct dst_entry *dst;
        struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
 
+       if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
+               goto err;
+
+       iph = ipv6_hdr(skb);
+
+       memset(&fl6, 0, sizeof(fl6));
+       /* needed to match OIF rule */
+       fl6.flowi6_oif = dev->ifindex;
+       fl6.flowi6_iif = LOOPBACK_IFINDEX;
+       fl6.daddr = iph->daddr;
+       fl6.saddr = iph->saddr;
+       fl6.flowlabel = ip6_flowinfo(iph);
+       fl6.flowi6_mark = skb->mark;
+       fl6.flowi6_proto = iph->nexthdr;
+       fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF;
+
        dst = ip6_route_output(net, NULL, &fl6);
        if (dst == dst_null)
                goto err;
@@ -237,21 +243,27 @@ static int vrf_ip_local_out(struct net *net, struct sock *sk,
 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
                                           struct net_device *vrf_dev)
 {
-       struct iphdr *ip4h = ip_hdr(skb);
+       struct iphdr *ip4h;
        int ret = NET_XMIT_DROP;
-       struct flowi4 fl4 = {
-               /* needed to match OIF rule */
-               .flowi4_oif = vrf_dev->ifindex,
-               .flowi4_iif = LOOPBACK_IFINDEX,
-               .flowi4_tos = RT_TOS(ip4h->tos),
-               .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF,
-               .flowi4_proto = ip4h->protocol,
-               .daddr = ip4h->daddr,
-               .saddr = ip4h->saddr,
-       };
+       struct flowi4 fl4;
        struct net *net = dev_net(vrf_dev);
        struct rtable *rt;
 
+       if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
+               goto err;
+
+       ip4h = ip_hdr(skb);
+
+       memset(&fl4, 0, sizeof(fl4));
+       /* needed to match OIF rule */
+       fl4.flowi4_oif = vrf_dev->ifindex;
+       fl4.flowi4_iif = LOOPBACK_IFINDEX;
+       fl4.flowi4_tos = RT_TOS(ip4h->tos);
+       fl4.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF;
+       fl4.flowi4_proto = ip4h->protocol;
+       fl4.daddr = ip4h->daddr;
+       fl4.saddr = ip4h->saddr;
+
        rt = ip_route_output_flow(net, &fl4, NULL);
        if (IS_ERR(rt))
                goto err;