From ca3a1b856636f596c691ab5b3764045a142186db Mon Sep 17 00:00:00 2001 From: Yossi Kuperman Date: Thu, 22 Jun 2017 11:37:11 +0300 Subject: [PATCH] esp6_offload: Fix IP6CB(skb)->nhoff for ESP GRO IP6CB(skb)->nhoff is the offset of the nexthdr field in an IPv6 header, unless there are extension headers present, in which case nhoff points to the nexthdr field of the last extension header. In non-GRO code path, nhoff is set by ipv6_rcv before any XFRM code is executed. Conversely, in GRO code path (when esp6_offload is loaded), nhoff is not set. The following functions fail to read the correct value and eventually the packet is dropped: xfrm6_transport_finish xfrm6_tunnel_input xfrm6_rcv_tnl Set nhoff to the proper offset of nexthdr in esp6_gro_receive. Fixes: 7785bba299a8 ("esp: Add a software GRO codepath") Signed-off-by: Yossi Kuperman Signed-off-by: Steffen Klassert --- net/ipv6/esp6_offload.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/net/ipv6/esp6_offload.c b/net/ipv6/esp6_offload.c index d950d43ba255..f02f131f6435 100644 --- a/net/ipv6/esp6_offload.c +++ b/net/ipv6/esp6_offload.c @@ -30,6 +30,25 @@ #include #include +static __u16 esp6_nexthdr_esp_offset(struct ipv6hdr *ipv6_hdr, int nhlen) +{ + int off = sizeof(struct ipv6hdr); + struct ipv6_opt_hdr *exthdr; + + if (likely(ipv6_hdr->nexthdr == NEXTHDR_ESP)) + return offsetof(struct ipv6hdr, nexthdr); + + while (off < nhlen) { + exthdr = (void *)ipv6_hdr + off; + if (exthdr->nexthdr == NEXTHDR_ESP) + return off; + + off += ipv6_optlen(exthdr); + } + + return 0; +} + static struct sk_buff **esp6_gro_receive(struct sk_buff **head, struct sk_buff *skb) { @@ -38,6 +57,7 @@ static struct sk_buff **esp6_gro_receive(struct sk_buff **head, struct xfrm_state *x; __be32 seq; __be32 spi; + int nhoff; int err; skb_pull(skb, offset); @@ -72,6 +92,11 @@ static struct sk_buff **esp6_gro_receive(struct sk_buff **head, xo->flags |= XFRM_GRO; + nhoff = esp6_nexthdr_esp_offset(ipv6_hdr(skb), offset); + if (!nhoff) + goto out; + + IP6CB(skb)->nhoff = nhoff; XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL; XFRM_SPI_SKB_CB(skb)->family = AF_INET6; XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);