From 1e2bd517c108816220f262d7954b697af03b5f9c Mon Sep 17 00:00:00 2001 From: Pravin B Shelar Date: Thu, 30 May 2013 06:45:27 +0000 Subject: [PATCH] udp6: Fix udp fragmentation for tunnel traffic. udp6 over GRE tunnel does not work after to GRE tso changes. GRE tso handler passes inner packet but keeps track of outer header start in SKB_GSO_CB(skb)->mac_offset. udp6 fragment need to take care of outer header, which start at the mac_offset, while adding fragment header. This bug is introduced by commit 68c3316311 (GRE: Add TCP segmentation offload for GRE). Reported-by: Dmitry Kravkov Signed-off-by: Pravin B Shelar Tested-by: Dmitry Kravkov Signed-off-by: David S. Miller --- include/linux/skbuff.h | 15 +++++++++++++++ net/ipv6/udp_offload.c | 20 ++++++++++++-------- 2 files changed, 27 insertions(+), 8 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 2e0ced1af3b1..9c676eae3968 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2852,6 +2852,21 @@ static inline int skb_tnl_header_len(const struct sk_buff *inner_skb) SKB_GSO_CB(inner_skb)->mac_offset; } +static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra) +{ + int new_headroom, headroom; + int ret; + + headroom = skb_headroom(skb); + ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC); + if (ret) + return ret; + + new_headroom = skb_headroom(skb); + SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom); + return 0; +} + static inline bool skb_is_gso(const struct sk_buff *skb) { return skb_shinfo(skb)->gso_size; diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c index 3bb3a891a424..d3cfaf9c7a08 100644 --- a/net/ipv6/udp_offload.c +++ b/net/ipv6/udp_offload.c @@ -46,11 +46,12 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, unsigned int mss; unsigned int unfrag_ip6hlen, unfrag_len; struct frag_hdr *fptr; - u8 *mac_start, *prevhdr; + u8 *packet_start, *prevhdr; u8 nexthdr; u8 frag_hdr_sz = sizeof(struct frag_hdr); int offset; __wsum csum; + int tnl_hlen; mss = skb_shinfo(skb)->gso_size; if (unlikely(skb->len <= mss)) @@ -83,9 +84,11 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, skb->ip_summed = CHECKSUM_NONE; /* Check if there is enough headroom to insert fragment header. */ - if ((skb_mac_header(skb) < skb->head + frag_hdr_sz) && - pskb_expand_head(skb, frag_hdr_sz, 0, GFP_ATOMIC)) - goto out; + tnl_hlen = skb_tnl_header_len(skb); + if (skb_headroom(skb) < (tnl_hlen + frag_hdr_sz)) { + if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz)) + goto out; + } /* Find the unfragmentable header and shift it left by frag_hdr_sz * bytes to insert fragment header. @@ -93,11 +96,12 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr); nexthdr = *prevhdr; *prevhdr = NEXTHDR_FRAGMENT; - unfrag_len = skb_network_header(skb) - skb_mac_header(skb) + - unfrag_ip6hlen; - mac_start = skb_mac_header(skb); - memmove(mac_start-frag_hdr_sz, mac_start, unfrag_len); + unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) + + unfrag_ip6hlen + tnl_hlen; + packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset; + memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len); + SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz; skb->mac_header -= frag_hdr_sz; skb->network_header -= frag_hdr_sz; -- 2.20.1