From: Dongseok Yi <dseok.yi@xxxxxxxxxxx> commit c3df39ac9b0e3747bf8233ea9ce4ed5ceb3199d3 upstream. UDP/IP header of UDP GROed frag_skbs are not updated even after NAT forwarding. Only the header of head_skb from ip_finish_output_gso -> skb_gso_segment is updated but following frag_skbs are not updated. A call path skb_mac_gso_segment -> inet_gso_segment -> udp4_ufo_fragment -> __udp_gso_segment -> __udp_gso_segment_list does not try to update UDP/IP header of the segment list but copy only the MAC header. Update port, addr and check of each skb of the segment list in __udp_gso_segment_list. It covers both SNAT and DNAT. Fixes: 9fd1ff5d2ac7 (udp: Support UDP fraglist GRO/GSO.) Signed-off-by: Dongseok Yi <dseok.yi@xxxxxxxxxxx> Acked-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx> Link: https://lore.kernel.org/r/1611962007-80092-1-git-send-email-dseok.yi@xxxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/net/udp.h | 2 - net/ipv4/udp_offload.c | 69 +++++++++++++++++++++++++++++++++++++++++++++---- net/ipv6/udp_offload.c | 2 - 3 files changed, 66 insertions(+), 7 deletions(-) --- a/include/net/udp.h +++ b/include/net/udp.h @@ -178,7 +178,7 @@ struct sk_buff *udp_gro_receive(struct l int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup); struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, - netdev_features_t features); + netdev_features_t features, bool is_ipv6); static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb) { --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -184,8 +184,67 @@ out_unlock: } EXPORT_SYMBOL(skb_udp_tunnel_segment); +static void __udpv4_gso_segment_csum(struct sk_buff *seg, + __be32 *oldip, __be32 *newip, + __be16 *oldport, __be16 *newport) +{ + struct udphdr *uh; + struct iphdr *iph; + + if (*oldip == *newip && *oldport == *newport) + return; + + uh = udp_hdr(seg); + iph = ip_hdr(seg); + + if (uh->check) { + inet_proto_csum_replace4(&uh->check, seg, *oldip, *newip, + true); + inet_proto_csum_replace2(&uh->check, seg, *oldport, *newport, + false); + if (!uh->check) + uh->check = CSUM_MANGLED_0; + } + *oldport = *newport; + + csum_replace4(&iph->check, *oldip, *newip); + *oldip = *newip; +} + +static struct sk_buff *__udpv4_gso_segment_list_csum(struct sk_buff *segs) +{ + struct sk_buff *seg; + struct udphdr *uh, *uh2; + struct iphdr *iph, *iph2; + + seg = segs; + uh = udp_hdr(seg); + iph = ip_hdr(seg); + + if ((udp_hdr(seg)->dest == udp_hdr(seg->next)->dest) && + (udp_hdr(seg)->source == udp_hdr(seg->next)->source) && + (ip_hdr(seg)->daddr == ip_hdr(seg->next)->daddr) && + (ip_hdr(seg)->saddr == ip_hdr(seg->next)->saddr)) + return segs; + + while ((seg = seg->next)) { + uh2 = udp_hdr(seg); + iph2 = ip_hdr(seg); + + __udpv4_gso_segment_csum(seg, + &iph2->saddr, &iph->saddr, + &uh2->source, &uh->source); + __udpv4_gso_segment_csum(seg, + &iph2->daddr, &iph->daddr, + &uh2->dest, &uh->dest); + } + + return segs; +} + static struct sk_buff *__udp_gso_segment_list(struct sk_buff *skb, - netdev_features_t features) + netdev_features_t features, + bool is_ipv6) { unsigned int mss = skb_shinfo(skb)->gso_size; @@ -195,11 +254,11 @@ static struct sk_buff *__udp_gso_segment udp_hdr(skb)->len = htons(sizeof(struct udphdr) + mss); - return skb; + return is_ipv6 ? skb : __udpv4_gso_segment_list_csum(skb); } struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, - netdev_features_t features) + netdev_features_t features, bool is_ipv6) { struct sock *sk = gso_skb->sk; unsigned int sum_truesize = 0; @@ -211,7 +270,7 @@ struct sk_buff *__udp_gso_segment(struct __be16 newlen; if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) - return __udp_gso_segment_list(gso_skb, features); + return __udp_gso_segment_list(gso_skb, features, is_ipv6); mss = skb_shinfo(gso_skb)->gso_size; if (gso_skb->len <= sizeof(*uh) + mss) @@ -325,7 +384,7 @@ static struct sk_buff *udp4_ufo_fragment goto out; if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) - return __udp_gso_segment(skb, features); + return __udp_gso_segment(skb, features, false); mss = skb_shinfo(skb)->gso_size; if (unlikely(skb->len <= mss)) --- a/net/ipv6/udp_offload.c +++ b/net/ipv6/udp_offload.c @@ -46,7 +46,7 @@ static struct sk_buff *udp6_ufo_fragment goto out; if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) - return __udp_gso_segment(skb, features); + return __udp_gso_segment(skb, features, true); /* Do software UFO. Complete and fill in the UDP checksum as HW cannot * do checksum of UDP packets sent as multiple IP fragments.
