1 /* 2 * IPV6 GSO/GRO offload support 3 * Linux INET6 implementation 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License 7 * as published by the Free Software Foundation; either version 8 * 2 of the License, or (at your option) any later version. 9 * 10 * UDPv6 GSO support 11 */ 12 #include <linux/skbuff.h> 13 #include <linux/netdevice.h> 14 #include <net/protocol.h> 15 #include <net/ipv6.h> 16 #include <net/udp.h> 17 #include <net/ip6_checksum.h> 18 #include "ip6_offload.h" 19 20 static struct sk_buff *udp6_tunnel_segment(struct sk_buff *skb, 21 netdev_features_t features) 22 { 23 struct sk_buff *segs = ERR_PTR(-EINVAL); 24 25 if (skb->encapsulation && skb_shinfo(skb)->gso_type & 26 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM)) 27 segs = skb_udp_tunnel_segment(skb, features, true); 28 29 return segs; 30 } 31 32 static struct sk_buff **udp6_gro_receive(struct sk_buff **head, 33 struct sk_buff *skb) 34 { 35 struct udphdr *uh = udp_gro_udphdr(skb); 36 37 if (unlikely(!uh)) 38 goto flush; 39 40 /* Don't bother verifying checksum if we're going to flush anyway. */ 41 if (NAPI_GRO_CB(skb)->flush) 42 goto skip; 43 44 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, 45 ip6_gro_compute_pseudo)) 46 goto flush; 47 else if (uh->check) 48 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check, 49 ip6_gro_compute_pseudo); 50 51 skip: 52 NAPI_GRO_CB(skb)->is_ipv6 = 1; 53 return udp_gro_receive(head, skb, uh, udp6_lib_lookup_skb); 54 55 flush: 56 NAPI_GRO_CB(skb)->flush = 1; 57 return NULL; 58 } 59 60 static int udp6_gro_complete(struct sk_buff *skb, int nhoff) 61 { 62 const struct ipv6hdr *ipv6h = ipv6_hdr(skb); 63 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 64 65 if (uh->check) { 66 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM; 67 uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr, 68 &ipv6h->daddr, 0); 69 } else { 70 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL; 71 } 72 73 return udp_gro_complete(skb, nhoff, udp6_lib_lookup_skb); 74 } 75 76 static const struct net_offload udpv6_offload = { 77 .callbacks = { 78 .gso_segment = udp6_tunnel_segment, 79 .gro_receive = udp6_gro_receive, 80 .gro_complete = udp6_gro_complete, 81 }, 82 }; 83 84 int udpv6_offload_init(void) 85 { 86 return inet6_add_offload(&udpv6_offload, IPPROTO_UDP); 87 } 88 89 int udpv6_offload_exit(void) 90 { 91 return inet6_del_offload(&udpv6_offload, IPPROTO_UDP); 92 } 93