1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * IPV6 GSO/GRO offload support 4 * Linux INET6 implementation 5 * 6 * TCPv6 GSO/GRO support 7 */ 8 #include <linux/indirect_call_wrapper.h> 9 #include <linux/skbuff.h> 10 #include <net/inet6_hashtables.h> 11 #include <net/gro.h> 12 #include <net/protocol.h> 13 #include <net/tcp.h> 14 #include <net/ip6_checksum.h> 15 #include "ip6_offload.h" 16 17 static void tcp6_check_fraglist_gro(struct list_head *head, struct sk_buff *skb, 18 struct tcphdr *th) 19 { 20 #if IS_ENABLED(CONFIG_IPV6) 21 const struct ipv6hdr *hdr; 22 struct sk_buff *p; 23 struct sock *sk; 24 struct net *net; 25 int iif, sdif; 26 27 p = tcp_gro_lookup(head, th); 28 if (p) { 29 NAPI_GRO_CB(skb)->is_flist = NAPI_GRO_CB(p)->is_flist; 30 return; 31 } 32 33 inet6_get_iif_sdif(skb, &iif, &sdif); 34 hdr = skb_gro_network_header(skb); 35 net = dev_net_rcu(skb->dev); 36 sk = __inet6_lookup_established(net, &hdr->saddr, th->source, 37 &hdr->daddr, ntohs(th->dest), 38 iif, sdif); 39 NAPI_GRO_CB(skb)->is_flist = !sk; 40 if (sk) 41 sock_gen_put(sk); 42 #endif /* IS_ENABLED(CONFIG_IPV6) */ 43 } 44 45 static __always_inline struct sk_buff *tcp6_gro_receive(struct list_head *head, 46 struct sk_buff *skb) 47 { 48 struct tcphdr *th; 49 50 /* Don't bother verifying checksum if we're going to flush anyway. */ 51 if (!NAPI_GRO_CB(skb)->flush && 52 skb_gro_checksum_validate(skb, IPPROTO_TCP, 53 ip6_gro_compute_pseudo)) 54 goto flush; 55 56 th = tcp_gro_pull_header(skb); 57 if (!th) 58 goto flush; 59 60 if (unlikely(skb->dev->features & NETIF_F_GRO_FRAGLIST)) 61 tcp6_check_fraglist_gro(head, skb, th); 62 63 return tcp_gro_receive(head, skb, th); 64 65 flush: 66 NAPI_GRO_CB(skb)->flush = 1; 67 return NULL; 68 } 69 70 static __always_inline int tcp6_gro_complete(struct sk_buff *skb, int thoff) 71 { 72 const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation]; 73 const struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + offset); 74 struct tcphdr *th = tcp_hdr(skb); 75 76 if (unlikely(NAPI_GRO_CB(skb)->is_flist)) { 77 skb_shinfo(skb)->gso_type |= SKB_GSO_FRAGLIST | SKB_GSO_TCPV6; 78 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 79 80 __skb_incr_checksum_unnecessary(skb); 81 82 return 0; 83 } 84 85 th->check = ~tcp_v6_check(skb->len - thoff, &iph->saddr, 86 &iph->daddr, 0); 87 skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6; 88 89 tcp_gro_complete(skb); 90 return 0; 91 } 92 93 static void __tcpv6_gso_segment_csum(struct sk_buff *seg, 94 struct in6_addr *oldip, 95 const struct in6_addr *newip, 96 __be16 *oldport, __be16 newport) 97 { 98 struct tcphdr *th = tcp_hdr(seg); 99 100 if (!ipv6_addr_equal(oldip, newip)) { 101 inet_proto_csum_replace16(&th->check, seg, 102 oldip->s6_addr32, 103 newip->s6_addr32, 104 true); 105 *oldip = *newip; 106 } 107 108 if (*oldport == newport) 109 return; 110 111 inet_proto_csum_replace2(&th->check, seg, *oldport, newport, false); 112 *oldport = newport; 113 } 114 115 static struct sk_buff *__tcpv6_gso_segment_list_csum(struct sk_buff *segs) 116 { 117 const struct tcphdr *th; 118 const struct ipv6hdr *iph; 119 struct sk_buff *seg; 120 struct tcphdr *th2; 121 struct ipv6hdr *iph2; 122 123 seg = segs; 124 th = tcp_hdr(seg); 125 iph = ipv6_hdr(seg); 126 th2 = tcp_hdr(seg->next); 127 iph2 = ipv6_hdr(seg->next); 128 129 if (!(*(const u32 *)&th->source ^ *(const u32 *)&th2->source) && 130 ipv6_addr_equal(&iph->saddr, &iph2->saddr) && 131 ipv6_addr_equal(&iph->daddr, &iph2->daddr)) 132 return segs; 133 134 while ((seg = seg->next)) { 135 th2 = tcp_hdr(seg); 136 iph2 = ipv6_hdr(seg); 137 138 __tcpv6_gso_segment_csum(seg, &iph2->saddr, &iph->saddr, 139 &th2->source, th->source); 140 __tcpv6_gso_segment_csum(seg, &iph2->daddr, &iph->daddr, 141 &th2->dest, th->dest); 142 } 143 144 return segs; 145 } 146 147 static struct sk_buff *__tcp6_gso_segment_list(struct sk_buff *skb, 148 netdev_features_t features) 149 { 150 skb = skb_segment_list(skb, features, skb_mac_header_len(skb)); 151 if (IS_ERR(skb)) 152 return skb; 153 154 return __tcpv6_gso_segment_list_csum(skb); 155 } 156 157 static struct sk_buff *tcp6_gso_segment(struct sk_buff *skb, 158 netdev_features_t features) 159 { 160 struct tcphdr *th; 161 162 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)) 163 return ERR_PTR(-EINVAL); 164 165 if (!pskb_may_pull(skb, sizeof(*th))) 166 return ERR_PTR(-EINVAL); 167 168 if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST) { 169 struct tcphdr *th = tcp_hdr(skb); 170 171 if ((skb_pagelen(skb) - th->doff * 4 == skb_shinfo(skb)->gso_size) && 172 !(skb_shinfo(skb)->gso_type & SKB_GSO_DODGY)) 173 return __tcp6_gso_segment_list(skb, features); 174 175 skb->ip_summed = CHECKSUM_NONE; 176 } 177 178 if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) { 179 const struct ipv6hdr *ipv6h = ipv6_hdr(skb); 180 struct tcphdr *th = tcp_hdr(skb); 181 182 /* Set up pseudo header, usually expect stack to have done 183 * this. 184 */ 185 186 th->check = 0; 187 skb->ip_summed = CHECKSUM_PARTIAL; 188 __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr); 189 } 190 191 return tcp_gso_segment(skb, features); 192 } 193 194 int __init tcpv6_offload_init(void) 195 { 196 net_hotdata.tcpv6_offload = (struct net_offload) { 197 .callbacks = { 198 .gso_segment = tcp6_gso_segment, 199 .gro_receive = tcp6_gro_receive, 200 .gro_complete = tcp6_gro_complete, 201 }, 202 }; 203 return inet6_add_offload(&net_hotdata.tcpv6_offload, IPPROTO_TCP); 204 } 205