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
tcp6_check_fraglist_gro(struct list_head * head,struct sk_buff * skb,struct tcphdr * th)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 if (likely(!(skb->dev->features & NETIF_F_GRO_FRAGLIST)))
28 return;
29
30 p = tcp_gro_lookup(head, th);
31 if (p) {
32 NAPI_GRO_CB(skb)->is_flist = NAPI_GRO_CB(p)->is_flist;
33 return;
34 }
35
36 inet6_get_iif_sdif(skb, &iif, &sdif);
37 hdr = skb_gro_network_header(skb);
38 net = dev_net_rcu(skb->dev);
39 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
40 &hdr->saddr, th->source,
41 &hdr->daddr, ntohs(th->dest),
42 iif, sdif);
43 NAPI_GRO_CB(skb)->is_flist = !sk;
44 if (sk)
45 sock_put(sk);
46 #endif /* IS_ENABLED(CONFIG_IPV6) */
47 }
48
49 INDIRECT_CALLABLE_SCOPE
tcp6_gro_receive(struct list_head * head,struct sk_buff * skb)50 struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)
51 {
52 struct tcphdr *th;
53
54 /* Don't bother verifying checksum if we're going to flush anyway. */
55 if (!NAPI_GRO_CB(skb)->flush &&
56 skb_gro_checksum_validate(skb, IPPROTO_TCP,
57 ip6_gro_compute_pseudo))
58 goto flush;
59
60 th = tcp_gro_pull_header(skb);
61 if (!th)
62 goto flush;
63
64 tcp6_check_fraglist_gro(head, skb, th);
65
66 return tcp_gro_receive(head, skb, th);
67
68 flush:
69 NAPI_GRO_CB(skb)->flush = 1;
70 return NULL;
71 }
72
tcp6_gro_complete(struct sk_buff * skb,int thoff)73 INDIRECT_CALLABLE_SCOPE int tcp6_gro_complete(struct sk_buff *skb, int thoff)
74 {
75 const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
76 const struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + offset);
77 struct tcphdr *th = tcp_hdr(skb);
78
79 if (unlikely(NAPI_GRO_CB(skb)->is_flist)) {
80 skb_shinfo(skb)->gso_type |= SKB_GSO_FRAGLIST | SKB_GSO_TCPV6;
81 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
82
83 __skb_incr_checksum_unnecessary(skb);
84
85 return 0;
86 }
87
88 th->check = ~tcp_v6_check(skb->len - thoff, &iph->saddr,
89 &iph->daddr, 0);
90 skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
91
92 tcp_gro_complete(skb);
93 return 0;
94 }
95
__tcpv6_gso_segment_csum(struct sk_buff * seg,struct in6_addr * oldip,const struct in6_addr * newip,__be16 * oldport,__be16 newport)96 static void __tcpv6_gso_segment_csum(struct sk_buff *seg,
97 struct in6_addr *oldip,
98 const struct in6_addr *newip,
99 __be16 *oldport, __be16 newport)
100 {
101 struct tcphdr *th = tcp_hdr(seg);
102
103 if (!ipv6_addr_equal(oldip, newip)) {
104 inet_proto_csum_replace16(&th->check, seg,
105 oldip->s6_addr32,
106 newip->s6_addr32,
107 true);
108 *oldip = *newip;
109 }
110
111 if (*oldport == newport)
112 return;
113
114 inet_proto_csum_replace2(&th->check, seg, *oldport, newport, false);
115 *oldport = newport;
116 }
117
__tcpv6_gso_segment_list_csum(struct sk_buff * segs)118 static struct sk_buff *__tcpv6_gso_segment_list_csum(struct sk_buff *segs)
119 {
120 const struct tcphdr *th;
121 const struct ipv6hdr *iph;
122 struct sk_buff *seg;
123 struct tcphdr *th2;
124 struct ipv6hdr *iph2;
125
126 seg = segs;
127 th = tcp_hdr(seg);
128 iph = ipv6_hdr(seg);
129 th2 = tcp_hdr(seg->next);
130 iph2 = ipv6_hdr(seg->next);
131
132 if (!(*(const u32 *)&th->source ^ *(const u32 *)&th2->source) &&
133 ipv6_addr_equal(&iph->saddr, &iph2->saddr) &&
134 ipv6_addr_equal(&iph->daddr, &iph2->daddr))
135 return segs;
136
137 while ((seg = seg->next)) {
138 th2 = tcp_hdr(seg);
139 iph2 = ipv6_hdr(seg);
140
141 __tcpv6_gso_segment_csum(seg, &iph2->saddr, &iph->saddr,
142 &th2->source, th->source);
143 __tcpv6_gso_segment_csum(seg, &iph2->daddr, &iph->daddr,
144 &th2->dest, th->dest);
145 }
146
147 return segs;
148 }
149
__tcp6_gso_segment_list(struct sk_buff * skb,netdev_features_t features)150 static struct sk_buff *__tcp6_gso_segment_list(struct sk_buff *skb,
151 netdev_features_t features)
152 {
153 skb = skb_segment_list(skb, features, skb_mac_header_len(skb));
154 if (IS_ERR(skb))
155 return skb;
156
157 return __tcpv6_gso_segment_list_csum(skb);
158 }
159
tcp6_gso_segment(struct sk_buff * skb,netdev_features_t features)160 static struct sk_buff *tcp6_gso_segment(struct sk_buff *skb,
161 netdev_features_t features)
162 {
163 struct tcphdr *th;
164
165 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6))
166 return ERR_PTR(-EINVAL);
167
168 if (!pskb_may_pull(skb, sizeof(*th)))
169 return ERR_PTR(-EINVAL);
170
171 if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST) {
172 struct tcphdr *th = tcp_hdr(skb);
173
174 if (skb_pagelen(skb) - th->doff * 4 == skb_shinfo(skb)->gso_size)
175 return __tcp6_gso_segment_list(skb, features);
176
177 skb->ip_summed = CHECKSUM_NONE;
178 }
179
180 if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
181 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
182 struct tcphdr *th = tcp_hdr(skb);
183
184 /* Set up pseudo header, usually expect stack to have done
185 * this.
186 */
187
188 th->check = 0;
189 skb->ip_summed = CHECKSUM_PARTIAL;
190 __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
191 }
192
193 return tcp_gso_segment(skb, features);
194 }
195
tcpv6_offload_init(void)196 int __init tcpv6_offload_init(void)
197 {
198 net_hotdata.tcpv6_offload = (struct net_offload) {
199 .callbacks = {
200 .gso_segment = tcp6_gso_segment,
201 .gro_receive = tcp6_gro_receive,
202 .gro_complete = tcp6_gro_complete,
203 },
204 };
205 return inet6_add_offload(&net_hotdata.tcpv6_offload, IPPROTO_TCP);
206 }
207