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 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(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
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
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
96 static void __tcpv6_gso_segment_csum(struct sk_buff *seg,
97 __be16 *oldport, __be16 newport)
98 {
99 struct tcphdr *th;
100
101 if (*oldport == newport)
102 return;
103
104 th = tcp_hdr(seg);
105 inet_proto_csum_replace2(&th->check, seg, *oldport, newport, false);
106 *oldport = newport;
107 }
108
109 static struct sk_buff *__tcpv6_gso_segment_list_csum(struct sk_buff *segs)
110 {
111 const struct tcphdr *th;
112 const struct ipv6hdr *iph;
113 struct sk_buff *seg;
114 struct tcphdr *th2;
115 struct ipv6hdr *iph2;
116
117 seg = segs;
118 th = tcp_hdr(seg);
119 iph = ipv6_hdr(seg);
120 th2 = tcp_hdr(seg->next);
121 iph2 = ipv6_hdr(seg->next);
122
123 if (!(*(const u32 *)&th->source ^ *(const u32 *)&th2->source) &&
124 ipv6_addr_equal(&iph->saddr, &iph2->saddr) &&
125 ipv6_addr_equal(&iph->daddr, &iph2->daddr))
126 return segs;
127
128 while ((seg = seg->next)) {
129 th2 = tcp_hdr(seg);
130 iph2 = ipv6_hdr(seg);
131
132 iph2->saddr = iph->saddr;
133 iph2->daddr = iph->daddr;
134 __tcpv6_gso_segment_csum(seg, &th2->source, th->source);
135 __tcpv6_gso_segment_csum(seg, &th2->dest, th->dest);
136 }
137
138 return segs;
139 }
140
141 static struct sk_buff *__tcp6_gso_segment_list(struct sk_buff *skb,
142 netdev_features_t features)
143 {
144 skb = skb_segment_list(skb, features, skb_mac_header_len(skb));
145 if (IS_ERR(skb))
146 return skb;
147
148 return __tcpv6_gso_segment_list_csum(skb);
149 }
150
151 static struct sk_buff *tcp6_gso_segment(struct sk_buff *skb,
152 netdev_features_t features)
153 {
154 struct tcphdr *th;
155
156 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6))
157 return ERR_PTR(-EINVAL);
158
159 if (!pskb_may_pull(skb, sizeof(*th)))
160 return ERR_PTR(-EINVAL);
161
162 if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST)
163 return __tcp6_gso_segment_list(skb, features);
164
165 if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
166 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
167 struct tcphdr *th = tcp_hdr(skb);
168
169 /* Set up pseudo header, usually expect stack to have done
170 * this.
171 */
172
173 th->check = 0;
174 skb->ip_summed = CHECKSUM_PARTIAL;
175 __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
176 }
177
178 return tcp_gso_segment(skb, features);
179 }
180
181 int __init tcpv6_offload_init(void)
182 {
183 net_hotdata.tcpv6_offload = (struct net_offload) {
184 .callbacks = {
185 .gso_segment = tcp6_gso_segment,
186 .gro_receive = tcp6_gro_receive,
187 .gro_complete = tcp6_gro_complete,
188 },
189 };
190 return inet6_add_offload(&net_hotdata.tcpv6_offload, IPPROTO_TCP);
191 }
192
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