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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 <net/protocol.h>
14#include <net/ipv6.h>
15#include <net/udp.h>
16#include <net/ip6_checksum.h>
17#include "ip6_offload.h"
18
19static int udp6_ufo_send_check(struct sk_buff *skb)
20{
21 const struct ipv6hdr *ipv6h;
22 struct udphdr *uh;
23
24 if (!pskb_may_pull(skb, sizeof(*uh)))
25 return -EINVAL;
26
27 if (likely(!skb->encapsulation)) {
28 ipv6h = ipv6_hdr(skb);
29 uh = udp_hdr(skb);
30
31 uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
32 IPPROTO_UDP, 0);
33 skb->csum_start = skb_transport_header(skb) - skb->head;
34 skb->csum_offset = offsetof(struct udphdr, check);
35 skb->ip_summed = CHECKSUM_PARTIAL;
36 }
37
38 return 0;
39}
40
41static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
42 netdev_features_t features)
43{
44 struct sk_buff *segs = ERR_PTR(-EINVAL);
45 unsigned int mss;
46 unsigned int unfrag_ip6hlen, unfrag_len;
47 struct frag_hdr *fptr;
48 u8 *packet_start, *prevhdr;
49 u8 nexthdr;
50 u8 frag_hdr_sz = sizeof(struct frag_hdr);
51 int offset;
52 __wsum csum;
53 int tnl_hlen;
54
55 mss = skb_shinfo(skb)->gso_size;
56 if (unlikely(skb->len <= mss))
57 goto out;
58
59 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
60 /* Packet is from an untrusted source, reset gso_segs. */
61 int type = skb_shinfo(skb)->gso_type;
62
63 if (unlikely(type & ~(SKB_GSO_UDP |
64 SKB_GSO_DODGY |
65 SKB_GSO_UDP_TUNNEL |
66 SKB_GSO_GRE |
67 SKB_GSO_IPIP |
68 SKB_GSO_SIT |
69 SKB_GSO_MPLS) ||
70 !(type & (SKB_GSO_UDP))))
71 goto out;
72
73 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
74
75 segs = NULL;
76 goto out;
77 }
78
79 if (skb->encapsulation && skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL)
80 segs = skb_udp_tunnel_segment(skb, features);
81 else {
82 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
83 * do checksum of UDP packets sent as multiple IP fragments.
84 */
85 offset = skb_checksum_start_offset(skb);
86 csum = skb_checksum(skb, offset, skb->len - offset, 0);
87 offset += skb->csum_offset;
88 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
89 skb->ip_summed = CHECKSUM_NONE;
90
91 /* Check if there is enough headroom to insert fragment header. */
92 tnl_hlen = skb_tnl_header_len(skb);
93 if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
94 if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
95 goto out;
96 }
97
98 /* Find the unfragmentable header and shift it left by frag_hdr_sz
99 * bytes to insert fragment header.
100 */
101 unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
102 nexthdr = *prevhdr;
103 *prevhdr = NEXTHDR_FRAGMENT;
104 unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) +
105 unfrag_ip6hlen + tnl_hlen;
106 packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset;
107 memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len);
108
109 SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz;
110 skb->mac_header -= frag_hdr_sz;
111 skb->network_header -= frag_hdr_sz;
112
113 fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
114 fptr->nexthdr = nexthdr;
115 fptr->reserved = 0;
116 fptr->identification = skb_shinfo(skb)->ip6_frag_id;
117
118 /* Fragment the skb. ipv6 header and the remaining fields of the
119 * fragment header are updated in ipv6_gso_segment()
120 */
121 segs = skb_segment(skb, features);
122 }
123
124out:
125 return segs;
126}
127static const struct net_offload udpv6_offload = {
128 .callbacks = {
129 .gso_send_check = udp6_ufo_send_check,
130 .gso_segment = udp6_ufo_fragment,
131 },
132};
133
134int __init udp_offload_init(void)
135{
136 return inet6_add_offload(&udpv6_offload, IPPROTO_UDP);
137}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * IPV6 GSO/GRO offload support
4 * Linux INET6 implementation
5 *
6 * UDPv6 GSO support
7 */
8#include <linux/skbuff.h>
9#include <linux/netdevice.h>
10#include <linux/indirect_call_wrapper.h>
11#include <net/protocol.h>
12#include <net/ipv6.h>
13#include <net/udp.h>
14#include <net/ip6_checksum.h>
15#include "ip6_offload.h"
16#include <net/gro.h>
17#include <net/gso.h>
18
19static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
20 netdev_features_t features)
21{
22 struct sk_buff *segs = ERR_PTR(-EINVAL);
23 unsigned int mss;
24 unsigned int unfrag_ip6hlen, unfrag_len;
25 struct frag_hdr *fptr;
26 u8 *packet_start, *prevhdr;
27 u8 nexthdr;
28 u8 frag_hdr_sz = sizeof(struct frag_hdr);
29 __wsum csum;
30 int tnl_hlen;
31 int err;
32
33 if (skb->encapsulation && skb_shinfo(skb)->gso_type &
34 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))
35 segs = skb_udp_tunnel_segment(skb, features, true);
36 else {
37 const struct ipv6hdr *ipv6h;
38 struct udphdr *uh;
39
40 if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4)))
41 goto out;
42
43 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
44 goto out;
45
46 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
47 return __udp_gso_segment(skb, features, true);
48
49 mss = skb_shinfo(skb)->gso_size;
50 if (unlikely(skb->len <= mss))
51 goto out;
52
53 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
54 * do checksum of UDP packets sent as multiple IP fragments.
55 */
56
57 uh = udp_hdr(skb);
58 ipv6h = ipv6_hdr(skb);
59
60 uh->check = 0;
61 csum = skb_checksum(skb, 0, skb->len, 0);
62 uh->check = udp_v6_check(skb->len, &ipv6h->saddr,
63 &ipv6h->daddr, csum);
64 if (uh->check == 0)
65 uh->check = CSUM_MANGLED_0;
66
67 skb->ip_summed = CHECKSUM_UNNECESSARY;
68
69 /* If there is no outer header we can fake a checksum offload
70 * due to the fact that we have already done the checksum in
71 * software prior to segmenting the frame.
72 */
73 if (!skb->encap_hdr_csum)
74 features |= NETIF_F_HW_CSUM;
75
76 /* Check if there is enough headroom to insert fragment header. */
77 tnl_hlen = skb_tnl_header_len(skb);
78 if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
79 if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
80 goto out;
81 }
82
83 /* Find the unfragmentable header and shift it left by frag_hdr_sz
84 * bytes to insert fragment header.
85 */
86 err = ip6_find_1stfragopt(skb, &prevhdr);
87 if (err < 0)
88 return ERR_PTR(err);
89 unfrag_ip6hlen = err;
90 nexthdr = *prevhdr;
91 *prevhdr = NEXTHDR_FRAGMENT;
92 unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) +
93 unfrag_ip6hlen + tnl_hlen;
94 packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset;
95 memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len);
96
97 SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz;
98 skb->mac_header -= frag_hdr_sz;
99 skb->network_header -= frag_hdr_sz;
100
101 fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
102 fptr->nexthdr = nexthdr;
103 fptr->reserved = 0;
104 fptr->identification = ipv6_proxy_select_ident(dev_net(skb->dev), skb);
105
106 /* Fragment the skb. ipv6 header and the remaining fields of the
107 * fragment header are updated in ipv6_gso_segment()
108 */
109 segs = skb_segment(skb, features);
110 }
111
112out:
113 return segs;
114}
115
116static struct sock *udp6_gro_lookup_skb(struct sk_buff *skb, __be16 sport,
117 __be16 dport)
118{
119 const struct ipv6hdr *iph = skb_gro_network_header(skb);
120 struct net *net = dev_net(skb->dev);
121 int iif, sdif;
122
123 inet6_get_iif_sdif(skb, &iif, &sdif);
124
125 return __udp6_lib_lookup(net, &iph->saddr, sport,
126 &iph->daddr, dport, iif,
127 sdif, net->ipv4.udp_table, NULL);
128}
129
130INDIRECT_CALLABLE_SCOPE
131struct sk_buff *udp6_gro_receive(struct list_head *head, struct sk_buff *skb)
132{
133 struct udphdr *uh = udp_gro_udphdr(skb);
134 struct sock *sk = NULL;
135 struct sk_buff *pp;
136
137 if (unlikely(!uh))
138 goto flush;
139
140 /* Don't bother verifying checksum if we're going to flush anyway. */
141 if (NAPI_GRO_CB(skb)->flush)
142 goto skip;
143
144 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
145 ip6_gro_compute_pseudo))
146 goto flush;
147 else if (uh->check)
148 skb_gro_checksum_try_convert(skb, IPPROTO_UDP,
149 ip6_gro_compute_pseudo);
150
151skip:
152 NAPI_GRO_CB(skb)->is_ipv6 = 1;
153
154 if (static_branch_unlikely(&udpv6_encap_needed_key))
155 sk = udp6_gro_lookup_skb(skb, uh->source, uh->dest);
156
157 pp = udp_gro_receive(head, skb, uh, sk);
158 return pp;
159
160flush:
161 NAPI_GRO_CB(skb)->flush = 1;
162 return NULL;
163}
164
165INDIRECT_CALLABLE_SCOPE int udp6_gro_complete(struct sk_buff *skb, int nhoff)
166{
167 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
168 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
169
170 /* do fraglist only if there is no outer UDP encap (or we already processed it) */
171 if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) {
172 uh->len = htons(skb->len - nhoff);
173
174 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4);
175 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
176
177 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
178 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
179 skb->csum_level++;
180 } else {
181 skb->ip_summed = CHECKSUM_UNNECESSARY;
182 skb->csum_level = 0;
183 }
184
185 return 0;
186 }
187
188 if (uh->check)
189 uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr,
190 &ipv6h->daddr, 0);
191
192 return udp_gro_complete(skb, nhoff, udp6_lib_lookup_skb);
193}
194
195static const struct net_offload udpv6_offload = {
196 .callbacks = {
197 .gso_segment = udp6_ufo_fragment,
198 .gro_receive = udp6_gro_receive,
199 .gro_complete = udp6_gro_complete,
200 },
201};
202
203int udpv6_offload_init(void)
204{
205 return inet6_add_offload(&udpv6_offload, IPPROTO_UDP);
206}
207
208int udpv6_offload_exit(void)
209{
210 return inet6_del_offload(&udpv6_offload, IPPROTO_UDP);
211}