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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 <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
20static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
21 netdev_features_t features)
22{
23 struct sk_buff *segs = ERR_PTR(-EINVAL);
24 unsigned int mss;
25 unsigned int unfrag_ip6hlen, unfrag_len;
26 struct frag_hdr *fptr;
27 u8 *packet_start, *prevhdr;
28 u8 nexthdr;
29 u8 frag_hdr_sz = sizeof(struct frag_hdr);
30 __wsum csum;
31 int tnl_hlen;
32
33 mss = skb_shinfo(skb)->gso_size;
34 if (unlikely(skb->len <= mss))
35 goto out;
36
37 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
38 /* Packet is from an untrusted source, reset gso_segs. */
39 int type = skb_shinfo(skb)->gso_type;
40
41 if (unlikely(type & ~(SKB_GSO_UDP |
42 SKB_GSO_DODGY |
43 SKB_GSO_UDP_TUNNEL |
44 SKB_GSO_UDP_TUNNEL_CSUM |
45 SKB_GSO_TUNNEL_REMCSUM |
46 SKB_GSO_GRE |
47 SKB_GSO_GRE_CSUM |
48 SKB_GSO_IPIP |
49 SKB_GSO_SIT) ||
50 !(type & (SKB_GSO_UDP))))
51 goto out;
52
53 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
54
55 /* Set the IPv6 fragment id if not set yet */
56 if (!skb_shinfo(skb)->ip6_frag_id)
57 ipv6_proxy_select_ident(dev_net(skb->dev), skb);
58
59 segs = NULL;
60 goto out;
61 }
62
63 if (skb->encapsulation && skb_shinfo(skb)->gso_type &
64 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))
65 segs = skb_udp_tunnel_segment(skb, features, true);
66 else {
67 const struct ipv6hdr *ipv6h;
68 struct udphdr *uh;
69
70 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
71 goto out;
72
73 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
74 * do checksum of UDP packets sent as multiple IP fragments.
75 */
76
77 uh = udp_hdr(skb);
78 ipv6h = ipv6_hdr(skb);
79
80 uh->check = 0;
81 csum = skb_checksum(skb, 0, skb->len, 0);
82 uh->check = udp_v6_check(skb->len, &ipv6h->saddr,
83 &ipv6h->daddr, csum);
84 if (uh->check == 0)
85 uh->check = CSUM_MANGLED_0;
86
87 skb->ip_summed = CHECKSUM_NONE;
88
89 /* If there is no outer header we can fake a checksum offload
90 * due to the fact that we have already done the checksum in
91 * software prior to segmenting the frame.
92 */
93 if (!skb->encap_hdr_csum)
94 features |= NETIF_F_HW_CSUM;
95
96 /* Check if there is enough headroom to insert fragment header. */
97 tnl_hlen = skb_tnl_header_len(skb);
98 if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
99 if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
100 goto out;
101 }
102
103 /* Find the unfragmentable header and shift it left by frag_hdr_sz
104 * bytes to insert fragment header.
105 */
106 unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
107 nexthdr = *prevhdr;
108 *prevhdr = NEXTHDR_FRAGMENT;
109 unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) +
110 unfrag_ip6hlen + tnl_hlen;
111 packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset;
112 memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len);
113
114 SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz;
115 skb->mac_header -= frag_hdr_sz;
116 skb->network_header -= frag_hdr_sz;
117
118 fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
119 fptr->nexthdr = nexthdr;
120 fptr->reserved = 0;
121 if (!skb_shinfo(skb)->ip6_frag_id)
122 ipv6_proxy_select_ident(dev_net(skb->dev), skb);
123 fptr->identification = skb_shinfo(skb)->ip6_frag_id;
124
125 /* Fragment the skb. ipv6 header and the remaining fields of the
126 * fragment header are updated in ipv6_gso_segment()
127 */
128 segs = skb_segment(skb, features);
129 }
130
131out:
132 return segs;
133}
134
135static struct sk_buff **udp6_gro_receive(struct sk_buff **head,
136 struct sk_buff *skb)
137{
138 struct udphdr *uh = udp_gro_udphdr(skb);
139
140 if (unlikely(!uh))
141 goto flush;
142
143 /* Don't bother verifying checksum if we're going to flush anyway. */
144 if (NAPI_GRO_CB(skb)->flush)
145 goto skip;
146
147 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
148 ip6_gro_compute_pseudo))
149 goto flush;
150 else if (uh->check)
151 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
152 ip6_gro_compute_pseudo);
153
154skip:
155 NAPI_GRO_CB(skb)->is_ipv6 = 1;
156 return udp_gro_receive(head, skb, uh);
157
158flush:
159 NAPI_GRO_CB(skb)->flush = 1;
160 return NULL;
161}
162
163static int udp6_gro_complete(struct sk_buff *skb, int nhoff)
164{
165 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
166 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
167
168 if (uh->check) {
169 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
170 uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr,
171 &ipv6h->daddr, 0);
172 } else {
173 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL;
174 }
175
176 return udp_gro_complete(skb, nhoff);
177}
178
179static const struct net_offload udpv6_offload = {
180 .callbacks = {
181 .gso_segment = udp6_ufo_fragment,
182 .gro_receive = udp6_gro_receive,
183 .gro_complete = udp6_gro_complete,
184 },
185};
186
187int __init udp_offload_init(void)
188{
189 return inet6_add_offload(&udpv6_offload, IPPROTO_UDP);
190}
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 u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
168 const struct ipv6hdr *ipv6h = (struct ipv6hdr *)(skb->data + offset);
169 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
170
171 /* do fraglist only if there is no outer UDP encap (or we already processed it) */
172 if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) {
173 uh->len = htons(skb->len - nhoff);
174
175 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4);
176 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
177
178 __skb_incr_checksum_unnecessary(skb);
179
180 return 0;
181 }
182
183 if (uh->check)
184 uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr,
185 &ipv6h->daddr, 0);
186
187 return udp_gro_complete(skb, nhoff, udp6_lib_lookup_skb);
188}
189
190int __init udpv6_offload_init(void)
191{
192 net_hotdata.udpv6_offload = (struct net_offload) {
193 .callbacks = {
194 .gso_segment = udp6_ufo_fragment,
195 .gro_receive = udp6_gro_receive,
196 .gro_complete = udp6_gro_complete,
197 },
198 };
199 return inet6_add_offload(&net_hotdata.udpv6_offload, IPPROTO_UDP);
200}
201
202int udpv6_offload_exit(void)
203{
204 return inet6_del_offload(&net_hotdata.udpv6_offload, IPPROTO_UDP);
205}