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Commit | Line | Data |
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5edbb07d VY |
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> | |
57c67ff4 | 13 | #include <linux/netdevice.h> |
5edbb07d VY |
14 | #include <net/protocol.h> |
15 | #include <net/ipv6.h> | |
16 | #include <net/udp.h> | |
d4d0d355 | 17 | #include <net/ip6_checksum.h> |
5edbb07d VY |
18 | #include "ip6_offload.h" |
19 | ||
0c19f846 WB |
20 | static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, |
21 | netdev_features_t features) | |
5edbb07d VY |
22 | { |
23 | struct sk_buff *segs = ERR_PTR(-EINVAL); | |
0c19f846 WB |
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 | int err; | |
33 | ||
34 | mss = skb_shinfo(skb)->gso_size; | |
35 | if (unlikely(skb->len <= mss)) | |
36 | goto out; | |
5edbb07d | 37 | |
0f4f4ffa TH |
38 | if (skb->encapsulation && skb_shinfo(skb)->gso_type & |
39 | (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM)) | |
8bce6d7d | 40 | segs = skb_udp_tunnel_segment(skb, features, true); |
0c19f846 WB |
41 | else { |
42 | const struct ipv6hdr *ipv6h; | |
43 | struct udphdr *uh; | |
44 | ||
121d57af WB |
45 | if (!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP)) |
46 | goto out; | |
47 | ||
0c19f846 WB |
48 | if (!pskb_may_pull(skb, sizeof(struct udphdr))) |
49 | goto out; | |
50 | ||
51 | /* Do software UFO. Complete and fill in the UDP checksum as HW cannot | |
52 | * do checksum of UDP packets sent as multiple IP fragments. | |
53 | */ | |
54 | ||
55 | uh = udp_hdr(skb); | |
56 | ipv6h = ipv6_hdr(skb); | |
57 | ||
58 | uh->check = 0; | |
59 | csum = skb_checksum(skb, 0, skb->len, 0); | |
60 | uh->check = udp_v6_check(skb->len, &ipv6h->saddr, | |
61 | &ipv6h->daddr, csum); | |
62 | if (uh->check == 0) | |
63 | uh->check = CSUM_MANGLED_0; | |
64 | ||
65 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
66 | ||
67 | /* If there is no outer header we can fake a checksum offload | |
68 | * due to the fact that we have already done the checksum in | |
69 | * software prior to segmenting the frame. | |
70 | */ | |
71 | if (!skb->encap_hdr_csum) | |
72 | features |= NETIF_F_HW_CSUM; | |
73 | ||
74 | /* Check if there is enough headroom to insert fragment header. */ | |
75 | tnl_hlen = skb_tnl_header_len(skb); | |
76 | if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) { | |
77 | if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz)) | |
78 | goto out; | |
79 | } | |
80 | ||
81 | /* Find the unfragmentable header and shift it left by frag_hdr_sz | |
82 | * bytes to insert fragment header. | |
83 | */ | |
84 | err = ip6_find_1stfragopt(skb, &prevhdr); | |
85 | if (err < 0) | |
86 | return ERR_PTR(err); | |
87 | unfrag_ip6hlen = err; | |
88 | nexthdr = *prevhdr; | |
89 | *prevhdr = NEXTHDR_FRAGMENT; | |
90 | unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) + | |
91 | unfrag_ip6hlen + tnl_hlen; | |
92 | packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset; | |
93 | memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len); | |
94 | ||
95 | SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz; | |
96 | skb->mac_header -= frag_hdr_sz; | |
97 | skb->network_header -= frag_hdr_sz; | |
98 | ||
99 | fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen); | |
100 | fptr->nexthdr = nexthdr; | |
101 | fptr->reserved = 0; | |
102 | fptr->identification = ipv6_proxy_select_ident(dev_net(skb->dev), skb); | |
103 | ||
104 | /* Fragment the skb. ipv6 header and the remaining fields of the | |
105 | * fragment header are updated in ipv6_gso_segment() | |
106 | */ | |
107 | segs = skb_segment(skb, features); | |
108 | } | |
5edbb07d | 109 | |
0c19f846 | 110 | out: |
5edbb07d VY |
111 | return segs; |
112 | } | |
57c67ff4 TH |
113 | |
114 | static struct sk_buff **udp6_gro_receive(struct sk_buff **head, | |
115 | struct sk_buff *skb) | |
116 | { | |
117 | struct udphdr *uh = udp_gro_udphdr(skb); | |
118 | ||
2abb7cdc TH |
119 | if (unlikely(!uh)) |
120 | goto flush; | |
121 | ||
57c67ff4 | 122 | /* Don't bother verifying checksum if we're going to flush anyway. */ |
2d8f7e2c | 123 | if (NAPI_GRO_CB(skb)->flush) |
2abb7cdc | 124 | goto skip; |
57c67ff4 | 125 | |
2abb7cdc TH |
126 | if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, |
127 | ip6_gro_compute_pseudo)) | |
128 | goto flush; | |
129 | else if (uh->check) | |
130 | skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check, | |
131 | ip6_gro_compute_pseudo); | |
132 | ||
133 | skip: | |
efc98d08 | 134 | NAPI_GRO_CB(skb)->is_ipv6 = 1; |
a6024562 | 135 | return udp_gro_receive(head, skb, uh, udp6_lib_lookup_skb); |
2abb7cdc TH |
136 | |
137 | flush: | |
138 | NAPI_GRO_CB(skb)->flush = 1; | |
139 | return NULL; | |
57c67ff4 TH |
140 | } |
141 | ||
cc9c668a | 142 | static int udp6_gro_complete(struct sk_buff *skb, int nhoff) |
57c67ff4 TH |
143 | { |
144 | const struct ipv6hdr *ipv6h = ipv6_hdr(skb); | |
145 | struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); | |
146 | ||
6db93ea1 TH |
147 | if (uh->check) { |
148 | skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM; | |
57c67ff4 TH |
149 | uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr, |
150 | &ipv6h->daddr, 0); | |
6db93ea1 TH |
151 | } else { |
152 | skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL; | |
153 | } | |
57c67ff4 | 154 | |
a6024562 | 155 | return udp_gro_complete(skb, nhoff, udp6_lib_lookup_skb); |
57c67ff4 TH |
156 | } |
157 | ||
5edbb07d | 158 | static const struct net_offload udpv6_offload = { |
f191a1d1 | 159 | .callbacks = { |
0c19f846 | 160 | .gso_segment = udp6_ufo_fragment, |
57c67ff4 TH |
161 | .gro_receive = udp6_gro_receive, |
162 | .gro_complete = udp6_gro_complete, | |
f191a1d1 | 163 | }, |
5edbb07d VY |
164 | }; |
165 | ||
a6024562 | 166 | int udpv6_offload_init(void) |
5edbb07d VY |
167 | { |
168 | return inet6_add_offload(&udpv6_offload, IPPROTO_UDP); | |
169 | } | |
a6024562 TH |
170 | |
171 | int udpv6_offload_exit(void) | |
172 | { | |
173 | return inet6_del_offload(&udpv6_offload, IPPROTO_UDP); | |
174 | } |