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