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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 | ||
5edbb07d | 20 | static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, |
d949d826 | 21 | netdev_features_t features) |
5edbb07d VY |
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; | |
1e2bd517 | 27 | u8 *packet_start, *prevhdr; |
5edbb07d VY |
28 | u8 nexthdr; |
29 | u8 frag_hdr_sz = sizeof(struct frag_hdr); | |
5edbb07d | 30 | __wsum csum; |
1e2bd517 | 31 | int tnl_hlen; |
7dd7eb95 | 32 | int err; |
5edbb07d VY |
33 | |
34 | mss = skb_shinfo(skb)->gso_size; | |
35 | if (unlikely(skb->len <= mss)) | |
36 | goto out; | |
37 | ||
38 | if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { | |
39 | /* Packet is from an untrusted source, reset gso_segs. */ | |
5edbb07d VY |
40 | |
41 | skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); | |
42 | ||
0508c07f VY |
43 | /* Set the IPv6 fragment id if not set yet */ |
44 | if (!skb_shinfo(skb)->ip6_frag_id) | |
5a352dd0 | 45 | ipv6_proxy_select_ident(dev_net(skb->dev), skb); |
0508c07f | 46 | |
5edbb07d VY |
47 | segs = NULL; |
48 | goto out; | |
49 | } | |
50 | ||
0f4f4ffa TH |
51 | if (skb->encapsulation && skb_shinfo(skb)->gso_type & |
52 | (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM)) | |
8bce6d7d | 53 | segs = skb_udp_tunnel_segment(skb, features, true); |
d949d826 | 54 | else { |
f71470b3 TH |
55 | const struct ipv6hdr *ipv6h; |
56 | struct udphdr *uh; | |
57 | ||
58 | if (!pskb_may_pull(skb, sizeof(struct udphdr))) | |
59 | goto out; | |
60 | ||
d949d826 CW |
61 | /* Do software UFO. Complete and fill in the UDP checksum as HW cannot |
62 | * do checksum of UDP packets sent as multiple IP fragments. | |
63 | */ | |
f71470b3 TH |
64 | |
65 | uh = udp_hdr(skb); | |
66 | ipv6h = ipv6_hdr(skb); | |
67 | ||
68 | uh->check = 0; | |
69 | csum = skb_checksum(skb, 0, skb->len, 0); | |
70 | uh->check = udp_v6_check(skb->len, &ipv6h->saddr, | |
71 | &ipv6h->daddr, csum); | |
f71470b3 TH |
72 | if (uh->check == 0) |
73 | uh->check = CSUM_MANGLED_0; | |
74 | ||
8d63bee6 | 75 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
d949d826 | 76 | |
22463876 AD |
77 | /* If there is no outer header we can fake a checksum offload |
78 | * due to the fact that we have already done the checksum in | |
79 | * software prior to segmenting the frame. | |
80 | */ | |
81 | if (!skb->encap_hdr_csum) | |
82 | features |= NETIF_F_HW_CSUM; | |
83 | ||
d949d826 CW |
84 | /* Check if there is enough headroom to insert fragment header. */ |
85 | tnl_hlen = skb_tnl_header_len(skb); | |
0e033e04 | 86 | if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) { |
d949d826 CW |
87 | if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz)) |
88 | goto out; | |
89 | } | |
90 | ||
91 | /* Find the unfragmentable header and shift it left by frag_hdr_sz | |
92 | * bytes to insert fragment header. | |
93 | */ | |
7dd7eb95 DM |
94 | err = ip6_find_1stfragopt(skb, &prevhdr); |
95 | if (err < 0) | |
96 | return ERR_PTR(err); | |
97 | unfrag_ip6hlen = err; | |
d949d826 CW |
98 | nexthdr = *prevhdr; |
99 | *prevhdr = NEXTHDR_FRAGMENT; | |
100 | unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) + | |
101 | unfrag_ip6hlen + tnl_hlen; | |
102 | packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset; | |
103 | memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len); | |
104 | ||
105 | SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz; | |
106 | skb->mac_header -= frag_hdr_sz; | |
107 | skb->network_header -= frag_hdr_sz; | |
108 | ||
109 | fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen); | |
110 | fptr->nexthdr = nexthdr; | |
111 | fptr->reserved = 0; | |
8e199dfd | 112 | if (!skb_shinfo(skb)->ip6_frag_id) |
5a352dd0 | 113 | ipv6_proxy_select_ident(dev_net(skb->dev), skb); |
8e199dfd | 114 | fptr->identification = skb_shinfo(skb)->ip6_frag_id; |
d949d826 CW |
115 | |
116 | /* Fragment the skb. ipv6 header and the remaining fields of the | |
117 | * fragment header are updated in ipv6_gso_segment() | |
118 | */ | |
119 | segs = skb_segment(skb, features); | |
1e2bd517 | 120 | } |
5edbb07d | 121 | |
5edbb07d VY |
122 | out: |
123 | return segs; | |
124 | } | |
57c67ff4 TH |
125 | |
126 | static struct sk_buff **udp6_gro_receive(struct sk_buff **head, | |
127 | struct sk_buff *skb) | |
128 | { | |
129 | struct udphdr *uh = udp_gro_udphdr(skb); | |
130 | ||
2abb7cdc TH |
131 | if (unlikely(!uh)) |
132 | goto flush; | |
133 | ||
57c67ff4 | 134 | /* Don't bother verifying checksum if we're going to flush anyway. */ |
2d8f7e2c | 135 | if (NAPI_GRO_CB(skb)->flush) |
2abb7cdc | 136 | goto skip; |
57c67ff4 | 137 | |
2abb7cdc TH |
138 | if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, |
139 | ip6_gro_compute_pseudo)) | |
140 | goto flush; | |
141 | else if (uh->check) | |
142 | skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check, | |
143 | ip6_gro_compute_pseudo); | |
144 | ||
145 | skip: | |
efc98d08 | 146 | NAPI_GRO_CB(skb)->is_ipv6 = 1; |
a6024562 | 147 | return udp_gro_receive(head, skb, uh, udp6_lib_lookup_skb); |
2abb7cdc TH |
148 | |
149 | flush: | |
150 | NAPI_GRO_CB(skb)->flush = 1; | |
151 | return NULL; | |
57c67ff4 TH |
152 | } |
153 | ||
cc9c668a | 154 | static int udp6_gro_complete(struct sk_buff *skb, int nhoff) |
57c67ff4 TH |
155 | { |
156 | const struct ipv6hdr *ipv6h = ipv6_hdr(skb); | |
157 | struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); | |
158 | ||
6db93ea1 TH |
159 | if (uh->check) { |
160 | skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM; | |
57c67ff4 TH |
161 | uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr, |
162 | &ipv6h->daddr, 0); | |
6db93ea1 TH |
163 | } else { |
164 | skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL; | |
165 | } | |
57c67ff4 | 166 | |
a6024562 | 167 | return udp_gro_complete(skb, nhoff, udp6_lib_lookup_skb); |
57c67ff4 TH |
168 | } |
169 | ||
5edbb07d | 170 | static const struct net_offload udpv6_offload = { |
f191a1d1 | 171 | .callbacks = { |
f191a1d1 | 172 | .gso_segment = udp6_ufo_fragment, |
57c67ff4 TH |
173 | .gro_receive = udp6_gro_receive, |
174 | .gro_complete = udp6_gro_complete, | |
f191a1d1 | 175 | }, |
5edbb07d VY |
176 | }; |
177 | ||
a6024562 | 178 | int udpv6_offload_init(void) |
5edbb07d VY |
179 | { |
180 | return inet6_add_offload(&udpv6_offload, IPPROTO_UDP); | |
181 | } | |
a6024562 TH |
182 | |
183 | int udpv6_offload_exit(void) | |
184 | { | |
185 | return inet6_del_offload(&udpv6_offload, IPPROTO_UDP); | |
186 | } |