Commit | Line | Data |
---|---|---|
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 | ||
20 | static int udp6_ufo_send_check(struct sk_buff *skb) | |
21 | { | |
22 | const struct ipv6hdr *ipv6h; | |
23 | struct udphdr *uh; | |
24 | ||
25 | if (!pskb_may_pull(skb, sizeof(*uh))) | |
26 | return -EINVAL; | |
27 | ||
d949d826 CW |
28 | if (likely(!skb->encapsulation)) { |
29 | ipv6h = ipv6_hdr(skb); | |
30 | uh = udp_hdr(skb); | |
31 | ||
32 | uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len, | |
33 | IPPROTO_UDP, 0); | |
34 | skb->csum_start = skb_transport_header(skb) - skb->head; | |
35 | skb->csum_offset = offsetof(struct udphdr, check); | |
36 | skb->ip_summed = CHECKSUM_PARTIAL; | |
37 | } | |
5edbb07d | 38 | |
5edbb07d VY |
39 | return 0; |
40 | } | |
41 | ||
42 | static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, | |
d949d826 | 43 | netdev_features_t features) |
5edbb07d VY |
44 | { |
45 | struct sk_buff *segs = ERR_PTR(-EINVAL); | |
46 | unsigned int mss; | |
47 | unsigned int unfrag_ip6hlen, unfrag_len; | |
48 | struct frag_hdr *fptr; | |
1e2bd517 | 49 | u8 *packet_start, *prevhdr; |
5edbb07d VY |
50 | u8 nexthdr; |
51 | u8 frag_hdr_sz = sizeof(struct frag_hdr); | |
52 | int offset; | |
53 | __wsum csum; | |
1e2bd517 | 54 | int tnl_hlen; |
5edbb07d VY |
55 | |
56 | mss = skb_shinfo(skb)->gso_size; | |
57 | if (unlikely(skb->len <= mss)) | |
58 | goto out; | |
59 | ||
60 | if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { | |
61 | /* Packet is from an untrusted source, reset gso_segs. */ | |
62 | int type = skb_shinfo(skb)->gso_type; | |
63 | ||
73136267 PS |
64 | if (unlikely(type & ~(SKB_GSO_UDP | |
65 | SKB_GSO_DODGY | | |
66 | SKB_GSO_UDP_TUNNEL | | |
0f4f4ffa | 67 | SKB_GSO_UDP_TUNNEL_CSUM | |
0d89d203 | 68 | SKB_GSO_GRE | |
4749c09c | 69 | SKB_GSO_GRE_CSUM | |
cb32f511 | 70 | SKB_GSO_IPIP | |
61c1db7f | 71 | SKB_GSO_SIT | |
0d89d203 | 72 | SKB_GSO_MPLS) || |
5edbb07d VY |
73 | !(type & (SKB_GSO_UDP)))) |
74 | goto out; | |
75 | ||
76 | skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); | |
77 | ||
78 | segs = NULL; | |
79 | goto out; | |
80 | } | |
81 | ||
0f4f4ffa TH |
82 | if (skb->encapsulation && skb_shinfo(skb)->gso_type & |
83 | (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM)) | |
eb3c0d83 | 84 | segs = skb_udp_tunnel_segment(skb, features); |
d949d826 CW |
85 | else { |
86 | /* Do software UFO. Complete and fill in the UDP checksum as HW cannot | |
87 | * do checksum of UDP packets sent as multiple IP fragments. | |
88 | */ | |
89 | offset = skb_checksum_start_offset(skb); | |
90 | csum = skb_checksum(skb, offset, skb->len - offset, 0); | |
91 | offset += skb->csum_offset; | |
92 | *(__sum16 *)(skb->data + offset) = csum_fold(csum); | |
93 | skb->ip_summed = CHECKSUM_NONE; | |
94 | ||
95 | /* Check if there is enough headroom to insert fragment header. */ | |
96 | tnl_hlen = skb_tnl_header_len(skb); | |
0e033e04 | 97 | if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) { |
d949d826 CW |
98 | if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz)) |
99 | goto out; | |
100 | } | |
101 | ||
102 | /* Find the unfragmentable header and shift it left by frag_hdr_sz | |
103 | * bytes to insert fragment header. | |
104 | */ | |
105 | unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr); | |
106 | nexthdr = *prevhdr; | |
107 | *prevhdr = NEXTHDR_FRAGMENT; | |
108 | unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) + | |
109 | unfrag_ip6hlen + tnl_hlen; | |
110 | packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset; | |
111 | memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len); | |
112 | ||
113 | SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz; | |
114 | skb->mac_header -= frag_hdr_sz; | |
115 | skb->network_header -= frag_hdr_sz; | |
116 | ||
117 | fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen); | |
118 | fptr->nexthdr = nexthdr; | |
119 | fptr->reserved = 0; | |
916e4cf4 | 120 | fptr->identification = skb_shinfo(skb)->ip6_frag_id; |
d949d826 CW |
121 | |
122 | /* Fragment the skb. ipv6 header and the remaining fields of the | |
123 | * fragment header are updated in ipv6_gso_segment() | |
124 | */ | |
125 | segs = skb_segment(skb, features); | |
1e2bd517 | 126 | } |
5edbb07d | 127 | |
5edbb07d VY |
128 | out: |
129 | return segs; | |
130 | } | |
57c67ff4 TH |
131 | |
132 | static struct sk_buff **udp6_gro_receive(struct sk_buff **head, | |
133 | struct sk_buff *skb) | |
134 | { | |
135 | struct udphdr *uh = udp_gro_udphdr(skb); | |
136 | ||
137 | /* Don't bother verifying checksum if we're going to flush anyway. */ | |
138 | if (unlikely(!uh) || | |
139 | (!NAPI_GRO_CB(skb)->flush && | |
140 | skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, | |
141 | ip6_gro_compute_pseudo))) { | |
142 | NAPI_GRO_CB(skb)->flush = 1; | |
143 | return NULL; | |
144 | } | |
145 | ||
146 | return udp_gro_receive(head, skb, uh); | |
147 | } | |
148 | ||
149 | int udp6_gro_complete(struct sk_buff *skb, int nhoff) | |
150 | { | |
151 | const struct ipv6hdr *ipv6h = ipv6_hdr(skb); | |
152 | struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); | |
153 | ||
154 | if (uh->check) | |
155 | uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr, | |
156 | &ipv6h->daddr, 0); | |
157 | ||
158 | return udp_gro_complete(skb, nhoff); | |
159 | } | |
160 | ||
5edbb07d | 161 | static const struct net_offload udpv6_offload = { |
f191a1d1 VY |
162 | .callbacks = { |
163 | .gso_send_check = udp6_ufo_send_check, | |
164 | .gso_segment = udp6_ufo_fragment, | |
57c67ff4 TH |
165 | .gro_receive = udp6_gro_receive, |
166 | .gro_complete = udp6_gro_complete, | |
f191a1d1 | 167 | }, |
5edbb07d VY |
168 | }; |
169 | ||
170 | int __init udp_offload_init(void) | |
171 | { | |
172 | return inet6_add_offload(&udpv6_offload, IPPROTO_UDP); | |
173 | } |