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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> | |
13 | #include <net/protocol.h> | |
14 | #include <net/ipv6.h> | |
15 | #include <net/udp.h> | |
d4d0d355 | 16 | #include <net/ip6_checksum.h> |
5edbb07d VY |
17 | #include "ip6_offload.h" |
18 | ||
19 | static int udp6_ufo_send_check(struct sk_buff *skb) | |
20 | { | |
21 | const struct ipv6hdr *ipv6h; | |
22 | struct udphdr *uh; | |
23 | ||
24 | if (!pskb_may_pull(skb, sizeof(*uh))) | |
25 | return -EINVAL; | |
26 | ||
d949d826 CW |
27 | if (likely(!skb->encapsulation)) { |
28 | ipv6h = ipv6_hdr(skb); | |
29 | uh = udp_hdr(skb); | |
30 | ||
31 | uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len, | |
32 | IPPROTO_UDP, 0); | |
33 | skb->csum_start = skb_transport_header(skb) - skb->head; | |
34 | skb->csum_offset = offsetof(struct udphdr, check); | |
35 | skb->ip_summed = CHECKSUM_PARTIAL; | |
36 | } | |
5edbb07d | 37 | |
5edbb07d VY |
38 | return 0; |
39 | } | |
40 | ||
41 | static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, | |
d949d826 | 42 | netdev_features_t features) |
5edbb07d VY |
43 | { |
44 | struct sk_buff *segs = ERR_PTR(-EINVAL); | |
45 | unsigned int mss; | |
46 | unsigned int unfrag_ip6hlen, unfrag_len; | |
47 | struct frag_hdr *fptr; | |
1e2bd517 | 48 | u8 *packet_start, *prevhdr; |
5edbb07d VY |
49 | u8 nexthdr; |
50 | u8 frag_hdr_sz = sizeof(struct frag_hdr); | |
51 | int offset; | |
52 | __wsum csum; | |
1e2bd517 | 53 | int tnl_hlen; |
5edbb07d VY |
54 | |
55 | mss = skb_shinfo(skb)->gso_size; | |
56 | if (unlikely(skb->len <= mss)) | |
57 | goto out; | |
58 | ||
59 | if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { | |
60 | /* Packet is from an untrusted source, reset gso_segs. */ | |
61 | int type = skb_shinfo(skb)->gso_type; | |
62 | ||
73136267 PS |
63 | if (unlikely(type & ~(SKB_GSO_UDP | |
64 | SKB_GSO_DODGY | | |
65 | SKB_GSO_UDP_TUNNEL | | |
0d89d203 | 66 | SKB_GSO_GRE | |
cb32f511 | 67 | SKB_GSO_IPIP | |
61c1db7f | 68 | SKB_GSO_SIT | |
0d89d203 | 69 | SKB_GSO_MPLS) || |
5edbb07d VY |
70 | !(type & (SKB_GSO_UDP)))) |
71 | goto out; | |
72 | ||
73 | skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); | |
74 | ||
75 | segs = NULL; | |
76 | goto out; | |
77 | } | |
78 | ||
d949d826 | 79 | if (skb->encapsulation && skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL) |
eb3c0d83 | 80 | segs = skb_udp_tunnel_segment(skb, features); |
d949d826 CW |
81 | else { |
82 | /* Do software UFO. Complete and fill in the UDP checksum as HW cannot | |
83 | * do checksum of UDP packets sent as multiple IP fragments. | |
84 | */ | |
85 | offset = skb_checksum_start_offset(skb); | |
86 | csum = skb_checksum(skb, offset, skb->len - offset, 0); | |
87 | offset += skb->csum_offset; | |
88 | *(__sum16 *)(skb->data + offset) = csum_fold(csum); | |
89 | skb->ip_summed = CHECKSUM_NONE; | |
90 | ||
91 | /* Check if there is enough headroom to insert fragment header. */ | |
92 | tnl_hlen = skb_tnl_header_len(skb); | |
0e033e04 | 93 | if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) { |
d949d826 CW |
94 | if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz)) |
95 | goto out; | |
96 | } | |
97 | ||
98 | /* Find the unfragmentable header and shift it left by frag_hdr_sz | |
99 | * bytes to insert fragment header. | |
100 | */ | |
101 | unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr); | |
102 | nexthdr = *prevhdr; | |
103 | *prevhdr = NEXTHDR_FRAGMENT; | |
104 | unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) + | |
105 | unfrag_ip6hlen + tnl_hlen; | |
106 | packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset; | |
107 | memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len); | |
108 | ||
109 | SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz; | |
110 | skb->mac_header -= frag_hdr_sz; | |
111 | skb->network_header -= frag_hdr_sz; | |
112 | ||
113 | fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen); | |
114 | fptr->nexthdr = nexthdr; | |
115 | fptr->reserved = 0; | |
916e4cf4 | 116 | fptr->identification = skb_shinfo(skb)->ip6_frag_id; |
d949d826 CW |
117 | |
118 | /* Fragment the skb. ipv6 header and the remaining fields of the | |
119 | * fragment header are updated in ipv6_gso_segment() | |
120 | */ | |
121 | segs = skb_segment(skb, features); | |
1e2bd517 | 122 | } |
5edbb07d | 123 | |
5edbb07d VY |
124 | out: |
125 | return segs; | |
126 | } | |
127 | static const struct net_offload udpv6_offload = { | |
f191a1d1 VY |
128 | .callbacks = { |
129 | .gso_send_check = udp6_ufo_send_check, | |
130 | .gso_segment = udp6_ufo_fragment, | |
131 | }, | |
5edbb07d VY |
132 | }; |
133 | ||
134 | int __init udp_offload_init(void) | |
135 | { | |
136 | return inet6_add_offload(&udpv6_offload, IPPROTO_UDP); | |
137 | } |