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Vlad Yasevich5edbb072012-11-15 08:49:18 +00001/*
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>
Tom Herbert57c67ff2014-08-22 13:34:44 -070013#include <linux/netdevice.h>
Vlad Yasevich5edbb072012-11-15 08:49:18 +000014#include <net/protocol.h>
15#include <net/ipv6.h>
16#include <net/udp.h>
Vlad Yasevichd4d0d352012-11-15 16:35:37 +000017#include <net/ip6_checksum.h>
Vlad Yasevich5edbb072012-11-15 08:49:18 +000018#include "ip6_offload.h"
19
20static 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
Cong Wangd949d822013-08-31 13:44:37 +080028 if (likely(!skb->encapsulation)) {
29 ipv6h = ipv6_hdr(skb);
30 uh = udp_hdr(skb);
Vlad Yasevich5edbb072012-11-15 08:49:18 +000031
Cong Wangd949d822013-08-31 13:44:37 +080032 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 }
38
Vlad Yasevich5edbb072012-11-15 08:49:18 +000039 return 0;
40}
41
42static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
Cong Wangd949d822013-08-31 13:44:37 +080043 netdev_features_t features)
Vlad Yasevich5edbb072012-11-15 08:49:18 +000044{
45 struct sk_buff *segs = ERR_PTR(-EINVAL);
46 unsigned int mss;
47 unsigned int unfrag_ip6hlen, unfrag_len;
48 struct frag_hdr *fptr;
Pravin B Shelar1e2bd512013-05-30 06:45:27 +000049 u8 *packet_start, *prevhdr;
Vlad Yasevich5edbb072012-11-15 08:49:18 +000050 u8 nexthdr;
51 u8 frag_hdr_sz = sizeof(struct frag_hdr);
52 int offset;
53 __wsum csum;
Pravin B Shelar1e2bd512013-05-30 06:45:27 +000054 int tnl_hlen;
Vlad Yasevich5edbb072012-11-15 08:49:18 +000055
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
Pravin B Shelar73136262013-03-07 13:21:51 +000064 if (unlikely(type & ~(SKB_GSO_UDP |
65 SKB_GSO_DODGY |
66 SKB_GSO_UDP_TUNNEL |
Tom Herbert0f4f4ff2014-06-04 17:20:16 -070067 SKB_GSO_UDP_TUNNEL_CSUM |
Simon Horman0d89d202013-05-23 21:02:52 +000068 SKB_GSO_GRE |
Tom Herbert4749c092014-06-04 17:20:23 -070069 SKB_GSO_GRE_CSUM |
Eric Dumazetcb32f512013-10-19 11:42:57 -070070 SKB_GSO_IPIP |
Eric Dumazet61c1db72013-10-20 20:47:30 -070071 SKB_GSO_SIT |
Simon Horman0d89d202013-05-23 21:02:52 +000072 SKB_GSO_MPLS) ||
Vlad Yasevich5edbb072012-11-15 08:49:18 +000073 !(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
Tom Herbert0f4f4ff2014-06-04 17:20:16 -070082 if (skb->encapsulation && skb_shinfo(skb)->gso_type &
83 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))
Cong Wangeb3c0d82013-08-31 13:44:38 +080084 segs = skb_udp_tunnel_segment(skb, features);
Cong Wangd949d822013-08-31 13:44:37 +080085 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;
Vlad Yasevich5edbb072012-11-15 08:49:18 +000094
Cong Wangd949d822013-08-31 13:44:37 +080095 /* Check if there is enough headroom to insert fragment header. */
96 tnl_hlen = skb_tnl_header_len(skb);
Hannes Frederic Sowa0e033e02013-11-05 02:41:27 +010097 if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
Cong Wangd949d822013-08-31 13:44:37 +080098 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;
Hannes Frederic Sowa916e4cf2014-02-21 02:55:35 +0100120 fptr->identification = skb_shinfo(skb)->ip6_frag_id;
Cong Wangd949d822013-08-31 13:44:37 +0800121
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);
Pravin B Shelar1e2bd512013-05-30 06:45:27 +0000126 }
Vlad Yasevich5edbb072012-11-15 08:49:18 +0000127
Vlad Yasevich5edbb072012-11-15 08:49:18 +0000128out:
129 return segs;
130}
Tom Herbert57c67ff2014-08-22 13:34:44 -0700131
132static 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
Tom Herbert2abb7cd2014-08-31 15:12:43 -0700137 if (unlikely(!uh))
138 goto flush;
Tom Herbert57c67ff2014-08-22 13:34:44 -0700139
Tom Herbert2abb7cd2014-08-31 15:12:43 -0700140 /* Don't bother verifying checksum if we're going to flush anyway. */
Scott Wood2d8f7e22014-09-10 21:23:18 -0500141 if (NAPI_GRO_CB(skb)->flush)
Tom Herbert2abb7cd2014-08-31 15:12:43 -0700142 goto skip;
143
144 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
145 ip6_gro_compute_pseudo))
146 goto flush;
147 else if (uh->check)
148 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
149 ip6_gro_compute_pseudo);
150
151skip:
Tom Herbert57c67ff2014-08-22 13:34:44 -0700152 return udp_gro_receive(head, skb, uh);
Tom Herbert2abb7cd2014-08-31 15:12:43 -0700153
154flush:
155 NAPI_GRO_CB(skb)->flush = 1;
156 return NULL;
Tom Herbert57c67ff2014-08-22 13:34:44 -0700157}
158
Eric Dumazetcc9c6682014-09-09 08:16:17 -0700159static int udp6_gro_complete(struct sk_buff *skb, int nhoff)
Tom Herbert57c67ff2014-08-22 13:34:44 -0700160{
161 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
162 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
163
164 if (uh->check)
165 uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr,
166 &ipv6h->daddr, 0);
167
168 return udp_gro_complete(skb, nhoff);
169}
170
Vlad Yasevich5edbb072012-11-15 08:49:18 +0000171static const struct net_offload udpv6_offload = {
Vlad Yasevichf191a1d2012-11-15 08:49:23 +0000172 .callbacks = {
173 .gso_send_check = udp6_ufo_send_check,
174 .gso_segment = udp6_ufo_fragment,
Tom Herbert57c67ff2014-08-22 13:34:44 -0700175 .gro_receive = udp6_gro_receive,
176 .gro_complete = udp6_gro_complete,
Vlad Yasevichf191a1d2012-11-15 08:49:23 +0000177 },
Vlad Yasevich5edbb072012-11-15 08:49:18 +0000178};
179
180int __init udp_offload_init(void)
181{
182 return inet6_add_offload(&udpv6_offload, IPPROTO_UDP);
183}