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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
Vlad Yasevich5edbb072012-11-15 08:49:18 +000020static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
Cong Wangd949d822013-08-31 13:44:37 +080021 netdev_features_t features)
Vlad Yasevich5edbb072012-11-15 08:49:18 +000022{
23 struct sk_buff *segs = ERR_PTR(-EINVAL);
24 unsigned int mss;
25 unsigned int unfrag_ip6hlen, unfrag_len;
26 struct frag_hdr *fptr;
Pravin B Shelar1e2bd512013-05-30 06:45:27 +000027 u8 *packet_start, *prevhdr;
Vlad Yasevich5edbb072012-11-15 08:49:18 +000028 u8 nexthdr;
29 u8 frag_hdr_sz = sizeof(struct frag_hdr);
Vlad Yasevich5edbb072012-11-15 08:49:18 +000030 __wsum csum;
Pravin B Shelar1e2bd512013-05-30 06:45:27 +000031 int tnl_hlen;
Vlad Yasevich5edbb072012-11-15 08:49:18 +000032
33 mss = skb_shinfo(skb)->gso_size;
34 if (unlikely(skb->len <= mss))
35 goto out;
36
37 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
38 /* Packet is from an untrusted source, reset gso_segs. */
39 int type = skb_shinfo(skb)->gso_type;
40
Pravin B Shelar73136262013-03-07 13:21:51 +000041 if (unlikely(type & ~(SKB_GSO_UDP |
42 SKB_GSO_DODGY |
43 SKB_GSO_UDP_TUNNEL |
Tom Herbert0f4f4ff2014-06-04 17:20:16 -070044 SKB_GSO_UDP_TUNNEL_CSUM |
Tom Herberte585f232014-11-04 09:06:54 -080045 SKB_GSO_TUNNEL_REMCSUM |
Simon Horman0d89d202013-05-23 21:02:52 +000046 SKB_GSO_GRE |
Tom Herbert4749c092014-06-04 17:20:23 -070047 SKB_GSO_GRE_CSUM |
Eric Dumazetcb32f512013-10-19 11:42:57 -070048 SKB_GSO_IPIP |
Pravin B Shelar59b93b42014-11-05 15:27:48 -080049 SKB_GSO_SIT) ||
Vlad Yasevich5edbb072012-11-15 08:49:18 +000050 !(type & (SKB_GSO_UDP))))
51 goto out;
52
53 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
54
Vlad Yasevich0508c072015-02-03 16:36:15 -050055 /* Set the IPv6 fragment id if not set yet */
56 if (!skb_shinfo(skb)->ip6_frag_id)
Hannes Frederic Sowa5a352dd2015-03-25 17:07:45 +010057 ipv6_proxy_select_ident(dev_net(skb->dev), skb);
Vlad Yasevich0508c072015-02-03 16:36:15 -050058
Vlad Yasevich5edbb072012-11-15 08:49:18 +000059 segs = NULL;
60 goto out;
61 }
62
Tom Herbert0f4f4ff2014-06-04 17:20:16 -070063 if (skb->encapsulation && skb_shinfo(skb)->gso_type &
64 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))
Tom Herbert8bce6d72014-09-29 20:22:29 -070065 segs = skb_udp_tunnel_segment(skb, features, true);
Cong Wangd949d822013-08-31 13:44:37 +080066 else {
Tom Herbertf71470b2014-09-20 14:52:29 -070067 const struct ipv6hdr *ipv6h;
68 struct udphdr *uh;
69
70 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
71 goto out;
72
Cong Wangd949d822013-08-31 13:44:37 +080073 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
74 * do checksum of UDP packets sent as multiple IP fragments.
75 */
Tom Herbertf71470b2014-09-20 14:52:29 -070076
77 uh = udp_hdr(skb);
78 ipv6h = ipv6_hdr(skb);
79
80 uh->check = 0;
81 csum = skb_checksum(skb, 0, skb->len, 0);
82 uh->check = udp_v6_check(skb->len, &ipv6h->saddr,
83 &ipv6h->daddr, csum);
84
85 if (uh->check == 0)
86 uh->check = CSUM_MANGLED_0;
87
Cong Wangd949d822013-08-31 13:44:37 +080088 skb->ip_summed = CHECKSUM_NONE;
Vlad Yasevich5edbb072012-11-15 08:49:18 +000089
Cong Wangd949d822013-08-31 13:44:37 +080090 /* Check if there is enough headroom to insert fragment header. */
91 tnl_hlen = skb_tnl_header_len(skb);
Hannes Frederic Sowa0e033e02013-11-05 02:41:27 +010092 if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
Cong Wangd949d822013-08-31 13:44:37 +080093 if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
94 goto out;
95 }
96
97 /* Find the unfragmentable header and shift it left by frag_hdr_sz
98 * bytes to insert fragment header.
99 */
100 unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
101 nexthdr = *prevhdr;
102 *prevhdr = NEXTHDR_FRAGMENT;
103 unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) +
104 unfrag_ip6hlen + tnl_hlen;
105 packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset;
106 memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len);
107
108 SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz;
109 skb->mac_header -= frag_hdr_sz;
110 skb->network_header -= frag_hdr_sz;
111
112 fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
113 fptr->nexthdr = nexthdr;
114 fptr->reserved = 0;
Sabrina Dubroca8e199df2015-03-19 11:22:32 +0100115 if (!skb_shinfo(skb)->ip6_frag_id)
Hannes Frederic Sowa5a352dd2015-03-25 17:07:45 +0100116 ipv6_proxy_select_ident(dev_net(skb->dev), skb);
Sabrina Dubroca8e199df2015-03-19 11:22:32 +0100117 fptr->identification = skb_shinfo(skb)->ip6_frag_id;
Cong Wangd949d822013-08-31 13:44:37 +0800118
119 /* Fragment the skb. ipv6 header and the remaining fields of the
120 * fragment header are updated in ipv6_gso_segment()
121 */
122 segs = skb_segment(skb, features);
Pravin B Shelar1e2bd512013-05-30 06:45:27 +0000123 }
Vlad Yasevich5edbb072012-11-15 08:49:18 +0000124
Vlad Yasevich5edbb072012-11-15 08:49:18 +0000125out:
126 return segs;
127}
Tom Herbert57c67ff2014-08-22 13:34:44 -0700128
129static struct sk_buff **udp6_gro_receive(struct sk_buff **head,
130 struct sk_buff *skb)
131{
132 struct udphdr *uh = udp_gro_udphdr(skb);
133
Tom Herbert2abb7cd2014-08-31 15:12:43 -0700134 if (unlikely(!uh))
135 goto flush;
Tom Herbert57c67ff2014-08-22 13:34:44 -0700136
Tom Herbert2abb7cd2014-08-31 15:12:43 -0700137 /* Don't bother verifying checksum if we're going to flush anyway. */
Scott Wood2d8f7e22014-09-10 21:23:18 -0500138 if (NAPI_GRO_CB(skb)->flush)
Tom Herbert2abb7cd2014-08-31 15:12:43 -0700139 goto skip;
140
141 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
142 ip6_gro_compute_pseudo))
143 goto flush;
144 else if (uh->check)
145 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
146 ip6_gro_compute_pseudo);
147
148skip:
Tom Herbertefc98d02014-10-03 15:48:08 -0700149 NAPI_GRO_CB(skb)->is_ipv6 = 1;
Tom Herbert57c67ff2014-08-22 13:34:44 -0700150 return udp_gro_receive(head, skb, uh);
Tom Herbert2abb7cd2014-08-31 15:12:43 -0700151
152flush:
153 NAPI_GRO_CB(skb)->flush = 1;
154 return NULL;
Tom Herbert57c67ff2014-08-22 13:34:44 -0700155}
156
Eric Dumazetcc9c6682014-09-09 08:16:17 -0700157static int udp6_gro_complete(struct sk_buff *skb, int nhoff)
Tom Herbert57c67ff2014-08-22 13:34:44 -0700158{
159 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
160 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
161
Tom Herbert6db93ea2015-02-10 16:30:29 -0800162 if (uh->check) {
163 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
Tom Herbert57c67ff2014-08-22 13:34:44 -0700164 uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr,
165 &ipv6h->daddr, 0);
Tom Herbert6db93ea2015-02-10 16:30:29 -0800166 } else {
167 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL;
168 }
Tom Herbert57c67ff2014-08-22 13:34:44 -0700169
170 return udp_gro_complete(skb, nhoff);
171}
172
Vlad Yasevich5edbb072012-11-15 08:49:18 +0000173static const struct net_offload udpv6_offload = {
Vlad Yasevichf191a1d2012-11-15 08:49:23 +0000174 .callbacks = {
Vlad Yasevichf191a1d2012-11-15 08:49:23 +0000175 .gso_segment = udp6_ufo_fragment,
Tom Herbert57c67ff2014-08-22 13:34:44 -0700176 .gro_receive = udp6_gro_receive,
177 .gro_complete = udp6_gro_complete,
Vlad Yasevichf191a1d2012-11-15 08:49:23 +0000178 },
Vlad Yasevich5edbb072012-11-15 08:49:18 +0000179};
180
181int __init udp_offload_init(void)
182{
183 return inet6_add_offload(&udpv6_offload, IPPROTO_UDP);
184}