1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
/*
* IPV6 GSO/GRO offload support
* Linux INET6 implementation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* UDPv6 GSO support
*/
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <net/protocol.h>
#include <net/ipv6.h>
#include <net/udp.h>
#include <net/ip6_checksum.h>
#include "ip6_offload.h"
static struct sk_buff *__udp6_gso_segment(struct sk_buff *gso_skb,
netdev_features_t features)
{
const struct ipv6hdr *ip6h = ipv6_hdr(gso_skb);
unsigned int mss = skb_shinfo(gso_skb)->gso_size;
if (!can_checksum_protocol(features, htons(ETH_P_IPV6)))
return ERR_PTR(-EIO);
return __udp_gso_segment(gso_skb, features,
udp_v6_check(sizeof(struct udphdr) + mss,
&ip6h->saddr, &ip6h->daddr, 0));
}
static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
netdev_features_t features)
{
struct sk_buff *segs = ERR_PTR(-EINVAL);
unsigned int mss;
unsigned int unfrag_ip6hlen, unfrag_len;
struct frag_hdr *fptr;
u8 *packet_start, *prevhdr;
u8 nexthdr;
u8 frag_hdr_sz = sizeof(struct frag_hdr);
__wsum csum;
int tnl_hlen;
int err;
mss = skb_shinfo(skb)->gso_size;
if (unlikely(skb->len <= mss))
goto out;
if (skb->encapsulation && skb_shinfo(skb)->gso_type &
(SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))
segs = skb_udp_tunnel_segment(skb, features, true);
else {
const struct ipv6hdr *ipv6h;
struct udphdr *uh;
if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4)))
goto out;
if (!pskb_may_pull(skb, sizeof(struct udphdr)))
goto out;
if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
return __udp6_gso_segment(skb, features);
/* Do software UFO. Complete and fill in the UDP checksum as HW cannot
* do checksum of UDP packets sent as multiple IP fragments.
*/
uh = udp_hdr(skb);
ipv6h = ipv6_hdr(skb);
uh->check = 0;
csum = skb_checksum(skb, 0, skb->len, 0);
uh->check = udp_v6_check(skb->len, &ipv6h->saddr,
&ipv6h->daddr, csum);
if (uh->check == 0)
uh->check = CSUM_MANGLED_0;
skb->ip_summed = CHECKSUM_UNNECESSARY;
/* If there is no outer header we can fake a checksum offload
* due to the fact that we have already done the checksum in
* software prior to segmenting the frame.
*/
if (!skb->encap_hdr_csum)
features |= NETIF_F_HW_CSUM;
/* Check if there is enough headroom to insert fragment header. */
tnl_hlen = skb_tnl_header_len(skb);
if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
goto out;
}
/* Find the unfragmentable header and shift it left by frag_hdr_sz
* bytes to insert fragment header.
*/
err = ip6_find_1stfragopt(skb, &prevhdr);
if (err < 0)
return ERR_PTR(err);
unfrag_ip6hlen = err;
nexthdr = *prevhdr;
*prevhdr = NEXTHDR_FRAGMENT;
unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) +
unfrag_ip6hlen + tnl_hlen;
packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset;
memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len);
SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz;
skb->mac_header -= frag_hdr_sz;
skb->network_header -= frag_hdr_sz;
fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
fptr->nexthdr = nexthdr;
fptr->reserved = 0;
fptr->identification = ipv6_proxy_select_ident(dev_net(skb->dev), skb);
/* Fragment the skb. ipv6 header and the remaining fields of the
* fragment header are updated in ipv6_gso_segment()
*/
segs = skb_segment(skb, features);
}
out:
return segs;
}
static struct sk_buff **udp6_gro_receive(struct sk_buff **head,
struct sk_buff *skb)
{
struct udphdr *uh = udp_gro_udphdr(skb);
if (unlikely(!uh))
goto flush;
/* Don't bother verifying checksum if we're going to flush anyway. */
if (NAPI_GRO_CB(skb)->flush)
goto skip;
if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
ip6_gro_compute_pseudo))
goto flush;
else if (uh->check)
skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
ip6_gro_compute_pseudo);
skip:
NAPI_GRO_CB(skb)->is_ipv6 = 1;
return udp_gro_receive(head, skb, uh, udp6_lib_lookup_skb);
flush:
NAPI_GRO_CB(skb)->flush = 1;
return NULL;
}
static int udp6_gro_complete(struct sk_buff *skb, int nhoff)
{
const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
if (uh->check) {
skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr,
&ipv6h->daddr, 0);
} else {
skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL;
}
return udp_gro_complete(skb, nhoff, udp6_lib_lookup_skb);
}
static const struct net_offload udpv6_offload = {
.callbacks = {
.gso_segment = udp6_ufo_fragment,
.gro_receive = udp6_gro_receive,
.gro_complete = udp6_gro_complete,
},
};
int udpv6_offload_init(void)
{
return inet6_add_offload(&udpv6_offload, IPPROTO_UDP);
}
int udpv6_offload_exit(void)
{
return inet6_del_offload(&udpv6_offload, IPPROTO_UDP);
}
|
