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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
|
/*
* IPv6 specific functions of netfilter core
*
* Rusty Russell (C) 2000 -- This code is GPL.
* Patrick McHardy (C) 2006-2012
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/ipv6.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
#include <linux/export.h>
#include <net/addrconf.h>
#include <net/dst.h>
#include <net/ipv6.h>
#include <net/ip6_route.h>
#include <net/xfrm.h>
#include <net/netfilter/nf_queue.h>
#include <net/netfilter/nf_conntrack_bridge.h>
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
#include "../bridge/br_private.h"
int ip6_route_me_harder(struct net *net, struct sock *sk_partial, struct sk_buff *skb)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
struct sock *sk = sk_to_full_sk(sk_partial);
struct net_device *dev = skb_dst(skb)->dev;
struct flow_keys flkeys;
unsigned int hh_len;
struct dst_entry *dst;
int strict = (ipv6_addr_type(&iph->daddr) &
(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
struct flowi6 fl6 = {
.flowi6_l3mdev = l3mdev_master_ifindex(dev),
.flowi6_mark = skb->mark,
.flowi6_uid = sock_net_uid(net, sk),
.daddr = iph->daddr,
.saddr = iph->saddr,
.flowlabel = ip6_flowinfo(iph),
};
int err;
if (sk && sk->sk_bound_dev_if)
fl6.flowi6_oif = sk->sk_bound_dev_if;
else if (strict)
fl6.flowi6_oif = dev->ifindex;
fib6_rules_early_flow_dissect(net, skb, &fl6, &flkeys);
dst = ip6_route_output(net, sk, &fl6);
err = dst->error;
if (err) {
IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
net_dbg_ratelimited("ip6_route_me_harder: No more route\n");
dst_release(dst);
return err;
}
/* Drop old route. */
skb_dst_drop(skb);
skb_dst_set(skb, dst);
#ifdef CONFIG_XFRM
if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
xfrm_decode_session(net, skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
skb_dst_set(skb, NULL);
dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
if (IS_ERR(dst))
return PTR_ERR(dst);
skb_dst_set(skb, dst);
}
#endif
/* Change in oif may mean change in hh_len. */
hh_len = skb_dst(skb)->dev->hard_header_len;
if (skb_headroom(skb) < hh_len &&
pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
0, GFP_ATOMIC))
return -ENOMEM;
return 0;
}
EXPORT_SYMBOL(ip6_route_me_harder);
static int nf_ip6_reroute(struct sk_buff *skb,
const struct nf_queue_entry *entry)
{
struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
if (entry->state.hook == NF_INET_LOCAL_OUT) {
const struct ipv6hdr *iph = ipv6_hdr(skb);
if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
!ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
skb->mark != rt_info->mark)
return ip6_route_me_harder(entry->state.net, entry->state.sk, skb);
}
return 0;
}
int __nf_ip6_route(struct net *net, struct dst_entry **dst,
struct flowi *fl, bool strict)
{
static const struct ipv6_pinfo fake_pinfo;
static const struct inet_sock fake_sk = {
/* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
.sk.sk_bound_dev_if = 1,
.pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
};
const void *sk = strict ? &fake_sk : NULL;
struct dst_entry *result;
int err;
result = ip6_route_output(net, sk, &fl->u.ip6);
err = result->error;
if (err)
dst_release(result);
else
*dst = result;
return err;
}
EXPORT_SYMBOL_GPL(__nf_ip6_route);
int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
struct nf_bridge_frag_data *data,
int (*output)(struct net *, struct sock *sk,
const struct nf_bridge_frag_data *data,
struct sk_buff *))
{
int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
u8 tstamp_type = skb->tstamp_type;
ktime_t tstamp = skb->tstamp;
struct ip6_frag_state state;
u8 *prevhdr, nexthdr = 0;
unsigned int mtu, hlen;
int hroom, err = 0;
__be32 frag_id;
err = ip6_find_1stfragopt(skb, &prevhdr);
if (err < 0)
goto blackhole;
hlen = err;
nexthdr = *prevhdr;
mtu = skb->dev->mtu;
if (frag_max_size > mtu ||
frag_max_size < IPV6_MIN_MTU)
goto blackhole;
mtu = frag_max_size;
if (mtu < hlen + sizeof(struct frag_hdr) + 8)
goto blackhole;
mtu -= hlen + sizeof(struct frag_hdr);
frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
&ipv6_hdr(skb)->saddr);
if (skb->ip_summed == CHECKSUM_PARTIAL &&
(err = skb_checksum_help(skb)))
goto blackhole;
hroom = LL_RESERVED_SPACE(skb->dev);
if (skb_has_frag_list(skb)) {
unsigned int first_len = skb_pagelen(skb);
struct ip6_fraglist_iter iter;
struct sk_buff *frag2;
if (first_len - hlen > mtu ||
skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
goto blackhole;
if (skb_cloned(skb))
goto slow_path;
skb_walk_frags(skb, frag2) {
if (frag2->len > mtu ||
skb_headroom(frag2) < (hlen + hroom + sizeof(struct frag_hdr)))
goto blackhole;
/* Partially cloned skb? */
if (skb_shared(frag2))
goto slow_path;
}
err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id,
&iter);
if (err < 0)
goto blackhole;
for (;;) {
/* Prepare header of the next frame,
* before previous one went down.
*/
if (iter.frag)
ip6_fraglist_prepare(skb, &iter);
skb_set_delivery_time(skb, tstamp, tstamp_type);
err = output(net, sk, data, skb);
if (err || !iter.frag)
break;
skb = ip6_fraglist_next(&iter);
}
kfree(iter.tmp_hdr);
if (!err)
return 0;
kfree_skb_list(iter.frag);
return err;
}
slow_path:
/* This is a linearized skbuff, the original geometry is lost for us.
* This may also be a clone skbuff, we could preserve the geometry for
* the copies but probably not worth the effort.
*/
ip6_frag_init(skb, hlen, mtu, skb->dev->needed_tailroom,
LL_RESERVED_SPACE(skb->dev), prevhdr, nexthdr, frag_id,
&state);
while (state.left > 0) {
struct sk_buff *skb2;
skb2 = ip6_frag_next(skb, &state);
if (IS_ERR(skb2)) {
err = PTR_ERR(skb2);
goto blackhole;
}
skb_set_delivery_time(skb2, tstamp, tstamp_type);
err = output(net, sk, data, skb2);
if (err)
goto blackhole;
}
consume_skb(skb);
return err;
blackhole:
kfree_skb(skb);
return 0;
}
EXPORT_SYMBOL_GPL(br_ip6_fragment);
static const struct nf_ipv6_ops ipv6ops = {
#if IS_MODULE(CONFIG_IPV6)
.chk_addr = ipv6_chk_addr,
.route_me_harder = ip6_route_me_harder,
.dev_get_saddr = ipv6_dev_get_saddr,
.route = __nf_ip6_route,
#if IS_ENABLED(CONFIG_SYN_COOKIES)
.cookie_init_sequence = __cookie_v6_init_sequence,
.cookie_v6_check = __cookie_v6_check,
#endif
#endif
.route_input = ip6_route_input,
.fragment = ip6_fragment,
.reroute = nf_ip6_reroute,
#if IS_MODULE(CONFIG_IPV6)
.br_fragment = br_ip6_fragment,
#endif
};
int __init ipv6_netfilter_init(void)
{
RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
return 0;
}
/* This can be called from inet6_init() on errors, so it cannot
* be marked __exit. -DaveM
*/
void ipv6_netfilter_fini(void)
{
RCU_INIT_POINTER(nf_ipv6_ops, NULL);
}
|
