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13#include <linux/module.h>
14#include <linux/kernel.h>
15#include <linux/slab.h>
16#include <linux/ip.h>
17#include <linux/netdevice.h>
18#include <linux/skbuff.h>
19#include <linux/if_arp.h>
20#include <linux/if_ether.h>
21#include <linux/if_vlan.h>
22#include <linux/if_pppox.h>
23#include <linux/ppp_defs.h>
24#include <linux/netfilter_bridge.h>
25#include <linux/netfilter_ipv4.h>
26#include <linux/netfilter_ipv6.h>
27#include <linux/netfilter_arp.h>
28#include <linux/in_route.h>
29#include <linux/inetdevice.h>
30
31#include <net/ip.h>
32#include <net/ipv6.h>
33#include <net/addrconf.h>
34#include <net/route.h>
35#include <net/netfilter/br_netfilter.h>
36
37#include <linux/uaccess.h>
38#include "br_private.h"
39#ifdef CONFIG_SYSCTL
40#include <linux/sysctl.h>
41#endif
42
43
44
45
46static int br_nf_check_hbh_len(struct sk_buff *skb)
47{
48 unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1);
49 u32 pkt_len;
50 const unsigned char *nh = skb_network_header(skb);
51 int off = raw - nh;
52 int len = (raw[1] + 1) << 3;
53
54 if ((raw + len) - skb->data > skb_headlen(skb))
55 goto bad;
56
57 off += 2;
58 len -= 2;
59
60 while (len > 0) {
61 int optlen = nh[off + 1] + 2;
62
63 switch (nh[off]) {
64 case IPV6_TLV_PAD1:
65 optlen = 1;
66 break;
67
68 case IPV6_TLV_PADN:
69 break;
70
71 case IPV6_TLV_JUMBO:
72 if (nh[off + 1] != 4 || (off & 3) != 2)
73 goto bad;
74 pkt_len = ntohl(*(__be32 *)(nh + off + 2));
75 if (pkt_len <= IPV6_MAXPLEN ||
76 ipv6_hdr(skb)->payload_len)
77 goto bad;
78 if (pkt_len > skb->len - sizeof(struct ipv6hdr))
79 goto bad;
80 if (pskb_trim_rcsum(skb,
81 pkt_len + sizeof(struct ipv6hdr)))
82 goto bad;
83 nh = skb_network_header(skb);
84 break;
85 default:
86 if (optlen > len)
87 goto bad;
88 break;
89 }
90 off += optlen;
91 len -= optlen;
92 }
93 if (len == 0)
94 return 0;
95bad:
96 return -1;
97}
98
99int br_validate_ipv6(struct net *net, struct sk_buff *skb)
100{
101 const struct ipv6hdr *hdr;
102 struct inet6_dev *idev = __in6_dev_get(skb->dev);
103 u32 pkt_len;
104 u8 ip6h_len = sizeof(struct ipv6hdr);
105
106 if (!pskb_may_pull(skb, ip6h_len))
107 goto inhdr_error;
108
109 if (skb->len < ip6h_len)
110 goto drop;
111
112 hdr = ipv6_hdr(skb);
113
114 if (hdr->version != 6)
115 goto inhdr_error;
116
117 pkt_len = ntohs(hdr->payload_len);
118
119 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
120 if (pkt_len + ip6h_len > skb->len) {
121 __IP6_INC_STATS(net, idev,
122 IPSTATS_MIB_INTRUNCATEDPKTS);
123 goto drop;
124 }
125 if (pskb_trim_rcsum(skb, pkt_len + ip6h_len)) {
126 __IP6_INC_STATS(net, idev,
127 IPSTATS_MIB_INDISCARDS);
128 goto drop;
129 }
130 hdr = ipv6_hdr(skb);
131 }
132 if (hdr->nexthdr == NEXTHDR_HOP && br_nf_check_hbh_len(skb))
133 goto drop;
134
135 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
136
137
138
139 return 0;
140
141inhdr_error:
142 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
143drop:
144 return -1;
145}
146
147static inline bool
148br_nf_ipv6_daddr_was_changed(const struct sk_buff *skb,
149 const struct nf_bridge_info *nf_bridge)
150{
151 return memcmp(&nf_bridge->ipv6_daddr, &ipv6_hdr(skb)->daddr,
152 sizeof(ipv6_hdr(skb)->daddr)) != 0;
153}
154
155
156
157
158
159
160static int br_nf_pre_routing_finish_ipv6(struct net *net, struct sock *sk, struct sk_buff *skb)
161{
162 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
163 struct rtable *rt;
164 struct net_device *dev = skb->dev;
165 const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
166
167 nf_bridge->frag_max_size = IP6CB(skb)->frag_max_size;
168
169 if (nf_bridge->pkt_otherhost) {
170 skb->pkt_type = PACKET_OTHERHOST;
171 nf_bridge->pkt_otherhost = false;
172 }
173 nf_bridge->in_prerouting = 0;
174 if (br_nf_ipv6_daddr_was_changed(skb, nf_bridge)) {
175 skb_dst_drop(skb);
176 v6ops->route_input(skb);
177
178 if (skb_dst(skb)->error) {
179 kfree_skb(skb);
180 return 0;
181 }
182
183 if (skb_dst(skb)->dev == dev) {
184 skb->dev = nf_bridge->physindev;
185 nf_bridge_update_protocol(skb);
186 nf_bridge_push_encap_header(skb);
187 br_nf_hook_thresh(NF_BR_PRE_ROUTING,
188 net, sk, skb, skb->dev, NULL,
189 br_nf_pre_routing_finish_bridge);
190 return 0;
191 }
192 ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr);
193 skb->pkt_type = PACKET_HOST;
194 } else {
195 rt = bridge_parent_rtable(nf_bridge->physindev);
196 if (!rt) {
197 kfree_skb(skb);
198 return 0;
199 }
200 skb_dst_set_noref(skb, &rt->dst);
201 }
202
203 skb->dev = nf_bridge->physindev;
204 nf_bridge_update_protocol(skb);
205 nf_bridge_push_encap_header(skb);
206 br_nf_hook_thresh(NF_BR_PRE_ROUTING, net, sk, skb,
207 skb->dev, NULL, br_handle_frame_finish);
208
209 return 0;
210}
211
212
213
214
215unsigned int br_nf_pre_routing_ipv6(void *priv,
216 struct sk_buff *skb,
217 const struct nf_hook_state *state)
218{
219 struct nf_bridge_info *nf_bridge;
220
221 if (br_validate_ipv6(state->net, skb))
222 return NF_DROP;
223
224 nf_bridge = nf_bridge_alloc(skb);
225 if (!nf_bridge)
226 return NF_DROP;
227 if (!setup_pre_routing(skb, state->net))
228 return NF_DROP;
229
230 nf_bridge = nf_bridge_info_get(skb);
231 nf_bridge->ipv6_daddr = ipv6_hdr(skb)->daddr;
232
233 skb->protocol = htons(ETH_P_IPV6);
234 skb->transport_header = skb->network_header + sizeof(struct ipv6hdr);
235
236 NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, state->net, state->sk, skb,
237 skb->dev, NULL,
238 br_nf_pre_routing_finish_ipv6);
239
240 return NF_STOLEN;
241}
242
