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17#include <linux/module.h>
18#include <linux/kernel.h>
19#include <linux/slab.h>
20#include <linux/ip.h>
21#include <linux/netdevice.h>
22#include <linux/skbuff.h>
23#include <linux/if_arp.h>
24#include <linux/if_ether.h>
25#include <linux/if_vlan.h>
26#include <linux/if_pppox.h>
27#include <linux/ppp_defs.h>
28#include <linux/netfilter_bridge.h>
29#include <linux/netfilter_ipv4.h>
30#include <linux/netfilter_ipv6.h>
31#include <linux/netfilter_arp.h>
32#include <linux/in_route.h>
33#include <linux/inetdevice.h>
34
35#include <net/ip.h>
36#include <net/ipv6.h>
37#include <net/addrconf.h>
38#include <net/route.h>
39#include <net/netfilter/br_netfilter.h>
40
41#include <asm/uaccess.h>
42#include "br_private.h"
43#ifdef CONFIG_SYSCTL
44#include <linux/sysctl.h>
45#endif
46
47
48
49
50static int br_nf_check_hbh_len(struct sk_buff *skb)
51{
52 unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1);
53 u32 pkt_len;
54 const unsigned char *nh = skb_network_header(skb);
55 int off = raw - nh;
56 int len = (raw[1] + 1) << 3;
57
58 if ((raw + len) - skb->data > skb_headlen(skb))
59 goto bad;
60
61 off += 2;
62 len -= 2;
63
64 while (len > 0) {
65 int optlen = nh[off + 1] + 2;
66
67 switch (nh[off]) {
68 case IPV6_TLV_PAD1:
69 optlen = 1;
70 break;
71
72 case IPV6_TLV_PADN:
73 break;
74
75 case IPV6_TLV_JUMBO:
76 if (nh[off + 1] != 4 || (off & 3) != 2)
77 goto bad;
78 pkt_len = ntohl(*(__be32 *)(nh + off + 2));
79 if (pkt_len <= IPV6_MAXPLEN ||
80 ipv6_hdr(skb)->payload_len)
81 goto bad;
82 if (pkt_len > skb->len - sizeof(struct ipv6hdr))
83 goto bad;
84 if (pskb_trim_rcsum(skb,
85 pkt_len + sizeof(struct ipv6hdr)))
86 goto bad;
87 nh = skb_network_header(skb);
88 break;
89 default:
90 if (optlen > len)
91 goto bad;
92 break;
93 }
94 off += optlen;
95 len -= optlen;
96 }
97 if (len == 0)
98 return 0;
99bad:
100 return -1;
101}
102
103int br_validate_ipv6(struct net *net, struct sk_buff *skb)
104{
105 const struct ipv6hdr *hdr;
106 struct inet6_dev *idev = __in6_dev_get(skb->dev);
107 u32 pkt_len;
108 u8 ip6h_len = sizeof(struct ipv6hdr);
109
110 if (!pskb_may_pull(skb, ip6h_len))
111 goto inhdr_error;
112
113 if (skb->len < ip6h_len)
114 goto drop;
115
116 hdr = ipv6_hdr(skb);
117
118 if (hdr->version != 6)
119 goto inhdr_error;
120
121 pkt_len = ntohs(hdr->payload_len);
122
123 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
124 if (pkt_len + ip6h_len > skb->len) {
125 __IP6_INC_STATS(net, idev,
126 IPSTATS_MIB_INTRUNCATEDPKTS);
127 goto drop;
128 }
129 if (pskb_trim_rcsum(skb, pkt_len + ip6h_len)) {
130 __IP6_INC_STATS(net, idev,
131 IPSTATS_MIB_INDISCARDS);
132 goto drop;
133 }
134 }
135 if (hdr->nexthdr == NEXTHDR_HOP && br_nf_check_hbh_len(skb))
136 goto drop;
137
138 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
139
140
141
142 return 0;
143
144inhdr_error:
145 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
146drop:
147 return -1;
148}
149
150static inline bool
151br_nf_ipv6_daddr_was_changed(const struct sk_buff *skb,
152 const struct nf_bridge_info *nf_bridge)
153{
154 return memcmp(&nf_bridge->ipv6_daddr, &ipv6_hdr(skb)->daddr,
155 sizeof(ipv6_hdr(skb)->daddr)) != 0;
156}
157
158
159
160
161
162
163static int br_nf_pre_routing_finish_ipv6(struct net *net, struct sock *sk, struct sk_buff *skb)
164{
165 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
166 struct rtable *rt;
167 struct net_device *dev = skb->dev;
168 const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
169
170 nf_bridge->frag_max_size = IP6CB(skb)->frag_max_size;
171
172 if (nf_bridge->pkt_otherhost) {
173 skb->pkt_type = PACKET_OTHERHOST;
174 nf_bridge->pkt_otherhost = false;
175 }
176 nf_bridge->in_prerouting = 0;
177 if (br_nf_ipv6_daddr_was_changed(skb, nf_bridge)) {
178 skb_dst_drop(skb);
179 v6ops->route_input(skb);
180
181 if (skb_dst(skb)->error) {
182 kfree_skb(skb);
183 return 0;
184 }
185
186 if (skb_dst(skb)->dev == dev) {
187 skb->dev = nf_bridge->physindev;
188 nf_bridge_update_protocol(skb);
189 nf_bridge_push_encap_header(skb);
190 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING,
191 net, sk, skb, skb->dev, NULL,
192 br_nf_pre_routing_finish_bridge,
193 1);
194 return 0;
195 }
196 ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr);
197 skb->pkt_type = PACKET_HOST;
198 } else {
199 rt = bridge_parent_rtable(nf_bridge->physindev);
200 if (!rt) {
201 kfree_skb(skb);
202 return 0;
203 }
204 skb_dst_set_noref(skb, &rt->dst);
205 }
206
207 skb->dev = nf_bridge->physindev;
208 nf_bridge_update_protocol(skb);
209 nf_bridge_push_encap_header(skb);
210 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, net, sk, skb,
211 skb->dev, NULL,
212 br_handle_frame_finish, 1);
213
214 return 0;
215}
216
217
218
219
220unsigned int br_nf_pre_routing_ipv6(void *priv,
221 struct sk_buff *skb,
222 const struct nf_hook_state *state)
223{
224 struct nf_bridge_info *nf_bridge;
225
226 if (br_validate_ipv6(state->net, skb))
227 return NF_DROP;
228
229 nf_bridge_put(skb->nf_bridge);
230 if (!nf_bridge_alloc(skb))
231 return NF_DROP;
232 if (!setup_pre_routing(skb))
233 return NF_DROP;
234
235 nf_bridge = nf_bridge_info_get(skb);
236 nf_bridge->ipv6_daddr = ipv6_hdr(skb)->daddr;
237
238 skb->protocol = htons(ETH_P_IPV6);
239 NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, state->net, state->sk, skb,
240 skb->dev, NULL,
241 br_nf_pre_routing_finish_ipv6);
242
243 return NF_STOLEN;
244}
245
