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96518518 PM |
1 | /* |
2 | * Copyright (c) 2008 Patrick McHardy <kaber@trash.net> | |
46413825 | 3 | * Copyright (c) 2013 Pablo Neira Ayuso <pablo@netfilter.org> |
96518518 PM |
4 | * |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * Development of this code funded by Astaro AG (http://www.astaro.com/) | |
10 | */ | |
11 | ||
12 | #include <linux/init.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/netfilter_bridge.h> | |
15 | #include <net/netfilter/nf_tables.h> | |
68b0faa8 AN |
16 | #include <net/netfilter/nf_tables_bridge.h> |
17 | #include <linux/ip.h> | |
18 | #include <linux/ipv6.h> | |
1b63d4b9 AN |
19 | #include <net/netfilter/nf_tables_ipv4.h> |
20 | #include <net/netfilter/nf_tables_ipv6.h> | |
68b0faa8 AN |
21 | |
22 | int nft_bridge_iphdr_validate(struct sk_buff *skb) | |
23 | { | |
24 | struct iphdr *iph; | |
25 | u32 len; | |
26 | ||
27 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
28 | return 0; | |
29 | ||
30 | iph = ip_hdr(skb); | |
31 | if (iph->ihl < 5 || iph->version != 4) | |
32 | return 0; | |
33 | ||
34 | len = ntohs(iph->tot_len); | |
35 | if (skb->len < len) | |
36 | return 0; | |
37 | else if (len < (iph->ihl*4)) | |
38 | return 0; | |
39 | ||
40 | if (!pskb_may_pull(skb, iph->ihl*4)) | |
41 | return 0; | |
42 | ||
43 | return 1; | |
44 | } | |
45 | EXPORT_SYMBOL_GPL(nft_bridge_iphdr_validate); | |
46 | ||
47 | int nft_bridge_ip6hdr_validate(struct sk_buff *skb) | |
48 | { | |
49 | struct ipv6hdr *hdr; | |
50 | u32 pkt_len; | |
51 | ||
52 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
53 | return 0; | |
54 | ||
55 | hdr = ipv6_hdr(skb); | |
56 | if (hdr->version != 6) | |
57 | return 0; | |
58 | ||
59 | pkt_len = ntohs(hdr->payload_len); | |
60 | if (pkt_len + sizeof(struct ipv6hdr) > skb->len) | |
61 | return 0; | |
62 | ||
63 | return 1; | |
64 | } | |
65 | EXPORT_SYMBOL_GPL(nft_bridge_ip6hdr_validate); | |
96518518 | 66 | |
1b63d4b9 | 67 | static inline void nft_bridge_set_pktinfo_ipv4(struct nft_pktinfo *pkt, |
1b63d4b9 | 68 | struct sk_buff *skb, |
073bfd56 | 69 | const struct nf_hook_state *state) |
1b63d4b9 AN |
70 | { |
71 | if (nft_bridge_iphdr_validate(skb)) | |
6aa187f2 | 72 | nft_set_pktinfo_ipv4(pkt, skb, state); |
1b63d4b9 | 73 | else |
6aa187f2 | 74 | nft_set_pktinfo(pkt, skb, state); |
1b63d4b9 AN |
75 | } |
76 | ||
77 | static inline void nft_bridge_set_pktinfo_ipv6(struct nft_pktinfo *pkt, | |
073bfd56 DM |
78 | struct sk_buff *skb, |
79 | const struct nf_hook_state *state) | |
1b63d4b9 AN |
80 | { |
81 | #if IS_ENABLED(CONFIG_IPV6) | |
82 | if (nft_bridge_ip6hdr_validate(skb) && | |
6aa187f2 | 83 | nft_set_pktinfo_ipv6(pkt, skb, state) == 0) |
1b63d4b9 AN |
84 | return; |
85 | #endif | |
6aa187f2 | 86 | nft_set_pktinfo(pkt, skb, state); |
1b63d4b9 AN |
87 | } |
88 | ||
3b088c4b | 89 | static unsigned int |
06198b34 | 90 | nft_do_chain_bridge(void *priv, |
3b088c4b | 91 | struct sk_buff *skb, |
238e54c9 | 92 | const struct nf_hook_state *state) |
3b088c4b PM |
93 | { |
94 | struct nft_pktinfo pkt; | |
95 | ||
1b63d4b9 AN |
96 | switch (eth_hdr(skb)->h_proto) { |
97 | case htons(ETH_P_IP): | |
6aa187f2 | 98 | nft_bridge_set_pktinfo_ipv4(&pkt, skb, state); |
1b63d4b9 AN |
99 | break; |
100 | case htons(ETH_P_IPV6): | |
6aa187f2 | 101 | nft_bridge_set_pktinfo_ipv6(&pkt, skb, state); |
1b63d4b9 AN |
102 | break; |
103 | default: | |
6aa187f2 | 104 | nft_set_pktinfo(&pkt, skb, state); |
1b63d4b9 AN |
105 | break; |
106 | } | |
3b088c4b | 107 | |
06198b34 | 108 | return nft_do_chain(&pkt, priv); |
3b088c4b PM |
109 | } |
110 | ||
96518518 PM |
111 | static struct nft_af_info nft_af_bridge __read_mostly = { |
112 | .family = NFPROTO_BRIDGE, | |
113 | .nhooks = NF_BR_NUMHOOKS, | |
114 | .owner = THIS_MODULE, | |
115a60b1 | 115 | .nops = 1, |
3b088c4b | 116 | .hooks = { |
36d2af59 | 117 | [NF_BR_PRE_ROUTING] = nft_do_chain_bridge, |
3b088c4b PM |
118 | [NF_BR_LOCAL_IN] = nft_do_chain_bridge, |
119 | [NF_BR_FORWARD] = nft_do_chain_bridge, | |
120 | [NF_BR_LOCAL_OUT] = nft_do_chain_bridge, | |
36d2af59 | 121 | [NF_BR_POST_ROUTING] = nft_do_chain_bridge, |
3b088c4b | 122 | }, |
96518518 PM |
123 | }; |
124 | ||
99633ab2 PNA |
125 | static int nf_tables_bridge_init_net(struct net *net) |
126 | { | |
127 | net->nft.bridge = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL); | |
128 | if (net->nft.bridge == NULL) | |
129 | return -ENOMEM; | |
130 | ||
131 | memcpy(net->nft.bridge, &nft_af_bridge, sizeof(nft_af_bridge)); | |
132 | ||
133 | if (nft_register_afinfo(net, net->nft.bridge) < 0) | |
134 | goto err; | |
135 | ||
136 | return 0; | |
137 | err: | |
138 | kfree(net->nft.bridge); | |
139 | return -ENOMEM; | |
140 | } | |
141 | ||
142 | static void nf_tables_bridge_exit_net(struct net *net) | |
143 | { | |
df05ef87 | 144 | nft_unregister_afinfo(net, net->nft.bridge); |
99633ab2 PNA |
145 | kfree(net->nft.bridge); |
146 | } | |
147 | ||
148 | static struct pernet_operations nf_tables_bridge_net_ops = { | |
149 | .init = nf_tables_bridge_init_net, | |
150 | .exit = nf_tables_bridge_exit_net, | |
151 | }; | |
152 | ||
2a37d755 | 153 | static const struct nf_chain_type filter_bridge = { |
46413825 PNA |
154 | .name = "filter", |
155 | .type = NFT_CHAIN_T_DEFAULT, | |
fa2c1de0 PM |
156 | .family = NFPROTO_BRIDGE, |
157 | .owner = THIS_MODULE, | |
4d87716c PNA |
158 | .hook_mask = (1 << NF_BR_PRE_ROUTING) | |
159 | (1 << NF_BR_LOCAL_IN) | | |
46413825 | 160 | (1 << NF_BR_FORWARD) | |
4d87716c PNA |
161 | (1 << NF_BR_LOCAL_OUT) | |
162 | (1 << NF_BR_POST_ROUTING), | |
46413825 PNA |
163 | }; |
164 | ||
96518518 PM |
165 | static int __init nf_tables_bridge_init(void) |
166 | { | |
46413825 PNA |
167 | int ret; |
168 | ||
169 | nft_register_chain_type(&filter_bridge); | |
170 | ret = register_pernet_subsys(&nf_tables_bridge_net_ops); | |
171 | if (ret < 0) | |
172 | nft_unregister_chain_type(&filter_bridge); | |
173 | ||
174 | return ret; | |
96518518 PM |
175 | } |
176 | ||
177 | static void __exit nf_tables_bridge_exit(void) | |
178 | { | |
46413825 PNA |
179 | unregister_pernet_subsys(&nf_tables_bridge_net_ops); |
180 | nft_unregister_chain_type(&filter_bridge); | |
96518518 PM |
181 | } |
182 | ||
183 | module_init(nf_tables_bridge_init); | |
184 | module_exit(nf_tables_bridge_exit); | |
185 | ||
186 | MODULE_LICENSE("GPL"); | |
187 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); | |
188 | MODULE_ALIAS_NFT_FAMILY(AF_BRIDGE); |