Pablo Neira Ayuso | ed6c413 | 2015-05-26 18:41:40 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/init.h> |
| 10 | #include <linux/module.h> |
Pablo Neira Ayuso | 835b803 | 2015-06-15 12:12:01 +0200 | [diff] [blame] | 11 | #include <linux/netdevice.h> |
Pablo Neira Ayuso | ed6c413 | 2015-05-26 18:41:40 +0200 | [diff] [blame] | 12 | #include <net/netfilter/nf_tables.h> |
| 13 | #include <linux/ip.h> |
| 14 | #include <linux/ipv6.h> |
| 15 | #include <net/netfilter/nf_tables_ipv4.h> |
| 16 | #include <net/netfilter/nf_tables_ipv6.h> |
| 17 | |
| 18 | static inline void |
| 19 | nft_netdev_set_pktinfo_ipv4(struct nft_pktinfo *pkt, |
| 20 | const struct nf_hook_ops *ops, struct sk_buff *skb, |
| 21 | const struct nf_hook_state *state) |
| 22 | { |
| 23 | struct iphdr *iph, _iph; |
| 24 | u32 len, thoff; |
| 25 | |
| 26 | nft_set_pktinfo(pkt, ops, skb, state); |
| 27 | |
| 28 | iph = skb_header_pointer(skb, skb_network_offset(skb), sizeof(*iph), |
| 29 | &_iph); |
| 30 | if (!iph) |
| 31 | return; |
| 32 | |
| 33 | iph = ip_hdr(skb); |
| 34 | if (iph->ihl < 5 || iph->version != 4) |
| 35 | return; |
| 36 | |
| 37 | len = ntohs(iph->tot_len); |
| 38 | thoff = iph->ihl * 4; |
| 39 | if (skb->len < len) |
| 40 | return; |
| 41 | else if (len < thoff) |
| 42 | return; |
| 43 | |
| 44 | pkt->tprot = iph->protocol; |
| 45 | pkt->xt.thoff = thoff; |
| 46 | pkt->xt.fragoff = ntohs(iph->frag_off) & IP_OFFSET; |
| 47 | } |
| 48 | |
| 49 | static inline void |
| 50 | __nft_netdev_set_pktinfo_ipv6(struct nft_pktinfo *pkt, |
| 51 | const struct nf_hook_ops *ops, |
| 52 | struct sk_buff *skb, |
| 53 | const struct nf_hook_state *state) |
| 54 | { |
| 55 | #if IS_ENABLED(CONFIG_IPV6) |
| 56 | struct ipv6hdr *ip6h, _ip6h; |
| 57 | unsigned int thoff = 0; |
| 58 | unsigned short frag_off; |
| 59 | int protohdr; |
| 60 | u32 pkt_len; |
| 61 | |
| 62 | ip6h = skb_header_pointer(skb, skb_network_offset(skb), sizeof(*ip6h), |
| 63 | &_ip6h); |
| 64 | if (!ip6h) |
| 65 | return; |
| 66 | |
| 67 | if (ip6h->version != 6) |
| 68 | return; |
| 69 | |
| 70 | pkt_len = ntohs(ip6h->payload_len); |
| 71 | if (pkt_len + sizeof(*ip6h) > skb->len) |
| 72 | return; |
| 73 | |
| 74 | protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, NULL); |
| 75 | if (protohdr < 0) |
| 76 | return; |
| 77 | |
| 78 | pkt->tprot = protohdr; |
| 79 | pkt->xt.thoff = thoff; |
| 80 | pkt->xt.fragoff = frag_off; |
| 81 | #endif |
| 82 | } |
| 83 | |
| 84 | static inline void nft_netdev_set_pktinfo_ipv6(struct nft_pktinfo *pkt, |
| 85 | const struct nf_hook_ops *ops, |
| 86 | struct sk_buff *skb, |
| 87 | const struct nf_hook_state *state) |
| 88 | { |
| 89 | nft_set_pktinfo(pkt, ops, skb, state); |
| 90 | __nft_netdev_set_pktinfo_ipv6(pkt, ops, skb, state); |
| 91 | } |
| 92 | |
| 93 | static unsigned int |
| 94 | nft_do_chain_netdev(const struct nf_hook_ops *ops, struct sk_buff *skb, |
| 95 | const struct nf_hook_state *state) |
| 96 | { |
| 97 | struct nft_pktinfo pkt; |
| 98 | |
| 99 | switch (eth_hdr(skb)->h_proto) { |
| 100 | case htons(ETH_P_IP): |
| 101 | nft_netdev_set_pktinfo_ipv4(&pkt, ops, skb, state); |
| 102 | break; |
| 103 | case htons(ETH_P_IPV6): |
| 104 | nft_netdev_set_pktinfo_ipv6(&pkt, ops, skb, state); |
| 105 | break; |
| 106 | default: |
| 107 | nft_set_pktinfo(&pkt, ops, skb, state); |
| 108 | break; |
| 109 | } |
| 110 | |
| 111 | return nft_do_chain(&pkt, ops); |
| 112 | } |
| 113 | |
| 114 | static struct nft_af_info nft_af_netdev __read_mostly = { |
| 115 | .family = NFPROTO_NETDEV, |
| 116 | .nhooks = NF_NETDEV_NUMHOOKS, |
| 117 | .owner = THIS_MODULE, |
| 118 | .flags = NFT_AF_NEEDS_DEV, |
| 119 | .nops = 1, |
| 120 | .hooks = { |
| 121 | [NF_NETDEV_INGRESS] = nft_do_chain_netdev, |
| 122 | }, |
| 123 | }; |
| 124 | |
| 125 | static int nf_tables_netdev_init_net(struct net *net) |
| 126 | { |
| 127 | net->nft.netdev = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL); |
| 128 | if (net->nft.netdev == NULL) |
| 129 | return -ENOMEM; |
| 130 | |
| 131 | memcpy(net->nft.netdev, &nft_af_netdev, sizeof(nft_af_netdev)); |
| 132 | |
| 133 | if (nft_register_afinfo(net, net->nft.netdev) < 0) |
| 134 | goto err; |
| 135 | |
| 136 | return 0; |
| 137 | err: |
| 138 | kfree(net->nft.netdev); |
| 139 | return -ENOMEM; |
| 140 | } |
| 141 | |
| 142 | static void nf_tables_netdev_exit_net(struct net *net) |
| 143 | { |
| 144 | nft_unregister_afinfo(net->nft.netdev); |
| 145 | kfree(net->nft.netdev); |
| 146 | } |
| 147 | |
| 148 | static struct pernet_operations nf_tables_netdev_net_ops = { |
| 149 | .init = nf_tables_netdev_init_net, |
| 150 | .exit = nf_tables_netdev_exit_net, |
| 151 | }; |
| 152 | |
| 153 | static const struct nf_chain_type nft_filter_chain_netdev = { |
| 154 | .name = "filter", |
| 155 | .type = NFT_CHAIN_T_DEFAULT, |
| 156 | .family = NFPROTO_NETDEV, |
| 157 | .owner = THIS_MODULE, |
| 158 | .hook_mask = (1 << NF_NETDEV_INGRESS), |
| 159 | }; |
| 160 | |
Pablo Neira Ayuso | 835b803 | 2015-06-15 12:12:01 +0200 | [diff] [blame] | 161 | static void nft_netdev_event(unsigned long event, struct nft_af_info *afi, |
| 162 | struct net_device *dev, struct nft_table *table, |
| 163 | struct nft_base_chain *basechain) |
| 164 | { |
| 165 | switch (event) { |
| 166 | case NETDEV_REGISTER: |
| 167 | if (strcmp(basechain->dev_name, dev->name) != 0) |
| 168 | return; |
| 169 | |
| 170 | BUG_ON(!(basechain->flags & NFT_BASECHAIN_DISABLED)); |
| 171 | |
| 172 | dev_hold(dev); |
| 173 | basechain->ops[0].dev = dev; |
| 174 | basechain->flags &= ~NFT_BASECHAIN_DISABLED; |
| 175 | if (!(table->flags & NFT_TABLE_F_DORMANT)) |
| 176 | nft_register_basechain(basechain, afi->nops); |
| 177 | break; |
| 178 | case NETDEV_UNREGISTER: |
| 179 | if (strcmp(basechain->dev_name, dev->name) != 0) |
| 180 | return; |
| 181 | |
| 182 | BUG_ON(basechain->flags & NFT_BASECHAIN_DISABLED); |
| 183 | |
| 184 | if (!(table->flags & NFT_TABLE_F_DORMANT)) |
| 185 | nft_unregister_basechain(basechain, afi->nops); |
| 186 | |
| 187 | dev_put(basechain->ops[0].dev); |
| 188 | basechain->ops[0].dev = NULL; |
| 189 | basechain->flags |= NFT_BASECHAIN_DISABLED; |
| 190 | break; |
| 191 | case NETDEV_CHANGENAME: |
| 192 | if (dev->ifindex != basechain->ops[0].dev->ifindex) |
| 193 | return; |
| 194 | |
| 195 | strncpy(basechain->dev_name, dev->name, IFNAMSIZ); |
| 196 | break; |
| 197 | } |
| 198 | } |
| 199 | |
| 200 | static int nf_tables_netdev_event(struct notifier_block *this, |
| 201 | unsigned long event, void *ptr) |
| 202 | { |
| 203 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
| 204 | struct nft_af_info *afi; |
| 205 | struct nft_table *table; |
| 206 | struct nft_chain *chain; |
| 207 | |
| 208 | nfnl_lock(NFNL_SUBSYS_NFTABLES); |
| 209 | list_for_each_entry(afi, &dev_net(dev)->nft.af_info, list) { |
| 210 | if (afi->family != NFPROTO_NETDEV) |
| 211 | continue; |
| 212 | |
| 213 | list_for_each_entry(table, &afi->tables, list) { |
| 214 | list_for_each_entry(chain, &table->chains, list) { |
| 215 | if (!(chain->flags & NFT_BASE_CHAIN)) |
| 216 | continue; |
| 217 | |
| 218 | nft_netdev_event(event, afi, dev, table, |
| 219 | nft_base_chain(chain)); |
| 220 | } |
| 221 | } |
| 222 | } |
| 223 | nfnl_unlock(NFNL_SUBSYS_NFTABLES); |
| 224 | |
| 225 | return NOTIFY_DONE; |
| 226 | } |
| 227 | |
| 228 | static struct notifier_block nf_tables_netdev_notifier = { |
| 229 | .notifier_call = nf_tables_netdev_event, |
| 230 | }; |
| 231 | |
Pablo Neira Ayuso | ed6c413 | 2015-05-26 18:41:40 +0200 | [diff] [blame] | 232 | static int __init nf_tables_netdev_init(void) |
| 233 | { |
| 234 | int ret; |
| 235 | |
| 236 | nft_register_chain_type(&nft_filter_chain_netdev); |
| 237 | ret = register_pernet_subsys(&nf_tables_netdev_net_ops); |
| 238 | if (ret < 0) |
| 239 | nft_unregister_chain_type(&nft_filter_chain_netdev); |
| 240 | |
Pablo Neira Ayuso | 835b803 | 2015-06-15 12:12:01 +0200 | [diff] [blame] | 241 | register_netdevice_notifier(&nf_tables_netdev_notifier); |
| 242 | |
Pablo Neira Ayuso | ed6c413 | 2015-05-26 18:41:40 +0200 | [diff] [blame] | 243 | return ret; |
| 244 | } |
| 245 | |
| 246 | static void __exit nf_tables_netdev_exit(void) |
| 247 | { |
Pablo Neira Ayuso | 835b803 | 2015-06-15 12:12:01 +0200 | [diff] [blame] | 248 | unregister_netdevice_notifier(&nf_tables_netdev_notifier); |
Pablo Neira Ayuso | ed6c413 | 2015-05-26 18:41:40 +0200 | [diff] [blame] | 249 | unregister_pernet_subsys(&nf_tables_netdev_net_ops); |
| 250 | nft_unregister_chain_type(&nft_filter_chain_netdev); |
| 251 | } |
| 252 | |
| 253 | module_init(nf_tables_netdev_init); |
| 254 | module_exit(nf_tables_netdev_exit); |
| 255 | |
| 256 | MODULE_LICENSE("GPL"); |
| 257 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); |
| 258 | MODULE_ALIAS_NFT_FAMILY(5); /* NFPROTO_NETDEV */ |