| 1 | /* |
| 2 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
| 3 | * Copyright (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org> |
| 4 | * Copyright (c) 2012 Intel Corporation |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify it |
| 7 | * under the terms and conditions of the GNU General Public License, |
| 8 | * version 2, as published by the Free Software Foundation. |
| 9 | * |
| 10 | */ |
| 11 | |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/init.h> |
| 14 | #include <linux/skbuff.h> |
| 15 | #include <linux/ip.h> |
| 16 | #include <linux/string.h> |
| 17 | #include <linux/netlink.h> |
| 18 | #include <linux/netfilter.h> |
| 19 | #include <linux/netfilter_ipv4.h> |
| 20 | #include <linux/netfilter/nfnetlink.h> |
| 21 | #include <linux/netfilter/nf_tables.h> |
| 22 | #include <net/netfilter/nf_conntrack.h> |
| 23 | #include <net/netfilter/nf_nat.h> |
| 24 | #include <net/netfilter/nf_nat_core.h> |
| 25 | #include <net/netfilter/nf_tables.h> |
| 26 | #include <net/netfilter/nf_nat_l3proto.h> |
| 27 | #include <net/ip.h> |
| 28 | |
| 29 | struct nft_nat { |
| 30 | enum nft_registers sreg_addr_min:8; |
| 31 | enum nft_registers sreg_addr_max:8; |
| 32 | enum nft_registers sreg_proto_min:8; |
| 33 | enum nft_registers sreg_proto_max:8; |
| 34 | enum nf_nat_manip_type type:8; |
| 35 | u8 family; |
| 36 | u16 flags; |
| 37 | }; |
| 38 | |
| 39 | static void nft_nat_eval(const struct nft_expr *expr, |
| 40 | struct nft_regs *regs, |
| 41 | const struct nft_pktinfo *pkt) |
| 42 | { |
| 43 | const struct nft_nat *priv = nft_expr_priv(expr); |
| 44 | enum ip_conntrack_info ctinfo; |
| 45 | struct nf_conn *ct = nf_ct_get(pkt->skb, &ctinfo); |
| 46 | struct nf_nat_range range; |
| 47 | |
| 48 | memset(&range, 0, sizeof(range)); |
| 49 | if (priv->sreg_addr_min) { |
| 50 | if (priv->family == AF_INET) { |
| 51 | range.min_addr.ip = (__force __be32) |
| 52 | regs->data[priv->sreg_addr_min]; |
| 53 | range.max_addr.ip = (__force __be32) |
| 54 | regs->data[priv->sreg_addr_max]; |
| 55 | |
| 56 | } else { |
| 57 | memcpy(range.min_addr.ip6, |
| 58 | ®s->data[priv->sreg_addr_min], |
| 59 | sizeof(range.min_addr.ip6)); |
| 60 | memcpy(range.max_addr.ip6, |
| 61 | ®s->data[priv->sreg_addr_max], |
| 62 | sizeof(range.max_addr.ip6)); |
| 63 | } |
| 64 | range.flags |= NF_NAT_RANGE_MAP_IPS; |
| 65 | } |
| 66 | |
| 67 | if (priv->sreg_proto_min) { |
| 68 | range.min_proto.all = |
| 69 | *(__be16 *)®s->data[priv->sreg_proto_min]; |
| 70 | range.max_proto.all = |
| 71 | *(__be16 *)®s->data[priv->sreg_proto_max]; |
| 72 | range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED; |
| 73 | } |
| 74 | |
| 75 | range.flags |= priv->flags; |
| 76 | |
| 77 | regs->verdict.code = nf_nat_setup_info(ct, &range, priv->type); |
| 78 | } |
| 79 | |
| 80 | static const struct nla_policy nft_nat_policy[NFTA_NAT_MAX + 1] = { |
| 81 | [NFTA_NAT_TYPE] = { .type = NLA_U32 }, |
| 82 | [NFTA_NAT_FAMILY] = { .type = NLA_U32 }, |
| 83 | [NFTA_NAT_REG_ADDR_MIN] = { .type = NLA_U32 }, |
| 84 | [NFTA_NAT_REG_ADDR_MAX] = { .type = NLA_U32 }, |
| 85 | [NFTA_NAT_REG_PROTO_MIN] = { .type = NLA_U32 }, |
| 86 | [NFTA_NAT_REG_PROTO_MAX] = { .type = NLA_U32 }, |
| 87 | [NFTA_NAT_FLAGS] = { .type = NLA_U32 }, |
| 88 | }; |
| 89 | |
| 90 | static int nft_nat_validate(const struct nft_ctx *ctx, |
| 91 | const struct nft_expr *expr, |
| 92 | const struct nft_data **data) |
| 93 | { |
| 94 | struct nft_nat *priv = nft_expr_priv(expr); |
| 95 | int err; |
| 96 | |
| 97 | err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT); |
| 98 | if (err < 0) |
| 99 | return err; |
| 100 | |
| 101 | switch (priv->type) { |
| 102 | case NFT_NAT_SNAT: |
| 103 | err = nft_chain_validate_hooks(ctx->chain, |
| 104 | (1 << NF_INET_POST_ROUTING) | |
| 105 | (1 << NF_INET_LOCAL_IN)); |
| 106 | break; |
| 107 | case NFT_NAT_DNAT: |
| 108 | err = nft_chain_validate_hooks(ctx->chain, |
| 109 | (1 << NF_INET_PRE_ROUTING) | |
| 110 | (1 << NF_INET_LOCAL_OUT)); |
| 111 | break; |
| 112 | } |
| 113 | |
| 114 | return err; |
| 115 | } |
| 116 | |
| 117 | static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr, |
| 118 | const struct nlattr * const tb[]) |
| 119 | { |
| 120 | struct nft_nat *priv = nft_expr_priv(expr); |
| 121 | unsigned int alen, plen; |
| 122 | u32 family; |
| 123 | int err; |
| 124 | |
| 125 | if (tb[NFTA_NAT_TYPE] == NULL || |
| 126 | (tb[NFTA_NAT_REG_ADDR_MIN] == NULL && |
| 127 | tb[NFTA_NAT_REG_PROTO_MIN] == NULL)) |
| 128 | return -EINVAL; |
| 129 | |
| 130 | switch (ntohl(nla_get_be32(tb[NFTA_NAT_TYPE]))) { |
| 131 | case NFT_NAT_SNAT: |
| 132 | priv->type = NF_NAT_MANIP_SRC; |
| 133 | break; |
| 134 | case NFT_NAT_DNAT: |
| 135 | priv->type = NF_NAT_MANIP_DST; |
| 136 | break; |
| 137 | default: |
| 138 | return -EINVAL; |
| 139 | } |
| 140 | |
| 141 | err = nft_nat_validate(ctx, expr, NULL); |
| 142 | if (err < 0) |
| 143 | return err; |
| 144 | |
| 145 | if (tb[NFTA_NAT_FAMILY] == NULL) |
| 146 | return -EINVAL; |
| 147 | |
| 148 | family = ntohl(nla_get_be32(tb[NFTA_NAT_FAMILY])); |
| 149 | if (family != ctx->afi->family) |
| 150 | return -EOPNOTSUPP; |
| 151 | |
| 152 | switch (family) { |
| 153 | case NFPROTO_IPV4: |
| 154 | alen = FIELD_SIZEOF(struct nf_nat_range, min_addr.ip); |
| 155 | break; |
| 156 | case NFPROTO_IPV6: |
| 157 | alen = FIELD_SIZEOF(struct nf_nat_range, min_addr.ip6); |
| 158 | break; |
| 159 | default: |
| 160 | return -EAFNOSUPPORT; |
| 161 | } |
| 162 | priv->family = family; |
| 163 | |
| 164 | if (tb[NFTA_NAT_REG_ADDR_MIN]) { |
| 165 | priv->sreg_addr_min = |
| 166 | nft_parse_register(tb[NFTA_NAT_REG_ADDR_MIN]); |
| 167 | err = nft_validate_register_load(priv->sreg_addr_min, alen); |
| 168 | if (err < 0) |
| 169 | return err; |
| 170 | |
| 171 | if (tb[NFTA_NAT_REG_ADDR_MAX]) { |
| 172 | priv->sreg_addr_max = |
| 173 | nft_parse_register(tb[NFTA_NAT_REG_ADDR_MAX]); |
| 174 | |
| 175 | err = nft_validate_register_load(priv->sreg_addr_max, |
| 176 | alen); |
| 177 | if (err < 0) |
| 178 | return err; |
| 179 | } else { |
| 180 | priv->sreg_addr_max = priv->sreg_addr_min; |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | plen = FIELD_SIZEOF(struct nf_nat_range, min_addr.all); |
| 185 | if (tb[NFTA_NAT_REG_PROTO_MIN]) { |
| 186 | priv->sreg_proto_min = |
| 187 | nft_parse_register(tb[NFTA_NAT_REG_PROTO_MIN]); |
| 188 | |
| 189 | err = nft_validate_register_load(priv->sreg_proto_min, plen); |
| 190 | if (err < 0) |
| 191 | return err; |
| 192 | |
| 193 | if (tb[NFTA_NAT_REG_PROTO_MAX]) { |
| 194 | priv->sreg_proto_max = |
| 195 | nft_parse_register(tb[NFTA_NAT_REG_PROTO_MAX]); |
| 196 | |
| 197 | err = nft_validate_register_load(priv->sreg_proto_max, |
| 198 | plen); |
| 199 | if (err < 0) |
| 200 | return err; |
| 201 | } else { |
| 202 | priv->sreg_proto_max = priv->sreg_proto_min; |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | if (tb[NFTA_NAT_FLAGS]) { |
| 207 | priv->flags = ntohl(nla_get_be32(tb[NFTA_NAT_FLAGS])); |
| 208 | if (priv->flags & ~NF_NAT_RANGE_MASK) |
| 209 | return -EINVAL; |
| 210 | } |
| 211 | |
| 212 | return 0; |
| 213 | } |
| 214 | |
| 215 | static int nft_nat_dump(struct sk_buff *skb, const struct nft_expr *expr) |
| 216 | { |
| 217 | const struct nft_nat *priv = nft_expr_priv(expr); |
| 218 | |
| 219 | switch (priv->type) { |
| 220 | case NF_NAT_MANIP_SRC: |
| 221 | if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_SNAT))) |
| 222 | goto nla_put_failure; |
| 223 | break; |
| 224 | case NF_NAT_MANIP_DST: |
| 225 | if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_DNAT))) |
| 226 | goto nla_put_failure; |
| 227 | break; |
| 228 | } |
| 229 | |
| 230 | if (nla_put_be32(skb, NFTA_NAT_FAMILY, htonl(priv->family))) |
| 231 | goto nla_put_failure; |
| 232 | |
| 233 | if (priv->sreg_addr_min) { |
| 234 | if (nft_dump_register(skb, NFTA_NAT_REG_ADDR_MIN, |
| 235 | priv->sreg_addr_min) || |
| 236 | nft_dump_register(skb, NFTA_NAT_REG_ADDR_MAX, |
| 237 | priv->sreg_addr_max)) |
| 238 | goto nla_put_failure; |
| 239 | } |
| 240 | |
| 241 | if (priv->sreg_proto_min) { |
| 242 | if (nft_dump_register(skb, NFTA_NAT_REG_PROTO_MIN, |
| 243 | priv->sreg_proto_min) || |
| 244 | nft_dump_register(skb, NFTA_NAT_REG_PROTO_MAX, |
| 245 | priv->sreg_proto_max)) |
| 246 | goto nla_put_failure; |
| 247 | } |
| 248 | |
| 249 | if (priv->flags != 0) { |
| 250 | if (nla_put_be32(skb, NFTA_NAT_FLAGS, htonl(priv->flags))) |
| 251 | goto nla_put_failure; |
| 252 | } |
| 253 | |
| 254 | return 0; |
| 255 | |
| 256 | nla_put_failure: |
| 257 | return -1; |
| 258 | } |
| 259 | |
| 260 | static struct nft_expr_type nft_nat_type; |
| 261 | static const struct nft_expr_ops nft_nat_ops = { |
| 262 | .type = &nft_nat_type, |
| 263 | .size = NFT_EXPR_SIZE(sizeof(struct nft_nat)), |
| 264 | .eval = nft_nat_eval, |
| 265 | .init = nft_nat_init, |
| 266 | .dump = nft_nat_dump, |
| 267 | .validate = nft_nat_validate, |
| 268 | }; |
| 269 | |
| 270 | static struct nft_expr_type nft_nat_type __read_mostly = { |
| 271 | .name = "nat", |
| 272 | .ops = &nft_nat_ops, |
| 273 | .policy = nft_nat_policy, |
| 274 | .maxattr = NFTA_NAT_MAX, |
| 275 | .owner = THIS_MODULE, |
| 276 | }; |
| 277 | |
| 278 | static int __init nft_nat_module_init(void) |
| 279 | { |
| 280 | return nft_register_expr(&nft_nat_type); |
| 281 | } |
| 282 | |
| 283 | static void __exit nft_nat_module_exit(void) |
| 284 | { |
| 285 | nft_unregister_expr(&nft_nat_type); |
| 286 | } |
| 287 | |
| 288 | module_init(nft_nat_module_init); |
| 289 | module_exit(nft_nat_module_exit); |
| 290 | |
| 291 | MODULE_LICENSE("GPL"); |
| 292 | MODULE_AUTHOR("Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>"); |
| 293 | MODULE_ALIAS_NFT_EXPR("nat"); |