Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 1 | /* |
| 2 | * (C) 1999-2001 Paul `Rusty' Russell |
| 3 | * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> |
| 4 | * (C) 2011 Patrick McHardy <kaber@trash.net> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/types.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/skbuff.h> |
| 14 | #include <linux/ip.h> |
| 15 | #include <linux/icmp.h> |
| 16 | #include <linux/netfilter.h> |
| 17 | #include <linux/netfilter_ipv4.h> |
| 18 | #include <net/secure_seq.h> |
| 19 | #include <net/checksum.h> |
| 20 | #include <net/route.h> |
| 21 | #include <net/ip.h> |
| 22 | |
| 23 | #include <net/netfilter/nf_conntrack_core.h> |
| 24 | #include <net/netfilter/nf_conntrack.h> |
| 25 | #include <net/netfilter/nf_nat_core.h> |
| 26 | #include <net/netfilter/nf_nat_l3proto.h> |
| 27 | #include <net/netfilter/nf_nat_l4proto.h> |
| 28 | |
| 29 | static const struct nf_nat_l3proto nf_nat_l3proto_ipv4; |
| 30 | |
| 31 | #ifdef CONFIG_XFRM |
| 32 | static void nf_nat_ipv4_decode_session(struct sk_buff *skb, |
| 33 | const struct nf_conn *ct, |
| 34 | enum ip_conntrack_dir dir, |
| 35 | unsigned long statusbit, |
| 36 | struct flowi *fl) |
| 37 | { |
| 38 | const struct nf_conntrack_tuple *t = &ct->tuplehash[dir].tuple; |
| 39 | struct flowi4 *fl4 = &fl->u.ip4; |
| 40 | |
| 41 | if (ct->status & statusbit) { |
| 42 | fl4->daddr = t->dst.u3.ip; |
| 43 | if (t->dst.protonum == IPPROTO_TCP || |
| 44 | t->dst.protonum == IPPROTO_UDP || |
| 45 | t->dst.protonum == IPPROTO_UDPLITE || |
| 46 | t->dst.protonum == IPPROTO_DCCP || |
| 47 | t->dst.protonum == IPPROTO_SCTP) |
| 48 | fl4->fl4_dport = t->dst.u.all; |
| 49 | } |
| 50 | |
| 51 | statusbit ^= IPS_NAT_MASK; |
| 52 | |
| 53 | if (ct->status & statusbit) { |
| 54 | fl4->saddr = t->src.u3.ip; |
| 55 | if (t->dst.protonum == IPPROTO_TCP || |
| 56 | t->dst.protonum == IPPROTO_UDP || |
| 57 | t->dst.protonum == IPPROTO_UDPLITE || |
| 58 | t->dst.protonum == IPPROTO_DCCP || |
| 59 | t->dst.protonum == IPPROTO_SCTP) |
| 60 | fl4->fl4_sport = t->src.u.all; |
| 61 | } |
| 62 | } |
| 63 | #endif /* CONFIG_XFRM */ |
| 64 | |
| 65 | static bool nf_nat_ipv4_in_range(const struct nf_conntrack_tuple *t, |
| 66 | const struct nf_nat_range *range) |
| 67 | { |
| 68 | return ntohl(t->src.u3.ip) >= ntohl(range->min_addr.ip) && |
| 69 | ntohl(t->src.u3.ip) <= ntohl(range->max_addr.ip); |
| 70 | } |
| 71 | |
| 72 | static u32 nf_nat_ipv4_secure_port(const struct nf_conntrack_tuple *t, |
| 73 | __be16 dport) |
| 74 | { |
| 75 | return secure_ipv4_port_ephemeral(t->src.u3.ip, t->dst.u3.ip, dport); |
| 76 | } |
| 77 | |
| 78 | static bool nf_nat_ipv4_manip_pkt(struct sk_buff *skb, |
| 79 | unsigned int iphdroff, |
| 80 | const struct nf_nat_l4proto *l4proto, |
| 81 | const struct nf_conntrack_tuple *target, |
| 82 | enum nf_nat_manip_type maniptype) |
| 83 | { |
| 84 | struct iphdr *iph; |
| 85 | unsigned int hdroff; |
| 86 | |
| 87 | if (!skb_make_writable(skb, iphdroff + sizeof(*iph))) |
| 88 | return false; |
| 89 | |
| 90 | iph = (void *)skb->data + iphdroff; |
| 91 | hdroff = iphdroff + iph->ihl * 4; |
| 92 | |
| 93 | if (!l4proto->manip_pkt(skb, &nf_nat_l3proto_ipv4, iphdroff, hdroff, |
| 94 | target, maniptype)) |
| 95 | return false; |
| 96 | iph = (void *)skb->data + iphdroff; |
| 97 | |
| 98 | if (maniptype == NF_NAT_MANIP_SRC) { |
| 99 | csum_replace4(&iph->check, iph->saddr, target->src.u3.ip); |
| 100 | iph->saddr = target->src.u3.ip; |
| 101 | } else { |
| 102 | csum_replace4(&iph->check, iph->daddr, target->dst.u3.ip); |
| 103 | iph->daddr = target->dst.u3.ip; |
| 104 | } |
| 105 | return true; |
| 106 | } |
| 107 | |
| 108 | static void nf_nat_ipv4_csum_update(struct sk_buff *skb, |
| 109 | unsigned int iphdroff, __sum16 *check, |
| 110 | const struct nf_conntrack_tuple *t, |
| 111 | enum nf_nat_manip_type maniptype) |
| 112 | { |
| 113 | struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff); |
| 114 | __be32 oldip, newip; |
| 115 | |
| 116 | if (maniptype == NF_NAT_MANIP_SRC) { |
| 117 | oldip = iph->saddr; |
| 118 | newip = t->src.u3.ip; |
| 119 | } else { |
| 120 | oldip = iph->daddr; |
| 121 | newip = t->dst.u3.ip; |
| 122 | } |
Tom Herbert | 4b048d6 | 2015-08-17 13:42:25 -0700 | [diff] [blame] | 123 | inet_proto_csum_replace4(check, skb, oldip, newip, true); |
Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 124 | } |
| 125 | |
| 126 | static void nf_nat_ipv4_csum_recalc(struct sk_buff *skb, |
| 127 | u8 proto, void *data, __sum16 *check, |
| 128 | int datalen, int oldlen) |
| 129 | { |
Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 130 | if (skb->ip_summed != CHECKSUM_PARTIAL) { |
Jarno Rajahalme | 2646190 | 2016-03-10 10:54:17 -0800 | [diff] [blame] | 131 | const struct iphdr *iph = ip_hdr(skb); |
| 132 | |
| 133 | skb->ip_summed = CHECKSUM_PARTIAL; |
| 134 | skb->csum_start = skb_headroom(skb) + skb_network_offset(skb) + |
| 135 | ip_hdrlen(skb); |
| 136 | skb->csum_offset = (void *)check - data; |
| 137 | *check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, datalen, |
| 138 | proto, 0); |
Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 139 | } else |
| 140 | inet_proto_csum_replace2(check, skb, |
Tom Herbert | 4b048d6 | 2015-08-17 13:42:25 -0700 | [diff] [blame] | 141 | htons(oldlen), htons(datalen), true); |
Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 142 | } |
| 143 | |
Duan Jiong | 24de3d3 | 2014-06-30 09:19:32 +0800 | [diff] [blame] | 144 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 145 | static int nf_nat_ipv4_nlattr_to_range(struct nlattr *tb[], |
| 146 | struct nf_nat_range *range) |
| 147 | { |
| 148 | if (tb[CTA_NAT_V4_MINIP]) { |
| 149 | range->min_addr.ip = nla_get_be32(tb[CTA_NAT_V4_MINIP]); |
| 150 | range->flags |= NF_NAT_RANGE_MAP_IPS; |
| 151 | } |
| 152 | |
| 153 | if (tb[CTA_NAT_V4_MAXIP]) |
| 154 | range->max_addr.ip = nla_get_be32(tb[CTA_NAT_V4_MAXIP]); |
| 155 | else |
| 156 | range->max_addr.ip = range->min_addr.ip; |
| 157 | |
| 158 | return 0; |
| 159 | } |
Duan Jiong | 24de3d3 | 2014-06-30 09:19:32 +0800 | [diff] [blame] | 160 | #endif |
Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 161 | |
| 162 | static const struct nf_nat_l3proto nf_nat_l3proto_ipv4 = { |
| 163 | .l3proto = NFPROTO_IPV4, |
| 164 | .in_range = nf_nat_ipv4_in_range, |
| 165 | .secure_port = nf_nat_ipv4_secure_port, |
| 166 | .manip_pkt = nf_nat_ipv4_manip_pkt, |
| 167 | .csum_update = nf_nat_ipv4_csum_update, |
| 168 | .csum_recalc = nf_nat_ipv4_csum_recalc, |
Duan Jiong | 24de3d3 | 2014-06-30 09:19:32 +0800 | [diff] [blame] | 169 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 170 | .nlattr_to_range = nf_nat_ipv4_nlattr_to_range, |
Duan Jiong | 24de3d3 | 2014-06-30 09:19:32 +0800 | [diff] [blame] | 171 | #endif |
Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 172 | #ifdef CONFIG_XFRM |
| 173 | .decode_session = nf_nat_ipv4_decode_session, |
| 174 | #endif |
| 175 | }; |
| 176 | |
| 177 | int nf_nat_icmp_reply_translation(struct sk_buff *skb, |
| 178 | struct nf_conn *ct, |
| 179 | enum ip_conntrack_info ctinfo, |
| 180 | unsigned int hooknum) |
| 181 | { |
| 182 | struct { |
| 183 | struct icmphdr icmp; |
| 184 | struct iphdr ip; |
| 185 | } *inside; |
| 186 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 187 | enum nf_nat_manip_type manip = HOOK2MANIP(hooknum); |
| 188 | unsigned int hdrlen = ip_hdrlen(skb); |
| 189 | const struct nf_nat_l4proto *l4proto; |
| 190 | struct nf_conntrack_tuple target; |
| 191 | unsigned long statusbit; |
| 192 | |
| 193 | NF_CT_ASSERT(ctinfo == IP_CT_RELATED || ctinfo == IP_CT_RELATED_REPLY); |
| 194 | |
| 195 | if (!skb_make_writable(skb, hdrlen + sizeof(*inside))) |
| 196 | return 0; |
| 197 | if (nf_ip_checksum(skb, hooknum, hdrlen, 0)) |
| 198 | return 0; |
| 199 | |
| 200 | inside = (void *)skb->data + hdrlen; |
| 201 | if (inside->icmp.type == ICMP_REDIRECT) { |
| 202 | if ((ct->status & IPS_NAT_DONE_MASK) != IPS_NAT_DONE_MASK) |
| 203 | return 0; |
| 204 | if (ct->status & IPS_NAT_MASK) |
| 205 | return 0; |
| 206 | } |
| 207 | |
| 208 | if (manip == NF_NAT_MANIP_SRC) |
| 209 | statusbit = IPS_SRC_NAT; |
| 210 | else |
| 211 | statusbit = IPS_DST_NAT; |
| 212 | |
| 213 | /* Invert if this is reply direction */ |
| 214 | if (dir == IP_CT_DIR_REPLY) |
| 215 | statusbit ^= IPS_NAT_MASK; |
| 216 | |
| 217 | if (!(ct->status & statusbit)) |
| 218 | return 1; |
| 219 | |
| 220 | l4proto = __nf_nat_l4proto_find(NFPROTO_IPV4, inside->ip.protocol); |
| 221 | if (!nf_nat_ipv4_manip_pkt(skb, hdrlen + sizeof(inside->icmp), |
| 222 | l4proto, &ct->tuplehash[!dir].tuple, !manip)) |
| 223 | return 0; |
| 224 | |
| 225 | if (skb->ip_summed != CHECKSUM_PARTIAL) { |
| 226 | /* Reloading "inside" here since manip_pkt may reallocate */ |
| 227 | inside = (void *)skb->data + hdrlen; |
| 228 | inside->icmp.checksum = 0; |
| 229 | inside->icmp.checksum = |
| 230 | csum_fold(skb_checksum(skb, hdrlen, |
| 231 | skb->len - hdrlen, 0)); |
| 232 | } |
| 233 | |
| 234 | /* Change outer to look like the reply to an incoming packet */ |
| 235 | nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); |
| 236 | l4proto = __nf_nat_l4proto_find(NFPROTO_IPV4, 0); |
| 237 | if (!nf_nat_ipv4_manip_pkt(skb, 0, l4proto, &target, manip)) |
| 238 | return 0; |
| 239 | |
| 240 | return 1; |
| 241 | } |
| 242 | EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation); |
| 243 | |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 244 | unsigned int |
Eric W. Biederman | 06198b3 | 2015-09-18 14:33:06 -0500 | [diff] [blame] | 245 | nf_nat_ipv4_fn(void *priv, struct sk_buff *skb, |
David S. Miller | d7cf408 | 2015-04-03 20:51:13 -0400 | [diff] [blame] | 246 | const struct nf_hook_state *state, |
Eric W. Biederman | 06198b3 | 2015-09-18 14:33:06 -0500 | [diff] [blame] | 247 | unsigned int (*do_chain)(void *priv, |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 248 | struct sk_buff *skb, |
David S. Miller | d7cf408 | 2015-04-03 20:51:13 -0400 | [diff] [blame] | 249 | const struct nf_hook_state *state, |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 250 | struct nf_conn *ct)) |
| 251 | { |
| 252 | struct nf_conn *ct; |
| 253 | enum ip_conntrack_info ctinfo; |
| 254 | struct nf_conn_nat *nat; |
| 255 | /* maniptype == SRC for postrouting. */ |
Eric W. Biederman | 082a758 | 2015-09-18 14:32:56 -0500 | [diff] [blame] | 256 | enum nf_nat_manip_type maniptype = HOOK2MANIP(state->hook); |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 257 | |
| 258 | /* We never see fragments: conntrack defrags on pre-routing |
| 259 | * and local-out, and nf_nat_out protects post-routing. |
| 260 | */ |
| 261 | NF_CT_ASSERT(!ip_is_fragment(ip_hdr(skb))); |
| 262 | |
| 263 | ct = nf_ct_get(skb, &ctinfo); |
| 264 | /* Can't track? It's not due to stress, or conntrack would |
| 265 | * have dropped it. Hence it's the user's responsibilty to |
| 266 | * packet filter it out, or implement conntrack/NAT for that |
| 267 | * protocol. 8) --RR |
| 268 | */ |
| 269 | if (!ct) |
| 270 | return NF_ACCEPT; |
| 271 | |
| 272 | /* Don't try to NAT if this packet is not conntracked */ |
| 273 | if (nf_ct_is_untracked(ct)) |
| 274 | return NF_ACCEPT; |
| 275 | |
| 276 | nat = nf_ct_nat_ext_add(ct); |
| 277 | if (nat == NULL) |
| 278 | return NF_ACCEPT; |
| 279 | |
| 280 | switch (ctinfo) { |
| 281 | case IP_CT_RELATED: |
| 282 | case IP_CT_RELATED_REPLY: |
| 283 | if (ip_hdr(skb)->protocol == IPPROTO_ICMP) { |
| 284 | if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo, |
Eric W. Biederman | 082a758 | 2015-09-18 14:32:56 -0500 | [diff] [blame] | 285 | state->hook)) |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 286 | return NF_DROP; |
| 287 | else |
| 288 | return NF_ACCEPT; |
| 289 | } |
| 290 | /* Fall thru... (Only ICMPs can be IP_CT_IS_REPLY) */ |
| 291 | case IP_CT_NEW: |
| 292 | /* Seen it before? This can happen for loopback, retrans, |
| 293 | * or local packets. |
| 294 | */ |
| 295 | if (!nf_nat_initialized(ct, maniptype)) { |
| 296 | unsigned int ret; |
| 297 | |
Eric W. Biederman | 06198b3 | 2015-09-18 14:33:06 -0500 | [diff] [blame] | 298 | ret = do_chain(priv, skb, state, ct); |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 299 | if (ret != NF_ACCEPT) |
| 300 | return ret; |
| 301 | |
Eric W. Biederman | 082a758 | 2015-09-18 14:32:56 -0500 | [diff] [blame] | 302 | if (nf_nat_initialized(ct, HOOK2MANIP(state->hook))) |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 303 | break; |
| 304 | |
Eric W. Biederman | 082a758 | 2015-09-18 14:32:56 -0500 | [diff] [blame] | 305 | ret = nf_nat_alloc_null_binding(ct, state->hook); |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 306 | if (ret != NF_ACCEPT) |
| 307 | return ret; |
| 308 | } else { |
| 309 | pr_debug("Already setup manip %s for ct %p\n", |
| 310 | maniptype == NF_NAT_MANIP_SRC ? "SRC" : "DST", |
| 311 | ct); |
Eric W. Biederman | 082a758 | 2015-09-18 14:32:56 -0500 | [diff] [blame] | 312 | if (nf_nat_oif_changed(state->hook, ctinfo, nat, |
David S. Miller | d7cf408 | 2015-04-03 20:51:13 -0400 | [diff] [blame] | 313 | state->out)) |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 314 | goto oif_changed; |
| 315 | } |
| 316 | break; |
| 317 | |
| 318 | default: |
| 319 | /* ESTABLISHED */ |
| 320 | NF_CT_ASSERT(ctinfo == IP_CT_ESTABLISHED || |
| 321 | ctinfo == IP_CT_ESTABLISHED_REPLY); |
Eric W. Biederman | 082a758 | 2015-09-18 14:32:56 -0500 | [diff] [blame] | 322 | if (nf_nat_oif_changed(state->hook, ctinfo, nat, state->out)) |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 323 | goto oif_changed; |
| 324 | } |
| 325 | |
Eric W. Biederman | 082a758 | 2015-09-18 14:32:56 -0500 | [diff] [blame] | 326 | return nf_nat_packet(ct, ctinfo, state->hook, skb); |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 327 | |
| 328 | oif_changed: |
| 329 | nf_ct_kill_acct(ct, ctinfo, skb); |
| 330 | return NF_DROP; |
| 331 | } |
| 332 | EXPORT_SYMBOL_GPL(nf_nat_ipv4_fn); |
| 333 | |
| 334 | unsigned int |
Eric W. Biederman | 06198b3 | 2015-09-18 14:33:06 -0500 | [diff] [blame] | 335 | nf_nat_ipv4_in(void *priv, struct sk_buff *skb, |
David S. Miller | d7cf408 | 2015-04-03 20:51:13 -0400 | [diff] [blame] | 336 | const struct nf_hook_state *state, |
Eric W. Biederman | 06198b3 | 2015-09-18 14:33:06 -0500 | [diff] [blame] | 337 | unsigned int (*do_chain)(void *priv, |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 338 | struct sk_buff *skb, |
David S. Miller | d7cf408 | 2015-04-03 20:51:13 -0400 | [diff] [blame] | 339 | const struct nf_hook_state *state, |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 340 | struct nf_conn *ct)) |
| 341 | { |
| 342 | unsigned int ret; |
| 343 | __be32 daddr = ip_hdr(skb)->daddr; |
| 344 | |
Eric W. Biederman | 06198b3 | 2015-09-18 14:33:06 -0500 | [diff] [blame] | 345 | ret = nf_nat_ipv4_fn(priv, skb, state, do_chain); |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 346 | if (ret != NF_DROP && ret != NF_STOLEN && |
| 347 | daddr != ip_hdr(skb)->daddr) |
| 348 | skb_dst_drop(skb); |
| 349 | |
| 350 | return ret; |
| 351 | } |
| 352 | EXPORT_SYMBOL_GPL(nf_nat_ipv4_in); |
| 353 | |
| 354 | unsigned int |
Eric W. Biederman | 06198b3 | 2015-09-18 14:33:06 -0500 | [diff] [blame] | 355 | nf_nat_ipv4_out(void *priv, struct sk_buff *skb, |
David S. Miller | d7cf408 | 2015-04-03 20:51:13 -0400 | [diff] [blame] | 356 | const struct nf_hook_state *state, |
Eric W. Biederman | 06198b3 | 2015-09-18 14:33:06 -0500 | [diff] [blame] | 357 | unsigned int (*do_chain)(void *priv, |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 358 | struct sk_buff *skb, |
David S. Miller | d7cf408 | 2015-04-03 20:51:13 -0400 | [diff] [blame] | 359 | const struct nf_hook_state *state, |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 360 | struct nf_conn *ct)) |
| 361 | { |
| 362 | #ifdef CONFIG_XFRM |
| 363 | const struct nf_conn *ct; |
| 364 | enum ip_conntrack_info ctinfo; |
| 365 | int err; |
| 366 | #endif |
| 367 | unsigned int ret; |
| 368 | |
| 369 | /* root is playing with raw sockets. */ |
| 370 | if (skb->len < sizeof(struct iphdr) || |
| 371 | ip_hdrlen(skb) < sizeof(struct iphdr)) |
| 372 | return NF_ACCEPT; |
| 373 | |
Eric W. Biederman | 06198b3 | 2015-09-18 14:33:06 -0500 | [diff] [blame] | 374 | ret = nf_nat_ipv4_fn(priv, skb, state, do_chain); |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 375 | #ifdef CONFIG_XFRM |
| 376 | if (ret != NF_DROP && ret != NF_STOLEN && |
| 377 | !(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && |
| 378 | (ct = nf_ct_get(skb, &ctinfo)) != NULL) { |
| 379 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 380 | |
| 381 | if ((ct->tuplehash[dir].tuple.src.u3.ip != |
| 382 | ct->tuplehash[!dir].tuple.dst.u3.ip) || |
| 383 | (ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP && |
| 384 | ct->tuplehash[dir].tuple.src.u.all != |
| 385 | ct->tuplehash[!dir].tuple.dst.u.all)) { |
Eric W. Biederman | c7af648 | 2015-09-18 14:33:07 -0500 | [diff] [blame] | 386 | err = nf_xfrm_me_harder(state->net, skb, AF_INET); |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 387 | if (err < 0) |
| 388 | ret = NF_DROP_ERR(err); |
| 389 | } |
| 390 | } |
| 391 | #endif |
| 392 | return ret; |
| 393 | } |
| 394 | EXPORT_SYMBOL_GPL(nf_nat_ipv4_out); |
| 395 | |
| 396 | unsigned int |
Eric W. Biederman | 06198b3 | 2015-09-18 14:33:06 -0500 | [diff] [blame] | 397 | nf_nat_ipv4_local_fn(void *priv, struct sk_buff *skb, |
David S. Miller | d7cf408 | 2015-04-03 20:51:13 -0400 | [diff] [blame] | 398 | const struct nf_hook_state *state, |
Eric W. Biederman | 06198b3 | 2015-09-18 14:33:06 -0500 | [diff] [blame] | 399 | unsigned int (*do_chain)(void *priv, |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 400 | struct sk_buff *skb, |
David S. Miller | d7cf408 | 2015-04-03 20:51:13 -0400 | [diff] [blame] | 401 | const struct nf_hook_state *state, |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 402 | struct nf_conn *ct)) |
| 403 | { |
| 404 | const struct nf_conn *ct; |
| 405 | enum ip_conntrack_info ctinfo; |
| 406 | unsigned int ret; |
| 407 | int err; |
| 408 | |
| 409 | /* root is playing with raw sockets. */ |
| 410 | if (skb->len < sizeof(struct iphdr) || |
| 411 | ip_hdrlen(skb) < sizeof(struct iphdr)) |
| 412 | return NF_ACCEPT; |
| 413 | |
Eric W. Biederman | 06198b3 | 2015-09-18 14:33:06 -0500 | [diff] [blame] | 414 | ret = nf_nat_ipv4_fn(priv, skb, state, do_chain); |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 415 | if (ret != NF_DROP && ret != NF_STOLEN && |
| 416 | (ct = nf_ct_get(skb, &ctinfo)) != NULL) { |
| 417 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 418 | |
| 419 | if (ct->tuplehash[dir].tuple.dst.u3.ip != |
| 420 | ct->tuplehash[!dir].tuple.src.u3.ip) { |
Eric W. Biederman | e45f506 | 2015-09-25 15:07:30 -0500 | [diff] [blame] | 421 | err = ip_route_me_harder(state->net, skb, RTN_UNSPEC); |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 422 | if (err < 0) |
| 423 | ret = NF_DROP_ERR(err); |
| 424 | } |
| 425 | #ifdef CONFIG_XFRM |
| 426 | else if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && |
| 427 | ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP && |
| 428 | ct->tuplehash[dir].tuple.dst.u.all != |
| 429 | ct->tuplehash[!dir].tuple.src.u.all) { |
Eric W. Biederman | c7af648 | 2015-09-18 14:33:07 -0500 | [diff] [blame] | 430 | err = nf_xfrm_me_harder(state->net, skb, AF_INET); |
Pablo Neira Ayuso | 30766f4 | 2014-08-05 20:02:42 +0200 | [diff] [blame] | 431 | if (err < 0) |
| 432 | ret = NF_DROP_ERR(err); |
| 433 | } |
| 434 | #endif |
| 435 | } |
| 436 | return ret; |
| 437 | } |
| 438 | EXPORT_SYMBOL_GPL(nf_nat_ipv4_local_fn); |
| 439 | |
Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 440 | static int __init nf_nat_l3proto_ipv4_init(void) |
| 441 | { |
| 442 | int err; |
| 443 | |
| 444 | err = nf_nat_l4proto_register(NFPROTO_IPV4, &nf_nat_l4proto_icmp); |
| 445 | if (err < 0) |
| 446 | goto err1; |
| 447 | err = nf_nat_l3proto_register(&nf_nat_l3proto_ipv4); |
| 448 | if (err < 0) |
| 449 | goto err2; |
| 450 | return err; |
| 451 | |
| 452 | err2: |
| 453 | nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_icmp); |
| 454 | err1: |
| 455 | return err; |
| 456 | } |
| 457 | |
| 458 | static void __exit nf_nat_l3proto_ipv4_exit(void) |
| 459 | { |
| 460 | nf_nat_l3proto_unregister(&nf_nat_l3proto_ipv4); |
| 461 | nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_icmp); |
| 462 | } |
| 463 | |
| 464 | MODULE_LICENSE("GPL"); |
| 465 | MODULE_ALIAS("nf-nat-" __stringify(AF_INET)); |
| 466 | |
| 467 | module_init(nf_nat_l3proto_ipv4_init); |
| 468 | module_exit(nf_nat_l3proto_ipv4_exit); |