Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 1 | /* NAT for netfilter; shared with compatibility layer. */ |
| 2 | |
| 3 | /* (C) 1999-2001 Paul `Rusty' Russell |
| 4 | * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> |
| 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/module.h> |
| 12 | #include <linux/types.h> |
| 13 | #include <linux/timer.h> |
| 14 | #include <linux/skbuff.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 15 | #include <linux/gfp.h> |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 16 | #include <net/checksum.h> |
| 17 | #include <net/icmp.h> |
| 18 | #include <net/ip.h> |
| 19 | #include <net/tcp.h> /* For tcp_prot in getorigdst */ |
| 20 | #include <linux/icmp.h> |
| 21 | #include <linux/udp.h> |
| 22 | #include <linux/jhash.h> |
| 23 | |
| 24 | #include <linux/netfilter_ipv4.h> |
| 25 | #include <net/netfilter/nf_conntrack.h> |
| 26 | #include <net/netfilter/nf_conntrack_core.h> |
| 27 | #include <net/netfilter/nf_nat.h> |
| 28 | #include <net/netfilter/nf_nat_protocol.h> |
| 29 | #include <net/netfilter/nf_nat_core.h> |
| 30 | #include <net/netfilter/nf_nat_helper.h> |
| 31 | #include <net/netfilter/nf_conntrack_helper.h> |
| 32 | #include <net/netfilter/nf_conntrack_l3proto.h> |
| 33 | #include <net/netfilter/nf_conntrack_l4proto.h> |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 34 | #include <net/netfilter/nf_conntrack_zones.h> |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 35 | |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 36 | static DEFINE_SPINLOCK(nf_nat_lock); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 37 | |
Patrick McHardy | ce4b1ce | 2007-12-17 22:37:52 -0800 | [diff] [blame] | 38 | static struct nf_conntrack_l3proto *l3proto __read_mostly; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 39 | |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 40 | #define MAX_IP_NAT_PROTO 256 |
Arnd Bergmann | 0906a37 | 2010-03-09 20:59:15 +0100 | [diff] [blame] | 41 | static const struct nf_nat_protocol __rcu *nf_nat_protos[MAX_IP_NAT_PROTO] |
Patrick McHardy | ce4b1ce | 2007-12-17 22:37:52 -0800 | [diff] [blame] | 42 | __read_mostly; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 43 | |
Patrick McHardy | 2b628a0 | 2007-12-17 22:37:36 -0800 | [diff] [blame] | 44 | static inline const struct nf_nat_protocol * |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 45 | __nf_nat_proto_find(u_int8_t protonum) |
| 46 | { |
Patrick McHardy | e22a054 | 2007-02-12 11:12:26 -0800 | [diff] [blame] | 47 | return rcu_dereference(nf_nat_protos[protonum]); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 48 | } |
| 49 | |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 50 | /* We keep an extra hash for each conntrack, for fast searching. */ |
| 51 | static inline unsigned int |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 52 | hash_by_src(const struct net *net, u16 zone, |
| 53 | const struct nf_conntrack_tuple *tuple) |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 54 | { |
Patrick McHardy | 3449882 | 2007-12-17 22:45:52 -0800 | [diff] [blame] | 55 | unsigned int hash; |
| 56 | |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 57 | /* Original src, to ensure we map it consistently if poss. */ |
Patrick McHardy | 3449882 | 2007-12-17 22:45:52 -0800 | [diff] [blame] | 58 | hash = jhash_3words((__force u32)tuple->src.u3.ip, |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 59 | (__force u32)tuple->src.u.all ^ zone, |
Patrick McHardy | 3449882 | 2007-12-17 22:45:52 -0800 | [diff] [blame] | 60 | tuple->dst.protonum, 0); |
Patrick McHardy | d696c7b | 2010-02-08 11:18:07 -0800 | [diff] [blame] | 61 | return ((u64)hash * net->ipv4.nat_htable_size) >> 32; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 62 | } |
| 63 | |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 64 | /* Is this tuple already taken? (not by us) */ |
| 65 | int |
| 66 | nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple, |
| 67 | const struct nf_conn *ignored_conntrack) |
| 68 | { |
| 69 | /* Conntrack tracking doesn't keep track of outgoing tuples; only |
| 70 | incoming ones. NAT means they don't have a fixed mapping, |
| 71 | so we invert the tuple and look for the incoming reply. |
| 72 | |
| 73 | We could keep a separate hash if this proves too slow. */ |
| 74 | struct nf_conntrack_tuple reply; |
| 75 | |
| 76 | nf_ct_invert_tuplepr(&reply, tuple); |
| 77 | return nf_conntrack_tuple_taken(&reply, ignored_conntrack); |
| 78 | } |
| 79 | EXPORT_SYMBOL(nf_nat_used_tuple); |
| 80 | |
| 81 | /* If we source map this tuple so reply looks like reply_tuple, will |
| 82 | * that meet the constraints of range. */ |
| 83 | static int |
| 84 | in_range(const struct nf_conntrack_tuple *tuple, |
| 85 | const struct nf_nat_range *range) |
| 86 | { |
Patrick McHardy | 2b628a0 | 2007-12-17 22:37:36 -0800 | [diff] [blame] | 87 | const struct nf_nat_protocol *proto; |
Patrick McHardy | e22a054 | 2007-02-12 11:12:26 -0800 | [diff] [blame] | 88 | int ret = 0; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 89 | |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 90 | /* If we are supposed to map IPs, then we must be in the |
| 91 | range specified, otherwise let this drag us onto a new src IP. */ |
| 92 | if (range->flags & IP_NAT_RANGE_MAP_IPS) { |
| 93 | if (ntohl(tuple->src.u3.ip) < ntohl(range->min_ip) || |
| 94 | ntohl(tuple->src.u3.ip) > ntohl(range->max_ip)) |
| 95 | return 0; |
| 96 | } |
| 97 | |
Patrick McHardy | e22a054 | 2007-02-12 11:12:26 -0800 | [diff] [blame] | 98 | rcu_read_lock(); |
| 99 | proto = __nf_nat_proto_find(tuple->dst.protonum); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 100 | if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED) || |
| 101 | proto->in_range(tuple, IP_NAT_MANIP_SRC, |
| 102 | &range->min, &range->max)) |
Patrick McHardy | e22a054 | 2007-02-12 11:12:26 -0800 | [diff] [blame] | 103 | ret = 1; |
| 104 | rcu_read_unlock(); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 105 | |
Patrick McHardy | e22a054 | 2007-02-12 11:12:26 -0800 | [diff] [blame] | 106 | return ret; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 107 | } |
| 108 | |
| 109 | static inline int |
| 110 | same_src(const struct nf_conn *ct, |
| 111 | const struct nf_conntrack_tuple *tuple) |
| 112 | { |
| 113 | const struct nf_conntrack_tuple *t; |
| 114 | |
| 115 | t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; |
| 116 | return (t->dst.protonum == tuple->dst.protonum && |
| 117 | t->src.u3.ip == tuple->src.u3.ip && |
| 118 | t->src.u.all == tuple->src.u.all); |
| 119 | } |
| 120 | |
| 121 | /* Only called for SRC manip */ |
| 122 | static int |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 123 | find_appropriate_src(struct net *net, u16 zone, |
Alexey Dobriyan | 0c4c928 | 2008-10-08 11:35:11 +0200 | [diff] [blame] | 124 | const struct nf_conntrack_tuple *tuple, |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 125 | struct nf_conntrack_tuple *result, |
| 126 | const struct nf_nat_range *range) |
| 127 | { |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 128 | unsigned int h = hash_by_src(net, zone, tuple); |
Jan Engelhardt | 72b7294 | 2008-04-14 11:15:42 +0200 | [diff] [blame] | 129 | const struct nf_conn_nat *nat; |
| 130 | const struct nf_conn *ct; |
| 131 | const struct hlist_node *n; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 132 | |
Patrick McHardy | 4d354c5 | 2008-01-31 04:42:37 -0800 | [diff] [blame] | 133 | rcu_read_lock(); |
Alexey Dobriyan | 0c4c928 | 2008-10-08 11:35:11 +0200 | [diff] [blame] | 134 | hlist_for_each_entry_rcu(nat, n, &net->ipv4.nat_bysource[h], bysource) { |
Yasuyuki Kozakai | b6b84d4 | 2007-07-07 22:26:35 -0700 | [diff] [blame] | 135 | ct = nat->ct; |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 136 | if (same_src(ct, tuple) && nf_ct_zone(ct) == zone) { |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 137 | /* Copy source part from reply tuple. */ |
| 138 | nf_ct_invert_tuplepr(result, |
| 139 | &ct->tuplehash[IP_CT_DIR_REPLY].tuple); |
| 140 | result->dst = tuple->dst; |
| 141 | |
| 142 | if (in_range(result, range)) { |
Patrick McHardy | 4d354c5 | 2008-01-31 04:42:37 -0800 | [diff] [blame] | 143 | rcu_read_unlock(); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 144 | return 1; |
| 145 | } |
| 146 | } |
| 147 | } |
Patrick McHardy | 4d354c5 | 2008-01-31 04:42:37 -0800 | [diff] [blame] | 148 | rcu_read_unlock(); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 149 | return 0; |
| 150 | } |
| 151 | |
| 152 | /* For [FUTURE] fragmentation handling, we want the least-used |
| 153 | src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus |
| 154 | if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports |
| 155 | 1-65535, we don't do pro-rata allocation based on ports; we choose |
| 156 | the ip with the lowest src-ip/dst-ip/proto usage. |
| 157 | */ |
| 158 | static void |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 159 | find_best_ips_proto(u16 zone, struct nf_conntrack_tuple *tuple, |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 160 | const struct nf_nat_range *range, |
| 161 | const struct nf_conn *ct, |
| 162 | enum nf_nat_manip_type maniptype) |
| 163 | { |
| 164 | __be32 *var_ipp; |
| 165 | /* Host order */ |
| 166 | u_int32_t minip, maxip, j; |
| 167 | |
| 168 | /* No IP mapping? Do nothing. */ |
| 169 | if (!(range->flags & IP_NAT_RANGE_MAP_IPS)) |
| 170 | return; |
| 171 | |
| 172 | if (maniptype == IP_NAT_MANIP_SRC) |
| 173 | var_ipp = &tuple->src.u3.ip; |
| 174 | else |
| 175 | var_ipp = &tuple->dst.u3.ip; |
| 176 | |
| 177 | /* Fast path: only one choice. */ |
| 178 | if (range->min_ip == range->max_ip) { |
| 179 | *var_ipp = range->min_ip; |
| 180 | return; |
| 181 | } |
| 182 | |
| 183 | /* Hashing source and destination IPs gives a fairly even |
| 184 | * spread in practice (if there are a small number of IPs |
| 185 | * involved, there usually aren't that many connections |
| 186 | * anyway). The consistency means that servers see the same |
| 187 | * client coming from the same IP (some Internet Banking sites |
| 188 | * like this), even across reboots. */ |
| 189 | minip = ntohl(range->min_ip); |
| 190 | maxip = ntohl(range->max_ip); |
| 191 | j = jhash_2words((__force u32)tuple->src.u3.ip, |
Patrick McHardy | 98d500d | 2009-04-16 18:33:01 +0200 | [diff] [blame] | 192 | range->flags & IP_NAT_RANGE_PERSISTENT ? |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 193 | 0 : (__force u32)tuple->dst.u3.ip ^ zone, 0); |
Patrick McHardy | 3449882 | 2007-12-17 22:45:52 -0800 | [diff] [blame] | 194 | j = ((u64)j * (maxip - minip + 1)) >> 32; |
| 195 | *var_ipp = htonl(minip + j); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 196 | } |
| 197 | |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 198 | /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING, |
| 199 | * we change the source to map into the range. For NF_INET_PRE_ROUTING |
| 200 | * and NF_INET_LOCAL_OUT, we change the destination to map into the |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 201 | * range. It might not be possible to get a unique tuple, but we try. |
| 202 | * At worst (or if we race), we will end up with a final duplicate in |
| 203 | * __ip_conntrack_confirm and drop the packet. */ |
| 204 | static void |
| 205 | get_unique_tuple(struct nf_conntrack_tuple *tuple, |
| 206 | const struct nf_conntrack_tuple *orig_tuple, |
| 207 | const struct nf_nat_range *range, |
| 208 | struct nf_conn *ct, |
| 209 | enum nf_nat_manip_type maniptype) |
| 210 | { |
Alexey Dobriyan | 0c4c928 | 2008-10-08 11:35:11 +0200 | [diff] [blame] | 211 | struct net *net = nf_ct_net(ct); |
Patrick McHardy | 2b628a0 | 2007-12-17 22:37:36 -0800 | [diff] [blame] | 212 | const struct nf_nat_protocol *proto; |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 213 | u16 zone = nf_ct_zone(ct); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 214 | |
| 215 | /* 1) If this srcip/proto/src-proto-part is currently mapped, |
| 216 | and that same mapping gives a unique tuple within the given |
| 217 | range, use that. |
| 218 | |
| 219 | This is only required for source (ie. NAT/masq) mappings. |
| 220 | So far, we don't do local source mappings, so multiple |
| 221 | manips not an issue. */ |
Changli Gao | 0dbff68 | 2008-07-21 10:00:51 -0700 | [diff] [blame] | 222 | if (maniptype == IP_NAT_MANIP_SRC && |
| 223 | !(range->flags & IP_NAT_RANGE_PROTO_RANDOM)) { |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 224 | if (find_appropriate_src(net, zone, orig_tuple, tuple, range)) { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 225 | pr_debug("get_unique_tuple: Found current src map\n"); |
Changli Gao | 0dbff68 | 2008-07-21 10:00:51 -0700 | [diff] [blame] | 226 | if (!nf_nat_used_tuple(tuple, ct)) |
| 227 | return; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 228 | } |
| 229 | } |
| 230 | |
| 231 | /* 2) Select the least-used IP/proto combination in the given |
| 232 | range. */ |
| 233 | *tuple = *orig_tuple; |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 234 | find_best_ips_proto(zone, tuple, range, ct, maniptype); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 235 | |
| 236 | /* 3) The per-protocol part of the manip is made to map into |
| 237 | the range to make a unique tuple. */ |
| 238 | |
Patrick McHardy | e22a054 | 2007-02-12 11:12:26 -0800 | [diff] [blame] | 239 | rcu_read_lock(); |
| 240 | proto = __nf_nat_proto_find(orig_tuple->dst.protonum); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 241 | |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 242 | /* Only bother mapping if it's not already in range and unique */ |
Changli Gao | 99ad3c5 | 2010-09-16 19:45:19 +0200 | [diff] [blame] | 243 | if (!(range->flags & IP_NAT_RANGE_PROTO_RANDOM)) { |
| 244 | if (range->flags & IP_NAT_RANGE_PROTO_SPECIFIED) { |
| 245 | if (proto->in_range(tuple, maniptype, &range->min, |
| 246 | &range->max) && |
| 247 | (range->min.all == range->max.all || |
| 248 | !nf_nat_used_tuple(tuple, ct))) |
| 249 | goto out; |
| 250 | } else if (!nf_nat_used_tuple(tuple, ct)) { |
| 251 | goto out; |
| 252 | } |
| 253 | } |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 254 | |
| 255 | /* Last change: get protocol to try to obtain unique tuple. */ |
| 256 | proto->unique_tuple(tuple, range, maniptype, ct); |
Patrick McHardy | e22a054 | 2007-02-12 11:12:26 -0800 | [diff] [blame] | 257 | out: |
| 258 | rcu_read_unlock(); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 259 | } |
| 260 | |
| 261 | unsigned int |
| 262 | nf_nat_setup_info(struct nf_conn *ct, |
| 263 | const struct nf_nat_range *range, |
Patrick McHardy | cc01dcb | 2007-12-17 22:38:20 -0800 | [diff] [blame] | 264 | enum nf_nat_manip_type maniptype) |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 265 | { |
Alexey Dobriyan | 0c4c928 | 2008-10-08 11:35:11 +0200 | [diff] [blame] | 266 | struct net *net = nf_ct_net(ct); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 267 | struct nf_conntrack_tuple curr_tuple, new_tuple; |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 268 | struct nf_conn_nat *nat; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 269 | int have_to_hash = !(ct->status & IPS_NAT_DONE_MASK); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 270 | |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 271 | /* nat helper or nfctnetlink also setup binding */ |
| 272 | nat = nfct_nat(ct); |
| 273 | if (!nat) { |
| 274 | nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC); |
| 275 | if (nat == NULL) { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 276 | pr_debug("failed to add NAT extension\n"); |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 277 | return NF_ACCEPT; |
| 278 | } |
| 279 | } |
| 280 | |
Patrick McHardy | cc01dcb | 2007-12-17 22:38:20 -0800 | [diff] [blame] | 281 | NF_CT_ASSERT(maniptype == IP_NAT_MANIP_SRC || |
| 282 | maniptype == IP_NAT_MANIP_DST); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 283 | BUG_ON(nf_nat_initialized(ct, maniptype)); |
| 284 | |
| 285 | /* What we've got will look like inverse of reply. Normally |
| 286 | this is what is in the conntrack, except for prior |
| 287 | manipulations (future optimization: if num_manips == 0, |
| 288 | orig_tp = |
| 289 | conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple) */ |
| 290 | nf_ct_invert_tuplepr(&curr_tuple, |
| 291 | &ct->tuplehash[IP_CT_DIR_REPLY].tuple); |
| 292 | |
| 293 | get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype); |
| 294 | |
| 295 | if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) { |
| 296 | struct nf_conntrack_tuple reply; |
| 297 | |
| 298 | /* Alter conntrack table so will recognize replies. */ |
| 299 | nf_ct_invert_tuplepr(&reply, &new_tuple); |
| 300 | nf_conntrack_alter_reply(ct, &reply); |
| 301 | |
| 302 | /* Non-atomic: we own this at the moment. */ |
| 303 | if (maniptype == IP_NAT_MANIP_SRC) |
| 304 | ct->status |= IPS_SRC_NAT; |
| 305 | else |
| 306 | ct->status |= IPS_DST_NAT; |
| 307 | } |
| 308 | |
| 309 | /* Place in source hash if this is the first time. */ |
| 310 | if (have_to_hash) { |
| 311 | unsigned int srchash; |
| 312 | |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 313 | srchash = hash_by_src(net, nf_ct_zone(ct), |
| 314 | &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 315 | spin_lock_bh(&nf_nat_lock); |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 316 | /* nf_conntrack_alter_reply might re-allocate exntension aera */ |
Yasuyuki Kozakai | b6b84d4 | 2007-07-07 22:26:35 -0700 | [diff] [blame] | 317 | nat = nfct_nat(ct); |
| 318 | nat->ct = ct; |
Alexey Dobriyan | 0c4c928 | 2008-10-08 11:35:11 +0200 | [diff] [blame] | 319 | hlist_add_head_rcu(&nat->bysource, |
| 320 | &net->ipv4.nat_bysource[srchash]); |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 321 | spin_unlock_bh(&nf_nat_lock); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 322 | } |
| 323 | |
| 324 | /* It's done. */ |
| 325 | if (maniptype == IP_NAT_MANIP_DST) |
Changli Gao | a7c2f4d | 2011-01-18 15:02:48 +0100 | [diff] [blame^] | 326 | ct->status |= IPS_DST_NAT_DONE; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 327 | else |
Changli Gao | a7c2f4d | 2011-01-18 15:02:48 +0100 | [diff] [blame^] | 328 | ct->status |= IPS_SRC_NAT_DONE; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 329 | |
| 330 | return NF_ACCEPT; |
| 331 | } |
| 332 | EXPORT_SYMBOL(nf_nat_setup_info); |
| 333 | |
| 334 | /* Returns true if succeeded. */ |
Jan Engelhardt | f2ea825 | 2008-04-14 11:15:53 +0200 | [diff] [blame] | 335 | static bool |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 336 | manip_pkt(u_int16_t proto, |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 337 | struct sk_buff *skb, |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 338 | unsigned int iphdroff, |
| 339 | const struct nf_conntrack_tuple *target, |
| 340 | enum nf_nat_manip_type maniptype) |
| 341 | { |
| 342 | struct iphdr *iph; |
Patrick McHardy | 2b628a0 | 2007-12-17 22:37:36 -0800 | [diff] [blame] | 343 | const struct nf_nat_protocol *p; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 344 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 345 | if (!skb_make_writable(skb, iphdroff + sizeof(*iph))) |
Jan Engelhardt | f2ea825 | 2008-04-14 11:15:53 +0200 | [diff] [blame] | 346 | return false; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 347 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 348 | iph = (void *)skb->data + iphdroff; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 349 | |
| 350 | /* Manipulate protcol part. */ |
Patrick McHardy | e22a054 | 2007-02-12 11:12:26 -0800 | [diff] [blame] | 351 | |
| 352 | /* rcu_read_lock()ed by nf_hook_slow */ |
| 353 | p = __nf_nat_proto_find(proto); |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 354 | if (!p->manip_pkt(skb, iphdroff, target, maniptype)) |
Jan Engelhardt | f2ea825 | 2008-04-14 11:15:53 +0200 | [diff] [blame] | 355 | return false; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 356 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 357 | iph = (void *)skb->data + iphdroff; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 358 | |
| 359 | if (maniptype == IP_NAT_MANIP_SRC) { |
Patrick McHardy | be0ea7d | 2007-11-30 01:17:11 +1100 | [diff] [blame] | 360 | csum_replace4(&iph->check, iph->saddr, target->src.u3.ip); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 361 | iph->saddr = target->src.u3.ip; |
| 362 | } else { |
Patrick McHardy | be0ea7d | 2007-11-30 01:17:11 +1100 | [diff] [blame] | 363 | csum_replace4(&iph->check, iph->daddr, target->dst.u3.ip); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 364 | iph->daddr = target->dst.u3.ip; |
| 365 | } |
Jan Engelhardt | f2ea825 | 2008-04-14 11:15:53 +0200 | [diff] [blame] | 366 | return true; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 367 | } |
| 368 | |
| 369 | /* Do packet manipulations according to nf_nat_setup_info. */ |
| 370 | unsigned int nf_nat_packet(struct nf_conn *ct, |
| 371 | enum ip_conntrack_info ctinfo, |
| 372 | unsigned int hooknum, |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 373 | struct sk_buff *skb) |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 374 | { |
| 375 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 376 | unsigned long statusbit; |
| 377 | enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum); |
| 378 | |
| 379 | if (mtype == IP_NAT_MANIP_SRC) |
| 380 | statusbit = IPS_SRC_NAT; |
| 381 | else |
| 382 | statusbit = IPS_DST_NAT; |
| 383 | |
| 384 | /* Invert if this is reply dir. */ |
| 385 | if (dir == IP_CT_DIR_REPLY) |
| 386 | statusbit ^= IPS_NAT_MASK; |
| 387 | |
| 388 | /* Non-atomic: these bits don't change. */ |
| 389 | if (ct->status & statusbit) { |
| 390 | struct nf_conntrack_tuple target; |
| 391 | |
| 392 | /* We are aiming to look like inverse of other direction. */ |
| 393 | nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); |
| 394 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 395 | if (!manip_pkt(target.dst.protonum, skb, 0, &target, mtype)) |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 396 | return NF_DROP; |
| 397 | } |
| 398 | return NF_ACCEPT; |
| 399 | } |
| 400 | EXPORT_SYMBOL_GPL(nf_nat_packet); |
| 401 | |
| 402 | /* Dir is direction ICMP is coming from (opposite to packet it contains) */ |
| 403 | int nf_nat_icmp_reply_translation(struct nf_conn *ct, |
| 404 | enum ip_conntrack_info ctinfo, |
| 405 | unsigned int hooknum, |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 406 | struct sk_buff *skb) |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 407 | { |
| 408 | struct { |
| 409 | struct icmphdr icmp; |
| 410 | struct iphdr ip; |
| 411 | } *inside; |
Jan Engelhardt | 72b7294 | 2008-04-14 11:15:42 +0200 | [diff] [blame] | 412 | const struct nf_conntrack_l4proto *l4proto; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 413 | struct nf_conntrack_tuple inner, target; |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 414 | int hdrlen = ip_hdrlen(skb); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 415 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 416 | unsigned long statusbit; |
| 417 | enum nf_nat_manip_type manip = HOOK2MANIP(hooknum); |
| 418 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 419 | if (!skb_make_writable(skb, hdrlen + sizeof(*inside))) |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 420 | return 0; |
| 421 | |
Changli Gao | 794dbc1 | 2010-08-02 17:15:30 +0200 | [diff] [blame] | 422 | inside = (void *)skb->data + hdrlen; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 423 | |
| 424 | /* We're actually going to mangle it beyond trivial checksum |
| 425 | adjustment, so make sure the current checksum is correct. */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 426 | if (nf_ip_checksum(skb, hooknum, hdrlen, 0)) |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 427 | return 0; |
| 428 | |
| 429 | /* Must be RELATED */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 430 | NF_CT_ASSERT(skb->nfctinfo == IP_CT_RELATED || |
| 431 | skb->nfctinfo == IP_CT_RELATED+IP_CT_IS_REPLY); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 432 | |
| 433 | /* Redirects on non-null nats must be dropped, else they'll |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 434 | start talking to each other without our translation, and be |
| 435 | confused... --RR */ |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 436 | if (inside->icmp.type == ICMP_REDIRECT) { |
| 437 | /* If NAT isn't finished, assume it and drop. */ |
| 438 | if ((ct->status & IPS_NAT_DONE_MASK) != IPS_NAT_DONE_MASK) |
| 439 | return 0; |
| 440 | |
| 441 | if (ct->status & IPS_NAT_MASK) |
| 442 | return 0; |
| 443 | } |
| 444 | |
Julian Anastasov | b0aeef3 | 2010-10-11 11:23:07 +0300 | [diff] [blame] | 445 | if (manip == IP_NAT_MANIP_SRC) |
| 446 | statusbit = IPS_SRC_NAT; |
| 447 | else |
| 448 | statusbit = IPS_DST_NAT; |
| 449 | |
| 450 | /* Invert if this is reply dir. */ |
| 451 | if (dir == IP_CT_DIR_REPLY) |
| 452 | statusbit ^= IPS_NAT_MASK; |
| 453 | |
| 454 | if (!(ct->status & statusbit)) |
| 455 | return 1; |
| 456 | |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 457 | pr_debug("icmp_reply_translation: translating error %p manip %u " |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 458 | "dir %s\n", skb, manip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 459 | dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY"); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 460 | |
Patrick McHardy | 923f490 | 2007-02-12 11:12:57 -0800 | [diff] [blame] | 461 | /* rcu_read_lock()ed by nf_hook_slow */ |
| 462 | l4proto = __nf_ct_l4proto_find(PF_INET, inside->ip.protocol); |
| 463 | |
Changli Gao | 794dbc1 | 2010-08-02 17:15:30 +0200 | [diff] [blame] | 464 | if (!nf_ct_get_tuple(skb, hdrlen + sizeof(struct icmphdr), |
| 465 | (hdrlen + |
Arnaldo Carvalho de Melo | c9bdd4b | 2007-03-12 20:09:15 -0300 | [diff] [blame] | 466 | sizeof(struct icmphdr) + inside->ip.ihl * 4), |
Changli Gao | 794dbc1 | 2010-08-02 17:15:30 +0200 | [diff] [blame] | 467 | (u_int16_t)AF_INET, inside->ip.protocol, |
Patrick McHardy | 923f490 | 2007-02-12 11:12:57 -0800 | [diff] [blame] | 468 | &inner, l3proto, l4proto)) |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 469 | return 0; |
| 470 | |
| 471 | /* Change inner back to look like incoming packet. We do the |
| 472 | opposite manip on this hook to normal, because it might not |
| 473 | pass all hooks (locally-generated ICMP). Consider incoming |
| 474 | packet: PREROUTING (DST manip), routing produces ICMP, goes |
| 475 | through POSTROUTING (which must correct the DST manip). */ |
Changli Gao | 794dbc1 | 2010-08-02 17:15:30 +0200 | [diff] [blame] | 476 | if (!manip_pkt(inside->ip.protocol, skb, hdrlen + sizeof(inside->icmp), |
| 477 | &ct->tuplehash[!dir].tuple, !manip)) |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 478 | return 0; |
| 479 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 480 | if (skb->ip_summed != CHECKSUM_PARTIAL) { |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 481 | /* Reloading "inside" here since manip_pkt inner. */ |
Changli Gao | 794dbc1 | 2010-08-02 17:15:30 +0200 | [diff] [blame] | 482 | inside = (void *)skb->data + hdrlen; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 483 | inside->icmp.checksum = 0; |
| 484 | inside->icmp.checksum = |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 485 | csum_fold(skb_checksum(skb, hdrlen, |
| 486 | skb->len - hdrlen, 0)); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 487 | } |
| 488 | |
| 489 | /* Change outer to look the reply to an incoming packet |
| 490 | * (proto 0 means don't invert per-proto part). */ |
Julian Anastasov | b0aeef3 | 2010-10-11 11:23:07 +0300 | [diff] [blame] | 491 | nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); |
| 492 | if (!manip_pkt(0, skb, 0, &target, manip)) |
| 493 | return 0; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 494 | |
| 495 | return 1; |
| 496 | } |
| 497 | EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation); |
| 498 | |
| 499 | /* Protocol registration. */ |
Patrick McHardy | 2b628a0 | 2007-12-17 22:37:36 -0800 | [diff] [blame] | 500 | int nf_nat_protocol_register(const struct nf_nat_protocol *proto) |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 501 | { |
| 502 | int ret = 0; |
| 503 | |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 504 | spin_lock_bh(&nf_nat_lock); |
Eric Dumazet | eb73316 | 2010-11-15 18:43:59 +0100 | [diff] [blame] | 505 | if (rcu_dereference_protected( |
| 506 | nf_nat_protos[proto->protonum], |
| 507 | lockdep_is_held(&nf_nat_lock) |
| 508 | ) != &nf_nat_unknown_protocol) { |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 509 | ret = -EBUSY; |
| 510 | goto out; |
| 511 | } |
Patrick McHardy | e22a054 | 2007-02-12 11:12:26 -0800 | [diff] [blame] | 512 | rcu_assign_pointer(nf_nat_protos[proto->protonum], proto); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 513 | out: |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 514 | spin_unlock_bh(&nf_nat_lock); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 515 | return ret; |
| 516 | } |
| 517 | EXPORT_SYMBOL(nf_nat_protocol_register); |
| 518 | |
| 519 | /* Noone stores the protocol anywhere; simply delete it. */ |
Patrick McHardy | 2b628a0 | 2007-12-17 22:37:36 -0800 | [diff] [blame] | 520 | void nf_nat_protocol_unregister(const struct nf_nat_protocol *proto) |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 521 | { |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 522 | spin_lock_bh(&nf_nat_lock); |
Patrick McHardy | e22a054 | 2007-02-12 11:12:26 -0800 | [diff] [blame] | 523 | rcu_assign_pointer(nf_nat_protos[proto->protonum], |
| 524 | &nf_nat_unknown_protocol); |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 525 | spin_unlock_bh(&nf_nat_lock); |
Patrick McHardy | e22a054 | 2007-02-12 11:12:26 -0800 | [diff] [blame] | 526 | synchronize_rcu(); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 527 | } |
| 528 | EXPORT_SYMBOL(nf_nat_protocol_unregister); |
| 529 | |
Yasuyuki Kozakai | d8a0509 | 2007-07-07 22:26:16 -0700 | [diff] [blame] | 530 | /* Noone using conntrack by the time this called. */ |
| 531 | static void nf_nat_cleanup_conntrack(struct nf_conn *ct) |
| 532 | { |
| 533 | struct nf_conn_nat *nat = nf_ct_ext_find(ct, NF_CT_EXT_NAT); |
| 534 | |
Yasuyuki Kozakai | b6b84d4 | 2007-07-07 22:26:35 -0700 | [diff] [blame] | 535 | if (nat == NULL || nat->ct == NULL) |
Yasuyuki Kozakai | d8a0509 | 2007-07-07 22:26:16 -0700 | [diff] [blame] | 536 | return; |
| 537 | |
Yasuyuki Kozakai | b6b84d4 | 2007-07-07 22:26:35 -0700 | [diff] [blame] | 538 | NF_CT_ASSERT(nat->ct->status & IPS_NAT_DONE_MASK); |
Yasuyuki Kozakai | d8a0509 | 2007-07-07 22:26:16 -0700 | [diff] [blame] | 539 | |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 540 | spin_lock_bh(&nf_nat_lock); |
Patrick McHardy | 4d354c5 | 2008-01-31 04:42:37 -0800 | [diff] [blame] | 541 | hlist_del_rcu(&nat->bysource); |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 542 | spin_unlock_bh(&nf_nat_lock); |
Yasuyuki Kozakai | d8a0509 | 2007-07-07 22:26:16 -0700 | [diff] [blame] | 543 | } |
| 544 | |
Patrick McHardy | 86577c6 | 2008-02-07 17:56:34 -0800 | [diff] [blame] | 545 | static void nf_nat_move_storage(void *new, void *old) |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 546 | { |
Patrick McHardy | 86577c6 | 2008-02-07 17:56:34 -0800 | [diff] [blame] | 547 | struct nf_conn_nat *new_nat = new; |
| 548 | struct nf_conn_nat *old_nat = old; |
Yasuyuki Kozakai | b6b84d4 | 2007-07-07 22:26:35 -0700 | [diff] [blame] | 549 | struct nf_conn *ct = old_nat->ct; |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 550 | |
Evgeniy Polyakov | 1f30532 | 2007-11-20 04:27:35 -0800 | [diff] [blame] | 551 | if (!ct || !(ct->status & IPS_NAT_DONE_MASK)) |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 552 | return; |
| 553 | |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 554 | spin_lock_bh(&nf_nat_lock); |
Yasuyuki Kozakai | b6b84d4 | 2007-07-07 22:26:35 -0700 | [diff] [blame] | 555 | new_nat->ct = ct; |
Patrick McHardy | 68b80f1 | 2008-06-17 15:51:47 -0700 | [diff] [blame] | 556 | hlist_replace_rcu(&old_nat->bysource, &new_nat->bysource); |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 557 | spin_unlock_bh(&nf_nat_lock); |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 558 | } |
| 559 | |
Patrick McHardy | 61eb310 | 2007-07-07 22:27:06 -0700 | [diff] [blame] | 560 | static struct nf_ct_ext_type nat_extend __read_mostly = { |
Yasuyuki Kozakai | d8a0509 | 2007-07-07 22:26:16 -0700 | [diff] [blame] | 561 | .len = sizeof(struct nf_conn_nat), |
| 562 | .align = __alignof__(struct nf_conn_nat), |
| 563 | .destroy = nf_nat_cleanup_conntrack, |
| 564 | .move = nf_nat_move_storage, |
| 565 | .id = NF_CT_EXT_NAT, |
| 566 | .flags = NF_CT_EXT_F_PREALLOC, |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 567 | }; |
| 568 | |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 569 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
| 570 | |
| 571 | #include <linux/netfilter/nfnetlink.h> |
| 572 | #include <linux/netfilter/nfnetlink_conntrack.h> |
| 573 | |
Patrick McHardy | 64e4674 | 2010-10-29 16:28:07 +0200 | [diff] [blame] | 574 | static const struct nf_nat_protocol * |
| 575 | nf_nat_proto_find_get(u_int8_t protonum) |
| 576 | { |
| 577 | const struct nf_nat_protocol *p; |
| 578 | |
| 579 | rcu_read_lock(); |
| 580 | p = __nf_nat_proto_find(protonum); |
| 581 | if (!try_module_get(p->me)) |
| 582 | p = &nf_nat_unknown_protocol; |
| 583 | rcu_read_unlock(); |
| 584 | |
| 585 | return p; |
| 586 | } |
| 587 | |
| 588 | static void |
| 589 | nf_nat_proto_put(const struct nf_nat_protocol *p) |
| 590 | { |
| 591 | module_put(p->me); |
| 592 | } |
| 593 | |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 594 | static const struct nla_policy protonat_nla_policy[CTA_PROTONAT_MAX+1] = { |
| 595 | [CTA_PROTONAT_PORT_MIN] = { .type = NLA_U16 }, |
| 596 | [CTA_PROTONAT_PORT_MAX] = { .type = NLA_U16 }, |
| 597 | }; |
| 598 | |
| 599 | static int nfnetlink_parse_nat_proto(struct nlattr *attr, |
| 600 | const struct nf_conn *ct, |
| 601 | struct nf_nat_range *range) |
| 602 | { |
| 603 | struct nlattr *tb[CTA_PROTONAT_MAX+1]; |
| 604 | const struct nf_nat_protocol *npt; |
| 605 | int err; |
| 606 | |
| 607 | err = nla_parse_nested(tb, CTA_PROTONAT_MAX, attr, protonat_nla_policy); |
| 608 | if (err < 0) |
| 609 | return err; |
| 610 | |
| 611 | npt = nf_nat_proto_find_get(nf_ct_protonum(ct)); |
| 612 | if (npt->nlattr_to_range) |
| 613 | err = npt->nlattr_to_range(tb, range); |
| 614 | nf_nat_proto_put(npt); |
| 615 | return err; |
| 616 | } |
| 617 | |
| 618 | static const struct nla_policy nat_nla_policy[CTA_NAT_MAX+1] = { |
| 619 | [CTA_NAT_MINIP] = { .type = NLA_U32 }, |
| 620 | [CTA_NAT_MAXIP] = { .type = NLA_U32 }, |
| 621 | }; |
| 622 | |
| 623 | static int |
Patrick McHardy | 3993832 | 2009-08-25 16:07:58 +0200 | [diff] [blame] | 624 | nfnetlink_parse_nat(const struct nlattr *nat, |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 625 | const struct nf_conn *ct, struct nf_nat_range *range) |
| 626 | { |
| 627 | struct nlattr *tb[CTA_NAT_MAX+1]; |
| 628 | int err; |
| 629 | |
| 630 | memset(range, 0, sizeof(*range)); |
| 631 | |
| 632 | err = nla_parse_nested(tb, CTA_NAT_MAX, nat, nat_nla_policy); |
| 633 | if (err < 0) |
| 634 | return err; |
| 635 | |
| 636 | if (tb[CTA_NAT_MINIP]) |
| 637 | range->min_ip = nla_get_be32(tb[CTA_NAT_MINIP]); |
| 638 | |
| 639 | if (!tb[CTA_NAT_MAXIP]) |
| 640 | range->max_ip = range->min_ip; |
| 641 | else |
| 642 | range->max_ip = nla_get_be32(tb[CTA_NAT_MAXIP]); |
| 643 | |
| 644 | if (range->min_ip) |
| 645 | range->flags |= IP_NAT_RANGE_MAP_IPS; |
| 646 | |
| 647 | if (!tb[CTA_NAT_PROTO]) |
| 648 | return 0; |
| 649 | |
| 650 | err = nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO], ct, range); |
| 651 | if (err < 0) |
| 652 | return err; |
| 653 | |
| 654 | return 0; |
| 655 | } |
| 656 | |
| 657 | static int |
| 658 | nfnetlink_parse_nat_setup(struct nf_conn *ct, |
| 659 | enum nf_nat_manip_type manip, |
Patrick McHardy | 3993832 | 2009-08-25 16:07:58 +0200 | [diff] [blame] | 660 | const struct nlattr *attr) |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 661 | { |
| 662 | struct nf_nat_range range; |
| 663 | |
| 664 | if (nfnetlink_parse_nat(attr, ct, &range) < 0) |
| 665 | return -EINVAL; |
| 666 | if (nf_nat_initialized(ct, manip)) |
| 667 | return -EEXIST; |
| 668 | |
| 669 | return nf_nat_setup_info(ct, &range, manip); |
| 670 | } |
| 671 | #else |
| 672 | static int |
| 673 | nfnetlink_parse_nat_setup(struct nf_conn *ct, |
| 674 | enum nf_nat_manip_type manip, |
Patrick McHardy | 3993832 | 2009-08-25 16:07:58 +0200 | [diff] [blame] | 675 | const struct nlattr *attr) |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 676 | { |
| 677 | return -EOPNOTSUPP; |
| 678 | } |
| 679 | #endif |
| 680 | |
Alexey Dobriyan | 0c4c928 | 2008-10-08 11:35:11 +0200 | [diff] [blame] | 681 | static int __net_init nf_nat_net_init(struct net *net) |
| 682 | { |
Patrick McHardy | d696c7b | 2010-02-08 11:18:07 -0800 | [diff] [blame] | 683 | /* Leave them the same for the moment. */ |
| 684 | net->ipv4.nat_htable_size = net->ct.htable_size; |
Patrick McHardy | d862a66 | 2011-01-14 15:45:56 +0100 | [diff] [blame] | 685 | net->ipv4.nat_bysource = nf_ct_alloc_hashtable(&net->ipv4.nat_htable_size, 0); |
Alexey Dobriyan | 0c4c928 | 2008-10-08 11:35:11 +0200 | [diff] [blame] | 686 | if (!net->ipv4.nat_bysource) |
| 687 | return -ENOMEM; |
| 688 | return 0; |
| 689 | } |
| 690 | |
| 691 | /* Clear NAT section of all conntracks, in case we're loaded again. */ |
| 692 | static int clean_nat(struct nf_conn *i, void *data) |
| 693 | { |
| 694 | struct nf_conn_nat *nat = nfct_nat(i); |
| 695 | |
| 696 | if (!nat) |
| 697 | return 0; |
| 698 | memset(nat, 0, sizeof(*nat)); |
| 699 | i->status &= ~(IPS_NAT_MASK | IPS_NAT_DONE_MASK | IPS_SEQ_ADJUST); |
| 700 | return 0; |
| 701 | } |
| 702 | |
| 703 | static void __net_exit nf_nat_net_exit(struct net *net) |
| 704 | { |
| 705 | nf_ct_iterate_cleanup(net, &clean_nat, NULL); |
| 706 | synchronize_rcu(); |
Patrick McHardy | d862a66 | 2011-01-14 15:45:56 +0100 | [diff] [blame] | 707 | nf_ct_free_hashtable(net->ipv4.nat_bysource, net->ipv4.nat_htable_size); |
Alexey Dobriyan | 0c4c928 | 2008-10-08 11:35:11 +0200 | [diff] [blame] | 708 | } |
| 709 | |
| 710 | static struct pernet_operations nf_nat_net_ops = { |
| 711 | .init = nf_nat_net_init, |
| 712 | .exit = nf_nat_net_exit, |
| 713 | }; |
| 714 | |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 715 | static int __init nf_nat_init(void) |
| 716 | { |
| 717 | size_t i; |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 718 | int ret; |
| 719 | |
Jan Engelhardt | 475959d | 2008-04-09 15:14:58 -0700 | [diff] [blame] | 720 | need_ipv4_conntrack(); |
| 721 | |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 722 | ret = nf_ct_extend_register(&nat_extend); |
| 723 | if (ret < 0) { |
| 724 | printk(KERN_ERR "nf_nat_core: Unable to register extension\n"); |
| 725 | return ret; |
| 726 | } |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 727 | |
Alexey Dobriyan | 0c4c928 | 2008-10-08 11:35:11 +0200 | [diff] [blame] | 728 | ret = register_pernet_subsys(&nf_nat_net_ops); |
| 729 | if (ret < 0) |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 730 | goto cleanup_extend; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 731 | |
| 732 | /* Sew in builtin protocols. */ |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 733 | spin_lock_bh(&nf_nat_lock); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 734 | for (i = 0; i < MAX_IP_NAT_PROTO; i++) |
Patrick McHardy | e22a054 | 2007-02-12 11:12:26 -0800 | [diff] [blame] | 735 | rcu_assign_pointer(nf_nat_protos[i], &nf_nat_unknown_protocol); |
| 736 | rcu_assign_pointer(nf_nat_protos[IPPROTO_TCP], &nf_nat_protocol_tcp); |
| 737 | rcu_assign_pointer(nf_nat_protos[IPPROTO_UDP], &nf_nat_protocol_udp); |
| 738 | rcu_assign_pointer(nf_nat_protos[IPPROTO_ICMP], &nf_nat_protocol_icmp); |
Patrick McHardy | 02502f6 | 2008-01-31 04:43:06 -0800 | [diff] [blame] | 739 | spin_unlock_bh(&nf_nat_lock); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 740 | |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 741 | /* Initialize fake conntrack so that NAT will skip it */ |
Eric Dumazet | 5bfddbd | 2010-06-08 16:09:52 +0200 | [diff] [blame] | 742 | nf_ct_untracked_status_or(IPS_NAT_DONE_MASK); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 743 | |
| 744 | l3proto = nf_ct_l3proto_find_get((u_int16_t)AF_INET); |
Patrick McHardy | dd13b01 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 745 | |
| 746 | BUG_ON(nf_nat_seq_adjust_hook != NULL); |
| 747 | rcu_assign_pointer(nf_nat_seq_adjust_hook, nf_nat_seq_adjust); |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 748 | BUG_ON(nfnetlink_parse_nat_setup_hook != NULL); |
| 749 | rcu_assign_pointer(nfnetlink_parse_nat_setup_hook, |
| 750 | nfnetlink_parse_nat_setup); |
Jozsef Kadlecsik | f9dd09c | 2009-11-06 00:43:42 -0800 | [diff] [blame] | 751 | BUG_ON(nf_ct_nat_offset != NULL); |
| 752 | rcu_assign_pointer(nf_ct_nat_offset, nf_nat_get_offset); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 753 | return 0; |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 754 | |
| 755 | cleanup_extend: |
| 756 | nf_ct_extend_unregister(&nat_extend); |
| 757 | return ret; |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 758 | } |
| 759 | |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 760 | static void __exit nf_nat_cleanup(void) |
| 761 | { |
Alexey Dobriyan | 0c4c928 | 2008-10-08 11:35:11 +0200 | [diff] [blame] | 762 | unregister_pernet_subsys(&nf_nat_net_ops); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 763 | nf_ct_l3proto_put(l3proto); |
Yasuyuki Kozakai | 2d59e5c | 2007-07-07 22:24:28 -0700 | [diff] [blame] | 764 | nf_ct_extend_unregister(&nat_extend); |
Patrick McHardy | dd13b01 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 765 | rcu_assign_pointer(nf_nat_seq_adjust_hook, NULL); |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 766 | rcu_assign_pointer(nfnetlink_parse_nat_setup_hook, NULL); |
Jozsef Kadlecsik | f9dd09c | 2009-11-06 00:43:42 -0800 | [diff] [blame] | 767 | rcu_assign_pointer(nf_ct_nat_offset, NULL); |
Patrick McHardy | dd13b01 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 768 | synchronize_net(); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 769 | } |
| 770 | |
| 771 | MODULE_LICENSE("GPL"); |
Pablo Neira Ayuso | e6a7d3c | 2008-10-14 11:58:31 -0700 | [diff] [blame] | 772 | MODULE_ALIAS("nf-nat-ipv4"); |
Jozsef Kadlecsik | 5b1158e | 2006-12-02 22:07:13 -0800 | [diff] [blame] | 773 | |
| 774 | module_init(nf_nat_init); |
| 775 | module_exit(nf_nat_cleanup); |