Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 1 | /* |
| 2 | * H.323 extension for NAT alteration. |
| 3 | * |
| 4 | * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net> |
| 5 | * |
| 6 | * This source code is licensed under General Public License version 2. |
| 7 | * |
| 8 | * Based on the 'brute force' H.323 NAT module by |
| 9 | * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> |
| 10 | */ |
| 11 | |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/moduleparam.h> |
| 14 | #include <linux/tcp.h> |
| 15 | #include <net/tcp.h> |
| 16 | |
| 17 | #include <net/netfilter/nf_nat.h> |
| 18 | #include <net/netfilter/nf_nat_helper.h> |
| 19 | #include <net/netfilter/nf_nat_rule.h> |
| 20 | #include <net/netfilter/nf_conntrack_helper.h> |
| 21 | #include <net/netfilter/nf_conntrack_expect.h> |
| 22 | #include <linux/netfilter/nf_conntrack_h323.h> |
| 23 | |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 24 | /****************************************************************************/ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 25 | static int set_addr(struct sk_buff *skb, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 26 | unsigned char **data, int dataoff, |
| 27 | unsigned int addroff, __be32 ip, __be16 port) |
| 28 | { |
| 29 | enum ip_conntrack_info ctinfo; |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 30 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 31 | struct { |
| 32 | __be32 ip; |
| 33 | __be16 port; |
| 34 | } __attribute__ ((__packed__)) buf; |
Jan Engelhardt | 905e3e8 | 2008-01-31 04:50:05 -0800 | [diff] [blame] | 35 | const struct tcphdr *th; |
| 36 | struct tcphdr _tcph; |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 37 | |
| 38 | buf.ip = ip; |
| 39 | buf.port = port; |
| 40 | addroff += dataoff; |
| 41 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 42 | if (ip_hdr(skb)->protocol == IPPROTO_TCP) { |
| 43 | if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 44 | addroff, sizeof(buf), |
| 45 | (char *) &buf, sizeof(buf))) { |
| 46 | if (net_ratelimit()) |
| 47 | printk("nf_nat_h323: nf_nat_mangle_tcp_packet" |
| 48 | " error\n"); |
| 49 | return -1; |
| 50 | } |
| 51 | |
| 52 | /* Relocate data pointer */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 53 | th = skb_header_pointer(skb, ip_hdrlen(skb), |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 54 | sizeof(_tcph), &_tcph); |
| 55 | if (th == NULL) |
| 56 | return -1; |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 57 | *data = skb->data + ip_hdrlen(skb) + th->doff * 4 + dataoff; |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 58 | } else { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 59 | if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 60 | addroff, sizeof(buf), |
| 61 | (char *) &buf, sizeof(buf))) { |
| 62 | if (net_ratelimit()) |
| 63 | printk("nf_nat_h323: nf_nat_mangle_udp_packet" |
| 64 | " error\n"); |
| 65 | return -1; |
| 66 | } |
| 67 | /* nf_nat_mangle_udp_packet uses skb_make_writable() to copy |
| 68 | * or pull everything in a linear buffer, so we can safely |
| 69 | * use the skb pointers now */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 70 | *data = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 71 | } |
| 72 | |
| 73 | return 0; |
| 74 | } |
| 75 | |
| 76 | /****************************************************************************/ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 77 | static int set_h225_addr(struct sk_buff *skb, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 78 | unsigned char **data, int dataoff, |
| 79 | TransportAddress *taddr, |
Jan Engelhardt | 643a2c1 | 2007-12-17 22:43:50 -0800 | [diff] [blame] | 80 | union nf_inet_addr *addr, __be16 port) |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 81 | { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 82 | return set_addr(skb, data, dataoff, taddr->ipAddress.ip, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 83 | addr->ip, port); |
| 84 | } |
| 85 | |
| 86 | /****************************************************************************/ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 87 | static int set_h245_addr(struct sk_buff *skb, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 88 | unsigned char **data, int dataoff, |
| 89 | H245_TransportAddress *taddr, |
Jan Engelhardt | 643a2c1 | 2007-12-17 22:43:50 -0800 | [diff] [blame] | 90 | union nf_inet_addr *addr, __be16 port) |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 91 | { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 92 | return set_addr(skb, data, dataoff, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 93 | taddr->unicastAddress.iPAddress.network, |
| 94 | addr->ip, port); |
| 95 | } |
| 96 | |
| 97 | /****************************************************************************/ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 98 | static int set_sig_addr(struct sk_buff *skb, struct nf_conn *ct, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 99 | enum ip_conntrack_info ctinfo, |
| 100 | unsigned char **data, |
| 101 | TransportAddress *taddr, int count) |
| 102 | { |
Jan Engelhardt | 905e3e8 | 2008-01-31 04:50:05 -0800 | [diff] [blame] | 103 | const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info; |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 104 | int dir = CTINFO2DIR(ctinfo); |
| 105 | int i; |
| 106 | __be16 port; |
Jan Engelhardt | 643a2c1 | 2007-12-17 22:43:50 -0800 | [diff] [blame] | 107 | union nf_inet_addr addr; |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 108 | |
| 109 | for (i = 0; i < count; i++) { |
| 110 | if (get_h225_addr(ct, *data, &taddr[i], &addr, &port)) { |
| 111 | if (addr.ip == ct->tuplehash[dir].tuple.src.u3.ip && |
| 112 | port == info->sig_port[dir]) { |
| 113 | /* GW->GK */ |
| 114 | |
| 115 | /* Fix for Gnomemeeting */ |
| 116 | if (i > 0 && |
| 117 | get_h225_addr(ct, *data, &taddr[0], |
| 118 | &addr, &port) && |
| 119 | (ntohl(addr.ip) & 0xff000000) == 0x7f000000) |
| 120 | i = 0; |
| 121 | |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 122 | pr_debug("nf_nat_ras: set signal address %pI4:%hu->%pI4:%hu\n", |
| 123 | &addr.ip, port, |
| 124 | &ct->tuplehash[!dir].tuple.dst.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 125 | info->sig_port[!dir]); |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 126 | return set_h225_addr(skb, data, 0, &taddr[i], |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 127 | &ct->tuplehash[!dir]. |
| 128 | tuple.dst.u3, |
| 129 | info->sig_port[!dir]); |
| 130 | } else if (addr.ip == ct->tuplehash[dir].tuple.dst.u3.ip && |
| 131 | port == info->sig_port[dir]) { |
| 132 | /* GK->GW */ |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 133 | pr_debug("nf_nat_ras: set signal address %pI4:%hu->%pI4:%hu\n", |
| 134 | &addr.ip, port, |
| 135 | &ct->tuplehash[!dir].tuple.src.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 136 | info->sig_port[!dir]); |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 137 | return set_h225_addr(skb, data, 0, &taddr[i], |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 138 | &ct->tuplehash[!dir]. |
| 139 | tuple.src.u3, |
| 140 | info->sig_port[!dir]); |
| 141 | } |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | return 0; |
| 146 | } |
| 147 | |
| 148 | /****************************************************************************/ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 149 | static int set_ras_addr(struct sk_buff *skb, struct nf_conn *ct, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 150 | enum ip_conntrack_info ctinfo, |
| 151 | unsigned char **data, |
| 152 | TransportAddress *taddr, int count) |
| 153 | { |
| 154 | int dir = CTINFO2DIR(ctinfo); |
| 155 | int i; |
| 156 | __be16 port; |
Jan Engelhardt | 643a2c1 | 2007-12-17 22:43:50 -0800 | [diff] [blame] | 157 | union nf_inet_addr addr; |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 158 | |
| 159 | for (i = 0; i < count; i++) { |
| 160 | if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) && |
| 161 | addr.ip == ct->tuplehash[dir].tuple.src.u3.ip && |
| 162 | port == ct->tuplehash[dir].tuple.src.u.udp.port) { |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 163 | pr_debug("nf_nat_ras: set rasAddress %pI4:%hu->%pI4:%hu\n", |
| 164 | &addr.ip, ntohs(port), |
| 165 | &ct->tuplehash[!dir].tuple.dst.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 166 | ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port)); |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 167 | return set_h225_addr(skb, data, 0, &taddr[i], |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 168 | &ct->tuplehash[!dir].tuple.dst.u3, |
| 169 | ct->tuplehash[!dir].tuple. |
| 170 | dst.u.udp.port); |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | return 0; |
| 175 | } |
| 176 | |
| 177 | /****************************************************************************/ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 178 | static int nat_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 179 | enum ip_conntrack_info ctinfo, |
| 180 | unsigned char **data, int dataoff, |
| 181 | H245_TransportAddress *taddr, |
| 182 | __be16 port, __be16 rtp_port, |
| 183 | struct nf_conntrack_expect *rtp_exp, |
| 184 | struct nf_conntrack_expect *rtcp_exp) |
| 185 | { |
| 186 | struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info; |
| 187 | int dir = CTINFO2DIR(ctinfo); |
| 188 | int i; |
| 189 | u_int16_t nated_port; |
| 190 | |
| 191 | /* Set expectations for NAT */ |
| 192 | rtp_exp->saved_proto.udp.port = rtp_exp->tuple.dst.u.udp.port; |
| 193 | rtp_exp->expectfn = nf_nat_follow_master; |
| 194 | rtp_exp->dir = !dir; |
| 195 | rtcp_exp->saved_proto.udp.port = rtcp_exp->tuple.dst.u.udp.port; |
| 196 | rtcp_exp->expectfn = nf_nat_follow_master; |
| 197 | rtcp_exp->dir = !dir; |
| 198 | |
| 199 | /* Lookup existing expects */ |
| 200 | for (i = 0; i < H323_RTP_CHANNEL_MAX; i++) { |
| 201 | if (info->rtp_port[i][dir] == rtp_port) { |
| 202 | /* Expected */ |
| 203 | |
| 204 | /* Use allocated ports first. This will refresh |
| 205 | * the expects */ |
| 206 | rtp_exp->tuple.dst.u.udp.port = info->rtp_port[i][dir]; |
| 207 | rtcp_exp->tuple.dst.u.udp.port = |
| 208 | htons(ntohs(info->rtp_port[i][dir]) + 1); |
| 209 | break; |
| 210 | } else if (info->rtp_port[i][dir] == 0) { |
| 211 | /* Not expected */ |
| 212 | break; |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | /* Run out of expectations */ |
| 217 | if (i >= H323_RTP_CHANNEL_MAX) { |
| 218 | if (net_ratelimit()) |
| 219 | printk("nf_nat_h323: out of expectations\n"); |
| 220 | return 0; |
| 221 | } |
| 222 | |
| 223 | /* Try to get a pair of ports. */ |
| 224 | for (nated_port = ntohs(rtp_exp->tuple.dst.u.udp.port); |
| 225 | nated_port != 0; nated_port += 2) { |
| 226 | rtp_exp->tuple.dst.u.udp.port = htons(nated_port); |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 227 | if (nf_ct_expect_related(rtp_exp) == 0) { |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 228 | rtcp_exp->tuple.dst.u.udp.port = |
| 229 | htons(nated_port + 1); |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 230 | if (nf_ct_expect_related(rtcp_exp) == 0) |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 231 | break; |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 232 | nf_ct_unexpect_related(rtp_exp); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 233 | } |
| 234 | } |
| 235 | |
| 236 | if (nated_port == 0) { /* No port available */ |
| 237 | if (net_ratelimit()) |
| 238 | printk("nf_nat_h323: out of RTP ports\n"); |
| 239 | return 0; |
| 240 | } |
| 241 | |
| 242 | /* Modify signal */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 243 | if (set_h245_addr(skb, data, dataoff, taddr, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 244 | &ct->tuplehash[!dir].tuple.dst.u3, |
| 245 | htons((port & htons(1)) ? nated_port + 1 : |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 246 | nated_port)) == 0) { |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 247 | /* Save ports */ |
| 248 | info->rtp_port[i][dir] = rtp_port; |
| 249 | info->rtp_port[i][!dir] = htons(nated_port); |
| 250 | } else { |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 251 | nf_ct_unexpect_related(rtp_exp); |
| 252 | nf_ct_unexpect_related(rtcp_exp); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 253 | return -1; |
| 254 | } |
| 255 | |
| 256 | /* Success */ |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 257 | pr_debug("nf_nat_h323: expect RTP %pI4:%hu->%pI4:%hu\n", |
| 258 | &rtp_exp->tuple.src.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 259 | ntohs(rtp_exp->tuple.src.u.udp.port), |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 260 | &rtp_exp->tuple.dst.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 261 | ntohs(rtp_exp->tuple.dst.u.udp.port)); |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 262 | pr_debug("nf_nat_h323: expect RTCP %pI4:%hu->%pI4:%hu\n", |
| 263 | &rtcp_exp->tuple.src.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 264 | ntohs(rtcp_exp->tuple.src.u.udp.port), |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 265 | &rtcp_exp->tuple.dst.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 266 | ntohs(rtcp_exp->tuple.dst.u.udp.port)); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 267 | |
| 268 | return 0; |
| 269 | } |
| 270 | |
| 271 | /****************************************************************************/ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 272 | static int nat_t120(struct sk_buff *skb, struct nf_conn *ct, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 273 | enum ip_conntrack_info ctinfo, |
| 274 | unsigned char **data, int dataoff, |
| 275 | H245_TransportAddress *taddr, __be16 port, |
| 276 | struct nf_conntrack_expect *exp) |
| 277 | { |
| 278 | int dir = CTINFO2DIR(ctinfo); |
| 279 | u_int16_t nated_port = ntohs(port); |
| 280 | |
| 281 | /* Set expectations for NAT */ |
| 282 | exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port; |
| 283 | exp->expectfn = nf_nat_follow_master; |
| 284 | exp->dir = !dir; |
| 285 | |
| 286 | /* Try to get same port: if not, try to change it. */ |
| 287 | for (; nated_port != 0; nated_port++) { |
| 288 | exp->tuple.dst.u.tcp.port = htons(nated_port); |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 289 | if (nf_ct_expect_related(exp) == 0) |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 290 | break; |
| 291 | } |
| 292 | |
| 293 | if (nated_port == 0) { /* No port available */ |
| 294 | if (net_ratelimit()) |
| 295 | printk("nf_nat_h323: out of TCP ports\n"); |
| 296 | return 0; |
| 297 | } |
| 298 | |
| 299 | /* Modify signal */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 300 | if (set_h245_addr(skb, data, dataoff, taddr, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 301 | &ct->tuplehash[!dir].tuple.dst.u3, |
| 302 | htons(nated_port)) < 0) { |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 303 | nf_ct_unexpect_related(exp); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 304 | return -1; |
| 305 | } |
| 306 | |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 307 | pr_debug("nf_nat_h323: expect T.120 %pI4:%hu->%pI4:%hu\n", |
| 308 | &exp->tuple.src.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 309 | ntohs(exp->tuple.src.u.tcp.port), |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 310 | &exp->tuple.dst.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 311 | ntohs(exp->tuple.dst.u.tcp.port)); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 312 | |
| 313 | return 0; |
| 314 | } |
| 315 | |
| 316 | /****************************************************************************/ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 317 | static int nat_h245(struct sk_buff *skb, struct nf_conn *ct, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 318 | enum ip_conntrack_info ctinfo, |
| 319 | unsigned char **data, int dataoff, |
| 320 | TransportAddress *taddr, __be16 port, |
| 321 | struct nf_conntrack_expect *exp) |
| 322 | { |
| 323 | struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info; |
| 324 | int dir = CTINFO2DIR(ctinfo); |
| 325 | u_int16_t nated_port = ntohs(port); |
| 326 | |
| 327 | /* Set expectations for NAT */ |
| 328 | exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port; |
| 329 | exp->expectfn = nf_nat_follow_master; |
| 330 | exp->dir = !dir; |
| 331 | |
| 332 | /* Check existing expects */ |
| 333 | if (info->sig_port[dir] == port) |
| 334 | nated_port = ntohs(info->sig_port[!dir]); |
| 335 | |
| 336 | /* Try to get same port: if not, try to change it. */ |
| 337 | for (; nated_port != 0; nated_port++) { |
| 338 | exp->tuple.dst.u.tcp.port = htons(nated_port); |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 339 | if (nf_ct_expect_related(exp) == 0) |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 340 | break; |
| 341 | } |
| 342 | |
| 343 | if (nated_port == 0) { /* No port available */ |
| 344 | if (net_ratelimit()) |
| 345 | printk("nf_nat_q931: out of TCP ports\n"); |
| 346 | return 0; |
| 347 | } |
| 348 | |
| 349 | /* Modify signal */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 350 | if (set_h225_addr(skb, data, dataoff, taddr, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 351 | &ct->tuplehash[!dir].tuple.dst.u3, |
| 352 | htons(nated_port)) == 0) { |
| 353 | /* Save ports */ |
| 354 | info->sig_port[dir] = port; |
| 355 | info->sig_port[!dir] = htons(nated_port); |
| 356 | } else { |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 357 | nf_ct_unexpect_related(exp); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 358 | return -1; |
| 359 | } |
| 360 | |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 361 | pr_debug("nf_nat_q931: expect H.245 %pI4:%hu->%pI4:%hu\n", |
| 362 | &exp->tuple.src.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 363 | ntohs(exp->tuple.src.u.tcp.port), |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 364 | &exp->tuple.dst.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 365 | ntohs(exp->tuple.dst.u.tcp.port)); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 366 | |
| 367 | return 0; |
| 368 | } |
| 369 | |
| 370 | /**************************************************************************** |
| 371 | * This conntrack expect function replaces nf_conntrack_q931_expect() |
| 372 | * which was set by nf_conntrack_h323.c. |
| 373 | ****************************************************************************/ |
| 374 | static void ip_nat_q931_expect(struct nf_conn *new, |
| 375 | struct nf_conntrack_expect *this) |
| 376 | { |
Patrick McHardy | 587aa64 | 2007-03-14 16:37:25 -0700 | [diff] [blame] | 377 | struct nf_nat_range range; |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 378 | |
| 379 | if (this->tuple.src.u3.ip != 0) { /* Only accept calls from GK */ |
| 380 | nf_nat_follow_master(new, this); |
| 381 | return; |
| 382 | } |
| 383 | |
| 384 | /* This must be a fresh one. */ |
| 385 | BUG_ON(new->status & IPS_NAT_DONE_MASK); |
| 386 | |
| 387 | /* Change src to where master sends to */ |
| 388 | range.flags = IP_NAT_RANGE_MAP_IPS; |
| 389 | range.min_ip = range.max_ip = new->tuplehash[!this->dir].tuple.src.u3.ip; |
Patrick McHardy | cc01dcb | 2007-12-17 22:38:20 -0800 | [diff] [blame] | 390 | nf_nat_setup_info(new, &range, IP_NAT_MANIP_SRC); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 391 | |
| 392 | /* For DST manip, map port here to where it's expected. */ |
| 393 | range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED); |
| 394 | range.min = range.max = this->saved_proto; |
| 395 | range.min_ip = range.max_ip = |
| 396 | new->master->tuplehash[!this->dir].tuple.src.u3.ip; |
Patrick McHardy | cc01dcb | 2007-12-17 22:38:20 -0800 | [diff] [blame] | 397 | nf_nat_setup_info(new, &range, IP_NAT_MANIP_DST); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 398 | } |
| 399 | |
| 400 | /****************************************************************************/ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 401 | static int nat_q931(struct sk_buff *skb, struct nf_conn *ct, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 402 | enum ip_conntrack_info ctinfo, |
| 403 | unsigned char **data, TransportAddress *taddr, int idx, |
| 404 | __be16 port, struct nf_conntrack_expect *exp) |
| 405 | { |
| 406 | struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info; |
| 407 | int dir = CTINFO2DIR(ctinfo); |
| 408 | u_int16_t nated_port = ntohs(port); |
Jan Engelhardt | 643a2c1 | 2007-12-17 22:43:50 -0800 | [diff] [blame] | 409 | union nf_inet_addr addr; |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 410 | |
| 411 | /* Set expectations for NAT */ |
| 412 | exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port; |
| 413 | exp->expectfn = ip_nat_q931_expect; |
| 414 | exp->dir = !dir; |
| 415 | |
| 416 | /* Check existing expects */ |
| 417 | if (info->sig_port[dir] == port) |
| 418 | nated_port = ntohs(info->sig_port[!dir]); |
| 419 | |
| 420 | /* Try to get same port: if not, try to change it. */ |
| 421 | for (; nated_port != 0; nated_port++) { |
| 422 | exp->tuple.dst.u.tcp.port = htons(nated_port); |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 423 | if (nf_ct_expect_related(exp) == 0) |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 424 | break; |
| 425 | } |
| 426 | |
| 427 | if (nated_port == 0) { /* No port available */ |
| 428 | if (net_ratelimit()) |
| 429 | printk("nf_nat_ras: out of TCP ports\n"); |
| 430 | return 0; |
| 431 | } |
| 432 | |
| 433 | /* Modify signal */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 434 | if (set_h225_addr(skb, data, 0, &taddr[idx], |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 435 | &ct->tuplehash[!dir].tuple.dst.u3, |
| 436 | htons(nated_port)) == 0) { |
| 437 | /* Save ports */ |
| 438 | info->sig_port[dir] = port; |
| 439 | info->sig_port[!dir] = htons(nated_port); |
| 440 | |
| 441 | /* Fix for Gnomemeeting */ |
| 442 | if (idx > 0 && |
| 443 | get_h225_addr(ct, *data, &taddr[0], &addr, &port) && |
| 444 | (ntohl(addr.ip) & 0xff000000) == 0x7f000000) { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 445 | set_h225_addr(skb, data, 0, &taddr[0], |
Jing Min Zhao | 1ff75ed | 2007-05-24 16:44:40 -0700 | [diff] [blame] | 446 | &ct->tuplehash[!dir].tuple.dst.u3, |
| 447 | info->sig_port[!dir]); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 448 | } |
| 449 | } else { |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 450 | nf_ct_unexpect_related(exp); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 451 | return -1; |
| 452 | } |
| 453 | |
| 454 | /* Success */ |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 455 | pr_debug("nf_nat_ras: expect Q.931 %pI4:%hu->%pI4:%hu\n", |
| 456 | &exp->tuple.src.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 457 | ntohs(exp->tuple.src.u.tcp.port), |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 458 | &exp->tuple.dst.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 459 | ntohs(exp->tuple.dst.u.tcp.port)); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 460 | |
| 461 | return 0; |
| 462 | } |
| 463 | |
| 464 | /****************************************************************************/ |
| 465 | static void ip_nat_callforwarding_expect(struct nf_conn *new, |
| 466 | struct nf_conntrack_expect *this) |
| 467 | { |
| 468 | struct nf_nat_range range; |
| 469 | |
| 470 | /* This must be a fresh one. */ |
| 471 | BUG_ON(new->status & IPS_NAT_DONE_MASK); |
| 472 | |
| 473 | /* Change src to where master sends to */ |
| 474 | range.flags = IP_NAT_RANGE_MAP_IPS; |
| 475 | range.min_ip = range.max_ip = new->tuplehash[!this->dir].tuple.src.u3.ip; |
Patrick McHardy | cc01dcb | 2007-12-17 22:38:20 -0800 | [diff] [blame] | 476 | nf_nat_setup_info(new, &range, IP_NAT_MANIP_SRC); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 477 | |
| 478 | /* For DST manip, map port here to where it's expected. */ |
| 479 | range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED); |
| 480 | range.min = range.max = this->saved_proto; |
| 481 | range.min_ip = range.max_ip = this->saved_ip; |
Patrick McHardy | cc01dcb | 2007-12-17 22:38:20 -0800 | [diff] [blame] | 482 | nf_nat_setup_info(new, &range, IP_NAT_MANIP_DST); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 483 | } |
| 484 | |
| 485 | /****************************************************************************/ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 486 | static int nat_callforwarding(struct sk_buff *skb, struct nf_conn *ct, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 487 | enum ip_conntrack_info ctinfo, |
| 488 | unsigned char **data, int dataoff, |
| 489 | TransportAddress *taddr, __be16 port, |
| 490 | struct nf_conntrack_expect *exp) |
| 491 | { |
| 492 | int dir = CTINFO2DIR(ctinfo); |
| 493 | u_int16_t nated_port; |
| 494 | |
| 495 | /* Set expectations for NAT */ |
| 496 | exp->saved_ip = exp->tuple.dst.u3.ip; |
| 497 | exp->tuple.dst.u3.ip = ct->tuplehash[!dir].tuple.dst.u3.ip; |
| 498 | exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port; |
| 499 | exp->expectfn = ip_nat_callforwarding_expect; |
| 500 | exp->dir = !dir; |
| 501 | |
| 502 | /* Try to get same port: if not, try to change it. */ |
| 503 | for (nated_port = ntohs(port); nated_port != 0; nated_port++) { |
| 504 | exp->tuple.dst.u.tcp.port = htons(nated_port); |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 505 | if (nf_ct_expect_related(exp) == 0) |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 506 | break; |
| 507 | } |
| 508 | |
| 509 | if (nated_port == 0) { /* No port available */ |
| 510 | if (net_ratelimit()) |
| 511 | printk("nf_nat_q931: out of TCP ports\n"); |
| 512 | return 0; |
| 513 | } |
| 514 | |
| 515 | /* Modify signal */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 516 | if (!set_h225_addr(skb, data, dataoff, taddr, |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 517 | &ct->tuplehash[!dir].tuple.dst.u3, |
| 518 | htons(nated_port)) == 0) { |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 519 | nf_ct_unexpect_related(exp); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 520 | return -1; |
| 521 | } |
| 522 | |
| 523 | /* Success */ |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 524 | pr_debug("nf_nat_q931: expect Call Forwarding %pI4:%hu->%pI4:%hu\n", |
| 525 | &exp->tuple.src.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 526 | ntohs(exp->tuple.src.u.tcp.port), |
Harvey Harrison | cffee38 | 2008-10-31 00:53:08 -0700 | [diff] [blame] | 527 | &exp->tuple.dst.u3.ip, |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 528 | ntohs(exp->tuple.dst.u.tcp.port)); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 529 | |
| 530 | return 0; |
| 531 | } |
| 532 | |
| 533 | /****************************************************************************/ |
| 534 | static int __init init(void) |
| 535 | { |
Patrick McHardy | d1332e0 | 2007-11-05 20:43:30 -0800 | [diff] [blame] | 536 | BUG_ON(set_h245_addr_hook != NULL); |
| 537 | BUG_ON(set_h225_addr_hook != NULL); |
| 538 | BUG_ON(set_sig_addr_hook != NULL); |
| 539 | BUG_ON(set_ras_addr_hook != NULL); |
| 540 | BUG_ON(nat_rtp_rtcp_hook != NULL); |
| 541 | BUG_ON(nat_t120_hook != NULL); |
| 542 | BUG_ON(nat_h245_hook != NULL); |
| 543 | BUG_ON(nat_callforwarding_hook != NULL); |
| 544 | BUG_ON(nat_q931_hook != NULL); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 545 | |
| 546 | rcu_assign_pointer(set_h245_addr_hook, set_h245_addr); |
| 547 | rcu_assign_pointer(set_h225_addr_hook, set_h225_addr); |
| 548 | rcu_assign_pointer(set_sig_addr_hook, set_sig_addr); |
| 549 | rcu_assign_pointer(set_ras_addr_hook, set_ras_addr); |
| 550 | rcu_assign_pointer(nat_rtp_rtcp_hook, nat_rtp_rtcp); |
| 551 | rcu_assign_pointer(nat_t120_hook, nat_t120); |
| 552 | rcu_assign_pointer(nat_h245_hook, nat_h245); |
| 553 | rcu_assign_pointer(nat_callforwarding_hook, nat_callforwarding); |
| 554 | rcu_assign_pointer(nat_q931_hook, nat_q931); |
Patrick McHardy | f587de0 | 2006-12-02 22:08:46 -0800 | [diff] [blame] | 555 | return 0; |
| 556 | } |
| 557 | |
| 558 | /****************************************************************************/ |
| 559 | static void __exit fini(void) |
| 560 | { |
| 561 | rcu_assign_pointer(set_h245_addr_hook, NULL); |
| 562 | rcu_assign_pointer(set_h225_addr_hook, NULL); |
| 563 | rcu_assign_pointer(set_sig_addr_hook, NULL); |
| 564 | rcu_assign_pointer(set_ras_addr_hook, NULL); |
| 565 | rcu_assign_pointer(nat_rtp_rtcp_hook, NULL); |
| 566 | rcu_assign_pointer(nat_t120_hook, NULL); |
| 567 | rcu_assign_pointer(nat_h245_hook, NULL); |
| 568 | rcu_assign_pointer(nat_callforwarding_hook, NULL); |
| 569 | rcu_assign_pointer(nat_q931_hook, NULL); |
| 570 | synchronize_rcu(); |
| 571 | } |
| 572 | |
| 573 | /****************************************************************************/ |
| 574 | module_init(init); |
| 575 | module_exit(fini); |
| 576 | |
| 577 | MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>"); |
| 578 | MODULE_DESCRIPTION("H.323 NAT helper"); |
| 579 | MODULE_LICENSE("GPL"); |
| 580 | MODULE_ALIAS("ip_nat_h323"); |