Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 1 | /* |
| 2 | * This is a module which is used for setting the MSS option in TCP packets. |
| 3 | * |
| 4 | * Copyright (C) 2000 Marc Boucher <marc@mbsi.ca> |
| 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/skbuff.h> |
| 13 | #include <linux/ip.h> |
| 14 | #include <linux/ipv6.h> |
| 15 | #include <linux/tcp.h> |
Jan Engelhardt | 37c0838 | 2008-01-31 04:06:10 -0800 | [diff] [blame] | 16 | #include <net/dst.h> |
| 17 | #include <net/flow.h> |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 18 | #include <net/ipv6.h> |
Jan Engelhardt | 37c0838 | 2008-01-31 04:06:10 -0800 | [diff] [blame] | 19 | #include <net/route.h> |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 20 | #include <net/tcp.h> |
| 21 | |
| 22 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 23 | #include <linux/netfilter_ipv6/ip6_tables.h> |
| 24 | #include <linux/netfilter/x_tables.h> |
| 25 | #include <linux/netfilter/xt_tcpudp.h> |
| 26 | #include <linux/netfilter/xt_TCPMSS.h> |
| 27 | |
| 28 | MODULE_LICENSE("GPL"); |
| 29 | MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>"); |
Jan Engelhardt | 2ae15b6 | 2008-01-14 23:42:28 -0800 | [diff] [blame] | 30 | MODULE_DESCRIPTION("Xtables: TCP Maximum Segment Size (MSS) adjustment"); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 31 | MODULE_ALIAS("ipt_TCPMSS"); |
| 32 | MODULE_ALIAS("ip6t_TCPMSS"); |
| 33 | |
| 34 | static inline unsigned int |
| 35 | optlen(const u_int8_t *opt, unsigned int offset) |
| 36 | { |
| 37 | /* Beware zero-length options: make finite progress */ |
| 38 | if (opt[offset] <= TCPOPT_NOP || opt[offset+1] == 0) |
| 39 | return 1; |
| 40 | else |
| 41 | return opt[offset+1]; |
| 42 | } |
| 43 | |
| 44 | static int |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 45 | tcpmss_mangle_packet(struct sk_buff *skb, |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 46 | const struct xt_tcpmss_info *info, |
Jan Engelhardt | 37c0838 | 2008-01-31 04:06:10 -0800 | [diff] [blame] | 47 | unsigned int in_mtu, |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 48 | unsigned int tcphoff, |
| 49 | unsigned int minlen) |
| 50 | { |
| 51 | struct tcphdr *tcph; |
| 52 | unsigned int tcplen, i; |
| 53 | __be16 oldval; |
| 54 | u16 newmss; |
| 55 | u8 *opt; |
| 56 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 57 | if (!skb_make_writable(skb, skb->len)) |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 58 | return -1; |
| 59 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 60 | tcplen = skb->len - tcphoff; |
| 61 | tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 62 | |
| 63 | /* Since it passed flags test in tcp match, we know it is is |
| 64 | not a fragment, and has data >= tcp header length. SYN |
| 65 | packets should not contain data: if they did, then we risk |
| 66 | running over MTU, sending Frag Needed and breaking things |
| 67 | badly. --RR */ |
| 68 | if (tcplen != tcph->doff*4) { |
| 69 | if (net_ratelimit()) |
| 70 | printk(KERN_ERR "xt_TCPMSS: bad length (%u bytes)\n", |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 71 | skb->len); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 72 | return -1; |
| 73 | } |
| 74 | |
| 75 | if (info->mss == XT_TCPMSS_CLAMP_PMTU) { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 76 | if (dst_mtu(skb->dst) <= minlen) { |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 77 | if (net_ratelimit()) |
| 78 | printk(KERN_ERR "xt_TCPMSS: " |
| 79 | "unknown or invalid path-MTU (%u)\n", |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 80 | dst_mtu(skb->dst)); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 81 | return -1; |
| 82 | } |
Jan Engelhardt | 37c0838 | 2008-01-31 04:06:10 -0800 | [diff] [blame] | 83 | if (in_mtu <= minlen) { |
| 84 | if (net_ratelimit()) |
| 85 | printk(KERN_ERR "xt_TCPMSS: unknown or " |
| 86 | "invalid path-MTU (%u)\n", in_mtu); |
| 87 | return -1; |
| 88 | } |
| 89 | newmss = min(dst_mtu(skb->dst), in_mtu) - minlen; |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 90 | } else |
| 91 | newmss = info->mss; |
| 92 | |
| 93 | opt = (u_int8_t *)tcph; |
| 94 | for (i = sizeof(struct tcphdr); i < tcph->doff*4; i += optlen(opt, i)) { |
| 95 | if (opt[i] == TCPOPT_MSS && tcph->doff*4 - i >= TCPOLEN_MSS && |
| 96 | opt[i+1] == TCPOLEN_MSS) { |
| 97 | u_int16_t oldmss; |
| 98 | |
| 99 | oldmss = (opt[i+2] << 8) | opt[i+3]; |
| 100 | |
Benjamin LaHaise | 1700806 | 2007-12-17 22:27:36 -0800 | [diff] [blame] | 101 | /* Never increase MSS, even when setting it, as |
| 102 | * doing so results in problems for hosts that rely |
| 103 | * on MSS being set correctly. |
| 104 | */ |
| 105 | if (oldmss <= newmss) |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 106 | return 0; |
| 107 | |
| 108 | opt[i+2] = (newmss & 0xff00) >> 8; |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 109 | opt[i+3] = newmss & 0x00ff; |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 110 | |
Patrick McHardy | be0ea7d | 2007-11-30 01:17:11 +1100 | [diff] [blame] | 111 | inet_proto_csum_replace2(&tcph->check, skb, |
| 112 | htons(oldmss), htons(newmss), |
| 113 | 0); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 114 | return 0; |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | /* |
| 119 | * MSS Option not found ?! add it.. |
| 120 | */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 121 | if (skb_tailroom(skb) < TCPOLEN_MSS) { |
| 122 | if (pskb_expand_head(skb, 0, |
| 123 | TCPOLEN_MSS - skb_tailroom(skb), |
Herbert Xu | 2ca7b0a | 2007-10-14 00:39:55 -0700 | [diff] [blame] | 124 | GFP_ATOMIC)) |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 125 | return -1; |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 126 | tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 127 | } |
| 128 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 129 | skb_put(skb, TCPOLEN_MSS); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 130 | |
| 131 | opt = (u_int8_t *)tcph + sizeof(struct tcphdr); |
| 132 | memmove(opt + TCPOLEN_MSS, opt, tcplen - sizeof(struct tcphdr)); |
| 133 | |
Patrick McHardy | be0ea7d | 2007-11-30 01:17:11 +1100 | [diff] [blame] | 134 | inet_proto_csum_replace2(&tcph->check, skb, |
| 135 | htons(tcplen), htons(tcplen + TCPOLEN_MSS), 1); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 136 | opt[0] = TCPOPT_MSS; |
| 137 | opt[1] = TCPOLEN_MSS; |
| 138 | opt[2] = (newmss & 0xff00) >> 8; |
Jan Engelhardt | 7c4e36b | 2007-07-07 22:19:08 -0700 | [diff] [blame] | 139 | opt[3] = newmss & 0x00ff; |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 140 | |
Patrick McHardy | be0ea7d | 2007-11-30 01:17:11 +1100 | [diff] [blame] | 141 | inet_proto_csum_replace4(&tcph->check, skb, 0, *((__be32 *)opt), 0); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 142 | |
| 143 | oldval = ((__be16 *)tcph)[6]; |
| 144 | tcph->doff += TCPOLEN_MSS/4; |
Patrick McHardy | be0ea7d | 2007-11-30 01:17:11 +1100 | [diff] [blame] | 145 | inet_proto_csum_replace2(&tcph->check, skb, |
| 146 | oldval, ((__be16 *)tcph)[6], 0); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 147 | return TCPOLEN_MSS; |
| 148 | } |
| 149 | |
Jan Engelhardt | 37c0838 | 2008-01-31 04:06:10 -0800 | [diff] [blame] | 150 | static u_int32_t tcpmss_reverse_mtu4(const struct iphdr *iph) |
| 151 | { |
| 152 | struct flowi fl = { |
| 153 | .fl4_dst = iph->saddr, |
| 154 | }; |
| 155 | const struct nf_afinfo *ai; |
| 156 | struct rtable *rt = NULL; |
| 157 | u_int32_t mtu = ~0U; |
| 158 | |
| 159 | rcu_read_lock(); |
| 160 | ai = nf_get_afinfo(AF_INET); |
| 161 | if (ai != NULL) |
| 162 | ai->route((struct dst_entry **)&rt, &fl); |
| 163 | rcu_read_unlock(); |
| 164 | |
| 165 | if (rt != NULL) { |
| 166 | mtu = dst_mtu(&rt->u.dst); |
| 167 | dst_release(&rt->u.dst); |
| 168 | } |
| 169 | return mtu; |
| 170 | } |
| 171 | |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 172 | static unsigned int |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 173 | tcpmss_tg4(struct sk_buff *skb, const struct net_device *in, |
| 174 | const struct net_device *out, unsigned int hooknum, |
| 175 | const struct xt_target *target, const void *targinfo) |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 176 | { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 177 | struct iphdr *iph = ip_hdr(skb); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 178 | __be16 newlen; |
| 179 | int ret; |
| 180 | |
Jan Engelhardt | 37c0838 | 2008-01-31 04:06:10 -0800 | [diff] [blame] | 181 | ret = tcpmss_mangle_packet(skb, targinfo, tcpmss_reverse_mtu4(iph), |
| 182 | iph->ihl * 4, |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 183 | sizeof(*iph) + sizeof(struct tcphdr)); |
| 184 | if (ret < 0) |
| 185 | return NF_DROP; |
| 186 | if (ret > 0) { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 187 | iph = ip_hdr(skb); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 188 | newlen = htons(ntohs(iph->tot_len) + ret); |
Patrick McHardy | be0ea7d | 2007-11-30 01:17:11 +1100 | [diff] [blame] | 189 | csum_replace2(&iph->check, iph->tot_len, newlen); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 190 | iph->tot_len = newlen; |
| 191 | } |
| 192 | return XT_CONTINUE; |
| 193 | } |
| 194 | |
| 195 | #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) |
Jan Engelhardt | 37c0838 | 2008-01-31 04:06:10 -0800 | [diff] [blame] | 196 | static u_int32_t tcpmss_reverse_mtu6(const struct ipv6hdr *iph) |
| 197 | { |
| 198 | struct flowi fl = { |
| 199 | .fl6_dst = iph->saddr, |
| 200 | }; |
| 201 | const struct nf_afinfo *ai; |
| 202 | struct rtable *rt = NULL; |
| 203 | u_int32_t mtu = ~0U; |
| 204 | |
| 205 | rcu_read_lock(); |
| 206 | ai = nf_get_afinfo(AF_INET6); |
| 207 | if (ai != NULL) |
| 208 | ai->route((struct dst_entry **)&rt, &fl); |
| 209 | rcu_read_unlock(); |
| 210 | |
| 211 | if (rt != NULL) { |
| 212 | mtu = dst_mtu(&rt->u.dst); |
| 213 | dst_release(&rt->u.dst); |
| 214 | } |
| 215 | return mtu; |
| 216 | } |
| 217 | |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 218 | static unsigned int |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 219 | tcpmss_tg6(struct sk_buff *skb, const struct net_device *in, |
| 220 | const struct net_device *out, unsigned int hooknum, |
| 221 | const struct xt_target *target, const void *targinfo) |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 222 | { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 223 | struct ipv6hdr *ipv6h = ipv6_hdr(skb); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 224 | u8 nexthdr; |
| 225 | int tcphoff; |
| 226 | int ret; |
| 227 | |
| 228 | nexthdr = ipv6h->nexthdr; |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 229 | tcphoff = ipv6_skip_exthdr(skb, sizeof(*ipv6h), &nexthdr); |
Patrick McHardy | 9dc0564 | 2007-11-30 23:58:03 +1100 | [diff] [blame] | 230 | if (tcphoff < 0) |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 231 | return NF_DROP; |
Jan Engelhardt | 37c0838 | 2008-01-31 04:06:10 -0800 | [diff] [blame] | 232 | ret = tcpmss_mangle_packet(skb, targinfo, tcpmss_reverse_mtu6(ipv6h), |
| 233 | tcphoff, |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 234 | sizeof(*ipv6h) + sizeof(struct tcphdr)); |
| 235 | if (ret < 0) |
| 236 | return NF_DROP; |
| 237 | if (ret > 0) { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 238 | ipv6h = ipv6_hdr(skb); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 239 | ipv6h->payload_len = htons(ntohs(ipv6h->payload_len) + ret); |
| 240 | } |
| 241 | return XT_CONTINUE; |
| 242 | } |
| 243 | #endif |
| 244 | |
| 245 | #define TH_SYN 0x02 |
| 246 | |
| 247 | /* Must specify -p tcp --syn */ |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 248 | static inline bool find_syn_match(const struct xt_entry_match *m) |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 249 | { |
| 250 | const struct xt_tcp *tcpinfo = (const struct xt_tcp *)m->data; |
| 251 | |
| 252 | if (strcmp(m->u.kernel.match->name, "tcp") == 0 && |
| 253 | tcpinfo->flg_cmp & TH_SYN && |
| 254 | !(tcpinfo->invflags & XT_TCP_INV_FLAGS)) |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 255 | return true; |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 256 | |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 257 | return false; |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 258 | } |
| 259 | |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 260 | static bool |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 261 | tcpmss_tg4_check(const char *tablename, const void *entry, |
| 262 | const struct xt_target *target, void *targinfo, |
| 263 | unsigned int hook_mask) |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 264 | { |
| 265 | const struct xt_tcpmss_info *info = targinfo; |
| 266 | const struct ipt_entry *e = entry; |
| 267 | |
| 268 | if (info->mss == XT_TCPMSS_CLAMP_PMTU && |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 269 | (hook_mask & ~((1 << NF_INET_FORWARD) | |
| 270 | (1 << NF_INET_LOCAL_OUT) | |
| 271 | (1 << NF_INET_POST_ROUTING))) != 0) { |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 272 | printk("xt_TCPMSS: path-MTU clamping only supported in " |
| 273 | "FORWARD, OUTPUT and POSTROUTING hooks\n"); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 274 | return false; |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 275 | } |
| 276 | if (IPT_MATCH_ITERATE(e, find_syn_match)) |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 277 | return true; |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 278 | printk("xt_TCPMSS: Only works on TCP SYN packets\n"); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 279 | return false; |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 280 | } |
| 281 | |
| 282 | #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 283 | static bool |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 284 | tcpmss_tg6_check(const char *tablename, const void *entry, |
| 285 | const struct xt_target *target, void *targinfo, |
| 286 | unsigned int hook_mask) |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 287 | { |
| 288 | const struct xt_tcpmss_info *info = targinfo; |
| 289 | const struct ip6t_entry *e = entry; |
| 290 | |
| 291 | if (info->mss == XT_TCPMSS_CLAMP_PMTU && |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 292 | (hook_mask & ~((1 << NF_INET_FORWARD) | |
| 293 | (1 << NF_INET_LOCAL_OUT) | |
| 294 | (1 << NF_INET_POST_ROUTING))) != 0) { |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 295 | printk("xt_TCPMSS: path-MTU clamping only supported in " |
| 296 | "FORWARD, OUTPUT and POSTROUTING hooks\n"); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 297 | return false; |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 298 | } |
| 299 | if (IP6T_MATCH_ITERATE(e, find_syn_match)) |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 300 | return true; |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 301 | printk("xt_TCPMSS: Only works on TCP SYN packets\n"); |
Jan Engelhardt | e1931b7 | 2007-07-07 22:16:26 -0700 | [diff] [blame] | 302 | return false; |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 303 | } |
| 304 | #endif |
| 305 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 306 | static struct xt_target tcpmss_tg_reg[] __read_mostly = { |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 307 | { |
| 308 | .family = AF_INET, |
| 309 | .name = "TCPMSS", |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 310 | .checkentry = tcpmss_tg4_check, |
| 311 | .target = tcpmss_tg4, |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 312 | .targetsize = sizeof(struct xt_tcpmss_info), |
| 313 | .proto = IPPROTO_TCP, |
| 314 | .me = THIS_MODULE, |
| 315 | }, |
| 316 | #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) |
| 317 | { |
| 318 | .family = AF_INET6, |
| 319 | .name = "TCPMSS", |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 320 | .checkentry = tcpmss_tg6_check, |
| 321 | .target = tcpmss_tg6, |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 322 | .targetsize = sizeof(struct xt_tcpmss_info), |
| 323 | .proto = IPPROTO_TCP, |
| 324 | .me = THIS_MODULE, |
| 325 | }, |
| 326 | #endif |
| 327 | }; |
| 328 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 329 | static int __init tcpmss_tg_init(void) |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 330 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 331 | return xt_register_targets(tcpmss_tg_reg, ARRAY_SIZE(tcpmss_tg_reg)); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 332 | } |
| 333 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 334 | static void __exit tcpmss_tg_exit(void) |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 335 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 336 | xt_unregister_targets(tcpmss_tg_reg, ARRAY_SIZE(tcpmss_tg_reg)); |
Patrick McHardy | cdd289a | 2007-02-07 15:09:46 -0800 | [diff] [blame] | 337 | } |
| 338 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 339 | module_init(tcpmss_tg_init); |
| 340 | module_exit(tcpmss_tg_exit); |