1 /* 2 * net/sched/act_ipt.c iptables target interface 3 * 4 *TODO: Add other tables. For now we only support the ipv4 table targets 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 * Copyright: Jamal Hadi Salim (2002-13) 12 */ 13 14 #include <linux/types.h> 15 #include <linux/kernel.h> 16 #include <linux/string.h> 17 #include <linux/errno.h> 18 #include <linux/skbuff.h> 19 #include <linux/rtnetlink.h> 20 #include <linux/module.h> 21 #include <linux/init.h> 22 #include <linux/slab.h> 23 #include <net/netlink.h> 24 #include <net/pkt_sched.h> 25 #include <linux/tc_act/tc_ipt.h> 26 #include <net/tc_act/tc_ipt.h> 27 28 #include <linux/netfilter_ipv4/ip_tables.h> 29 30 31 #define IPT_TAB_MASK 15 32 33 static int ipt_net_id; 34 35 static int xt_net_id; 36 37 static int ipt_init_target(struct xt_entry_target *t, char *table, unsigned int hook) 38 { 39 struct xt_tgchk_param par; 40 struct xt_target *target; 41 int ret = 0; 42 43 target = xt_request_find_target(AF_INET, t->u.user.name, 44 t->u.user.revision); 45 if (IS_ERR(target)) 46 return PTR_ERR(target); 47 48 t->u.kernel.target = target; 49 par.table = table; 50 par.entryinfo = NULL; 51 par.target = target; 52 par.targinfo = t->data; 53 par.hook_mask = hook; 54 par.family = NFPROTO_IPV4; 55 56 ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false); 57 if (ret < 0) { 58 module_put(t->u.kernel.target->me); 59 return ret; 60 } 61 return 0; 62 } 63 64 static void ipt_destroy_target(struct xt_entry_target *t) 65 { 66 struct xt_tgdtor_param par = { 67 .target = t->u.kernel.target, 68 .targinfo = t->data, 69 .family = NFPROTO_IPV4, 70 }; 71 if (par.target->destroy != NULL) 72 par.target->destroy(&par); 73 module_put(par.target->me); 74 } 75 76 static void tcf_ipt_release(struct tc_action *a, int bind) 77 { 78 struct tcf_ipt *ipt = to_ipt(a); 79 ipt_destroy_target(ipt->tcfi_t); 80 kfree(ipt->tcfi_tname); 81 kfree(ipt->tcfi_t); 82 } 83 84 static const struct nla_policy ipt_policy[TCA_IPT_MAX + 1] = { 85 [TCA_IPT_TABLE] = { .type = NLA_STRING, .len = IFNAMSIZ }, 86 [TCA_IPT_HOOK] = { .type = NLA_U32 }, 87 [TCA_IPT_INDEX] = { .type = NLA_U32 }, 88 [TCA_IPT_TARG] = { .len = sizeof(struct xt_entry_target) }, 89 }; 90 91 static int __tcf_ipt_init(struct tc_action_net *tn, struct nlattr *nla, 92 struct nlattr *est, struct tc_action *a, int ovr, 93 int bind) 94 { 95 struct nlattr *tb[TCA_IPT_MAX + 1]; 96 struct tcf_ipt *ipt; 97 struct xt_entry_target *td, *t; 98 char *tname; 99 int ret = 0, err; 100 u32 hook = 0; 101 u32 index = 0; 102 103 if (nla == NULL) 104 return -EINVAL; 105 106 err = nla_parse_nested(tb, TCA_IPT_MAX, nla, ipt_policy); 107 if (err < 0) 108 return err; 109 110 if (tb[TCA_IPT_HOOK] == NULL) 111 return -EINVAL; 112 if (tb[TCA_IPT_TARG] == NULL) 113 return -EINVAL; 114 115 td = (struct xt_entry_target *)nla_data(tb[TCA_IPT_TARG]); 116 if (nla_len(tb[TCA_IPT_TARG]) < td->u.target_size) 117 return -EINVAL; 118 119 if (tb[TCA_IPT_INDEX] != NULL) 120 index = nla_get_u32(tb[TCA_IPT_INDEX]); 121 122 if (!tcf_hash_check(tn, index, a, bind)) { 123 ret = tcf_hash_create(tn, index, est, a, sizeof(*ipt), bind, 124 false); 125 if (ret) 126 return ret; 127 ret = ACT_P_CREATED; 128 } else { 129 if (bind)/* dont override defaults */ 130 return 0; 131 tcf_hash_release(a, bind); 132 133 if (!ovr) 134 return -EEXIST; 135 } 136 ipt = to_ipt(a); 137 138 hook = nla_get_u32(tb[TCA_IPT_HOOK]); 139 140 err = -ENOMEM; 141 tname = kmalloc(IFNAMSIZ, GFP_KERNEL); 142 if (unlikely(!tname)) 143 goto err1; 144 if (tb[TCA_IPT_TABLE] == NULL || 145 nla_strlcpy(tname, tb[TCA_IPT_TABLE], IFNAMSIZ) >= IFNAMSIZ) 146 strcpy(tname, "mangle"); 147 148 t = kmemdup(td, td->u.target_size, GFP_KERNEL); 149 if (unlikely(!t)) 150 goto err2; 151 152 err = ipt_init_target(t, tname, hook); 153 if (err < 0) 154 goto err3; 155 156 spin_lock_bh(&ipt->tcf_lock); 157 if (ret != ACT_P_CREATED) { 158 ipt_destroy_target(ipt->tcfi_t); 159 kfree(ipt->tcfi_tname); 160 kfree(ipt->tcfi_t); 161 } 162 ipt->tcfi_tname = tname; 163 ipt->tcfi_t = t; 164 ipt->tcfi_hook = hook; 165 spin_unlock_bh(&ipt->tcf_lock); 166 if (ret == ACT_P_CREATED) 167 tcf_hash_insert(tn, a); 168 return ret; 169 170 err3: 171 kfree(t); 172 err2: 173 kfree(tname); 174 err1: 175 if (ret == ACT_P_CREATED) 176 tcf_hash_cleanup(a, est); 177 return err; 178 } 179 180 static int tcf_ipt_init(struct net *net, struct nlattr *nla, 181 struct nlattr *est, struct tc_action *a, int ovr, 182 int bind) 183 { 184 struct tc_action_net *tn = net_generic(net, ipt_net_id); 185 186 return __tcf_ipt_init(tn, nla, est, a, ovr, bind); 187 } 188 189 static int tcf_xt_init(struct net *net, struct nlattr *nla, 190 struct nlattr *est, struct tc_action *a, int ovr, 191 int bind) 192 { 193 struct tc_action_net *tn = net_generic(net, xt_net_id); 194 195 return __tcf_ipt_init(tn, nla, est, a, ovr, bind); 196 } 197 198 static int tcf_ipt(struct sk_buff *skb, const struct tc_action *a, 199 struct tcf_result *res) 200 { 201 int ret = 0, result = 0; 202 struct tcf_ipt *ipt = a->priv; 203 struct xt_action_param par; 204 205 if (skb_unclone(skb, GFP_ATOMIC)) 206 return TC_ACT_UNSPEC; 207 208 spin_lock(&ipt->tcf_lock); 209 210 ipt->tcf_tm.lastuse = jiffies; 211 bstats_update(&ipt->tcf_bstats, skb); 212 213 /* yes, we have to worry about both in and out dev 214 * worry later - danger - this API seems to have changed 215 * from earlier kernels 216 */ 217 par.net = dev_net(skb->dev); 218 par.in = skb->dev; 219 par.out = NULL; 220 par.hooknum = ipt->tcfi_hook; 221 par.target = ipt->tcfi_t->u.kernel.target; 222 par.targinfo = ipt->tcfi_t->data; 223 par.family = NFPROTO_IPV4; 224 ret = par.target->target(skb, &par); 225 226 switch (ret) { 227 case NF_ACCEPT: 228 result = TC_ACT_OK; 229 break; 230 case NF_DROP: 231 result = TC_ACT_SHOT; 232 ipt->tcf_qstats.drops++; 233 break; 234 case XT_CONTINUE: 235 result = TC_ACT_PIPE; 236 break; 237 default: 238 net_notice_ratelimited("tc filter: Bogus netfilter code %d assume ACCEPT\n", 239 ret); 240 result = TC_POLICE_OK; 241 break; 242 } 243 spin_unlock(&ipt->tcf_lock); 244 return result; 245 246 } 247 248 static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 249 { 250 unsigned char *b = skb_tail_pointer(skb); 251 struct tcf_ipt *ipt = a->priv; 252 struct xt_entry_target *t; 253 struct tcf_t tm; 254 struct tc_cnt c; 255 256 /* for simple targets kernel size == user size 257 * user name = target name 258 * for foolproof you need to not assume this 259 */ 260 261 t = kmemdup(ipt->tcfi_t, ipt->tcfi_t->u.user.target_size, GFP_ATOMIC); 262 if (unlikely(!t)) 263 goto nla_put_failure; 264 265 c.bindcnt = ipt->tcf_bindcnt - bind; 266 c.refcnt = ipt->tcf_refcnt - ref; 267 strcpy(t->u.user.name, ipt->tcfi_t->u.kernel.target->name); 268 269 if (nla_put(skb, TCA_IPT_TARG, ipt->tcfi_t->u.user.target_size, t) || 270 nla_put_u32(skb, TCA_IPT_INDEX, ipt->tcf_index) || 271 nla_put_u32(skb, TCA_IPT_HOOK, ipt->tcfi_hook) || 272 nla_put(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c) || 273 nla_put_string(skb, TCA_IPT_TABLE, ipt->tcfi_tname)) 274 goto nla_put_failure; 275 tm.install = jiffies_to_clock_t(jiffies - ipt->tcf_tm.install); 276 tm.lastuse = jiffies_to_clock_t(jiffies - ipt->tcf_tm.lastuse); 277 tm.expires = jiffies_to_clock_t(ipt->tcf_tm.expires); 278 if (nla_put(skb, TCA_IPT_TM, sizeof (tm), &tm)) 279 goto nla_put_failure; 280 kfree(t); 281 return skb->len; 282 283 nla_put_failure: 284 nlmsg_trim(skb, b); 285 kfree(t); 286 return -1; 287 } 288 289 static int tcf_ipt_walker(struct net *net, struct sk_buff *skb, 290 struct netlink_callback *cb, int type, 291 struct tc_action *a) 292 { 293 struct tc_action_net *tn = net_generic(net, ipt_net_id); 294 295 return tcf_generic_walker(tn, skb, cb, type, a); 296 } 297 298 static int tcf_ipt_search(struct net *net, struct tc_action *a, u32 index) 299 { 300 struct tc_action_net *tn = net_generic(net, ipt_net_id); 301 302 return tcf_hash_search(tn, a, index); 303 } 304 305 static struct tc_action_ops act_ipt_ops = { 306 .kind = "ipt", 307 .type = TCA_ACT_IPT, 308 .owner = THIS_MODULE, 309 .act = tcf_ipt, 310 .dump = tcf_ipt_dump, 311 .cleanup = tcf_ipt_release, 312 .init = tcf_ipt_init, 313 .walk = tcf_ipt_walker, 314 .lookup = tcf_ipt_search, 315 }; 316 317 static __net_init int ipt_init_net(struct net *net) 318 { 319 struct tc_action_net *tn = net_generic(net, ipt_net_id); 320 321 return tc_action_net_init(tn, &act_ipt_ops, IPT_TAB_MASK); 322 } 323 324 static void __net_exit ipt_exit_net(struct net *net) 325 { 326 struct tc_action_net *tn = net_generic(net, ipt_net_id); 327 328 tc_action_net_exit(tn); 329 } 330 331 static struct pernet_operations ipt_net_ops = { 332 .init = ipt_init_net, 333 .exit = ipt_exit_net, 334 .id = &ipt_net_id, 335 .size = sizeof(struct tc_action_net), 336 }; 337 338 static int tcf_xt_walker(struct net *net, struct sk_buff *skb, 339 struct netlink_callback *cb, int type, 340 struct tc_action *a) 341 { 342 struct tc_action_net *tn = net_generic(net, xt_net_id); 343 344 return tcf_generic_walker(tn, skb, cb, type, a); 345 } 346 347 static int tcf_xt_search(struct net *net, struct tc_action *a, u32 index) 348 { 349 struct tc_action_net *tn = net_generic(net, xt_net_id); 350 351 return tcf_hash_search(tn, a, index); 352 } 353 354 static struct tc_action_ops act_xt_ops = { 355 .kind = "xt", 356 .type = TCA_ACT_XT, 357 .owner = THIS_MODULE, 358 .act = tcf_ipt, 359 .dump = tcf_ipt_dump, 360 .cleanup = tcf_ipt_release, 361 .init = tcf_xt_init, 362 .walk = tcf_xt_walker, 363 .lookup = tcf_xt_search, 364 }; 365 366 static __net_init int xt_init_net(struct net *net) 367 { 368 struct tc_action_net *tn = net_generic(net, xt_net_id); 369 370 return tc_action_net_init(tn, &act_xt_ops, IPT_TAB_MASK); 371 } 372 373 static void __net_exit xt_exit_net(struct net *net) 374 { 375 struct tc_action_net *tn = net_generic(net, xt_net_id); 376 377 tc_action_net_exit(tn); 378 } 379 380 static struct pernet_operations xt_net_ops = { 381 .init = xt_init_net, 382 .exit = xt_exit_net, 383 .id = &xt_net_id, 384 .size = sizeof(struct tc_action_net), 385 }; 386 387 MODULE_AUTHOR("Jamal Hadi Salim(2002-13)"); 388 MODULE_DESCRIPTION("Iptables target actions"); 389 MODULE_LICENSE("GPL"); 390 MODULE_ALIAS("act_xt"); 391 392 static int __init ipt_init_module(void) 393 { 394 int ret1, ret2; 395 396 ret1 = tcf_register_action(&act_xt_ops, &xt_net_ops); 397 if (ret1 < 0) 398 pr_err("Failed to load xt action\n"); 399 400 ret2 = tcf_register_action(&act_ipt_ops, &ipt_net_ops); 401 if (ret2 < 0) 402 pr_err("Failed to load ipt action\n"); 403 404 if (ret1 < 0 && ret2 < 0) { 405 return ret1; 406 } else 407 return 0; 408 } 409 410 static void __exit ipt_cleanup_module(void) 411 { 412 tcf_unregister_action(&act_ipt_ops, &ipt_net_ops); 413 tcf_unregister_action(&act_xt_ops, &xt_net_ops); 414 } 415 416 module_init(ipt_init_module); 417 module_exit(ipt_cleanup_module); 418