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 33static int ipt_init_target(struct xt_entry_target *t, char *table, unsigned int hook) 34{ 35 struct xt_tgchk_param par; 36 struct xt_target *target; 37 int ret = 0; 38 39 target = xt_request_find_target(AF_INET, t->u.user.name, 40 t->u.user.revision); 41 if (IS_ERR(target)) 42 return PTR_ERR(target); 43 44 t->u.kernel.target = target; 45 par.table = table; 46 par.entryinfo = NULL; 47 par.target = target; 48 par.targinfo = t->data; 49 par.hook_mask = hook; 50 par.family = NFPROTO_IPV4; 51 52 ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false); 53 if (ret < 0) { 54 module_put(t->u.kernel.target->me); 55 return ret; 56 } 57 return 0; 58} 59 60static void ipt_destroy_target(struct xt_entry_target *t) 61{ 62 struct xt_tgdtor_param par = { 63 .target = t->u.kernel.target, 64 .targinfo = t->data, 65 }; 66 if (par.target->destroy != NULL) 67 par.target->destroy(&par); 68 module_put(par.target->me); 69} 70 71static void tcf_ipt_release(struct tc_action *a, int bind) 72{ 73 struct tcf_ipt *ipt = to_ipt(a); 74 ipt_destroy_target(ipt->tcfi_t); 75 kfree(ipt->tcfi_tname); 76 kfree(ipt->tcfi_t); 77} 78 79static const struct nla_policy ipt_policy[TCA_IPT_MAX + 1] = { 80 [TCA_IPT_TABLE] = { .type = NLA_STRING, .len = IFNAMSIZ }, 81 [TCA_IPT_HOOK] = { .type = NLA_U32 }, 82 [TCA_IPT_INDEX] = { .type = NLA_U32 }, 83 [TCA_IPT_TARG] = { .len = sizeof(struct xt_entry_target) }, 84}; 85 86static int tcf_ipt_init(struct net *net, struct nlattr *nla, struct nlattr *est, 87 struct tc_action *a, int ovr, int bind) 88{ 89 struct nlattr *tb[TCA_IPT_MAX + 1]; 90 struct tcf_ipt *ipt; 91 struct xt_entry_target *td, *t; 92 char *tname; 93 int ret = 0, err; 94 u32 hook = 0; 95 u32 index = 0; 96 97 if (nla == NULL) 98 return -EINVAL; 99 100 err = nla_parse_nested(tb, TCA_IPT_MAX, nla, ipt_policy); 101 if (err < 0) 102 return err; 103 104 if (tb[TCA_IPT_HOOK] == NULL) 105 return -EINVAL; 106 if (tb[TCA_IPT_TARG] == NULL) 107 return -EINVAL; 108 109 td = (struct xt_entry_target *)nla_data(tb[TCA_IPT_TARG]); 110 if (nla_len(tb[TCA_IPT_TARG]) < td->u.target_size) 111 return -EINVAL; 112 113 if (tb[TCA_IPT_INDEX] != NULL) 114 index = nla_get_u32(tb[TCA_IPT_INDEX]); 115 116 if (!tcf_hash_check(index, a, bind) ) { 117 ret = tcf_hash_create(index, est, a, sizeof(*ipt), bind); 118 if (ret) 119 return ret; 120 ret = ACT_P_CREATED; 121 } else { 122 if (bind)/* dont override defaults */ 123 return 0; 124 tcf_hash_release(a, bind); 125 126 if (!ovr) 127 return -EEXIST; 128 } 129 ipt = to_ipt(a); 130 131 hook = nla_get_u32(tb[TCA_IPT_HOOK]); 132 133 err = -ENOMEM; 134 tname = kmalloc(IFNAMSIZ, GFP_KERNEL); 135 if (unlikely(!tname)) 136 goto err1; 137 if (tb[TCA_IPT_TABLE] == NULL || 138 nla_strlcpy(tname, tb[TCA_IPT_TABLE], IFNAMSIZ) >= IFNAMSIZ) 139 strcpy(tname, "mangle"); 140 141 t = kmemdup(td, td->u.target_size, GFP_KERNEL); 142 if (unlikely(!t)) 143 goto err2; 144 145 err = ipt_init_target(t, tname, hook); 146 if (err < 0) 147 goto err3; 148 149 spin_lock_bh(&ipt->tcf_lock); 150 if (ret != ACT_P_CREATED) { 151 ipt_destroy_target(ipt->tcfi_t); 152 kfree(ipt->tcfi_tname); 153 kfree(ipt->tcfi_t); 154 } 155 ipt->tcfi_tname = tname; 156 ipt->tcfi_t = t; 157 ipt->tcfi_hook = hook; 158 spin_unlock_bh(&ipt->tcf_lock); 159 if (ret == ACT_P_CREATED) 160 tcf_hash_insert(a); 161 return ret; 162 163err3: 164 kfree(t); 165err2: 166 kfree(tname); 167err1: 168 if (ret == ACT_P_CREATED) 169 tcf_hash_cleanup(a, est); 170 return err; 171} 172 173static int tcf_ipt(struct sk_buff *skb, const struct tc_action *a, 174 struct tcf_result *res) 175{ 176 int ret = 0, result = 0; 177 struct tcf_ipt *ipt = a->priv; 178 struct xt_action_param par; 179 180 if (skb_unclone(skb, GFP_ATOMIC)) 181 return TC_ACT_UNSPEC; 182 183 spin_lock(&ipt->tcf_lock); 184 185 ipt->tcf_tm.lastuse = jiffies; 186 bstats_update(&ipt->tcf_bstats, skb); 187 188 /* yes, we have to worry about both in and out dev 189 * worry later - danger - this API seems to have changed 190 * from earlier kernels 191 */ 192 par.in = skb->dev; 193 par.out = NULL; 194 par.hooknum = ipt->tcfi_hook; 195 par.target = ipt->tcfi_t->u.kernel.target; 196 par.targinfo = ipt->tcfi_t->data; 197 ret = par.target->target(skb, &par); 198 199 switch (ret) { 200 case NF_ACCEPT: 201 result = TC_ACT_OK; 202 break; 203 case NF_DROP: 204 result = TC_ACT_SHOT; 205 ipt->tcf_qstats.drops++; 206 break; 207 case XT_CONTINUE: 208 result = TC_ACT_PIPE; 209 break; 210 default: 211 net_notice_ratelimited("tc filter: Bogus netfilter code %d assume ACCEPT\n", 212 ret); 213 result = TC_POLICE_OK; 214 break; 215 } 216 spin_unlock(&ipt->tcf_lock); 217 return result; 218 219} 220 221static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 222{ 223 unsigned char *b = skb_tail_pointer(skb); 224 struct tcf_ipt *ipt = a->priv; 225 struct xt_entry_target *t; 226 struct tcf_t tm; 227 struct tc_cnt c; 228 229 /* for simple targets kernel size == user size 230 * user name = target name 231 * for foolproof you need to not assume this 232 */ 233 234 t = kmemdup(ipt->tcfi_t, ipt->tcfi_t->u.user.target_size, GFP_ATOMIC); 235 if (unlikely(!t)) 236 goto nla_put_failure; 237 238 c.bindcnt = ipt->tcf_bindcnt - bind; 239 c.refcnt = ipt->tcf_refcnt - ref; 240 strcpy(t->u.user.name, ipt->tcfi_t->u.kernel.target->name); 241 242 if (nla_put(skb, TCA_IPT_TARG, ipt->tcfi_t->u.user.target_size, t) || 243 nla_put_u32(skb, TCA_IPT_INDEX, ipt->tcf_index) || 244 nla_put_u32(skb, TCA_IPT_HOOK, ipt->tcfi_hook) || 245 nla_put(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c) || 246 nla_put_string(skb, TCA_IPT_TABLE, ipt->tcfi_tname)) 247 goto nla_put_failure; 248 tm.install = jiffies_to_clock_t(jiffies - ipt->tcf_tm.install); 249 tm.lastuse = jiffies_to_clock_t(jiffies - ipt->tcf_tm.lastuse); 250 tm.expires = jiffies_to_clock_t(ipt->tcf_tm.expires); 251 if (nla_put(skb, TCA_IPT_TM, sizeof (tm), &tm)) 252 goto nla_put_failure; 253 kfree(t); 254 return skb->len; 255 256nla_put_failure: 257 nlmsg_trim(skb, b); 258 kfree(t); 259 return -1; 260} 261 262static struct tc_action_ops act_ipt_ops = { 263 .kind = "ipt", 264 .type = TCA_ACT_IPT, 265 .owner = THIS_MODULE, 266 .act = tcf_ipt, 267 .dump = tcf_ipt_dump, 268 .cleanup = tcf_ipt_release, 269 .init = tcf_ipt_init, 270}; 271 272static struct tc_action_ops act_xt_ops = { 273 .kind = "xt", 274 .type = TCA_ACT_XT, 275 .owner = THIS_MODULE, 276 .act = tcf_ipt, 277 .dump = tcf_ipt_dump, 278 .cleanup = tcf_ipt_release, 279 .init = tcf_ipt_init, 280}; 281 282MODULE_AUTHOR("Jamal Hadi Salim(2002-13)"); 283MODULE_DESCRIPTION("Iptables target actions"); 284MODULE_LICENSE("GPL"); 285MODULE_ALIAS("act_xt"); 286 287static int __init ipt_init_module(void) 288{ 289 int ret1, ret2; 290 291 ret1 = tcf_register_action(&act_xt_ops, IPT_TAB_MASK); 292 if (ret1 < 0) 293 printk("Failed to load xt action\n"); 294 ret2 = tcf_register_action(&act_ipt_ops, IPT_TAB_MASK); 295 if (ret2 < 0) 296 printk("Failed to load ipt action\n"); 297 298 if (ret1 < 0 && ret2 < 0) { 299 return ret1; 300 } else 301 return 0; 302} 303 304static void __exit ipt_cleanup_module(void) 305{ 306 tcf_unregister_action(&act_xt_ops); 307 tcf_unregister_action(&act_ipt_ops); 308} 309 310module_init(ipt_init_module); 311module_exit(ipt_cleanup_module); 312