1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * net/sched/act_ipt.c iptables target interface
5 *TODO: Add other tables. For now we only support the ipv4 table targets
7 * Copyright: Jamal Hadi Salim (2002-13)
10 #include <linux/types.h>
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/errno.h>
14 #include <linux/skbuff.h>
15 #include <linux/rtnetlink.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/slab.h>
19 #include <net/netlink.h>
20 #include <net/pkt_sched.h>
21 #include <linux/tc_act/tc_ipt.h>
22 #include <net/tc_act/tc_ipt.h>
24 #include <linux/netfilter_ipv4/ip_tables.h>
27 static struct tc_action_ops act_ipt_ops;
28 static struct tc_action_ops act_xt_ops;
30 static int ipt_init_target(struct net *net, struct xt_entry_target *t,
31 char *table, unsigned int hook)
33 struct xt_tgchk_param par;
34 struct xt_target *target;
35 struct ipt_entry e = {};
38 target = xt_request_find_target(AF_INET, t->u.user.name,
41 return PTR_ERR(target);
43 t->u.kernel.target = target;
44 memset(&par, 0, sizeof(par));
49 par.targinfo = t->data;
50 par.hook_mask = 1 << hook;
51 par.family = NFPROTO_IPV4;
53 ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
55 module_put(t->u.kernel.target->me);
61 static void ipt_destroy_target(struct xt_entry_target *t, struct net *net)
63 struct xt_tgdtor_param par = {
64 .target = t->u.kernel.target,
66 .family = NFPROTO_IPV4,
69 if (par.target->destroy != NULL)
70 par.target->destroy(&par);
71 module_put(par.target->me);
74 static void tcf_ipt_release(struct tc_action *a)
76 struct tcf_ipt *ipt = to_ipt(a);
79 ipt_destroy_target(ipt->tcfi_t, a->idrinfo->net);
82 kfree(ipt->tcfi_tname);
85 static const struct nla_policy ipt_policy[TCA_IPT_MAX + 1] = {
86 [TCA_IPT_TABLE] = { .type = NLA_STRING, .len = IFNAMSIZ },
87 [TCA_IPT_HOOK] = NLA_POLICY_RANGE(NLA_U32, NF_INET_PRE_ROUTING,
89 [TCA_IPT_INDEX] = { .type = NLA_U32 },
90 [TCA_IPT_TARG] = { .len = sizeof(struct xt_entry_target) },
93 static int __tcf_ipt_init(struct net *net, unsigned int id, struct nlattr *nla,
94 struct nlattr *est, struct tc_action **a,
95 const struct tc_action_ops *ops,
96 struct tcf_proto *tp, u32 flags)
98 struct tc_action_net *tn = net_generic(net, id);
99 bool bind = flags & TCA_ACT_FLAGS_BIND;
100 struct nlattr *tb[TCA_IPT_MAX + 1];
102 struct xt_entry_target *td, *t;
112 err = nla_parse_nested_deprecated(tb, TCA_IPT_MAX, nla, ipt_policy,
117 if (tb[TCA_IPT_INDEX] != NULL)
118 index = nla_get_u32(tb[TCA_IPT_INDEX]);
120 err = tcf_idr_check_alloc(tn, &index, a, bind);
127 if (tb[TCA_IPT_HOOK] == NULL || tb[TCA_IPT_TARG] == NULL) {
129 tcf_idr_release(*a, bind);
131 tcf_idr_cleanup(tn, index);
135 td = (struct xt_entry_target *)nla_data(tb[TCA_IPT_TARG]);
136 if (nla_len(tb[TCA_IPT_TARG]) != td->u.target_size) {
138 tcf_idr_release(*a, bind);
140 tcf_idr_cleanup(tn, index);
145 ret = tcf_idr_create(tn, index, est, a, ops, bind,
148 tcf_idr_cleanup(tn, index);
153 if (bind)/* dont override defaults */
156 if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
157 tcf_idr_release(*a, bind);
163 hook = nla_get_u32(tb[TCA_IPT_HOOK]);
165 case NF_INET_PRE_ROUTING:
167 case NF_INET_POST_ROUTING:
173 if (tb[TCA_IPT_TABLE]) {
174 /* mangle only for now */
175 if (nla_strcmp(tb[TCA_IPT_TABLE], "mangle"))
179 tname = kstrdup("mangle", GFP_KERNEL);
180 if (unlikely(!tname))
183 t = kmemdup(td, td->u.target_size, GFP_KERNEL);
187 err = ipt_init_target(net, t, tname, hook);
193 spin_lock_bh(&ipt->tcf_lock);
194 if (ret != ACT_P_CREATED) {
195 ipt_destroy_target(ipt->tcfi_t, net);
196 kfree(ipt->tcfi_tname);
199 ipt->tcfi_tname = tname;
201 ipt->tcfi_hook = hook;
202 spin_unlock_bh(&ipt->tcf_lock);
210 tcf_idr_release(*a, bind);
214 static int tcf_ipt_init(struct net *net, struct nlattr *nla,
215 struct nlattr *est, struct tc_action **a,
216 struct tcf_proto *tp,
217 u32 flags, struct netlink_ext_ack *extack)
219 return __tcf_ipt_init(net, act_ipt_ops.net_id, nla, est,
220 a, &act_ipt_ops, tp, flags);
223 static int tcf_xt_init(struct net *net, struct nlattr *nla,
224 struct nlattr *est, struct tc_action **a,
225 struct tcf_proto *tp,
226 u32 flags, struct netlink_ext_ack *extack)
228 return __tcf_ipt_init(net, act_xt_ops.net_id, nla, est,
229 a, &act_xt_ops, tp, flags);
232 static bool tcf_ipt_act_check(struct sk_buff *skb)
234 const struct iphdr *iph;
235 unsigned int nhoff, len;
237 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
240 nhoff = skb_network_offset(skb);
242 if (iph->ihl < 5 || iph->version != 4)
245 len = skb_ip_totlen(skb);
246 if (skb->len < nhoff + len || len < (iph->ihl * 4u))
249 return pskb_may_pull(skb, iph->ihl * 4u);
252 static int tcf_ipt_act(struct sk_buff *skb, const struct tc_action *a,
253 struct tcf_result *res)
255 int ret = 0, result = 0;
256 struct tcf_ipt *ipt = to_ipt(a);
257 struct xt_action_param par;
258 struct nf_hook_state state = {
259 .net = dev_net(skb->dev),
261 .hook = ipt->tcfi_hook,
265 if (skb_protocol(skb, false) != htons(ETH_P_IP))
266 return TC_ACT_UNSPEC;
268 if (skb_unclone(skb, GFP_ATOMIC))
269 return TC_ACT_UNSPEC;
271 if (!tcf_ipt_act_check(skb))
272 return TC_ACT_UNSPEC;
274 if (state.hook == NF_INET_POST_ROUTING) {
276 return TC_ACT_UNSPEC;
278 state.out = skb->dev;
281 spin_lock(&ipt->tcf_lock);
283 tcf_lastuse_update(&ipt->tcf_tm);
284 bstats_update(&ipt->tcf_bstats, skb);
286 /* yes, we have to worry about both in and out dev
287 * worry later - danger - this API seems to have changed
288 * from earlier kernels
291 par.target = ipt->tcfi_t->u.kernel.target;
292 par.targinfo = ipt->tcfi_t->data;
293 ret = par.target->target(skb, &par);
300 result = TC_ACT_SHOT;
301 ipt->tcf_qstats.drops++;
304 result = TC_ACT_PIPE;
307 net_notice_ratelimited("tc filter: Bogus netfilter code %d assume ACCEPT\n",
312 spin_unlock(&ipt->tcf_lock);
317 static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind,
320 unsigned char *b = skb_tail_pointer(skb);
321 struct tcf_ipt *ipt = to_ipt(a);
322 struct xt_entry_target *t;
326 /* for simple targets kernel size == user size
327 * user name = target name
328 * for foolproof you need to not assume this
331 spin_lock_bh(&ipt->tcf_lock);
332 t = kmemdup(ipt->tcfi_t, ipt->tcfi_t->u.user.target_size, GFP_ATOMIC);
334 goto nla_put_failure;
336 c.bindcnt = atomic_read(&ipt->tcf_bindcnt) - bind;
337 c.refcnt = refcount_read(&ipt->tcf_refcnt) - ref;
338 strcpy(t->u.user.name, ipt->tcfi_t->u.kernel.target->name);
340 if (nla_put(skb, TCA_IPT_TARG, ipt->tcfi_t->u.user.target_size, t) ||
341 nla_put_u32(skb, TCA_IPT_INDEX, ipt->tcf_index) ||
342 nla_put_u32(skb, TCA_IPT_HOOK, ipt->tcfi_hook) ||
343 nla_put(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c) ||
344 nla_put_string(skb, TCA_IPT_TABLE, ipt->tcfi_tname))
345 goto nla_put_failure;
347 tcf_tm_dump(&tm, &ipt->tcf_tm);
348 if (nla_put_64bit(skb, TCA_IPT_TM, sizeof(tm), &tm, TCA_IPT_PAD))
349 goto nla_put_failure;
351 spin_unlock_bh(&ipt->tcf_lock);
356 spin_unlock_bh(&ipt->tcf_lock);
362 static struct tc_action_ops act_ipt_ops = {
365 .owner = THIS_MODULE,
367 .dump = tcf_ipt_dump,
368 .cleanup = tcf_ipt_release,
369 .init = tcf_ipt_init,
370 .size = sizeof(struct tcf_ipt),
373 static __net_init int ipt_init_net(struct net *net)
375 struct tc_action_net *tn = net_generic(net, act_ipt_ops.net_id);
377 return tc_action_net_init(net, tn, &act_ipt_ops);
380 static void __net_exit ipt_exit_net(struct list_head *net_list)
382 tc_action_net_exit(net_list, act_ipt_ops.net_id);
385 static struct pernet_operations ipt_net_ops = {
386 .init = ipt_init_net,
387 .exit_batch = ipt_exit_net,
388 .id = &act_ipt_ops.net_id,
389 .size = sizeof(struct tc_action_net),
392 static struct tc_action_ops act_xt_ops = {
395 .owner = THIS_MODULE,
397 .dump = tcf_ipt_dump,
398 .cleanup = tcf_ipt_release,
400 .size = sizeof(struct tcf_ipt),
403 static __net_init int xt_init_net(struct net *net)
405 struct tc_action_net *tn = net_generic(net, act_xt_ops.net_id);
407 return tc_action_net_init(net, tn, &act_xt_ops);
410 static void __net_exit xt_exit_net(struct list_head *net_list)
412 tc_action_net_exit(net_list, act_xt_ops.net_id);
415 static struct pernet_operations xt_net_ops = {
417 .exit_batch = xt_exit_net,
418 .id = &act_xt_ops.net_id,
419 .size = sizeof(struct tc_action_net),
422 MODULE_AUTHOR("Jamal Hadi Salim(2002-13)");
423 MODULE_DESCRIPTION("Iptables target actions");
424 MODULE_LICENSE("GPL");
425 MODULE_ALIAS("act_xt");
427 static int __init ipt_init_module(void)
431 ret1 = tcf_register_action(&act_xt_ops, &xt_net_ops);
433 pr_err("Failed to load xt action\n");
435 ret2 = tcf_register_action(&act_ipt_ops, &ipt_net_ops);
437 pr_err("Failed to load ipt action\n");
439 if (ret1 < 0 && ret2 < 0) {
445 static void __exit ipt_cleanup_module(void)
447 tcf_unregister_action(&act_ipt_ops, &ipt_net_ops);
448 tcf_unregister_action(&act_xt_ops, &xt_net_ops);
451 module_init(ipt_init_module);
452 module_exit(ipt_cleanup_module);