315 lines
7.4 KiB
C
315 lines
7.4 KiB
C
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/*
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* net/sched/ipt.c iptables target interface
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*
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*TODO: Add other tables. For now we only support the ipv4 table targets
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Copyright: Jamal Hadi Salim (2002-4)
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/skbuff.h>
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#include <linux/rtnetlink.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <net/netlink.h>
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#include <net/pkt_sched.h>
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#include <linux/tc_act/tc_ipt.h>
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#include <net/tc_act/tc_ipt.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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#define IPT_TAB_MASK 15
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static struct tcf_common *tcf_ipt_ht[IPT_TAB_MASK + 1];
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static u32 ipt_idx_gen;
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static DEFINE_RWLOCK(ipt_lock);
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static struct tcf_hashinfo ipt_hash_info = {
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.htab = tcf_ipt_ht,
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.hmask = IPT_TAB_MASK,
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.lock = &ipt_lock,
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};
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static int ipt_init_target(struct ipt_entry_target *t, char *table, unsigned int hook)
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{
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struct xt_tgchk_param par;
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struct xt_target *target;
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int ret = 0;
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target = xt_request_find_target(AF_INET, t->u.user.name,
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t->u.user.revision);
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if (!target)
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return -ENOENT;
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t->u.kernel.target = target;
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par.table = table;
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par.entryinfo = NULL;
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par.target = target;
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par.targinfo = t->data;
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par.hook_mask = hook;
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par.family = NFPROTO_IPV4;
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ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
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if (ret < 0) {
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module_put(t->u.kernel.target->me);
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return ret;
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}
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return 0;
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}
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static void ipt_destroy_target(struct ipt_entry_target *t)
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{
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struct xt_tgdtor_param par = {
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.target = t->u.kernel.target,
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.targinfo = t->data,
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};
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if (par.target->destroy != NULL)
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par.target->destroy(&par);
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module_put(par.target->me);
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}
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static int tcf_ipt_release(struct tcf_ipt *ipt, int bind)
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{
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int ret = 0;
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if (ipt) {
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if (bind)
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ipt->tcf_bindcnt--;
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ipt->tcf_refcnt--;
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if (ipt->tcf_bindcnt <= 0 && ipt->tcf_refcnt <= 0) {
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ipt_destroy_target(ipt->tcfi_t);
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kfree(ipt->tcfi_tname);
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kfree(ipt->tcfi_t);
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tcf_hash_destroy(&ipt->common, &ipt_hash_info);
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ret = ACT_P_DELETED;
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}
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}
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return ret;
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}
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static const struct nla_policy ipt_policy[TCA_IPT_MAX + 1] = {
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[TCA_IPT_TABLE] = { .type = NLA_STRING, .len = IFNAMSIZ },
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[TCA_IPT_HOOK] = { .type = NLA_U32 },
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[TCA_IPT_INDEX] = { .type = NLA_U32 },
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[TCA_IPT_TARG] = { .len = sizeof(struct ipt_entry_target) },
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};
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static int tcf_ipt_init(struct nlattr *nla, struct nlattr *est,
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struct tc_action *a, int ovr, int bind)
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{
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struct nlattr *tb[TCA_IPT_MAX + 1];
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struct tcf_ipt *ipt;
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struct tcf_common *pc;
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struct ipt_entry_target *td, *t;
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char *tname;
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int ret = 0, err;
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u32 hook = 0;
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u32 index = 0;
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if (nla == NULL)
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return -EINVAL;
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err = nla_parse_nested(tb, TCA_IPT_MAX, nla, ipt_policy);
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if (err < 0)
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return err;
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if (tb[TCA_IPT_HOOK] == NULL)
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return -EINVAL;
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if (tb[TCA_IPT_TARG] == NULL)
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return -EINVAL;
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td = (struct ipt_entry_target *)nla_data(tb[TCA_IPT_TARG]);
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if (nla_len(tb[TCA_IPT_TARG]) < td->u.target_size)
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return -EINVAL;
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if (tb[TCA_IPT_INDEX] != NULL)
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index = nla_get_u32(tb[TCA_IPT_INDEX]);
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pc = tcf_hash_check(index, a, bind, &ipt_hash_info);
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if (!pc) {
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pc = tcf_hash_create(index, est, a, sizeof(*ipt), bind,
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&ipt_idx_gen, &ipt_hash_info);
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if (IS_ERR(pc))
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return PTR_ERR(pc);
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ret = ACT_P_CREATED;
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} else {
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if (!ovr) {
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tcf_ipt_release(to_ipt(pc), bind);
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return -EEXIST;
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}
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}
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ipt = to_ipt(pc);
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hook = nla_get_u32(tb[TCA_IPT_HOOK]);
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err = -ENOMEM;
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tname = kmalloc(IFNAMSIZ, GFP_KERNEL);
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if (unlikely(!tname))
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goto err1;
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if (tb[TCA_IPT_TABLE] == NULL ||
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nla_strlcpy(tname, tb[TCA_IPT_TABLE], IFNAMSIZ) >= IFNAMSIZ)
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strcpy(tname, "mangle");
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t = kmemdup(td, td->u.target_size, GFP_KERNEL);
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if (unlikely(!t))
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goto err2;
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if ((err = ipt_init_target(t, tname, hook)) < 0)
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goto err3;
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spin_lock_bh(&ipt->tcf_lock);
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if (ret != ACT_P_CREATED) {
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ipt_destroy_target(ipt->tcfi_t);
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kfree(ipt->tcfi_tname);
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kfree(ipt->tcfi_t);
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}
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ipt->tcfi_tname = tname;
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ipt->tcfi_t = t;
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ipt->tcfi_hook = hook;
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spin_unlock_bh(&ipt->tcf_lock);
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if (ret == ACT_P_CREATED)
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tcf_hash_insert(pc, &ipt_hash_info);
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return ret;
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err3:
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kfree(t);
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err2:
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kfree(tname);
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err1:
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kfree(pc);
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return err;
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}
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static int tcf_ipt_cleanup(struct tc_action *a, int bind)
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{
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struct tcf_ipt *ipt = a->priv;
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return tcf_ipt_release(ipt, bind);
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}
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static int tcf_ipt(struct sk_buff *skb, struct tc_action *a,
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struct tcf_result *res)
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{
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int ret = 0, result = 0;
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struct tcf_ipt *ipt = a->priv;
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struct xt_target_param par;
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if (skb_cloned(skb)) {
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if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
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return TC_ACT_UNSPEC;
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}
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spin_lock(&ipt->tcf_lock);
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ipt->tcf_tm.lastuse = jiffies;
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ipt->tcf_bstats.bytes += qdisc_pkt_len(skb);
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ipt->tcf_bstats.packets++;
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/* yes, we have to worry about both in and out dev
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worry later - danger - this API seems to have changed
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from earlier kernels */
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par.in = skb->dev;
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par.out = NULL;
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par.hooknum = ipt->tcfi_hook;
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par.target = ipt->tcfi_t->u.kernel.target;
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par.targinfo = ipt->tcfi_t->data;
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ret = par.target->target(skb, &par);
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switch (ret) {
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case NF_ACCEPT:
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result = TC_ACT_OK;
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break;
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case NF_DROP:
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result = TC_ACT_SHOT;
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ipt->tcf_qstats.drops++;
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break;
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case IPT_CONTINUE:
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result = TC_ACT_PIPE;
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break;
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default:
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if (net_ratelimit())
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printk("Bogus netfilter code %d assume ACCEPT\n", ret);
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result = TC_POLICE_OK;
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break;
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}
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spin_unlock(&ipt->tcf_lock);
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return result;
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}
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static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
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{
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unsigned char *b = skb_tail_pointer(skb);
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struct tcf_ipt *ipt = a->priv;
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struct ipt_entry_target *t;
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struct tcf_t tm;
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struct tc_cnt c;
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/* for simple targets kernel size == user size
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** user name = target name
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** for foolproof you need to not assume this
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*/
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t = kmemdup(ipt->tcfi_t, ipt->tcfi_t->u.user.target_size, GFP_ATOMIC);
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if (unlikely(!t))
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goto nla_put_failure;
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c.bindcnt = ipt->tcf_bindcnt - bind;
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c.refcnt = ipt->tcf_refcnt - ref;
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strcpy(t->u.user.name, ipt->tcfi_t->u.kernel.target->name);
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NLA_PUT(skb, TCA_IPT_TARG, ipt->tcfi_t->u.user.target_size, t);
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NLA_PUT_U32(skb, TCA_IPT_INDEX, ipt->tcf_index);
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NLA_PUT_U32(skb, TCA_IPT_HOOK, ipt->tcfi_hook);
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NLA_PUT(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c);
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NLA_PUT_STRING(skb, TCA_IPT_TABLE, ipt->tcfi_tname);
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tm.install = jiffies_to_clock_t(jiffies - ipt->tcf_tm.install);
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tm.lastuse = jiffies_to_clock_t(jiffies - ipt->tcf_tm.lastuse);
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tm.expires = jiffies_to_clock_t(ipt->tcf_tm.expires);
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NLA_PUT(skb, TCA_IPT_TM, sizeof (tm), &tm);
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kfree(t);
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return skb->len;
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nla_put_failure:
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nlmsg_trim(skb, b);
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kfree(t);
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return -1;
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}
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static struct tc_action_ops act_ipt_ops = {
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.kind = "ipt",
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.hinfo = &ipt_hash_info,
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.type = TCA_ACT_IPT,
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.capab = TCA_CAP_NONE,
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.owner = THIS_MODULE,
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.act = tcf_ipt,
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.dump = tcf_ipt_dump,
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.cleanup = tcf_ipt_cleanup,
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.lookup = tcf_hash_search,
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.init = tcf_ipt_init,
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.walk = tcf_generic_walker
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};
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MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
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MODULE_DESCRIPTION("Iptables target actions");
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MODULE_LICENSE("GPL");
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static int __init ipt_init_module(void)
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{
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return tcf_register_action(&act_ipt_ops);
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}
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static void __exit ipt_cleanup_module(void)
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{
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tcf_unregister_action(&act_ipt_ops);
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}
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module_init(ipt_init_module);
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module_exit(ipt_cleanup_module);
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