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