/* * 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 <linux/types.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/skbuff.h> #include <linux/rtnetlink.h> #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <net/netlink.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 xt_entry_target *t, char *table, unsigned int hook) { struct xt_tgchk_param par; struct xt_target *target; int ret = 0; target = xt_request_find_target(AF_INET, t->u.user.name, t->u.user.revision); if (IS_ERR(target)) return PTR_ERR(target); t->u.kernel.target = target; par.table = table; par.entryinfo = NULL; par.target = target; par.targinfo = t->data; par.hook_mask = hook; par.family = NFPROTO_IPV4; ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false); if (ret < 0) { module_put(t->u.kernel.target->me); return ret; } return 0; } static void ipt_destroy_target(struct xt_entry_target *t) { struct xt_tgdtor_param par = { .target = t->u.kernel.target, .targinfo = t->data, }; if (par.target->destroy != NULL) par.target->destroy(&par); module_put(par.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 const struct nla_policy ipt_policy[TCA_IPT_MAX + 1] = { [TCA_IPT_TABLE] = { .type = NLA_STRING, .len = IFNAMSIZ }, [TCA_IPT_HOOK] = { .type = NLA_U32 }, [TCA_IPT_INDEX] = { .type = NLA_U32 }, [TCA_IPT_TARG] = { .len = sizeof(struct xt_entry_target) }, }; static int tcf_ipt_init(struct nlattr *nla, struct nlattr *est, struct tc_action *a, int ovr, int bind) { struct nlattr *tb[TCA_IPT_MAX + 1]; struct tcf_ipt *ipt; struct tcf_common *pc; struct xt_entry_target *td, *t; char *tname; int ret = 0, err; u32 hook = 0; u32 index = 0; if (nla == NULL) return -EINVAL; err = nla_parse_nested(tb, TCA_IPT_MAX, nla, ipt_policy); if (err < 0) return err; if (tb[TCA_IPT_HOOK] == NULL) return -EINVAL; if (tb[TCA_IPT_TARG] == NULL) return -EINVAL; td = (struct xt_entry_target *)nla_data(tb[TCA_IPT_TARG]); if (nla_len(tb[TCA_IPT_TARG]) < td->u.target_size) return -EINVAL; if (tb[TCA_IPT_INDEX] != NULL) index = nla_get_u32(tb[TCA_IPT_INDEX]); 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 (IS_ERR(pc)) return PTR_ERR(pc); ret = ACT_P_CREATED; } else { if (!ovr) { tcf_ipt_release(to_ipt(pc), bind); return -EEXIST; } } ipt = to_ipt(pc); hook = nla_get_u32(tb[TCA_IPT_HOOK]); err = -ENOMEM; tname = kmalloc(IFNAMSIZ, GFP_KERNEL); if (unlikely(!tname)) goto err1; if (tb[TCA_IPT_TABLE] == NULL || nla_strlcpy(tname, tb[TCA_IPT_TABLE], IFNAMSIZ) >= IFNAMSIZ) strcpy(tname, "mangle"); t = kmemdup(td, td->u.target_size, GFP_KERNEL); if (unlikely(!t)) goto err2; err = ipt_init_target(t, tname, hook); if (err < 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; struct xt_action_param par; 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; bstats_update(&ipt->tcf_bstats, skb); /* yes, we have to worry about both in and out dev * worry later - danger - this API seems to have changed * from earlier kernels */ par.in = skb->dev; par.out = NULL; par.hooknum = ipt->tcfi_hook; par.target = ipt->tcfi_t->u.kernel.target; par.targinfo = ipt->tcfi_t->data; ret = par.target->target(skb, &par); switch (ret) { case NF_ACCEPT: result = TC_ACT_OK; break; case NF_DROP: result = TC_ACT_SHOT; ipt->tcf_qstats.drops++; break; case XT_CONTINUE: result = TC_ACT_PIPE; break; default: if (net_ratelimit()) pr_notice("tc filter: 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 xt_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 nla_put_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); NLA_PUT(skb, TCA_IPT_TARG, ipt->tcfi_t->u.user.target_size, t); NLA_PUT_U32(skb, TCA_IPT_INDEX, ipt->tcf_index); NLA_PUT_U32(skb, TCA_IPT_HOOK, ipt->tcfi_hook); NLA_PUT(skb, TCA_IPT_CNT, sizeof(struct tc_cnt), &c); NLA_PUT_STRING(skb, TCA_IPT_TABLE, 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); NLA_PUT(skb, TCA_IPT_TM, sizeof (tm), &tm); kfree(t); return skb->len; nla_put_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);