1 files changed, 452 insertions, 0 deletions

diff --git a/net/sched/act_ipt.c b/net/sched/act_ipt.c
new file mode 100644
index 000000000..29974de68
--- /dev/null
+++ b/net/sched/act_ipt.c
@@ -0,0 +1,452 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * net/sched/act_ipt.c		iptables target interface
+ *
+ *TODO: Add other tables. For now we only support the ipv4 table targets
+ *
+ * Copyright:	Jamal Hadi Salim (2002-13)
+ */
+
+#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>
+
+
+static struct tc_action_ops act_ipt_ops;
+static struct tc_action_ops act_xt_ops;
+
+static int ipt_init_target(struct net *net, struct xt_entry_target *t,
+			   char *table, unsigned int hook)
+{
+	struct xt_tgchk_param par;
+	struct xt_target *target;
+	struct ipt_entry e = {};
+	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;
+	memset(&par, 0, sizeof(par));
+	par.net       = net;
+	par.table     = table;
+	par.entryinfo = &e;
+	par.target    = target;
+	par.targinfo  = t->data;
+	par.hook_mask = 1 << 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 net *net)
+{
+	struct xt_tgdtor_param par = {
+		.target   = t->u.kernel.target,
+		.targinfo = t->data,
+		.family   = NFPROTO_IPV4,
+		.net      = net,
+	};
+	if (par.target->destroy != NULL)
+		par.target->destroy(&par);
+	module_put(par.target->me);
+}
+
+static void tcf_ipt_release(struct tc_action *a)
+{
+	struct tcf_ipt *ipt = to_ipt(a);
+
+	if (ipt->tcfi_t) {
+		ipt_destroy_target(ipt->tcfi_t, a->idrinfo->net);
+		kfree(ipt->tcfi_t);
+	}
+	kfree(ipt->tcfi_tname);
+}
+
+static const struct nla_policy ipt_policy[TCA_IPT_MAX + 1] = {
+	[TCA_IPT_TABLE]	= { .type = NLA_STRING, .len = IFNAMSIZ },
+	[TCA_IPT_HOOK]	= NLA_POLICY_RANGE(NLA_U32, NF_INET_PRE_ROUTING,
+					   NF_INET_NUMHOOKS),
+	[TCA_IPT_INDEX]	= { .type = NLA_U32 },
+	[TCA_IPT_TARG]	= { .len = sizeof(struct xt_entry_target) },
+};
+
+static int __tcf_ipt_init(struct net *net, unsigned int id, struct nlattr *nla,
+			  struct nlattr *est, struct tc_action **a,
+			  const struct tc_action_ops *ops,
+			  struct tcf_proto *tp, u32 flags)
+{
+	struct tc_action_net *tn = net_generic(net, id);
+	bool bind = flags & TCA_ACT_FLAGS_BIND;
+	struct nlattr *tb[TCA_IPT_MAX + 1];
+	struct tcf_ipt *ipt;
+	struct xt_entry_target *td, *t;
+	char *tname;
+	bool exists = false;
+	int ret = 0, err;
+	u32 hook = 0;
+	u32 index = 0;
+
+	if (nla == NULL)
+		return -EINVAL;
+
+	err = nla_parse_nested_deprecated(tb, TCA_IPT_MAX, nla, ipt_policy,
+					  NULL);
+	if (err < 0)
+		return err;
+
+	if (tb[TCA_IPT_INDEX] != NULL)
+		index = nla_get_u32(tb[TCA_IPT_INDEX]);
+
+	err = tcf_idr_check_alloc(tn, &index, a, bind);
+	if (err < 0)
+		return err;
+	exists = err;
+	if (exists && bind)
+		return 0;
+
+	if (tb[TCA_IPT_HOOK] == NULL || tb[TCA_IPT_TARG] == NULL) {
+		if (exists)
+			tcf_idr_release(*a, bind);
+		else
+			tcf_idr_cleanup(tn, index);
+		return -EINVAL;
+	}
+
+	td = (struct xt_entry_target *)nla_data(tb[TCA_IPT_TARG]);
+	if (nla_len(tb[TCA_IPT_TARG]) != td->u.target_size) {
+		if (exists)
+			tcf_idr_release(*a, bind);
+		else
+			tcf_idr_cleanup(tn, index);
+		return -EINVAL;
+	}
+
+	if (!exists) {
+		ret = tcf_idr_create(tn, index, est, a, ops, bind,
+				     false, flags);
+		if (ret) {
+			tcf_idr_cleanup(tn, index);
+			return ret;
+		}
+		ret = ACT_P_CREATED;
+	} else {
+		if (bind)/* dont override defaults */
+			return 0;
+
+		if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
+			tcf_idr_release(*a, bind);
+			return -EEXIST;
+		}
+	}
+
+	err = -EINVAL;
+	hook = nla_get_u32(tb[TCA_IPT_HOOK]);
+	switch (hook) {
+	case NF_INET_PRE_ROUTING:
+		break;
+	case NF_INET_POST_ROUTING:
+		break;
+	default:
+		goto err1;
+	}
+
+	if (tb[TCA_IPT_TABLE]) {
+		/* mangle only for now */
+		if (nla_strcmp(tb[TCA_IPT_TABLE], "mangle"))
+			goto err1;
+	}
+
+	tname = kstrdup("mangle", GFP_KERNEL);
+	if (unlikely(!tname))
+		goto err1;
+
+	t = kmemdup(td, td->u.target_size, GFP_KERNEL);
+	if (unlikely(!t))
+		goto err2;
+
+	err = ipt_init_target(net, t, tname, hook);
+	if (err < 0)
+		goto err3;
+
+	ipt = to_ipt(*a);
+
+	spin_lock_bh(&ipt->tcf_lock);
+	if (ret != ACT_P_CREATED) {
+		ipt_destroy_target(ipt->tcfi_t, net);
+		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);
+	return ret;
+
+err3:
+	kfree(t);
+err2:
+	kfree(tname);
+err1:
+	tcf_idr_release(*a, bind);
+	return err;
+}
+
+static int tcf_ipt_init(struct net *net, struct nlattr *nla,
+			struct nlattr *est, struct tc_action **a,
+			struct tcf_proto *tp,
+			u32 flags, struct netlink_ext_ack *extack)
+{
+	return __tcf_ipt_init(net, act_ipt_ops.net_id, nla, est,
+			      a, &act_ipt_ops, tp, flags);
+}
+
+static int tcf_xt_init(struct net *net, struct nlattr *nla,
+		       struct nlattr *est, struct tc_action **a,
+		       struct tcf_proto *tp,
+		       u32 flags, struct netlink_ext_ack *extack)
+{
+	return __tcf_ipt_init(net, act_xt_ops.net_id, nla, est,
+			      a, &act_xt_ops, tp, flags);
+}
+
+static bool tcf_ipt_act_check(struct sk_buff *skb)
+{
+	const struct iphdr *iph;
+	unsigned int nhoff, len;
+
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		return false;
+
+	nhoff = skb_network_offset(skb);
+	iph = ip_hdr(skb);
+	if (iph->ihl < 5 || iph->version != 4)
+		return false;
+
+	len = skb_ip_totlen(skb);
+	if (skb->len < nhoff + len || len < (iph->ihl * 4u))
+		return false;
+
+	return pskb_may_pull(skb, iph->ihl * 4u);
+}
+
+static int tcf_ipt_act(struct sk_buff *skb, const struct tc_action *a,
+		       struct tcf_result *res)
+{
+	int ret = 0, result = 0;
+	struct tcf_ipt *ipt = to_ipt(a);
+	struct xt_action_param par;
+	struct nf_hook_state state = {
+		.net	= dev_net(skb->dev),
+		.in	= skb->dev,
+		.hook	= ipt->tcfi_hook,
+		.pf	= NFPROTO_IPV4,
+	};
+
+	if (skb_protocol(skb, false) != htons(ETH_P_IP))
+		return TC_ACT_UNSPEC;
+
+	if (skb_unclone(skb, GFP_ATOMIC))
+		return TC_ACT_UNSPEC;
+
+	if (!tcf_ipt_act_check(skb))
+		return TC_ACT_UNSPEC;
+
+	if (state.hook == NF_INET_POST_ROUTING) {
+		if (!skb_dst(skb))
+			return TC_ACT_UNSPEC;
+
+		state.out = skb->dev;
+	}
+
+	spin_lock(&ipt->tcf_lock);
+
+	tcf_lastuse_update(&ipt->tcf_tm);
+	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.state    = &state;
+	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:
+		net_notice_ratelimited("tc filter: Bogus netfilter code %d assume ACCEPT\n",
+				       ret);
+		result = TC_ACT_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 = to_ipt(a);
+	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
+	 */
+
+	spin_lock_bh(&ipt->tcf_lock);
+	t = kmemdup(ipt->tcfi_t, ipt->tcfi_t->u.user.target_size, GFP_ATOMIC);
+	if (unlikely(!t))
+		goto nla_put_failure;
+
+	c.bindcnt = atomic_read(&ipt->tcf_bindcnt) - bind;
+	c.refcnt = refcount_read(&ipt->tcf_refcnt) - ref;
+	strcpy(t->u.user.name, ipt->tcfi_t->u.kernel.target->name);
+
+	if (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))
+		goto nla_put_failure;
+
+	tcf_tm_dump(&tm, &ipt->tcf_tm);
+	if (nla_put_64bit(skb, TCA_IPT_TM, sizeof(tm), &tm, TCA_IPT_PAD))
+		goto nla_put_failure;
+
+	spin_unlock_bh(&ipt->tcf_lock);
+	kfree(t);
+	return skb->len;
+
+nla_put_failure:
+	spin_unlock_bh(&ipt->tcf_lock);
+	nlmsg_trim(skb, b);
+	kfree(t);
+	return -1;
+}
+
+static struct tc_action_ops act_ipt_ops = {
+	.kind		=	"ipt",
+	.id		=	TCA_ID_IPT,
+	.owner		=	THIS_MODULE,
+	.act		=	tcf_ipt_act,
+	.dump		=	tcf_ipt_dump,
+	.cleanup	=	tcf_ipt_release,
+	.init		=	tcf_ipt_init,
+	.size		=	sizeof(struct tcf_ipt),
+};
+
+static __net_init int ipt_init_net(struct net *net)
+{
+	struct tc_action_net *tn = net_generic(net, act_ipt_ops.net_id);
+
+	return tc_action_net_init(net, tn, &act_ipt_ops);
+}
+
+static void __net_exit ipt_exit_net(struct list_head *net_list)
+{
+	tc_action_net_exit(net_list, act_ipt_ops.net_id);
+}
+
+static struct pernet_operations ipt_net_ops = {
+	.init = ipt_init_net,
+	.exit_batch = ipt_exit_net,
+	.id   = &act_ipt_ops.net_id,
+	.size = sizeof(struct tc_action_net),
+};
+
+static struct tc_action_ops act_xt_ops = {
+	.kind		=	"xt",
+	.id		=	TCA_ID_XT,
+	.owner		=	THIS_MODULE,
+	.act		=	tcf_ipt_act,
+	.dump		=	tcf_ipt_dump,
+	.cleanup	=	tcf_ipt_release,
+	.init		=	tcf_xt_init,
+	.size		=	sizeof(struct tcf_ipt),
+};
+
+static __net_init int xt_init_net(struct net *net)
+{
+	struct tc_action_net *tn = net_generic(net, act_xt_ops.net_id);
+
+	return tc_action_net_init(net, tn, &act_xt_ops);
+}
+
+static void __net_exit xt_exit_net(struct list_head *net_list)
+{
+	tc_action_net_exit(net_list, act_xt_ops.net_id);
+}
+
+static struct pernet_operations xt_net_ops = {
+	.init = xt_init_net,
+	.exit_batch = xt_exit_net,
+	.id   = &act_xt_ops.net_id,
+	.size = sizeof(struct tc_action_net),
+};
+
+MODULE_AUTHOR("Jamal Hadi Salim(2002-13)");
+MODULE_DESCRIPTION("Iptables target actions");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("act_xt");
+
+static int __init ipt_init_module(void)
+{
+	int ret1, ret2;
+
+	ret1 = tcf_register_action(&act_xt_ops, &xt_net_ops);
+	if (ret1 < 0)
+		pr_err("Failed to load xt action\n");
+
+	ret2 = tcf_register_action(&act_ipt_ops, &ipt_net_ops);
+	if (ret2 < 0)
+		pr_err("Failed to load ipt action\n");
+
+	if (ret1 < 0 && ret2 < 0) {
+		return ret1;
+	} else
+		return 0;
+}
+
+static void __exit ipt_cleanup_module(void)
+{
+	tcf_unregister_action(&act_ipt_ops, &ipt_net_ops);
+	tcf_unregister_action(&act_xt_ops, &xt_net_ops);
+}
+
+module_init(ipt_init_module);
+module_exit(ipt_cleanup_module);