Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 269 insertions, 0 deletions

diff --git a/net/netfilter/xt_TPROXY.c b/net/netfilter/xt_TPROXY.c
new file mode 100644
index 000000000..e4bea1d34
--- /dev/null
+++ b/net/netfilter/xt_TPROXY.c
@@ -0,0 +1,269 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Transparent proxy support for Linux/iptables
+ *
+ * Copyright (c) 2006-2010 BalaBit IT Ltd.
+ * Author: Balazs Scheidler, Krisztian Kovacs
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <net/checksum.h>
+#include <net/udp.h>
+#include <net/tcp.h>
+#include <net/inet_sock.h>
+#include <net/inet_hashtables.h>
+#include <linux/inetdevice.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+
+#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
+
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
+#define XT_TPROXY_HAVE_IPV6 1
+#include <net/if_inet6.h>
+#include <net/addrconf.h>
+#include <net/inet6_hashtables.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
+#endif
+
+#include <net/netfilter/nf_tproxy.h>
+#include <linux/netfilter/xt_TPROXY.h>
+
+static unsigned int
+tproxy_tg4(struct net *net, struct sk_buff *skb, __be32 laddr, __be16 lport,
+	   u_int32_t mark_mask, u_int32_t mark_value)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+	struct udphdr _hdr, *hp;
+	struct sock *sk;
+
+	hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
+	if (hp == NULL)
+		return NF_DROP;
+
+	/* check if there's an ongoing connection on the packet
+	 * addresses, this happens if the redirect already happened
+	 * and the current packet belongs to an already established
+	 * connection */
+	sk = nf_tproxy_get_sock_v4(net, skb, iph->protocol,
+				   iph->saddr, iph->daddr,
+				   hp->source, hp->dest,
+				   skb->dev, NF_TPROXY_LOOKUP_ESTABLISHED);
+
+	laddr = nf_tproxy_laddr4(skb, laddr, iph->daddr);
+	if (!lport)
+		lport = hp->dest;
+
+	/* UDP has no TCP_TIME_WAIT state, so we never enter here */
+	if (sk && sk->sk_state == TCP_TIME_WAIT)
+		/* reopening a TIME_WAIT connection needs special handling */
+		sk = nf_tproxy_handle_time_wait4(net, skb, laddr, lport, sk);
+	else if (!sk)
+		/* no, there's no established connection, check if
+		 * there's a listener on the redirected addr/port */
+		sk = nf_tproxy_get_sock_v4(net, skb, iph->protocol,
+					   iph->saddr, laddr,
+					   hp->source, lport,
+					   skb->dev, NF_TPROXY_LOOKUP_LISTENER);
+
+	/* NOTE: assign_sock consumes our sk reference */
+	if (sk && nf_tproxy_sk_is_transparent(sk)) {
+		/* This should be in a separate target, but we don't do multiple
+		   targets on the same rule yet */
+		skb->mark = (skb->mark & ~mark_mask) ^ mark_value;
+		nf_tproxy_assign_sock(skb, sk);
+		return NF_ACCEPT;
+	}
+
+	return NF_DROP;
+}
+
+static unsigned int
+tproxy_tg4_v0(struct sk_buff *skb, const struct xt_action_param *par)
+{
+	const struct xt_tproxy_target_info *tgi = par->targinfo;
+
+	return tproxy_tg4(xt_net(par), skb, tgi->laddr, tgi->lport,
+			  tgi->mark_mask, tgi->mark_value);
+}
+
+static unsigned int
+tproxy_tg4_v1(struct sk_buff *skb, const struct xt_action_param *par)
+{
+	const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
+
+	return tproxy_tg4(xt_net(par), skb, tgi->laddr.ip, tgi->lport,
+			  tgi->mark_mask, tgi->mark_value);
+}
+
+#ifdef XT_TPROXY_HAVE_IPV6
+
+static unsigned int
+tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par)
+{
+	const struct ipv6hdr *iph = ipv6_hdr(skb);
+	const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
+	struct udphdr _hdr, *hp;
+	struct sock *sk;
+	const struct in6_addr *laddr;
+	__be16 lport;
+	int thoff = 0;
+	int tproto;
+
+	tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL);
+	if (tproto < 0)
+		return NF_DROP;
+
+	hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr);
+	if (!hp)
+		return NF_DROP;
+
+	/* check if there's an ongoing connection on the packet
+	 * addresses, this happens if the redirect already happened
+	 * and the current packet belongs to an already established
+	 * connection */
+	sk = nf_tproxy_get_sock_v6(xt_net(par), skb, thoff, tproto,
+				   &iph->saddr, &iph->daddr,
+				   hp->source, hp->dest,
+				   xt_in(par), NF_TPROXY_LOOKUP_ESTABLISHED);
+
+	laddr = nf_tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr);
+	lport = tgi->lport ? tgi->lport : hp->dest;
+
+	/* UDP has no TCP_TIME_WAIT state, so we never enter here */
+	if (sk && sk->sk_state == TCP_TIME_WAIT) {
+		const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
+		/* reopening a TIME_WAIT connection needs special handling */
+		sk = nf_tproxy_handle_time_wait6(skb, tproto, thoff,
+					      xt_net(par),
+					      &tgi->laddr.in6,
+					      tgi->lport,
+					      sk);
+	}
+	else if (!sk)
+		/* no there's no established connection, check if
+		 * there's a listener on the redirected addr/port */
+		sk = nf_tproxy_get_sock_v6(xt_net(par), skb, thoff,
+					   tproto, &iph->saddr, laddr,
+					   hp->source, lport,
+					   xt_in(par), NF_TPROXY_LOOKUP_LISTENER);
+
+	/* NOTE: assign_sock consumes our sk reference */
+	if (sk && nf_tproxy_sk_is_transparent(sk)) {
+		/* This should be in a separate target, but we don't do multiple
+		   targets on the same rule yet */
+		skb->mark = (skb->mark & ~tgi->mark_mask) ^ tgi->mark_value;
+		nf_tproxy_assign_sock(skb, sk);
+		return NF_ACCEPT;
+	}
+
+	return NF_DROP;
+}
+
+static int tproxy_tg6_check(const struct xt_tgchk_param *par)
+{
+	const struct ip6t_ip6 *i = par->entryinfo;
+	int err;
+
+	err = nf_defrag_ipv6_enable(par->net);
+	if (err)
+		return err;
+
+	if ((i->proto == IPPROTO_TCP || i->proto == IPPROTO_UDP) &&
+	    !(i->invflags & IP6T_INV_PROTO))
+		return 0;
+
+	pr_info_ratelimited("Can be used only with -p tcp or -p udp\n");
+	return -EINVAL;
+}
+
+static void tproxy_tg6_destroy(const struct xt_tgdtor_param *par)
+{
+	nf_defrag_ipv6_disable(par->net);
+}
+#endif
+
+static int tproxy_tg4_check(const struct xt_tgchk_param *par)
+{
+	const struct ipt_ip *i = par->entryinfo;
+	int err;
+
+	err = nf_defrag_ipv4_enable(par->net);
+	if (err)
+		return err;
+
+	if ((i->proto == IPPROTO_TCP || i->proto == IPPROTO_UDP)
+	    && !(i->invflags & IPT_INV_PROTO))
+		return 0;
+
+	pr_info_ratelimited("Can be used only with -p tcp or -p udp\n");
+	return -EINVAL;
+}
+
+static void tproxy_tg4_destroy(const struct xt_tgdtor_param *par)
+{
+	nf_defrag_ipv4_disable(par->net);
+}
+
+static struct xt_target tproxy_tg_reg[] __read_mostly = {
+	{
+		.name		= "TPROXY",
+		.family		= NFPROTO_IPV4,
+		.table		= "mangle",
+		.target		= tproxy_tg4_v0,
+		.revision	= 0,
+		.targetsize	= sizeof(struct xt_tproxy_target_info),
+		.checkentry	= tproxy_tg4_check,
+		.destroy	= tproxy_tg4_destroy,
+		.hooks		= 1 << NF_INET_PRE_ROUTING,
+		.me		= THIS_MODULE,
+	},
+	{
+		.name		= "TPROXY",
+		.family		= NFPROTO_IPV4,
+		.table		= "mangle",
+		.target		= tproxy_tg4_v1,
+		.revision	= 1,
+		.targetsize	= sizeof(struct xt_tproxy_target_info_v1),
+		.checkentry	= tproxy_tg4_check,
+		.destroy	= tproxy_tg4_destroy,
+		.hooks		= 1 << NF_INET_PRE_ROUTING,
+		.me		= THIS_MODULE,
+	},
+#ifdef XT_TPROXY_HAVE_IPV6
+	{
+		.name		= "TPROXY",
+		.family		= NFPROTO_IPV6,
+		.table		= "mangle",
+		.target		= tproxy_tg6_v1,
+		.revision	= 1,
+		.targetsize	= sizeof(struct xt_tproxy_target_info_v1),
+		.checkentry	= tproxy_tg6_check,
+		.destroy	= tproxy_tg6_destroy,
+		.hooks		= 1 << NF_INET_PRE_ROUTING,
+		.me		= THIS_MODULE,
+	},
+#endif
+
+};
+
+static int __init tproxy_tg_init(void)
+{
+	return xt_register_targets(tproxy_tg_reg, ARRAY_SIZE(tproxy_tg_reg));
+}
+
+static void __exit tproxy_tg_exit(void)
+{
+	xt_unregister_targets(tproxy_tg_reg, ARRAY_SIZE(tproxy_tg_reg));
+}
+
+module_init(tproxy_tg_init);
+module_exit(tproxy_tg_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Balazs Scheidler, Krisztian Kovacs");
+MODULE_DESCRIPTION("Netfilter transparent proxy (TPROXY) target module.");
+MODULE_ALIAS("ipt_TPROXY");
+MODULE_ALIAS("ip6t_TPROXY");