Initial import

1 files changed, 368 insertions, 0 deletions

diff --git a/net/netfilter/nf_conntrack_proto_udp.c b/net/netfilter/nf_conntrack_proto_udp.c
new file mode 100644
index 000000000..6957281ff
--- /dev/null
+++ b/net/netfilter/nf_conntrack_proto_udp.c
@@ -0,0 +1,368 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/module.h>
+#include <linux/udp.h>
+#include <linux/seq_file.h>
+#include <linux/skbuff.h>
+#include <linux/ipv6.h>
+#include <net/ip6_checksum.h>
+#include <net/checksum.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv6.h>
+#include <net/netfilter/nf_conntrack_l4proto.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
+#include <net/netfilter/nf_log.h>
+#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
+#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
+
+static unsigned int udp_timeouts[UDP_CT_MAX] = {
+	[UDP_CT_UNREPLIED]	= 30*HZ,
+	[UDP_CT_REPLIED]	= 180*HZ,
+};
+
+static inline struct nf_udp_net *udp_pernet(struct net *net)
+{
+	return &net->ct.nf_ct_proto.udp;
+}
+
+static bool udp_pkt_to_tuple(const struct sk_buff *skb,
+			     unsigned int dataoff,
+			     struct nf_conntrack_tuple *tuple)
+{
+	const struct udphdr *hp;
+	struct udphdr _hdr;
+
+	/* Actually only need first 8 bytes. */
+	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
+	if (hp == NULL)
+		return false;
+
+	tuple->src.u.udp.port = hp->source;
+	tuple->dst.u.udp.port = hp->dest;
+
+	return true;
+}
+
+static bool udp_invert_tuple(struct nf_conntrack_tuple *tuple,
+			     const struct nf_conntrack_tuple *orig)
+{
+	tuple->src.u.udp.port = orig->dst.u.udp.port;
+	tuple->dst.u.udp.port = orig->src.u.udp.port;
+	return true;
+}
+
+/* Print out the per-protocol part of the tuple. */
+static void udp_print_tuple(struct seq_file *s,
+			    const struct nf_conntrack_tuple *tuple)
+{
+	seq_printf(s, "sport=%hu dport=%hu ",
+		   ntohs(tuple->src.u.udp.port),
+		   ntohs(tuple->dst.u.udp.port));
+}
+
+static unsigned int *udp_get_timeouts(struct net *net)
+{
+	return udp_pernet(net)->timeouts;
+}
+
+/* Returns verdict for packet, and may modify conntracktype */
+static int udp_packet(struct nf_conn *ct,
+		      const struct sk_buff *skb,
+		      unsigned int dataoff,
+		      enum ip_conntrack_info ctinfo,
+		      u_int8_t pf,
+		      unsigned int hooknum,
+		      unsigned int *timeouts)
+{
+	/* If we've seen traffic both ways, this is some kind of UDP
+	   stream.  Extend timeout. */
+	if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
+		nf_ct_refresh_acct(ct, ctinfo, skb,
+				   timeouts[UDP_CT_REPLIED]);
+		/* Also, more likely to be important, and not a probe */
+		if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
+			nf_conntrack_event_cache(IPCT_ASSURED, ct);
+	} else {
+		nf_ct_refresh_acct(ct, ctinfo, skb,
+				   timeouts[UDP_CT_UNREPLIED]);
+	}
+	return NF_ACCEPT;
+}
+
+/* Called when a new connection for this protocol found. */
+static bool udp_new(struct nf_conn *ct, const struct sk_buff *skb,
+		    unsigned int dataoff, unsigned int *timeouts)
+{
+	return true;
+}
+
+static int udp_error(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
+		     unsigned int dataoff, enum ip_conntrack_info *ctinfo,
+		     u_int8_t pf,
+		     unsigned int hooknum)
+{
+	unsigned int udplen = skb->len - dataoff;
+	const struct udphdr *hdr;
+	struct udphdr _hdr;
+
+	/* Header is too small? */
+	hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
+	if (hdr == NULL) {
+		if (LOG_INVALID(net, IPPROTO_UDP))
+			nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
+				      "nf_ct_udp: short packet ");
+		return -NF_ACCEPT;
+	}
+
+	/* Truncated/malformed packets */
+	if (ntohs(hdr->len) > udplen || ntohs(hdr->len) < sizeof(*hdr)) {
+		if (LOG_INVALID(net, IPPROTO_UDP))
+			nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
+				"nf_ct_udp: truncated/malformed packet ");
+		return -NF_ACCEPT;
+	}
+
+	/* Packet with no checksum */
+	if (!hdr->check)
+		return NF_ACCEPT;
+
+	/* Checksum invalid? Ignore.
+	 * We skip checking packets on the outgoing path
+	 * because the checksum is assumed to be correct.
+	 * FIXME: Source route IP option packets --RR */
+	if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
+	    nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) {
+		if (LOG_INVALID(net, IPPROTO_UDP))
+			nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
+				"nf_ct_udp: bad UDP checksum ");
+		return -NF_ACCEPT;
+	}
+
+	return NF_ACCEPT;
+}
+
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_cttimeout.h>
+
+static int udp_timeout_nlattr_to_obj(struct nlattr *tb[],
+				     struct net *net, void *data)
+{
+	unsigned int *timeouts = data;
+	struct nf_udp_net *un = udp_pernet(net);
+
+	/* set default timeouts for UDP. */
+	timeouts[UDP_CT_UNREPLIED] = un->timeouts[UDP_CT_UNREPLIED];
+	timeouts[UDP_CT_REPLIED] = un->timeouts[UDP_CT_REPLIED];
+
+	if (tb[CTA_TIMEOUT_UDP_UNREPLIED]) {
+		timeouts[UDP_CT_UNREPLIED] =
+			ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_UNREPLIED])) * HZ;
+	}
+	if (tb[CTA_TIMEOUT_UDP_REPLIED]) {
+		timeouts[UDP_CT_REPLIED] =
+			ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_REPLIED])) * HZ;
+	}
+	return 0;
+}
+
+static int
+udp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
+{
+	const unsigned int *timeouts = data;
+
+	if (nla_put_be32(skb, CTA_TIMEOUT_UDP_UNREPLIED,
+			 htonl(timeouts[UDP_CT_UNREPLIED] / HZ)) ||
+	    nla_put_be32(skb, CTA_TIMEOUT_UDP_REPLIED,
+			 htonl(timeouts[UDP_CT_REPLIED] / HZ)))
+		goto nla_put_failure;
+	return 0;
+
+nla_put_failure:
+	return -ENOSPC;
+}
+
+static const struct nla_policy
+udp_timeout_nla_policy[CTA_TIMEOUT_UDP_MAX+1] = {
+       [CTA_TIMEOUT_UDP_UNREPLIED]	= { .type = NLA_U32 },
+       [CTA_TIMEOUT_UDP_REPLIED]	= { .type = NLA_U32 },
+};
+#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table udp_sysctl_table[] = {
+	{
+		.procname	= "nf_conntrack_udp_timeout",
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+	{
+		.procname	= "nf_conntrack_udp_timeout_stream",
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+	{ }
+};
+#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
+static struct ctl_table udp_compat_sysctl_table[] = {
+	{
+		.procname	= "ip_conntrack_udp_timeout",
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+	{
+		.procname	= "ip_conntrack_udp_timeout_stream",
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+	{ }
+};
+#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
+#endif /* CONFIG_SYSCTL */
+
+static int udp_kmemdup_sysctl_table(struct nf_proto_net *pn,
+				    struct nf_udp_net *un)
+{
+#ifdef CONFIG_SYSCTL
+	if (pn->ctl_table)
+		return 0;
+	pn->ctl_table = kmemdup(udp_sysctl_table,
+				sizeof(udp_sysctl_table),
+				GFP_KERNEL);
+	if (!pn->ctl_table)
+		return -ENOMEM;
+	pn->ctl_table[0].data = &un->timeouts[UDP_CT_UNREPLIED];
+	pn->ctl_table[1].data = &un->timeouts[UDP_CT_REPLIED];
+#endif
+	return 0;
+}
+
+static int udp_kmemdup_compat_sysctl_table(struct nf_proto_net *pn,
+					   struct nf_udp_net *un)
+{
+#ifdef CONFIG_SYSCTL
+#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
+	pn->ctl_compat_table = kmemdup(udp_compat_sysctl_table,
+				       sizeof(udp_compat_sysctl_table),
+				       GFP_KERNEL);
+	if (!pn->ctl_compat_table)
+		return -ENOMEM;
+
+	pn->ctl_compat_table[0].data = &un->timeouts[UDP_CT_UNREPLIED];
+	pn->ctl_compat_table[1].data = &un->timeouts[UDP_CT_REPLIED];
+#endif
+#endif
+	return 0;
+}
+
+static int udp_init_net(struct net *net, u_int16_t proto)
+{
+	int ret;
+	struct nf_udp_net *un = udp_pernet(net);
+	struct nf_proto_net *pn = &un->pn;
+
+	if (!pn->users) {
+		int i;
+
+		for (i = 0; i < UDP_CT_MAX; i++)
+			un->timeouts[i] = udp_timeouts[i];
+	}
+
+	if (proto == AF_INET) {
+		ret = udp_kmemdup_compat_sysctl_table(pn, un);
+		if (ret < 0)
+			return ret;
+
+		ret = udp_kmemdup_sysctl_table(pn, un);
+		if (ret < 0)
+			nf_ct_kfree_compat_sysctl_table(pn);
+	} else
+		ret = udp_kmemdup_sysctl_table(pn, un);
+
+	return ret;
+}
+
+static struct nf_proto_net *udp_get_net_proto(struct net *net)
+{
+	return &net->ct.nf_ct_proto.udp.pn;
+}
+
+struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 __read_mostly =
+{
+	.l3proto		= PF_INET,
+	.l4proto		= IPPROTO_UDP,
+	.name			= "udp",
+	.pkt_to_tuple		= udp_pkt_to_tuple,
+	.invert_tuple		= udp_invert_tuple,
+	.print_tuple		= udp_print_tuple,
+	.packet			= udp_packet,
+	.get_timeouts		= udp_get_timeouts,
+	.new			= udp_new,
+	.error			= udp_error,
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
+	.tuple_to_nlattr	= nf_ct_port_tuple_to_nlattr,
+	.nlattr_to_tuple	= nf_ct_port_nlattr_to_tuple,
+	.nlattr_tuple_size	= nf_ct_port_nlattr_tuple_size,
+	.nla_policy		= nf_ct_port_nla_policy,
+#endif
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
+	.ctnl_timeout		= {
+		.nlattr_to_obj	= udp_timeout_nlattr_to_obj,
+		.obj_to_nlattr	= udp_timeout_obj_to_nlattr,
+		.nlattr_max	= CTA_TIMEOUT_UDP_MAX,
+		.obj_size	= sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX,
+		.nla_policy	= udp_timeout_nla_policy,
+	},
+#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
+	.init_net		= udp_init_net,
+	.get_net_proto		= udp_get_net_proto,
+};
+EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4);
+
+struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 __read_mostly =
+{
+	.l3proto		= PF_INET6,
+	.l4proto		= IPPROTO_UDP,
+	.name			= "udp",
+	.pkt_to_tuple		= udp_pkt_to_tuple,
+	.invert_tuple		= udp_invert_tuple,
+	.print_tuple		= udp_print_tuple,
+	.packet			= udp_packet,
+	.get_timeouts		= udp_get_timeouts,
+	.new			= udp_new,
+	.error			= udp_error,
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
+	.tuple_to_nlattr	= nf_ct_port_tuple_to_nlattr,
+	.nlattr_to_tuple	= nf_ct_port_nlattr_to_tuple,
+	.nlattr_tuple_size	= nf_ct_port_nlattr_tuple_size,
+	.nla_policy		= nf_ct_port_nla_policy,
+#endif
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
+	.ctnl_timeout		= {
+		.nlattr_to_obj	= udp_timeout_nlattr_to_obj,
+		.obj_to_nlattr	= udp_timeout_obj_to_nlattr,
+		.nlattr_max	= CTA_TIMEOUT_UDP_MAX,
+		.obj_size	= sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX,
+		.nla_policy	= udp_timeout_nla_policy,
+	},
+#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
+	.init_net		= udp_init_net,
+	.get_net_proto		= udp_get_net_proto,
+};
+EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6);