1 files changed, 150 insertions, 0 deletions
diff --git a/net/netfilter/ipset/ip_set_getport.c b/net/netfilter/ipset/ip_set_getport.c
new file mode 100644
index 000000000..36615eb3e
--- /dev/null
+++ b/net/netfilter/ipset/ip_set_getport.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2003-2011 Jozsef Kadlecsik <kadlec@netfilter.org>
+ *
+ * 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.
+ */
+
+/* Get Layer-4 data from the packets */
+
+#include <linux/ip.h>
+#include <linux/skbuff.h>
+#include <linux/icmp.h>
+#include <linux/icmpv6.h>
+#include <linux/sctp.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+
+#include <linux/netfilter/ipset/ip_set_getport.h>
+#include <linux/export.h>
+
+/* We must handle non-linear skbs */
+static bool
+get_port(const struct sk_buff *skb, int protocol, unsigned int protooff,
+	 bool src, __be16 *port, u8 *proto)
+{
+	switch (protocol) {
+	case IPPROTO_TCP: {
+		struct tcphdr _tcph;
+		const struct tcphdr *th;
+
+		th = skb_header_pointer(skb, protooff, sizeof(_tcph), &_tcph);
+		if (!th)
+			/* No choice either */
+			return false;
+
+		*port = src ? th->source : th->dest;
+		break;
+	}
+	case IPPROTO_SCTP: {
+		struct sctphdr _sh;
+		const struct sctphdr *sh;
+
+		sh = skb_header_pointer(skb, protooff, sizeof(_sh), &_sh);
+		if (!sh)
+			/* No choice either */
+			return false;
+
+		*port = src ? sh->source : sh->dest;
+		break;
+	}
+	case IPPROTO_UDP:
+	case IPPROTO_UDPLITE: {
+		struct udphdr _udph;
+		const struct udphdr *uh;
+
+		uh = skb_header_pointer(skb, protooff, sizeof(_udph), &_udph);
+		if (!uh)
+			/* No choice either */
+			return false;
+
+		*port = src ? uh->source : uh->dest;
+		break;
+	}
+	case IPPROTO_ICMP: {
+		struct icmphdr _ich;
+		const struct icmphdr *ic;
+
+		ic = skb_header_pointer(skb, protooff, sizeof(_ich), &_ich);
+		if (!ic)
+			return false;
+
+		*port = (__force __be16)htons((ic->type << 8) | ic->code);
+		break;
+	}
+	case IPPROTO_ICMPV6: {
+		struct icmp6hdr _ich;
+		const struct icmp6hdr *ic;
+
+		ic = skb_header_pointer(skb, protooff, sizeof(_ich), &_ich);
+		if (!ic)
+			return false;
+
+		*port = (__force __be16)
+			htons((ic->icmp6_type << 8) | ic->icmp6_code);
+		break;
+	}
+	default:
+		break;
+	}
+	*proto = protocol;
+
+	return true;
+}
+
+bool
+ip_set_get_ip4_port(const struct sk_buff *skb, bool src,
+		    __be16 *port, u8 *proto)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+	unsigned int protooff = skb_network_offset(skb) + ip_hdrlen(skb);
+	int protocol = iph->protocol;
+
+	/* See comments at tcp_match in ip_tables.c */
+	if (protocol <= 0)
+		return false;
+
+	if (ntohs(iph->frag_off) & IP_OFFSET)
+		switch (protocol) {
+		case IPPROTO_TCP:
+		case IPPROTO_SCTP:
+		case IPPROTO_UDP:
+		case IPPROTO_UDPLITE:
+		case IPPROTO_ICMP:
+			/* Port info not available for fragment offset > 0 */
+			return false;
+		default:
+			/* Other protocols doesn't have ports,
+			 * so we can match fragments.
+			 */
+			*proto = protocol;
+			return true;
+		}
+
+	return get_port(skb, protocol, protooff, src, port, proto);
+}
+EXPORT_SYMBOL_GPL(ip_set_get_ip4_port);
+
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
+bool
+ip_set_get_ip6_port(const struct sk_buff *skb, bool src,
+		    __be16 *port, u8 *proto)
+{
+	int protoff;
+	u8 nexthdr;
+	__be16 frag_off = 0;
+
+	nexthdr = ipv6_hdr(skb)->nexthdr;
+	protoff = ipv6_skip_exthdr(skb,
+				   skb_network_offset(skb) +
+					sizeof(struct ipv6hdr), &nexthdr,
+				   &frag_off);
+	if (protoff < 0 || (frag_off & htons(~0x7)) != 0)
+		return false;
+
+	return get_port(skb, nexthdr, protoff, src, port, proto);
+}
+EXPORT_SYMBOL_GPL(ip_set_get_ip6_port);
+#endif