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- // 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
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