| /* Copyright (C) 2003-2011 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> |
| * |
| * 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: { |
| sctp_sctphdr_t _sh; |
| const sctp_sctphdr_t *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 |
| |
| bool |
| ip_set_get_ip_port(const struct sk_buff *skb, u8 pf, bool src, __be16 *port) |
| { |
| bool ret; |
| u8 proto; |
| |
| switch (pf) { |
| case NFPROTO_IPV4: |
| ret = ip_set_get_ip4_port(skb, src, port, &proto); |
| break; |
| case NFPROTO_IPV6: |
| ret = ip_set_get_ip6_port(skb, src, port, &proto); |
| break; |
| default: |
| return false; |
| } |
| if (!ret) |
| return ret; |
| switch (proto) { |
| case IPPROTO_TCP: |
| case IPPROTO_UDP: |
| return true; |
| default: |
| return false; |
| } |
| } |
| EXPORT_SYMBOL_GPL(ip_set_get_ip_port); |