tproxy: added IPv6 support to the socket match
The ICMP extraction bits were contributed by Harry Mason. Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Balazs Scheidler
Patrick McHardy
parent
6ad7889327
commit
b64c9256a9
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@ -14,6 +14,7 @@
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#include <linux/skbuff.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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#include <linux/netfilter_ipv6/ip6_tables.h>
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#include <net/tcp.h>
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#include <net/udp.h>
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#include <net/icmp.h>
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@ -21,6 +22,7 @@
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#include <net/inet_sock.h>
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#include <net/netfilter/nf_tproxy_core.h>
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#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
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#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
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#include <linux/netfilter/xt_socket.h>
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@ -30,7 +32,7 @@
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#endif
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static int
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extract_icmp_fields(const struct sk_buff *skb,
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extract_icmp4_fields(const struct sk_buff *skb,
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u8 *protocol,
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__be32 *raddr,
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__be32 *laddr,
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@ -86,7 +88,6 @@ extract_icmp_fields(const struct sk_buff *skb,
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return 0;
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}
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static bool
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socket_match(const struct sk_buff *skb, struct xt_action_param *par,
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const struct xt_socket_mtinfo1 *info)
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@ -115,7 +116,7 @@ socket_match(const struct sk_buff *skb, struct xt_action_param *par,
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dport = hp->dest;
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} else if (iph->protocol == IPPROTO_ICMP) {
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if (extract_icmp_fields(skb, &protocol, &saddr, &daddr,
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if (extract_icmp4_fields(skb, &protocol, &saddr, &daddr,
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&sport, &dport))
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return false;
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} else {
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@ -165,32 +166,157 @@ socket_match(const struct sk_buff *skb, struct xt_action_param *par,
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sk = NULL;
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}
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pr_debug("proto %u %08x:%u -> %08x:%u (orig %08x:%u) sock %p\n",
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protocol, ntohl(saddr), ntohs(sport),
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ntohl(daddr), ntohs(dport),
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ntohl(iph->daddr), hp ? ntohs(hp->dest) : 0, sk);
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pr_debug("proto %hhu %pI4:%hu -> %pI4:%hu (orig %pI4:%hu) sock %p\n",
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protocol, &saddr, ntohs(sport),
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&daddr, ntohs(dport),
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&iph->daddr, hp ? ntohs(hp->dest) : 0, sk);
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return (sk != NULL);
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}
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static bool
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socket_mt_v0(const struct sk_buff *skb, struct xt_action_param *par)
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socket_mt4_v0(const struct sk_buff *skb, struct xt_action_param *par)
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{
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return socket_match(skb, par, NULL);
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}
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static bool
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socket_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
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socket_mt4_v1(const struct sk_buff *skb, struct xt_action_param *par)
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{
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return socket_match(skb, par, par->matchinfo);
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}
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#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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static int
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extract_icmp6_fields(const struct sk_buff *skb,
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unsigned int outside_hdrlen,
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u8 *protocol,
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struct in6_addr **raddr,
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struct in6_addr **laddr,
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__be16 *rport,
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__be16 *lport)
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{
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struct ipv6hdr *inside_iph, _inside_iph;
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struct icmp6hdr *icmph, _icmph;
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__be16 *ports, _ports[2];
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u8 inside_nexthdr;
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int inside_hdrlen;
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icmph = skb_header_pointer(skb, outside_hdrlen,
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sizeof(_icmph), &_icmph);
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if (icmph == NULL)
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return 1;
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if (icmph->icmp6_type & ICMPV6_INFOMSG_MASK)
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return 1;
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inside_iph = skb_header_pointer(skb, outside_hdrlen + sizeof(_icmph), sizeof(_inside_iph), &_inside_iph);
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if (inside_iph == NULL)
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return 1;
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inside_nexthdr = inside_iph->nexthdr;
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inside_hdrlen = ipv6_skip_exthdr(skb, outside_hdrlen + sizeof(_icmph) + sizeof(_inside_iph), &inside_nexthdr);
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if (inside_hdrlen < 0)
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return 1; /* hjm: Packet has no/incomplete transport layer headers. */
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if (inside_nexthdr != IPPROTO_TCP &&
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inside_nexthdr != IPPROTO_UDP)
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return 1;
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ports = skb_header_pointer(skb, inside_hdrlen,
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sizeof(_ports), &_ports);
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if (ports == NULL)
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return 1;
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/* the inside IP packet is the one quoted from our side, thus
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* its saddr is the local address */
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*protocol = inside_nexthdr;
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*laddr = &inside_iph->saddr;
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*lport = ports[0];
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*raddr = &inside_iph->daddr;
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*rport = ports[1];
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return 0;
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}
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static bool
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socket_mt6_v1(const struct sk_buff *skb, struct xt_action_param *par)
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{
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struct ipv6hdr *iph = ipv6_hdr(skb);
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struct udphdr _hdr, *hp = NULL;
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struct sock *sk;
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struct in6_addr *daddr, *saddr;
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__be16 dport, sport;
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int thoff;
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u8 tproto;
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const struct xt_socket_mtinfo1 *info = (struct xt_socket_mtinfo1 *) par->matchinfo;
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tproto = ipv6_find_hdr(skb, &thoff, -1, NULL);
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if (tproto < 0) {
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pr_debug("unable to find transport header in IPv6 packet, dropping\n");
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return NF_DROP;
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}
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if (tproto == IPPROTO_UDP || tproto == IPPROTO_TCP) {
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hp = skb_header_pointer(skb, thoff,
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sizeof(_hdr), &_hdr);
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if (hp == NULL)
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return false;
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saddr = &iph->saddr;
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sport = hp->source;
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daddr = &iph->daddr;
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dport = hp->dest;
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} else if (tproto == IPPROTO_ICMPV6) {
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if (extract_icmp6_fields(skb, thoff, &tproto, &saddr, &daddr,
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&sport, &dport))
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return false;
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} else {
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return false;
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}
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sk = nf_tproxy_get_sock_v6(dev_net(skb->dev), tproto,
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saddr, daddr, sport, dport, par->in, NFT_LOOKUP_ANY);
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if (sk != NULL) {
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bool wildcard;
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bool transparent = true;
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/* Ignore sockets listening on INADDR_ANY */
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wildcard = (sk->sk_state != TCP_TIME_WAIT &&
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ipv6_addr_any(&inet6_sk(sk)->rcv_saddr));
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/* Ignore non-transparent sockets,
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if XT_SOCKET_TRANSPARENT is used */
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if (info && info->flags & XT_SOCKET_TRANSPARENT)
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transparent = ((sk->sk_state != TCP_TIME_WAIT &&
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inet_sk(sk)->transparent) ||
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(sk->sk_state == TCP_TIME_WAIT &&
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inet_twsk(sk)->tw_transparent));
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nf_tproxy_put_sock(sk);
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if (wildcard || !transparent)
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sk = NULL;
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}
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pr_debug("proto %hhu %pI6:%hu -> %pI6:%hu "
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"(orig %pI6:%hu) sock %p\n",
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tproto, saddr, ntohs(sport),
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daddr, ntohs(dport),
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&iph->daddr, hp ? ntohs(hp->dest) : 0, sk);
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return (sk != NULL);
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}
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#endif
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static struct xt_match socket_mt_reg[] __read_mostly = {
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{
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.name = "socket",
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.revision = 0,
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.family = NFPROTO_IPV4,
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.match = socket_mt_v0,
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.match = socket_mt4_v0,
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.hooks = (1 << NF_INET_PRE_ROUTING) |
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(1 << NF_INET_LOCAL_IN),
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.me = THIS_MODULE,
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@ -199,17 +325,33 @@ static struct xt_match socket_mt_reg[] __read_mostly = {
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.name = "socket",
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.revision = 1,
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.family = NFPROTO_IPV4,
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.match = socket_mt_v1,
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.match = socket_mt4_v1,
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.matchsize = sizeof(struct xt_socket_mtinfo1),
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.hooks = (1 << NF_INET_PRE_ROUTING) |
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(1 << NF_INET_LOCAL_IN),
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.me = THIS_MODULE,
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},
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#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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{
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.name = "socket",
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.revision = 1,
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.family = NFPROTO_IPV6,
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.match = socket_mt6_v1,
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.matchsize = sizeof(struct xt_socket_mtinfo1),
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.hooks = (1 << NF_INET_PRE_ROUTING) |
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(1 << NF_INET_LOCAL_IN),
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.me = THIS_MODULE,
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},
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#endif
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};
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static int __init socket_mt_init(void)
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{
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nf_defrag_ipv4_enable();
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#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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nf_defrag_ipv6_enable();
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#endif
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return xt_register_matches(socket_mt_reg, ARRAY_SIZE(socket_mt_reg));
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}
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@ -225,3 +367,4 @@ MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Krisztian Kovacs, Balazs Scheidler");
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MODULE_DESCRIPTION("x_tables socket match module");
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MODULE_ALIAS("ipt_socket");
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MODULE_ALIAS("ip6t_socket");
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