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 2010-10-21 16:19:42 +02:00 committed by Patrick McHardy
parent 6ad7889327
commit b64c9256a9

View File

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