From: Balazs Scheidler <bazsi@xxxxxxxxxx>
The ICMP extraction bits were contributed by Harry Mason.
Signed-off-by: Balazs Scheidler <bazsi@xxxxxxxxxx>
Signed-off-by: KOVACS Krisztian <hidden@xxxxxxxxxx>
---
net/netfilter/xt_socket.c | 165 ++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 154 insertions(+), 11 deletions(-)
diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c
index 266faa0..1dc2784 100644
--- a/net/netfilter/xt_socket.c
+++ b/net/netfilter/xt_socket.c
@@ -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 %u %pI4:%u -> %pI4:%u (orig %pI4:%u) 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 %u %pI6:%u -> %pI6:%u "
+ "(orig %pI6:%u) 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");
--
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