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authorPatrick McHardy <kaber@trash.net>2010-02-11 12:29:38 +0100
committerPatrick McHardy <kaber@trash.net>2010-02-11 12:29:38 +0100
commit48f8ac26537c1b7b1a2422f5232f45d06c945348 (patch)
tree352aab0881ef9e449dc86b3dc1da2b4b329ead44 /net/ipv4
parent010c0b9f34a4c567b431f8b49a58b7332ed42e47 (diff)
downloadlinux-48f8ac26537c1b7b1a2422f5232f45d06c945348.tar.bz2
netfilter: nf_nat_sip: add TCP support
Add support for mangling TCP SIP packets. Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/netfilter/nf_nat_sip.c53
1 files changed, 47 insertions, 6 deletions
diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index b232e4040dc6..11b538deaaec 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -1,4 +1,4 @@
-/* SIP extension for UDP NAT alteration.
+/* SIP extension for NAT alteration.
*
* (C) 2005 by Christian Hentschel <chentschel@arnet.com.ar>
* based on RR's ip_nat_ftp.c and other modules.
@@ -15,6 +15,7 @@
#include <linux/ip.h>
#include <net/ip.h>
#include <linux/udp.h>
+#include <linux/tcp.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_helper.h>
@@ -36,10 +37,27 @@ static unsigned int mangle_packet(struct sk_buff *skb, unsigned int dataoff,
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
-
- if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, matchoff, matchlen,
- buffer, buflen))
- return 0;
+ struct tcphdr *th;
+ unsigned int baseoff;
+
+ if (nf_ct_protonum(ct) == IPPROTO_TCP) {
+ th = (struct tcphdr *)(skb->data + ip_hdrlen(skb));
+ baseoff = ip_hdrlen(skb) + th->doff * 4;
+ matchoff += dataoff - baseoff;
+
+ if (!__nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
+ matchoff, matchlen,
+ buffer, buflen, false))
+ return 0;
+ } else {
+ baseoff = ip_hdrlen(skb) + sizeof(struct udphdr);
+ matchoff += dataoff - baseoff;
+
+ if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo,
+ matchoff, matchlen,
+ buffer, buflen))
+ return 0;
+ }
/* Reload data pointer and adjust datalen value */
*dptr = skb->data + dataoff;
@@ -104,6 +122,7 @@ static unsigned int ip_nat_sip(struct sk_buff *skb, unsigned int dataoff,
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
unsigned int coff, matchoff, matchlen;
+ enum sip_header_types hdr;
union nf_inet_addr addr;
__be16 port;
int request, in_header;
@@ -120,9 +139,14 @@ static unsigned int ip_nat_sip(struct sk_buff *skb, unsigned int dataoff,
} else
request = 0;
+ if (nf_ct_protonum(ct) == IPPROTO_TCP)
+ hdr = SIP_HDR_VIA_TCP;
+ else
+ hdr = SIP_HDR_VIA_UDP;
+
/* Translate topmost Via header and parameters */
if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
- SIP_HDR_VIA_UDP, NULL, &matchoff, &matchlen,
+ hdr, NULL, &matchoff, &matchlen,
&addr, &port) > 0) {
unsigned int matchend, poff, plen, buflen, n;
char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
@@ -204,9 +228,23 @@ next:
if (!map_sip_addr(skb, dataoff, dptr, datalen, SIP_HDR_FROM) ||
!map_sip_addr(skb, dataoff, dptr, datalen, SIP_HDR_TO))
return NF_DROP;
+
return NF_ACCEPT;
}
+static void ip_nat_sip_seq_adjust(struct sk_buff *skb, s16 off)
+{
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+ const struct tcphdr *th;
+
+ if (nf_ct_protonum(ct) != IPPROTO_TCP || off == 0)
+ return;
+
+ th = (struct tcphdr *)(skb->data + ip_hdrlen(skb));
+ nf_nat_set_seq_adjust(ct, ctinfo, th->seq, off);
+}
+
/* Handles expected signalling connections and media streams */
static void ip_nat_sip_expected(struct nf_conn *ct,
struct nf_conntrack_expect *exp)
@@ -472,6 +510,7 @@ err1:
static void __exit nf_nat_sip_fini(void)
{
rcu_assign_pointer(nf_nat_sip_hook, NULL);
+ rcu_assign_pointer(nf_nat_sip_seq_adjust_hook, NULL);
rcu_assign_pointer(nf_nat_sip_expect_hook, NULL);
rcu_assign_pointer(nf_nat_sdp_addr_hook, NULL);
rcu_assign_pointer(nf_nat_sdp_port_hook, NULL);
@@ -483,12 +522,14 @@ static void __exit nf_nat_sip_fini(void)
static int __init nf_nat_sip_init(void)
{
BUG_ON(nf_nat_sip_hook != NULL);
+ BUG_ON(nf_nat_sip_seq_adjust_hook != NULL);
BUG_ON(nf_nat_sip_expect_hook != NULL);
BUG_ON(nf_nat_sdp_addr_hook != NULL);
BUG_ON(nf_nat_sdp_port_hook != NULL);
BUG_ON(nf_nat_sdp_session_hook != NULL);
BUG_ON(nf_nat_sdp_media_hook != NULL);
rcu_assign_pointer(nf_nat_sip_hook, ip_nat_sip);
+ rcu_assign_pointer(nf_nat_sip_seq_adjust_hook, ip_nat_sip_seq_adjust);
rcu_assign_pointer(nf_nat_sip_expect_hook, ip_nat_sip_expect);
rcu_assign_pointer(nf_nat_sdp_addr_hook, ip_nat_sdp_addr);
rcu_assign_pointer(nf_nat_sdp_port_hook, ip_nat_sdp_port);