|
@@ -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);
|