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path: root/net/ipv4/netfilter/nf_nat_sip.c
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Diffstat (limited to 'net/ipv4/netfilter/nf_nat_sip.c')
-rw-r--r--net/ipv4/netfilter/nf_nat_sip.c154
1 files changed, 98 insertions, 56 deletions
diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index 07d61a57613c..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>
@@ -29,25 +30,42 @@ MODULE_DESCRIPTION("SIP NAT helper");
MODULE_ALIAS("ip_nat_sip");
-static unsigned int mangle_packet(struct sk_buff *skb,
+static unsigned int mangle_packet(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
unsigned int matchoff, unsigned int matchlen,
const char *buffer, unsigned int buflen)
{
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 + ip_hdrlen(skb) + sizeof(struct udphdr);
+ *dptr = skb->data + dataoff;
*datalen += buflen - matchlen;
return 1;
}
-static int map_addr(struct sk_buff *skb,
+static int map_addr(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
unsigned int matchoff, unsigned int matchlen,
union nf_inet_addr *addr, __be16 port)
@@ -76,11 +94,11 @@ static int map_addr(struct sk_buff *skb,
buflen = sprintf(buffer, "%pI4:%u", &newaddr, ntohs(newport));
- return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+ return mangle_packet(skb, dataoff, dptr, datalen, matchoff, matchlen,
buffer, buflen);
}
-static int map_sip_addr(struct sk_buff *skb,
+static int map_sip_addr(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
enum sip_header_types type)
{
@@ -93,16 +111,18 @@ static int map_sip_addr(struct sk_buff *skb,
if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, type, NULL,
&matchoff, &matchlen, &addr, &port) <= 0)
return 1;
- return map_addr(skb, dptr, datalen, matchoff, matchlen, &addr, port);
+ return map_addr(skb, dataoff, dptr, datalen, matchoff, matchlen,
+ &addr, port);
}
-static unsigned int ip_nat_sip(struct sk_buff *skb,
+static unsigned int ip_nat_sip(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen)
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
- unsigned int dataoff, matchoff, matchlen;
+ unsigned int coff, matchoff, matchlen;
+ enum sip_header_types hdr;
union nf_inet_addr addr;
__be16 port;
int request, in_header;
@@ -112,16 +132,21 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
if (ct_sip_parse_request(ct, *dptr, *datalen,
&matchoff, &matchlen,
&addr, &port) > 0 &&
- !map_addr(skb, dptr, datalen, matchoff, matchlen,
+ !map_addr(skb, dataoff, dptr, datalen, matchoff, matchlen,
&addr, port))
return NF_DROP;
request = 1;
} 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, 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")];
@@ -138,7 +163,7 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
goto next;
}
- if (!map_addr(skb, dptr, datalen, matchoff, matchlen,
+ if (!map_addr(skb, dataoff, dptr, datalen, matchoff, matchlen,
&addr, port))
return NF_DROP;
@@ -153,8 +178,8 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
addr.ip != ct->tuplehash[!dir].tuple.dst.u3.ip) {
buflen = sprintf(buffer, "%pI4",
&ct->tuplehash[!dir].tuple.dst.u3.ip);
- if (!mangle_packet(skb, dptr, datalen, poff, plen,
- buffer, buflen))
+ if (!mangle_packet(skb, dataoff, dptr, datalen,
+ poff, plen, buffer, buflen))
return NF_DROP;
}
@@ -167,8 +192,8 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
addr.ip != ct->tuplehash[!dir].tuple.src.u3.ip) {
buflen = sprintf(buffer, "%pI4",
&ct->tuplehash[!dir].tuple.src.u3.ip);
- if (!mangle_packet(skb, dptr, datalen, poff, plen,
- buffer, buflen))
+ if (!mangle_packet(skb, dataoff, dptr, datalen,
+ poff, plen, buffer, buflen))
return NF_DROP;
}
@@ -181,31 +206,45 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
htons(n) != ct->tuplehash[!dir].tuple.src.u.udp.port) {
__be16 p = ct->tuplehash[!dir].tuple.src.u.udp.port;
buflen = sprintf(buffer, "%u", ntohs(p));
- if (!mangle_packet(skb, dptr, datalen, poff, plen,
- buffer, buflen))
+ if (!mangle_packet(skb, dataoff, dptr, datalen,
+ poff, plen, buffer, buflen))
return NF_DROP;
}
}
next:
/* Translate Contact headers */
- dataoff = 0;
+ coff = 0;
in_header = 0;
- while (ct_sip_parse_header_uri(ct, *dptr, &dataoff, *datalen,
+ while (ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen,
SIP_HDR_CONTACT, &in_header,
&matchoff, &matchlen,
&addr, &port) > 0) {
- if (!map_addr(skb, dptr, datalen, matchoff, matchlen,
+ if (!map_addr(skb, dataoff, dptr, datalen, matchoff, matchlen,
&addr, port))
return NF_DROP;
}
- if (!map_sip_addr(skb, dptr, datalen, SIP_HDR_FROM) ||
- !map_sip_addr(skb, dptr, datalen, SIP_HDR_TO))
+ 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)
@@ -232,7 +271,7 @@ static void ip_nat_sip_expected(struct nf_conn *ct,
}
}
-static unsigned int ip_nat_sip_expect(struct sk_buff *skb,
+static unsigned int ip_nat_sip_expect(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
struct nf_conntrack_expect *exp,
unsigned int matchoff,
@@ -279,8 +318,8 @@ static unsigned int ip_nat_sip_expect(struct sk_buff *skb,
if (exp->tuple.dst.u3.ip != exp->saved_ip ||
exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port) {
buflen = sprintf(buffer, "%pI4:%u", &newip, port);
- if (!mangle_packet(skb, dptr, datalen, matchoff, matchlen,
- buffer, buflen))
+ if (!mangle_packet(skb, dataoff, dptr, datalen,
+ matchoff, matchlen, buffer, buflen))
goto err;
}
return NF_ACCEPT;
@@ -290,7 +329,7 @@ err:
return NF_DROP;
}
-static int mangle_content_len(struct sk_buff *skb,
+static int mangle_content_len(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen)
{
enum ip_conntrack_info ctinfo;
@@ -312,12 +351,13 @@ static int mangle_content_len(struct sk_buff *skb,
return 0;
buflen = sprintf(buffer, "%u", c_len);
- return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+ return mangle_packet(skb, dataoff, dptr, datalen, matchoff, matchlen,
buffer, buflen);
}
-static int mangle_sdp_packet(struct sk_buff *skb, const char **dptr,
- unsigned int dataoff, unsigned int *datalen,
+static int mangle_sdp_packet(struct sk_buff *skb, unsigned int dataoff,
+ const char **dptr, unsigned int *datalen,
+ unsigned int sdpoff,
enum sdp_header_types type,
enum sdp_header_types term,
char *buffer, int buflen)
@@ -326,16 +366,16 @@ static int mangle_sdp_packet(struct sk_buff *skb, const char **dptr,
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
unsigned int matchlen, matchoff;
- if (ct_sip_get_sdp_header(ct, *dptr, dataoff, *datalen, type, term,
+ if (ct_sip_get_sdp_header(ct, *dptr, sdpoff, *datalen, type, term,
&matchoff, &matchlen) <= 0)
return -ENOENT;
- return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+ return mangle_packet(skb, dataoff, dptr, datalen, matchoff, matchlen,
buffer, buflen) ? 0 : -EINVAL;
}
-static unsigned int ip_nat_sdp_addr(struct sk_buff *skb, const char **dptr,
- unsigned int dataoff,
- unsigned int *datalen,
+static unsigned int ip_nat_sdp_addr(struct sk_buff *skb, unsigned int dataoff,
+ const char **dptr, unsigned int *datalen,
+ unsigned int sdpoff,
enum sdp_header_types type,
enum sdp_header_types term,
const union nf_inet_addr *addr)
@@ -344,16 +384,15 @@ static unsigned int ip_nat_sdp_addr(struct sk_buff *skb, const char **dptr,
unsigned int buflen;
buflen = sprintf(buffer, "%pI4", &addr->ip);
- if (mangle_sdp_packet(skb, dptr, dataoff, datalen, type, term,
+ if (mangle_sdp_packet(skb, dataoff, dptr, datalen, sdpoff, type, term,
buffer, buflen))
return 0;
- return mangle_content_len(skb, dptr, datalen);
+ return mangle_content_len(skb, dataoff, dptr, datalen);
}
-static unsigned int ip_nat_sdp_port(struct sk_buff *skb,
- const char **dptr,
- unsigned int *datalen,
+static unsigned int ip_nat_sdp_port(struct sk_buff *skb, unsigned int dataoff,
+ const char **dptr, unsigned int *datalen,
unsigned int matchoff,
unsigned int matchlen,
u_int16_t port)
@@ -362,16 +401,16 @@ static unsigned int ip_nat_sdp_port(struct sk_buff *skb,
unsigned int buflen;
buflen = sprintf(buffer, "%u", port);
- if (!mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+ if (!mangle_packet(skb, dataoff, dptr, datalen, matchoff, matchlen,
buffer, buflen))
return 0;
- return mangle_content_len(skb, dptr, datalen);
+ return mangle_content_len(skb, dataoff, dptr, datalen);
}
-static unsigned int ip_nat_sdp_session(struct sk_buff *skb, const char **dptr,
- unsigned int dataoff,
- unsigned int *datalen,
+static unsigned int ip_nat_sdp_session(struct sk_buff *skb, unsigned int dataoff,
+ const char **dptr, unsigned int *datalen,
+ unsigned int sdpoff,
const union nf_inet_addr *addr)
{
char buffer[sizeof("nnn.nnn.nnn.nnn")];
@@ -379,12 +418,12 @@ static unsigned int ip_nat_sdp_session(struct sk_buff *skb, const char **dptr,
/* Mangle session description owner and contact addresses */
buflen = sprintf(buffer, "%pI4", &addr->ip);
- if (mangle_sdp_packet(skb, dptr, dataoff, datalen,
+ if (mangle_sdp_packet(skb, dataoff, dptr, datalen, sdpoff,
SDP_HDR_OWNER_IP4, SDP_HDR_MEDIA,
buffer, buflen))
return 0;
- switch (mangle_sdp_packet(skb, dptr, dataoff, datalen,
+ switch (mangle_sdp_packet(skb, dataoff, dptr, datalen, sdpoff,
SDP_HDR_CONNECTION_IP4, SDP_HDR_MEDIA,
buffer, buflen)) {
case 0:
@@ -401,14 +440,13 @@ static unsigned int ip_nat_sdp_session(struct sk_buff *skb, const char **dptr,
return 0;
}
- return mangle_content_len(skb, dptr, datalen);
+ return mangle_content_len(skb, dataoff, dptr, datalen);
}
/* So, this packet has hit the connection tracking matching code.
Mangle it, and change the expectation to match the new version. */
-static unsigned int ip_nat_sdp_media(struct sk_buff *skb,
- const char **dptr,
- unsigned int *datalen,
+static unsigned int ip_nat_sdp_media(struct sk_buff *skb, unsigned int dataoff,
+ const char **dptr, unsigned int *datalen,
struct nf_conntrack_expect *rtp_exp,
struct nf_conntrack_expect *rtcp_exp,
unsigned int mediaoff,
@@ -456,7 +494,8 @@ static unsigned int ip_nat_sdp_media(struct sk_buff *skb,
/* Update media port. */
if (rtp_exp->tuple.dst.u.udp.port != rtp_exp->saved_proto.udp.port &&
- !ip_nat_sdp_port(skb, dptr, datalen, mediaoff, medialen, port))
+ !ip_nat_sdp_port(skb, dataoff, dptr, datalen,
+ mediaoff, medialen, port))
goto err2;
return NF_ACCEPT;
@@ -471,6 +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);
@@ -482,12 +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);
generated by cgit v1.2.3 (git 2.0.4) at 2024-05-11 19:00:47 +0000