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 coff, matchoff, matchlen;
enum sip_header_types hdr;
union nf_inet_addr addr;
__be16 port;
int request, in_header;
/* Basic rules: requests and responses. */
if (strnicmp(*dptr, "SIP/2.0", strlen("SIP/2.0")) != 0) {
if (ct_sip_parse_request(ct, *dptr, *datalen,
&matchoff, &matchlen,
&addr, &port) > 0 &&
!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,
hdr, NULL, &matchoff, &matchlen,
&addr, &port) > 0) {
unsigned int matchend, poff, plen, buflen, n;
char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
/* We're only interested in headers related to this
* connection */
if (request) {
if (addr.ip != ct->tuplehash[dir].tuple.src.u3.ip ||
port != ct->tuplehash[dir].tuple.src.u.udp.port)
goto next;
} else {
if (addr.ip != ct->tuplehash[dir].tuple.dst.u3.ip ||
port != ct->tuplehash[dir].tuple.dst.u.udp.port)
goto next;
}
if (!map_addr(skb, dataoff, dptr, datalen, matchoff, matchlen,
&addr, port))
return NF_DROP;
matchend = matchoff + matchlen;
/* The maddr= parameter (RFC 2361) specifies where to send
* the reply. */
if (ct_sip_parse_address_param(ct, *dptr, matchend, *datalen,
"maddr=", &poff, &plen,
&addr) > 0 &&
addr.ip == ct->tuplehash[dir].tuple.src.u3.ip &&
addr.ip != ct->tuplehash[!dir].tuple.dst.u3.ip) {
buflen = sprintf(buffer, "%pI4",
&ct->tuplehash[!dir].tuple.dst.u3.ip);
if (!mangle_packet(skb, dataoff, dptr, datalen,
poff, plen, buffer, buflen))
return NF_DROP;
}
/* The received= parameter (RFC 2361) contains the address
* from which the server received the request. */
if (ct_sip_parse_address_param(ct, *dptr, matchend, *datalen,
"received=", &poff, &plen,
&addr) > 0 &&
addr.ip == ct->tuplehash[dir].tuple.dst.u3.ip &&
addr.ip != ct->tuplehash[!dir].tuple.src.u3.ip) {
buflen = sprintf(buffer, "%pI4",
&ct->tuplehash[!dir].tuple.src.u3.ip);
if (!mangle_packet(skb, dataoff, dptr, datalen,
poff, plen, buffer, buflen))
return NF_DROP;
}
/* The rport= parameter (RFC 3581) contains the port number
* from which the server received the request. */
if (ct_sip_parse_numerical_param(ct, *dptr, matchend, *datalen,
"rport=", &poff, &plen,
&n) > 0 &&
htons(n) == ct->tuplehash[dir].tuple.dst.u.udp.port &&
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, dataoff, dptr, datalen,
poff, plen, buffer, buflen))
return NF_DROP;
}
}
next:
/* Translate Contact headers */
coff = 0;
in_header = 0;
while (ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen,
SIP_HDR_CONTACT, &in_header,
&matchoff, &matchlen,
&addr, &port) > 0) {
if (!map_addr(skb, dataoff, dptr, datalen, matchoff, matchlen,
&addr, port))
return NF_DROP;
}
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 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 coff, matchoff, matchlen;
enum sip_header_types hdr;
union nf_inet_addr addr;
__be16 port;
int request, in_header;
if (strnicmp(*dptr, "SIP/2.0", strlen("SIP/2.0")) != 0) {
if (ct_sip_parse_request(ct, *dptr, *datalen,
&matchoff, &matchlen,
&addr, &port) > 0 &&
!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;
if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
hdr, NULL, &matchoff, &matchlen,
&addr, &port) > 0) {
unsigned int olen, matchend, poff, plen, buflen, n;
char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
if (request) {
if (addr.ip != ct->tuplehash[dir].tuple.src.u3.ip ||
port != ct->tuplehash[dir].tuple.src.u.udp.port)
goto next;
} else {
if (addr.ip != ct->tuplehash[dir].tuple.dst.u3.ip ||
port != ct->tuplehash[dir].tuple.dst.u.udp.port)
goto next;
}
olen = *datalen;
if (!map_addr(skb, dataoff, dptr, datalen, matchoff, matchlen,
&addr, port))
return NF_DROP;
matchend = matchoff + matchlen + *datalen - olen;
if (ct_sip_parse_address_param(ct, *dptr, matchend, *datalen,
"maddr=", &poff, &plen,
&addr) > 0 &&
addr.ip == ct->tuplehash[dir].tuple.src.u3.ip &&
addr.ip != ct->tuplehash[!dir].tuple.dst.u3.ip) {
buflen = sprintf(buffer, "%pI4",
&ct->tuplehash[!dir].tuple.dst.u3.ip);
if (!mangle_packet(skb, dataoff, dptr, datalen,
poff, plen, buffer, buflen))
return NF_DROP;
}
if (ct_sip_parse_address_param(ct, *dptr, matchend, *datalen,
"received=", &poff, &plen,
&addr) > 0 &&
addr.ip == ct->tuplehash[dir].tuple.dst.u3.ip &&
addr.ip != ct->tuplehash[!dir].tuple.src.u3.ip) {
buflen = sprintf(buffer, "%pI4",
&ct->tuplehash[!dir].tuple.src.u3.ip);
if (!mangle_packet(skb, dataoff, dptr, datalen,
poff, plen, buffer, buflen))
return NF_DROP;
}
if (ct_sip_parse_numerical_param(ct, *dptr, matchend, *datalen,
"rport=", &poff, &plen,
&n) > 0 &&
htons(n) == ct->tuplehash[dir].tuple.dst.u.udp.port &&
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, dataoff, dptr, datalen,
poff, plen, buffer, buflen))
return NF_DROP;
}
}
next:
coff = 0;
in_header = 0;
while (ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen,
SIP_HDR_CONTACT, &in_header,
&matchoff, &matchlen,
&addr, &port) > 0) {
if (!map_addr(skb, dataoff, dptr, datalen, matchoff, matchlen,
&addr, port))
return NF_DROP;
}
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;
}
