static int map_addr(struct sk_buff *skb, unsigned int protoff,
unsigned int dataoff,
const char **dptr, unsigned int *datalen,
unsigned int matchoff, unsigned int matchlen,
union nf_inet_addr *addr, __be16 port)
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
char buffer[INET6_ADDRSTRLEN + sizeof("[]:nnnnn")];
unsigned int buflen;
union nf_inet_addr newaddr;
__be16 newport;
if (nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, addr) &&
ct->tuplehash[dir].tuple.src.u.udp.port == port) {
newaddr = ct->tuplehash[!dir].tuple.dst.u3;
newport = ct->tuplehash[!dir].tuple.dst.u.udp.port;
} else if (nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, addr) &&
ct->tuplehash[dir].tuple.dst.u.udp.port == port) {
newaddr = ct->tuplehash[!dir].tuple.src.u3;
newport = ct->tuplehash[!dir].tuple.src.u.udp.port;
} else
return 1;
if (nf_inet_addr_cmp(&newaddr, addr) && newport == port)
return 1;
buflen = sip_sprintf_addr_port(ct, buffer, &newaddr, ntohs(newport));
return mangle_packet(skb, protoff, dataoff, dptr, datalen,
matchoff, matchlen, buffer, buflen);
}
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)
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
unsigned int buflen;
__be32 newaddr;
__be16 newport;
if (ct->tuplehash[dir].tuple.src.u3.ip == addr->ip &&
ct->tuplehash[dir].tuple.src.u.udp.port == port) {
newaddr = ct->tuplehash[!dir].tuple.dst.u3.ip;
newport = ct->tuplehash[!dir].tuple.dst.u.udp.port;
} else if (ct->tuplehash[dir].tuple.dst.u3.ip == addr->ip &&
ct->tuplehash[dir].tuple.dst.u.udp.port == port) {
newaddr = ct->tuplehash[!dir].tuple.src.u3.ip;
newport = ct->tuplehash[!dir].tuple.src.u.udp.port;
} else
return 1;
if (newaddr == addr->ip && newport == port)
return 1;
buflen = sprintf(buffer, "%pI4:%u", &newaddr, ntohs(newport));
return mangle_packet(skb, dataoff, dptr, datalen, matchoff, matchlen,
buffer, buflen);
}
static int mangle_content_len(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);
unsigned int matchoff, matchlen;
char buffer[sizeof("65536")];
int buflen, c_len;
/* Get actual SDP length */
if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen,
SDP_HDR_VERSION, SDP_HDR_UNSPEC,
&matchoff, &matchlen) <= 0)
return 0;
c_len = *datalen - matchoff + strlen("v=");
/* Now, update SDP length */
if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CONTENT_LENGTH,
&matchoff, &matchlen) <= 0)
return 0;
buflen = sprintf(buffer, "%u", c_len);
return mangle_packet(skb, dataoff, dptr, datalen, matchoff, matchlen,
buffer, buflen);
}
static int talk_help_msg(struct ip_conntrack *ct,
struct sk_buff **pskb,
u_char type,
struct talk_addr *addr,
struct talk_addr *ctl_addr)
{
u_int32_t newip;
u_int16_t port;
unsigned int verdict = NF_ACCEPT;
DEBUGP("ip_nat_talk_help_msg: addr: %u.%u.%u.%u:%u, ctl_addr: %u.%u.%u.%u:%u, type %d\n",
NIPQUAD(addr->ta_addr), ntohs(addr->ta_port),
NIPQUAD(ctl_addr->ta_addr), ntohs(ctl_addr->ta_port),
type);
/* Change address inside packet to match way we're mapping
this connection. */
newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
port = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.udp.port;
DEBUGP("ip_nat_talk_help_msg: inserting: %u.%u.%u.%u:%u\n",
NIPQUAD(newip), ntohs(port));
if (!mangle_packet(pskb, ct, newip, port, addr, ctl_addr))
verdict = NF_DROP;
return verdict;
}
static int talk_help_response(struct ip_conntrack *ct,
struct ip_conntrack_expect *exp,
struct sk_buff **pskb,
u_char type,
u_char answer,
struct talk_addr *addr)
{
u_int32_t newip;
u_int16_t port;
struct ip_conntrack_tuple t;
struct ip_ct_talk_expect *ct_talk_info;
DEBUGP("ip_nat_talk_help_response: addr: %u.%u.%u.%u:%u, type %d answer %d\n",
NIPQUAD(addr->ta_addr), ntohs(addr->ta_port),
type, answer);
LOCK_BH(&ip_talk_lock);
ct_talk_info = &exp->help.exp_talk_info;
if (!(answer == SUCCESS
&& (type == LOOK_UP || type == ANNOUNCE)
&& exp != NULL)) {
UNLOCK_BH(&ip_talk_lock);
return NF_ACCEPT;
}
DEBUGP("ip_nat_talk_help_response: talkinfo port %u (%s)\n",
ntohs(ct_talk_info->port),
type == LOOK_UP ? "LOOK_UP" : "ANNOUNCE");
/* Change address inside packet to match way we're mapping
this connection. */
newip = ct->tuplehash[type == LOOK_UP ? IP_CT_DIR_ORIGINAL :
IP_CT_DIR_REPLY].tuple.dst.ip;
/* We can read expect here without conntrack lock, since it's
only set in ip_conntrack_talk , with ip_talk_lock held
writable */
t = exp->tuple;
t.dst.ip = newip;
/* Try to get same port: if not, try to change it. */
for (port = ntohs(ct_talk_info->port); port != 0; port++) {
if (type == LOOK_UP)
t.dst.u.tcp.port = htons(port);
else
t.dst.u.udp.port = htons(port);
if (ip_conntrack_change_expect(exp, &t) == 0) {
DEBUGP("ip_nat_talk_help_response: using %u.%u.%u.%u:%u\n", NIPQUAD(newip), port);
break;
}
}
UNLOCK_BH(&ip_talk_lock);
if (port == 0 || !mangle_packet(pskb, ct, newip, htons(port), addr, NULL))
return NF_DROP;
return NF_ACCEPT;
}
static unsigned int ip_nat_sip_expect(struct sk_buff *skb,
const char **dptr, unsigned int *datalen,
struct nf_conntrack_expect *exp,
unsigned int matchoff,
unsigned int matchlen)
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
__be32 newip;
u_int16_t port;
char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
unsigned buflen;
/* Connection will come from reply */
if (ct->tuplehash[dir].tuple.src.u3.ip == ct->tuplehash[!dir].tuple.dst.u3.ip)
newip = exp->tuple.dst.u3.ip;
else
newip = ct->tuplehash[!dir].tuple.dst.u3.ip;
/* If the signalling port matches the connection's source port in the
* original direction, try to use the destination port in the opposite
* direction. */
if (exp->tuple.dst.u.udp.port ==
ct->tuplehash[dir].tuple.src.u.udp.port)
port = ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port);
else
port = ntohs(exp->tuple.dst.u.udp.port);
exp->saved_ip = exp->tuple.dst.u3.ip;
exp->tuple.dst.u3.ip = newip;
exp->saved_proto.udp.port = exp->tuple.dst.u.udp.port;
exp->dir = !dir;
exp->expectfn = ip_nat_sip_expected;
for (; port != 0; port++) {
exp->tuple.dst.u.udp.port = htons(port);
if (nf_ct_expect_related(exp) == 0)
break;
}
if (port == 0)
return NF_DROP;
if (exp->tuple.dst.u3.ip != exp->saved_ip ||
exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port) {
buflen = sprintf(buffer, "%u.%u.%u.%u:%u",
NIPQUAD(newip), port);
if (!mangle_packet(skb, dptr, datalen, matchoff, matchlen,
buffer, buflen))
goto err;
}
return NF_ACCEPT;
err:
nf_ct_unexpect_related(exp);
return NF_DROP;
}
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)
{
char buffer[sizeof("nnnnn")];
unsigned int buflen;
buflen = sprintf(buffer, "%u", port);
if (!mangle_packet(skb, dataoff, dptr, datalen, matchoff, matchlen,
buffer, buflen))
return 0;
return mangle_content_len(skb, dataoff, dptr, datalen);
}
static unsigned mangle_sdp_packet(struct sk_buff *skb, const char **dptr,
unsigned int dataoff, unsigned int *datalen,
enum sdp_header_types type,
enum sdp_header_types term,
char *buffer, int buflen)
{
enum ip_conntrack_info ctinfo;
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,
&matchoff, &matchlen) <= 0)
return 0;
return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
buffer, buflen);
}
static int sc_data_fixup(const struct ip_ct_sc_expect *exp_sc_info,
struct ip_conntrack *ct,
unsigned int datalen,
struct sk_buff **pskb,
enum ip_conntrack_info ctinfo)
{
u_int32_t newip;
struct iphdr *iph = (*pskb)->nh.iph;
struct tcphdr *tcph = (void *)iph + iph->ihl*4;
u_int16_t port, new_port;
struct ip_conntrack_tuple tuple;
struct sc_ip_port_data *list_t=sc_list;
int ret=0;
/* Don't care about source port */
const struct ip_conntrack_tuple mask
= { { 0xFFFFFFFF, { 0xFFFFFFFF } },
{ 0x0, { 0xFFFF }, 0xFFFF } };
memset(&tuple, 0, sizeof(tuple));
MUST_BE_LOCKED(&ip_sc_lock);
#if 0
DEBUGP("SC_NAT: seq %u + %u in %u + %u\n",
exp_sc_info->seq, exp_sc_info->len, ntohl(tcph->seq), datalen);
#endif
/* Change address inside packet to match way we're mapping
this connection. */
newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
DEBUGP("sc_data_fixup: %u.%u.%u.%u->%u.%u.%u.%u\n", NIPQUAD(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip), NIPQUAD(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip));
/* Expect something from server->client */
tuple.src.ip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
tuple.dst.protonum = IPPROTO_UDP;
jiq_task.routine = open_sc_socket;
memset(task_data, 0, 64);
sprintf(task_data,"IP:%u.%u.%u.%uPORT:%dEND",NIPQUAD(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip), port);
jiq_task.data = (void *)task_data;
schedule_task(&jiq_task);
if (!mangle_packet(pskb, newip, exp_sc_info->seq - ntohl(tcph->seq), exp_sc_info->len, ct, ctinfo))
return 0;
return 1;
}
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_expect(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
struct nf_conntrack_expect *exp,
unsigned int matchoff,
unsigned int matchlen)
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
__be32 newip;
u_int16_t port;
char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
unsigned buflen;
if (ct->tuplehash[dir].tuple.src.u3.ip == ct->tuplehash[!dir].tuple.dst.u3.ip)
newip = exp->tuple.dst.u3.ip;
else
newip = ct->tuplehash[!dir].tuple.dst.u3.ip;
if (exp->tuple.dst.u.udp.port ==
ct->tuplehash[dir].tuple.src.u.udp.port)
port = ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port);
else
port = ntohs(exp->tuple.dst.u.udp.port);
exp->saved_ip = exp->tuple.dst.u3.ip;
exp->tuple.dst.u3.ip = newip;
exp->saved_proto.udp.port = exp->tuple.dst.u.udp.port;
exp->dir = !dir;
exp->expectfn = ip_nat_sip_expected;
for (; port != 0; port++) {
int ret;
exp->tuple.dst.u.udp.port = htons(port);
ret = nf_ct_expect_related(exp);
if (ret == 0)
break;
else if (ret != -EBUSY) {
port = 0;
break;
}
}
if (port == 0)
return NF_DROP;
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, dataoff, dptr, datalen,
matchoff, matchlen, buffer, buflen))
goto err;
}
return NF_ACCEPT;
err:
nf_ct_unexpect_related(exp);
return NF_DROP;
}
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;
}
static unsigned int nf_nat_sip_expect(struct sk_buff *skb, unsigned int protoff,
unsigned int dataoff,
const char **dptr, unsigned int *datalen,
struct nf_conntrack_expect *exp,
unsigned int matchoff,
unsigned int matchlen)
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
union nf_inet_addr newaddr;
u_int16_t port;
char buffer[INET6_ADDRSTRLEN + sizeof("[]:nnnnn")];
unsigned int buflen;
/* Connection will come from reply */
if (nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3,
&ct->tuplehash[!dir].tuple.dst.u3))
newaddr = exp->tuple.dst.u3;
else
newaddr = ct->tuplehash[!dir].tuple.dst.u3;
/* If the signalling port matches the connection's source port in the
* original direction, try to use the destination port in the opposite
* direction. */
if (exp->tuple.dst.u.udp.port ==
ct->tuplehash[dir].tuple.src.u.udp.port)
port = ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port);
else
port = ntohs(exp->tuple.dst.u.udp.port);
exp->saved_addr = exp->tuple.dst.u3;
exp->tuple.dst.u3 = newaddr;
exp->saved_proto.udp.port = exp->tuple.dst.u.udp.port;
exp->dir = !dir;
exp->expectfn = nf_nat_sip_expected;
for (; port != 0; port++) {
int ret;
exp->tuple.dst.u.udp.port = htons(port);
ret = nf_ct_expect_related(exp);
if (ret == 0)
break;
else if (ret != -EBUSY) {
port = 0;
break;
}
}
if (port == 0)
return NF_DROP;
if (!nf_inet_addr_cmp(&exp->tuple.dst.u3, &exp->saved_addr) ||
exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port) {
buflen = sip_sprintf_addr_port(ct, buffer, &newaddr, port);
if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
matchoff, matchlen, buffer, buflen))
goto err;
}
return NF_ACCEPT;
err:
nf_ct_unexpect_related(exp);
return NF_DROP;
}
