static unsigned int nf_nat_ftp(struct sk_buff *skb,
enum ip_conntrack_info ctinfo,
enum nf_ct_ftp_type type,
unsigned int matchoff,
unsigned int matchlen,
struct nf_conntrack_expect *exp)
{
__be32 newip;
u_int16_t port;
int dir = CTINFO2DIR(ctinfo);
struct nf_conn *ct = exp->master;
char buffer[sizeof("|1|255.255.255.255|65535|")];
unsigned int buflen;
pr_debug("FTP_NAT: type %i, off %u len %u\n", type, matchoff, matchlen);
/* */
newip = ct->tuplehash[!dir].tuple.dst.u3.ip;
exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
exp->dir = !dir;
/*
*/
exp->expectfn = nf_nat_follow_master;
/* */
for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
int ret;
exp->tuple.dst.u.tcp.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;
buflen = nf_nat_ftp_fmt_cmd(type, buffer, sizeof(buffer), newip, port);
if (!buflen)
goto out;
pr_debug("calling nf_nat_mangle_tcp_packet\n");
if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff,
matchlen, buffer, buflen))
goto out;
return NF_ACCEPT;
out:
nf_ct_unexpect_related(exp);
return NF_DROP;
}
/* So, this packet has hit the connection tracking matching code.
Mangle it, and change the expectation to match the new version. */
static unsigned int nf_nat_ftp(struct sk_buff *skb,
enum ip_conntrack_info ctinfo,
enum nf_ct_ftp_type type,
unsigned int matchoff,
unsigned int matchlen,
struct nf_conntrack_expect *exp)
{
__be32 newip;
u_int16_t port;
int dir = CTINFO2DIR(ctinfo);
struct nf_conn *ct = exp->master;
char buffer[sizeof("|1|255.255.255.255|65535|")];
unsigned int buflen;
pr_debug("FTP_NAT: type %i, off %u len %u\n", type, matchoff, matchlen);
/* Connection will come from wherever this packet goes, hence !dir */
newip = ct->tuplehash[!dir].tuple.dst.u3.ip;
exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
exp->dir = !dir;
/* When you see the packet, we need to NAT it the same as the
* this one. */
exp->expectfn = nf_nat_follow_master;
/* Try to get same port: if not, try to change it. */
for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
exp->tuple.dst.u.tcp.port = htons(port);
if (nf_ct_expect_related(exp) == 0)
break;
}
if (port == 0)
return NF_DROP;
buflen = nf_nat_ftp_fmt_cmd(type, buffer, sizeof(buffer), newip, port);
if (!buflen)
goto out;
pr_debug("calling nf_nat_mangle_tcp_packet\n");
if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff,
matchlen, buffer, buflen))
goto out;
return NF_ACCEPT;
out:
nf_ct_unexpect_related(exp);
return NF_DROP;
}
/* So, this packet has hit the connection tracking matching code.
Mangle it, and change the expectation to match the new version. */
static unsigned int nf_nat_ftp(struct sk_buff *skb,
enum ip_conntrack_info ctinfo,
enum nf_ct_ftp_type type,
unsigned int protoff,
unsigned int matchoff,
unsigned int matchlen,
struct nf_conntrack_expect *exp)
{
union nf_inet_addr newaddr;
u_int16_t port;
int dir = CTINFO2DIR(ctinfo);
struct nf_conn *ct = exp->master;
char buffer[sizeof("|1||65535|") + INET6_ADDRSTRLEN];
unsigned int buflen;
pr_debug("FTP_NAT: type %i, off %u len %u\n", type, matchoff, matchlen);
/* Connection will come from wherever this packet goes, hence !dir */
newaddr = ct->tuplehash[!dir].tuple.dst.u3;
exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
exp->dir = !dir;
/* When you see the packet, we need to NAT it the same as the
* this one. */
exp->expectfn = nf_nat_follow_master;
/* Try to get same port: if not, try to change it. */
for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
int ret;
exp->tuple.dst.u.tcp.port = htons(port);
ret = nf_ct_expect_related(exp);
if (ret == 0)
break;
else if (ret != -EBUSY) {
port = 0;
break;
}
}
if (port == 0) {
nf_ct_helper_log(skb, ct, "all ports in use");
return NF_DROP;
}
buflen = nf_nat_ftp_fmt_cmd(ct, type, buffer, sizeof(buffer),
&newaddr, port);
if (!buflen)
goto out;
pr_debug("calling nf_nat_mangle_tcp_packet\n");
if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, protoff, matchoff,
matchlen, buffer, buflen))
goto out;
return NF_ACCEPT;
out:
nf_ct_helper_log(skb, ct, "cannot mangle packet");
nf_ct_unexpect_related(exp);
return NF_DROP;
}
