int
masq_irc_out (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, struct device *dev)
{
struct sk_buff *skb;
struct iphdr *iph;
struct tcphdr *th;
char *data, *data_limit;
__u32 s_addr;
__u16 s_port;
struct ip_masq *n_ms;
char buf[20]; /* "m_addr m_port" (dec base)*/
unsigned buf_len;
int diff;
int xtra_args = 0; /* extra int args wanted after addr */
char *dcc_p, *addr_beg_p, *addr_end_p;
skb = *skb_p;
iph = skb->h.iph;
th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
data = (char *)&th[1];
/*
* Hunt irc DCC string, the _shortest_:
*
* strlen("DCC CHAT chat AAAAAAAA P\x01\n")=26
* strlen("DCC SEND F AAAAAAAA P S\x01\n")=25
* AAAAAAAAA: bound addr (1.0.0.0==16777216, min 8 digits)
* P: bound port (min 1 d )
* F: filename (min 1 d )
* S: size (min 1 d )
* 0x01, \n: terminators
*/
data_limit = skb->h.raw + skb->len;
while (data < (data_limit - 25) )
{
if (memcmp(data,"DCC ",4)) {
data ++;
continue;
}
dcc_p = data;
data += 4; /* point to DCC cmd */
if (memcmp(data, "CHAT ", 5) == 0 ||
memcmp(data, "SEND ", 5) == 0)
{
/*
* extra arg (file_size) req. for "SEND"
*/
if (*data == 'S') xtra_args++;
data += 5;
}
else
continue;
/*
* skip next string.
*/
while( *data++ != ' ')
/*
* must still parse, at least, "AAAAAAAA P\x01\n",
* 12 bytes left.
*/
if (data > (data_limit-12)) return 0;
addr_beg_p = data;
/*
* client bound address in dec base
*/
s_addr = simple_strtoul(data,&data,10);
if (*data++ !=' ')
continue;
/*
* client bound port in dec base
*/
s_port = simple_strtoul(data,&data,10);
addr_end_p = data;
/*
* should check args consistency?
*/
while(xtra_args) {
if (*data != ' ')
break;
data++;
simple_strtoul(data,&data,10);
xtra_args--;
}
if (xtra_args != 0) continue;
/*
* terminators.
*/
if (data[0] != 0x01)
continue;
if (data[1]!='\r' && data[1]!='\n')
continue;
/*
* Now create an masquerade entry for it
* must set NO_DPORT and NO_DADDR because
* connection is requested by another client.
*/
n_ms = ip_masq_new(dev, IPPROTO_TCP,
htonl(s_addr),htons(s_port),
0, 0,
IP_MASQ_F_NO_DPORT|IP_MASQ_F_NO_DADDR
);
if (n_ms==NULL)
return 0;
ip_masq_set_expire(n_ms, ip_masq_expire->tcp_fin_timeout);
/*
* Replace the old "address port" with the new one
*/
buf_len = sprintf(buf,"%lu %u",
ntohl(n_ms->maddr),ntohs(n_ms->mport));
/*
* Calculate required delta-offset to keep TCP happy
*/
diff = buf_len - (addr_end_p-addr_beg_p);
#if DEBUG_CONFIG_IP_MASQ_IRC
*addr_beg_p = '\0';
printk("masq_irc_out(): '%s' %X:%X detected (diff=%d)\n", dcc_p, s_addr,s_port, diff);
#endif
/*
* No shift.
*/
if (diff==0)
{
/*
* simple case, just copy.
*/
memcpy(addr_beg_p,buf,buf_len);
return 0;
}
*skb_p = ip_masq_skb_replace(skb, GFP_ATOMIC,
addr_beg_p, addr_end_p-addr_beg_p,
buf, buf_len);
return diff;
}
return 0;
}
int
masq_ftp_out (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, struct device *dev)
{
struct sk_buff *skb;
struct iphdr *iph;
struct tcphdr *th;
char *p, *data, *data_limit;
unsigned char p1,p2,p3,p4,p5,p6;
__u32 from;
__u16 port;
struct ip_masq *n_ms;
char buf[24]; /* xxx.xxx.xxx.xxx,ppp,ppp\000 */
unsigned buf_len;
int diff;
skb = *skb_p;
iph = skb->h.iph;
th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
data = (char *)&th[1];
data_limit = skb->h.raw + skb->len - 18;
if (skb->len >= 6 && (memcmp(data, "PASV\r\n", 6) == 0 || memcmp(data, "pasv\r\n", 6) == 0))
ms->flags |= IP_MASQ_F_FTP_PASV;
while (data < data_limit)
{
if (memcmp(data,"PORT ",5) && memcmp(data,"port ",5))
{
data ++;
continue;
}
p = data+5;
p1 = simple_strtoul(data+5,&data,10);
if (*data!=',')
continue;
p2 = simple_strtoul(data+1,&data,10);
if (*data!=',')
continue;
p3 = simple_strtoul(data+1,&data,10);
if (*data!=',')
continue;
p4 = simple_strtoul(data+1,&data,10);
if (*data!=',')
continue;
p5 = simple_strtoul(data+1,&data,10);
if (*data!=',')
continue;
p6 = simple_strtoul(data+1,&data,10);
if (*data!='\r' && *data!='\n')
continue;
from = (p1<<24) | (p2<<16) | (p3<<8) | p4;
port = (p5<<8) | p6;
#if DEBUG_CONFIG_IP_MASQ_FTP
printk("PORT %X:%X detected\n",from,port);
#endif
/*
* Now update or create an masquerade entry for it
*/
#if DEBUG_CONFIG_IP_MASQ_FTP
printk("protocol %d %lX:%X %X:%X\n", iph->protocol, htonl(from), htons(port), iph->daddr, 0);
#endif
n_ms = ip_masq_out_get_2(iph->protocol,
htonl(from), htons(port),
iph->daddr, 0);
if (n_ms) {
/* existing masquerade, clear timer */
ip_masq_set_expire(n_ms,0);
}
else {
n_ms = ip_masq_new(dev, IPPROTO_TCP,
htonl(from), htons(port),
iph->daddr, 0,
IP_MASQ_F_NO_DPORT);
if (n_ms==NULL)
return 0;
n_ms->control = ms; /* keepalive from data to the control channel */
ms->flags |= IP_MASQ_F_CONTROL; /* this is a control channel */
}
/*
* keep for a bit longer than tcp_fin, caller may not reissue
* PORT before tcp_fin_timeout.
*/
ip_masq_set_expire(n_ms, ip_masq_expire->tcp_fin_timeout*3);
/*
* Replace the old PORT with the new one
*/
from = ntohl(n_ms->maddr);
port = ntohs(n_ms->mport);
sprintf(buf,"%d,%d,%d,%d,%d,%d",
from>>24&255,from>>16&255,from>>8&255,from&255,
port>>8&255,port&255);
buf_len = strlen(buf);
#if DEBUG_CONFIG_IP_MASQ_FTP
printk("new PORT %X:%X\n",from,port);
#endif
/*
* Calculate required delta-offset to keep TCP happy
*/
diff = buf_len - (data-p);
/*
* No shift.
*/
if (diff==0)
{
/*
* simple case, just replace the old PORT cmd
*/
memcpy(p,buf,buf_len);
return 0;
}
*skb_p = ip_masq_skb_replace(skb, GFP_ATOMIC, p, data-p, buf, buf_len);
return diff;
}
return 0;
}
int
masq_ftp_out (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, __u32 maddr)
{
struct sk_buff *skb;
struct iphdr *iph;
struct tcphdr *th;
char *p, *data, *data_limit;
unsigned char p1,p2,p3,p4,p5,p6;
__u32 from;
__u16 port;
struct ip_masq *n_ms;
char buf[24]; /* xxx.xxx.xxx.xxx,ppp,ppp\000 */
unsigned buf_len;
int diff;
skb = *skb_p;
iph = skb->nh.iph;
th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
data = (char *)&th[1];
data_limit = skb->h.raw + skb->len - 18;
if (skb->len >= 6 && (memcmp(data, "PASV\r\n", 6) == 0 || memcmp(data, "pasv\r\n", 6) == 0))
ms->app_data = &masq_ftp_pasv;
while (data < data_limit)
{
if (memcmp(data,"PORT ",5) && memcmp(data,"port ",5))
{
data ++;
continue;
}
p = data+5;
p1 = simple_strtoul(data+5,&data,10);
if (*data!=',')
continue;
p2 = simple_strtoul(data+1,&data,10);
if (*data!=',')
continue;
p3 = simple_strtoul(data+1,&data,10);
if (*data!=',')
continue;
p4 = simple_strtoul(data+1,&data,10);
if (*data!=',')
continue;
p5 = simple_strtoul(data+1,&data,10);
if (*data!=',')
continue;
p6 = simple_strtoul(data+1,&data,10);
if (*data!='\r' && *data!='\n')
continue;
from = (p1<<24) | (p2<<16) | (p3<<8) | p4;
port = (p5<<8) | p6;
IP_MASQ_DEBUG(1-debug, "PORT %X:%X detected\n",from,port);
/*
* Now update or create an masquerade entry for it
*/
IP_MASQ_DEBUG(1-debug, "protocol %d %lX:%X %X:%X\n", iph->protocol, htonl(from), htons(port), iph->daddr, 0);
n_ms = ip_masq_out_get(iph->protocol,
htonl(from), htons(port),
iph->daddr, 0);
if (!n_ms) {
n_ms = ip_masq_new(IPPROTO_TCP,
maddr, 0,
htonl(from), htons(port),
iph->daddr, 0,
IP_MASQ_F_NO_DPORT);
if (n_ms==NULL)
return 0;
ip_masq_control_add(n_ms, ms);
}
/*
* Replace the old PORT with the new one
*/
from = ntohl(n_ms->maddr);
port = ntohs(n_ms->mport);
sprintf(buf,"%d,%d,%d,%d,%d,%d",
from>>24&255,from>>16&255,from>>8&255,from&255,
port>>8&255,port&255);
buf_len = strlen(buf);
IP_MASQ_DEBUG(1-debug, "new PORT %X:%X\n",from,port);
/*
* Calculate required delta-offset to keep TCP happy
*/
diff = buf_len - (data-p);
/*
* No shift.
*/
if (diff==0) {
/*
* simple case, just replace the old PORT cmd
*/
memcpy(p,buf,buf_len);
} else {
*skb_p = ip_masq_skb_replace(skb, GFP_ATOMIC, p, data-p, buf, buf_len);
}
/*
* Move tunnel to listen state
*/
ip_masq_listen(n_ms);
ip_masq_put(n_ms);
return diff;
}
return 0;
}
int
masq_irc_out (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, __u32 maddr)
{
struct sk_buff *skb;
struct iphdr *iph;
struct tcphdr *th;
char *data, *data_limit;
__u32 s_addr;
__u16 s_port;
struct ip_masq *n_ms;
char buf[20]; /* "m_addr m_port" (dec base)*/
unsigned buf_len;
int diff;
char *dcc_p, *addr_beg_p, *addr_end_p;
skb = *skb_p;
iph = skb->nh.iph;
th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
data = (char *)&th[1];
/*
* Hunt irc DCC string, the _shortest_:
*
* strlen("\1DCC CHAT chat AAAAAAAA P\1\n")=27
* strlen("\1DCC SCHAT chat AAAAAAAA P\1\n")=28
* strlen("\1DCC SEND F AAAAAAAA P S\1\n")=26
* strlen("\1DCC MOVE F AAAAAAAA P S\1\n")=26
* strlen("\1DCC TSEND F AAAAAAAA P S\1\n")=27
* AAAAAAAAA: bound addr (1.0.0.0==16777216, min 8 digits)
* P: bound port (min 1 d )
* F: filename (min 1 d )
* S: size (min 1 d )
* 0x01, \n: terminators
*/
data_limit = skb->h.raw + skb->len;
while (data < (data_limit - ( 22 + MAXMATCHLEN ) ) )
{
int i;
if (memcmp(data,"\1DCC ",5)) {
data ++;
continue;
}
dcc_p = data;
data += 5; /* point to DCC cmd */
for(i=0; i<NUM_DCCPROTO; i++)
{
/*
* go through the table and hunt a match string
*/
if( memcmp(data, dccprotos[i].match, dccprotos[i].matchlen ) == 0 )
{
data += dccprotos[i].matchlen;
/*
* skip next string.
*/
while( *data++ != ' ')
/*
* must still parse, at least, "AAAAAAAA P\1\n",
* 12 bytes left.
*/
if (data > (data_limit-12)) return 0;
addr_beg_p = data;
/*
* client bound address in dec base
*/
s_addr = simple_strtoul(data,&data,10);
if (*data++ !=' ')
continue;
/*
* client bound port in dec base
*/
s_port = simple_strtoul(data,&data,10);
addr_end_p = data;
/*
* Now create an masquerade entry for it
* must set NO_DPORT and NO_DADDR because
* connection is requested by another client.
*/
n_ms = ip_masq_new(IPPROTO_TCP,
maddr, 0,
htonl(s_addr),htons(s_port),
0, 0,
IP_MASQ_F_NO_DPORT|IP_MASQ_F_NO_DADDR);
if (n_ms==NULL)
return 0;
/*
* Replace the old "address port" with the new one
*/
buf_len = sprintf(buf,"%lu %u",
ntohl(n_ms->maddr),ntohs(n_ms->mport));
/*
* Calculate required delta-offset to keep TCP happy
*/
diff = buf_len - (addr_end_p-addr_beg_p);
*addr_beg_p = '\0';
IP_MASQ_DEBUG(1-debug, "masq_irc_out(): '%s' %X:%X detected (diff=%d)\n", dcc_p, s_addr,s_port, diff);
/*
* No shift.
*/
if (diff==0) {
/*
* simple case, just copy.
*/
memcpy(addr_beg_p,buf,buf_len);
} else {
*skb_p = ip_masq_skb_replace(skb, GFP_ATOMIC,
addr_beg_p, addr_end_p-addr_beg_p,
buf, buf_len);
}
ip_masq_listen(n_ms);
ip_masq_put(n_ms);
return diff;
}
}
}
return 0;
}
