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/*
Unix SMB/Netbios implementation.
Version 2
SMB filter/socket plugin
Copyright (C) Andrew Tridgell 1999
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
#include "smb.h"
#define SECURITY_MASK 0
#define SECURITY_SET 0
/* this forces non-unicode */
#define CAPABILITY_MASK CAP_UNICODE
#define CAPABILITY_SET 0
/* and non-unicode for the client too */
#define CLI_CAPABILITY_MASK CAP_UNICODE
#define CLI_CAPABILITY_SET 0
static char *netbiosname;
static char packet[BUFFER_SIZE];
extern int DEBUGLEVEL;
static void filter_reply(char *buf)
{
int msg_type = CVAL(buf,0);
int type = CVAL(buf,smb_com);
unsigned x;
if (msg_type) return;
switch (type) {
case SMBnegprot:
/* force the security bits */
x = CVAL(buf, smb_vwv1);
x = (x | SECURITY_SET) & ~SECURITY_MASK;
SCVAL(buf, smb_vwv1, x);
/* force the capabilities */
x = IVAL(buf,smb_vwv9+1);
x = (x | CAPABILITY_SET) & ~CAPABILITY_MASK;
SIVAL(buf, smb_vwv9+1, x);
break;
}
}
static void filter_request(char *buf)
{
int msg_type = CVAL(buf,0);
int type = CVAL(buf,smb_com);
pstring name1,name2;
unsigned x;
if (msg_type) {
/* it's a netbios special */
switch (msg_type) {
case 0x81:
/* session request */
name_extract(buf,4,name1);
name_extract(buf,4 + name_len(buf + 4),name2);
DEBUG(0,("sesion_request: %s -> %s\n",
name1, name2));
if (netbiosname) {
/* replace the destination netbios name */
name_mangle(netbiosname, buf+4, 0x20);
}
}
return;
}
/* it's an ordinary SMB request */
switch (type) {
case SMBsesssetupX:
/* force the client capabilities */
x = IVAL(buf,smb_vwv11);
x = (x | CLI_CAPABILITY_SET) & ~CLI_CAPABILITY_MASK;
SIVAL(buf, smb_vwv11, x);
break;
}
}
static void filter_child(int c, struct in_addr dest_ip)
{
int s;
/* we have a connection from a new client, now connect to the server */
s = open_socket_out(SOCK_STREAM, &dest_ip, 139, LONG_CONNECT_TIMEOUT);
if (s == -1) {
DEBUG(0,("Unable to connect to %s\n", inet_ntoa(dest_ip)));
exit(1);
}
while (c != -1 || s != -1) {
fd_set fds;
int num;
FD_ZERO(&fds);
if (s != -1) FD_SET(s, &fds);
if (c != -1) FD_SET(c, &fds);
num = sys_select(MAX(s+1, c+1),&fds,NULL);
if (num <= 0) continue;
if (c != -1 && FD_ISSET(c, &fds)) {
if (!receive_smb(c, packet, 0)) {
DEBUG(0,("client closed connection\n"));
exit(0);
}
filter_request(packet);
if (!send_smb(s, packet)) {
DEBUG(0,("server is dead\n"));
exit(1);
}
}
if (s != -1 && FD_ISSET(s, &fds)) {
if (!receive_smb(s, packet, 0)) {
DEBUG(0,("server closed connection\n"));
exit(0);
}
filter_reply(packet);
if (!send_smb(c, packet)) {
DEBUG(0,("client is dead\n"));
exit(1);
}
}
}
DEBUG(0,("Connection closed\n"));
exit(0);
}
static void start_filter(char *desthost)
{
int s, c;
struct in_addr dest_ip;
CatchChild();
/* start listening on port 139 locally */
s = open_socket_in(SOCK_STREAM, 139, 0, 0, True);
if (s == -1) {
DEBUG(0,("bind failed\n"));
exit(1);
}
if (listen(s, 5) == -1) {
DEBUG(0,("listen failed\n"));
}
if (!resolve_name(desthost, &dest_ip, 0x20)) {
DEBUG(0,("Unable to resolve host %s\n", desthost));
exit(1);
}
while (1) {
fd_set fds;
int num;
struct sockaddr addr;
int in_addrlen = sizeof(addr);
FD_ZERO(&fds);
FD_SET(s, &fds);
num = sys_select(s+1,&fds,NULL);
if (num > 0) {
c = accept(s, &addr, &in_addrlen);
if (c != -1) {
if (fork() == 0) {
close(s);
filter_child(c, dest_ip);
exit(0);
} else {
close(c);
}
}
}
}
}
int main(int argc, char *argv[])
{
char *desthost;
pstring configfile;
TimeInit();
setup_logging(argv[0],True);
charset_initialise();
pstrcpy(configfile,CONFIGFILE);
if (argc < 2) {
fprintf(stderr,"smbfilter <desthost> <netbiosname>\n");
exit(1);
}
desthost = argv[1];
if (argc > 2) {
netbiosname = argv[2];
}
if (!lp_load(configfile,True,False,False)) {
DEBUG(0,("Unable to load config file\n"));
}
start_filter(desthost);
return 0;
}
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