source3/utils/smbfilter.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    SMB filter/socket plugin
   4    Copyright (C) Andrew Tridgell 1999
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 #include "module_dummy.h"
  24
  25 #define SECURITY_MASK 0
  26 #define SECURITY_SET  0
  27
  28 /* this forces non-unicode */
  29 #define CAPABILITY_MASK 0
  30 #define CAPABILITY_SET  0
  31
  32 /* and non-unicode for the client too */
  33 #define CLI_CAPABILITY_MASK 0
  34 #define CLI_CAPABILITY_SET  0
  35
  36 static char *netbiosname;
  37 static char packet[BUFFER_SIZE];
  38
  39 static void save_file(const char *fname, void *packet, size_t length)
  40 {
  41         int fd;
  42         fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0644);
  43         if (fd == -1) {
  44                 perror(fname);
  45                 return;
  46         }
  47         if (write(fd, packet, length) != length) {
  48                 fprintf(stderr,"Failed to write %s\n", fname);
  49                 return;
  50         }
  51         close(fd);
  52         printf("Wrote %d bytes to %s\n", length, fname);
  53 }
  54
  55 static void filter_reply(char *buf)
  56 {
  57         int msg_type = CVAL(buf,0);
  58         int type = CVAL(buf,smb_com);
  59         unsigned x;
  60
  61         if (msg_type) return;
  62
  63         switch (type) {
  64
  65         case SMBnegprot:
  66                 /* force the security bits */
  67                 x = CVAL(buf, smb_vwv1);
  68                 x = (x | SECURITY_SET) & ~SECURITY_MASK;
  69                 SCVAL(buf, smb_vwv1, x);
  70
  71                 /* force the capabilities */
  72                 x = IVAL(buf,smb_vwv9+1);
  73                 x = (x | CAPABILITY_SET) & ~CAPABILITY_MASK;
  74                 SIVAL(buf, smb_vwv9+1, x);
  75                 break;
  76
  77         }
  78 }
  79
  80 static void filter_request(char *buf)
  81 {
  82         int msg_type = CVAL(buf,0);
  83         int type = CVAL(buf,smb_com);
  84         pstring name1,name2;
  85         unsigned x;
  86
  87         if (msg_type) {
  88                 /* it's a netbios special */
  89                 switch (msg_type) {
  90                 case 0x81:
  91                         /* session request */
  92                         name_extract(buf,4,name1);
  93                         name_extract(buf,4 + name_len(buf + 4),name2);
  94                         d_printf("sesion_request: %s -> %s\n",
  95                                  name1, name2);
  96                         if (netbiosname) {
  97                                 /* replace the destination netbios name */
  98                                 name_mangle(netbiosname, buf+4, 0x20);
  99                         }
 100                 }
 101                 return;
 102         }
 103
 104         /* it's an ordinary SMB request */
 105         switch (type) {
 106         case SMBsesssetupX:
 107                 /* force the client capabilities */
 108                 x = IVAL(buf,smb_vwv11);
 109                 d_printf("SMBsesssetupX cap=0x%08x\n", x);
 110                 d_printf("pwlen=%d/%d\n", SVAL(buf, smb_vwv7), SVAL(buf, smb_vwv8));
 111                 system("mv sessionsetup.dat sessionsetup1.dat");
 112                 save_file("sessionsetup.dat", smb_buf(buf), SVAL(buf, smb_vwv7));
 113                 x = (x | CLI_CAPABILITY_SET) & ~CLI_CAPABILITY_MASK;
 114                 SIVAL(buf, smb_vwv11, x);
 115                 break;
 116         }
 117
 118 }
 119
 120
 121 static void filter_child(int c, struct in_addr dest_ip)
 122 {
 123         int s;
 124
 125         /* we have a connection from a new client, now connect to the server */
 126         s = open_socket_out(SOCK_STREAM, &dest_ip, 445, LONG_CONNECT_TIMEOUT);
 127
 128         if (s == -1) {
 129                 d_printf("Unable to connect to %s\n", inet_ntoa(dest_ip));
 130                 exit(1);
 131         }
 132
 133         while (c != -1 || s != -1) {
 134                 fd_set fds;
 135                 int num;
 136
 137                 FD_ZERO(&fds);
 138                 if (s != -1) FD_SET(s, &fds);
 139                 if (c != -1) FD_SET(c, &fds);
 140
 141                 num = sys_select_intr(MAX(s+1, c+1),&fds,NULL,NULL,NULL);
 142                 if (num <= 0) continue;
 143
 144                 if (c != -1 && FD_ISSET(c, &fds)) {
 145                         if (!receive_smb(c, packet, 0)) {
 146                                 d_printf("client closed connection\n");
 147                                 exit(0);
 148                         }
 149                         filter_request(packet);
 150                         if (!send_smb(s, packet)) {
 151                                 d_printf("server is dead\n");
 152                                 exit(1);
 153                         }
 154                 }
 155                 if (s != -1 && FD_ISSET(s, &fds)) {
 156                         if (!receive_smb(s, packet, 0)) {
 157                                 d_printf("server closed connection\n");
 158                                 exit(0);
 159                         }
 160                         filter_reply(packet);
 161                         if (!send_smb(c, packet)) {
 162                                 d_printf("client is dead\n");
 163                                 exit(1);
 164                         }
 165                 }
 166         }
 167         d_printf("Connection closed\n");
 168         exit(0);
 169 }
 170
 171
 172 static void start_filter(char *desthost)
 173 {
 174         int s, c;
 175         struct in_addr dest_ip;
 176
 177         CatchChild();
 178
 179         /* start listening on port 445 locally */
 180         s = open_socket_in(SOCK_STREAM, 445, 0, 0, True);
 181
 182         if (s == -1) {
 183                 d_printf("bind failed\n");
 184                 exit(1);
 185         }
 186
 187         if (listen(s, 5) == -1) {
 188                 d_printf("listen failed\n");
 189         }
 190
 191         if (!resolve_name(desthost, &dest_ip, 0x20)) {
 192                 d_printf("Unable to resolve host %s\n", desthost);
 193                 exit(1);
 194         }
 195
 196         while (1) {
 197                 fd_set fds;
 198                 int num;
 199                 struct sockaddr addr;
 200                 socklen_t in_addrlen = sizeof(addr);
 201
 202                 FD_ZERO(&fds);
 203                 FD_SET(s, &fds);
 204
 205                 num = sys_select_intr(s+1,&fds,NULL,NULL,NULL);
 206                 if (num > 0) {
 207                         c = accept(s, &addr, &in_addrlen);
 208                         if (c != -1) {
 209                                 if (fork() == 0) {
 210                                         close(s);
 211                                         filter_child(c, dest_ip);
 212                                         exit(0);
 213                                 } else {
 214                                         close(c);
 215                                 }
 216                         }
 217                 }
 218         }
 219 }
 220
 221
 222 int main(int argc, char *argv[])
 223 {
 224         char *desthost;
 225         pstring configfile;
 226
 227         setup_logging(argv[0],True);
 228
 229         pstrcpy(configfile,dyn_CONFIGFILE);
 230
 231         if (argc < 2) {
 232                 fprintf(stderr,"smbfilter <desthost> <netbiosname>\n");
 233                 exit(1);
 234         }
 235
 236         desthost = argv[1];
 237         if (argc > 2) {
 238                 netbiosname = argv[2];
 239         }
 240
 241         if (!lp_load(configfile,True,False,False)) {
 242                 d_printf("Unable to load config file\n");
 243         }
 244
 245         start_filter(desthost);
 246         return 0;
 247 }