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 #include "smb.h"
  23
  24 #define SECURITY_MASK 0
  25 #define SECURITY_SET  0
  26
  27 /* this forces non-unicode */
  28 #define CAPABILITY_MASK 0
  29 #define CAPABILITY_SET  0
  30
  31 /* and non-unicode for the client too */
  32 #define CLI_CAPABILITY_MASK 0
  33 #define CLI_CAPABILITY_SET  0
  34
  35 static char *netbiosname;
  36 static char packet[BUFFER_SIZE];
  37
  38 static void save_file(const char *fname, void *packet, size_t length)
  39 {
  40         int fd;
  41         fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0644);
  42         if (fd == -1) {
  43                 perror(fname);
  44                 return;
  45         }
  46         if (write(fd, packet, length) != length) {
  47                 fprintf(stderr,"Failed to write %s\n", fname);
  48                 return;
  49         }
  50         close(fd);
  51         printf("Wrote %d bytes to %s\n", length, fname);
  52 }
  53
  54 static void filter_reply(char *buf)
  55 {
  56         int msg_type = CVAL(buf,0);
  57         int type = CVAL(buf,smb_com);
  58         unsigned x;
  59
  60         if (msg_type) return;
  61
  62         switch (type) {
  63
  64         case SMBnegprot:
  65                 /* force the security bits */
  66                 x = CVAL(buf, smb_vwv1);
  67                 x = (x | SECURITY_SET) & ~SECURITY_MASK;
  68                 SCVAL(buf, smb_vwv1, x);
  69
  70                 /* force the capabilities */
  71                 x = IVAL(buf,smb_vwv9+1);
  72                 x = (x | CAPABILITY_SET) & ~CAPABILITY_MASK;
  73                 SIVAL(buf, smb_vwv9+1, x);
  74                 break;
  75
  76         }
  77 }
  78
  79 static void filter_request(char *buf)
  80 {
  81         int msg_type = CVAL(buf,0);
  82         int type = CVAL(buf,smb_com);
  83         pstring name1,name2;
  84         unsigned x;
  85
  86         if (msg_type) {
  87                 /* it's a netbios special */
  88                 switch (msg_type) {
  89                 case 0x81:
  90                         /* session request */
  91                         name_extract(buf,4,name1);
  92                         name_extract(buf,4 + name_len(buf + 4),name2);
  93                         d_printf("sesion_request: %s -> %s\n",
  94                                  name1, name2);
  95                         if (netbiosname) {
  96                                 /* replace the destination netbios name */
  97                                 name_mangle(netbiosname, buf+4, 0x20);
  98                         }
  99                 }
 100                 return;
 101         }
 102
 103         /* it's an ordinary SMB request */
 104         switch (type) {
 105         case SMBsesssetupX:
 106                 /* force the client capabilities */
 107                 x = IVAL(buf,smb_vwv11);
 108                 d_printf("SMBsesssetupX cap=0x%08x\n", x);
 109                 d_printf("pwlen=%d/%d\n", SVAL(buf, smb_vwv7), SVAL(buf, smb_vwv8));
 110                 system("mv sessionsetup.dat sessionsetup1.dat");
 111                 save_file("sessionsetup.dat", smb_buf(buf), SVAL(buf, smb_vwv7));
 112                 x = (x | CLI_CAPABILITY_SET) & ~CLI_CAPABILITY_MASK;
 113                 SIVAL(buf, smb_vwv11, x);
 114                 break;
 115         }
 116
 117 }
 118
 119
 120 static void filter_child(int c, struct in_addr dest_ip)
 121 {
 122         int s;
 123
 124         /* we have a connection from a new client, now connect to the server */
 125         s = open_socket_out(SOCK_STREAM, &dest_ip, 445, LONG_CONNECT_TIMEOUT);
 126
 127         if (s == -1) {
 128                 d_printf("Unable to connect to %s\n", inet_ntoa(dest_ip));
 129                 exit(1);
 130         }
 131
 132         while (c != -1 || s != -1) {
 133                 fd_set fds;
 134                 int num;
 135
 136                 FD_ZERO(&fds);
 137                 if (s != -1) FD_SET(s, &fds);
 138                 if (c != -1) FD_SET(c, &fds);
 139
 140                 num = sys_select_intr(MAX(s+1, c+1),&fds,NULL);
 141                 if (num <= 0) continue;
 142
 143                 if (c != -1 && FD_ISSET(c, &fds)) {
 144                         if (!receive_smb(c, packet, 0)) {
 145                                 d_printf("client closed connection\n");
 146                                 exit(0);
 147                         }
 148                         filter_request(packet);
 149                         if (!send_smb(s, packet)) {
 150                                 d_printf("server is dead\n");
 151                                 exit(1);
 152                         }
 153                 }
 154                 if (s != -1 && FD_ISSET(s, &fds)) {
 155                         if (!receive_smb(s, packet, 0)) {
 156                                 d_printf("server closed connection\n");
 157                                 exit(0);
 158                         }
 159                         filter_reply(packet);
 160                         if (!send_smb(c, packet)) {
 161                                 d_printf("client is dead\n");
 162                                 exit(1);
 163                         }
 164                 }
 165         }
 166         d_printf("Connection closed\n");
 167         exit(0);
 168 }
 169
 170
 171 static void start_filter(char *desthost)
 172 {
 173         int s, c;
 174         struct in_addr dest_ip;
 175
 176         CatchChild();
 177
 178         /* start listening on port 445 locally */
 179         s = open_socket_in(SOCK_STREAM, 445, 0, 0, True);
 180
 181         if (s == -1) {
 182                 d_printf("bind failed\n");
 183                 exit(1);
 184         }
 185
 186         if (listen(s, 5) == -1) {
 187                 d_printf("listen failed\n");
 188         }
 189
 190         if (!resolve_name(desthost, &dest_ip, 0x20)) {
 191                 d_printf("Unable to resolve host %s\n", desthost);
 192                 exit(1);
 193         }
 194
 195         while (1) {
 196                 fd_set fds;
 197                 int num;
 198                 struct sockaddr addr;
 199                 socklen_t in_addrlen = sizeof(addr);
 200
 201                 FD_ZERO(&fds);
 202                 FD_SET(s, &fds);
 203
 204                 num = sys_select_intr(s+1,&fds,NULL);
 205                 if (num > 0) {
 206                         c = accept(s, &addr, &in_addrlen);
 207                         if (c != -1) {
 208                                 if (fork() == 0) {
 209                                         close(s);
 210                                         filter_child(c, dest_ip);
 211                                         exit(0);
 212                                 } else {
 213                                         close(c);
 214                                 }
 215                         }
 216                 }
 217         }
 218 }
 219
 220
 221 int main(int argc, char *argv[])
 222 {
 223         char *desthost;
 224         pstring configfile;
 225
 226         setup_logging(argv[0],True);
 227
 228         pstrcpy(configfile,dyn_CONFIGFILE);
 229
 230         if (argc < 2) {
 231                 fprintf(stderr,"smbfilter <desthost> <netbiosname>\n");
 232                 exit(1);
 233         }
 234
 235         desthost = argv[1];
 236         if (argc > 2) {
 237                 netbiosname = argv[2];
 238         }
 239
 240         if (!lp_load(configfile,True,False,False)) {
 241                 d_printf("Unable to load config file\n");
 242         }
 243
 244         start_filter(desthost);
 245         return 0;
 246 }