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