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 3 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, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "../lib/util/select.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, size_t buf_len)
  79 {
  80         int msg_type = CVAL(buf,0);
  81         int type = CVAL(buf,smb_com);
  82         unsigned x;
  83         fstring name1,name2;
  84         int name_len1, name_len2;
  85         int name_type1, name_type2;
  86
  87         if (msg_type) {
  88                 /* it's a netbios special */
  89                 switch (msg_type)
  90                 case 0x81:
  91                         /* session request */
  92                         /* inbuf_size is guaranteed to be at least 4. */
  93                         name_len1 = name_len((unsigned char *)(buf+4),
  94                                         buf_len - 4);
  95                         if (name_len1 <= 0 || name_len1 > buf_len - 4) {
  96                                 DEBUG(0,("Invalid name length in session request\n"));
  97                                 return;
  98                         }
  99                         name_len2 = name_len((unsigned char *)(buf+4+name_len1),
 100                                         buf_len - 4 - name_len1);
 101                         if (name_len2 <= 0 || name_len2 > buf_len - 4 - name_len1) {
 102                                 DEBUG(0,("Invalid name length in session request\n"));
 103                                 return;
 104                         }
 105
 106                         name_type1 = name_extract((unsigned char *)buf,
 107                                         buf_len,(unsigned int)4,name1);
 108                         name_type2 = name_extract((unsigned char *)buf,
 109                                         buf_len,(unsigned int)(4 + name_len1),name2);
 110
 111                         if (name_type1 == -1 || name_type2 == -1) {
 112                                 DEBUG(0,("Invalid name type in session request\n"));
 113                                 return;
 114                         }
 115
 116                         d_printf("sesion_request: %s -> %s\n",
 117                                  name1, name2);
 118                         if (netbiosname) {
 119                                 char *mangled = name_mangle(
 120                                         talloc_tos(), netbiosname, 0x20);
 121                                 if (mangled != NULL) {
 122                                         /* replace the destination netbios
 123                                          * name */
 124                                         memcpy(buf+4, mangled,
 125                                                name_len((unsigned char *)mangled,
 126                                                         talloc_get_size(mangled)));
 127                                         TALLOC_FREE(mangled);
 128                                 }
 129                         }
 130                 return;
 131         }
 132
 133         /* it's an ordinary SMB request */
 134         switch (type) {
 135         case SMBsesssetupX:
 136                 /* force the client capabilities */
 137                 x = IVAL(buf,smb_vwv11);
 138                 d_printf("SMBsesssetupX cap=0x%08x\n", x);
 139                 d_printf("pwlen=%d/%d\n", SVAL(buf, smb_vwv7), SVAL(buf, smb_vwv8));
 140                 system("mv sessionsetup.dat sessionsetup1.dat");
 141                 save_file("sessionsetup.dat", smb_buf(buf), SVAL(buf, smb_vwv7));
 142                 x = (x | CLI_CAPABILITY_SET) & ~CLI_CAPABILITY_MASK;
 143                 SIVAL(buf, smb_vwv11, x);
 144                 break;
 145         }
 146 }
 147
 148 /****************************************************************************
 149  Send an smb to a fd.
 150 ****************************************************************************/
 151
 152 static bool send_smb(int fd, char *buffer)
 153 {
 154         size_t len;
 155         size_t nwritten=0;
 156         ssize_t ret;
 157
 158         len = smb_len(buffer) + 4;
 159
 160         while (nwritten < len) {
 161                 ret = write_data(fd,buffer+nwritten,len - nwritten);
 162                 if (ret <= 0) {
 163                         DEBUG(0,("Error writing %d bytes to client. %d. (%s)\n",
 164                                 (int)len,(int)ret, strerror(errno) ));
 165                         return false;
 166                 }
 167                 nwritten += ret;
 168         }
 169
 170         return true;
 171 }
 172
 173 static void filter_child(int c, struct sockaddr_storage *dest_ss)
 174 {
 175         NTSTATUS status;
 176         int s = -1;
 177
 178         /* we have a connection from a new client, now connect to the server */
 179         status = open_socket_out(dest_ss, 445, LONG_CONNECT_TIMEOUT, &s);
 180
 181         if (s == -1) {
 182                 char addr[INET6_ADDRSTRLEN];
 183                 if (dest_ss) {
 184                         print_sockaddr(addr, sizeof(addr), dest_ss);
 185                 }
 186
 187                 d_printf("Unable to connect to %s (%s)\n",
 188                          dest_ss?addr:"NULL",strerror(errno));
 189                 exit(1);
 190         }
 191
 192         while (c != -1 || s != -1) {
 193                 fd_set fds;
 194                 int num;
 195
 196                 FD_ZERO(&fds);
 197                 if (s != -1) FD_SET(s, &fds);
 198                 if (c != -1) FD_SET(c, &fds);
 199
 200                 num = sys_select_intr(MAX(s+1, c+1),&fds,NULL,NULL,NULL);
 201                 if (num <= 0) continue;
 202
 203                 if (c != -1 && FD_ISSET(c, &fds)) {
 204                         size_t len;
 205                         if (!NT_STATUS_IS_OK(receive_smb_raw(
 206                                                         c, packet, sizeof(packet),
 207                                                         0, 0, &len))) {
 208                                 d_printf("client closed connection\n");
 209                                 exit(0);
 210                         }
 211                         filter_request(packet, len);
 212                         if (!send_smb(s, packet)) {
 213                                 d_printf("server is dead\n");
 214                                 exit(1);
 215                         }
 216                 }
 217                 if (s != -1 && FD_ISSET(s, &fds)) {
 218                         size_t len;
 219                         if (!NT_STATUS_IS_OK(receive_smb_raw(
 220                                                         s, packet, sizeof(packet),
 221                                                         0, 0, &len))) {
 222                                 d_printf("server closed connection\n");
 223                                 exit(0);
 224                         }
 225                         filter_reply(packet);
 226                         if (!send_smb(c, packet)) {
 227                                 d_printf("client is dead\n");
 228                                 exit(1);
 229                         }
 230                 }
 231         }
 232         d_printf("Connection closed\n");
 233         exit(0);
 234 }
 235
 236
 237 static void start_filter(char *desthost)
 238 {
 239         int s, c;
 240         struct sockaddr_storage dest_ss;
 241         struct sockaddr_storage my_ss;
 242
 243         CatchChild();
 244
 245         /* start listening on port 445 locally */
 246
 247         zero_sockaddr(&my_ss);
 248         s = open_socket_in(SOCK_STREAM, 445, 0, &my_ss, True);
 249
 250         if (s == -1) {
 251                 d_printf("bind failed\n");
 252                 exit(1);
 253         }
 254
 255         if (listen(s, 5) == -1) {
 256                 d_printf("listen failed\n");
 257         }
 258
 259         if (!resolve_name(desthost, &dest_ss, 0x20, false)) {
 260                 d_printf("Unable to resolve host %s\n", desthost);
 261                 exit(1);
 262         }
 263
 264         while (1) {
 265                 fd_set fds;
 266                 int num;
 267                 struct sockaddr_storage ss;
 268                 socklen_t in_addrlen = sizeof(ss);
 269
 270                 FD_ZERO(&fds);
 271                 FD_SET(s, &fds);
 272
 273                 num = sys_select_intr(s+1,&fds,NULL,NULL,NULL);
 274                 if (num > 0) {
 275                         c = accept(s, (struct sockaddr *)&ss, &in_addrlen);
 276                         if (c != -1) {
 277                                 if (fork() == 0) {
 278                                         close(s);
 279                                         filter_child(c, &dest_ss);
 280                                         exit(0);
 281                                 } else {
 282                                         close(c);
 283                                 }
 284                         }
 285                 }
 286         }
 287 }
 288
 289
 290 int main(int argc, char *argv[])
 291 {
 292         char *desthost;
 293         const char *configfile;
 294         TALLOC_CTX *frame = talloc_stackframe();
 295
 296         load_case_tables();
 297
 298         setup_logging(argv[0],True);
 299
 300         configfile = get_dyn_CONFIGFILE();
 301
 302         if (argc < 2) {
 303                 fprintf(stderr,"smbfilter <desthost> <netbiosname>\n");
 304                 exit(1);
 305         }
 306
 307         desthost = argv[1];
 308         if (argc > 2) {
 309                 netbiosname = argv[2];
 310         }
 311
 312         if (!lp_load(configfile,True,False,False,True)) {
 313                 d_printf("Unable to load config file\n");
 314         }
 315
 316         start_filter(desthost);
 317         TALLOC_FREE(frame);
 318         return 0;
 319 }