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 "system/filesys.h"
  22 #include "system/select.h"
  23 #include "../lib/util/select.h"
  24 #include "libsmb/nmblib.h"
  25 #include "lib/sys_rw_data.h"
  26
  27 #define SECURITY_MASK 0
  28 #define SECURITY_SET  0
  29
  30 /* this forces non-unicode */
  31 #define CAPABILITY_MASK 0
  32 #define CAPABILITY_SET  0
  33
  34 /* and non-unicode for the client too */
  35 #define CLI_CAPABILITY_MASK 0
  36 #define CLI_CAPABILITY_SET  0
  37
  38 static char *netbiosname;
  39
  40 static void save_file(const char *fname, void *ppacket, size_t length)
  41 {
  42         int fd;
  43         fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0644);
  44         if (fd == -1) {
  45                 perror(fname);
  46                 return;
  47         }
  48         if (write(fd, ppacket, length) != length) {
  49                 fprintf(stderr,"Failed to write %s\n", fname);
  50                 close(fd);
  51                 return;
  52         }
  53         close(fd);
  54         printf("Wrote %ld bytes to %s\n", (unsigned long)length, fname);
  55 }
  56
  57 static void filter_reply(char *buf)
  58 {
  59         int msg_type = CVAL(buf,0);
  60         int type = CVAL(buf,smb_com);
  61         unsigned x;
  62
  63         if (msg_type) return;
  64
  65         switch (type) {
  66
  67         case SMBnegprot:
  68                 /* force the security bits */
  69                 x = CVAL(buf, smb_vwv1);
  70                 x = (x | SECURITY_SET) & ~SECURITY_MASK;
  71                 SCVAL(buf, smb_vwv1, x);
  72
  73                 /* force the capabilities */
  74                 x = IVAL(buf,smb_vwv9+1);
  75                 x = (x | CAPABILITY_SET) & ~CAPABILITY_MASK;
  76                 SIVAL(buf, smb_vwv9+1, x);
  77                 break;
  78
  79         }
  80 }
  81
  82 static void filter_request(char *buf, size_t buf_len)
  83 {
  84         int msg_type = CVAL(buf,0);
  85         int type = CVAL(buf,smb_com);
  86         unsigned x;
  87         fstring name1,name2;
  88         int name_len1 = 0;
  89         int name_len2;
  90         int name_type1, name_type2;
  91
  92         if (msg_type) {
  93                 /* it's a netbios special */
  94                 switch (msg_type)
  95                 case 0x81:
  96                         /* session request */
  97                         /* inbuf_size is guaranteed to be at least 4. */
  98                         name_len1 = name_len((unsigned char *)(buf+4),
  99                                         buf_len - 4);
 100                         if (name_len1 <= 0 || name_len1 > buf_len - 4) {
 101                                 DEBUG(0,("Invalid name length in session request\n"));
 102                                 return;
 103                         }
 104                         name_len2 = name_len((unsigned char *)(buf+4+name_len1),
 105                                         buf_len - 4 - name_len1);
 106                         if (name_len2 <= 0 || name_len2 > buf_len - 4 - name_len1) {
 107                                 DEBUG(0,("Invalid name length in session request\n"));
 108                                 return;
 109                         }
 110
 111                         name_type1 = name_extract((unsigned char *)buf,
 112                                         buf_len,(unsigned int)4,name1);
 113                         name_type2 = name_extract((unsigned char *)buf,
 114                                         buf_len,(unsigned int)(4 + name_len1),name2);
 115
 116                         if (name_type1 == -1 || name_type2 == -1) {
 117                                 DEBUG(0,("Invalid name type in session request\n"));
 118                                 return;
 119                         }
 120
 121                         d_printf("sesion_request: %s -> %s\n",
 122                                  name1, name2);
 123                         if (netbiosname) {
 124                                 char *mangled = name_mangle(
 125                                         talloc_tos(), netbiosname, 0x20);
 126                                 if (mangled != NULL) {
 127                                         /* replace the destination netbios
 128                                          * name */
 129                                         memcpy(buf+4, mangled,
 130                                                name_len((unsigned char *)mangled,
 131                                                         talloc_get_size(mangled)));
 132                                         TALLOC_FREE(mangled);
 133                                 }
 134                         }
 135                 return;
 136         }
 137
 138         /* it's an ordinary SMB request */
 139         switch (type) {
 140         case SMBsesssetupX:
 141                 /* force the client capabilities */
 142                 x = IVAL(buf,smb_vwv11);
 143                 d_printf("SMBsesssetupX cap=0x%08x\n", x);
 144                 d_printf("pwlen=%d/%d\n", SVAL(buf, smb_vwv7), SVAL(buf, smb_vwv8));
 145                 system("mv sessionsetup.dat sessionsetup1.dat");
 146                 save_file("sessionsetup.dat", smb_buf(buf), SVAL(buf, smb_vwv7));
 147                 x = (x | CLI_CAPABILITY_SET) & ~CLI_CAPABILITY_MASK;
 148                 SIVAL(buf, smb_vwv11, x);
 149                 break;
 150         }
 151 }
 152
 153 /****************************************************************************
 154  Send an smb to a fd.
 155 ****************************************************************************/
 156
 157 static bool send_smb(int fd, char *buffer)
 158 {
 159         size_t len;
 160         size_t nwritten=0;
 161         ssize_t ret;
 162
 163         len = smb_len(buffer) + 4;
 164
 165         while (nwritten < len) {
 166                 ret = write_data(fd,buffer+nwritten,len - nwritten);
 167                 if (ret <= 0) {
 168                         DEBUG(0,("Error writing %d bytes to client. %d. (%s)\n",
 169                                 (int)len,(int)ret, strerror(errno) ));
 170                         return false;
 171                 }
 172                 nwritten += ret;
 173         }
 174
 175         return true;
 176 }
 177
 178 static void filter_child(int c, struct sockaddr_storage *dest_ss)
 179 {
 180         NTSTATUS status;
 181         int s = -1;
 182         char packet[128*1024];
 183
 184         /* we have a connection from a new client, now connect to the server */
 185         status = open_socket_out(dest_ss, TCP_SMB_PORT, LONG_CONNECT_TIMEOUT, &s);
 186         if (!NT_STATUS_IS_OK(status)) {
 187                 char addr[INET6_ADDRSTRLEN];
 188                 if (dest_ss) {
 189                         print_sockaddr(addr, sizeof(addr), dest_ss);
 190                 }
 191
 192                 d_printf("Unable to connect to %s (%s)\n",
 193                          dest_ss?addr:"NULL", nt_errstr(status));
 194                 exit(1);
 195         }
 196
 197         while (c != -1 || s != -1) {
 198                 struct pollfd fds[2];
 199                 int num_fds, ret;
 200
 201                 memset(fds, 0, sizeof(struct pollfd) * 2);
 202                 fds[0].fd = -1;
 203                 fds[1].fd = -1;
 204                 num_fds = 0;
 205
 206                 if (s != -1) {
 207                         fds[num_fds].fd = s;
 208                         fds[num_fds].events = POLLIN|POLLHUP;
 209                         num_fds += 1;
 210                 }
 211                 if (c != -1) {
 212                         fds[num_fds].fd = c;
 213                         fds[num_fds].events = POLLIN|POLLHUP;
 214                         num_fds += 1;
 215                 }
 216
 217                 ret = sys_poll_intr(fds, num_fds, -1);
 218                 if (ret <= 0) {
 219                         continue;
 220                 }
 221
 222                 /*
 223                  * find c in fds and see if it's readable
 224                  */
 225                 if ((c != -1) &&
 226                     (((fds[0].fd == c)
 227                       && (fds[0].revents & (POLLIN|POLLHUP|POLLERR))) ||
 228                      ((fds[1].fd == c)
 229                       && (fds[1].revents & (POLLIN|POLLHUP|POLLERR))))) {
 230                         size_t len;
 231                         if (!NT_STATUS_IS_OK(receive_smb_raw(
 232                                                         c, packet, sizeof(packet),
 233                                                         0, 0, &len))) {
 234                                 d_printf("client closed connection\n");
 235                                 exit(0);
 236                         }
 237                         filter_request(packet, len);
 238                         if (!send_smb(s, packet)) {
 239                                 d_printf("server is dead\n");
 240                                 exit(1);
 241                         }
 242                 }
 243
 244                 /*
 245                  * find s in fds and see if it's readable
 246                  */
 247                 if ((s != -1) &&
 248                     (((fds[0].fd == s)
 249                       && (fds[0].revents & (POLLIN|POLLHUP|POLLERR))) ||
 250                      ((fds[1].fd == s)
 251                       && (fds[1].revents & (POLLIN|POLLHUP|POLLERR))))) {
 252                         size_t len;
 253                         if (!NT_STATUS_IS_OK(receive_smb_raw(
 254                                                         s, packet, sizeof(packet),
 255                                                         0, 0, &len))) {
 256                                 d_printf("server closed connection\n");
 257                                 exit(0);
 258                         }
 259                         filter_reply(packet);
 260                         if (!send_smb(c, packet)) {
 261                                 d_printf("client is dead\n");
 262                                 exit(1);
 263                         }
 264                 }
 265         }
 266         d_printf("Connection closed\n");
 267         exit(0);
 268 }
 269
 270
 271 static void start_filter(char *desthost)
 272 {
 273         int s, c;
 274         struct sockaddr_storage dest_ss;
 275         struct sockaddr_storage my_ss;
 276
 277         CatchChild();
 278
 279         /* start listening on port 445 locally */
 280
 281         zero_sockaddr(&my_ss);
 282         s = open_socket_in(SOCK_STREAM, TCP_SMB_PORT, 0, &my_ss, True);
 283
 284         if (s == -1) {
 285                 d_printf("bind failed\n");
 286                 exit(1);
 287         }
 288
 289         if (listen(s, 5) == -1) {
 290                 d_printf("listen failed\n");
 291         }
 292
 293         if (!resolve_name(desthost, &dest_ss, 0x20, false)) {
 294                 d_printf("Unable to resolve host %s\n", desthost);
 295                 exit(1);
 296         }
 297
 298         while (1) {
 299                 int num, revents;
 300                 struct sockaddr_storage ss;
 301                 socklen_t in_addrlen = sizeof(ss);
 302
 303                 num = poll_intr_one_fd(s, POLLIN|POLLHUP, -1, &revents);
 304                 if ((num > 0) && (revents & (POLLIN|POLLHUP|POLLERR))) {
 305                         c = accept(s, (struct sockaddr *)&ss, &in_addrlen);
 306                         if (c != -1) {
 307                                 if (fork() == 0) {
 308                                         close(s);
 309                                         filter_child(c, &dest_ss);
 310                                         exit(0);
 311                                 } else {
 312                                         close(c);
 313                                 }
 314                         }
 315                 }
 316         }
 317 }
 318
 319
 320 int main(int argc, char *argv[])
 321 {
 322         char *desthost;
 323         const char *configfile;
 324         TALLOC_CTX *frame = talloc_stackframe();
 325
 326         smb_init_locale();
 327
 328         setup_logging(argv[0], DEBUG_STDOUT);
 329
 330         configfile = get_dyn_CONFIGFILE();
 331
 332         if (argc < 2) {
 333                 fprintf(stderr,"smbfilter <desthost> <netbiosname>\n");
 334                 exit(1);
 335         }
 336
 337         desthost = argv[1];
 338         if (argc > 2) {
 339                 netbiosname = argv[2];
 340         }
 341
 342         if (!lp_load_global(configfile)) {
 343                 d_printf("Unable to load config file\n");
 344         }
 345
 346         start_filter(desthost);
 347         TALLOC_FREE(frame);
 348         return 0;
 349 }