source/libcli/raw/clitransport.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    SMB client transport context management functions
   4    Copyright (C) Andrew Tridgell 1994-2003
   5    Copyright (C) James Myers 2003 <myersjj@samba.org>
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23 #include "libcli/raw/libcliraw.h"
  24 #include "system/time.h"
  25 #include "dlinklist.h"
  26 #include "events.h"
  27
  28
  29 static void smbcli_transport_process_recv(struct smbcli_transport *transport);
  30 static void smbcli_transport_process_send(struct smbcli_transport *transport);
  31
  32 /*
  33   an event has happened on the socket
  34 */
  35 static void smbcli_transport_event_handler(struct event_context *ev, struct fd_event *fde,
  36                                         time_t t, uint16_t flags)
  37 {
  38         struct smbcli_transport *transport = fde->private;
  39
  40         if (flags & EVENT_FD_READ) {
  41                 smbcli_transport_process_recv(transport);
  42         }
  43         if (flags & EVENT_FD_WRITE) {
  44                 smbcli_transport_process_send(transport);
  45         }
  46 }
  47
  48 /*
  49   destroy a transport
  50  */
  51 static int transport_destructor(void *ptr)
  52 {
  53         struct smbcli_transport *transport = ptr;
  54
  55         smbcli_transport_dead(transport);
  56         event_remove_fd(transport->event.ctx, transport->event.fde);
  57         event_remove_timed(transport->event.ctx, transport->event.te);
  58         return 0;
  59 }
  60
  61 /*
  62   create a transport structure based on an established socket
  63 */
  64 struct smbcli_transport *smbcli_transport_init(struct smbcli_socket *sock)
  65 {
  66         struct smbcli_transport *transport;
  67         struct fd_event fde;
  68
  69         transport = talloc_p(sock, struct smbcli_transport);
  70         if (!transport) return NULL;
  71
  72         ZERO_STRUCTP(transport);
  73
  74         transport->event.ctx = event_context_init(transport);
  75         if (transport->event.ctx == NULL) {
  76                 talloc_free(transport);
  77                 return NULL;
  78         }
  79
  80         transport->socket = talloc_reference(transport, sock);
  81         transport->negotiate.protocol = PROTOCOL_NT1;
  82         transport->options.use_spnego = lp_use_spnego();
  83         transport->options.max_xmit = lp_max_xmit();
  84         transport->options.max_mux = lp_maxmux();
  85
  86         transport->negotiate.max_xmit = transport->options.max_xmit;
  87
  88         smbcli_init_signing(transport);
  89
  90         ZERO_STRUCT(transport->called);
  91
  92         fde.fd = socket_get_fd(sock->sock);
  93         fde.flags = EVENT_FD_READ;
  94         fde.handler = smbcli_transport_event_handler;
  95         fde.private = transport;
  96         fde.ref_count = 1;
  97
  98         transport->event.fde = event_add_fd(transport->event.ctx, &fde);
  99
 100         talloc_set_destructor(transport, transport_destructor);
 101
 102         return transport;
 103 }
 104
 105 /*
 106   mark the transport as dead
 107 */
 108 void smbcli_transport_dead(struct smbcli_transport *transport)
 109 {
 110         smbcli_sock_dead(transport->socket);
 111
 112         /* all pending sends become errors */
 113         while (transport->pending_send) {
 114                 struct smbcli_request *req = transport->pending_send;
 115                 req->state = SMBCLI_REQUEST_ERROR;
 116                 req->status = NT_STATUS_NET_WRITE_FAULT;
 117                 DLIST_REMOVE(transport->pending_send, req);
 118                 if (req->async.fn) {
 119                         req->async.fn(req);
 120                 }
 121         }
 122
 123         /* as do all pending receives */
 124         while (transport->pending_recv) {
 125                 struct smbcli_request *req = transport->pending_recv;
 126                 req->state = SMBCLI_REQUEST_ERROR;
 127                 req->status = NT_STATUS_NET_WRITE_FAULT;
 128                 DLIST_REMOVE(transport->pending_recv, req);
 129                 if (req->async.fn) {
 130                         req->async.fn(req);
 131                 }
 132         }
 133 }
 134
 135
 136 /*
 137   enable select for write on a transport
 138 */
 139 static void smbcli_transport_write_enable(struct smbcli_transport *transport)
 140 {
 141         transport->event.fde->flags |= EVENT_FD_WRITE;
 142 }
 143
 144 /*
 145   disable select for write on a transport
 146 */
 147 static void smbcli_transport_write_disable(struct smbcli_transport *transport)
 148 {
 149         transport->event.fde->flags &= ~EVENT_FD_WRITE;
 150 }
 151
 152 /****************************************************************************
 153 send a session request (if appropriate)
 154 ****************************************************************************/
 155 BOOL smbcli_transport_connect(struct smbcli_transport *transport,
 156                            struct nmb_name *calling,
 157                            struct nmb_name *called)
 158 {
 159         char *p;
 160         int len = NBT_HDR_SIZE;
 161         struct smbcli_request *req;
 162
 163         if (called) {
 164                 transport->called = *called;
 165         }
 166
 167         /* 445 doesn't have session request */
 168         if (transport->socket->port == 445) {
 169                 return True;
 170         }
 171
 172         /* allocate output buffer */
 173         req = smbcli_request_setup_nonsmb(transport, NBT_HDR_SIZE + 2*nbt_mangled_name_len());
 174
 175         /* put in the destination name */
 176         p = req->out.buffer + NBT_HDR_SIZE;
 177         name_mangle(called->name, p, called->name_type);
 178         len += name_len(p);
 179
 180         /* and my name */
 181         p = req->out.buffer+len;
 182         name_mangle(calling->name, p, calling->name_type);
 183         len += name_len(p);
 184
 185         _smb_setlen(req->out.buffer,len-4);
 186         SCVAL(req->out.buffer,0,0x81);
 187
 188         if (!smbcli_request_send(req) ||
 189             !smbcli_request_receive(req)) {
 190                 smbcli_request_destroy(req);
 191                 return False;
 192         }
 193
 194         if (CVAL(req->in.buffer,0) != 0x82) {
 195                 transport->error.etype = ETYPE_NBT;
 196                 transport->error.e.nbt_error = CVAL(req->in.buffer,4);
 197                 smbcli_request_destroy(req);
 198                 return False;
 199         }
 200
 201         smbcli_request_destroy(req);
 202         return True;
 203 }
 204
 205
 206 /****************************************************************************
 207 get next mid in sequence
 208 ****************************************************************************/
 209 uint16_t smbcli_transport_next_mid(struct smbcli_transport *transport)
 210 {
 211         uint16_t mid;
 212         struct smbcli_request *req;
 213
 214         mid = transport->next_mid;
 215
 216 again:
 217         /* now check to see if this mid is being used by one of the
 218            pending requests. This is quite efficient because the list is
 219            usually very short */
 220
 221         /* the zero mid is reserved for requests that don't have a mid */
 222         if (mid == 0) mid = 1;
 223
 224         for (req=transport->pending_recv; req; req=req->next) {
 225                 if (req->mid == mid) {
 226                         mid++;
 227                         goto again;
 228                 }
 229         }
 230
 231         transport->next_mid = mid+1;
 232         return mid;
 233 }
 234
 235 static void idle_handler(struct event_context *ev,
 236                          struct timed_event *te, time_t t)
 237 {
 238         struct smbcli_transport *transport = te->private;
 239         te->next_event = t + transport->idle.period;
 240         transport->idle.func(transport, transport->idle.private);
 241 }
 242
 243 /*
 244   setup the idle handler for a transport
 245   the period is in seconds
 246 */
 247 void smbcli_transport_idle_handler(struct smbcli_transport *transport,
 248                                 void (*idle_func)(struct smbcli_transport *, void *),
 249                                 uint_t period,
 250                                 void *private)
 251 {
 252         struct timed_event te;
 253         transport->idle.func = idle_func;
 254         transport->idle.private = private;
 255         transport->idle.period = period;
 256
 257         if (transport->event.te != NULL) {
 258                 event_remove_timed(transport->event.ctx, transport->event.te);
 259         }
 260
 261         te.next_event = time(NULL) + period;
 262         te.handler = idle_handler;
 263         te.private = transport;
 264         transport->event.te = event_add_timed(transport->event.ctx, &te);
 265 }
 266
 267 /*
 268   process some pending sends
 269 */
 270 static void smbcli_transport_process_send(struct smbcli_transport *transport)
 271 {
 272         while (transport->pending_send) {
 273                 struct smbcli_request *req = transport->pending_send;
 274                 ssize_t ret;
 275                 ret = smbcli_sock_write(transport->socket, req->out.buffer, req->out.size);
 276                 if (ret == -1) {
 277                         if (errno == EAGAIN || errno == EINTR) {
 278                                 return;
 279                         }
 280                         smbcli_transport_dead(transport);
 281                         return;
 282                 }
 283                 req->out.buffer += ret;
 284                 req->out.size -= ret;
 285                 if (req->out.size == 0) {
 286                         DLIST_REMOVE(transport->pending_send, req);
 287                         if (req->one_way_request) {
 288                                 req->state = SMBCLI_REQUEST_DONE;
 289                                 smbcli_request_destroy(req);
 290                         } else {
 291                                 req->state = SMBCLI_REQUEST_RECV;
 292                                 DLIST_ADD(transport->pending_recv, req);
 293                         }
 294                 }
 295         }
 296
 297         /* we're out of requests to send, so don't wait for write
 298            events any more */
 299         smbcli_transport_write_disable(transport);
 300 }
 301
 302 /*
 303   we have a full request in our receive buffer - match it to a pending request
 304   and process
 305  */
 306 static void smbcli_transport_finish_recv(struct smbcli_transport *transport)
 307 {
 308         uint8_t *buffer, *hdr, *vwv;
 309         int len;
 310         uint16_t wct=0, mid = 0;
 311         struct smbcli_request *req;
 312
 313         buffer = transport->recv_buffer.buffer;
 314         len = transport->recv_buffer.req_size;
 315
 316         ZERO_STRUCT(transport->recv_buffer);
 317
 318         hdr = buffer+NBT_HDR_SIZE;
 319         vwv = hdr + HDR_VWV;
 320
 321         /* see if it could be an oplock break request */
 322         if (handle_oplock_break(transport, len, hdr, vwv)) {
 323                 talloc_free(buffer);
 324                 return;
 325         }
 326
 327         /* at this point we need to check for a readbraw reply, as
 328            these can be any length */
 329         if (transport->readbraw_pending) {
 330                 transport->readbraw_pending = 0;
 331
 332                 /* it must match the first entry in the pending queue
 333                    as the client is not allowed to have outstanding
 334                    readbraw requests */
 335                 req = transport->pending_recv;
 336                 if (!req) goto error;
 337
 338                 req->in.buffer = buffer;
 339                 talloc_steal(req, buffer);
 340                 req->in.size = len;
 341                 req->in.allocated = req->in.size;
 342                 goto async;
 343         }
 344
 345         if (len >= MIN_SMB_SIZE) {
 346                 /* extract the mid for matching to pending requests */
 347                 mid = SVAL(hdr, HDR_MID);
 348                 wct = CVAL(hdr, HDR_WCT);
 349         }
 350
 351         /* match the incoming request against the list of pending requests */
 352         for (req=transport->pending_recv; req; req=req->next) {
 353                 if (req->mid == mid) break;
 354         }
 355
 356         if (!req) {
 357                 DEBUG(1,("Discarding unmatched reply with mid %d op %d\n",
 358                          mid, CVAL(hdr, HDR_COM)));
 359                 goto error;
 360         }
 361
 362         /* fill in the 'in' portion of the matching request */
 363         req->in.buffer = buffer;
 364         talloc_steal(req, buffer);
 365         req->in.size = len;
 366         req->in.allocated = req->in.size;
 367
 368         /* handle NBT session replies */
 369         if (req->in.size >= 4 && req->in.buffer[0] != 0) {
 370                 req->status = NT_STATUS_OK;
 371                 goto async;
 372         }
 373
 374         /* handle non-SMB replies */
 375         if (req->in.size < NBT_HDR_SIZE + MIN_SMB_SIZE) {
 376                 req->state = SMBCLI_REQUEST_ERROR;
 377                 goto error;
 378         }
 379
 380         if (req->in.size < NBT_HDR_SIZE + MIN_SMB_SIZE + VWV(wct)) {
 381                 DEBUG(2,("bad reply size for mid %d\n", mid));
 382                 req->status = NT_STATUS_UNSUCCESSFUL;
 383                 req->state = SMBCLI_REQUEST_ERROR;
 384                 goto error;
 385         }
 386
 387         req->in.hdr = hdr;
 388         req->in.vwv = vwv;
 389         req->in.wct = wct;
 390         if (req->in.size >= NBT_HDR_SIZE + MIN_SMB_SIZE + VWV(wct)) {
 391                 req->in.data = req->in.vwv + VWV(wct) + 2;
 392                 req->in.data_size = SVAL(req->in.vwv, VWV(wct));
 393                 if (req->in.size < NBT_HDR_SIZE + MIN_SMB_SIZE + VWV(wct) + req->in.data_size) {
 394                         DEBUG(3,("bad data size for mid %d\n", mid));
 395                         /* blergh - w2k3 gives a bogus data size values in some
 396                            openX replies */
 397                         req->in.data_size = req->in.size - (NBT_HDR_SIZE + MIN_SMB_SIZE + VWV(wct));
 398                 }
 399         }
 400         req->in.ptr = req->in.data;
 401         req->flags2 = SVAL(req->in.hdr, HDR_FLG2);
 402
 403         if (!(req->flags2 & FLAGS2_32_BIT_ERROR_CODES)) {
 404                 transport->error.etype = ETYPE_DOS;
 405                 transport->error.e.dos.eclass = CVAL(req->in.hdr,HDR_RCLS);
 406                 transport->error.e.dos.ecode = SVAL(req->in.hdr,HDR_ERR);
 407                 req->status = dos_to_ntstatus(transport->error.e.dos.eclass,
 408                                               transport->error.e.dos.ecode);
 409         } else {
 410                 transport->error.etype = ETYPE_NT;
 411                 transport->error.e.nt_status = NT_STATUS(IVAL(req->in.hdr, HDR_RCLS));
 412                 req->status = transport->error.e.nt_status;
 413         }
 414
 415         if (!smbcli_request_check_sign_mac(req)) {
 416                 transport->error.etype = ETYPE_SOCKET;
 417                 transport->error.e.socket_error = SOCKET_READ_BAD_SIG;
 418                 req->state = SMBCLI_REQUEST_ERROR;
 419                 goto error;
 420         };
 421
 422 async:
 423         /* if this request has an async handler then call that to
 424            notify that the reply has been received. This might destroy
 425            the request so it must happen last */
 426         DLIST_REMOVE(transport->pending_recv, req);
 427         req->state = SMBCLI_REQUEST_DONE;
 428         if (req->async.fn) {
 429                 req->async.fn(req);
 430         }
 431         return;
 432
 433 error:
 434         if (req) {
 435                 DLIST_REMOVE(transport->pending_recv, req);
 436                 req->state = SMBCLI_REQUEST_ERROR;
 437         }
 438 }
 439
 440 /*
 441   process some pending receives
 442 */
 443 static void smbcli_transport_process_recv(struct smbcli_transport *transport)
 444 {
 445         /* a incoming packet goes through 2 stages - first we read the
 446            4 byte header, which tells us how much more is coming. Then
 447            we read the rest */
 448         if (transport->recv_buffer.received < NBT_HDR_SIZE) {
 449                 ssize_t ret;
 450                 ret = smbcli_sock_read(transport->socket,
 451                                     transport->recv_buffer.header +
 452                                     transport->recv_buffer.received,
 453                                     NBT_HDR_SIZE - transport->recv_buffer.received);
 454                 if (ret == -1) {
 455                         smbcli_transport_dead(transport);
 456                         return;
 457                 }
 458
 459                 transport->recv_buffer.received += ret;
 460
 461                 if (transport->recv_buffer.received == NBT_HDR_SIZE) {
 462                         /* we've got a full header */
 463                         transport->recv_buffer.req_size = smb_len(transport->recv_buffer.header) + NBT_HDR_SIZE;
 464                         transport->recv_buffer.buffer = talloc(transport,
 465                                                                NBT_HDR_SIZE+transport->recv_buffer.req_size);
 466                         if (transport->recv_buffer.buffer == NULL) {
 467                                 smbcli_transport_dead(transport);
 468                                 return;
 469                         }
 470                         memcpy(transport->recv_buffer.buffer, transport->recv_buffer.header, NBT_HDR_SIZE);
 471                 }
 472         }
 473
 474         if (transport->recv_buffer.received < transport->recv_buffer.req_size) {
 475                 ssize_t ret;
 476                 ret = smbcli_sock_read(transport->socket,
 477                                     transport->recv_buffer.buffer +
 478                                     transport->recv_buffer.received,
 479                                     transport->recv_buffer.req_size -
 480                                     transport->recv_buffer.received);
 481                 if (ret == -1) {
 482                         smbcli_transport_dead(transport);
 483                         return;
 484                 }
 485                 transport->recv_buffer.received += ret;
 486         }
 487
 488         if (transport->recv_buffer.received != 0 &&
 489             transport->recv_buffer.received == transport->recv_buffer.req_size) {
 490                 smbcli_transport_finish_recv(transport);
 491         }
 492 }
 493
 494 /*
 495   process some read/write requests that are pending
 496   return False if the socket is dead
 497 */
 498 BOOL smbcli_transport_process(struct smbcli_transport *transport)
 499 {
 500         smbcli_transport_process_send(transport);
 501         smbcli_transport_process_recv(transport);
 502         if (transport->socket->sock == NULL) {
 503                 return False;
 504         }
 505         return True;
 506 }
 507
 508
 509
 510 /*
 511   put a request into the send queue
 512 */
 513 void smbcli_transport_send(struct smbcli_request *req)
 514 {
 515         /* check if the transport is dead */
 516         if (req->transport->socket->sock == NULL) {
 517                 req->state = SMBCLI_REQUEST_ERROR;
 518                 req->status = NT_STATUS_NET_WRITE_FAULT;
 519                 return;
 520         }
 521
 522         /* put it on the outgoing socket queue */
 523         req->state = SMBCLI_REQUEST_SEND;
 524         DLIST_ADD_END(req->transport->pending_send, req, struct smbcli_request *);
 525
 526         /* make sure we look for write events */
 527         smbcli_transport_write_enable(req->transport);
 528 }