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
  24 /*
  25   an event has happened on the socket
  26 */
  27 static void cli_transport_event_handler(struct event_context *ev, struct fd_event *fde,
  28                                         time_t t, uint16_t flags)
  29 {
  30         struct cli_transport *transport = fde->private;
  31
  32         cli_transport_process(transport);
  33 }
  34
  35 /*
  36   create a transport structure based on an established socket
  37 */
  38 struct cli_transport *cli_transport_init(struct cli_socket *sock)
  39 {
  40         TALLOC_CTX *mem_ctx;
  41         struct cli_transport *transport;
  42         struct fd_event fde;
  43
  44         mem_ctx = talloc_init("cli_transport");
  45         if (!mem_ctx) return NULL;
  46
  47         transport = talloc_zero(mem_ctx, sizeof(*transport));
  48         if (!transport) return NULL;
  49
  50         transport->event.ctx = event_context_init();
  51         if (transport->event.ctx == NULL) {
  52                 talloc_destroy(mem_ctx);
  53                 return NULL;
  54         }
  55
  56         transport->mem_ctx = mem_ctx;
  57         transport->socket = sock;
  58         transport->negotiate.protocol = PROTOCOL_NT1;
  59         transport->options.use_spnego = lp_use_spnego();
  60         transport->negotiate.max_xmit = ~0;
  61
  62         cli_init_signing(transport);
  63
  64         transport->socket->reference_count++;
  65
  66         ZERO_STRUCT(transport->called);
  67
  68         fde.fd = sock->fd;
  69         fde.flags = EVENT_FD_READ;
  70         fde.handler = cli_transport_event_handler;
  71         fde.private = transport;
  72         fde.ref_count = 1;
  73
  74         transport->event.fde = event_add_fd(transport->event.ctx, &fde);
  75
  76         return transport;
  77 }
  78
  79 /*
  80   decrease reference count on a transport, and destroy if it becomes
  81   zero
  82 */
  83 void cli_transport_close(struct cli_transport *transport)
  84 {
  85         transport->reference_count--;
  86         if (transport->reference_count <= 0) {
  87                 cli_sock_close(transport->socket);
  88                 event_remove_fd(transport->event.ctx, transport->event.fde);
  89                 event_remove_timed(transport->event.ctx, transport->event.te);
  90                 event_context_destroy(transport->event.ctx);
  91                 talloc_destroy(transport->mem_ctx);
  92         }
  93 }
  94
  95 /*
  96   mark the transport as dead
  97 */
  98 void cli_transport_dead(struct cli_transport *transport)
  99 {
 100         cli_sock_dead(transport->socket);
 101 }
 102
 103
 104 /*
 105   enable select for write on a transport
 106 */
 107 static void cli_transport_write_enable(struct cli_transport *transport)
 108 {
 109         transport->event.fde->flags |= EVENT_FD_WRITE;
 110 }
 111
 112 /*
 113   disable select for write on a transport
 114 */
 115 static void cli_transport_write_disable(struct cli_transport *transport)
 116 {
 117         transport->event.fde->flags &= ~EVENT_FD_WRITE;
 118 }
 119
 120 /****************************************************************************
 121 send a session request (if appropriate)
 122 ****************************************************************************/
 123 BOOL cli_transport_connect(struct cli_transport *transport,
 124                            struct nmb_name *calling,
 125                            struct nmb_name *called)
 126 {
 127         char *p;
 128         int len = NBT_HDR_SIZE;
 129         struct cli_request *req;
 130
 131         if (called) {
 132                 transport->called = *called;
 133         }
 134
 135         /* 445 doesn't have session request */
 136         if (transport->socket->port == 445) {
 137                 return True;
 138         }
 139
 140         /* allocate output buffer */
 141         req = cli_request_setup_nonsmb(transport, NBT_HDR_SIZE + 2*nbt_mangled_name_len());
 142
 143         /* put in the destination name */
 144         p = req->out.buffer + NBT_HDR_SIZE;
 145         name_mangle(called->name, p, called->name_type);
 146         len += name_len(p);
 147
 148         /* and my name */
 149         p = req->out.buffer+len;
 150         name_mangle(calling->name, p, calling->name_type);
 151         len += name_len(p);
 152
 153         _smb_setlen(req->out.buffer,len-4);
 154         SCVAL(req->out.buffer,0,0x81);
 155
 156         if (!cli_request_send(req) ||
 157             !cli_request_receive(req)) {
 158                 cli_request_destroy(req);
 159                 return False;
 160         }
 161
 162         if (CVAL(req->in.buffer,0) != 0x82) {
 163                 transport->error.etype = ETYPE_NBT;
 164                 transport->error.e.nbt_error = CVAL(req->in.buffer,4);
 165                 cli_request_destroy(req);
 166                 return False;
 167         }
 168
 169         cli_request_destroy(req);
 170         return True;
 171 }
 172
 173
 174 /****************************************************************************
 175 get next mid in sequence
 176 ****************************************************************************/
 177 uint16_t cli_transport_next_mid(struct cli_transport *transport)
 178 {
 179         uint16_t mid;
 180         struct cli_request *req;
 181
 182         mid = transport->next_mid;
 183
 184 again:
 185         /* now check to see if this mid is being used by one of the
 186            pending requests. This is quite efficient because the list is
 187            usually very short */
 188
 189         /* the zero mid is reserved for requests that don't have a mid */
 190         if (mid == 0) mid = 1;
 191
 192         for (req=transport->pending_recv; req; req=req->next) {
 193                 if (req->mid == mid) {
 194                         mid++;
 195                         goto again;
 196                 }
 197         }
 198
 199         transport->next_mid = mid+1;
 200         return mid;
 201 }
 202
 203 static void idle_handler(struct event_context *ev,
 204                          struct timed_event *te, time_t t)
 205 {
 206         struct cli_transport *transport = te->private;
 207         te->next_event = t + transport->idle.period;
 208         transport->idle.func(transport, transport->idle.private);
 209 }
 210
 211 /*
 212   setup the idle handler for a transport
 213   the period is in seconds
 214 */
 215 void cli_transport_idle_handler(struct cli_transport *transport,
 216                                 void (*idle_func)(struct cli_transport *, void *),
 217                                 uint_t period,
 218                                 void *private)
 219 {
 220         struct timed_event te;
 221         transport->idle.func = idle_func;
 222         transport->idle.private = private;
 223         transport->idle.period = period;
 224
 225         if (transport->event.te != NULL) {
 226                 event_remove_timed(transport->event.ctx, transport->event.te);
 227         }
 228
 229         te.next_event = time(NULL) + period;
 230         te.handler = idle_handler;
 231         te.private = transport;
 232         transport->event.te = event_add_timed(transport->event.ctx, &te);
 233 }
 234
 235 /*
 236   process some pending sends
 237 */
 238 static void cli_transport_process_send(struct cli_transport *transport)
 239 {
 240         while (transport->pending_send) {
 241                 struct cli_request *req = transport->pending_send;
 242                 ssize_t ret;
 243                 ret = cli_sock_write(transport->socket, req->out.buffer, req->out.size);
 244                 if (ret == -1) {
 245                         if (errno == EAGAIN || errno == EINTR) {
 246                                 return;
 247                         }
 248                         cli_transport_dead(transport);
 249                 }
 250                 req->out.buffer += ret;
 251                 req->out.size -= ret;
 252                 if (req->out.size == 0) {
 253                         req->state = CLI_REQUEST_RECV;
 254                         DLIST_REMOVE(transport->pending_send, req);
 255                         DLIST_ADD(transport->pending_recv, req);
 256                 }
 257         }
 258
 259         /* we're out of requests to send, so don't wait for write
 260            events any more */
 261         cli_transport_write_disable(transport);
 262 }
 263
 264 /*
 265   we have a full request in our receive buffer - match it to a pending request
 266   and process
 267  */
 268 static void cli_transport_finish_recv(struct cli_transport *transport)
 269 {
 270         uint8_t *buffer, *hdr, *vwv;
 271         int len;
 272         uint16_t wct, mid = 0;
 273         struct cli_request *req;
 274
 275         buffer = transport->recv_buffer.buffer;
 276         len = transport->recv_buffer.req_size;
 277
 278         hdr = buffer+NBT_HDR_SIZE;
 279         vwv = hdr + HDR_VWV;
 280
 281         /* see if it could be an oplock break request */
 282         if (handle_oplock_break(transport, len, hdr, vwv)) {
 283                 talloc_free(transport->mem_ctx, buffer);
 284                 ZERO_STRUCT(transport->recv_buffer);
 285                 return;
 286         }
 287
 288         /* at this point we need to check for a readbraw reply, as
 289            these can be any length */
 290         if (transport->readbraw_pending) {
 291                 transport->readbraw_pending = 0;
 292
 293                 /* it must match the first entry in the pending queue
 294                    as the client is not allowed to have outstanding
 295                    readbraw requests */
 296                 req = transport->pending_recv;
 297                 if (!req) goto error;
 298
 299                 req->in.buffer = buffer;
 300                 talloc_steal(transport->mem_ctx, req->mem_ctx, buffer);
 301                 req->in.size = len + NBT_HDR_SIZE;
 302                 req->in.allocated = req->in.size;
 303                 goto async;
 304         }
 305
 306         if (len >= MIN_SMB_SIZE) {
 307                 /* extract the mid for matching to pending requests */
 308                 mid = SVAL(hdr, HDR_MID);
 309                 wct = CVAL(hdr, HDR_WCT);
 310         }
 311
 312         /* match the incoming request against the list of pending requests */
 313         for (req=transport->pending_recv; req; req=req->next) {
 314                 if (req->mid == mid) break;
 315         }
 316
 317         if (!req) {
 318                 DEBUG(1,("Discarding unmatched reply with mid %d\n", mid));
 319                 goto error;
 320         }
 321
 322         /* fill in the 'in' portion of the matching request */
 323         req->in.buffer = buffer;
 324         talloc_steal(transport->mem_ctx, req->mem_ctx, buffer);
 325         req->in.size = len + NBT_HDR_SIZE;
 326         req->in.allocated = req->in.size;
 327
 328         /* handle non-SMB replies */
 329         if (req->in.size < NBT_HDR_SIZE + MIN_SMB_SIZE) {
 330                 req->state = CLI_REQUEST_ERROR;
 331                 goto error;
 332         }
 333
 334         if (req->in.size < NBT_HDR_SIZE + MIN_SMB_SIZE + VWV(wct)) {
 335                 DEBUG(2,("bad reply size for mid %d\n", mid));
 336                 req->status = NT_STATUS_UNSUCCESSFUL;
 337                 req->state = CLI_REQUEST_ERROR;
 338                 goto error;
 339         }
 340
 341         req->in.hdr = hdr;
 342         req->in.vwv = vwv;
 343         req->in.wct = wct;
 344         if (req->in.size >= NBT_HDR_SIZE + MIN_SMB_SIZE + VWV(wct)) {
 345                 req->in.data = req->in.vwv + VWV(wct) + 2;
 346                 req->in.data_size = SVAL(req->in.vwv, VWV(wct));
 347                 if (req->in.size < NBT_HDR_SIZE + MIN_SMB_SIZE + VWV(wct) + req->in.data_size) {
 348                         DEBUG(3,("bad data size for mid %d\n", mid));
 349                         /* blergh - w2k3 gives a bogus data size values in some
 350                            openX replies */
 351                         req->in.data_size = req->in.size - (NBT_HDR_SIZE + MIN_SMB_SIZE + VWV(wct));
 352                 }
 353         }
 354         req->in.ptr = req->in.data;
 355         req->flags2 = SVAL(req->in.hdr, HDR_FLG2);
 356
 357         if (!(req->flags2 & FLAGS2_32_BIT_ERROR_CODES)) {
 358                 transport->error.etype = ETYPE_DOS;
 359                 transport->error.e.dos.eclass = CVAL(req->in.hdr,HDR_RCLS);
 360                 transport->error.e.dos.ecode = SVAL(req->in.hdr,HDR_ERR);
 361                 req->status = dos_to_ntstatus(transport->error.e.dos.eclass,
 362                                               transport->error.e.dos.ecode);
 363         } else {
 364                 transport->error.etype = ETYPE_NT;
 365                 transport->error.e.nt_status = NT_STATUS(IVAL(req->in.hdr, HDR_RCLS));
 366                 req->status = transport->error.e.nt_status;
 367         }
 368
 369         if (!cli_request_check_sign_mac(req)) {
 370                 transport->error.etype = ETYPE_SOCKET;
 371                 transport->error.e.socket_error = SOCKET_READ_BAD_SIG;
 372                 req->state = CLI_REQUEST_ERROR;
 373                 goto error;
 374         };
 375
 376 async:
 377         /* if this request has an async handler then call that to
 378            notify that the reply has been received. This might destroy
 379            the request so it must happen last */
 380         ZERO_STRUCT(transport->recv_buffer);
 381         DLIST_REMOVE(transport->pending_recv, req);
 382         req->state = CLI_REQUEST_DONE;
 383         if (req->async.fn) {
 384                 req->async.fn(req);
 385         }
 386         return;
 387
 388 error:
 389         if (req) {
 390                 DLIST_REMOVE(transport->pending_recv, req);
 391                 req->state = CLI_REQUEST_ERROR;
 392         }
 393         ZERO_STRUCT(transport->recv_buffer);
 394 }
 395
 396 /*
 397   process some pending receives
 398 */
 399 static void cli_transport_process_recv(struct cli_transport *transport)
 400 {
 401         /* a incoming packet goes through 2 stages - first we read the
 402            4 byte header, which tells us how much more is coming. Then
 403            we read the rest */
 404         if (transport->recv_buffer.received < NBT_HDR_SIZE) {
 405                 ssize_t ret;
 406                 ret = cli_sock_read(transport->socket,
 407                                     transport->recv_buffer.header +
 408                                     transport->recv_buffer.received,
 409                                     NBT_HDR_SIZE - transport->recv_buffer.received);
 410                 if (ret == -1) {
 411                         if (errno == EINTR || errno == EAGAIN) {
 412                                 return;
 413                         }
 414                         cli_transport_dead(transport);
 415                         return;
 416                 }
 417
 418                 transport->recv_buffer.received += ret;
 419
 420                 if (transport->recv_buffer.received == NBT_HDR_SIZE) {
 421                         /* we've got a full header */
 422                         transport->recv_buffer.req_size = smb_len(transport->recv_buffer.header) + NBT_HDR_SIZE;
 423                         transport->recv_buffer.buffer = talloc(transport->mem_ctx,
 424                                                                NBT_HDR_SIZE+transport->recv_buffer.req_size);
 425                         if (transport->recv_buffer.buffer == NULL) {
 426                                 cli_transport_dead(transport);
 427                                 return;
 428                         }
 429                         memcpy(transport->recv_buffer.buffer, transport->recv_buffer.header, NBT_HDR_SIZE);
 430                 }
 431         }
 432
 433         if (transport->recv_buffer.received < transport->recv_buffer.req_size) {
 434                 ssize_t ret;
 435                 ret = cli_sock_read(transport->socket,
 436                                     transport->recv_buffer.buffer +
 437                                     transport->recv_buffer.received,
 438                                     transport->recv_buffer.req_size -
 439                                     transport->recv_buffer.received);
 440                 if (ret == -1) {
 441                         if (errno == EINTR || errno == EAGAIN) {
 442                                 return;
 443                         }
 444                         cli_transport_dead(transport);
 445                         return;
 446                 }
 447                 transport->recv_buffer.received += ret;
 448         }
 449
 450         if (transport->recv_buffer.received != 0 &&
 451             transport->recv_buffer.received == transport->recv_buffer.req_size) {
 452                 cli_transport_finish_recv(transport);
 453         }
 454 }
 455
 456 /*
 457   process some read/write requests that are pending
 458   return False if the socket is dead
 459 */
 460 BOOL cli_transport_process(struct cli_transport *transport)
 461 {
 462         cli_transport_process_send(transport);
 463         cli_transport_process_recv(transport);
 464         if (transport->socket->fd == -1) {
 465                 return False;
 466         }
 467         return True;
 468 }
 469
 470
 471
 472 /*
 473   put a request into the send queue
 474 */
 475 void cli_transport_send(struct cli_request *req)
 476 {
 477         /* put it on the outgoing socket queue */
 478         req->state = CLI_REQUEST_SEND;
 479         DLIST_ADD(req->transport->pending_send, req);
 480
 481         /* make sure we look for write events */
 482         cli_transport_write_enable(req->transport);
 483 }