source3/smbd/smb2_read.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Core SMB2 server
   4
   5    Copyright (C) Stefan Metzmacher 2009
   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 3 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, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "smbd/globals.h"
  23 #include "../libcli/smb/smb_common.h"
  24 #include "libcli/security/security.h"
  25
  26 static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
  27                                               struct tevent_context *ev,
  28                                               struct smbd_smb2_request *smb2req,
  29                                               uint32_t in_smbpid,
  30                                               uint64_t in_file_id_volatile,
  31                                               uint32_t in_length,
  32                                               uint64_t in_offset,
  33                                               uint32_t in_minimum,
  34                                               uint32_t in_remaining);
  35 static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
  36                                     TALLOC_CTX *mem_ctx,
  37                                     DATA_BLOB *out_data,
  38                                     uint32_t *out_remaining);
  39
  40 static void smbd_smb2_request_read_done(struct tevent_req *subreq);
  41 NTSTATUS smbd_smb2_request_process_read(struct smbd_smb2_request *req)
  42 {
  43         const uint8_t *inhdr;
  44         const uint8_t *inbody;
  45         int i = req->current_idx;
  46         size_t expected_body_size = 0x31;
  47         size_t body_size;
  48         uint32_t in_smbpid;
  49         uint32_t in_length;
  50         uint64_t in_offset;
  51         uint64_t in_file_id_persistent;
  52         uint64_t in_file_id_volatile;
  53         uint32_t in_minimum_count;
  54         uint32_t in_remaining_bytes;
  55         struct tevent_req *subreq;
  56
  57         inhdr = (const uint8_t *)req->in.vector[i+0].iov_base;
  58         if (req->in.vector[i+1].iov_len != (expected_body_size & 0xFFFFFFFE)) {
  59                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
  60         }
  61
  62         inbody = (const uint8_t *)req->in.vector[i+1].iov_base;
  63
  64         body_size = SVAL(inbody, 0x00);
  65         if (body_size != expected_body_size) {
  66                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
  67         }
  68
  69         in_smbpid = IVAL(inhdr, SMB2_HDR_PID);
  70
  71         in_length               = IVAL(inbody, 0x04);
  72         in_offset               = BVAL(inbody, 0x08);
  73         in_file_id_persistent   = BVAL(inbody, 0x10);
  74         in_file_id_volatile     = BVAL(inbody, 0x18);
  75         in_minimum_count        = IVAL(inbody, 0x20);
  76         in_remaining_bytes      = IVAL(inbody, 0x28);
  77
  78         /* check the max read size */
  79         if (in_length > lp_smb2_max_read()) {
  80                 DEBUG(0,("here:%s: 0x%08X: 0x%08X\n",
  81                         __location__, in_length, lp_smb2_max_read()));
  82                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
  83         }
  84
  85         if (req->compat_chain_fsp) {
  86                 /* skip check */
  87         } else if (in_file_id_persistent != in_file_id_volatile) {
  88                 return smbd_smb2_request_error(req, NT_STATUS_FILE_CLOSED);
  89         }
  90
  91         subreq = smbd_smb2_read_send(req,
  92                                      req->sconn->smb2.event_ctx,
  93                                      req,
  94                                      in_smbpid,
  95                                      in_file_id_volatile,
  96                                      in_length,
  97                                      in_offset,
  98                                      in_minimum_count,
  99                                      in_remaining_bytes);
 100         if (subreq == NULL) {
 101                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 102         }
 103         tevent_req_set_callback(subreq, smbd_smb2_request_read_done, req);
 104
 105         return smbd_smb2_request_pending_queue(req, subreq);
 106 }
 107
 108 static void smbd_smb2_request_read_done(struct tevent_req *subreq)
 109 {
 110         struct smbd_smb2_request *req = tevent_req_callback_data(subreq,
 111                                         struct smbd_smb2_request);
 112         int i = req->current_idx;
 113         uint8_t *outhdr;
 114         DATA_BLOB outbody;
 115         DATA_BLOB outdyn;
 116         uint8_t out_data_offset;
 117         DATA_BLOB out_data_buffer = data_blob_null;
 118         uint32_t out_data_remaining = 0;
 119         NTSTATUS status;
 120         NTSTATUS error; /* transport error */
 121
 122         status = smbd_smb2_read_recv(subreq,
 123                                      req,
 124                                      &out_data_buffer,
 125                                      &out_data_remaining);
 126         TALLOC_FREE(subreq);
 127         if (!NT_STATUS_IS_OK(status)) {
 128                 error = smbd_smb2_request_error(req, status);
 129                 if (!NT_STATUS_IS_OK(error)) {
 130                         smbd_server_connection_terminate(req->sconn,
 131                                                          nt_errstr(error));
 132                         return;
 133                 }
 134                 return;
 135         }
 136
 137         out_data_offset = SMB2_HDR_BODY + 0x10;
 138
 139         outhdr = (uint8_t *)req->out.vector[i].iov_base;
 140
 141         outbody = data_blob_talloc(req->out.vector, NULL, 0x10);
 142         if (outbody.data == NULL) {
 143                 error = smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 144                 if (!NT_STATUS_IS_OK(error)) {
 145                         smbd_server_connection_terminate(req->sconn,
 146                                                          nt_errstr(error));
 147                         return;
 148                 }
 149                 return;
 150         }
 151
 152         SSVAL(outbody.data, 0x00, 0x10 + 1);    /* struct size */
 153         SCVAL(outbody.data, 0x02,
 154               out_data_offset);                 /* data offset */
 155         SCVAL(outbody.data, 0x03, 0);           /* reserved */
 156         SIVAL(outbody.data, 0x04,
 157               out_data_buffer.length);          /* data length */
 158         SIVAL(outbody.data, 0x08,
 159               out_data_remaining);              /* data remaining */
 160         SIVAL(outbody.data, 0x0C, 0);           /* reserved */
 161
 162         outdyn = out_data_buffer;
 163
 164         error = smbd_smb2_request_done(req, outbody, &outdyn);
 165         if (!NT_STATUS_IS_OK(error)) {
 166                 smbd_server_connection_terminate(req->sconn,
 167                                                  nt_errstr(error));
 168                 return;
 169         }
 170 }
 171
 172 struct smbd_smb2_read_state {
 173         struct smbd_smb2_request *smb2req;
 174         files_struct *fsp;
 175         uint32_t in_length;
 176         uint64_t in_offset;
 177         uint32_t in_minimum;
 178         DATA_BLOB out_data;
 179         uint32_t out_remaining;
 180 };
 181
 182 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq);
 183
 184 /*******************************************************************
 185  Common read complete processing function for both synchronous and
 186  asynchronous reads.
 187 *******************************************************************/
 188
 189 NTSTATUS smb2_read_complete(struct tevent_req *req, ssize_t nread, int err)
 190 {
 191         struct smbd_smb2_read_state *state = tevent_req_data(req,
 192                                         struct smbd_smb2_read_state);
 193         files_struct *fsp = state->fsp;
 194
 195         if (nread < 0) {
 196                 NTSTATUS status = map_nt_error_from_unix(err);
 197
 198                 DEBUG( 3,( "smb2_read_complete: file %s nread = %d. "
 199                         "Error = %s (NTSTATUS %s)\n",
 200                         fsp_str_dbg(fsp),
 201                         (int)nread,
 202                         strerror(err),
 203                         nt_errstr(status)));
 204
 205                 return status;
 206         }
 207         if (nread == 0 && state->in_length != 0) {
 208                 DEBUG(5,("smb2_read_complete: read_file[%s] end of file\n",
 209                         fsp_str_dbg(fsp)));
 210                 return NT_STATUS_END_OF_FILE;
 211         }
 212
 213         if (nread < state->in_minimum) {
 214                 DEBUG(5,("smb2_read_complete: read_file[%s] read less %d than "
 215                         "minimum requested %u. Returning end of file\n",
 216                         fsp_str_dbg(fsp),
 217                         (int)nread,
 218                         (unsigned int)state->in_minimum));
 219                 return NT_STATUS_END_OF_FILE;
 220         }
 221
 222         DEBUG(3,("smbd_smb2_read: fnum=[%d/%s] length=%lu offset=%lu read=%lu\n",
 223                 fsp->fnum,
 224                 fsp_str_dbg(fsp),
 225                 (unsigned long)state->in_length,
 226                 (unsigned long)state->in_offset,
 227                 (unsigned long)nread));
 228
 229         state->out_data.length = nread;
 230         state->out_remaining = 0;
 231
 232         return NT_STATUS_OK;
 233 }
 234
 235 static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
 236                                               struct tevent_context *ev,
 237                                               struct smbd_smb2_request *smb2req,
 238                                               uint32_t in_smbpid,
 239                                               uint64_t in_file_id_volatile,
 240                                               uint32_t in_length,
 241                                               uint64_t in_offset,
 242                                               uint32_t in_minimum,
 243                                               uint32_t in_remaining)
 244 {
 245         NTSTATUS status;
 246         struct tevent_req *req = NULL;
 247         struct smbd_smb2_read_state *state = NULL;
 248         struct smb_request *smbreq = NULL;
 249         connection_struct *conn = smb2req->tcon->compat_conn;
 250         files_struct *fsp = NULL;
 251         ssize_t nread = -1;
 252         struct lock_struct lock;
 253         int saved_errno;
 254
 255         req = tevent_req_create(mem_ctx, &state,
 256                                 struct smbd_smb2_read_state);
 257         if (req == NULL) {
 258                 return NULL;
 259         }
 260         state->smb2req = smb2req;
 261         state->in_length = in_length;
 262         state->in_offset = in_offset;
 263         state->in_minimum = in_minimum;
 264         state->out_data = data_blob_null;
 265         state->out_remaining = 0;
 266
 267         DEBUG(10,("smbd_smb2_read: file_id[0x%016llX]\n",
 268                   (unsigned long long)in_file_id_volatile));
 269
 270         smbreq = smbd_smb2_fake_smb_request(smb2req);
 271         if (tevent_req_nomem(smbreq, req)) {
 272                 return tevent_req_post(req, ev);
 273         }
 274
 275         fsp = file_fsp(smbreq, (uint16_t)in_file_id_volatile);
 276         if (fsp == NULL) {
 277                 tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
 278                 return tevent_req_post(req, ev);
 279         }
 280         if (conn != fsp->conn) {
 281                 tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
 282                 return tevent_req_post(req, ev);
 283         }
 284         if (smb2req->session->vuid != fsp->vuid) {
 285                 tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
 286                 return tevent_req_post(req, ev);
 287         }
 288         if (fsp->is_directory) {
 289                 tevent_req_nterror(req, NT_STATUS_INVALID_DEVICE_REQUEST);
 290                 return tevent_req_post(req, ev);
 291         }
 292
 293         state->out_data = data_blob_talloc(state, NULL, in_length);
 294         if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
 295                 return tevent_req_post(req, ev);
 296         }
 297
 298         state->fsp = fsp;
 299
 300         if (IS_IPC(smbreq->conn)) {
 301                 struct tevent_req *subreq = NULL;
 302
 303                 if (!fsp_is_np(fsp)) {
 304                         tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
 305                         return tevent_req_post(req, ev);
 306                 }
 307
 308                 subreq = np_read_send(state, smbd_event_context(),
 309                                       fsp->fake_file_handle,
 310                                       state->out_data.data,
 311                                       state->out_data.length);
 312                 if (tevent_req_nomem(subreq, req)) {
 313                         return tevent_req_post(req, ev);
 314                 }
 315                 tevent_req_set_callback(subreq,
 316                                         smbd_smb2_read_pipe_done,
 317                                         req);
 318                 return req;
 319         }
 320
 321         if (!CHECK_READ(fsp, smbreq)) {
 322                 tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
 323                 return tevent_req_post(req, ev);
 324         }
 325
 326         status = schedule_smb2_aio_read(fsp->conn,
 327                                 smbreq,
 328                                 fsp,
 329                                 (char *)state->out_data.data,
 330                                 (SMB_OFF_T)in_offset,
 331                                 (size_t)in_length);
 332
 333         if (NT_STATUS_IS_OK(status)) {
 334                 /*
 335                  * Doing an async read. Don't
 336                  * send a "gone async" message
 337                  * as we expect this to be less
 338                  * than the client timeout period.
 339                  * JRA. FIXME for offline files..
 340                  * FIXME. Add cancel code..
 341                  */
 342                 smb2req->async = true;
 343                 return req;
 344         }
 345
 346         if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
 347                 /* Real error in setting up aio. Fail. */
 348                 tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
 349                 return tevent_req_post(req, ev);
 350         }
 351
 352         /* Fallback to synchronous. */
 353
 354         init_strict_lock_struct(fsp,
 355                                 in_file_id_volatile,
 356                                 in_offset,
 357                                 in_length,
 358                                 READ_LOCK,
 359                                 &lock);
 360
 361         if (!SMB_VFS_STRICT_LOCK(conn, fsp, &lock)) {
 362                 tevent_req_nterror(req, NT_STATUS_FILE_LOCK_CONFLICT);
 363                 return tevent_req_post(req, ev);
 364         }
 365
 366         nread = read_file(fsp,
 367                           (char *)state->out_data.data,
 368                           in_offset,
 369                           in_length);
 370
 371         saved_errno = errno;
 372
 373         SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
 374
 375         DEBUG(10,("smbd_smb2_read: file %s handle [0x%016llX] offset=%llu "
 376                 "len=%llu returned %lld\n",
 377                 fsp_str_dbg(fsp),
 378                 (unsigned long long)in_file_id_volatile,
 379                 (unsigned long long)in_offset,
 380                 (unsigned long long)in_length,
 381                 (long long)nread));
 382
 383         status = smb2_read_complete(req, nread, saved_errno);
 384         if (!NT_STATUS_IS_OK(status)) {
 385                 tevent_req_nterror(req, status);
 386         } else {
 387                 /* Success. */
 388                 tevent_req_done(req);
 389         }
 390         return tevent_req_post(req, ev);
 391 }
 392
 393 static void smbd_smb2_read_pipe_done(struct tevent_req *subreq)
 394 {
 395         struct tevent_req *req = tevent_req_callback_data(subreq,
 396                                  struct tevent_req);
 397         struct smbd_smb2_read_state *state = tevent_req_data(req,
 398                                              struct smbd_smb2_read_state);
 399         NTSTATUS status;
 400         ssize_t nread = -1;
 401         bool is_data_outstanding;
 402
 403         status = np_read_recv(subreq, &nread, &is_data_outstanding);
 404         TALLOC_FREE(subreq);
 405         if (!NT_STATUS_IS_OK(status)) {
 406                 tevent_req_nterror(req, status);
 407                 return;
 408         }
 409
 410         if (nread == 0 && state->out_data.length != 0) {
 411                 tevent_req_nterror(req, NT_STATUS_END_OF_FILE);
 412                 return;
 413         }
 414
 415         state->out_data.length = nread;
 416         state->out_remaining = 0;
 417
 418         tevent_req_done(req);
 419 }
 420
 421 static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
 422                                     TALLOC_CTX *mem_ctx,
 423                                     DATA_BLOB *out_data,
 424                                     uint32_t *out_remaining)
 425 {
 426         NTSTATUS status;
 427         struct smbd_smb2_read_state *state = tevent_req_data(req,
 428                                              struct smbd_smb2_read_state);
 429
 430         if (tevent_req_is_nterror(req, &status)) {
 431                 tevent_req_received(req);
 432                 return status;
 433         }
 434
 435         *out_data = state->out_data;
 436         talloc_steal(mem_ctx, out_data->data);
 437         *out_remaining = state->out_remaining;
 438
 439         tevent_req_received(req);
 440         return NT_STATUS_OK;
 441 }