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