source3/smbd/smb2_notify.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Core SMB2 server
   4
   5    Copyright (C) Stefan Metzmacher 2009
   6    Copyright (C) Jeremy Allison 2010
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "smbd/smbd.h"
  24 #include "smbd/globals.h"
  25 #include "../libcli/smb/smb_common.h"
  26 #include "../lib/util/tevent_ntstatus.h"
  27
  28 struct smbd_smb2_notify_state {
  29         struct smbd_smb2_request *smb2req;
  30         struct smb_request *smbreq;
  31         bool has_request;
  32         bool skip_reply;
  33         NTSTATUS status;
  34         DATA_BLOB out_output_buffer;
  35 };
  36
  37 static struct tevent_req *smbd_smb2_notify_send(TALLOC_CTX *mem_ctx,
  38                                                 struct tevent_context *ev,
  39                                                 struct smbd_smb2_request *smb2req,
  40                                                 struct files_struct *in_fsp,
  41                                                 uint16_t in_flags,
  42                                                 uint32_t in_output_buffer_length,
  43                                                 uint64_t in_completion_filter);
  44 static NTSTATUS smbd_smb2_notify_recv(struct tevent_req *req,
  45                                       TALLOC_CTX *mem_ctx,
  46                                       DATA_BLOB *out_output_buffer);
  47
  48 static void smbd_smb2_request_notify_done(struct tevent_req *subreq);
  49 NTSTATUS smbd_smb2_request_process_notify(struct smbd_smb2_request *req)
  50 {
  51         struct smbXsrv_connection *xconn = req->xconn;
  52         NTSTATUS status;
  53         const uint8_t *inbody;
  54         uint16_t in_flags;
  55         uint32_t in_output_buffer_length;
  56         uint64_t in_file_id_persistent;
  57         uint64_t in_file_id_volatile;
  58         struct files_struct *in_fsp;
  59         uint64_t in_completion_filter;
  60         struct tevent_req *subreq;
  61
  62         status = smbd_smb2_request_verify_sizes(req, 0x20);
  63         if (!NT_STATUS_IS_OK(status)) {
  64                 return smbd_smb2_request_error(req, status);
  65         }
  66         inbody = SMBD_SMB2_IN_BODY_PTR(req);
  67
  68         in_flags                = SVAL(inbody, 0x02);
  69         in_output_buffer_length = IVAL(inbody, 0x04);
  70         in_file_id_persistent   = BVAL(inbody, 0x08);
  71         in_file_id_volatile     = BVAL(inbody, 0x10);
  72         in_completion_filter    = IVAL(inbody, 0x18);
  73
  74         /*
  75          * 0x00010000 is what Windows 7 uses,
  76          * Windows 2008 uses 0x00080000
  77          */
  78         if (in_output_buffer_length > xconn->smb2.server.max_trans) {
  79                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
  80         }
  81
  82         status = smbd_smb2_request_verify_creditcharge(req,
  83                                                 in_output_buffer_length);
  84
  85         if (!NT_STATUS_IS_OK(status)) {
  86                 return smbd_smb2_request_error(req, status);
  87         }
  88
  89         in_fsp = file_fsp_smb2(req, in_file_id_persistent, in_file_id_volatile);
  90         if (in_fsp == NULL) {
  91                 return smbd_smb2_request_error(req, NT_STATUS_FILE_CLOSED);
  92         }
  93
  94         subreq = smbd_smb2_notify_send(req, req->sconn->ev_ctx,
  95                                        req, in_fsp,
  96                                        in_flags,
  97                                        in_output_buffer_length,
  98                                        in_completion_filter);
  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_notify_done, req);
 103
 104         return smbd_smb2_request_pending_queue(req, subreq, 500);
 105 }
 106
 107 static void smbd_smb2_request_notify_done(struct tevent_req *subreq)
 108 {
 109         struct smbd_smb2_request *req = tevent_req_callback_data(subreq,
 110                                         struct smbd_smb2_request);
 111         DATA_BLOB outbody;
 112         DATA_BLOB outdyn;
 113         uint16_t out_output_buffer_offset;
 114         DATA_BLOB out_output_buffer = data_blob_null;
 115         NTSTATUS status;
 116         NTSTATUS error; /* transport error */
 117
 118         status = smbd_smb2_notify_recv(subreq,
 119                                        req,
 120                                        &out_output_buffer);
 121         TALLOC_FREE(subreq);
 122         if (!NT_STATUS_IS_OK(status)) {
 123                 error = smbd_smb2_request_error(req, status);
 124                 if (!NT_STATUS_IS_OK(error)) {
 125                         smbd_server_connection_terminate(req->xconn,
 126                                                          nt_errstr(error));
 127                         return;
 128                 }
 129                 return;
 130         }
 131
 132         out_output_buffer_offset = SMB2_HDR_BODY + 0x08;
 133
 134         outbody = smbd_smb2_generate_outbody(req, 0x08);
 135         if (outbody.data == NULL) {
 136                 error = smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 137                 if (!NT_STATUS_IS_OK(error)) {
 138                         smbd_server_connection_terminate(req->xconn,
 139                                                          nt_errstr(error));
 140                         return;
 141                 }
 142                 return;
 143         }
 144
 145         SSVAL(outbody.data, 0x00, 0x08 + 1);    /* struct size */
 146         SSVAL(outbody.data, 0x02,
 147               out_output_buffer_offset);        /* output buffer offset */
 148         SIVAL(outbody.data, 0x04,
 149               out_output_buffer.length);        /* output buffer length */
 150
 151         outdyn = out_output_buffer;
 152
 153         error = smbd_smb2_request_done(req, outbody, &outdyn);
 154         if (!NT_STATUS_IS_OK(error)) {
 155                 smbd_server_connection_terminate(req->xconn,
 156                                                  nt_errstr(error));
 157                 return;
 158         }
 159 }
 160
 161 static void smbd_smb2_notify_reply(struct smb_request *smbreq,
 162                                    NTSTATUS error_code,
 163                                    uint8_t *buf, size_t len);
 164 static bool smbd_smb2_notify_cancel(struct tevent_req *req);
 165
 166 static int smbd_smb2_notify_state_destructor(struct smbd_smb2_notify_state *state)
 167 {
 168         if (!state->has_request) {
 169                 return 0;
 170         }
 171
 172         state->skip_reply = true;
 173         smbd_notify_cancel_by_smbreq(state->smbreq);
 174         return 0;
 175 }
 176
 177 static int smbd_smb2_notify_smbreq_destructor(struct smb_request *smbreq)
 178 {
 179         struct tevent_req *req = talloc_get_type_abort(smbreq->async_priv,
 180                                                        struct tevent_req);
 181         struct smbd_smb2_notify_state *state = tevent_req_data(req,
 182                                                struct smbd_smb2_notify_state);
 183
 184         /*
 185          * Our temporary parent from change_notify_add_request()
 186          * goes away.
 187          */
 188         state->has_request = false;
 189
 190         /*
 191          * move it back to its original parent,
 192          * which means we no longer need the destructor
 193          * to protect it.
 194          */
 195         talloc_steal(smbreq->smb2req, smbreq);
 196         talloc_set_destructor(smbreq, NULL);
 197
 198         /*
 199          * We want to keep smbreq!
 200          */
 201         return -1;
 202 }
 203
 204 static struct tevent_req *smbd_smb2_notify_send(TALLOC_CTX *mem_ctx,
 205                                                 struct tevent_context *ev,
 206                                                 struct smbd_smb2_request *smb2req,
 207                                                 struct files_struct *fsp,
 208                                                 uint16_t in_flags,
 209                                                 uint32_t in_output_buffer_length,
 210                                                 uint64_t in_completion_filter)
 211 {
 212         struct tevent_req *req;
 213         struct smbd_smb2_notify_state *state;
 214         struct smb_request *smbreq;
 215         connection_struct *conn = smb2req->tcon->compat;
 216         bool recursive = (in_flags & SMB2_WATCH_TREE) ? true : false;
 217         NTSTATUS status;
 218
 219         req = tevent_req_create(mem_ctx, &state,
 220                                 struct smbd_smb2_notify_state);
 221         if (req == NULL) {
 222                 return NULL;
 223         }
 224         state->smb2req = smb2req;
 225         state->status = NT_STATUS_INTERNAL_ERROR;
 226         state->out_output_buffer = data_blob_null;
 227         talloc_set_destructor(state, smbd_smb2_notify_state_destructor);
 228
 229         DEBUG(10,("smbd_smb2_notify_send: %s - %s\n",
 230                   fsp_str_dbg(fsp), fsp_fnum_dbg(fsp)));
 231
 232         smbreq = smbd_smb2_fake_smb_request(smb2req);
 233         if (tevent_req_nomem(smbreq, req)) {
 234                 return tevent_req_post(req, ev);
 235         }
 236
 237         state->smbreq = smbreq;
 238         smbreq->async_priv = (void *)req;
 239
 240         if (DEBUGLEVEL >= 3) {
 241                 char *filter_string;
 242
 243                 filter_string = notify_filter_string(NULL, in_completion_filter);
 244                 if (tevent_req_nomem(filter_string, req)) {
 245                         return tevent_req_post(req, ev);
 246                 }
 247
 248                 DEBUG(3,("smbd_smb2_notify_send: notify change "
 249                          "called on %s, filter = %s, recursive = %d\n",
 250                          fsp_str_dbg(fsp), filter_string, recursive));
 251
 252                 TALLOC_FREE(filter_string);
 253         }
 254
 255         if ((!fsp->is_directory) || (conn != fsp->conn)) {
 256                 tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
 257                 return tevent_req_post(req, ev);
 258         }
 259
 260         if (fsp->notify == NULL) {
 261
 262                 status = change_notify_create(fsp,
 263                                               in_completion_filter,
 264                                               recursive);
 265                 if (!NT_STATUS_IS_OK(status)) {
 266                         DEBUG(10, ("change_notify_create returned %s\n",
 267                                    nt_errstr(status)));
 268                         tevent_req_nterror(req, status);
 269                         return tevent_req_post(req, ev);
 270                 }
 271         }
 272
 273         if (change_notify_fsp_has_changes(fsp)) {
 274
 275                 /*
 276                  * We've got changes pending, respond immediately
 277                  */
 278
 279                 /*
 280                  * TODO: write a torture test to check the filtering behaviour
 281                  * here.
 282                  */
 283
 284                 change_notify_reply(smbreq,
 285                                     NT_STATUS_OK,
 286                                     in_output_buffer_length,
 287                                     fsp->notify,
 288                                     smbd_smb2_notify_reply);
 289
 290                 /*
 291                  * change_notify_reply() above has independently
 292                  * called tevent_req_done().
 293                  */
 294                 return tevent_req_post(req, ev);
 295         }
 296
 297         /*
 298          * No changes pending, queue the request
 299          */
 300
 301         status = change_notify_add_request(smbreq,
 302                         in_output_buffer_length,
 303                         in_completion_filter,
 304                         recursive, fsp,
 305                         smbd_smb2_notify_reply);
 306         if (!NT_STATUS_IS_OK(status)) {
 307                 tevent_req_nterror(req, status);
 308                 return tevent_req_post(req, ev);
 309         }
 310
 311         /*
 312          * This is a HACK!
 313          *
 314          * change_notify_add_request() talloc_moves()
 315          * smbreq away from us, so we need a destructor
 316          * which moves it back at the end.
 317          */
 318         state->has_request = true;
 319         talloc_set_destructor(smbreq, smbd_smb2_notify_smbreq_destructor);
 320
 321         /* allow this request to be canceled */
 322         tevent_req_set_cancel_fn(req, smbd_smb2_notify_cancel);
 323
 324         return req;
 325 }
 326
 327 static void smbd_smb2_notify_reply(struct smb_request *smbreq,
 328                                    NTSTATUS error_code,
 329                                    uint8_t *buf, size_t len)
 330 {
 331         struct tevent_req *req = talloc_get_type_abort(smbreq->async_priv,
 332                                                        struct tevent_req);
 333         struct smbd_smb2_notify_state *state = tevent_req_data(req,
 334                                                struct smbd_smb2_notify_state);
 335
 336         if (state->skip_reply) {
 337                 return;
 338         }
 339
 340         state->status = error_code;
 341         if (!NT_STATUS_IS_OK(error_code)) {
 342                 /* nothing */
 343         } else if (len == 0) {
 344                 state->status = STATUS_NOTIFY_ENUM_DIR;
 345         } else {
 346                 state->out_output_buffer = data_blob_talloc(state, buf, len);
 347                 if (state->out_output_buffer.data == NULL) {
 348                         state->status = NT_STATUS_NO_MEMORY;
 349                 }
 350         }
 351
 352         tevent_req_defer_callback(req, state->smb2req->sconn->ev_ctx);
 353
 354         if (!NT_STATUS_IS_OK(state->status)) {
 355                 tevent_req_nterror(req, state->status);
 356                 return;
 357         }
 358
 359         tevent_req_done(req);
 360 }
 361
 362 static bool smbd_smb2_notify_cancel(struct tevent_req *req)
 363 {
 364         struct smbd_smb2_notify_state *state = tevent_req_data(req,
 365                                                struct smbd_smb2_notify_state);
 366
 367         smbd_notify_cancel_by_smbreq(state->smbreq);
 368
 369         return true;
 370 }
 371
 372 static NTSTATUS smbd_smb2_notify_recv(struct tevent_req *req,
 373                                       TALLOC_CTX *mem_ctx,
 374                                       DATA_BLOB *out_output_buffer)
 375 {
 376         NTSTATUS status;
 377         struct smbd_smb2_notify_state *state = tevent_req_data(req,
 378                                                struct smbd_smb2_notify_state);
 379
 380         if (tevent_req_is_nterror(req, &status)) {
 381                 tevent_req_received(req);
 382                 return status;
 383         }
 384
 385         *out_output_buffer = state->out_output_buffer;
 386         talloc_steal(mem_ctx, out_output_buffer->data);
 387
 388         tevent_req_received(req);
 389         return NT_STATUS_OK;
 390 }