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         NTSTATUS status;
  52         const uint8_t *inbody;
  53         uint16_t in_flags;
  54         uint32_t in_output_buffer_length;
  55         uint64_t in_file_id_persistent;
  56         uint64_t in_file_id_volatile;
  57         struct files_struct *in_fsp;
  58         uint64_t in_completion_filter;
  59         struct tevent_req *subreq;
  60
  61         status = smbd_smb2_request_verify_sizes(req, 0x20);
  62         if (!NT_STATUS_IS_OK(status)) {
  63                 return smbd_smb2_request_error(req, status);
  64         }
  65         inbody = SMBD_SMB2_IN_BODY_PTR(req);
  66
  67         in_flags                = SVAL(inbody, 0x02);
  68         in_output_buffer_length = IVAL(inbody, 0x04);
  69         in_file_id_persistent   = BVAL(inbody, 0x08);
  70         in_file_id_volatile     = BVAL(inbody, 0x10);
  71         in_completion_filter    = IVAL(inbody, 0x18);
  72
  73         /*
  74          * 0x00010000 is what Windows 7 uses,
  75          * Windows 2008 uses 0x00080000
  76          */
  77         if (in_output_buffer_length > req->sconn->smb2.max_trans) {
  78                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
  79         }
  80
  81         status = smbd_smb2_request_verify_creditcharge(req,
  82                                                 in_output_buffer_length);
  83
  84         if (!NT_STATUS_IS_OK(status)) {
  85                 return smbd_smb2_request_error(req, status);
  86         }
  87
  88         in_fsp = file_fsp_smb2(req, in_file_id_persistent, in_file_id_volatile);
  89         if (in_fsp == NULL) {
  90                 return smbd_smb2_request_error(req, NT_STATUS_FILE_CLOSED);
  91         }
  92
  93         subreq = smbd_smb2_notify_send(req, req->sconn->ev_ctx,
  94                                        req, in_fsp,
  95                                        in_flags,
  96                                        in_output_buffer_length,
  97                                        in_completion_filter);
  98         if (subreq == NULL) {
  99                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 100         }
 101         tevent_req_set_callback(subreq, smbd_smb2_request_notify_done, req);
 102
 103         return smbd_smb2_request_pending_queue(req, subreq, 500);
 104 }
 105
 106 static void smbd_smb2_request_notify_done(struct tevent_req *subreq)
 107 {
 108         struct smbd_smb2_request *req = tevent_req_callback_data(subreq,
 109                                         struct smbd_smb2_request);
 110         DATA_BLOB outbody;
 111         DATA_BLOB outdyn;
 112         uint16_t out_output_buffer_offset;
 113         DATA_BLOB out_output_buffer = data_blob_null;
 114         NTSTATUS status;
 115         NTSTATUS error; /* transport error */
 116
 117         status = smbd_smb2_notify_recv(subreq,
 118                                        req,
 119                                        &out_output_buffer);
 120         TALLOC_FREE(subreq);
 121         if (!NT_STATUS_IS_OK(status)) {
 122                 error = smbd_smb2_request_error(req, status);
 123                 if (!NT_STATUS_IS_OK(error)) {
 124                         smbd_server_connection_terminate(req->sconn,
 125                                                          nt_errstr(error));
 126                         return;
 127                 }
 128                 return;
 129         }
 130
 131         out_output_buffer_offset = SMB2_HDR_BODY + 0x08;
 132
 133         outbody = smbd_smb2_generate_outbody(req, 0x08);
 134         if (outbody.data == NULL) {
 135                 error = smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 136                 if (!NT_STATUS_IS_OK(error)) {
 137                         smbd_server_connection_terminate(req->sconn,
 138                                                          nt_errstr(error));
 139                         return;
 140                 }
 141                 return;
 142         }
 143
 144         SSVAL(outbody.data, 0x00, 0x08 + 1);    /* struct size */
 145         SSVAL(outbody.data, 0x02,
 146               out_output_buffer_offset);        /* output buffer offset */
 147         SIVAL(outbody.data, 0x04,
 148               out_output_buffer.length);        /* output buffer length */
 149
 150         outdyn = out_output_buffer;
 151
 152         error = smbd_smb2_request_done(req, outbody, &outdyn);
 153         if (!NT_STATUS_IS_OK(error)) {
 154                 smbd_server_connection_terminate(req->sconn,
 155                                                  nt_errstr(error));
 156                 return;
 157         }
 158 }
 159
 160 static void smbd_smb2_notify_reply(struct smb_request *smbreq,
 161                                    NTSTATUS error_code,
 162                                    uint8_t *buf, size_t len);
 163 static bool smbd_smb2_notify_cancel(struct tevent_req *req);
 164
 165 static int smbd_smb2_notify_state_destructor(struct smbd_smb2_notify_state *state)
 166 {
 167         if (!state->has_request) {
 168                 return 0;
 169         }
 170
 171         state->skip_reply = true;
 172         smbd_notify_cancel_by_smbreq(state->smbreq);
 173         return 0;
 174 }
 175
 176 static int smbd_smb2_notify_smbreq_destructor(struct smb_request *smbreq)
 177 {
 178         struct tevent_req *req = talloc_get_type_abort(smbreq->async_priv,
 179                                                        struct tevent_req);
 180         struct smbd_smb2_notify_state *state = tevent_req_data(req,
 181                                                struct smbd_smb2_notify_state);
 182
 183         /*
 184          * Our temporary parent from change_notify_add_request()
 185          * goes away.
 186          */
 187         state->has_request = false;
 188
 189         /*
 190          * move it back to its original parent,
 191          * which means we no longer need the destructor
 192          * to protect it.
 193          */
 194         talloc_steal(smbreq->smb2req, smbreq);
 195         talloc_set_destructor(smbreq, NULL);
 196
 197         /*
 198          * We want to keep smbreq!
 199          */
 200         return -1;
 201 }
 202
 203 static struct tevent_req *smbd_smb2_notify_send(TALLOC_CTX *mem_ctx,
 204                                                 struct tevent_context *ev,
 205                                                 struct smbd_smb2_request *smb2req,
 206                                                 struct files_struct *fsp,
 207                                                 uint16_t in_flags,
 208                                                 uint32_t in_output_buffer_length,
 209                                                 uint64_t in_completion_filter)
 210 {
 211         struct tevent_req *req;
 212         struct smbd_smb2_notify_state *state;
 213         struct smb_request *smbreq;
 214         connection_struct *conn = smb2req->tcon->compat;
 215         bool recursive = (in_flags & SMB2_WATCH_TREE) ? true : false;
 216         NTSTATUS status;
 217
 218         req = tevent_req_create(mem_ctx, &state,
 219                                 struct smbd_smb2_notify_state);
 220         if (req == NULL) {
 221                 return NULL;
 222         }
 223         state->smb2req = smb2req;
 224         state->status = NT_STATUS_INTERNAL_ERROR;
 225         state->out_output_buffer = data_blob_null;
 226         talloc_set_destructor(state, smbd_smb2_notify_state_destructor);
 227
 228         DEBUG(10,("smbd_smb2_notify_send: %s - %s\n",
 229                   fsp_str_dbg(fsp), fsp_fnum_dbg(fsp)));
 230
 231         smbreq = smbd_smb2_fake_smb_request(smb2req);
 232         if (tevent_req_nomem(smbreq, req)) {
 233                 return tevent_req_post(req, ev);
 234         }
 235
 236         state->smbreq = smbreq;
 237         smbreq->async_priv = (void *)req;
 238
 239         if (DEBUGLEVEL >= 3) {
 240                 char *filter_string;
 241
 242                 filter_string = notify_filter_string(NULL, in_completion_filter);
 243                 if (tevent_req_nomem(filter_string, req)) {
 244                         return tevent_req_post(req, ev);
 245                 }
 246
 247                 DEBUG(3,("smbd_smb2_notify_send: notify change "
 248                          "called on %s, filter = %s, recursive = %d\n",
 249                          fsp_str_dbg(fsp), filter_string, recursive));
 250
 251                 TALLOC_FREE(filter_string);
 252         }
 253
 254         if ((!fsp->is_directory) || (conn != fsp->conn)) {
 255                 tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
 256                 return tevent_req_post(req, ev);
 257         }
 258
 259         if (fsp->notify == NULL) {
 260
 261                 status = change_notify_create(fsp,
 262                                               in_completion_filter,
 263                                               recursive);
 264                 if (!NT_STATUS_IS_OK(status)) {
 265                         DEBUG(10, ("change_notify_create returned %s\n",
 266                                    nt_errstr(status)));
 267                         tevent_req_nterror(req, status);
 268                         return tevent_req_post(req, ev);
 269                 }
 270         }
 271
 272         if (change_notify_fsp_has_changes(fsp)) {
 273
 274                 /*
 275                  * We've got changes pending, respond immediately
 276                  */
 277
 278                 /*
 279                  * TODO: write a torture test to check the filtering behaviour
 280                  * here.
 281                  */
 282
 283                 change_notify_reply(smbreq,
 284                                     NT_STATUS_OK,
 285                                     in_output_buffer_length,
 286                                     fsp->notify,
 287                                     smbd_smb2_notify_reply);
 288
 289                 /*
 290                  * change_notify_reply() above has independently
 291                  * called tevent_req_done().
 292                  */
 293                 return tevent_req_post(req, ev);
 294         }
 295
 296         /*
 297          * No changes pending, queue the request
 298          */
 299
 300         status = change_notify_add_request(smbreq,
 301                         in_output_buffer_length,
 302                         in_completion_filter,
 303                         recursive, fsp,
 304                         smbd_smb2_notify_reply);
 305         if (!NT_STATUS_IS_OK(status)) {
 306                 tevent_req_nterror(req, status);
 307                 return tevent_req_post(req, ev);
 308         }
 309
 310         /*
 311          * This is a HACK!
 312          *
 313          * change_notify_add_request() talloc_moves()
 314          * smbreq away from us, so we need a destructor
 315          * which moves it back at the end.
 316          */
 317         state->has_request = true;
 318         talloc_set_destructor(smbreq, smbd_smb2_notify_smbreq_destructor);
 319
 320         /* allow this request to be canceled */
 321         tevent_req_set_cancel_fn(req, smbd_smb2_notify_cancel);
 322
 323         return req;
 324 }
 325
 326 static void smbd_smb2_notify_reply(struct smb_request *smbreq,
 327                                    NTSTATUS error_code,
 328                                    uint8_t *buf, size_t len)
 329 {
 330         struct tevent_req *req = talloc_get_type_abort(smbreq->async_priv,
 331                                                        struct tevent_req);
 332         struct smbd_smb2_notify_state *state = tevent_req_data(req,
 333                                                struct smbd_smb2_notify_state);
 334
 335         if (state->skip_reply) {
 336                 return;
 337         }
 338
 339         state->status = error_code;
 340         if (!NT_STATUS_IS_OK(error_code)) {
 341                 /* nothing */
 342         } else if (len == 0) {
 343                 state->status = STATUS_NOTIFY_ENUM_DIR;
 344         } else {
 345                 state->out_output_buffer = data_blob_talloc(state, buf, len);
 346                 if (state->out_output_buffer.data == NULL) {
 347                         state->status = NT_STATUS_NO_MEMORY;
 348                 }
 349         }
 350
 351         tevent_req_defer_callback(req, state->smb2req->sconn->ev_ctx);
 352
 353         if (!NT_STATUS_IS_OK(state->status)) {
 354                 tevent_req_nterror(req, state->status);
 355                 return;
 356         }
 357
 358         tevent_req_done(req);
 359 }
 360
 361 static bool smbd_smb2_notify_cancel(struct tevent_req *req)
 362 {
 363         struct smbd_smb2_notify_state *state = tevent_req_data(req,
 364                                                struct smbd_smb2_notify_state);
 365
 366         smbd_notify_cancel_by_smbreq(state->smbreq);
 367
 368         return true;
 369 }
 370
 371 static NTSTATUS smbd_smb2_notify_recv(struct tevent_req *req,
 372                                       TALLOC_CTX *mem_ctx,
 373                                       DATA_BLOB *out_output_buffer)
 374 {
 375         NTSTATUS status;
 376         struct smbd_smb2_notify_state *state = tevent_req_data(req,
 377                                                struct smbd_smb2_notify_state);
 378
 379         if (tevent_req_is_nterror(req, &status)) {
 380                 tevent_req_received(req);
 381                 return status;
 382         }
 383
 384         *out_output_buffer = state->out_output_buffer;
 385         talloc_steal(mem_ctx, out_output_buffer->data);
 386
 387         tevent_req_received(req);
 388         return NT_STATUS_OK;
 389 }