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         struct tevent_immediate *im;
  32         NTSTATUS status;
  33         DATA_BLOB out_output_buffer;
  34 };
  35
  36 static struct tevent_req *smbd_smb2_notify_send(TALLOC_CTX *mem_ctx,
  37                                                 struct tevent_context *ev,
  38                                                 struct smbd_smb2_request *smb2req,
  39                                                 struct files_struct *in_fsp,
  40                                                 uint16_t in_flags,
  41                                                 uint32_t in_output_buffer_length,
  42                                                 uint64_t in_completion_filter);
  43 static NTSTATUS smbd_smb2_notify_recv(struct tevent_req *req,
  44                                       TALLOC_CTX *mem_ctx,
  45                                       DATA_BLOB *out_output_buffer);
  46
  47 static void smbd_smb2_request_notify_done(struct tevent_req *subreq);
  48 NTSTATUS smbd_smb2_request_process_notify(struct smbd_smb2_request *req)
  49 {
  50         NTSTATUS status;
  51         const uint8_t *inbody;
  52         uint16_t in_flags;
  53         uint32_t in_output_buffer_length;
  54         uint64_t in_file_id_persistent;
  55         uint64_t in_file_id_volatile;
  56         struct files_struct *in_fsp;
  57         uint64_t in_completion_filter;
  58         struct tevent_req *subreq;
  59
  60         status = smbd_smb2_request_verify_sizes(req, 0x20);
  61         if (!NT_STATUS_IS_OK(status)) {
  62                 return smbd_smb2_request_error(req, status);
  63         }
  64         inbody = SMBD_SMB2_IN_BODY_PTR(req);
  65
  66         in_flags                = SVAL(inbody, 0x02);
  67         in_output_buffer_length = IVAL(inbody, 0x04);
  68         in_file_id_persistent   = BVAL(inbody, 0x08);
  69         in_file_id_volatile     = BVAL(inbody, 0x10);
  70         in_completion_filter    = IVAL(inbody, 0x18);
  71
  72         /*
  73          * 0x00010000 is what Windows 7 uses,
  74          * Windows 2008 uses 0x00080000
  75          */
  76         if (in_output_buffer_length > req->sconn->smb2.max_trans) {
  77                 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
  78         }
  79
  80         status = smbd_smb2_request_verify_creditcharge(req,
  81                                                 in_output_buffer_length);
  82
  83         if (!NT_STATUS_IS_OK(status)) {
  84                 return smbd_smb2_request_error(req, status);
  85         }
  86
  87         in_fsp = file_fsp_smb2(req, in_file_id_persistent, in_file_id_volatile);
  88         if (in_fsp == NULL) {
  89                 return smbd_smb2_request_error(req, NT_STATUS_FILE_CLOSED);
  90         }
  91
  92         subreq = smbd_smb2_notify_send(req, req->sconn->ev_ctx,
  93                                        req, in_fsp,
  94                                        in_flags,
  95                                        in_output_buffer_length,
  96                                        in_completion_filter);
  97         if (subreq == NULL) {
  98                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
  99         }
 100         tevent_req_set_callback(subreq, smbd_smb2_request_notify_done, req);
 101
 102         return smbd_smb2_request_pending_queue(req, subreq, 500);
 103 }
 104
 105 static void smbd_smb2_request_notify_done(struct tevent_req *subreq)
 106 {
 107         struct smbd_smb2_request *req = tevent_req_callback_data(subreq,
 108                                         struct smbd_smb2_request);
 109         DATA_BLOB outbody;
 110         DATA_BLOB outdyn;
 111         uint16_t out_output_buffer_offset;
 112         DATA_BLOB out_output_buffer = data_blob_null;
 113         NTSTATUS status;
 114         NTSTATUS error; /* transport error */
 115
 116         if (req->cancelled) {
 117                 struct smbd_smb2_notify_state *state = tevent_req_data(subreq,
 118                                                struct smbd_smb2_notify_state);
 119                 const uint8_t *inhdr = SMBD_SMB2_IN_HDR_PTR(req);
 120                 uint64_t mid = BVAL(inhdr, SMB2_HDR_MESSAGE_ID);
 121
 122                 DEBUG(10,("smbd_smb2_request_notify_done: cancelled mid %llu\n",
 123                         (unsigned long long)mid ));
 124                 error = smbd_smb2_request_error(req, NT_STATUS_CANCELLED);
 125                 if (!NT_STATUS_IS_OK(error)) {
 126                         smbd_server_connection_terminate(req->sconn,
 127                                 nt_errstr(error));
 128                         return;
 129                 }
 130                 TALLOC_FREE(state->im);
 131                 return;
 132         }
 133
 134         status = smbd_smb2_notify_recv(subreq,
 135                                        req,
 136                                        &out_output_buffer);
 137         TALLOC_FREE(subreq);
 138         if (!NT_STATUS_IS_OK(status)) {
 139                 error = smbd_smb2_request_error(req, status);
 140                 if (!NT_STATUS_IS_OK(error)) {
 141                         smbd_server_connection_terminate(req->sconn,
 142                                                          nt_errstr(error));
 143                         return;
 144                 }
 145                 return;
 146         }
 147
 148         out_output_buffer_offset = SMB2_HDR_BODY + 0x08;
 149
 150         outbody = data_blob_talloc(req->out.vector, NULL, 0x08);
 151         if (outbody.data == NULL) {
 152                 error = smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 153                 if (!NT_STATUS_IS_OK(error)) {
 154                         smbd_server_connection_terminate(req->sconn,
 155                                                          nt_errstr(error));
 156                         return;
 157                 }
 158                 return;
 159         }
 160
 161         SSVAL(outbody.data, 0x00, 0x08 + 1);    /* struct size */
 162         SSVAL(outbody.data, 0x02,
 163               out_output_buffer_offset);        /* output buffer offset */
 164         SIVAL(outbody.data, 0x04,
 165               out_output_buffer.length);        /* output buffer length */
 166
 167         outdyn = out_output_buffer;
 168
 169         error = smbd_smb2_request_done(req, outbody, &outdyn);
 170         if (!NT_STATUS_IS_OK(error)) {
 171                 smbd_server_connection_terminate(req->sconn,
 172                                                  nt_errstr(error));
 173                 return;
 174         }
 175 }
 176
 177 static void smbd_smb2_notify_reply(struct smb_request *smbreq,
 178                                    NTSTATUS error_code,
 179                                    uint8_t *buf, size_t len);
 180 static void smbd_smb2_notify_reply_trigger(struct tevent_context *ctx,
 181                                            struct tevent_immediate *im,
 182                                            void *private_data);
 183 static bool smbd_smb2_notify_cancel(struct tevent_req *req);
 184
 185 static struct tevent_req *smbd_smb2_notify_send(TALLOC_CTX *mem_ctx,
 186                                                 struct tevent_context *ev,
 187                                                 struct smbd_smb2_request *smb2req,
 188                                                 struct files_struct *fsp,
 189                                                 uint16_t in_flags,
 190                                                 uint32_t in_output_buffer_length,
 191                                                 uint64_t in_completion_filter)
 192 {
 193         struct tevent_req *req;
 194         struct smbd_smb2_notify_state *state;
 195         struct smb_request *smbreq;
 196         connection_struct *conn = smb2req->tcon->compat;
 197         bool recursive = (in_flags & SMB2_WATCH_TREE) ? true : false;
 198         NTSTATUS status;
 199
 200         req = tevent_req_create(mem_ctx, &state,
 201                                 struct smbd_smb2_notify_state);
 202         if (req == NULL) {
 203                 return NULL;
 204         }
 205         state->smb2req = smb2req;
 206         state->status = NT_STATUS_INTERNAL_ERROR;
 207         state->out_output_buffer = data_blob_null;
 208         state->im = NULL;
 209
 210         DEBUG(10,("smbd_smb2_notify_send: %s - %s\n",
 211                   fsp_str_dbg(fsp), fsp_fnum_dbg(fsp)));
 212
 213         smbreq = smbd_smb2_fake_smb_request(smb2req);
 214         if (tevent_req_nomem(smbreq, req)) {
 215                 return tevent_req_post(req, ev);
 216         }
 217
 218         state->smbreq = smbreq;
 219         smbreq->async_priv = (void *)req;
 220
 221         {
 222                 char *filter_string;
 223
 224                 filter_string = notify_filter_string(NULL, in_completion_filter);
 225                 if (tevent_req_nomem(filter_string, req)) {
 226                         return tevent_req_post(req, ev);
 227                 }
 228
 229                 DEBUG(3,("smbd_smb2_notify_send: notify change "
 230                          "called on %s, filter = %s, recursive = %d\n",
 231                          fsp_str_dbg(fsp), filter_string, recursive));
 232
 233                 TALLOC_FREE(filter_string);
 234         }
 235
 236         if ((!fsp->is_directory) || (conn != fsp->conn)) {
 237                 tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
 238                 return tevent_req_post(req, ev);
 239         }
 240
 241         if (fsp->notify == NULL) {
 242
 243                 status = change_notify_create(fsp,
 244                                               in_completion_filter,
 245                                               recursive);
 246                 if (!NT_STATUS_IS_OK(status)) {
 247                         DEBUG(10, ("change_notify_create returned %s\n",
 248                                    nt_errstr(status)));
 249                         tevent_req_nterror(req, status);
 250                         return tevent_req_post(req, ev);
 251                 }
 252         }
 253
 254         if (change_notify_fsp_has_changes(fsp)) {
 255
 256                 /*
 257                  * We've got changes pending, respond immediately
 258                  */
 259
 260                 /*
 261                  * TODO: write a torture test to check the filtering behaviour
 262                  * here.
 263                  */
 264
 265                 change_notify_reply(smbreq,
 266                                     NT_STATUS_OK,
 267                                     in_output_buffer_length,
 268                                     fsp->notify,
 269                                     smbd_smb2_notify_reply);
 270
 271                 /*
 272                  * change_notify_reply() above has independently
 273                  * called tevent_req_done().
 274                  */
 275                 return tevent_req_post(req, ev);
 276         }
 277
 278         state->im = tevent_create_immediate(state);
 279         if (tevent_req_nomem(state->im, req)) {
 280                 return tevent_req_post(req, ev);
 281         }
 282
 283         /*
 284          * No changes pending, queue the request
 285          */
 286
 287         status = change_notify_add_request(smbreq,
 288                         in_output_buffer_length,
 289                         in_completion_filter,
 290                         recursive, fsp,
 291                         smbd_smb2_notify_reply);
 292         if (!NT_STATUS_IS_OK(status)) {
 293                 tevent_req_nterror(req, status);
 294                 return tevent_req_post(req, ev);
 295         }
 296
 297         /* allow this request to be canceled */
 298         tevent_req_set_cancel_fn(req, smbd_smb2_notify_cancel);
 299
 300         return req;
 301 }
 302
 303 static void smbd_smb2_notify_reply(struct smb_request *smbreq,
 304                                    NTSTATUS error_code,
 305                                    uint8_t *buf, size_t len)
 306 {
 307         struct tevent_req *req = talloc_get_type_abort(smbreq->async_priv,
 308                                                        struct tevent_req);
 309         struct smbd_smb2_notify_state *state = tevent_req_data(req,
 310                                                struct smbd_smb2_notify_state);
 311
 312         state->status = error_code;
 313         if (!NT_STATUS_IS_OK(error_code)) {
 314                 /* nothing */
 315         } else if (len == 0) {
 316                 state->status = STATUS_NOTIFY_ENUM_DIR;
 317         } else {
 318                 state->out_output_buffer = data_blob_talloc(state, buf, len);
 319                 if (state->out_output_buffer.data == NULL) {
 320                         state->status = NT_STATUS_NO_MEMORY;
 321                 }
 322         }
 323
 324         if (state->im == NULL) {
 325                 smbd_smb2_notify_reply_trigger(NULL, NULL, req);
 326                 return;
 327         }
 328
 329         /*
 330          * if this is called async, we need to go via an immediate event
 331          * because the caller replies on the smb_request (a child of req
 332          * being arround after calling this function
 333          */
 334         tevent_schedule_immediate(state->im,
 335                                   state->smb2req->sconn->ev_ctx,
 336                                   smbd_smb2_notify_reply_trigger,
 337                                   req);
 338 }
 339
 340 static void smbd_smb2_notify_reply_trigger(struct tevent_context *ctx,
 341                                            struct tevent_immediate *im,
 342                                            void *private_data)
 343 {
 344         struct tevent_req *req = talloc_get_type_abort(private_data,
 345                                                        struct tevent_req);
 346         struct smbd_smb2_notify_state *state = tevent_req_data(req,
 347                                                struct smbd_smb2_notify_state);
 348
 349         if (!NT_STATUS_IS_OK(state->status)) {
 350                 tevent_req_nterror(req, state->status);
 351                 return;
 352         }
 353
 354         tevent_req_done(req);
 355 }
 356
 357 static bool smbd_smb2_notify_cancel(struct tevent_req *req)
 358 {
 359         struct smbd_smb2_notify_state *state = tevent_req_data(req,
 360                                                struct smbd_smb2_notify_state);
 361
 362         smbd_notify_cancel_by_smbreq(state->smbreq);
 363
 364         state->smb2req->cancelled = true;
 365         tevent_req_done(req);
 366         return true;
 367 }
 368
 369 static NTSTATUS smbd_smb2_notify_recv(struct tevent_req *req,
 370                                       TALLOC_CTX *mem_ctx,
 371                                       DATA_BLOB *out_output_buffer)
 372 {
 373         NTSTATUS status;
 374         struct smbd_smb2_notify_state *state = tevent_req_data(req,
 375                                                struct smbd_smb2_notify_state);
 376
 377         if (tevent_req_is_nterror(req, &status)) {
 378                 tevent_req_received(req);
 379                 return status;
 380         }
 381
 382         *out_output_buffer = state->out_output_buffer;
 383         talloc_steal(mem_ctx, out_output_buffer->data);
 384
 385         tevent_req_received(req);
 386         return NT_STATUS_OK;
 387 }