source3/libsmb/smb2cli_read.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    smb2 lib
   4    Copyright (C) Volker Lendecke 2011
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "client.h"
  22 #include "async_smb.h"
  23 #include "smb2cli_base.h"
  24 #include "smb2cli.h"
  25 #include "libsmb/proto.h"
  26 #include "lib/util/tevent_ntstatus.h"
  27
  28 struct smb2cli_read_state {
  29         uint8_t fixed[48];
  30         uint8_t dyn_pad[1];
  31         struct iovec *recv_iov;
  32         uint8_t *data;
  33         uint32_t data_length;
  34 };
  35
  36 static void smb2cli_read_done(struct tevent_req *subreq);
  37
  38 struct tevent_req *smb2cli_read_send(TALLOC_CTX *mem_ctx,
  39                                      struct tevent_context *ev,
  40                                      struct cli_state *cli,
  41                                      uint32_t length,
  42                                      uint64_t offset,
  43                                      uint64_t fid_persistent,
  44                                      uint64_t fid_volatile,
  45                                      uint64_t minimum_count,
  46                                      uint64_t remaining_bytes)
  47 {
  48         struct tevent_req *req, *subreq;
  49         struct smb2cli_read_state *state;
  50         uint8_t *fixed;
  51
  52         req = tevent_req_create(mem_ctx, &state,
  53                                 struct smb2cli_read_state);
  54         if (req == NULL) {
  55                 return NULL;
  56         }
  57
  58         fixed = state->fixed;
  59
  60         SSVAL(fixed, 0, 49);
  61         SIVAL(fixed, 4, length);
  62         SBVAL(fixed, 8, offset);
  63         SBVAL(fixed, 16, fid_persistent);
  64         SBVAL(fixed, 24, fid_volatile);
  65         SBVAL(fixed, 32, minimum_count);
  66         SBVAL(fixed, 40, remaining_bytes);
  67
  68         subreq = smb2cli_req_send(state, ev, cli, SMB2_OP_READ,
  69                                   0, 0, /* flags */
  70                                   cli->smb2.pid,
  71                                   cli->smb2.tid,
  72                                   cli->smb2.uid,
  73                                   state->fixed, sizeof(state->fixed),
  74                                   state->dyn_pad, sizeof(state->dyn_pad));
  75         if (tevent_req_nomem(subreq, req)) {
  76                 return tevent_req_post(req, ev);
  77         }
  78         tevent_req_set_callback(subreq, smb2cli_read_done, req);
  79         return req;
  80 }
  81
  82 static void smb2cli_read_done(struct tevent_req *subreq)
  83 {
  84         struct tevent_req *req = tevent_req_callback_data(
  85                 subreq, struct tevent_req);
  86         struct smb2cli_read_state *state =
  87                 tevent_req_data(req,
  88                 struct smb2cli_read_state);
  89         NTSTATUS status;
  90         struct iovec *iov;
  91         uint8_t data_offset;
  92
  93         status = smb2cli_req_recv(subreq, state, &iov, 17);
  94         if (tevent_req_nterror(req, status)) {
  95                 return;
  96         }
  97
  98         data_offset = CVAL(iov[1].iov_base, 2);
  99         state->data_length = IVAL(iov[1].iov_base, 4);
 100
 101         if ((data_offset != SMB2_HDR_BODY + 16) ||
 102             (state->data_length > iov[2].iov_len)) {
 103                 tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
 104                 return;
 105         }
 106
 107         state->recv_iov = iov;
 108         state->data = (uint8_t *)iov[2].iov_base;
 109         tevent_req_done(req);
 110 }
 111
 112 NTSTATUS smb2cli_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 113                            uint8_t **data, uint32_t *data_length)
 114 {
 115         struct smb2cli_read_state *state =
 116                 tevent_req_data(req,
 117                 struct smb2cli_read_state);
 118         NTSTATUS status;
 119
 120         if (tevent_req_is_nterror(req, &status)) {
 121                 return status;
 122         }
 123         talloc_steal(mem_ctx, state->recv_iov);
 124         *data_length = state->data_length;
 125         *data = state->data;
 126         return NT_STATUS_OK;
 127 }
 128
 129 NTSTATUS smb2cli_read(struct cli_state *cli,
 130                       uint32_t length,
 131                       uint64_t offset,
 132                       uint64_t fid_persistent,
 133                       uint64_t fid_volatile,
 134                       uint64_t minimum_count,
 135                       uint64_t remaining_bytes,
 136                       TALLOC_CTX *mem_ctx,
 137                       uint8_t **data,
 138                       uint32_t *data_length)
 139 {
 140         TALLOC_CTX *frame = talloc_stackframe();
 141         struct event_context *ev;
 142         struct tevent_req *req;
 143         NTSTATUS status = NT_STATUS_NO_MEMORY;
 144
 145         if (cli_has_async_calls(cli)) {
 146                 /*
 147                  * Can't use sync call while an async call is in flight
 148                  */
 149                 status = NT_STATUS_INVALID_PARAMETER;
 150                 goto fail;
 151         }
 152         ev = event_context_init(frame);
 153         if (ev == NULL) {
 154                 goto fail;
 155         }
 156         req = smb2cli_read_send(frame, ev, cli, length, offset,
 157                                 fid_persistent, fid_volatile,
 158                                 minimum_count, remaining_bytes);
 159         if (req == NULL) {
 160                 goto fail;
 161         }
 162         if (!tevent_req_poll_ntstatus(req, ev, &status)) {
 163                 goto fail;
 164         }
 165         status = smb2cli_read_recv(req, mem_ctx, data, data_length);
 166  fail:
 167         TALLOC_FREE(frame);
 168         return status;
 169 }