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 *inbuf;
  31         uint8_t *data;
  32         uint32_t data_length;
  33 };
  34
  35 static void smb2cli_read_done(struct tevent_req *subreq);
  36
  37 struct tevent_req *smb2cli_read_send(TALLOC_CTX *mem_ctx,
  38                                      struct tevent_context *ev,
  39                                      struct cli_state *cli,
  40                                      uint32_t length,
  41                                      uint64_t offset,
  42                                      uint64_t fid_persistent,
  43                                      uint64_t fid_volatile,
  44                                      uint64_t minimum_count,
  45                                      uint64_t remaining_bytes)
  46 {
  47         struct tevent_req *req, *subreq;
  48         struct smb2cli_read_state *state;
  49         uint8_t *fixed;
  50
  51         req = tevent_req_create(mem_ctx, &state,
  52                                 struct smb2cli_read_state);
  53         if (req == NULL) {
  54                 return NULL;
  55         }
  56
  57         fixed = state->fixed;
  58
  59         SSVAL(fixed, 0, 49);
  60         SIVAL(fixed, 4, length);
  61         SBVAL(fixed, 8, offset);
  62         SBVAL(fixed, 16, fid_persistent);
  63         SBVAL(fixed, 24, fid_volatile);
  64         SBVAL(fixed, 32, minimum_count);
  65         SBVAL(fixed, 40, remaining_bytes);
  66
  67         subreq = smb2cli_req_send(state, ev, cli, SMB2_OP_READ, 0,
  68                                   state->fixed, sizeof(state->fixed),
  69                                   NULL, 0);
  70         if (tevent_req_nomem(subreq, req)) {
  71                 return tevent_req_post(req, ev);
  72         }
  73         tevent_req_set_callback(subreq, smb2cli_read_done, req);
  74         return req;
  75 }
  76
  77 static void smb2cli_read_done(struct tevent_req *subreq)
  78 {
  79         struct tevent_req *req = tevent_req_callback_data(
  80                 subreq, struct tevent_req);
  81         struct smb2cli_read_state *state =
  82                 tevent_req_data(req,
  83                 struct smb2cli_read_state);
  84         NTSTATUS status;
  85         struct iovec *iov;
  86         uint8_t data_offset;
  87
  88         status = smb2cli_req_recv(subreq, talloc_tos(), &iov, 17);
  89         if (tevent_req_nterror(req, status)) {
  90                 return;
  91         }
  92
  93         data_offset = CVAL(iov[1].iov_base, 2);
  94         state->data_length = IVAL(iov[1].iov_base, 4);
  95
  96         if ((data_offset != SMB2_HDR_BODY + 16) ||
  97             (state->data_length > iov[2].iov_len)) {
  98                 tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
  99                 return;
 100         }
 101         state->inbuf = smb2cli_req_inbuf(subreq);
 102         state->data = (uint8_t *)iov[2].iov_base;
 103         tevent_req_done(req);
 104 }
 105
 106 NTSTATUS smb2cli_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 107                            uint8_t **data, uint32_t *data_length)
 108 {
 109         struct smb2cli_read_state *state =
 110                 tevent_req_data(req,
 111                 struct smb2cli_read_state);
 112         NTSTATUS status;
 113
 114         if (tevent_req_is_nterror(req, &status)) {
 115                 return status;
 116         }
 117         talloc_steal(mem_ctx, state->inbuf);
 118         *data_length = state->data_length;
 119         *data = state->data;
 120         return NT_STATUS_OK;
 121 }
 122
 123 NTSTATUS smb2cli_read(struct cli_state *cli,
 124                       uint32_t length,
 125                       uint64_t offset,
 126                       uint64_t fid_persistent,
 127                       uint64_t fid_volatile,
 128                       uint64_t minimum_count,
 129                       uint64_t remaining_bytes,
 130                       TALLOC_CTX *mem_ctx,
 131                       uint8_t **data,
 132                       uint32_t *data_length)
 133 {
 134         TALLOC_CTX *frame = talloc_stackframe();
 135         struct event_context *ev;
 136         struct tevent_req *req;
 137         NTSTATUS status = NT_STATUS_NO_MEMORY;
 138
 139         if (cli_has_async_calls(cli)) {
 140                 /*
 141                  * Can't use sync call while an async call is in flight
 142                  */
 143                 status = NT_STATUS_INVALID_PARAMETER;
 144                 goto fail;
 145         }
 146         ev = event_context_init(frame);
 147         if (ev == NULL) {
 148                 goto fail;
 149         }
 150         req = smb2cli_read_send(frame, ev, cli, length, offset,
 151                                 fid_persistent, fid_volatile,
 152                                 minimum_count, remaining_bytes);
 153         if (req == NULL) {
 154                 goto fail;
 155         }
 156         if (!tevent_req_poll_ntstatus(req, ev, &status)) {
 157                 goto fail;
 158         }
 159         status = smb2cli_read_recv(req, mem_ctx, data, data_length);
 160  fail:
 161         TALLOC_FREE(frame);
 162         return status;
 163 }