libcli/smb/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 "system/network.h"
  22 #include "lib/util/tevent_ntstatus.h"
  23 #include "smb_common.h"
  24 #include "smbXcli_base.h"
  25
  26 struct smb2cli_read_state {
  27         uint8_t fixed[48];
  28         uint8_t dyn_pad[1];
  29         struct iovec *recv_iov;
  30         uint8_t *data;
  31         uint32_t data_length;
  32 };
  33
  34 static void smb2cli_read_done(struct tevent_req *subreq);
  35
  36 struct tevent_req *smb2cli_read_send(TALLOC_CTX *mem_ctx,
  37                                      struct tevent_context *ev,
  38                                      struct smbXcli_conn *conn,
  39                                      uint32_t timeout_msec,
  40                                      struct smbXcli_session *session,
  41                                      struct smbXcli_tcon *tcon,
  42                                      uint32_t length,
  43                                      uint64_t offset,
  44                                      uint64_t fid_persistent,
  45                                      uint64_t fid_volatile,
  46                                      uint64_t minimum_count,
  47                                      uint64_t remaining_bytes)
  48 {
  49         struct tevent_req *req, *subreq;
  50         struct smb2cli_read_state *state;
  51         uint8_t *fixed;
  52
  53         req = tevent_req_create(mem_ctx, &state,
  54                                 struct smb2cli_read_state);
  55         if (req == NULL) {
  56                 return NULL;
  57         }
  58
  59         fixed = state->fixed;
  60
  61         SSVAL(fixed, 0, 49);
  62         SIVAL(fixed, 4, length);
  63         SBVAL(fixed, 8, offset);
  64         SBVAL(fixed, 16, fid_persistent);
  65         SBVAL(fixed, 24, fid_volatile);
  66         SBVAL(fixed, 32, minimum_count);
  67         SBVAL(fixed, 40, remaining_bytes);
  68
  69         subreq = smb2cli_req_send(state, ev, conn, SMB2_OP_READ,
  70                                   0, 0, /* flags */
  71                                   timeout_msec,
  72                                   tcon,
  73                                   session,
  74                                   state->fixed, sizeof(state->fixed),
  75                                   state->dyn_pad, sizeof(state->dyn_pad));
  76         if (tevent_req_nomem(subreq, req)) {
  77                 return tevent_req_post(req, ev);
  78         }
  79         tevent_req_set_callback(subreq, smb2cli_read_done, req);
  80         return req;
  81 }
  82
  83 static void smb2cli_read_done(struct tevent_req *subreq)
  84 {
  85         struct tevent_req *req = tevent_req_callback_data(
  86                 subreq, struct tevent_req);
  87         struct smb2cli_read_state *state =
  88                 tevent_req_data(req,
  89                 struct smb2cli_read_state);
  90         NTSTATUS status;
  91         struct iovec *iov;
  92         uint8_t data_offset;
  93         static const struct smb2cli_req_expected_response expected[] = {
  94         {
  95                 .status = STATUS_BUFFER_OVERFLOW,
  96                 .body_size = 0x11
  97         },
  98         {
  99                 .status = NT_STATUS_OK,
 100                 .body_size = 0x11
 101         }
 102         };
 103
 104         status = smb2cli_req_recv(subreq, state, &iov,
 105                                   expected, ARRAY_SIZE(expected));
 106         if (tevent_req_nterror(req, status)) {
 107                 return;
 108         }
 109
 110         data_offset = CVAL(iov[1].iov_base, 2);
 111         state->data_length = IVAL(iov[1].iov_base, 4);
 112
 113         if ((data_offset != SMB2_HDR_BODY + 16) ||
 114             (state->data_length > iov[2].iov_len)) {
 115                 tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
 116                 return;
 117         }
 118
 119         state->recv_iov = iov;
 120         state->data = (uint8_t *)iov[2].iov_base;
 121         tevent_req_done(req);
 122 }
 123
 124 NTSTATUS smb2cli_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 125                            uint8_t **data, uint32_t *data_length)
 126 {
 127         struct smb2cli_read_state *state =
 128                 tevent_req_data(req,
 129                 struct smb2cli_read_state);
 130         NTSTATUS status;
 131
 132         if (tevent_req_is_nterror(req, &status)) {
 133                 return status;
 134         }
 135         talloc_steal(mem_ctx, state->recv_iov);
 136         *data_length = state->data_length;
 137         *data = state->data;
 138         return NT_STATUS_OK;
 139 }
 140
 141 NTSTATUS smb2cli_read(struct smbXcli_conn *conn,
 142                       uint32_t timeout_msec,
 143                       struct smbXcli_session *session,
 144                       struct smbXcli_tcon *tcon,
 145                       uint32_t length,
 146                       uint64_t offset,
 147                       uint64_t fid_persistent,
 148                       uint64_t fid_volatile,
 149                       uint64_t minimum_count,
 150                       uint64_t remaining_bytes,
 151                       TALLOC_CTX *mem_ctx,
 152                       uint8_t **data,
 153                       uint32_t *data_length)
 154 {
 155         TALLOC_CTX *frame = talloc_stackframe();
 156         struct tevent_context *ev;
 157         struct tevent_req *req;
 158         NTSTATUS status = NT_STATUS_NO_MEMORY;
 159
 160         if (smbXcli_conn_has_async_calls(conn)) {
 161                 /*
 162                  * Can't use sync call while an async call is in flight
 163                  */
 164                 status = NT_STATUS_INVALID_PARAMETER;
 165                 goto fail;
 166         }
 167         ev = tevent_context_init(frame);
 168         if (ev == NULL) {
 169                 goto fail;
 170         }
 171         req = smb2cli_read_send(frame, ev,
 172                                 conn, timeout_msec, session, tcon,
 173                                 length, offset,
 174                                 fid_persistent, fid_volatile,
 175                                 minimum_count, remaining_bytes);
 176         if (req == NULL) {
 177                 goto fail;
 178         }
 179         if (!tevent_req_poll_ntstatus(req, ev, &status)) {
 180                 goto fail;
 181         }
 182         status = smb2cli_read_recv(req, mem_ctx, data, data_length);
 183  fail:
 184         TALLOC_FREE(frame);
 185         return status;
 186 }