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                                   length); /* max_dyn_len */
  77         if (tevent_req_nomem(subreq, req)) {
  78                 return tevent_req_post(req, ev);
  79         }
  80         tevent_req_set_callback(subreq, smb2cli_read_done, req);
  81         return req;
  82 }
  83
  84 static void smb2cli_read_done(struct tevent_req *subreq)
  85 {
  86         struct tevent_req *req = tevent_req_callback_data(
  87                 subreq, struct tevent_req);
  88         struct smb2cli_read_state *state =
  89                 tevent_req_data(req,
  90                 struct smb2cli_read_state);
  91         NTSTATUS status;
  92         struct iovec *iov;
  93         uint8_t data_offset;
  94         static const struct smb2cli_req_expected_response expected[] = {
  95         {
  96                 .status = STATUS_BUFFER_OVERFLOW,
  97                 .body_size = 0x11
  98         },
  99         {
 100                 .status = NT_STATUS_OK,
 101                 .body_size = 0x11
 102         }
 103         };
 104
 105         status = smb2cli_req_recv(subreq, state, &iov,
 106                                   expected, ARRAY_SIZE(expected));
 107         TALLOC_FREE(subreq);
 108         if (tevent_req_nterror(req, status)) {
 109                 return;
 110         }
 111
 112         data_offset = CVAL(iov[1].iov_base, 2);
 113         state->data_length = IVAL(iov[1].iov_base, 4);
 114
 115         if ((data_offset != SMB2_HDR_BODY + 16) ||
 116             (state->data_length > iov[2].iov_len)) {
 117                 tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
 118                 return;
 119         }
 120
 121         state->recv_iov = iov;
 122         state->data = (uint8_t *)iov[2].iov_base;
 123         tevent_req_done(req);
 124 }
 125
 126 NTSTATUS smb2cli_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 127                            uint8_t **data, uint32_t *data_length)
 128 {
 129         struct smb2cli_read_state *state =
 130                 tevent_req_data(req,
 131                 struct smb2cli_read_state);
 132         NTSTATUS status;
 133
 134         if (tevent_req_is_nterror(req, &status)) {
 135                 return status;
 136         }
 137         talloc_steal(mem_ctx, state->recv_iov);
 138         *data_length = state->data_length;
 139         *data = state->data;
 140         return NT_STATUS_OK;
 141 }
 142
 143 NTSTATUS smb2cli_read(struct smbXcli_conn *conn,
 144                       uint32_t timeout_msec,
 145                       struct smbXcli_session *session,
 146                       struct smbXcli_tcon *tcon,
 147                       uint32_t length,
 148                       uint64_t offset,
 149                       uint64_t fid_persistent,
 150                       uint64_t fid_volatile,
 151                       uint64_t minimum_count,
 152                       uint64_t remaining_bytes,
 153                       TALLOC_CTX *mem_ctx,
 154                       uint8_t **data,
 155                       uint32_t *data_length)
 156 {
 157         TALLOC_CTX *frame = talloc_stackframe();
 158         struct tevent_context *ev;
 159         struct tevent_req *req;
 160         NTSTATUS status = NT_STATUS_NO_MEMORY;
 161
 162         if (smbXcli_conn_has_async_calls(conn)) {
 163                 /*
 164                  * Can't use sync call while an async call is in flight
 165                  */
 166                 status = NT_STATUS_INVALID_PARAMETER;
 167                 goto fail;
 168         }
 169         ev = samba_tevent_context_init(frame);
 170         if (ev == NULL) {
 171                 goto fail;
 172         }
 173         req = smb2cli_read_send(frame, ev,
 174                                 conn, timeout_msec, session, tcon,
 175                                 length, offset,
 176                                 fid_persistent, fid_volatile,
 177                                 minimum_count, remaining_bytes);
 178         if (req == NULL) {
 179                 goto fail;
 180         }
 181         if (!tevent_req_poll_ntstatus(req, ev, &status)) {
 182                 goto fail;
 183         }
 184         status = smb2cli_read_recv(req, mem_ctx, data, data_length);
 185  fail:
 186         TALLOC_FREE(frame);
 187         return status;
 188 }