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         bool out_valid;
  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 smbXcli_conn *conn,
  40                                      uint32_t timeout_msec,
  41                                      struct smbXcli_session *session,
  42                                      struct smbXcli_tcon *tcon,
  43                                      uint32_t length,
  44                                      uint64_t offset,
  45                                      uint64_t fid_persistent,
  46                                      uint64_t fid_volatile,
  47                                      uint64_t minimum_count,
  48                                      uint64_t remaining_bytes)
  49 {
  50         struct tevent_req *req, *subreq;
  51         struct smb2cli_read_state *state;
  52         uint8_t *fixed;
  53
  54         req = tevent_req_create(mem_ctx, &state,
  55                                 struct smb2cli_read_state);
  56         if (req == NULL) {
  57                 return NULL;
  58         }
  59
  60         fixed = state->fixed;
  61
  62         SSVAL(fixed, 0, 49);
  63         SIVAL(fixed, 4, length);
  64         SBVAL(fixed, 8, offset);
  65         SBVAL(fixed, 16, fid_persistent);
  66         SBVAL(fixed, 24, fid_volatile);
  67         SBVAL(fixed, 32, minimum_count);
  68         SBVAL(fixed, 40, remaining_bytes);
  69
  70         subreq = smb2cli_req_send(state, ev, conn, SMB2_OP_READ,
  71                                   0, 0, /* flags */
  72                                   timeout_msec,
  73                                   tcon,
  74                                   session,
  75                                   state->fixed, sizeof(state->fixed),
  76                                   state->dyn_pad, sizeof(state->dyn_pad),
  77                                   length); /* max_dyn_len */
  78         if (tevent_req_nomem(subreq, req)) {
  79                 return tevent_req_post(req, ev);
  80         }
  81         tevent_req_set_callback(subreq, smb2cli_read_done, req);
  82         return req;
  83 }
  84
  85 static void smb2cli_read_done(struct tevent_req *subreq)
  86 {
  87         struct tevent_req *req = tevent_req_callback_data(
  88                 subreq, struct tevent_req);
  89         struct smb2cli_read_state *state =
  90                 tevent_req_data(req,
  91                 struct smb2cli_read_state);
  92         NTSTATUS status;
  93         struct iovec *iov;
  94         uint8_t data_offset;
  95         static const struct smb2cli_req_expected_response expected[] = {
  96         {
  97                 .status = STATUS_BUFFER_OVERFLOW,
  98                 .body_size = 0x11
  99         },
 100         {
 101                 .status = NT_STATUS_OK,
 102                 .body_size = 0x11
 103         }
 104         };
 105
 106         status = smb2cli_req_recv(subreq, state, &iov,
 107                                   expected, ARRAY_SIZE(expected));
 108         TALLOC_FREE(subreq);
 109         if (NT_STATUS_EQUAL(status, STATUS_BUFFER_OVERFLOW)) {
 110                 /* no error */
 111         } else {
 112                 if (tevent_req_nterror(req, status)) {
 113                         return;
 114                 }
 115         }
 116
 117         data_offset = CVAL(iov[1].iov_base, 2);
 118         state->data_length = IVAL(iov[1].iov_base, 4);
 119
 120         if ((data_offset != SMB2_HDR_BODY + 16) ||
 121             (state->data_length > iov[2].iov_len)) {
 122                 tevent_req_nterror(req, NT_STATUS_INVALID_NETWORK_RESPONSE);
 123                 return;
 124         }
 125
 126         state->recv_iov = iov;
 127         state->data = (uint8_t *)iov[2].iov_base;
 128
 129         state->out_valid = true;
 130
 131         if (tevent_req_nterror(req, status)) {
 132                 return;
 133         }
 134
 135         tevent_req_done(req);
 136 }
 137
 138 NTSTATUS smb2cli_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 139                            uint8_t **data, uint32_t *data_length)
 140 {
 141         struct smb2cli_read_state *state =
 142                 tevent_req_data(req,
 143                 struct smb2cli_read_state);
 144         NTSTATUS status = NT_STATUS_OK;
 145
 146         if (tevent_req_is_nterror(req, &status) && !state->out_valid) {
 147                 *data_length = 0;
 148                 *data = NULL;
 149                 tevent_req_received(req);
 150                 return status;
 151         }
 152         talloc_steal(mem_ctx, state->recv_iov);
 153         *data_length = state->data_length;
 154         *data = state->data;
 155         tevent_req_received(req);
 156         return status;
 157 }
 158
 159 NTSTATUS smb2cli_read(struct smbXcli_conn *conn,
 160                       uint32_t timeout_msec,
 161                       struct smbXcli_session *session,
 162                       struct smbXcli_tcon *tcon,
 163                       uint32_t length,
 164                       uint64_t offset,
 165                       uint64_t fid_persistent,
 166                       uint64_t fid_volatile,
 167                       uint64_t minimum_count,
 168                       uint64_t remaining_bytes,
 169                       TALLOC_CTX *mem_ctx,
 170                       uint8_t **data,
 171                       uint32_t *data_length)
 172 {
 173         TALLOC_CTX *frame = talloc_stackframe();
 174         struct tevent_context *ev;
 175         struct tevent_req *req;
 176         NTSTATUS status = NT_STATUS_NO_MEMORY;
 177
 178         if (smbXcli_conn_has_async_calls(conn)) {
 179                 /*
 180                  * Can't use sync call while an async call is in flight
 181                  */
 182                 status = NT_STATUS_INVALID_PARAMETER;
 183                 goto fail;
 184         }
 185         ev = samba_tevent_context_init(frame);
 186         if (ev == NULL) {
 187                 goto fail;
 188         }
 189         req = smb2cli_read_send(frame, ev,
 190                                 conn, timeout_msec, session, tcon,
 191                                 length, offset,
 192                                 fid_persistent, fid_volatile,
 193                                 minimum_count, remaining_bytes);
 194         if (req == NULL) {
 195                 goto fail;
 196         }
 197         if (!tevent_req_poll_ntstatus(req, ev, &status)) {
 198                 goto fail;
 199         }
 200         status = smb2cli_read_recv(req, mem_ctx, data, data_length);
 201  fail:
 202         TALLOC_FREE(frame);
 203         return status;
 204 }