source4/libcli/smb2/read.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    SMB2 client read call
   5
   6    Copyright (C) Andrew Tridgell 2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "libcli/smb2/smb2.h"
  24 #include "libcli/smb2/smb2_calls.h"
  25
  26 /*
  27   send a read request
  28 */
  29 struct smb2_request *smb2_read_send(struct smb2_tree *tree, struct smb2_read *io)
  30 {
  31         struct smb2_request *req;
  32
  33         req = smb2_request_init_tree(tree, SMB2_OP_READ, 0x30, true, 0);
  34         if (req == NULL) return NULL;
  35
  36         SCVAL(req->out.body, 0x02, 0); /* pad */
  37         SCVAL(req->out.body, 0x03, 0); /* reserved */
  38         SIVAL(req->out.body, 0x04, io->in.length);
  39         SBVAL(req->out.body, 0x08, io->in.offset);
  40         smb2_push_handle(req->out.body+0x10, &io->in.file.handle);
  41         SIVAL(req->out.body, 0x20, io->in.min_count);
  42         SIVAL(req->out.body, 0x24, io->in.channel);
  43         SIVAL(req->out.body, 0x28, io->in.remaining);
  44         SSVAL(req->out.body, 0x2C, io->in.channel_offset);
  45         SSVAL(req->out.body, 0x2E, io->in.channel_length);
  46
  47         req->credit_charge = (MAX(io->in.length, 1) - 1)/ 65536 + 1;
  48
  49         smb2_transport_send(req);
  50
  51         return req;
  52 }
  53
  54
  55 /*
  56   recv a read reply
  57 */
  58 NTSTATUS smb2_read_recv(struct smb2_request *req,
  59                         TALLOC_CTX *mem_ctx, struct smb2_read *io)
  60 {
  61         NTSTATUS status;
  62
  63         if (!smb2_request_receive(req) ||
  64             !smb2_request_is_ok(req)) {
  65                 return smb2_request_destroy(req);
  66         }
  67
  68         SMB2_CHECK_PACKET_RECV(req, 0x10, true);
  69
  70         status = smb2_pull_o16s32_blob(&req->in, mem_ctx, req->in.body+0x02, &io->out.data);
  71         if (!NT_STATUS_IS_OK(status)) {
  72                 smb2_request_destroy(req);
  73                 return status;
  74         }
  75
  76         io->out.remaining = IVAL(req->in.body, 0x08);
  77         io->out.reserved  = IVAL(req->in.body, 0x0C);
  78
  79         return smb2_request_destroy(req);
  80 }
  81
  82 /*
  83   sync read request
  84 */
  85 NTSTATUS smb2_read(struct smb2_tree *tree, TALLOC_CTX *mem_ctx, struct smb2_read *io)
  86 {
  87         struct smb2_request *req = smb2_read_send(tree, io);
  88         return smb2_read_recv(req, mem_ctx, io);
  89 }