1/* 2 Unix SMB/CIFS implementation. 3 4 POSIX NTVFS backend - read 5 6 Copyright (C) Andrew Tridgell 2004 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 "vfs_posix.h" 24#include "lib/events/events.h" 25 26/* 27 read from a file 28*/ 29NTSTATUS pvfs_read(struct ntvfs_module_context *ntvfs, 30 struct ntvfs_request *req, union smb_read *rd) 31{ 32 struct pvfs_state *pvfs = talloc_get_type(ntvfs->private_data, 33 struct pvfs_state); 34 ssize_t ret; 35 struct pvfs_file *f; 36 NTSTATUS status; 37 uint32_t maxcnt; 38 uint32_t mask; 39 40 if (rd->generic.level != RAW_READ_READX) { 41 return ntvfs_map_read(ntvfs, req, rd); 42 } 43 44 f = pvfs_find_fd(pvfs, req, rd->readx.in.file.ntvfs); 45 if (!f) { 46 return NT_STATUS_INVALID_HANDLE; 47 } 48 49 if (f->handle->fd == -1) { 50 return NT_STATUS_INVALID_DEVICE_REQUEST; 51 } 52 53 mask = SEC_FILE_READ_DATA; 54 if (rd->readx.in.read_for_execute) { 55 mask |= SEC_FILE_EXECUTE; 56 } 57 if (!(f->access_mask & mask)) { 58 return NT_STATUS_ACCESS_DENIED; 59 } 60 61 maxcnt = rd->readx.in.maxcnt; 62 if (maxcnt > 2*UINT16_MAX && req->ctx->protocol < PROTOCOL_SMB2) { 63 return NT_STATUS_INVALID_PARAMETER; 64 } 65 66 status = pvfs_check_lock(pvfs, f, req->smbpid, 67 rd->readx.in.offset, 68 maxcnt, 69 READ_LOCK); 70 if (!NT_STATUS_IS_OK(status)) { 71 return status; 72 } 73 74 if (f->handle->name->stream_name) { 75 ret = pvfs_stream_read(pvfs, f->handle, 76 rd->readx.out.data, maxcnt, rd->readx.in.offset); 77 } else { 78#if HAVE_LINUX_AIO 79 /* possibly try an aio read */ 80 if ((req->async_states->state & NTVFS_ASYNC_STATE_MAY_ASYNC) && 81 (pvfs->flags & PVFS_FLAG_LINUX_AIO)) { 82 status = pvfs_aio_pread(req, rd, f, maxcnt); 83 if (NT_STATUS_IS_OK(status)) { 84 return NT_STATUS_OK; 85 } 86 } 87#endif 88 ret = pread(f->handle->fd, 89 rd->readx.out.data, 90 maxcnt, 91 rd->readx.in.offset); 92 } 93 if (ret == -1) { 94 return pvfs_map_errno(pvfs, errno); 95 } 96 97 /* only SMB2 honors mincnt */ 98 if (req->ctx->protocol == PROTOCOL_SMB2) { 99 if (rd->readx.in.mincnt > ret || 100 (ret == 0 && maxcnt > 0)) { 101 return NT_STATUS_END_OF_FILE; 102 } 103 } 104 105 f->handle->position = f->handle->seek_offset = rd->readx.in.offset + ret; 106 107 rd->readx.out.nread = ret; 108 rd->readx.out.remaining = 0xFFFF; 109 rd->readx.out.compaction_mode = 0; 110 111 return NT_STATUS_OK; 112} 113