fs/smbsrv/smb2_read.c

/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
 */

/*
 * Dispatch function for SMB2_READ
 */

#include <smbsrv/smb2_kproto.h>
#include <smbsrv/smb_fsops.h>

smb_sdrc_t
smb2_read(smb_request_t *sr)
{
    smb_ofile_t *of = NULL;
    smb_vdb_t *vdb = NULL;
    struct mbuf *m = NULL;
    uint16_t StructSize;
    uint8_t Padding;
    uint8_t DataOff;
    uint32_t Length;
    uint64_t Offset;
    smb2fid_t smb2fid;
    uint32_t MinCount;
    uint32_t Channel;
    uint32_t Remaining;
    uint16_t ChanInfoOffset;
    uint16_t ChanInfoLength;
    uint32_t XferCount;
    uint32_t status;
    int rc = 0;

    /*
     * SMB2 Read request
     */
    rc = smb_mbc_decodef(
        &sr->smb_data,
        "wb.lqqqlllww",
        &StructSize,        /* w */
        &Padding,           /* b. */
        &Length,            /* l */
        &Offset,            /* q */
        &smb2fid.persistent,    /* q */
        &smb2fid.temporal,      /* q */
        &MinCount,          /* l */
        &Channel,           /* l */
        &Remaining,         /* l */
        &ChanInfoOffset,        /* w */
        &ChanInfoLength);       /* w */
    if (rc)
        return (SDRC_ERROR);
    if (StructSize != 49)
        return (SDRC_ERROR);

    status = smb2sr_lookup_fid(sr, &smb2fid);
    if (status) {
        smb2sr_put_error(sr, status);
        return (SDRC_SUCCESS);
    }
    of = sr->fid_ofile;

    if (Length > smb2_max_rwsize) {
        smb2sr_put_error(sr, NT_STATUS_INVALID_PARAMETER);
        return (SDRC_SUCCESS);
    }
    if (MinCount > Length)
        MinCount = Length;

    /* This is automatically free'd. */
    vdb = smb_srm_zalloc(sr, sizeof (*vdb));
    vdb->vdb_tag = 0;
    vdb->vdb_uio.uio_iov = &vdb->vdb_iovec[0];
    vdb->vdb_uio.uio_iovcnt = MAX_IOVEC;
    vdb->vdb_uio.uio_resid = Length;
    vdb->vdb_uio.uio_loffset = (offset_t)Offset;
    vdb->vdb_uio.uio_segflg = UIO_SYSSPACE;
    vdb->vdb_uio.uio_extflg = UIO_COPY_DEFAULT;

    sr->raw_data.max_bytes = Length;
    m = smb_mbuf_allocate(&vdb->vdb_uio);

    switch (of->f_tree->t_res_type & STYPE_MASK) {
    case STYPE_DISKTREE:
        if (!smb_node_is_dir(of->f_node)) {
            /* Check for conflicting locks. */
            rc = smb_lock_range_access(sr, of->f_node,
                Offset, Length, B_FALSE);
            if (rc) {
                rc = ERANGE;
                break;
            }
        }
        rc = smb_fsop_read(sr, of->f_cr, of->f_node, &vdb->vdb_uio);
        break;
    case STYPE_IPC:
        rc = smb_opipe_read(sr, &vdb->vdb_uio);
        break;
    default:
    case STYPE_PRINTQ:
        rc = EACCES;
        break;
    }

    /* How much data we moved. */
    XferCount = Length - vdb->vdb_uio.uio_resid;

    sr->raw_data.max_bytes = XferCount;
    smb_mbuf_trim(m, XferCount);
    MBC_ATTACH_MBUF(&sr->raw_data, m);

    /*
     * Checking the error return _after_ dealing with
     * the returned data so that if m was allocated,
     * it will be free'd via sr->raw_data cleanup.
     */
    if (rc) {
        smb2sr_put_errno(sr, rc);
        return (SDRC_SUCCESS);
    }

    /*
     * SMB2 Read reply
     */
    DataOff = SMB2_HDR_SIZE + 16;
    rc = smb_mbc_encodef(
        &sr->reply,
        "wb.lllC",
        17, /* StructSize */    /* w */
        DataOff,            /* b. */
        XferCount,          /* l */
        0, /* DataRemaining */  /* l */
        0, /* reserved */       /* l */
        &sr->raw_data);     /* C */
    if (rc)
        return (SDRC_ERROR);

    mutex_enter(&of->f_mutex);
    of->f_seek_pos = Offset + XferCount;
    mutex_exit(&of->f_mutex);

    return (SDRC_SUCCESS);
}