/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2016 Nexenta Systems, Inc.  All rights reserved.
 */

#include <smbsrv/smb_kproto.h>

static void smb_encode_sacl(mbuf_chain_t *, smb_acl_t *);
static void smb_encode_dacl(mbuf_chain_t *, smb_acl_t *);
static smb_acl_t *smb_decode_acl(mbuf_chain_t *, uint32_t);

/*
 * smb_nt_transact_query_security_info
 *
 * This command allows the client to retrieve the security descriptor
 * on a file. The result of the call is returned to the client in the
 * Data part of the transaction response.
 *
 * Some clients specify a non-zero maximum data return size (mdrcnt)
 * for the SD and some specify zero. In either case, if the mdrcnt is
 * too small we need to return NT_STATUS_BUFFER_TOO_SMALL and a buffer
 * size hint. The client should then retry with the appropriate buffer
 * size.
 *
 *  Client Parameter Block             Description
 *  ================================== =================================
 *
 *  USHORT Fid;                        FID of target
 *  USHORT Reserved;                   MBZ
 *  ULONG secinfo;                     Fields of descriptor to set
 *
 *   Data Block Encoding                Description
 *   ================================== ==================================
 *
 *   Data[TotalDataCount]               Security Descriptor information
 */

smb_sdrc_t
smb_nt_transact_query_security_info(struct smb_request *sr, struct smb_xa *xa)
{
        smb_sd_t sd;
        uint32_t secinfo;
        uint32_t sdlen;
        uint32_t status;
        smb_error_t err;

        if (smb_mbc_decodef(&xa->req_param_mb, "w2.l",
            &sr->smb_fid, &secinfo) != 0) {
                smbsr_error(sr, NT_STATUS_INVALID_PARAMETER, 0, 0);
                return (SDRC_ERROR);
        }

        smbsr_lookup_file(sr);
        if (sr->fid_ofile == NULL) {
                smbsr_error(sr, NT_STATUS_INVALID_HANDLE, ERRDOS, ERRbadfid);
                return (SDRC_ERROR);
        }


        if ((sr->fid_ofile->f_node == NULL) ||
            (sr->fid_ofile->f_ftype != SMB_FTYPE_DISK)) {
                smbsr_error(sr, NT_STATUS_ACCESS_DENIED,
                    ERRDOS, ERROR_ACCESS_DENIED);
                return (SDRC_ERROR);
        }

        sr->user_cr = smb_ofile_getcred(sr->fid_ofile);

        if (sr->tid_tree->t_acltype != ACE_T) {
                /*
                 * If target filesystem doesn't support ACE_T acls then
                 * don't process SACL
                 */
                secinfo &= ~SMB_SACL_SECINFO;
        }

        status = smb_sd_read(sr, &sd, secinfo);
        if (status != NT_STATUS_SUCCESS) {
                smbsr_error(sr, status, 0, 0);
                return (SDRC_ERROR);
        }

        sdlen = smb_sd_len(&sd, secinfo);
        if (sdlen == 0) {
                smb_sd_term(&sd);
                smbsr_error(sr, NT_STATUS_INVALID_SECURITY_DESCR, 0, 0);
                return (SDRC_ERROR);
        }

        if (sdlen > xa->smb_mdrcnt) {
                /*
                 * The maximum data return count specified by the
                 * client is not big enough to hold the security
                 * descriptor. We have to return an error but we
                 * should provide a buffer size hint for the client.
                 */
                (void) smb_mbc_encodef(&xa->rep_param_mb, "l", sdlen);
                err.status   = NT_STATUS_BUFFER_TOO_SMALL;
                err.errcls   = ERRDOS;
                err.errcode  = ERROR_INSUFFICIENT_BUFFER;
                smbsr_set_error(sr, &err);
                smb_sd_term(&sd);
                return (SDRC_SUCCESS);
        }

        smb_encode_sd(&xa->rep_data_mb, &sd, secinfo);
        (void) smb_mbc_encodef(&xa->rep_param_mb, "l", sdlen);
        smb_sd_term(&sd);
        return (SDRC_SUCCESS);
}

/*
 * smb_nt_transact_set_security_info
 *
 * This command allows the client to change the security descriptor on a
 * file. All we do here is decode the parameters and the data. The data
 * is passed directly to smb_nt_set_security_object, with the security
 * information describing the information to set. There are no response
 * parameters or data.
 *
 *   Client Parameter Block Encoding    Description
 *   ================================== ==================================
 *   USHORT Fid;                        FID of target
 *   USHORT Reserved;                   MBZ
 *   ULONG SecurityInformation;         Fields of SD that to set
 *
 *   Data Block Encoding                Description
 *   ================================== ==================================
 *   Data[TotalDataCount]               Security Descriptor information
 */
smb_sdrc_t
smb_nt_transact_set_security_info(struct smb_request *sr, struct smb_xa *xa)
{
        smb_sd_t sd;
        uint32_t secinfo;
        uint32_t status;

        if (smb_mbc_decodef(&xa->req_param_mb, "w2.l",
            &sr->smb_fid, &secinfo) != 0) {
                smbsr_error(sr, NT_STATUS_INVALID_PARAMETER, 0, 0);
                return (SDRC_ERROR);
        }

        smbsr_lookup_file(sr);
        if (sr->fid_ofile == NULL) {
                smbsr_error(sr, NT_STATUS_INVALID_HANDLE, ERRDOS, ERRbadfid);
                return (SDRC_ERROR);
        }

        if ((sr->fid_ofile->f_node == NULL) ||
            (sr->fid_ofile->f_ftype != SMB_FTYPE_DISK)) {
                smbsr_error(sr, NT_STATUS_ACCESS_DENIED, 0, 0);
                return (SDRC_ERROR);
        }

        sr->user_cr = smb_ofile_getcred(sr->fid_ofile);

        if (SMB_TREE_IS_READONLY(sr)) {
                smbsr_error(sr, NT_STATUS_MEDIA_WRITE_PROTECTED, 0, 0);
                return (SDRC_ERROR);
        }

        if (sr->tid_tree->t_acltype != ACE_T) {
                /*
                 * If target filesystem doesn't support ACE_T acls then
                 * don't process SACL
                 */
                secinfo &= ~SMB_SACL_SECINFO;
        }

        if ((secinfo & SMB_ALL_SECINFO) == 0) {
                return (NT_STATUS_SUCCESS);
        }

        status = smb_decode_sd(&xa->req_data_mb, &sd);
        if (status != NT_STATUS_SUCCESS) {
                smbsr_error(sr, status, 0, 0);
                return (SDRC_ERROR);
        }

        if (((secinfo & SMB_OWNER_SECINFO) && (sd.sd_owner == NULL)) ||
            ((secinfo & SMB_GROUP_SECINFO) && (sd.sd_group == NULL))) {
                smbsr_error(sr, NT_STATUS_INVALID_PARAMETER, 0, 0);
                return (SDRC_ERROR);
        }

        if (!smb_node_is_system(sr->fid_ofile->f_node))
                status = smb_sd_write(sr, &sd, secinfo);

        smb_sd_term(&sd);
        if (status != NT_STATUS_SUCCESS) {
                smbsr_error(sr, status, 0, 0);
                return (SDRC_ERROR);
        }

        return (SDRC_SUCCESS);
}

/*
 * smb_encode_sd
 *
 * Encodes given security descriptor in the reply buffer.
 */
void
smb_encode_sd(mbuf_chain_t *mbc, smb_sd_t *sd, uint32_t secinfo)
{
        uint32_t offset = SMB_SD_HDRSIZE;

        /* encode header */
        (void) smb_mbc_encodef(mbc, "b.w",
            sd->sd_revision, sd->sd_control | SE_SELF_RELATIVE);

        /* owner offset */
        if (secinfo & SMB_OWNER_SECINFO) {
                ASSERT(sd->sd_owner);
                (void) smb_mbc_encodef(mbc, "l", offset);
                offset += smb_sid_len(sd->sd_owner);
        } else {
                (void) smb_mbc_encodef(mbc, "l", 0);
        }

        /* group offset */
        if (secinfo & SMB_GROUP_SECINFO) {
                ASSERT(sd->sd_group);
                (void) smb_mbc_encodef(mbc, "l", offset);
                offset += smb_sid_len(sd->sd_group);
        } else {
                (void) smb_mbc_encodef(mbc, "l", 0);
        }

        /* SACL offset */
        if ((secinfo & SMB_SACL_SECINFO) && (sd->sd_sacl)) {
                (void) smb_mbc_encodef(mbc, "l", offset);
                offset += smb_acl_len(sd->sd_sacl);
        } else {
                (void) smb_mbc_encodef(mbc, "l", 0);
        }

        /* DACL offset */
        if ((secinfo & SMB_DACL_SECINFO) && (sd->sd_dacl))
                (void) smb_mbc_encodef(mbc, "l", offset);
        else
                (void) smb_mbc_encodef(mbc, "l", 0);

        if (secinfo & SMB_OWNER_SECINFO)
                smb_encode_sid(mbc, sd->sd_owner);

        if (secinfo & SMB_GROUP_SECINFO)
                smb_encode_sid(mbc, sd->sd_group);

        if (secinfo & SMB_SACL_SECINFO)
                smb_encode_sacl(mbc, sd->sd_sacl);

        if (secinfo & SMB_DACL_SECINFO)
                smb_encode_dacl(mbc, sd->sd_dacl);
}

/*
 * smb_encode_sid
 *
 * Encodes given SID in the reply buffer.
 */
void
smb_encode_sid(mbuf_chain_t *mbc, smb_sid_t *sid)
{
        int i;

        (void) smb_mbc_encodef(mbc, "bb",
            sid->sid_revision, sid->sid_subauthcnt);

        for (i = 0; i < NT_SID_AUTH_MAX; i++) {
                (void) smb_mbc_encodef(mbc, "b",
                    sid->sid_authority[i]);
        }

        for (i = 0; i < sid->sid_subauthcnt; i++) {
                (void) smb_mbc_encodef(mbc, "l",
                    sid->sid_subauth[i]);
        }
}

/*
 * smb_encode_sacl
 *
 * Encodes given SACL in the reply buffer.
 */
static void
smb_encode_sacl(mbuf_chain_t *mbc, smb_acl_t *acl)
{
        smb_ace_t *ace;
        int i;

        if (acl == NULL)
                return;

        /* encode header */
        (void) smb_mbc_encodef(mbc, "b.ww2.", acl->sl_revision,
            acl->sl_bsize, acl->sl_acecnt);

        for (i = 0, ace = acl->sl_aces; i < acl->sl_acecnt; i++, ace++) {
                (void) smb_mbc_encodef(mbc, "bbwl",
                    ace->se_hdr.se_type, ace->se_hdr.se_flags,
                    ace->se_hdr.se_bsize, ace->se_mask);

                smb_encode_sid(mbc, ace->se_sid);
        }
}

/*
 * smb_encode_dacl
 *
 * Encodes given DACL in the reply buffer.
 */
static void
smb_encode_dacl(mbuf_chain_t *mbc, smb_acl_t *acl)
{
        smb_ace_t *ace;

        if (acl == NULL)
                return;

        /* encode header */
        (void) smb_mbc_encodef(mbc, "b.ww2.", acl->sl_revision,
            acl->sl_bsize, acl->sl_acecnt);

        ace = list_head(&acl->sl_sorted);
        while (ace) {
                (void) smb_mbc_encodef(mbc, "bbwl",
                    ace->se_hdr.se_type, ace->se_hdr.se_flags,
                    ace->se_hdr.se_bsize, ace->se_mask);

                smb_encode_sid(mbc, ace->se_sid);
                ace = list_next(&acl->sl_sorted, ace);
        }
}

/*
 * smb_decode_sd
 *
 * Decodes the security descriptor in the request buffer
 * and set the fields of 'sd' appropraitely. Upon successful
 * return, caller must free allocated memories by calling
 * smb_sd_term().
 */
uint32_t
smb_decode_sd(mbuf_chain_t *mbc, smb_sd_t *sd)
{
        struct mbuf_chain sdbuf;
        uint32_t owner_offs;
        uint32_t group_offs;
        uint32_t sacl_offs;
        uint32_t dacl_offs;
        int rc;

        smb_sd_init(sd, SECURITY_DESCRIPTOR_REVISION);

        (void) MBC_SHADOW_CHAIN(&sdbuf, mbc,
            mbc->chain_offset,
            mbc->max_bytes - mbc->chain_offset);

        rc = smb_mbc_decodef(&sdbuf, "b.wllll",
            &sd->sd_revision, &sd->sd_control,
            &owner_offs, &group_offs, &sacl_offs, &dacl_offs);

        /* Prevent disallowed flags in smb_sd_term. */
        sd->sd_control &= ~SE_SELF_RELATIVE;
        if (rc != 0)
                goto decode_error;

        if (owner_offs != 0) {
                if (owner_offs < SMB_SD_HDRSIZE)
                        goto decode_error;

                sd->sd_owner = smb_decode_sid(mbc, owner_offs);
                if (sd->sd_owner == NULL)
                        goto decode_error;
        }

        if (group_offs != 0) {
                if (group_offs < SMB_SD_HDRSIZE)
                        goto decode_error;

                sd->sd_group = smb_decode_sid(mbc, group_offs);
                if (sd->sd_group == NULL)
                        goto decode_error;
        }

        if (sacl_offs != 0) {
                if ((sd->sd_control & SE_SACL_PRESENT) == 0)
                        goto decode_error;

                if (sacl_offs < SMB_SD_HDRSIZE)
                        goto decode_error;

                sd->sd_sacl = smb_decode_acl(mbc, sacl_offs);
                if (sd->sd_sacl == NULL)
                        goto decode_error;
        }

        if (dacl_offs != 0) {
                if ((sd->sd_control & SE_DACL_PRESENT) == 0)
                        goto decode_error;

                if (dacl_offs < SMB_SD_HDRSIZE)
                        goto decode_error;

                sd->sd_dacl = smb_decode_acl(mbc, dacl_offs);
                if (sd->sd_dacl == NULL)
                        goto decode_error;
        }

        return (NT_STATUS_SUCCESS);

decode_error:
        smb_sd_term(sd);
        return (NT_STATUS_INVALID_SECURITY_DESCR);
}

/*
 * smb_decode_sid
 *
 * Allocates memory and decodes the SID in the request buffer
 * Upon successful return, caller must free the allocated memory
 * by calling smb_sid_free()
 */
smb_sid_t *
smb_decode_sid(mbuf_chain_t *mbc, uint32_t offset)
{
        uint8_t revision;
        uint8_t subauth_cnt;
        struct mbuf_chain sidbuf;
        smb_sid_t *sid;
        int sidlen;
        int bytes_left;
        int i;

        offset += mbc->chain_offset;
        bytes_left = mbc->max_bytes - offset;
        if (bytes_left < (int)sizeof (smb_sid_t))
                return (NULL);

        if (MBC_SHADOW_CHAIN(&sidbuf, mbc, offset, bytes_left) != 0)
                return (NULL);

        if (smb_mbc_decodef(&sidbuf, "bb", &revision, &subauth_cnt))
                return (NULL);

        sidlen = sizeof (smb_sid_t) - sizeof (uint32_t) +
            (subauth_cnt * sizeof (uint32_t));
        sid = kmem_alloc(sidlen, KM_SLEEP);

        sid->sid_revision = revision;
        sid->sid_subauthcnt = subauth_cnt;

        for (i = 0; i < NT_SID_AUTH_MAX; i++) {
                if (smb_mbc_decodef(&sidbuf, "b", &sid->sid_authority[i]))
                        goto decode_err;
        }

        for (i = 0; i < sid->sid_subauthcnt; i++) {
                if (smb_mbc_decodef(&sidbuf, "l", &sid->sid_subauth[i]))
                        goto decode_err;
        }

        return (sid);

decode_err:
        kmem_free(sid, sidlen);
        return (NULL);
}

/*
 * smb_decode_acl
 *
 * Allocates memory and decodes the ACL in the request buffer
 * Upon successful return, caller must free the allocated memory
 * by calling smb_acl_free().
 */
static smb_acl_t *
smb_decode_acl(mbuf_chain_t *mbc, uint32_t offset)
{
        struct mbuf_chain aclbuf;
        smb_acl_t *acl;
        smb_ace_t *ace;
        uint8_t revision;
        uint16_t size;
        uint16_t acecnt;
        int bytes_left;
        uint32_t sid_offs = offset;
        int sidlen;
        int i;

        offset += mbc->chain_offset;
        bytes_left = mbc->max_bytes - offset;
        if (bytes_left < SMB_ACL_HDRSIZE)
                return (NULL);

        if (MBC_SHADOW_CHAIN(&aclbuf, mbc, offset, bytes_left) != 0)
                return (NULL);

        if (smb_mbc_decodef(&aclbuf, "b.ww2.", &revision, &size, &acecnt))
                return (NULL);

        if (size == 0)
                return (NULL);

        acl = smb_acl_alloc(revision, size, acecnt);

        sid_offs += SMB_ACL_HDRSIZE;
        for (i = 0, ace = acl->sl_aces; i < acl->sl_acecnt; i++, ace++) {
                if (smb_mbc_decodef(&aclbuf, "bbwl",
                    &ace->se_hdr.se_type, &ace->se_hdr.se_flags,
                    &ace->se_hdr.se_bsize, &ace->se_mask))
                        goto decode_error;

                sid_offs += SMB_ACE_HDRSIZE + sizeof (ace->se_mask);
                ace->se_sid = smb_decode_sid(mbc, sid_offs);
                if (ace->se_sid == NULL)
                        goto decode_error;
                /* This is SID length plus any paddings between ACEs */
                sidlen = ace->se_hdr.se_bsize -
                    (SMB_ACE_HDRSIZE + sizeof (ace->se_mask));
                aclbuf.chain_offset += sidlen;
                sid_offs += sidlen;
        }

        return (acl);

decode_error:
        smb_acl_free(acl);
        return (NULL);
}