/*
 * 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.
 * Copyright 2018 Nexenta Systems, Inc.  All rights reserved.
 * Copyright 2022-2025 RackTop Systems, Inc.
 */

/*
 * Dispatch function for SMB2_CHANGE_NOTIFY
 */

#include <smbsrv/smb2_kproto.h>

/* For the output DataOffset fields in here. */
#define DATA_OFF        (SMB2_HDR_SIZE + 8)

smb_sdrc_t
smb2_change_notify(smb_request_t *sr)
{
        uint16_t StructSize;
        uint16_t iFlags;
        uint32_t oBufLength;
        smb2fid_t smb2fid;
        uint32_t CompletionFilter;
        uint32_t reserved;
        uint32_t status;
        int rc = 0;

        /*
         * SMB2 Change Notify request
         */
        rc = smb_mbc_decodef(
            &sr->smb_data,              "wwlqqll",
            &StructSize,                /* w */
            &iFlags,                    /* w */
            &oBufLength,                /* l */
            &smb2fid.persistent,        /* q */
            &smb2fid.temporal,          /* q */
            &CompletionFilter,          /* l */
            &reserved);                 /* l */
        if (rc || StructSize != 32)
                return (SDRC_ERROR);

        status = smb2sr_lookup_fid(sr, &smb2fid);
        DTRACE_SMB2_START(op__ChangeNotify, smb_request_t *, sr);

        if (status != 0)
                goto errout; /* Bad FID */

        /*
         * Only deal with change notify last in a compound,
         * because it blocks indefinitely.  This status gets
         * "sticky" handling in smb2sr_work().
         */
        if (sr->smb2_next_command != 0) {
                status = NT_STATUS_INSUFFICIENT_RESOURCES;
                goto errout;
        }

        CompletionFilter &= FILE_NOTIFY_VALID_MASK;
        if (iFlags & SMB2_WATCH_TREE)
                CompletionFilter |= FILE_NOTIFY_CHANGE_EV_SUBDIR;

        if (oBufLength > smb2_max_trans) {
                status = NT_STATUS_INVALID_PARAMETER;
                goto errout;
        }

        /*
         * Check for events and consume, non-blocking.
         * Special return STATUS_PENDING means:
         *   No events; caller must call "act2" next.
         * SMB2 does that in "async mode".
         */
        status = smb_notify_act1(sr, oBufLength, CompletionFilter);
        if (status == NT_STATUS_PENDING) {
                smb_disp_stats_t *sds;
                hrtime_t start_time = sr->sr_time_start;

                ASSERT(sr->smb2_cmd_code == SMB2_CHANGE_NOTIFY);
                sds = &sr->sr_server->sv_disp_stats2[SMB2_CHANGE_NOTIFY];

                status = smb2sr_go_async_indefinite(sr);
                if (status != 0)
                        goto errout;
                status = smb_notify_act2(sr);
                if (status == NT_STATUS_PENDING) {
                        /*
                         * NOTE: at this point, the sr can no longer be
                         * referenced, as smb2_change_notify_finish() may have
                         * freed the sr.
                         *
                         * Change Notify is expected to block for a long time.
                         * Record a latency sample before we go async
                         * so as not to mislead users of SMB statistics.
                         */
                        smb_latency_add_sample(&sds->sdt_lat,
                            gethrtime() - start_time);

                        /* See next: smb2_change_notify_finish */
                        return (SDRC_SR_KEPT);
                }
        }

errout:
        sr->smb2_status = status;
        DTRACE_SMB2_DONE(op__ChangeNotify, smb_request_t *, sr);

        if (NT_SC_SEVERITY(status) == NT_STATUS_SEVERITY_SUCCESS) {
                oBufLength = sr->raw_data.chain_offset;
                (void) smb_mbc_encodef(
                    &sr->reply, "wwlC",
                    9,  /* StructSize */        /* w */
                    DATA_OFF,                   /* w */
                    oBufLength,                 /* l */
                    &sr->raw_data);             /* C */
        } else {
                smb2sr_put_error(sr, status);
        }

        return (SDRC_SUCCESS);
}

/*
 * This is called via taskq_dispatch in smb_notify.c
 * to finish up an NT transact notify change request.
 * Build an SMB2 Change Notify reply and send it.
 */
void
smb2_change_notify_finish(void *arg)
{
        smb_request_t *sr = arg;
        smb_disp_stats_t *sds;
        uint32_t status;
        uint32_t oBufLength;

        SMB_REQ_VALID(sr);

        /*
         * Common part of notify, puts data in sr->raw_data
         */
        status = smb_notify_act3(sr);

        /*
         * The prior thread returned SDRC_SR_KEPT and skiped
         * the dtrace DONE probe, so fire that here.
         */
        sr->smb2_status = status;
        DTRACE_SMB2_DONE(op__ChangeNotify, smb_request_t *, sr);

        if (NT_SC_SEVERITY(status) == NT_STATUS_SEVERITY_SUCCESS) {
                oBufLength = sr->raw_data.chain_offset;
                (void) smb_mbc_encodef(
                    &sr->reply, "wwlC",
                    9,  /* StructSize */        /* w */
                    DATA_OFF,                   /* w */
                    oBufLength,                 /* l */
                    &sr->raw_data);             /* C */
        } else {
                smb2sr_put_error(sr, status);
        }

        /*
         * Record some statistics.
         * We already took a latency sample before we went async.
         */
        sds = &sr->session->s_server->sv_disp_stats2[SMB2_CHANGE_NOTIFY];
        smb2_record_stats(sr, sds, B_FALSE);

        /*
         * Put (overwrite) the final SMB2 header,
         * sign, send.
         */
        (void) smb2_encode_header(sr, B_TRUE);
        if (sr->smb2_hdr_flags & SMB2_FLAGS_SIGNED)
                smb2_sign_reply(sr);
        smb2_send_reply(sr);

        mutex_enter(&sr->sr_mutex);
        sr->sr_state = SMB_REQ_STATE_COMPLETED;
        mutex_exit(&sr->sr_mutex);

        smb_request_free(sr);
}