/*-
 * ssr.c
 *
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2004 Maksim Yevmenkin <m_evmenkin@yahoo.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Id: ssr.c,v 1.5 2004/01/13 01:54:39 max Exp $
 */

#include <sys/param.h>
#include <sys/queue.h>
#include <sys/uio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#define L2CAP_SOCKET_CHECKED
#include <bluetooth.h>
#include <errno.h>
#include <sdp.h>
#include <string.h>
#include "profile.h"
#include "provider.h"
#include "server.h"
#include "uuid-private.h"

/*
 * Prepare SDP Service Search Response
 */

int32_t
server_prepare_service_search_response(server_p srv, int32_t fd)
{
        uint8_t const   *req = srv->req + sizeof(sdp_pdu_t);
        uint8_t const   *req_end = req + ((sdp_pdu_p)(srv->req))->len;
        uint8_t         *rsp = srv->fdidx[fd].rsp;
        uint8_t const   *rsp_end = rsp + NG_L2CAP_MTU_MAXIMUM;

        uint8_t         *ptr = NULL;
        provider_t      *provider = NULL;
        int32_t          type, ssplen, rsp_limit, rcount, cslen, cs;
        uint128_t        uuid, puuid;

        /*
         * Minimal SDP Service Search Request
         *
         * seq8 len8            - 2 bytes
         *      uuid16 value16  - 3 bytes ServiceSearchPattern
         * value16              - 2 bytes MaximumServiceRecordCount
         * value8               - 1 byte  ContinuationState
         */

        if (req_end - req < 8)
                return (SDP_ERROR_CODE_INVALID_REQUEST_SYNTAX);

        /* Get size of ServiceSearchPattern */
        ssplen = 0;
        SDP_GET8(type, req);
        switch (type) {
        case SDP_DATA_SEQ8:
                SDP_GET8(ssplen, req);
                break;

        case SDP_DATA_SEQ16:
                SDP_GET16(ssplen, req);
                break;

        case SDP_DATA_SEQ32:
                SDP_GET32(ssplen, req);
                break;
        }
        if (ssplen <= 0)
                return (SDP_ERROR_CODE_INVALID_REQUEST_SYNTAX);

        ptr = (uint8_t *) req + ssplen;

        /* Get MaximumServiceRecordCount */
        if (ptr + 2 > req_end)
                return (SDP_ERROR_CODE_INVALID_REQUEST_SYNTAX);
        
        SDP_GET16(rsp_limit, ptr);
        if (rsp_limit <= 0)
                return (SDP_ERROR_CODE_INVALID_REQUEST_SYNTAX);

        /* Get ContinuationState */
        if (ptr + 1 > req_end)
                return (SDP_ERROR_CODE_INVALID_REQUEST_SYNTAX);

        SDP_GET8(cslen, ptr);
        if (cslen != 0) {
                if (cslen != 2 || req_end - ptr != 2)
                        return (SDP_ERROR_CODE_INVALID_REQUEST_SYNTAX);

                SDP_GET16(cs, ptr);
        } else
                cs = 0;

        /* Process the request. First, check continuation state */
        if (srv->fdidx[fd].rsp_cs != cs)
                return (SDP_ERROR_CODE_INVALID_CONTINUATION_STATE);
        if (srv->fdidx[fd].rsp_size > 0)
                return (0);

        /*
         * Service Search Response format
         *
         * value16      - 2 bytes TotalServiceRecordCount (not incl.)
         * value16      - 2 bytes CurrentServiceRecordCount (not incl.)
         * value32      - 4 bytes handle
         * [ value32 ]
         *
         * Calculate how many record handles we can fit 
         * in our reply buffer and adjust rlimit.
         */

        ptr = rsp;
        rcount = (rsp_end - ptr) / 4;
        if (rcount < rsp_limit)
                rsp_limit = rcount;

        /* Look for the record handles */
        for (rcount = 0; ssplen > 0 && rcount < rsp_limit; ) {
                SDP_GET8(type, req);
                ssplen --;

                switch (type) {
                case SDP_DATA_UUID16:
                        if (ssplen < 2)
                                return (SDP_ERROR_CODE_INVALID_REQUEST_SYNTAX);

                        memcpy(&uuid, &uuid_base, sizeof(uuid));
                        uuid.b[2] = *req ++;
                        uuid.b[3] = *req ++;
                        ssplen -= 2;
                        break;

                case SDP_DATA_UUID32:
                        if (ssplen < 4)
                                return (SDP_ERROR_CODE_INVALID_REQUEST_SYNTAX);

                        memcpy(&uuid, &uuid_base, sizeof(uuid));
                        uuid.b[0] = *req ++;
                        uuid.b[1] = *req ++;
                        uuid.b[2] = *req ++;
                        uuid.b[3] = *req ++;
                        ssplen -= 4;
                        break;

                case SDP_DATA_UUID128:
                        if (ssplen < 16)
                                return (SDP_ERROR_CODE_INVALID_REQUEST_SYNTAX);

                        memcpy(uuid.b, req, 16);
                        req += 16;
                        ssplen -= 16; 
                        break;

                default:
                        return (SDP_ERROR_CODE_INVALID_REQUEST_SYNTAX);
                        /* NOT REACHED */
                }

                for (provider = provider_get_first();
                     provider != NULL && rcount < rsp_limit;
                     provider = provider_get_next(provider)) {
                        if (!provider_match_bdaddr(provider, &srv->req_sa.l2cap_bdaddr))
                                continue;

                        memcpy(&puuid, &uuid_base, sizeof(puuid));
                        puuid.b[2] = provider->profile->uuid >> 8;
                        puuid.b[3] = provider->profile->uuid;

                        if (memcmp(&uuid, &puuid, sizeof(uuid)) == 0 ||
                            memcmp(&uuid, &uuid_public_browse_group, sizeof(uuid)) == 0) {
                                SDP_PUT32(provider->handle, ptr);
                                rcount ++;
                        }
                }
        }

        /* Set reply size (not counting PDU header and continuation state) */
        srv->fdidx[fd].rsp_limit = srv->fdidx[fd].omtu - sizeof(sdp_pdu_t) - 4;
        srv->fdidx[fd].rsp_size = ptr - rsp;
        srv->fdidx[fd].rsp_cs = 0;

        return (0);
}

/*
 * Send SDP Service Search Response
 */

int32_t
server_send_service_search_response(server_p srv, int32_t fd)
{
        uint8_t         *rsp = srv->fdidx[fd].rsp + srv->fdidx[fd].rsp_cs;
        uint8_t         *rsp_end = srv->fdidx[fd].rsp + srv->fdidx[fd].rsp_size;

        struct iovec    iov[4];
        sdp_pdu_t       pdu;
        uint16_t        rcounts[2];
        uint8_t         cs[3];
        int32_t         size;

        /* First update continuation state (assume we will send all data) */
        size = rsp_end - rsp;
        srv->fdidx[fd].rsp_cs += size;

        if (size + 1 > srv->fdidx[fd].rsp_limit) {
                /*
                 * We need to split out response. Add 3 more bytes for the
                 * continuation state and move rsp_end and rsp_cs backwards. 
                 */

                while ((rsp_end - rsp) + 3 > srv->fdidx[fd].rsp_limit) {
                        rsp_end -= 4;
                        srv->fdidx[fd].rsp_cs -= 4;
                }

                cs[0] = 2;
                cs[1] = srv->fdidx[fd].rsp_cs >> 8;
                cs[2] = srv->fdidx[fd].rsp_cs & 0xff;
        } else
                cs[0] = 0;

        assert(rsp_end >= rsp);

        rcounts[0] = srv->fdidx[fd].rsp_size / 4; /* TotalServiceRecordCount */
        rcounts[1] = (rsp_end - rsp) / 4; /* CurrentServiceRecordCount */

        pdu.pid = SDP_PDU_SERVICE_SEARCH_RESPONSE;
        pdu.tid = ((sdp_pdu_p)(srv->req))->tid;
        pdu.len = htons(sizeof(rcounts) + rcounts[1] * 4 + 1 + cs[0]);

        rcounts[0] = htons(rcounts[0]);
        rcounts[1] = htons(rcounts[1]);

        iov[0].iov_base = &pdu;
        iov[0].iov_len = sizeof(pdu);

        iov[1].iov_base = rcounts;
        iov[1].iov_len = sizeof(rcounts);

        iov[2].iov_base = rsp;
        iov[2].iov_len = rsp_end - rsp;

        iov[3].iov_base = cs;
        iov[3].iov_len = 1 + cs[0];

        do {
                size = writev(fd, (struct iovec const *) &iov, nitems(iov));
        } while (size < 0 && errno == EINTR);

        /* Check if we have sent (or failed to sent) last response chunk */
        if (srv->fdidx[fd].rsp_cs == srv->fdidx[fd].rsp_size) {
                srv->fdidx[fd].rsp_cs = 0;
                srv->fdidx[fd].rsp_size = 0;
                srv->fdidx[fd].rsp_limit = 0;
        }

        return ((size < 0)? errno : 0);
}