if (msglen > pReqSpec->maxlen)        {        /*         * Option field is full.  New option would either exceed MTU size         * or overflow the transmit buffer.         */        errno = S_dhcpcLib_OPTION_NOT_STORED;        return (ERROR);        }    pReqSpec->reqlist.list [pReqSpec->reqlist.len++] = option;    return (OK);    }/********************************************************************************* dhcpcOptionAdd - add an option to the client messages** This routine inserts option tags and associated values into the body of* all outgoing messages for the lease indicated by the <pCookie> parameter.* Each lease can accept option data up to the MTU size of the underlying* interface, minus the link-level header size and the additional 283 bytes* required for a minimum DHCP message (including mandatory options).** The <option> parameter specifies an option tag defined in RFC 2132. See* the dhcp/dhcp.h include file for a listing of defined aliases for the* available option tags. This routine will not accept the following <option>* values, which are used for control purposes and cannot be included* arbitrarily:**     _DHCP_PAD_TAG*     _DHCP_OPT_OVERLOAD_TAG*     _DHCP_MSGTYPE_TAG*     _DHCP_SERVER_ID_TAG*     _DHCP_MAXMSGSIZE_TAG*     _DHCP_END_TAG** This routine also will not accept <option> values 62 or 63, which are not* currently defined.** The <length> parameter indicates the number of bytes in the option body* provided by the <pData> parameter. ** The maximum length of the option field in a DHCP message depends on the* MTU size of the associated interface and the maximum DHCP message size set* during the DHCP library initialization. These option settings share that* field with any option request list created through the dhcpcOptionSet()* routine. Options which exceed the limit will not be stored.** Each call to this routine with the same <option> value usually replaces* the value of the existing option, if any. However, the routine will append* the new data for the <option> values which contain variable length lists,* corresponding to tags 3-11, 21, 25, 33, 41-45, 48-49, 55, 65, and 68-76.** WARNING: The _DHCP_REQ_LIST_TAG <option> value (55) will replace* any existing list created with the dhcpcOptionSet() routine.** RETURNS: OK if the option was inserted successfully, or ERROR if the option* is invalid or storage failed.** ERRNO: S_dhcpcLib_BAD_OPTION, S_dhcpcLib_OPTION_NOT_STORED**/STATUS dhcpcOptionAdd    (    void * 	pCookie, 	/* identifier returned by dhcpcInit() */    UCHAR 	option, 	/* RFC 2132 tag of desired option */    int 	length, 	/* length of option data */    UCHAR * 	pData 		/* option data */    )    {    LEASE_DATA *                pLeaseData;    struct dhcp_reqspec *       pReqSpec;    char * 			pDest;    struct dhcpcOpts * 		pOptList;    int msglen = 0; 	/* Length of DHCP message after inserting option */    /*     * Use the cookie to access the lease-specific data structures.  For now,     * just typecast the cookie.  This translation could be replaced with a more     * sophisticated lookup at some point.     */    pLeaseData = (LEASE_DATA *)pCookie;    pReqSpec = &pLeaseData->leaseReqSpec;    /* Check for restricted or invalid options. */    switch (option)        {        case _DHCP_PAD_TAG:             /* fall-through */        case _DHCP_OPT_OVERLOAD_TAG:    /* fall-through */        case _DHCP_MSGTYPE_TAG:         /* fall-through */        case _DHCP_SERVER_ID_TAG:       /* fall-through */        case _DHCP_MAXMSGSIZE_TAG:      /* fall-through */        case _DHCP_END_TAG:            errno = S_dhcpcLib_BAD_OPTION;            return (ERROR);            break;        default:            break;        }    if (option == 62 || option == 63)        {        errno = S_dhcpcLib_BAD_OPTION;        return (ERROR);        }            /*     * Verify that the option won't exceed the MTU size for a message.     * Start with an initial length equal to the UDP and IP headers and     * the fixed-length portion of a DHCP message.     */    msglen = UDPHL + IPHL + (DFLTDHCPLEN - DFLTOPTLEN);    /* Include size of existing options and option request list. */    pOptList = pReqSpec->pOptList;    if (pOptList)        msglen += pReqSpec->pOptList->optlen;    if (option == _DHCP_REQ_LIST_TAG)    /* Replacing request list? */        msglen -= pReqSpec->reqlist.len;    else        msglen += pReqSpec->reqlist.len;    /*     * Include space for required magic cookie (4 bytes), message     * type option (3 bytes), maximum message size (4 bytes), and     * server identifier option (6 bytes).     */    msglen += 17;    /* Include space for required requested IP address option (6 bytes). */    msglen += 6;    /* Add size of any other option (don't double-count IP address). */    if (option != _DHCP_REQUEST_IPADDR_TAG)        msglen += length + 2;    /* +2 includes tag and length values */    if (msglen > dhcpcBufSize)        {        /* Option field is full.  New option would overflow transmit buffer. */        errno = S_dhcpcLib_OPTION_NOT_STORED;        return (ERROR);        }    if (msglen > pReqSpec->maxlen)        {        /*         * Option field is full.  New option would either exceed MTU size         * or overflow the transmit buffer.         */        errno = S_dhcpcLib_OPTION_NOT_STORED;        return (ERROR);        }    if (pData == NULL)        {        errno = S_dhcpcLib_BAD_OPTION;        return (ERROR);        }    /* Validate the length of each option. */    switch (option)        {        /* 1 byte values */        case _DHCP_IP_FORWARD_TAG: 		/* Option Tag 19 */        case _DHCP_NONLOCAL_SRCROUTE_TAG: 	/* Option Tag 20 */        case _DHCP_DEFAULT_IP_TTL_TAG: 		/* Option Tag 23 */        case _DHCP_ALL_SUBNET_LOCAL_TAG: 	/* Option Tag 27 */        case _DHCP_MASK_DISCOVER_TAG: 		/* Option Tag 29 */        case _DHCP_MASK_SUPPLIER_TAG: 		/* Option Tag 30 */        case _DHCP_ROUTER_DISCOVER_TAG: 	/* Option Tag 31 */        case _DHCP_TRAILER_TAG: 		/* Option Tag 34 */        case _DHCP_ETHER_ENCAP_TAG: 		/* Option Tag 36 */        case _DHCP_DEFAULT_TCP_TTL_TAG: 	/* Option Tag 37 */        case _DHCP_KEEPALIVE_GARBAGE_TAG: 	/* Option Tag 39 */        case _DHCP_NB_NODETYPE_TAG: 		/* Option Tag 46 */            if (length != 1)                {                errno = S_dhcpcLib_BAD_OPTION;                return (ERROR);                }            break;        /* 2 byte values */        case _DHCP_BOOTSIZE_TAG: 		/* Option Tag 13 */        case _DHCP_MAX_DGRAM_SIZE_TAG: 		/* Option Tag 22 */        case _DHCP_IF_MTU_TAG: 			/* Option Tag 26 */            if (length != 2)                {                errno = S_dhcpcLib_BAD_OPTION;                return (ERROR);                }            break;        /* 4 byte values */        case _DHCP_SUBNET_MASK_TAG: 		/* Option Tag 1 */        case _DHCP_TIME_OFFSET_TAG: 		/* Option Tag 2 */        case _DHCP_SWAP_SERVER_TAG: 		/* Option Tag 16 */        case _DHCP_MTU_AGING_TIMEOUT_TAG: 	/* Option Tag 24 */        case _DHCP_BRDCAST_ADDR_TAG: 		/* Option Tag 28 */        case _DHCP_ROUTER_SOLICIT_TAG: 		/* Option Tag 32 */        case _DHCP_ARP_CACHE_TIMEOUT_TAG: 	/* Option Tag 35 */        case _DHCP_KEEPALIVE_INTERVAL_TAG: 	/* Option Tag 38 */        case _DHCP_REQUEST_IPADDR_TAG: 		/* Option Tag 50 */        case _DHCP_LEASE_TIME_TAG: 		/* Option Tag 51 */        case _DHCP_T1_TAG: 			/* Option Tag 58 */        case _DHCP_T2_TAG: 			/* Option Tag 59 */            if (length != 4)                {                errno = S_dhcpcLib_BAD_OPTION;                return (ERROR);                }            break;        /* Table entries (2 bytes each) */        case _DHCP_MTU_PLATEAU_TABLE_TAG: 	/* Option Tag 25 */            if (length % 2)                {                errno = S_dhcpcLib_BAD_OPTION;                return (ERROR);                }            break;        /* Address values (4 bytes each) */        case _DHCP_ROUTER_TAG: 			/* Option Tag 3 */        case _DHCP_TIME_SERVER_TAG: 		/* Option Tag 4 */        case _DHCP_NAME_SERVER_TAG: 		/* Option Tag 5 */        case _DHCP_DNS_SERVER_TAG: 		/* Option Tag 6 */        case _DHCP_LOG_SERVER_TAG: 		/* Option Tag 7 */        case _DHCP_COOKIE_SERVER_TAG: 		/* Option Tag 8 */        case _DHCP_LPR_SERVER_TAG: 		/* Option Tag 9 */        case _DHCP_IMPRESS_SERVER_TAG: 		/* Option Tag 10 */        case _DHCP_RLS_SERVER_TAG: 		/* Option Tag 11 */        case _DHCP_NIS_SERVER_TAG: 		/* Option Tag 41 */        case _DHCP_NTP_SERVER_TAG: 		/* Option Tag 42 */        case _DHCP_NBN_SERVER_TAG: 		/* Option Tag 44 */        case _DHCP_NBDD_SERVER_TAG: 		/* Option Tag 45 */        case _DHCP_XFONT_SERVER_TAG: 		/* Option Tag 48 */        case _DHCP_XDISPLAY_MANAGER_TAG: 	/* Option Tag 49 */        case _DHCP_NISP_SERVER_TAG: 		/* Option Tag 65 */        case _DHCP_MOBILEIP_HA_TAG: 		/* Option Tag 68 */        case _DHCP_SMTP_SERVER_TAG: 		/* Option Tag 69 */        case _DHCP_POP3_SERVER_TAG: 		/* Option Tag 70 */        case _DHCP_NNTP_SERVER_TAG: 		/* Option Tag 71 */        case _DHCP_DFLT_WWW_SERVER_TAG: 	/* Option Tag 72 */        case _DHCP_DFLT_FINGER_SERVER_TAG: 	/* Option Tag 73 */        case _DHCP_DFLT_IRC_SERVER_TAG:  	/* Option Tag 74 */        case _DHCP_STREETTALK_SERVER_TAG:  	/* Option Tag 75 */        case _DHCP_STDA_SERVER_TAG: 		/* Option Tag 76 */            if (length % 4)                {                errno = S_dhcpcLib_BAD_OPTION;                return (ERROR);                }            break;        /* Address pairs or address/mask values (8 bytes each). */        case _DHCP_POLICY_FILTER_TAG: 		/* Option Tag 21 */        case _DHCP_STATIC_ROUTE_TAG: 		/* Option Tag 33 */            if (length % 8)                {                errno = S_dhcpcLib_BAD_OPTION;                return (ERROR);                }            break;        /* Variable-length values */        case _DHCP_HOSTNAME_TAG: 		/* Option Tag 12 */        case _DHCP_MERIT_DUMP_TAG: 		/* Option Tag 14 */        case _DHCP_DNS_DOMAIN_TAG: 		/* Option Tag 15 */        case _DHCP_ROOT_PATH_TAG: 		/* Option Tag 17 */        case _DHCP_EXTENSIONS_PATH_TAG: 	/* Option Tag 18 */        case _DHCP_NIS_DOMAIN_TAG: 		/* Option Tag 40 */        case _DHCP_VENDOR_SPEC_TAG: 		/* Option Tag 43 */        case _DHCP_NB_SCOPE_TAG: 		/* Option Tag 47 */        case _DHCP_REQ_LIST_TAG: 		/* Option Tag 55 */        case _DHCP_ERRMSG_TAG: 			/* Option Tag 56 */        case _DHCP_CLASS_ID_TAG: 		/* Option Tag 60 */        case _DHCP_CLIENT_ID_TAG: 		/* Option Tag 61 */        case _DHCP_NISP_DOMAIN_TAG: 		/* Option Tag 64 */        case _DHCP_TFTP_SERVERNAME_TAG: 	/* Option Tag 66 */        case _DHCP_BOOTFILE_TAG: 		/* Option Tag 67 */            if (length < 1 || length > _DHCP_MAX_OPTLEN)                {                errno = S_dhcpcLib_BAD_OPTION;                return (ERROR);                }            break;        }    /* Store the option body in the space provided. */    if (pOptList == NULL)        {        pOptList = malloc (sizeof (struct dhcpcOpts));        if (pOptList == NULL)            {            errno = S_dhcpcLib_OPTION_NOT_STORED;            return (ERROR);            }        bzero ( (char *)pOptList, sizeof (struct dhcpcOpts));        pReqSpec->pOptList = pOptList;        }    switch (option)        {        /* 1 byte values */        case _DHCP_IP_FORWARD_TAG: 		/* Option Tag 19 */            pOptList->tag19 = *pData;            break;            case _DHCP_NONLOCAL_SRCROUTE_TAG: 	/* Option Tag 20 */            pOptList->tag20 = *pData;            break;        case _DHCP_DEFAULT_IP_TTL_TAG: 		/* Option Tag 23 */            pOptList->tag23 = *pData;            break;        case _DHCP_ALL_SUBNET_LOCAL_TAG: 	/* Option Tag 27 */            pOptList->tag27 = *pData;            break;        case _DHCP_MASK_DISCOVER_TAG: 		/* Option Tag 29 */            pOptList->tag29 = *pData;            break;        case _DHCP_MASK_SUPPLIER_TAG: 		/* Option Tag 30 */            pOptList->tag30 = *pData;            break;        case _DHCP_ROUTER_DISCOVER_TAG: 	/* Option Tag 31 */            pOptList->tag31 = *pData;            break;        case _DHCP_TRAILER_TAG: 		/* Option Tag 34 */            pOptList->tag34 = *pData;            break;        case _DHCP_ETHER_ENCAP_TAG: 		/* Option Tag 36 */            pOptList->tag36 = *pData;            break;        case _DHCP_DEFAULT_TCP_TTL_TAG: 	/* Option Tag 37 */            pOptList->tag37 = *pData;            break;        case _DHCP_KEEPALIVE_GARBAGE_TAG: 	/* Option Tag 39 */            pOptList->tag39 = *pData;            break;        case _DHCP_NB_NODETYPE_TAG: 		/* Option Tag 46 */            pOptList->tag46 = *pData;            break;        /* 2 byte values */        case _DHCP_BOOTSIZE_TAG: 		/* Option Tag 13 */            bcopy (pData, (char *)&pOptList->tag13, sizeof (USHORT));