dhcpccommonlib.c

VXWORKS源代码

    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));