bootplib.c

VxWORKS的BOOTP协议栈

/* bootpLib.c - BOOTP client library */

/* Copyright 1984 - 1999 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
modification history
--------------------
01v,17mar99,spm  added support for identical unit numbers (SPR #20913)
01u,04sep98,ham  corrected lack of params for etherInputHookAdd(),SPR#21909
01t,28aug98,n_s  corrected MAC address comparison in bootpInputHook. spr #20902
01s,17jul97,dgp  doc: correct unsupported interfaces per SPR 8940
02c,14dec97,jdi  doc: cleanup.
02b,10dec97,gnn  making man page fixes
02a,08dec97,gnn  END code review fixes
01z,03dec97,spm  corrected parameter description for bootpMsgSend (SPR #9401);
                 minor changes to man pages and code spacing
01y,03oct97,gnn  removed references to endDriver global.
01x,25sep97,gnn  SENS beta feedback fixes
01w,26aug97,spm  fixed bootpParamsGet - gateway not retrieved (SPR #9137)
01v,12aug97,gnn  changes necessitated by MUX/END update.
01u,30apr97,jag  man page edit for function bootParamsGet()
01t,07apr97,spm  changed BOOTP interface to DHCP style: all options supported
01s,17dec96,gnn  added code to handle the new etherHooks and END stuff.
01r,08nov96,spm  Updated example of bootpParamsGet() for SPR 7120
01q,22sep96,spm  Fixed SPR 7120: added support for gateways to bootpParamsGet()
01p,01feb96,gnn	 added the end of vendor data (0xff) to the request packet
		 we send
01o,16jan94,rhp  fix typo in library man page
01n,17oct94,rhp  remove docn reference to bootpdLib (SPR#2351)
01n,22sep92,jdi  documentation cleanup.
01m,14aug92,elh  documentation changes.
01l,11jun92,elh  modified parameters to bootpParamsGet.
01k,26may92,rrr  the tree shuffle
		  -changed includes to have absolute path from h/
01j,16apr92,elh	 moved routines shared by icmp to icmpLib.
01i,28feb92,elh  ansified.
01h,27aug91,elh  rewritten to use standard bootp protocol,
		 redesigned to be more modular, rewrote documentation.
01g,15aug90,dnw  added slot parameter to bootpParamsGet()
	   +hjb  fixed bug in bootpForwarder() not setting hw addr in arp ioctl
01f,12aug90,dnw  changed bootpParamsGet() to check every tick for reply message
                 instead of every 4 seconds, for faster response.
		 changed bootpParamsGet() to print '.' every time it broadcasts
                 request.
01e,12aug90,hjb  major redesign and implementation of the protocol
01d,07may90,hjb  made bootp IP checksum portable; modifications to the protocol
		 for better forwarding service.
01c,19apr90,hjb  minor fixups bootpRequestSend(), added protocol extension
		 to solve the routing problem when bootp forwarder is used.
01b,11apr90,hjb  de-linted.
01a,11mar90,hjb  written.
*/

/*
DESCRIPTION
This library implements the client side of the Bootstrap Protocol
(BOOTP).  This network protocol allows the dynamic configuration of 
the target's boot parameters at boot time.  This is in contrast to using the 
boot information encoded in system non-volatile RAM or ROM.  
Thus, at boot time, BOOTP goes over the network to get an IP address, 
a boot file name, and the boot host's IP address.  

The actual transfer of the boot image is handled by a file transfer 
protocol, such as TFTP or FTP, or by an RSH command.

To access BOOTP services, you can use either the high-level interface
supported by bootpParamsGet(), or the low-level interface supported
by bootpMsgSend().

HIGH-LEVEL INTERFACE
The bootpParamsGet() routine provides the highest level interface to BOOTP.  
It accepts a parameter descriptor structure that allows the retrieval of any 
combination of the options described in RFC 1533 (if supported by the 
BOOTP server and if specified in the database). During system boot, the routine 
obtains the boot file, the Internet address, and the host Internet address.  
It also obtains the subnet mask and the Internet address of an IP router, 
if available.

LOW-LEVEL INTERFACE
The bootpMsgSend() routine provides a lower-level interface to BOOTP.  It 
accepts and returns a BOOTP message as a parameter.  This interface is more
flexible because it gives the caller direct access to the data in the
BOOTP request/reply messages. For example, if the BOOTP message includes 
implementation-specific options not defined in an RFC, the caller can
use bootpMsgSend() to retrieve them from the vendor-specific field in 
the BOOTP message.  The bootpParamsGet() routine already provides 
all defined options.

EXAMPLE
The following code provides and example of how to use bootpParamsGet():  
.CS
    #include "bootpLib.h"

    struct bootpParams 	bootParams;

    struct in_addr 	clntAddr;
    struct in_addr 	hostAddr;
    char 		bootFile [FILENAME_SIZE];
    int 		subnetMask;
    struct in_addr_list routerList;
    struct in_addr 	gateway;

    char        clntAddr [INET_ADDR_LEN];
    char        bootServer [INET_ADDR_LEN];
    char 	bootFile [SIZE_FILE];
    int         fileSize; 
    int         subnetMask;
    char        gateway [INET_ADDR_LEN];
 
    bzero ( (char *)&clntAddr, sizeof (struct in_addr));
    bzero ( (char *)&hostAddr, sizeof (struct in_addr));
    bzero (bootFile, FILENAME_SIZE);
    subnetMask  = 0;
    bzero ( (char *)&gateway, sizeof (struct in_addr));

    /@ Set all pointers in parameter descriptor to NULL. @/

    bzero ((char *)&bootParams, sizeof (struct bootpParams));

    /@ Set pointers corresponding to desired options. @/

    bootParams.clientAddr = &clntAddr;
    bootParams.bootHostAddr = &hostAddr;
    bootParams.bootfile = pBootFile;

    bootParams.netmask = (struct in_addr *)&subnetMask;
    routerlist.addr = &gateway;
    routerlist.num = 1;
    bootParams.routers = &routerlist;

    if (bootpParamsGet ("ln0", 0, 0, &bootParams) == ERROR)
        return (ERROR);
.CE

NOTE
Certain targets (typically those with no NVRAM) construct their 
Ethernet address based on the target's IP address.  An IP address
must be entered for these targets in order to boot over the network.
The remaining information can be obtained with BOOTP.

BOOTP is not supported over the following network interfaces: if_sl (SLIP) 
and if_ie (Sun IE driver).
if_sl (SLIP) and if_ppp (PPP).

INCLUDE FILES: bootpLib.h

SEE ALSO: bootLib, RFC 951, RFC 1542, RFC 1533,
.pG "Network"

INTERNAL

The BOOTP implementation uses driver input hooks to access the network 
interface. The link-level access that mechanism provides is required since 
the network is not initially available during boot time because the Internet 
address is unknown.

The diagram below defines the structure chart of bootpLib.


                                   (network interface driver)
                 |                           |
                 v                           v
	    bootpParamsGet	      bootpInputHook
	     / 		\		     |
	    |		|		     v
	    v		v	     
      bootpMsgSend   bootpParamsFill
*/

/* includes */

#include "vxWorks.h"
#include "bootpLib.h"
#include "netinet/in.h"

#include "netinet/udp.h"
#include "netinet/in_var.h"
#include "netinet/if_ether.h"

#include "etherLib.h"
#include "taskLib.h"
#include "string.h"
#include "stdio.h"
#include "errno.h"
#include "sysLib.h"
#include "tickLib.h"
#include "icmpLib.h"
#include "inetLib.h"

#include "end.h"
#include "muxLib.h"
#include "ipProto.h"
    
/* defines */

#define ETHER_ADDR_TYPE		1		/* ethernet type   */
#define ETHER_ADDR_LEN		6  		/* ethernet length  */

/* globals */

LOCAL struct
    {
    struct ip		ih;		/* IP header		*/
    struct udphdr	uh;		/* UDP header		*/
    BOOTP_MSG		bp;    		/* Bootp message	*/
    } bootpMsg;

u_long	bootpBroadcastAddr = INADDR_BROADCAST;		/* bootp broadcast   */
int 	bootpReXmitSecs    = INIT_BOOTP_DELAY; 		/* bootp delay */

/* locals */

LOCAL BOOTP_MSG	* 	pBootpReply;			/* pointer to reply  */
LOCAL BOOL		bootpReplyReceived; 		/* received reply?   */
LOCAL char		inputBuffer [ETHERMTU];		/* message buffer    */
							/* 1048 cookie type  */
LOCAL u_char		magicCookie1048 [4] = VM_RFC1048;

#define VEOF_RFC1048 {255}

LOCAL u_char		endOfVend[1] = VEOF_RFC1048;

/* forward declarations */

LOCAL BOOL bootpInputHook (struct ifnet * pIf, char *einput, int length);
extern	   in_broadcast ();

/******************************************************************************
*
* bootpParamsGet - retrieve boot parameters using BOOTP
*
* This routine transmits a BOOTP request message over the network interface
* associated with <ifName>.  This interface must already be attached and
* initialized prior to calling this routine.
*
* A non-zero value for <port> specifies an alternate BOOTP server port.
* A zero value means the default BOOTP server port (67).
*
* <timeOut> specifies a timeout value in ticks.  If no reply is received 
* within this period, an error is returned.  Specify zero for an infinite
* <timeout> value.
*
* <pBootpParams> is a structure pointer to a `bootpParams' structure that
* you can use to indicate the parameters of interest to you. The `bootpParams' 
* structure is defined as follows:
*
* .CS
*    struct bootpParams
*        {
*        struct in_addr *            clientAddr;
*        struct in_addr *            bootHostAddr;
*        char *                      bootfile;
*        char *                      serverName;
*
*        struct in_addr *            netmask;
*        unsigned short *            timeOffset;
*        struct in_addr_list *       routers;
*        struct in_addr_list *       timeServers;
*        struct in_addr_list *       nameServers;
*        struct in_addr_list *       dnsServers;
*        struct in_addr_list *       logServers;
*        struct in_addr_list *       cookieServers;
*        struct in_addr_list *       lprServers;
*        struct in_addr_list *       impressServers;
*        struct in_addr_list *       rlpServers;
*        char *                      clientName;
*        unsigned short *            filesize;
*        char *                      dumpfile;
*        char *                      domainName;
*        struct in_addr *            swapServer;
*        char *                      rootPath;
*        char *                      extoptPath;
*        unsigned char *             ipForward;
*        unsigned char *             nonlocalSourceRoute;
*        struct in_addr_list *       policyFilter;
*        unsigned short *            maxDgramSize;
*        unsigned char *             ipTTL;
*        unsigned long *             mtuTimeout;
*        struct ushort_list *        mtuTable;
*        unsigned short *            intfaceMTU;
*        unsigned char *             allSubnetsLocal;
*        struct in_addr *            broadcastAddr;
*        unsigned char *             maskDiscover;
*        unsigned char *             maskSupplier;
*        unsigned char *             routerDiscover;
*        struct in_addr *            routerDiscAddr;
*        struct in_addr_list *       staticRoutes;
*        unsigned char *             arpTrailers;
*        unsigned long *             arpTimeout;
*        unsigned char *             etherPacketType;
*        unsigned char *             tcpTTL;
*        unsigned long *             tcpInterval;
*        unsigned char *             tcpGarbage;
*        char *                      nisDomain;
*        struct in_addr_list *       nisServers;
*        struct in_addr_list *       ntpServers;
*        char *                      vendString;
*        struct in_addr_list *       nbnServers;
*        struct in_addr_list *       nbddServers;
*        unsigned char *             nbNodeType;
*        char *                      nbScope;
*        struct in_addr_list *       xFontServers;
*        struct in_addr_list *       xDisplayManagers;
*        char *                      nispDomain;
*        struct in_addr_list *       nispServers;
*        struct in_addr_list *       ipAgents;
*        struct in_addr_list *       smtpServers;
*        struct in_addr_list *       pop3Servers;
*        struct in_addr_list *       nntpServers;
*        struct in_addr_list *       wwwServers;
*        struct in_addr_list *       fingerServers;
*        struct in_addr_list *       ircServers;
*        struct in_addr_list *       stServers;
*        struct in_addr_list *       stdaServers; 
*        };
* .CE
*
* This structure allows the retrieval of any BOOTP option specified in
* RFC 1533. The list of 2-byte (unsigned short) values is defined as:
*
* .CS
*    struct ushort_list
*        {
*        unsigned char       num;
*        unsigned short *    shortlist;
*        };
* .CE
*
* The IP address lists use the following similar definition:
*
* .CS
*    struct in_addr_list
*        {
*        unsigned char       num;
*        struct in_addr *    addrlist;
*        };
* .CE
*
* When these lists are present, the routine stores values retrieved from
* the BOOTP reply in the location indicated by the `shortlist' or `addrlist'
* members.  The amount of space available is indicated by the `num' member.
* When the routine returns, the `num' member indicates the actual number of
* entries retrieved.  In the case of `bootpParams.policyFilter.num' 
* and `bootpParams.staticRoutes.num', the `num' member value should be 
* interpreted as the number of IP address pairs requested and received.
*
* The following members of the `bootpParams' structure are also used for 
* both input and output:
*
* .IP `clientAddr' 
* Contains a pointer that holds the client's Internet address.  
* On input, if it contains a non-NULL value, it is interpreted as a 
* pointer to an Internet address of type `struct in_addr' and passed 
* on to the BOOTP server in the `bp_ciaddr' member of the BOOTP 
* message structure (BOOTP_MSG).  The server will use it as a lookup 
* field into the BOOTP database.  When a reply is received, the client's
* assigned Internet address is copied to the `clientAddr' member.
*
* .IP `bootHostAddr' 
* Contains a pointer that holds the host's IP address.  On input, 
* if it contains a non-NULL value, it is interpreted as the host where 
* the BOOTP message is to be sent.  Note that this host must be local
* to the <pIf> network.  If NULL, the BOOTP message is sent to the local
* broadcast address.  On return, the host's IP address is copied to
* the `bootHostAddr' member.
*
* On input, if the `bootpParams.bootfile' member  points to a non-empty 
* string, the contents are passed to the BOOTP server in the `bp_file' 
* member of the BOOTP message structure (BOOTP_MSG).  When a reply is 
* received, the file name retrieved from the BOOTP server is copied to 
* the `bootpParams.bootfile' member as a NULL-terminated string.
*
* .LP
* The remaining elements in the BOOTP parameters descriptor are used to select
* options for retrieval from the BOOTP server.  The BOOTP library attempts to
* retrieve the values for any options whose corresponding field pointers are
* non-NULL values.  To obtain these parameters, the BOOTP server must support
* the vendor-specific options described in RFC 1048 (or its successors) and the 
* corresponding parameters must be specified in the BOOTP server database. 
* Where meaningful, the values are returned in host byte order. 
*
* The BOOTP request issued during system startup attempts to retrieve a subnet
* mask for the boot device, in addition to the host and client addresses,
* and the boot file name.
*
* RETURNS: OK, or ERROR if unsuccessful.
*
* SEE ALSO: bootLib, RFC 1048, RFC 1533
*/