dhcp_00.c

来自「umon bootloader source code, support mip」· C语言 代码 · 共 253 行

/* dhcp_00.c:
 *	This file contains the functions that are called from dhcpboot.c if the
 *	the default DHCP interaction is to be done by the monitor.  Whenever a 
 *	new dhcp_XX.c file is created, this file should be used as the template.
 *
 *	General notice:
 *	This code is part of a boot-monitor package developed as a generic base
 *	platform for embedded system designs.  As such, it is likely to be
 *	distributed to various projects beyond the control of the original
 *	author.  Please notify the author of any enhancements made or bugs found
 *	so that all may benefit from the changes.  In addition, notification back
 *	to the author will allow the new user to pick up changes that may have
 *	been made by other users after this version of the code was distributed.
 *
 *	Note1: the majority of this code was edited with 4-space tabs.
 *	Note2: as more and more contributions are accepted, the term "author"
 *		   is becoming a mis-representation of credit.
 *
 *	Original author:	Ed Sutter
 *	Email:				[e-mail]
 *	Phone:				[phone]
 */

#include "config.h"
#include "cpuio.h"
#include "ether.h"
#include "tfs.h"
#include "tfsprivate.h"
#include "genlib.h"
#include "endian.h"
#include "stddefs.h"

#if INCLUDE_DHCPBOOT

/* ValidDHCPOffer():
 *	Target issued the DISCOVER, the incoming packet is the server's
 *	OFFER reply.  If the DHCPOFFRFLTR shell variable is not present, then
 *	return 1 indicating acceptance of the offer.  If the DHCPOFFRFLTR variable
 *	exists, then use its content to determine if the offer should be accepted...
 *	
 *	Shell variable syntax:
 *	
 *	DHCP_FIELD_IDENTIFIER,EXPECTED_STRING
 *	
 *	where DHCP_FIELD_IDENTIFIER can be...
 *		BFN		bootfile name
 *		SHN		server-host name
 *		VSO###	vendor-specific option number (options encapsulated within
 *			    the Vendor-Specific Information (#43) option)
 *		SSO###	site-specific option number (range 128-254)
 * 
 *	For example:
 *	1...
 *		if DHCPOFFRFLTR contains "BFN,abcfile"
 *		then the offer will only be accepted if the bootfile specified by the
 *		dhcp server contains the string "abcfile".
 *	2...
 *		if DHCPOFFRFLTR contains "SHN,a_host_name"
 *		then the offer will only be accepted if the server-hostname specified
 *		by the dhcp server contains the string "a_host_name".
 *	3...
 *		if DHCPOFFRFLTR contains "VSO18,some_String"
 *		then the offer will only be accepted if the server returns vendor-
 *		specific option # 18 and it contains the string "some_String".
 *
 *	Note that "containing the string" means that the string specified in
 *	the DHCPOFFRFLTR shell variable can be the entire string or a sub-string
 *	within the server's response.
 */
int
ValidDHCPOffer(struct	dhcphdr *dhdr)
{
	char *var;
	int	offeraccepted, badsyntax;

	/* If no DHCPOFFRFLTR var, accept the offer... */
	var = getenv("DHCPOFFRFLTR");
	if (!var)	
		return(1);

	/* Start off by assuming acceptance... */
	badsyntax = 0;
	offeraccepted = 1;

	/* Now process the DHCPOFFRFLTR variable and incoming dhcp data,
	 * and clear the offeraccepted (or set badsyntax) flag if necessary...
	 */

	if (!strncmp(var,"BFN,",4)) {
		if (!strstr(dhdr->bootfile,var+4))
			offeraccepted = 0;
	}
	else if (!strncmp(var,"SHN,",4)) {
		if (!strstr(dhdr->server_hostname,var+4))
			offeraccepted = 0;
	}
	else if ((!strncmp(var,"SSO",3)) || (!strncmp(var,"VSO",3))) {
		int	optno;
		ulong cookie;
		char *comma, *optval, *vso;

		optno = atoi(var+3);
		comma = strchr(var,',');
		memcpy((char *)&cookie,(char *)&dhdr->magic_cookie,4);
		if (cookie != ecl(STANDARD_MAGIC_COOKIE))
			offeraccepted = 0;
		else if (!comma)
			badsyntax = 1;
		else if (var[0] == 'S') {
			if ((optno < 128) || (optno > 254))
				badsyntax = 1;
			else {
				optval = DhcpGetOption(optno,(char *)(dhdr+1));
				if (!optval)
					offeraccepted = 0;
				else {
					if (!strstr(optval+2,comma+1))
						offeraccepted = 0;
				}
			}
		}
		else if (var[0] == 'V') {
			if ((optno < 0) || (optno > 254))
				badsyntax = 1;
			else {
				vso = DhcpGetOption(DHCPOPT_VENDORSPECIFICINFO,
					(char *)(dhdr+1));
				if (!vso)
					offeraccepted = 0;
				else {
					optval = DhcpGetOption(optno,vso+2);
					if (!optval)
						offeraccepted = 0;
					else {
						if (!strstr(optval+2,comma+1))
							offeraccepted = 0;
					}
				}
			}
		}
	}
	else {
		badsyntax = 1;
	}
	if (badsyntax) {
		printf("Bad DHCPOFFRFLTR syntax.\n");
		offeraccepted = 0;
	}
	return(offeraccepted);
}

/* DhcpVendorSpecific():
 *	Process any vendor specific data from the incoming header.
 */
void
DhcpVendorSpecific(struct dhcphdr *dhdr)
{
	return;			/* Obviously, the default is no processing. */
}

/* printDhcpVSopt():
 *	Input is the option, the option length and the pointer to the options.
 *	Print the option.
 */
int
printDhcpVSopt(int vsopt, int vsoptlen, char *options)
{
	return(0);
}

/* buildDhcpHdr():
 *	Called by dhcpboot.c to allow application-specific header stuff to
 *	be added to header.  Return 0 if generic stuff in dhcpboot.c is to be
 *	used; else return 1 and the calling code will assume this function is
 *	dealing with it (see dhcpboot.c for basic idea).
 */
int
buildDhcpHdr(struct dhcphdr *dhdr)
{
	return(0);
}

/* DhcpBootpLoadVSA():
 *	Called by DhcpBootpDone to store an ascii-coded-hex copy of the 
 *	vendor-specific-area (BOOTP) or options (DHCP) in the shell variable
 *	DHCPVSA.
 */
void
DhcpBootpLoadVSA(uchar *vsabin, int vsize)
{
	int i;
	uchar	*cp, *vsaacx;

	/* If after the transaction has completed, the RLYAGNT is	*/
	/* set, but GIPADD is not set, copy RLYAGNT to GIPADD...	*/
	if (!getenv("GIPADD") && getenv("RLYAGNT"))
		setenv("GIPADD",getenv("RLYAGNT"));

	/* Since the VSA (bootp) or options list (DHCP) can be large,
	 * This code looks for the presence of the DHCPVSA shell variable
	 * as an indication as to whether or not this data should be stored
	 * in the DHCPVSA variable...
	 * If the variable is present, then this code will load the DHCPVSA
	 * shell variable; else it just returns here.
	 * Note that it doesn't matter what the content of DHCPVSA is, as
	 * long as it is present, so just loading it with "TRUE" in monrc
	 * will be sufficient to tell this logic to load the variable with
	 * the data.
	 */
	if (!getenv("DHCPVSA"))
		return;

	/* If allocation succeeds, then copy BOOTP VendorSpecificArea to the */
	/* DHCPVSA shell variable. Copy it as ascii-coded hex */
	vsaacx = (uchar *)malloc((vsize*2)+4);
	if (vsaacx) {
		cp = vsaacx;
		for(i=0;i<vsize;i++,cp+=2)
			sprintf(cp,"%02x",vsabin[i]);
		*cp = 0;
		setenv("DHCPVSA",vsaacx);
		free(vsaacx);
	}
	else
		printf("DHCPVSA space allocation failed\n");
}


/* DhcpBootpDone():
 *	Called at the end of the Bootp or Dhcp transaction.
 *	Input...
 *	bootp:	1 if BOOTP; else DHCP.
 *	dhdr:	pointer to dhcp or bootp header.
 *	vsize:	size of vendor specific area (for bootp this is fixed at 64, 
 *			but for dhcp it is variable).
 */
void
DhcpBootpDone(int bootp, struct dhcphdr *dhdr, int vsize)
{
	if (bootp) {
		struct bootphdr *bhdr;

		bhdr = (struct bootphdr *)dhdr;
		DhcpBootpLoadVSA(bhdr->vsa,vsize);
	}
	else {
		DhcpBootpLoadVSA((uchar *)&dhdr->magic_cookie,vsize);
	}
	return;
}

#endif