hostlib.c

vxworks的完整的源代码

/* hostLib.c - host table subroutine library */

/* Copyright 1984 - 2001 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
modification history
--------------------
02d,10may02,kbw  making man page edits
02c,15oct01,rae  merge from truestack ver 02g, base 02b (SPR #63610)
02b,15mar99,c_c  Doc: updated hostGetByName manual page (SPR #5184).
02a,14mar99,jdi  doc: removed refs to config.h and/or configAll.h (SPR 25663).
01z,20aug,97,jag added functions hostTblSearchByAddr(), hostTblSearchByName() 
		 to address (SPR #9175)
01x,19may97,spm  added checks for NULL pointers to user interface routines
01w,20apr97,kbw  fixed man page format problems, did a spell check
01v,07apr97,jag  added hooks for the resolver library.
01w,17nov97,dgp  doc: SPR 9410, hostGetByName() returns addr in network byte
			order
01v,29aug97,dgp  doc: SPR 9196 correct ERROR return for hostAdd()
01u,16feb94,caf  added check for NULL pointer in hostGetByName() (SPR #2920).
01t,02feb93,jdi  documentation cleanup for 5.1.
01s,13nov92,dnw  added include of semLibP.h
01r,27jul92,elh  Moved hostShow to netShow.c
01q,18jul92,smb  Changed errno.h to errnoLib.h.
01p,26may92,rrr  the tree shuffle
		  -changed includes to have absolute path from h/
01o,10dec91,gae  more cleanup of ANSI warnings.
01n,25oct91,rrr  cleanup of some ansi warnings.
01m,04oct91,rrr  passed through the ansification filter
                  -changed functions to ansi style
		  -changed includes to have absolute path from h/
		  -changed VOID to void
		  -changed copyright notice
01l,05apr91,jdi	 documentation -- removed header parens and x-ref numbers;
		 doc review by dnw.
01k,12feb91,jaa	 documentation.
01j,02oct90,hjb  defined HOSTNAME_LEN. added sethostname() and gethostname().
01i,15jul90,dnw  changed hostNameFill() to coerce malloc() to (char*)
01h,26jun90,jcf  changed hostList semaphore to type mutex.
01g,23may89,shl  changed addr parameter in hostGetByAddr() from char* to int.
01f,21apr89,shl  added hostGetByAddr().
		 added hostDelete ().
01e,18mar88,gae  documentation.
01d,07jul88,jcf  fixed malloc to match new declaration.
01c,04jun88,gae  changed S_remLib_* to S_hostLib_*.
01b,30may88,dnw  changed to v4 names.
01a,28may88,dnw  extracted from remLib.
*/

/*
DESCRIPTION
This library provides routines to store and access the network host database.
The host table contains information regarding the known hosts on the
local network.  The host table (displayed with hostShow()) contains
the Internet address, the official host name, and aliases.

By convention, network addresses are specified in dotted (".") decimal 
notation.  The library inetLib contains Internet address manipulation 
routines.  Host names and aliases may contain any printable character.

Before any of the routines in this module can be used, the library must be
initialized by hostTblInit().  This is done automatically if INCLUDE_HOST_TBL
is defined.

INCLUDE FILES: hostLib.h

SEE ALSO
inetLib
*/

#include "vxWorks.h"
#include "sys/types.h"
#include "netinet/in.h"
#include "stdlib.h"
#include "semLib.h"
#include "string.h"
#include "inetLib.h"
#include "lstLib.h"
#include "hostLib.h"
#include "errnoLib.h"
#include "stdio.h"
#include "private/semLibP.h"
#include "memPartLib.h"

#ifdef VIRTUAL_STACK
#include "netinet/vsLib.h"
#endif

#ifndef VIRTUAL_STACK

#define HOSTNAME_LEN 128

/* globals */

LIST hostList;
SEM_ID hostListSem = NULL;
BOOL hostInitFlag = FALSE;

#endif /* VIRTUAL_STACK */

/* Function pointers installed by resolvLib, when the resolver is included */
														/* Use DNS resolver for the name query */
FUNCPTR _presolvHostLibGetByName = NULL;  

				/* Use DNS resolver for the pointer query */
FUNCPTR _presolvHostLibGetByAddr = NULL;  

/* mutual exclusion options */

int mutexOptionsHostLib = SEM_Q_FIFO | SEM_DELETE_SAFE;

#ifndef VIRTUAL_STACK

/* locals */

LOCAL char targetName [HOSTNAME_LEN];	/* name for this target machine */

#endif /* VIRTUAL_STACK */

/* forward static functions */

static STATUS hostNameFill (HOSTNAME *pHostName, char *newHostName);


/*******************************************************************************
*
* hostTblInit - initialize the network host table
*
* This routine initializes the host list data structure used by routines
* throughout this module.  It should be called before any other routines in
* this module.  This is done automatically if INCLUDE_HOST_TBL is defined.
*
* RETURNS: N/A
*
* SEE ALSO: usrConfig
*/

void hostTblInit (void)
    {

    if (!hostInitFlag)
	{
	hostInitFlag = TRUE;
	lstInit (&hostList);
	hostListSem = semMCreate (mutexOptionsHostLib);
	}
    }

/*******************************************************************************
*
* hostAdd - add a host to the host table
*
* This routine adds a host name to the local host table.
* This must be called before sockets on the remote host are opened,
* or before files on the remote host are accessed via netDrv or nfsDrv.
*
* The host table has one entry per Internet address.
* More than one name may be used for an address.
* Additional host names are added as aliases.
*
* EXAMPLE
* .CS
*    -> hostAdd "wrs", "90.2"
*    -> hostShow
*    hostname         inet address       aliases
*    --------         ------------       -------
*    localhost        127.0.0.1
*    yuba             90.0.0.3
*    wrs              90.0.0.2
*    value = 12288 = 0x3000 = _bzero + 0x18
* .CE
* RETURNS:
* OK, or ERROR if the host table is full, the host name/inet address pair
* is already entered, the Internet address is invalid, or memory is 
* insufficient.
*
* SEE ALSO: netDrv, nfsDrv
*/

STATUS hostAdd
    (
    char *hostName,     /* host name */
    char *hostAddr      /* host addr in standard Internet format */
    )
    {
    HOSTNAME *pHostNamePrev = NULL;	/* pointer to previous host name entry */
    FAST HOSTNAME *pHostName;		/* pointer to host name entry */
    FAST HOSTENTRY *pHostEntry;
    struct in_addr netAddr;		/* network address */

    if (hostName == NULL || hostAddr == NULL)
        {
        errnoSet (S_hostLib_INVALID_PARAMETER);
        return (ERROR);
        }

    if ((netAddr.s_addr = inet_addr (hostAddr)) == ERROR)
	return (ERROR);

    if (semTake (hostListSem, WAIT_FOREVER) == ERROR)
	return (ERROR);

    for (pHostEntry = (HOSTENTRY *)lstFirst (&hostList);
	 pHostEntry != NULL;
	 pHostEntry = (HOSTENTRY *)lstNext (&pHostEntry->node))
	{
	if (pHostEntry->netAddr.s_addr == netAddr.s_addr)
	    {
	    /* host internet address already in table, add name as an alias */

	    pHostNamePrev = &pHostEntry->hostName;

	    for (pHostName = &pHostEntry->hostName;
		 pHostName != NULL;
		 pHostName = pHostName->link)
		{
		/* make sure name is not already used for this address */

		if (strcmp (pHostName->name, hostName) == 0)
		    {
		    semGive (hostListSem);
		    errnoSet (S_hostLib_HOST_ALREADY_ENTERED);
		    return (ERROR);
		    }

		pHostNamePrev = pHostName;
		}

	    if (pHostNamePrev == NULL)
		{
		/* XXX corrupted list! */
		return (ERROR);
		}

	    /* name not used for this address, add it as an alias */

	    if ((pHostNamePrev->link = (HOSTNAME *)
		 KHEAP_ALLOC(sizeof (HOSTNAME))) == NULL)
		{
		semGive (hostListSem);
		return (ERROR);
		}

	    bzero ((char *)pHostNamePrev->link, sizeof(HOSTNAME));

	    if (hostNameFill (pHostNamePrev->link, hostName) == ERROR)
		{
		semGive (hostListSem);
		return (ERROR);
		}

	    semGive (hostListSem);
	    return (OK);
	    }
	}

    /* host name and internet address not in host table, add new host */

    if ((pHostEntry = (HOSTENTRY *) KHEAP_ALLOC(sizeof (HOSTENTRY))) == NULL)
	{
	semGive (hostListSem);
	return (ERROR);
	}
	
    bzero ((char *)pHostEntry, sizeof(HOSTENTRY));

    if ((hostNameFill (&pHostEntry->hostName, hostName)) == ERROR)
	{
	semGive (hostListSem);
	return (ERROR);
	}

    
    pHostEntry->netAddr = netAddr;

    lstAdd (&hostList, &pHostEntry->node);

    semGive (hostListSem);
    return (OK);
    }

/*******************************************************************************
*
* hostDelete - delete a host from the host table
*
* This routine deletes a host name from the local host table.  If <name> is
* a host name, the host entry is deleted.  If <name> is a host name alias,
* the alias is deleted.
*
* RETURNS: OK, or ERROR if the parameters are invalid or the host is unknown.
*
* ERRNO: S_hostLib_INVALID_PARAMETER, S_hostLib_UNKNOWN_HOST
*/

STATUS hostDelete
    (
    char *name, /* host name or alias */
    char *addr  /* host addr in standard Internet format */
    )
    {
    HOSTNAME *pHostNamePrev;	/* pointer to previous host name entry */
    HOSTNAME *pHostNameNext;	/* pointer to next host name entry */
    FAST HOSTNAME *pHostName;
    FAST HOSTENTRY *pHostEntry;
    struct in_addr netAddr;

    if (name == NULL || addr == NULL)
        {
        errnoSet (S_hostLib_INVALID_PARAMETER);
        return (ERROR);
        }

    /* convert from string to int format */

    if ((netAddr.s_addr = inet_addr (addr)) == ERROR)
	return ERROR;

    semTake (hostListSem, WAIT_FOREVER);

    /* search inet address */

    for (pHostEntry = (HOSTENTRY *)lstFirst (&hostList);
	 pHostEntry != NULL;
	 pHostEntry = (HOSTENTRY *)lstNext (&pHostEntry->node))
        {

	if (pHostEntry->netAddr.s_addr != netAddr.s_addr)
	    continue;

	if (strcmp (pHostEntry->hostName.name, name) == 0)	/* given name is exact match */
	    {
	    FAST HOSTNAME * pAlias = pHostEntry->hostName.link;
	    FAST HOSTNAME * pNext = NULL;

	    /* free all associated alias(es) 1st if any, then free itself */

	    for ( ; pAlias != NULL; pAlias = pNext)
		{
		pNext = pAlias->link;
		KHEAP_FREE(pAlias->name);
		KHEAP_FREE((char *) pAlias);
		}

	    lstDelete (&hostList, &pHostEntry->node);
	    semGive (hostListSem);