slpd_main.c

SLP协议在linux下的实现。此版本为1.2.1版。官方网站为www.openslp.org

/***************************************************************************/
/*                                                                         */
/* Project:     OpenSLP - OpenSource implementation of Service Location    */
/*              Protocol Version 2                                         */
/*                                                                         */
/* File:        slpd_main.c                                                */
/*                                                                         */
/* Abstract:    Main daemon loop                                           */
/*                                                                         */
/*-------------------------------------------------------------------------*/
/*                                                                         */
/*     Please submit patches to http://www.openslp.org                     */
/*                                                                         */
/*-------------------------------------------------------------------------*/
/*                                                                         */
/* Copyright (C) 2000 Caldera Systems, Inc                                 */
/* All rights reserved.                                                    */
/*                                                                         */
/* Redistribution and use in source and binary forms, with or without      */
/* modification, are permitted provided that the following conditions are  */
/* met:                                                                    */ 
/*                                                                         */
/*      Redistributions of source code must retain the above copyright     */
/*      notice, this list of conditions and the following disclaimer.      */
/*                                                                         */
/*      Redistributions in binary form must reproduce the above copyright  */
/*      notice, this list of conditions and the following disclaimer in    */
/*      the documentation and/or other materials provided with the         */
/*      distribution.                                                      */
/*                                                                         */
/*      Neither the name of Caldera Systems nor the names of its           */
/*      contributors may be used to endorse or promote products derived    */
/*      from this software without specific prior written permission.      */
/*                                                                         */
/* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS     */
/* `AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT      */
/* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR   */
/* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE CALDERA      */
/* SYSTEMS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, */
/* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT        */
/* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;  LOSS OF USE,  */
/* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON       */
/* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT */
/* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE   */
/* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.    */
/*                                                                         */
/***************************************************************************/

#include "slpd.h"

/*=========================================================================*/
/* slpd includes                                                           */
/*=========================================================================*/
#include "slpd_log.h"
#include "slpd_socket.h"
#include "slpd_incoming.h"
#include "slpd_outgoing.h"
#include "slpd_database.h"
#include "slpd_cmdline.h"
#include "slpd_knownda.h"
#include "slpd_property.h"
#ifdef ENABLE_SLPv2_SECURITY
#include "slpd_spi.h"
#endif

/*=========================================================================*/
/* common code includes                                                    */
/*=========================================================================*/
#include "slp_xmalloc.h"
#include "slp_xid.h"


/*==========================================================================*/
int G_SIGALRM;
int G_SIGTERM;
int G_SIGHUP;                                                                                                 
#ifdef DEBUG
int G_SIGINT;		/* Signal being used for dumping registrations */
#endif 
/*==========================================================================*/


/*-------------------------------------------------------------------------*/
void LoadFdSets(SLPList* socklist, 
                int* highfd, 
                fd_set* readfds, 
                fd_set* writefds)
/*-------------------------------------------------------------------------*/
{
    SLPDSocket* sock = 0;
    SLPDSocket* del = 0;

    sock = (SLPDSocket*)socklist->head;
    while(sock)
    {
        if(sock->fd > *highfd)
        {
            *highfd = sock->fd;
        }

        switch(sock->state)
        {
        case DATAGRAM_UNICAST:
        case DATAGRAM_MULTICAST:
        case DATAGRAM_BROADCAST:
            FD_SET(sock->fd,readfds);
            break;

        case SOCKET_LISTEN:
            if(socklist->count < SLPD_MAX_SOCKETS)
            {
                FD_SET(sock->fd,readfds);
            }
            break;

        case STREAM_READ:
        case STREAM_READ_FIRST:
            FD_SET(sock->fd,readfds);
            break;

        case STREAM_WRITE:
        case STREAM_WRITE_FIRST:
        case STREAM_CONNECT_BLOCK:
            FD_SET(sock->fd,writefds);
            break;

        case SOCKET_CLOSE:
            del = sock;
            break;

        default:
            break;
        }

        sock = (SLPDSocket*)sock->listitem.next;

        if(del)
        {
            SLPDSocketFree((SLPDSocket*)SLPListUnlink(socklist,(SLPListItem*)del));     
            del = 0;
        }
    }
}


/*------------------------------------------------------------------------*/
void HandleSigTerm()
/*------------------------------------------------------------------------*/
{
    struct timeval  timeout;
    fd_set          readfds;
    fd_set          writefds;
    int             highfd          = 0;
    int             fdcount         = 0;

    SLPDLog("****************************************\n");
    SLPDLogTime();
    SLPDLog("SLPD daemon shutting down\n");
    SLPDLog("****************************************\n");

    /* close all incoming sockets */
    SLPDIncomingDeinit();

    /* unregister with all DAs */
    SLPDKnownDADeinit();

    timeout.tv_sec  = 5;
    timeout.tv_usec = 0; 

    /* Do a dead DA passive advert to tell everyone we're goin' down */
    SLPDKnownDAPassiveDAAdvert(0, 1);

    /* if possible wait until all outgoing socket are done and closed */
    while(SLPDOutgoingDeinit(1))
    {
        FD_ZERO(&writefds);
        FD_ZERO(&readfds);
        LoadFdSets(&G_OutgoingSocketList, &highfd, &readfds,&writefds);
        fdcount = select(highfd+1,&readfds,&writefds,0,&timeout);
        if(fdcount == 0)
        {
            break;
        }

        SLPDOutgoingHandler(&fdcount,&readfds,&writefds);
    }

    SLPDOutgoingDeinit(0);

    SLPDLog("****************************************\n");
    SLPDLogTime();
    SLPDLog("SLPD daemon shut down\n");
    SLPDLog("****************************************\n");

#ifdef DEBUG
    #ifdef ENABLE_SLPv2_SECURITY
    SLPDSpiDeinit();
    #endif
    SLPDDatabaseDeinit();
    SLPDPropertyDeinit();
    SLPDLogFileClose();
    xmalloc_deinit();    
#endif

}

/*------------------------------------------------------------------------*/
void HandleSigHup()
/*------------------------------------------------------------------------*/
{
    /* Reinitialize */
    SLPDLog("****************************************\n");
    SLPDLogTime();
    SLPDLog("SLPD daemon reset by SIGHUP\n");
    SLPDLog("****************************************\n\n");

    /* unregister with all DAs */
    SLPDKnownDADeinit();

    /* re-read properties */
    SLPDPropertyInit(G_SlpdCommandLine.cfgfile);

#ifdef ENABLE_SLPv2_SECURITY
    /* Re-initialize SPI stuff*/
    SLPDSpiInit(G_SlpdCommandLine.spifile);
#endif
    
    /* Re-read the static registration file (slp.reg)*/
    SLPDDatabaseReInit(G_SlpdCommandLine.regfile);

    /* Rebuild Known DA database */
    SLPDKnownDAInit();

    SLPDLog("****************************************\n");
    SLPDLogTime();
    SLPDLog("SLPD daemon reset finished\n");
    SLPDLog("****************************************\n\n");
}

/*------------------------------------------------------------------------*/
void HandleSigAlrm()
/*------------------------------------------------------------------------*/
{
    SLPDIncomingAge(SLPD_AGE_INTERVAL);
    SLPDOutgoingAge(SLPD_AGE_INTERVAL);
    SLPDKnownDAImmortalRefresh(SLPD_AGE_INTERVAL);
    SLPDKnownDAPassiveDAAdvert(SLPD_AGE_INTERVAL,0);
    SLPDKnownDAActiveDiscovery(SLPD_AGE_INTERVAL);
    SLPDDatabaseAge(SLPD_AGE_INTERVAL,G_SlpdProperty.isDA);
}


#ifdef DEBUG
/*--------------------------------------------------------------------------*/
void HandleSigInt()
/*--------------------------------------------------------------------------*/
{
    SLPDIncomingSocketDump();
    SLPDOutgoingSocketDump();
    SLPDKnownDADump();
    SLPDDatabaseDump();
}
#endif


#ifndef _WIN32
/*-------------------------------------------------------------------------*/
int CheckPid(const char* pidfile)
/* Check a pid file to see if slpd is already running                      */
/*                                                                         */
/* Returns: 0 on success.  non-zero on failure                             */
/*-------------------------------------------------------------------------*/
{
    pid_t   pid;
    FILE*   fd;
    char    pidstr[14];

    /*------------------------------------------*/
    /* make sure that we're not running already */
    /*------------------------------------------*/
    /* read the pid from the file */
    fd = fopen(pidfile,"r");
    if(fd)
    {
        memset(pidstr,0,14);
        fread(pidstr,13,1,fd);
        pid = atoi(pidstr);
        if(pid)
        {
            if(kill(pid,0) == 0)
            {
                /* we are already running */
                return -1;
            }
        }

        fclose(fd);
    }

    return 0;
}


/*-------------------------------------------------------------------------*/
int WritePid(const char* pidfile, pid_t pid)
/* Write the pid file                                                      */
/*                                                                         */
/* Returns: 0 on success.  non-zero on failure                             */
/*-------------------------------------------------------------------------*/
{
    FILE*   fd;
    char    pidstr[14];

    /* write my pid to the pidfile */
    fd = fopen(pidfile,"w");
    if(fd)
    {
        sprintf(pidstr,"%i",(int)pid);
        fwrite(pidstr,strlen(pidstr),1,fd);
        fclose(fd);
    }