net_client.c

openPBS的开放源代码

/*
*         OpenPBS (Portable Batch System) v2.3 Software License
* 
* Copyright (c) 1999-2000 Veridian Information Solutions, Inc.
* All rights reserved.
* 
* ---------------------------------------------------------------------------
* For a license to use or redistribute the OpenPBS software under conditions
* other than those described below, or to purchase support for this software,
* please contact Veridian Systems, PBS Products Department ("Licensor") at:
* 
*    www.OpenPBS.org  [phone]                  [e-mail]
*                        877 902-4PBS (US toll-free)
* ---------------------------------------------------------------------------
* 
* This license covers use of the OpenPBS v2.3 software (the "Software") at
* your site or location, and, for certain users, redistribution of the
* Software to other sites and locations.  Use and redistribution of
* OpenPBS v2.3 in source and binary forms, with or without modification,
* are permitted provided that all of the following conditions are met.
* After December 31, 2001, only conditions 3-6 must be met:
* 
* 1. Commercial and/or non-commercial use of the Software is permitted
*    provided a current software registration is on file at www.OpenPBS.org.
*    If use of this software contributes to a publication, product, or
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* 
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*    software incorporating the Software.  Further, there can be no
*    expectation of revenue generated as a consequence of redistributing
*    the Software.
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* 3. Any Redistribution of source code must retain the above copyright notice
*    and the acknowledgment contained in paragraph 6, this list of conditions
*    and the disclaimer contained in paragraph 7.
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* 6. All advertising materials mentioning features or use of the Software must
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*     "This product includes software developed by NASA Ames Research Center,
*     Lawrence Livermore National Laboratory, and Veridian Information 
*     Solutions, Inc.
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* 7. DISCLAIMER OF WARRANTY
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* THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT
* ARE EXPRESSLY DISCLAIMED.
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* IN NO EVENT SHALL VERIDIAN CORPORATION, ITS AFFILIATED COMPANIES, OR THE
* U.S. GOVERNMENT OR ANY OF ITS AGENCIES BE LIABLE FOR ANY DIRECT OR INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
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* 
* This license will be governed by the laws of the Commonwealth of Virginia,
* without reference to its choice of law rules.
*/
#include <pbs_config.h>   /* the master config generated by configure */

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <netdb.h>
#include "portability.h"
#include "server_limits.h"
#include "net_connect.h"

static char ident[] = "@(#) $RCSfile: net_client.c,v $ $Revision: 2.1.10.4 $";

/*
 * client_to_svr - connect to a server
 *
 *	Perform socket/tcp/ip stuff to connect to a server.
 *
 *	Returns: >=0 the socket obtained, or
 *		 PBS_NET_RC_FATAL (-1) if fatal error, just quit, or
 *		 PBS_NET_RC_RETRY (-2) if temp error, should retry
 *
 * Note, the server's host address and port are was chosen as parameters
 * rather than their names to possibly save extra look-ups.  It seems likely
 * that the caller "might" make several calls to the same host or different
 * hosts with the same port.  Let the caller keep the addresses arround
 * rather than look it up each time.
 */

int client_to_svr(hostaddr, port, local_port)
	pbs_net_t	hostaddr;	/* Internet addr  of host */
	unsigned int    port;		/* port to which to connect */
	int	        local_port;	/* not 0 if use local reserved port */
{
	struct sockaddr_in local;
	struct sockaddr_in remote;
	int		 sock;
	unsigned short	 tryport;

	local.sin_family = AF_INET;
	local.sin_addr.s_addr = 0;

	/* get socket					*/

	sock = socket(AF_INET, SOCK_STREAM, 0);
	if (sock < 0) {
		return (PBS_NET_RC_FATAL);
	} else if (sock >= PBS_NET_MAX_CONNECTIONS) {
		(void)close(sock);		/* too many connections */
		return (PBS_NET_RC_RETRY);
	}

	/*	If local privilege port requested, bind to one	*/
	/*	Must be root privileged to do this		*/

	if (local_port) {
		tryport = IPPORT_RESERVED - 1;
		local.sin_port = htons(tryport);

		while (bind(sock,(struct sockaddr *)&local,sizeof(local)) < 0) {
			if ((errno != EADDRINUSE) && 
			    (errno != EADDRNOTAVAIL)) {
				(void)close(sock);
				return (PBS_NET_RC_FATAL);
			} else if (--tryport < (unsigned short)(IPPORT_RESERVED/2)) {
				(void)close(sock);
				return (PBS_NET_RC_RETRY);
			}
			local.sin_port = htons(tryport);
		}
	}
			
/*	connect to specified server host and port	*/

	remote.sin_addr.s_addr = htonl(hostaddr);
	remote.sin_port = htons((unsigned short)port);
	remote.sin_family = AF_INET;
	if (connect(sock, (struct sockaddr *)&remote, sizeof(remote)) < 0) {
		switch (errno) {
		    case EINTR:
		    case EADDRINUSE:
		    case ETIMEDOUT:
		    case ECONNREFUSED:
			close(sock);
			return (PBS_NET_RC_RETRY);
		    default:
			close(sock);
			return (PBS_NET_RC_FATAL);
		}
			
	} else {
		return (sock);
	}
}