httcp.c

www工具包

/*									HTTCP.c
**	TCP SPECIFIC CODE
**
**	(c) COPYRIGHT MIT 1995.
**	Please first read the full copyright statement in the file COPYRIGH.
**	@(#) $Id: HTTCP.c,v 2.114 1999/02/22 22:10:12 frystyk Exp $
**
**	This code is in common between client and server sides.
**
**	16 Jan 92  TBL	Fix strtol() undefined on CMU Mach.
**	25 Jun 92  JFG  Added DECNET option through TCP socket emulation.
**	13 Sep 93  MD   Added correct return of vmserrorno for HTInetStatus.
**			Added decoding of vms error message for MULTINET.
**	31 May 94  HF	Added cache on host id's; now use inet_ntoa() to
**			HTInetString and some other fixes. Added HTDoConnect
**			and HTDoAccept
*/

/* Library include files */
#include "wwwsys.h"
#include "WWWUtil.h"
#include "WWWCore.h"
#include "HTReqMan.h"
#include "HTNetMan.h"
#include "HTTCP.h"					 /* Implemented here */

#include "HTHstMan.h"

/* VMS stuff */
#ifdef VMS
#ifndef MULTINET
#define FD_SETSIZE 32
#else /* Multinet */
#define FD_SETSIZE 256
#endif /* Multinet */
#endif /* VMS */

/* Macros and other defines */
/* x ms penalty on a multi-homed host if IP-address is unreachable */
#define TCP_DELAY		30000

/* x ms penalty on a multi-homed host if IP-address is down for unknown reason */
#define TCP_PENALTY		60000

/* imperical study in socket call error codes
 */
#ifdef _WINSOCKAPI_					/* windows */
#define NETCALL_ERROR(ret)	(ret == SOCKET_ERROR)
#define NETCALL_DEADSOCKET(err)	(err == WSAEBADF)
#define NETCALL_WOULDBLOCK(err)	(err == WSAEWOULDBLOCK)
#else /* _WINSOCKAPI_ 					   unix    */
#define NETCALL_ERROR(ret)	(ret < 0)
#define NETCALL_DEADSOCKET(err)	(err == EBADF)
#if defined(EAGAIN) && defined(EALREADY)
#define NETCALL_WOULDBLOCK(err)	(err == EINPROGRESS || \
				 err == EALREADY || \
				 err == EAGAIN)
#else /* (EAGAIN && EALREADY) */
#ifdef EALREADY
#define NETCALL_WOULDBLOCK(err)	(err == EINPROGRESS || err == EALREADY)
#else /* EALREADY */
#ifdef EAGAIN
#define NETCALL_WOULDBLOCK(err)	(err == EINPROGRESS || err == EAGAIN)
#else /* EAGAIN */
#define NETCALL_WOULDBLOCK(err)	(err == EINPROGRESS)
#endif /* !EAGAIN */
#endif /* !EALREADY */
#endif /* !(EAGAIN && EALREADY) */
#endif /* !_WINSOCKAPI_ 				   done */

#if defined(__svr4__) || defined (_WINSOCKAPI_)
#define HT_HOSTUNREACHABLE(e)	((e)==ECONNREFUSED || (e)==ETIMEDOUT || \
				 (e)==ENETUNREACH || (e)==EHOSTUNREACH || \
				 (e)==EHOSTDOWN)
#else
#define HT_HOSTUNREACHABLE(e)	((e)==ECONNREFUSED || (e)==ETIMEDOUT || \
				 (e)==ENETUNREACH || (e)==EHOSTUNREACH || \
				 (e)==EHOSTDOWN || (e)==EINVAL)
#endif

/* ------------------------------------------------------------------------- */
/*	       	      CONNECTION ESTABLISHMENT MANAGEMENT 		     */
/* ------------------------------------------------------------------------- */

/* _makeSocket - create a socket, if !preemptive, set FIONBIO
 * returns 1: blocking
 *	   0: non-blocking
 *	  -1: creation error
 */
PRIVATE int _makeSocket(HTHost * host, HTRequest * request, int preemptive, HTTransport * transport)
{
    int status = 1;
    SOCKET sockfd;
#ifdef DECNET
    if ((sockfd=socket(AF_DECnet, SOCK_STREAM, 0))==INVSOC)
#else
    if ((sockfd=socket(AF_INET, SOCK_STREAM,IPPROTO_TCP))==INVSOC)
#endif
    {
	HTRequest_addSystemError(request, ERR_FATAL, socerrno, NO, "socket");
	return -1;
    }
    HTTRACE(PROT_TRACE, "Socket...... Created %d\n" _ sockfd);

    /* Increase the number of sockets by one */
    HTNet_increaseSocket();

    /*
    **  If we have compiled without Nagle's algorithm then try and turn
    **  it off now
    */
#if defined(HT_NO_NAGLE) && defined(HAVE_SETSOCKOPT) && defined(TCP_NODELAY)
    {
	int disable = 1;
	status = setsockopt(sockfd, IPPROTO_TCP, TCP_NODELAY,
			    (char *) &disable, sizeof(int));
	if (status == -1) {
	    HTTRACE(PROT_TRACE, "Socket...... Could not disable Nagle's algorithm - error %d\n" _ 
			sockfd);
	} else {
	    HTTRACE(PROT_TRACE, "Socket...... Turned off Nagle's algorithm\n");
	}
    }
#endif

    /* If non-blocking protocol then change socket status
    ** I use fcntl() so that I can ask the status before I set it.
    ** See W. Richard Stevens (Advan. Prog. in UNIX environment, p.364)
    ** Be CAREFULL with the old `O_NDELAY' - it will not work as read()
    ** returns 0 when blocking and NOT -1. FNDELAY is ONLY for BSD and
    ** does NOT work on SVR4 systems. O_NONBLOCK is POSIX.
    */
    if (!preemptive) {
#ifdef _WINSOCKAPI_
	{		/* begin windows scope  */
	    long levents = FD_READ | FD_WRITE | FD_ACCEPT | 
			   FD_CONNECT | FD_CLOSE ;
	    int rv = 0 ;
	    u_long one = 1;

	    status = ioctlsocket(sockfd, FIONBIO, &one) == 
		     SOCKET_ERROR ? -1 : 0;
	} /* end scope */
#else /* _WINSOCKAPI_ */
#if defined(VMS)
	{
	    int enable = 1;
	    status = IOCTL(sockfd, FIONBIO, &enable);
	}
#else /* VMS */
	if((status = fcntl(sockfd, F_GETFL, 0)) != -1) {
#ifdef O_NONBLOCK
	    status |= O_NONBLOCK;			    /* POSIX */
#else /* O_NONBLOCK */
#ifdef F_NDELAY
		    status |= F_NDELAY;				      /* BSD */
#endif /* F_NDELAY */
#endif /* !O_NONBLOCK */
		    status = fcntl(sockfd, F_SETFL, status);
	}
#endif /* !VMS */
#endif /* !_WINSOCKAPI_ */
	HTTRACE(PROT_TRACE, "Socket...... %slocking socket\n" _ status == -1 ? "B" : "Non-b");
    } else
	HTTRACE(PROT_TRACE, "Socket...... Blocking socket\n");

    /*
    **  Associate the channel with the host and create an input and and output stream
    **  for this host/channel
    */
    HTHost_setChannel(host, HTChannel_new(sockfd, NULL, YES));
    HTHost_getInput(host, transport, NULL, 0);
    HTHost_getOutput(host, transport, NULL, 0);

    return status == -1 ? 1 : 0;
}

/*								HTDoConnect()
**
**	Note: Any port indication in URL, e.g., as `host:port' overwrites
**	the default port value.
**
**	returns		HT_ERROR	Error has occured or interrupted
**			HT_OK		if connected
**			HT_WOULD_BLOCK  if operation would have blocked
*/
PUBLIC int HTDoConnect (HTNet * net, char * url, u_short default_port)
{
    HTHost * me = HTNet_host(net);
    HTRequest * request = HTNet_request(net);
    int preemptive = net->preemptive;
    int status = HT_OK;
    char * hostname = HTHost_name(me);

    /* Jump into the state machine */
    while (1) {
	switch (me->tcpstate) {
	  case TCP_BEGIN:
	  {
	      /*
	      ** Add the net object to the host object found above. If the
	      ** host is idle then we can start the request right away,
	      ** otherwise we must wait until it is free. 
	      */
	      if ((status = HTHost_addNet(net->host, net)) == HT_PENDING)
		  HTTRACE(PROT_TRACE, "HTDoConnect. Pending...\n");

	      /*
	      ** If we are pending then return here, otherwise go to next state
	      ** which is setting up a channel
	      */
	      me->tcpstate = TCP_CHANNEL;
	      HTTRACE(PROT_TRACE, "HTHost %p going to state TCP_CHANNEL.\n" _ me);
	      if (status == HT_PENDING) return HT_PENDING;
	  }
	  break;

	case TCP_CHANNEL:
	    /*
	    **  The next state depends on whether we have a connection
	    **  or not - if so then we can jump directly to connect() to
	    **  test it - otherwise we must around DNS to get the name
	    **  Resolved
	    */
	    if (HTHost_channel(me) == NULL) {
		me->tcpstate = TCP_DNS;
		HTTRACE(PROT_TRACE, "HTHost %p going to state TCP_DNS.\n" _ me);
	    } else {

		/*
		**  There is now one more using the channel
		*/
		HTChannel_upSemaphore(me->channel);

		/*
		**  We are now all set and can jump to connected mode
		*/
		me->tcpstate = TCP_CONNECTED;
		HTTRACE(PROT_TRACE, "HTHost %p going to state TCP_CONNECTED.\n" _ me);
	    }
	    hostname = HTHost_name(me);
	    break;

	case TCP_DNS:
	    if ((status = HTParseInet(me, hostname, request)) < 0) {
		HTTRACE(PROT_TRACE, "HTDoConnect. Can't locate `%s\'\n" _ hostname);
		HTRequest_addError(request, ERR_FATAL, NO,
				   HTERR_NO_REMOTE_HOST,
				   (void *) hostname, strlen(hostname),
				   "HTDoConnect");
		me->tcpstate = TCP_DNS_ERROR;
		HTTRACE(PROT_TRACE, "HTHost %p going to state TCP_ERROR.\n" _ me);
		break;
	    }
	    if (!HTHost_retry(me) && status > 1)		/* If multiple homes */
		HTHost_setRetry(me, status);
	    me->tcpstate = TCP_NEED_SOCKET;
	    HTTRACE(PROT_TRACE, "HTHost %p going to state TCP_NEED_SOCKET.\n" _ me);
	    break;

	  case TCP_NEED_SOCKET:
	      if (_makeSocket(me, request, preemptive, net->transport) == -1) {
		  me->tcpstate = TCP_ERROR;
		  break;
	      }

	    /* If multi-homed host then start timer on connection */
	    if (HTHost_retry(me)) me->connecttime = HTGetTimeInMillis();

	    /* Progress */
	    {
		HTAlertCallback *cbf = HTAlert_find(HT_PROG_CONNECT);
		if (cbf) (*cbf)(request, HT_PROG_CONNECT, HT_MSG_NULL,
				NULL, hostname, NULL);
	    }
	    me->tcpstate = TCP_NEED_CONNECT;
	    HTTRACE(PROT_TRACE, "HTHost %p going to state TCP_NEED_CONNECT.\n" _ me);
	    break;
	  case TCP_NEED_CONNECT:
	    status = connect(HTChannel_socket(me->channel), (struct sockaddr *) &me->sock_addr,
			     sizeof(me->sock_addr));
	    /*
	     * According to the Sun man page for connect:
	     *     EINPROGRESS         The socket is non-blocking and the  con-
	     *                         nection cannot be completed immediately.
	     *                         It is possible to select(2) for  comple-
	     *                         tion  by  selecting the socket for writ-
	     *                         ing.
	     * According to the Motorola SVR4 man page for connect:
	     *     EAGAIN              The socket is non-blocking and the  con-
	     *                         nection cannot be completed immediately.
	     *                         It is possible to select for  completion
	     *                         by  selecting  the  socket  for writing.
	     *                         However, this is only  possible  if  the
	     *                         socket  STREAMS  module  is  the topmost
	     *                         module on  the  protocol  stack  with  a
	     *                         write  service  procedure.  This will be
	     *                         the normal case.
	     */
	    if (NETCALL_ERROR(status))
	    {
		if (NETCALL_WOULDBLOCK(socerrno))
		{
		    HTTRACE(PROT_TRACE, "HTDoConnect. WOULD BLOCK `%s'\n" _ hostname);
		    HTHost_register(me, net, HTEvent_CONNECT);
		    return HT_WOULD_BLOCK;
		}
		if (socerrno == EISCONN) {
		    me->tcpstate = TCP_CONNECTED;
		    HTTRACE(PROT_TRACE, "HTHost %p going to state TCP_CONNECTED.\n" _ me);
		    break;
		}
		if (NETCALL_DEADSOCKET(socerrno))     /* We lost the socket */
		{
		    me->tcpstate = TCP_NEED_SOCKET;
		    HTTRACE(PROT_TRACE, "HTHost %p going to state TCP_NEED_SOCKET.\n" _ me);