Interlisp.maiko/src/socket.c

/* $Id: socket.c,v 1.2 1999/01/03 02:07:34 sybalsky Exp $ (C) Copyright Venue, All Rights Reserved
 */
static char *id = "$Id: socket.c,v 1.2 1999/01/03 02:07:34 sybalsky Exp $ Copyright (C) Venue";
/* Copyright    Massachusetts Institute of Technology    1988	*/
/*
 * THIS IS AN OS DEPENDENT FILE! It should work on 4.2BSD derived
 * systems.  VMS and System V should plan to have their own version.
 *
 * This code was cribbed from lib/X/XConnDis.c.
 * Compile using
 *                    % cc -c socket.c -DUNIXCONN
 */

#include "version.h"

#include <stdio.h>
#include <X11/Xos.h>
#include <X11/Xproto.h>
#include <errno.h>
#include <netinet/in.h>
#include <sys/ioctl.h>
#include <netdb.h>
#include <sys/socket.h>
#ifndef hpux
#include <netinet/tcp.h>
#endif

extern int errno; /* Certain (broken) OS's don't have this */
                  /* decl in errno.h */

#ifdef UNIXCONN
#include <sys/un.h>
#ifndef X_UNIX_PATH
#define X_UNIX_PATH "/tmp/.X11-unix/X"
#endif /* X_UNIX_PATH */
#endif /* UNIXCONN */
void bcopy();

/*
 * Attempts to connect to server, given host and display. Returns file
 * descriptor (network socket) or 0 if connection fails.
 */

int connect_to_server(char *host, int display)
{
  struct sockaddr_in inaddr; /* INET socket address. */
  struct sockaddr *addr;     /* address to connect to */
  struct hostent *host_ptr;
  int addrlen; /* length of address */
#ifdef UNIXCONN
  struct sockaddr_un unaddr; /* UNIX socket address. */
#endif
  extern char *getenv();
  extern struct hostent *gethostbyname();
  int fd; /* Network socket */
  {
#ifdef UNIXCONN
    if ((host[0] == '\0') || (strcmp("unix", host) == 0)) {
      /* Connect locally using Unix domain. */
      unaddr.sun_family = AF_UNIX;
      (void)strcpy(unaddr.sun_path, X_UNIX_PATH);
      sprintf(&unaddr.sun_path[strlen(unaddr.sun_path)], "%d", display);
      addr = (struct sockaddr *)&unaddr;
      addrlen = strlen(unaddr.sun_path) + 2;
      /*
       * Open the network connection.
       */
      if ((fd = socket((int)addr->sa_family, SOCK_STREAM, 0)) < 0)
        return (-1); /* errno set by system call. */
    } else
#endif
    {
      /* Get the statistics on the specified host. */
      if ((inaddr.sin_addr.s_addr = inet_addr(host)) == -1) {
        if ((host_ptr = gethostbyname(host)) == NULL) {
          /* No such host! */
          errno = EINVAL;
          return (-1);
        }
        /* Check the address type for an internet host. */
        if (host_ptr->h_addrtype != AF_INET) {
          /* Not an Internet host! */
          errno = EPROTOTYPE;
          return (-1);
        }
        /* Set up the socket data. */
        inaddr.sin_family = host_ptr->h_addrtype;
        bcopy((char *)host_ptr->h_addr, (char *)&inaddr.sin_addr, sizeof(inaddr.sin_addr));
      } else {
        inaddr.sin_family = AF_INET;
      }
      addr = (struct sockaddr *)&inaddr;
      addrlen = sizeof(struct sockaddr_in);
      inaddr.sin_port = display + X_TCP_PORT;
      inaddr.sin_port = htons(inaddr.sin_port);
      /*
       * Open the network connection.
       */
      if ((fd = socket((int)addr->sa_family, SOCK_STREAM, 0)) < 0) {
        return (-1); /* errno set by system call. */
      }
/* make sure to turn off TCP coalescence */
#ifdef TCP_NODELAY
      {
        int mi = 1;
        setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &mi, sizeof(int));
      }
#endif
    }

    /*
     * Changed 9/89 to retry connection if system call was interrupted.  This
     * is necessary for multiprocessing implementations that use timers,
     * since the timer results in a SIGALRM.	-- jdi
     */
    while (connect(fd, addr, addrlen) == -1) {
      if (errno != EINTR) {
        (void)close(fd);
        return (-1); /* errno set by system call. */
      }
    }
  }
  /*
   * Return the id if the connection succeeded.
   */
  return (fd);
}