source: trunk/athena/bin/xcluster/net.c @ 22709

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <hesiod.h>

#define CVIEW_FALLBACK_PORT 3704

int net(progname, num, names)
     char *progname;
     int num;
     char **names;
{
  static char *host;            /* name of host running cview daemon. */
  static char **serv;           /* cview service hesiod info. */
  static struct hostent *hp;    /* hostent struct for cview server. */
  static struct servent *sp;    /* servent struct for cview service. */
  static struct sockaddr_in sin; /* Socket address. */
  static int init = 0;          /* Have we been here before? */
  int s;                        /* Socket to connect to cview daemon. */
  int j;                        /* Counter. */
  char buf[BUFSIZ];             /* Temporary buffer. */

  if (!init)
    {
#ifdef TEST
      host = "fries.mit.edu";
#else
      serv = hes_resolve("cview","sloc"); 

      if (serv == NULL)
        host = "doghouse.mit.edu";      /* fall back if hesiod is broken... */
      else
        host = *serv;
#endif

      hp = gethostbyname(host);

      if (hp == NULL) 
        {
          fprintf(stderr, "%s: Unable to resolve hostname '%s'.\n",
                  progname, host);
          return(-1);
        }
  
      if (hp->h_length != sizeof(sin.sin_addr))
        {
          fprintf(stderr, "%s: Unexpected h_length value for '%s'.\n",
                  progname, host);
          return(-1);
        }

      sp = getservbyname("cview", "tcp");

      memset(&sin, 0, sizeof (sin));
      memcpy(&sin.sin_addr, hp->h_addr, hp->h_length);
      sin.sin_family = hp->h_addrtype;
      sin.sin_port = (sp) ? sp->s_port : htons(CVIEW_FALLBACK_PORT);

      init = 1;
    }
  
  s = socket(hp->h_addrtype, SOCK_STREAM, 0);
  if (s < 0) 
    {
      perror("socket"); 
      return(-1);
    }

  if (connect(s, (struct sockaddr *)&sin, sizeof (sin)) < 0) 
    {
      perror("connect");
      close(s);
      return(-1);
    }

  for (j=0; j<num; j++)
    {
      strncpy(buf, *names, sizeof(buf) - 2);
      buf[sizeof(buf) - 2] = '\0';
      strcat(buf, " ");
      if (write(s, buf, strlen(buf)) == -1)
        {
          perror("write");
          close(s);
          return(-1);
        }
      names++;
    }

  if (write(s, "\n", 1) == -1)
    {
      perror("write");
      close(s);
      return(-1);
    }

  return(s);
}