src/tests/kits/net/sock/cliopen.c

   1 /* -*- c-basic-offset: 8; -*-
   2  *
   3  * Copyright (c) 1993 W. Richard Stevens.  All rights reserved.
   4  * Permission to use or modify this software and its documentation only for
   5  * educational purposes and without fee is hereby granted, provided that
   6  * the above copyright notice appear in all copies.  The author makes no
   7  * representations about the suitability of this software for any purpose.
   8  * It is provided "as is" without express or implied warranty.
   9  */
  10
  11 #include "sock.h"
  12
  13 int cliopen(char *host, char *port)
  14 {
  15         int                     fd, i, on;
  16         char                    *protocol;
  17         struct in_addr          inaddr;
  18         struct servent          *sp;
  19         struct hostent          *hp;
  20
  21         protocol = udp ? "udp" : "tcp";
  22
  23         /* initialize socket address structure */
  24         bzero(&servaddr, sizeof(servaddr));
  25         servaddr.sin_family = AF_INET;
  26
  27         /* see if "port" is a service name or number */
  28         if ( (i = atoi(port)) == 0) {
  29                 if ( (sp = getservbyname(port, protocol)) == NULL)
  30                         err_quit("getservbyname() error for: %s/%s", port, protocol);
  31
  32                 servaddr.sin_port = sp->s_port;
  33         } else
  34                 servaddr.sin_port = htons(i);
  35
  36         /*
  37          * First try to convert the host name as a dotted-decimal number.
  38          * Only if that fails do we call gethostbyname().
  39          */
  40
  41         if (inet_aton(host, &inaddr) == 1)
  42                 servaddr.sin_addr = inaddr;     /* it's dotted-decimal */
  43         else if ( (hp = gethostbyname(host)) != NULL)
  44                 bcopy(hp->h_addr, &servaddr.sin_addr, hp->h_length);
  45         else
  46                 err_quit("invalid hostname: %s", host);
  47
  48         if ( (fd = socket(AF_INET, udp ? SOCK_DGRAM : SOCK_STREAM, 0)) < 0)
  49                 err_sys("socket() error");
  50
  51         if (reuseaddr) {
  52                 on = 1;
  53                 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof (on)) < 0)
  54                         err_sys("setsockopt of SO_REUSEADDR error");
  55         }
  56
  57 #ifdef  SO_REUSEPORT
  58         if (reuseport) {
  59                 on = 1;
  60                 if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &on, sizeof (on)) < 0)
  61                         err_sys("setsockopt of SO_REUSEPORT error");
  62         }
  63 #endif
  64
  65         /*
  66          * User can specify port number for client to bind.  Only real use
  67          * is to see a TCP connection initiated by both ends at the same time.
  68          * Also, if UDP is being used, we specifically call bind() to assign
  69          * an ephemeral port to the socket.
  70          * Also, for experimentation, client can also set local IP address
  71          * (and port) using -l option.  Allow localip[] to be set but bindport
  72          * to be 0.
  73          */
  74
  75         if (bindport != 0 || localip[0] != 0 || udp) {
  76                 bzero(&cliaddr, sizeof(cliaddr));
  77                 cliaddr.sin_family      = AF_INET;
  78                 cliaddr.sin_port        = htons(bindport);   /* can be 0 */
  79                 if (localip[0] != 0) {
  80                         if (inet_aton(localip, &cliaddr.sin_addr) == 0)
  81                                 err_quit("invalid IP address: %s", localip);
  82                 } else
  83                         cliaddr.sin_addr.s_addr = htonl(INADDR_ANY);    /* wildcard */
  84
  85                 if (bind(fd, (struct sockaddr *) &cliaddr, sizeof(cliaddr)) < 0)
  86                         err_sys("bind() error");
  87         }
  88
  89         /* Need to allocate buffers before connect(), since they can affect
  90          * TCP options (window scale, etc.).
  91          */
  92
  93         buffers(fd);
  94         sockopts(fd, 0);        /* may also want to set SO_DEBUG */
  95
  96         /*
  97          * Connect to the server.  Required for TCP, optional for UDP.
  98          */
  99
 100         if (udp == 0 || connectudp) {
 101                 for ( ; ; ) {
 102                         if (connect(fd, (struct sockaddr *) &servaddr, sizeof(servaddr))
 103                             == 0)
 104                                 break;          /* all OK */
 105                         if (errno == EINTR)             /* can happen with SIGIO */
 106                                 continue;
 107                         if (errno == EISCONN)   /* can happen with SIGIO */
 108                                 break;
 109                         err_sys("connect() error");
 110                 }
 111         }
 112
 113         if (verbose) {
 114                 /* Call getsockname() to find local address bound to socket:
 115                    TCP ephemeral port was assigned by connect() or bind();
 116                    UDP ephemeral port was assigned by bind(). */
 117                 i = sizeof(cliaddr);
 118                 if (getsockname(fd, (struct sockaddr *) &cliaddr, &i) < 0)
 119                         err_sys("getsockname() error");
 120
 121                 /* Can't do one fprintf() since inet_ntoa() stores
 122                    the result in a static location. */
 123                 fprintf(stderr, "connected on %s.%d ",
 124                         INET_NTOA(cliaddr.sin_addr), ntohs(cliaddr.sin_port));
 125                 fprintf(stderr, "to %s.%d\n",
 126                         INET_NTOA(servaddr.sin_addr), ntohs(servaddr.sin_port));
 127         }
 128
 129         sockopts(fd, 1);        /* some options get set after connect() */
 130
 131         return(fd);
 132 }