11638Srgrimes.\" Copyright (c) 1986, 1993 21638Srgrimes.\" The Regents of the University of California. All rights reserved. 31638Srgrimes.\" 41638Srgrimes.\" Redistribution and use in source and binary forms, with or without 51638Srgrimes.\" modification, are permitted provided that the following conditions 61638Srgrimes.\" are met: 71638Srgrimes.\" 1. Redistributions of source code must retain the above copyright 81638Srgrimes.\" notice, this list of conditions and the following disclaimer. 91638Srgrimes.\" 2. Redistributions in binary form must reproduce the above copyright 101638Srgrimes.\" notice, this list of conditions and the following disclaimer in the 111638Srgrimes.\" documentation and/or other materials provided with the distribution. 121638Srgrimes.\" 3. All advertising materials mentioning features or use of this software 131638Srgrimes.\" must display the following acknowledgement: 141638Srgrimes.\" This product includes software developed by the University of 151638Srgrimes.\" California, Berkeley and its contributors. 161638Srgrimes.\" 4. Neither the name of the University nor the names of its contributors 171638Srgrimes.\" may be used to endorse or promote products derived from this software 181638Srgrimes.\" without specific prior written permission. 191638Srgrimes.\" 201638Srgrimes.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 211638Srgrimes.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 221638Srgrimes.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 231638Srgrimes.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 241638Srgrimes.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 251638Srgrimes.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 261638Srgrimes.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 271638Srgrimes.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 281638Srgrimes.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 291638Srgrimes.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 301638Srgrimes.\" SUCH DAMAGE. 311638Srgrimes.\" 321638Srgrimes.\" @(#)dgramread.c 8.1 (Berkeley) 6/8/93 331638Srgrimes.\" 341638Srgrimes#include <sys/types.h> 351638Srgrimes#include <sys/socket.h> 361638Srgrimes#include <netinet/in.h> 371638Srgrimes#include <stdio.h> 381638Srgrimes 391638Srgrimes/* 401638Srgrimes * In the included file <netinet/in.h> a sockaddr_in is defined as follows: 411638Srgrimes * struct sockaddr_in { 421638Srgrimes * short sin_family; 431638Srgrimes * u_short sin_port; 441638Srgrimes * struct in_addr sin_addr; 451638Srgrimes * char sin_zero[8]; 468875Srgrimes * }; 471638Srgrimes * 481638Srgrimes * This program creates a datagram socket, binds a name to it, then reads 491638Srgrimes * from the socket. 501638Srgrimes */ 511638Srgrimesmain() 521638Srgrimes{ 531638Srgrimes int sock, length; 541638Srgrimes struct sockaddr_in name; 551638Srgrimes char buf[1024]; 561638Srgrimes 571638Srgrimes /* Create socket from which to read. */ 581638Srgrimes sock = socket(AF_INET, SOCK_DGRAM, 0); 591638Srgrimes if (sock < 0) { 601638Srgrimes perror("opening datagram socket"); 611638Srgrimes exit(1); 621638Srgrimes } 631638Srgrimes /* Create name with wildcards. */ 641638Srgrimes name.sin_family = AF_INET; 651638Srgrimes name.sin_addr.s_addr = INADDR_ANY; 661638Srgrimes name.sin_port = 0; 671638Srgrimes if (bind(sock, &name, sizeof(name))) { 681638Srgrimes perror("binding datagram socket"); 691638Srgrimes exit(1); 701638Srgrimes } 711638Srgrimes /* Find assigned port value and print it out. */ 721638Srgrimes length = sizeof(name); 731638Srgrimes if (getsockname(sock, &name, &length)) { 741638Srgrimes perror("getting socket name"); 751638Srgrimes exit(1); 761638Srgrimes } 771638Srgrimes printf("Socket has port #%d\en", ntohs(name.sin_port)); 781638Srgrimes /* Read from the socket */ 791638Srgrimes if (read(sock, buf, 1024) < 0) 801638Srgrimes perror("receiving datagram packet"); 811638Srgrimes printf("-->%s\en", buf); 821638Srgrimes close(sock); 831638Srgrimes} 84