97 lines
3.5 KiB
C
97 lines
3.5 KiB
C
/*
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* server-udp.c
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*
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* Copyright (C) 2006-2020 wolfSSL Inc.
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*
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* This file is part of wolfSSL. (formerly known as CyaSSL)
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*
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* wolfSSL is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* wolfSSL is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
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*
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*=============================================================================
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*
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* Bare-bones example of a UDP server for instructional/learning purposes.
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*/
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#include <stdio.h> /* standard in/out procedures */
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#include <stdlib.h> /* defines system calls */
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#include <string.h> /* necessary for memset */
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#include <netdb.h>
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#include <sys/socket.h> /* used for all socket calls */
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#include <netinet/in.h> /* used for sockaddr_in */
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#include <arpa/inet.h>
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#define SERV_PORT 11111 /* define our server port number */
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#define MSGLEN 4096 /* limit incoming message size */
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int main (void)
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{
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int sockfd; /* Initialize our socket */
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int recvLen; /* number of bytes received */
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int msgNum = 0; /* number of msg received */
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unsigned char buf[MSGLEN]; /* the incoming message */
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struct sockaddr_in servAddr; /* our server's address */
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struct sockaddr_in cliAddr; /* the client's address */
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socklen_t cliAddrLen = sizeof(cliAddr); /* length of address' */
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/* create a UDP/IP socket */
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if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
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perror("cannot create socket");
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return 0;
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}
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memset((char *)&servAddr, 0, sizeof(servAddr));
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/* host-to-network-long conversion (htonl) */
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/* host-to-network-short conversion (htons) */
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servAddr.sin_family = AF_INET;
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servAddr.sin_addr.s_addr = htonl(INADDR_ANY);
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servAddr.sin_port = htons(SERV_PORT);
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if (bind(sockfd, (struct sockaddr *)&servAddr, sizeof(servAddr)) < 0) {
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perror("bind failed");
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return 0;
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}
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/* loop, listen for client, print received, reply to client */
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for (;;) {
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memset(buf, 0, sizeof(buf));
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printf("waiting for client message on port %d\n", SERV_PORT);
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recvLen = recvfrom(sockfd, buf, MSGLEN, 0,
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(struct sockaddr *)&cliAddr, &cliAddrLen);
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printf("heard %d bytes\n", recvLen);
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if (recvLen > 0) {
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buf[recvLen] = 0;
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printf("I heard this: \"%s\"\n", buf);
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}
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else
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printf("lost the connection to client\n");
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printf("Message #%d received\n", msgNum++);
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printf("reply sent \"%s\"\n", buf);
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if (sendto(sockfd, buf, sizeof(buf), 0,
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(struct sockaddr *)&cliAddr, cliAddrLen) < 0) {
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printf("\"sendto\" failed.\n");
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return 1;
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}
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/* continues to loop, use "Ctrl+C" to terminate listening */
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}
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return 0;
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}
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