3 * Copyright (C) 2001 Simone Piccardi
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or (at
8 * your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 /****************************************************************
22 * Elementary TCP server for echo service (port 7)
24 * Author: Simone Piccardi
27 * Usage: echod -h give all info
29 * $Id: ElemEchoTCPServer.c,v 1.5 2003/02/02 20:35:33 piccardi Exp $
31 ****************************************************************/
33 * Include needed headers
35 #include <sys/types.h> /* predefined types */
36 #include <unistd.h> /* include unix standard library */
37 #include <arpa/inet.h> /* IP addresses conversion utiliites */
38 #include <sys/socket.h> /* socket library */
39 #include <stdio.h> /* include standard I/O library */
46 /* Subroutines declaration */
48 void ServEcho(int sockfd);
49 /* Program beginning */
50 int main(int argc, char *argv[])
53 * Variables definition
57 struct sockaddr_in serv_add;
59 * Input section: decode parameters passed in the calling
63 opterr = 0; /* don't want writing to stderr */
64 while ( (i = getopt(argc, argv, "h")) != -1) {
70 printf("Wrong -h option use\n");
74 case '?': /* unrecognized options */
75 printf("Unrecognized options -%c\n",optopt);
77 default: /* should not reached */
81 /* ***********************************************************
83 * Options processing completed
87 * ***********************************************************/
89 if ( (list_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
90 perror("Socket creation error");
93 /* initialize address */
94 memset((void *)&serv_add, 0, sizeof(serv_add)); /* clear server address */
95 serv_add.sin_family = AF_INET; /* address type is INET */
96 serv_add.sin_port = htons(7); /* echo port is 7 */
97 serv_add.sin_addr.s_addr = htonl(INADDR_ANY); /* connect from anywhere */
99 if (bind(list_fd, (struct sockaddr *)&serv_add, sizeof(serv_add)) < 0) {
100 perror("bind error");
103 /* listen on socket */
104 if (listen(list_fd, BACKLOG) < 0 ) {
105 perror("listen error");
108 /* handle echo to client */
110 /* accept connection */
111 if ( (conn_fd = accept(list_fd, NULL, NULL)) < 0) {
112 perror("accept error");
115 /* fork to handle connection */
116 if ( (pid = fork()) < 0 ){
117 perror("fork error");
120 if (pid == 0) { /* child */
121 close(list_fd); /* close listening socket */
122 SockEcho(conn_fd); /* handle echo */
124 } else { /* parent */
125 close(conn_fd); /* close connected socket */
128 /* normal exit, never reached */
132 * routine to print usage info and exit
135 printf("Elementary echo server\n");
137 printf(" echod [-h] \n");
138 printf(" -h print this help\n");
142 * routine to handle echo for connection
144 void ServEcho(int sockfd) {
145 char buffer[MAXLINE];
148 /* main loop, reading 0 char means client close connection */
149 while ( (nread = read(sockfd, buffer, MAXLINE)) != 0) {
150 printf("Letti %d bytes, %s ", nread, buffer);
151 nwrite = FullWrite(sockfd, buffer, nread);