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 /****************************************************************
21 * Program TCP_cunc_daytimed.c
22 * Elementary TCP cuncurrent server for daytime service (port 13)
24 * Author: Simone Piccardi
27 * Usage: daytimed -h give all info
29 ****************************************************************/
31 * Include needed headers
33 #include <sys/types.h> /* primitive system data types */
34 #include <unistd.h> /* unix standard library */
35 #include <arpa/inet.h> /* IP addresses conversion utilities */
36 #include <sys/socket.h> /* socket constants, types and functions */
37 #include <stdio.h> /* standard I/O library */
38 #include <time.h> /* date and time constants, types and functions */
39 #include <string.h> /* C strings library */
40 #include <stdlib.h> /* C standard library */
46 int main(int argc, char *argv[])
49 * Variables definition
53 struct sockaddr_in serv_add, client;
60 * Input section: decode parameters passed in the calling
63 opterr = 0; /* don't want writing to stderr */
64 while ( (i = getopt(argc, argv, "hv")) != -1) {
70 printf("Wrong -h option use\n");
74 case '?': /* unrecognized options */
75 printf("Unrecognized options -%c\n",optopt);
82 default: /* should not reached */
87 /* ***********************************************************
89 * Options processing completed
93 * ***********************************************************/
95 if ( (list_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
96 perror("Socket creation error");
99 /* initialize address */
100 memset((void *)&serv_add, 0, sizeof(serv_add)); /* clear server address */
101 serv_add.sin_family = AF_INET; /* address type is INET */
102 serv_add.sin_port = htons(13); /* daytime port is 13 */
103 serv_add.sin_addr.s_addr = htonl(INADDR_ANY); /* connect from anywhere */
105 if (bind(list_fd, (struct sockaddr *)&serv_add, sizeof(serv_add)) < 0) {
106 perror("bind error");
109 /* listen on socket */
110 if (listen(list_fd, BACKLOG) < 0 ) {
111 perror("listen error");
114 /* write daytime to client */
116 len = sizeof(client);
118 accept(list_fd, (struct sockaddr *)&client, &len)) <0 ) {
119 perror("accept error");
122 /* fork to handle connection */
123 if ( (pid = fork()) < 0 ){
124 perror("fork error");
127 if (pid == 0) { /* child */
129 timeval = time(NULL);
130 snprintf(buffer, sizeof(buffer), "%.24s\r\n", ctime(&timeval));
131 if ( (write(conn_fd, buffer, strlen(buffer))) < 0 ) {
132 perror("write error");
136 inet_ntop(AF_INET, &client.sin_addr, buffer, sizeof(buffer));
137 printf("Request from host %s, port %d\n", buffer,
138 ntohs(client.sin_port));
142 } else { /* parent */
146 /* normal exit, never reached */
150 * routine to print usage info and exit
153 printf("Simple daytime server\n");
155 printf(" daytimed [-hv] \n");
156 printf(" -h print this help\n");
157 printf(" -v print request source on stdout\n");