X-Git-Url: https://gapil.gnulinux.it/gitweb/?p=gapil.git;a=blobdiff_plain;f=sources%2FUDP_daytimed.c;fp=sources%2FUDP_daytimed.c;h=4a7e03490b01ed76bfbc4229bed4b3eafab45d7d;hp=0000000000000000000000000000000000000000;hb=6907e5e6ff5c69a34dc9d3664388cdb9f76ede82;hpb=d2027180b43e664093ce2bae3fb4fdf4942709cb diff --git a/sources/UDP_daytimed.c b/sources/UDP_daytimed.c new file mode 100644 index 0000000..4a7e034 --- /dev/null +++ b/sources/UDP_daytimed.c @@ -0,0 +1,136 @@ +/* UDP_daytimed.c + * + * Copyright (C) 2004 Simone Piccardi + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ +/**************************************************************** + * + * Program daytimed: + * Elementary TCP server for daytime service (port 13) + * + * Author: Simone Piccardi + * Mar. 2004 + * + * Usage: daytimed -h give all info + * + * $Id: UDP_daytimed.c,v 1.1 2004/03/21 18:30:35 piccardi Exp $ + * + ****************************************************************/ +/* + * Include needed headers + */ +#include /* predefined types */ +#include /* include unix standard library */ +#include /* IP addresses conversion utiliites */ +#include /* socket library */ +#include /* include standard I/O library */ +#include + +#define MAXLINE 80 +/* Program begin */ +void usage(void); +int main(int argc, char *argv[]) +{ +/* + * Variables definition + */ + int sock; + int i, n, len, verbose=0; + struct sockaddr_in addr; + char buffer[MAXLINE]; + time_t timeval; + /* + * Input section: decode parameters passed in the calling + * Use getopt function + */ + opterr = 0; /* don't want writing to stderr */ + while ( (i = getopt(argc, argv, "hv")) != -1) { + switch (i) { + /* + * Handling options + */ + case 'h': + printf("Wrong -h option use\n"); + usage(); + return(0); + break; + case 'v': + verbose = 1; + break; + case '?': /* unrecognized options */ + printf("Unrecognized options -%c\n",optopt); + usage(); + default: /* should not reached */ + usage(); + } + } + /* *********************************************************** + * + * Options processing completed + * + * Main code beginning + * + * ***********************************************************/ + /* create socket */ + if ( (sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { + perror("Socket creation error"); + exit(-1); + } + /* initialize address */ + memset((void *)&addr, 0, sizeof(addr)); /* clear server address */ + addr.sin_family = AF_INET; /* address type is INET */ + addr.sin_port = htons(13); /* daytime port is 13 */ + addr.sin_addr.s_addr = htonl(INADDR_ANY); /* connect from anywhere */ + /* bind socket */ + if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) { + perror("bind error"); + exit(-1); + } + /* write daytime to client */ + while (1) { + timeval = time(NULL); + n = recvfrom(sock, buffer, MAXLINE, 0, (struct sockaddr *)&addr, &len); + if (n < 0) { + perror("recvfrom error"); + exit(-1); + } + if (verbose) { + inet_ntop(AF_INET, &addr.sin_addr, buffer, sizeof(buffer)); + printf("Request from host %s, port %d\n", buffer, + ntohs(addr.sin_port)); + } + snprintf(buffer, sizeof(buffer), "%.24s\r\n", ctime(&timeval)); + n = sendto(sock, buffer, strlen(buffer), 0, + (struct sockaddr *)&addr, sizeof(addr)); + if (n < 0) { + perror("sendto error"); + exit(-1); + } + } + /* normal exit */ + exit(0); +} +/* + * routine to print usage info and exit + */ +void usage(void) { + printf("Simple daytime server\n"); + printf("Usage:\n"); + printf(" daytimed [-hv] \n"); + printf(" -h print this help\n"); + printf(" -v print request source on stdout\n"); + exit(1); +}