Files
finit/plugins/time.c
T

117 lines
2.9 KiB
C

/* Optional inetd plugin for Time Protocol (rdate), RFC 868
*
* Copyright (c) 2015 Joachim Nilsson <troglobit@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <arpa/inet.h>
#include <time.h>
#include <unistd.h> /* STDIN_FILENO */
#include <sys/socket.h>
#include "plugin.h"
#define NAME "time"
/* UNIX epoch starts midnight, 1st Jan, 1970 */
#define EPOCH_OFFSET 2208988800ULL
/* Return number of seconds since midnight, 1st Jan, 1900 */
static char *rfctime(char *buf, size_t *len)
{
time_t now;
now = time(NULL);
if ((time_t)-1 == now)
return NULL;
/*
* Account for UNIX epoch offset, and
* convert to network byte order
*/
now += EPOCH_OFFSET;
now = htonl(now);
*len = sizeof(now);
memcpy(buf, &now, *len);
return buf;
}
static int recv_peer(int sd, char *buf, ssize_t len, struct sockaddr *sa, socklen_t *sa_len)
{
len = recvfrom(sd, buf, sizeof(buf), MSG_DONTWAIT, sa, sa_len);
if (-1 == len)
return -1; /* On error, close connection. */
if (inetd_check_loop(sa, *sa_len, NAME))
return -1;
return 0;
}
static int send_peer(int sd, char *buf, ssize_t len, struct sockaddr *sa, socklen_t sa_len)
{
char *now;
now = rfctime(buf, (size_t *)&len);
if (!now)
return -1; /* On error, close connection. */
return sendto(sd, now, len, MSG_DONTWAIT, sa, sa_len);
}
static int cb(int type)
{
int sd = STDIN_FILENO;
char buf[BUFSIZ];
struct sockaddr_storage sa;
socklen_t sa_len = sizeof(sa);
if (recv_peer(sd, buf, sizeof(buf), (struct sockaddr *)&sa, &sa_len))
return -1; /* On error, close connection. */
return send_peer(sd, buf, sizeof(buf), (struct sockaddr *)&sa, sa_len);
}
static plugin_t plugin = {
.name = NAME, /* Must match the inetd /etc/services entry */
.inetd = {
.cmd = cb
}
};
PLUGIN_INIT(plugin_init)
{
plugin_register(&plugin);
}
PLUGIN_EXIT(plugin_exit)
{
plugin_unregister(&plugin);
}
/**
* Local Variables:
* indent-tabs-mode: t
* c-file-style: "linux"
* End:
*/