minix/commands/telnetd/wtmp.c
2009-11-09 10:26:00 +00:00

113 lines
2.9 KiB
C

/*
* TNET A server program for MINIX which implements the TCP/IP
* suite of networking protocols. It is based on the
* TCP/IP code written by Phil Karn et al, as found in
* his NET package for Packet Radio communications.
*
* This file contains an implementation of the "server"
* for the TELNET protocol. This protocol can be used to
* remote-login on other systems, just like a normal TTY
* session.
*
* Usage: telnetd [-dv]
*
* Version: @(#)telnetd.c 1.00 07/26/92
*
* Author: Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
* Michael Temari, <temari@temari.ae.ge.com>
*/
#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <utmp.h>
#include <time.h>
#include <stdio.h>
#include "telnetd.h"
static char PATH_UTMP[] = "/etc/utmp";
static char PATH_WTMP[] = "/usr/adm/wtmp";
_PROTOTYPE(void wtmp, (int type, int linenr, char *line, pid_t pid,
char *host));
_PROTOTYPE(void report, (char *label));
void wtmp(type, linenr, line, pid, host)
int type; /* type of entry */
int linenr; /* line number in ttytab */
char *line; /* tty name (only good on login) */
pid_t pid; /* pid of process */
char *host; /* name of the remote host */
{
/* Log an event into the UTMP and WTMP files. */
struct utmp utmp; /* UTMP/WTMP User Accounting */
int fd;
/* Clear the utmp record. */
memset((void *) &utmp, 0, sizeof(utmp));
/* Fill in utmp. */
switch (type) {
case LOGIN_PROCESS:
/* A new login, fill in line and host name. */
strncpy(utmp.ut_line, line, sizeof(utmp.ut_line));
strncpy(utmp.ut_host, host, sizeof(utmp.ut_host));
break;
case DEAD_PROCESS:
/* A logout. Use the current utmp entry, but make sure it is a
* user process exiting, and not getty or login giving up.
*/
if ((fd = open(PATH_UTMP, O_RDONLY)) < 0) {
if (errno != ENOENT) report(PATH_UTMP);
return;
}
if (lseek(fd, (off_t) (linenr+1) * sizeof(utmp), SEEK_SET) == -1
|| read(fd, &utmp, sizeof(utmp)) == -1
) {
report(PATH_UTMP);
close(fd);
return;
}
close(fd);
if (utmp.ut_type != USER_PROCESS) return;
strncpy(utmp.ut_name, "", sizeof(utmp.ut_name));
break;
}
/* Finish new utmp entry. */
utmp.ut_pid = pid;
utmp.ut_type = type;
utmp.ut_time = time((time_t *) 0);
/* Write new entry to utmp. */
if ((fd = open(PATH_UTMP, O_WRONLY)) < 0
|| lseek(fd, (off_t) (linenr+1) * sizeof(utmp), SEEK_SET) == -1
|| write(fd, &utmp, sizeof(utmp)) == -1
) {
if (errno != ENOENT) report(PATH_UTMP);
}
if (fd != -1) close(fd);
if (type == DEAD_PROCESS) {
/* Add new wtmp entry. */
if ((fd = open(PATH_WTMP, O_WRONLY | O_APPEND)) < 0
|| write(fd, &utmp, sizeof(utmp)) == -1
) {
if (errno != ENOENT) report(PATH_WTMP);
}
if (fd != -1) close(fd);
}
}
void report(label)
char *label;
{
char message[128];
sprintf(message, "telnetd: %s: %s\r\n", strerror(errno));
(void) write(1, message, strlen(message));
}