112 lines
2.9 KiB
C
112 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";
|
|
|
|
void wtmp(int type, int linenr, char *line, pid_t pid, char *host);
|
|
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));
|
|
}
|