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/* $OpenBSD: sshlogin.c,v 1.17 2006/03/25 18:36:15 deraadt Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* This file performs some of the things login(1) normally does. We cannot
* easily use something like login -p -h host -f user, because there are
* several different logins around, and it is hard to determined what kind of
* login the current system has. Also, we want to be able to execute commands
* on a tty.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*
* Copyright (c) 1999 Theo de Raadt. All rights reserved.
* Copyright (c) 1999 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
#include <util.h>
#include <utmp.h>
#include "sshlogin.h"
#include "log.h"
#include "buffer.h"
#include "servconf.h"
extern Buffer loginmsg;
extern ServerOptions options;
/*
* Returns the time when the user last logged in. Returns 0 if the
* information is not available. This must be called before record_login.
* The host the user logged in from will be returned in buf.
*/
time_t
get_last_login_time(uid_t uid, const char *logname,
char *buf, size_t bufsize)
{
struct lastlog ll;
char *lastlog;
int fd;
off_t pos, r;
lastlog = _PATH_LASTLOG;
buf[0] = '\0';
fd = open(lastlog, O_RDONLY);
if (fd < 0)
return 0;
pos = (long) uid * sizeof(ll);
r = lseek(fd, pos, SEEK_SET);
if (r == -1) {
error("%s: lseek: %s", __func__, strerror(errno));
return (0);
}
if (r != pos) {
debug("%s: truncated lastlog", __func__);
return (0);
}
if (read(fd, &ll, sizeof(ll)) != sizeof(ll)) {
close(fd);
return 0;
}
close(fd);
if (bufsize > sizeof(ll.ll_host) + 1)
bufsize = sizeof(ll.ll_host) + 1;
strncpy(buf, ll.ll_host, bufsize - 1);
buf[bufsize - 1] = '\0';
return (time_t)ll.ll_time;
}
/*
* Generate and store last login message. This must be done before
* login_login() is called and lastlog is updated.
*/
static void
store_lastlog_message(const char *user, uid_t uid)
{
char *time_string, hostname[MAXHOSTNAMELEN] = "", buf[512];
time_t last_login_time;
if (!options.print_lastlog)
return;
last_login_time = get_last_login_time(uid, user, hostname,
sizeof(hostname));
if (last_login_time != 0) {
time_string = ctime(&last_login_time);
if (strchr(time_string, '\n'))
*strchr(time_string, '\n') = '\0';
if (strcmp(hostname, "") == 0)
snprintf(buf, sizeof(buf), "Last login: %s\r\n",
time_string);
else
snprintf(buf, sizeof(buf), "Last login: %s from %s\r\n",
time_string, hostname);
buffer_append(&loginmsg, buf, strlen(buf));
}
}
/*
* Records that the user has logged in. I wish these parts of operating
* systems were more standardized.
*/
void
record_login(pid_t pid, const char *tty, const char *user, uid_t uid,
const char *host, struct sockaddr *addr, socklen_t addrlen)
{
int fd;
struct lastlog ll;
char *lastlog;
struct utmp u;
/* save previous login details before writing new */
store_lastlog_message(user, uid);
/* Construct an utmp/wtmp entry. */
memset(&u, 0, sizeof(u));
strncpy(u.ut_line, tty + 5, sizeof(u.ut_line));
u.ut_time = time(NULL);
strncpy(u.ut_name, user, sizeof(u.ut_name));
strncpy(u.ut_host, host, sizeof(u.ut_host));
login(&u);
lastlog = _PATH_LASTLOG;
/* Update lastlog unless actually recording a logout. */
if (strcmp(user, "") != 0) {
/*
* It is safer to bzero the lastlog structure first because
* some systems might have some extra fields in it (e.g. SGI)
*/
memset(&ll, 0, sizeof(ll));
/* Update lastlog. */
ll.ll_time = time(NULL);
strncpy(ll.ll_line, tty + 5, sizeof(ll.ll_line));
strncpy(ll.ll_host, host, sizeof(ll.ll_host));
fd = open(lastlog, O_RDWR);
if (fd >= 0) {
lseek(fd, (off_t) ((long) uid * sizeof(ll)), SEEK_SET);
if (write(fd, &ll, sizeof(ll)) != sizeof(ll))
logit("Could not write %.100s: %.100s", lastlog, strerror(errno));
close(fd);
}
}
}
/* Records that the user has logged out. */
void
record_logout(pid_t pid, const char *tty)
{
const char *line = tty + 5; /* /dev/ttyq8 -> ttyq8 */
if (logout(line))
logwtmp(line, "", "");
}
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