sshlogin.c revision 162856 
1/* $OpenBSD: sshlogin.c,v 1.25 2006/08/03 03:34:42 deraadt Exp $ */
2/*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 *                    All rights reserved
6 * This file performs some of the things login(1) normally does.  We cannot
7 * easily use something like login -p -h host -f user, because there are
8 * several different logins around, and it is hard to determined what kind of
9 * login the current system has.  Also, we want to be able to execute commands
10 * on a tty.
11 *
12 * As far as I am concerned, the code I have written for this software
13 * can be used freely for any purpose.  Any derived versions of this
14 * software must be clearly marked as such, and if the derived work is
15 * incompatible with the protocol description in the RFC file, it must be
16 * called by a name other than "ssh" or "Secure Shell".
17 *
18 * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
19 * Copyright (c) 1999 Markus Friedl.  All rights reserved.
20 *
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
23 * are met:
24 * 1. Redistributions of source code must retain the above copyright
25 *    notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 *    notice, this list of conditions and the following disclaimer in the
28 *    documentation and/or other materials provided with the distribution.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
40 */
41
42#include "includes.h"
43
44#include <sys/types.h>
45#include <sys/param.h>
46#include <sys/socket.h>
47
48#include <netinet/in.h>
49
50#include <errno.h>
51#include <fcntl.h>
52#include <stdarg.h>
53#include <stdio.h>
54#include <string.h>
55#include <time.h>
56#include <unistd.h>
57
58#include "loginrec.h"
59#include "log.h"
60#include "buffer.h"
61#include "servconf.h"
62
63extern Buffer loginmsg;
64extern ServerOptions options;
65
66/*
67 * Returns the time when the user last logged in.  Returns 0 if the
68 * information is not available.  This must be called before record_login.
69 * The host the user logged in from will be returned in buf.
70 */
71time_t
72get_last_login_time(uid_t uid, const char *logname,
73    char *buf, size_t bufsize)
74{
75	struct logininfo li;
76
77	login_get_lastlog(&li, uid);
78	strlcpy(buf, li.hostname, bufsize);
79	return (time_t)li.tv_sec;
80}
81
82/*
83 * Generate and store last login message.  This must be done before
84 * login_login() is called and lastlog is updated.
85 */
86static void
87store_lastlog_message(const char *user, uid_t uid)
88{
89	char *time_string, hostname[MAXHOSTNAMELEN] = "", buf[512];
90	time_t last_login_time;
91
92#ifndef NO_SSH_LASTLOG
93	if (!options.print_lastlog)
94		return;
95
96	last_login_time = get_last_login_time(uid, user, hostname,
97	    sizeof(hostname));
98
99	if (last_login_time != 0) {
100		time_string = ctime(&last_login_time);
101		if (strchr(time_string, '\n'))
102		    *strchr(time_string, '\n') = '\0';
103		if (strcmp(hostname, "") == 0)
104			snprintf(buf, sizeof(buf), "Last login: %s\r\n",
105			    time_string);
106		else
107			snprintf(buf, sizeof(buf), "Last login: %s from %s\r\n",
108			    time_string, hostname);
109		buffer_append(&loginmsg, buf, strlen(buf));
110	}
111#endif /* NO_SSH_LASTLOG */
112}
113
114/*
115 * Records that the user has logged in.  I wish these parts of operating
116 * systems were more standardized.
117 */
118void
119record_login(pid_t pid, const char *tty, const char *user, uid_t uid,
120    const char *host, struct sockaddr *addr, socklen_t addrlen)
121{
122	struct logininfo *li;
123
124	/* save previous login details before writing new */
125	store_lastlog_message(user, uid);
126
127	li = login_alloc_entry(pid, user, host, tty);
128	login_set_addr(li, addr, addrlen);
129	login_login(li);
130	login_free_entry(li);
131}
132
133#ifdef LOGIN_NEEDS_UTMPX
134void
135record_utmp_only(pid_t pid, const char *ttyname, const char *user,
136		 const char *host, struct sockaddr *addr, socklen_t addrlen)
137{
138	struct logininfo *li;
139
140	li = login_alloc_entry(pid, user, host, ttyname);
141	login_set_addr(li, addr, addrlen);
142	login_utmp_only(li);
143	login_free_entry(li);
144}
145#endif
146
147/* Records that the user has logged out. */
148void
149record_logout(pid_t pid, const char *tty, const char *user)
150{
151	struct logininfo *li;
152
153	li = login_alloc_entry(pid, user, NULL, tty);
154	login_logout(li);
155	login_free_entry(li);
156}
157