sshlogin.c

   1 /*
   2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *                    All rights reserved
   5  * This file performs some of the things login(1) normally does.  We cannot
   6  * easily use something like login -p -h host -f user, because there are
   7  * several different logins around, and it is hard to determined what kind of
   8  * login the current system has.  Also, we want to be able to execute commands
   9  * on a tty.
  10  *
  11  * As far as I am concerned, the code I have written for this software
  12  * can be used freely for any purpose.  Any derived versions of this
  13  * software must be clearly marked as such, and if the derived work is
  14  * incompatible with the protocol description in the RFC file, it must be
  15  * called by a name other than "ssh" or "Secure Shell".
  16  *
  17  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
  18  * Copyright (c) 1999 Markus Friedl.  All rights reserved.
  19  *
  20  * Redistribution and use in source and binary forms, with or without
  21  * modification, are permitted provided that the following conditions
  22  * are met:
  23  * 1. Redistributions of source code must retain the above copyright
  24  *    notice, this list of conditions and the following disclaimer.
  25  * 2. Redistributions in binary form must reproduce the above copyright
  26  *    notice, this list of conditions and the following disclaimer in the
  27  *    documentation and/or other materials provided with the distribution.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  30  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  31  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  32  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  33  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  34  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  35  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  36  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  37  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  38  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  39  */
  40
  41 #include "includes.h"
  42 RCSID("$OpenBSD: sshlogin.c,v 1.13 2004/08/12 09:18:24 djm Exp $");
  43
  44 #include "loginrec.h"
  45 #include "log.h"
  46 #include "buffer.h"
  47 #include "servconf.h"
  48
  49 extern Buffer loginmsg;
  50 extern ServerOptions options;
  51
  52 /*
  53  * Returns the time when the user last logged in.  Returns 0 if the
  54  * information is not available.  This must be called before record_login.
  55  * The host the user logged in from will be returned in buf.
  56  */
  57 u_long
  58 get_last_login_time(uid_t uid, const char *logname,
  59     char *buf, u_int bufsize)
  60 {
  61         struct logininfo li;
  62
  63         login_get_lastlog(&li, uid);
  64         strlcpy(buf, li.hostname, bufsize);
  65         return li.tv_sec;
  66 }
  67
  68 /*
  69  * Generate and store last login message.  This must be done before
  70  * login_login() is called and lastlog is updated.
  71  */
  72 static void
  73 store_lastlog_message(const char *user, uid_t uid)
  74 {
  75         char *time_string, hostname[MAXHOSTNAMELEN] = "", buf[512];
  76         time_t last_login_time;
  77
  78 #ifndef NO_SSH_LASTLOG
  79         if (!options.print_lastlog)
  80                 return;
  81
  82         last_login_time = get_last_login_time(uid, user, hostname,
  83             sizeof(hostname));
  84
  85         if (last_login_time != 0) {
  86                 time_string = ctime(&last_login_time);
  87                 if (strchr(time_string, '\n'))
  88                     *strchr(time_string, '\n') = '\0';
  89                 if (strcmp(hostname, "") == 0)
  90                         snprintf(buf, sizeof(buf), "Last login: %s\r\n",
  91                             time_string);
  92                 else
  93                         snprintf(buf, sizeof(buf), "Last login: %s from %s\r\n",
  94                             time_string, hostname);
  95                 buffer_append(&loginmsg, buf, strlen(buf));
  96         }
  97 #endif /* NO_SSH_LASTLOG */
  98 }
  99
 100 /*
 101  * Records that the user has logged in.  I wish these parts of operating
 102  * systems were more standardized.
 103  */
 104 void
 105 record_login(pid_t pid, const char *tty, const char *user, uid_t uid,
 106     const char *host, struct sockaddr * addr, socklen_t addrlen)
 107 {
 108         struct logininfo *li;
 109
 110         /* save previous login details before writing new */
 111         store_lastlog_message(user, uid);
 112
 113         li = login_alloc_entry(pid, user, host, tty);
 114         login_set_addr(li, addr, addrlen);
 115         login_login(li);
 116         login_free_entry(li);
 117 }
 118
 119 #ifdef LOGIN_NEEDS_UTMPX
 120 void
 121 record_utmp_only(pid_t pid, const char *ttyname, const char *user,
 122                  const char *host, struct sockaddr * addr, socklen_t addrlen)
 123 {
 124         struct logininfo *li;
 125
 126         li = login_alloc_entry(pid, user, host, ttyname);
 127         login_set_addr(li, addr, addrlen);
 128         login_utmp_only(li);
 129         login_free_entry(li);
 130 }
 131 #endif
 132
 133 /* Records that the user has logged out. */
 134 void
 135 record_logout(pid_t pid, const char *tty, const char *user)
 136 {
 137         struct logininfo *li;
 138
 139         li = login_alloc_entry(pid, user, NULL, tty);
 140         login_logout(li);
 141         login_free_entry(li);
 142 }