sshlogin.c

   1 /* $OpenBSD: sshlogin.c,v 1.20 2006/07/17 01:31:10 stevesk 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
  46 #include <errno.h>
  47 #include <fcntl.h>
  48 #include <unistd.h>
  49
  50 #include "loginrec.h"
  51 #include "log.h"
  52 #include "buffer.h"
  53 #include "servconf.h"
  54
  55 extern Buffer loginmsg;
  56 extern ServerOptions options;
  57
  58 /*
  59  * Returns the time when the user last logged in.  Returns 0 if the
  60  * information is not available.  This must be called before record_login.
  61  * The host the user logged in from will be returned in buf.
  62  */
  63 time_t
  64 get_last_login_time(uid_t uid, const char *logname,
  65     char *buf, size_t bufsize)
  66 {
  67         struct logininfo li;
  68
  69         login_get_lastlog(&li, uid);
  70         strlcpy(buf, li.hostname, bufsize);
  71         return (time_t)li.tv_sec;
  72 }
  73
  74 /*
  75  * Generate and store last login message.  This must be done before
  76  * login_login() is called and lastlog is updated.
  77  */
  78 static void
  79 store_lastlog_message(const char *user, uid_t uid)
  80 {
  81         char *time_string, hostname[MAXHOSTNAMELEN] = "", buf[512];
  82         time_t last_login_time;
  83
  84 #ifndef NO_SSH_LASTLOG
  85         if (!options.print_lastlog)
  86                 return;
  87
  88         last_login_time = get_last_login_time(uid, user, hostname,
  89             sizeof(hostname));
  90
  91         if (last_login_time != 0) {
  92                 time_string = ctime(&last_login_time);
  93                 if (strchr(time_string, '\n'))
  94                     *strchr(time_string, '\n') = '\0';
  95                 if (strcmp(hostname, "") == 0)
  96                         snprintf(buf, sizeof(buf), "Last login: %s\r\n",
  97                             time_string);
  98                 else
  99                         snprintf(buf, sizeof(buf), "Last login: %s from %s\r\n",
 100                             time_string, hostname);
 101                 buffer_append(&loginmsg, buf, strlen(buf));
 102         }
 103 #endif /* NO_SSH_LASTLOG */
 104 }
 105
 106 /*
 107  * Records that the user has logged in.  I wish these parts of operating
 108  * systems were more standardized.
 109  */
 110 void
 111 record_login(pid_t pid, const char *tty, const char *user, uid_t uid,
 112     const char *host, struct sockaddr *addr, socklen_t addrlen)
 113 {
 114         struct logininfo *li;
 115
 116         /* save previous login details before writing new */
 117         store_lastlog_message(user, uid);
 118
 119         li = login_alloc_entry(pid, user, host, tty);
 120         login_set_addr(li, addr, addrlen);
 121         login_login(li);
 122         login_free_entry(li);
 123 }
 124
 125 #ifdef LOGIN_NEEDS_UTMPX
 126 void
 127 record_utmp_only(pid_t pid, const char *ttyname, const char *user,
 128                  const char *host, struct sockaddr *addr, socklen_t addrlen)
 129 {
 130         struct logininfo *li;
 131
 132         li = login_alloc_entry(pid, user, host, ttyname);
 133         login_set_addr(li, addr, addrlen);
 134         login_utmp_only(li);
 135         login_free_entry(li);
 136 }
 137 #endif
 138
 139 /* Records that the user has logged out. */
 140 void
 141 record_logout(pid_t pid, const char *tty, const char *user)
 142 {
 143         struct logininfo *li;
 144
 145         li = login_alloc_entry(pid, user, NULL, tty);
 146         login_logout(li);
 147         login_free_entry(li);
 148 }