appl/login/utmp_login.c

   1 /*
   2  * Copyright (c) 1995 - 2001 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "login_locl.h"
  35
  36 RCSID("$Id$");
  37
  38 /* try to put something useful from hostname into dst, dst_sz:
  39  * full name, first component or address */
  40
  41 void
  42 shrink_hostname (const char *hostname,
  43                  char *dst, size_t dst_sz)
  44 {
  45     char local_hostname[MaxHostNameLen];
  46     char *ld, *hd;
  47     int ret;
  48     struct addrinfo *ai;
  49
  50     if (strlen(hostname) < dst_sz) {
  51         strlcpy (dst, hostname, dst_sz);
  52         return;
  53     }
  54     gethostname (local_hostname, sizeof(local_hostname));
  55     hd = strchr (hostname, '.');
  56     ld = strchr (local_hostname, '.');
  57     if (hd != NULL && ld != NULL && strcmp(hd, ld) == 0
  58         && hd - hostname < dst_sz) {
  59         strlcpy (dst, hostname, dst_sz);
  60         dst[hd - hostname] = '\0';
  61         return;
  62     }
  63
  64     ret = getaddrinfo (hostname, NULL, NULL, &ai);
  65     if (ret) {
  66         strncpy (dst, hostname, dst_sz);
  67         return;
  68     }
  69     ret = getnameinfo (ai->ai_addr, ai->ai_addrlen,
  70                        dst, dst_sz,
  71                        NULL, 0,
  72                        NI_NUMERICHOST);
  73     freeaddrinfo (ai);
  74     if (ret) {
  75         strncpy (dst, hostname, dst_sz);
  76         return;
  77     }
  78 }
  79
  80 /* update utmp and wtmp - the BSD way */
  81
  82 #if !defined(HAVE_UTMPX_H) || (defined(WTMP_FILE) && !defined(WTMPX_FILE))
  83
  84 void
  85 prepare_utmp (struct utmp *utmp, char *tty,
  86               const char *username, const char *hostname)
  87 {
  88     char *ttyx = clean_ttyname (tty);
  89
  90     memset(utmp, 0, sizeof(*utmp));
  91     utmp->ut_time = time(NULL);
  92     strncpy(utmp->ut_line, ttyx, sizeof(utmp->ut_line));
  93     strncpy(utmp->ut_name, username, sizeof(utmp->ut_name));
  94
  95 # ifdef HAVE_STRUCT_UTMP_UT_USER
  96     strncpy(utmp->ut_user, username, sizeof(utmp->ut_user));
  97 # endif
  98
  99 # ifdef HAVE_STRUCT_UTMP_UT_ADDR
 100     if (hostname[0]) {
 101         struct hostent *he;
 102         if ((he = gethostbyname(hostname)))
 103             memcpy(&utmp->ut_addr, he->h_addr_list[0],
 104                    sizeof(utmp->ut_addr));
 105     }
 106 # endif
 107
 108 # ifdef HAVE_STRUCT_UTMP_UT_HOST
 109     shrink_hostname (hostname, utmp->ut_host, sizeof(utmp->ut_host));
 110 # endif
 111
 112 # ifdef HAVE_STRUCT_UTMP_UT_TYPE
 113     utmp->ut_type = USER_PROCESS;
 114 # endif
 115
 116 # ifdef HAVE_STRUCT_UTMP_UT_PID
 117     utmp->ut_pid = getpid();
 118 # endif
 119
 120 # ifdef HAVE_STRUCT_UTMP_UT_ID
 121     strncpy(utmp->ut_id, make_id(ttyx), sizeof(utmp->ut_id));
 122 # endif
 123 }
 124 #endif
 125
 126 #ifdef HAVE_UTMPX_H
 127 void utmp_login(char *tty, const char *username, const char *hostname)
 128 {
 129     return;
 130 }
 131 #else
 132
 133 void utmp_login(char *tty, const char *username, const char *hostname)
 134 {
 135     struct utmp utmp;
 136     int fd;
 137
 138     prepare_utmp (&utmp, tty, username, hostname);
 139
 140 #ifdef HAVE_SETUTENT
 141     utmpname(_PATH_UTMP);
 142     setutent();
 143     pututline(&utmp);
 144     endutent();
 145 #else
 146
 147 #ifdef HAVE_TTYSLOT
 148     {
 149       int ttyno;
 150       ttyno = ttyslot();
 151       if (ttyno > 0 && (fd = open(_PATH_UTMP, O_WRONLY, 0)) >= 0) {
 152         lseek(fd, (long)(ttyno * sizeof(struct utmp)), SEEK_SET);
 153         write(fd, &utmp, sizeof(struct utmp));
 154         close(fd);
 155       }
 156     }
 157 #endif /* HAVE_TTYSLOT */
 158 #endif /* HAVE_SETUTENT */
 159
 160     if ((fd = open(_PATH_WTMP, O_WRONLY|O_APPEND, 0)) >= 0) {
 161         write(fd, &utmp, sizeof(struct utmp));
 162         close(fd);
 163     }
 164 }
 165
 166 #endif /* !HAVE_UTMPX_H */