lib/libutil/logwtmp.c

   1 /*-
   2  * Copyright (c) 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)logwtmp.c        8.1 (Berkeley) 6/4/93
  30  * $FreeBSD: src/lib/libutil/logwtmp.c,v 1.14 2000/01/15 03:26:54 shin Exp $
  31  * $DragonFly: src/lib/libutil/logwtmp.c,v 1.5 2007/12/30 13:44:33 matthias Exp $
  32  */
  33
  34 #include <sys/cdefs.h>
  35 #include <sys/param.h>
  36 #include <sys/file.h>
  37 #include <sys/socket.h>
  38 #include <sys/stat.h>
  39
  40 #include <netdb.h>
  41 #include <stdio.h>
  42 #include <string.h>
  43 #include <time.h>
  44 #include <unistd.h>
  45 #include <utmp.h>
  46
  47 #include "libutil.h"
  48
  49 /* wrapper for KAME-special getnameinfo() */
  50 #ifndef NI_WITHSCOPEID
  51 #define NI_WITHSCOPEID  0
  52 #endif
  53
  54
  55 void
  56 logwtmp(const char *line, const char *name, const char *host)
  57 {
  58         struct utmp ut;
  59         struct stat buf;
  60         char   fullhost[MAXHOSTNAMELEN];
  61         int fd;
  62
  63         strncpy(fullhost, host, sizeof(fullhost) - 1);
  64         fullhost[sizeof(fullhost) - 1] = '\0';
  65         trimdomain(fullhost, UT_HOSTSIZE);
  66         host = fullhost;
  67
  68         if (strlen(host) > UT_HOSTSIZE) {
  69                 int error;
  70                 struct addrinfo hints, *res;
  71
  72                 bzero(&hints, sizeof(struct addrinfo));
  73                 hints.ai_family = AF_UNSPEC;
  74                 hints.ai_flags = AI_CANONNAME;
  75                 error = getaddrinfo(host, NULL, &hints, &res);
  76                 if (error != 0 || res->ai_addr == NULL)
  77                         host = "invalid hostname";
  78                 else {
  79                         error = getnameinfo(res->ai_addr, res->ai_addrlen,
  80                                           fullhost, strlen(fullhost), NULL, 0,
  81                                           NI_NUMERICHOST|NI_WITHSCOPEID);
  82                         if (error != 0) {
  83                           fprintf(stderr, "%d", error);
  84                                 host = "invalid hostname";
  85                         }
  86                 }
  87         }
  88
  89         if ((fd = open(_PATH_WTMP, O_WRONLY|O_APPEND, 0)) < 0)
  90                 return;
  91         if (fstat(fd, &buf) == 0) {
  92                 (void) strncpy(ut.ut_line, line, sizeof(ut.ut_line));
  93                 (void) strncpy(ut.ut_name, name, sizeof(ut.ut_name));
  94                 (void) strncpy(ut.ut_host, host, sizeof(ut.ut_host));
  95                 (void) time(&ut.ut_time);
  96                 if (write(fd, (char *)&ut, sizeof(struct utmp)) !=
  97                     sizeof(struct utmp))
  98                         (void) ftruncate(fd, buf.st_size);
  99         }
 100         (void) close(fd);
 101 }