workspace/kdm/backend/sessreg.c

   1 /*
   2
   3 Copyright 1990, 1998  The Open Group
   4 Copyright 2005 Oswald Buddenhagen <ossi@kde.org>
   5
   6 Permission to use, copy, modify, distribute, and sell this software and its
   7 documentation for any purpose is hereby granted without fee, provided that
   8 the above copyright notice appear in all copies and that both that
   9 copyright notice and this permission notice appear in supporting
  10 documentation.
  11
  12 The above copyright notice and this permission notice shall be included
  13 in all copies or substantial portions of the Software.
  14
  15 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  16 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  18 IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
  19 OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  20 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  21 OTHER DEALINGS IN THE SOFTWARE.
  22
  23 Except as contained in this notice, the name of The Open Group shall
  24 not be used in advertising or otherwise to promote the sale, use or
  25 other dealings in this Software without prior written authorization
  26 from The Open Group.
  27
  28 */
  29
  30 /*
  31
  32   Author: Keith Packard, MIT X Consortium
  33   Lastlog support and dynamic utmp entry allocation
  34     by Andreas Stolcke <stolcke@icsi.berkeley.edu>
  35
  36 */
  37
  38 #define _FILE_OFFSET_BITS 64
  39 #include "dm.h"
  40 #include "dm_error.h"
  41
  42 #if defined(__svr4__) || defined(__Lynx__) || defined(__QNX__) || defined(__APPLE__) || defined(_SEQUENT_) /*|| defined(USE_PAM)*/
  43 # define NO_LASTLOG
  44 #endif
  45
  46 #ifndef NO_LASTLOG
  47 # ifdef HAVE_LASTLOG_H
  48 #  include <lastlog.h>
  49 # endif
  50 # ifndef LLOG_FILE
  51 #  ifdef _PATH_LASTLOGX
  52 #   define LLOG_FILE _PATH_LASTLOGX
  53 #  elif defined(_PATH_LASTLOG)
  54 #   define LLOG_FILE _PATH_LASTLOG
  55 #  else
  56 #   define LLOG_FILE "/usr/adm/lastlog"
  57 #  endif
  58 # endif
  59 #endif
  60
  61 #ifdef BSD
  62 # if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__)
  63 /* *BSD doesn't like a ':0' type entry in utmp */
  64 #  define NO_UTMP
  65 # endif
  66 #endif
  67
  68 #ifdef BSD_UTMP
  69 # ifndef TTYS_FILE
  70 #  define TTYS_FILE "/etc/ttys"
  71 # endif
  72 #endif
  73
  74 #ifdef _AIX
  75 # define UTL_PFX "xdm/"
  76 # define UTL_OFF strlen(UTL_PFX)
  77 #else
  78 # define UTL_OFF 0
  79 #endif
  80
  81 #ifndef BSD_UTMP
  82 static unsigned
  83 crc32s( const char *str )
  84 {
  85         int b;
  86         unsigned crc = 0xffffffff, by;
  87
  88         for (; *str; str++) {
  89                 by = (crc & 255) ^ *(const unsigned char *)str;
  90                 for (b = 0; b < 8; b++)
  91                         by = (by >> 1) ^ (-(by & 1) & 0xedb88320);
  92                 crc = (crc >> 8) ^ by;
  93         }
  94         return crc;
  95 }
  96 #endif
  97
  98 void
  99 sessreg( struct display *d, int pid, const char *user, int uid )
 100 {
 101         const char *dot, *colon;
 102         int left, clen, c;
 103 #ifdef BSD_UTMP
 104         FILE *ttys;
 105         int utmp, slot, freeslot;
 106         STRUCTUTMP entry;
 107 #else
 108         unsigned crc, i;
 109 #endif
 110 #ifndef HAVE_UPDWTMP
 111         int wtmp;
 112 #endif
 113 #ifndef NO_LASTLOG
 114 # ifdef HAVE_LASTLOGX
 115         struct lastlogx ll;
 116 #  define ll_time ll_tv.tv_sec
 117 # else
 118         int llog;
 119         struct lastlog ll;
 120 # endif
 121 #endif
 122         STRUCTUTMP ut_ent;
 123
 124         if (!d->useSessReg)
 125                 return;
 126
 127         bzero( &ut_ent, sizeof(ut_ent) );
 128
 129         if (pid) {
 130                 strncpy( ut_ent.ut_user, user, sizeof(ut_ent.ut_user) );
 131 #ifndef BSD_UTMP
 132                 ut_ent.ut_pid = pid;
 133                 ut_ent.ut_type = USER_PROCESS;
 134         } else {
 135                 ut_ent.ut_type = DEAD_PROCESS;
 136 #endif
 137         }
 138         ut_ent.ut_time = time( 0 );
 139
 140         colon = strchr( d->name, ':' );
 141         clen = strlen( colon );
 142         if (clen > (int)(sizeof(ut_ent.ut_line) - UTL_OFF) - 2)
 143                 return; /* uhm, well ... */
 144         if (colon == d->name) {
 145 #ifndef BSD_UTMP
 146                 strncpy( ut_ent.ut_id, d->name, sizeof(ut_ent.ut_id) );
 147 #endif
 148                 left = 0;
 149         } else {
 150 #ifdef HAVE_STRUCT_UTMP_UT_HOST
 151 # ifndef BSD_UTMP
 152                 if (pid)
 153 # endif
 154                 {
 155                         if (colon - d->name > (int)sizeof(ut_ent.ut_host)) {
 156                                 ut_ent.ut_host[0] = '~';
 157                                 memcpy( ut_ent.ut_host + 1,
 158                                         colon - (sizeof(ut_ent.ut_host) - 1),
 159                                         sizeof(ut_ent.ut_host) - 1 );
 160                         } else
 161                                 memcpy( ut_ent.ut_host, d->name, colon - d->name );
 162                 }
 163 #endif
 164 #ifndef BSD_UTMP
 165                 crc = crc32s( d->name );
 166                 ut_ent.ut_id[0] = crc % 26 + 'A';
 167                 crc /= 26;
 168                 for (i = 1; i < sizeof(ut_ent.ut_id); i++) {
 169                         c = crc % 62;
 170                         crc /= 62;
 171                         ut_ent.ut_id[i] = c < 26 ? c + 'A' :
 172                                                           c < 52 ? c - 26 + 'a' : c - 52 + '0';
 173                 }
 174 #endif
 175                 left = sizeof(ut_ent.ut_line) - UTL_OFF - clen;
 176                 if (colon - d->name <= left) {
 177                         clen += colon - d->name;
 178                         colon = d->name;
 179                         left = 0;
 180                 } else {
 181                         dot = strchr( d->name, '.' );
 182                         if (dot && dot - d->name < left) {
 183                                 memcpy( ut_ent.ut_line + UTL_OFF, d->name, left - 1 );
 184                                 ut_ent.ut_line[UTL_OFF + left - 1] = '~';
 185                         } else {
 186                                 memcpy( ut_ent.ut_line + UTL_OFF, d->name, left/2 - 1 );
 187                                 ut_ent.ut_line[UTL_OFF + left/2 - 1] = '~';
 188                                 if (dot) {
 189                                         memcpy( ut_ent.ut_line + UTL_OFF + left/2,
 190                                                 dot - (left - left/2 - 1),
 191                                                 left - left/2 - 1 );
 192                                         ut_ent.ut_line[UTL_OFF + left - 1] = '~';
 193                                 } else
 194                                         memcpy( ut_ent.ut_line + UTL_OFF + left/2,
 195                                                 colon - (left - left/2), left - left/2 );
 196                         }
 197                 }
 198         }
 199 #ifdef UTL_PFX
 200         memcpy( ut_ent.ut_line, UTL_PFX, UTL_OFF );
 201 #endif
 202         memcpy( ut_ent.ut_line + UTL_OFF + left, colon, clen );
 203
 204 #ifndef NO_UTMP
 205 # ifdef BSD_UTMP
 206         if ((utmp = open( UTMP_FILE, O_RDWR )) < 0)
 207                 debug( "cannot open utmp file " UTMP_FILE ": %m\n" );
 208         else {
 209
 210                 slot = 1;
 211                 if (pid) {
 212                         if (!(ttys = fopen( TTYS_FILE, "r" )))
 213                                 logWarn( "Cannot open tty file " TTYS_FILE ": %m\n" );
 214                         else {
 215                                 int column0 = True;
 216                                 while ((c = getc( ttys )) != EOF)
 217                                         if (c == '\n') {
 218                                                 slot++;
 219                                                 column0 = True;
 220                                         } else
 221                                                 column0 = False;
 222                                 if (!column0)
 223                                         slot++;
 224                                 fclose( ttys );
 225                         }
 226                 }
 227                 freeslot = -1;
 228                 lseek( utmp, slot * sizeof(entry), SEEK_SET );
 229                 while (read( utmp, (char *)&entry, sizeof(entry) ) == sizeof(entry)) {
 230                         if (!strncmp( entry.ut_line, ut_ent.ut_line,
 231                                       sizeof(entry.ut_line) ))
 232 #  ifdef HAVE_STRUCT_UTMP_UT_HOST
 233                                 if (!strncmp( entry.ut_host, ut_ent.ut_host,
 234                                               sizeof(entry.ut_host) ))
 235 #  endif
 236                                         goto found;
 237                         if (freeslot < 0 && *entry.ut_user == '\0')
 238                                 freeslot = slot;
 239                         slot++;
 240                 }
 241                 if (!pid) {
 242                         debug( "utmp entry for display %s vanished\n", d->name );
 243                         goto skip;
 244                 }
 245                 if (freeslot >= 0)
 246                         slot = freeslot;
 247           found:
 248
 249 #  ifdef HAVE_STRUCT_UTMP_UT_HOST
 250                 if (!pid)
 251                         bzero( ut_ent.ut_host, sizeof(ut_ent.ut_host) );
 252 #  endif
 253                 lseek( utmp, slot * sizeof(ut_ent), SEEK_SET );
 254                 if (write( utmp, (char *)&ut_ent, sizeof(ut_ent) ) != sizeof(ut_ent))
 255                         logError( "Cannot write utmp file " UTMP_FILE ": %m\n" );
 256           skip:
 257                 close( utmp );
 258         }
 259 # else
 260         UTMPNAME( UTMP_FILE );
 261         SETUTENT();
 262         PUTUTLINE( &ut_ent );
 263         ENDUTENT();
 264 # endif
 265 #endif
 266
 267 #ifdef HAVE_UPDWTMP
 268 # ifdef HAVE_UTMPX
 269         updwtmpx( WTMP_FILE, &ut_ent );
 270 # else
 271         updwtmp( WTMP_FILE, &ut_ent );
 272 # endif
 273 #else
 274         if ((wtmp = open( WTMP_FILE, O_WRONLY|O_APPEND )) < 0)
 275                 debug( "cannot open wtmp file " WTMP_FILE ": %m\n" );
 276         else {
 277                 if (write( wtmp, (char *)&ut_ent, sizeof(ut_ent) ) != sizeof(ut_ent))
 278                         logError( "Cannot write wtmp file " WTMP_FILE ": %m\n" );
 279                 close( wtmp );
 280         }
 281 #endif
 282
 283 #ifndef NO_LASTLOG
 284         if (pid) {
 285                 bzero( (char *)&ll, sizeof(ll) );
 286                 ll.ll_time = ut_ent.ut_time;
 287                 memcpy( ll.ll_line, ut_ent.ut_line, sizeof(ll.ll_line) );
 288                 memcpy( ll.ll_host, ut_ent.ut_host, sizeof(ll.ll_host) );
 289 # ifdef HAVE_LASTLOGX
 290                 updlastlogx( LLOG_FILE, uid, &ll );
 291 # else
 292                 if ((llog = open( LLOG_FILE, O_RDWR )) < 0)
 293                         debug( "cannot open lastlog file " LLOG_FILE ": %m\n" );
 294                 else {
 295                         lseek( llog, (off_t)uid * sizeof(ll), SEEK_SET );
 296                         if (write( llog, (char *)&ll, sizeof(ll) ) != sizeof(ll))
 297                                 logError( "Cannot write llog file " WTMP_FILE ": %m\n" );
 298                         close( llog );
 299                 }
 300 # endif
 301         }
 302 #else
 303         (void)uid;
 304 #endif
 305
 306 #ifdef UTL_PFX
 307         {
 308                 char tmp[sizeof("/dev/") + sizeof(ut_ent.ut_line)];
 309                 mkdir( "/dev/" UTL_PFX, 0755 );
 310                 chmod( "/dev/" UTL_PFX, 0755 );
 311                 sprintf( tmp, "/dev/%.*s", sizeof(ut_ent.ut_line), ut_ent.ut_line );
 312                 if (pid)
 313                         close( creat( tmp, 0644 ) );
 314                 else
 315                         unlink( tmp );
 316         }
 317 #endif
 318 }