modules/FvwmCommand/fifos.c

   1 /* -*-c-*- */
   2 /*
   3  * Fvwm command input interface.
   4  *
   5  * Copyright 1998, Toshi Isogai.
   6  * Use this program at your own risk.
   7  * Permission to use this program for any purpose is given,
   8  * as long as the copyright is kept intact.
   9  *
  10  */
  11
  12 /* This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  */
  26
  27 #include "config.h"
  28 #include "FvwmCommand.h"
  29
  30 #define MAXHOSTNAME 32
  31
  32 char * fifos_get_default_name(void)
  33 {
  34         char file_suffix[] = { 'R', 'C', 'M', '\0' };
  35         char *f_stem;
  36         char *dpy_name;
  37         char dpy_name_add[3];
  38         char *c;
  39         int i;
  40         struct stat stat_buf;
  41         char hostname[MAXHOSTNAME];
  42         int type_pos;
  43         uid_t owner;
  44         Bool is_path_valid;
  45
  46         /* default name */
  47         dpy_name = getenv("DISPLAY");
  48         if (!dpy_name || *dpy_name == 0)
  49         {
  50                 dpy_name = ":0.0";
  51         }
  52         if (strncmp(dpy_name, "unix:", 5) == 0)
  53         {
  54                 dpy_name += 4;
  55         }
  56         dpy_name_add[0] = 0;
  57         c = strrchr(dpy_name, '.');
  58         i = 0;
  59         if (c != NULL)
  60         {
  61                 if (*(c + 1) != 0)
  62                 {
  63                         for (c++, i = 0; isdigit(*c); c++, i++)
  64                         {
  65                                 /* nothing */
  66                         }
  67                 }
  68                 else
  69                 {
  70                         /* cut off trailing period */
  71                         *c = 0;
  72                 }
  73         }
  74         if (i == 0)
  75         {
  76                 /* append screen number */
  77                 strcpy(dpy_name_add, ".0");
  78         }
  79         f_stem = safemalloc(11 + strlen(F_NAME) + MAXHOSTNAME +
  80                             strlen(dpy_name) + strlen(dpy_name_add));
  81
  82         if (
  83                 (stat("/var/tmp", &stat_buf) == 0) &&
  84                 (stat_buf.st_mode & S_IFDIR))
  85         {
  86                 strcpy (f_stem, "/var/tmp/");
  87         }
  88         else
  89         {
  90                 strcpy (f_stem, "/tmp/");
  91         }
  92         strcat(f_stem, F_NAME);
  93
  94         /* Make it unique */
  95         if (!dpy_name[0] || ':' == dpy_name[0])
  96         {
  97                 /* Put hostname before dpy if not there */
  98                 gethostname(hostname, MAXHOSTNAME);
  99                 strcat(f_stem, hostname);
 100         }
 101         strcat(f_stem, dpy_name);
 102         strcat(f_stem, dpy_name_add);
 103
 104         /* Verify that all files are either non-symlinks owned by the current
 105          * user or non-existing. If not: use FVWM_USERDIR as base instead. */
 106
 107         type_pos = strlen(f_stem);
 108         owner = geteuid();
 109         is_path_valid = True;
 110
 111         f_stem[type_pos+1] = 0;
 112
 113         for (c = file_suffix; *c != 0 && is_path_valid; c++)
 114         {
 115                 int rc;
 116
 117                 f_stem[type_pos] = *c;
 118                 if (DO_USE_LSTAT)
 119                 {
 120                         rc = fvwm_lstat(f_stem, &stat_buf);
 121                 }
 122                 else
 123                 {
 124                         rc = stat(f_stem, &stat_buf);
 125                 }
 126                 if (rc == 0)
 127                 {
 128                         /* stat successful */
 129                         if (
 130                                 stat_buf.st_uid != owner ||
 131                                 stat_buf.st_nlink > 1 ||
 132                                 S_ISDIR(stat_buf.st_mode) ||
 133                                 FVWM_S_ISLNK(stat_buf.st_mode) ||
 134                                 (stat_buf.st_mode & FVWM_S_IFLNK) != 0)
 135                         {
 136                                 is_path_valid = False;
 137                         }
 138                         break;
 139                 }
 140                 else if (errno != ENOENT)
 141                 {
 142                         is_path_valid = False;
 143                 }
 144         }
 145         f_stem[type_pos] = 0;
 146         if (!is_path_valid)
 147         {
 148                 char *userdir;
 149                 char *tailname;
 150                 char *tmp;
 151                 tmp = f_stem;
 152
 153                 if (f_stem[1] == 't') /* /tmp/ */
 154                 {
 155                         tailname = f_stem + 4;
 156                 }
 157                 else /* /var/tmp/ */
 158                 {
 159                         tailname = f_stem + 8;
 160                 }
 161
 162                 userdir = getenv("FVWM_USERDIR");
 163                 if (userdir == NULL)
 164                 {
 165                         free(tmp);
 166                         return NULL;
 167                 }
 168                 f_stem = safemalloc(strlen(userdir) + strlen(tailname) + 1);
 169                 strcpy(f_stem, userdir);
 170                 strcat(f_stem, tailname);
 171                 free(tmp);
 172         }
 173
 174         return f_stem;
 175 }