mdw@git.distorted.org.uk Git - fwd/blob - fattr.c

   1 /* -*-c-*-
   2  *
   3  * $Id: fattr.c,v 1.1 1999/07/26 23:33:56 mdw Exp $
   4  *
   5  * Handling of file attributes
   6  *
   7  * (c) 1999 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of the `fw' port forwarder.
  13  *
  14  * `fw' is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * `fw' is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with `fw'; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: fattr.c,v $
  32  * Revision 1.1  1999/07/26 23:33:56  mdw
  33  * Support code for new design.
  34  *
  35  */
  36
  37 /*----- Header files ------------------------------------------------------*/
  38
  39 #include "config.h"
  40
  41 #include <ctype.h>
  42 #include <errno.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46
  47 #include <sys/types.h>
  48 #include <sys/stat.h>
  49 #include <unistd.h>
  50
  51 #include <pwd.h>
  52 #include <grp.h>
  53
  54 #include "conf.h"
  55 #include "fattr.h"
  56 #include "scan.h"
  57
  58 /*----- Global variables --------------------------------------------------*/
  59
  60 fattr fattr_global;
  61
  62 /*----- Main code ---------------------------------------------------------*/
  63
  64 /* --- @fattr_init@ --- *
  65  *
  66  * Arguments:   @fattr *f@ = pointer to file attributes
  67  *
  68  * Returns:     ---
  69  *
  70  * Use:         Initializes a set of file attributes to default values.
  71  */
  72
  73 void fattr_init(fattr *f)
  74 {
  75   unsigned um = umask(0);
  76   umask(um);
  77   f->mode = 0666 & ~um;
  78   f->uid = -1;
  79   f->gid = -1;
  80 }
  81
  82 /* --- @fattr_option@ --- *
  83  *
  84  * Arguments:   @scanner *sc@ = pointer to scanner to read
  85  *              @fattr *f@ = pointer to file attributes to set
  86  *
  87  * Returns:     Whether the option was claimed.
  88  *
  89  * Use:         Reads file attributes from a scanner.
  90  */
  91
  92 int fattr_option(scanner *sc, fattr *f)
  93 {
  94   CONF_BEGIN(sc, "fattr", "file attribute")
  95
  96   /* --- Read a file mode specification --- */
  97
  98   if (strcmp(sc->d.buf, "mode") == 0) {
  99     unsigned mode = 0;
 100
 101     /* --- Gobble an optional `=' sign --- */
 102
 103     token(sc);
 104     if (sc->t == '=')
 105       token(sc);
 106
 107     if (sc->t != CTOK_WORD)
 108       error(sc, "parse error, expected file mode");
 109
 110     /* --- If it looks digitlike, read as octal --- */
 111
 112     if (isdigit((unsigned char)*sc->d.buf))
 113       mode = strtoul(sc->d.buf, 0, 8) & 07777;
 114
 115     /* --- Otherise read as chmod-like characters --- */
 116
 117     else {
 118       const char *p;
 119       unsigned mask = 07777;
 120       unsigned or = 1;
 121
 122       /* --- Set the default from the umask --- */
 123
 124       {
 125         unsigned um = umask(0);
 126         umask(um);
 127         mode = 0666 & ~um;
 128       }
 129
 130       /* --- Parse the characters --- *
 131        *
 132        * This is a particularly lenient implementation of the usual chmod-
 133        * style mode language.
 134        */
 135
 136       for (p = sc->d.buf; *p; p++) {
 137         switch (*p) {
 138           case ',': break;
 139
 140           case 'a': mask = 07777; break;
 141           case 'u': mask = 04700; break;
 142           case 'g': mask = 02070; break;
 143           case 'o': mask = 01007; break;
 144
 145           case '=': mode &= ~mask; break;
 146           case '-': or = 0; break;
 147           case '+': or = 1; break;
 148
 149 #define APPLY(m) if (or) mode |= ((m) & mask); else mode &= ~((m) & mask);
 150           case 'r': APPLY(00444); break;
 151           case 'w': APPLY(00222); break;
 152           case 'x': APPLY(00111); break;
 153           case 's': APPLY(06000); break;
 154           case 't': APPLY(01000); break;
 155 #undef APPLY
 156
 157           default: error(sc, "unknown mode character `%c'", *p);
 158         }
 159       }
 160     }
 161
 162     token(sc);
 163     f->mode = mode;
 164     CONF_ACCEPT;
 165   }
 166
 167   /* --- Read a file uid specification --- */
 168
 169   if (strcmp(sc->d.buf, "uid") == 0 ||
 170       strcmp(sc->d.buf, "user") == 0 ||
 171       strcmp(sc->d.buf, "owner") == 0) {
 172     token(sc);
 173     if (sc->t == '=')
 174       token(sc);
 175     if (sc->t != CTOK_WORD)
 176       error(sc, "parse error, expected user name or uid");
 177     if (isdigit((unsigned char)*sc->d.buf))
 178       f->uid = atoi(sc->d.buf);
 179     else {
 180       struct passwd *pw = getpwnam(sc->d.buf);
 181       if (!pw)
 182         error(sc, "unknown user name `%s'", sc->d.buf);
 183       f->uid = pw->pw_uid;
 184     }
 185     token(sc);
 186     CONF_ACCEPT;
 187   }
 188
 189   /* --- Read a file gid specification --- */
 190
 191   if (strcmp(sc->d.buf, "gid") == 0 ||
 192       strcmp(sc->d.buf, "group") == 0) {
 193     token(sc);
 194     if (sc->t == '=')
 195       token(sc);
 196     if (sc->t != CTOK_WORD)
 197       error(sc, "parse error, expected group name or gid");
 198     if (isdigit((unsigned char)*sc->d.buf))
 199       f->gid = atoi(sc->d.buf);
 200     else {
 201       struct group *gr = getgrnam(sc->d.buf);
 202       if (!gr)
 203         error(sc, "unknown user name `%s'", sc->d.buf);
 204       f->gid = gr->gr_gid;
 205     }
 206     token(sc);
 207     CONF_ACCEPT;
 208   }
 209
 210   /* --- Nothing here for me --- */
 211
 212   CONF_END;
 213 }
 214
 215 /* --- @fattr_apply@ --- *
 216  *
 217  * Arguments:   @const char *file@ = pointer to filename
 218  *              @fattr *f@ = pointer to attribute set
 219  *
 220  * Returns:     @-1@ if it failed.
 221  *
 222  * Use:         Applies file attributes to a file.  For best results, try to
 223  *              create the file with the right permissions and so on.  This
 224  *              call will fix everything up, but there are potential races
 225  *              which might catch you out if you're not careful.
 226  */
 227
 228 int fattr_apply(const char *file, fattr *f)
 229 {
 230   if (chown(file, f->uid, f->gid) == -1 ||
 231       chmod(file, f->mode) == -1)
 232     return (-1);
 233   return (0);
 234 }
 235
 236 /*----- That's all, folks -------------------------------------------------*/