mdw@git.distorted.org.uk Git - dpkg/blob - src/infodb-format.c

   1 /*
   2  * dpkg - main program for package management
   3  * infodb-format.c - package control information database format
   4  *
   5  * Copyright © 2011-2014 Guillem Jover <guillem@debian.org>
   6  *
   7  * This is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22 #include <compat.h>
  23
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26
  27 #include <errno.h>
  28 #include <stdlib.h>
  29 #include <stdio.h>
  30
  31 #include <dpkg/i18n.h>
  32 #include <dpkg/dpkg.h>
  33 #include <dpkg/dpkg-db.h>
  34 #include <dpkg/varbuf.h>
  35
  36 #include "infodb.h"
  37
  38 static enum pkg_infodb_format db_format = PKG_INFODB_FORMAT_UNKNOWN;
  39 static bool db_upgrading;
  40
  41 static enum pkg_infodb_format
  42 pkg_infodb_parse_format(const char *file)
  43 {
  44         FILE *fp;
  45         int format;
  46
  47         fp = fopen(file, "r");
  48         if (fp == NULL) {
  49                 /* A missing format file means legacy format (0). */
  50                 if (errno == ENOENT)
  51                         return PKG_INFODB_FORMAT_LEGACY;
  52                 ohshite(_("error trying to open %.250s"), file);
  53         }
  54
  55         if (fscanf(fp, "%u", &format) != 1)
  56                 ohshit(_("corrupt info database format file '%s'"), file);
  57
  58         fclose(fp);
  59
  60         return format;
  61 }
  62
  63 static enum pkg_infodb_format
  64 pkg_infodb_read_format(void)
  65 {
  66         struct atomic_file *file;
  67         struct stat st;
  68         char *filename;
  69
  70         filename = dpkg_db_get_path(INFODIR "/format");
  71         file = atomic_file_new(filename, 0);
  72
  73         db_format = pkg_infodb_parse_format(file->name);
  74
  75         /* Check if a previous upgrade got interrupted. Because we are only
  76          * supposed to upgrade the db layout one format at a time, if the
  77          * new file exists that means the new format is just one ahead,
  78          * we don't try to read it because it contains unreliable data. */
  79         if (stat(file->name_new, &st) == 0) {
  80                 db_format++;
  81                 db_upgrading = true;
  82         }
  83
  84         atomic_file_free(file);
  85         free(filename);
  86
  87         if (db_format < 0 || db_format >= PKG_INFODB_FORMAT_LAST)
  88                 ohshit(_("info database format (%d) is bogus or too new; "
  89                          "try getting a newer dpkg"), db_format);
  90
  91         return db_format;
  92 }
  93
  94 enum pkg_infodb_format
  95 pkg_infodb_get_format(void)
  96 {
  97         if (db_format > PKG_INFODB_FORMAT_UNKNOWN)
  98                 return db_format;
  99         else
 100                 return pkg_infodb_read_format();
 101 }
 102
 103 void
 104 pkg_infodb_set_format(enum pkg_infodb_format version)
 105 {
 106         db_format = version;
 107 }
 108
 109 bool
 110 pkg_infodb_is_upgrading(void)
 111 {
 112         if (db_format < 0)
 113                 pkg_infodb_read_format();
 114
 115         return db_upgrading;
 116 }
 117
 118 const char *
 119 pkg_infodb_get_dir(void)
 120 {
 121         static char *infodir;
 122
 123         if (infodir == NULL)
 124                 infodir = dpkg_db_get_path(INFODIR);
 125
 126         return infodir;
 127 }
 128
 129 const char *
 130 pkg_infodb_get_file(struct pkginfo *pkg, struct pkgbin *pkgbin,
 131                     const char *filetype)
 132 {
 133         static struct varbuf vb;
 134         enum pkg_infodb_format format;
 135
 136         /* Make sure to always read and verify the format version. */
 137         format = pkg_infodb_get_format();
 138
 139         varbuf_reset(&vb);
 140         varbuf_add_str(&vb, pkg_infodb_get_dir());
 141         varbuf_add_char(&vb, '/');
 142         varbuf_add_str(&vb, pkg->set->name);
 143         if (pkgbin->multiarch == PKG_MULTIARCH_SAME &&
 144             format == PKG_INFODB_FORMAT_MULTIARCH)
 145                 varbuf_add_archqual(&vb, pkgbin->arch);
 146         varbuf_add_char(&vb, '.');
 147         varbuf_add_str(&vb, filetype);
 148         varbuf_end_str(&vb);
 149
 150         return vb.buf;
 151 }