Line data    Source code

       1             : /* version.c - Version checking
       2             :  * Copyright (C) 2001, 2002, 2012, 2013, 2014 g10 Code GmbH
       3             :  *
       4             :  * This file is part of libgpg-error.
       5             :  *
       6             :  * libgpg-error is free software; you can redistribute it and/or
       7             :  * modify it under the terms of the GNU Lesser General Public License
       8             :  * as published by the Free Software Foundation; either version 2.1 of
       9             :  * the License, or (at your option) any later version.
      10             :  *
      11             :  * libgpg-error is distributed in the hope that it will be useful, but
      12             :  * WITHOUT ANY WARRANTY; without even the implied warranty of
      13             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14             :  * Lesser General Public License for more details.
      15             :  *
      16             :  * You should have received a copy of the GNU Lesser General Public
      17             :  * License along with this program; if not, see <https://www.gnu.org/licenses/>.
      18             :  */
      19             : 
      20             : #if HAVE_CONFIG_H
      21             : #include <config.h>
      22             : #endif
      23             : 
      24             : #include <stdlib.h>
      25             : #include <stdio.h>
      26             : #include <string.h>
      27             : 
      28             : #include <gpg-error.h>
      29             : 
      30             : 
      31             : #define digitp(a) ((a) >= '0' && (a) <= '9')
      32             : 
      33             : 
      34             : /* This is actually a dummy function to make sure that is module is
      35             :    not empty.  Some compilers barf on empty modules.  */
      36             : static const char *
      37             : cright_blurb (void)
      38             : {
      39             :   static const char blurb[] =
      40             :     "\n\n"
      41             :     "This is Libgpg-error " PACKAGE_VERSION " - An error code library\n"
      42             :     "Copyright 2003-2004, 2010, 2013-2017 g10 Code GmbH\n"
      43             :     "\n"
      44             :     "(" BUILD_REVISION " " BUILD_TIMESTAMP ")\n"
      45             :     "\n\n";
      46             :   return blurb;
      47             : }
      48             : 
      49             : 
      50             : static const char*
      51             : parse_version_number (const char *s, int *number)
      52             : {
      53             :   int val = 0;
      54             : 
      55          23 :   if (*s == '0' && digitp (s[1]))
      56             :     return NULL;  /* Leading zeros are not allowed.  */
      57          35 :   for (; digitp (*s); s++)
      58             :     {
      59          35 :       val *= 10;
      60          35 :       val += *s - '0';
      61             :     }
      62          23 :   *number = val;
      63          23 :   return val < 0 ? NULL : s;
      64             : }
      65             : 
      66             : 
      67             : static const char *
      68          12 : parse_version_string (const char *s, int *major, int *minor)
      69             : {
      70             :   s = parse_version_number (s, major);
      71          12 :   if (!s || *s != '.')
      72             :     return NULL;
      73          11 :   s++;
      74             :   s = parse_version_number (s, minor);
      75          11 :   if (!s)
      76             :     return NULL;
      77          11 :   return s;  /* Patchlevel.  */
      78             : }
      79             : 
      80             : 
      81             : static const char *
      82           6 : compare_versions (const char *my_version, const char *req_version)
      83             : {
      84             :   int my_major, my_minor;
      85             :   int rq_major, rq_minor;
      86             :   const char *my_plvl, *rq_plvl;
      87             : 
      88           6 :   if (!req_version)
      89             :     return my_version;
      90           6 :   if (!my_version)
      91             :     return NULL;
      92             : 
      93           6 :   my_plvl = parse_version_string (my_version, &my_major, &my_minor);
      94           6 :   if (!my_plvl)
      95             :     return NULL;        /* Very strange: our own version is bogus.  */
      96           6 :   rq_plvl = parse_version_string(req_version, &rq_major, &rq_minor);
      97           6 :   if (!rq_plvl)
      98             :     return NULL;        /* Requested version string is invalid.  */
      99             : 
     100           5 :   if (my_major > rq_major
     101           5 :       || (my_major == rq_major && my_minor >= rq_minor))
     102             :     {
     103             :       return my_version;
     104             :     }
     105           0 :   return NULL;
     106             : }
     107             : 
     108             : 
     109             : /*
     110             :  * Check that the the version of the library is at minimum REQ_VERSION
     111             :  * and return the actual version string; return NULL if the condition
     112             :  * is not met.  If NULL is passed to this function, no check is done
     113             :  * and the version string is simply returned.
     114             :  */
     115             : const char *
     116           6 : _gpg_error_check_version (const char *req_version)
     117             : {
     118           6 :   if (req_version && req_version[0] == 1 && req_version[1] == 1)
     119             :     return cright_blurb ();
     120           6 :   return compare_versions (PACKAGE_VERSION, req_version);
     121             : }