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Add pgmagic header block to store compile-time constants:

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It now only checks four things:

Major version number (7.4 or 8.1 for example)
NAMEDATALEN
FUNC_MAX_ARGS
INDEX_MAX_KEYS

The three constants were chosen because:

1. We document them in the config page in the docs
2. We mark them as changable in pg_config_manual.h
3. Changing any of these will break some of the more popular modules:

FUNC_MAX_ARGS changes fmgr interface, every module uses this NAMEDATALEN
changes syscache interface, every PL as well as tsearch uses this
INDEX_MAX_KEYS breaks tsearch and anything using GiST.

Martijn van Oosterhout
This commit is contained in:
Bruce Momjian
2006-05-30 14:09:32 +00:00
parent 87bd07d979
commit 01b2168c90
4 changed files with 149 additions and 5 deletions
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47
src/backend/utils/fmgr/dfmgr.c
View File

@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/fmgr/dfmgr.c,v 1.82 2006/03/05 15:58:46 momjian Exp $
* $PostgreSQL: pgsql/src/backend/utils/fmgr/dfmgr.c,v 1.83 2006/05/30 14:09:32 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -20,7 +20,7 @@
#include "dynloader.h"
#include "miscadmin.h"
#include "utils/dynamic_loader.h"
#include "pgmagic.h"
/*
* List of dynamically loaded files (kept in malloc'd memory).
@@ -60,6 +60,9 @@ static char *find_in_dynamic_libpath(const char *basename);
static char *expand_dynamic_library_name(const char *name);
static char *substitute_libpath_macro(const char *name);
/* Magic structure that module needs to match to be accepted */
static Pg_magic_struct magic_data = PG_MODULE_MAGIC_DATA;
/*
* Load the specified dynamic-link library file, and look for a function
* named funcname in it. (funcname can be NULL to just load the file.)
@@ -116,6 +119,7 @@ load_external_function(char *filename, char *funcname,
if (file_scanner == NULL)
{
PGModuleMagicFunction magic_func;
/*
* File not loaded yet.
*/
@@ -146,6 +150,45 @@ load_external_function(char *filename, char *funcname,
fullname, load_error)));
}
/* Check the magic function to determine compatability */
magic_func = pg_dlsym( file_scanner->handle, PG_MAGIC_FUNCTION_NAME_STRING );
if( magic_func )
{
Pg_magic_struct *module_magic_data = magic_func();
if( module_magic_data->len != magic_data.len ||
memcmp( module_magic_data, &magic_data, magic_data.len ) != 0 )
{
pg_dlclose( file_scanner->handle );
if( module_magic_data->len != magic_data.len )
ereport(ERROR,
(errmsg("incompatible library \"%s\": Magic block length mismatch",
fullname)));
if( module_magic_data->version != magic_data.version )
ereport(ERROR,
(errmsg("incompatible library \"%s\": Version mismatch",
fullname),
errdetail("Expected %d.%d, got %d.%d",
magic_data.version/100, magic_data.version % 100,
module_magic_data->version/100, module_magic_data->version % 100)));
if( module_magic_data->magic != magic_data.magic )
ereport(ERROR,
(errmsg("incompatible library \"%s\": Magic constant mismatch",
fullname),
errdetail("Expected 0x%08X, got 0x%08X",
magic_data.magic, magic_data.magic)));
/* Should never get here */
ereport(ERROR,(errmsg("incompatible library \"%s\": Reason unknown",
fullname)));
}
}
else
/* Currently we do not penalize modules for not having a
magic block, it would break every external module in
existance. At some point though... */
ereport(LOG, (errmsg("external library \"%s\" did not have magic block", fullname )));
/* OK to link it into list */
if (file_list == NULL)
file_list = file_scanner;