To help combat problems where people build external modules (asterisk-addons or others) and then change the build options of the Asterisk build in a way that makes the incompatible without warning, this commit introduces an MD5 signature of the important build-time options and includes that signature into modules when they are built. When the loader loads one of these modules and notices the problem, it will emit a warning to console and refuse to initialize the module, as doing so could cause the system to be unstable or even crash.

If you upgrade to this version of Asterisk, you must rebuild *all* of your modules that came from other sources before trying to run this version. If you are using Digium's G.729 binary codec module, you will need v33 or newer.


git-svn-id: http://svn.digium.com/svn/asterisk/branches/1.4@89325 f38db490-d61c-443f-a65b-d21fe96a405b

3 files changed, 18 insertions, 1 deletions

diff --git a/build_tools/make_buildopts_h b/build_tools/make_buildopts_h
index ac41a006a..7d85836eb 100755
--- a/build_tools/make_buildopts_h
+++ b/build_tools/make_buildopts_h
@@ -14,4 +14,7 @@ done
 if ${GREP} AST_DEVMODE makeopts | ${GREP} -q yes
 then
 	echo "#define AST_DEVMODE 1"
+	TMP="${TMP} AST_DEVMODE"
 fi
+BUILDSUM=`echo ${TMP} | md5sum`
+echo "#define AST_BUILDOPT_SUM {0x${BUILDSUM:0:8}, 0x${BUILDSUM:8:8}, 0x${BUILDSUM:16:8}, 0x${BUILDSUM:24:8}}"
diff --git a/include/asterisk/module.h b/include/asterisk/module.h
index 7f14df7f9..2c39cc2d7 100644
--- a/include/asterisk/module.h
+++ b/include/asterisk/module.h
@@ -203,6 +203,7 @@ struct ast_module_info {
 
 	const char *key;
 	unsigned int flags;
+	unsigned int buildopt_sum[4];		/* The value of AST_BUILDOPT_SUM when this module was compiled */
 };
 
 void ast_module_register(const struct ast_module_info *);
@@ -229,7 +230,8 @@ void ast_module_unref(struct ast_module *);
 		AST_MODULE,				\
 		desc,					\
 		keystr,					\
-		flags_to_set				\
+		flags_to_set,				\
+		AST_BUILDOPT_SUM,			\
 	};						\
 	static void  __attribute__ ((constructor)) __reg_module(void) \
 	{ \
@@ -259,6 +261,7 @@ const static __attribute__((unused)) struct ast_module_info *ast_module_info;
 		.flags = flags_to_set,				\
 		.description = desc,				\
 		.key = keystr,					\
+		.buildopt_sum = AST_BUILDOPT_SUM,		\
 		fields						\
 	};							\
 	static void  __attribute__ ((constructor)) __reg_module(void) \
diff --git a/main/loader.c b/main/loader.c
index 7df486251..f0b98f9b9 100644
--- a/main/loader.c
+++ b/main/loader.c
@@ -76,6 +76,8 @@ static unsigned char expected_key[] =
 { 0x87, 0x76, 0x79, 0x35, 0x23, 0xea, 0x3a, 0xd3,
   0x25, 0x2a, 0xbb, 0x35, 0x87, 0xe4, 0x22, 0x24 };
 
+static unsigned int buildopt_sum[4] = AST_BUILDOPT_SUM;
+
 static unsigned int embedding = 1; /* we always start out by registering embedded modules,
 				      since they are here before we dlopen() any
 				   */
@@ -598,6 +600,8 @@ int ast_module_reload(const char *name)
 
 static unsigned int inspect_module(const struct ast_module *mod)
 {
+	unsigned int buildopt_empty[4] = { 0, };
+
 	if (!mod->info->description) {
 		ast_log(LOG_WARNING, "Module '%s' does not provide a description.\n", mod->resource);
 		return 1;
@@ -613,6 +617,13 @@ static unsigned int inspect_module(const struct ast_module *mod)
 		return 1;
 	}
 
+	if (memcmp(buildopt_empty, mod->info->buildopt_sum, sizeof(buildopt_empty)) &&
+	    memcmp(buildopt_sum, mod->info->buildopt_sum, sizeof(buildopt_sum))) {
+		ast_log(LOG_WARNING, "Module '%s' was not compiled with the same compile-time options as this version of Asterisk.\n", mod->resource);
+		ast_log(LOG_WARNING, "Module '%s' will not be initialized as it may cause instability.\n", mod->resource);
+		return 1;
+	}
+
 	return 0;
 }