From: Ondřej Surý <ondrej@isc.org>
Date: Wed, 28 Oct 2020 14:25:44 +0000 (+0100)
Subject: Unify lt_dlopen() error handling
X-Git-Tag: v9.17.7~38^2~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4e9a58a3e68a7500b581f301ba837563178948c9;p=thirdparty%2Fbind9.git

Unify lt_dlopen() error handling

Make sure an error gets logged when any lt_dlopen() call in the source
tree fails.  Also make sure that NULL values returned by lt_dlerror()
are replaced with a generic error message to prevent passing NULL as an
argument for the %s format specifier.
---

diff --git a/bin/named/unix/dlz_dlopen_driver.c b/bin/named/unix/dlz_dlopen_driver.c
index fb9ce8d459f..0f8ff4d33c2 100644
--- a/bin/named/unix/dlz_dlopen_driver.c
+++ b/bin/named/unix/dlz_dlopen_driver.c
@@ -235,9 +235,13 @@ dlopen_dlz_create(const char *dlzname, unsigned int argc, char *argv[],
 
 	cd->dl_handle = lt_dlopenext(cd->dl_path);
 	if (cd->dl_handle == NULL) {
+		const char *errmsg = lt_dlerror();
+		if (errmsg == NULL) {
+			errmsg = "unknown error";
+		}
 		dlopen_log(ISC_LOG_ERROR,
 			   "dlz_dlopen failed to open library '%s': %s",
-			   cd->dl_path, lt_dlerror());
+			   cd->dl_path, errmsg);
 		result = ISC_R_FAILURE;
 		goto failed;
 	}
diff --git a/lib/dns/dyndb.c b/lib/dns/dyndb.c
index e35293ece62..38e320e4cc4 100644
--- a/lib/dns/dyndb.c
+++ b/lib/dns/dyndb.c
@@ -95,7 +95,7 @@ load_symbol(lt_dlhandle handle, const char *filename, const char *symbol_name,
 		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
 			      DNS_LOGMODULE_DYNDB, ISC_LOG_ERROR,
 			      "failed to lookup symbol %s in "
-			      "dyndb module '%s': %s",
+			      "DynDB module '%s': %s",
 			      symbol_name, filename, errmsg);
 		return (ISC_R_FAILURE);
 	}
@@ -128,6 +128,15 @@ load_library(isc_mem_t *mctx, const char *filename, const char *instname,
 
 	handle = lt_dlopen(filename);
 	if (handle == NULL) {
+		const char *errmsg = lt_dlerror();
+		if (errmsg == NULL) {
+			errmsg = "unknown error";
+		}
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
+			      DNS_LOGMODULE_DYNDB, ISC_LOG_ERROR,
+			      "failed to dlopen() DynDB instance '%s' driver "
+			      "'%s': %s",
+			      instname, filename, errmsg);
 		CHECK(ISC_R_FAILURE);
 	}