nl: Print file:line:func in debugging messages and provide --disable-debug to disable debugging

Compiling libnl with --disable-debug will result in the ignorance
of the 'NLDBG' environment variable.

Signed-off-by: Thomas Graf <tgraf@suug.ch>

configure.ac

@@ -92,6 +92,11 @@ AC_ARG_ENABLE([pthreads],
 	[enable_pthreads="$enableval"], [enable_pthreads="yes"])
 AM_CONDITIONAL([DISABLE_PTHREADS], [test "$enable_pthreads" = "no"])
 
+AC_ARG_ENABLE([debug],
+	AS_HELP_STRING([--disable-debug], [Do not include debugging statements]),
+	[enable_debug="$enableval"], [enable_debug="yes"])
+AM_CONDITIONAL([ENABLE_DEBUG], [test "$enable_debug" = "no" ])
+
 AC_CHECK_LIB([m], [pow], [], AC_MSG_ERROR([libm is required]))
 
 if test "x$enable_pthreads" = "xno"; then
@@ -100,6 +105,10 @@ else
     AC_CHECK_LIB([pthread], [pthread_mutex_lock], [], AC_MSG_ERROR([libpthread is required]))
 fi
 
+if test "x$enable_debug" = "xyes"; then
+    AC_DEFINE([NL_DEBUG], [1], [Define to 1 to enable debugging])
+fi
+
 AC_CONFIG_SUBDIRS([doc])
 
 AC_CONFIG_FILES([

include/netlink-private/netlink.h

@@ -80,24 +80,29 @@ struct trans_list {
 	struct nl_list_head list;
 };
 
-#define NL_DEBUG	1
-
-#define NL_DBG(LVL,FMT,ARG...) \
-	do {	\
-		if (LVL <= nl_debug) \
-			fprintf(stderr, "DBG<" #LVL ">: " FMT, ##ARG); \
+#ifdef NL_DEBUG
+#define NL_DBG(LVL,FMT,ARG...)						\
+	do {								\
+		if (LVL <= nl_debug)					\
+			fprintf(stderr,					\
+				"DBG<" #LVL ">%20s:%-4u %s: " FMT,	\
+				__FILE__, __LINE__,			\
+				__PRETTY_FUNCTION__, ##ARG);		\
 	} while (0)
+#else /* NL_DEBUG */
+#define NL_DBG(LVL,FMT,ARG...) do { } while(0)
+#endif /* NL_DEBUG */
 
 #define BUG()                            				\
 	do {                                 				\
-		NL_DBG(1, "BUG: %s:%d\n",  				\
-			__FILE__, __LINE__);         			\
+		fprintf(stderr, "BUG at file position %s:%d:%s\n",  	\
+			__FILE__, __LINE__, __PRETTY_FUNCTION__); 	\
 		assert(0);						\
 	} while (0)
 
 #define APPBUG(msg)							\
 	do {								\
-		NL_DBG(1, "APPLICATION BUG: %s:%d:%s: %s\n",		\
+		fprintf(stderr, "APPLICATION BUG: %s:%d:%s: %s\n",	\
 			__FILE__, __LINE__, __PRETTY_FUNCTION__, msg);	\
 		assert(0);						\
 	} while(0)

lib/route/neigh.c

@@ -211,7 +211,9 @@ static void neigh_keygen(struct nl_object *obj, uint32_t *hashkey,
 		uint32_t	n_ifindex;
 		char		n_addr[0];
 	} __attribute__((packed)) *nkey;
+#ifdef NL_DEBUG
 	char buf[INET6_ADDRSTRLEN+5];
+#endif
 
 	if (neigh->n_family == AF_BRIDGE) {
 		if (neigh->n_lladdr)

lib/route/route_obj.c

@@ -307,7 +307,9 @@ static void route_keygen(struct nl_object *obj, uint32_t *hashkey,
 		uint32_t	rt_prio;
 		char 		rt_addr[0];
 	} __attribute__((packed)) *rkey;
+#ifdef NL_DEBUG
 	char buf[INET6_ADDRSTRLEN+5];
+#endif
 
 	if (route->rt_dst)
 		addr = route->rt_dst;
@@ -449,8 +451,10 @@ static int route_update(struct nl_object *old_obj, struct nl_object *new_obj)
 	struct rtnl_route *new_route = (struct rtnl_route *) new_obj;
 	struct rtnl_route *old_route = (struct rtnl_route *) old_obj;
 	struct rtnl_nexthop *new_nh;
-	char buf[INET6_ADDRSTRLEN+5];
 	int action = new_obj->ce_msgtype;
+#ifdef NL_DEBUG
+	char buf[INET6_ADDRSTRLEN+5];
+#endif
 
 	/*
 	 * ipv6 ECMP route notifications from the kernel come as

lib/utils.c

@@ -49,6 +49,7 @@
 int nl_debug = 0;
 
 /** @cond SKIP */
+#ifdef NL_DEBUG
 struct nl_dump_params nl_debug_dp = {
 	.dp_type = NL_DUMP_DETAILS,
 };
@@ -65,6 +66,7 @@ static void __init nl_debug_init(void)
 
 	nl_debug_dp.dp_fd = stderr;
 }
+#endif
 
 int __nl_read_num_str_file(const char *path, int (*cb)(long, const char *))
 {