core: add nm_utils_to_string_buffer global buffer

Having a static string buffer for convenience is useful not only
for platform. Define the string buffer in NetworkManagerUtils.h,
so that all to-string functions can reuse *one* buffer.

Of course, this has the potential danger, that different
to-string method might reuse the same buffer. Hence, low-level
library functions are adviced to use their own buffer, because
an upper level might already use the global buffer for another
string.

8 files changed, 52 insertions, 39 deletions

diff --git a/include/nm-test-utils.h b/include/nm-test-utils.h
index 85a6e78385..9f40be9c12 100644
--- a/include/nm-test-utils.h
+++ b/include/nm-test-utils.h
@@ -983,7 +983,7 @@ nmtst_platform_ip4_routes_equal (const NMPlatformIP4Route *a, const NMPlatformIP
 
 	for (i = 0; i < len; i++) {
 		if (nm_platform_ip4_route_cmp (&a[i], &b[i]) != 0) {
-			char buf[sizeof (_nm_platform_to_string_buffer)];
+			char buf[sizeof (_nm_utils_to_string_buffer)];
 
 			g_error ("Error comparing IPv4 route[%lu]: %s vs %s", (long unsigned) i,
 			         nm_platform_ip4_route_to_string (&a[i], NULL, 0),
@@ -1017,7 +1017,7 @@ nmtst_platform_ip6_routes_equal (const NMPlatformIP6Route *a, const NMPlatformIP
 
 	for (i = 0; i < len; i++) {
 		if (nm_platform_ip6_route_cmp (&a[i], &b[i]) != 0) {
-			char buf[sizeof (_nm_platform_to_string_buffer)];
+			char buf[sizeof (_nm_utils_to_string_buffer)];
 
 			g_error ("Error comparing IPv6 route[%lu]: %s vs %s", (long unsigned) i,
 			         nm_platform_ip6_route_to_string (&a[i], NULL, 0),
diff --git a/src/NetworkManagerUtils.c b/src/NetworkManagerUtils.c
index 726ceb9b4a..b2d98ca58d 100644
--- a/src/NetworkManagerUtils.c
+++ b/src/NetworkManagerUtils.c
@@ -1725,6 +1725,32 @@ nm_match_spec_join (GSList *specs)
 	return g_string_free (str, FALSE);
 }
 
+/*****************************************************************************/
+
+char _nm_utils_to_string_buffer[];
+
+void
+nm_utils_to_string_buffer_init (char **buf, gsize *len)
+{
+	if (!*buf) {
+		*buf = _nm_utils_to_string_buffer;
+		*len = sizeof (_nm_utils_to_string_buffer);
+	}
+}
+
+gboolean
+nm_utils_to_string_buffer_init_null (gconstpointer obj, char **buf, gsize *len)
+{
+	nm_utils_to_string_buffer_init (buf, len);
+	if (!obj) {
+		g_strlcpy (*buf, "(null)", *len);
+		return FALSE;
+	}
+	return TRUE;
+}
+
+/*****************************************************************************/
+
 /**
  * nm_utils_get_shared_wifi_permission:
  * @connection: the NMConnection to lookup the permission.
diff --git a/src/NetworkManagerUtils.h b/src/NetworkManagerUtils.h
index bf90e741cd..b4cc180013 100644
--- a/src/NetworkManagerUtils.h
+++ b/src/NetworkManagerUtils.h
@@ -191,6 +191,11 @@ NMMatchSpecMatchType nm_match_spec_match_config (const GSList *specs, guint nm_v
 GSList *nm_match_spec_split (const char *value);
 char *nm_match_spec_join (GSList *specs);
 
+extern char _nm_utils_to_string_buffer[2096];
+
+void     nm_utils_to_string_buffer_init (char **buf, gsize *len);
+gboolean nm_utils_to_string_buffer_init_null (gconstpointer obj, char **buf, gsize *len);
+
 const char *nm_utils_get_shared_wifi_permission (NMConnection *connection);
 
 const char *nm_utils_get_ip_config_method (NMConnection *connection,
diff --git a/src/platform/nm-linux-platform.c b/src/platform/nm-linux-platform.c
index 2c60b8419e..b092e080b1 100644
--- a/src/platform/nm-linux-platform.c
+++ b/src/platform/nm-linux-platform.c
@@ -2391,8 +2391,8 @@ cache_pre_hook (NMPCache *cache, const NMPObject *old, const NMPObject *new, NMP
 	NMPlatform *platform = NM_PLATFORM (user_data);
 	NMLinuxPlatformPrivate *priv = NM_LINUX_PLATFORM_GET_PRIVATE (platform);
 	const NMPClass *klass;
-	char str_buf[sizeof (_nm_platform_to_string_buffer)];
-	char str_buf2[sizeof (_nm_platform_to_string_buffer)];
+	char str_buf[sizeof (_nm_utils_to_string_buffer)];
+	char str_buf2[sizeof (_nm_utils_to_string_buffer)];
 
 	nm_assert (old || new);
 	nm_assert (NM_IN_SET (ops_type, NMP_CACHE_OPS_ADDED, NMP_CACHE_OPS_REMOVED, NMP_CACHE_OPS_UPDATED));
diff --git a/src/platform/nm-platform.c b/src/platform/nm-platform.c
index 4827638137..480b07e18a 100644
--- a/src/platform/nm-platform.c
+++ b/src/platform/nm-platform.c
@@ -2477,22 +2477,6 @@ _lifetime_summary_to_string (gint32 now, guint32 timestamp, guint32 preferred, g
 	return buf;
 }
 
-char _nm_platform_to_string_buffer[];
-
-static gboolean
-_to_string_buffer_init (gconstpointer obj, char **buf, gsize *len)
-{
-	if (!*buf) {
-		*buf = _nm_platform_to_string_buffer;
-		*len = sizeof (_nm_platform_to_string_buffer);
-	}
-	if (!obj) {
-		g_strlcpy (*buf, "(null)", *len);
-		return FALSE;
-	}
-	return TRUE;
-}
-
 /**
  * nm_platform_link_to_string:
  * @route: pointer to NMPlatformLink address structure
@@ -2514,7 +2498,7 @@ nm_platform_link_to_string (const NMPlatformLink *link, char *buf, gsize len)
 	gs_free char *str_inet6_token = NULL;
 	const char *str_link_type;
 
-	if (!_to_string_buffer_init (link, &buf, &len))
+	if (!nm_utils_to_string_buffer_init_null (link, &buf, &len))
 		return buf;
 
 	str_flags = g_string_new (NULL);
@@ -2623,7 +2607,7 @@ nm_platform_lnk_gre_to_string (const NMPlatformLnkGre *lnk, char *buf, gsize len
 	char str_output_key[30];
 	char str_output_key1[NM_UTILS_INET_ADDRSTRLEN];
 
-	if (!_to_string_buffer_init (lnk, &buf, &len))
+	if (!nm_utils_to_string_buffer_init_null (lnk, &buf, &len))
 		return buf;
 
 	g_snprintf (buf, len,
@@ -2657,7 +2641,7 @@ nm_platform_lnk_infiniband_to_string (const NMPlatformLnkInfiniband *lnk, char *
 {
 	char str_p_key[64];
 
-	if (!_to_string_buffer_init (lnk, &buf, &len))
+	if (!nm_utils_to_string_buffer_init_null (lnk, &buf, &len))
 		return buf;
 
 	g_snprintf (buf, len,
@@ -2674,7 +2658,7 @@ nm_platform_lnk_infiniband_to_string (const NMPlatformLnkInfiniband *lnk, char *
 const char *
 nm_platform_lnk_macvlan_to_string (const NMPlatformLnkMacvlan *lnk, char *buf, gsize len)
 {
-	if (!_to_string_buffer_init (lnk, &buf, &len))
+	if (!nm_utils_to_string_buffer_init_null (lnk, &buf, &len))
 		return buf;
 
 	g_snprintf (buf, len,
@@ -2688,7 +2672,7 @@ nm_platform_lnk_macvlan_to_string (const NMPlatformLnkMacvlan *lnk, char *buf, g
 const char *
 nm_platform_lnk_vlan_to_string (const NMPlatformLnkVlan *lnk, char *buf, gsize len)
 {
-	if (!_to_string_buffer_init (lnk, &buf, &len))
+	if (!nm_utils_to_string_buffer_init_null (lnk, &buf, &len))
 		return buf;
 
 	g_snprintf (buf, len, "vlan %u", (guint) lnk->id);
@@ -2709,7 +2693,7 @@ nm_platform_lnk_vxlan_to_string (const NMPlatformLnkVxlan *lnk, char *buf, gsize
 	char str_tos[25];
 	char str_ttl[25];
 
-	if (!_to_string_buffer_init (lnk, &buf, &len))
+	if (!nm_utils_to_string_buffer_init_null (lnk, &buf, &len))
 		return buf;
 
 	if (lnk->group == 0)
@@ -2806,7 +2790,7 @@ nm_platform_ip4_address_to_string (const NMPlatformIP4Address *address, char *bu
 	const char *str_lft_p, *str_pref_p, *str_time_p;
 	gint32 now = nm_utils_get_monotonic_timestamp_s ();
 
-	if (!_to_string_buffer_init (address, &buf, &len))
+	if (!nm_utils_to_string_buffer_init_null (address, &buf, &len))
 		return buf;
 
 	inet_ntop (AF_INET, &address->address, s_address, sizeof (s_address));
@@ -2912,7 +2896,7 @@ nm_platform_ip6_address_to_string (const NMPlatformIP6Address *address, char *bu
 	const char *str_lft_p, *str_pref_p, *str_time_p;
 	gint32 now = nm_utils_get_monotonic_timestamp_s ();
 
-	if (!_to_string_buffer_init (address, &buf, &len))
+	if (!nm_utils_to_string_buffer_init_null (address, &buf, &len))
 		return buf;
 
 	inet_ntop (AF_INET6, &address->address, s_address, sizeof (s_address));
@@ -2971,7 +2955,7 @@ nm_platform_ip4_route_to_string (const NMPlatformIP4Route *route, char *buf, gsi
 	char str_dev[TO_STRING_DEV_BUF_SIZE];
 	char str_scope[30];
 
-	if (!_to_string_buffer_init (route, &buf, &len))
+	if (!nm_utils_to_string_buffer_init_null (route, &buf, &len))
 		return buf;
 
 	inet_ntop (AF_INET, &route->network, s_network, sizeof(s_network));
@@ -3020,7 +3004,7 @@ nm_platform_ip6_route_to_string (const NMPlatformIP6Route *route, char *buf, gsi
 	char s_network[INET6_ADDRSTRLEN], s_gateway[INET6_ADDRSTRLEN];
 	char str_dev[TO_STRING_DEV_BUF_SIZE];
 
-	if (!_to_string_buffer_init (route, &buf, &len))
+	if (!nm_utils_to_string_buffer_init_null (route, &buf, &len))
 		return buf;
 
 	inet_ntop (AF_INET6, &route->network, s_network, sizeof(s_network));
diff --git a/src/platform/nm-platform.h b/src/platform/nm-platform.h
index 2522f3092f..2c6831e32d 100644
--- a/src/platform/nm-platform.h
+++ b/src/platform/nm-platform.h
@@ -770,8 +770,6 @@ gboolean nm_platform_ip6_route_add (NMPlatform *self, int ifindex, NMIPConfigSou
 gboolean nm_platform_ip4_route_delete (NMPlatform *self, int ifindex, in_addr_t network, int plen, guint32 metric);
 gboolean nm_platform_ip6_route_delete (NMPlatform *self, int ifindex, struct in6_addr network, int plen, guint32 metric);
 
-extern char _nm_platform_to_string_buffer[1024];
-
 const char *nm_platform_link_to_string (const NMPlatformLink *link, char *buf, gsize len);
 const char *nm_platform_lnk_gre_to_string (const NMPlatformLnkGre *lnk, char *buf, gsize len);
 const char *nm_platform_lnk_infiniband_to_string (const NMPlatformLnkInfiniband *lnk, char *buf, gsize len);
diff --git a/src/platform/nmp-object.c b/src/platform/nmp-object.c
index a783021d83..ae09332736 100644
--- a/src/platform/nmp-object.c
+++ b/src/platform/nmp-object.c
@@ -379,13 +379,13 @@ const char *
 nmp_object_to_string (const NMPObject *obj, NMPObjectToStringMode to_string_mode, char *buf, gsize buf_size)
 {
 	const NMPClass *klass;
-	char buf2[sizeof (_nm_platform_to_string_buffer)];
-	char buf3[sizeof (_nm_platform_to_string_buffer)];
-	char buf4[sizeof (_nm_platform_to_string_buffer)];
+	char buf2[sizeof (_nm_utils_to_string_buffer)];
+	char buf3[sizeof (_nm_utils_to_string_buffer)];
+	char buf4[sizeof (_nm_utils_to_string_buffer)];
 
 	if (!buf) {
-		buf = _nm_platform_to_string_buffer;
-		buf_size = sizeof (_nm_platform_to_string_buffer);
+		buf = _nm_utils_to_string_buffer;
+		buf_size = sizeof (_nm_utils_to_string_buffer);
 	}
 
 	if (!obj) {
@@ -413,7 +413,7 @@ nmp_object_to_string (const NMPObject *obj, NMPObjectToStringMode to_string_mode
 			            obj->_link.netlink.is_in_netlink ? '+' : '-',
 			            obj->_link.udev.device);
 			if (obj->_link.netlink.lnk) {
-				char b[sizeof (_nm_platform_to_string_buffer)];
+				char b[sizeof (_nm_utils_to_string_buffer)];
 
 				g_snprintf (buf4, sizeof (buf4),
 				            ", link:%s, %s",
diff --git a/src/tests/test-route-manager.c b/src/tests/test-route-manager.c
index 09862d2368..eba7d9ef77 100644
--- a/src/tests/test-route-manager.c
+++ b/src/tests/test-route-manager.c
@@ -797,7 +797,7 @@ _assert_route_check (const NMPlatformVTableRoute *vtable, gboolean has, const NM
 	if (!has) {
 		g_assert (!r);
 	} else {
-		char buf[sizeof (_nm_platform_to_string_buffer)];
+		char buf[sizeof (_nm_utils_to_string_buffer)];
 
 		if (!r || vtable->route_cmp (route, r) != 0)
 			g_error ("Invalid route. Expect %s, has %s",