core: load jansson on demand

Avoid using it if the symbols clash is detected.

Makefile.am

@@ -516,6 +516,14 @@ libnm_core_lib_c_real = \
 	libnm-core/nm-utils.c \
 	libnm-core/nm-vpn-editor-plugin.c \
 	libnm-core/nm-vpn-plugin-info.c
+
+if WITH_JSON_VALIDATION
+libnm_core_lib_h_priv += \
+	libnm-core/nm-jansson.h
+libnm_core_lib_c_real += \
+	libnm-core/nm-jansson.c
+endif
+
 libnm_core_lib_c_mkenums = \
 	libnm-core/nm-core-enum-types.c
 
@@ -596,10 +604,6 @@ libnm_core_libnm_core_la_LIBADD = \
 	$(UUID_LIBS) \
 	$(LIBUDEV_LIBS)
 
-if WITH_JSON_VALIDATION
-libnm_core_libnm_core_la_LIBADD += $(JANSSON_LIBS)
-endif
-
 libnm_core_libnm_core_la_LDFLAGS = \
 	$(CODE_COVERAGE_LDFLAGS)
 

config.h.meson

@@ -71,6 +71,9 @@
 /* Define to path of iptables binary */
 #mesondefine IPTABLES_PATH
 
+/* Define to path to the Jansson shared library */
+#mesondefine JANSSON_SONAME
+
 /* Define to path of the kernel firmware directory */
 #mesondefine KERNEL_FIRMWARE_DIR
 

configure.ac

@@ -629,12 +629,20 @@ PKG_CHECK_MODULES(UUID, uuid)
 PKG_CHECK_MODULES(JANSSON, [jansson], [have_jansson=yes], [have_jansson=no])
 if test "$have_jansson" = "yes"; then
 	AC_DEFINE(WITH_JANSSON, 1, [Define if JANSSON is enabled])
+
+	AC_CHECK_TOOLS(READELF, [eu-readelf readelf])
+	JANSSON_LIBDIR=`$PKG_CONFIG --variable=libdir jansson`
+	JANSSON_SONAME=`$READELF -d $JANSSON_LIBDIR/libjansson.so |sed -n 's/.*SONAME.*\[[\([^]]*\)]]/\1/p'`
+
+	if test "$JANSSON_SONAME" = ""; then
+		AC_MSG_ERROR(Unable to locate the Jansson library)
+	fi
+	AC_DEFINE_UNQUOTED(JANSSON_SONAME, "$JANSSON_SONAME", [Define to path to the Jansson shared library])
 else
 	AC_DEFINE(WITH_JANSSON, 0, [Define if JANSSON is enabled])
 fi
 AM_CONDITIONAL(WITH_JANSSON, test "${have_jansson}" = "yes")
 
-
 PKG_CHECK_MODULES(LIBTEAMDCTL, [libteamdctl >= 1.9], [have_teamdctl=yes],[have_teamdctl=no])
 if test "$have_jansson" = "yes" -a "$have_teamdctl" = "yes"; then
 	have_team_prereq=yes

libnm-core/meson.build

@@ -151,6 +151,7 @@ cflags = [
 ]
 
 if enable_json_validation
+  libnm_core_sources += files('nm-jansson.c')
   deps += jansson_dep
 endif
 

libnm-core/nm-jansson.c

+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Copyright 2017, 2018 Red Hat, Inc.
+ */
+
+#define _GNU_SOURCE
+#include <link.h>
+
+#include "nm-default.h"
+
+#define NM_JAONSSON_C
+#include "nm-jansson.h"
+
+void *_nm_jansson_json_object_iter_value;
+void *_nm_jansson_json_object_key_to_iter;
+void *_nm_jansson_json_integer;
+void *_nm_jansson_json_object_del;
+void *_nm_jansson_json_array_get;
+void *_nm_jansson_json_array_size;
+void *_nm_jansson_json_array_append_new;
+void *_nm_jansson_json_string;
+void *_nm_jansson_json_object_iter_next;
+void *_nm_jansson_json_loads;
+void *_nm_jansson_json_dumps;
+void *_nm_jansson_json_object_iter_key;
+void *_nm_jansson_json_object;
+void *_nm_jansson_json_object_get;
+void *_nm_jansson_json_array;
+void *_nm_jansson_json_false;
+void *_nm_jansson_json_delete;
+void *_nm_jansson_json_true;
+void *_nm_jansson_json_object_size;
+void *_nm_jansson_json_object_set_new;
+void *_nm_jansson_json_object_iter;
+void *_nm_jansson_json_integer_value;
+void *_nm_jansson_json_string_value;
+
+#define TRY_BIND_SYMBOL(symbol) \
+	G_STMT_START { \
+		void *sym = dlsym (handle, #symbol); \
+		if (_nm_jansson_ ## symbol && sym != _nm_jansson_ ## symbol) \
+			return FALSE; \
+		_nm_jansson_ ## symbol = sym; \
+	} G_STMT_END
+
+static gboolean
+bind_symbols (void *handle)
+{
+	TRY_BIND_SYMBOL (json_object_iter_value);
+	TRY_BIND_SYMBOL (json_object_key_to_iter);
+	TRY_BIND_SYMBOL (json_integer);
+	TRY_BIND_SYMBOL (json_object_del);
+	TRY_BIND_SYMBOL (json_array_get);
+	TRY_BIND_SYMBOL (json_array_size);
+	TRY_BIND_SYMBOL (json_array_append_new);
+	TRY_BIND_SYMBOL (json_string);
+	TRY_BIND_SYMBOL (json_object_iter_next);
+	TRY_BIND_SYMBOL (json_loads);
+	TRY_BIND_SYMBOL (json_dumps);
+	TRY_BIND_SYMBOL (json_object_iter_key);
+	TRY_BIND_SYMBOL (json_object);
+	TRY_BIND_SYMBOL (json_object_get);
+	TRY_BIND_SYMBOL (json_array);
+	TRY_BIND_SYMBOL (json_false);
+	TRY_BIND_SYMBOL (json_delete);
+	TRY_BIND_SYMBOL (json_true);
+	TRY_BIND_SYMBOL (json_object_size);
+	TRY_BIND_SYMBOL (json_object_set_new);
+	TRY_BIND_SYMBOL (json_object_iter);
+	TRY_BIND_SYMBOL (json_integer_value);
+	TRY_BIND_SYMBOL (json_string_value);
+
+	return TRUE;
+}
+
+gboolean
+nm_jansson_load (void)
+{
+	static enum {
+		UNKNOWN,
+		AVAILABLE,
+		MISSING,
+	} state = UNKNOWN;
+	void *handle;
+
+	if (G_LIKELY (state != UNKNOWN))
+		goto out;
+
+	/* First just resolve the symbols to see if there's a conflict already. */
+	if (!bind_symbols (RTLD_DEFAULT))
+		goto out;
+
+	handle = dlopen (JANSSON_SONAME, RTLD_LAZY | RTLD_LOCAL | RTLD_NODELETE | RTLD_DEEPBIND);
+	if (!handle)
+		goto out;
+
+	/* Now do the actual binding. */
+	if (!bind_symbols (handle))
+		goto out;
+
+	state = AVAILABLE;
+out:
+	return state == AVAILABLE;
+}

libnm-core/nm-jansson.h

+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Copyright 2017, 2018 Red Hat, Inc.
+ */
+
+gboolean nm_jansson_load (void);
+
+#ifndef NM_JAONSSON_C
+#define json_object_iter_value	(*_nm_jansson_json_object_iter_value)
+#define json_object_key_to_iter	(*_nm_jansson_json_object_key_to_iter)
+#define json_integer		(*_nm_jansson_json_integer)
+#define json_object_del		(*_nm_jansson_json_object_del)
+#define json_array_get		(*_nm_jansson_json_array_get)
+#define json_array_size		(*_nm_jansson_json_array_size)
+#define json_array_append_new	(*_nm_jansson_json_array_append_new)
+#define json_string		(*_nm_jansson_json_string)
+#define json_object_iter_next	(*_nm_jansson_json_object_iter_next)
+#define json_loads		(*_nm_jansson_json_loads)
+#define json_dumps		(*_nm_jansson_json_dumps)
+#define json_object_iter_key	(*_nm_jansson_json_object_iter_key)
+#define json_object		(*_nm_jansson_json_object)
+#define json_object_get		(*_nm_jansson_json_object_get)
+#define json_array		(*_nm_jansson_json_array)
+#define json_false		(*_nm_jansson_json_false)
+#define json_delete		(*_nm_jansson_json_delete)
+#define json_true		(*_nm_jansson_json_true)
+#define json_object_size	(*_nm_jansson_json_object_size)
+#define json_object_set_new	(*_nm_jansson_json_object_set_new)
+#define json_object_iter	(*_nm_jansson_json_object_iter)
+#define json_integer_value	(*_nm_jansson_json_integer_value)
+#define json_string_value	(*_nm_jansson_json_string_value)
+#endif

libnm-core/nm-utils.c

@@ -35,6 +35,10 @@
 #include <net/if.h>
 #include <linux/pkt_sched.h>
 
+#if WITH_JSON_VALIDATION
+#include "nm-jansson.h"
+#endif
+
 #include "nm-utils/nm-jansson.h"
 #include "nm-utils/nm-enum-utils.h"
 #include "nm-common-macros.h"
@@ -4852,6 +4856,41 @@ const char **nm_utils_enum_get_values (GType type, gint from, gint to)
 
 /*****************************************************************************/
 
+static gboolean
+_nm_utils_is_json_object_no_validation (const char *str, GError **error)
+{
+	if (str) {
+		/* libjansson also requires only utf-8 encoding. */
+		if (!g_utf8_validate (str, -1, NULL)) {
+			g_set_error_literal (error,
+			                     NM_CONNECTION_ERROR,
+			                     NM_CONNECTION_ERROR_INVALID_PROPERTY,
+			                     _("not valid utf-8"));
+			return FALSE;
+		}
+		while (g_ascii_isspace (str[0]))
+			str++;
+	}
+
+	/* do some very basic validation to see if this might be a JSON object. */
+	if (str[0] == '{') {
+		gsize l;
+
+		l = strlen (str) - 1;
+		while (l > 0 && g_ascii_isspace (str[l]))
+			l--;
+
+		if (str[l] == '}')
+			return TRUE;
+	}
+
+	g_set_error_literal (error,
+	                     NM_CONNECTION_ERROR,
+	                     NM_CONNECTION_ERROR_INVALID_PROPERTY,
+	                     _("is not a JSON object"));
+	return FALSE;
+}
+
 #if WITH_JSON_VALIDATION
 
 static void
@@ -5298,6 +5337,9 @@ nm_utils_is_json_object (const char *str, GError **error)
 		return FALSE;
 	}
 
+	if (!nm_jansson_load ())
+		return _nm_utils_is_json_object_no_validation (str, error);
+
 	json = json_loads (str, JSON_REJECT_DUPLICATES, &jerror);
 	if (!json) {
 		g_set_error (error,
@@ -5339,6 +5381,8 @@ _nm_utils_team_config_equal (const char *conf1,
 
 	if (nm_streq0 (conf1, conf2))
 		return TRUE;
+	else if (!nm_jansson_load ())
+		return FALSE;
 
 	/* A NULL configuration is equivalent to default value '{}' */
 	json1 = json_loads (conf1 ?: "{}", JSON_REJECT_DUPLICATES, &jerror);
@@ -5396,6 +5440,9 @@ _nm_utils_team_config_get (const char *conf,
 	if (!key)
 		return NULL;
 
+	if (!nm_jansson_load ())
+		return NULL;
+
 	json = json_loads (conf ?: "{}", JSON_REJECT_DUPLICATES, &jerror);
 
 	/* Invalid json in conf */
@@ -5503,6 +5550,9 @@ _nm_utils_team_config_set (char **conf,
 
 	g_return_val_if_fail (key, FALSE);
 
+	if (!nm_jansson_load ())
+		return FALSE;
+
 	json = json_loads (*conf?: "{}", JSON_REJECT_DUPLICATES, &jerror);
 	if (!json)
 		return FALSE;
@@ -5620,19 +5670,6 @@ nm_utils_is_json_object (const char *str, GError **error)
 {
 	g_return_val_if_fail (!error || !*error, FALSE);
 
-	if (str) {
-		/* libjansson also requires only utf-8 encoding. */
-		if (!g_utf8_validate (str, -1, NULL)) {
-			g_set_error_literal (error,
-			                     NM_CONNECTION_ERROR,
-			                     NM_CONNECTION_ERROR_INVALID_PROPERTY,
-			                     _("not valid utf-8"));
-			return FALSE;
-		}
-		while (g_ascii_isspace (str[0]))
-			str++;
-	}
-
 	if (!str || !str[0]) {
 		g_set_error_literal (error,
 		                     NM_CONNECTION_ERROR,
@@ -5641,23 +5678,7 @@ nm_utils_is_json_object (const char *str, GError **error)
 		return FALSE;
 	}
 
-	/* do some very basic validation to see if this might be a JSON object. */
-	if (str[0] == '{') {
-		gsize l;
-
-		l = strlen (str) - 1;
-		while (l > 0 && g_ascii_isspace (str[l]))
-			l--;
-
-		if (str[l] == '}')
-			return TRUE;
-	}
-
-	g_set_error_literal (error,
-	                     NM_CONNECTION_ERROR,
-	                     NM_CONNECTION_ERROR_INVALID_PROPERTY,
-	                     _("is not a JSON object"));
-	return FALSE;
+	return _nm_utils_is_json_object_no_validation (str, error);
 }
 
 gboolean

meson.build

@@ -179,6 +179,20 @@ libnl_dep = dependency('libnl-3.0', version: '>= 3.2.8', required: false)
 jansson_dep = dependency('jansson', required: false)
 config_h.set10('WITH_JANSSON', jansson_dep.found())
 
+if jansson_dep.found()
+  jansson_libdir = jansson_dep.get_pkgconfig_variable('libdir')
+  readelf = find_program('readelf', 'readelf')
+  res = run_command(readelf, '-d', join_paths(jansson_libdir, 'libjansson.so'))
+  jansson_soname = ''
+  foreach line: res.stdout().split('\n')
+    if line.strip().contains('SONAME')
+       jansson_soname = line.split('[')[1].split(']')[0]
+    endif
+  endforeach
+  assert(jansson_soname != '', 'Unable to determine Jansson SONAME')
+  config_h.set_quoted('JANSSON_SONAME', jansson_soname)
+endif
+
 libsystemd_dep = dependency('libsystemd', version: '>= 209', required: false)
 config_h.set10('HAVE_LIBSYSTEMD', libsystemd_dep.found())