shared,platform: add "shared/nm-platform" library

NetworkManager core is huge. We should try to split out
parts that are independent.

Platform code is already mostly independent. But due to having it
under "src/", there is no strict separation/layering which determines
the parts that can work independently. So, while the code is mostly
independent (in practice), that is not obvious from looking at the
source tree. It thus still contributes to cognitive load.

Add a shared library "shared/nm-platform", which should have no
dependencies on libnm-core or NetworkManager core.

In a first step, move the netlink code there. More should follow.

.gitignore

@@ -135,6 +135,7 @@ test-*.trs
 
 /shared/nm-glib-aux/tests/test-json-aux
 /shared/nm-glib-aux/tests/test-shared-general
+/shared/nm-platform/tests/test-nm-platform
 /shared/nm-version-macros.h
 
 /introspection/org.freedesktop.NetworkManager*.[ch]

Makefile.am

@@ -464,6 +464,59 @@ shared_nm_udev_aux_libnm_udev_aux_la_LIBADD = \
 
 ###############################################################################
 
+noinst_LTLIBRARIES += shared/nm-platform/libnm-platform.la
+
+shared_nm_platform_libnm_platform_la_CPPFLAGS = \
+	$(shared_nm_glib_aux_cppflags) \
+	$(NULL)
+
+shared_nm_platform_libnm_platform_la_SOURCES = \
+	shared/nm-platform/nm-netlink.c \
+	shared/nm-platform/nm-netlink.h \
+	$(NULL)
+
+shared_nm_platform_libnm_platform_la_LDFLAGS = \
+	$(CODE_COVERAGE_LDFLAGS) \
+	$(SANITIZER_LIB_LDFLAGS) \
+	$(NULL)
+
+shared_nm_platform_libnm_platform_la_LIBADD = \
+	$(GLIB_LIBS) \
+	$(NULL)
+
+###############################################################################
+
+check_programs += shared/nm-platform/tests/test-nm-platform
+
+shared_nm_platform_tests_test_nm_platform_CPPFLAGS = \
+	$(dflt_cppflags) \
+	-I$(srcdir)/shared \
+	-DNETWORKMANAGER_COMPILATION_TEST \
+	-DNETWORKMANAGER_COMPILATION='(NM_NETWORKMANAGER_COMPILATION_GLIB|NM_NETWORKMANAGER_COMPILATION_WITH_GLIB_I18N_PROG)' \
+	$(CODE_COVERAGE_CFLAGS) \
+	$(GLIB_CFLAGS) \
+	$(SANITIZER_LIB_CFLAGS) \
+	$(NULL)
+
+shared_nm_platform_tests_test_nm_platform_LDFLAGS = \
+	$(CODE_COVERAGE_LDFLAGS) \
+	$(SANITIZER_EXEC_LDFLAGS) \
+	$(NULL)
+
+shared_nm_platform_tests_test_nm_platform_LDADD = \
+	shared/nm-platform/libnm-platform.la \
+	shared/nm-glib-aux/libnm-glib-aux.la \
+	shared/nm-std-aux/libnm-std-aux.la \
+	shared/libcsiphash.la \
+	$(GLIB_LIBS) \
+	$(NULL)
+
+EXTRA_DIST += \
+	shared/nm-platform/tests/meson.build \
+	$(NULL)
+
+###############################################################################
+
 noinst_LTLIBRARIES += libnm-core/nm-libnm-core-intern/libnm-libnm-core-intern.la
 
 libnm_core_nm_libnm_core_intern_libnm_libnm_core_intern_la_CPPFLAGS = \
@@ -2121,9 +2174,6 @@ src_libNetworkManagerBase_la_SOURCES = \
 	src/NetworkManagerUtils.c \
 	src/NetworkManagerUtils.h \
 	\
-	src/platform/nm-netlink.c \
-	src/platform/nm-netlink.h \
-	\
 	src/platform/nmp-netns.c \
 	src/platform/nmp-netns.h \
 	src/platform/nmp-object.c \
@@ -2392,6 +2442,7 @@ src_libNetworkManager_la_LIBADD = \
 	libnm-core/libnm-core.la \
 	$(libnm_crypto_lib) \
 	libnm-core/nm-libnm-core-intern/libnm-libnm-core-intern.la \
+	shared/nm-platform/libnm-platform.la \
 	shared/nm-udev-aux/libnm-udev-aux.la \
 	shared/nm-glib-aux/libnm-glib-aux.la \
 	shared/nm-std-aux/libnm-std-aux.la \
@@ -2503,6 +2554,7 @@ src_nm_iface_helper_LDADD = \
 	libnm-core/libnm-core.la \
 	$(libnm_crypto_lib) \
 	libnm-core/nm-libnm-core-intern/libnm-libnm-core-intern.la \
+	shared/nm-platform/libnm-platform.la \
 	shared/nm-udev-aux/libnm-udev-aux.la \
 	shared/nm-glib-aux/libnm-glib-aux.la \
 	shared/nm-std-aux/libnm-std-aux.la \
@@ -2555,6 +2607,7 @@ src_initrd_nm_initrd_generator_LDADD = \
 	libnm-core/libnm-core.la \
 	$(libnm_crypto_lib) \
 	libnm-core/nm-libnm-core-intern/libnm-libnm-core-intern.la \
+	shared/nm-platform/libnm-platform.la \
 	shared/nm-udev-aux/libnm-udev-aux.la \
 	shared/nm-glib-aux/libnm-glib-aux.la \
 	shared/nm-std-aux/libnm-std-aux.la \

shared/meson.build

@@ -182,6 +182,28 @@ libnm_udev_aux_dep = declare_dependency(
   link_with: libnm_udev_aux,
 )
 
+libnm_platform = static_library(
+  'nm-platform',
+  sources: [
+    'nm-platform/nm-netlink.c',
+  ],
+  dependencies: [
+    glib_nm_default_dep,
+  ],
+  c_args: [
+    '-DG_LOG_DOMAIN="NetworkManager"',
+    '-DNETWORKMANAGER_COMPILATION=(NM_NETWORKMANAGER_COMPILATION_GLIB|NM_NETWORKMANAGER_COMPILATION_WITH_GLIB_I18N_LIB)',
+  ],
+)
+
+libnm_platform_dep = declare_dependency(
+  include_directories: shared_inc,
+  dependencies: [
+    libnm_utils_base_dep,
+  ],
+  link_with: libnm_platform,
+)
+
 sources = files(
   'systemd/nm-sd-utils-shared.c',
   'systemd/src/basic/alloc-util.c',
@@ -257,4 +279,5 @@ libnm_systemd_logging_stub = static_library(
 
 if enable_tests
   subdir('nm-glib-aux/tests')
+  subdir('nm-platform/tests')
 endif

shared/nm-platform/tests/meson.build

@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+exe = executable(
+  'test-nm-platform',
+  'test-nm-platform.c',
+  c_args: [
+    '-DNETWORKMANAGER_COMPILATION_TEST',
+    '-DNETWORKMANAGER_COMPILATION=(NM_NETWORKMANAGER_COMPILATION_GLIB|NM_NETWORKMANAGER_COMPILATION_WITH_GLIB_I18N_PROG)',
+  ],
+  dependencies: libnm_platform_dep,
+  link_with: libnm_systemd_logging_stub,
+)
+
+test(
+  'shared/nm-glib-aux/test-nm-platform',
+  test_script,
+  args: test_args + [exe.full_path()],
+  timeout: default_test_timeout,
+)

shared/nm-platform/tests/test-nm-platform.c

@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#define NM_TEST_UTILS_NO_LIBNM 1
+
+#include "nm-default.h"
+
+#include "nm-platform/nm-netlink.h"
+
+#include "nm-utils/nm-test-utils.h"
+
+/*****************************************************************************/
+
+static void
+test_use_symbols(void)
+{
+    static void (*const SYMBOLS[])(void) = {
+        (void (*)(void)) nl_nlmsghdr_to_str,
+        (void (*)(void)) nlmsg_hdr,
+        (void (*)(void)) nlmsg_reserve,
+        (void (*)(void)) nla_reserve,
+        (void (*)(void)) nlmsg_alloc_size,
+        (void (*)(void)) nlmsg_alloc,
+        (void (*)(void)) nlmsg_alloc_convert,
+        (void (*)(void)) nlmsg_alloc_simple,
+        (void (*)(void)) nlmsg_free,
+        (void (*)(void)) nlmsg_append,
+        (void (*)(void)) nlmsg_parse,
+        (void (*)(void)) nlmsg_put,
+        (void (*)(void)) nla_strlcpy,
+        (void (*)(void)) nla_memcpy,
+        (void (*)(void)) nla_put,
+        (void (*)(void)) nla_find,
+        (void (*)(void)) nla_nest_cancel,
+        (void (*)(void)) nla_nest_start,
+        (void (*)(void)) nla_nest_end,
+        (void (*)(void)) nla_parse,
+        (void (*)(void)) nlmsg_get_proto,
+        (void (*)(void)) nlmsg_set_proto,
+        (void (*)(void)) nlmsg_set_src,
+        (void (*)(void)) nlmsg_get_creds,
+        (void (*)(void)) nlmsg_set_creds,
+        (void (*)(void)) genlmsg_put,
+        (void (*)(void)) genlmsg_data,
+        (void (*)(void)) genlmsg_user_hdr,
+        (void (*)(void)) genlmsg_hdr,
+        (void (*)(void)) genlmsg_user_data,
+        (void (*)(void)) genlmsg_attrdata,
+        (void (*)(void)) genlmsg_len,
+        (void (*)(void)) genlmsg_attrlen,
+        (void (*)(void)) genlmsg_valid_hdr,
+        (void (*)(void)) genlmsg_parse,
+        (void (*)(void)) genl_ctrl_resolve,
+        (void (*)(void)) nl_socket_alloc,
+        (void (*)(void)) nl_socket_free,
+        (void (*)(void)) nl_socket_get_fd,
+        (void (*)(void)) nl_socket_get_local_port,
+        (void (*)(void)) nl_socket_get_msg_buf_size,
+        (void (*)(void)) nl_socket_set_passcred,
+        (void (*)(void)) nl_socket_set_msg_buf_size,
+        (void (*)(void)) nlmsg_get_dst,
+        (void (*)(void)) nl_socket_set_nonblocking,
+        (void (*)(void)) nl_socket_set_buffer_size,
+        (void (*)(void)) nl_socket_add_memberships,
+        (void (*)(void)) nl_socket_set_ext_ack,
+        (void (*)(void)) nl_socket_disable_msg_peek,
+        (void (*)(void)) nl_connect,
+        (void (*)(void)) nl_wait_for_ack,
+        (void (*)(void)) nl_recvmsgs,
+        (void (*)(void)) nl_sendmsg,
+        (void (*)(void)) nl_send_iovec,
+        (void (*)(void)) nl_complete_msg,
+        (void (*)(void)) nl_send,
+        (void (*)(void)) nl_send_auto,
+        (void (*)(void)) nl_recv,
+        NULL,
+    };
+
+    /* The only (not very exciting) purpose of this test is to see that
+     * we can use various symbols and don't get a linker error. */
+    assert(G_N_ELEMENTS(SYMBOLS) == NM_PTRARRAY_LEN(SYMBOLS) + 1);
+}
+
+/*****************************************************************************/
+
+NMTST_DEFINE();
+
+int
+main(int argc, char **argv)
+{
+    nmtst_init(&argc, &argv, TRUE);
+
+    g_test_add_func("/nm-platform/test_use_symbols", test_use_symbols);
+
+    return g_test_run();
+}

src/meson.build

@@ -5,7 +5,10 @@ src_inc = include_directories('.')
 daemon_nm_default_dep = declare_dependency(
   sources: libnm_core_enum_sources[1],
   include_directories: src_inc,
-  dependencies: libnm_core_nm_default_dep,
+  dependencies: [
+    libnm_core_nm_default_dep,
+    libnm_platform_dep,
+  ],
 )
 
 install_data(
@@ -28,7 +31,6 @@ sources = files(
   'dhcp/nm-dhcp-options.c',
   'ndisc/nm-lndp-ndisc.c',
   'ndisc/nm-ndisc.c',
-  'platform/nm-netlink.c',
   'platform/wifi/nm-wifi-utils-nl80211.c',
   'platform/wifi/nm-wifi-utils.c',
   'platform/wpan/nm-wpan-utils.c',

src/platform/nm-linux-platform.c

@@ -40,7 +40,7 @@
 
 #include "nm-glib-aux/nm-secret-utils.h"
 #include "nm-glib-aux/nm-c-list.h"
-#include "nm-netlink.h"
+#include "nm-platform/nm-netlink.h"
 #include "nm-core-utils.h"
 #include "nmp-object.h"
 #include "nmp-netns.h"

src/platform/wifi/nm-wifi-utils-nl80211.c

@@ -15,7 +15,7 @@
 #include <linux/nl80211.h>
 #include <linux/if.h>
 
-#include "platform/nm-netlink.h"
+#include "nm-platform/nm-netlink.h"
 #include "nm-wifi-utils-private.h"
 #include "platform/nm-platform.h"
 #include "platform/nm-platform-utils.h"

src/platform/wifi/nm-wifi-utils-nl80211.h

@@ -8,7 +8,7 @@
 #define __WIFI_UTILS_NL80211_H__
 
 #include "nm-wifi-utils.h"
-#include "platform/nm-netlink.h"
+#include "nm-platform/nm-netlink.h"
 
 #define NM_TYPE_WIFI_UTILS_NL80211 (nm_wifi_utils_nl80211_get_type())
 #define NM_WIFI_UTILS_NL80211(obj) \

src/platform/wifi/nm-wifi-utils.h

@@ -11,7 +11,7 @@
 
 #include "nm-dbus-interface.h"
 #include "nm-setting-wireless.h"
-#include "platform/nm-netlink.h"
+#include "nm-platform/nm-netlink.h"
 
 typedef struct NMWifiUtils NMWifiUtils;
 

src/platform/wpan/nm-wpan-utils.c

@@ -9,8 +9,8 @@
 
 #include <linux/if.h>
 
+#include "nm-platform/nm-netlink.h"
 #include "platform/linux/nl802154.h"
-#include "platform/nm-netlink.h"
 #include "platform/nm-platform-utils.h"
 
 #define _NMLOG_PREFIX_NAME "wpan-nl802154"

src/platform/wpan/nm-wpan-utils.h

@@ -9,7 +9,7 @@
 #include <net/ethernet.h>
 
 #include "nm-dbus-interface.h"
-#include "platform/nm-netlink.h"
+#include "nm-platform/nm-netlink.h"
 
 typedef struct NMWpanUtils NMWpanUtils;