selftests: net: Fix cross-tree inclusion of scripts

When exporting and running a subset of selftests via kselftest, files from
parts of the source tree which were not exported are not available. A few
tests are trying to source such files. Address the problem by using
symlinks.

The problem can be reproduced by running:
make -C tools/testing/selftests gen_tar TARGETS="drivers/net/bonding"
[... extract archive ...]
./run_kselftest.sh

or:
make kselftest KBUILD_OUTPUT=/tmp/kselftests TARGETS="drivers/net/bonding"

Fixes: bbb774d ("net: Add tests for bonding and team address list management")
Fixes: eccd0a8 ("selftests: net: dsa: add a stress test for unlocked FDB operations")
Link: https://lore.kernel.org/netdev/40f04ded-0c86-8669-24b1-9a313ca21076@redhat.com/
Reported-by: Jonathan Toppins <jtoppins@redhat.com>
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Reviewed-by: Jonathan Toppins <jtoppins@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/drivers/net/bonding/Makefile

@@ -7,6 +7,8 @@ TEST_PROGS := \
 	bond-lladdr-target.sh \
 	dev_addr_lists.sh
 
-TEST_FILES := lag_lib.sh
+TEST_FILES := \
+	lag_lib.sh \
+	net_forwarding_lib.sh
 
 include ../../../lib.mk

tools/testing/selftests/drivers/net/bonding/dev_addr_lists.sh

@@ -14,7 +14,7 @@ ALL_TESTS="
 REQUIRE_MZ=no
 NUM_NETIFS=0
 lib_dir=$(dirname "$0")
-source "$lib_dir"/../../../net/forwarding/lib.sh
+source "$lib_dir"/net_forwarding_lib.sh
 
 source "$lib_dir"/lag_lib.sh
 

tools/testing/selftests/drivers/net/bonding/net_forwarding_lib.sh

@@ -0,0 +1 @@
+../../../net/forwarding/lib.sh

tools/testing/selftests/drivers/net/dsa/test_bridge_fdb_stress.sh

@@ -18,8 +18,8 @@ NUM_NETIFS=1
 REQUIRE_JQ="no"
 REQUIRE_MZ="no"
 NETIF_CREATE="no"
-lib_dir=$(dirname $0)/../../../net/forwarding
-source $lib_dir/lib.sh
+lib_dir=$(dirname "$0")
+source "$lib_dir"/lib.sh
 
 cleanup() {
 	echo "Cleaning up"

tools/testing/selftests/drivers/net/team/Makefile

@@ -3,4 +3,8 @@
 
 TEST_PROGS := dev_addr_lists.sh
 
+TEST_FILES := \
+	lag_lib.sh \
+	net_forwarding_lib.sh
+
 include ../../../lib.mk

tools/testing/selftests/drivers/net/team/dev_addr_lists.sh

@@ -11,9 +11,9 @@ ALL_TESTS="
 REQUIRE_MZ=no
 NUM_NETIFS=0
 lib_dir=$(dirname "$0")
-source "$lib_dir"/../../../net/forwarding/lib.sh
+source "$lib_dir"/net_forwarding_lib.sh
 
-source "$lib_dir"/../bonding/lag_lib.sh
+source "$lib_dir"/lag_lib.sh
 
 
 destroy()

tools/testing/selftests/drivers/net/team/lag_lib.sh

@@ -0,0 +1 @@
+../bonding/lag_lib.sh

tools/testing/selftests/drivers/net/team/net_forwarding_lib.sh

@@ -0,0 +1 @@
+../../../net/forwarding/lib.sh

tools/testing/selftests/lib.mk

@@ -70,7 +70,7 @@ endef
 run_tests: all
 ifdef building_out_of_srctree
 	@if [ "X$(TEST_PROGS)$(TEST_PROGS_EXTENDED)$(TEST_FILES)" != "X" ]; then \
-		rsync -aq $(TEST_PROGS) $(TEST_PROGS_EXTENDED) $(TEST_FILES) $(OUTPUT); \
+		rsync -aLq $(TEST_PROGS) $(TEST_PROGS_EXTENDED) $(TEST_FILES) $(OUTPUT); \
 	fi
 	@if [ "X$(TEST_PROGS)" != "X" ]; then \
 		$(call RUN_TESTS, $(TEST_GEN_PROGS) $(TEST_CUSTOM_PROGS) \
@@ -84,7 +84,7 @@ endif
 
 define INSTALL_SINGLE_RULE
 	$(if $(INSTALL_LIST),@mkdir -p $(INSTALL_PATH))
-	$(if $(INSTALL_LIST),rsync -a $(INSTALL_LIST) $(INSTALL_PATH)/)
+	$(if $(INSTALL_LIST),rsync -aL $(INSTALL_LIST) $(INSTALL_PATH)/)
 endef
 
 define INSTALL_RULE