[RFC PATCH net-next 03/10] selftests: forwarding: Import top-level lib.sh through absolute path

[Benjamin Poirier <bpoirier@nvidia.com>]

From: Petr Machata <petrm@nvidia.com>

The commit cited below moved code from net/forwarding/lib.sh to net/lib.sh,
and had the former source the latter. This causes issues with selftests
from directories other than net/forwarding/, in particular drivers/net/...
For those files, the line "source ../lib.sh" would look for lib.sh in the
directory above the script file's one, which is incorrect.

Instead, use $BASH_SOURCE and dirname to determine which directory the
forwarding/lib.sh resides in, and use that to find net/lib.sh.

Some selftests (namely drivers/net/bonding) use a symbolic link to
forwarding/lib.sh, and source that instead. Therefore pass $BASH_SOURCE
through readlink to resolve to the ultimate file.

Fixes: 25ae948b4478 ("selftests/net: add lib.sh")
Suggested-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
---
 tools/testing/selftests/net/forwarding/lib.sh | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/forwarding/lib.sh b/tools/testing/selftests/net/forwarding/lib.sh
index e3740163c384..f9e32152f23d 100644
--- a/tools/testing/selftests/net/forwarding/lib.sh
+++ b/tools/testing/selftests/net/forwarding/lib.sh
@@ -38,7 +38,9 @@ if [[ -f $relative_path/forwarding.config ]]; then
 	source "$relative_path/forwarding.config"
 fi
 
-source ../lib.sh
+libdir=$(dirname "$(readlink -f "${BASH_SOURCE[0]}")")
+source "$libdir"/../lib.sh
+
 ##############################################################################
 # Sanity checks
 
-- 
2.43.0