gbmc /
linux /
4039ce7ef40474d5ba46f414c50cc7020b9cf8ae netfilter: nf_tables: Introduce NFTA_DEVICE_PREFIX
This new attribute is supposed to be used instead of NFTA_DEVICE_NAME
for simple wildcard interface specs. It holds a NUL-terminated string
representing an interface name prefix to match on.
While kernel code to distinguish full names from prefixes in
NFTA_DEVICE_NAME is simpler than this solution, reusing the existing
attribute with different semantics leads to confusion between different
versions of kernel and user space though:
* With old kernels, wildcards submitted by user space are accepted yet
silently treated as regular names.
* With old user space, wildcards submitted by kernel may cause crashes
since libnftnl expects NUL-termination when there is none.
Using a distinct attribute type sanitizes these situations as the
receiving part detects and rejects the unexpected attribute nested in
*_HOOK_DEVS attributes.
Fixes: 6d07a289504a ("netfilter: nf_tables: Support wildcard netdev hook specs")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
2 files changed
