[ Upstream commit a287f5b0cf ]
This change adds methods in the XFRM-I input path that ensures that
policies are checked prior to processing of the subsequent decapsulated
packet, after which the relevant policies may no longer be resolvable
(due to changing src/dst/proto/etc).
Notably, raw ESP/AH packets did not perform policy checks inherently,
whereas all other encapsulated packets (UDP, TCP encapsulated) do policy
checks after calling xfrm_input handling in the respective encapsulation
layer.
Fixes: b0355dbbf1 ("Fix XFRM-I support for nested ESP tunnels")
Test: Verified with additional Android Kernel Unit tests
Test: Verified against Android CTS
Signed-off-by: Benedict Wong <benedictwong@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5fc46f9421 ]
This reverts commit b0355dbbf1.
The reverted commit clears the secpath on packets received via xfrm interfaces
to support nested IPsec tunnels. This breaks Netfilter policy matching using
xt_policy in the FORWARD chain, as the secpath is missing during forwarding.
Additionally, Benedict Wong reports that it breaks Transport-in-Tunnel mode.
Fix this regression by reverting the commit until we have a better approach
for nested IPsec tunnels.
Fixes: b0355dbbf1 ("Fix XFRM-I support for nested ESP tunnels")
Link: https://lore.kernel.org/netdev/20230412085615.124791-1-martin@strongswan.org/
Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This change adds support for nested IPsec tunnels by ensuring that
XFRM-I verifies existing policies before decapsulating a subsequent
policies. Addtionally, this clears the secpath entries after policies
are verified, ensuring that previous tunnels with no-longer-valid
do not pollute subsequent policy checks.
This is necessary especially for nested tunnels, as the IP addresses,
protocol and ports may all change, thus not matching the previous
policies. In order to ensure that packets match the relevant inbound
templates, the xfrm_policy_check should be done before handing off to
the inner XFRM protocol to decrypt and decapsulate.
Notably, raw ESP/AH packets did not perform policy checks inherently,
whereas all other encapsulated packets (UDP, TCP encapsulated) do policy
checks after calling xfrm_input handling in the respective encapsulation
layer.
Test: Verified with additional Android Kernel Unit tests
Signed-off-by: Benedict Wong <benedictwong@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
This change adds xfrm metadata helpers using the unstable kfunc call
interface for the TC-BPF hooks. This allows steering traffic towards
different IPsec connections based on logic implemented in bpf programs.
This object is built based on the availability of BTF debug info.
When setting the xfrm metadata, percpu metadata dsts are used in order
to avoid allocating a metadata dst per packet.
In order to guarantee safe module unload, the percpu dsts are allocated
on first use and never freed. The percpu pointer is stored in
net/core/filter.c so that it can be reused on module reload.
The metadata percpu dsts take ownership of the original skb dsts so
that they may be used as part of the xfrm transmission logic - e.g.
for MTU calculations.
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Link: https://lore.kernel.org/r/20221203084659.1837829-3-eyal.birger@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
