docs: networking: convert xfrm_proc.txt to ReST

- add SPDX header;
- adjust title markup;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 113 insertions, 0 deletions

diff --git a/Documentation/networking/xfrm_proc.rst b/Documentation/networking/xfrm_proc.rst
new file mode 100644
index 000000000000..0a771c5a7399
--- /dev/null
+++ b/Documentation/networking/xfrm_proc.rst
@@ -0,0 +1,113 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==================================
+XFRM proc - /proc/net/xfrm_* files
+==================================
+
+Masahide NAKAMURA <nakam@linux-ipv6.org>
+
+
+Transformation Statistics
+-------------------------
+
+The xfrm_proc code is a set of statistics showing numbers of packets
+dropped by the transformation code and why.  These counters are defined
+as part of the linux private MIB.  These counters can be viewed in
+/proc/net/xfrm_stat.
+
+
+Inbound errors
+~~~~~~~~~~~~~~
+
+XfrmInError:
+	All errors which is not matched others
+
+XfrmInBufferError:
+	No buffer is left
+
+XfrmInHdrError:
+	Header error
+
+XfrmInNoStates:
+	No state is found
+	i.e. Either inbound SPI, address, or IPsec protocol at SA is wrong
+
+XfrmInStateProtoError:
+	Transformation protocol specific error
+	e.g. SA key is wrong
+
+XfrmInStateModeError:
+	Transformation mode specific error
+
+XfrmInStateSeqError:
+	Sequence error
+	i.e. Sequence number is out of window
+
+XfrmInStateExpired:
+	State is expired
+
+XfrmInStateMismatch:
+	State has mismatch option
+	e.g. UDP encapsulation type is mismatch
+
+XfrmInStateInvalid:
+	State is invalid
+
+XfrmInTmplMismatch:
+	No matching template for states
+	e.g. Inbound SAs are correct but SP rule is wrong
+
+XfrmInNoPols:
+	No policy is found for states
+	e.g. Inbound SAs are correct but no SP is found
+
+XfrmInPolBlock:
+	Policy discards
+
+XfrmInPolError:
+	Policy error
+
+XfrmAcquireError:
+	State hasn't been fully acquired before use
+
+XfrmFwdHdrError:
+	Forward routing of a packet is not allowed
+
+Outbound errors
+~~~~~~~~~~~~~~~
+XfrmOutError:
+	All errors which is not matched others
+
+XfrmOutBundleGenError:
+	Bundle generation error
+
+XfrmOutBundleCheckError:
+	Bundle check error
+
+XfrmOutNoStates:
+	No state is found
+
+XfrmOutStateProtoError:
+	Transformation protocol specific error
+
+XfrmOutStateModeError:
+	Transformation mode specific error
+
+XfrmOutStateSeqError:
+	Sequence error
+	i.e. Sequence number overflow
+
+XfrmOutStateExpired:
+	State is expired
+
+XfrmOutPolBlock:
+	Policy discards
+
+XfrmOutPolDead:
+	Policy is dead
+
+XfrmOutPolError:
+	Policy error
+
+XfrmOutStateInvalid:
+	State is invalid, perhaps expired