docs: networking: convert ipsec.txt to ReST

Not much to be done here:

- add SPDX header;
- add a document title;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.

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

diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
index 505eaa41ca2baa7b4f1dcf2c63b79df287c64c70..3efb4608649a03cc6404401de3128b5ec6c87693 100644 (file)
--- a/Documentation/networking/index.rst
+++ b/Documentation/networking/index.rst
@@ -68,6 +68,7 @@ Contents:
    ipddp
    ip_dynaddr
    iphase
+   ipsec
 
 .. only::  subproject and html
 

diff --git a/Documentation/networking/ipsec.rst b/Documentation/networking/ipsec.rst
new file mode 100644 (file)
index 0000000..afe9d7b
--- /dev/null
+++ b/Documentation/networking/ipsec.rst
@@ -0,0 +1,46 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====
+IPsec
+=====
+
+
+Here documents known IPsec corner cases which need to be keep in mind when
+deploy various IPsec configuration in real world production environment.
+
+1. IPcomp:
+          Small IP packet won't get compressed at sender, and failed on
+          policy check on receiver.
+
+Quote from RFC3173::
+
+  2.2. Non-Expansion Policy
+
+   If the total size of a compressed payload and the IPComp header, as
+   defined in section 3, is not smaller than the size of the original
+   payload, the IP datagram MUST be sent in the original non-compressed
+   form.  To clarify: If an IP datagram is sent non-compressed, no
+
+   IPComp header is added to the datagram.  This policy ensures saving
+   the decompression processing cycles and avoiding incurring IP
+   datagram fragmentation when the expanded datagram is larger than the
+   MTU.
+
+   Small IP datagrams are likely to expand as a result of compression.
+   Therefore, a numeric threshold should be applied before compression,
+   where IP datagrams of size smaller than the threshold are sent in the
+   original form without attempting compression.  The numeric threshold
+   is implementation dependent.
+
+Current IPComp implementation is indeed by the book, while as in practice
+when sending non-compressed packet to the peer (whether or not packet len
+is smaller than the threshold or the compressed len is larger than original
+packet len), the packet is dropped when checking the policy as this packet
+matches the selector but not coming from any XFRM layer, i.e., with no
+security path. Such naked packet will not eventually make it to upper layer.
+The result is much more wired to the user when ping peer with different
+payload length.
+
+One workaround is try to set "level use" for each policy if user observed
+above scenario. The consequence of doing so is small packet(uncompressed)
+will skip policy checking on receiver side.

diff --git a/Documentation/networking/ipsec.txt b/Documentation/networking/ipsec.txt
deleted file mode 100644 (file)
index ba794b7..0000000
--- a/Documentation/networking/ipsec.txt
+++ /dev/null
@@ -1,38 +0,0 @@
-
-Here documents known IPsec corner cases which need to be keep in mind when
-deploy various IPsec configuration in real world production environment.
-
-1. IPcomp: Small IP packet won't get compressed at sender, and failed on
-          policy check on receiver.
-
-Quote from RFC3173:
-2.2. Non-Expansion Policy
-
-   If the total size of a compressed payload and the IPComp header, as
-   defined in section 3, is not smaller than the size of the original
-   payload, the IP datagram MUST be sent in the original non-compressed
-   form.  To clarify: If an IP datagram is sent non-compressed, no
-
-   IPComp header is added to the datagram.  This policy ensures saving
-   the decompression processing cycles and avoiding incurring IP
-   datagram fragmentation when the expanded datagram is larger than the
-   MTU.
-
-   Small IP datagrams are likely to expand as a result of compression.
-   Therefore, a numeric threshold should be applied before compression,
-   where IP datagrams of size smaller than the threshold are sent in the
-   original form without attempting compression.  The numeric threshold
-   is implementation dependent.
-
-Current IPComp implementation is indeed by the book, while as in practice
-when sending non-compressed packet to the peer (whether or not packet len
-is smaller than the threshold or the compressed len is larger than original
-packet len), the packet is dropped when checking the policy as this packet
-matches the selector but not coming from any XFRM layer, i.e., with no
-security path. Such naked packet will not eventually make it to upper layer.
-The result is much more wired to the user when ping peer with different
-payload length.
-
-One workaround is try to set "level use" for each policy if user observed
-above scenario. The consequence of doing so is small packet(uncompressed)
-will skip policy checking on receiver side.