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authorDaniel W. S. Almeida <dwlsalmeida@gmail.com>2020-01-29 05:49:15 +0100
committerJonathan Corbet <corbet@lwn.net>2020-02-13 19:21:28 +0100
commit250baf06aacf4eafb5641c86c91f2b1df4cf7d86 (patch)
tree235db597735c1d68f2a4ef4f897190b97d83878c /Documentation/filesystems/nfs
parentDocumentation: nfs: rpc-cache: convert to ReST (diff)
downloadlinux-250baf06aacf4eafb5641c86c91f2b1df4cf7d86.tar.xz
linux-250baf06aacf4eafb5641c86c91f2b1df4cf7d86.zip
Documentation: nfs: rpc-server-gss: convert to ReST
Convert rpc-server-gss.txt to ReST. Content remains mostly unchanged. Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com> Link: https://lore.kernel.org/r/20200129044917.566906-4-dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/filesystems/nfs')
-rw-r--r--Documentation/filesystems/nfs/index.rst1
-rw-r--r--Documentation/filesystems/nfs/rpc-server-gss.rst (renamed from Documentation/filesystems/nfs/rpc-server-gss.txt)19
2 files changed, 12 insertions, 8 deletions
diff --git a/Documentation/filesystems/nfs/index.rst b/Documentation/filesystems/nfs/index.rst
index 52f4956e7770..9d5365cbe2c3 100644
--- a/Documentation/filesystems/nfs/index.rst
+++ b/Documentation/filesystems/nfs/index.rst
@@ -8,3 +8,4 @@ NFS
pnfs
rpc-cache
+ rpc-server-gss
diff --git a/Documentation/filesystems/nfs/rpc-server-gss.txt b/Documentation/filesystems/nfs/rpc-server-gss.rst
index 310bbbaf9080..812754576845 100644
--- a/Documentation/filesystems/nfs/rpc-server-gss.txt
+++ b/Documentation/filesystems/nfs/rpc-server-gss.rst
@@ -1,4 +1,4 @@
-
+=========================================
rpcsec_gss support for kernel RPC servers
=========================================
@@ -9,14 +9,17 @@ NFSv4.1 and higher don't require the client to act as a server for the
purposes of authentication.)
RPCGSS is specified in a few IETF documents:
+
- RFC2203 v1: http://tools.ietf.org/rfc/rfc2203.txt
- RFC5403 v2: http://tools.ietf.org/rfc/rfc5403.txt
+
and there is a 3rd version being proposed:
+
- http://tools.ietf.org/id/draft-williams-rpcsecgssv3.txt
(At draft n. 02 at the time of writing)
Background
-----------
+==========
The RPCGSS Authentication method describes a way to perform GSSAPI
Authentication for NFS. Although GSSAPI is itself completely mechanism
@@ -29,6 +32,7 @@ depends on GSSAPI extensions that are KRB5 specific.
GSSAPI is a complex library, and implementing it completely in kernel is
unwarranted. However GSSAPI operations are fundementally separable in 2
parts:
+
- initial context establishment
- integrity/privacy protection (signing and encrypting of individual
packets)
@@ -41,7 +45,7 @@ kernel, but leave the initial context establishment to userspace. We
need upcalls to request userspace to perform context establishment.
NFS Server Legacy Upcall Mechanism
-----------------------------------
+==================================
The classic upcall mechanism uses a custom text based upcall mechanism
to talk to a custom daemon called rpc.svcgssd that is provide by the
@@ -62,21 +66,20 @@ groups) due to limitation on the size of the buffer that can be send
back to the kernel (4KiB).
NFS Server New RPC Upcall Mechanism
------------------------------------
+===================================
The newer upcall mechanism uses RPC over a unix socket to a daemon
called gss-proxy, implemented by a userspace program called Gssproxy.
-The gss_proxy RPC protocol is currently documented here:
-
- https://fedorahosted.org/gss-proxy/wiki/ProtocolDocumentation
+The gss_proxy RPC protocol is currently documented `here
+<https://fedorahosted.org/gss-proxy/wiki/ProtocolDocumentation>`_.
This upcall mechanism uses the kernel rpc client and connects to the gssproxy
userspace program over a regular unix socket. The gssproxy protocol does not
suffer from the size limitations of the legacy protocol.
Negotiating Upcall Mechanisms
------------------------------
+=============================
To provide backward compatibility, the kernel defaults to using the
legacy mechanism. To switch to the new mechanism, gss-proxy must bind