svn commit: r331674 - user/markj/netdump/share/man/man4

[Mark Johnston]

Author: markj
Date: Wed Mar 28 14:29:34 2018
New Revision: 331674
URL: https://svnweb.freebsd.org/changeset/base/331674

Log:
  Add a rough description of the protocol.

Modified:
  user/markj/netdump/share/man/man4/netdump.4

Modified: user/markj/netdump/share/man/man4/netdump.4
==============================================================================
--- user/markj/netdump/share/man/man4/netdump.4	Wed Mar 28 14:01:26 2018	(r331673)
+++ user/markj/netdump/share/man/man4/netdump.4	Wed Mar 28 14:29:34 2018	(r331674)
@@ -25,8 +25,8 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 6, 2018
-.Dt netdump 4
+.Dd March 27, 2018
+.Dt NETDUMP 4
 .Os
 .Sh NAME
 .Nm netdump
@@ -54,6 +54,54 @@ clients are configured using the
 .Xr dumpon 8
 utility.
 .Pp
+.Nm
+client messages consist of a fixed-size header followed by a variable-sized
+payload.
+The header contains the message type, a sequence number, the offset of
+the payload data in the kernel dump, and the length of the payload data
+(not including the header).
+The message types are
+.Dv HERALD , FINISHED , KDH , VMCORE ,
+and
+.Dv EKCD_KEY .
+.Nm
+server messages have a fixed size and contain only the sequence number of
+the client message.
+These messages indicate that the server has successfully processed the
+client message with the corresponding sequence number.
+All client messages are acknowledged this way.
+Server messages are always sent to port 20024 of the client.
+.Pp
+To initiate a
+.Nm ,
+the client sends a
+.Dv HERALD
+message to the server at port 20023.
+The client may include a relative path in its payload, in which case the
+.Nm
+server should attempt to save the dump at that path relative to its configured
+dump directory.
+The server will acknowledge the
+.Dv HERALD
+using a random source port, and the client must send all subsequent messages
+to that port.
+.Pp
+The
+.Dv KDH , VMCORE ,
+and
+.Dv EKCD_KEY
+message payloads contain the kernel dump header, dump contents, and
+dump encryption key respectively.
+The offset in the message header should be treated as a seek offset
+in the corresponding file.
+There are no ordering requirements for these messages.
+.Pp
+A
+.Nm
+is completed by sending the
+.Dv FINISHED
+message to the server.
+.Pp
 The following network drivers support netdump:
 .Xr alc 4 ,
 .Xr bge 4 ,
@@ -63,7 +111,9 @@ The following network drivers support netdump:
 .Xr re 4 ,
 .Xr vtnet 4 .
 .Sh SEE ALSO
-.Xr dumpon 8
+.Xr decryptcore 8 ,
+.Xr dumpon 8 ,
+.Xr savecore 8
 .Sh HISTORY
 .Nm
 client support first appeared in