===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/PROTOCOL,v
retrieving revision 1.39
retrieving revision 1.40
diff -u -r1.39 -r1.40
--- src/usr.bin/ssh/PROTOCOL	2021/02/12 03:49:09	1.39
+++ src/usr.bin/ssh/PROTOCOL	2021/02/18 00:30:17	1.40
@@ -481,6 +481,49 @@
 This extension is advertised in the SSH_FXP_VERSION hello with version
 "1".
 
+3.8. sftp: Extension request "limits@openssh.com"
+
+This request is used to determine various limits the server might impose.
+Clients should not attempt to exceed these limits as the server might sever
+the connection immediately.
+
+	uint32		id
+	string		"limits@openssh.com"
+
+The server will respond with a SSH_FXP_EXTENDED_REPLY reply:
+
+	uint32		id
+	uint64		max-packet-length
+	uint64		max-read-length
+	uint64		max-write-length
+	uint64		max-open-handles
+
+The 'max-packet-length' applies to the total number of bytes in a
+single SFTP packet.  Servers SHOULD set this at least to 34000.
+
+The 'max-read-length' is the largest length in a SSH_FXP_READ packet.
+Even if the client requests a larger size, servers will usually respond
+with a shorter SSH_FXP_DATA packet.  Servers SHOULD set this at least to
+32768.
+
+The 'max-write-length' is the largest length in a SSH_FXP_WRITE packet
+the server will accept.  Servers SHOULD set this at least to 32768.
+
+The 'max-open-handles' is the maximum number of active handles that the
+server allows (e.g. handles created by SSH_FXP_OPEN and SSH_FXP_OPENDIR
+packets).  Servers MAY count internal file handles against this limit
+(e.g. system logging or stdout/stderr), so clients SHOULD NOT expect to
+open this many handles in practice.
+
+If the server doesn't enforce a specific limit, then the field may be
+set to 0.  This implies the server relies on the OS to enforce limits
+(e.g. available memory or file handles), and such limits might be
+dynamic.  The client SHOULD take care to not try to exceed reasonable
+limits.
+
+This extension is advertised in the SSH_FXP_VERSION hello with version
+"1".
+
 4. Miscellaneous changes
 
 4.1 Public key format
@@ -512,4 +555,4 @@
 PROTOCOL.mux over a Unix domain socket for communications between a
 master instance and later clients.
 
-$OpenBSD: PROTOCOL,v 1.39 2021/02/12 03:49:09 djm Exp $
+$OpenBSD: PROTOCOL,v 1.40 2021/02/18 00:30:17 djm Exp $