v4.19.13 snapshot.
diff --git a/net/rxrpc/protocol.h b/net/rxrpc/protocol.h
new file mode 100644
index 0000000..f9cb83c
--- /dev/null
+++ b/net/rxrpc/protocol.h
@@ -0,0 +1,181 @@
+/* packet.h: Rx packet layout and definitions
+ *
+ * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_RXRPC_PACKET_H
+#define _LINUX_RXRPC_PACKET_H
+
+typedef u32 rxrpc_seq_t; /* Rx message sequence number */
+typedef u32 rxrpc_serial_t; /* Rx message serial number */
+typedef __be32 rxrpc_seq_net_t; /* on-the-wire Rx message sequence number */
+typedef __be32 rxrpc_serial_net_t; /* on-the-wire Rx message serial number */
+
+/*****************************************************************************/
+/*
+ * on-the-wire Rx packet header
+ * - all multibyte fields should be in network byte order
+ */
+struct rxrpc_wire_header {
+ __be32 epoch; /* client boot timestamp */
+#define RXRPC_RANDOM_EPOCH 0x80000000 /* Random if set, date-based if not */
+
+ __be32 cid; /* connection and channel ID */
+#define RXRPC_MAXCALLS 4 /* max active calls per conn */
+#define RXRPC_CHANNELMASK (RXRPC_MAXCALLS-1) /* mask for channel ID */
+#define RXRPC_CIDMASK (~RXRPC_CHANNELMASK) /* mask for connection ID */
+#define RXRPC_CIDSHIFT ilog2(RXRPC_MAXCALLS) /* shift for connection ID */
+#define RXRPC_CID_INC (1 << RXRPC_CIDSHIFT) /* connection ID increment */
+
+ __be32 callNumber; /* call ID (0 for connection-level packets) */
+ __be32 seq; /* sequence number of pkt in call stream */
+ __be32 serial; /* serial number of pkt sent to network */
+
+ uint8_t type; /* packet type */
+#define RXRPC_PACKET_TYPE_DATA 1 /* data */
+#define RXRPC_PACKET_TYPE_ACK 2 /* ACK */
+#define RXRPC_PACKET_TYPE_BUSY 3 /* call reject */
+#define RXRPC_PACKET_TYPE_ABORT 4 /* call/connection abort */
+#define RXRPC_PACKET_TYPE_ACKALL 5 /* ACK all outstanding packets on call */
+#define RXRPC_PACKET_TYPE_CHALLENGE 6 /* connection security challenge (SRVR->CLNT) */
+#define RXRPC_PACKET_TYPE_RESPONSE 7 /* connection secutity response (CLNT->SRVR) */
+#define RXRPC_PACKET_TYPE_DEBUG 8 /* debug info request */
+#define RXRPC_PACKET_TYPE_PARAMS 9 /* Parameter negotiation (unspec'd, ignore) */
+#define RXRPC_PACKET_TYPE_10 10 /* Ignored */
+#define RXRPC_PACKET_TYPE_11 11 /* Ignored */
+#define RXRPC_PACKET_TYPE_VERSION 13 /* version string request */
+
+ uint8_t flags; /* packet flags */
+#define RXRPC_CLIENT_INITIATED 0x01 /* signifies a packet generated by a client */
+#define RXRPC_REQUEST_ACK 0x02 /* request an unconditional ACK of this packet */
+#define RXRPC_LAST_PACKET 0x04 /* the last packet from this side for this call */
+#define RXRPC_MORE_PACKETS 0x08 /* more packets to come */
+#define RXRPC_JUMBO_PACKET 0x20 /* [DATA] this is a jumbo packet */
+#define RXRPC_SLOW_START_OK 0x20 /* [ACK] slow start supported */
+
+ uint8_t userStatus; /* app-layer defined status */
+#define RXRPC_USERSTATUS_SERVICE_UPGRADE 0x01 /* AuriStor service upgrade request */
+
+ uint8_t securityIndex; /* security protocol ID */
+ union {
+ __be16 _rsvd; /* reserved */
+ __be16 cksum; /* kerberos security checksum */
+ };
+ __be16 serviceId; /* service ID */
+
+} __packed;
+
+/*****************************************************************************/
+/*
+ * jumbo packet secondary header
+ * - can be mapped to read header by:
+ * - new_serial = serial + 1
+ * - new_seq = seq + 1
+ * - new_flags = j_flags
+ * - new__rsvd = j__rsvd
+ * - duplicating all other fields
+ */
+struct rxrpc_jumbo_header {
+ uint8_t flags; /* packet flags (as per rxrpc_header) */
+ uint8_t pad;
+ union {
+ __be16 _rsvd; /* reserved */
+ __be16 cksum; /* kerberos security checksum */
+ };
+};
+
+#define RXRPC_JUMBO_DATALEN 1412 /* non-terminal jumbo packet data length */
+#define RXRPC_JUMBO_SUBPKTLEN (RXRPC_JUMBO_DATALEN + sizeof(struct rxrpc_jumbo_header))
+
+/*****************************************************************************/
+/*
+ * on-the-wire Rx ACK packet data payload
+ * - all multibyte fields should be in network byte order
+ */
+struct rxrpc_ackpacket {
+ __be16 bufferSpace; /* number of packet buffers available */
+ __be16 maxSkew; /* diff between serno being ACK'd and highest serial no
+ * received */
+ __be32 firstPacket; /* sequence no of first ACK'd packet in attached list */
+ __be32 previousPacket; /* sequence no of previous packet received */
+ __be32 serial; /* serial no of packet that prompted this ACK */
+
+ uint8_t reason; /* reason for ACK */
+#define RXRPC_ACK_REQUESTED 1 /* ACK was requested on packet */
+#define RXRPC_ACK_DUPLICATE 2 /* duplicate packet received */
+#define RXRPC_ACK_OUT_OF_SEQUENCE 3 /* out of sequence packet received */
+#define RXRPC_ACK_EXCEEDS_WINDOW 4 /* packet received beyond end of ACK window */
+#define RXRPC_ACK_NOSPACE 5 /* packet discarded due to lack of buffer space */
+#define RXRPC_ACK_PING 6 /* keep alive ACK */
+#define RXRPC_ACK_PING_RESPONSE 7 /* response to RXRPC_ACK_PING */
+#define RXRPC_ACK_DELAY 8 /* nothing happened since received packet */
+#define RXRPC_ACK_IDLE 9 /* ACK due to fully received ACK window */
+#define RXRPC_ACK__INVALID 10 /* Representation of invalid ACK reason */
+
+ uint8_t nAcks; /* number of ACKs */
+#define RXRPC_MAXACKS 255
+
+ uint8_t acks[0]; /* list of ACK/NAKs */
+#define RXRPC_ACK_TYPE_NACK 0
+#define RXRPC_ACK_TYPE_ACK 1
+
+} __packed;
+
+/* Some ACKs refer to specific packets and some are general and can be updated. */
+#define RXRPC_ACK_UPDATEABLE ((1 << RXRPC_ACK_REQUESTED) | \
+ (1 << RXRPC_ACK_PING_RESPONSE) | \
+ (1 << RXRPC_ACK_DELAY) | \
+ (1 << RXRPC_ACK_IDLE))
+
+
+/*
+ * ACK packets can have a further piece of information tagged on the end
+ */
+struct rxrpc_ackinfo {
+ __be32 rxMTU; /* maximum Rx MTU size (bytes) [AFS 3.3] */
+ __be32 maxMTU; /* maximum interface MTU size (bytes) [AFS 3.3] */
+ __be32 rwind; /* Rx window size (packets) [AFS 3.4] */
+ __be32 jumbo_max; /* max packets to stick into a jumbo packet [AFS 3.5] */
+};
+
+/*****************************************************************************/
+/*
+ * Kerberos security type-2 challenge packet
+ */
+struct rxkad_challenge {
+ __be32 version; /* version of this challenge type */
+ __be32 nonce; /* encrypted random number */
+ __be32 min_level; /* minimum security level */
+ __be32 __padding; /* padding to 8-byte boundary */
+} __packed;
+
+/*****************************************************************************/
+/*
+ * Kerberos security type-2 response packet
+ */
+struct rxkad_response {
+ __be32 version; /* version of this response type */
+ __be32 __pad;
+
+ /* encrypted bit of the response */
+ struct {
+ __be32 epoch; /* current epoch */
+ __be32 cid; /* parent connection ID */
+ __be32 checksum; /* checksum */
+ __be32 securityIndex; /* security type */
+ __be32 call_id[4]; /* encrypted call IDs */
+ __be32 inc_nonce; /* challenge nonce + 1 */
+ __be32 level; /* desired level */
+ } encrypted;
+
+ __be32 kvno; /* Kerberos key version number */
+ __be32 ticket_len; /* Kerberos ticket length */
+} __packed;
+
+#endif /* _LINUX_RXRPC_PACKET_H */