1/* Copyright 2011-2014 Autronica Fire and Security AS
  2 *
  3 * This program is free software; you can redistribute it and/or modify it
  4 * under the terms of the GNU General Public License as published by the Free
  5 * Software Foundation; either version 2 of the License, or (at your option)
  6 * any later version.
  7 *
  8 * Author(s):
  9 *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
 10 */
 11
 12#ifndef __HSR_PRIVATE_H
 13#define __HSR_PRIVATE_H
 14
 15#include <linux/netdevice.h>
 16#include <linux/list.h>
 17
 18
 19/* Time constants as specified in the HSR specification (IEC-62439-3 2010)
 20 * Table 8.
 21 * All values in milliseconds.
 22 */
 23#define HSR_LIFE_CHECK_INTERVAL		 2000 /* ms */
 24#define HSR_NODE_FORGET_TIME		60000 /* ms */
 25#define HSR_ANNOUNCE_INTERVAL		  100 /* ms */
 26
 27
 28/* By how much may slave1 and slave2 timestamps of latest received frame from
 29 * each node differ before we notify of communication problem?
 30 */
 31#define MAX_SLAVE_DIFF			 3000 /* ms */
 32#define HSR_SEQNR_START			(USHRT_MAX - 1024)
 33
 34
 35/* How often shall we check for broken ring and remove node entries older than
 36 * HSR_NODE_FORGET_TIME?
 37 */
 38#define PRUNE_PERIOD			 3000 /* ms */
 39
 40
 41#define HSR_TLV_ANNOUNCE		   22
 42#define HSR_TLV_LIFE_CHECK		   23
 43
 44
 45/* HSR Tag.
 46 * As defined in IEC-62439-3:2010, the HSR tag is really { ethertype = 0x88FB,
 47 * path, LSDU_size, sequence Nr }. But we let eth_header() create { h_dest,
 48 * h_source, h_proto = 0x88FB }, and add { path, LSDU_size, sequence Nr,
 49 * encapsulated protocol } instead.
 50 *
 51 * Field names as defined in the IEC:2010 standard for HSR.
 52 */
 53struct hsr_tag {
 54	__be16		path_and_LSDU_size;
 55	__be16		sequence_nr;
 56	__be16		encap_proto;
 57} __packed;
 58
 59#define HSR_HLEN	6
 60
 61/* The helper functions below assumes that 'path' occupies the 4 most
 62 * significant bits of the 16-bit field shared by 'path' and 'LSDU_size' (or
 63 * equivalently, the 4 most significant bits of HSR tag byte 14).
 64 *
 65 * This is unclear in the IEC specification; its definition of MAC addresses
 66 * indicates the spec is written with the least significant bit first (to the
 67 * left). This, however, would mean that the LSDU field would be split in two
 68 * with the path field in-between, which seems strange. I'm guessing the MAC
 69 * address definition is in error.
 70 */
 71static inline u16 get_hsr_tag_path(struct hsr_tag *ht)
 72{
 73	return ntohs(ht->path_and_LSDU_size) >> 12;
 74}
 75
 76static inline u16 get_hsr_tag_LSDU_size(struct hsr_tag *ht)
 77{
 78	return ntohs(ht->path_and_LSDU_size) & 0x0FFF;
 79}
 80
 81static inline void set_hsr_tag_path(struct hsr_tag *ht, u16 path)
 82{
 83	ht->path_and_LSDU_size = htons(
 84			(ntohs(ht->path_and_LSDU_size) & 0x0FFF) | (path << 12));
 85}
 86
 87static inline void set_hsr_tag_LSDU_size(struct hsr_tag *ht, u16 LSDU_size)
 88{
 89	ht->path_and_LSDU_size = htons(
 90			(ntohs(ht->path_and_LSDU_size) & 0xF000) |
 91			(LSDU_size & 0x0FFF));
 92}
 93
 94struct hsr_ethhdr {
 95	struct ethhdr	ethhdr;
 96	struct hsr_tag	hsr_tag;
 97} __packed;
 98
 99
100/* HSR Supervision Frame data types.
101 * Field names as defined in the IEC:2010 standard for HSR.
102 */
103struct hsr_sup_tag {
104	__be16		path_and_HSR_Ver;
105	__be16		sequence_nr;
106	__u8		HSR_TLV_Type;
107	__u8		HSR_TLV_Length;
108} __packed;
109
110struct hsr_sup_payload {
111	unsigned char	MacAddressA[ETH_ALEN];
112} __packed;
113
114static inline u16 get_hsr_stag_path(struct hsr_sup_tag *hst)
115{
116	return get_hsr_tag_path((struct hsr_tag *) hst);
117}
118
119static inline u16 get_hsr_stag_HSR_ver(struct hsr_sup_tag *hst)
120{
121	return get_hsr_tag_LSDU_size((struct hsr_tag *) hst);
122}
123
124static inline void set_hsr_stag_path(struct hsr_sup_tag *hst, u16 path)
125{
126	set_hsr_tag_path((struct hsr_tag *) hst, path);
127}
128
129static inline void set_hsr_stag_HSR_Ver(struct hsr_sup_tag *hst, u16 HSR_Ver)
130{
131	set_hsr_tag_LSDU_size((struct hsr_tag *) hst, HSR_Ver);
132}
133
134struct hsr_ethhdr_sp {
135	struct ethhdr		ethhdr;
136	struct hsr_sup_tag	hsr_sup;
137} __packed;
138
139
140enum hsr_port_type {
141	HSR_PT_NONE = 0,	/* Must be 0, used by framereg */
142	HSR_PT_SLAVE_A,
143	HSR_PT_SLAVE_B,
144	HSR_PT_INTERLINK,
145	HSR_PT_MASTER,
146	HSR_PT_PORTS,	/* This must be the last item in the enum */
147};
148
149struct hsr_port {
150	struct list_head	port_list;
151	struct net_device	*dev;
152	struct hsr_priv		*hsr;
153	enum hsr_port_type	type;
154};
155
156struct hsr_priv {
157	struct rcu_head		rcu_head;
158	struct list_head	ports;
159	struct list_head	node_db;	/* Known HSR nodes */
160	struct list_head	self_node_db;	/* MACs of slaves */
161	struct timer_list	announce_timer;	/* Supervision frame dispatch */
162	struct timer_list	prune_timer;
163	int announce_count;
164	u16 sequence_nr;
165	spinlock_t seqnr_lock;			/* locking for sequence_nr */
166	unsigned char		sup_multicast_addr[ETH_ALEN];
167};
168
169#define hsr_for_each_port(hsr, port) \
170	list_for_each_entry_rcu((port), &(hsr)->ports, port_list)
171
172struct hsr_port *hsr_port_get_hsr(struct hsr_priv *hsr, enum hsr_port_type pt);
173
174/* Caller must ensure skb is a valid HSR frame */
175static inline u16 hsr_get_skb_sequence_nr(struct sk_buff *skb)
176{
177	struct hsr_ethhdr *hsr_ethhdr;
178
179	hsr_ethhdr = (struct hsr_ethhdr *) skb_mac_header(skb);
180	return ntohs(hsr_ethhdr->hsr_tag.sequence_nr);
181}
182
183#endif /*  __HSR_PRIVATE_H */