net/hsr/hsr_main.h

   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  */
  53 struct 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  */
  71 static inline u16 get_hsr_tag_path(struct hsr_tag *ht)
  72 {
  73         return ntohs(ht->path_and_LSDU_size) >> 12;
  74 }
  75
  76 static inline u16 get_hsr_tag_LSDU_size(struct hsr_tag *ht)
  77 {
  78         return ntohs(ht->path_and_LSDU_size) & 0x0FFF;
  79 }
  80
  81 static 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
  87 static 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
  94 struct 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  */
 103 struct 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
 110 struct hsr_sup_payload {
 111         unsigned char   MacAddressA[ETH_ALEN];
 112 } __packed;
 113
 114 static inline u16 get_hsr_stag_path(struct hsr_sup_tag *hst)
 115 {
 116         return get_hsr_tag_path((struct hsr_tag *) hst);
 117 }
 118
 119 static 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
 124 static 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
 129 static 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
 134 struct hsr_ethhdr_sp {
 135         struct ethhdr           ethhdr;
 136         struct hsr_sup_tag      hsr_sup;
 137 } __packed;
 138
 139
 140 enum 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
 149 struct 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
 156 struct 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
 172 struct 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 */
 175 static 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 */