[deliverable/linux.git] / net / hsr / hsr_framereg.c

/* Copyright 2011-2014 Autronica Fire and Security AS
 *
 * 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.
 *
 * Author(s):
 *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
 *
 * The HSR spec says never to forward the same frame twice on the same
 * interface. A frame is identified by its source MAC address and its HSR
 * sequence number. This code keeps track of senders and their sequence numbers
 * to allow filtering of duplicate frames, and to detect HSR ring errors.
 */

#include <linux/if_ether.h>
#include <linux/etherdevice.h>
#include <linux/slab.h>
#include <linux/rculist.h>
#include "hsr_main.h"
#include "hsr_framereg.h"
#include "hsr_netlink.h"


struct hsr_node {
	struct list_head	mac_list;
	unsigned char		MacAddressA[ETH_ALEN];
	unsigned char		MacAddressB[ETH_ALEN];
	/* Local slave through which AddrB frames are received from this node */
	enum hsr_port_type	AddrB_port;
	unsigned long		time_in[HSR_PT_PORTS];
	bool			time_in_stale[HSR_PT_PORTS];
	u16			seq_out[HSR_PT_PORTS];
	struct rcu_head		rcu_head;
};

/*	TODO: use hash lists for mac addresses (linux/jhash.h)?    */


/* Search for mac entry. Caller must hold rcu read lock.
 */
static struct hsr_node *find_node_by_AddrA(struct list_head *node_db,
					   const unsigned char addr[ETH_ALEN])
{
	struct hsr_node *node;

	list_for_each_entry_rcu(node, node_db, mac_list) {
		if (ether_addr_equal(node->MacAddressA, addr))
			return node;
	}

	return NULL;
}


/* Search for mac entry. Caller must hold rcu read lock.
 */
static struct hsr_node *find_node_by_AddrB(struct list_head *node_db,
					   const unsigned char addr[ETH_ALEN])
{
	struct hsr_node *node;

	list_for_each_entry_rcu(node, node_db, mac_list) {
		if (ether_addr_equal(node->MacAddressB, addr))
			return node;
	}

	return NULL;
}


/* Search for mac entry. Caller must hold rcu read lock.
 */
struct hsr_node *hsr_find_node(struct list_head *node_db, struct sk_buff *skb)
{
	struct hsr_node *node;
	struct ethhdr *ethhdr;

	if (!skb_mac_header_was_set(skb))
		return NULL;

	ethhdr = (struct ethhdr *) skb_mac_header(skb);

	list_for_each_entry_rcu(node, node_db, mac_list) {
		if (ether_addr_equal(node->MacAddressA, ethhdr->h_source))
			return node;
		if (ether_addr_equal(node->MacAddressB, ethhdr->h_source))
			return node;
	}

	return NULL;
}


/* Helper for device init; the self_node_db is used in hsr_rcv() to recognize
 * frames from self that's been looped over the HSR ring.
 */
int hsr_create_self_node(struct list_head *self_node_db,
			 unsigned char addr_a[ETH_ALEN],
			 unsigned char addr_b[ETH_ALEN])
{
	struct hsr_node *node, *oldnode;

	node = kmalloc(sizeof(*node), GFP_KERNEL);
	if (!node)
		return -ENOMEM;

	ether_addr_copy(node->MacAddressA, addr_a);
	ether_addr_copy(node->MacAddressB, addr_b);

	rcu_read_lock();
	oldnode = list_first_or_null_rcu(self_node_db,
						struct hsr_node, mac_list);
	if (oldnode) {
		list_replace_rcu(&oldnode->mac_list, &node->mac_list);
		rcu_read_unlock();
		synchronize_rcu();
		kfree(oldnode);
	} else {
		rcu_read_unlock();
		list_add_tail_rcu(&node->mac_list, self_node_db);
	}

	return 0;
}


/* Add/merge node to the database of nodes. 'skb' must contain an HSR
 * supervision frame.
 * - If the supervision header's MacAddressA field is not yet in the database,
 * this frame is from an hitherto unknown node - add it to the database.
 * - If the sender's MAC address is not the same as its MacAddressA address,
 * the node is using PICS_SUBS (address substitution). Record the sender's
 * address as the node's MacAddressB.
 *
 * This function needs to work even if the sender node has changed one of its
 * slaves' MAC addresses. In this case, there are four different cases described
 * by (Addr-changed, received-from) pairs as follows. Note that changing the
 * SlaveA address is equal to changing the node's own address:
 *
 * - (AddrB, SlaveB): The new AddrB will be recorded by PICS_SUBS code since
 *		      node == NULL.
 * - (AddrB, SlaveA): Will work as usual (the AddrB change won't be detected
 *		      from this frame).
 *
 * - (AddrA, SlaveB): The old node will be found. We need to detect this and
 *		      remove the node.
 * - (AddrA, SlaveA): A new node will be registered (non-PICS_SUBS at first).
 *		      The old one will be pruned after HSR_NODE_FORGET_TIME.
 *
 * We also need to detect if the sender's SlaveA and SlaveB cables have been
 * swapped.
 */
struct hsr_node *hsr_merge_node(struct hsr_node *node, struct sk_buff *skb,
				struct hsr_port *port)
{
	struct hsr_priv *hsr;
	struct hsr_sup_payload *hsr_sp;
	struct hsr_ethhdr_sp *hsr_ethsup;
	int i;
	unsigned long now;

	hsr_ethsup = (struct hsr_ethhdr_sp *) skb_mac_header(skb);
	hsr_sp = (struct hsr_sup_payload *) skb->data;
	hsr = port->hsr;

	if (node && !ether_addr_equal(node->MacAddressA, hsr_sp->MacAddressA)) {
		/* Node has changed its AddrA, frame was received from SlaveB */
		list_del_rcu(&node->mac_list);
		kfree_rcu(node, rcu_head);
		node = NULL;
	}

	if (node && (port->type == node->AddrB_port) &&
	    !ether_addr_equal(node->MacAddressB, hsr_ethsup->ethhdr.h_source)) {
		/* Cables have been swapped */
		list_del_rcu(&node->mac_list);
		kfree_rcu(node, rcu_head);
		node = NULL;
	}

	if (node && (port->type != node->AddrB_port) &&
	    (node->AddrB_port != HSR_PT_NONE) &&
	    !ether_addr_equal(node->MacAddressA, hsr_ethsup->ethhdr.h_source)) {
		/* Cables have been swapped */
		list_del_rcu(&node->mac_list);
		kfree_rcu(node, rcu_head);
		node = NULL;
	}

	if (node)
		return node;

	node = find_node_by_AddrA(&hsr->node_db, hsr_sp->MacAddressA);
	if (node) {
		/* Node is known, but frame was received from an unknown
		 * address. Node is PICS_SUBS capable; merge its AddrB.
		 */
		ether_addr_copy(node->MacAddressB, hsr_ethsup->ethhdr.h_source);
		node->AddrB_port = port->type;
		return node;
	}

	node = kzalloc(sizeof(*node), GFP_ATOMIC);
	if (!node)
		return NULL;

	ether_addr_copy(node->MacAddressA, hsr_sp->MacAddressA);
	ether_addr_copy(node->MacAddressB, hsr_ethsup->ethhdr.h_source);
	if (!ether_addr_equal(hsr_sp->MacAddressA, hsr_ethsup->ethhdr.h_source))
		node->AddrB_port = port->type;

	/* We are only interested in time diffs here, so use current jiffies
	 * as initialization. (0 could trigger an spurious ring error warning).
	 */
	now = jiffies;
	for (i = 0; i < HSR_PT_PORTS; i++)
		node->time_in[i] = now;
	for (i = 0; i < HSR_PT_PORTS; i++)
		node->seq_out[i] = ntohs(hsr_ethsup->hsr_sup.sequence_nr) - 1;

	list_add_tail_rcu(&node->mac_list, &hsr->node_db);

	return node;
}


/* 'skb' is a frame meant for this host, that is to be passed to upper layers.
 *
 * If the frame was sent by a node's B interface, replace the sender
 * address with that node's "official" address (MacAddressA) so that upper
 * layers recognize where it came from.
 */
void hsr_addr_subst_source(struct hsr_priv *hsr, struct sk_buff *skb)
{
	struct ethhdr *ethhdr;
	struct hsr_node *node;

	if (!skb_mac_header_was_set(skb)) {
		WARN_ONCE(1, "%s: Mac header not set\n", __func__);
		return;
	}
	ethhdr = (struct ethhdr *) skb_mac_header(skb);

	rcu_read_lock();
	node = find_node_by_AddrB(&hsr->node_db, ethhdr->h_source);
	if (node)
		ether_addr_copy(ethhdr->h_source, node->MacAddressA);
	rcu_read_unlock();
}


/* 'skb' is a frame meant for another host.
 * 'hsr_dev_idx' is the HSR index of the outgoing device
 *
 * Substitute the target (dest) MAC address if necessary, so the it matches the
 * recipient interface MAC address, regardless of whether that is the
 * recipient's A or B interface.
 * This is needed to keep the packets flowing through switches that learn on
 * which "side" the different interfaces are.
 */
void hsr_addr_subst_dest(struct hsr_priv *hsr, struct ethhdr *ethhdr,
			 struct hsr_port *port)
{
	struct hsr_node *node;

	rcu_read_lock();
	node = find_node_by_AddrA(&hsr->node_db, ethhdr->h_dest);
	if (node && (node->AddrB_port == port->type))
		ether_addr_copy(ethhdr->h_dest, node->MacAddressB);
	rcu_read_unlock();
}


/* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
 * false otherwise.
 */
static bool seq_nr_after(u16 a, u16 b)
{
	/* Remove inconsistency where
	 * seq_nr_after(a, b) == seq_nr_before(a, b)
	 */
	if ((int) b - a == 32768)
		return false;

	return (((s16) (b - a)) < 0);
}
#define seq_nr_before(a, b)		seq_nr_after((b), (a))
#define seq_nr_after_or_eq(a, b)	(!seq_nr_before((a), (b)))
#define seq_nr_before_or_eq(a, b)	(!seq_nr_after((a), (b)))


void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port)
{
	node->time_in[port->type] = jiffies;
	node->time_in_stale[port->type] = false;
}


/* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
 * ethhdr->h_source address and skb->mac_header set.
 *
 * Return:
 *	 1 if frame can be shown to have been sent recently on this interface,
 *	 0 otherwise, or
 *	 negative error code on error
 */
int hsr_register_frame_out(struct hsr_node *node, struct hsr_port *port,
			   struct sk_buff *skb)
{
	struct hsr_ethhdr *hsr_ethhdr;
	u16 sequence_nr;

	if (!skb_mac_header_was_set(skb)) {
		WARN_ONCE(1, "%s: Mac header not set\n", __func__);
		return -EINVAL;
	}
	hsr_ethhdr = (struct hsr_ethhdr *) skb_mac_header(skb);

	sequence_nr = ntohs(hsr_ethhdr->hsr_tag.sequence_nr);
	if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]))
		return 1;

	node->seq_out[port->type] = sequence_nr;
	return 0;
}


static struct hsr_port *get_late_port(struct hsr_priv *hsr,
				      struct hsr_node *node)
{
	if (node->time_in_stale[HSR_PT_SLAVE_A])
		return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
	if (node->time_in_stale[HSR_PT_SLAVE_B])
		return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);

	if (time_after(node->time_in[HSR_PT_SLAVE_B],
		       node->time_in[HSR_PT_SLAVE_A] +
					msecs_to_jiffies(MAX_SLAVE_DIFF)))
		return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
	if (time_after(node->time_in[HSR_PT_SLAVE_A],
		       node->time_in[HSR_PT_SLAVE_B] +
					msecs_to_jiffies(MAX_SLAVE_DIFF)))
		return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);

	return NULL;
}


/* Remove stale sequence_nr records. Called by timer every
 * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
 */
void hsr_prune_nodes(unsigned long data)
{
	struct hsr_priv *hsr;
	struct hsr_node *node;
	struct hsr_port *port;
	unsigned long timestamp;
	unsigned long time_a, time_b;

	hsr = (struct hsr_priv *) data;

	rcu_read_lock();
	list_for_each_entry_rcu(node, &hsr->node_db, mac_list) {
		/* Shorthand */
		time_a = node->time_in[HSR_PT_SLAVE_A];
		time_b = node->time_in[HSR_PT_SLAVE_B];

		/* Check for timestamps old enough to risk wrap-around */
		if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET/2))
			node->time_in_stale[HSR_PT_SLAVE_A] = true;
		if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET/2))
			node->time_in_stale[HSR_PT_SLAVE_B] = true;

		/* Get age of newest frame from node.
		 * At least one time_in is OK here; nodes get pruned long
		 * before both time_ins can get stale
		 */
		timestamp = time_a;
		if (node->time_in_stale[HSR_PT_SLAVE_A] ||
		    (!node->time_in_stale[HSR_PT_SLAVE_B] &&
		    time_after(time_b, time_a)))
			timestamp = time_b;

		/* Warn of ring error only as long as we get frames at all */
		if (time_is_after_jiffies(timestamp +
					msecs_to_jiffies(1.5*MAX_SLAVE_DIFF))) {
			rcu_read_lock();
			port = get_late_port(hsr, node);
			if (port != NULL)
				hsr_nl_ringerror(hsr, node->MacAddressA, port);
			rcu_read_unlock();
		}

		/* Prune old entries */
		if (time_is_before_jiffies(timestamp +
					msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
			hsr_nl_nodedown(hsr, node->MacAddressA);
			list_del_rcu(&node->mac_list);
			/* Note that we need to free this entry later: */
			kfree_rcu(node, rcu_head);
		}
	}
	rcu_read_unlock();
}


void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
			unsigned char addr[ETH_ALEN])
{
	struct hsr_node *node;

	if (!_pos) {
		node = list_first_or_null_rcu(&hsr->node_db,
					      struct hsr_node, mac_list);
		if (node)
			ether_addr_copy(addr, node->MacAddressA);
		return node;
	}

	node = _pos;
	list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
		ether_addr_copy(addr, node->MacAddressA);
		return node;
	}

	return NULL;
}


int hsr_get_node_data(struct hsr_priv *hsr,
		      const unsigned char *addr,
		      unsigned char addr_b[ETH_ALEN],
		      unsigned int *addr_b_ifindex,
		      int *if1_age,
		      u16 *if1_seq,
		      int *if2_age,
		      u16 *if2_seq)
{
	struct hsr_node *node;
	struct hsr_port *port;
	unsigned long tdiff;


	rcu_read_lock();
	node = find_node_by_AddrA(&hsr->node_db, addr);
	if (!node) {
		rcu_read_unlock();
		return -ENOENT;	/* No such entry */
	}

	ether_addr_copy(addr_b, node->MacAddressB);

	tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
	if (node->time_in_stale[HSR_PT_SLAVE_A])
		*if1_age = INT_MAX;
#if HZ <= MSEC_PER_SEC
	else if (tdiff > msecs_to_jiffies(INT_MAX))
		*if1_age = INT_MAX;
#endif
	else
		*if1_age = jiffies_to_msecs(tdiff);

	tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
	if (node->time_in_stale[HSR_PT_SLAVE_B])
		*if2_age = INT_MAX;
#if HZ <= MSEC_PER_SEC
	else if (tdiff > msecs_to_jiffies(INT_MAX))
		*if2_age = INT_MAX;
#endif
	else
		*if2_age = jiffies_to_msecs(tdiff);

	/* Present sequence numbers as if they were incoming on interface */
	*if1_seq = node->seq_out[HSR_PT_SLAVE_B];
	*if2_seq = node->seq_out[HSR_PT_SLAVE_A];

	if (node->AddrB_port != HSR_PT_NONE) {
		port = hsr_port_get_hsr(hsr, node->AddrB_port);
		*addr_b_ifindex = port->dev->ifindex;
	} else {
		*addr_b_ifindex = -1;
	}

	rcu_read_unlock();

	return 0;
}
Commit	Line	Data
70ebe4a4	1	/* Copyright 2011-2014 Autronica Fire and Security AS
f421436a AB	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):
70ebe4a4	9	* 2011-2014 Arvid Brodin, arvid.brodin@alten.se
f421436a AB	10	*
	11	* The HSR spec says never to forward the same frame twice on the same
	12	* interface. A frame is identified by its source MAC address and its HSR
	13	* sequence number. This code keeps track of senders and their sequence numbers
	14	* to allow filtering of duplicate frames, and to detect HSR ring errors.
	15	*/
	16
	17	#include <linux/if_ether.h>
	18	#include <linux/etherdevice.h>
	19	#include <linux/slab.h>
	20	#include <linux/rculist.h>
	21	#include "hsr_main.h"
	22	#include "hsr_framereg.h"
	23	#include "hsr_netlink.h"
	24
	25
70ebe4a4 AB	26	struct hsr_node {
	27	struct list_head mac_list;
	28	unsigned char MacAddressA[ETH_ALEN];
	29	unsigned char MacAddressB[ETH_ALEN];
c5a75911 AB	30	/* Local slave through which AddrB frames are received from this node */
	31	enum hsr_port_type AddrB_port;
	32	unsigned long time_in[HSR_PT_PORTS];
	33	bool time_in_stale[HSR_PT_PORTS];
	34	u16 seq_out[HSR_PT_PORTS];
70ebe4a4	35	struct rcu_head rcu_head;
f421436a AB	36	};
	37
	38	/* TODO: use hash lists for mac addresses (linux/jhash.h)? */
	39
	40
	41
	42	/* Search for mac entry. Caller must hold rcu read lock.
	43	*/
70ebe4a4 AB	44	static struct hsr_node find_node_by_AddrA(struct list_head node_db,
70ebe4a4 AB	45	const unsigned char addr[ETH_ALEN])
f421436a	46	{
70ebe4a4	47	struct hsr_node *node;
f421436a AB	48
	49	list_for_each_entry_rcu(node, node_db, mac_list) {
	50	if (ether_addr_equal(node->MacAddressA, addr))
	51	return node;
	52	}
	53
	54	return NULL;
	55	}
	56
	57
	58	/* Search for mac entry. Caller must hold rcu read lock.
	59	*/
70ebe4a4 AB	60	static struct hsr_node find_node_by_AddrB(struct list_head node_db,
70ebe4a4 AB	61	const unsigned char addr[ETH_ALEN])
f421436a	62	{
70ebe4a4	63	struct hsr_node *node;
f421436a AB	64
	65	list_for_each_entry_rcu(node, node_db, mac_list) {
	66	if (ether_addr_equal(node->MacAddressB, addr))
	67	return node;
	68	}
	69
	70	return NULL;
	71	}
	72
	73
	74	/* Search for mac entry. Caller must hold rcu read lock.
	75	*/
70ebe4a4	76	struct hsr_node hsr_find_node(struct list_head node_db, struct sk_buff *skb)
f421436a	77	{
70ebe4a4	78	struct hsr_node *node;
f421436a AB	79	struct ethhdr *ethhdr;
	80
	81	if (!skb_mac_header_was_set(skb))
	82	return NULL;
	83
	84	ethhdr = (struct ethhdr *) skb_mac_header(skb);
	85
	86	list_for_each_entry_rcu(node, node_db, mac_list) {
	87	if (ether_addr_equal(node->MacAddressA, ethhdr->h_source))
	88	return node;
	89	if (ether_addr_equal(node->MacAddressB, ethhdr->h_source))
	90	return node;
	91	}
	92
	93	return NULL;
	94	}
	95
	96
	97	/* Helper for device init; the self_node_db is used in hsr_rcv() to recognize
	98	* frames from self that's been looped over the HSR ring.
	99	*/
	100	int hsr_create_self_node(struct list_head *self_node_db,
	101	unsigned char addr_a[ETH_ALEN],
	102	unsigned char addr_b[ETH_ALEN])
	103	{
70ebe4a4	104	struct hsr_node node, oldnode;
f421436a AB	105
	106	node = kmalloc(sizeof(*node), GFP_KERNEL);
	107	if (!node)
	108	return -ENOMEM;
	109
e83abe37 JP	110	ether_addr_copy(node->MacAddressA, addr_a);
e83abe37 JP	111	ether_addr_copy(node->MacAddressB, addr_b);
f421436a AB	112
	113	rcu_read_lock();
	114	oldnode = list_first_or_null_rcu(self_node_db,
70ebe4a4	115	struct hsr_node, mac_list);
f421436a AB	116	if (oldnode) {
	117	list_replace_rcu(&oldnode->mac_list, &node->mac_list);
	118	rcu_read_unlock();
	119	synchronize_rcu();
	120	kfree(oldnode);
	121	} else {
	122	rcu_read_unlock();
	123	list_add_tail_rcu(&node->mac_list, self_node_db);
	124	}
	125
	126	return 0;
	127	}
	128
f421436a AB	129
	130	/* Add/merge node to the database of nodes. 'skb' must contain an HSR
	131	* supervision frame.
	132	* - If the supervision header's MacAddressA field is not yet in the database,
	133	* this frame is from an hitherto unknown node - add it to the database.
	134	* - If the sender's MAC address is not the same as its MacAddressA address,
	135	* the node is using PICS_SUBS (address substitution). Record the sender's
	136	* address as the node's MacAddressB.
	137	*
	138	* This function needs to work even if the sender node has changed one of its
	139	* slaves' MAC addresses. In this case, there are four different cases described
	140	* by (Addr-changed, received-from) pairs as follows. Note that changing the
	141	* SlaveA address is equal to changing the node's own address:
	142	*
	143	* - (AddrB, SlaveB): The new AddrB will be recorded by PICS_SUBS code since
	144	* node == NULL.
	145	* - (AddrB, SlaveA): Will work as usual (the AddrB change won't be detected
	146	* from this frame).
	147	*
	148	* - (AddrA, SlaveB): The old node will be found. We need to detect this and
	149	* remove the node.
	150	* - (AddrA, SlaveA): A new node will be registered (non-PICS_SUBS at first).
	151	* The old one will be pruned after HSR_NODE_FORGET_TIME.
	152	*
	153	* We also need to detect if the sender's SlaveA and SlaveB cables have been
	154	* swapped.
	155	*/
c5a75911 AB	156	struct hsr_node hsr_merge_node(struct hsr_node node, struct sk_buff *skb,
c5a75911 AB	157	struct hsr_port *port)
f421436a	158	{
c5a75911	159	struct hsr_priv *hsr;
f421436a AB	160	struct hsr_sup_payload *hsr_sp;
	161	struct hsr_ethhdr_sp *hsr_ethsup;
	162	int i;
	163	unsigned long now;
	164
	165	hsr_ethsup = (struct hsr_ethhdr_sp *) skb_mac_header(skb);
	166	hsr_sp = (struct hsr_sup_payload *) skb->data;
c5a75911	167	hsr = port->hsr;
f421436a AB	168
	169	if (node && !ether_addr_equal(node->MacAddressA, hsr_sp->MacAddressA)) {
	170	/* Node has changed its AddrA, frame was received from SlaveB */
	171	list_del_rcu(&node->mac_list);
1aee6cc2	172	kfree_rcu(node, rcu_head);
f421436a AB	173	node = NULL;
	174	}
	175
c5a75911	176	if (node && (port->type == node->AddrB_port) &&
f421436a AB	177	!ether_addr_equal(node->MacAddressB, hsr_ethsup->ethhdr.h_source)) {
	178	/* Cables have been swapped */
	179	list_del_rcu(&node->mac_list);
1aee6cc2	180	kfree_rcu(node, rcu_head);
f421436a AB	181	node = NULL;
	182	}
	183
c5a75911 AB	184	if (node && (port->type != node->AddrB_port) &&
c5a75911 AB	185	(node->AddrB_port != HSR_PT_NONE) &&
f421436a AB	186	!ether_addr_equal(node->MacAddressA, hsr_ethsup->ethhdr.h_source)) {
	187	/* Cables have been swapped */
	188	list_del_rcu(&node->mac_list);
1aee6cc2	189	kfree_rcu(node, rcu_head);
f421436a AB	190	node = NULL;
	191	}
	192
	193	if (node)
	194	return node;
	195
70ebe4a4	196	node = find_node_by_AddrA(&hsr->node_db, hsr_sp->MacAddressA);
f421436a AB	197	if (node) {
	198	/* Node is known, but frame was received from an unknown
	199	* address. Node is PICS_SUBS capable; merge its AddrB.
	200	*/
e83abe37	201	ether_addr_copy(node->MacAddressB, hsr_ethsup->ethhdr.h_source);
c5a75911	202	node->AddrB_port = port->type;
f421436a AB	203	return node;
	204	}
	205
	206	node = kzalloc(sizeof(*node), GFP_ATOMIC);
	207	if (!node)
	208	return NULL;
	209
e83abe37 JP	210	ether_addr_copy(node->MacAddressA, hsr_sp->MacAddressA);
e83abe37 JP	211	ether_addr_copy(node->MacAddressB, hsr_ethsup->ethhdr.h_source);
f421436a	212	if (!ether_addr_equal(hsr_sp->MacAddressA, hsr_ethsup->ethhdr.h_source))
c5a75911	213	node->AddrB_port = port->type;
f421436a AB	214
	215	/* We are only interested in time diffs here, so use current jiffies
	216	* as initialization. (0 could trigger an spurious ring error warning).
	217	*/
	218	now = jiffies;
c5a75911	219	for (i = 0; i < HSR_PT_PORTS; i++)
f421436a	220	node->time_in[i] = now;
c5a75911	221	for (i = 0; i < HSR_PT_PORTS; i++)
f421436a AB	222	node->seq_out[i] = ntohs(hsr_ethsup->hsr_sup.sequence_nr) - 1;
f421436a AB	223
70ebe4a4	224	list_add_tail_rcu(&node->mac_list, &hsr->node_db);
f421436a AB	225
	226	return node;
	227	}
	228
	229
	230	/* 'skb' is a frame meant for this host, that is to be passed to upper layers.
	231	*
	232	* If the frame was sent by a node's B interface, replace the sender
	233	* address with that node's "official" address (MacAddressA) so that upper
	234	* layers recognize where it came from.
	235	*/
70ebe4a4	236	void hsr_addr_subst_source(struct hsr_priv hsr, struct sk_buff skb)
f421436a AB	237	{
f421436a AB	238	struct ethhdr *ethhdr;
70ebe4a4	239	struct hsr_node *node;
f421436a AB	240
	241	if (!skb_mac_header_was_set(skb)) {
	242	WARN_ONCE(1, "%s: Mac header not set\n", __func__);
	243	return;
	244	}
	245	ethhdr = (struct ethhdr *) skb_mac_header(skb);
	246
	247	rcu_read_lock();
70ebe4a4	248	node = find_node_by_AddrB(&hsr->node_db, ethhdr->h_source);
f421436a	249	if (node)
e83abe37	250	ether_addr_copy(ethhdr->h_source, node->MacAddressA);
f421436a AB	251	rcu_read_unlock();
	252	}
	253
	254
	255	/* 'skb' is a frame meant for another host.
	256	* 'hsr_dev_idx' is the HSR index of the outgoing device
	257	*
	258	* Substitute the target (dest) MAC address if necessary, so the it matches the
	259	* recipient interface MAC address, regardless of whether that is the
	260	* recipient's A or B interface.
	261	* This is needed to keep the packets flowing through switches that learn on
	262	* which "side" the different interfaces are.
	263	*/
70ebe4a4	264	void hsr_addr_subst_dest(struct hsr_priv hsr, struct ethhdr ethhdr,
c5a75911	265	struct hsr_port *port)
f421436a	266	{
70ebe4a4	267	struct hsr_node *node;
f421436a AB	268
f421436a AB	269	rcu_read_lock();
70ebe4a4	270	node = find_node_by_AddrA(&hsr->node_db, ethhdr->h_dest);
c5a75911	271	if (node && (node->AddrB_port == port->type))
e83abe37	272	ether_addr_copy(ethhdr->h_dest, node->MacAddressB);
f421436a AB	273	rcu_read_unlock();
	274	}
	275
	276
	277	/* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
	278	* false otherwise.
	279	*/
	280	static bool seq_nr_after(u16 a, u16 b)
	281	{
	282	/* Remove inconsistency where
213e3bc7 AB	283	* seq_nr_after(a, b) == seq_nr_before(a, b)
213e3bc7 AB	284	*/
f421436a AB	285	if ((int) b - a == 32768)
	286	return false;
	287
	288	return (((s16) (b - a)) < 0);
	289	}
	290	#define seq_nr_before(a, b) seq_nr_after((b), (a))
	291	#define seq_nr_after_or_eq(a, b) (!seq_nr_before((a), (b)))
	292	#define seq_nr_before_or_eq(a, b) (!seq_nr_after((a), (b)))
	293
	294
c5a75911	295	void hsr_register_frame_in(struct hsr_node node, struct hsr_port port)
f421436a	296	{
c5a75911 AB	297	node->time_in[port->type] = jiffies;
c5a75911 AB	298	node->time_in_stale[port->type] = false;
f421436a AB	299	}
	300
	301
	302	/* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
	303	* ethhdr->h_source address and skb->mac_header set.
	304	*
	305	* Return:
	306	* 1 if frame can be shown to have been sent recently on this interface,
	307	* 0 otherwise, or
	308	* negative error code on error
	309	*/
c5a75911	310	int hsr_register_frame_out(struct hsr_node node, struct hsr_port port,
f421436a AB	311	struct sk_buff *skb)
	312	{
	313	struct hsr_ethhdr *hsr_ethhdr;
	314	u16 sequence_nr;
	315
f421436a AB	316	if (!skb_mac_header_was_set(skb)) {
	317	WARN_ONCE(1, "%s: Mac header not set\n", __func__);
	318	return -EINVAL;
	319	}
	320	hsr_ethhdr = (struct hsr_ethhdr *) skb_mac_header(skb);
	321
	322	sequence_nr = ntohs(hsr_ethhdr->hsr_tag.sequence_nr);
c5a75911	323	if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]))
f421436a AB	324	return 1;
f421436a AB	325
c5a75911	326	node->seq_out[port->type] = sequence_nr;
f421436a AB	327	return 0;
	328	}
	329
	330
c5a75911 AB	331	static struct hsr_port get_late_port(struct hsr_priv hsr,
c5a75911 AB	332	struct hsr_node *node)
f421436a	333	{
c5a75911 AB	334	if (node->time_in_stale[HSR_PT_SLAVE_A])
	335	return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
	336	if (node->time_in_stale[HSR_PT_SLAVE_B])
	337	return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
	338
	339	if (time_after(node->time_in[HSR_PT_SLAVE_B],
	340	node->time_in[HSR_PT_SLAVE_A] +
	341	msecs_to_jiffies(MAX_SLAVE_DIFF)))
	342	return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
	343	if (time_after(node->time_in[HSR_PT_SLAVE_A],
	344	node->time_in[HSR_PT_SLAVE_B] +
	345	msecs_to_jiffies(MAX_SLAVE_DIFF)))
	346	return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
f421436a	347
c5a75911	348	return NULL;
f421436a AB	349	}
	350
	351
	352	/* Remove stale sequence_nr records. Called by timer every
	353	* HSR_LIFE_CHECK_INTERVAL (two seconds or so).
	354	*/
abff7162	355	void hsr_prune_nodes(unsigned long data)
f421436a	356	{
abff7162	357	struct hsr_priv *hsr;
70ebe4a4	358	struct hsr_node *node;
c5a75911	359	struct hsr_port *port;
f421436a AB	360	unsigned long timestamp;
	361	unsigned long time_a, time_b;
	362
abff7162 AB	363	hsr = (struct hsr_priv *) data;
abff7162 AB	364
f421436a	365	rcu_read_lock();
70ebe4a4	366	list_for_each_entry_rcu(node, &hsr->node_db, mac_list) {
f421436a	367	/* Shorthand */
c5a75911 AB	368	time_a = node->time_in[HSR_PT_SLAVE_A];
c5a75911 AB	369	time_b = node->time_in[HSR_PT_SLAVE_B];
f421436a AB	370
	371	/* Check for timestamps old enough to risk wrap-around */
	372	if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET/2))
c5a75911	373	node->time_in_stale[HSR_PT_SLAVE_A] = true;
f421436a	374	if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET/2))
c5a75911	375	node->time_in_stale[HSR_PT_SLAVE_B] = true;
f421436a AB	376
	377	/* Get age of newest frame from node.
	378	* At least one time_in is OK here; nodes get pruned long
	379	* before both time_ins can get stale
	380	*/
	381	timestamp = time_a;
c5a75911 AB	382	if (node->time_in_stale[HSR_PT_SLAVE_A] \|\|
c5a75911 AB	383	(!node->time_in_stale[HSR_PT_SLAVE_B] &&
f421436a AB	384	time_after(time_b, time_a)))
	385	timestamp = time_b;
	386
	387	/* Warn of ring error only as long as we get frames at all */
	388	if (time_is_after_jiffies(timestamp +
	389	msecs_to_jiffies(1.5*MAX_SLAVE_DIFF))) {
c5a75911 AB	390	rcu_read_lock();
	391	port = get_late_port(hsr, node);
	392	if (port != NULL)
	393	hsr_nl_ringerror(hsr, node->MacAddressA, port);
	394	rcu_read_unlock();
f421436a AB	395	}
	396
	397	/* Prune old entries */
	398	if (time_is_before_jiffies(timestamp +
	399	msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
70ebe4a4	400	hsr_nl_nodedown(hsr, node->MacAddressA);
f421436a AB	401	list_del_rcu(&node->mac_list);
f421436a AB	402	/* Note that we need to free this entry later: */
1aee6cc2	403	kfree_rcu(node, rcu_head);
f421436a AB	404	}
	405	}
	406	rcu_read_unlock();
	407	}
	408
	409
70ebe4a4	410	void hsr_get_next_node(struct hsr_priv hsr, void *_pos,
f421436a AB	411	unsigned char addr[ETH_ALEN])
f421436a AB	412	{
70ebe4a4	413	struct hsr_node *node;
f421436a AB	414
f421436a AB	415	if (!_pos) {
70ebe4a4 AB	416	node = list_first_or_null_rcu(&hsr->node_db,
70ebe4a4 AB	417	struct hsr_node, mac_list);
f421436a	418	if (node)
e83abe37	419	ether_addr_copy(addr, node->MacAddressA);
f421436a AB	420	return node;
	421	}
	422
	423	node = _pos;
70ebe4a4	424	list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
e83abe37	425	ether_addr_copy(addr, node->MacAddressA);
f421436a AB	426	return node;
	427	}
	428
	429	return NULL;
	430	}
	431
	432
70ebe4a4	433	int hsr_get_node_data(struct hsr_priv *hsr,
f421436a AB	434	const unsigned char *addr,
	435	unsigned char addr_b[ETH_ALEN],
	436	unsigned int *addr_b_ifindex,
	437	int *if1_age,
	438	u16 *if1_seq,
	439	int *if2_age,
	440	u16 *if2_seq)
	441	{
70ebe4a4	442	struct hsr_node *node;
c5a75911	443	struct hsr_port *port;
f421436a AB	444	unsigned long tdiff;
	445
	446
	447	rcu_read_lock();
70ebe4a4	448	node = find_node_by_AddrA(&hsr->node_db, addr);
f421436a AB	449	if (!node) {
	450	rcu_read_unlock();
	451	return -ENOENT; /* No such entry */
	452	}
	453
e83abe37	454	ether_addr_copy(addr_b, node->MacAddressB);
f421436a	455
c5a75911 AB	456	tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
c5a75911 AB	457	if (node->time_in_stale[HSR_PT_SLAVE_A])
f421436a AB	458	*if1_age = INT_MAX;
	459	#if HZ <= MSEC_PER_SEC
	460	else if (tdiff > msecs_to_jiffies(INT_MAX))
	461	*if1_age = INT_MAX;
	462	#endif
	463	else
	464	*if1_age = jiffies_to_msecs(tdiff);
	465
c5a75911 AB	466	tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
c5a75911 AB	467	if (node->time_in_stale[HSR_PT_SLAVE_B])
f421436a AB	468	*if2_age = INT_MAX;
	469	#if HZ <= MSEC_PER_SEC
	470	else if (tdiff > msecs_to_jiffies(INT_MAX))
	471	*if2_age = INT_MAX;
	472	#endif
	473	else
	474	*if2_age = jiffies_to_msecs(tdiff);
	475
	476	/* Present sequence numbers as if they were incoming on interface */
c5a75911 AB	477	*if1_seq = node->seq_out[HSR_PT_SLAVE_B];
c5a75911 AB	478	*if2_seq = node->seq_out[HSR_PT_SLAVE_A];
f421436a	479
c5a75911 AB	480	if (node->AddrB_port != HSR_PT_NONE) {
	481	port = hsr_port_get_hsr(hsr, node->AddrB_port);
	482	*addr_b_ifindex = port->dev->ifindex;
	483	} else {
f421436a	484	*addr_b_ifindex = -1;
c5a75911	485	}
f421436a AB	486
	487	rcu_read_unlock();
	488
	489	return 0;
	490	}