[linux-block.git] / net / hsr / hsr_framereg.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright 2011-2014 Autronica Fire and Security AS
 *
 * 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"

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

/* 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)))

bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr)
{
	struct hsr_node *node;

	node = list_first_or_null_rcu(&hsr->self_node_db, struct hsr_node,
				      mac_list);
	if (!node) {
		WARN_ONCE(1, "HSR: No self node\n");
		return false;
	}

	if (ether_addr_equal(addr, node->macaddress_A))
		return true;
	if (ether_addr_equal(addr, node->macaddress_B))
		return true;

	return false;
}

/* Search for mac entry. Caller must hold rcu read lock.
 */
static struct hsr_node *find_node_by_addr_A(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->macaddress_A, addr))
			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->macaddress_A, addr_a);
	ether_addr_copy(node->macaddress_B, 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;
}

void hsr_del_self_node(struct list_head *self_node_db)
{
	struct hsr_node *node;

	rcu_read_lock();
	node = list_first_or_null_rcu(self_node_db, struct hsr_node, mac_list);
	rcu_read_unlock();
	if (node) {
		list_del_rcu(&node->mac_list);
		kfree(node);
	}
}

void hsr_del_nodes(struct list_head *node_db)
{
	struct hsr_node *node;
	struct hsr_node *tmp;

	list_for_each_entry_safe(node, tmp, node_db, mac_list)
		kfree(node);
}

/* Allocate an hsr_node and add it to node_db. 'addr' is the node's address_A;
 * seq_out is used to initialize filtering of outgoing duplicate frames
 * originating from the newly added node.
 */
struct hsr_node *hsr_add_node(struct list_head *node_db, unsigned char addr[],
			      u16 seq_out)
{
	struct hsr_node *node;
	unsigned long now;
	int i;

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

	ether_addr_copy(node->macaddress_A, addr);

	/* 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] = seq_out;

	list_add_tail_rcu(&node->mac_list, node_db);

	return node;
}

/* Get the hsr_node from which 'skb' was sent.
 */
struct hsr_node *hsr_get_node(struct hsr_port *port, struct sk_buff *skb,
			      bool is_sup)
{
	struct list_head *node_db = &port->hsr->node_db;
	struct hsr_node *node;
	struct ethhdr *ethhdr;
	u16 seq_out;

	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->macaddress_A, ethhdr->h_source))
			return node;
		if (ether_addr_equal(node->macaddress_B, ethhdr->h_source))
			return node;
	}

	/* Everyone may create a node entry, connected node to a HSR device. */

	if (ethhdr->h_proto == htons(ETH_P_PRP) ||
	    ethhdr->h_proto == htons(ETH_P_HSR)) {
		/* Use the existing sequence_nr from the tag as starting point
		 * for filtering duplicate frames.
		 */
		seq_out = hsr_get_skb_sequence_nr(skb) - 1;
	} else {
		/* this is called also for frames from master port and
		 * so warn only for non master ports
		 */
		if (port->type != HSR_PT_MASTER)
			WARN_ONCE(1, "%s: Non-HSR frame\n", __func__);
		seq_out = HSR_SEQNR_START;
	}

	return hsr_add_node(node_db, ethhdr->h_source, seq_out);
}

/* Use the Supervision frame's info about an eventual macaddress_B for merging
 * nodes that has previously had their macaddress_B registered as a separate
 * node.
 */
void hsr_handle_sup_frame(struct sk_buff *skb, struct hsr_node *node_curr,
			  struct hsr_port *port_rcv)
{
	struct ethhdr *ethhdr;
	struct hsr_node *node_real;
	struct hsr_sup_payload *hsr_sp;
	struct list_head *node_db;
	int i;

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

	/* Leave the ethernet header. */
	skb_pull(skb, sizeof(struct ethhdr));

	/* And leave the HSR tag. */
	if (ethhdr->h_proto == htons(ETH_P_HSR))
		skb_pull(skb, sizeof(struct hsr_tag));

	/* And leave the HSR sup tag. */
	skb_pull(skb, sizeof(struct hsr_sup_tag));

	hsr_sp = (struct hsr_sup_payload *)skb->data;

	/* Merge node_curr (registered on macaddress_B) into node_real */
	node_db = &port_rcv->hsr->node_db;
	node_real = find_node_by_addr_A(node_db, hsr_sp->macaddress_A);
	if (!node_real)
		/* No frame received from AddrA of this node yet */
		node_real = hsr_add_node(node_db, hsr_sp->macaddress_A,
					 HSR_SEQNR_START - 1);
	if (!node_real)
		goto done; /* No mem */
	if (node_real == node_curr)
		/* Node has already been merged */
		goto done;

	ether_addr_copy(node_real->macaddress_B, ethhdr->h_source);
	for (i = 0; i < HSR_PT_PORTS; i++) {
		if (!node_curr->time_in_stale[i] &&
		    time_after(node_curr->time_in[i], node_real->time_in[i])) {
			node_real->time_in[i] = node_curr->time_in[i];
			node_real->time_in_stale[i] =
						node_curr->time_in_stale[i];
		}
		if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
			node_real->seq_out[i] = node_curr->seq_out[i];
	}
	node_real->addr_B_port = port_rcv->type;

	list_del_rcu(&node_curr->mac_list);
	kfree_rcu(node_curr, rcu_head);

done:
	skb_push(skb, sizeof(struct hsrv1_ethhdr_sp));
}

/* '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 source
 * address with that node's "official" address (macaddress_A) so that upper
 * layers recognize where it came from.
 */
void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb)
{
	if (!skb_mac_header_was_set(skb)) {
		WARN_ONCE(1, "%s: Mac header not set\n", __func__);
		return;
	}

	memcpy(&eth_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN);
}

/* 'skb' is a frame meant for another host.
 * 'port' is the outgoing interface
 *
 * 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_node *node_src, struct sk_buff *skb,
			 struct hsr_port *port)
{
	struct hsr_node *node_dst;

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

	if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
		return;

	node_dst = find_node_by_addr_A(&port->hsr->node_db,
				       eth_hdr(skb)->h_dest);
	if (!node_dst) {
		WARN_ONCE(1, "%s: Unknown node\n", __func__);
		return;
	}
	if (port->type != node_dst->addr_B_port)
		return;

	ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B);
}

void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
			   u16 sequence_nr)
{
	/* Don't register incoming frames without a valid sequence number. This
	 * ensures entries of restarted nodes gets pruned so that they can
	 * re-register and resume communications.
	 */
	if (seq_nr_before(sequence_nr, node->seq_out[port->type]))
		return;

	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_port *port, struct hsr_node *node,
			   u16 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(struct timer_list *t)
{
	struct hsr_priv *hsr = from_timer(hsr, t, prune_timer);
	struct hsr_node *node;
	struct hsr_port *port;
	unsigned long timestamp;
	unsigned long time_a, time_b;

	rcu_read_lock();
	list_for_each_entry_rcu(node, &hsr->node_db, mac_list) {
		/* Don't prune own node. Neither time_in[HSR_PT_SLAVE_A]
		 * nor time_in[HSR_PT_SLAVE_B], will ever be updated for
		 * the master port. Thus the master node will be repeatedly
		 * pruned leading to packet loss.
		 */
		if (hsr_addr_is_self(hsr, node->macaddress_A))
			continue;

		/* 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)
				hsr_nl_ringerror(hsr, node->macaddress_A, 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->macaddress_A);
			list_del_rcu(&node->mac_list);
			/* Note that we need to free this entry later: */
			kfree_rcu(node, rcu_head);
		}
	}
	rcu_read_unlock();

	/* Restart timer */
	mod_timer(&hsr->prune_timer,
		  jiffies + msecs_to_jiffies(PRUNE_PERIOD));
}

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->macaddress_A);
		return node;
	}

	node = _pos;
	list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
		ether_addr_copy(addr, node->macaddress_A);
		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_addr_A(&hsr->node_db, addr);
	if (!node) {
		rcu_read_unlock();
		return -ENOENT;	/* No such entry */
	}

	ether_addr_copy(addr_b, node->macaddress_B);

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

	rcu_read_unlock();

	return 0;
}
Commit	Line	Data
0e7623bd	1	// SPDX-License-Identifier: GPL-2.0
70ebe4a4	2	/* Copyright 2011-2014 Autronica Fire and Security AS
f421436a AB	3	*
f421436a AB	4	* Author(s):
70ebe4a4	5	* 2011-2014 Arvid Brodin, arvid.brodin@alten.se
f421436a AB	6	*
	7	* The HSR spec says never to forward the same frame twice on the same
	8	* interface. A frame is identified by its source MAC address and its HSR
	9	* sequence number. This code keeps track of senders and their sequence numbers
	10	* to allow filtering of duplicate frames, and to detect HSR ring errors.
	11	*/
	12
	13	#include <linux/if_ether.h>
	14	#include <linux/etherdevice.h>
	15	#include <linux/slab.h>
	16	#include <linux/rculist.h>
	17	#include "hsr_main.h"
	18	#include "hsr_framereg.h"
	19	#include "hsr_netlink.h"
	20
f266a683	21	/* TODO: use hash lists for mac addresses (linux/jhash.h)? */
f421436a	22
f266a683 AB	23	/* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
f266a683 AB	24	* false otherwise.
f421436a	25	*/
f266a683	26	static bool seq_nr_after(u16 a, u16 b)
f421436a	27	{
f266a683 AB	28	/* Remove inconsistency where
	29	* seq_nr_after(a, b) == seq_nr_before(a, b)
	30	*/
5fa96778	31	if ((int)b - a == 32768)
f266a683	32	return false;
f421436a	33
5fa96778	34	return (((s16)(b - a)) < 0);
f421436a	35	}
9f73c2bb	36
f266a683 AB	37	#define seq_nr_before(a, b) seq_nr_after((b), (a))
	38	#define seq_nr_after_or_eq(a, b) (!seq_nr_before((a), (b)))
	39	#define seq_nr_before_or_eq(a, b) (!seq_nr_after((a), (b)))
f421436a	40
f266a683	41	bool hsr_addr_is_self(struct hsr_priv hsr, unsigned char addr)
f421436a	42	{
70ebe4a4	43	struct hsr_node *node;
f421436a	44
f266a683 AB	45	node = list_first_or_null_rcu(&hsr->self_node_db, struct hsr_node,
	46	mac_list);
	47	if (!node) {
	48	WARN_ONCE(1, "HSR: No self node\n");
	49	return false;
f421436a AB	50	}
f421436a AB	51
b1b4aa91	52	if (ether_addr_equal(addr, node->macaddress_A))
f266a683	53	return true;
b1b4aa91	54	if (ether_addr_equal(addr, node->macaddress_B))
f266a683	55	return true;
f421436a	56
f266a683 AB	57	return false;
f266a683 AB	58	}
f421436a AB	59
	60	/* Search for mac entry. Caller must hold rcu read lock.
	61	*/
b1b4aa91 MK	62	static struct hsr_node find_node_by_addr_A(struct list_head node_db,
b1b4aa91 MK	63	const unsigned char addr[ETH_ALEN])
f421436a	64	{
70ebe4a4	65	struct hsr_node *node;
f421436a AB	66
f421436a AB	67	list_for_each_entry_rcu(node, node_db, mac_list) {
b1b4aa91	68	if (ether_addr_equal(node->macaddress_A, addr))
f421436a AB	69	return node;
	70	}
	71
	72	return NULL;
	73	}
	74
f421436a AB	75	/* Helper for device init; the self_node_db is used in hsr_rcv() to recognize
	76	* frames from self that's been looped over the HSR ring.
	77	*/
	78	int hsr_create_self_node(struct list_head *self_node_db,
	79	unsigned char addr_a[ETH_ALEN],
	80	unsigned char addr_b[ETH_ALEN])
	81	{
70ebe4a4	82	struct hsr_node node, oldnode;
f421436a AB	83
	84	node = kmalloc(sizeof(*node), GFP_KERNEL);
	85	if (!node)
	86	return -ENOMEM;
	87
b1b4aa91 MK	88	ether_addr_copy(node->macaddress_A, addr_a);
b1b4aa91 MK	89	ether_addr_copy(node->macaddress_B, addr_b);
f421436a AB	90
	91	rcu_read_lock();
	92	oldnode = list_first_or_null_rcu(self_node_db,
4fe25bd8	93	struct hsr_node, mac_list);
f421436a AB	94	if (oldnode) {
	95	list_replace_rcu(&oldnode->mac_list, &node->mac_list);
	96	rcu_read_unlock();
	97	synchronize_rcu();
	98	kfree(oldnode);
	99	} else {
	100	rcu_read_unlock();
	101	list_add_tail_rcu(&node->mac_list, self_node_db);
	102	}
	103
	104	return 0;
	105	}
	106
b9a1e627	107	void hsr_del_self_node(struct list_head *self_node_db)
6caabe7f MW	108	{
	109	struct hsr_node *node;
	110
	111	rcu_read_lock();
	112	node = list_first_or_null_rcu(self_node_db, struct hsr_node, mac_list);
	113	rcu_read_unlock();
	114	if (node) {
	115	list_del_rcu(&node->mac_list);
	116	kfree(node);
	117	}
	118	}
f421436a	119
b9a1e627 CW	120	void hsr_del_nodes(struct list_head *node_db)
	121	{
	122	struct hsr_node *node;
	123	struct hsr_node *tmp;
	124
	125	list_for_each_entry_safe(node, tmp, node_db, mac_list)
	126	kfree(node);
	127	}
	128
b1b4aa91	129	/* Allocate an hsr_node and add it to node_db. 'addr' is the node's address_A;
f266a683 AB	130	* seq_out is used to initialize filtering of outgoing duplicate frames
f266a683 AB	131	* originating from the newly added node.
f421436a	132	*/
f266a683 AB	133	struct hsr_node hsr_add_node(struct list_head node_db, unsigned char addr[],
f266a683 AB	134	u16 seq_out)
f421436a	135	{
f266a683	136	struct hsr_node *node;
f421436a	137	unsigned long now;
f266a683	138	int i;
f421436a AB	139
	140	node = kzalloc(sizeof(*node), GFP_ATOMIC);
	141	if (!node)
	142	return NULL;
	143
b1b4aa91	144	ether_addr_copy(node->macaddress_A, addr);
f421436a AB	145
	146	/* We are only interested in time diffs here, so use current jiffies
	147	* as initialization. (0 could trigger an spurious ring error warning).
	148	*/
	149	now = jiffies;
c5a75911	150	for (i = 0; i < HSR_PT_PORTS; i++)
f421436a	151	node->time_in[i] = now;
c5a75911	152	for (i = 0; i < HSR_PT_PORTS; i++)
f266a683	153	node->seq_out[i] = seq_out;
f421436a	154
f266a683	155	list_add_tail_rcu(&node->mac_list, node_db);
f421436a AB	156
	157	return node;
	158	}
	159
f266a683 AB	160	/* Get the hsr_node from which 'skb' was sent.
f266a683 AB	161	*/
675c8da0	162	struct hsr_node hsr_get_node(struct hsr_port port, struct sk_buff *skb,
f266a683 AB	163	bool is_sup)
f266a683 AB	164	{
675c8da0	165	struct list_head *node_db = &port->hsr->node_db;
f266a683 AB	166	struct hsr_node *node;
	167	struct ethhdr *ethhdr;
	168	u16 seq_out;
	169
	170	if (!skb_mac_header_was_set(skb))
	171	return NULL;
	172
5fa96778	173	ethhdr = (struct ethhdr *)skb_mac_header(skb);
f266a683 AB	174
f266a683 AB	175	list_for_each_entry_rcu(node, node_db, mac_list) {
b1b4aa91	176	if (ether_addr_equal(node->macaddress_A, ethhdr->h_source))
f266a683	177	return node;
b1b4aa91	178	if (ether_addr_equal(node->macaddress_B, ethhdr->h_source))
f266a683 AB	179	return node;
	180	}
	181
ee1c2797	182	/* Everyone may create a node entry, connected node to a HSR device. */
f266a683	183
05947783 MK	184	if (ethhdr->h_proto == htons(ETH_P_PRP) \|\|
05947783 MK	185	ethhdr->h_proto == htons(ETH_P_HSR)) {
f266a683 AB	186	/* Use the existing sequence_nr from the tag as starting point
	187	* for filtering duplicate frames.
	188	*/
	189	seq_out = hsr_get_skb_sequence_nr(skb) - 1;
	190	} else {
675c8da0 KM	191	/* this is called also for frames from master port and
	192	* so warn only for non master ports
	193	*/
	194	if (port->type != HSR_PT_MASTER)
	195	WARN_ONCE(1, "%s: Non-HSR frame\n", __func__);
ee1c2797	196	seq_out = HSR_SEQNR_START;
f266a683 AB	197	}
	198
	199	return hsr_add_node(node_db, ethhdr->h_source, seq_out);
	200	}
	201
b1b4aa91 MK	202	/* Use the Supervision frame's info about an eventual macaddress_B for merging
b1b4aa91 MK	203	* nodes that has previously had their macaddress_B registered as a separate
f266a683 AB	204	* node.
	205	*/
	206	void hsr_handle_sup_frame(struct sk_buff skb, struct hsr_node node_curr,
	207	struct hsr_port *port_rcv)
	208	{
ee1c2797	209	struct ethhdr *ethhdr;
f266a683 AB	210	struct hsr_node *node_real;
	211	struct hsr_sup_payload *hsr_sp;
	212	struct list_head *node_db;
	213	int i;
	214
5fa96778	215	ethhdr = (struct ethhdr *)skb_mac_header(skb);
f266a683	216
ee1c2797 PH	217	/* Leave the ethernet header. */
	218	skb_pull(skb, sizeof(struct ethhdr));
	219
	220	/* And leave the HSR tag. */
	221	if (ethhdr->h_proto == htons(ETH_P_HSR))
	222	skb_pull(skb, sizeof(struct hsr_tag));
	223
	224	/* And leave the HSR sup tag. */
	225	skb_pull(skb, sizeof(struct hsr_sup_tag));
	226
5fa96778	227	hsr_sp = (struct hsr_sup_payload *)skb->data;
f266a683	228
b1b4aa91	229	/* Merge node_curr (registered on macaddress_B) into node_real */
f266a683	230	node_db = &port_rcv->hsr->node_db;
b1b4aa91	231	node_real = find_node_by_addr_A(node_db, hsr_sp->macaddress_A);
f266a683 AB	232	if (!node_real)
f266a683 AB	233	/* No frame received from AddrA of this node yet */
b1b4aa91	234	node_real = hsr_add_node(node_db, hsr_sp->macaddress_A,
f266a683 AB	235	HSR_SEQNR_START - 1);
	236	if (!node_real)
	237	goto done; /* No mem */
	238	if (node_real == node_curr)
	239	/* Node has already been merged */
	240	goto done;
	241
b1b4aa91	242	ether_addr_copy(node_real->macaddress_B, ethhdr->h_source);
f266a683 AB	243	for (i = 0; i < HSR_PT_PORTS; i++) {
	244	if (!node_curr->time_in_stale[i] &&
	245	time_after(node_curr->time_in[i], node_real->time_in[i])) {
	246	node_real->time_in[i] = node_curr->time_in[i];
d595b85a MK	247	node_real->time_in_stale[i] =
d595b85a MK	248	node_curr->time_in_stale[i];
f266a683 AB	249	}
	250	if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
	251	node_real->seq_out[i] = node_curr->seq_out[i];
	252	}
b1b4aa91	253	node_real->addr_B_port = port_rcv->type;
f266a683 AB	254
	255	list_del_rcu(&node_curr->mac_list);
	256	kfree_rcu(node_curr, rcu_head);
	257
	258	done:
ee1c2797	259	skb_push(skb, sizeof(struct hsrv1_ethhdr_sp));
f266a683 AB	260	}
f266a683 AB	261
f421436a AB	262	/* 'skb' is a frame meant for this host, that is to be passed to upper layers.
f421436a AB	263	*
f266a683	264	* If the frame was sent by a node's B interface, replace the source
b1b4aa91	265	* address with that node's "official" address (macaddress_A) so that upper
f421436a AB	266	* layers recognize where it came from.
f421436a AB	267	*/
f266a683	268	void hsr_addr_subst_source(struct hsr_node node, struct sk_buff skb)
f421436a	269	{
f421436a AB	270	if (!skb_mac_header_was_set(skb)) {
	271	WARN_ONCE(1, "%s: Mac header not set\n", __func__);
	272	return;
	273	}
f421436a	274
b1b4aa91	275	memcpy(&eth_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN);
f421436a AB	276	}
f421436a AB	277
f421436a	278	/* 'skb' is a frame meant for another host.
f266a683	279	* 'port' is the outgoing interface
f421436a AB	280	*
	281	* Substitute the target (dest) MAC address if necessary, so the it matches the
	282	* recipient interface MAC address, regardless of whether that is the
	283	* recipient's A or B interface.
	284	* This is needed to keep the packets flowing through switches that learn on
	285	* which "side" the different interfaces are.
	286	*/
f266a683	287	void hsr_addr_subst_dest(struct hsr_node node_src, struct sk_buff skb,
c5a75911	288	struct hsr_port *port)
f421436a	289	{
f266a683	290	struct hsr_node *node_dst;
f421436a	291
f266a683 AB	292	if (!skb_mac_header_was_set(skb)) {
	293	WARN_ONCE(1, "%s: Mac header not set\n", __func__);
	294	return;
	295	}
f421436a	296
f266a683 AB	297	if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
f266a683 AB	298	return;
f421436a	299
b1b4aa91 MK	300	node_dst = find_node_by_addr_A(&port->hsr->node_db,
b1b4aa91 MK	301	eth_hdr(skb)->h_dest);
f266a683 AB	302	if (!node_dst) {
	303	WARN_ONCE(1, "%s: Unknown node\n", __func__);
	304	return;
	305	}
b1b4aa91	306	if (port->type != node_dst->addr_B_port)
f266a683	307	return;
f421436a	308
b1b4aa91	309	ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B);
f421436a	310	}
f421436a	311
f266a683 AB	312	void hsr_register_frame_in(struct hsr_node node, struct hsr_port port,
f266a683 AB	313	u16 sequence_nr)
f421436a	314	{
f266a683 AB	315	/* Don't register incoming frames without a valid sequence number. This
	316	* ensures entries of restarted nodes gets pruned so that they can
	317	* re-register and resume communications.
	318	*/
	319	if (seq_nr_before(sequence_nr, node->seq_out[port->type]))
	320	return;
	321
c5a75911 AB	322	node->time_in[port->type] = jiffies;
c5a75911 AB	323	node->time_in_stale[port->type] = false;
f421436a AB	324	}
f421436a AB	325
f421436a AB	326	/* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
	327	* ethhdr->h_source address and skb->mac_header set.
	328	*
	329	* Return:
	330	* 1 if frame can be shown to have been sent recently on this interface,
	331	* 0 otherwise, or
	332	* negative error code on error
	333	*/
f266a683 AB	334	int hsr_register_frame_out(struct hsr_port port, struct hsr_node node,
f266a683 AB	335	u16 sequence_nr)
f421436a	336	{
c5a75911	337	if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]))
f421436a AB	338	return 1;
f421436a AB	339
c5a75911	340	node->seq_out[port->type] = sequence_nr;
f421436a AB	341	return 0;
	342	}
	343
c5a75911 AB	344	static struct hsr_port get_late_port(struct hsr_priv hsr,
c5a75911 AB	345	struct hsr_node *node)
f421436a	346	{
c5a75911 AB	347	if (node->time_in_stale[HSR_PT_SLAVE_A])
	348	return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
	349	if (node->time_in_stale[HSR_PT_SLAVE_B])
	350	return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
	351
	352	if (time_after(node->time_in[HSR_PT_SLAVE_B],
	353	node->time_in[HSR_PT_SLAVE_A] +
	354	msecs_to_jiffies(MAX_SLAVE_DIFF)))
	355	return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
	356	if (time_after(node->time_in[HSR_PT_SLAVE_A],
	357	node->time_in[HSR_PT_SLAVE_B] +
	358	msecs_to_jiffies(MAX_SLAVE_DIFF)))
	359	return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
f421436a	360
c5a75911	361	return NULL;
f421436a AB	362	}
f421436a AB	363
f421436a AB	364	/* Remove stale sequence_nr records. Called by timer every
	365	* HSR_LIFE_CHECK_INTERVAL (two seconds or so).
	366	*/
dda436b7	367	void hsr_prune_nodes(struct timer_list *t)
f421436a	368	{
dda436b7	369	struct hsr_priv *hsr = from_timer(hsr, t, prune_timer);
70ebe4a4	370	struct hsr_node *node;
c5a75911	371	struct hsr_port *port;
f421436a AB	372	unsigned long timestamp;
	373	unsigned long time_a, time_b;
	374
	375	rcu_read_lock();
70ebe4a4	376	list_for_each_entry_rcu(node, &hsr->node_db, mac_list) {
d2daa127 AO	377	/* Don't prune own node. Neither time_in[HSR_PT_SLAVE_A]
	378	* nor time_in[HSR_PT_SLAVE_B], will ever be updated for
	379	* the master port. Thus the master node will be repeatedly
	380	* pruned leading to packet loss.
	381	*/
	382	if (hsr_addr_is_self(hsr, node->macaddress_A))
	383	continue;
	384
f421436a	385	/* Shorthand */
c5a75911 AB	386	time_a = node->time_in[HSR_PT_SLAVE_A];
c5a75911 AB	387	time_b = node->time_in[HSR_PT_SLAVE_B];
f421436a AB	388
f421436a AB	389	/* Check for timestamps old enough to risk wrap-around */
d131fcc6	390	if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET / 2))
c5a75911	391	node->time_in_stale[HSR_PT_SLAVE_A] = true;
d131fcc6	392	if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET / 2))
c5a75911	393	node->time_in_stale[HSR_PT_SLAVE_B] = true;
f421436a AB	394
	395	/* Get age of newest frame from node.
	396	* At least one time_in is OK here; nodes get pruned long
	397	* before both time_ins can get stale
	398	*/
	399	timestamp = time_a;
c5a75911 AB	400	if (node->time_in_stale[HSR_PT_SLAVE_A] \|\|
c5a75911 AB	401	(!node->time_in_stale[HSR_PT_SLAVE_B] &&
f421436a AB	402	time_after(time_b, time_a)))
	403	timestamp = time_b;
	404
	405	/* Warn of ring error only as long as we get frames at all */
	406	if (time_is_after_jiffies(timestamp +
d131fcc6	407	msecs_to_jiffies(1.5 * MAX_SLAVE_DIFF))) {
c5a75911 AB	408	rcu_read_lock();
c5a75911 AB	409	port = get_late_port(hsr, node);
05ca6e64	410	if (port)
b1b4aa91	411	hsr_nl_ringerror(hsr, node->macaddress_A, port);
c5a75911	412	rcu_read_unlock();
f421436a AB	413	}
	414
	415	/* Prune old entries */
	416	if (time_is_before_jiffies(timestamp +
d595b85a	417	msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
b1b4aa91	418	hsr_nl_nodedown(hsr, node->macaddress_A);
f421436a AB	419	list_del_rcu(&node->mac_list);
f421436a AB	420	/* Note that we need to free this entry later: */
1aee6cc2	421	kfree_rcu(node, rcu_head);
f421436a AB	422	}
	423	}
	424	rcu_read_unlock();
5150b45f AK	425
	426	/* Restart timer */
	427	mod_timer(&hsr->prune_timer,
	428	jiffies + msecs_to_jiffies(PRUNE_PERIOD));
f421436a AB	429	}
f421436a AB	430
70ebe4a4	431	void hsr_get_next_node(struct hsr_priv hsr, void *_pos,
f421436a AB	432	unsigned char addr[ETH_ALEN])
f421436a AB	433	{
70ebe4a4	434	struct hsr_node *node;
f421436a AB	435
f421436a AB	436	if (!_pos) {
70ebe4a4 AB	437	node = list_first_or_null_rcu(&hsr->node_db,
70ebe4a4 AB	438	struct hsr_node, mac_list);
f421436a	439	if (node)
b1b4aa91	440	ether_addr_copy(addr, node->macaddress_A);
f421436a AB	441	return node;
	442	}
	443
	444	node = _pos;
70ebe4a4	445	list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
b1b4aa91	446	ether_addr_copy(addr, node->macaddress_A);
f421436a AB	447	return node;
	448	}
	449
	450	return NULL;
	451	}
	452
70ebe4a4	453	int hsr_get_node_data(struct hsr_priv *hsr,
f421436a AB	454	const unsigned char *addr,
	455	unsigned char addr_b[ETH_ALEN],
	456	unsigned int *addr_b_ifindex,
	457	int *if1_age,
	458	u16 *if1_seq,
	459	int *if2_age,
	460	u16 *if2_seq)
	461	{
70ebe4a4	462	struct hsr_node *node;
c5a75911	463	struct hsr_port *port;
f421436a AB	464	unsigned long tdiff;
f421436a AB	465
f421436a	466	rcu_read_lock();
b1b4aa91	467	node = find_node_by_addr_A(&hsr->node_db, addr);
f421436a AB	468	if (!node) {
	469	rcu_read_unlock();
	470	return -ENOENT; /* No such entry */
	471	}
	472
b1b4aa91	473	ether_addr_copy(addr_b, node->macaddress_B);
f421436a	474
c5a75911 AB	475	tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
c5a75911 AB	476	if (node->time_in_stale[HSR_PT_SLAVE_A])
f421436a AB	477	*if1_age = INT_MAX;
	478	#if HZ <= MSEC_PER_SEC
	479	else if (tdiff > msecs_to_jiffies(INT_MAX))
	480	*if1_age = INT_MAX;
	481	#endif
	482	else
	483	*if1_age = jiffies_to_msecs(tdiff);
	484
c5a75911 AB	485	tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
c5a75911 AB	486	if (node->time_in_stale[HSR_PT_SLAVE_B])
f421436a AB	487	*if2_age = INT_MAX;
	488	#if HZ <= MSEC_PER_SEC
	489	else if (tdiff > msecs_to_jiffies(INT_MAX))
	490	*if2_age = INT_MAX;
	491	#endif
	492	else
	493	*if2_age = jiffies_to_msecs(tdiff);
	494
	495	/* Present sequence numbers as if they were incoming on interface */
c5a75911 AB	496	*if1_seq = node->seq_out[HSR_PT_SLAVE_B];
c5a75911 AB	497	*if2_seq = node->seq_out[HSR_PT_SLAVE_A];
f421436a	498
b1b4aa91 MK	499	if (node->addr_B_port != HSR_PT_NONE) {
b1b4aa91 MK	500	port = hsr_port_get_hsr(hsr, node->addr_B_port);
c5a75911 AB	501	*addr_b_ifindex = port->dev->ifindex;
c5a75911 AB	502	} else {
f421436a	503	*addr_b_ifindex = -1;
c5a75911	504	}
f421436a AB	505
	506	rcu_read_unlock();
	507
	508	return 0;
	509	}