linux/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, [email protected]
 *
 * 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.
 * Same code handles filtering of duplicates for PRP as well.
 */

#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"

/* 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)
{ … }

#define seq_nr_before(a, b) …
#define seq_nr_before_or_eq(a, b) …

bool hsr_addr_is_redbox(struct hsr_priv *hsr, unsigned char *addr)
{ … }

bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr)
{ … }

/* 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])
{ … }

/* Check if node for a given MAC address is already present in data base
 */
bool hsr_is_node_in_db(struct list_head *node_db,
		       const unsigned char addr[ETH_ALEN])
{ … }

/* Helper for device init; the self_node is used in hsr_rcv() to recognize
 * frames from self that's been looped over the HSR ring.
 */
int hsr_create_self_node(struct hsr_priv *hsr,
			 const unsigned char addr_a[ETH_ALEN],
			 const unsigned char addr_b[ETH_ALEN])
{ … }

void hsr_del_self_node(struct hsr_priv *hsr)
{ … }

void hsr_del_nodes(struct list_head *node_db)
{ … }

void prp_handle_san_frame(bool san, enum hsr_port_type port,
			  struct hsr_node *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.
 */
static struct hsr_node *hsr_add_node(struct hsr_priv *hsr,
				     struct list_head *node_db,
				     unsigned char addr[],
				     u16 seq_out, bool san,
				     enum hsr_port_type rx_port)
{ … }

void prp_update_san_info(struct hsr_node *node, bool is_sup)
{ … }

/* Get the hsr_node from which 'skb' was sent.
 */
struct hsr_node *hsr_get_node(struct hsr_port *port, struct list_head *node_db,
			      struct sk_buff *skb, bool is_sup,
			      enum hsr_port_type rx_port)
{ … }

/* 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 hsr_frame_info *frame)
{ … }

/* '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)
{ … }

/* '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)
{ … }

void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
			   u16 sequence_nr)
{ … }

/* '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)
{ … }

static struct hsr_port *get_late_port(struct hsr_priv *hsr,
				      struct hsr_node *node)
{ … }

/* 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)
{ … }

void hsr_prune_proxy_nodes(struct timer_list *t)
{ … }

void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
			unsigned char addr[ETH_ALEN])
{ … }

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)
{ … }