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Release 4.8 net/hsr/hsr_framereg.c

Directory: net/hsr
/* 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,
 * 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)?    */

/* 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); }


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#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->MacAddressA)) return true; if (ether_addr_equal(addr, node->MacAddressB)) return true; return false; }


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/* 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; }


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/* 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; }


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joe perchesjoe perches21.47%133.33%

/* Allocate an hsr_node and add it to node_db. 'addr' is the node's AddressA; * 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->MacAddressA, 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; }


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/* Get the hsr_node from which 'skb' was sent. */
struct hsr_node *hsr_get_node(struct list_head *node_db, struct sk_buff *skb, bool is_sup) { 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->MacAddressA, ethhdr->h_source)) return node; if (ether_addr_equal(node->MacAddressB, 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 { 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); }


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peter heisepeter heise116.92%125.00%

/* Use the Supervision frame's info about an eventual MacAddressB for merging * nodes that has previously had their MacAddressB 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 MacAddressB) into node_real */ node_db = &port_rcv->hsr->node_db; node_real = find_node_by_AddrA(node_db, hsr_sp->MacAddressA); if (!node_real) /* No frame received from AddrA of this node yet */ node_real = hsr_add_node(node_db, hsr_sp->MacAddressA, 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->MacAddressB, 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->AddrB_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)); }


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peter heisepeter heise5617.18%125.00%

/* '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 (MacAddressA) 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->MacAddressA, ETH_ALEN); }


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/* '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_AddrA(&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->AddrB_port) return; ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->MacAddressB); }


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joe perchesjoe perches10.83%120.00%

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; }


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/* '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; }


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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; }


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/* 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(); }


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wei yongjunwei yongjun20.81%120.00%

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; }


arvid brodinarvid brodin9297.87%266.67%
joe perchesjoe perches22.13%133.33%

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; }


arvid brodinarvid brodin27499.64%480.00%
joe perchesjoe perches10.36%120.00%

Overall Contributors

arvid brodinarvid brodin197696.34%666.67%
peter heisepeter heise673.27%111.11%
joe perchesjoe perches60.29%111.11%
wei yongjunwei yongjun20.10%111.11%
Directory: net/hsr
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