| // 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_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); |
| } |
| } |
| |
| /* 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(ð_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) { |
| /* 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; |
| } |