// SPDX-License-Identifier: GPL-2.0
/* Copyright 2011-2014 Autronica Fire and Security AS
*
* Author(s):
* 2011-2014 Arvid Brodin, [email protected]
*
* Frame router for HSR and PRP.
*/
#include "hsr_forward.h"
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/if_vlan.h>
#include "hsr_main.h"
#include "hsr_framereg.h"
struct hsr_node;
/* The uses I can see for these HSR supervision frames are:
* 1) Use the frames that are sent after node initialization ("HSR_TLV.Type =
* 22") to reset any sequence_nr counters belonging to that node. Useful if
* the other node's counter has been reset for some reason.
* --
* Or not - resetting the counter and bridging the frame would create a
* loop, unfortunately.
*
* 2) Use the LifeCheck frames to detect ring breaks. I.e. if no LifeCheck
* frame is received from a particular node, we know something is wrong.
* We just register these (as with normal frames) and throw them away.
*
* 3) Allow different MAC addresses for the two slave interfaces, using the
* MacAddressA field.
*/
static bool is_supervision_frame(struct hsr_priv *hsr, struct sk_buff *skb)
{
struct ethhdr *eth_hdr;
struct hsr_sup_tag *hsr_sup_tag;
struct hsrv1_ethhdr_sp *hsr_V1_hdr;
struct hsr_sup_tlv *hsr_sup_tlv;
u16 total_length = 0;
WARN_ON_ONCE(!skb_mac_header_was_set(skb));
eth_hdr = (struct ethhdr *)skb_mac_header(skb);
/* Correct addr? */
if (!ether_addr_equal(eth_hdr->h_dest,
hsr->sup_multicast_addr))
return false;
/* Correct ether type?. */
if (!(eth_hdr->h_proto == htons(ETH_P_PRP) ||
eth_hdr->h_proto == htons(ETH_P_HSR)))
return false;
/* Get the supervision header from correct location. */
if (eth_hdr->h_proto == htons(ETH_P_HSR)) { /* Okay HSRv1. */
total_length = sizeof(struct hsrv1_ethhdr_sp);
if (!pskb_may_pull(skb, total_length))
return false;
hsr_V1_hdr = (struct hsrv1_ethhdr_sp *)skb_mac_header(skb);
if (hsr_V1_hdr->hsr.encap_proto != htons(ETH_P_PRP))
return false;
hsr_sup_tag = &hsr_V1_hdr->hsr_sup;
} else {
total_length = sizeof(struct hsrv0_ethhdr_sp);
if (!pskb_may_pull(skb, total_length))
return false;
hsr_sup_tag =
&((struct hsrv0_ethhdr_sp *)skb_mac_header(skb))->hsr_sup;
}
if (hsr_sup_tag->tlv.HSR_TLV_type != HSR_TLV_ANNOUNCE &&
hsr_sup_tag->tlv.HSR_TLV_type != HSR_TLV_LIFE_CHECK &&
hsr_sup_tag->tlv.HSR_TLV_type != PRP_TLV_LIFE_CHECK_DD &&
hsr_sup_tag->tlv.HSR_TLV_type != PRP_TLV_LIFE_CHECK_DA)
return false;
if (hsr_sup_tag->tlv.HSR_TLV_length != 12 &&
hsr_sup_tag->tlv.HSR_TLV_length != sizeof(struct hsr_sup_payload))
return false;
/* Get next tlv */
total_length += hsr_sup_tag->tlv.HSR_TLV_length;
if (!pskb_may_pull(skb, total_length))
return false;
skb_pull(skb, total_length);
hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
skb_push(skb, total_length);
/* if this is a redbox supervision frame we need to verify
* that more data is available
*/
if (hsr_sup_tlv->HSR_TLV_type == PRP_TLV_REDBOX_MAC) {
/* tlv length must be a length of a mac address */
if (hsr_sup_tlv->HSR_TLV_length != sizeof(struct hsr_sup_payload))
return false;
/* make sure another tlv follows */
total_length += sizeof(struct hsr_sup_tlv) + hsr_sup_tlv->HSR_TLV_length;
if (!pskb_may_pull(skb, total_length))
return false;
/* get next tlv */
skb_pull(skb, total_length);
hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
skb_push(skb, total_length);
}
/* end of tlvs must follow at the end */
if (hsr_sup_tlv->HSR_TLV_type == HSR_TLV_EOT &&
hsr_sup_tlv->HSR_TLV_length != 0)
return false;
return true;
}
static bool is_proxy_supervision_frame(struct hsr_priv *hsr,
struct sk_buff *skb)
{
struct hsr_sup_payload *payload;
struct ethhdr *eth_hdr;
u16 total_length = 0;
eth_hdr = (struct ethhdr *)skb_mac_header(skb);
/* Get the HSR protocol revision. */
if (eth_hdr->h_proto == htons(ETH_P_HSR))
total_length = sizeof(struct hsrv1_ethhdr_sp);
else
total_length = sizeof(struct hsrv0_ethhdr_sp);
if (!pskb_may_pull(skb, total_length + sizeof(struct hsr_sup_payload)))
return false;
skb_pull(skb, total_length);
payload = (struct hsr_sup_payload *)skb->data;
skb_push(skb, total_length);
/* For RedBox (HSR-SAN) check if we have received the supervision
* frame with MAC addresses from own ProxyNodeTable.
*/
return hsr_is_node_in_db(&hsr->proxy_node_db,
payload->macaddress_A);
}
static struct sk_buff *create_stripped_skb_hsr(struct sk_buff *skb_in,
struct hsr_frame_info *frame)
{
struct sk_buff *skb;
int copylen;
unsigned char *dst, *src;
skb_pull(skb_in, HSR_HLEN);
skb = __pskb_copy(skb_in, skb_headroom(skb_in) - HSR_HLEN, GFP_ATOMIC);
skb_push(skb_in, HSR_HLEN);
if (!skb)
return NULL;
skb_reset_mac_header(skb);
if (skb->ip_summed == CHECKSUM_PARTIAL)
skb->csum_start -= HSR_HLEN;
copylen = 2 * ETH_ALEN;
if (frame->is_vlan)
copylen += VLAN_HLEN;
src = skb_mac_header(skb_in);
dst = skb_mac_header(skb);
memcpy(dst, src, copylen);
skb->protocol = eth_hdr(skb)->h_proto;
return skb;
}
struct sk_buff *hsr_get_untagged_frame(struct hsr_frame_info *frame,
struct hsr_port *port)
{
if (!frame->skb_std) {
if (frame->skb_hsr)
frame->skb_std =
create_stripped_skb_hsr(frame->skb_hsr, frame);
else
netdev_warn_once(port->dev,
"Unexpected frame received in hsr_get_untagged_frame()\n");
if (!frame->skb_std)
return NULL;
}
return skb_clone(frame->skb_std, GFP_ATOMIC);
}
struct sk_buff *prp_get_untagged_frame(struct hsr_frame_info *frame,
struct hsr_port *port)
{
if (!frame->skb_std) {
if (frame->skb_prp) {
/* trim the skb by len - HSR_HLEN to exclude RCT */
skb_trim(frame->skb_prp,
frame->skb_prp->len - HSR_HLEN);
frame->skb_std =
__pskb_copy(frame->skb_prp,
skb_headroom(frame->skb_prp),
GFP_ATOMIC);
} else {
/* Unexpected */
WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n",
__FILE__, __LINE__, port->dev->name);
return NULL;
}
}
return skb_clone(frame->skb_std, GFP_ATOMIC);
}
static void prp_set_lan_id(struct prp_rct *trailer,
struct hsr_port *port)
{
int lane_id;
if (port->type == HSR_PT_SLAVE_A)
lane_id = 0;
else
lane_id = 1;
/* Add net_id in the upper 3 bits of lane_id */
lane_id |= port->hsr->net_id;
set_prp_lan_id(trailer, lane_id);
}
/* Tailroom for PRP rct should have been created before calling this */
static struct sk_buff *prp_fill_rct(struct sk_buff *skb,
struct hsr_frame_info *frame,
struct hsr_port *port)
{
struct prp_rct *trailer;
int min_size = ETH_ZLEN;
int lsdu_size;
if (!skb)
return skb;
if (frame->is_vlan)
min_size = VLAN_ETH_ZLEN;
if (skb_put_padto(skb, min_size))
return NULL;
trailer = (struct prp_rct *)skb_put(skb, HSR_HLEN);
lsdu_size = skb->len - 14;
if (frame->is_vlan)
lsdu_size -= 4;
prp_set_lan_id(trailer, port);
set_prp_LSDU_size(trailer, lsdu_size);
trailer->sequence_nr = htons(frame->sequence_nr);
trailer->PRP_suffix = htons(ETH_P_PRP);
skb->protocol = eth_hdr(skb)->h_proto;
return skb;
}
static void hsr_set_path_id(struct hsr_ethhdr *hsr_ethhdr,
struct hsr_port *port)
{
int path_id;
if (port->type == HSR_PT_SLAVE_A)
path_id = 0;
else
path_id = 1;
set_hsr_tag_path(&hsr_ethhdr->hsr_tag, path_id);
}
static struct sk_buff *hsr_fill_tag(struct sk_buff *skb,
struct hsr_frame_info *frame,
struct hsr_port *port, u8 proto_version)
{
struct hsr_ethhdr *hsr_ethhdr;
int lsdu_size;
/* pad to minimum packet size which is 60 + 6 (HSR tag) */
if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
return NULL;
lsdu_size = skb->len - 14;
if (frame->is_vlan)
lsdu_size -= 4;
hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(skb);
hsr_set_path_id(hsr_ethhdr, port);
set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size);
hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr);
hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
hsr_ethhdr->ethhdr.h_proto = htons(proto_version ?
ETH_P_HSR : ETH_P_PRP);
skb->protocol = hsr_ethhdr->ethhdr.h_proto;
return skb;
}
/* If the original frame was an HSR tagged frame, just clone it to be sent
* unchanged. Otherwise, create a private frame especially tagged for 'port'.
*/
struct sk_buff *hsr_create_tagged_frame(struct hsr_frame_info *frame,
struct hsr_port *port)
{
unsigned char *dst, *src;
struct sk_buff *skb;
int movelen;
if (frame->skb_hsr) {
struct hsr_ethhdr *hsr_ethhdr =
(struct hsr_ethhdr *)skb_mac_header(frame->skb_hsr);
/* set the lane id properly */
hsr_set_path_id(hsr_ethhdr, port);
return skb_clone(frame->skb_hsr, GFP_ATOMIC);
} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
return skb_clone(frame->skb_std, GFP_ATOMIC);
}
/* Create the new skb with enough headroom to fit the HSR tag */
skb = __pskb_copy(frame->skb_std,
skb_headroom(frame->skb_std) + HSR_HLEN, GFP_ATOMIC);
if (!skb)
return NULL;
skb_reset_mac_header(skb);
if (skb->ip_summed == CHECKSUM_PARTIAL)
skb->csum_start += HSR_HLEN;
movelen = ETH_HLEN;
if (frame->is_vlan)
movelen += VLAN_HLEN;
src = skb_mac_header(skb);
dst = skb_push(skb, HSR_HLEN);
memmove(dst, src, movelen);
skb_reset_mac_header(skb);
/* skb_put_padto free skb on error and hsr_fill_tag returns NULL in
* that case
*/
return hsr_fill_tag(skb, frame, port, port->hsr->prot_version);
}
struct sk_buff *prp_create_tagged_frame(struct hsr_frame_info *frame,
struct hsr_port *port)
{
struct sk_buff *skb;
if (frame->skb_prp) {
struct prp_rct *trailer = skb_get_PRP_rct(frame->skb_prp);
if (trailer) {
prp_set_lan_id(trailer, port);
} else {
WARN_ONCE(!trailer, "errored PRP skb");
return NULL;
}
return skb_clone(frame->skb_prp, GFP_ATOMIC);
} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
return skb_clone(frame->skb_std, GFP_ATOMIC);
}
skb = skb_copy_expand(frame->skb_std, 0,
skb_tailroom(frame->skb_std) + HSR_HLEN,
GFP_ATOMIC);
return prp_fill_rct(skb, frame, port);
}
static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev,
struct hsr_node *node_src)
{
bool was_multicast_frame;
int res, recv_len;
was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST);
hsr_addr_subst_source(node_src, skb);
skb_pull(skb, ETH_HLEN);
recv_len = skb->len;
res = netif_rx(skb);
if (res == NET_RX_DROP) {
dev->stats.rx_dropped++;
} else {
dev->stats.rx_packets++;
dev->stats.rx_bytes += recv_len;
if (was_multicast_frame)
dev->stats.multicast++;
}
}
static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port,
struct hsr_frame_info *frame)
{
if (frame->port_rcv->type == HSR_PT_MASTER) {
hsr_addr_subst_dest(frame->node_src, skb, port);
/* Address substitution (IEC62439-3 pp 26, 50): replace mac
* address of outgoing frame with that of the outgoing slave's.
*/
ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr);
}
/* When HSR node is used as RedBox - the frame received from HSR ring
* requires source MAC address (SA) replacement to one which can be
* recognized by SAN devices (otherwise, frames are dropped by switch)
*/
if (port->type == HSR_PT_INTERLINK)
ether_addr_copy(eth_hdr(skb)->h_source,
port->hsr->macaddress_redbox);
return dev_queue_xmit(skb);
}
bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
{
return ((frame->port_rcv->type == HSR_PT_SLAVE_A &&
port->type == HSR_PT_SLAVE_B) ||
(frame->port_rcv->type == HSR_PT_SLAVE_B &&
port->type == HSR_PT_SLAVE_A));
}
bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
{
struct sk_buff *skb;
if (port->dev->features & NETIF_F_HW_HSR_FWD)
return prp_drop_frame(frame, port);
/* RedBox specific frames dropping policies
*
* Do not send HSR supervisory frames to SAN devices
*/
if (frame->is_supervision && port->type == HSR_PT_INTERLINK)
return true;
/* Do not forward to other HSR port (A or B) unicast frames which
* are addressed to interlink port (and are in the ProxyNodeTable).
*/
skb = frame->skb_hsr;
if (skb && prp_drop_frame(frame, port) &&
is_unicast_ether_addr(eth_hdr(skb)->h_dest) &&
hsr_is_node_in_db(&port->hsr->proxy_node_db,
eth_hdr(skb)->h_dest)) {
return true;
}
/* Do not forward to port C (Interlink) frames from nodes A and B
* if DA is in NodeTable.
*/
if ((frame->port_rcv->type == HSR_PT_SLAVE_A ||
frame->port_rcv->type == HSR_PT_SLAVE_B) &&
port->type == HSR_PT_INTERLINK) {
skb = frame->skb_hsr;
if (skb && is_unicast_ether_addr(eth_hdr(skb)->h_dest) &&
hsr_is_node_in_db(&port->hsr->node_db,
eth_hdr(skb)->h_dest)) {
return true;
}
}
/* Do not forward to port A and B unicast frames received on the
* interlink port if it is addressed to one of nodes registered in
* the ProxyNodeTable.
*/
if ((port->type == HSR_PT_SLAVE_A || port->type == HSR_PT_SLAVE_B) &&
frame->port_rcv->type == HSR_PT_INTERLINK) {
skb = frame->skb_std;
if (skb && is_unicast_ether_addr(eth_hdr(skb)->h_dest) &&
hsr_is_node_in_db(&port->hsr->proxy_node_db,
eth_hdr(skb)->h_dest)) {
return true;
}
}
return false;
}
/* Forward the frame through all devices except:
* - Back through the receiving device
* - If it's a HSR frame: through a device where it has passed before
* - if it's a PRP frame: through another PRP slave device (no bridge)
* - To the local HSR master only if the frame is directly addressed to it, or
* a non-supervision multicast or broadcast frame.
*
* HSR slave devices should insert a HSR tag into the frame, or forward the
* frame unchanged if it's already tagged. Interlink devices should strip HSR
* tags if they're of the non-HSR type (but only after duplicate discard). The
* master device always strips HSR tags.
*/
static void hsr_forward_do(struct hsr_frame_info *frame)
{
struct hsr_port *port;
struct sk_buff *skb;
bool sent = false;
hsr_for_each_port(frame->port_rcv->hsr, port) {
struct hsr_priv *hsr = port->hsr;
/* Don't send frame back the way it came */
if (port == frame->port_rcv)
continue;
/* Don't deliver locally unless we should */
if (port->type == HSR_PT_MASTER && !frame->is_local_dest)
continue;
/* Deliver frames directly addressed to us to master only */
if (port->type != HSR_PT_MASTER && frame->is_local_exclusive)
continue;
/* If hardware duplicate generation is enabled, only send out
* one port.
*/
if ((port->dev->features & NETIF_F_HW_HSR_DUP) && sent)
continue;
/* Don't send frame over port where it has been sent before.
* Also for SAN, this shouldn't be done.
*/
if (!frame->is_from_san &&
hsr_register_frame_out(port, frame->node_src,
frame->sequence_nr))
continue;
if (frame->is_supervision && port->type == HSR_PT_MASTER &&
!frame->is_proxy_supervision) {
hsr_handle_sup_frame(frame);
continue;
}
/* Check if frame is to be dropped. Eg. for PRP no forward
* between ports, or sending HSR supervision to RedBox.
*/
if (hsr->proto_ops->drop_frame &&
hsr->proto_ops->drop_frame(frame, port))
continue;
if (port->type == HSR_PT_SLAVE_A ||
port->type == HSR_PT_SLAVE_B)
skb = hsr->proto_ops->create_tagged_frame(frame, port);
else
skb = hsr->proto_ops->get_untagged_frame(frame, port);
if (!skb) {
frame->port_rcv->dev->stats.rx_dropped++;
continue;
}
skb->dev = port->dev;
if (port->type == HSR_PT_MASTER) {
hsr_deliver_master(skb, port->dev, frame->node_src);
} else {
if (!hsr_xmit(skb, port, frame))
if (port->type == HSR_PT_SLAVE_A ||
port->type == HSR_PT_SLAVE_B)
sent = true;
}
}
}
static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb,
struct hsr_frame_info *frame)
{
if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) {
frame->is_local_exclusive = true;
skb->pkt_type = PACKET_HOST;
} else {
frame->is_local_exclusive = false;
}
if (skb->pkt_type == PACKET_HOST ||
skb->pkt_type == PACKET_MULTICAST ||
skb->pkt_type == PACKET_BROADCAST) {
frame->is_local_dest = true;
} else {
frame->is_local_dest = false;
}
}
static void handle_std_frame(struct sk_buff *skb,
struct hsr_frame_info *frame)
{
struct hsr_port *port = frame->port_rcv;
struct hsr_priv *hsr = port->hsr;
frame->skb_hsr = NULL;
frame->skb_prp = NULL;
frame->skb_std = skb;
if (port->type != HSR_PT_MASTER)
frame->is_from_san = true;
if (port->type == HSR_PT_MASTER ||
port->type == HSR_PT_INTERLINK) {
/* Sequence nr for the master/interlink node */
lockdep_assert_held(&hsr->seqnr_lock);
frame->sequence_nr = hsr->sequence_nr;
hsr->sequence_nr++;
}
}
int hsr_fill_frame_info(__be16 proto, struct sk_buff *skb,
struct hsr_frame_info *frame)
{
struct hsr_port *port = frame->port_rcv;
struct hsr_priv *hsr = port->hsr;
/* HSRv0 supervisory frames double as a tag so treat them as tagged. */
if ((!hsr->prot_version && proto == htons(ETH_P_PRP)) ||
proto == htons(ETH_P_HSR)) {
/* Check if skb contains hsr_ethhdr */
if (skb->mac_len < sizeof(struct hsr_ethhdr))
return -EINVAL;
/* HSR tagged frame :- Data or Supervision */
frame->skb_std = NULL;
frame->skb_prp = NULL;
frame->skb_hsr = skb;
frame->sequence_nr = hsr_get_skb_sequence_nr(skb);
return 0;
}
/* Standard frame or PRP from master port */
handle_std_frame(skb, frame);
return 0;
}
int prp_fill_frame_info(__be16 proto, struct sk_buff *skb,
struct hsr_frame_info *frame)
{
/* Supervision frame */
struct prp_rct *rct = skb_get_PRP_rct(skb);
if (rct &&
prp_check_lsdu_size(skb, rct, frame->is_supervision)) {
frame->skb_hsr = NULL;
frame->skb_std = NULL;
frame->skb_prp = skb;
frame->sequence_nr = prp_get_skb_sequence_nr(rct);
return 0;
}
handle_std_frame(skb, frame);
return 0;
}
static int fill_frame_info(struct hsr_frame_info *frame,
struct sk_buff *skb, struct hsr_port *port)
{
struct hsr_priv *hsr = port->hsr;
struct hsr_vlan_ethhdr *vlan_hdr;
struct list_head *n_db;
struct ethhdr *ethhdr;
__be16 proto;
int ret;
/* Check if skb contains ethhdr */
if (skb->mac_len < sizeof(struct ethhdr))
return -EINVAL;
memset(frame, 0, sizeof(*frame));
frame->is_supervision = is_supervision_frame(port->hsr, skb);
if (frame->is_supervision && hsr->redbox)
frame->is_proxy_supervision =
is_proxy_supervision_frame(port->hsr, skb);
n_db = &hsr->node_db;
if (port->type == HSR_PT_INTERLINK)
n_db = &hsr->proxy_node_db;
frame->node_src = hsr_get_node(port, n_db, skb,
frame->is_supervision, port->type);
if (!frame->node_src)
return -1; /* Unknown node and !is_supervision, or no mem */
ethhdr = (struct ethhdr *)skb_mac_header(skb);
frame->is_vlan = false;
proto = ethhdr->h_proto;
if (proto == htons(ETH_P_8021Q))
frame->is_vlan = true;
if (frame->is_vlan) {
vlan_hdr = (struct hsr_vlan_ethhdr *)ethhdr;
proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto;
/* FIXME: */
netdev_warn_once(skb->dev, "VLAN not yet supported");
return -EINVAL;
}
frame->is_from_san = false;
frame->port_rcv = port;
ret = hsr->proto_ops->fill_frame_info(proto, skb, frame);
if (ret)
return ret;
check_local_dest(port->hsr, skb, frame);
return 0;
}
/* Must be called holding rcu read lock (because of the port parameter) */
void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
{
struct hsr_frame_info frame;
rcu_read_lock();
if (fill_frame_info(&frame, skb, port) < 0)
goto out_drop;
hsr_register_frame_in(frame.node_src, port, frame.sequence_nr);
hsr_forward_do(&frame);
rcu_read_unlock();
/* Gets called for ingress frames as well as egress from master port.
* So check and increment stats for master port only here.
*/
if (port->type == HSR_PT_MASTER || port->type == HSR_PT_INTERLINK) {
port->dev->stats.tx_packets++;
port->dev->stats.tx_bytes += skb->len;
}
kfree_skb(frame.skb_hsr);
kfree_skb(frame.skb_prp);
kfree_skb(frame.skb_std);
return;
out_drop:
rcu_read_unlock();
port->dev->stats.tx_dropped++;
kfree_skb(skb);
}
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