swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
Tip revision: ba47d845d715a010f7b51f6f89bae32845e6acb7 authored by Linus Torvalds on 19 July 2020, 22:41:18 UTC
Linux 5.8-rc6
Linux 5.8-rc6
Tip revision: ba47d84
br_mrp.c
// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/mrp_bridge.h>
#include "br_private_mrp.h"
static const u8 mrp_test_dmac[ETH_ALEN] = { 0x1, 0x15, 0x4e, 0x0, 0x0, 0x1 };
static struct net_bridge_port *br_mrp_get_port(struct net_bridge *br,
u32 ifindex)
{
struct net_bridge_port *res = NULL;
struct net_bridge_port *port;
list_for_each_entry(port, &br->port_list, list) {
if (port->dev->ifindex == ifindex) {
res = port;
break;
}
}
return res;
}
static struct br_mrp *br_mrp_find_id(struct net_bridge *br, u32 ring_id)
{
struct br_mrp *res = NULL;
struct br_mrp *mrp;
list_for_each_entry_rcu(mrp, &br->mrp_list, list,
lockdep_rtnl_is_held()) {
if (mrp->ring_id == ring_id) {
res = mrp;
break;
}
}
return res;
}
static bool br_mrp_unique_ifindex(struct net_bridge *br, u32 ifindex)
{
struct br_mrp *mrp;
list_for_each_entry_rcu(mrp, &br->mrp_list, list,
lockdep_rtnl_is_held()) {
struct net_bridge_port *p;
p = rtnl_dereference(mrp->p_port);
if (p && p->dev->ifindex == ifindex)
return false;
p = rtnl_dereference(mrp->s_port);
if (p && p->dev->ifindex == ifindex)
return false;
}
return true;
}
static struct br_mrp *br_mrp_find_port(struct net_bridge *br,
struct net_bridge_port *p)
{
struct br_mrp *res = NULL;
struct br_mrp *mrp;
list_for_each_entry_rcu(mrp, &br->mrp_list, list,
lockdep_rtnl_is_held()) {
if (rcu_access_pointer(mrp->p_port) == p ||
rcu_access_pointer(mrp->s_port) == p) {
res = mrp;
break;
}
}
return res;
}
static int br_mrp_next_seq(struct br_mrp *mrp)
{
mrp->seq_id++;
return mrp->seq_id;
}
static struct sk_buff *br_mrp_skb_alloc(struct net_bridge_port *p,
const u8 *src, const u8 *dst)
{
struct ethhdr *eth_hdr;
struct sk_buff *skb;
__be16 *version;
skb = dev_alloc_skb(MRP_MAX_FRAME_LENGTH);
if (!skb)
return NULL;
skb->dev = p->dev;
skb->protocol = htons(ETH_P_MRP);
skb->priority = MRP_FRAME_PRIO;
skb_reserve(skb, sizeof(*eth_hdr));
eth_hdr = skb_push(skb, sizeof(*eth_hdr));
ether_addr_copy(eth_hdr->h_dest, dst);
ether_addr_copy(eth_hdr->h_source, src);
eth_hdr->h_proto = htons(ETH_P_MRP);
version = skb_put(skb, sizeof(*version));
*version = cpu_to_be16(MRP_VERSION);
return skb;
}
static void br_mrp_skb_tlv(struct sk_buff *skb,
enum br_mrp_tlv_header_type type,
u8 length)
{
struct br_mrp_tlv_hdr *hdr;
hdr = skb_put(skb, sizeof(*hdr));
hdr->type = type;
hdr->length = length;
}
static void br_mrp_skb_common(struct sk_buff *skb, struct br_mrp *mrp)
{
struct br_mrp_common_hdr *hdr;
br_mrp_skb_tlv(skb, BR_MRP_TLV_HEADER_COMMON, sizeof(*hdr));
hdr = skb_put(skb, sizeof(*hdr));
hdr->seq_id = cpu_to_be16(br_mrp_next_seq(mrp));
memset(hdr->domain, 0xff, MRP_DOMAIN_UUID_LENGTH);
}
static struct sk_buff *br_mrp_alloc_test_skb(struct br_mrp *mrp,
struct net_bridge_port *p,
enum br_mrp_port_role_type port_role)
{
struct br_mrp_ring_test_hdr *hdr = NULL;
struct sk_buff *skb = NULL;
if (!p)
return NULL;
skb = br_mrp_skb_alloc(p, p->dev->dev_addr, mrp_test_dmac);
if (!skb)
return NULL;
br_mrp_skb_tlv(skb, BR_MRP_TLV_HEADER_RING_TEST, sizeof(*hdr));
hdr = skb_put(skb, sizeof(*hdr));
hdr->prio = cpu_to_be16(mrp->prio);
ether_addr_copy(hdr->sa, p->br->dev->dev_addr);
hdr->port_role = cpu_to_be16(port_role);
hdr->state = cpu_to_be16(mrp->ring_state);
hdr->transitions = cpu_to_be16(mrp->ring_transitions);
hdr->timestamp = cpu_to_be32(jiffies_to_msecs(jiffies));
br_mrp_skb_common(skb, mrp);
br_mrp_skb_tlv(skb, BR_MRP_TLV_HEADER_END, 0x0);
return skb;
}
/* This function is continuously called in the following cases:
* - when node role is MRM, in this case test_monitor is always set to false
* because it needs to notify the userspace that the ring is open and needs to
* send MRP_Test frames
* - when node role is MRA, there are 2 subcases:
* - when MRA behaves as MRM, in this case is similar with MRM role
* - when MRA behaves as MRC, in this case test_monitor is set to true,
* because it needs to detect when it stops seeing MRP_Test frames
* from MRM node but it doesn't need to send MRP_Test frames.
*/
static void br_mrp_test_work_expired(struct work_struct *work)
{
struct delayed_work *del_work = to_delayed_work(work);
struct br_mrp *mrp = container_of(del_work, struct br_mrp, test_work);
struct net_bridge_port *p;
bool notify_open = false;
struct sk_buff *skb;
if (time_before_eq(mrp->test_end, jiffies))
return;
if (mrp->test_count_miss < mrp->test_max_miss) {
mrp->test_count_miss++;
} else {
/* Notify that the ring is open only if the ring state is
* closed, otherwise it would continue to notify at every
* interval.
* Also notify that the ring is open when the node has the
* role MRA and behaves as MRC. The reason is that the
* userspace needs to know when the MRM stopped sending
* MRP_Test frames so that the current node to try to take
* the role of a MRM.
*/
if (mrp->ring_state == BR_MRP_RING_STATE_CLOSED ||
mrp->test_monitor)
notify_open = true;
}
rcu_read_lock();
p = rcu_dereference(mrp->p_port);
if (p) {
if (!mrp->test_monitor) {
skb = br_mrp_alloc_test_skb(mrp, p,
BR_MRP_PORT_ROLE_PRIMARY);
if (!skb)
goto out;
skb_reset_network_header(skb);
dev_queue_xmit(skb);
}
if (notify_open && !mrp->ring_role_offloaded)
br_mrp_port_open(p->dev, true);
}
p = rcu_dereference(mrp->s_port);
if (p) {
if (!mrp->test_monitor) {
skb = br_mrp_alloc_test_skb(mrp, p,
BR_MRP_PORT_ROLE_SECONDARY);
if (!skb)
goto out;
skb_reset_network_header(skb);
dev_queue_xmit(skb);
}
if (notify_open && !mrp->ring_role_offloaded)
br_mrp_port_open(p->dev, true);
}
out:
rcu_read_unlock();
queue_delayed_work(system_wq, &mrp->test_work,
usecs_to_jiffies(mrp->test_interval));
}
/* Deletes the MRP instance.
* note: called under rtnl_lock
*/
static void br_mrp_del_impl(struct net_bridge *br, struct br_mrp *mrp)
{
struct net_bridge_port *p;
u8 state;
/* Stop sending MRP_Test frames */
cancel_delayed_work_sync(&mrp->test_work);
br_mrp_switchdev_send_ring_test(br, mrp, 0, 0, 0, 0);
br_mrp_switchdev_del(br, mrp);
/* Reset the ports */
p = rtnl_dereference(mrp->p_port);
if (p) {
spin_lock_bh(&br->lock);
state = netif_running(br->dev) ?
BR_STATE_FORWARDING : BR_STATE_DISABLED;
p->state = state;
p->flags &= ~BR_MRP_AWARE;
spin_unlock_bh(&br->lock);
br_mrp_port_switchdev_set_state(p, state);
rcu_assign_pointer(mrp->p_port, NULL);
}
p = rtnl_dereference(mrp->s_port);
if (p) {
spin_lock_bh(&br->lock);
state = netif_running(br->dev) ?
BR_STATE_FORWARDING : BR_STATE_DISABLED;
p->state = state;
p->flags &= ~BR_MRP_AWARE;
spin_unlock_bh(&br->lock);
br_mrp_port_switchdev_set_state(p, state);
rcu_assign_pointer(mrp->s_port, NULL);
}
list_del_rcu(&mrp->list);
kfree_rcu(mrp, rcu);
}
/* Adds a new MRP instance.
* note: called under rtnl_lock
*/
int br_mrp_add(struct net_bridge *br, struct br_mrp_instance *instance)
{
struct net_bridge_port *p;
struct br_mrp *mrp;
int err;
/* If the ring exists, it is not possible to create another one with the
* same ring_id
*/
mrp = br_mrp_find_id(br, instance->ring_id);
if (mrp)
return -EINVAL;
if (!br_mrp_get_port(br, instance->p_ifindex) ||
!br_mrp_get_port(br, instance->s_ifindex))
return -EINVAL;
/* It is not possible to have the same port part of multiple rings */
if (!br_mrp_unique_ifindex(br, instance->p_ifindex) ||
!br_mrp_unique_ifindex(br, instance->s_ifindex))
return -EINVAL;
mrp = kzalloc(sizeof(*mrp), GFP_KERNEL);
if (!mrp)
return -ENOMEM;
mrp->ring_id = instance->ring_id;
mrp->prio = instance->prio;
p = br_mrp_get_port(br, instance->p_ifindex);
spin_lock_bh(&br->lock);
p->state = BR_STATE_FORWARDING;
p->flags |= BR_MRP_AWARE;
spin_unlock_bh(&br->lock);
rcu_assign_pointer(mrp->p_port, p);
p = br_mrp_get_port(br, instance->s_ifindex);
spin_lock_bh(&br->lock);
p->state = BR_STATE_FORWARDING;
p->flags |= BR_MRP_AWARE;
spin_unlock_bh(&br->lock);
rcu_assign_pointer(mrp->s_port, p);
INIT_DELAYED_WORK(&mrp->test_work, br_mrp_test_work_expired);
list_add_tail_rcu(&mrp->list, &br->mrp_list);
err = br_mrp_switchdev_add(br, mrp);
if (err)
goto delete_mrp;
return 0;
delete_mrp:
br_mrp_del_impl(br, mrp);
return err;
}
/* Deletes the MRP instance from which the port is part of
* note: called under rtnl_lock
*/
void br_mrp_port_del(struct net_bridge *br, struct net_bridge_port *p)
{
struct br_mrp *mrp = br_mrp_find_port(br, p);
/* If the port is not part of a MRP instance just bail out */
if (!mrp)
return;
br_mrp_del_impl(br, mrp);
}
/* Deletes existing MRP instance based on ring_id
* note: called under rtnl_lock
*/
int br_mrp_del(struct net_bridge *br, struct br_mrp_instance *instance)
{
struct br_mrp *mrp = br_mrp_find_id(br, instance->ring_id);
if (!mrp)
return -EINVAL;
br_mrp_del_impl(br, mrp);
return 0;
}
/* Set port state, port state can be forwarding, blocked or disabled
* note: already called with rtnl_lock
*/
int br_mrp_set_port_state(struct net_bridge_port *p,
enum br_mrp_port_state_type state)
{
if (!p || !(p->flags & BR_MRP_AWARE))
return -EINVAL;
spin_lock_bh(&p->br->lock);
if (state == BR_MRP_PORT_STATE_FORWARDING)
p->state = BR_STATE_FORWARDING;
else
p->state = BR_STATE_BLOCKING;
spin_unlock_bh(&p->br->lock);
br_mrp_port_switchdev_set_state(p, state);
return 0;
}
/* Set port role, port role can be primary or secondary
* note: already called with rtnl_lock
*/
int br_mrp_set_port_role(struct net_bridge_port *p,
enum br_mrp_port_role_type role)
{
struct br_mrp *mrp;
if (!p || !(p->flags & BR_MRP_AWARE))
return -EINVAL;
mrp = br_mrp_find_port(p->br, p);
if (!mrp)
return -EINVAL;
switch (role) {
case BR_MRP_PORT_ROLE_PRIMARY:
rcu_assign_pointer(mrp->p_port, p);
break;
case BR_MRP_PORT_ROLE_SECONDARY:
rcu_assign_pointer(mrp->s_port, p);
break;
default:
return -EINVAL;
}
br_mrp_port_switchdev_set_role(p, role);
return 0;
}
/* Set ring state, ring state can be only Open or Closed
* note: already called with rtnl_lock
*/
int br_mrp_set_ring_state(struct net_bridge *br,
struct br_mrp_ring_state *state)
{
struct br_mrp *mrp = br_mrp_find_id(br, state->ring_id);
if (!mrp)
return -EINVAL;
if (mrp->ring_state == BR_MRP_RING_STATE_CLOSED &&
state->ring_state != BR_MRP_RING_STATE_CLOSED)
mrp->ring_transitions++;
mrp->ring_state = state->ring_state;
br_mrp_switchdev_set_ring_state(br, mrp, state->ring_state);
return 0;
}
/* Set ring role, ring role can be only MRM(Media Redundancy Manager) or
* MRC(Media Redundancy Client).
* note: already called with rtnl_lock
*/
int br_mrp_set_ring_role(struct net_bridge *br,
struct br_mrp_ring_role *role)
{
struct br_mrp *mrp = br_mrp_find_id(br, role->ring_id);
int err;
if (!mrp)
return -EINVAL;
mrp->ring_role = role->ring_role;
/* If there is an error just bailed out */
err = br_mrp_switchdev_set_ring_role(br, mrp, role->ring_role);
if (err && err != -EOPNOTSUPP)
return err;
/* Now detect if the HW actually applied the role or not. If the HW
* applied the role it means that the SW will not to do those operations
* anymore. For example if the role ir MRM then the HW will notify the
* SW when ring is open, but if the is not pushed to the HW the SW will
* need to detect when the ring is open
*/
mrp->ring_role_offloaded = err == -EOPNOTSUPP ? 0 : 1;
return 0;
}
/* Start to generate or monitor MRP test frames, the frames are generated by
* HW and if it fails, they are generated by the SW.
* note: already called with rtnl_lock
*/
int br_mrp_start_test(struct net_bridge *br,
struct br_mrp_start_test *test)
{
struct br_mrp *mrp = br_mrp_find_id(br, test->ring_id);
if (!mrp)
return -EINVAL;
/* Try to push it to the HW and if it fails then continue with SW
* implementation and if that also fails then return error.
*/
if (!br_mrp_switchdev_send_ring_test(br, mrp, test->interval,
test->max_miss, test->period,
test->monitor))
return 0;
mrp->test_interval = test->interval;
mrp->test_end = jiffies + usecs_to_jiffies(test->period);
mrp->test_max_miss = test->max_miss;
mrp->test_monitor = test->monitor;
mrp->test_count_miss = 0;
queue_delayed_work(system_wq, &mrp->test_work,
usecs_to_jiffies(test->interval));
return 0;
}
/* Process only MRP Test frame. All the other MRP frames are processed by
* userspace application
* note: already called with rcu_read_lock
*/
static void br_mrp_mrm_process(struct br_mrp *mrp, struct net_bridge_port *port,
struct sk_buff *skb)
{
const struct br_mrp_tlv_hdr *hdr;
struct br_mrp_tlv_hdr _hdr;
/* Each MRP header starts with a version field which is 16 bits.
* Therefore skip the version and get directly the TLV header.
*/
hdr = skb_header_pointer(skb, sizeof(uint16_t), sizeof(_hdr), &_hdr);
if (!hdr)
return;
if (hdr->type != BR_MRP_TLV_HEADER_RING_TEST)
return;
mrp->test_count_miss = 0;
/* Notify the userspace that the ring is closed only when the ring is
* not closed
*/
if (mrp->ring_state != BR_MRP_RING_STATE_CLOSED)
br_mrp_port_open(port->dev, false);
}
/* Determin if the test hdr has a better priority than the node */
static bool br_mrp_test_better_than_own(struct br_mrp *mrp,
struct net_bridge *br,
const struct br_mrp_ring_test_hdr *hdr)
{
u16 prio = be16_to_cpu(hdr->prio);
if (prio < mrp->prio ||
(prio == mrp->prio &&
ether_addr_to_u64(hdr->sa) < ether_addr_to_u64(br->dev->dev_addr)))
return true;
return false;
}
/* Process only MRP Test frame. All the other MRP frames are processed by
* userspace application
* note: already called with rcu_read_lock
*/
static void br_mrp_mra_process(struct br_mrp *mrp, struct net_bridge *br,
struct net_bridge_port *port,
struct sk_buff *skb)
{
const struct br_mrp_ring_test_hdr *test_hdr;
struct br_mrp_ring_test_hdr _test_hdr;
const struct br_mrp_tlv_hdr *hdr;
struct br_mrp_tlv_hdr _hdr;
/* Each MRP header starts with a version field which is 16 bits.
* Therefore skip the version and get directly the TLV header.
*/
hdr = skb_header_pointer(skb, sizeof(uint16_t), sizeof(_hdr), &_hdr);
if (!hdr)
return;
if (hdr->type != BR_MRP_TLV_HEADER_RING_TEST)
return;
test_hdr = skb_header_pointer(skb, sizeof(uint16_t) + sizeof(_hdr),
sizeof(_test_hdr), &_test_hdr);
if (!test_hdr)
return;
/* Only frames that have a better priority than the node will
* clear the miss counter because otherwise the node will need to behave
* as MRM.
*/
if (br_mrp_test_better_than_own(mrp, br, test_hdr))
mrp->test_count_miss = 0;
}
/* This will just forward the frame to the other mrp ring port(MRC role) or will
* not do anything.
* note: already called with rcu_read_lock
*/
static int br_mrp_rcv(struct net_bridge_port *p,
struct sk_buff *skb, struct net_device *dev)
{
struct net_device *s_dev, *p_dev, *d_dev;
struct net_bridge_port *p_port, *s_port;
struct net_bridge *br;
struct sk_buff *nskb;
struct br_mrp *mrp;
/* If port is disabled don't accept any frames */
if (p->state == BR_STATE_DISABLED)
return 0;
br = p->br;
mrp = br_mrp_find_port(br, p);
if (unlikely(!mrp))
return 0;
p_port = rcu_dereference(mrp->p_port);
if (!p_port)
return 0;
s_port = rcu_dereference(mrp->s_port);
if (!s_port)
return 0;
/* If the role is MRM then don't forward the frames */
if (mrp->ring_role == BR_MRP_RING_ROLE_MRM) {
br_mrp_mrm_process(mrp, p, skb);
return 1;
}
/* If the role is MRA then don't forward the frames if it behaves as
* MRM node
*/
if (mrp->ring_role == BR_MRP_RING_ROLE_MRA) {
if (!mrp->test_monitor) {
br_mrp_mrm_process(mrp, p, skb);
return 1;
}
br_mrp_mra_process(mrp, br, p, skb);
}
/* Clone the frame and forward it on the other MRP port */
nskb = skb_clone(skb, GFP_ATOMIC);
if (!nskb)
return 0;
p_dev = p_port->dev;
s_dev = s_port->dev;
if (p_dev == dev)
d_dev = s_dev;
else
d_dev = p_dev;
nskb->dev = d_dev;
skb_push(nskb, ETH_HLEN);
dev_queue_xmit(nskb);
return 1;
}
/* Check if the frame was received on a port that is part of MRP ring
* and if the frame has MRP eth. In that case process the frame otherwise do
* normal forwarding.
* note: already called with rcu_read_lock
*/
int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb)
{
/* If there is no MRP instance do normal forwarding */
if (likely(!(p->flags & BR_MRP_AWARE)))
goto out;
if (unlikely(skb->protocol == htons(ETH_P_MRP)))
return br_mrp_rcv(p, skb, p->dev);
out:
return 0;
}
bool br_mrp_enabled(struct net_bridge *br)
{
return !list_empty(&br->mrp_list);
}