[PATCH net-next 08/12] bridge: mrp: Implement the MRP Interconnect API

From: Horatiu Vultur
Date: Mon Jul 06 2020 - 05:21:14 EST


Thie patch adds support for MRP Interconnect. Similar with the MRP ring,
if the HW can't generate MRP_InTest frames, then the SW will try to
generate them. And if also the SW fails to generate the frames then an
error is return to userspace.

The forwarding/termination of MRP_In frames is happening in the kernel
and is done by MRP instances.

Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
---
net/bridge/br_mrp.c | 525 +++++++++++++++++++++++++++++++++---
net/bridge/br_private_mrp.h | 4 +
2 files changed, 498 insertions(+), 31 deletions(-)

diff --git a/net/bridge/br_mrp.c b/net/bridge/br_mrp.c
index d4176f8956d05..a82f311e968d7 100644
--- a/net/bridge/br_mrp.c
+++ b/net/bridge/br_mrp.c
@@ -4,6 +4,27 @@
#include "br_private_mrp.h"

static const u8 mrp_test_dmac[ETH_ALEN] = { 0x1, 0x15, 0x4e, 0x0, 0x0, 0x1 };
+static const u8 mrp_in_test_dmac[ETH_ALEN] = { 0x1, 0x15, 0x4e, 0x0, 0x0, 0x3 };
+
+static bool br_mrp_is_ring_port(struct net_bridge_port *p_port,
+ struct net_bridge_port *s_port,
+ struct net_bridge_port *port)
+{
+ if (port == p_port ||
+ port == s_port)
+ return true;
+
+ return false;
+}
+
+static bool br_mrp_is_in_port(struct net_bridge_port *i_port,
+ struct net_bridge_port *port)
+{
+ if (port == i_port)
+ return true;
+
+ return false;
+}

static struct net_bridge_port *br_mrp_get_port(struct net_bridge *br,
u32 ifindex)
@@ -37,6 +58,22 @@ static struct br_mrp *br_mrp_find_id(struct net_bridge *br, u32 ring_id)
return res;
}

+static struct br_mrp *br_mrp_find_in_id(struct net_bridge *br, u32 in_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->in_id == in_id) {
+ res = mrp;
+ break;
+ }
+ }
+
+ return res;
+}
+
static bool br_mrp_unique_ifindex(struct net_bridge *br, u32 ifindex)
{
struct br_mrp *mrp;
@@ -52,6 +89,10 @@ static bool br_mrp_unique_ifindex(struct net_bridge *br, u32 ifindex)
p = rtnl_dereference(mrp->s_port);
if (p && p->dev->ifindex == ifindex)
return false;
+
+ p = rtnl_dereference(mrp->i_port);
+ if (p && p->dev->ifindex == ifindex)
+ return false;
}

return true;
@@ -66,7 +107,8 @@ static struct br_mrp *br_mrp_find_port(struct net_bridge *br,
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) {
+ rcu_access_pointer(mrp->s_port) == p ||
+ rcu_access_pointer(mrp->i_port) == p) {
res = mrp;
break;
}
@@ -160,6 +202,36 @@ static struct sk_buff *br_mrp_alloc_test_skb(struct br_mrp *mrp,
return skb;
}

+static struct sk_buff *br_mrp_alloc_in_test_skb(struct br_mrp *mrp,
+ struct net_bridge_port *p,
+ enum br_mrp_port_role_type port_role)
+{
+ struct br_mrp_in_test_hdr *hdr = NULL;
+ struct sk_buff *skb = NULL;
+
+ if (!p)
+ return NULL;
+
+ skb = br_mrp_skb_alloc(p, p->dev->dev_addr, mrp_in_test_dmac);
+ if (!skb)
+ return NULL;
+
+ br_mrp_skb_tlv(skb, BR_MRP_TLV_HEADER_IN_TEST, sizeof(*hdr));
+ hdr = skb_put(skb, sizeof(*hdr));
+
+ hdr->id = cpu_to_be16(mrp->in_id);
+ ether_addr_copy(hdr->sa, p->br->dev->dev_addr);
+ hdr->port_role = cpu_to_be16(port_role);
+ hdr->state = cpu_to_be16(mrp->in_state);
+ hdr->transitions = cpu_to_be16(mrp->in_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
@@ -239,6 +311,83 @@ static void br_mrp_test_work_expired(struct work_struct *work)
usecs_to_jiffies(mrp->test_interval));
}

+/* This function is continuously called when the node has the interconnect rol
+ * MIM. It would generate interconnect test frames and will send them on all 3
+ * ports. But will also check if it stop receiving interconnect test frames.
+ */
+static void br_mrp_in_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, in_test_work);
+ struct net_bridge_port *p;
+ bool notify_open = false;
+ struct sk_buff *skb;
+
+ if (time_before_eq(mrp->in_test_end, jiffies))
+ return;
+
+ if (mrp->in_test_count_miss < mrp->in_test_max_miss) {
+ mrp->in_test_count_miss++;
+ } else {
+ /* Notify that the interconnect ring is open only if the
+ * interconnect ring state is closed, otherwise it would
+ * continue to notify at every interval.
+ */
+ if (mrp->in_state == BR_MRP_IN_STATE_CLOSED)
+ notify_open = true;
+ }
+
+ rcu_read_lock();
+
+ p = rcu_dereference(mrp->p_port);
+ if (p) {
+ skb = br_mrp_alloc_in_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->in_role_offloaded)
+ br_mrp_in_port_open(p->dev, true);
+ }
+
+ p = rcu_dereference(mrp->s_port);
+ if (p) {
+ skb = br_mrp_alloc_in_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->in_role_offloaded)
+ br_mrp_in_port_open(p->dev, true);
+ }
+
+ p = rcu_dereference(mrp->i_port);
+ if (p) {
+ skb = br_mrp_alloc_in_test_skb(mrp, p,
+ BR_MRP_PORT_ROLE_INTER);
+ if (!skb)
+ goto out;
+
+ skb_reset_network_header(skb);
+ dev_queue_xmit(skb);
+
+ if (notify_open && !mrp->in_role_offloaded)
+ br_mrp_in_port_open(p->dev, true);
+ }
+
+out:
+ rcu_read_unlock();
+
+ queue_delayed_work(system_wq, &mrp->in_test_work,
+ usecs_to_jiffies(mrp->in_test_interval));
+}
+
/* Deletes the MRP instance.
* note: called under rtnl_lock
*/
@@ -278,6 +427,18 @@ static void br_mrp_del_impl(struct net_bridge *br, struct br_mrp *mrp)
rcu_assign_pointer(mrp->s_port, NULL);
}

+ p = rtnl_dereference(mrp->i_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->i_port, NULL);
+ }
+
list_del_rcu(&mrp->list);
kfree_rcu(mrp, rcu);
}
@@ -511,6 +672,140 @@ int br_mrp_start_test(struct net_bridge *br,
return 0;
}

+/* Set in state, int state can be only Open or Closed
+ * note: already called with rtnl_lock
+ */
+int br_mrp_set_in_state(struct net_bridge *br, struct br_mrp_in_state *state)
+{
+ struct br_mrp *mrp = br_mrp_find_in_id(br, state->in_id);
+
+ if (!mrp)
+ return -EINVAL;
+
+ if (mrp->in_state == BR_MRP_IN_STATE_CLOSED &&
+ state->in_state != BR_MRP_IN_STATE_CLOSED)
+ mrp->in_transitions++;
+
+ mrp->in_state = state->in_state;
+
+ br_mrp_switchdev_set_in_state(br, mrp, state->in_state);
+
+ return 0;
+}
+
+/* Set in role, in role can be only MIM(Media Interconnection Manager) or
+ * MIC(Media Interconnection Client).
+ * note: already called with rtnl_lock
+ */
+int br_mrp_set_in_role(struct net_bridge *br, struct br_mrp_in_role *role)
+{
+ struct br_mrp *mrp = br_mrp_find_id(br, role->ring_id);
+ struct net_bridge_port *p;
+ int err;
+
+ if (!mrp)
+ return -EINVAL;
+
+ if (!br_mrp_get_port(br, role->i_ifindex))
+ return -EINVAL;
+
+ /* It is not possible to have the same port part of multiple rings */
+ if (!br_mrp_unique_ifindex(br, role->i_ifindex))
+ return -EINVAL;
+
+ p = br_mrp_get_port(br, role->i_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->i_port, p);
+
+ mrp->in_role = role->in_role;
+ mrp->in_id = role->in_id;
+
+ INIT_DELAYED_WORK(&mrp->in_test_work, br_mrp_in_test_work_expired);
+
+ /* If there is an error just bailed out */
+ err = br_mrp_switchdev_set_in_role(br, mrp, role->in_id,
+ role->ring_id, role->in_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 is MIM then the HW will notify the
+ * SW when interconnect ring is open, but if the is not pushed to the HW
+ * the SW will need to detect when the interconnect ring is open.
+ */
+ mrp->in_role_offloaded = err == -EOPNOTSUPP ? 0 : 1;
+
+ return 0;
+}
+
+int br_mrp_start_in_test(struct net_bridge *br,
+ struct br_mrp_start_in_test *in_test)
+{
+ struct br_mrp *mrp = br_mrp_find_in_id(br, in_test->in_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_in_test(br, mrp, in_test->interval,
+ in_test->max_miss, in_test->period))
+ return 0;
+
+ mrp->in_test_interval = in_test->interval;
+ mrp->in_test_end = jiffies + usecs_to_jiffies(in_test->period);
+ mrp->in_test_max_miss = in_test->max_miss;
+ mrp->in_test_count_miss = 0;
+ queue_delayed_work(system_wq, &mrp->in_test_work,
+ usecs_to_jiffies(in_test->interval));
+
+ return 0;
+}
+
+/* Determin if the frame type is a ring frame */
+static bool br_mrp_ring_frame(struct sk_buff *skb)
+{
+ const struct br_mrp_tlv_hdr *hdr;
+ struct br_mrp_tlv_hdr _hdr;
+
+ hdr = skb_header_pointer(skb, sizeof(uint16_t), sizeof(_hdr), &_hdr);
+ if (!hdr)
+ return false;
+
+ if (hdr->type == BR_MRP_TLV_HEADER_RING_TEST ||
+ hdr->type == BR_MRP_TLV_HEADER_RING_TOPO ||
+ hdr->type == BR_MRP_TLV_HEADER_RING_LINK_DOWN ||
+ hdr->type == BR_MRP_TLV_HEADER_RING_LINK_UP ||
+ hdr->type == BR_MRP_TLV_HEADER_OPTION)
+ return true;
+
+ return false;
+}
+
+/* Determin if the frame type is an interconnect frame */
+static bool br_mrp_in_frame(struct sk_buff *skb)
+{
+ const struct br_mrp_tlv_hdr *hdr;
+ struct br_mrp_tlv_hdr _hdr;
+
+ hdr = skb_header_pointer(skb, sizeof(uint16_t), sizeof(_hdr), &_hdr);
+ if (!hdr)
+ return false;
+
+ if (hdr->type == BR_MRP_TLV_HEADER_IN_TEST ||
+ hdr->type == BR_MRP_TLV_HEADER_IN_TOPO ||
+ hdr->type == BR_MRP_TLV_HEADER_IN_LINK_DOWN ||
+ hdr->type == BR_MRP_TLV_HEADER_IN_LINK_UP)
+ 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
@@ -591,17 +886,92 @@ static void br_mrp_mra_process(struct br_mrp *mrp, struct net_bridge *br,
mrp->test_count_miss = 0;
}

-/* This will just forward the frame to the other mrp ring port(MRC role) or will
- * not do anything.
+/* Process only MRP InTest frame. All the other MRP frames are processed by
+ * userspace application
+ * note: already called with rcu_read_lock
+ */
+static bool br_mrp_mim_process(struct br_mrp *mrp, struct net_bridge_port *port,
+ struct sk_buff *skb)
+{
+ const struct br_mrp_in_test_hdr *in_hdr;
+ struct br_mrp_in_test_hdr _in_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 false;
+
+ /* The check for InTest frame type was already done */
+ in_hdr = skb_header_pointer(skb, sizeof(uint16_t) + sizeof(_hdr),
+ sizeof(_in_hdr), &_in_hdr);
+ if (!in_hdr)
+ return false;
+
+ /* It needs to process only it's own InTest frames. */
+ if (mrp->in_id != ntohs(in_hdr->id))
+ return false;
+
+ mrp->in_test_count_miss = 0;
+
+ /* Notify the userspace that the ring is closed only when the ring is
+ * not closed
+ */
+ if (mrp->in_state != BR_MRP_IN_STATE_CLOSED)
+ br_mrp_in_port_open(port->dev, false);
+
+ return true;
+}
+
+/* Get the MRP frame type
+ * note: already called with rcu_read_lock
+ */
+static u8 br_mrp_get_frame_type(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 0xff;
+
+ return hdr->type;
+}
+
+static bool br_mrp_mrm_behaviour(struct br_mrp *mrp)
+{
+ if (mrp->ring_role == BR_MRP_RING_ROLE_MRM ||
+ (mrp->ring_role == BR_MRP_RING_ROLE_MRA && !mrp->test_monitor))
+ return true;
+
+ return false;
+}
+
+static bool br_mrp_mrc_behaviour(struct br_mrp *mrp)
+{
+ if (mrp->ring_role == BR_MRP_RING_ROLE_MRC ||
+ (mrp->ring_role == BR_MRP_RING_ROLE_MRA && mrp->test_monitor))
+ return true;
+
+ return false;
+}
+
+/* This will just forward the frame to the other mrp ring ports, depending on
+ * the frame type, ring role and interconnect role
* 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_port *p_port, *s_port, *i_port = NULL;
+ struct net_bridge_port *p_dst, *s_dst, *i_dst = NULL;
struct net_bridge *br;
- struct sk_buff *nskb;
struct br_mrp *mrp;

/* If port is disabled don't accept any frames */
@@ -616,46 +986,139 @@ static int br_mrp_rcv(struct net_bridge_port *p,
p_port = rcu_dereference(mrp->p_port);
if (!p_port)
return 0;
+ p_dst = p_port;

s_port = rcu_dereference(mrp->s_port);
if (!s_port)
return 0;
+ s_dst = s_port;

- /* 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 the frame is a ring frame then it is not required to check the
+ * interconnect role and ports to process or forward the frame
*/
- if (mrp->ring_role == BR_MRP_RING_ROLE_MRA) {
- if (!mrp->test_monitor) {
+ if (br_mrp_ring_frame(skb)) {
+ /* 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;
+ goto no_forward;
}

- br_mrp_mra_process(mrp, br, p, skb);
+ /* 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);
+ goto no_forward;
+ }
+
+ br_mrp_mra_process(mrp, br, p, skb);
+ }
+
+ goto forward;
}

- /* Clone the frame and forward it on the other MRP port */
- nskb = skb_clone(skb, GFP_ATOMIC);
- if (!nskb)
- return 0;
+ if (br_mrp_in_frame(skb)) {
+ u8 in_type = br_mrp_get_frame_type(skb);

- p_dev = p_port->dev;
- s_dev = s_port->dev;
+ i_port = rcu_dereference(mrp->i_port);
+ i_dst = i_port;

- if (p_dev == dev)
- d_dev = s_dev;
- else
- d_dev = p_dev;
+ /* If the ring port is in block state it should not forward
+ * In_Test frames
+ */
+ if (br_mrp_is_ring_port(p_port, s_port, p) &&
+ p->state == BR_STATE_BLOCKING &&
+ in_type == BR_MRP_TLV_HEADER_IN_TEST)
+ goto no_forward;
+
+ /* Nodes that behaves as MRM needs to stop forwarding the
+ * frames in case the ring is closed, otherwise will be a loop.
+ * In this case the frame is no forward between the ring ports.
+ */
+ if (br_mrp_mrm_behaviour(mrp) &&
+ br_mrp_is_ring_port(p_port, s_port, p) &&
+ (s_port->state != BR_STATE_FORWARDING ||
+ p_port->state != BR_STATE_FORWARDING)) {
+ p_dst = NULL;
+ s_dst = NULL;
+ }
+
+ /* A node that behaves as MRC and doesn't have a interconnect
+ * role then it should forward all frames between the ring ports
+ * because it doesn't have an interconnect port
+ */
+ if (br_mrp_mrc_behaviour(mrp) &&
+ mrp->in_role == BR_MRP_IN_ROLE_DISABLED)
+ goto forward;
+
+ if (mrp->in_role == BR_MRP_IN_ROLE_MIM) {
+ if (in_type == BR_MRP_TLV_HEADER_IN_TEST) {
+ /* MIM should not forward it's own InTest
+ * frames
+ */
+ if (br_mrp_mim_process(mrp, p, skb)) {
+ goto no_forward;
+ } else {
+ if (br_mrp_is_ring_port(p_port, s_port,
+ p))
+ i_dst = NULL;
+
+ if (br_mrp_is_in_port(i_port, p))
+ goto no_forward;
+ }
+ } else {
+ /* MIM should forward IntLinkChange and
+ * IntTopoChange between ring ports but MIM
+ * should not forward IntLinkChange and
+ * IntTopoChange if the frame was received at
+ * the interconnect port
+ */
+ if (br_mrp_is_ring_port(p_port, s_port, p))
+ i_dst = NULL;
+
+ if (br_mrp_is_in_port(i_port, p))
+ goto no_forward;
+ }
+ }
+
+ if (mrp->in_role == BR_MRP_IN_ROLE_MIC) {
+ /* MIC should forward InTest frames on all ports
+ * regardless of the received port
+ */
+ if (in_type == BR_MRP_TLV_HEADER_IN_TEST)
+ goto forward;
+
+ /* MIC should forward IntLinkChange frames only if they
+ * are received on ring ports to all the ports
+ */
+ if (br_mrp_is_ring_port(p_port, s_port, p) &&
+ (in_type == BR_MRP_TLV_HEADER_IN_LINK_UP ||
+ in_type == BR_MRP_TLV_HEADER_IN_LINK_DOWN))
+ goto forward;
+
+ /* Should forward the InTopo frames only between the
+ * ring ports
+ */
+ if (in_type == BR_MRP_TLV_HEADER_IN_TOPO) {
+ i_dst = NULL;
+ goto forward;
+ }
+
+ /* In all the other cases don't forward the frames */
+ goto no_forward;
+ }
+ }

- nskb->dev = d_dev;
- skb_push(nskb, ETH_HLEN);
- dev_queue_xmit(nskb);
+forward:
+ if (p_dst)
+ br_forward(p_dst, skb, true, false);
+ if (s_dst)
+ br_forward(s_dst, skb, true, false);
+ if (i_dst)
+ br_forward(i_dst, skb, true, false);

+no_forward:
return 1;
}

diff --git a/net/bridge/br_private_mrp.h b/net/bridge/br_private_mrp.h
index 50dbf046a9be3..81e7955190456 100644
--- a/net/bridge/br_private_mrp.h
+++ b/net/bridge/br_private_mrp.h
@@ -57,6 +57,10 @@ int br_mrp_set_ring_state(struct net_bridge *br,
struct br_mrp_ring_state *state);
int br_mrp_set_ring_role(struct net_bridge *br, struct br_mrp_ring_role *role);
int br_mrp_start_test(struct net_bridge *br, struct br_mrp_start_test *test);
+int br_mrp_set_in_state(struct net_bridge *br, struct br_mrp_in_state *state);
+int br_mrp_set_in_role(struct net_bridge *br, struct br_mrp_in_role *role);
+int br_mrp_start_in_test(struct net_bridge *br,
+ struct br_mrp_start_in_test *test);

/* br_mrp_switchdev.c */
int br_mrp_switchdev_add(struct net_bridge *br, struct br_mrp *mrp);
--
2.27.0