From c6676e7d62cfb5cb7c1c5320a26f3634a11afdb0 Mon Sep 17 00:00:00 2001 From: Horatiu Vultur Date: Sat, 30 May 2020 18:09:48 +0000 Subject: bridge: mrp: Add support for role MRA A node that has the MRA role, it can behave as MRM or MRC. Initially it starts as MRM and sends MRP_Test frames on both ring ports. If it detects that there are MRP_Test send by another MRM, then it checks if these frames have a lower priority than itself. In this case it would send MRP_Nack frames to notify the other node that it needs to stop sending MRP_Test frames. If it receives a MRP_Nack frame then it stops sending MRP_Test frames and starts to behave as a MRC but it would continue to monitor the MRP_Test frames send by MRM. If at a point the MRM stops to send MRP_Test frames it would get the MRM role and start to send MRP_Test frames. Signed-off-by: Horatiu Vultur Signed-off-by: David S. Miller --- net/bridge/br_mrp.c | 125 ++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 106 insertions(+), 19 deletions(-) (limited to 'net/bridge/br_mrp.c') diff --git a/net/bridge/br_mrp.c b/net/bridge/br_mrp.c index f8fd037219fe..24986ec7d38c 100644 --- a/net/bridge/br_mrp.c +++ b/net/bridge/br_mrp.c @@ -160,6 +160,16 @@ static struct sk_buff *br_mrp_alloc_test_skb(struct br_mrp *mrp, 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); @@ -177,8 +187,14 @@ static void br_mrp_test_work_expired(struct work_struct *work) /* 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) + if (mrp->ring_state == BR_MRP_RING_STATE_CLOSED || + mrp->test_monitor) notify_open = true; } @@ -186,12 +202,15 @@ static void br_mrp_test_work_expired(struct work_struct *work) p = rcu_dereference(mrp->p_port); if (p) { - 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 (!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); @@ -199,12 +218,15 @@ static void br_mrp_test_work_expired(struct work_struct *work) p = rcu_dereference(mrp->s_port); if (p) { - 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 (!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); @@ -227,7 +249,7 @@ static void br_mrp_del_impl(struct net_bridge *br, struct br_mrp *mrp) /* Stop sending MRP_Test frames */ cancel_delayed_work_sync(&mrp->test_work); - br_mrp_switchdev_send_ring_test(br, mrp, 0, 0, 0); + br_mrp_switchdev_send_ring_test(br, mrp, 0, 0, 0, 0); br_mrp_switchdev_del(br, mrp); @@ -452,8 +474,8 @@ int br_mrp_set_ring_role(struct net_bridge *br, return 0; } -/* Start to generate MRP test frames, the frames are generated by HW and if it - * fails, they are generated by the SW. +/* 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, @@ -464,16 +486,18 @@ int br_mrp_start_test(struct net_bridge *br, if (!mrp) return -EINVAL; - /* Try to push it to the HW and if it fails then continue to generate in - * SW and if that also fails then return error + /* 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->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)); @@ -510,6 +534,57 @@ static void br_mrp_mrm_process(struct br_mrp *mrp, struct net_bridge_port *port, 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 @@ -546,6 +621,18 @@ static int br_mrp_rcv(struct net_bridge_port *p, 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) -- cgit