1 files changed, 269 insertions, 0 deletions

diff --git a/net/bridge/br_cfm.c b/net/bridge/br_cfm.c
index 382e003f5b92..6331f731024f 100644
--- a/net/bridge/br_cfm.c
+++ b/net/bridge/br_cfm.c
@@ -101,6 +101,56 @@ static u32 interval_to_pdu(enum br_cfm_ccm_interval interval)
 	return 0;
 }
 
+/* Convert the CCM PDU value to interval on interface. */
+static u32 pdu_to_interval(u32 value)
+{
+	switch (value) {
+	case 0:
+		return BR_CFM_CCM_INTERVAL_NONE;
+	case 1:
+		return BR_CFM_CCM_INTERVAL_3_3_MS;
+	case 2:
+		return BR_CFM_CCM_INTERVAL_10_MS;
+	case 3:
+		return BR_CFM_CCM_INTERVAL_100_MS;
+	case 4:
+		return BR_CFM_CCM_INTERVAL_1_SEC;
+	case 5:
+		return BR_CFM_CCM_INTERVAL_10_SEC;
+	case 6:
+		return BR_CFM_CCM_INTERVAL_1_MIN;
+	case 7:
+		return BR_CFM_CCM_INTERVAL_10_MIN;
+	}
+	return BR_CFM_CCM_INTERVAL_NONE;
+}
+
+static void ccm_rx_timer_start(struct br_cfm_peer_mep *peer_mep)
+{
+	u32 interval_us;
+
+	interval_us = interval_to_us(peer_mep->mep->cc_config.exp_interval);
+	/* Function ccm_rx_dwork must be called with 1/4
+	 * of the configured CC 'expected_interval'
+	 * in order to detect CCM defect after 3.25 interval.
+	 */
+	queue_delayed_work(system_wq, &peer_mep->ccm_rx_dwork,
+			   usecs_to_jiffies(interval_us / 4));
+}
+
+static void cc_peer_enable(struct br_cfm_peer_mep *peer_mep)
+{
+	memset(&peer_mep->cc_status, 0, sizeof(peer_mep->cc_status));
+	peer_mep->ccm_rx_count_miss = 0;
+
+	ccm_rx_timer_start(peer_mep);
+}
+
+static void cc_peer_disable(struct br_cfm_peer_mep *peer_mep)
+{
+	cancel_delayed_work_sync(&peer_mep->ccm_rx_dwork);
+}
+
 static struct sk_buff *ccm_frame_build(struct br_cfm_mep *mep,
 				       const struct br_cfm_cc_ccm_tx_info *const tx_info)
 
@@ -232,6 +282,200 @@ static void ccm_tx_work_expired(struct work_struct *work)
 			   usecs_to_jiffies(interval_us));
 }
 
+/* This function is called with 1/4 of the configured CC 'expected_interval'
+ * in order to detect CCM defect after 3.25 interval.
+ */
+static void ccm_rx_work_expired(struct work_struct *work)
+{
+	struct br_cfm_peer_mep *peer_mep;
+	struct delayed_work *del_work;
+
+	del_work = to_delayed_work(work);
+	peer_mep = container_of(del_work, struct br_cfm_peer_mep, ccm_rx_dwork);
+
+	/* After 13 counts (4 * 3,25) then 3.25 intervals are expired */
+	if (peer_mep->ccm_rx_count_miss < 13) {
+		/* 3.25 intervals are NOT expired without CCM reception */
+		peer_mep->ccm_rx_count_miss++;
+
+		/* Start timer again */
+		ccm_rx_timer_start(peer_mep);
+	} else {
+		/* 3.25 intervals are expired without CCM reception.
+		 * CCM defect detected
+		 */
+		peer_mep->cc_status.ccm_defect = true;
+	}
+}
+
+static u32 ccm_tlv_extract(struct sk_buff *skb, u32 index,
+			   struct br_cfm_peer_mep *peer_mep)
+{
+	__be32 *s_tlv;
+	__be32 _s_tlv;
+	u32 h_s_tlv;
+	u8 *e_tlv;
+	u8 _e_tlv;
+
+	e_tlv = skb_header_pointer(skb, index, sizeof(_e_tlv), &_e_tlv);
+	if (!e_tlv)
+		return 0;
+
+	/* TLV is present - get the status TLV */
+	s_tlv = skb_header_pointer(skb,
+				   index,
+				   sizeof(_s_tlv), &_s_tlv);
+	if (!s_tlv)
+		return 0;
+
+	h_s_tlv = ntohl(*s_tlv);
+	if ((h_s_tlv >> 24) == CFM_IF_STATUS_TLV_TYPE) {
+		/* Interface status TLV */
+		peer_mep->cc_status.tlv_seen = true;
+		peer_mep->cc_status.if_tlv_value = (h_s_tlv & 0xFF);
+	}
+
+	if ((h_s_tlv >> 24) == CFM_PORT_STATUS_TLV_TYPE) {
+		/* Port status TLV */
+		peer_mep->cc_status.tlv_seen = true;
+		peer_mep->cc_status.port_tlv_value = (h_s_tlv & 0xFF);
+	}
+
+	/* The Sender ID TLV is not handled */
+	/* The Organization-Specific TLV is not handled */
+
+	/* Return the length of this tlv.
+	 * This is the length of the value field plus 3 bytes for size of type
+	 * field and length field
+	 */
+	return ((h_s_tlv >> 8) & 0xFFFF) + 3;
+}
+
+/* note: already called with rcu_read_lock */
+static int br_cfm_frame_rx(struct net_bridge_port *port, struct sk_buff *skb)
+{
+	u32 mdlevel, interval, size, index, max;
+	const struct br_cfm_common_hdr *hdr;
+	struct br_cfm_peer_mep *peer_mep;
+	const struct br_cfm_maid *maid;
+	struct br_cfm_common_hdr _hdr;
+	struct br_cfm_maid _maid;
+	struct br_cfm_mep *mep;
+	struct net_bridge *br;
+	__be32 *snumber;
+	__be32 _snumber;
+	__be16 *mepid;
+	__be16 _mepid;
+
+	if (port->state == BR_STATE_DISABLED)
+		return 0;
+
+	hdr = skb_header_pointer(skb, 0, sizeof(_hdr), &_hdr);
+	if (!hdr)
+		return 1;
+
+	br = port->br;
+	mep = br_mep_find_ifindex(br, port->dev->ifindex);
+	if (unlikely(!mep))
+		/* No MEP on this port - must be forwarded */
+		return 0;
+
+	mdlevel = hdr->mdlevel_version >> 5;
+	if (mdlevel > mep->config.mdlevel)
+		/* The level is above this MEP level - must be forwarded */
+		return 0;
+
+	if ((hdr->mdlevel_version & 0x1F) != 0) {
+		/* Invalid version */
+		mep->status.version_unexp_seen = true;
+		return 1;
+	}
+
+	if (mdlevel < mep->config.mdlevel) {
+		/* The level is below this MEP level */
+		mep->status.rx_level_low_seen = true;
+		return 1;
+	}
+
+	if (hdr->opcode == BR_CFM_OPCODE_CCM) {
+		/* CCM PDU received. */
+		/* MA ID is after common header + sequence number + MEP ID */
+		maid = skb_header_pointer(skb,
+					  CFM_CCM_PDU_MAID_OFFSET,
+					  sizeof(_maid), &_maid);
+		if (!maid)
+			return 1;
+		if (memcmp(maid->data, mep->cc_config.exp_maid.data,
+			   sizeof(maid->data)))
+			/* MA ID not as expected */
+			return 1;
+
+		/* MEP ID is after common header + sequence number */
+		mepid = skb_header_pointer(skb,
+					   CFM_CCM_PDU_MEPID_OFFSET,
+					   sizeof(_mepid), &_mepid);
+		if (!mepid)
+			return 1;
+		peer_mep = br_peer_mep_find(mep, (u32)ntohs(*mepid));
+		if (!peer_mep)
+			return 1;
+
+		/* Interval is in common header flags */
+		interval = hdr->flags & 0x07;
+		if (mep->cc_config.exp_interval != pdu_to_interval(interval))
+			/* Interval not as expected */
+			return 1;
+
+		/* A valid CCM frame is received */
+		if (peer_mep->cc_status.ccm_defect) {
+			peer_mep->cc_status.ccm_defect = false;
+
+			/* Start CCM RX timer */
+			ccm_rx_timer_start(peer_mep);
+		}
+
+		peer_mep->cc_status.seen = true;
+		peer_mep->ccm_rx_count_miss = 0;
+
+		/* RDI is in common header flags */
+		peer_mep->cc_status.rdi = (hdr->flags & 0x80) ? true : false;
+
+		/* Sequence number is after common header */
+		snumber = skb_header_pointer(skb,
+					     CFM_CCM_PDU_SEQNR_OFFSET,
+					     sizeof(_snumber), &_snumber);
+		if (!snumber)
+			return 1;
+		if (ntohl(*snumber) != (mep->ccm_rx_snumber + 1))
+			/* Unexpected sequence number */
+			peer_mep->cc_status.seq_unexp_seen = true;
+
+		mep->ccm_rx_snumber = ntohl(*snumber);
+
+		/* TLV end is after common header + sequence number + MEP ID +
+		 * MA ID + ITU reserved
+		 */
+		index = CFM_CCM_PDU_TLV_OFFSET;
+		max = 0;
+		do { /* Handle all TLVs */
+			size = ccm_tlv_extract(skb, index, peer_mep);
+			index += size;
+			max += 1;
+		} while (size != 0 && max < 4); /* Max four TLVs possible */
+
+		return 1;
+	}
+
+	mep->status.opcode_unexp_seen = true;
+
+	return 1;
+}
+
+static struct br_frame_type cfm_frame_type __read_mostly = {
+	.type = cpu_to_be16(ETH_P_CFM),
+	.frame_handler = br_cfm_frame_rx,
+};
+
 int br_cfm_mep_create(struct net_bridge *br,
 		      const u32 instance,
 		      struct br_cfm_mep_create *const create,
@@ -296,6 +540,9 @@ int br_cfm_mep_create(struct net_bridge *br,
 	INIT_HLIST_HEAD(&mep->peer_mep_list);
 	INIT_DELAYED_WORK(&mep->ccm_tx_dwork, ccm_tx_work_expired);
 
+	if (hlist_empty(&br->mep_list))
+		br_add_frame(br, &cfm_frame_type);
+
 	hlist_add_tail_rcu(&mep->head, &br->mep_list);
 
 	return 0;
@@ -311,6 +558,7 @@ static void mep_delete_implementation(struct net_bridge *br,
 
 	/* Empty and free peer MEP list */
 	hlist_for_each_entry_safe(peer_mep, n_store, &mep->peer_mep_list, head) {
+		cancel_delayed_work_sync(&peer_mep->ccm_rx_dwork);
 		hlist_del_rcu(&peer_mep->head);
 		kfree_rcu(peer_mep, rcu);
 	}
@@ -320,6 +568,9 @@ static void mep_delete_implementation(struct net_bridge *br,
 	RCU_INIT_POINTER(mep->b_port, NULL);
 	hlist_del_rcu(&mep->head);
 	kfree_rcu(mep, rcu);
+
+	if (hlist_empty(&br->mep_list))
+		br_del_frame(br, &cfm_frame_type);
 }
 
 int br_cfm_mep_delete(struct net_bridge *br,
@@ -368,6 +619,7 @@ int br_cfm_cc_config_set(struct net_bridge *br,
 			 const struct br_cfm_cc_config *const config,
 			 struct netlink_ext_ack *extack)
 {
+	struct br_cfm_peer_mep *peer_mep;
 	struct br_cfm_mep *mep;
 
 	ASSERT_RTNL();
@@ -383,7 +635,18 @@ int br_cfm_cc_config_set(struct net_bridge *br,
 	if (memcmp(config, &mep->cc_config, sizeof(*config)) == 0)
 		return 0;
 
+	if (config->enable && !mep->cc_config.enable)
+		/* CC is enabled */
+		hlist_for_each_entry(peer_mep, &mep->peer_mep_list, head)
+			cc_peer_enable(peer_mep);
+
+	if (!config->enable && mep->cc_config.enable)
+		/* CC is disabled */
+		hlist_for_each_entry(peer_mep, &mep->peer_mep_list, head)
+			cc_peer_disable(peer_mep);
+
 	mep->cc_config = *config;
+	mep->ccm_rx_snumber = 0;
 	mep->ccm_tx_snumber = 1;
 
 	return 0;
@@ -418,6 +681,10 @@ int br_cfm_cc_peer_mep_add(struct net_bridge *br, const u32 instance,
 
 	peer_mep->mepid = mepid;
 	peer_mep->mep = mep;
+	INIT_DELAYED_WORK(&peer_mep->ccm_rx_dwork, ccm_rx_work_expired);
+
+	if (mep->cc_config.enable)
+		cc_peer_enable(peer_mep);
 
 	hlist_add_tail_rcu(&peer_mep->head, &mep->peer_mep_list);
 
@@ -447,6 +714,8 @@ int br_cfm_cc_peer_mep_remove(struct net_bridge *br, const u32 instance,
 		return -ENOENT;
 	}
 
+	cc_peer_disable(peer_mep);
+
 	hlist_del_rcu(&peer_mep->head);
 	kfree_rcu(peer_mep, rcu);