From: Andrew Lunn <andrew@lunn.ch>
Date: Mon, 20 Apr 2020 00:11:50 +0200
Subject: net: Add IF_OPER_TESTING
Patch-mainline: v5.8-rc1
Git-commit: eec517cdb4810b3843eb7707971de3164088bff1
References: bsc#1176447

RFC 2863 defines the operational state testing. Add support for this
state, both as a IF_LINK_MODE_ and __LINK_STATE_.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 include/linux/netdevice.h |   41 +++++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/if.h   |    1 +
 net/core/dev.c            |    5 +++++
 net/core/link_watch.c     |   12 ++++++++++--
 net/core/rtnetlink.c      |    9 ++++++++-
 5 files changed, 65 insertions(+), 3 deletions(-)

--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -286,6 +286,7 @@ enum netdev_state_t {
 	__LINK_STATE_NOCARRIER,
 	__LINK_STATE_LINKWATCH_PENDING,
 	__LINK_STATE_DORMANT,
+	__LINK_STATE_TESTING,
 };
 
 
@@ -3858,6 +3859,46 @@ static inline bool netif_dormant(const s
 }
 
 
+/**
+ *	netif_testing_on - mark device as under test.
+ *	@dev: network device
+ *
+ * Mark device as under test (as per RFC2863).
+ *
+ * The testing state indicates that some test(s) must be performed on
+ * the interface. After completion, of the test, the interface state
+ * will change to up, dormant, or down, as appropriate.
+ */
+static inline void netif_testing_on(struct net_device *dev)
+{
+	if (!test_and_set_bit(__LINK_STATE_TESTING, &dev->state))
+		linkwatch_fire_event(dev);
+}
+
+/**
+ *	netif_testing_off - set device as not under test.
+ *	@dev: network device
+ *
+ * Device is not in testing state.
+ */
+static inline void netif_testing_off(struct net_device *dev)
+{
+	if (test_and_clear_bit(__LINK_STATE_TESTING, &dev->state))
+		linkwatch_fire_event(dev);
+}
+
+/**
+ *	netif_testing - test if device is under test
+ *	@dev: network device
+ *
+ * Check if device is under test
+ */
+static inline bool netif_testing(const struct net_device *dev)
+{
+	return test_bit(__LINK_STATE_TESTING, &dev->state);
+}
+
+
 /**
  *	netif_oper_up - test if device is operational
  *	@dev: network device
--- a/include/uapi/linux/if.h
+++ b/include/uapi/linux/if.h
@@ -178,6 +178,7 @@ enum {
 enum {
 	IF_LINK_MODE_DEFAULT,
 	IF_LINK_MODE_DORMANT,	/* limit upward transition to dormant */
+	IF_LINK_MODE_TESTING,	/* limit upward transition to testing */
 };
 
 /*
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9064,6 +9064,11 @@ void netif_stacked_transfer_operstate(co
 	else
 		netif_dormant_off(dev);
 
+	if (rootdev->operstate == IF_OPER_TESTING)
+		netif_testing_on(dev);
+	else
+		netif_testing_off(dev);
+
 	if (netif_carrier_ok(rootdev))
 		netif_carrier_on(dev);
 	else
--- a/net/core/link_watch.c
+++ b/net/core/link_watch.c
@@ -34,6 +34,9 @@ static DEFINE_SPINLOCK(lweventlist_lock)
 
 static unsigned char default_operstate(const struct net_device *dev)
 {
+	if (netif_testing(dev))
+		return IF_OPER_TESTING;
+
 	if (!netif_carrier_ok(dev))
 		return (dev->ifindex != dev_get_iflink(dev) ?
 			IF_OPER_LOWERLAYERDOWN : IF_OPER_DOWN);
@@ -55,11 +58,15 @@ static void rfc2863_policy(struct net_de
 	write_lock_bh(&dev_base_lock);
 
 	switch(dev->link_mode) {
+	case IF_LINK_MODE_TESTING:
+		if (operstate == IF_OPER_UP)
+			operstate = IF_OPER_TESTING;
+		break;
+
 	case IF_LINK_MODE_DORMANT:
 		if (operstate == IF_OPER_UP)
 			operstate = IF_OPER_DORMANT;
 		break;
-
 	case IF_LINK_MODE_DEFAULT:
 	default:
 		break;
@@ -74,7 +81,8 @@ static void rfc2863_policy(struct net_de
 void linkwatch_init_dev(struct net_device *dev)
 {
 	/* Handle pre-registration link state changes */
-	if (!netif_carrier_ok(dev) || netif_dormant(dev))
+	if (!netif_carrier_ok(dev) || netif_dormant(dev) ||
+	    netif_testing(dev))
 		rfc2863_policy(dev);
 }
 
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -829,11 +829,18 @@ static void set_operstate(struct net_dev
 	switch (transition) {
 	case IF_OPER_UP:
 		if ((operstate == IF_OPER_DORMANT ||
+		     operstate == IF_OPER_TESTING ||
 		     operstate == IF_OPER_UNKNOWN) &&
-		    !netif_dormant(dev))
+		    !netif_dormant(dev) && !netif_testing(dev))
 			operstate = IF_OPER_UP;
 		break;
 
+	case IF_OPER_TESTING:
+		if (operstate == IF_OPER_UP ||
+		    operstate == IF_OPER_UNKNOWN)
+			operstate = IF_OPER_TESTING;
+		break;
+
 	case IF_OPER_DORMANT:
 		if (operstate == IF_OPER_UP ||
 		    operstate == IF_OPER_UNKNOWN)