1 files changed, 184 insertions, 6 deletions

diff --git a/drivers/net/netdevsim/bus.c b/drivers/net/netdevsim/bus.c
index 0787ad252dd9..70e8c38ddad6 100644
--- a/drivers/net/netdevsim/bus.c
+++ b/drivers/net/netdevsim/bus.c
@@ -3,11 +3,13 @@
  * Copyright (C) 2019 Mellanox Technologies. All rights reserved
  */
 
+#include <linux/completion.h>
 #include <linux/device.h>
 #include <linux/idr.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
+#include <linux/refcount.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 
@@ -17,6 +19,8 @@ static DEFINE_IDA(nsim_bus_dev_ids);
 static LIST_HEAD(nsim_bus_dev_list);
 static DEFINE_MUTEX(nsim_bus_dev_list_lock);
 static bool nsim_bus_enable;
+static refcount_t nsim_bus_devs; /* Including the bus itself. */
+static DECLARE_COMPLETION(nsim_bus_devs_released);
 
 static struct nsim_bus_dev *to_nsim_bus_dev(struct device *dev)
 {
@@ -62,17 +66,35 @@ new_port_store(struct device *dev, struct device_attribute *attr,
 	       const char *buf, size_t count)
 {
 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
+	u8 eth_addr[ETH_ALEN] = {};
 	unsigned int port_index;
+	bool addr_set = false;
 	int ret;
 
 	/* Prevent to use nsim_bus_dev before initialization. */
 	if (!smp_load_acquire(&nsim_bus_dev->init))
 		return -EBUSY;
-	ret = kstrtouint(buf, 0, &port_index);
-	if (ret)
-		return ret;
 
-	ret = nsim_drv_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
+	ret = sscanf(buf, "%u %hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &port_index,
+		     &eth_addr[0], &eth_addr[1], &eth_addr[2], &eth_addr[3],
+		     &eth_addr[4], &eth_addr[5]);
+	switch (ret) {
+	case 7:
+		if (!is_valid_ether_addr(eth_addr)) {
+			pr_err("The supplied perm_addr is not a valid MAC address\n");
+			return -EINVAL;
+		}
+		addr_set = true;
+		fallthrough;
+	case 1:
+		break;
+	default:
+		pr_err("Format for adding new port is \"id [perm_addr]\" (uint MAC).\n");
+		return -EINVAL;
+	}
+
+	ret = nsim_drv_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index,
+				addr_set ? eth_addr : NULL);
 	return ret ? ret : count;
 }
 
@@ -121,9 +143,11 @@ static void nsim_bus_dev_release(struct device *dev)
 
 	nsim_bus_dev = container_of(dev, struct nsim_bus_dev, dev);
 	kfree(nsim_bus_dev);
+	if (refcount_dec_and_test(&nsim_bus_devs))
+		complete(&nsim_bus_devs_released);
 }
 
-static struct device_type nsim_bus_dev_type = {
+static const struct device_type nsim_bus_dev_type = {
 	.groups = nsim_bus_dev_attr_groups,
 	.release = nsim_bus_dev_release,
 };
@@ -170,6 +194,7 @@ new_device_store(const struct bus_type *bus, const char *buf, size_t count)
 		goto err;
 	}
 
+	refcount_inc(&nsim_bus_devs);
 	/* Allow using nsim_bus_dev */
 	smp_store_release(&nsim_bus_dev->init, true);
 
@@ -225,9 +250,157 @@ del_device_store(const struct bus_type *bus, const char *buf, size_t count)
 }
 static BUS_ATTR_WO(del_device);
 
+static ssize_t link_device_store(const struct bus_type *bus, const char *buf, size_t count)
+{
+	struct netdevsim *nsim_a, *nsim_b, *peer;
+	struct net_device *dev_a, *dev_b;
+	unsigned int ifidx_a, ifidx_b;
+	int netnsfd_a, netnsfd_b, err;
+	struct net *ns_a, *ns_b;
+
+	err = sscanf(buf, "%d:%u %d:%u", &netnsfd_a, &ifidx_a, &netnsfd_b,
+		     &ifidx_b);
+	if (err != 4) {
+		pr_err("Format for linking two devices is \"netnsfd_a:ifidx_a netnsfd_b:ifidx_b\" (int uint int uint).\n");
+		return -EINVAL;
+	}
+
+	ns_a = get_net_ns_by_fd(netnsfd_a);
+	if (IS_ERR(ns_a)) {
+		pr_err("Could not find netns with fd: %d\n", netnsfd_a);
+		return -EINVAL;
+	}
+
+	ns_b = get_net_ns_by_fd(netnsfd_b);
+	if (IS_ERR(ns_b)) {
+		pr_err("Could not find netns with fd: %d\n", netnsfd_b);
+		put_net(ns_a);
+		return -EINVAL;
+	}
+
+	err = -EINVAL;
+	rtnl_lock();
+	dev_a = __dev_get_by_index(ns_a, ifidx_a);
+	if (!dev_a) {
+		pr_err("Could not find device with ifindex %u in netnsfd %d\n",
+		       ifidx_a, netnsfd_a);
+		goto out_err;
+	}
+
+	if (!netdev_is_nsim(dev_a)) {
+		pr_err("Device with ifindex %u in netnsfd %d is not a netdevsim\n",
+		       ifidx_a, netnsfd_a);
+		goto out_err;
+	}
+
+	dev_b = __dev_get_by_index(ns_b, ifidx_b);
+	if (!dev_b) {
+		pr_err("Could not find device with ifindex %u in netnsfd %d\n",
+		       ifidx_b, netnsfd_b);
+		goto out_err;
+	}
+
+	if (!netdev_is_nsim(dev_b)) {
+		pr_err("Device with ifindex %u in netnsfd %d is not a netdevsim\n",
+		       ifidx_b, netnsfd_b);
+		goto out_err;
+	}
+
+	if (dev_a == dev_b) {
+		pr_err("Cannot link a netdevsim to itself\n");
+		goto out_err;
+	}
+
+	err = -EBUSY;
+	nsim_a = netdev_priv(dev_a);
+	peer = rtnl_dereference(nsim_a->peer);
+	if (peer) {
+		pr_err("Netdevsim %d:%u is already linked\n", netnsfd_a,
+		       ifidx_a);
+		goto out_err;
+	}
+
+	nsim_b = netdev_priv(dev_b);
+	peer = rtnl_dereference(nsim_b->peer);
+	if (peer) {
+		pr_err("Netdevsim %d:%u is already linked\n", netnsfd_b,
+		       ifidx_b);
+		goto out_err;
+	}
+
+	err = 0;
+	rcu_assign_pointer(nsim_a->peer, nsim_b);
+	rcu_assign_pointer(nsim_b->peer, nsim_a);
+
+out_err:
+	put_net(ns_b);
+	put_net(ns_a);
+	rtnl_unlock();
+
+	return !err ? count : err;
+}
+static BUS_ATTR_WO(link_device);
+
+static ssize_t unlink_device_store(const struct bus_type *bus, const char *buf, size_t count)
+{
+	struct netdevsim *nsim, *peer;
+	struct net_device *dev;
+	unsigned int ifidx;
+	int netnsfd, err;
+	struct net *ns;
+
+	err = sscanf(buf, "%u:%u", &netnsfd, &ifidx);
+	if (err != 2) {
+		pr_err("Format for unlinking a device is \"netnsfd:ifidx\" (int uint).\n");
+		return -EINVAL;
+	}
+
+	ns = get_net_ns_by_fd(netnsfd);
+	if (IS_ERR(ns)) {
+		pr_err("Could not find netns with fd: %d\n", netnsfd);
+		return -EINVAL;
+	}
+
+	err = -EINVAL;
+	rtnl_lock();
+	dev = __dev_get_by_index(ns, ifidx);
+	if (!dev) {
+		pr_err("Could not find device with ifindex %u in netnsfd %d\n",
+		       ifidx, netnsfd);
+		goto out_put_netns;
+	}
+
+	if (!netdev_is_nsim(dev)) {
+		pr_err("Device with ifindex %u in netnsfd %d is not a netdevsim\n",
+		       ifidx, netnsfd);
+		goto out_put_netns;
+	}
+
+	nsim = netdev_priv(dev);
+	peer = rtnl_dereference(nsim->peer);
+	if (!peer)
+		goto out_put_netns;
+
+	err = 0;
+	RCU_INIT_POINTER(nsim->peer, NULL);
+	RCU_INIT_POINTER(peer->peer, NULL);
+	synchronize_net();
+	netif_tx_wake_all_queues(dev);
+	netif_tx_wake_all_queues(peer->netdev);
+
+out_put_netns:
+	put_net(ns);
+	rtnl_unlock();
+
+	return !err ? count : err;
+}
+static BUS_ATTR_WO(unlink_device);
+
 static struct attribute *nsim_bus_attrs[] = {
 	&bus_attr_new_device.attr,
 	&bus_attr_del_device.attr,
+	&bus_attr_link_device.attr,
+	&bus_attr_unlink_device.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(nsim_bus);
@@ -253,7 +426,7 @@ static int nsim_num_vf(struct device *dev)
 	return nsim_bus_dev->num_vfs;
 }
 
-static struct bus_type nsim_bus = {
+static const struct bus_type nsim_bus = {
 	.name		= DRV_NAME,
 	.dev_name	= DRV_NAME,
 	.bus_groups	= nsim_bus_groups,
@@ -326,6 +499,7 @@ int nsim_bus_init(void)
 	err = driver_register(&nsim_driver);
 	if (err)
 		goto err_bus_unregister;
+	refcount_set(&nsim_bus_devs, 1);
 	/* Allow using resources */
 	smp_store_release(&nsim_bus_enable, true);
 	return 0;
@@ -341,6 +515,8 @@ void nsim_bus_exit(void)
 
 	/* Disallow using resources */
 	smp_store_release(&nsim_bus_enable, false);
+	if (refcount_dec_and_test(&nsim_bus_devs))
+		complete(&nsim_bus_devs_released);
 
 	mutex_lock(&nsim_bus_dev_list_lock);
 	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
@@ -349,6 +525,8 @@ void nsim_bus_exit(void)
 	}
 	mutex_unlock(&nsim_bus_dev_list_lock);
 
+	wait_for_completion(&nsim_bus_devs_released);
+
 	driver_unregister(&nsim_driver);
 	bus_unregister(&nsim_bus);
 }