diff mbox series

[net-next,v7,1/4] netdevsim: allow two netdevsim ports to be connected

Message ID 20240127040354.944744-2-dw@davidwei.uk (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series netdevsim: link and forward skbs between ports | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit fail Errors and warnings before: 1064 this patch: 1065
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 0 of 0 maintainers
netdev/build_clang success Errors and warnings before: 1081 this patch: 1081
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api warning Found: 'put_net(' was: 0 now: 3
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn fail Errors and warnings before: 1081 this patch: 1082
netdev/checkpatch warning WARNING: line length of 100 exceeds 80 columns WARNING: line length of 104 exceeds 80 columns WARNING: line length of 82 exceeds 80 columns WARNING: line length of 85 exceeds 80 columns WARNING: line length of 91 exceeds 80 columns WARNING: line length of 93 exceeds 80 columns WARNING: line length of 96 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

David Wei Jan. 27, 2024, 4:03 a.m. UTC
Add two netdevsim bus attribute to sysfs:
/sys/bus/netdevsim/link_device
/sys/bus/netdevsim/unlink_device

Writing "A M B N" to link_device will link netdevsim M in netnsid A with
netdevsim N in netnsid B.

Writing "A M" to unlink_device will unlink netdevsim M in netnsid A from
its peer and vice versa, if any.

rtnl_lock is taken to ensure nothing changes during the linking.

Signed-off-by: David Wei <dw@davidwei.uk>
---
 drivers/net/netdevsim/bus.c       | 130 ++++++++++++++++++++++++++++++
 drivers/net/netdevsim/netdev.c    |  11 +++
 drivers/net/netdevsim/netdevsim.h |   2 +
 3 files changed, 143 insertions(+)

Comments

kernel test robot Jan. 27, 2024, 10:48 p.m. UTC | #1
Hi David,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/David-Wei/netdevsim-allow-two-netdevsim-ports-to-be-connected/20240127-121234
base:   net-next/main
patch link:    https://lore.kernel.org/r/20240127040354.944744-2-dw%40davidwei.uk
patch subject: [PATCH net-next v7 1/4] netdevsim: allow two netdevsim ports to be connected
config: x86_64-randconfig-r122-20240127 (https://download.01.org/0day-ci/archive/20240128/202401280644.lnmk82jI-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240128/202401280644.lnmk82jI-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401280644.lnmk82jI-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/net/netdevsim/bus.c:349:14: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected struct netdevsim *peer @@     got struct netdevsim [noderef] __rcu *peer @@
   drivers/net/netdevsim/bus.c:349:14: sparse:     expected struct netdevsim *peer
   drivers/net/netdevsim/bus.c:349:14: sparse:     got struct netdevsim [noderef] __rcu *peer

vim +349 drivers/net/netdevsim/bus.c

   311	
   312	static ssize_t unlink_device_store(const struct bus_type *bus, const char *buf, size_t count)
   313	{
   314		struct netdevsim *nsim, *peer;
   315		unsigned int netnsid, ifidx;
   316		struct net_device *dev;
   317		struct net *ns;
   318		int err;
   319	
   320		err = sscanf(buf, "%u:%u", &netnsid, &ifidx);
   321		if (err != 2) {
   322			pr_err("Format for unlinking a device is \"netnsid:ifidx\" (uint uint).\n");
   323			return -EINVAL;
   324		}
   325	
   326		err = -EINVAL;
   327		rtnl_lock();
   328		ns = get_net_ns_by_id(current->nsproxy->net_ns, netnsid);
   329		if (!ns) {
   330			pr_err("Could not find netns with id: %u\n", netnsid);
   331			goto out_unlock_rtnl;
   332		}
   333	
   334		dev = __dev_get_by_index(ns, ifidx);
   335		if (!dev) {
   336			pr_err("Could not find device with ifindex %u in netnsid %u\n", ifidx, netnsid);
   337			goto out_put_netns;
   338		}
   339	
   340		if (!netdev_is_nsim(dev)) {
   341			pr_err("Device with ifindex %u in netnsid %u is not a netdevsim\n", ifidx, netnsid);
   342			goto out_put_netns;
   343		}
   344	
   345		err = 0;
   346		nsim = netdev_priv(dev);
   347		if (!nsim->peer)
   348			goto out_put_netns;
 > 349		peer = nsim->peer;
   350	
   351		RCU_INIT_POINTER(nsim->peer, NULL);
   352		RCU_INIT_POINTER(peer->peer, NULL);
   353	
   354	out_put_netns:
   355		put_net(ns);
   356	out_unlock_rtnl:
   357		rtnl_unlock();
   358	
   359		return !err ? count : err;
   360	}
   361	static BUS_ATTR_WO(unlink_device);
   362
diff mbox series

Patch

diff --git a/drivers/net/netdevsim/bus.c b/drivers/net/netdevsim/bus.c
index bcbc1e19edde..3162f88b88ec 100644
--- a/drivers/net/netdevsim/bus.c
+++ b/drivers/net/netdevsim/bus.c
@@ -232,9 +232,139 @@  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)
+{
+	unsigned int netnsid_a, netnsid_b, ifidx_a, ifidx_b;
+	struct netdevsim *nsim_a, *nsim_b;
+	struct net_device *dev_a, *dev_b;
+	struct net *ns_a, *ns_b;
+	int err;
+
+	err = sscanf(buf, "%u:%u %u:%u", &netnsid_a, &ifidx_a, &netnsid_b, &ifidx_b);
+	if (err != 4) {
+		pr_err("Format for linking two devices is \"netnsid_a:ifidx_a netnsid_b:ifidx_b\" (uint uint unit uint).\n");
+		return -EINVAL;
+	}
+
+	err = -EINVAL;
+	rtnl_lock();
+	ns_a = get_net_ns_by_id(current->nsproxy->net_ns, netnsid_a);
+	if (!ns_a) {
+		pr_err("Could not find netns with id: %u\n", netnsid_a);
+		goto out_unlock_rtnl;
+	}
+
+	dev_a = __dev_get_by_index(ns_a, ifidx_a);
+	if (!dev_a) {
+		pr_err("Could not find device with ifindex %u in netnsid %u\n", ifidx_a, netnsid_a);
+		goto out_put_netns_a;
+	}
+
+	if (!netdev_is_nsim(dev_a)) {
+		pr_err("Device with ifindex %u in netnsid %u is not a netdevsim\n", ifidx_a, netnsid_a);
+		goto out_put_netns_a;
+	}
+
+	ns_b = get_net_ns_by_id(current->nsproxy->net_ns, netnsid_b);
+	if (!ns_b) {
+		pr_err("Could not find netns with id: %u\n", netnsid_b);
+		goto out_put_netns_a;
+	}
+
+	dev_b = __dev_get_by_index(ns_b, ifidx_b);
+	if (!dev_b) {
+		pr_err("Could not find device with ifindex %u in netnsid %u\n", ifidx_b, netnsid_b);
+		goto out_put_netns_b;
+	}
+
+	if (!netdev_is_nsim(dev_b)) {
+		pr_err("Device with ifindex %u in netnsid %u is not a netdevsim\n", ifidx_b, netnsid_b);
+		goto out_put_netns_b;
+	}
+
+	err = 0;
+	nsim_a = netdev_priv(dev_a);
+	if (nsim_a->peer) {
+		pr_err("Netdevsim %u:%u is already linked\n", netnsid_a, ifidx_a);
+		goto out_put_netns_b;
+	}
+
+	nsim_b = netdev_priv(dev_b);
+	if (nsim_b->peer) {
+		pr_err("Netdevsim %u:%u is already linked\n", netnsid_b, ifidx_b);
+		goto out_put_netns_b;
+	}
+
+	rcu_assign_pointer(nsim_a->peer, nsim_b);
+	rcu_assign_pointer(nsim_b->peer, nsim_a);
+
+out_put_netns_b:
+	put_net(ns_b);
+out_put_netns_a:
+	put_net(ns_a);
+out_unlock_rtnl:
+	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;
+	unsigned int netnsid, ifidx;
+	struct net_device *dev;
+	struct net *ns;
+	int err;
+
+	err = sscanf(buf, "%u:%u", &netnsid, &ifidx);
+	if (err != 2) {
+		pr_err("Format for unlinking a device is \"netnsid:ifidx\" (uint uint).\n");
+		return -EINVAL;
+	}
+
+	err = -EINVAL;
+	rtnl_lock();
+	ns = get_net_ns_by_id(current->nsproxy->net_ns, netnsid);
+	if (!ns) {
+		pr_err("Could not find netns with id: %u\n", netnsid);
+		goto out_unlock_rtnl;
+	}
+
+	dev = __dev_get_by_index(ns, ifidx);
+	if (!dev) {
+		pr_err("Could not find device with ifindex %u in netnsid %u\n", ifidx, netnsid);
+		goto out_put_netns;
+	}
+
+	if (!netdev_is_nsim(dev)) {
+		pr_err("Device with ifindex %u in netnsid %u is not a netdevsim\n", ifidx, netnsid);
+		goto out_put_netns;
+	}
+
+	err = 0;
+	nsim = netdev_priv(dev);
+	if (!nsim->peer)
+		goto out_put_netns;
+	peer = nsim->peer;
+
+	RCU_INIT_POINTER(nsim->peer, NULL);
+	RCU_INIT_POINTER(peer->peer, NULL);
+
+out_put_netns:
+	put_net(ns);
+out_unlock_rtnl:
+	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);
diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index 77e8250282a5..969248ffeca8 100644
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -394,6 +394,7 @@  nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port)
 	ns->nsim_dev = nsim_dev;
 	ns->nsim_dev_port = nsim_dev_port;
 	ns->nsim_bus_dev = nsim_dev->nsim_bus_dev;
+	RCU_INIT_POINTER(ns->peer, NULL);
 	SET_NETDEV_DEV(dev, &ns->nsim_bus_dev->dev);
 	SET_NETDEV_DEVLINK_PORT(dev, &nsim_dev_port->devlink_port);
 	nsim_ethtool_init(ns);
@@ -413,8 +414,13 @@  nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port)
 void nsim_destroy(struct netdevsim *ns)
 {
 	struct net_device *dev = ns->netdev;
+	struct netdevsim *peer;
 
 	rtnl_lock();
+	peer = rtnl_dereference(ns->peer);
+	if (peer)
+		RCU_INIT_POINTER(peer->peer, NULL);
+	RCU_INIT_POINTER(ns->peer, NULL);
 	unregister_netdevice(dev);
 	if (nsim_dev_port_is_pf(ns->nsim_dev_port)) {
 		nsim_macsec_teardown(ns);
@@ -427,6 +433,11 @@  void nsim_destroy(struct netdevsim *ns)
 	free_netdev(dev);
 }
 
+bool netdev_is_nsim(struct net_device *dev)
+{
+	return dev->netdev_ops == &nsim_netdev_ops;
+}
+
 static int nsim_validate(struct nlattr *tb[], struct nlattr *data[],
 			 struct netlink_ext_ack *extack)
 {
diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index 028c825b86db..c8b45b0d955e 100644
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -125,11 +125,13 @@  struct netdevsim {
 	} udp_ports;
 
 	struct nsim_ethtool ethtool;
+	struct netdevsim __rcu *peer;
 };
 
 struct netdevsim *
 nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port);
 void nsim_destroy(struct netdevsim *ns);
+bool netdev_is_nsim(struct net_device *dev);
 
 void nsim_ethtool_init(struct netdevsim *ns);