| Message ID | 20240228232253.2875900-2-dw@davidwei.uk (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | f532957d76de89b8ee2545cb6ad5265e1701d0ba |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | netdevsim: link and forward skbs between ports | expand |
On 29/02/2024 00:22, David Wei wrote: > 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, 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 | 145 ++++++++++++++++++++++++++++++ > drivers/net/netdevsim/netdev.c | 10 +++ > drivers/net/netdevsim/netdevsim.h | 2 + > 3 files changed, 157 insertions(+) > > diff --git a/drivers/net/netdevsim/bus.c b/drivers/net/netdevsim/bus.c > index 0c5aff63d242..64c0cdd31bf8 100644 > --- a/drivers/net/netdevsim/bus.c > +++ b/drivers/net/netdevsim/bus.c > @@ -232,9 +232,154 @@ 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); > + > +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); > diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c > index 77e8250282a5..9063f4f2971b 100644 > --- a/drivers/net/netdevsim/netdev.c > +++ b/drivers/net/netdevsim/netdev.c > @@ -413,8 +413,13 @@ 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 +432,11 @@ 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); > Reviewed-by: Maciek Machnikowski <maciek@machnikowski.net>
diff --git a/drivers/net/netdevsim/bus.c b/drivers/net/netdevsim/bus.c index 0c5aff63d242..64c0cdd31bf8 100644 --- a/drivers/net/netdevsim/bus.c +++ b/drivers/net/netdevsim/bus.c @@ -232,9 +232,154 @@ 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); + +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); diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c index 77e8250282a5..9063f4f2971b 100644 --- a/drivers/net/netdevsim/netdev.c +++ b/drivers/net/netdevsim/netdev.c @@ -413,8 +413,13 @@ 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 +432,11 @@ 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);
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, 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 | 145 ++++++++++++++++++++++++++++++ drivers/net/netdevsim/netdev.c | 10 +++ drivers/net/netdevsim/netdevsim.h | 2 + 3 files changed, 157 insertions(+)