Re: [PATCHv1 7/7] IPVTAP: IP-VLAN based tap driver

From: Mahesh Bandewar (àààà ààààààà)
Date: Fri Jan 06 2017 - 18:47:22 EST

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Previous message: Vladimir Zapolskiy: "Re: [PATCH] i2c: core: helper function to detect slave mode"
In reply to: Eric Dumazet: "Re: [PATCHv1 7/7] IPVTAP: IP-VLAN based tap driver"
Next in thread: Sainath Grandhi: "[PATCHv1 6/7] TAP: tap as an independent module"
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few superficial comments inline.

On Fri, Jan 6, 2017 at 2:33 PM, Sainath Grandhi
<sainath.grandhi@xxxxxxxxx> wrote:
> This patch adds a tap character device driver that is based on the
> IP-VLAN network interface, called ipvtap. An ipvtap device can be created
> in the same way as an ipvlan device, using 'type ipvtap', and then accessed
> using the tap user space interface.
>
> Signed-off-by: Sainath Grandhi <sainath.grandhi@xxxxxxxxx>
> Tested-by: Sainath Grandhi <sainath.grandhi@xxxxxxxxx>
> ---
> drivers/net/Kconfig | 12 ++
> drivers/net/Makefile | 1 +
> drivers/net/ipvlan/Makefile | 1 +
> drivers/net/ipvlan/ipvlan.h | 7 ++
> drivers/net/ipvlan/ipvlan_core.c | 5 +-
> drivers/net/ipvlan/ipvlan_main.c | 37 +++---
> drivers/net/ipvlan/ipvtap.c | 238 +++++++++++++++++++++++++++++++++++++++
> 7 files changed, 282 insertions(+), 19 deletions(-)
> create mode 100644 drivers/net/ipvlan/ipvtap.c
>
> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
> index 280380d..ddfb30a 100644
> --- a/drivers/net/Kconfig
> +++ b/drivers/net/Kconfig
> @@ -165,6 +165,18 @@ config IPVLAN
> To compile this driver as a module, choose M here: the module
> will be called ipvlan.
>
> +config IPVTAP
> + tristate "IP-VLAN based tap driver"
> + depends on IPVLAN
> + depends on INET
> + help
> + This adds a specialized tap character device driver that is based
> + on the IP-VLAN network interface, called ipvtap. An ipvtap device
> + can be added in the same way as a ipvlan device, using 'type
> + ipvtap', and then be accessed through the tap user space interface.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called macvtap.
>
> config VXLAN
> tristate "Virtual eXtensible Local Area Network (VXLAN)"
> diff --git a/drivers/net/Makefile b/drivers/net/Makefile
> index 7dd86ca..98ed4d9 100644
> --- a/drivers/net/Makefile
> +++ b/drivers/net/Makefile
> @@ -7,6 +7,7 @@
> #
> obj-$(CONFIG_BONDING) += bonding/
> obj-$(CONFIG_IPVLAN) += ipvlan/
> +obj-$(CONFIG_IPVTAP) += ipvlan/
> obj-$(CONFIG_DUMMY) += dummy.o
> obj-$(CONFIG_EQUALIZER) += eql.o
> obj-$(CONFIG_IFB) += ifb.o
> diff --git a/drivers/net/ipvlan/Makefile b/drivers/net/ipvlan/Makefile
> index df79910..8a2c64d 100644
> --- a/drivers/net/ipvlan/Makefile
> +++ b/drivers/net/ipvlan/Makefile
> @@ -3,5 +3,6 @@
> #
>
> obj-$(CONFIG_IPVLAN) += ipvlan.o
> +obj-$(CONFIG_IPVTAP) += ipvtap.o
>
> ipvlan-objs := ipvlan_core.o ipvlan_main.o
> diff --git a/drivers/net/ipvlan/ipvlan.h b/drivers/net/ipvlan/ipvlan.h
> index dbfbb33..4362d88 100644
> --- a/drivers/net/ipvlan/ipvlan.h
> +++ b/drivers/net/ipvlan/ipvlan.h
> @@ -133,4 +133,11 @@ struct sk_buff *ipvlan_l3_rcv(struct net_device *dev, struct sk_buff *skb,
> u16 proto);
> unsigned int ipvlan_nf_input(void *priv, struct sk_buff *skb,
> const struct nf_hook_state *state);
> +void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
> + unsigned int len, bool success, bool mcast);
> +int ipvlan_link_new(struct net *src_net, struct net_device *dev,
> + struct nlattr *tb[], struct nlattr *data[]);
> +void ipvlan_link_delete(struct net_device *dev, struct list_head *head);
> +void ipvlan_link_setup(struct net_device *dev);
> +int ipvlan_link_register(struct rtnl_link_ops *ops);
> #endif /* __IPVLAN_H */
> diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c
> index 83ce74a..9af16ab 100644
> --- a/drivers/net/ipvlan/ipvlan_core.c
> +++ b/drivers/net/ipvlan/ipvlan_core.c
> @@ -16,8 +16,8 @@ void ipvlan_init_secret(void)
> net_get_random_once(&ipvlan_jhash_secret, sizeof(ipvlan_jhash_secret));
> }
>
> -static void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
> - unsigned int len, bool success, bool mcast)
> +void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
> + unsigned int len, bool success, bool mcast)
> {
> if (!ipvlan)
> return;
> @@ -36,6 +36,7 @@ static void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
> this_cpu_inc(ipvlan->pcpu_stats->rx_errs);
> }
> }
> +EXPORT_SYMBOL_GPL(ipvlan_count_rx);
Why export, isn't just removing 'static' enough?
>
> static u8 ipvlan_get_v6_hash(const void *iaddr)
> {
> diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
> index 8b0f993..666a05d 100644
> --- a/drivers/net/ipvlan/ipvlan_main.c
> +++ b/drivers/net/ipvlan/ipvlan_main.c
> @@ -13,14 +13,14 @@ static u32 ipvl_nf_hook_refcnt = 0;
>
> static struct nf_hook_ops ipvl_nfops[] __read_mostly = {
> {
> - .hook = ipvlan_nf_input,
> - .pf = NFPROTO_IPV4,
> + .hook = ipvlan_nf_input,
> + .pf = NFPROTO_IPV4,
spurious?
> .hooknum = NF_INET_LOCAL_IN,
> .priority = INT_MAX,
> },
> {
> - .hook = ipvlan_nf_input,
> - .pf = NFPROTO_IPV6,
> + .hook = ipvlan_nf_input,
> + .pf = NFPROTO_IPV6,
spurious??
> .hooknum = NF_INET_LOCAL_IN,
> .priority = INT_MAX,
> },
> @@ -398,7 +398,7 @@ static int ipvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
> }
>
> static const struct header_ops ipvlan_header_ops = {
> - .create = ipvlan_hard_header,
> + .create = ipvlan_hard_header,
spurious???
> .parse = eth_header_parse,
> .cache = eth_header_cache,
> .cache_update = eth_header_cache_update,
> @@ -494,8 +494,8 @@ static int ipvlan_nl_fillinfo(struct sk_buff *skb,
> return ret;
> }
>
> -static int ipvlan_link_new(struct net *src_net, struct net_device *dev,
> - struct nlattr *tb[], struct nlattr *data[])
> +int ipvlan_link_new(struct net *src_net, struct net_device *dev,
> + struct nlattr *tb[], struct nlattr *data[])
> {
> struct ipvl_dev *ipvlan = netdev_priv(dev);
> struct ipvl_port *port;
> @@ -567,8 +567,9 @@ static int ipvlan_link_new(struct net *src_net, struct net_device *dev,
> ipvlan_port_destroy(phy_dev);
> return err;
> }
> +EXPORT_SYMBOL_GPL(ipvlan_link_new);
>
> -static void ipvlan_link_delete(struct net_device *dev, struct list_head *head)
> +void ipvlan_link_delete(struct net_device *dev, struct list_head *head)
> {
> struct ipvl_dev *ipvlan = netdev_priv(dev);
> struct ipvl_addr *addr, *next;
> @@ -583,8 +584,9 @@ static void ipvlan_link_delete(struct net_device *dev, struct list_head *head)
> unregister_netdevice_queue(dev, head);
> netdev_upper_dev_unlink(ipvlan->phy_dev, dev);
> }
> +EXPORT_SYMBOL_GPL(ipvlan_link_delete);
>
> -static void ipvlan_link_setup(struct net_device *dev)
> +void ipvlan_link_setup(struct net_device *dev)
> {
> ether_setup(dev);
>
> @@ -595,6 +597,7 @@ static void ipvlan_link_setup(struct net_device *dev)
> dev->header_ops = &ipvlan_header_ops;
> dev->ethtool_ops = &ipvlan_ethtool_ops;
> }
> +EXPORT_SYMBOL_GPL(ipvlan_link_setup);
>
> static const struct nla_policy ipvlan_nl_policy[IFLA_IPVLAN_MAX + 1] =
> {
> @@ -605,22 +608,22 @@ static struct rtnl_link_ops ipvlan_link_ops = {
> .kind = "ipvlan",
> .priv_size = sizeof(struct ipvl_dev),
>
> - .get_size = ipvlan_nl_getsize,
> - .policy = ipvlan_nl_policy,
> - .validate = ipvlan_nl_validate,
> - .fill_info = ipvlan_nl_fillinfo,
> - .changelink = ipvlan_nl_changelink,
> - .maxtype = IFLA_IPVLAN_MAX,
> -
> .setup = ipvlan_link_setup,
> .newlink = ipvlan_link_new,
> .dellink = ipvlan_link_delete,
> };
>
> -static int ipvlan_link_register(struct rtnl_link_ops *ops)
> +int ipvlan_link_register(struct rtnl_link_ops *ops)
> {
> + ops->get_size = ipvlan_nl_getsize;
> + ops->policy = ipvlan_nl_policy;
> + ops->validate = ipvlan_nl_validate;
> + ops->fill_info = ipvlan_nl_fillinfo;
> + ops->changelink = ipvlan_nl_changelink;
> + ops->maxtype = IFLA_IPVLAN_MAX;
> return rtnl_link_register(ops);
> }
> +EXPORT_SYMBOL_GPL(ipvlan_link_register);
>
> static int ipvlan_device_event(struct notifier_block *unused,
> unsigned long event, void *ptr)
> diff --git a/drivers/net/ipvlan/ipvtap.c b/drivers/net/ipvlan/ipvtap.c
> new file mode 100644
> index 0000000..0422cdf
> --- /dev/null
> +++ b/drivers/net/ipvlan/ipvtap.c
> @@ -0,0 +1,238 @@
> +#include <linux/etherdevice.h>
> +#include "ipvlan.h"
> +#include <linux/if_vlan.h>
> +#include <linux/if_tap.h>
> +#include <linux/interrupt.h>
> +#include <linux/nsproxy.h>
> +#include <linux/compat.h>
> +#include <linux/if_tun.h>
> +#include <linux/module.h>
> +#include <linux/skbuff.h>
> +#include <linux/cache.h>
> +#include <linux/sched.h>
> +#include <linux/types.h>
> +#include <linux/slab.h>
> +#include <linux/wait.h>
> +#include <linux/cdev.h>
> +#include <linux/idr.h>
> +#include <linux/fs.h>
> +#include <linux/uio.h>
> +
> +#include <net/net_namespace.h>
> +#include <net/rtnetlink.h>
> +#include <net/sock.h>
> +#include <linux/virtio_net.h>
> +
> +#define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
> + NETIF_F_TSO6 | NETIF_F_UFO)
> +
> +static dev_t ipvtap_major;
> +static struct cdev ipvtap_cdev;
> +
> +static const void *ipvtap_net_namespace(struct device *d)
> +{
> + struct net_device *dev = to_net_dev(d->parent);
> + return dev_net(dev);
> +}
> +
> +static struct class ipvtap_class = {
> + .name = "ipvtap",
> + .owner = THIS_MODULE,
> + .ns_type = &net_ns_type_operations,
> + .namespace = ipvtap_net_namespace,
> +};
> +
> +struct ipvtap_dev {
> + struct ipvl_dev vlan;
> + struct tap_dev tap;
> +};
> +
> +static void ipvtap_count_tx_dropped(struct tap_dev *tap)
> +{
> + struct ipvl_dev *vlan = (struct ipvl_dev *)container_of(tap, struct ipvtap_dev, tap);
> +
> + this_cpu_inc(vlan->pcpu_stats->tx_drps);
> +}
> +
> +static void ipvtap_count_rx_dropped(struct tap_dev *tap)
> +{
> + struct ipvl_dev *vlan = (struct ipvl_dev *)container_of(tap, struct ipvtap_dev, tap);
> +
> + ipvlan_count_rx(vlan, 0, 0, 0);
> +}
> +
> +static void ipvtap_update_features(struct tap_dev *tap,
> + netdev_features_t features)
> +{
> + struct ipvl_dev *vlan = (struct ipvl_dev *)container_of(tap, struct ipvtap_dev, tap);
> +
> + vlan->sfeatures = features;
> + netdev_update_features(vlan->dev);
> +}
> +
> +static int ipvtap_newlink(struct net *src_net,
> + struct net_device *dev,
> + struct nlattr *tb[],
> + struct nlattr *data[])
> +{
> + struct ipvtap_dev *vlantap = netdev_priv(dev);
> + int err;
> +
> + INIT_LIST_HEAD(&vlantap->tap.queue_list);
> +
> + /* Since macvlan supports all offloads by default, make
> + * tap support all offloads also.
> + */
> + vlantap->tap.tap_features = TUN_OFFLOADS;
> + vlantap->tap.count_tx_dropped = ipvtap_count_tx_dropped;
> + vlantap->tap.update_features = ipvtap_update_features;
> + vlantap->tap.count_rx_dropped = ipvtap_count_rx_dropped;
> +
> + err = netdev_rx_handler_register(dev, tap_handle_frame, &vlantap->tap);
> + if (err)
> + return err;
> +
> + /* Don't put anything that may fail after macvlan_common_newlink
> + * because we can't undo what it does.
> + */
> + err = ipvlan_link_new(src_net, dev, tb, data);
> + if (err) {
> + netdev_rx_handler_unregister(dev);
> + return err;
> + }
> +
> + vlantap->tap.dev = vlantap->vlan.dev;
> +
> + return err;
> +}
> +
> +static void ipvtap_dellink(struct net_device *dev,
> + struct list_head *head)
> +{
> + struct ipvtap_dev *vlan = netdev_priv(dev);
> +
> + netdev_rx_handler_unregister(dev);
> + tap_del_queues(&vlan->tap);
> + ipvlan_link_delete(dev, head);
> +}
> +
> +static void ipvtap_setup(struct net_device *dev)
> +{
> + ipvlan_link_setup(dev);
> + dev->tx_queue_len = TUN_READQ_SIZE;
> + dev->priv_flags &= ~IFF_NO_QUEUE;
> +}
> +
> +static struct rtnl_link_ops ipvtap_link_ops __read_mostly = {
> + .kind = "ipvtap",
> + .setup = ipvtap_setup,
> + .newlink = ipvtap_newlink,
> + .dellink = ipvtap_dellink,
> + .priv_size = sizeof(struct ipvtap_dev),
> +};
> +
> +static int ipvtap_device_event(struct notifier_block *unused,
> + unsigned long event, void *ptr)
> +{
> + struct net_device *dev = netdev_notifier_info_to_dev(ptr);
> + struct ipvtap_dev *vlantap;
> + struct device *classdev;
> + dev_t devt;
> + int err;
> + char tap_name[IFNAMSIZ];
> +
> + if (dev->rtnl_link_ops != &ipvtap_link_ops)
> + return NOTIFY_DONE;
> +
> + snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex);
> + vlantap = netdev_priv(dev);
> +
> + switch (event) {
> + case NETDEV_REGISTER:
> + /* Create the device node here after the network device has
> + * been registered but before register_netdevice has
> + * finished running.
> + */
> + err = tap_get_minor(ipvtap_major, &vlantap->tap);
> + if (err)
> + return notifier_from_errno(err);
> +
> + devt = MKDEV(MAJOR(ipvtap_major), vlantap->tap.minor);
> + classdev = device_create(&ipvtap_class, &dev->dev, devt,
> + dev, tap_name);
> + if (IS_ERR(classdev)) {
> + tap_free_minor(ipvtap_major, &vlantap->tap);
> + return notifier_from_errno(PTR_ERR(classdev));
> + }
> + err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj,
> + tap_name);
> + if (err)
> + return notifier_from_errno(err);
> + break;
> + case NETDEV_UNREGISTER:
> + /* vlan->minor == 0 if NETDEV_REGISTER above failed */
> + if (vlantap->tap.minor == 0)
> + break;
> + sysfs_remove_link(&dev->dev.kobj, tap_name);
> + devt = MKDEV(MAJOR(ipvtap_major), vlantap->tap.minor);
> + device_destroy(&ipvtap_class, devt);
> + tap_free_minor(ipvtap_major, &vlantap->tap);
> + break;
> + case NETDEV_CHANGE_TX_QUEUE_LEN:
> + if (tap_queue_resize(&vlantap->tap))
> + return NOTIFY_BAD;
> + break;
> + }
> +
> + return NOTIFY_DONE;
> +}
> +
> +static struct notifier_block ipvtap_notifier_block __read_mostly = {
> + .notifier_call = ipvtap_device_event,
> +};
> +
> +static int ipvtap_init(void)
> +{
> + int err;
> +
> + err = tap_create_cdev(&ipvtap_cdev, &ipvtap_major, "ipvtap");
> +
> + if (err)
> + goto out1;
> +
> + err = class_register(&ipvtap_class);
> + if (err)
> + goto out2;
> +
> + err = register_netdevice_notifier(&ipvtap_notifier_block);
> + if (err)
> + goto out3;
> +
> + err = ipvlan_link_register(&ipvtap_link_ops);
> + if (err)
> + goto out4;
> +
> + return 0;
> +
> +out4:
> + unregister_netdevice_notifier(&ipvtap_notifier_block);
> +out3:
> + class_unregister(&ipvtap_class);
> +out2:
> + cdev_del(&ipvtap_cdev);
> +out1:
> + return err;
> +}
> +module_init(ipvtap_init);
> +
> +static void ipvtap_exit(void)
> +{
> + rtnl_link_unregister(&ipvtap_link_ops);
> + unregister_netdevice_notifier(&ipvtap_notifier_block);
> + class_unregister(&ipvtap_class);
> + tap_destroy_cdev(ipvtap_major, &ipvtap_cdev);
> +}
> +module_exit(ipvtap_exit);
> +MODULE_ALIAS_RTNL_LINK("ipvtap");
> +MODULE_AUTHOR("Arnd Bergmann <arnd@xxxxxxxx>");
> +MODULE_LICENSE("GPL");
> --
> 2.7.4
>

Next message: Kweh, Hock Leong: "RE: [PATCH v3] net: stmmac: fix maxmtu assignment to be within valid range"
Previous message: Vladimir Zapolskiy: "Re: [PATCH] i2c: core: helper function to detect slave mode"
In reply to: Eric Dumazet: "Re: [PATCHv1 7/7] IPVTAP: IP-VLAN based tap driver"
Next in thread: Sainath Grandhi: "[PATCHv1 6/7] TAP: tap as an independent module"
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