[RTNETLINK]: Link creation API
Add rtnetlink API for creating, changing and deleting software devices. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller
parent
0157f60c0c
commit
38f7b870d4
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@ -76,6 +76,8 @@ enum
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#define IFLA_WEIGHT IFLA_WEIGHT
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IFLA_OPERSTATE,
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IFLA_LINKMODE,
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IFLA_LINKINFO,
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#define IFLA_LINKINFO IFLA_LINKINFO
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__IFLA_MAX
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};
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@ -140,4 +142,15 @@ struct ifla_cacheinfo
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__u32 retrans_time;
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};
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enum
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{
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IFLA_INFO_UNSPEC,
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IFLA_INFO_KIND,
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IFLA_INFO_DATA,
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IFLA_INFO_XSTATS,
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__IFLA_INFO_MAX,
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};
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#define IFLA_INFO_MAX (__IFLA_INFO_MAX - 1)
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#endif /* _LINUX_IF_LINK_H */
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@ -540,6 +540,9 @@ struct net_device
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struct device dev;
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/* space for optional statistics and wireless sysfs groups */
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struct attribute_group *sysfs_groups[3];
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/* rtnetlink link ops */
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const struct rtnl_link_ops *rtnl_link_ops;
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};
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#define to_net_dev(d) container_of(d, struct net_device, dev)
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@ -22,4 +22,62 @@ static inline int rtnl_msg_family(struct nlmsghdr *nlh)
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return AF_UNSPEC;
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}
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/**
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* struct rtnl_link_ops - rtnetlink link operations
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*
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* @list: Used internally
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* @kind: Identifier
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* @maxtype: Highest device specific netlink attribute number
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* @policy: Netlink policy for device specific attribute validation
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* @validate: Optional validation function for netlink/changelink parameters
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* @priv_size: sizeof net_device private space
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* @setup: net_device setup function
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* @newlink: Function for configuring and registering a new device
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* @changelink: Function for changing parameters of an existing device
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* @dellink: Function to remove a device
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* @get_size: Function to calculate required room for dumping device
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* specific netlink attributes
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* @fill_info: Function to dump device specific netlink attributes
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* @get_xstats_size: Function to calculate required room for dumping devic
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* specific statistics
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* @fill_xstats: Function to dump device specific statistics
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*/
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struct rtnl_link_ops {
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struct list_head list;
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const char *kind;
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size_t priv_size;
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void (*setup)(struct net_device *dev);
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int maxtype;
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const struct nla_policy *policy;
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int (*validate)(struct nlattr *tb[],
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struct nlattr *data[]);
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int (*newlink)(struct net_device *dev,
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struct nlattr *tb[],
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struct nlattr *data[]);
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int (*changelink)(struct net_device *dev,
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struct nlattr *tb[],
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struct nlattr *data[]);
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void (*dellink)(struct net_device *dev);
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size_t (*get_size)(const struct net_device *dev);
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int (*fill_info)(struct sk_buff *skb,
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const struct net_device *dev);
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size_t (*get_xstats_size)(const struct net_device *dev);
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int (*fill_xstats)(struct sk_buff *skb,
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const struct net_device *dev);
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};
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extern int __rtnl_link_register(struct rtnl_link_ops *ops);
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extern void __rtnl_link_unregister(struct rtnl_link_ops *ops);
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extern int rtnl_link_register(struct rtnl_link_ops *ops);
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extern void rtnl_link_unregister(struct rtnl_link_ops *ops);
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#define MODULE_ALIAS_RTNL_LINK(kind) MODULE_ALIAS("rtnl-link-" kind)
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#endif
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@ -243,6 +243,143 @@ void rtnl_unregister_all(int protocol)
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EXPORT_SYMBOL_GPL(rtnl_unregister_all);
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static LIST_HEAD(link_ops);
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/**
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* __rtnl_link_register - Register rtnl_link_ops with rtnetlink.
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* @ops: struct rtnl_link_ops * to register
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*
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* The caller must hold the rtnl_mutex. This function should be used
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* by drivers that create devices during module initialization. It
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* must be called before registering the devices.
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*
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* Returns 0 on success or a negative error code.
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*/
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int __rtnl_link_register(struct rtnl_link_ops *ops)
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{
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list_add_tail(&ops->list, &link_ops);
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return 0;
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}
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EXPORT_SYMBOL_GPL(__rtnl_link_register);
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/**
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* rtnl_link_register - Register rtnl_link_ops with rtnetlink.
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* @ops: struct rtnl_link_ops * to register
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*
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* Returns 0 on success or a negative error code.
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*/
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int rtnl_link_register(struct rtnl_link_ops *ops)
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{
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int err;
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rtnl_lock();
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err = __rtnl_link_register(ops);
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rtnl_unlock();
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return err;
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}
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EXPORT_SYMBOL_GPL(rtnl_link_register);
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/**
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* __rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
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* @ops: struct rtnl_link_ops * to unregister
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*
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* The caller must hold the rtnl_mutex. This function should be used
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* by drivers that unregister devices during module unloading. It must
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* be called after unregistering the devices.
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*/
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void __rtnl_link_unregister(struct rtnl_link_ops *ops)
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{
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list_del(&ops->list);
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}
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EXPORT_SYMBOL_GPL(__rtnl_link_unregister);
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/**
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* rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
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* @ops: struct rtnl_link_ops * to unregister
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*/
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void rtnl_link_unregister(struct rtnl_link_ops *ops)
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{
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rtnl_lock();
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__rtnl_link_unregister(ops);
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rtnl_unlock();
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}
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EXPORT_SYMBOL_GPL(rtnl_link_unregister);
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static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)
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{
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const struct rtnl_link_ops *ops;
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list_for_each_entry(ops, &link_ops, list) {
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if (!strcmp(ops->kind, kind))
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return ops;
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}
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return NULL;
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}
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static size_t rtnl_link_get_size(const struct net_device *dev)
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{
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const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
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size_t size;
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if (!ops)
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return 0;
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size = nlmsg_total_size(sizeof(struct nlattr)) + /* IFLA_LINKINFO */
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nlmsg_total_size(strlen(ops->kind) + 1); /* IFLA_INFO_KIND */
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if (ops->get_size)
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/* IFLA_INFO_DATA + nested data */
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size += nlmsg_total_size(sizeof(struct nlattr)) +
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ops->get_size(dev);
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if (ops->get_xstats_size)
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size += ops->get_xstats_size(dev); /* IFLA_INFO_XSTATS */
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return size;
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}
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static int rtnl_link_fill(struct sk_buff *skb, const struct net_device *dev)
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{
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const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
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struct nlattr *linkinfo, *data;
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int err = -EMSGSIZE;
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linkinfo = nla_nest_start(skb, IFLA_LINKINFO);
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if (linkinfo == NULL)
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goto out;
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if (nla_put_string(skb, IFLA_INFO_KIND, ops->kind) < 0)
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goto err_cancel_link;
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if (ops->fill_xstats) {
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err = ops->fill_xstats(skb, dev);
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if (err < 0)
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goto err_cancel_link;
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}
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if (ops->fill_info) {
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data = nla_nest_start(skb, IFLA_INFO_DATA);
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if (data == NULL)
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goto err_cancel_link;
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err = ops->fill_info(skb, dev);
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if (err < 0)
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goto err_cancel_data;
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nla_nest_end(skb, data);
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}
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nla_nest_end(skb, linkinfo);
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return 0;
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err_cancel_data:
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nla_nest_cancel(skb, data);
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err_cancel_link:
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nla_nest_cancel(skb, linkinfo);
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out:
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return err;
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}
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static const int rtm_min[RTM_NR_FAMILIES] =
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{
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[RTM_FAM(RTM_NEWLINK)] = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
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@ -437,7 +574,7 @@ static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
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a->tx_compressed = b->tx_compressed;
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};
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static inline size_t if_nlmsg_size(void)
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static inline size_t if_nlmsg_size(const struct net_device *dev)
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{
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return NLMSG_ALIGN(sizeof(struct ifinfomsg))
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+ nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
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@ -452,7 +589,8 @@ static inline size_t if_nlmsg_size(void)
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+ nla_total_size(4) /* IFLA_LINK */
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+ nla_total_size(4) /* IFLA_MASTER */
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+ nla_total_size(1) /* IFLA_OPERSTATE */
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+ nla_total_size(1); /* IFLA_LINKMODE */
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+ nla_total_size(1) /* IFLA_LINKMODE */
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+ rtnl_link_get_size(dev); /* IFLA_LINKINFO */
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}
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static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
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@ -522,6 +660,11 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
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}
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}
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if (dev->rtnl_link_ops) {
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if (rtnl_link_fill(skb, dev) < 0)
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goto nla_put_failure;
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}
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return nlmsg_end(skb, nlh);
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nla_put_failure:
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@ -553,6 +696,8 @@ cont:
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static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
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[IFLA_IFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ-1 },
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[IFLA_ADDRESS] = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
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[IFLA_BROADCAST] = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
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[IFLA_MAP] = { .len = sizeof(struct rtnl_link_ifmap) },
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[IFLA_MTU] = { .type = NLA_U32 },
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[IFLA_TXQLEN] = { .type = NLA_U32 },
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@ -561,10 +706,15 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
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[IFLA_LINKMODE] = { .type = NLA_U8 },
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};
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static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
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[IFLA_INFO_KIND] = { .type = NLA_STRING },
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[IFLA_INFO_DATA] = { .type = NLA_NESTED },
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};
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static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
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struct nlattr **tb, char *ifname)
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struct nlattr **tb, char *ifname, int modified)
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{
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int modified = 0, send_addr_notify = 0;
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int send_addr_notify = 0;
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int err;
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if (tb[IFLA_MAP]) {
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@ -729,13 +879,189 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
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nla_len(tb[IFLA_BROADCAST]) < dev->addr_len)
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goto errout_dev;
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err = do_setlink(dev, ifm, tb, ifname);
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err = do_setlink(dev, ifm, tb, ifname, 0);
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errout_dev:
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dev_put(dev);
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errout:
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return err;
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}
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static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
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{
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const struct rtnl_link_ops *ops;
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struct net_device *dev;
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struct ifinfomsg *ifm;
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char ifname[IFNAMSIZ];
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struct nlattr *tb[IFLA_MAX+1];
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int err;
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err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
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if (err < 0)
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return err;
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if (tb[IFLA_IFNAME])
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nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
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ifm = nlmsg_data(nlh);
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if (ifm->ifi_index > 0)
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dev = __dev_get_by_index(ifm->ifi_index);
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else if (tb[IFLA_IFNAME])
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dev = __dev_get_by_name(ifname);
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else
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return -EINVAL;
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if (!dev)
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return -ENODEV;
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ops = dev->rtnl_link_ops;
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if (!ops)
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return -EOPNOTSUPP;
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ops->dellink(dev);
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return 0;
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}
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static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
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{
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const struct rtnl_link_ops *ops;
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struct net_device *dev;
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struct ifinfomsg *ifm;
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char kind[MODULE_NAME_LEN];
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char ifname[IFNAMSIZ];
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struct nlattr *tb[IFLA_MAX+1];
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struct nlattr *linkinfo[IFLA_INFO_MAX+1];
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int err;
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replay:
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err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
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if (err < 0)
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return err;
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if (tb[IFLA_IFNAME])
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nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
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else
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ifname[0] = '\0';
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ifm = nlmsg_data(nlh);
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if (ifm->ifi_index > 0)
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dev = __dev_get_by_index(ifm->ifi_index);
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else if (ifname[0])
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dev = __dev_get_by_name(ifname);
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else
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dev = NULL;
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if (tb[IFLA_LINKINFO]) {
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err = nla_parse_nested(linkinfo, IFLA_INFO_MAX,
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tb[IFLA_LINKINFO], ifla_info_policy);
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if (err < 0)
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return err;
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} else
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memset(linkinfo, 0, sizeof(linkinfo));
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if (linkinfo[IFLA_INFO_KIND]) {
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nla_strlcpy(kind, linkinfo[IFLA_INFO_KIND], sizeof(kind));
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ops = rtnl_link_ops_get(kind);
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} else {
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kind[0] = '\0';
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ops = NULL;
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}
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if (1) {
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struct nlattr *attr[ops ? ops->maxtype + 1 : 0], **data = NULL;
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if (ops) {
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if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
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err = nla_parse_nested(attr, ops->maxtype,
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linkinfo[IFLA_INFO_DATA],
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ops->policy);
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if (err < 0)
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return err;
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data = attr;
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}
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if (ops->validate) {
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err = ops->validate(tb, data);
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if (err < 0)
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return err;
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}
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}
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if (dev) {
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int modified = 0;
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if (nlh->nlmsg_flags & NLM_F_EXCL)
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return -EEXIST;
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if (nlh->nlmsg_flags & NLM_F_REPLACE)
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return -EOPNOTSUPP;
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if (linkinfo[IFLA_INFO_DATA]) {
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if (!ops || ops != dev->rtnl_link_ops ||
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!ops->changelink)
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return -EOPNOTSUPP;
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err = ops->changelink(dev, tb, data);
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if (err < 0)
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return err;
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modified = 1;
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}
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return do_setlink(dev, ifm, tb, ifname, modified);
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}
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if (!(nlh->nlmsg_flags & NLM_F_CREATE))
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return -ENODEV;
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if (ifm->ifi_index || ifm->ifi_flags || ifm->ifi_change)
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return -EOPNOTSUPP;
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if (tb[IFLA_ADDRESS] || tb[IFLA_BROADCAST] || tb[IFLA_MAP] ||
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tb[IFLA_MASTER] || tb[IFLA_PROTINFO])
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return -EOPNOTSUPP;
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if (!ops) {
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#ifdef CONFIG_KMOD
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if (kind[0]) {
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__rtnl_unlock();
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request_module("rtnl-link-%s", kind);
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rtnl_lock();
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ops = rtnl_link_ops_get(kind);
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if (ops)
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goto replay;
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}
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#endif
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return -EOPNOTSUPP;
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}
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if (!ifname[0])
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snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);
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dev = alloc_netdev(ops->priv_size, ifname, ops->setup);
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if (!dev)
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return -ENOMEM;
|
||||
|
||||
if (strchr(dev->name, '%')) {
|
||||
err = dev_alloc_name(dev, dev->name);
|
||||
if (err < 0)
|
||||
goto err_free;
|
||||
}
|
||||
dev->rtnl_link_ops = ops;
|
||||
|
||||
if (tb[IFLA_MTU])
|
||||
dev->mtu = nla_get_u32(tb[IFLA_MTU]);
|
||||
if (tb[IFLA_TXQLEN])
|
||||
dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
|
||||
if (tb[IFLA_WEIGHT])
|
||||
dev->weight = nla_get_u32(tb[IFLA_WEIGHT]);
|
||||
if (tb[IFLA_OPERSTATE])
|
||||
set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
|
||||
if (tb[IFLA_LINKMODE])
|
||||
dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
|
||||
|
||||
err = ops->newlink(dev, tb, data);
|
||||
err_free:
|
||||
if (err < 0)
|
||||
free_netdev(dev);
|
||||
return err;
|
||||
}
|
||||
}
|
||||
|
||||
static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
|
||||
{
|
||||
struct ifinfomsg *ifm;
|
||||
|
|
@ -756,7 +1082,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
|
|||
} else
|
||||
return -EINVAL;
|
||||
|
||||
nskb = nlmsg_new(if_nlmsg_size(), GFP_KERNEL);
|
||||
nskb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
|
||||
if (nskb == NULL) {
|
||||
err = -ENOBUFS;
|
||||
goto errout;
|
||||
|
|
@ -806,7 +1132,7 @@ void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
|
|||
struct sk_buff *skb;
|
||||
int err = -ENOBUFS;
|
||||
|
||||
skb = nlmsg_new(if_nlmsg_size(), GFP_KERNEL);
|
||||
skb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
|
||||
if (skb == NULL)
|
||||
goto errout;
|
||||
|
||||
|
|
@ -961,6 +1287,8 @@ void __init rtnetlink_init(void)
|
|||
|
||||
rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink, rtnl_dump_ifinfo);
|
||||
rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL);
|
||||
rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL);
|
||||
rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL);
|
||||
|
||||
rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all);
|
||||
rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all);
|
||||
|
|
|
|||
Reference in New Issue