Classifiers

Modules
	Classifier Modules
	Classifier Object

Classifier Addition/Modification/Deletion
struct nl_msg *	rtnl_cls_build_add_request (struct rtnl_cls *cls, int flags)
	Build a netlink message to add a new classifier.
int	rtnl_cls_add (struct nl_handle *handle, struct rtnl_cls *cls, int flags)
	Add a new classifier.
struct nl_msg *	rtnl_cls_build_change_request (struct rtnl_cls *cls, int flags)
	Build a netlink message to change classifier attributes.
int	rtnl_cls_change (struct nl_handle *handle, struct rtnl_cls *cls, int flags)
	Change a classifier.
struct nl_msg *	rtnl_cls_build_delete_request (struct rtnl_cls *cls, int flags)
	Build a netlink request message to delete a classifier.
int	rtnl_cls_delete (struct nl_handle *handle, struct rtnl_cls *cls, int flags)
	Delete a classifier.

Cache Management
struct nl_cache *	rtnl_cls_alloc_cache (struct nl_handle *handle, int ifindex, uint32_t parent)
	Build a classifier cache including all classifiers attached to the specified class/qdisc on eht specified interface.

Detailed Description

Classifier Identification

• protocol
• priority
• parent
• interface
• kind
• handle

Function Documentation

rtnl_cls_build_add_request()

struct nl_msg * rtnl_cls_build_add_request	(	struct rtnl_cls *	cls,
		int	flags
	)

Parameters

cls	classifier to add
flags	additional netlink message flags

Builds a new netlink message requesting an addition of a classifier The netlink message header isn't fully equipped with all relevant fields and must be sent out via nl_send_auto_complete() or supplemented as needed. classifier must contain the attributes of the new classifier set via rtnl_cls_set_* functions. opts may point to the clsasifier specific options.

Returns

New netlink message

Definition at line 145 of file classifier.c.

{
        return cls_build(cls, RTM_NEWTFILTER, NLM_F_CREATE | flags);
}

References NLM_F_CREATE.

Referenced by rtnl_cls_add().

rtnl_cls_add()

int rtnl_cls_add	(	struct nl_handle *	handle,
		struct rtnl_cls *	cls,
		int	flags
	)

Parameters

handle	netlink handle
cls	classifier to add
flags	additional netlink message flags

Builds a netlink message by calling rtnl_cls_build_add_request(), sends the request to the kernel and waits for the next ACK to be received and thus blocks until the request has been processed.

Returns

0 on sucess or a negative error if an error occured.

Definition at line 162 of file classifier.c.

{
        int err;
        struct nl_msg *msg;
        
        msg = rtnl_cls_build_add_request(cls, flags);
        if (!msg)
                return nl_errno(ENOMEM);
        
        err = nl_send_auto_complete(handle, msg);
        nlmsg_free(msg);
        if (err < 0)
                return err;
 
        return nl_wait_for_ack(handle);
}

References nl_send_auto_complete(), nl_wait_for_ack(), nlmsg_free(), and rtnl_cls_build_add_request().

rtnl_cls_build_change_request()

struct nl_msg * rtnl_cls_build_change_request	(	struct rtnl_cls *	cls,
		int	flags
	)

Parameters

cls	classifier to change
flags	additional netlink message flags

Builds a new netlink message requesting a change of a neigh attributes. The netlink message header isn't fully equipped with all relevant fields and must thus be sent out via nl_send_auto_complete() or supplemented as needed.

Returns

The netlink message

Definition at line 191 of file classifier.c.

{
        return cls_build(cls, RTM_NEWTFILTER, NLM_F_REPLACE | flags);
}

References NLM_F_REPLACE.

Referenced by rtnl_cls_change().

rtnl_cls_change()

int rtnl_cls_change	(	struct nl_handle *	handle,
		struct rtnl_cls *	cls,
		int	flags
	)

Parameters

handle	netlink handle
cls	classifier to change
flags	additional netlink message flags

Builds a netlink message by calling rtnl_cls_build_change_request(), sends the request to the kernel and waits for the next ACK to be received and thus blocks until the request has been processed.

Returns

0 on sucess or a negative error if an error occured.

Definition at line 208 of file classifier.c.

{
        int err;
        struct nl_msg *msg;
        
        msg = rtnl_cls_build_change_request(cls, flags);
        if (!msg)
                return nl_errno(ENOMEM);
        
        err = nl_send_auto_complete(handle, msg);
        nlmsg_free(msg);
        if (err < 0)
                return err;
 
        return nl_wait_for_ack(handle);
}

References nl_send_auto_complete(), nl_wait_for_ack(), nlmsg_free(), and rtnl_cls_build_change_request().

rtnl_cls_build_delete_request()

struct nl_msg * rtnl_cls_build_delete_request	(	struct rtnl_cls *	cls,
		int	flags
	)

Parameters

cls	classifier to delete
flags	additional netlink message flags

Builds a new netlink message requesting a deletion of a classifier. The netlink message header isn't fully equipped with all relevant fields and must thus be sent out via nl_send_auto_complete() or supplemented as needed.

Returns

New netlink message

Definition at line 238 of file classifier.c.

{
        return cls_build(cls, RTM_DELTFILTER, flags);
}

Referenced by rtnl_cls_delete().

rtnl_cls_delete()

int rtnl_cls_delete	(	struct nl_handle *	handle,
		struct rtnl_cls *	cls,
		int	flags
	)

Parameters

handle	netlink handle
cls	classifier to delete
flags	additional netlink message flags

Builds a netlink message by calling rtnl_cls_build_delete_request(), sends the request to the kernel and waits for the next ACK to be received and thus blocks until the request has been processed.

Returns

0 on sucess or a negative error if an error occured.

Definition at line 256 of file classifier.c.

{
        int err;
        struct nl_msg *msg;
        
        msg = rtnl_cls_build_delete_request(cls, flags);
        if (!msg)
                return nl_errno(ENOMEM);
        
        err = nl_send_auto_complete(handle, msg);
        nlmsg_free(msg);
        if (err < 0)
                return err;
 
        return nl_wait_for_ack(handle);
}

References nl_send_auto_complete(), nl_wait_for_ack(), nlmsg_free(), and rtnl_cls_build_delete_request().

rtnl_cls_alloc_cache()

struct nl_cache * rtnl_cls_alloc_cache	(	struct nl_handle *	handle,
		int	ifindex,
		uint32_t	parent
	)

Parameters

handle	netlink handle
ifindex	interface index of the link the classes are attached to.
parent	parent qdisc/class

Allocates a new cache, initializes it properly and updates it to include all classes attached to the specified interface.

Note

The caller is responsible for destroying and freeing the cache after using it.

Returns

The cache or NULL if an error has occured.

Definition at line 295 of file classifier.c.

{
        struct nl_cache * cache;
        
        cache = nl_cache_alloc(&rtnl_cls_ops);
        if (cache == NULL)
                return NULL;
 
        cache->c_iarg1 = ifindex;
        cache->c_iarg2 = parent;
        
        if (handle && nl_cache_refill(handle, cache) < 0) {
                nl_cache_free(cache);
                return NULL;
        }
 
        return cache;
}

References nl_cache_alloc(), nl_cache_free(), and nl_cache_refill().