/**
* Add/Update classifier
* @arg sk Netlink socket
* @arg cls Classifier to add/update
* @arg flags Additional netlink message flags
*
* Builds a \c RTM_NEWTFILTER netlink message requesting the addition
* of a new classifier and sends the message to the kernel. The
* configuration of the classifier is derived from the attributes of
* the specified traffic class.
*
* The following flags may be specified:
* - \c NLM_F_CREATE: Create classifier if it does not exist,
* otherwise -NLE_OBJ_NOTFOUND is returned.
* - \c NLM_F_EXCL: Return -NLE_EXISTS if a classifier with
* matching handle exists already.
*
* Existing classifiers with matching handles will be updated, unless
* the flag \c NLM_F_EXCL is specified. If no matching classifier
* exists, it will be created if the flag \c NLM_F_CREATE is set,
* otherwise the error -NLE_OBJ_NOTFOUND is returned.
*
* If the parent qdisc does not support classes, the error
* \c NLE_OPNOTSUPP is returned.
*
* After sending, the function will wait for the ACK or an eventual
* error message to be received and will therefore block until the
* operation has been completed.
*
* @note Disabling auto-ack (nl_socket_disable_auto_ack()) will cause
* this function to return immediately after sending. In this case,
* it is the responsibility of the caller to handle any error
* messages returned.
*
* @return 0 on success or a negative error code.
*/
int rtnl_cls_add(struct nl_sock *sk, struct rtnl_cls *cls, int flags)
{
struct nl_msg *msg;
int err;
if ((err = rtnl_cls_build_add_request(cls, flags, &msg)) < 0)
return err;
return nl_send_sync(sk, msg);
}
/**
* Add a new classifier
* @arg sk Netlink socket.
* @arg cls classifier to add
* @arg 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.
*
* @return 0 on sucess or a negative error if an error occured.
*/
int rtnl_cls_add(struct nl_sock *sk, struct rtnl_cls *cls, int flags)
{
struct nl_msg *msg;
int err;
if ((err = rtnl_cls_build_add_request(cls, flags, &msg)) < 0)
return err;
err = nl_send_auto_complete(sk, msg);
nlmsg_free(msg);
if (err < 0)
return err;
return nl_wait_for_ack(sk);
}
static int cls_request_update(struct nl_cache *cache, struct nl_sock *sk)
{
struct tcmsg tchdr = {
.tcm_family = AF_UNSPEC,
.tcm_ifindex = cache->c_iarg1,
.tcm_parent = cache->c_iarg2,
};
return nl_send_simple(sk, RTM_GETTFILTER, NLM_F_DUMP, &tchdr,
sizeof(tchdr));
}
static int cls_build(struct rtnl_cls *cls, int type, int flags,
struct nl_msg **result)
{
struct rtnl_cls_ops *cops;
int err, prio, proto;
struct tcmsg *tchdr;
err = tca_build_msg((struct rtnl_tca *) cls, type, flags, result);
if (err < 0)
return err;
tchdr = nlmsg_data(nlmsg_hdr(*result));
prio = rtnl_cls_get_prio(cls);
proto = rtnl_cls_get_protocol(cls);
tchdr->tcm_info = TC_H_MAKE(prio << 16, htons(proto));
cops = rtnl_cls_lookup_ops(cls);
if (cops && cops->co_get_opts) {
struct nl_msg *opts;
if (!(opts = nlmsg_alloc())) {
err = -NLE_NOMEM;
goto errout;
}
if (!(err = cops->co_get_opts(cls, opts)))
err = nla_put_nested(*result, TCA_OPTIONS, opts);
nlmsg_free(opts);
if (err < 0)
goto errout;
}
return 0;
errout:
nlmsg_free(*result);
return err;
}
/**
* @name Classifier Addition/Modification/Deletion
* @{
*/
/**
* Build a netlink message to add a new classifier
* @arg cls classifier to add
* @arg flags additional netlink message flags
* @arg result Pointer to store resulting message.
*
* 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. \a classifier must contain the attributes of
* the new classifier set via \c rtnl_cls_set_* functions. \a opts
* may point to the clsasifier specific options.
*
* @return 0 on success or a negative error code.
*/
int rtnl_cls_build_add_request(struct rtnl_cls *cls, int flags,
struct nl_msg **result)
{
return cls_build(cls, RTM_NEWTFILTER, NLM_F_CREATE | flags, result);
}
/**
* Add a new classifier
* @arg sk Netlink socket.
* @arg cls classifier to add
* @arg 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.
*
* @return 0 on sucess or a negative error if an error occured.
*/
int rtnl_cls_add(struct nl_sock *sk, struct rtnl_cls *cls, int flags)
{
struct nl_msg *msg;
int err;
if ((err = rtnl_cls_build_add_request(cls, flags, &msg)) < 0)
return err;
err = nl_send_auto_complete(sk, msg);
nlmsg_free(msg);
if (err < 0)
return err;
return nl_wait_for_ack(sk);
}
/**
* Build a netlink message to change classifier attributes
* @arg cls classifier to change
* @arg flags additional netlink message flags
* @arg result Pointer to store resulting message.
*
* 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.
*
* @return 0 on success or a negative error code.
*/
int rtnl_cls_build_change_request(struct rtnl_cls *cls, int flags,
struct nl_msg **result)
{
return cls_build(cls, RTM_NEWTFILTER, NLM_F_REPLACE | flags, result);
}
/**
* Change a classifier
* @arg sk Netlink socket.
* @arg cls classifier to change
* @arg 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.
*
* @return 0 on sucess or a negative error if an error occured.
*/
int rtnl_cls_change(struct nl_sock *sk, struct rtnl_cls *cls, int flags)
{
struct nl_msg *msg;
int err;
if ((err = rtnl_cls_build_change_request(cls, flags, &msg)) < 0)
return err;
err = nl_send_auto_complete(sk, msg);
nlmsg_free(msg);
if (err < 0)
return err;
return nl_wait_for_ack(sk);
}
/**
* Build a netlink request message to delete a classifier
* @arg cls classifier to delete
* @arg flags additional netlink message flags
* @arg result Pointer to store resulting message.
*
* 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.
*
* @return 0 on success or a negative error code.
*/
int rtnl_cls_build_delete_request(struct rtnl_cls *cls, int flags,
struct nl_msg **result)
{
return cls_build(cls, RTM_DELTFILTER, flags, result);
}
/**
* Delete a classifier
* @arg sk Netlink socket.
* @arg cls classifier to delete
* @arg 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.
*
* @return 0 on sucess or a negative error if an error occured.
*/
int rtnl_cls_delete(struct nl_sock *sk, struct rtnl_cls *cls, int flags)
{
struct nl_msg *msg;
int err;
if ((err = rtnl_cls_build_delete_request(cls, flags, &msg)) < 0)
return err;
err = nl_send_auto_complete(sk, msg);
nlmsg_free(msg);
if (err < 0)
return err;
return nl_wait_for_ack(sk);
}
/** @} */
/**
* @name Cache Management
* @{
*/
/**
* Build a classifier cache including all classifiers attached to the
* specified class/qdisc on eht specified interface.
* @arg sk Netlink socket.
* @arg ifindex interface index of the link the classes are
* attached to.
* @arg parent parent qdisc/class
* @arg result Pointer to store resulting cache.
*
* 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.
* @return 0 on success or a negative error code.
*/
int rtnl_cls_alloc_cache(struct nl_sock *sk, int ifindex, uint32_t parent, struct nl_cache **result)
{
struct nl_cache * cache;
int err;
if (!(cache = nl_cache_alloc(&rtnl_cls_ops)))
return -NLE_NOMEM;
cache->c_iarg1 = ifindex;
cache->c_iarg2 = parent;
if (sk && (err = nl_cache_refill(sk, cache)) < 0) {
nl_cache_free(cache);
return err;
}
*result = cache;
return 0;
}
/** @} */
static struct nl_cache_ops rtnl_cls_ops = {
.co_name = "route/cls",
.co_hdrsize = sizeof(struct tcmsg),
.co_msgtypes = {
{ RTM_NEWTFILTER, NL_ACT_NEW, "new" },
{ RTM_DELTFILTER, NL_ACT_DEL, "del" },
{ RTM_GETTFILTER, NL_ACT_GET, "get" },
END_OF_MSGTYPES_LIST,
},
.co_protocol = NETLINK_ROUTE,
.co_request_update = cls_request_update,
.co_msg_parser = cls_msg_parser,
.co_obj_ops = &cls_obj_ops,
};
static void __init cls_init(void)
{
nl_cache_mngt_register(&rtnl_cls_ops);
}
static void __exit cls_exit(void)
{
nl_cache_mngt_unregister(&rtnl_cls_ops);
}