/*
* lib/route/qdisc.c Queueing Disciplines
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation version 2.1
* of the License.
*
* Copyright (c) 2003-2006 Thomas Graf <tgraf@suug.ch>
*/
/**
* @ingroup tc
* @defgroup qdisc Queueing Disciplines
*
* @par Qdisc Handles
* In general, qdiscs are identified by the major part of a traffic control
* handle (the upper 16 bits). A few special values exist though:
* - \c TC_H_ROOT: root qdisc (directly attached to the device)
* - \c TC_H_INGRESS: ingress qdisc (directly attached to the device)
* - \c TC_H_UNSPEC: unspecified qdisc (no reference)
*
* @par 1) Adding a Qdisc
* @code
* // Allocate a new empty qdisc to be filled out
* struct rtnl_qdisc *qdisc = rtnl_qdisc_alloc();
*
* // ... specify the kind of the Qdisc
* rtnl_qdisc_set_kind(qdisc, "pfifo");
*
* // Specify the device the qdisc should be attached to
* rtnl_qdisc_set_ifindex(qdisc, ifindex);
*
* // ... specify the parent qdisc
* rtnl_qdisc_set_parent(qdisc, TC_H_ROOT);
*
* // Specifying the handle is not required but makes reidentifying easier
* // and may help to avoid adding a qdisc twice.
* rtnl_qdisc_set_handle(qdisc, 0x000A0000);
*
* // Now on to specify the qdisc specific options, see the relevant qdisc
* // modules for documentation, in this example we set the upper limit of
* // the packet fifo qdisc to 64
* rtnl_qdisc_fifo_set_limit(qdisc, 64);
*
* rtnl_qdisc_add(handle, qdisc, NLM_R_REPLACE);
*
* // Free up the memory
* rtnl_qdisc_put(qdisc);
* @endcode
*
* @par 2) Deleting a Qdisc
* @code
* // Allocate a new empty qdisc to be filled out with the parameters
* // specifying the qdisc to be deleted. Alternatively a fully equiped
* // Qdisc object from a cache can be used.
* struct rtnl_qdisc *qdisc = rtnl_qdisc_alloc();
*
* // The interface index of the device the qdisc is on and the parent handle
* // are the least required fields to be filled out.
* // Note: Specify TC_H_ROOT or TC_H_INGRESS as parent handle to delete the
* // root respectively root ingress qdisc.
* rtnl_qdisc_set_ifindex(qdisc, ifindex);
* rtnl_qdisc_set_parent(qdisc, parent_handle);
*
* // If required for identification, the handle can be specified as well.
* rtnl_qdisc_set_handle(qdisc, qdisc_handle);
*
* // Not required but maybe helpful as sanity check, the kind of the qdisc
* // can be specified to avoid mistakes.
* rtnl_qdisc_set_kind(qdisc, "pfifo");
*
* // Finally delete the qdisc with rtnl_qdisc_delete(), alternatively
* // rtnl_qdisc_build_delete_request() can be invoked to generate an
* // appropritate netlink message to send out.
* rtnl_qdisc_delete(handle, qdisc);
*
* // Free up the memory
* rtnl_qdisc_put(qdisc);
* @endcode
*
* @{
*/
#include <netlink-local.h>
#include <netlink-tc.h>
#include <netlink/netlink.h>
#include <netlink/utils.h>
#include <netlink/route/link.h>
#include <netlink/route/tc.h>
#include <netlink/route/qdisc.h>
#include <netlink/route/class.h>
#include <netlink/route/classifier.h>
#include <netlink/route/qdisc-modules.h>
static struct nl_cache_ops rtnl_qdisc_ops;
static int qdisc_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
struct nlmsghdr *n, struct nl_parser_param *pp)
{
int err = -ENOMEM;
struct rtnl_qdisc *qdisc;
struct rtnl_qdisc_ops *qops;
qdisc = rtnl_qdisc_alloc();
if (!qdisc) {
err = nl_errno(ENOMEM);
goto errout;
}
qdisc->ce_msgtype = n->nlmsg_type;
err = tca_msg_parser(n, (struct rtnl_tca *) qdisc);
if (err < 0)
goto errout_free;
qops = rtnl_qdisc_lookup_ops(qdisc);
if (qops && qops->qo_msg_parser) {
err = qops->qo_msg_parser(qdisc);
if (err < 0)
goto errout_free;
}
err = pp->pp_cb((struct nl_object *) qdisc, pp);
if (err < 0)
goto errout_free;
err = P_ACCEPT;
errout_free:
rtnl_qdisc_put(qdisc);
errout:
return err;
}
static int qdisc_request_update(struct nl_cache *c, struct nl_handle *h)
{
struct tcmsg tchdr = {
.tcm_family = AF_UNSPEC,
.tcm_ifindex = c->c_iarg1,
};
return nl_send_simple(h, RTM_GETQDISC, NLM_F_DUMP, &tchdr,
sizeof(tchdr));
}
/**
* @name QDisc Addition
* @{
*/
static struct nl_msg *qdisc_build(struct rtnl_qdisc *qdisc, int type, int flags)
{
struct rtnl_qdisc_ops *qops;
struct nl_msg *msg;
int err;
msg = tca_build_msg((struct rtnl_tca *) qdisc, type, flags);
if (!msg)
goto errout;
qops = rtnl_qdisc_lookup_ops(qdisc);
if (qops && qops->qo_get_opts) {
struct nl_msg *opts;
opts = qops->qo_get_opts(qdisc);
if (opts) {
err = nla_put_nested(msg, TCA_OPTIONS, opts);
nlmsg_free(opts);
if (err < 0)
goto errout;
}
}
return msg;
errout:
nlmsg_free(msg);
return NULL;
}
/**
* Build a netlink message to add a new qdisc
* @arg qdisc qdisc to add
* @arg flags additional netlink message flags
*
* Builds a new netlink message requesting an addition of a qdisc.
* 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.
*
* Common message flags used:
* - NLM_F_REPLACE - replace a potential existing qdisc
*
* @return New netlink message
*/
struct nl_msg *rtnl_qdisc_build_add_request(struct rtnl_qdisc *qdisc,
int flags)
{
struct nl_msg *msg;
msg = qdisc_build(qdisc, RTM_NEWQDISC, NLM_F_CREATE | flags);
if (!msg)
nl_errno(ENOMEM);
return msg;
}
/**
* Add a new qdisc
* @arg handle netlink handle
* @arg qdisc qdisc to delete
* @arg flags additional netlink message flags
*
* Builds a netlink message by calling rtnl_qdisc_build_add_request(),
* sends the request to the kernel and waits for the ACK to be
* received and thus blocks until the request has been processed.
*
* Common message flags used:
* - NLM_F_REPLACE - replace a potential existing qdisc
*
* @return 0 on success or a negative error code
*/
int rtnl_qdisc_add(struct nl_handle *handle, struct rtnl_qdisc *qdisc,
int flags)
{
struct nl_msg *msg;
int err;
msg = rtnl_qdisc_build_add_request(qdisc, flags);
if (!msg)
return nl_errno(ENOMEM);
err = nl_send_auto_complete(handle, msg);
if (err < 0)
return err;
nlmsg_free(msg);
return nl_wait_for_ack(handle);
}
/** @} */
/**
* @name QDisc Modification
* @{
*/
/**
* Build a netlink message to change attributes of a existing qdisc
* @arg qdisc qdisc to change
* @arg new new qdisc attributes
*
* Builds a new netlink message requesting an change of qdisc
* attributes. 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.
*
* @return New netlink message
*/
struct nl_msg *rtnl_qdisc_build_change_request(struct rtnl_qdisc *qdisc,
struct rtnl_qdisc *new)
{
return qdisc_build(qdisc, RTM_NEWQDISC, NLM_F_REPLACE);
}
/**
* Change attributes of a qdisc
* @arg handle netlink handle
* @arg qdisc qdisc to change
* @arg new new qdisc attributes
*
* Builds a netlink message by calling rtnl_qdisc_build_change_request(),
* sends the request to the kernel and waits for the ACK to be
* received and thus blocks until the request has been processed.
*
* @return 0 on success or a negative error code
*/
int rtnl_qdisc_change(struct nl_handle *handle, struct rtnl_qdisc *qdisc,
struct rtnl_qdisc *new)
{
struct nl_msg *msg;
int err;
msg = rtnl_qdisc_build_change_request(qdisc, new);
if (!msg)
return nl_errno(ENOMEM);
err = nl_send_auto_complete(handle, msg);
if (err < 0)
return err;
nlmsg_free(msg);
return nl_wait_for_ack(handle);
}
/** @} */
/**
* @name QDisc Deletion
* @{
*/
/**
* Build a netlink request message to delete a qdisc
* @arg qdisc qdisc to delete
*
* Builds a new netlink message requesting a deletion of a qdisc.
* 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 New netlink message
*/
struct nl_msg *rtnl_qdisc_build_delete_request(struct rtnl_qdisc *qdisc)
{
struct nl_msg *msg;
struct tcmsg tchdr;
int required = TCA_ATTR_IFINDEX | TCA_ATTR_PARENT;
if ((qdisc->ce_mask & required) != required)
BUG();
msg = nlmsg_alloc_simple(RTM_DELQDISC, 0);
if (!msg)
return NULL;
tchdr.tcm_family = AF_UNSPEC,
tchdr.tcm_handle = qdisc->q_handle,
tchdr.tcm_parent = qdisc->q_parent,
tchdr.tcm_ifindex = qdisc->q_ifindex,
nlmsg_append(msg, &tchdr, sizeof(tchdr), NLMSG_ALIGNTO);
return msg;
}
/**
* Delete a qdisc
* @arg handle netlink handle
* @arg qdisc qdisc to delete
*
* Builds a netlink message by calling rtnl_qdisc_build_delete_request(),
* sends the request to the kernel and waits for the ACK to be
* received and thus blocks until the request has been processed.
*
* @return 0 on success or a negative error code
*/
int rtnl_qdisc_delete(struct nl_handle *handle, struct rtnl_qdisc *qdisc)
{
struct nl_msg *msg;
int err;
msg = rtnl_qdisc_build_delete_request(qdisc);
if (!msg)
return nl_errno(ENOMEM);
err = nl_send_auto_complete(handle, msg);
if (err < 0)
return err;
nlmsg_free(msg);
return nl_wait_for_ack(handle);
}
/** @} */
/**
* @name Qdisc Cache Management
* @{
*/
/**
* Build a qdisc cache including all qdiscs currently configured in
* the kernel
* @arg handle netlink handle
*
* Allocates a new cache, initializes it properly and updates it to
* include all qdiscs currently configured in the kernel.
*
* @note The caller is responsible for destroying and freeing the
* cache after using it.
* @return The cache or NULL if an error has occured.
*/
struct nl_cache * rtnl_qdisc_alloc_cache(struct nl_handle *handle)
{
struct nl_cache * cache;
cache = nl_cache_alloc(&rtnl_qdisc_ops);
if (cache == NULL)
return NULL;
if (handle && nl_cache_refill(handle, cache) < 0) {
nl_cache_free(cache);
return NULL;
}
return cache;
}
/**
* Look up qdisc by its parent in the provided cache
* @arg cache qdisc cache
* @arg ifindex interface the qdisc is attached to
* @arg parent parent handle
* @return pointer to qdisc inside the cache or NULL if no match was found.
*/
struct rtnl_qdisc * rtnl_qdisc_get_by_parent(struct nl_cache *cache,
int ifindex, uint32_t parent)
{
struct rtnl_qdisc *q;
if (cache->c_ops != &rtnl_qdisc_ops)
return NULL;
nl_list_for_each_entry(q, &cache->c_items, ce_list) {
if (q->q_parent == parent && q->q_ifindex == ifindex) {
nl_object_get((struct nl_object *) q);
return q;
}
}
return NULL;
}
/**
* Look up qdisc by its handle in the provided cache
* @arg cache qdisc cache
* @arg ifindex interface the qdisc is attached to
* @arg handle qdisc handle
* @return pointer to qdisc inside the cache or NULL if no match was found.
*/
struct rtnl_qdisc * rtnl_qdisc_get(struct nl_cache *cache,
int ifindex, uint32_t handle)
{
struct rtnl_qdisc *q;
if (cache->c_ops != &rtnl_qdisc_ops)
return NULL;
nl_list_for_each_entry(q, &cache->c_items, ce_list) {
if (q->q_handle == handle && q->q_ifindex == ifindex) {
nl_object_get((struct nl_object *) q);
return q;
}
}
return NULL;
}
/** @} */
static struct nl_cache_ops rtnl_qdisc_ops = {
.co_name = "route/qdisc",
.co_hdrsize = sizeof(struct tcmsg),
.co_msgtypes = {
{ RTM_NEWQDISC, NL_ACT_NEW, "new" },
{ RTM_DELQDISC, NL_ACT_DEL, "del" },
{ RTM_GETQDISC, NL_ACT_GET, "get" },
END_OF_MSGTYPES_LIST,
},
.co_protocol = NETLINK_ROUTE,
.co_request_update = qdisc_request_update,
.co_msg_parser = qdisc_msg_parser,
.co_obj_ops = &qdisc_obj_ops,
};
static void __init qdisc_init(void)
{
nl_cache_mngt_register(&rtnl_qdisc_ops);
}
static void __exit qdisc_exit(void)
{
nl_cache_mngt_unregister(&rtnl_qdisc_ops);
}
/** @} */