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/*
* Copyright (c) 2010 Riccardo Panicucci, Luigi Rizzo, Universita` di Pisa
* All rights reserved
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* The API to write a packet scheduling algorithm for dummynet.
*
* $FreeBSD$
*/
#ifndef _DN_SCHED_H
#define _DN_SCHED_H
#define DN_MULTIQUEUE 0x01
/*
* Descriptor for a scheduling algorithm.
* Contains all function pointers for a given scheduler
* This is typically created when a module is loaded, and stored
* in a global list of schedulers.
*/
struct dn_alg {
uint32_t type; /* the scheduler type */
const char *name; /* scheduler name */
uint32_t flags; /* DN_MULTIQUEUE if supports multiple queues */
/*
* The following define the size of 3 optional data structures
* that may need to be allocated at runtime, and are appended
* to each of the base data structures: scheduler, sched.inst,
* and queue. We don't have a per-flowset structure.
*/
/* + parameters attached to the template, e.g.
* default queue sizes, weights, quantum size, and so on;
*/
size_t schk_datalen;
/* + per-instance parameters, such as timestamps,
* containers for queues, etc;
*/
size_t si_datalen;
size_t q_datalen; /* per-queue parameters (e.g. S,F) */
/*
* Methods implemented by the scheduler:
* enqueue enqueue packet 'm' on scheduler 's', queue 'q'.
* q is NULL for !MULTIQUEUE.
* Return 0 on success, 1 on drop (packet consumed anyways).
*
* dequeue Called when scheduler instance 's' can
* dequeue a packet. Return NULL if none are available.
* XXX what about non work-conserving ?
*
* config called on 'sched X config ...', normally writes
* in the area of size sch_arg
*
* destroy called on 'sched delete', frees everything
* in sch_arg (other parts are handled by more specific
* functions)
*
* new_sched called when a new instance is created, e.g.
* to create the local queue for !MULTIQUEUE, set V or
* copy parameters for WFQ, and so on.
*
* free_sched called when deleting an instance, cleans
* extra data in the per-instance area.
*
* new_fsk called when a flowset is linked to a scheduler,
* e.g. to validate parameters such as weights etc.
* free_fsk when a flowset is unlinked from a scheduler.
* (probably unnecessary)
*
* new_queue called to set the per-queue parameters,
* e.g. S and F, adjust sum of weights in the parent, etc.
* If the queue has packets in it, add them to the scheduler
* as well.
*
* free_queue actions related to a queue removal, e.g. undo
* all the above. If the queue has data in it, also remove
* from the scheduler. This can e.g. happen during a reconfigure.
*/
int (*enqueue)(struct dn_sch_inst *, struct dn_queue *,
struct mbuf *);
struct mbuf * (*dequeue)(struct dn_sch_inst *);
int (*config)(struct dn_schk *);
int (*destroy)(struct dn_schk*);
int (*new_sched)(struct dn_sch_inst *);
int (*free_sched)(struct dn_sch_inst *);
int (*new_fsk)(struct dn_fsk *f);
int (*free_fsk)(struct dn_fsk *f);
int (*new_queue)(struct dn_queue *q);
int (*free_queue)(struct dn_queue *q);
/* run-time fields */
int ref_count; /* XXX number of instances in the system */
SLIST_ENTRY(dn_alg) next; /* Next scheduler in the list */
};
/* MSVC does not support initializers so we need this ugly macro */
#ifdef _WIN32
#define _SI(fld)
#else
#define _SI(fld) fld
#endif
/*
* Additionally, dummynet exports some functions and macros
* to be used by schedulers:
*/
void dn_free_pkts(struct mbuf *mnext);
int dn_enqueue(struct dn_queue *q, struct mbuf* m, int drop);
/* bound a variable between min and max */
int ipdn_bound_var(int *v, int dflt, int lo, int hi, const char *msg);
/*
* Extract the head of a queue, update stats. Must be the very last
* thing done on a dequeue as the queue itself may go away.
*/
static __inline struct mbuf*
dn_dequeue(struct dn_queue *q)
{
struct mbuf *m = q->mq.head;
if (m == NULL)
return NULL;
q->mq.head = m->m_nextpkt;
q->ni.length--;
q->ni.len_bytes -= m->m_pkthdr.len;
if (q->_si) {
q->_si->ni.length--;
q->_si->ni.len_bytes -= m->m_pkthdr.len;
}
if (q->ni.length == 0) /* queue is now idle */
q->q_time = dn_cfg.curr_time;
return m;
}
int dn_sched_modevent(module_t mod, int cmd, void *arg);
#define DECLARE_DNSCHED_MODULE(name, dnsched) \
static moduledata_t name##_mod = { \
#name, dn_sched_modevent, dnsched \
}; \
DECLARE_MODULE(name, name##_mod, \
SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); \
MODULE_DEPEND(name, dummynet, 3, 3, 3);
#endif /* _DN_SCHED_H */
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