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/*-
* Copyright (c) 2009 Sam Leffler, Errno Consulting
* 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 ``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 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* IEEE 802.11 age queue support.
*/
#include "opt_wlan.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_media.h>
#include <net/ethernet.h>
#include <net80211/ieee80211_var.h>
/*
* Initialize an ageq.
*/
void
ieee80211_ageq_init(struct ieee80211_ageq *aq, int maxlen, const char *name)
{
memset(aq, 0, sizeof(*aq));
aq->aq_maxlen = maxlen;
IEEE80211_AGEQ_INIT(aq, name); /* OS-dependent setup */
}
/*
* Cleanup an ageq initialized with ieee80211_ageq_init. Note
* the queue is assumed empty; this can be done with ieee80211_ageq_drain.
*/
void
ieee80211_ageq_cleanup(struct ieee80211_ageq *aq)
{
KASSERT(aq->aq_len == 0, ("%d frames on ageq", aq->aq_len));
IEEE80211_AGEQ_DESTROY(aq); /* OS-dependent cleanup */
}
/*
* Free an mbuf according to ageq rules: if marked as holding
* and 802.11 frame then also reclaim a node reference from
* the packet header; this handles packets q'd in the tx path.
*/
static void
ageq_mfree(struct mbuf *m)
{
if (m->m_flags & M_ENCAP) {
struct ieee80211_node *ni = (void *) m->m_pkthdr.rcvif;
ieee80211_free_node(ni);
}
m->m_nextpkt = NULL;
m_freem(m);
}
/*
* Free a list of mbufs using ageq rules (see above).
*/
void
ieee80211_ageq_mfree(struct mbuf *m)
{
struct mbuf *next;
for (; m != NULL; m = next) {
next = m->m_nextpkt;
ageq_mfree(m);
}
}
/*
* Append an mbuf to the ageq and mark it with the specified max age
* If the frame is not removed before the age (in seconds) expires
* then it is reclaimed (along with any node reference).
*/
int
ieee80211_ageq_append(struct ieee80211_ageq *aq, struct mbuf *m, int age)
{
IEEE80211_AGEQ_LOCK(aq);
if (__predict_true(aq->aq_len < aq->aq_maxlen)) {
if (aq->aq_tail == NULL) {
aq->aq_head = m;
} else {
aq->aq_tail->m_nextpkt = m;
age -= M_AGE_GET(aq->aq_head);
}
KASSERT(age >= 0, ("age %d", age));
M_AGE_SET(m, age);
m->m_nextpkt = NULL;
aq->aq_tail = m;
aq->aq_len++;
IEEE80211_AGEQ_UNLOCK(aq);
return 0;
} else {
/*
* No space, drop and cleanup references.
*/
aq->aq_drops++;
IEEE80211_AGEQ_UNLOCK(aq);
/* XXX tail drop? */
ageq_mfree(m);
return ENOSPC;
}
}
/*
* Drain/reclaim all frames from an ageq.
*/
void
ieee80211_ageq_drain(struct ieee80211_ageq *aq)
{
ieee80211_ageq_mfree(ieee80211_ageq_remove(aq, NULL));
}
/*
* Drain/reclaim frames associated with a specific node from an ageq.
*/
void
ieee80211_ageq_drain_node(struct ieee80211_ageq *aq,
struct ieee80211_node *ni)
{
ieee80211_ageq_mfree(ieee80211_ageq_remove(aq, ni));
}
/*
* Age frames on the age queue. Ages are stored as time
* deltas (in seconds) relative to the head so we can check
* and/or adjust only the head of the list. If a frame's age
* exceeds the time quanta then remove it. The list of removed
* frames is returned to the caller joined by m_nextpkt.
*/
struct mbuf *
ieee80211_ageq_age(struct ieee80211_ageq *aq, int quanta)
{
struct mbuf *head, **phead;
struct mbuf *m;
phead = &head;
if (aq->aq_len != 0) {
IEEE80211_AGEQ_LOCK(aq);
while ((m = aq->aq_head) != NULL && M_AGE_GET(m) < quanta) {
if ((aq->aq_head = m->m_nextpkt) == NULL)
aq->aq_tail = NULL;
KASSERT(aq->aq_len > 0, ("aq len %d", aq->aq_len));
aq->aq_len--;
/* add to private list for return */
*phead = m;
phead = &m->m_nextpkt;
}
if (m != NULL)
M_AGE_SUB(m, quanta);
IEEE80211_AGEQ_UNLOCK(aq);
}
*phead = NULL;
return head;
}
/*
* Remove all frames matching the specified node identifier
* (NULL matches all). Frames are returned as a list joined
* by m_nextpkt.
*/
struct mbuf *
ieee80211_ageq_remove(struct ieee80211_ageq *aq,
struct ieee80211_node *match)
{
struct mbuf *m, **prev, *ohead;
struct mbuf *head, **phead;
IEEE80211_AGEQ_LOCK(aq);
ohead = aq->aq_head;
prev = &aq->aq_head;
phead = &head;
while ((m = *prev) != NULL) {
if (match != NULL && m->m_pkthdr.rcvif != (void *) match) {
prev = &m->m_nextpkt;
continue;
}
/*
* Adjust q length.
*/
KASSERT(aq->aq_len > 0, ("aq len %d", aq->aq_len));
aq->aq_len--;
/*
* Remove from forward list; tail pointer is harder.
*/
if (aq->aq_tail == m) {
KASSERT(m->m_nextpkt == NULL, ("not last"));
if (aq->aq_head == m) { /* list empty */
KASSERT(aq->aq_len == 0,
("not empty, len %d", aq->aq_len));
aq->aq_tail = NULL;
} else { /* must be one before */
aq->aq_tail = (struct mbuf *)((uintptr_t)prev -
offsetof(struct mbuf, m_nextpkt));
}
}
*prev = m->m_nextpkt;
/* add to private list for return */
*phead = m;
phead = &m->m_nextpkt;
}
if (head == ohead && aq->aq_head != NULL) /* correct age */
M_AGE_SET(aq->aq_head, M_AGE_GET(head));
IEEE80211_AGEQ_UNLOCK(aq);
*phead = NULL;
return head;
}
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