2 * Copyright (c) 2009 Sam Leffler, Errno Consulting
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
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19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 * $FreeBSD: head/sys/net80211/ieee80211_ageq.c 195527 2009-07-10 02:19:57Z sam $
30 * IEEE 802.11 age queue support.
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
38 #include <sys/socket.h>
41 #include <net/if_media.h>
42 #include <net/ethernet.h>
43 #include <net/route.h>
45 #include <netproto/802_11/ieee80211_var.h>
51 ieee80211_ageq_init(struct ieee80211_ageq *aq, int maxlen, const char *name)
53 memset(aq, 0, sizeof(aq));
54 aq->aq_maxlen = maxlen;
58 * Cleanup an ageq initialized with ieee80211_ageq_init. Note
59 * the queue is assumed empty; this can be done with ieee80211_ageq_drain.
62 ieee80211_ageq_cleanup(struct ieee80211_ageq *aq)
64 KASSERT(aq->aq_len == 0, ("%d frames on ageq", aq->aq_len));
68 * Free an mbuf according to ageq rules: if marked as holding
69 * and 802.11 frame then also reclaim a node reference from
70 * the packet header; this handles packets q'd in the tx path.
73 ageq_mfree(struct mbuf *m)
75 if (m->m_flags & M_ENCAP) {
76 struct ieee80211_node *ni = (void *) m->m_pkthdr.rcvif;
77 ieee80211_free_node(ni);
84 * Free a list of mbufs using ageq rules (see above).
87 ieee80211_ageq_mfree(struct mbuf *m)
91 for (; m != NULL; m = next) {
98 * Append an mbuf to the ageq and mark it with the specified max age
99 * If the frame is not removed before the age (in seconds) expires
100 * then it is reclaimed (along with any node reference).
103 ieee80211_ageq_append(struct ieee80211_ageq *aq, struct mbuf *m, int age)
105 if (__predict_true(aq->aq_len < aq->aq_maxlen)) {
106 if (aq->aq_tail == NULL) {
109 aq->aq_tail->m_nextpkt = m;
110 age -= M_AGE_GET(aq->aq_head);
112 KASSERT(age >= 0, ("age %d", age));
120 * No space, drop and cleanup references.
130 * Drain/reclaim all frames from an ageq.
133 ieee80211_ageq_drain(struct ieee80211_ageq *aq)
135 ieee80211_ageq_mfree(ieee80211_ageq_remove(aq, NULL));
139 * Drain/reclaim frames associated with a specific node from an ageq.
142 ieee80211_ageq_drain_node(struct ieee80211_ageq *aq,
143 struct ieee80211_node *ni)
145 ieee80211_ageq_mfree(ieee80211_ageq_remove(aq, ni));
149 * Age frames on the age queue. Ages are stored as time
150 * deltas (in seconds) relative to the head so we can check
151 * and/or adjust only the head of the list. If a frame's age
152 * exceeds the time quanta then remove it. The list of removed
153 * frames is is returned to the caller joined by m_nextpkt.
156 ieee80211_ageq_age(struct ieee80211_ageq *aq, int quanta)
158 struct mbuf *head, **phead;
162 if (aq->aq_len != 0) {
163 while ((m = aq->aq_head) != NULL && M_AGE_GET(m) < quanta) {
164 if ((aq->aq_head = m->m_nextpkt) == NULL)
166 KASSERT(aq->aq_len > 0, ("aq len %d", aq->aq_len));
168 /* add to private list for return */
170 phead = &m->m_nextpkt;
173 M_AGE_SUB(m, quanta);
180 * Remove all frames matching the specified node identifier
181 * (NULL matches all). Frames are returned as a list joined
185 ieee80211_ageq_remove(struct ieee80211_ageq *aq,
186 struct ieee80211_node *match)
188 struct mbuf *m, **prev, *ohead;
189 struct mbuf *head, **phead;
194 while ((m = *prev) != NULL) {
195 if (match != NULL && m->m_pkthdr.rcvif != (void *) match) {
196 prev = &m->m_nextpkt;
202 KASSERT(aq->aq_len > 0, ("aq len %d", aq->aq_len));
205 * Remove from forward list; tail pointer is harder.
207 if (aq->aq_tail == m) {
208 KASSERT(m->m_nextpkt == NULL, ("not last"));
209 if (aq->aq_head == m) { /* list empty */
210 KASSERT(aq->aq_len == 0,
211 ("not empty, len %d", aq->aq_len));
213 } else { /* must be one before */
214 aq->aq_tail = (struct mbuf *)((uintptr_t)prev -
215 offsetof(struct mbuf, m_nextpkt));
218 *prev = m->m_nextpkt;
220 /* add to private list for return */
222 phead = &m->m_nextpkt;
224 if (head == ohead && aq->aq_head != NULL) /* correct age */
225 M_AGE_SET(aq->aq_head, M_AGE_GET(head));