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authorsam <sam@FreeBSD.org>2009-07-05 18:17:37 +0000
committersam <sam@FreeBSD.org>2009-07-05 18:17:37 +0000
commit9f7eae50beb38e763f8614fed575eec619707621 (patch)
treeffdb2fa7b2375a389404116eb68c653e193a6558 /sys/net80211/ieee80211_ageq.c
parent488931f6d96dba8045a1f97876133c24072f46e9 (diff)
downloadFreeBSD-src-9f7eae50beb38e763f8614fed575eec619707621.zip
FreeBSD-src-9f7eae50beb38e763f8614fed575eec619707621.tar.gz
Add ieee80211_ageq; a facility for staging packets that require
long-term work before they can be serviced. Packets are tagged and assigned an age (in seconds) at the point they are added to the queue. If a packet is not retrieved before it's age expires it is reclaimed. Tagging can take two forms: a reference to an ieee80211_node (as happens in the tx path) or an opaque token in cases where there is no reference or the node structure is not stable (i.e. it's going to be destroyed). o add ic_stageq to replace the per-node wds staging queue used for dynamic wds o add ieee80211_mac_hash for building ageq tokens; this computes a 32-bit hash from an 802.11 mac address (copied from the bridge) o while here fix a stray ';' noticed in IEEE80211_PSQ_INIT Reviewed by: rpaulo Approved by: re (kensmith)
Diffstat (limited to 'sys/net80211/ieee80211_ageq.c')
-rw-r--r--sys/net80211/ieee80211_ageq.c236
1 files changed, 236 insertions, 0 deletions
diff --git a/sys/net80211/ieee80211_ageq.c b/sys/net80211/ieee80211_ageq.c
new file mode 100644
index 0000000..b7aad74
--- /dev/null
+++ b/sys/net80211/ieee80211_ageq.c
@@ -0,0 +1,236 @@
+/*-
+ * 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_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 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.
+ */
+ *prev = m->m_nextpkt;
+ 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));
+ }
+ }
+ /* 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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