Implement very basic ALQ logging for net80211.

This is destined to be a lightweight and optional set of ALQ
probes for debugging events which are just impossible to debug
with printf/log (eg packet TX/RX handling; AMPDU handling.)

The probes and operations themselves will appear in subsequent
commits.

1 files changed, 144 insertions, 0 deletions

diff --git a/sys/net80211/ieee80211_alq.c b/sys/net80211/ieee80211_alq.c
new file mode 100644
index 0000000..1ba996c
--- /dev/null
+++ b/sys/net80211/ieee80211_alq.c
@@ -0,0 +1,144 @@
+/*-
+ * Copyright (c) 2011 Adrian Chadd, Xenion Lty Ltd
+ * 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>
+#ifdef __FreeBSD__
+__FBSDID("$FreeBSD$");
+#endif
+
+/*
+ * net80211 fast-logging support, primarily for debugging.
+ *
+ * This implements a single debugging queue which includes
+ * per-device enumeration where needed.
+ */
+
+#include "opt_wlan.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/mbuf.h>
+#include <sys/malloc.h>
+#include <sys/endian.h>
+#include <sys/kernel.h>
+#include <sys/sysctl.h>
+#include <sys/pcpu.h>
+#include <sys/proc.h>
+#include <sys/ucred.h>
+#include <sys/alq.h>
+
+#include <sys/socket.h>
+
+#include <net/if.h>
+#include <net/if_var.h>
+#include <net/if_dl.h>
+#include <net/if_clone.h>
+#include <net/if_media.h>
+#include <net/if_types.h>
+
+#include <net80211/ieee80211_var.h>
+#include <net80211/ieee80211_freebsd.h>
+#include <net80211/ieee80211_alq.h>
+
+static struct alq *ieee80211_alq;
+static int ieee80211_alq_lost;
+static char ieee80211_alq_logfile[MAXPATHLEN] = "/tmp/net80211.log";
+static unsigned int ieee80211_alq_qsize = 64*1024;
+
+static int
+ieee80211_alq_setlogging(int enable)
+{
+	int error;
+
+	if (enable) {
+		if (ieee80211_alq)
+			alq_close(ieee80211_alq);
+
+		error = alq_open(&ieee80211_alq,
+		    ieee80211_alq_logfile,
+		    curthread->td_ucred,
+		    ALQ_DEFAULT_CMODE,
+		    sizeof (struct ieee80211_alq_rec),
+		    ieee80211_alq_qsize);
+		ieee80211_alq_lost = 0;
+		printf("net80211: logging to %s enabled\n", ieee80211_alq_logfile);
+	} else {
+		if (ieee80211_alq)
+			alq_close(ieee80211_alq);
+		ieee80211_alq = NULL;
+		printf("net80211: logging disabled\n");
+		error = 0;
+	}
+	return (error);
+}
+
+static int
+sysctl_ieee80211_alq_log(SYSCTL_HANDLER_ARGS)
+{
+        int error, enable;
+
+        enable = (ieee80211_alq != NULL);
+        error = sysctl_handle_int(oidp, &enable, 0, req);
+        if (error || !req->newptr)
+                return (error);
+        else   
+                return (ieee80211_alq_setlogging(enable));
+}
+
+SYSCTL_PROC(_net_wlan, OID_AUTO, alq, CTLTYPE_INT|CTLFLAG_RW,
+	0, 0, sysctl_ieee80211_alq_log, "I", "Enable net80211 alq logging");
+SYSCTL_INT(_net_wlan, OID_AUTO, alq_size, CTLFLAG_RW,
+	&ieee80211_alq_qsize, 0, "In-memory log size (#records)");
+SYSCTL_INT(_net_wlan, OID_AUTO, alq_lost, CTLFLAG_RW,
+	&ieee80211_alq_lost, 0, "Debugging operations not logged");
+
+static struct ale *
+ieee80211_alq_get(void)
+{
+	struct ale *ale;
+
+	ale = alq_get(ieee80211_alq, ALQ_NOWAIT);
+	if (!ale)
+		ieee80211_alq_lost++;
+	return ale;
+}
+
+void
+ieee80211_alq_log(struct ieee80211vap *vap, uint8_t op, u_char *p, int l)
+{
+	struct ale *ale;
+	struct ieee80211_alq_rec *r;
+
+	ale = ieee80211_alq_get();
+	if (! ale)
+		return;
+
+	r = (struct ieee80211_alq_rec *) ale;
+	r->r_timestamp = ticks;
+	r->r_version = 1;
+	r->r_wlan = vap->iv_ifp->if_dunit;
+	r->r_op = op;
+	memcpy(&r->r_payload, p, MIN(l, sizeof(r->r_payload)));
+}