Add ieee80211_rate2plcp() and ieee80211_plcp2rate() functions, which

convert the PLCP header signal field to a rate value and vice versa.

This implementation has been discussed with Damien and doesn't change
any existing net80211 structures.

ok damien@

4 files changed, 103 insertions, 8 deletions

diff --git a/share/man/man9/Makefile b/share/man/man9/Makefile
index 04378adc5f4..6b952a8c0b2 100644
--- a/share/man/man9/Makefile
+++ b/share/man/man9/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.135 2007/11/03 14:59:55 mglocker Exp $
+#	$OpenBSD: Makefile,v 1.136 2007/11/14 11:16:27 mglocker Exp $
 #	$NetBSD: Makefile,v 1.4 1996/01/09 03:23:01 thorpej Exp $
 
 #	Makefile for section 9 (kernel function and variable) manual pages.
@@ -139,7 +139,9 @@ MLINKS+=ieee80211.9 ieee80211_ifattach.9 \
 	ieee80211.9 ieee80211_setmode.9 \
 	ieee80211.9 ieee80211_chan2mode.9 \
 	ieee80211.9 ieee80211_rate2media.9 \
-	ieee80211.9 ieee80211_media2rate.9
+	ieee80211.9 ieee80211_media2rate.9 \
+	ieee80211.9 ieee80211_rate2plcp.9 \
+	ieee80211.9 ieee80211_plcp2rate.9
 MLINKS+=ieee80211_crypto.9 ieee80211_crypto_attach.9 \
 	ieee80211_crypto.9 ieee80211_crypto_detach.9 \
 	ieee80211_crypto.9 ieee80211_wep_crypt.9
diff --git a/share/man/man9/ieee80211.9 b/share/man/man9/ieee80211.9
index ef1e83f8a44..53fb26fa480 100644
--- a/share/man/man9/ieee80211.9
+++ b/share/man/man9/ieee80211.9
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: ieee80211.9,v 1.9 2007/11/03 14:59:55 mglocker Exp $
+.\"	$OpenBSD: ieee80211.9,v 1.10 2007/11/14 11:16:27 mglocker Exp $
 .\"
 .\" Copyright (c) 2004 Bruce M. Simpson <bms@spc.org>
 .\" Copyright (c) 2004 Darron Broad <darron@kewl.org>
@@ -26,9 +26,9 @@
 .\" SUCH DAMAGE.
 .\"
 .\" $FreeBSD: src/share/man/man9/ieee80211.9,v 1.3 2004/07/07 12:59:39 ru Exp $
-.\" $Id: ieee80211.9,v 1.9 2007/11/03 14:59:55 mglocker Exp $
+.\" $Id: ieee80211.9,v 1.10 2007/11/14 11:16:27 mglocker Exp $
 .\"
-.Dd $Mdocdate: November 3 2007 $
+.Dd $Mdocdate: November 14 2007 $
 .Dt IEEE80211 9
 .Os
 .Sh NAME
@@ -37,7 +37,8 @@
 .Nm ieee80211_media_init , ieee80211_media_change , ieee80211_media_status ,
 .Nm ieee80211_watchdog ,
 .Nm ieee80211_setmode , ieee80211_chan2mode ,
-.Nm ieee80211_rate2media , ieee80211_media2rate
+.Nm ieee80211_rate2media , ieee80211_media2rate ,
+.Nm ieee80211_rate2plcp , ieee80211_plcp2rate
 .Nd core 802.11 network stack functions
 .Sh SYNOPSIS
 .In net80211/ieee80211_var.h
@@ -76,6 +77,10 @@
 .Fc
 .Ft int
 .Fn ieee80211_media2rate "int mword"
+.Ft int
+.Fn ieee80211_rate2plcp "int rate" "enum ieee80211_phymode mode"
+.Ft int
+.Fn ieee80211_plcp2rate "int plcp" "enum ieee80211_phymode mode"
 .Sh DESCRIPTION
 The
 .Nm ieee80211
@@ -237,6 +242,21 @@ performs the reverse of this conversion, returning the bit rate (in 0.5Mbps
 units) corresponding to an
 .Vt ifmedia
 sub-type.
+.Pp
+.\"
+The
+.Fn ieee80211_rate2plcp
+function converts the bit rate
+.Fa rate
+(measured in units of 0.5Mbps) to a
+.Vt plcp
+signal.
+The
+.Fn ieee80211_plcp2rate
+function performs the reverse of this conversion,
+returning the bit rate (in 0.5Mbps units) corresponding to a
+.Vt plcp
+signal.
 .\"
 .Sh SEE ALSO
 .Xr ifmedia 4 ,
diff --git a/sys/net80211/ieee80211.c b/sys/net80211/ieee80211.c
index 51bb6bebe92..3989fe59080 100644
--- a/sys/net80211/ieee80211.c
+++ b/sys/net80211/ieee80211.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ieee80211.c,v 1.27 2007/11/03 14:59:55 mglocker Exp $	*/
+/*	$OpenBSD: ieee80211.c,v 1.28 2007/11/14 11:16:27 mglocker Exp $	*/
 /*	$NetBSD: ieee80211.c,v 1.19 2004/06/06 05:45:29 dyoung Exp $	*/
 
 /*-
@@ -922,3 +922,74 @@ ieee80211_media2rate(int mword)
 	return 0;
 #undef N
 }
+
+/*
+ * Convert bit rate (in 0.5Mbps units) to PLCP signal and vice versa.
+ */
+int
+ieee80211_rate2plcp(int rate, enum ieee80211_phymode mode)
+{
+	rate &= IEEE80211_RATE_VAL;
+
+	if (mode == IEEE80211_MODE_11B) {
+		/* IEEE Std 802.11b-1999 page 15, subclause 18.2.3.3 */
+		switch (rate) {
+		case 2:		return 10;
+		case 4:		return 20;
+		case 11:	return 55;
+		case 22:	return 110;
+		/* IEEE Std 802.11g-2003 page 19, subclause 19.3.2.1 */
+		case 44:	return 220;
+		}
+	} else if (mode == IEEE80211_MODE_11G || mode == IEEE80211_MODE_11A) {
+		/* IEEE Std 802.11a-1999 page 14, subclause 17.3.4.1 */
+		switch (rate) {
+		case 12:	return 0x0b;
+		case 18:	return 0x0f;
+		case 24:	return 0x0a;
+		case 36:	return 0x0e;
+		case 48:	return 0x09;
+		case 72:	return 0x0d;
+		case 96:	return 0x08;
+		case 108:	return 0x0c;
+		}
+        } else
+		panic("Unexpected mode %u", mode);
+
+	IEEE80211_DPRINTF(("%s: unsupported rate %u\n", __func__, rate));
+
+	return 0;
+}
+
+int
+ieee80211_plcp2rate(int plcp, enum ieee80211_phymode mode)
+{
+	if (mode == IEEE80211_MODE_11B) {
+		/* IEEE Std 802.11g-2003 page 19, subclause 19.3.2.1 */
+		switch (plcp) {
+		case 10:	return 2;
+		case 20:	return 4;
+		case 55:	return 11;
+		case 110:	return 22;
+		/* IEEE Std 802.11g-2003 page 19, subclause 19.3.2.1 */
+		case 220:	return 44;
+		}
+	} else if (mode == IEEE80211_MODE_11G || mode == IEEE80211_MODE_11A) {
+		/* IEEE Std 802.11a-1999 page 14, subclause 17.3.4.1 */
+		switch (plcp) {
+		case 0x0b:	return 12;
+		case 0x0f:	return 18;
+		case 0x0a:	return 24;
+		case 0x0e:	return 36;
+		case 0x09:	return 48;
+		case 0x0d:	return 72;
+		case 0x08:	return 96;
+		case 0x0c:	return 108;
+		}
+	} else
+		panic("Unexpected mode %u", mode);
+
+	IEEE80211_DPRINTF(("%s: unsupported plcp %u\n", __func__, plcp));
+
+	return 0;
+}
diff --git a/sys/net80211/ieee80211_var.h b/sys/net80211/ieee80211_var.h
index f086f7eb1ca..b85796beab4 100644
--- a/sys/net80211/ieee80211_var.h
+++ b/sys/net80211/ieee80211_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ieee80211_var.h,v 1.35 2007/11/03 14:59:55 mglocker Exp $	*/
+/*	$OpenBSD: ieee80211_var.h,v 1.36 2007/11/14 11:16:27 mglocker Exp $	*/
 /*	$NetBSD: ieee80211_var.h,v 1.7 2004/05/06 03:07:10 dyoung Exp $	*/
 
 /*-
@@ -313,6 +313,8 @@ int	ieee80211_fix_rate(struct ieee80211com *, struct ieee80211_node *, int);
 int	ieee80211_rate2media(struct ieee80211com *, int,
 		enum ieee80211_phymode);
 int	ieee80211_media2rate(int);
+int	ieee80211_rate2plcp(int, enum ieee80211_phymode);
+int	ieee80211_plcp2rate(int, enum ieee80211_phymode);
 u_int	ieee80211_mhz2ieee(u_int, u_int);
 u_int	ieee80211_chan2ieee(struct ieee80211com *,
 		const struct ieee80211_channel *);