Regulatory fixups:

o add missing channel flags for ECM, indoor, and outdoor constraints
o use HT capabilities to short-circuit HT20/HT40 channel construction
o rewrite 1/2 and 1/4 width channel handling yet again; previously
  we assumed there was a full-width version of the channel in the
  calibration table but that's not always true (e.g. for the Public
  Safety Band), now we first check the calibration table for the
  exact channel we want then fall back to the heuristics we used before
o fix HT channel construction; wasn't adjusting band edges for HT40
  channel bandwidth requirements

1 files changed, 130 insertions, 66 deletions

diff --git a/sbin/ifconfig/ifieee80211.c b/sbin/ifconfig/ifieee80211.c
index a5d649c..bc1e89f 100644
--- a/sbin/ifconfig/ifieee80211.c
+++ b/sbin/ifconfig/ifieee80211.c
@@ -99,10 +99,6 @@
 #define	IEEE80211_FIXED_RATE_NONE	0xff
 #endif
 
-#define	REQ_ECM		0x01000000	/* enable if ECM set */
-#define	REQ_OUTDOOR	0x02000000	/* enable for outdoor operation */
-#define	REQ_FLAGS	0xff000000	/* private flags, don't pass to os */
-
 /* XXX need these publicly defined or similar */
 #ifndef IEEE80211_NODE_AUTH
 #define	IEEE80211_NODE_AUTH	0x0001		/* authorized for data */
@@ -1802,6 +1798,57 @@ chanfind(const struct ieee80211_channel chans[], int nchans, int flags)
 	return 0;
 }
 
+/*
+ * Check channel compatibility.
+ */
+static int
+checkchan(const struct ieee80211req_chaninfo *avail, int freq, int flags)
+{
+	flags &= ~REQ_FLAGS;
+	/*
+	 * Check if exact channel is in the calibration table;
+	 * everything below is to deal with channels that we
+	 * want to include but that are not explicitly listed.
+	 */
+	if (flags & IEEE80211_CHAN_HT40) {
+		/* NB: we use an HT40 channel center that matches HT20 */
+		flags = (flags &~ IEEE80211_CHAN_HT40) | IEEE80211_CHAN_HT20;
+	}
+	if (chanlookup(avail->ic_chans, avail->ic_nchans, freq, flags) != NULL)
+		return 1;
+	if (flags & IEEE80211_CHAN_GSM) {
+		/*
+		 * XXX GSM frequency mapping is handled in the kernel
+		 * so we cannot find them in the calibration table;
+		 * just accept the channel and the kernel will reject
+		 * the channel list if it's wrong.
+		 */
+		return 1;
+	}
+	/*
+	 * If this is a 1/2 or 1/4 width channel allow it if a full
+	 * width channel is present for this frequency, and the device
+	 * supports fractional channels on this band.  This is a hack
+	 * that avoids bloating the calibration table; it may be better
+	 * by per-band attributes though (we are effectively calculating
+	 * this attribute by scanning the channel list ourself).
+	 */
+	if ((flags & (IEEE80211_CHAN_HALF | IEEE80211_CHAN_QUARTER)) == 0)
+		return 0;
+	if (chanlookup(avail->ic_chans, avail->ic_nchans, freq,
+	    flags &~ (IEEE80211_CHAN_HALF | IEEE80211_CHAN_QUARTER)) == NULL)
+		return 0;
+	if (flags & IEEE80211_CHAN_HALF) {
+		return chanfind(avail->ic_chans, avail->ic_nchans,
+		    IEEE80211_CHAN_HALF |
+		       (flags & (IEEE80211_CHAN_2GHZ | IEEE80211_CHAN_5GHZ)));
+	} else {
+		return chanfind(avail->ic_chans, avail->ic_nchans,
+		    IEEE80211_CHAN_QUARTER |
+			(flags & (IEEE80211_CHAN_2GHZ | IEEE80211_CHAN_5GHZ)));
+	}
+}
+
 static void
 regdomain_addchans(struct ieee80211req_chaninfo *ci,
 	const netband_head *bands,
@@ -1812,15 +1859,12 @@ regdomain_addchans(struct ieee80211req_chaninfo *ci,
 	const struct netband *nb;
 	const struct freqband *b;
 	struct ieee80211_channel *c, *prev;
-	int freq, channelSep, hasHalfChans, hasQuarterChans;
+	int freq, hi_adj, lo_adj, channelSep;
+	uint32_t flags;
 
+	hi_adj = (chanFlags & IEEE80211_CHAN_HT40U) ? -20 : 0;
+	lo_adj = (chanFlags & IEEE80211_CHAN_HT40D) ? 20 : 0;
 	channelSep = (chanFlags & IEEE80211_CHAN_2GHZ) ? 0 : 40;
-	hasHalfChans = chanfind(avail->ic_chans, avail->ic_nchans,
-	    IEEE80211_CHAN_HALF |
-	       (chanFlags & (IEEE80211_CHAN_2GHZ | IEEE80211_CHAN_5GHZ)));
-	hasQuarterChans = chanfind(avail->ic_chans, avail->ic_nchans,
-	    IEEE80211_CHAN_QUARTER |
-	        (chanFlags & (IEEE80211_CHAN_2GHZ | IEEE80211_CHAN_5GHZ)));
 	LIST_FOREACH(nb, bands, next) {
 		b = nb->band;
 		if (verbose) {
@@ -1831,63 +1875,80 @@ regdomain_addchans(struct ieee80211req_chaninfo *ci,
 			putchar('\n');
 		}
 		prev = NULL;
-		for (freq = b->freqStart; freq <= b->freqEnd; freq += b->chanSep) {
-			uint32_t flags = nb->flags | b->flags;
-
-			/* check if device can operate on this frequency */
+		for (freq = b->freqStart + lo_adj;
+		     freq <= b->freqEnd + hi_adj; freq += b->chanSep) {
+			/*
+			 * Construct flags for the new channel.  We take
+			 * the attributes from the band descriptions except
+			 * for HT40 which is enabled generically (i.e. +/-
+			 * extension channel) in the band description and
+			 * then constrained according by channel separation.
+			 */
+			flags = nb->flags | b->flags;
+			if (flags & IEEE80211_CHAN_HT) {
+				/*
+				 * HT channels are generated specially; we're
+				 * called to add HT20, HT40+, and HT40- chan's
+				 * so we need to expand only band specs for
+				 * the HT channel type being added.
+				 */
+				if ((chanFlags & IEEE80211_CHAN_HT20) &&
+				    (flags & IEEE80211_CHAN_HT20) == 0) {
+					if (verbose)
+						printf("%u: skip, not an "
+						    "HT20 channel\n", freq);
+					continue;
+				}
+				if ((chanFlags & IEEE80211_CHAN_HT40) &&
+				    (flags & IEEE80211_CHAN_HT40) == 0) {
+					if (verbose)
+						printf("%u: skip, not an "
+						    "HT40 channel\n", freq);
+					continue;
+				}
+				/*
+				 * DFS and HT40 don't mix.  This should be
+				 * expressed in the regdomain database but
+				 * just in case enforce it here.
+				 */
+				if ((chanFlags & IEEE80211_CHAN_HT40) &&
+				    (flags & IEEE80211_CHAN_DFS)) {
+					if (verbose)
+						printf("%u: skip, HT40+DFS "
+						    "not permitted\n", freq);
+					continue;
+				}
+				/* NB: HT attribute comes from caller */
+				flags &= ~IEEE80211_CHAN_HT;
+				flags |= chanFlags & IEEE80211_CHAN_HT;
+			}
 			/*
-			 * XXX GSM frequency mapping is handled in the kernel
-			 * so we cannot find them in the calibration table;
-			 * just construct the list and the kernel will reject
-			 * if it's wrong.
+			 * Check if device can operate on this frequency.
 			 */
-			if (chanlookup(avail->ic_chans, avail->ic_nchans, freq, chanFlags) == NULL &&
-			    (flags & IEEE80211_CHAN_GSM) == 0) {
+			if (!checkchan(avail, freq, flags)) {
 				if (verbose) {
 					printf("%u: skip, ", freq);
-					printb("flags", chanFlags,
+					printb("flags", flags,
 					    IEEE80211_CHAN_BITS);
 					printf(" not available\n");
 				}
 				continue;
 			}
-			if ((flags & IEEE80211_CHAN_HALF) && !hasHalfChans) {
+			if ((flags & REQ_ECM) && !reg->ecm) {
 				if (verbose)
-					printf("%u: skip, device does not "
-					    "support half-rate channel\n",
-					    freq);
+					printf("%u: skip, ECM channel\n", freq);
 				continue;
 			}
-			if ((flags & IEEE80211_CHAN_QUARTER) &&
-			    !hasQuarterChans) {
+			if ((flags & REQ_INDOOR) && reg->location == 'O') {
 				if (verbose)
-					printf("%u: skip, device does not "
-					    "support quarter-rate channel\n",
+					printf("%u: skip, indoor channel\n",
 					    freq);
 				continue;
 			}
-			if ((flags & IEEE80211_CHAN_HT20) &&
-			    (chanFlags & IEEE80211_CHAN_HT20) == 0) {
-				if (verbose)
-					printf("%u: skip, device does not "
-					    "support HT20 operation\n", freq);
-				continue;
-			}
-			if ((flags & IEEE80211_CHAN_HT40) &&
-			    (chanFlags & IEEE80211_CHAN_HT40) == 0) {
-				if (verbose)
-					printf("%u: skip, device does not "
-					    "support HT40 operation\n", freq);
-				continue;
-			}
-			if ((flags & REQ_ECM) && !reg->ecm) {
-				if (verbose)
-					printf("%u: skip, ECM channel\n", freq);
-				continue;
-			}
 			if ((flags & REQ_OUTDOOR) && reg->location == 'I') {
 				if (verbose)
-					printf("%u: skip, outdoor channel\n", freq);
+					printf("%u: skip, outdoor channel\n",
+					    freq);
 				continue;
 			}
 			if ((flags & IEEE80211_CHAN_HT40) &&
@@ -1907,8 +1968,7 @@ regdomain_addchans(struct ieee80211req_chaninfo *ci,
 			c = &ci->ic_chans[ci->ic_nchans++];
 			memset(c, 0, sizeof(*c));
 			c->ic_freq = freq;
-			c->ic_flags = chanFlags |
-			    (flags &~ (REQ_FLAGS | IEEE80211_CHAN_HT40));
+			c->ic_flags = flags;
 			if (c->ic_flags & IEEE80211_CHAN_DFS)
 				c->ic_maxregpower = nb->maxPowerDFS;
 			else
@@ -1973,27 +2033,31 @@ regdomain_makechannels(
 		if (!LIST_EMPTY(&rd->bands_11a))
 			regdomain_addchans(ci, &rd->bands_11a, reg,
 			    IEEE80211_CHAN_A, &dc->dc_chaninfo);
-		if (!LIST_EMPTY(&rd->bands_11na)) {
+		if (!LIST_EMPTY(&rd->bands_11na) && dc->dc_htcaps != 0) {
 			regdomain_addchans(ci, &rd->bands_11na, reg,
 			    IEEE80211_CHAN_A | IEEE80211_CHAN_HT20,
 			    &dc->dc_chaninfo);
-			regdomain_addchans(ci, &rd->bands_11na, reg,
-			    IEEE80211_CHAN_A | IEEE80211_CHAN_HT40U,
-			    &dc->dc_chaninfo);
-			regdomain_addchans(ci, &rd->bands_11na, reg,
-			    IEEE80211_CHAN_A | IEEE80211_CHAN_HT40D,
-			    &dc->dc_chaninfo);
+			if (dc->dc_htcaps & IEEE80211_HTCAP_CHWIDTH40) {
+				regdomain_addchans(ci, &rd->bands_11na, reg,
+				    IEEE80211_CHAN_A | IEEE80211_CHAN_HT40U,
+				    &dc->dc_chaninfo);
+				regdomain_addchans(ci, &rd->bands_11na, reg,
+				    IEEE80211_CHAN_A | IEEE80211_CHAN_HT40D,
+				    &dc->dc_chaninfo);
+			}
 		}
-		if (!LIST_EMPTY(&rd->bands_11ng)) {
+		if (!LIST_EMPTY(&rd->bands_11ng) && dc->dc_htcaps != 0) {
 			regdomain_addchans(ci, &rd->bands_11ng, reg,
 			    IEEE80211_CHAN_G | IEEE80211_CHAN_HT20,
 			    &dc->dc_chaninfo);
-			regdomain_addchans(ci, &rd->bands_11ng, reg,
-			    IEEE80211_CHAN_G | IEEE80211_CHAN_HT40U,
-			    &dc->dc_chaninfo);
-			regdomain_addchans(ci, &rd->bands_11ng, reg,
-			    IEEE80211_CHAN_G | IEEE80211_CHAN_HT40D,
-			    &dc->dc_chaninfo);
+			if (dc->dc_htcaps & IEEE80211_HTCAP_CHWIDTH40) {
+				regdomain_addchans(ci, &rd->bands_11ng, reg,
+				    IEEE80211_CHAN_G | IEEE80211_CHAN_HT40U,
+				    &dc->dc_chaninfo);
+				regdomain_addchans(ci, &rd->bands_11ng, reg,
+				    IEEE80211_CHAN_G | IEEE80211_CHAN_HT40D,
+				    &dc->dc_chaninfo);
+			}
 		}
 		qsort(ci->ic_chans, ci->ic_nchans, sizeof(ci->ic_chans[0]),
 		    regdomain_sort);