P2P: Add more user friendly debug print of channel lists

This makes it easier to go through the P2P channel list operations in
the debug log without having to parse through the hexdump manually.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>

src/p2p/p2p_go_neg.c

@@ -465,9 +465,11 @@ static int p2p_go_select_channel(struct p2p_data *p2p, struct p2p_device *dev,
 				 u8 *status)
 {
 	struct p2p_channels intersection;
-	size_t i;
 
+	p2p_channels_dump(p2p, "own channels", &p2p->channels);
+	p2p_channels_dump(p2p, "peer channels", &dev->channels);
 	p2p_channels_intersect(&p2p->channels, &dev->channels, &intersection);
+	p2p_channels_dump(p2p, "intersection", &intersection);
 	if (intersection.reg_classes == 0 ||
 	    intersection.reg_class[0].channels == 0) {
 		*status = P2P_SC_FAIL_NO_COMMON_CHANNELS;
@@ -475,14 +477,6 @@ static int p2p_go_select_channel(struct p2p_data *p2p, struct p2p_device *dev,
 		return -1;
 	}
 
-	for (i = 0; i < intersection.reg_classes; i++) {
-		struct p2p_reg_class *c;
-		c = &intersection.reg_class[i];
-		p2p_dbg(p2p, "reg_class %u", c->reg_class);
-		wpa_hexdump(MSG_DEBUG, "P2P: channels",
-			    c->channel, c->channels);
-	}
-
 	if (!p2p_channels_includes(&intersection, p2p->op_reg_class,
 				   p2p->op_channel)) {
 		if (dev->flags & P2P_DEV_FORCE_FREQ) {

src/p2p/p2p_i.h

@@ -572,6 +572,8 @@ void p2p_channels_intersect(const struct p2p_channels *a,
 			    struct p2p_channels *res);
 int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class,
 			  u8 channel);
+void p2p_channels_dump(struct p2p_data *p2p, const char *title,
+		       const struct p2p_channels *chan);
 
 /* p2p_parse.c */
 int p2p_parse_p2p_ie(const struct wpabuf *buf, struct p2p_message *msg);

src/p2p/p2p_utils.c

@@ -280,3 +280,36 @@ unsigned int p2p_get_pref_freq(struct p2p_data *p2p,
 
 	return 0;
 }
+
+
+void p2p_channels_dump(struct p2p_data *p2p, const char *title,
+		       const struct p2p_channels *chan)
+{
+	char buf[500], *pos, *end;
+	size_t i, j;
+	int ret;
+
+	pos = buf;
+	end = pos + sizeof(buf);
+
+	for (i = 0; i < chan->reg_classes; i++) {
+		const struct p2p_reg_class *c;
+		c = &chan->reg_class[i];
+		ret = os_snprintf(pos, end - pos, " %u:", c->reg_class);
+		if (ret < 0 || ret >= end - pos)
+			break;
+		pos += ret;
+
+		for (j = 0; j < c->channels; j++) {
+			ret = os_snprintf(pos, end - pos, "%s%u",
+					  j == 0 ? "" : ",",
+					  c->channel[j]);
+			if (ret < 0 || ret >= end - pos)
+				break;
+			pos += ret;
+		}
+	}
+	*pos = '\0';
+
+	p2p_dbg(p2p, "%s:%s", title, buf);
+}