P2P: Share a single function for GO channel selection

The exact same mechanism was used for determining the operating channel
at the device that becomes the GO regardless of whether this was
triggered by reception of GO Negotiation Request of Response frame. Use
a shared function to avoid duplicated implementation and potential
differences in the future.

Signed-hostap: Jouni Malinen <j@w1.fi>

src/p2p/p2p_go_neg.c

@@ -418,6 +418,42 @@ void p2p_reselect_channel(struct p2p_data *p2p,
 }
 
 
+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_intersect(&p2p->channels, &dev->channels, &intersection);
+	if (intersection.reg_classes == 0 ||
+	    intersection.reg_class[0].channels == 0) {
+		*status = P2P_SC_FAIL_NO_COMMON_CHANNELS;
+		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
+			"P2P: No common channels found");
+		return -1;
+	}
+
+	for (i = 0; i < intersection.reg_classes; i++) {
+		struct p2p_reg_class *c;
+		c = &intersection.reg_class[i];
+		wpa_printf(MSG_DEBUG, "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))
+		p2p_reselect_channel(p2p, &intersection);
+
+	if (!p2p->ssid_set) {
+		p2p_build_ssid(p2p, p2p->ssid, &p2p->ssid_len);
+		p2p->ssid_set = 1;
+	}
+
+	return 0;
+}
+
+
 void p2p_process_go_neg_req(struct p2p_data *p2p, const u8 *sa,
 			    const u8 *data, size_t len, int rx_freq)
 {
@@ -634,36 +670,8 @@ void p2p_process_go_neg_req(struct p2p_data *p2p, const u8 *sa,
 			goto fail;
 		}
 
-		if (go) {
-			struct p2p_channels intersection;
-			size_t i;
-			p2p_channels_intersect(&p2p->channels, &dev->channels,
-					       &intersection);
-			if (intersection.reg_classes == 0 ||
-			    intersection.reg_class[0].channels == 0) {
-				status = P2P_SC_FAIL_NO_COMMON_CHANNELS;
-				wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
-					"P2P: No common channels found");
-				goto fail;
-			}
-			for (i = 0; i < intersection.reg_classes; i++) {
-				struct p2p_reg_class *c;
-				c = &intersection.reg_class[i];
-				wpa_printf(MSG_DEBUG, "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))
-				p2p_reselect_channel(p2p, &intersection);
-
-			if (!p2p->ssid_set) {
-				p2p_build_ssid(p2p, p2p->ssid, &p2p->ssid_len);
-				p2p->ssid_set = 1;
-			}
-		}
+		if (go && p2p_go_select_channel(p2p, dev, &status) < 0)
+			goto fail;
 
 		dev->go_state = go ? LOCAL_GO : REMOTE_GO;
 		dev->oper_freq = p2p_channel_to_freq((const char *)
@@ -1036,35 +1044,8 @@ void p2p_process_go_neg_resp(struct p2p_data *p2p, const u8 *sa,
 		goto fail;
 	}
 
-	if (go) {
-		struct p2p_channels intersection;
-		size_t i;
-		p2p_channels_intersect(&p2p->channels, &dev->channels,
-				       &intersection);
-		if (intersection.reg_classes == 0 ||
-		    intersection.reg_class[0].channels == 0) {
-			status = P2P_SC_FAIL_NO_COMMON_CHANNELS;
-			wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
-				"P2P: No common channels found");
-			goto fail;
-		}
-		for (i = 0; i < intersection.reg_classes; i++) {
-			struct p2p_reg_class *c;
-			c = &intersection.reg_class[i];
-			wpa_printf(MSG_DEBUG, "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))
-			p2p_reselect_channel(p2p, &intersection);
-
-		if (!p2p->ssid_set) {
-			p2p_build_ssid(p2p, p2p->ssid, &p2p->ssid_len);
-			p2p->ssid_set = 1;
-		}
-	}
+	if (go && p2p_go_select_channel(p2p, dev, &status) < 0)
+		goto fail;
 
 	p2p_set_state(p2p, P2P_GO_NEG);
 	p2p_clear_timeout(p2p);