P2P: Add a function to compute the group common freqs

Add a function to compute the group common frequencies, and
use it to update the group_common_frequencies as part of the
channel switch flows.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>

src/p2p/p2p.h

@@ -2325,4 +2325,14 @@ void p2p_set_own_pref_freq_list(struct p2p_data *p2p,
 				const unsigned int *pref_freq_list,
 				unsigned int size);
 
+/**
+ * p2p_group_get_common_freqs - Get the group common frequencies
+ * @group: P2P group context from p2p_group_init()
+ * @common_freqs: On return will hold the group common frequencies
+ * @num: On return will hold the number of group common frequencies
+ * Returns: 0 on success, -1 otherwise
+ */
+int p2p_group_get_common_freqs(struct p2p_group *group, int *common_freqs,
+			       unsigned int *num);
+
 #endif /* P2P_H */

src/p2p/p2p_group.c

@@ -1071,3 +1071,43 @@ void p2p_loop_on_all_groups(struct p2p_data *p2p,
 			break;
 	}
 }
+
+
+int p2p_group_get_common_freqs(struct p2p_group *group, int *common_freqs,
+			       unsigned int *num)
+
+{
+	struct p2p_channels intersect, res;
+	struct p2p_group_member *m;
+
+	if (!group || !common_freqs || !num)
+		return -1;
+
+	os_memset(&intersect, 0, sizeof(intersect));
+	os_memset(&res, 0, sizeof(res));
+
+	p2p_channels_union(&intersect, &group->p2p->cfg->channels,
+			   &intersect);
+
+	p2p_channels_dump(group->p2p,
+			  "Group common freqs before iterating members",
+			  &intersect);
+
+	for (m = group->members; m; m = m->next) {
+		struct p2p_device *dev;
+
+		dev = p2p_get_device(group->p2p, m->dev_addr);
+		if (!dev)
+			continue;
+
+		p2p_channels_intersect(&intersect, &dev->channels, &res);
+		intersect = res;
+	}
+
+	p2p_channels_dump(group->p2p, "Group common channels", &intersect);
+
+	os_memset(common_freqs, 0, *num * sizeof(int));
+	*num = p2p_channels_to_freqs(&intersect, common_freqs, *num);
+
+	return 0;
+}

wpa_supplicant/p2p_supplicant.c

@@ -2606,6 +2606,32 @@ static int freq_included(const struct p2p_channels *channels, unsigned int freq)
 }
 
 
+static void wpas_p2p_go_update_common_freqs(struct wpa_supplicant *wpa_s)
+{
+	unsigned int num = P2P_MAX_CHANNELS;
+	int *common_freqs;
+	int ret;
+
+	p2p_go_dump_common_freqs(wpa_s);
+	common_freqs = os_calloc(num, sizeof(int));
+	if (!common_freqs)
+		return;
+
+	ret = p2p_group_get_common_freqs(wpa_s->p2p_group, common_freqs, &num);
+	if (ret < 0) {
+		wpa_dbg(wpa_s, MSG_DEBUG,
+			"P2P: Failed to get group common freqs");
+		os_free(common_freqs);
+		return;
+	}
+
+	os_free(wpa_s->p2p_group_common_freqs);
+	wpa_s->p2p_group_common_freqs = common_freqs;
+	wpa_s->p2p_group_common_freqs_num = num;
+	p2p_go_dump_common_freqs(wpa_s);
+}
+
+
 /*
  * Check if the given frequency is one of the possible operating frequencies
  * set after the completion of the GO Negotiation.
@@ -8345,6 +8371,8 @@ static void wpas_p2p_move_go(void *eloop_ctx, void *timeout_ctx)
 	if (!wpa_s->ap_iface || !wpa_s->current_ssid)
 		return;
 
+	wpas_p2p_go_update_common_freqs(wpa_s);
+
 	/*
 	 * First, try a channel switch flow. If it is not supported or fails,
 	 * take down the GO and bring it up again.
@@ -8373,6 +8401,8 @@ static void wpas_p2p_consider_moving_one_go(struct wpa_supplicant *wpa_s,
 	unsigned int timeout;
 	int freq;
 
+	wpas_p2p_go_update_common_freqs(wpa_s);
+
 	freq = wpa_s->current_ssid->frequency;
 	for (i = 0, invalid_freq = 0; i < num; i++) {
 		if (freqs[i].freq == freq) {