handsfree-audio: Add SCO handling

Unlike the previous implementation in the plugin, the SCO/SLC matching
is done based on the Audio Card objects.

Audio Cards are created when the RFCOMM fd descriptor is received, and
registered when the service level connetion is established.

src/handsfree-audio.c

@@ -25,12 +25,17 @@
 
 #include <errno.h>
 #include <stdio.h>
+#include <stdint.h>
 #include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/socket.h>
 
 #include <gdbus.h>
 
 #include <ofono/handsfree-audio.h>
 
+#include "bluetooth.h"
 #include "ofono.h"
 
 #define HFP_AUDIO_MANAGER_INTERFACE	OFONO_SERVICE ".HandsfreeAudioManager"
@@ -60,6 +65,87 @@ struct agent {
 static struct agent *agent = NULL;
 static int ref_count = 0;
 static GSList *card_list = 0;
+static guint sco_watch = 0;
+
+static int card_cmp(gconstpointer a, gconstpointer b)
+{
+	const struct ofono_handsfree_card *card = a;
+	const char *remote = b;
+
+	return g_strcmp0(card->remote, remote);
+}
+
+static gboolean sco_accept(GIOChannel *io, GIOCondition cond,
+							gpointer user_data)
+{
+	struct sockaddr_sco saddr;
+	socklen_t alen;
+	int sk, nsk;
+	char remote[18];
+
+	if (cond & (G_IO_ERR | G_IO_HUP | G_IO_NVAL))
+		return FALSE;
+
+	sk = g_io_channel_unix_get_fd(io);
+
+	memset(&saddr, 0, sizeof(saddr));
+	alen = sizeof(saddr);
+
+	nsk = accept(sk, (struct sockaddr *) &saddr, &alen);
+	if (nsk < 0)
+		return TRUE;
+
+	bt_ba2str(&saddr.sco_bdaddr, remote);
+
+	if (g_slist_find_custom(card_list, remote, card_cmp) == NULL) {
+		ofono_error("Rejecting SCO: Audio Card not found!");
+		close(nsk);
+		return TRUE;
+	}
+
+	return TRUE;
+}
+
+static int sco_init(void)
+{
+	GIOChannel *sco_io;
+	struct sockaddr_sco saddr;
+	int sk, defer_setup = 1;
+
+	sk = socket(PF_BLUETOOTH, SOCK_SEQPACKET | O_NONBLOCK | SOCK_CLOEXEC,
+								BTPROTO_SCO);
+	if (sk < 0)
+		return -errno;
+
+	/* Bind to local address */
+	memset(&saddr, 0, sizeof(saddr));
+	saddr.sco_family = AF_BLUETOOTH;
+	bt_bacpy(&saddr.sco_bdaddr, BDADDR_ANY);
+
+	if (bind(sk, (struct sockaddr *) &saddr, sizeof(saddr)) < 0) {
+		close(sk);
+		return -errno;
+	}
+
+	if (setsockopt(sk, SOL_BLUETOOTH, BT_DEFER_SETUP,
+				&defer_setup, sizeof(defer_setup)) < 0)
+		ofono_warn("Can't enable deferred setup: %s (%d)",
+						strerror(errno), errno);
+
+	if (listen(sk, 5) < 0) {
+		close(sk);
+		return -errno;
+	}
+
+	sco_io = g_io_channel_unix_new(sk);
+	sco_watch = g_io_add_watch(sco_io,
+				G_IO_IN | G_IO_ERR | G_IO_HUP | G_IO_NVAL,
+				sco_accept, NULL);
+
+	g_io_channel_unref(sco_io);
+
+	return 0;
+}
 
 static void card_append_properties(struct ofono_handsfree_card *card,
 					DBusMessageIter *dict)
@@ -437,7 +523,7 @@ void ofono_handsfree_audio_unref(void)
 
 int __ofono_handsfree_audio_manager_init(void)
 {
-	return 0;
+	return sco_init();
 }
 
 void __ofono_handsfree_audio_manager_cleanup(void)
@@ -450,4 +536,7 @@ void __ofono_handsfree_audio_manager_cleanup(void)
 
 	ref_count = 1;
 	ofono_handsfree_audio_unref();
+
+	if (sco_watch > 0)
+		g_source_remove(sco_watch);
 }