gatchat: A full support for TUN/TAP pipe and GAtRawIP

gatchat/gatrawip.c

@@ -23,14 +23,25 @@
 #include <config.h>
 #endif
 
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <linux/if_tun.h>
+
 #include <glib.h>
 
+#include "ringbuffer.h"
 #include "gatrawip.h"
 
 struct _GAtRawIP {
 	gint ref_count;
 	GAtIO *io;
+	GAtIO *tun_io;
 	char *ifname;
+	struct ring_buffer *write_buffer;
+	struct ring_buffer *tun_write_buffer;
 	GAtDebugFunc debugf;
 	gpointer debug_data;
 };
@@ -61,6 +72,9 @@ GAtRawIP *g_at_rawip_new_from_io(GAtIO *io)
 
 	rawip->ref_count = 1;
 
+	rawip->write_buffer = NULL;
+	rawip->tun_write_buffer = NULL;
+
 	rawip->io = g_at_io_ref(io);
 
 	return rawip;
@@ -84,19 +98,130 @@ void g_at_rawip_unref(GAtRawIP *rawip)
 	if (g_atomic_int_dec_and_test(&rawip->ref_count) == FALSE)
 		return;
 
+	g_at_rawip_shutdown(rawip);
+
 	g_at_io_unref(rawip->io);
 	rawip->io = NULL;
 
 	g_free(rawip->ifname);
+	rawip->ifname = NULL;
+
 	g_free(rawip);
 }
 
+static gboolean can_write_data(gpointer data)
+{
+	GAtRawIP *rawip = data;
+	unsigned int len;
+	unsigned char *buf;
+	gsize bytes_written;
+
+	if (rawip->write_buffer == NULL)
+		return FALSE;
+
+	len = ring_buffer_len_no_wrap(rawip->write_buffer);
+	buf = ring_buffer_read_ptr(rawip->write_buffer, 0);
+
+	bytes_written = g_at_io_write(rawip->io, (gchar *) buf, len);
+	ring_buffer_drain(rawip->write_buffer, bytes_written);
+
+	if (ring_buffer_len(rawip->write_buffer) > 0)
+		return TRUE;
+
+	rawip->write_buffer = NULL;
+
+	return FALSE;
+}
+
+static gboolean tun_write_data(gpointer data)
+{
+	GAtRawIP *rawip = data;
+	unsigned int len;
+	unsigned char *buf;
+	gsize bytes_written;
+
+	if (rawip->tun_write_buffer == NULL)
+		return FALSE;
+
+	len = ring_buffer_len_no_wrap(rawip->tun_write_buffer);
+	buf = ring_buffer_read_ptr(rawip->tun_write_buffer, 0);
+
+	bytes_written = g_at_io_write(rawip->tun_io, (gchar *) buf, len);
+	ring_buffer_drain(rawip->tun_write_buffer, bytes_written);
+
+	if (ring_buffer_len(rawip->tun_write_buffer) > 0)
+		return TRUE;
+
+	rawip->tun_write_buffer = NULL;
+
+	return FALSE;
+}
+
+static void new_bytes(struct ring_buffer *rbuf, gpointer user_data)
+{
+	GAtRawIP *rawip = user_data;
+
+	rawip->tun_write_buffer = rbuf;
+
+	g_at_io_set_write_handler(rawip->tun_io, tun_write_data, rawip);
+}
+
+static void tun_bytes(struct ring_buffer *rbuf, gpointer user_data)
+{
+	GAtRawIP *rawip = user_data;
+
+	rawip->write_buffer = rbuf;
+
+	g_at_io_set_write_handler(rawip->io, can_write_data, rawip);
+}
+
+static void create_tun(GAtRawIP *rawip)
+{
+	GIOChannel *channel;
+	struct ifreq ifr;
+	int fd, err;
+
+	fd = open("/dev/net/tun", O_RDWR);
+	if (fd < 0)
+		return;
+
+	memset(&ifr, 0, sizeof(ifr));
+	ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
+	strcpy(ifr.ifr_name, "gprs%d");
+
+	err = ioctl(fd, TUNSETIFF, (void *) &ifr);
+	if (err < 0) {
+		close(fd);
+		return;
+	}
+
+	rawip->ifname = g_strdup(ifr.ifr_name);
+
+	channel = g_io_channel_unix_new(fd);
+	if (channel == NULL) {
+		close(fd);
+		return;
+	}
+
+	rawip->tun_io = g_at_io_new(channel);
+
+	g_io_channel_set_buffered(channel, FALSE);
+
+	g_io_channel_unref(channel);
+}
+
 void g_at_rawip_open(GAtRawIP *rawip)
 {
 	if (rawip == NULL)
 		return;
 
-	/* open TUN/TAP device */
+	create_tun(rawip);
+
+	if (rawip->tun_io == NULL)
+		return;
+
+	g_at_io_set_read_handler(rawip->io, new_bytes, rawip);
+	g_at_io_set_read_handler(rawip->tun_io, tun_bytes, rawip);
 }
 
 void g_at_rawip_shutdown(GAtRawIP *rawip)
@@ -104,7 +229,17 @@ void g_at_rawip_shutdown(GAtRawIP *rawip)
 	if (rawip == NULL)
 		return;
 
-	/* close TUN/TAP device */
+	if (rawip->tun_io == NULL)
+		return;
+
+	g_at_io_set_read_handler(rawip->io, NULL, NULL);
+	g_at_io_set_read_handler(rawip->tun_io, NULL, NULL);
+
+	rawip->write_buffer = NULL;
+	rawip->tun_write_buffer = NULL;
+
+	g_at_io_unref(rawip->tun_io);
+	rawip->tun_io = NULL;
 }
 
 const char *g_at_rawip_get_interface(GAtRawIP *rawip)