gatchat: Add support for sending HDLC frame start and end markers

diff --git a/gatchat/gathdlc.c b/gatchat/gathdlc.c
index de6a972..53dd1fb 100644 (file)
--- a/gatchat/gathdlc.c
+++ b/gatchat/gathdlc.c
@@ -70,6 +70,8 @@ struct _GAtHDLC {
        int record_fd;
        gboolean in_read_handler;
        gboolean destroyed;
+       gboolean wakeup_sent;
+       gboolean start_frame_marker;
        gboolean no_carrier_detect;
        GAtSuspendFunc suspend_func;
        gpointer suspend_data;
@@ -328,7 +330,6 @@ out:
 GAtHDLC *g_at_hdlc_new_from_io(GAtIO *io)
 {
        GAtHDLC *hdlc;
-       unsigned char *buf;
        struct ring_buffer* write_buffer;
 
        if (io == NULL)
@@ -357,11 +358,6 @@ GAtHDLC *g_at_hdlc_new_from_io(GAtIO *io)
 
        g_queue_push_tail(hdlc->write_queue, write_buffer);
 
-       /* Write an initial 0x7e as wakeup character */
-       buf = ring_buffer_write_ptr(write_buffer, 0);
-       *buf = HDLC_FLAG;
-       ring_buffer_write_advance(write_buffer, 1);
-
        hdlc->decode_buffer = g_try_malloc(BUFFER_SIZE);
        if (!hdlc->decode_buffer)
                goto error;
@@ -563,6 +559,17 @@ gboolean g_at_hdlc_send(GAtHDLC *hdlc, const unsigned char *data, gsize size)
        i = 0;
        buf = ring_buffer_write_ptr(write_buffer, 0);
 
+       if (hdlc->start_frame_marker == TRUE) {
+               /* Protocol requires 0x7e as start marker */
+               *buf++ = HDLC_FLAG;
+               pos++;
+       } else if (hdlc->wakeup_sent == FALSE) {
+               /* Write an initial 0x7e as wakeup character */
+               *buf++ = HDLC_FLAG;
+               pos++;
+               hdlc->wakeup_sent = TRUE;
+       }
+
        while (pos < avail && i < size) {
                if (escape == TRUE) {
                        fcs = HDLC_FCS(fcs, data[i]);
@@ -616,6 +623,7 @@ gboolean g_at_hdlc_send(GAtHDLC *hdlc, const unsigned char *data, gsize size)
        if (pos + 1 > avail)
                return FALSE;
 
+       /* Add 0x7e as end marker */
        *buf = HDLC_FLAG;
        pos++;
 
@@ -626,6 +634,14 @@ gboolean g_at_hdlc_send(GAtHDLC *hdlc, const unsigned char *data, gsize size)
        return TRUE;
 }
 
+void g_at_hdlc_set_start_frame_marker(GAtHDLC *hdlc, gboolean marker)
+{
+       if (hdlc == NULL)
+               return;
+
+       hdlc->start_frame_marker = marker;
+}
+
 void g_at_hdlc_set_no_carrier_detect(GAtHDLC *hdlc, gboolean detect)
 {
        if (hdlc == NULL)

diff --git a/gatchat/gathdlc.h b/gatchat/gathdlc.h
index e82b33e..a7aab2f 100644 (file)
--- a/gatchat/gathdlc.h
+++ b/gatchat/gathdlc.h
@@ -55,6 +55,7 @@ void g_at_hdlc_set_recording(GAtHDLC *hdlc, const char *filename);
 
 GAtIO *g_at_hdlc_get_io(GAtHDLC *hdlc);
 
+void g_at_hdlc_set_start_frame_marker(GAtHDLC *hdlc, gboolean marker);
 void g_at_hdlc_set_no_carrier_detect(GAtHDLC *hdlc, gboolean detect);
 
 void g_at_hdlc_set_suspend_function(GAtHDLC *hdlc, GAtSuspendFunc func,