Re: [PATCH 03/18] gathdlc: add mechansim to detect '+++' escape sequence

--- gatchat/gathdlc.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 114 insertions(+), 0 deletions(-) diff --git a/gatchat/gathdlc.c b/gatchat/gathdlc.c index 7c45454..21e4533 100644 --- a/gatchat/gathdlc.c +++ b/gatchat/gathdlc.c @@ -50,6 +50,13 @@ #define HDLC_FCS(fcs, c) crc_ccitt_byte(fcs, c) +/* Amount of fiftieths of second to detect '+++'. + * Range is 0 to 0xff. + */ +#define ESC_TIME 0x32

+ +#define GUARD_TIMEOUTS 1000 /* Pause time before and after '+++' sequence */ +

struct _GAtHDLC { gint ref_count; GAtIO *io; @@ -68,6 +75,12 @@ struct _GAtHDLC { gboolean in_read_handler; gboolean destroyed; gboolean no_carrier_detect; + GAtSuspendFunc suspend_func; + gpointer suspend_data; + guint cmpt; + guint suspend_timeout; + guint pause_timeout;

+ gboolean paused; }; static void hdlc_record(int fd, gboolean in, guint8 *data, guint16 length) @@ -130,6 +143,47 @@ guint32 g_at_hdlc_get_recv_accm(GAtHDLC *hdlc) return hdlc->recv_accm; } +void g_at_hdlc_set_suspend_function(GAtHDLC *hdlc, GAtSuspendFunc func, + gpointer user_data) +{ + if (hdlc == NULL) + return; + + hdlc->suspend_func = func; + hdlc->suspend_data = user_data; +} + +static gboolean paused_timeout_cb(gpointer user_data) +{ + GAtHDLC *hdlc = user_data; + + hdlc->paused = TRUE; + + return FALSE; +} + +static gboolean susp_timeout_cb(gpointer user_data) +{ + GAtHDLC *hdlc = user_data; + + hdlc->cmpt = 0; + + return FALSE; +} + +static gboolean hdlc_suspend(gpointer user_data) +{ + GAtHDLC *hdlc = user_data; + + g_at_io_set_write_handler(hdlc->io, NULL, NULL); + g_at_io_set_read_handler(hdlc->io, NULL, NULL); + + if (hdlc->suspend_func) + hdlc->suspend_func(hdlc->suspend_data); + + return FALSE; +} + static void new_bytes(struct ring_buffer *rbuf, gpointer user_data) { GAtHDLC *hdlc = user_data; @@ -142,6 +196,13 @@ static void new_bytes(struct ring_buffer *rbuf, gpointer user_data) hdlc->in_read_handler = TRUE; + /* + * We delete the the paused_timeout_cb or hdlc_suspend as soons as + * we read a data. + */ + if (hdlc->pause_timeout > 0) + g_source_remove(hdlc->pause_timeout); + while (pos < len) { /* * We try to detect NO CARRIER conditions here. We @@ -153,6 +214,21 @@ static void new_bytes(struct ring_buffer *rbuf, gpointer user_data) hdlc->decode_offset == 0 && *buf == '\r') break; + /* + * If there was no character for 1 second we try to detect + * the '+' character to suspend data call if 3 '+' are + * detected in less than 20 * ESC_TIME milliseconds. + */ + if (*buf == '+' && hdlc->paused) { + if (hdlc->cmpt == 0) + hdlc->suspend_timeout = g_timeout_add (20 * ESC_TIME, + susp_timeout_cb, hdlc); + hdlc->cmpt++; + } else { + hdlc->cmpt = 0; + hdlc->paused = FALSE; + } + if (hdlc->decode_escape == TRUE) { unsigned char val = *buf ^ HDLC_TRANS; @@ -190,6 +266,9 @@ static void new_bytes(struct ring_buffer *rbuf, gpointer user_data) } } + if (hdlc->cmpt == 3) + goto suspend; + out: ring_buffer_drain(rbuf, pos); @@ -197,6 +276,37 @@ out: if (hdlc->destroyed) g_free(hdlc); + + /* + * If there were no data pause for GUARD_TIMEOUTS ms, + * we try again to check it. + */ + if (!hdlc->paused) + hdlc->pause_timeout = g_timeout_add (GUARD_TIMEOUTS, + paused_timeout_cb, + hdlc); + + return; + +suspend: + /* + * If the suspend timeout still exists, + * delete it. + */ + if (hdlc->suspend_timeout > 0) + g_source_remove(hdlc->suspend_timeout); + + /* + * Restart the counter and reset the ring buffer. + */ + hdlc->cmpt = 0; + ring_buffer_reset(rbuf);

+ + /* + * Wait for another pause of GUARD_TIMEOUTS ms before returning to command mode. + */ + hdlc->paused = FALSE; + hdlc->pause_timeout = g_timeout_add (GUARD_TIMEOUTS, hdlc_suspend, hdlc); } GAtHDLC *g_at_hdlc_new_from_io(GAtIO *io) @@ -245,6 +355,10 @@ GAtHDLC *g_at_hdlc_new_from_io(GAtIO *io) hdlc->io = g_at_io_ref(io); g_at_io_set_read_handler(hdlc->io, new_bytes, hdlc); + hdlc->cmpt = 0; + + hdlc->paused = FALSE; +

return hdlc; error: