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); }
gboolean g_at_hdlc_send(GAtHDLC *hdlc, const unsigned char *data, gsize size) { unsigned int avail = ring_buffer_avail(hdlc->write_buffer); unsigned int wrap = ring_buffer_avail_no_wrap(hdlc->write_buffer); unsigned char *buf = ring_buffer_write_ptr(hdlc->write_buffer, 0); unsigned char tail[2]; unsigned int i = 0; guint16 fcs = HDLC_INITFCS; gboolean escape = FALSE; gsize pos = 0; if (avail < size) return FALSE; i = 0; while (pos < avail && i < size) { if (escape == TRUE) { fcs = HDLC_FCS(fcs, data[i]); *buf = data[i++] ^ HDLC_TRANS; escape = FALSE; } else if (NEED_ESCAPE(hdlc->xmit_accm, data[i])) { *buf = HDLC_ESCAPE; escape = TRUE; } else { fcs = HDLC_FCS(fcs, data[i]); *buf = data[i++]; } buf++; pos++; if (pos == wrap) buf = ring_buffer_write_ptr(hdlc->write_buffer, pos); } if (i < size) return FALSE; fcs ^= HDLC_INITFCS; tail[0] = fcs & 0xff; tail[1] = fcs >> 8; i = 0; while (pos < avail && i < sizeof(tail)) { if (escape == TRUE) { *buf = tail[i++] ^ HDLC_TRANS; escape = FALSE; } else if (NEED_ESCAPE(hdlc->xmit_accm, tail[i])) { *buf = HDLC_ESCAPE; escape = TRUE; } else { *buf = tail[i++]; } buf++; pos++; if (pos == wrap) buf = ring_buffer_write_ptr(hdlc->write_buffer, pos); } if (i < sizeof(tail)) return FALSE; if (pos + 1 > avail) return FALSE; *buf = HDLC_FLAG; pos++; ring_buffer_write_advance(hdlc->write_buffer, pos); g_at_io_set_write_handler(hdlc->io, can_write_data, hdlc); return TRUE; }