From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Simon Chow" Date: Fri, 23 Jul 2004 08:47:28 +0000 Subject: Re: pppd and AT+WMUX(Multiplex mode) Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ppp@vger.kernel.org wrote in message news:16638.36676.350168.813237@carlson.workingcode.com... > Simon Chow writes: > > I am researching how to handle the AT packets and Data packets offered by > > the Wavecom GSM modem in AT+WMUX=1 mode. I want to modify the pppd programme > > and I think that the tty.c in pppd may be the key to change. The charshunt > > function manipulates both the raw bytes sent from and received by the serial > > port. However, I am still in an initial stage. > > I don't think that analysis is right. The charshunt task is invoked > only in a few cases (e.g., where the 'record', 'notty', or 'socket' > options are used), and isn't the normal data path. The normal data > path is in the kernel, not user space. > > > I wonder if the pppd tool can handle the multiplex mode offered by Wavecom > > GSM modem. Thanks. > > Not today. I think you'd have to modify the PPP modules in the Linux > kernel to detect the switching mechanism and feed the data up to pppd > first. Otherwise, it'll probably be handled as bad PPP frames and > discarded. > > -- > James Carlson > - > To unsubscribe from this list: send the line "unsubscribe linux-ppp" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > How about I modify the ppp_async_input function in ppp_async.c to detect the 0xAA and 0xDD, and the ppp_async_push function to encapsulate the PPP frame with 0xDD?