From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Cameron Date: Thu, 24 Apr 2008 03:50:28 +0000 Subject: Re: question for ip packet Message-Id: <20080424035028.GE4395@hp.com> List-Id: References: <200804241041005531107@fiberhome.com.cn> In-Reply-To: <200804241041005531107@fiberhome.com.cn> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ppp@vger.kernel.org On Thu, Apr 24, 2008 at 10:41:00AM +0800, ?????? wrote: > 1. after pppd has negotiated the link, what it tell information to the > kernel network ppp code, which make kernel transmit IP packets > directly? Briefly, in function tty_establish_ppp() in sys-linux.c, an ioctl(2) syscall sets the TTY into PPP discipline (N_PPP). Once the interface is up, the kernel transmits network packets through the PPP link. > 2. where to receive the IP packets from ppp kernel? how to know the > ip packet come from not other device but PPP? I don't understand. It is very clear the packets are from the PPP link because they can be captured from the new network interface. -- James Cameron http://quozl.netrek.org/ HP Open Source, Volunteer http://opensource.hp.com/ PPTP Client Project, Release Engineer http://pptpclient.sourceforge.net/