From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============4986343416824555095==" MIME-Version: 1.0 From: Steven Subject: Re: About Connection between PPP and linux Sockets Date: Fri, 20 Aug 2010 16:53:35 +0800 Message-ID: <4C6E428F.8040507@neusoft.com> In-Reply-To: <1282292982.23399.195.camel@localhost.localdomain> List-Id: To: ofono@ofono.org --===============4986343416824555095== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Hi Marcel=EF=BC=8C Marcel Holtmann wrote: > Hi Zhenhua, > = >>>>>>>> I have a little question just as the title said? >>>>>>>> In Ofono how to connect PPP to Linux socket, when we receive >>>>>>>> packet from network, how the packet go through the kernel to >>>>>>>> application=EF=BC=9F = >>>>>>>> >>>>>>>> modem -->PPP-->? --> linux kernel(network part)--> socket --> >>>>>>>> application? >>>>>>> it is more like this: >>>>>>> >>>>>>> modem -> TTY -> PPP -> TUN/TAP -> Kernel Net-Stack -> socket -> >>>>>>> application. = >>>>>>> >>>>>>> With the TTY being in kernel, the PPP being in userspace, and >>>>>>> TUN/TAP etc. begin in the kernel again. >>>>>>> >>>>>>> A future enhancement is to use the kernel PPP layer, but we >>>>>>> haven't gotten there yet. >>>>>> I am interested to know how could we use kernel PPP layer instead >>>>>> of gatppp. Shall we add this item into our TODO? >>>>>> >>>>> Maybe you can reference to RILD in Android, it used kernel PPP. >>>> Thanks. Will take a look then. >>> This information is a good start point. >>> http://www.devdiv.net/viewthread-26543 >>> >>> But only for Chinese people:( >> Thanks. I have read this before. ;-). The original article is from maxle= ng's blog: >> >> http://blog.csdn.net/maxleng/archive/2010/05/10/5576509.aspx >> >> However, it's just a big picture about phone stack in Android. It said n= othing about how Android works with kernel PPP layer. > = > could be that Andoid uses the kernel PPP and also uses pppd for it. We > are not using pppd on purpose since it is the wrong piece for an > embedded phone solution. We are not using the kernel PPP part, because > we haven't gotten around that yet. It also only works when having real > TTY devices. I don't think using pppd is a wrong piece for embedded phone, if we = using pppd, we can ease the ppp part of ofono and also support full ppp = functionalities, such as auth method(plain text, pap, chap, eap and so on) If your multiplexer runs in userspace then you also have > the problem that you don't have a real TTY. And using a PTS, then you > can just run PPP also in userspace. A little question, if we runs multiplexer in kernel space, can we using = kernel ppp part? Steven ---------------------------------------------------------------------------= ------------------------ Confidentiality Notice: The information contained in this e-mail and any ac= companying attachment(s) = is intended only for the use of the intended recipient and may be confident= ial and/or privileged of = Neusoft Corporation, its subsidiaries and/or its affiliates. If any reader = of this communication is = not the intended recipient, unauthorized use, forwarding, printing, storin= g, disclosure or copying = is strictly prohibited, and may be unlawful.If you have received this commu= nication in error,please = immediately notify the sender by return e-mail, and delete the original mes= sage and all copies from = your system. Thank you. = ---------------------------------------------------------------------------= ------------------------ --===============4986343416824555095==--