Date: Thu, 17 May 2001 13:04:19 -0700 (PDT) From: Archie Cobbs <archie@dellroad.org> To: "Roman V. Palagin" <romanp@unshadow.net> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: How to transfer data from netgraph node to user program? Message-ID: <200105172004.f4HK4Jm76648@arch20m.dellroad.org> In-Reply-To: <Pine.SOL.4.33.0105142254130.3484-100000@abyss.unshadow.net> "from Roman V. Palagin at May 14, 2001 11:24:07 pm"
next in thread | previous in thread | raw e-mail | index | archive | help
Roman V. Palagin writes: > I've wrote netgraph node which collects some information from network. Now > I want to transfer collected data into user program. I've NGM_XXX_STAT > message which initiates data transfer and program which uses libnetgraph > to communicate with node. When I send NGM_XXX_STAT message node must > starts data transfer but I don't know exactly how much data should be > transfered so I can't use synhronous reply. Also, NgSendMsg(..., > NGM_XXX_STAT, ...) doesn't return until handler of NGM_XXX_STAT is > finished, so I can't use ng_send_msg() in NGM_XXX_STAT handler - nobody > will read sended messages and I finished up with "No buffer space > available". > > The question is: how I can initiate smth. like asynchronous reply (so I > can get data via NgRecvMsg later in my prgram)? Or I'm going wrong way and > should use another scheme for data transfer? Data size ranges from 10Kb to > 500Kb. Whenever you're ready to send the reply, just create one and send it. You'll want the same 'token' value in the reply and you'll want to set the NGF_REPLY bit in the flags word to indicate it's a reply. For an exmple of doing this, see pppoe_send_event() in ng_pppoe.c (this is not a reply but shows how to create and send a message). -Archie __________________________________________________________________________ Archie Cobbs * Packet Design * http://www.packetdesign.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200105172004.f4HK4Jm76648>