From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <d1c554290802150929w510ec9ealca115f9ab9efa708@mail.gmail.com>
Date: Fri, 15 Feb 2008 15:29:43 -0200
From: "Iruata Souza" <iru.muzgo@gmail.com>
To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu>
Subject: Re: [9fans] /net panic
In-Reply-To: <ee773d2313208a0317a98c67313d0841@quanstro.net>
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References: <140e7ec30802150120y1b0e4b33lf76787aaee84edd2@mail.gmail.com>
	<ee773d2313208a0317a98c67313d0841@quanstro.net>
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On Fri, Feb 15, 2008 at 2:23 PM, erik quanstrom <quanstro@quanstro.net> wrote:
>
>i'm not sure this is a perfect solution.  i just don't have enough
>of the plan 9 ip stack loaded into cache to be sure nothing's
>been forgotten.  but give this patch a whirl.  basically, i think
>the problem is that inittcpctl() was stepping on timers that might
>have been active.  these timers need to be shutdown.  unfortunately,
>tcpclose() and localclose() are too agressive.  cleanupconnection()
>is a chopped-down version of localclose.
>
>- erik
>
>
>/n/sources/plan9//sys/src/9/ip/tcp.c:782,787 - tcp.c:782,813
>  	return mtu;
>  }
>
>+ static void
>+ cleanupconnection(Conv *s)
>+ {
>+ 	Tcpctl *tcb;
>+ 	Reseq *rp,*rp1;
>+ 	Tcppriv *tpriv;
>+
>+ 	tpriv = s->p->priv;
>+ 	tcb = (Tcpctl*)s->ptcl;
>+
>+ 	iphtrem(&tpriv->ht, s);
>+
>+ 	tcphalt(tpriv, &tcb->timer);
>+ 	tcphalt(tpriv, &tcb->rtt_timer);
>+ 	tcphalt(tpriv, &tcb->acktimer);
>+ 	tcphalt(tpriv, &tcb->katimer);
>+
>+ 	/* Flush reassembly queue; nothing more can arrive */
>+ 	for(rp = tcb->reseq; rp != nil; rp = rp1) {
>+ 		rp1 = rp->next;
>+ 		freeblist(rp->bp);
>+ 		free(rp);
>+ 	}
>+ 	tcb->reseq = nil;
>+ }
>+
>  void
>  inittcpctl(Conv *s, int mode)
>  {
>/n/sources/plan9//sys/src/9/ip/tcp.c:792,798 - tcp.c:818,827
>
>  	tcb = (Tcpctl*)s->ptcl;
>
>- 	memset(tcb, 0, sizeof(Tcpctl));
>+ 	if(tcb->timer.arg)		// c->state != Idle?
>+ 		cleanupconnection(s);
>+ 	else
>+ 		memset(tcb, 0, sizeof(Tcpctl));
>
>  	tcb->ssthresh = 65535;
>  	tcb->srtt = tcp_irtt<<LOGAGAIN;
>

works for me.
I don't know the internal workings of the plan 9 ip stack so I take
the risk of being silly: could be that the bug is not tcp only?
iru