Re: CVS commit: src/sys

[Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>]

Hi,

On 2017/12/17 2:17, Robert Elz wrote:
>     Date:        Fri, 15 Dec 2017 21:24:20 +0700
>     From:        Robert Elz <kre%munnari.OZ.AU@localhost>
>     Message-ID:  <11642.1513347860%andromeda.noi.kre.to@localhost>
> 
>   | Unfortunately, because of the way it gets called, this might not be an
>   | easy change to make.
> 
> It wouldn't be, but it also turns out to be (I think) unnecessary.
> 
> The m_pullup() (or equiv) isn't needed at all, as you determined initially,
> m_copydata() handles fetching data from multiple mbufs (or an external
> cluster if needed).
> 
> The problem with your first fix was that you were checking whether the
> current mbuf contained the session-ID which it might not, it could be
> later - but we really do not need to care (and if it isn't there we
> do not need to fix it).
> 
> What I'd suggest doing (and the same for the inet6 case) is to make the
> function be ...
> 
> [aside don't cut& paste from this e-mail, it will have had most tabs
> turned into spaces...]
> 
> static int
> in_l2tp_match(struct mbuf *m, int off, int proto, void *arg)
> {
>         struct l2tp_variant *var = arg;
>         uint32_t sess_id;
> 
>         KASSERT(proto == IPPROTO_L2TP);
> 
> 	/*
> 	 * If the packet contains no session ID it cannot match
> 	 */
>         if (m_length(m) < off + sizeof(uint32_t))
> 		return 0;
>  
>         /* get L2TP session ID */
>         m_copydata(m, off, sizeof(uint32_t), (void *)&sess_id);
>         NTOHL(sess_id);
>         if (sess_id == 0) {
>                 /*
>                  * L2TPv3 control packet received.
>                  * userland daemon(l2tpd?) should process.
>                  */
>                 return 32 * 2;
>         } else if (sess_id == var->lv_my_sess_id)
>                 return 32 * 2;
>         else
>                 return 0;
> }

You are right. I fix it by your patch at in_l2tp.c:r1.9 and in6_l2tp.c:r1.12.


Thanks,

-- 
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Internet Initiative Japan Inc.

Device Engineering Section,
IoT Platform Development Department,
Network Division,
Technology Unit

Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>