From: Xie He <xie.he.0141@gmail.com>
To: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>,
Network Development <netdev@vger.kernel.org>,
syzbot <syzbot+4a2c52677a8a1aa283cb@syzkaller.appspotmail.com>,
William Tu <u9012063@gmail.com>
Subject: Re: [Patch net] ip_gre: set dev->hard_header_len properly
Date: Thu, 8 Oct 2020 13:10:42 -0700 [thread overview]
Message-ID: <CAJht_ENMFY_HwaJDjvxZbQgcDv7btC+bU6gzdjyddY-JS=a6Lg@mail.gmail.com> (raw)
In-Reply-To: <CA+FuTSdWYDs5u+3VzpTA1-Xs1OiVzv8QiKGTH4GUYrvXFfGT_A@mail.gmail.com>
On Thu, Oct 8, 2020 at 12:20 PM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Thu, Oct 8, 2020 at 3:17 PM Xie He <xie.he.0141@gmail.com> wrote:
> >
> > However, there's something I don't understand in the GRE code. The
> > ipgre_header function only creates an IP header (20 bytes) + a GRE
> > base header (4 bytes), but pushes and returns "t->hlen +
> > sizeof(*iph)". What is t->hlen?
>
> GRE is variable length depending on flags:
>
> tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
>
>
> > It seems to me it is the sum of
> > t->tun_hlen and t->encap_hlen. What are these two?
OK. I understand that t->tun_hlen is the GRE header length. What is
t->encap_hlen?
next prev parent reply other threads:[~2020-10-08 20:10 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-08 1:21 [Patch net] ip_gre: set dev->hard_header_len properly Cong Wang
2020-10-08 11:48 ` Willem de Bruijn
2020-10-08 17:33 ` Cong Wang
2020-10-08 19:04 ` Willem de Bruijn
2020-10-08 19:16 ` Xie He
2020-10-08 19:19 ` Willem de Bruijn
2020-10-08 20:10 ` Xie He [this message]
2020-10-08 20:31 ` Willem de Bruijn
2020-10-08 21:35 ` Xie He
2020-10-08 21:47 ` Willem de Bruijn
2020-10-08 21:54 ` Xie He
2020-10-08 23:40 ` Xie He
2020-10-09 17:43 ` Cong Wang
2020-10-09 19:41 ` Xie He
2020-10-09 19:51 ` Xie He
2020-10-09 20:38 ` Cong Wang
2020-10-10 1:07 ` Cong Wang
2020-10-10 3:10 ` Xie He
2020-10-10 18:58 ` Cong Wang
2020-10-10 21:49 ` Xie He
2020-10-11 3:55 ` Xie He
2020-10-11 14:35 ` Xie He
2020-10-08 19:18 ` Willem de Bruijn
2020-10-08 19:50 ` Cong Wang
2020-10-08 20:19 ` Willem de Bruijn
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