Date: Fri, 11 Sep 1998 13:12:46 +0200 (MET DST) From: Luigi Rizzo <luigi@labinfo.iet.unipi.it> To: net@FreeBSD.ORG Subject: PULLUP_TO in ip_fw.c Message-ID: <199809111112.NAA19733@labinfo.iet.unipi.it>
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Ok, i adapted the ipfw code to bridged and non-ip packets, but
there is one minor issue: the macro PULLUP_TO is defined as
#define PULLUP_TO(len) do { \
if ((*m)->m_len < (len) \
&& (*m = m_pullup(*m, (len))) == 0) { \
goto bogusfrag; \
} \
*pip = ip = mtod(*m, struct ip *); \
offset = (ip->ip_off & IP_OFFMASK); \
} while (0)
and as such it requires that the mbuf starts with the ip header
and always writes into *pip and ip.
In my case, I might pass the firewall an mbuf which includes an
ethernet header, and i make sure that m_pullup needs not to be called.
So i'd like to change the macro to
#define PULLUP_TO(len) do { \
if ((*m)->m_len < (len) ) { \
if (*m = m_pullup(*m, (len)) == 0) \
goto bogusfrag; \
*pip = ip = mtod(*m, struct ip *); \
offset = (ip->ip_off & IP_OFFMASK); \
}
} while (0)
which btw saves a few writes to variables in case m_pullup is not called.
If there are no objections i am going to do this in the weekend (assuming
our router will be fixed by then :(
luigi
-----------------------------+--------------------------------------
Luigi Rizzo | Dip. di Ingegneria dell'Informazione
email: luigi@iet.unipi.it | Universita' di Pisa
tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy)
fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/
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