On 6/13/18 1:28 PM, Andrey V. Elsukov wrote:
On 13.06.2018 23:04, Jeff Kletsky wrote:
The kernel version of libalias uses m_megapullup() function to make
single contiguous buffer. m_megapullup() uses m_get2() function to
allocate mbuf of appropriate size. If size of packet greater than 4k it
will fail. So, if you use MTU greater than 4k or if after fragments
reassembly you get a packet with length greater than 4k, ipfw_nat()
function will drop this packet.
Thanks!!
Mystery solved...
/usr/src/sys/netinet/libalias/alias.c
#ifdef _KERNEL
/*
* m_megapullup() - this function is a big hack.
* Thankfully, it's only used in ng_nat and ipfw+nat.
suggests that the "old school" approach of natd might resolve this. I'll
give it a try when I'm close enough to the box to resolve it when I make
a configuration error.
I didn't look at the rest of libalias, but you, probably, can improve
this hack to use 9k or 16k mbufs. You can replace m_get2() call in
m_megapullup() with the following code:
if (len <= MJUMPAGESIZE)
mcl = m_get2(len, M_NOWAIT, MT_DATA, M_PKTHDR);
else if (len <= MJUM9BYTES)
mcl = m_getjcl(M_NOWAIT, MT_DATA, M_PKTHDR, MJUM9BYTES);
else if (len <= MJUM16BYTES)
mcl = m_getjcl(M_NOWAIT, MT_DATA, M_PKTHDR, MJUM16BYTES);
else
goto bad;
Tested and "works for me" on 11.1-RELEASE-p10 with GENERIC kernconf
8<
--- alias.c.orig 2017-07-20 16:42:02.000000000 -0700
+++ alias.c 2018-06-13 15:41:46.862121000 -0700
@@ -1758,7 +1758,14 @@
if (m->m_next == NULL && M_WRITABLE(m))
return (m);
- mcl = m_get2(len, M_NOWAIT, MT_DATA, M_PKTHDR);
+ if (len <= MJUMPAGESIZE)
+ mcl = m_get2(len, M_NOWAIT, MT_DATA, M_PKTHDR);
+ else if (len <= MJUM9BYTES)
+ mcl = m_getjcl(M_NOWAIT, MT_DATA, M_PKTHDR, MJUM9BYTES);
+ else if (len <= MJUM16BYTES)
+ mcl = m_getjcl(M_NOWAIT, MT_DATA, M_PKTHDR, MJUM16BYTES);
+ else
+ goto bad;
if (mcl == NULL)
goto bad;
m_align(mcl, len);
>8
Thanks again!
Jeff
_______________________________________________
freebsd-ipfw@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-ipfw
To unsubscribe, send any mail to "freebsd-ipfw-unsubscr...@freebsd.org"
