Date: Fri, 29 Apr 2005 10:51:54 -0700 From: Maksim Yevmenkin <maksim.yevmenkin@savvis.net> To: Sten Spans <sten@blinkenlights.nl> Cc: net@freebsd.org Subject: Re: if_tap unaligned access problem Message-ID: <4272743A.2030003@savvis.net> In-Reply-To: <Pine.SOC.4.61.0504291132520.28551@tea.blinkenlights.nl> References: <20050428135120.GB21428@cell.sick.ru> <427111BF.2050607@savvis.net> <42712BAA.4070201@elischer.org> <42715269.3010306@errno.com> <Pine.SOC.4.61.0504291132520.28551@tea.blinkenlights.nl>
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[...]
>>>> i think we have few options here:
>>>>
>>>> 1) revert back original tapwrite function that was changed in v.
>>>> 1.48 and set offset to 2 bytes in top mbuf
>>>>
>>>> 2) change current version of tapwrite so it would m_prepend and
>>>> m_pullup mbuf after m_uiotombuf
>>>>
>>>> 3) change m_uiotombuf to accept one more parameter - mbuf offset at
>>>> which data should be copied. there are not that many users of
>>>> m_uiotombuf
please find and review the attached patch (untested) that implements
option (3) above.
> I could try to port the changes netbsd made using m_copyup and
> send you the resulting patchfile. IPv4 has already been serviced by
> John-Mark Gurney in perforce.
having these changes in the tree is a good thing, but it will require
more testing. maybe for now we could get away with simpler changes?
thanks,
max
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? sys/net/if_tap.c.altq
? usr.bin/bluetooth/rfcomm_sppd/log
? usr.sbin/bluetooth/bthidd/bthid_switch_keyboard
Index: sys/kern/uipc_mbuf.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/uipc_mbuf.c,v
retrieving revision 1.147
diff -u -r1.147 uipc_mbuf.c
--- sys/kern/uipc_mbuf.c 17 Mar 2005 19:34:57 -0000 1.147
+++ sys/kern/uipc_mbuf.c 29 Apr 2005 17:44:08 -0000
@@ -1333,7 +1333,7 @@
#endif
struct mbuf *
-m_uiotombuf(struct uio *uio, int how, int len)
+m_uiotombuf(struct uio *uio, int how, int len, int align)
{
struct mbuf *m_new = NULL, *m_final = NULL;
int progress = 0, error = 0, length, total;
@@ -1342,12 +1342,15 @@
total = min(uio->uio_resid, len);
else
total = uio->uio_resid;
+ if (align >= MHLEN)
+ goto nospace;
if (total > MHLEN)
m_final = m_getcl(how, MT_DATA, M_PKTHDR);
else
m_final = m_gethdr(how, MT_DATA);
if (m_final == NULL)
goto nospace;
+ m_adj(m_final, align);
m_new = m_final;
while (progress < total) {
length = total - progress;
Index: sys/kern/uipc_syscalls.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/uipc_syscalls.c,v
retrieving revision 1.219
diff -u -r1.219 uipc_syscalls.c
--- sys/kern/uipc_syscalls.c 16 Apr 2005 18:46:28 -0000 1.219
+++ sys/kern/uipc_syscalls.c 29 Apr 2005 17:44:08 -0000
@@ -1796,7 +1796,7 @@
hdr_uio->uio_td = td;
hdr_uio->uio_rw = UIO_WRITE;
if (hdr_uio->uio_resid > 0) {
- m_header = m_uiotombuf(hdr_uio, M_DONTWAIT, 0);
+ m_header = m_uiotombuf(hdr_uio, M_DONTWAIT, 0, 0);
if (m_header == NULL)
goto done;
headersize = m_header->m_pkthdr.len;
Index: sys/net/if_tap.c
===================================================================
RCS file: /home/ncvs/src/sys/net/if_tap.c,v
retrieving revision 1.52
diff -u -r1.52 if_tap.c
--- sys/net/if_tap.c 13 Apr 2005 00:30:19 -0000 1.52
+++ sys/net/if_tap.c 29 Apr 2005 17:44:08 -0000
@@ -827,7 +827,7 @@
return (EIO);
}
- if ((m = m_uiotombuf(uio, M_DONTWAIT, 0)) == NULL) {
+ if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, ETHER_ALIGN)) == NULL) {
ifp->if_ierrors ++;
return (error);
}
Index: sys/net/if_tun.c
===================================================================
RCS file: /home/ncvs/src/sys/net/if_tun.c,v
retrieving revision 1.149
diff -u -r1.149 if_tun.c
--- sys/net/if_tun.c 31 Mar 2005 12:19:44 -0000 1.149
+++ sys/net/if_tun.c 29 Apr 2005 17:44:08 -0000
@@ -761,7 +761,7 @@
return (EIO);
}
- if ((m = m_uiotombuf(uio, M_DONTWAIT, 0)) == NULL) {
+ if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, 0)) == NULL) {
ifp->if_ierrors++;
return (error);
}
Index: sys/netgraph/ng_device.c
===================================================================
RCS file: /home/ncvs/src/sys/netgraph/ng_device.c,v
retrieving revision 1.20
diff -u -r1.20 ng_device.c
--- sys/netgraph/ng_device.c 14 Mar 2005 16:02:53 -0000 1.20
+++ sys/netgraph/ng_device.c 29 Apr 2005 17:44:08 -0000
@@ -466,7 +466,7 @@
if (uio->uio_resid < 0 || uio->uio_resid > IP_MAXPACKET)
return (EIO);
- if ((m = m_uiotombuf(uio, M_DONTWAIT, 0)) == NULL)
+ if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, 0)) == NULL)
return (ENOBUFS);
NG_SEND_DATA_ONLY(error, priv->hook, m);
Index: sys/sys/mbuf.h
===================================================================
RCS file: /home/ncvs/src/sys/sys/mbuf.h,v
retrieving revision 1.169
diff -u -r1.169 mbuf.h
--- sys/sys/mbuf.h 17 Mar 2005 19:34:57 -0000 1.169
+++ sys/sys/mbuf.h 29 Apr 2005 17:44:08 -0000
@@ -582,7 +582,7 @@
struct mbuf *m_pulldown(struct mbuf *, int, int, int *);
struct mbuf *m_pullup(struct mbuf *, int);
struct mbuf *m_split(struct mbuf *, int, int);
-struct mbuf *m_uiotombuf(struct uio *, int, int);
+struct mbuf *m_uiotombuf(struct uio *, int, int, int);
/*-
* Network packets may have annotations attached by affixing a list
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