On Fri, Oct 30, 2015 at 02:04:52PM +0100, Reyk Floeter wrote:
> > Socket splicing somove() does the same thing. I will change it to
> > use m_resethdr() after that got commited.
I just compared code in somove() with m_resethdr(). Socket splicing
has to clear the whole packet header, not only the pf part. I think
this is also useful for pair(4) as it should behave like a cable.
Resetting the other m_flags seems wrong. I have put the M_PKTHDR
into an assert. If it is not an packet header, the memset() could
overwrite mbuf data.
ok?
bluhm
Index: kern/uipc_mbuf.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/kern/uipc_mbuf.c,v
retrieving revision 1.209
diff -u -p -r1.209 uipc_mbuf.c
--- kern/uipc_mbuf.c 30 Oct 2015 12:54:36 -0000 1.209
+++ kern/uipc_mbuf.c 30 Oct 2015 17:13:58 -0000
@@ -253,13 +253,17 @@ m_inithdr(struct mbuf *m)
void
m_resethdr(struct mbuf *m)
{
- /* like the previous, but keep any associated data and mbufs */
- m->m_flags = M_PKTHDR;
- memset(&m->m_pkthdr.pf, 0, sizeof(m->m_pkthdr.pf));
- m->m_pkthdr.pf.prio = IFQ_DEFPRIO;
+ int len = m->m_pkthdr.len;
+
+ KASSERT(m->m_flags & M_PKTHDR);
- /* also delete all mbuf tags to reset the state */
+ /* delete all mbuf tags to reset the state */
m_tag_delete_chain(m);
+
+ /* like m_inithdr(), but keep any associated data and mbufs */
+ memset(&m->m_pkthdr, 0, sizeof(m->m_pkthdr));
+ m->m_pkthdr.pf.prio = IFQ_DEFPRIO;
+ m->m_pkthdr.len = len;
}
struct mbuf *
Index: kern/uipc_socket.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/kern/uipc_socket.c,v
retrieving revision 1.142
diff -u -p -r1.142 uipc_socket.c
--- kern/uipc_socket.c 24 Aug 2015 14:28:25 -0000 1.142
+++ kern/uipc_socket.c 30 Oct 2015 17:06:57 -0000
@@ -1325,10 +1325,8 @@ somove(struct socket *so, int wait)
goto release;
m->m_nextpkt = NULL;
if (m->m_flags & M_PKTHDR) {
- m_tag_delete_chain(m);
- memset(&m->m_pkthdr, 0, sizeof(m->m_pkthdr));
+ m_resethdr(m);
m->m_pkthdr.len = len;
- m->m_pkthdr.pf.prio = IFQ_DEFPRIO;
}
/* Send window update to source peer as receive buffer has changed. */
