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authorBrad Smith <brad@cvs.openbsd.org>2006-03-17 04:21:58 +0000
committerBrad Smith <brad@cvs.openbsd.org>2006-03-17 04:21:58 +0000
commit45ae4194cfa278c1ec75c7bf097027ff73912310 (patch)
treec59a7de53cb85641c2e5c608839486bf01250b37 /sys/kern/uipc_mbuf.c
parentd766c542969ad80916e41a5110f08ba122d811c0 (diff)
rev 1.77
m_cat() - if it is safe, copy data portion into 1st mbuf even if 1st mbuf is M_EXT mbuf. rev 1.72 clarify comment on m_cat(). From itojun NetBSD ok claudio@ mcbride@
Diffstat (limited to 'sys/kern/uipc_mbuf.c')
-rw-r--r--sys/kern/uipc_mbuf.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c
index de19ca5cf4a..35a1f693213 100644
--- a/sys/kern/uipc_mbuf.c
+++ b/sys/kern/uipc_mbuf.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: uipc_mbuf.c,v 1.73 2006/03/05 00:44:25 brad Exp $ */
+/* $OpenBSD: uipc_mbuf.c,v 1.74 2006/03/17 04:21:57 brad Exp $ */
/* $NetBSD: uipc_mbuf.c,v 1.15.4.1 1996/06/13 17:11:44 cgd Exp $ */
/*
@@ -433,7 +433,9 @@ out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen))
/*
* Concatenate mbuf chain n to m.
- * Both chains must be of the same type (e.g. MT_DATA).
+ * n might be copied into m (when n->m_len is small), therefore data portion of
+ * n could be copied into an mbuf of different mbuf type.
+ * Therefore both chains should be of the same type (e.g. MT_DATA).
* Any m_pkthdr is not updated.
*/
void
@@ -442,8 +444,7 @@ m_cat(struct mbuf *m, struct mbuf *n)
while (m->m_next)
m = m->m_next;
while (n) {
- if (m->m_flags & M_EXT ||
- m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) {
+ if (M_READONLY(m) || n->m_len > M_TRAILINGSPACE(m)) {
/* just join the two chains */
m->m_next = n;
return;