svn commit: r187495 - head/sys/netgraph
Alexander Motin
mav at FreeBSD.org
Tue Jan 20 14:26:10 PST 2009
Author: mav
Date: Tue Jan 20 22:26:09 2009
New Revision: 187495
URL: http://svn.freebsd.org/changeset/base/187495
Log:
Check for infinite recursion possible on some broken PPTP/L2TP/... VPN setups.
Mark packets with mbuf_tag on first interface passage and drop on second.
PR: ports/129625, ports/125303,
MFC after: 2 weeks
Modified:
head/sys/netgraph/ng_iface.c
head/sys/netgraph/ng_iface.h
Modified: head/sys/netgraph/ng_iface.c
==============================================================================
--- head/sys/netgraph/ng_iface.c Tue Jan 20 22:17:05 2009 (r187494)
+++ head/sys/netgraph/ng_iface.c Tue Jan 20 22:26:09 2009 (r187495)
@@ -356,6 +356,7 @@ static int
ng_iface_output(struct ifnet *ifp, struct mbuf *m,
struct sockaddr *dst, struct rtentry *rt0)
{
+ struct m_tag *mtag;
uint32_t af;
int error;
@@ -366,6 +367,23 @@ ng_iface_output(struct ifnet *ifp, struc
return (ENETDOWN);
}
+ /* Protect from deadly infinite recursion. */
+ while ((mtag = m_tag_locate(m, MTAG_NGIF, MTAG_NGIF_CALLED, NULL))) {
+ if (*(struct ifnet **)(mtag + 1) == ifp) {
+ log(LOG_NOTICE, "Loop detected on %s\n", ifp->if_xname);
+ m_freem(m);
+ return (EDEADLK);
+ }
+ }
+ mtag = m_tag_alloc(MTAG_NGIF, MTAG_NGIF_CALLED, sizeof(struct ifnet *),
+ M_NOWAIT);
+ if (mtag == NULL) {
+ m_freem(m);
+ return (ENOMEM);
+ }
+ *(struct ifnet **)(mtag + 1) = ifp;
+ m_tag_prepend(m, mtag);
+
/* BPF writes need to be handled specially. */
if (dst->sa_family == AF_UNSPEC) {
bcopy(dst->sa_data, &af, sizeof(af));
Modified: head/sys/netgraph/ng_iface.h
==============================================================================
--- head/sys/netgraph/ng_iface.h Tue Jan 20 22:17:05 2009 (r187494)
+++ head/sys/netgraph/ng_iface.h Tue Jan 20 22:26:09 2009 (r187495)
@@ -72,4 +72,7 @@ enum {
NGM_IFACE_GET_IFINDEX,
};
+#define MTAG_NGIF NGM_IFACE_COOKIE
+#define MTAG_NGIF_CALLED 0 | MTAG_PERSISTENT
+
#endif /* _NETGRAPH_NG_IFACE_H_ */
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