diff options
| -rw-r--r-- | sys/netgraph/ng_iface.c | 18 | ||||
| -rw-r--r-- | sys/netgraph/ng_iface.h | 3 |
2 files changed, 21 insertions, 0 deletions
diff --git a/sys/netgraph/ng_iface.c b/sys/netgraph/ng_iface.c index 2295004..a22b85a 100644 --- a/sys/netgraph/ng_iface.c +++ b/sys/netgraph/ng_iface.c @@ -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, struct mbuf *m, 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)); diff --git a/sys/netgraph/ng_iface.h b/sys/netgraph/ng_iface.h index 54dfa8c..58fb442 100644 --- a/sys/netgraph/ng_iface.h +++ b/sys/netgraph/ng_iface.h @@ -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_ */ |
