From 89bc042679fc34eac731ecfc239e04173c30e1a8 Mon Sep 17 00:00:00 2001 From: Gleb Smirnoff Date: Wed, 7 Oct 2015 13:10:26 +0000 Subject: [PATCH] Fix regression from r287779, that bite me. If we call m_pullup() unconditionally, we end up with an mbuf chain of two mbufs, which later in in_arpreply() is rewritten from ARP request to ARP reply and is sent out. Looks like igb(4) (at least mine, and at least at my network) fails on such mbuf chain, so ARP reply doesn't go out wire. Thus, make the m_pullup() call conditional, as it is everywhere. Of course, the bug in igb(?) should be investigated, but better first fix the head. And unconditional m_pullup() was suboptimal, anyway. --- sys/netinet/if_ether.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c index ad07473f4725..aa616eb39d54 100644 --- a/sys/netinet/if_ether.c +++ b/sys/netinet/if_ether.c @@ -531,12 +531,15 @@ arpintr(struct mbuf *m) ar = mtod(m, struct arphdr *); /* Check if length is sufficient */ - if ((m = m_pullup(m, arphdr_len(ar))) == NULL) { - ARP_LOG(LOG_NOTICE, "short packet received on %s\n", - if_name(ifp)); - return; + if (m->m_len < arphdr_len(ar)) { + m = m_pullup(m, arphdr_len(ar)); + if (m == NULL) { + ARP_LOG(LOG_NOTICE, "short packet received on %s\n", + if_name(ifp)); + return; + } + ar = mtod(m, struct arphdr *); } - ar = mtod(m, struct arphdr *); hlen = 0; layer = "";