diff options
Diffstat (limited to 'sys/net')
| -rw-r--r-- | sys/net/if_ethersubr.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c index 5a507e3366dd..6893acdb6d00 100644 --- a/sys/net/if_ethersubr.c +++ b/sys/net/if_ethersubr.c @@ -306,7 +306,15 @@ ether_output(struct ifnet *ifp, struct mbuf *m, if (m->m_flags & M_BCAST) { struct mbuf *n; - if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { + /* + * Because if_simloop() modifies the packet, we need a + * writable copy through m_dup() instead of a readonly + * one as m_copy[m] would give us. The alternative would + * be to modify if_simloop() to handle the readonly mbuf, + * but performancewise it is mostly equivalent (trading + * extra data copying vs. extra locking). + */ + if ((n = m_dup(m, M_DONTWAIT)) != NULL) { n->m_pkthdr.csum_flags |= csum_flags; if (csum_flags & CSUM_DATA_VALID) n->m_pkthdr.csum_data = 0xffff; |