diff options
| -rw-r--r-- | sys/net/bpf.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/sys/net/bpf.c b/sys/net/bpf.c index 7c00b9c..6f6c9fe 100644 --- a/sys/net/bpf.c +++ b/sys/net/bpf.c @@ -1147,6 +1147,13 @@ bpf_tap(bp, pkt, pktlen) struct bpf_d *d; u_int slen; + /* + * Lockless read to avoid cost of locking the interface if there are + * no descriptors attached. + */ + if (bp->bif_dlist == NULL) + return; + BPFIF_LOCK(bp); for (d = bp->bif_dlist; d != NULL; d = d->bd_next) { BPFD_LOCK(d); @@ -1201,6 +1208,13 @@ bpf_mtap(bp, m) struct bpf_d *d; u_int pktlen, slen; + /* + * Lockless read to avoid cost of locking the interface if there are + * no descriptors attached. + */ + if (bp->bif_dlist == NULL) + return; + pktlen = m_length(m, NULL); if (pktlen == m->m_len) { bpf_tap(bp, mtod(m, u_char *), pktlen); @@ -1240,6 +1254,13 @@ bpf_mtap2(bp, data, dlen, m) struct bpf_d *d; u_int pktlen, slen; + /* + * Lockless read to avoid cost of locking the interface if there are + * no descriptors attached. + */ + if (bp->bif_dlist == NULL) + return; + pktlen = m_length(m, NULL); /* * Craft on-stack mbuf suitable for passing to bpf_filter. |
