diff options
| -rw-r--r-- | sys/net/bpf.c | 63 | ||||
| -rw-r--r-- | sys/net/bpf.h | 2 |
2 files changed, 65 insertions, 0 deletions
diff --git a/sys/net/bpf.c b/sys/net/bpf.c index 466227c..9d562e4 100644 --- a/sys/net/bpf.c +++ b/sys/net/bpf.c @@ -477,6 +477,18 @@ bpfread(dev, uio, ioflag) ROTATE_BUFFERS(d); break; } + + /* + * No data is available, check to see if the bpf device + * is still pointed at a real interface. If not, return + * ENXIO so that the userland process knows to rebind + * it before using it again. + */ + if (d->bd_bif == NULL) { + splx(s); + return (ENXIO); + } + if (ioflag & IO_NDELAY) error = EWOULDBLOCK; else @@ -1035,6 +1047,9 @@ bpfpoll(dev, events, p) */ d = dev->si_drv1; + if (d->bd_bif == NULL) + return (ENXIO); + s = splimp(); if (events & (POLLIN | POLLRDNORM)) { if (d->bd_hlen != 0 || (d->bd_immediate && d->bd_slen != 0)) @@ -1287,6 +1302,54 @@ bpfattach(ifp, dlt, hdrlen) printf("bpf: %s%d attached\n", ifp->if_name, ifp->if_unit); } +/* + * Detach bpf from an interface. This involves detaching each descriptor + * associated with the interface, and leaving bd_bif NULL. Notify each + * descriptor as it's detached so that any sleepers wake up and get + * ENXIO. + */ +void +bpfdetach(ifp) + struct ifnet *ifp; +{ + struct bpf_if *bp, *bp_prev; + struct bpf_d *d; + int s; + + s = splimp(); + + /* Locate BPF interface information */ + bp_prev = NULL; + for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { + if (ifp == bp->bif_ifp) + break; + bp_prev = bp; + } + + /* Interface wasn't attached */ + if (bp->bif_ifp == NULL) { + splx(s); + printf("bpfdetach: %s%d was not attached\n", ifp->if_name, + ifp->if_unit); + return; + } + + while ((d = bp->bif_dlist) != NULL) { + bpf_detachd(d); + bpf_wakeup(d); + } + + if (bp_prev) { + bp_prev->bif_next = bp->bif_next; + } else { + bpf_iflist = bp->bif_next; + } + + free(bp, M_BPF); + + splx(s); +} + static void bpf_drvinit __P((void *unused)); static void diff --git a/sys/net/bpf.h b/sys/net/bpf.h index 9494e83..a173b0a 100644 --- a/sys/net/bpf.h +++ b/sys/net/bpf.h @@ -232,6 +232,8 @@ int bpf_validate __P((const struct bpf_insn *, int)); void bpf_tap __P((struct ifnet *, u_char *, u_int)); void bpf_mtap __P((struct ifnet *, struct mbuf *)); void bpfattach __P((struct ifnet *, u_int, u_int)); +void bpfdetach __P((struct ifnet *)); + void bpfilterattach __P((int)); u_int bpf_filter __P((const struct bpf_insn *, u_char *, u_int, u_int)); #endif |
