possible for a panic to occur if BPF is in use on the interface at the
time of the call to if_detach. This happens because BPF maintains pointers
to the struct ifnet describing the interface, which is freed by if_detach.
To correct this problem, a new call, bpfdetach, is introduced. bpfdetach
locates BPF descriptor references to the interface, and NULLs them. Other
BPF code is modified so that discovery of a NULL interface results in
ENXIO (already implemented for some calls). Processes blocked on a BPF
call will also be woken up so that they can receive ENXIO.
Interface drivers that invoke bpfattach and if_detach must be modified to
also call bpfattach(ifp) before calling if_detach(ifp). This is relevant
for buses that support hot removal, such as pccard and usb. Patches to
all effected devices will not be committed, only to if_wi.c, due to
testing limitations. To reproduce the crash, load up tcpdump on you
favorite pccard ethernet card, and then eject the card. As some pccard
drivers do not invoke if_detach(ifp), this bug will not manifest itself
for those drivers.
Reviewed by: wes
not the current BPF device should report locally generated packets or not.
This allows sniffing applications to see only packets that are not generated
locally, which can be useful for debugging bridging problems, or other
situations where MAC addresses are not sufficient to identify locally
sourced packets. Default to true for this flag, so as to provide existing
behavior by default.
Introduce two new ioctls, BIOCGSEESENT and BIOCSSEESENT, which may be used
to manipulate this flag from userland, given appropriate privilege.
Modify bpf.4 to document these two new ioctl arguments.
Reviewed by: asmodai
|for high speed networks (even at 100Mbit/s this corresponds to 1/300th
|of a second). The default buffer size is 4KB, but libpcap and ipfilter
|both override this (using the BIOCSBLEN ioctl) and allocate 32KB.
|
|The following patch adds an sysctl for bpf_maxbufsize, similar to the
|one for bpf_bufsize that you added back in December 1995. I choose to
|make the default for this limit 512KB (the value suggested by NFR).
Submitted by: se
Reviewed by: phk
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot). This is consistant with the other
BSD's who made this change quite some time ago. More commits to come.
completion' flag. If set, the interface output routine will assume that
the packet already has a valid link-level source address. This defaults
to off (the address is overwritten)
PR: kern/10680
Submitted by: "Christopher N . Harrell" <cnh@mindspring.net>
Obtained from: NetBSD
sizeof(struct bpf_hdr) > 20. 20 is normal on 32-bit systems with
32-bit alignment, but we still assume that the last 2 bytes of the
struct are unnecessary padding on such systems. On systems with
64-bit longs, struct timeval is bloated to 16 bytes, so bpf headers
certainly don't fit in 18 bytes.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
- fill in and use ifp->if_softc
- use if_bpf rather than private cookie variables
- change bpf interface to take advantage of this
- call ether_ifattach() directly from Ethernet drivers
- delete kludge in if_attach() that did this indirectly
to <machine/conf.h>. conf.h was mechanically generated by
`grep ^d_ conf.c >conf.h'. This accounts for part of its ugliness. The
prototypes should be moved back to the driver sources when the functions
are staticalized.
