code requires it to be 0 when a jumbo payload option is contained.
PR: kern/77934
Submitted by: Gerd Rausch <gerd@juniper.net>
Obtained from: KAME
MFC after: 2 days
hosts to share an IP address, providing high availability and load
balancing.
Original work on CARP done by Michael Shalayeff, with many
additions by Marco Pfatschbacher and Ryan McBride.
FreeBSD port done solely by Max Laier.
Patch by: mlaier
Obtained from: OpenBSD (mickey, mcbride)
Approved by: Robert Watson <rwatson@freebsd.org>
Add locking to the IPv6 scoping code.
All spl() like calls have also been removed.
Cleaning up the handling of ifnet data will happen at a later date.
(sorele()/sotryfree()):
- This permits the caller to acquire the accept mutex before the socket
mutex, avoiding sofree() having to drop the socket mutex and re-order,
which could lead to races permitting more than one thread to enter
sofree() after a socket is ready to be free'd.
- This also covers clearing of the so_pcb weak socket reference from
the protocol to the socket, preventing races in clearing and
evaluation of the reference such that sofree() might be called more
than once on the same socket.
This appears to close a race I was able to easily trigger by repeatedly
opening and resetting TCP connections to a host, in which the
tcp_close() code called as a result of the RST raced with the close()
of the accepted socket in the user process resulting in simultaneous
attempts to de-allocate the same socket. The new locking increases
the overhead for operations that may potentially free the socket, so we
will want to revise the synchronization strategy here as we normalize
the reference counting model for sockets. The use of the accept mutex
in freeing of sockets that are not listen sockets is primarily
motivated by the potential need to remove the socket from the
incomplete connection queue on its parent (listen) socket, so cleaning
up the reference model here may allow us to substantially weaken the
synchronization requirements.
RELENG_5_3 candidate.
MFC after: 3 days
Reviewed by: dwhite
Discussed with: gnn, dwhite, green
Reported by: Marc UBM Bocklet <ubm at u-boot-man dot de>
Reported by: Vlad <marchenko at gmail dot com>
Discussed extensively with KAME. The API author's intent isn't clear at this
point, so rather than remove the code entirely, #if 0 out and put a big
comment in for now. The IPV6_RECVPATHMTU sockopt is available if the
application wants to be notified of the path MTU to optimize packet sizes.
Thanks to JINMEI Tatuya <jinmei@isl.rdc.toshiba.co.jp> for putting up
with my incessant badgering on this issue, and fenner for pointing out
the API issue and suggesting solutions.
passing along socket information. This is required to work around a LOR with
the socket code which results in an easy reproducible hard lockup with
debug.mpsafenet=1. This commit does *not* fix the LOR, but enables us to do
so later. The missing piece is to turn the filter locking into a leaf lock
and will follow in a seperate (later) commit.
This will hopefully be MT5'ed in order to fix the problem for RELENG_5 in
forseeable future.
Suggested by: rwatson
A lot of work by: csjp (he'd be even more helpful w/o mentor-reviews ;)
Reviewed by: rwatson, csjp
Tested by: -pf, -ipfw, LINT, csjp and myself
MFC after: 3 days
LOR IDs: 14 - 17 (not fixed yet)
the flags field will be improperly initialized resulting in inconsistent
operation (sometimes with Giant, sometimes without, et al).
RELENG_5 candidate.
operation using NET_NEEDS_GIANT(). This will result in a boot-time
restoration of Giant-enabled network operation, or run-time warning on
dynamic load (applicable only to the Netgraph component). Additional
components will likely need to be marked with this in the future.
its users.
netisr_queue() now returns (0) on success and ERRNO on failure. At the
moment ENXIO (netisr queue not functional) and ENOBUFS (netisr queue full)
are supported.
Previously it would return (1) on success but the return value of IF_HANDOFF()
was interpreted wrongly and (0) was actually returned on success. Due to this
schednetisr() was never called to kick the scheduling of the isr. However this
was masked by other normal packets coming through netisr_dispatch() causing the
dequeueing of waiting packets.
PR: kern/70988
Found by: MOROHOSHI Akihiko <moro@remus.dti.ne.jp>
MFC after: 3 days
compile option. All FreeBSD packet filters now use the PFIL_HOOKS API and
thus it becomes a standard part of the network stack.
If no hooks are connected the entire packet filter hooks section and related
activities are jumped over. This removes any performance impact if no hooks
are active.
Both OpenBSD and DragonFlyBSD have integrated PFIL_HOOKS permanently as well.
The prefix management code currently resides in nd6, leaving only the
unused router renumbering capability in the in6_prefix files. Removing
it will make it easier for us to provide locking for the remainder of
IPv6 by reducing the number of objects requiring synchronized access.
This functionality has also been removed from NetBSD and OpenBSD.
Submitted by: George Neville-Neil <gnn at neville-neil.com>
Discussed with/approved by: suz, keiichi at kame.net, core at kame.net
result of the notify() function to decide if we need to unlock the
in6pcb or not, rather than always unlocking. Otherwise, we may unlock
and already unlocked in6pcb.
Reported by: kuriyama, Gordon Bergling <gbergling at 0xfce3.net>
Tested by: kuriyama, Gordon Bergling <gbergling at 0xfce3.net>
Discussed with: mdodd
have already done this, so I have styled the patch on their work:
1) introduce a ip_newid() static inline function that checks
the sysctl and then decides if it should return a sequential
or random IP ID.
2) named the sysctl net.inet.ip.random_id
3) IPv6 flow IDs and fragment IDs are now always random.
Flow IDs and frag IDs are significantly less common in the
IPv6 world (ie. rarely generated per-packet), so there should
be smaller performance concerns.
The sysctl defaults to 0 (sequential IP IDs).
Reviewed by: andre, silby, mlaier, ume
Based on: NetBSD
MFC after: 2 months
structures, allowing in6_pcbnotify() to lock the pcbinfo and each
inpcb that it notifies of ICMPv6 events. This prevents inpcb
assertions from firing when IPv6 generates and delievers event
notifications for inpcbs.
Reported by: kuriyama
Tested by: kuriyama
Alice is too lazy to write a server application in PF-independent
manner. Therefore she knocks up the server using PF_INET6 only
and allows the IPv6 socket to accept mapped IPv4 as well. An evil
hacker known on IRC as cheshire_cat has an account in the same
system. He starts a process listening on the same port as used
by Alice's server, but in PF_INET. As a consequence, cheshire_cat
will distract all IPv4 traffic supposed to go to Alice's server.
Such sort of port theft was initially enabled by copying the code that
implemented the RFC 2553 semantics on IPv4/6 sockets (see inet6(4)) for
the implied case of the same owner for both connections. After this
change, the above scenario will be impossible. In the same setting,
the user who attempts to start his server last will get EADDRINUSE.
Of course, using IPv4 mapped to IPv6 leads to security complications
in the first place, but there is no reason to make it even more unsafe.
This change doesn't apply to KAME since it affects a FreeBSD-specific
part of the code. It doesn't modify the out-of-box behaviour of the
TCP/IP stack either as long as mapping IPv4 to IPv6 is off by default.
MFC after: 1 month
synchronizing IPv6 protocol control blocks and lists. These changes
are modeled on the inpcb locking for IPv4, submitted by Jennifer Yang,
and committed by Jeffrey Hsu. With these locking changes, IPv6 use of
inpcbs is now substantially more MPSAFE, and permits IPv4 inpcb locking
assertions to be run in the presence of IPv6 compiled into the kernel.
(i.e. with the foreign address being not wildcard) when checking
for possible port theft since such connections cannot be stolen.
The port theft check is FreeBSD-specific and isn't in the KAME tree.
PR: bin/65928 (in the audit trail)
Reviewed by: -net, -hackers (silence)
Tested by: Nick Leuta <skynick at mail.sc.ru>
MFC after: 1 month
somewhat clearer, but more importantly allows for a consistent naming
scheme for suser_cred flags.
The old name is still defined, but will be removed in a few days (unless I
hear any complaints...)
Discussed with: rwatson, scottl
Requested by: jhb
for unknown events.
A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".
your (network) modules as well as any userland that might make sense of
sizeof(struct ifnet).
This does not change the queueing yet. These changes will follow in a
seperate commit. Same with the driver changes, which need case by case
evaluation.
__FreeBSD_version bump will follow.
Tested-by: (i386)LINT
before calling sotryfree().
-- Body of earlier bulk commit this belonged with --
Log:
Extend coverage of SOCK_LOCK(so) to include so_count, the socket
reference count:
- Assert SOCK_LOCK(so) macros that directly manipulate so_count:
soref(), sorele().
- Assert SOCK_LOCK(so) in macros/functions that rely on the state of
so_count: sofree(), sotryfree().
- Acquire SOCK_LOCK(so) before calling these functions or macros in
various contexts in the stack, both at the socket and protocol
layers.
- In some cases, perform soisdisconnected() before sotryfree(), as
this could result in frobbing of a non-present socket if
sotryfree() actually frees the socket.
- Note that sofree()/sotryfree() will release the socket lock even if
they don't free the socket.
Submitted by: sam
Sponsored by: FreeBSD Foundation
Obtained from: BSD/OS
Wind River. In the IPv4 output path, one of the tests in ip_output()
checks how many slots are actually available in the interface output
queue before attempting to send a packet. If, for example, we need
to transmit a packet of 32K bytes over an interface with an MTU of
1500, we know it's going to take about 21 fragments to do it. If
there's less than 21 slots left in the output queue, there's no point
in transmitting anything at all: IP does not do retransmission, so
sending only some of the fragments would just be a waste of bandwidth.
(In an extreme case, if you're sending a heavy stream of fragmented
packets, you might find yourself sending nothing by the first fragment
of all your packets.) So if ip_output() notices there's not enough
room in the output queue to send the frame, it just dumps the packet
and returns ENOBUFS to the app.
It turns out ip6_output() lacks this code. Consequently, this caused
the netperf UDPIPV6_STREAM test to produce very poor results with large
write sizes. This commit adds code to check the remaining space in the
output queue and junk fragmented packets if they're too big to be
sent, just like with IPv4. (I can't imagine anyone's running an NFS
server using UDP over IPv6, but if they are, this will likely make them
a lot happier. :)
1. rt_check() cleanup:
rt_check() is only necessary for some address families to gain access
to the corresponding arp entry, so call it only in/near the *resolve()
routines where it is actually used -- at the moment this is
arpresolve(), nd6_storelladdr() (the call is embedded here),
and atmresolve() (the call is just before atmresolve to reduce
the number of changes).
This change will make it a lot easier to decouple the arp table
from the routing table.
There is an extra call to rt_check() in if_iso88025subr.c to
determine the routing info length. I have left it alone for
the time being.
The interface of arpresolve() and nd6_storelladdr() now changes slightly:
+ the 'rtentry' parameter (really a hint from the upper level layer)
is now passed unchanged from *_output(), so it becomes the route
to the final destination and not to the gateway.
+ the routines will return 0 if resolution is possible, non-zero
otherwise.
+ arpresolve() returns EWOULDBLOCK in case the mbuf is being held
waiting for an arp reply -- in this case the error code is masked
in the caller so the upper layer protocol will not see a failure.
2. arpcom untangling
Where possible, use 'struct ifnet' instead of 'struct arpcom' variables,
and use the IFP2AC macro to access arpcom fields.
This mostly affects the netatalk code.
=== Detailed changes: ===
net/if_arcsubr.c
rt_check() cleanup, remove a useless variable
net/if_atmsubr.c
rt_check() cleanup
net/if_ethersubr.c
rt_check() cleanup, arpcom untangling
net/if_fddisubr.c
rt_check() cleanup, arpcom untangling
net/if_iso88025subr.c
rt_check() cleanup
netatalk/aarp.c
arpcom untangling, remove a block of duplicated code
netatalk/at_extern.h
arpcom untangling
netinet/if_ether.c
rt_check() cleanup (change arpresolve)
netinet6/nd6.c
rt_check() cleanup (change nd6_storelladdr)
a static const global variable in ah_core.c. This makes it more clear
that this array does not require synchronization, as well as
synchronizing the layout to the ESP algorithm list. This is the
version of my patch that Itojun committed to the KAME tree.
Obtained from: me, via KAME
This enables pf to track dynamic address changes on interfaces (dailup) with
the "on (<ifname>)"-syntax. This also brings hooks in anticipation of
tracking cloned interfaces, which will be in future versions of pf.
Approved by: bms(mentor)
pf/pflog/pfsync as modules. Do not list them in NOTES or modules/Makefile
(i.e. do not connect it to any (automatic) builds - yet).
Approved by: bms(mentor)
address, even if we subsequently ignore its value by applying a >>8
to it.
Reported by: "Ted Unangst" <tedu@coverity.com>
Approved by: rwatson (mentor), {ume, suz} (KAME)
mode is applied, since tunneled packets are considered to be
generated packets from a tunnel encapsulating node.
- tunnel mode may not be applied if SA mode is ANY and policy
does not say "tunnel it". check if we have extra IPv6 header
on the packet after ipsec6_output_tunnel() and call ip6_output()
only if additional IPv6 header is added.
- free the copyed packet before returning.
Obtained from: KAME
- rejects IPv6 packet toward IPv4-mapped address if its source address
is not an IPv4-mapped IPv6 address, since the converted IPv4 packets
would have an unexpected IPv4 source address.
- when V6ONLY socket option is set, discard packets destined to a
v4/ipv4 mapped ipv6 address.
- have PULLDOWN_TEST codepath.
- get rid of in6_mcmatch().
Obtained from: KAME
This is the first of two commits; bringing in the kernel support first.
This can be enabled by compiling a kernel with options TCP_SIGNATURE
and FAST_IPSEC.
For the uninitiated, this is a TCP option which provides for a means of
authenticating TCP sessions which came into being before IPSEC. It is
still relevant today, however, as it is used by many commercial router
vendors, particularly with BGP, and as such has become a requirement for
interconnect at many major Internet points of presence.
Several parts of the TCP and IP headers, including the segment payload,
are digested with MD5, including a shared secret. The PF_KEY interface
is used to manage the secrets using security associations in the SADB.
There is a limitation here in that as there is no way to map a TCP flow
per-port back to an SPI without polluting tcpcb or using the SPD; the
code to do the latter is unstable at this time. Therefore this code only
supports per-host keying granularity.
Whilst FAST_IPSEC is mutually exclusive with KAME IPSEC (and thus IPv6),
TCP_SIGNATURE applies only to IPv4. For the vast majority of prospective
users of this feature, this will not pose any problem.
This implementation is output-only; that is, the option is honoured when
responding to a host initiating a TCP session, but no effort is made
[yet] to authenticate inbound traffic. This is, however, sufficient to
interwork with Cisco equipment.
Tested with a Cisco 2501 running IOS 12.0(27), and Quagga 0.96.4 with
local patches. Patches for tcpdump to validate TCP-MD5 sessions are also
available from me upon request.
Sponsored by: sentex.net
allnodes multicast route if the routing table has not been initialized.
This avoids a panic during boot if an interface detaches before the
routing table is initialized.
Submitted by: sam
add one if the SYN flag was set in the original packet. This seems to make
ip6fw reset work correctly for new and in-progress connections. Update
the man page to reflect the fact it now seems to work.
Glanced at by: ume
MFC after: 2 weeks
(not interface addresses) to see if a given address is on-link.
- skip offlink prefixes in neighbor determination in nd6_is_addr_neighbor.
- in nd6_is_addr_neighbor, regarded every address as on-link when the
default router list is empty. otherwise, we'd not be able make a neighbor
cache for the address.
this algorithm is applied to hosts only.
- in nd6_is_addr_neighbor, check if the default interface is equal to
the interface in question in addition to check if the default router
list is empty.
Obtained from: KAME
the routing table. Move all usage and references in the tcp stack
from the routing table metrics to the tcp hostcache.
It caches measured parameters of past tcp sessions to provide better
initial start values for following connections from or to the same
source or destination. Depending on the network parameters to/from
the remote host this can lead to significant speedups for new tcp
connections after the first one because they inherit and shortcut
the learning curve.
tcp_hostcache is designed for multiple concurrent access in SMP
environments with high contention and is hash indexed by remote
ip address.
It removes significant locking requirements from the tcp stack with
regard to the routing table.
Reviewed by: sam (mentor), bms
Reviewed by: -net, -current, core@kame.net (IPv6 parts)
Approved by: re (scottl)
the routing table. Move all usage and references in the tcp stack
from the routing table metrics to the tcp hostcache.
It caches measured parameters of past tcp sessions to provide better
initial start values for following connections from or to the same
source or destination. Depending on the network parameters to/from
the remote host this can lead to significant speedups for new tcp
connections after the first one because they inherit and shortcut
the learning curve.
tcp_hostcache is designed for multiple concurrent access in SMP
environments with high contention and is hash indexed by remote
ip address.
It removes significant locking requirements from the tcp stack with
regard to the routing table.
Reviewed by: sam (mentor), bms
Reviewed by: -net, -current, core@kame.net (IPv6 parts)
Approved by: re (scottl)
accordingly. The define is left intact for ABI compatibility
with userland.
This is a pre-step for the introduction of tcp_hostcache. The
network stack remains fully useable with this change.
Reviewed by: sam (mentor), bms
Reviewed by: -net, -current, core@kame.net (IPv6 parts)
Approved by: re (scottl)
the MAC label referenced from 'struct socket' in the IPv4 and
IPv6-based protocols. This permits MAC labels to be checked during
network delivery operations without dereferencing inp->inp_socket
to get to so->so_label, which will eventually avoid our having to
grab the socket lock during delivery at the network layer.
This change introduces 'struct inpcb' as a labeled object to the
MAC Framework, along with the normal circus of entry points:
initialization, creation from socket, destruction, as well as a
delivery access control check.
For most policies, the inpcb label will simply be a cache of the
socket label, so a new protocol switch method is introduced,
pr_sosetlabel() to notify protocols that the socket layer label
has been updated so that the cache can be updated while holding
appropriate locks. Most protocols implement this using
pru_sosetlabel_null(), but IPv4/IPv6 protocols using inpcbs use
the the worker function in_pcbsosetlabel(), which calls into the
MAC Framework to perform a cache update.
Biba, LOMAC, and MLS implement these entry points, as do the stub
policy, and test policy.
Reviewed by: sam, bms
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
whether or not the isr needs to hold Giant when running; Giant-less
operation is also controlled by the setting of debug_mpsafenet
o mark all netisr's except NETISR_IP as needing Giant
o add a GIANT_REQUIRED assertion to the top of netisr's that need Giant
o pickup Giant (when debug_mpsafenet is 1) inside ip_input before
calling up with a packet
o change netisr handling so swi_net runs w/o Giant; instead we grab
Giant before invoking handlers based on whether the handler needs Giant
o change netisr handling so that netisr's that are marked MPSAFE may
have multiple instances active at a time
o add netisr statistics for packets dropped because the isr is inactive
Supported by: FreeBSD Foundation
that it was obsoleted. it is better to fail than just hiding use
of ipsec_gethist() at build.
Sugessted by: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>
- share policy-on-socket for listening socket.
- don't copy policy-on-socket at all. secpolicy no longer contain
spidx, which saves a lot of memory.
- deep-copy pcb policy if it is an ipsec policy. assign ID field to
all SPD entries. make it possible for racoon to grab SPD entry on
pcb.
- fixed the order of searching SA table for packets.
- fixed to get a security association header. a mode is always needed
to compare them.
- fixed that the incorrect time was set to
sadb_comb_{hard|soft}_usetime.
- disallow port spec for tunnel mode policy (as we don't reassemble).
- an user can define a policy-id.
- clear enc/auth key before freeing.
- fixed that the kernel crashed when key_spdacquire() was called
because key_spdacquire() had been implemented imcopletely.
- preparation for 64bit sequence number.
- maintain ordered list of SA, based on SA id.
- cleanup secasvar management; refcnt is key.c responsibility;
alloc/free is keydb.c responsibility.
- cleanup, avoid double-loop.
- use hash for spi-based lookup.
- mark persistent SP "persistent".
XXX in theory refcnt should do the right thing, however, we have
"spdflush" which would touch all SPs. another solution would be to
de-register persistent SPs from sptree.
- u_short -> u_int16_t
- reduce kernel stack usage by auto variable secasindex.
- clarify function name confusion. ipsec_*_policy ->
ipsec_*_pcbpolicy.
- avoid variable name confusion.
(struct inpcbpolicy *)pcb_sp, spp (struct secpolicy **), sp (struct
secpolicy *)
- count number of ipsec encapsulations on ipsec4_output, so that we
can tell ip_output() how to handle the packet further.
- When the value of the ul_proto is ICMP or ICMPV6, the port field in
"src" of the spidx specifies ICMP type, and the port field in "dst"
of the spidx specifies ICMP code.
- avoid from applying IPsec transport mode to the packets when the
kernel forwards the packets.
Tested by: nork
Obtained from: KAME
if_xname, if_dname, and if_dunit. if_xname is the name of the interface
and if_dname/unit are the driver name and instance.
This change paves the way for interface renaming and enhanced pseudo
device creation and configuration symantics.
Approved By: re (in principle)
Reviewed By: njl, imp
Tested On: i386, amd64, sparc64
Obtained From: NetBSD (if_xname)
mbuf cluster, copy the data to a separate mbuf that do not use a
cluster. this change will reduce the possiblity of packet loss
in the socket layer.
Obtained from: KAME
routine that takes a locked routing table reference and removes all
references to the entry in the various data structures. This
eliminates instances of recursive locking and also closes races
where the lock on the entry had to be dropped prior to calling
rtrequest(RTM_DELETE). This also cleans up confusion where the
caller held a reference to an entry that might have been reclaimed
(and in some cases used that reference).
Supported by: FreeBSD Foundation
- implement the tunnel egress rule in ip_ecn_egress() in ip_ecn.c.
make ip{,6}_ecn_egress() return integer to tell the caller that
this packet should be dropped.
- handle ECN at fragment reassembly in ip_input.c and frag6.c.
Obtained from: KAME
(aka RFC2292bis). Though I believe this commit doesn't break
backward compatibility againt existing binaries, it breaks
backward compatibility of API.
Now, the applications which use Advanced Sockets API such as
telnet, ping6, mld6query and traceroute6 use RFC3542 API.
Obtained from: KAME
address has been changed when PFIL_HOOKS is enabled and, if it has,
arrange for the proper action by ip*_forward.
Submitted by: Pyun YongHyeon
Supported by: FreeBSD Foundation
- correct signedness mixups.
- log fix.
- preparation for 64bit sequence number.
introduce SA id (unique ID for SA - SPI is useless as duplicated
SPI is allowed)
- no need to malloc/free cksum buffer.
Obtained from: KAME
that covers updates to the contents. Note this is separate from holding
a reference and/or locking the routing table itself.
Other/related changes:
o rtredirect loses the final parameter by which an rtentry reference
may be returned; this was never used and added unwarranted complexity
for locking.
o minor style cleanups to routing code (e.g. ansi-fy function decls)
o remove the logic to bump the refcnt on the parent of cloned routes,
we assume the parent will remain as long as the clone; doing this avoids
a circularity in locking during delete
o convert some timeouts to MPSAFE callouts
Notes:
1. rt_mtx in struct rtentry is guarded by #ifdef _KERNEL as user-level
applications cannot/do-no know about mutex's. Doing this requires
that the mutex be the last element in the structure. A better solution
is to introduce an externalized version of struct rtentry but this is
a major task because of the intertwining of rtentry and other data
structures that are visible to user applications.
2. There are known LOR's that are expected to go away with forthcoming
work to eliminate many held references. If not these will be resolved
prior to release.
3. ATM changes are untested.
Sponsored by: FreeBSD Foundation
Obtained from: BSD/OS (partly)
then the mbuf has been consumed by a hook; otherwise beware of a null
mbuf return (gack). In particular the bridge was doing the wrong thing.
While in the ipv6 code make it's handling of pfil_run_hooks identical
to netbsd.
Pointed out by: Pyun YongHyeon <yongari@kt-is.co.kr>
o revamp IPv4+IPv6+bridge usage to match API changes
o remove pfil_head instances from protosw entries (no longer used)
o add locking
o bump FreeBSD version for 3rd party modules
Heavy lifting by: "Max Laier" <max@love2party.net>
Supported by: FreeBSD Foundation
Obtained from: NetBSD (bits of pfil.h and pfil.c)
in6_pcbpurgeif0(LIST_FIRST(udbinfo.listhead), ifp);
in6_pcbpurgeif0(LIST_FIRST(ripcbinfo.listhead), ifp);
The problem here is that udbinfo.listhead and ripcbinfo.listhead are
not initialized during the device probe/attach phase of the kernel
boot process. So if, for example, a network driver calls ether_ifattach()
in its foo_attach() routine and then decides that something is wrong
and calls ether_ifdetach() to reverse the process, we will panic trying
to dereference the uninitialized list head pointers. (Though the
same sequence of events performed after the kernel has come up works
file, i.e. doing kldload if_foo from multiuser.)
Change this to:
if (udbinfo.listhead != NULL)
in6_pcbpurgeif0(LIST_FIRST(udbinfo.listhead), ifp);
if (ripcbinfo.listhead != NULL)
in6_pcbpurgeif0(LIST_FIRST(ripcbinfo.listhead), ifp);
to avoid the NULL pointer dereferences.
