will intialize the the header length and re-initialize the mbuf pointer
to reference the mbuf that is allocated after moving user supplied packet
data in.
ioctl routines if we are running with !mpsafenet
- Change un-conditional Giant acquisition around ifpromisc
to occur only if we are running with !mpsafenet
With these locking bits in place, we can now remove the Giant
requirement from BPF, so drop the D_NEEDGIANT device flag.
This change removes Giant acquisitions around BPF device
handlers (read, write, ioctl etc).
MFC after: 1 month
Discussed with: rwatson
bridged, previously legitimate traffic was not passed as the bridge could not
tell that it was on a different Ethernet segment.
All non-tagged traffic is treated as vlan1 as per IEEE 802.1Q-2003
tunnels, and was not MPSAFE. The code can be easily restored in the
event that someone with an IPX over IP tunnel configuration can work
with me to test patches.
This removes one of five remaining consumers of NET_NEEDS_GIANT.
Approved by: re (kensmith)
o major overhaul of the way channels are handled: channels are now
fully enumerated and uniquely identify the operating characteristics;
these changes are visible to user applications which require changes
o make scanning support independent of the state machine to enable
background scanning and roaming
o move scanning support into loadable modules based on the operating
mode to enable different policies and reduce the memory footprint
on systems w/ constrained resources
o add background scanning in station mode (no support for adhoc/ibss
mode yet)
o significantly speedup sta mode scanning with a variety of techniques
o add roaming support when background scanning is supported; for now
we use a simple algorithm to trigger a roam: we threshold the rssi
and tx rate, if either drops too low we try to roam to a new ap
o add tx fragmentation support
o add first cut at 802.11n support: this code works with forthcoming
drivers but is incomplete; it's included now to establish a baseline
for other drivers to be developed and for user applications
o adjust max_linkhdr et. al. to reflect 802.11 requirements; this eliminates
prepending mbufs for traffic generated locally
o add support for Atheros protocol extensions; mainly the fast frames
encapsulation (note this can be used with any card that can tx+rx
large frames correctly)
o add sta support for ap's that beacon both WPA1+2 support
o change all data types from bsd-style to posix-style
o propagate noise floor data from drivers to net80211 and on to user apps
o correct various issues in the sta mode state machine related to handling
authentication and association failures
o enable the addition of sta mode power save support for drivers that need
net80211 support (not in this commit)
o remove old WI compatibility ioctls (wicontrol is officially dead)
o change the data structures returned for get sta info and get scan
results so future additions will not break user apps
o fixed tx rate is now maintained internally as an ieee rate and not an
index into the rate set; this needs to be extended to deal with
multi-mode operation
o add extended channel specifications to radiotap to enable 11n sniffing
Drivers:
o ath: add support for bg scanning, tx fragmentation, fast frames,
dynamic turbo (lightly tested), 11n (sniffing only and needs
new hal)
o awi: compile tested only
o ndis: lightly tested
o ipw: lightly tested
o iwi: add support for bg scanning (well tested but may have some
rough edges)
o ral, ural, rum: add suppoort for bg scanning, calibrate rssi data
o wi: lightly tested
This work is based on contributions by Atheros, kmacy, sephe, thompsa,
mlaier, kevlo, and others. Much of the scanning work was supported by
Atheros. The 11n work was supported by Marvell.
the value of ph_nhooks to zero, not the address. This removes
extranious calls to pfil_run_hooks (and an rw lock) from the
network stack's critical path when no pfil hooks are active.
Reviewed by: csjp
Sponsored by: Myricom Inc.
which support a 2.5Gbps mode over fiber using next page extensions during
autonegotiation. Typically only found in blade systems which also include
a Broadcom 2.5Gbps capable switch.
MFC after: 2 weeks
as to the type of the command argument: int -> u_long.
These types have different widths in the 64-bit world.
Add a note to UPDATING because the change breaks KBI
on 64-bit platforms.
Discussed on: -net, -current
Reviewed by: bms, ru
- In rt_check() remove the senderr() macro and the "bad" label. They
used to simplify code, but now aren't.
- Remove extra RT_LOCK_ASSERT() in rt_setgate(). The RT_REMREF macro
does this.
- In rtfree() convert panics to KASSERTs.
- Strict the routing API: rtfree() should be called only in a case
when we are completely sure we've got the last reference on the
rtentry. In all other cases RTFREE_LOCKED() macro should be used.
If the reference isn't the last one spit out a warning printf.
Correct the only(?) case for this in rt_check().
- Fix typos in comments.
of each port and any further packets are blocked, when the all the marker frames
have been returned to us from the remote network device then we can be sure
that all interface queues are empty.
This is needed when a port is added or removed from the aggregation since it
will affect the hash based distribution, if the queues are not empty then a
packet from an existing connection may be placed on a different interface and
arrive out of order. This was previously achieved by suppressing transmission for
1 second, now that there is an active feedback this timeout as been increased
to 3 seconds and used as a fallback.
The name trunk is misused as the networking term trunk means carrying multiple
VLANs over a single connection. The IEEE standard for link aggregation (802.3
section 3) does not talk about 'trunk' at all while it is used throughout IEEE
802.1Q in describing vlans.
The lagg(4) driver provides link aggregation, failover and fault tolerance.
Discussed on: current@
tolerance. This driver allows aggregation of multiple network interfaces as
one virtual interface using a number of different protocols/algorithms.
failover - Sends traffic through the secondary port if the master becomes
inactive.
fec - Supports Cisco Fast EtherChannel.
lacp - Supports the IEEE 802.3ad Link Aggregation Control Protocol
(LACP) and the Marker Protocol.
loadbalance - Static loadbalancing using an outgoing hash.
roundrobin - Distributes outgoing traffic using a round-robin scheduler
through all active ports.
This code was obtained from OpenBSD and this also includes 802.3ad LACP support
from agr(4) in NetBSD.
doesn't need to be first in softc now. (It was the whole
ifnet structure itself that needed to be first in the good
old days.) Fix the respective comment accordingly.
Add xrefs to ifnet(9) in some other comments while I'm here.
Pointed out by: thompsa
imitating an Ethernet device, so vlan(4) and if_bridge(4) can be
attached to it for testing and benchmarking purposes. Its source
can be an introduction to the anatomy of a network interface driver
due to its simplicity as well as to a bunch of comments in it.
(The rest of needed changes were in my previous commit, which got
interrupted in the middle. Alas, CVS commits are not atomic.)
sequence. First, if rt_ifa is going to be changed, then call
ifa_rtrequest(RTM_DELETE). Second, if gateway is going to be changed,
then call rt_setgate(). Third, change rt_ifa.
With this change we are able to change a link level route to a
gateway one, that wasn't possible before:
# ifconfig em0 192.168.22.1/24
# arp -s 192.168.22.99 00:11:22:33:44:55
# route change 192.168.22.99 192.168.22.199
# ping 192.168.22.99
db>
Reported by: avatar
structures. Detect when ifnet instances are detached from the network
stack and perform appropriate cleanup to prevent memory leaks.
This has been implemented in such a way as to be backwards ABI compatible.
Kernel consumers are changed to use if_delmulti_ifma(); in_delmulti()
is unable to detect interface removal by design, as it performs searches
on structures which are removed with the interface.
With this architectural change, the panics FreeBSD users have experienced
with carp and pfsync should be resolved.
Obtained from: p4 branch bms_netdev
Reviewed by: andre
Sponsored by: Garance A Drosehn
Idea from: NetBSD
MFC after: 1 month
Main points of this change:
* Drop frames immediately if the interface is not marked IFF_UP.
* Always trim off the frame checksum if present.
* Always use M_VLANTAG in preference to passing 802.1Q frames
to consumers.
* Use __func__ consistently for KASSERT().
* Use the M_PROMISC flag to detect situations where ether_input()
may reenter itself on the same call graph with the same mbuf which
was promiscuously received on behalf of subsystems such as
netgraph, carp, and vlan.
* 802.1P frames (that is, VLAN frames with an ID of 0) will now be
passed to layer 3 input paths.
* Deal with the special case for CARP in a sane way.
This is a significant rewrite of code on the critical path. Please report
any issues to me if they arise. Frames will now only pass through dummynet
if M_PROMISC is cleared, to avoid problems with re-entry.
The handling of CARP needs to be revisited architecturally. The M_PROMISC
flag may potentially be demoted to a link-layer flag only as it is in
NetBSD, where the idea originated.
Discussed on: net
Idea from: NetBSD
Reviewed by: yar
MFC after: 1 month
in case of multiple interfaces with the same MAC in the same bridge.
This commit do not solve the entire problem. Only case where packet
arrived from such interface.
PR: kern/109815
MFC after: 7 days
Submitted by: Eygene Ryabinkin and rik@
Discussed with: bms@, thompsa@, yar@
This can help to spot bugs (which it did for me,)
and let people know which mode the vlan module is
actually using if they suspect it isn't picking its
options from the main kernel config file.
- ifv_list member of struct ifvlan is unneeded in array mode,
it's used only in hash mode to resolve hash collisions.
- We don't need the list of trunks at all. (The initial reason for
having it was to be able to destroy all trunks in the MOD_UNLOAD
handler, but a trunk is not to be destroyed forcibly -- it will
go away when all vlan interfaces on it have been deleted.
Note that if_clone_detach() called first of all under MOD_UNLOAD
will delete all vlan interfaces and thus make all trunks go away
quietly.)
- It's enough to use a single [S]LIST_FIRST() in a typical list
destruction loop.
Add macro EVL_APPLY_VLID() which may be used to apply an 802.1q VLAN ID
to the M_VLANTAG field in an mbuf packet header non-destructively.
This will be used by net80211 to begin with.
Add macro EVL_APPLY_PRI() which may be used to apply an 802.1p priority
class to the M_VLANTAG field in an mbuf packet header non-destructively.
Add other macros for manipulating tags and the CFI bit.
Submitted by: Boris Kovalenko (EVL_CFIOFTAG(), EVL_MAKETAG())
- BIOCGDIRECTION and BIOCSDIRECTION get or set the setting determining
whether incoming, outgoing, or all packets on the interface should be
returned by BPF. Set to BPF_D_IN to see only incoming packets on the
interface. Set to BPF_D_INOUT to see packets originating locally and
remotely on the interface. Set to BPF_D_OUT to see only outgoing
packets on the interface. This setting is initialized to BPF_D_INOUT
by default. BIOCGSEESENT and BIOCSSEESENT are obsoleted by these but
kept for backward compatibility.
- BIOCFEEDBACK sets packet feedback mode. This allows injected packets
to be fed back as input to the interface when output via the interface is
successful. When BPF_D_INOUT direction is set, injected outgoing packet
is not returned by BPF to avoid duplication. This flag is initialized to
zero by default.
Note that libpcap has been modified to support BPF_D_OUT direction for
pcap_setdirection(3) and PCAP_D_OUT direction is functional now.
Reviewed by: rwatson
incoming packets have had their 802.1Q tags processed by the
hardware, resulting in them being stripped from the packets, and
placed on the mbuf. This fixes the processing of 802.1Q tags when
hardware offload of 802.1Q tags is enabled.
a link-layer multicast group membership.
Such memberships are needed in order to support protocols such as
IS-IS without putting the interface into PROMISC or ALLMULTI modes.
sa_equal() is not OK for comparing sockaddr_dl as it has deeper structure
than a simple byte array, so add sa_dl_equal() and use that instead.
Reviewed by: rwatson
Verified with: /usr/sbin/mtest
Bug found by: Jouke Witteveen
MFC after: 2 weeks
that of the tun instance even for the !AF_INET case, and properly
remove configured addresses by calling if_purgeaddrs().
Maintain the TUN_DSTADDR behaviour for compatibility with the OS/390
emulator.
MFC after: 3 weeks
PR: 100080
Reviewed by: bz
Make devfs cloning a sysctl/tunable which defaults to on.
If devfs cloning is enabled, only the super-user may create
tun(4)/tap(4)/vmnet(4) instances. Devfs cloning is still enabled by
default; it may be disabled from the loader or via sysctl with
"net.link.tap.devfs_cloning" and "net.link.tun.devfs_cloning".
Disabling its use affects potentially all tun(4)/tap(4) consumers
including OpenSSH, OpenVPN and VMware.
PR: 105228 (potentially also 90413, 105570)
Submitted by: Landon Fuller
Tested by: Andrej Tobola
Approved by: core (rwatson)
MFC after: 4 weeks
of a tap(4) instance, if IFF_PROMISC is not set.
In tap(4), we should emulate the effect IFF_PROMISC would have on
hardware, otherwise we risk introducing layer 2 loops if tap(4) is
used with bridges. This means not even bpf(4) gets to see them.
This patch has been tested in a variety of situations. Multicast and
broadcast frames are correctly allowed through. I have observed this
behaviour causing problems with multiple QEMU instances hosted on
the same FreeBSD machine.
The checks in in ether_demux() [if_ethersubr.c, rev 1.222, line 638]
are insufficient to prevent this bug from occurring, as ifp->if_vlantrunk
will always be NULL for the non-vlan case.
MFC after: 3 weeks
PR: 86429
Submitted by: Pieter de Boer (with changes)
not used in any of our code. Also remove explicit padding variable that
kept the bpf_d structure the same size before and after the change in
select implementation, since binary compatibility is not required for this
data structure on 7-CURRENT.
- Micro-optimize the addition of an 802.1q header to match the removal code.
- Consistently check for interfaces being up and running.
- Consistently use NULL instead of 0 with pointers.
semantics.
- Stop testing bpf pointers for NULL. In some cases use
bpf_peers_present() and then call the function directly inside the
conditional block instead of the macro.
- For places where the entire conditional block is the macro, remove the
test and make the macro unconditional.
- Use BPF_MTAP() in if_pfsync on FreeBSD instead of an expanded version of
the old semantics.
Reviewed by: csjp (older version)
in the Public Safety Band):
o add channel flags to identify half/quarter-rate operation
o add rate sets (need to check spec on 4Mb/s in 1/4 rate)
o add if_media definitions for new rates
o split net80211 channel setup out into ieee80211_chan_init
o fixup ieee80211_mhz2ieee and ieee80211_ieee2mhz to understand half/quarter
rate channels: note we temporarily use a nonstandard/hack numbering that
avoids overlap with 2.4G channels because we don't (yet) have enough
state to identify and/or map overlapping channel sets
o fixup ieee80211_ifmedia_init so it can be called post attach and will
recalculate the channel list and associated state; this enables changing
channel-related state like the regulatory domain after attach (will be
needed for 802.11d support too)
o add ieee80211_get_suprates to return a reference to the supported rate
set for a given channel
o add 3, 4.5, and 27 MB/s tx rates to rate <-> media conversion routines
o const-poison channel arg to ieee80211_chan2mode
Add a pointer to the relevant PR for future reference. The whole comment
will be OK to remove as soon as the general solution is applied.
PR: kern/105943
In ip6_sprintf no longer use and return one of eight static buffers
for printing/logging ipv6 addresses.
The caller now has to hand in a sufficiently large buffer as first
argument.
The symptoms were that outgoing DHCP requests for diskless kernels
had the IP header corrupt. After long investigations, the source of
the problem was found in ether_output() - for SIMPLEX interfaces
and broadcast traffic, a copy of the packet is passed back to the kernel
through if_simloop(). However if_simloop() modifies the mbuf, while
the copy obtained through m_copym() is a readonly one.
The bug has been there forever, but it has been triggered only recently
by a change in sosend_dgram() which passed down mbufs with sufficient
space to prepend the header.
This fix is trivial - use m_dup() instead of m_copy() to create
the copy. As an alternative, we could try and modify if_simloop()
to play safely with readonly mbufs, but i don't think it is worthwhile
because 1) this is a relatively infrequent code path so we do not need
to worry too much about performance, and 2) the cost of doing an
extra m_pullup in if_simloop() is probably the same as doing the
copy of the cluster, anyways.
MFC after: 1 week
of the bridge port and path cost have been administratively set or
calculated automatically by RSTP.
Make sure to transition from non-edge to edge when the port goes down
and the edge flag was manually set before.
This is needed to comply with the condition
((!portEnabled && AdminEdge) || ....)
in the Bridge Detection State Machine (IEE802.1D-2004, p. 171).
Reviewed by: thompsa
Approved by: bz (mentor)
on the arm. Add an assert to ensure that the size is 8 to prefent others
from falling into this trap (we should have more of these).
Why the construct:
struct foo {
union bar {
struct {
...
} __packed fred;
...
} __packed wilma;
} __packed;
has a different packing than:
struct foo {
union bar {
struct {
...
} fred __packed;
...
} wilma __packed;
} __packed;
is beyond my ability to ferret out of the gcc documentation. Most
likely some subtle binding issue (eg before it says the struct itself
is packed, while after it means that the whole struct is packed into
the thing it is in). Pointers to relevant documentation would be
appreciated.
sizeof ether_header is 2 * ETHER_ADDR_LEN + 2 (14) bytes long
sizeof ether_addr is ETHER_ADDR_LEN bytes long
On arm, this shows that struct ether_addr needs to be __packed.
The first condition muts be true for the bridging code to not dump core.
The second one appears to be implicitly relied upon by wi (but many
of the rids it sends down likely need __packed too to be safe) and
maybe others. It appears to not hurt anything.
if_watchdog/if_timer interface doesn't fit modern SMP network
stack design.
Device drivers that need watchdog to monitor their hardware should
implement it theirselves.
Eventually the if_watchdog/if_timer API will be removed. For now,
warn that driver uses it.
Reviewed by: scottl
enables direct dispatch of the network stack from the device driver
ithread, enabling input path parallelism by default when multiple
interfaces are present.
The strategy for network stack parallelism is something being actively
discussed, and this is just one of several possible (and perfectly
reasonable) strategies, but has the distinct advantage of reducing the
number of context switches and preemptions significantly, resulting in
higher efficiency in many cases. In some caes, this may reduce
network stack parallelism due to work not being deferred from the
ithread to the netisr. Therefore, the strategy may change in the
future, but this offers a reasonable first pass and enabling
parallelism while maintaining strong ordering.
Hopefully this will trigger lots of nice new bugs.
This change is not intended for MFC.
- use flags rather than sperate ioctls for edge, p2p
- implement p2p and autop2p flags
- define large pathcost constant as ULL
- show bridgeid and rootid in ifconfig
Obtained from: Reyk Floeter <reyk@openbsd.org>
at the start of rtalloc1(). This backs out part of revs 1.83 and 1.85.
Profiling on an i386 showed that that for sending tiny packets using
bge, -current takes 7 bzero()s where RELENG_4 takes only 1, and that
bzero()ing is now the dominant overhead (10-12%, up from 1%, but
profiling overestimated this a bit). This commit backs out 2 of the
6 extra bzero()s (1 in each of 2 calls per packet to rtalloc1()). They
were the largest ones by byte count (48 bytes each) but perhaps not
by time (small misaligned ones might take longer).
processing are forced to toggle this functionality when the card
is put in and out of promiscuous mode. The main reason for this
is because the hardware strips the VLAN tag, making it impossible
for the tag information to show up in network diagnostic tools like
tcpdump(1).
This change introduces ether_vlan_mtap(), which is called if the
mbuf has M_VLANTAG set. VLAN information is extracted from the
mbuf and inserted into a stack allocated ether vlan header which
is then inserted through the bpf machinery via bpf_mtap2(). The
original mbuf's data pointer and lengths are temporarily adjusted
to eliminate the original Ethernet header for the duration of the
tap operation. This should have no long term effects on the mbuf.
Also, define a new macro, ETHER_BPF_MTAP which should be used
by drivers which support hardware offload of VLAN tag processing.
The fixes for the relevant drivers will follow shortly.
Discussed with: rwatson, andre, jhb (and others)
Much feedback from: sam, ru
MFC after: 1 month [1]
[1] The version that is eventually MFCed will be somewhat
different then this, as there has been significant work
done to the VLAN code in HEAD.
constratins on arm; this fixes bridging when packets are
rx'd so ip headers are 32-bit aligned
Reviewed by: imp (and discussed elsewhere)
MFC after: 2 weeks
- Each stp port is added sequentially so it was possible for our bridgeid to
change every time because the new port has a lower MAC address. Instead
just find the lowest MAC address from all Ethernet adapters in the machine
as the value only needs to be unique, this stops a lot of churn on the
protocol.
- Update the states after enabling or disabling a port.
- Keep tabs if we have been stopped or started by our parent bridge.
- The callout only needs to be drained before destroying the mutex, move it to
bstp_detach.
address learned by the bridge is made permanent, the address will not age out
and most importantly will not migrate to another interface.
This can be used to stop mac address poisoning or clients roaming in much the
same way as static entries without the hassle of preloading the table.
specific privilege names to a broad range of privileges. These may
require some future tweaking.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
we never initialize it to anything else. However, in the case that
m_uiotombuf fails, we return error (effectively reporting success).
This appears to be a relic of an older revision of this file, where
"error" used to be doing something useful. (See revision 1.1, where
error is used in a loop with uiomove() instead of using m_uiotomubf).
So instead on unconditionally reporting success in the case there is
a failure in m_uiotombuf, explicitly return ENOBUFS. While we are
here, garbage collect the error variable since it's no longer required.
MFC after: 2 weeks
to, previously it was always broadcast to all interfaces (a bug). This is
useful when the bridge is the default gateway and vlans are used to isolate
each client, the reply is now kept private to the vlan which the client
resides.
Reported by: Jon Otterholm
Tested by: Jon Otterholm
MFC after: 3 days
work is not just mine, but it is also the works of Peter Lei
and Michael Tuexen. They both are my two key other developers
working on the project.. and they need ata-boy's too:
****
peterlei@cisco.comtuexen@fh-muenster.de
****
I did do a make sysent which updated the
syscall's and sysproto.. I hope that is correct... without
it you don't build since we have new syscalls for SCTP :-0
So go out and look at the NOTES, add
option SCTP (make sure inet and inet6 are present too)
and play with SCTP.
I will see about comitting some test tools I have after I
figure out where I should place them. I also have a
lib (libsctp.a) that adds some of the missing socketapi
functions that I need to put into lib's.. I will talk
to George about this :-)
There may still be some 64 bit issues in here, none of
us have a 64 bit processor to test with yet.. Michael
may have a MAC but thats another beast too..
If you have a mac and want to use SCTP contact Michael
he maintains a web site with a loadable module with
this code :-)
Reviewed by: gnn
Approved by: gnn
mbuf clusters. Add a flags parameter to accept M_PKTHDR and M_EOR mbuf
chain flags. Provide compatibility macro for m_getm() calling m_getm2()
with M_PKTHDR set.
Rewrite m_uiotombuf() to use m_getm2() for mbuf allocation and do the
uiomove() in a tight loop over the mbuf chain. Add a flags parameter to
accept mbuf flags to be passed to m_getm2(). Adjust all callers for the
extra parameter.
Sponsored by: TCP/IP Optimization Fundraise 2005
MFC after: 3 month
RSTP provides faster spanning tree convergence, the protocol will exchange
information with neighboring switches to quickly transition to forwarding
without creating loops. The code will default to RSTP mode but will downgrade
any port connected to a legacy STP network so is fully backward compatible.
Reviewed by: syrinx
Tested by: syrinx
begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.
This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA
ioctls passing integer arguments should use the _IOWINT() macro.
This fixes a lot of ioctl's not working on sparc64, most notable
being keyboard/syscons ioctls.
Full ABI compatibility is provided, with the bonus of fixing the
handling of old ioctls on sparc64.
Reviewed by: bde (with contributions)
Tested by: emax, marius
MFC after: 1 week
packets. Reimplement this correctly and use a sysctl that defaults to off so
the user doesnt get any suprises if ipfw blocks the ARP packet.
MFC after: 3 days
m_pkthdr.ether_vlan. The presence of the M_VLANTAG flag on the mbuf
signifies the presence and validity of its content.
Drivers that support hardware VLAN tag stripping fill in the received
VLAN tag (containing both vlan and priority information) into the
ether_vtag mbuf packet header field:
m->m_pkthdr.ether_vtag = vlan_id; /* ntohs()? */
m->m_flags |= M_VLANTAG;
to mark the packet m with the specified VLAN tag.
On output the driver should check the mbuf for the M_VLANTAG flag to
see if a VLAN tag is present and valid:
if (m->m_flags & M_VLANTAG) {
... = m->m_pkthdr.ether_vtag; /* htons()? */
... pass tag to hardware ...
}
VLAN tags are stored in host byte order. Byte swapping may be necessary.
(Note: This driver conversion was mechanic and did not add or remove any
byte swapping in the drivers.)
Remove zone_mtag_vlan UMA zone and MTAG_VLAN definition. No more tag
memory allocation have to be done.
Reviewed by: thompsa, yar
Sponsored by: TCP/IP Optimization Fundraise 2005
o add IFCAP_TSO[46] for drivers to announce this capability for IPv4 and IPv6
o add CSUM_TSO flag to mbuf pkthdr csum_flags field
o add tso_segsz field to mbuf pkthdr
o enhance ip_output() packet length check to allow for large TSO packets
o extend tcp_maxmtu[46]() with a flag pointer to pass interface capabilities
o adjust all callers of tcp_maxmtu[46]() accordingly
Discussed on: -current, -net
Sponsored by: TCP/IP Optimization Fundraise 2005
and skip over the normal IP processing.
Add a supporting function ifa_ifwithbroadaddr() to verify and validate the
supplied subnet broadcast address.
PR: kern/99558
Tested by: Andrey V. Elsukov <bu7cher-at-yandex.ru>
Sponsored by: TCP/IP Optimization Fundraise 2005
MFC after: 3 days
by restoring the ifv_proto field in the vlan softc and putting it to use
this time. It's a good companion for ifv_encaplen, which has already been
used throughout this driver.
before tagging them. This can help to work around brain-damage in some
switches that fail to pad a frame after untagging it if its length drops
below the minimum. This option is blessed by IEEE Std 802.1Q (2003 Ed.),
paragraph C.4.4.3.b. It's controlled by sysctl net.link.vlan.soft_pad.
Idea by: az
MFC after: 1 week
Two almost identical patches based on the if_tap work were submitted
via GNATS; I started out with the patch in 100796 from David Gilbert,
but could have easily started with the patch from Vilmos Nebehaj which
I found only later.
MFC after: 1 week
PR: 93976, 100796
were unused or already in if_var.h so add if_name() to if_var.h and
remove net_osdep.h along with all references to it.
Longer term we may want to kill off if_name() entierly since all modern
BSDs have if_xname variables rendering it unnecessicary.
interface, do not just assign -1 to tag because it breaks the logic of
the code to follow. The better way is to handle this case as an unsupported
protocol and return unless INVARIANTS is in effect and we can panic.
Panic is good there because the scenario can happen only because of a
coding error elsewhere.
We also should show the interface name in the panic message for easier
debugging of the problem, should it ever emerge.
Submitted by: qingli (initially)
as it tried to solve:
- it smuggled hidden 802.1q details into otherwise protocol-neutral code;
- it put an important code consistency check under DEBUG, which was never
defined by anyone but a developer hacking this file for the moment;
- lastly, the former bcopy() call had been correct as long as the "dead"
code was there.
(A new version of the fix for tag of -1 to come in the next commit.)
Agreed by: qingli
vlan tag processing, the code will use bcopy() to remove the vlan
tag field but the code copies 2 bytes too many, which essentially
overwrites the protocol type field.
Also, a tag value of -1 is generated for unrecognized interface type,
which would cause an invalid memory access in the vlans[] array.
In addition, removed a line of dead code and its associated comments.
Reviewed by: sam
take a timeval indicating when the packet was captured. Move
microtime() to the calling functions and grab the timestamp as soon
as we know that we're going to call catchpacket at least once.
This means that we call microtime() once per matched packet, as
opposed to once per matched packet per bpf listener. It also means
that we return the same timestamp to all bpf listeners, rather than
slightly different ones.
It would be more accurate to call microtime() even earlier for all
packets, as you have to grab (1+#listener) locks before you can
determine if the packet will be logged. You could always grab a
timestamp before the locks, but microtime() can be costly, so this
didn't seem like a good idea.
(I guess most ethernet interfaces will have a bpf listener these
days because of dhclient. That means that we could be doing two bpf
locks on most packets going through the interface.)
PR: 71711
function, pru_close, to notify protocols that the file descriptor or
other consumer of a socket is closing the socket. pru_abort is now a
notification of close also, and no longer detaches. pru_detach is no
longer used to notify of close, and will be called during socket
tear-down by sofree() when all references to a socket evaporate after
an earlier call to abort or close the socket. This means detach is now
an unconditional teardown of a socket, whereas previously sockets could
persist after detach of the protocol retained a reference.
This faciliates sharing mutexes between layers of the network stack as
the mutex is required during the checking and removal of references at
the head of sofree(). With this change, pru_detach can now assume that
the mutex will no longer be required by the socket layer after
completion, whereas before this was not necessarily true.
Reviewed by: gnn
parameter that can specify configuration parameters:
o rev cloner api's to add optional parameter block
o add SIOCCREATE2 that accepts parameter data
o rev vlan support to use new api (maintain old code)
Reviewed by: arch@
already locked. The reason to do this is to avoid two lock+unlock operations
in a row. We need the lock here to serialize access to bd_pid for stats
collection purposes.
Drop the locks all together on detach, as they will be picked up by
knlist_remove.
This should fix a failed locking assertion when kqueue is being used with bpf
descriptors.
Discussed with: jmg
except in places dealing with ifaddr creation or destruction; and
in such special places incomplete ifaddrs should never be linked
to system-wide data structures. Therefore we can eliminate all the
superfluous checks for "ifa->ifa_addr != NULL" and get ready
to the system crashing honestly instead of masking possible bugs.
Suggested by: glebius, jhb, ru
Previously, another thread could get a pointer to the
interface by scanning the system-wide list and sleep
on the global vlan mutex held by vlan_unconfig().
The interface was gone by the time the other thread
woke up.
In order to be able to call vlan_unconfig() on a detached
interface, remove the purely cosmetic bzero'ing of IF_LLADDR
from the function because a detached interface has no addresses.
Noticed by: a stress-testing script by maxim
Reviewed by: glebius
tested and then set. [1]
Reorganise things to eliminate this, we now ensure that enc0 can not be
destroyed which as the benefit of no longer needing to lock in
ipsec_filter and ipsec_bpf. The cloner will create one interface during the
init so we can guarantee that encif will be valid before any SPD entries are
added to ipsec.
Spotted by: glebius [1]
encryption. There are two functions, a bpf tap which has a basic header with
the SPI number which our current tcpdump knows how to display, and handoff to
pfil(9) for packet filtering.
Obtained from: OpenBSD
Based on: kern/94829
No objections: arch, net
MFC after: 1 month
departing trunk so that we don't get into trouble later
by dereferencing a stale pointer to dead trunk's things.
Prodded by: oleg
Sponsored by: RiNet (Cronyx Plus LLC)
MFC after: 1 week
list.
- First remove from global list, then start destroying.
PR: kern/97679
Submitted by: Alex Lyashkov <shadow itt.net.ru>
Reviewed by: rwatson, brooks
order to - for example - apply firewall rules to a whole group of
interfaces. This is required for importing pf from OpenBSD 3.9
Obtained from: OpenBSD (with changes)
Discussed on: -net (back in April)
pointer to a zeroed, statically allocated bpf_if structure. This way the
LIST_EMPTY() macro will always return true. This allows us to remove the
additional unconditional memory reference for each packet in the fast path.
Discussed with: sam
255.255.255.0, and a default route with gateway x.x.x.1. Now if
the address mask is changed to something more specific, e.g.,
255.255.255.128, then after the mask change the default gateway
is no longer reachable.
Since the default route is still present in the routing table,
when the output code tries to resolve the address of the default
gateway in function rt_check(), again, the default route will be
returned by rtalloc1(). Because the lock is currently held on the
rtentry structure, one more attempt to hold the lock will trigger
a crash due to "lock recursed on non-recursive mutex ..."
This is a general problem. The fix checks for the above condition
so that an existing route entry is not mistaken for a new cloned
route. Approriately, an ENETUNREACH error is returned back to the
caller
Approved by: andre
resulting in some build failures. Instead, to fix the problem of bpf not
being present, check the pointer before dereferencing it.
This is a temporary bandaid until we can decide on how we want to handle
the bpf code not being present. This will be fixed shortly.
(1) bpf peer attaches to interface netif0
(2) Packet is received by netif0
(3) ifp->if_bpf pointer is checked and handed off to bpf
(4) bpf peer detaches from netif0 resulting in ifp->if_bpf being
initialized to NULL.
(5) ifp->if_bpf is dereferenced by bpf machinery
(6) Kaboom
This race condition likely explains the various different kernel panics
reported around sending SIGINT to tcpdump or dhclient processes. But really
this race can result in kernel panics anywhere you have frequent bpf attach
and detach operations with high packet per second load.
Summary of changes:
- Remove the bpf interface's "driverp" member
- When we attach bpf interfaces, we now set the ifp->if_bpf member to the
bpf interface structure. Once this is done, ifp->if_bpf should never be
NULL. [1]
- Introduce bpf_peers_present function, an inline operation which will do
a lockless read bpf peer list associated with the interface. It should
be noted that the bpf code will pickup the bpf_interface lock before adding
or removing bpf peers. This should serialize the access to the bpf descriptor
list, removing the race.
- Expose the bpf_if structure in bpf.h so that the bpf_peers_present function
can use it. This also removes the struct bpf_if; hack that was there.
- Adjust all consumers of the raw if_bpf structure to use bpf_peers_present
Now what happens is:
(1) Packet is received by netif0
(2) Check to see if bpf descriptor list is empty
(3) Pickup the bpf interface lock
(4) Hand packet off to process
From the attach/detach side:
(1) Pickup the bpf interface lock
(2) Add/remove from bpf descriptor list
Now that we are storing the bpf interface structure with the ifnet, there is
is no need to walk the bpf interface list to locate the correct bpf interface.
We now simply look up the interface, and initialize the pointer. This has a
nice side effect of changing a bpf interface attach operation from O(N) (where
N is the number of bpf interfaces), to O(1).
[1] From now on, we can no longer check ifp->if_bpf to tell us whether or
not we have any bpf peers that might be interested in receiving packets.
In collaboration with: sam@
MFC after: 1 month
result, raw_uabort() now needs to call raw_detach() directly. As
raw_uabort() is never called, and raw_disconnect() is probably not ever
actually called in practice, this is likely not a functional change, but
improves congruence between protocols, and avoids a NULL raw cb pointer
after disconnect, which could result in a panic.
MFC after: 1 month
notification so all interfaces including pseudo are reported. When netif
creates the clones at startup devctl_disable has not been turned off yet so the
interfaces will not be initialised twice, enforce this by adding an explicit
order between rc.d/netif and rc.d/devd.
This change allows actions to taken in userland when an interface is cloned
and the pseudo interface will be automatically configured if a ifconfig_<int>=""
line exists in rc.conf.
Reviewed by: brooks
No objections on: net
for IOCTLs where casting data to intptr_t * isn't the right thing to do
as _IO() isn't used for them but _IOR(..., int)/_IOW(..., int) are (i.e.
for all IOCTLs except VMIO_SIOCSIFFLAGS), fixing tap(4) on big-endian
LP64 machines.
PR: sparc64/98084
OK'ed by: emax
MFC after: 1 week
actually destroyed. Also move call to knlist_init() into tapcreate(). This
should fix panic described in kern/95357.
PR: kern/95357
No response from: freebsd-current@
MFC after: 3 days
gateways which are unreachable except through the default router. For
example, assuming there is a default route configured, and inserting
a route
"route add 64.102.54.0/24 60.80.1.1"
is currently allowed even when 60.80.1.1 is only reachable through
the default route. However, an error is thrown when this route is
utilized, say,
"ping 64.102.54.1" will return an error
This type of route insertion should be disallowed becasue:
1) Let's say that somehow our code allowed this packet to flow to
the default router, and the default router knows the next hop is
60.80.1.1, then the question is why bother inserting this route in
the 1st place, just simply use the default route.
2) Since we're not talking about source routing here, the default
router could very well choose a different path than using 60.80.1.1
for the next hop, again it defeats the purpose of adding this route.
Reviewed by: ru, gnn, bz
Approved by: andre
destination. These checks are needed so we do not install
a route looking like this:
(0) 192.0.2.200 UH tun0 =>
When removing this route the kernel will start to walk
the address space which looks like a hang on 64bit platforms
because it'll take ages while on 32bit you should see a panic
when kernel debugging options are turned on.
The problem is in rtrequest1:
if (netmask) {
rt_maskedcopy(dst, ndst, netmask);
} else
bcopy(dst, ndst, dst->sa_len);
In both cases the len might be 0 if the application forgot to
set it. If so ndst will be all-zero leading to above
mentioned strange routes.
This is an application error but we must not fail/hang/panic
because of this.
Looks ok: gnn
No objections: net@ (silence)
MFC after: 8 weeks
The packet filter may reassemble the ip fragments and return a packet that is
larger than the MTU of the sending interface. There is no check for DF or icmp
replies as we can only get a large packet to fragment by reassembling a
previous fragment, and this only happens after a call to pfil(9).
Obtained from: OpenBSD (mostly)
Glanced at by: mlaier
MFC after: 1 month
protocols invoke after allocating a PCB, so so_pcb should be non-NULL.
It is only used by the two IPSEC implementations, so I didn't hit it in
my testing.
Reported by: pjd
MFC after: 3 months
the so_pcb pointer on the socket is always non-NULL. This eliminates
countless unnecessary error checks, replacing them with assertions.
MFC after: 3 months
rather than an error. Detaches do not "fail", they other occur or
the protocol flags SS_PROTOREF to take ownership of the socket.
soclose() no longer looks at so_pcb to see if it's NULL, relying
entirely on the protocol to decide whether it's time to free the
socket or not using SS_PROTOREF. so_pcb is now entirely owned and
managed by the protocol code. Likewise, no longer test so_pcb in
other socket functions, such as soreceive(), which have no business
digging into protocol internals.
Protocol detach routines no longer try to free the socket on detach,
this is performed in the socket code if the protocol permits it.
In rts_detach(), no longer test for rp != NULL in detach, and
likewise in other protocols that don't permit a NULL so_pcb, reduce
the incidence of testing for it during detach.
netinet and netinet6 are not fully updated to this change, which
will be in an upcoming commit. In their current state they may leak
memory or panic.
MFC after: 3 months
than an int, as an error here is not meaningful. Modify soabort() to
unconditionally free the socket on the return of pru_abort(), and
modify most protocols to no longer conditionally free the socket,
since the caller will do this.
This commit likely leaves parts of netinet and netinet6 in a situation
where they may panic or leak memory, as they have not are not fully
updated by this commit. This will be corrected shortly in followup
commits to these components.
MFC after: 3 months
details see PR kern/94448.
PR: kern/94448
Original patch: Eygene A. Ryabinkin <rea-fbsd at rea dot mbslab dot kiae dot ru>Final patch: thompsa@
Tested by: thompsa@, Eygene A. Ryabinkin
MFC after: 7 days
K&R style function declarations with ANSI style. Also fix endian bugs
accessing ioctl arguments that are passed by value.
PR: kern/93897
Submitted by: Vilmos Nebehaj < vili at huwico dot hu >
MFC after: 1 week
applications.
Open[BGP|OSPF]D make use of this to determine the link status of
interfaces to make the right routing descisions.
Obtained from: OpenBSD
MFC after: 3 days
- Allow RTM_CHANGE to change a number of route flags as specified by
RTF_FMASK.
- The unused rtm_use field in struct rt_msghdr is redesignated as
rtm_fmask field to communicate route flag changes in RTM_CHANGE
messages from userland. The use count of a route was moved to
rtm_rmx a long time ago. For source code compatibility reasons
a define of rtm_use to rtm_fmask is provided.
These changes faciliate running of multiple cooperating routing
daemons at the same time without causing undesired interference.
Open[BGP|OSPF]D make use of these features to have IGP routes
override EGP ones.
Obtained from: OpenBSD (claudio@)
MFC after: 3 days
will remain in the disabled state until another link event happens in the
future (if at all). Add a timer to periodically check the interface state and
recover.
Reported by: Nik Lam <freebsdnik j2d.lam.net.au>
MFC after: 3 days
re-organizing the monitor return logic. We perform interface monitoring
checks after we have determined if the CRC is still on the packet, if
it is, m_adj() is called which will adjust the packet length. This
ensures that we are not including CRC lengths in the byte counters for
each packet.
Discussed with: andre, glebius
that we might have address collisions, so make sure that this hardware address
isn't already in use on another bridge.
Submitted by: csjp
MFC after: 1 month
destination interface as a member of our bridge or this is a unicast packet,
push it through the bpf(4) machinery.
For broadcast or multicast packets, don't bother with the bpf(4) because it will
be re-injected into ether_input. We do this before we pass the packets through
the pfil(9) framework, as it is possible that pfil(9) will drop the packet or
possibly modify it, making it very difficult to debug firewall issues on the
bridge.
Further, implemented IFF_MONITOR for bridge interfaces. This does much the same
thing that it does for regular network interfaces: it pushes the packet to any
bpf(4) peers and then returns. This bypasses all of the bridge machinery,
saving mutex acquisitions, list traversals, and other operations performed by
the bridging code.
This change to the bridging code is useful in situations where individuals use a
bridge to multiplex RX/TX signals from two interfaces, as is required by some
network taps for de-multiplexing links and transmitting the RX/TX signals
out through two separate interfaces. This behaviour is quite common for network
taps monitoring links, especially for certain manufacturers.
Reviewed by: thompsa
MFC after: 1 month
Sponsored by: Seccuris Labs
- use the cu_bridge_id rather than the cu_rootid for the bridge address [1]
- the memcmp return value is not signed so the wrong interface may have been
selected
- fix up the calculation of sc_bridge_id
PR: kern/93909 [1]
MFC after: 3 days
and want to have crypto support loaded as KLD. By moving zlib to separate
module and adding MODULE_DEPEND directives, it is possible to use such
configuration without complication. Otherwise, since IPSEC is linked with
zlib (just like crypto.ko) you'll get following error:
interface zlib.1 already present in the KLD 'kernel'!
Approved by: cognet (mentor)
zero in this case.) A kernel driver has IFF_DRV_RUNNING
at its full disposal while IFF_UP may be toggled only by
humans or their daemonic deputies from the userland.
MFC after: 3 days
did not stop at the right node. Change the backtracking check from
smaller-than to smaller-or-equal to prevent this from happening.
While here fix one additional problem where the insertion of the
default route traversed the entire tree.
PR: kern/38752
Submitted by: qingli (before I became committer)
Reviewed by: andre
MFC after: 3 days
filtering mechanisms to use the new rwlock(9) locking API:
- Drop the variables stored in the phil_head structure which were specific to
conditions and the home rolled read/write locking mechanism.
- Drop some includes which were used for condition variables
- Drop the inline functions, and convert them to macros. Also, move these
macros into pfil.h
- Move pfil list locking macros intp phil.h as well
- Rename ph_busy_count to ph_nhooks. This variable will represent the number
of IN/OUT hooks registered with the pfil head structure
- Define PFIL_HOOKED macro which evaluates to true if there are any
hooks to be ran by pfil_run_hooks
- In the IP/IP6 stacks, change the ph_busy_count comparison to use the new
PFIL_HOOKED macro.
- Drop optimization in pfil_run_hooks which checks to see if there are any
hooks to be ran, and returns if not. This check is already performed by the
IP stacks when they call:
if (!PFIL_HOOKED(ph))
goto skip_hooks;
- Drop in assertion which makes sure that the number of hooks never drops
below 0 for good measure. This in theory should never happen, and if it
does than there are problems somewhere
- Drop special logic around PFIL_WAITOK because rw_wlock(9) does not sleep
- Drop variables which support home rolled read/write locking mechanism from
the IPFW firewall chain structure.
- Swap out the read/write firewall chain lock internal to use the rwlock(9)
API instead of our home rolled version
- Convert the inlined functions to macros
Reviewed by: mlaier, andre, glebius
Thanks to: jhb for the new locking API
- code expects memcmp() to return a signed value, our memcmp() returns 0 if
args are equal and > 0 if not.
- It's possible to hijack interface for static entry. If bridge recieves
packet from interface marked as learning it will replace the bridge_rtnode
entry for the source address even if such entry marked as static.
Submitted by: Gleb Kurtsov <k-gleb yandex.ru>
MFC after: 3 days
beginning and simply refuse to attach to a parent without either
flag.
Our network stack cannot handle well IFF_BROADCAST or IFF_MULTICAST
on an interface changing on the fly. E.g., IP will or won't assign
a broadcast address to an interface and join the all-hosts multicast
group on it depending on its IFF_BROADCAST and IFF_MULTICAST settings.
Should the flags alter later, IP will miss the change and keep using
bogus settings. This can lead to evil things like supplying an
invalid broadcast address or trying to leave a multicast group that
hasn't been joined. So just avoid touching the flags since an
interface was created. This has no practical purpose.
Discussed with: -net, glebius, oleg
MFC after: 1 week
work by yar, thompsa and myself. The checksum offloading part also involves
work done by Mihail Balikov.
The most important changes:
o Instead of global linked list of all vlan softc use a per-trunk
hash. The size of hash is dynamically adjusted, depending on
number of entries. This changes struct ifnet, replacing counter
of vlans with a pointer to trunk structure. This change is an
improvement for setups with big number of VLANs, several interfaces
and several CPUs. It is a small regression for a setup with a single
VLAN interface.
An alternative to dynamic hash is a per-trunk static array with
4096 entries, which is a compile time option - VLAN_ARRAY. In my
experiments the array is not an improvement, probably because such
a big trunk structure doesn't fit into CPU cache.
o Introduce an UMA zone for VLAN tags. Since drivers depend on it,
the zone is declared in kern_mbuf.c, not in optional vlan(4) driver.
This change is a big improvement for any setup utilizing vlan(4).
o Use rwlock(9) instead of mutex(9) for locking. We are the first
ones to do this! :)
o Some drivers can do hardware VLAN tagging + hardware checksum
offloading. Add an infrastructure for this. Whenever vlan(4) is
attached to a parent or parent configuration is changed, the flags
on vlan(4) interface are updated.
In collaboration with: yar, thompsa
In collaboration with: Mihail Balikov <mihail.balikov interbgc.com>
however IPv4-in-IPv4 tunnels are now stable on SMP. Details:
- Add per-softc mutex.
- Hold the mutex on output.
The main problem was the rtentry, placed in softc. It could be
freed by ip_output(). Meanwhile, another thread being in
in_gif_output() can read and write this rtentry.
Reported by: many
Tested by: Alexander Shiryaev <aixp mail.ru>
Vararg functions have a different calling convention than regular
functions on amd64. Casting a varag function to a regular one to
match the function pointer declaration will hide the varargs from
the caller and we will end up with an incorrectly setup stack.
Entirely remove the varargs from these functions and change the
functions to match the declaration of the function pointers.
Remove the now unnecessary casts.
Lots of explanations and help from: peter
Reviewed by: peter
PR: amd64/89261
MFC after: 6 days
may have changed by m_pullup() during fastforward processing.
While this is a bug it is actually never triggered in real world
situations and it is not remotely exploitable.
Found by: Coverity Prevent(tm)
Coverity ID: CID780
Sponsored by: TCP/IP Optimization Fundraise 2005
restored when its removed from the bridge.
At the moment we only clear IFCAP_TXCSUM. Since a locally generated packet on
the bridge may be sent out any one or more interfaces it cant be assumed that
every card does hardware csums. Most bridges don't generate a lot of traffic
themselves so turning off offloading won't hurt, bridged packets are
unaffected.
Tested by: Bruce Walker (bmw borderware.com)
MFC after: 5 days
ef_clone(); we were testing the original ifnet, not the one allocated.
When aborting ef_clone() due to if_alloc() failing, free the allocated
efnet structure rather than leaking it.
Noticed by: Coverity Prevent analysis tool
MFC after: 3 days
SLIST_FOREACH_SAFE() rather than SLIST_FOREACH(), as elements are
freed on each iteration of the loop. This prevents use-after-free.
Noticed by: Coverity Prevent analysis tool
MFC after: 3 days
attempted to cast a struct ifnet to a struct fw_com which resulted in
data corruption.
PR: kern/91307
Submitted by: Alex Semenyaka <alex at semenyaka do ru>
MFC After: 6 days
ETHERTYPE_IPV6 frames. Change this to be a sysctl knob so that is able to still
bridge non-IP packets if desired.
Also return early if all pfil_* sysctls are turned off, the user obviously does
not want to filter on the bridge.
interfaces to bridges, which will then send and receive IP protocol 97 packets.
Packets are Ethernet frames with an EtherIP header prepended.
Obtained from: NetBSD
MFC after: 2 weeks
case if memory allocation failed.
- Remove fourth argument from VLAN_INPUT_TAG(), that was used
incorrectly in almost all drivers. Indicate failure with
mbuf value of NULL.
In collaboration with: yongari, ru, sam
span ports when they disappear. The span port does not have a pointer to the
softc so revert r1.31 and bring back the softc linked-list.
MFC after: 2 weeks
