linux-toradex.git/net/core, branch v4.14-rc2

net: orphan frags on stand-alone ptype in dev_queue_xmit_nit

2017-09-23T03:31:29+00:00

Zerocopy skbs frags are copied when the skb is looped to a local sock.
Commit 1080e512d44d ("net: orphan frags on receive") introduced calls
to skb_orphan_frags to deliver_skb and __netif_receive_skb for this.

With msg_zerocopy, these skbs can also exist in the tx path and thus
loop from dev_queue_xmit_nit. This already calls deliver_skb in its
loop. But it does not orphan before a separate pt_prev->func().

Add the missing skb_orphan_frags_rx.

Changes
  v1->v2: handle skb_orphan_frags_rx failure

Fixes: 1f8b977ab32d ("sock: enable MSG_ZEROCOPY")
Signed-off-by: Willem de Bruijn 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: ethtool: Add back transceiver type

2017-09-21T22:20:40+00:00

Commit 3f1ac7a700d0 ("net: ethtool: add new ETHTOOL_xLINKSETTINGS API")
deprecated the ethtool_cmd::transceiver field, which was fine in
premise, except that the PHY library was actually using it to report the
type of transceiver: internal or external.

Use the first word of the reserved field to put this __u8 transceiver
field back in. It is made read-only, and we don't expect the
ETHTOOL_xLINKSETTINGS API to be doing anything with this anyway, so this
is mostly for the legacy path where we do:

ethtool_get_settings()
-> dev->ethtool_ops->get_link_ksettings()
   -> convert_link_ksettings_to_legacy_settings()

to have no information loss compared to the legacy get_settings API.

Fixes: 3f1ac7a700d0 ("net: ethtool: add new ETHTOOL_xLINKSETTINGS API")
Signed-off-by: Florian Fainelli 
Signed-off-by: David S. Miller

net: change skb->mac_header when Generic XDP calls adjust_head

2017-09-20T22:44:22+00:00

Since XDP's view of the packet includes the MAC header, moving the start-
 of-packet with bpf_xdp_adjust_head needs to also update the offset of the
 MAC header (which is relative to skb->head, not to the skb->data that was
 changed).
Without this, tcpdump sees packets starting from the old MAC header rather
 than the new one, at least in my tests on the loopback device.

Fixes: b5cdae3291f7 ("net: Generic XDP")
Signed-off-by: Edward Cree 
Signed-off-by: David S. Miller

bpf: fix ri->map_owner pointer on bpf_prog_realloc

2017-09-19T23:38:53+00:00

Commit 109980b894e9 ("bpf: don't select potentially stale
ri->map from buggy xdp progs") passed the pointer to the prog
itself to be loaded into r4 prior on bpf_redirect_map() helper
call, so that we can store the owner into ri->map_owner out of
the helper.

Issue with that is that the actual address of the prog is still
subject to change when subsequent rewrites occur that require
slow path in bpf_prog_realloc() to alloc more memory, e.g. from
patching inlining helper functions or constant blinding. Thus,
we really need to take prog->aux as the address we're holding,
which also works with prog clones as they share the same aux
object.

Instead of then fetching aux->prog during runtime, which could
potentially incur cache misses due to false sharing, we are
going to just use aux for comparison on the map owner. This
will also keep the patchlet of the same size, and later check
in xdp_map_invalid() only accesses read-only aux pointer from
the prog, it's also in the same cacheline already from prior
access when calling bpf_func.

Fixes: 109980b894e9 ("bpf: don't select potentially stale ri->map from buggy xdp progs")
Signed-off-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

net_sched: gen_estimator: fix scaling error in bytes/packets samples

2017-09-13T20:30:53+00:00

Denys reported wrong rate estimations with HTB classes.

It appears the bug was added in linux-4.10, since my tests
where using intervals of one second only.

HTB using 4 sec default rate estimators, reported rates
were 4x higher.

We need to properly scale the bytes/packets samples before
integrating them in EWMA.

Tested:
 echo 1 >/sys/module/sch_htb/parameters/htb_rate_est

 Setup HTB with one class with a rate/cail of 5Gbit

 Generate traffic on this class

 tc -s -d cl sh dev eth0 classid 7002:11
class htb 7002:11 parent 7002:1 prio 5 quantum 200000 rate 5Gbit ceil
5Gbit linklayer ethernet burst 80000b/1 mpu 0b cburst 80000b/1 mpu 0b
level 0 rate_handle 1
 Sent 1488215421648 bytes 982969243 pkt (dropped 0, overlimits 0
requeues 0)
 rate 5Gbit 412814pps backlog 136260b 2p requeues 0
 TCP pkts/rtx 982969327/45 bytes 1488215557414/68130
 lended: 22732826 borrowed: 0 giants: 0
 tokens: -1684 ctokens: -1684

Fixes: 1c0d32fde5bd ("net_sched: gen_estimator: complete rewrite of rate estimators")
Signed-off-by: Eric Dumazet 
Reported-by: Denys Fedoryshchenko 
Signed-off-by: David S. Miller

xdp: implement xdp_redirect_map for generic XDP

2017-09-11T21:33:00+00:00

Using bpf_redirect_map is allowed for generic XDP programs, but the
appropriate map lookup was never performed in xdp_do_generic_redirect().

Instead the map-index is directly used as the ifindex.  For the
xdp_redirect_map sample in SKB-mode '-S', this resulted in trying
sending on ifindex 0 which isn't valid, resulting in getting SKB
packets dropped.  Thus, the reported performance numbers are wrong in
commit 24251c264798 ("samples/bpf: add option for native and skb mode
for redirect apps") for the 'xdp_redirect_map -S' case.

Before commit 109980b894e9 ("bpf: don't select potentially stale
ri->map from buggy xdp progs") it could crash the kernel.  Like this
commit also check that the map_owner owner is correct before
dereferencing the map pointer.  But make sure that this API misusage
can be caught by a tracepoint. Thus, allowing userspace via
tracepoints to detect misbehaving bpf_progs.

Fixes: 6103aa96ec07 ("net: implement XDP_REDIRECT for xdp generic")
Fixes: 24251c264798 ("samples/bpf: add option for native and skb mode for redirect apps")
Signed-off-by: Jesper Dangaard Brouer 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-09-09T18:05:20+00:00

Pull networking fixes from David Miller:
 "The iwlwifi firmware compat fix is in here as well as some other
  stuff:

  1) Fix request socket leak introduced by BPF deadlock fix, from Eric
     Dumazet.

  2) Fix VLAN handling with TXQs in mac80211, from Johannes Berg.

  3) Missing __qdisc_drop conversions in prio and qfq schedulers, from
     Gao Feng.

  4) Use after free in netlink nlk groups handling, from Xin Long.

  5) Handle MTU update properly in ipv6 gre tunnels, from Xin Long.

  6) Fix leak of ipv6 fib tables on netns teardown, from Sabrina Dubroca
     with follow-on fix from Eric Dumazet.

  7) Need RCU and preemption disabled during generic XDP data patch,
     from John Fastabend"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (54 commits)
  bpf: make error reporting in bpf_warn_invalid_xdp_action more clear
  Revert "mdio_bus: Remove unneeded gpiod NULL check"
  bpf: devmap, use cond_resched instead of cpu_relax
  bpf: add support for sockmap detach programs
  net: rcu lock and preempt disable missing around generic xdp
  bpf: don't select potentially stale ri->map from buggy xdp progs
  net: tulip: Constify tulip_tbl
  net: ethernet: ti: netcp_core: no need in netif_napi_del
  davicom: Display proper debug level up to 6
  net: phy: sfp: rename dt properties to match the binding
  dt-binding: net: sfp binding documentation
  dt-bindings: add SFF vendor prefix
  dt-bindings: net: don't confuse with generic PHY property
  ip6_tunnel: fix setting hop_limit value for ipv6 tunnel
  ip_tunnel: fix setting ttl and tos value in collect_md mode
  ipv6: fix typo in fib6_net_exit()
  tcp: fix a request socket leak
  sctp: fix missing wake ups in some situations
  netfilter: xt_hashlimit: fix build error caused by 64bit division
  netfilter: xt_hashlimit: alloc hashtable with right size
  ...

bpf: make error reporting in bpf_warn_invalid_xdp_action more clear

2017-09-09T04:13:09+00:00

Differ between illegal XDP action code and just driver
unsupported one to provide better feedback when we throw
a one-time warning here. Reason is that with 814abfabef3c
("xdp: add bpf_redirect helper function") not all drivers
support the new XDP return code yet and thus they will
fall into their 'default' case when checking for return
codes after program return, which then triggers a
bpf_warn_invalid_xdp_action() stating that the return
code is illegal, but from XDP perspective it's not.

I decided not to place something like a XDP_ACT_MAX define
into uapi i) given we don't have this either for all other
program types, ii) future action codes could have further
encoding there, which would render such define unsuitable
and we wouldn't be able to rip it out again, and iii) we
rarely add new action codes.

Signed-off-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

net: rcu lock and preempt disable missing around generic xdp

2017-09-09T04:11:00+00:00

do_xdp_generic must be called inside rcu critical section with preempt
disabled to ensure BPF programs are valid and per-cpu variables used
for redirect operations are consistent. This patch ensures this is true
and fixes the splat below.

The netif_receive_skb_internal() code path is now broken into two rcu
critical sections. I decided it was better to limit the preempt_enable/disable
block to just the xdp static key portion and the fallout is more
rcu_read_lock/unlock calls. Seems like the best option to me.

[  607.596901] =============================
[  607.596906] WARNING: suspicious RCU usage
[  607.596912] 4.13.0-rc4+ #570 Not tainted
[  607.596917] -----------------------------
[  607.596923] net/core/dev.c:3948 suspicious rcu_dereference_check() usage!
[  607.596927]
[  607.596927] other info that might help us debug this:
[  607.596927]
[  607.596933]
[  607.596933] rcu_scheduler_active = 2, debug_locks = 1
[  607.596938] 2 locks held by pool/14624:
[  607.596943]  #0:  (rcu_read_lock_bh){......}, at: [] ip_finish_output2+0x14d/0x890
[  607.596973]  #1:  (rcu_read_lock_bh){......}, at: [] __dev_queue_xmit+0x14a/0xfd0
[  607.597000]
[  607.597000] stack backtrace:
[  607.597006] CPU: 5 PID: 14624 Comm: pool Not tainted 4.13.0-rc4+ #570
[  607.597011] Hardware name: Dell Inc. Precision Tower 5810/0HHV7N, BIOS A17 03/01/2017
[  607.597016] Call Trace:
[  607.597027]  dump_stack+0x67/0x92
[  607.597040]  lockdep_rcu_suspicious+0xdd/0x110
[  607.597054]  do_xdp_generic+0x313/0xa50
[  607.597068]  ? time_hardirqs_on+0x5b/0x150
[  607.597076]  ? mark_held_locks+0x6b/0xc0
[  607.597088]  ? netdev_pick_tx+0x150/0x150
[  607.597117]  netif_rx_internal+0x205/0x3f0
[  607.597127]  ? do_xdp_generic+0xa50/0xa50
[  607.597144]  ? lock_downgrade+0x2b0/0x2b0
[  607.597158]  ? __lock_is_held+0x93/0x100
[  607.597187]  netif_rx+0x119/0x190
[  607.597202]  loopback_xmit+0xfd/0x1b0
[  607.597214]  dev_hard_start_xmit+0x127/0x4e0

Fixes: d445516966dc ("net: xdp: support xdp generic on virtual devices")
Fixes: b5cdae3291f7 ("net: Generic XDP")
Acked-by: Daniel Borkmann 
Signed-off-by: John Fastabend 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

bpf: don't select potentially stale ri->map from buggy xdp progs

2017-09-09T03:58:09+00:00

We can potentially run into a couple of issues with the XDP
bpf_redirect_map() helper. The ri->map in the per CPU storage
can become stale in several ways, mostly due to misuse, where
we can then trigger a use after free on the map:

i) prog A is calling bpf_redirect_map(), returning XDP_REDIRECT
and running on a driver not supporting XDP_REDIRECT yet. The
ri->map on that CPU becomes stale when the XDP program is unloaded
on the driver, and a prog B loaded on a different driver which
supports XDP_REDIRECT return code. prog B would have to omit
calling to bpf_redirect_map() and just return XDP_REDIRECT, which
would then access the freed map in xdp_do_redirect() since not
cleared for that CPU.

ii) prog A is calling bpf_redirect_map(), returning a code other
than XDP_REDIRECT. prog A is then detached, which triggers release
of the map. prog B is attached which, similarly as in i), would
just return XDP_REDIRECT without having called bpf_redirect_map()
and thus be accessing the freed map in xdp_do_redirect() since
not cleared for that CPU.

iii) prog A is attached to generic XDP, calling the bpf_redirect_map()
helper and returning XDP_REDIRECT. xdp_do_generic_redirect() is
currently not handling ri->map (will be fixed by Jesper), so it's
not being reset. Later loading a e.g. native prog B which would,
say, call bpf_xdp_redirect() and then returns XDP_REDIRECT would
find in xdp_do_redirect() that a map was set and uses that causing
use after free on map access.

Fix thus needs to avoid accessing stale ri->map pointers, naive
way would be to call a BPF function from drivers that just resets
it to NULL for all XDP return codes but XDP_REDIRECT and including
XDP_REDIRECT for drivers not supporting it yet (and let ri->map
being handled in xdp_do_generic_redirect()). There is a less
intrusive way w/o letting drivers call a reset for each BPF run.

The verifier knows we're calling into bpf_xdp_redirect_map()
helper, so it can do a small insn rewrite transparent to the prog
itself in the sense that it fills R4 with a pointer to the own
bpf_prog. We have that pointer at verification time anyway and
R4 is allowed to be used as per calling convention we scratch
R0 to R5 anyway, so they become inaccessible and program cannot
read them prior to a write. Then, the helper would store the prog
pointer in the current CPUs struct redirect_info. Later in
xdp_do_*_redirect() we check whether the redirect_info's prog
pointer is the same as passed xdp_prog pointer, and if that's
the case then all good, since the prog holds a ref on the map
anyway, so it is always valid at that point in time and must
have a reference count of at least 1. If in the unlikely case
they are not equal, it means we got a stale pointer, so we clear
and bail out right there. Also do reset map and the owning prog
in bpf_xdp_redirect(), so that bpf_xdp_redirect_map() and
bpf_xdp_redirect() won't get mixed up, only the last call should
take precedence. A tc bpf_redirect() doesn't use map anywhere
yet, so no need to clear it there since never accessed in that
layer.

Note that in case the prog is released, and thus the map as
well we're still under RCU read critical section at that time
and have preemption disabled as well. Once we commit with the
__dev_map_insert_ctx() from xdp_do_redirect_map() and set the
map to ri->map_to_flush, we still wait for a xdp_do_flush_map()
to finish in devmap dismantle time once flush_needed bit is set,
so that is fine.

Fixes: 97f91a7cf04f ("bpf: add bpf_redirect_map helper routine")
Reported-by: Jesper Dangaard Brouer 
Signed-off-by: Daniel Borkmann 
Signed-off-by: John Fastabend 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller