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* Re: [PATCH net-next v3 02/17] zinc: introduce minimal cryptography library
From: Ard Biesheuvel @ 2018-09-13 15:07 UTC (permalink / raw)
  To: Jason A. Donenfeld
  Cc: Andrew Lutomirski, LKML, Netdev, David Miller, Greg Kroah-Hartman,
	Samuel Neves, Jean-Philippe Aumasson, Linux Crypto Mailing List
In-Reply-To: <CAHmME9pp8HoisxQWL_eELR-ziiBii-7mcA=oF9UF-WMucewX5w@mail.gmail.com>

On 13 September 2018 at 16:18, Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> On Thu, Sep 13, 2018 at 1:45 AM Andy Lutomirski <luto@kernel.org> wrote:
>> I'm not convinced that there's any real need for *all* crypto
>> algorithms to move into lib/zinc or to move at all.  As I see it,
>> there are two classes of crypto algorithms in the kernel:
>>
>> a) Crypto that is used by code that chooses its algorithm statically
>> and wants synchronous operations.  These include everything in
>> drivers/char/random.c, but also a bunch of various networking things
>> that are hardcoded and basically everything that uses stack buffers.
>> (This means it includes all the code that I broke when I did
>> VMAP_STACK.  Sign.)
>
> Right, exactly. This is what will wind up using Zinc. I'm working on
> an example usage of this for v4 of the patch submission, which you can
> ogle in a preview here if you're curious:
>
> https://git.zx2c4.com/linux-dev/commit/?h=big_key_rewrite
>
> 28 insertions, 206 deletions :-D
>

I must say, that actually looks pretty good.

>> b) Crypto that is used dynamically.  This includes dm-crypt
>> (aes-xts-plain64, aes-cbc-essiv, etc), all the ALG_IF interfaces, a
>> lot of IPSEC stuff, possibly KCM, and probably many more.  These will
>> get comparatively little benefit from being converted to a zinc-like
>> interface.  For some of these cases, it wouldn't make any sense at all
>> to convert them.  Certainly the ones that do async hardware crypto
>> using DMA engines will never look at all like zinc, even under the
>> hood.
>
> Right, this is what the crypto API will continue to be used for.
>
>
>> I think that, as a short-term goal, it makes a lot of sense to have
>> implementations of the crypto that *new* kernel code (like Wireguard)
>> wants to use in style (a) that live in /lib, and it obviously makes
>> sense to consolidate their implementations with the crypto/
>> implementations in a timely manner.  As a medium-term goal, adding
>> more algorithms as needed for things that could use the simpler APIs
>> (Bluetooth, perhaps) would make sense.
>
> Agreed 100%. With regards to "consolidate their implementations" --
> I've actually already done this after your urging yesterday, and so
> that will be a part of v4.
>
>> But I see no reason at all that /lib should ever contain a grab-bag of
>> crypto implementations just for the heck of it.  They should have real
>> in-kernel users IMO.  And this means that there will probably always
>> be some crypto implementations in crypto/ for things like aes-xts.
>
> Right, precisely.
>
> Jason

^ permalink raw reply

* [PATCH] hv_netvsc: fix schedule in RCU context
From: Stephen Hemminger @ 2018-09-13 15:03 UTC (permalink / raw)
  To: kys, haiyangz; +Cc: netdev, Stephen Hemminger

When netvsc device is removed it can call reschedule in RCU context.
This happens because canceling the subchannel setup work could (in theory)
cause a reschedule when manipulating the timer.

To reproduce, run with lockdep enabled kernel and unbind
a network device from hv_netvsc (via sysfs).

[  160.682011] WARNING: suspicious RCU usage
[  160.707466] 4.19.0-rc3-uio+ #2 Not tainted
[  160.709937] -----------------------------
[  160.712352] ./include/linux/rcupdate.h:302 Illegal context switch in RCU read-side critical section!
[  160.723691]
[  160.723691] other info that might help us debug this:
[  160.723691]
[  160.730955]
[  160.730955] rcu_scheduler_active = 2, debug_locks = 1
[  160.762813] 5 locks held by rebind-eth.sh/1812:
[  160.766851]  #0: 000000008befa37a (sb_writers#6){.+.+}, at: vfs_write+0x184/0x1b0
[  160.773416]  #1: 00000000b097f236 (&of->mutex){+.+.}, at: kernfs_fop_write+0xe2/0x1a0
[  160.783766]  #2: 0000000041ee6889 (kn->count#3){++++}, at: kernfs_fop_write+0xeb/0x1a0
[  160.787465]  #3: 0000000056d92a74 (&dev->mutex){....}, at: device_release_driver_internal+0x39/0x250
[  160.816987]  #4: 0000000030f6031e (rcu_read_lock){....}, at: netvsc_remove+0x1e/0x250 [hv_netvsc]
[  160.828629]
[  160.828629] stack backtrace:
[  160.831966] CPU: 1 PID: 1812 Comm: rebind-eth.sh Not tainted 4.19.0-rc3-uio+ #2
[  160.832952] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v1.0 11/26/2012
[  160.832952] Call Trace:
[  160.832952]  dump_stack+0x85/0xcb
[  160.832952]  ___might_sleep+0x1a3/0x240
[  160.832952]  __flush_work+0x57/0x2e0
[  160.832952]  ? __mutex_lock+0x83/0x990
[  160.832952]  ? __kernfs_remove+0x24f/0x2e0
[  160.832952]  ? __kernfs_remove+0x1b2/0x2e0
[  160.832952]  ? mark_held_locks+0x50/0x80
[  160.832952]  ? get_work_pool+0x90/0x90
[  160.832952]  __cancel_work_timer+0x13c/0x1e0
[  160.832952]  ? netvsc_remove+0x1e/0x250 [hv_netvsc]
[  160.832952]  ? __lock_is_held+0x55/0x90
[  160.832952]  netvsc_remove+0x9a/0x250 [hv_netvsc]
[  160.832952]  vmbus_remove+0x26/0x30
[  160.832952]  device_release_driver_internal+0x18a/0x250
[  160.832952]  unbind_store+0xb4/0x180
[  160.832952]  kernfs_fop_write+0x113/0x1a0
[  160.832952]  __vfs_write+0x36/0x1a0
[  160.832952]  ? rcu_read_lock_sched_held+0x6b/0x80
[  160.832952]  ? rcu_sync_lockdep_assert+0x2e/0x60
[  160.832952]  ? __sb_start_write+0x141/0x1a0
[  160.832952]  ? vfs_write+0x184/0x1b0
[  160.832952]  vfs_write+0xbe/0x1b0
[  160.832952]  ksys_write+0x55/0xc0
[  160.832952]  do_syscall_64+0x60/0x1b0
[  160.832952]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  160.832952] RIP: 0033:0x7fe48f4c8154

Resolve this by getting RTNL earlier. This is safe because the subchannel
work queue does trylock on RTNL and will detect the race.

Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
 drivers/net/hyperv/netvsc_drv.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 70921bbe0e28..915fbd66a02b 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2272,17 +2272,15 @@ static int netvsc_remove(struct hv_device *dev)
 
 	cancel_delayed_work_sync(&ndev_ctx->dwork);
 
-	rcu_read_lock();
-	nvdev = rcu_dereference(ndev_ctx->nvdev);
-
-	if  (nvdev)
+	rtnl_lock();
+	nvdev = rtnl_dereference(ndev_ctx->nvdev);
+	if (nvdev)
 		cancel_work_sync(&nvdev->subchan_work);
 
 	/*
 	 * Call to the vsc driver to let it know that the device is being
 	 * removed. Also blocks mtu and channel changes.
 	 */
-	rtnl_lock();
 	vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
 	if (vf_netdev)
 		netvsc_unregister_vf(vf_netdev);
@@ -2294,7 +2292,6 @@ static int netvsc_remove(struct hv_device *dev)
 	list_del(&ndev_ctx->list);
 
 	rtnl_unlock();
-	rcu_read_unlock();
 
 	hv_set_drvdata(dev, NULL);
 
-- 
2.18.0

^ permalink raw reply related

* Re: [PATCH net-next v3 02/17] zinc: introduce minimal cryptography library
From: Ard Biesheuvel @ 2018-09-13 15:04 UTC (permalink / raw)
  To: Jason A. Donenfeld
  Cc: LKML, Netdev, David Miller, Greg Kroah-Hartman, Andrew Lutomirski,
	Samuel Neves, Jean-Philippe Aumasson, Linux Crypto Mailing List
In-Reply-To: <CAHmME9oYAEwFQAriVRm5zZKCo0Sh1=t5YheNZ+MtKQLQPoMWeg@mail.gmail.com>

On 13 September 2018 at 16:15, Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> Hi Ard,
>
> On Thu, Sep 13, 2018 at 12:56 AM Ard Biesheuvel
> <ard.biesheuvel@linaro.org> wrote:
>> In this series, you are dumping a huge volume of unannotated,
>> generated asm into the kernel which has been modified [by you] to
>> [among other things?] adhere to the kernel API (without documenting
>> what the changes are exactly). How does that live up to the promise of
>> better, peer reviewed code?
>
> The code still benefits from the review that's gone into OpenSSL. It's
> not modified in ways that would affect the cryptographic operations
> being done. It's modified to be suitable for kernel space.
>

So could we please at least have those changes as a separate patch then?

>> Then there is the performance claim. We know for instance that the
>> OpenSSL ARM NEON code for ChaCha20 is faster on cores that happen to
>> possess a micro-architectural property that ALU instructions are
>> essentially free when they are interleaved with SIMD instructions. But
>> we also know that a) Cortex-A7, which is a relevant target, is not one
>> of those cores, and b) that chip designers are not likely to optimize
>> for that particular usage pattern so relying on it in generic code is
>> unwise in general.
>
> That's interesting. I'll bring this up with AndyP. FWIW, if you think
> you have a real and compelling claim here, I'd be much more likely to
> accept a different ChaCha20 implementation than I would be to accept a
> different Poly1305 implementation. (It's a *lot* harder to screw up
> ChaCha20 than it is to screw up Poly1305.)
>

The question is really whether we want different implementations in
the crypto API and in zinc.

>> I am also concerned about your claim that all software algorithms will
>> be moved into this crypto library.
>
> I'll defer to Andy's response here, which I think is a correct one:
> https://lkml.org/lkml/2018/9/13/27
>
> The short answer is that Zinc is going to be adding the ciphers that
> people want to use for normal reasons from normal code. For example,
> after this merges, we'll next be working on moving the remaining
> non-optimized C code out of lib/ that's called by places (such as
> SHA2).
>

Excellent.

>> You are not specific about whose
>> responsibility it will be that this is going to happen in a timely
>> fashion.
>
> I thought I laid out the roadmap for this in the commit message. In
> case I wasn't clear: my plan is to tackle lib/ after merging, and I
> plan to do so in a timely manner. It's a pretty common tactic to keep
> layering on tasks, "what about X?", "what about Y?", "I won't agree
> unless Z!" -- when in reality kernel development and refactorings are
> done incrementally. I've been around on this list contributing code
> for long enough that you should have a decent amount of confidence
> that I'm not just going to disappear working on this or something
> insane like that. And neither are the two academic cryptographers CC'd
> on this thread. So, as Andy said, we're going to be porting to Zinc
> the primitives that are useful for the various applications of Zinc.
> This means yes, we'll have SHA2 in there.
>
>> chaining modes
>> What are the APIs
>> going to look like for block ciphers, taking chaining modes into
>> account?
>
> As mentioned in the commit message and numerous times, we're not
> trying to make a win32-like crypto API here or to remake the existing
> Linux crypto API. Rather we're providing libraries of specific
> functions that are useful for various circumstances. For example, if
> AES-GCM is desired at some point, then we'll have a similar API for
> that as we do for ChaPoly -- one that takes buffers and one that takes
> sg. Likewise, hash functions use the familiar init/update/final.
> "Generic" chaining modes aren't really part of the equation or design
> goals.
>
> Again, I realize you've spent a long time working on the existing
> crypto API, and so your questions and concerns are in the line of,
> "how are we going to make Zinc look like the existing crypto API in
> functionality?"

You are completely missing my point. I am not particularly invested in
the crypto API, and I share the concerns about its usability. That is
why I want to make sure that your solution actually results in a net
improvement for everybody, not just for WireGuard, in a maintainable
way.

> But that's not what we're up to here. We have a
> different and complementary design goal. I understand why you're
> squirming, but please recognize we're working on different things.
>
>> I'm sure it is rather simple to port the crypto API implementation of
>> ChaCha20 to use your library. I am more concerned about how your
>> library is going to expand to cover all other software algorithms that
>> we currently use in the kernel.
>
> The subset of algorithms we add will be developed with the same
> methodology as the present ones. There is nothing making this
> particularly difficult or even more difficult for other primitives
> than it was for ChaCha20. It's especially easy, in fact, since we're
> following similar design methodologies as the vast majority of other
> cryptography libraries that have been developed. Namely, we're
> creating simple things called "functions".
>
>> Of course. But please respond to all the concerns,
>> You have not
>> responded to that concern yet.
>
> Sorry, it's certainly not my intention. I've been on vacation with my
> family for the last several weeks, and only returned home
> sleep-deprived last night after 4 days of plane delays. I've now
> rested and will resume working on this full-time and I'll try my best
> to address concerns, and also go back through emails to find things I
> might have missed. (First, though, I'm going to deal with getting back
> the three suitcases the airline lost in transit...)
>
>> > Anyway, it sounds like this whole thing may have ruffled your feathers
>> > a bit. Will you be at Linux Plumbers Conference in November? I'm
>> > planning on attending, and perhaps we could find some time there to
>> > sit down and talk one on one a bit.
>>
>> That would be good, yes. I will be there.
>
> Looking forward to talking to you there, and hopefully we can put to
> rest any lingering concerns.
>
> Jason

^ permalink raw reply

* Re: [PATCH 2/2] net: qcom/emac: add shared mdio bus support
From: Timur Tabi @ 2018-09-13 15:03 UTC (permalink / raw)
  To: Andrew Lunn, Wang Dongsheng; +Cc: davem, yu.zheng, netdev
In-Reply-To: <20180913124229.GD11702@lunn.ch>

On 9/13/18 7:42 AM, Andrew Lunn wrote:
> This is a pretty big patch, and is hard to review. Could you try to
> break it up into a number of smaller patches. You could for example
> first refactor emacs_phy_config(), without making any functional
> changes. Then add the sharing. Maybe do OF an ACPI in different
> patches?

Yes, please.

^ permalink raw reply

* Re: [PATCH net-next RFC] virtio_net: ethtool tx napi configuration
From: Willem de Bruijn @ 2018-09-13 15:00 UTC (permalink / raw)
  To: me
  Cc: Network Development, Jason Wang, Michael S. Tsirkin, f.fainelli,
	Willem de Bruijn
In-Reply-To: <20180913100425.GF11198@eros>

> > +static u32 virtnet_get_priv_flags(struct net_device *dev)
> > +{
> > +     struct virtnet_info *vi = netdev_priv(dev);
> > +     int priv_flags = 0;
> > +
> > +     if (vi->sq[0].napi.weight)
> > +             priv_flags |= 0x1;
> > +
> > +     return priv_flags;
> > +}
>
> Why the use of priv_flags here?  Is there some reason that we don't want
> to use the more simple
>
>     static u32 virtnet_get_priv_flags(struct net_device *dev)
>     {
>             struct virtnet_info *vi = netdev_priv(dev);
>
>             if (vi->sq[0].napi.weight)
>                     return 1;
>
>             return 0;
>     }

Sure, that's fine, too.

I just wanted to make it explicit that this is one of possibly many
private flags,
and only acts on bit 0. If another private flag is added, the existing
code needs
little change, just add a branch on another bit. But either way works.

^ permalink raw reply

* [PATCH v3 30/30] ip: frags: fix crash in ip_do_fragment()
From: Stephen Hemminger @ 2018-09-13 14:59 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet, Taehee Yoo
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Taehee Yoo <ap420073@gmail.com>

commit 5d407b071dc369c26a38398326ee2be53651cfe4 upstream

A kernel crash occurrs when defragmented packet is fragmented
in ip_do_fragment().
In defragment routine, skb_orphan() is called and
skb->ip_defrag_offset is set. but skb->sk and
skb->ip_defrag_offset are same union member. so that
frag->sk is not NULL.
Hence crash occurrs in skb->sk check routine in ip_do_fragment() when
defragmented packet is fragmented.

test commands:
   %iptables -t nat -I POSTROUTING -j MASQUERADE
   %hping3 192.168.4.2 -s 1000 -p 2000 -d 60000

splat looks like:
[  261.069429] kernel BUG at net/ipv4/ip_output.c:636!
[  261.075753] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[  261.083854] CPU: 1 PID: 1349 Comm: hping3 Not tainted 4.19.0-rc2+ #3
[  261.100977] RIP: 0010:ip_do_fragment+0x1613/0x2600
[  261.106945] Code: e8 e2 38 e3 fe 4c 8b 44 24 18 48 8b 74 24 08 e9 92 f6 ff ff 80 3c 02 00 0f 85 da 07 00 00 48 8b b5 d0 00 00 00 e9 25 f6 ff ff <0f> 0b 0f 0b 44 8b 54 24 58 4c 8b 4c 24 18 4c 8b 5c 24 60 4c 8b 6c
[  261.127015] RSP: 0018:ffff8801031cf2c0 EFLAGS: 00010202
[  261.134156] RAX: 1ffff1002297537b RBX: ffffed0020639e6e RCX: 0000000000000004
[  261.142156] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880114ba9bd8
[  261.150157] RBP: ffff880114ba8a40 R08: ffffed0022975395 R09: ffffed0022975395
[  261.158157] R10: 0000000000000001 R11: ffffed0022975394 R12: ffff880114ba9ca4
[  261.166159] R13: 0000000000000010 R14: ffff880114ba9bc0 R15: dffffc0000000000
[  261.174169] FS:  00007fbae2199700(0000) GS:ffff88011b400000(0000) knlGS:0000000000000000
[  261.183012] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  261.189013] CR2: 00005579244fe000 CR3: 0000000119bf4000 CR4: 00000000001006e0
[  261.198158] Call Trace:
[  261.199018]  ? dst_output+0x180/0x180
[  261.205011]  ? save_trace+0x300/0x300
[  261.209018]  ? ip_copy_metadata+0xb00/0xb00
[  261.213034]  ? sched_clock_local+0xd4/0x140
[  261.218158]  ? kill_l4proto+0x120/0x120 [nf_conntrack]
[  261.223014]  ? rt_cpu_seq_stop+0x10/0x10
[  261.227014]  ? find_held_lock+0x39/0x1c0
[  261.233008]  ip_finish_output+0x51d/0xb50
[  261.237006]  ? ip_fragment.constprop.56+0x220/0x220
[  261.243011]  ? nf_ct_l4proto_register_one+0x5b0/0x5b0 [nf_conntrack]
[  261.250152]  ? rcu_is_watching+0x77/0x120
[  261.255010]  ? nf_nat_ipv4_out+0x1e/0x2b0 [nf_nat_ipv4]
[  261.261033]  ? nf_hook_slow+0xb1/0x160
[  261.265007]  ip_output+0x1c7/0x710
[  261.269005]  ? ip_mc_output+0x13f0/0x13f0
[  261.273002]  ? __local_bh_enable_ip+0xe9/0x1b0
[  261.278152]  ? ip_fragment.constprop.56+0x220/0x220
[  261.282996]  ? nf_hook_slow+0xb1/0x160
[  261.287007]  raw_sendmsg+0x21f9/0x4420
[  261.291008]  ? dst_output+0x180/0x180
[  261.297003]  ? sched_clock_cpu+0x126/0x170
[  261.301003]  ? find_held_lock+0x39/0x1c0
[  261.306155]  ? stop_critical_timings+0x420/0x420
[  261.311004]  ? check_flags.part.36+0x450/0x450
[  261.315005]  ? _raw_spin_unlock_irq+0x29/0x40
[  261.320995]  ? _raw_spin_unlock_irq+0x29/0x40
[  261.326142]  ? cyc2ns_read_end+0x10/0x10
[  261.330139]  ? raw_bind+0x280/0x280
[  261.334138]  ? sched_clock_cpu+0x126/0x170
[  261.338995]  ? check_flags.part.36+0x450/0x450
[  261.342991]  ? __lock_acquire+0x4500/0x4500
[  261.348994]  ? inet_sendmsg+0x11c/0x500
[  261.352989]  ? dst_output+0x180/0x180
[  261.357012]  inet_sendmsg+0x11c/0x500
[ ... ]

v2:
 - clear skb->sk at reassembly routine.(Eric Dumarzet)

Fixes: fa0f527358bd ("ip: use rb trees for IP frag queue.")
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/ip_fragment.c                  | 1 +
 net/ipv6/netfilter/nf_conntrack_reasm.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 88281fbce88c..e7227128df2c 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -599,6 +599,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
 			nextp = &fp->next;
 			fp->prev = NULL;
 			memset(&fp->rbnode, 0, sizeof(fp->rbnode));
+			fp->sk = NULL;
 			head->data_len += fp->len;
 			head->len += fp->len;
 			if (head->ip_summed != fp->ip_summed)
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 82ce0d0f54bf..2ed8536e10b6 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -453,6 +453,7 @@ nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *prev,  struct net_devic
 		else if (head->ip_summed == CHECKSUM_COMPLETE)
 			head->csum = csum_add(head->csum, fp->csum);
 		head->truesize += fp->truesize;
+		fp->sk = NULL;
 	}
 	sub_frag_mem_limit(fq->q.net, head->truesize);
 
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 29/30] ip: process in-order fragments efficiently
From: Stephen Hemminger @ 2018-09-13 14:59 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet, Peter Oskolkov, Florian Westphal
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Peter Oskolkov <posk@google.com>

This patch changes the runtime behavior of IP defrag queue:
incoming in-order fragments are added to the end of the current
list/"run" of in-order fragments at the tail.

On some workloads, UDP stream performance is substantially improved:

RX: ./udp_stream -F 10 -T 2 -l 60
TX: ./udp_stream -c -H <host> -F 10 -T 5 -l 60

with this patchset applied on a 10Gbps receiver:

  throughput=9524.18
  throughput_units=Mbit/s

upstream (net-next):

  throughput=4608.93
  throughput_units=Mbit/s

Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit a4fd284a1f8fd4b6c59aa59db2185b1e17c5c11c)
---
 net/ipv4/inet_fragment.c |   2 +-
 net/ipv4/ip_fragment.c   | 110 ++++++++++++++++++++++++---------------
 2 files changed, 70 insertions(+), 42 deletions(-)

diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 6904cbb7de1a..f6764537148c 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -145,7 +145,7 @@ void inet_frag_destroy(struct inet_frag_queue *q)
 			fp = xp;
 		} while (fp);
 	} else {
-		sum_truesize = skb_rbtree_purge(&q->rb_fragments);
+		sum_truesize = inet_frag_rbtree_purge(&q->rb_fragments);
 	}
 	sum = sum_truesize + f->qsize;
 
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 26ace9d2d976..88281fbce88c 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -126,8 +126,8 @@ static u8 ip4_frag_ecn(u8 tos)
 
 static struct inet_frags ip4_frags;
 
-static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
-			 struct net_device *dev);
+static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
+			 struct sk_buff *prev_tail, struct net_device *dev);
 
 
 static void ip4_frag_init(struct inet_frag_queue *q, const void *a)
@@ -219,7 +219,12 @@ static void ip_expire(struct timer_list *t)
 		head = skb_rb_first(&qp->q.rb_fragments);
 		if (!head)
 			goto out;
-		rb_erase(&head->rbnode, &qp->q.rb_fragments);
+		if (FRAG_CB(head)->next_frag)
+			rb_replace_node(&head->rbnode,
+					&FRAG_CB(head)->next_frag->rbnode,
+					&qp->q.rb_fragments);
+		else
+			rb_erase(&head->rbnode, &qp->q.rb_fragments);
 		memset(&head->rbnode, 0, sizeof(head->rbnode));
 		barrier();
 	}
@@ -320,7 +325,7 @@ static int ip_frag_reinit(struct ipq *qp)
 		return -ETIMEDOUT;
 	}
 
-	sum_truesize = skb_rbtree_purge(&qp->q.rb_fragments);
+	sum_truesize = inet_frag_rbtree_purge(&qp->q.rb_fragments);
 	sub_frag_mem_limit(qp->q.net, sum_truesize);
 
 	qp->q.flags = 0;
@@ -329,6 +334,7 @@ static int ip_frag_reinit(struct ipq *qp)
 	qp->q.fragments = NULL;
 	qp->q.rb_fragments = RB_ROOT;
 	qp->q.fragments_tail = NULL;
+	qp->q.last_run_head = NULL;
 	qp->iif = 0;
 	qp->ecn = 0;
 
@@ -340,7 +346,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 {
 	struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
 	struct rb_node **rbn, *parent;
-	struct sk_buff *skb1;
+	struct sk_buff *skb1, *prev_tail;
 	struct net_device *dev;
 	unsigned int fragsize;
 	int flags, offset;
@@ -418,38 +424,41 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 	 */
 
 	/* Find out where to put this fragment.  */
-	skb1 = qp->q.fragments_tail;
-	if (!skb1) {
-		/* This is the first fragment we've received. */
-		rb_link_node(&skb->rbnode, NULL, &qp->q.rb_fragments.rb_node);
-		qp->q.fragments_tail = skb;
-	} else if ((skb1->ip_defrag_offset + skb1->len) < end) {
-		/* This is the common/special case: skb goes to the end. */
+	prev_tail = qp->q.fragments_tail;
+	if (!prev_tail)
+		ip4_frag_create_run(&qp->q, skb);  /* First fragment. */
+	else if (prev_tail->ip_defrag_offset + prev_tail->len < end) {
+		/* This is the common case: skb goes to the end. */
 		/* Detect and discard overlaps. */
-		if (offset < (skb1->ip_defrag_offset + skb1->len))
+		if (offset < prev_tail->ip_defrag_offset + prev_tail->len)
 			goto discard_qp;
-		/* Insert after skb1. */
-		rb_link_node(&skb->rbnode, &skb1->rbnode, &skb1->rbnode.rb_right);
-		qp->q.fragments_tail = skb;
+		if (offset == prev_tail->ip_defrag_offset + prev_tail->len)
+			ip4_frag_append_to_last_run(&qp->q, skb);
+		else
+			ip4_frag_create_run(&qp->q, skb);
 	} else {
-		/* Binary search. Note that skb can become the first fragment, but
-		 * not the last (covered above). */
+		/* Binary search. Note that skb can become the first fragment,
+		 * but not the last (covered above).
+		 */
 		rbn = &qp->q.rb_fragments.rb_node;
 		do {
 			parent = *rbn;
 			skb1 = rb_to_skb(parent);
 			if (end <= skb1->ip_defrag_offset)
 				rbn = &parent->rb_left;
-			else if (offset >= skb1->ip_defrag_offset + skb1->len)
+			else if (offset >= skb1->ip_defrag_offset +
+						FRAG_CB(skb1)->frag_run_len)
 				rbn = &parent->rb_right;
 			else /* Found an overlap with skb1. */
 				goto discard_qp;
 		} while (*rbn);
 		/* Here we have parent properly set, and rbn pointing to
-		 * one of its NULL left/right children. Insert skb. */
+		 * one of its NULL left/right children. Insert skb.
+		 */
+		ip4_frag_init_run(skb);
 		rb_link_node(&skb->rbnode, parent, rbn);
+		rb_insert_color(&skb->rbnode, &qp->q.rb_fragments);
 	}
-	rb_insert_color(&skb->rbnode, &qp->q.rb_fragments);
 
 	if (dev)
 		qp->iif = dev->ifindex;
@@ -476,7 +485,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 		unsigned long orefdst = skb->_skb_refdst;
 
 		skb->_skb_refdst = 0UL;
-		err = ip_frag_reasm(qp, skb, dev);
+		err = ip_frag_reasm(qp, skb, prev_tail, dev);
 		skb->_skb_refdst = orefdst;
 		return err;
 	}
@@ -495,7 +504,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 
 /* Build a new IP datagram from all its fragments. */
 static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
-			 struct net_device *dev)
+			 struct sk_buff *prev_tail, struct net_device *dev)
 {
 	struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
 	struct iphdr *iph;
@@ -519,10 +528,16 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
 		fp = skb_clone(skb, GFP_ATOMIC);
 		if (!fp)
 			goto out_nomem;
-		rb_replace_node(&skb->rbnode, &fp->rbnode, &qp->q.rb_fragments);
+		FRAG_CB(fp)->next_frag = FRAG_CB(skb)->next_frag;
+		if (RB_EMPTY_NODE(&skb->rbnode))
+			FRAG_CB(prev_tail)->next_frag = fp;
+		else
+			rb_replace_node(&skb->rbnode, &fp->rbnode,
+					&qp->q.rb_fragments);
 		if (qp->q.fragments_tail == skb)
 			qp->q.fragments_tail = fp;
 		skb_morph(skb, head);
+		FRAG_CB(skb)->next_frag = FRAG_CB(head)->next_frag;
 		rb_replace_node(&head->rbnode, &skb->rbnode,
 				&qp->q.rb_fragments);
 		consume_skb(head);
@@ -558,7 +573,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
 		for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
 			plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
 		clone->len = clone->data_len = head->data_len - plen;
-		skb->truesize += clone->truesize;
+		head->truesize += clone->truesize;
 		clone->csum = 0;
 		clone->ip_summed = head->ip_summed;
 		add_frag_mem_limit(qp->q.net, clone->truesize);
@@ -571,24 +586,36 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
 	skb_push(head, head->data - skb_network_header(head));
 
 	/* Traverse the tree in order, to build frag_list. */
+	fp = FRAG_CB(head)->next_frag;
 	rbn = rb_next(&head->rbnode);
 	rb_erase(&head->rbnode, &qp->q.rb_fragments);
-	while (rbn) {
-		struct rb_node *rbnext = rb_next(rbn);
-		fp = rb_to_skb(rbn);
-		rb_erase(rbn, &qp->q.rb_fragments);
-		rbn = rbnext;
-		*nextp = fp;
-		nextp = &fp->next;
-		fp->prev = NULL;
-		memset(&fp->rbnode, 0, sizeof(fp->rbnode));
-		head->data_len += fp->len;
-		head->len += fp->len;
-		if (head->ip_summed != fp->ip_summed)
-			head->ip_summed = CHECKSUM_NONE;
-		else if (head->ip_summed == CHECKSUM_COMPLETE)
-			head->csum = csum_add(head->csum, fp->csum);
-		head->truesize += fp->truesize;
+	while (rbn || fp) {
+		/* fp points to the next sk_buff in the current run;
+		 * rbn points to the next run.
+		 */
+		/* Go through the current run. */
+		while (fp) {
+			*nextp = fp;
+			nextp = &fp->next;
+			fp->prev = NULL;
+			memset(&fp->rbnode, 0, sizeof(fp->rbnode));
+			head->data_len += fp->len;
+			head->len += fp->len;
+			if (head->ip_summed != fp->ip_summed)
+				head->ip_summed = CHECKSUM_NONE;
+			else if (head->ip_summed == CHECKSUM_COMPLETE)
+				head->csum = csum_add(head->csum, fp->csum);
+			head->truesize += fp->truesize;
+			fp = FRAG_CB(fp)->next_frag;
+		}
+		/* Move to the next run. */
+		if (rbn) {
+			struct rb_node *rbnext = rb_next(rbn);
+
+			fp = rb_to_skb(rbn);
+			rb_erase(rbn, &qp->q.rb_fragments);
+			rbn = rbnext;
+		}
 	}
 	sub_frag_mem_limit(qp->q.net, head->truesize);
 
@@ -624,6 +651,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
 	qp->q.fragments = NULL;
 	qp->q.rb_fragments = RB_ROOT;
 	qp->q.fragments_tail = NULL;
+	qp->q.last_run_head = NULL;
 	return 0;
 
 out_nomem:
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 28/30] ip: add helpers to process in-order fragments faster.
From: Stephen Hemminger @ 2018-09-13 14:59 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet, Peter Oskolkov, Florian Westphal
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Peter Oskolkov <posk@google.com>

This patch introduces several helper functions/macros that will be
used in the follow-up patch. No runtime changes yet.

The new logic (fully implemented in the second patch) is as follows:

* Nodes in the rb-tree will now contain not single fragments, but lists
  of consecutive fragments ("runs").

* At each point in time, the current "active" run at the tail is
  maintained/tracked. Fragments that arrive in-order, adjacent
  to the previous tail fragment, are added to this tail run without
  triggering the re-balancing of the rb-tree.

* If a fragment arrives out of order with the offset _before_ the tail run,
  it is inserted into the rb-tree as a single fragment.

* If a fragment arrives after the current tail fragment (with a gap),
  it starts a new "tail" run, as is inserted into the rb-tree
  at the end as the head of the new run.

skb->cb is used to store additional information
needed here (suggested by Eric Dumazet).

Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 353c9cb360874e737fb000545f783df756c06f9a)
---
 include/net/inet_frag.h |  6 ++++
 net/ipv4/ip_fragment.c  | 73 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+)

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index e4c71a7644be..335cf7851f12 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -57,7 +57,9 @@ struct frag_v6_compare_key {
  * @lock: spinlock protecting this frag
  * @refcnt: reference count of the queue
  * @fragments: received fragments head
+ * @rb_fragments: received fragments rb-tree root
  * @fragments_tail: received fragments tail
+ * @last_run_head: the head of the last "run". see ip_fragment.c
  * @stamp: timestamp of the last received fragment
  * @len: total length of the original datagram
  * @meat: length of received fragments so far
@@ -78,6 +80,7 @@ struct inet_frag_queue {
 	struct sk_buff		*fragments;  /* Used in IPv6. */
 	struct rb_root		rb_fragments; /* Used in IPv4. */
 	struct sk_buff		*fragments_tail;
+	struct sk_buff		*last_run_head;
 	ktime_t			stamp;
 	int			len;
 	int			meat;
@@ -113,6 +116,9 @@ void inet_frag_kill(struct inet_frag_queue *q);
 void inet_frag_destroy(struct inet_frag_queue *q);
 struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, void *key);
 
+/* Free all skbs in the queue; return the sum of their truesizes. */
+unsigned int inet_frag_rbtree_purge(struct rb_root *root);
+
 static inline void inet_frag_put(struct inet_frag_queue *q)
 {
 	if (refcount_dec_and_test(&q->refcnt))
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 7cb7ed761d8c..26ace9d2d976 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -57,6 +57,57 @@
  */
 static const char ip_frag_cache_name[] = "ip4-frags";
 
+/* Use skb->cb to track consecutive/adjacent fragments coming at
+ * the end of the queue. Nodes in the rb-tree queue will
+ * contain "runs" of one or more adjacent fragments.
+ *
+ * Invariants:
+ * - next_frag is NULL at the tail of a "run";
+ * - the head of a "run" has the sum of all fragment lengths in frag_run_len.
+ */
+struct ipfrag_skb_cb {
+	struct inet_skb_parm	h;
+	struct sk_buff		*next_frag;
+	int			frag_run_len;
+};
+
+#define FRAG_CB(skb)		((struct ipfrag_skb_cb *)((skb)->cb))
+
+static void ip4_frag_init_run(struct sk_buff *skb)
+{
+	BUILD_BUG_ON(sizeof(struct ipfrag_skb_cb) > sizeof(skb->cb));
+
+	FRAG_CB(skb)->next_frag = NULL;
+	FRAG_CB(skb)->frag_run_len = skb->len;
+}
+
+/* Append skb to the last "run". */
+static void ip4_frag_append_to_last_run(struct inet_frag_queue *q,
+					struct sk_buff *skb)
+{
+	RB_CLEAR_NODE(&skb->rbnode);
+	FRAG_CB(skb)->next_frag = NULL;
+
+	FRAG_CB(q->last_run_head)->frag_run_len += skb->len;
+	FRAG_CB(q->fragments_tail)->next_frag = skb;
+	q->fragments_tail = skb;
+}
+
+/* Create a new "run" with the skb. */
+static void ip4_frag_create_run(struct inet_frag_queue *q, struct sk_buff *skb)
+{
+	if (q->last_run_head)
+		rb_link_node(&skb->rbnode, &q->last_run_head->rbnode,
+			     &q->last_run_head->rbnode.rb_right);
+	else
+		rb_link_node(&skb->rbnode, NULL, &q->rb_fragments.rb_node);
+	rb_insert_color(&skb->rbnode, &q->rb_fragments);
+
+	ip4_frag_init_run(skb);
+	q->fragments_tail = skb;
+	q->last_run_head = skb;
+}
+
 /* Describe an entry in the "incomplete datagrams" queue. */
 struct ipq {
 	struct inet_frag_queue q;
@@ -654,6 +705,28 @@ struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
 }
 EXPORT_SYMBOL(ip_check_defrag);
 
+unsigned int inet_frag_rbtree_purge(struct rb_root *root)
+{
+	struct rb_node *p = rb_first(root);
+	unsigned int sum = 0;
+
+	while (p) {
+		struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode);
+
+		p = rb_next(p);
+		rb_erase(&skb->rbnode, root);
+		while (skb) {
+			struct sk_buff *next = FRAG_CB(skb)->next_frag;
+
+			sum += skb->truesize;
+			kfree_skb(skb);
+			skb = next;
+		}
+	}
+	return sum;
+}
+EXPORT_SYMBOL(inet_frag_rbtree_purge);
+
 #ifdef CONFIG_SYSCTL
 static int dist_min;
 
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 26/30] net: sk_buff rbnode reorg
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh
  Cc: netdev, stable, edumazet, Soheil Hassas Yeganeh, Wei Wang,
	Willem de Bruijn
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

commit bffa72cf7f9df842f0016ba03586039296b4caaf upstream

skb->rbnode shares space with skb->next, skb->prev and skb->tstamp

Current uses (TCP receive ofo queue and netem) need to save/restore
tstamp, while skb->dev is either NULL (TCP) or a constant for a given
queue (netem).

Since we plan using an RB tree for TCP retransmit queue to speedup SACK
processing with large BDP, this patch exchanges skb->dev and
skb->tstamp.

This saves some overhead in both TCP and netem.

v2: removes the swtstamp field from struct tcp_skb_cb

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Wei Wang <weiwan@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/linux/skbuff.h                  |  24 ++--
 include/net/inet_frag.h                 |   3 +-
 net/ipv4/inet_fragment.c                |  16 ++-
 net/ipv4/ip_fragment.c                  | 182 +++++++++++++-----------
 net/ipv6/netfilter/nf_conntrack_reasm.c |   1 +
 net/ipv6/reassembly.c                   |   1 +
 6 files changed, 129 insertions(+), 98 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 2837e55df03e..f64e88444082 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -663,23 +663,27 @@ struct sk_buff {
 			struct sk_buff		*prev;
 
 			union {
-				ktime_t		tstamp;
-				u64		skb_mstamp;
+				struct net_device	*dev;
+				/* Some protocols might use this space to store information,
+				 * while device pointer would be NULL.
+				 * UDP receive path is one user.
+				 */
+				unsigned long		dev_scratch;
 			};
 		};
-		struct rb_node	rbnode; /* used in netem & tcp stack */
+		struct rb_node		rbnode; /* used in netem, ip4 defrag, and tcp stack */
+		struct list_head	list;
 	};
-	struct sock		*sk;
 
 	union {
-		struct net_device	*dev;
-		/* Some protocols might use this space to store information,
-		 * while device pointer would be NULL.
-		 * UDP receive path is one user.
-		 */
-		unsigned long		dev_scratch;
+		struct sock		*sk;
 		int			ip_defrag_offset;
 	};
+
+	union {
+		ktime_t		tstamp;
+		u64		skb_mstamp;
+	};
 	/*
 	 * This is the control buffer. It is free to use for every
 	 * layer. Please put your private variables there. If you
diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index ed07e3786d98..e4c71a7644be 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -75,7 +75,8 @@ struct inet_frag_queue {
 	struct timer_list	timer;
 	spinlock_t		lock;
 	refcount_t		refcnt;
-	struct sk_buff		*fragments;
+	struct sk_buff		*fragments;  /* Used in IPv6. */
+	struct rb_root		rb_fragments; /* Used in IPv4. */
 	struct sk_buff		*fragments_tail;
 	ktime_t			stamp;
 	int			len;
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index c9e35b81d093..6904cbb7de1a 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -136,12 +136,16 @@ void inet_frag_destroy(struct inet_frag_queue *q)
 	fp = q->fragments;
 	nf = q->net;
 	f = nf->f;
-	while (fp) {
-		struct sk_buff *xp = fp->next;
-
-		sum_truesize += fp->truesize;
-		kfree_skb(fp);
-		fp = xp;
+	if (fp) {
+		do {
+			struct sk_buff *xp = fp->next;
+
+			sum_truesize += fp->truesize;
+			kfree_skb(fp);
+			fp = xp;
+		} while (fp);
+	} else {
+		sum_truesize = skb_rbtree_purge(&q->rb_fragments);
 	}
 	sum = sum_truesize + f->qsize;
 
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 960bf5eab59f..0e8f8de77e71 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -136,7 +136,7 @@ static void ip_expire(struct timer_list *t)
 {
 	struct inet_frag_queue *frag = from_timer(frag, t, timer);
 	const struct iphdr *iph;
-	struct sk_buff *head;
+	struct sk_buff *head = NULL;
 	struct net *net;
 	struct ipq *qp;
 	int err;
@@ -152,14 +152,31 @@ static void ip_expire(struct timer_list *t)
 
 	ipq_kill(qp);
 	__IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
-
-	head = qp->q.fragments;
-
 	__IP_INC_STATS(net, IPSTATS_MIB_REASMTIMEOUT);
 
-	if (!(qp->q.flags & INET_FRAG_FIRST_IN) || !head)
+	if (!qp->q.flags & INET_FRAG_FIRST_IN)
 		goto out;
 
+	/* sk_buff::dev and sk_buff::rbnode are unionized. So we
+	 * pull the head out of the tree in order to be able to
+	 * deal with head->dev.
+	 */
+	if (qp->q.fragments) {
+		head = qp->q.fragments;
+		qp->q.fragments = head->next;
+	} else {
+		head = skb_rb_first(&qp->q.rb_fragments);
+		if (!head)
+			goto out;
+		rb_erase(&head->rbnode, &qp->q.rb_fragments);
+		memset(&head->rbnode, 0, sizeof(head->rbnode));
+		barrier();
+	}
+	if (head == qp->q.fragments_tail)
+		qp->q.fragments_tail = NULL;
+
+	sub_frag_mem_limit(qp->q.net, head->truesize);
+
 	head->dev = dev_get_by_index_rcu(net, qp->iif);
 	if (!head->dev)
 		goto out;
@@ -179,16 +196,16 @@ static void ip_expire(struct timer_list *t)
 	    (skb_rtable(head)->rt_type != RTN_LOCAL))
 		goto out;
 
-	skb_get(head);
 	spin_unlock(&qp->q.lock);
 	icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
-	kfree_skb(head);
 	goto out_rcu_unlock;
 
 out:
 	spin_unlock(&qp->q.lock);
 out_rcu_unlock:
 	rcu_read_unlock();
+	if (head)
+		kfree_skb(head);
 	ipq_put(qp);
 }
 
@@ -231,7 +248,7 @@ static int ip_frag_too_far(struct ipq *qp)
 	end = atomic_inc_return(&peer->rid);
 	qp->rid = end;
 
-	rc = qp->q.fragments && (end - start) > max;
+	rc = qp->q.fragments_tail && (end - start) > max;
 
 	if (rc) {
 		struct net *net;
@@ -245,7 +262,6 @@ static int ip_frag_too_far(struct ipq *qp)
 
 static int ip_frag_reinit(struct ipq *qp)
 {
-	struct sk_buff *fp;
 	unsigned int sum_truesize = 0;
 
 	if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) {
@@ -253,20 +269,14 @@ static int ip_frag_reinit(struct ipq *qp)
 		return -ETIMEDOUT;
 	}
 
-	fp = qp->q.fragments;
-	do {
-		struct sk_buff *xp = fp->next;
-
-		sum_truesize += fp->truesize;
-		kfree_skb(fp);
-		fp = xp;
-	} while (fp);
+	sum_truesize = skb_rbtree_purge(&qp->q.rb_fragments);
 	sub_frag_mem_limit(qp->q.net, sum_truesize);
 
 	qp->q.flags = 0;
 	qp->q.len = 0;
 	qp->q.meat = 0;
 	qp->q.fragments = NULL;
+	qp->q.rb_fragments = RB_ROOT;
 	qp->q.fragments_tail = NULL;
 	qp->iif = 0;
 	qp->ecn = 0;
@@ -278,7 +288,8 @@ static int ip_frag_reinit(struct ipq *qp)
 static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 {
 	struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
-	struct sk_buff *prev, *next;
+	struct rb_node **rbn, *parent;
+	struct sk_buff *skb1;
 	struct net_device *dev;
 	unsigned int fragsize;
 	int flags, offset;
@@ -341,58 +352,58 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 	if (err)
 		goto err;
 
-	/* Find out which fragments are in front and at the back of us
-	 * in the chain of fragments so far.  We must know where to put
-	 * this fragment, right?
-	 */
-	prev = qp->q.fragments_tail;
-	if (!prev || prev->ip_defrag_offset < offset) {
-		next = NULL;
-		goto found;
-	}
-	prev = NULL;
-	for (next = qp->q.fragments; next != NULL; next = next->next) {
-		if (next->ip_defrag_offset >= offset)
-			break;	/* bingo! */
-		prev = next;
-	}
+	/* Note : skb->rbnode and skb->dev share the same location. */
+	dev = skb->dev;
+	/* Makes sure compiler wont do silly aliasing games */
+	barrier();
 
-found:
 	/* RFC5722, Section 4, amended by Errata ID : 3089
 	 *                          When reassembling an IPv6 datagram, if
 	 *   one or more its constituent fragments is determined to be an
 	 *   overlapping fragment, the entire datagram (and any constituent
 	 *   fragments) MUST be silently discarded.
 	 *
-	 * We do the same here for IPv4.
+	 * We do the same here for IPv4 (and increment an snmp counter).
 	 */
 
-	/* Is there an overlap with the previous fragment? */
-	if (prev &&
-	    (prev->ip_defrag_offset + prev->len) > offset)
-		goto discard_qp;
-
-	/* Is there an overlap with the next fragment? */
-	if (next && next->ip_defrag_offset < end)
-		goto discard_qp;
+	/* Find out where to put this fragment.  */
+	skb1 = qp->q.fragments_tail;
+	if (!skb1) {
+		/* This is the first fragment we've received. */
+		rb_link_node(&skb->rbnode, NULL, &qp->q.rb_fragments.rb_node);
+		qp->q.fragments_tail = skb;
+	} else if ((skb1->ip_defrag_offset + skb1->len) < end) {
+		/* This is the common/special case: skb goes to the end. */
+		/* Detect and discard overlaps. */
+		if (offset < (skb1->ip_defrag_offset + skb1->len))
+			goto discard_qp;
+		/* Insert after skb1. */
+		rb_link_node(&skb->rbnode, &skb1->rbnode, &skb1->rbnode.rb_right);
+		qp->q.fragments_tail = skb;
+	} else {
+		/* Binary search. Note that skb can become the first fragment, but
+		 * not the last (covered above). */
+		rbn = &qp->q.rb_fragments.rb_node;
+		do {
+			parent = *rbn;
+			skb1 = rb_to_skb(parent);
+			if (end <= skb1->ip_defrag_offset)
+				rbn = &parent->rb_left;
+			else if (offset >= skb1->ip_defrag_offset + skb1->len)
+				rbn = &parent->rb_right;
+			else /* Found an overlap with skb1. */
+				goto discard_qp;
+		} while (*rbn);
+		/* Here we have parent properly set, and rbn pointing to
+		 * one of its NULL left/right children. Insert skb. */
+		rb_link_node(&skb->rbnode, parent, rbn);
+	}
+	rb_insert_color(&skb->rbnode, &qp->q.rb_fragments);
 
-	/* Note : skb->ip_defrag_offset and skb->dev share the same location */
-	dev = skb->dev;
 	if (dev)
 		qp->iif = dev->ifindex;
-	/* Makes sure compiler wont do silly aliasing games */
-	barrier();
 	skb->ip_defrag_offset = offset;
 
-	/* Insert this fragment in the chain of fragments. */
-	skb->next = next;
-	if (!next)
-		qp->q.fragments_tail = skb;
-	if (prev)
-		prev->next = skb;
-	else
-		qp->q.fragments = skb;
-
 	qp->q.stamp = skb->tstamp;
 	qp->q.meat += skb->len;
 	qp->ecn |= ecn;
@@ -414,7 +425,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 		unsigned long orefdst = skb->_skb_refdst;
 
 		skb->_skb_refdst = 0UL;
-		err = ip_frag_reasm(qp, prev, dev);
+		err = ip_frag_reasm(qp, skb, dev);
 		skb->_skb_refdst = orefdst;
 		return err;
 	}
@@ -431,15 +442,15 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 	return err;
 }
 
-
 /* Build a new IP datagram from all its fragments. */
-
-static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
+static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
 			 struct net_device *dev)
 {
 	struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
 	struct iphdr *iph;
-	struct sk_buff *fp, *head = qp->q.fragments;
+	struct sk_buff *fp, *head = skb_rb_first(&qp->q.rb_fragments);
+	struct sk_buff **nextp; /* To build frag_list. */
+	struct rb_node *rbn;
 	int len;
 	int ihlen;
 	int err;
@@ -453,25 +464,20 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 		goto out_fail;
 	}
 	/* Make the one we just received the head. */
-	if (prev) {
-		head = prev->next;
-		fp = skb_clone(head, GFP_ATOMIC);
+	if (head != skb) {
+		fp = skb_clone(skb, GFP_ATOMIC);
 		if (!fp)
 			goto out_nomem;
-
-		fp->next = head->next;
-		if (!fp->next)
+		rb_replace_node(&skb->rbnode, &fp->rbnode, &qp->q.rb_fragments);
+		if (qp->q.fragments_tail == skb)
 			qp->q.fragments_tail = fp;
-		prev->next = fp;
-
-		skb_morph(head, qp->q.fragments);
-		head->next = qp->q.fragments->next;
-
-		consume_skb(qp->q.fragments);
-		qp->q.fragments = head;
+		skb_morph(skb, head);
+		rb_replace_node(&head->rbnode, &skb->rbnode,
+				&qp->q.rb_fragments);
+		consume_skb(head);
+		head = skb;
 	}
 
-	WARN_ON(!head);
 	WARN_ON(head->ip_defrag_offset != 0);
 
 	/* Allocate a new buffer for the datagram. */
@@ -496,24 +502,35 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 		clone = alloc_skb(0, GFP_ATOMIC);
 		if (!clone)
 			goto out_nomem;
-		clone->next = head->next;
-		head->next = clone;
 		skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 		skb_frag_list_init(head);
 		for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
 			plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
 		clone->len = clone->data_len = head->data_len - plen;
-		head->data_len -= clone->len;
-		head->len -= clone->len;
+		skb->truesize += clone->truesize;
 		clone->csum = 0;
 		clone->ip_summed = head->ip_summed;
 		add_frag_mem_limit(qp->q.net, clone->truesize);
+		skb_shinfo(head)->frag_list = clone;
+		nextp = &clone->next;
+	} else {
+		nextp = &skb_shinfo(head)->frag_list;
 	}
 
-	skb_shinfo(head)->frag_list = head->next;
 	skb_push(head, head->data - skb_network_header(head));
 
-	for (fp=head->next; fp; fp = fp->next) {
+	/* Traverse the tree in order, to build frag_list. */
+	rbn = rb_next(&head->rbnode);
+	rb_erase(&head->rbnode, &qp->q.rb_fragments);
+	while (rbn) {
+		struct rb_node *rbnext = rb_next(rbn);
+		fp = rb_to_skb(rbn);
+		rb_erase(rbn, &qp->q.rb_fragments);
+		rbn = rbnext;
+		*nextp = fp;
+		nextp = &fp->next;
+		fp->prev = NULL;
+		memset(&fp->rbnode, 0, sizeof(fp->rbnode));
 		head->data_len += fp->len;
 		head->len += fp->len;
 		if (head->ip_summed != fp->ip_summed)
@@ -524,7 +541,9 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 	}
 	sub_frag_mem_limit(qp->q.net, head->truesize);
 
+	*nextp = NULL;
 	head->next = NULL;
+	head->prev = NULL;
 	head->dev = dev;
 	head->tstamp = qp->q.stamp;
 	IPCB(head)->frag_max_size = max(qp->max_df_size, qp->q.max_size);
@@ -552,6 +571,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 
 	__IP_INC_STATS(net, IPSTATS_MIB_REASMOKS);
 	qp->q.fragments = NULL;
+	qp->q.rb_fragments = RB_ROOT;
 	qp->q.fragments_tail = NULL;
 	return 0;
 
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 1d2f07cde01a..82ce0d0f54bf 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -471,6 +471,7 @@ nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *prev,  struct net_devic
 					  head->csum);
 
 	fq->q.fragments = NULL;
+	fq->q.rb_fragments = RB_ROOT;
 	fq->q.fragments_tail = NULL;
 
 	return true;
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index afaad60dc2ac..ede0061b6f5d 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -472,6 +472,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
 	rcu_read_unlock();
 	fq->q.fragments = NULL;
+	fq->q.rb_fragments = RB_ROOT;
 	fq->q.fragments_tail = NULL;
 	return 1;
 
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 24/30] net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

After working on IP defragmentation lately, I found that some large
packets defeat CHECKSUM_COMPLETE optimization because of NIC adding
zero paddings on the last (small) fragment.

While removing the padding with pskb_trim_rcsum(), we set skb->ip_summed
to CHECKSUM_NONE, forcing a full csum validation, even if all prior
fragments had CHECKSUM_COMPLETE set.

We can instead compute the checksum of the part we are trimming,
usually smaller than the part we keep.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 88078d98d1bb085d72af8437707279e203524fa5)
---
 include/linux/skbuff.h |  5 ++---
 net/core/skbuff.c      | 14 ++++++++++++++
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 9c8457375aee..758084b434c8 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3135,6 +3135,7 @@ static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len)
 	return skb->data;
 }
 
+int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len);
 /**
  *	pskb_trim_rcsum - trim received skb and update checksum
  *	@skb: buffer to trim
@@ -3148,9 +3149,7 @@ static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
 {
 	if (likely(len >= skb->len))
 		return 0;
-	if (skb->ip_summed == CHECKSUM_COMPLETE)
-		skb->ip_summed = CHECKSUM_NONE;
-	return __pskb_trim(skb, len);
+	return pskb_trim_rcsum_slow(skb, len);
 }
 
 static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 8fd690def5c1..168a3e8883d4 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1839,6 +1839,20 @@ int ___pskb_trim(struct sk_buff *skb, unsigned int len)
 }
 EXPORT_SYMBOL(___pskb_trim);
 
+/* Note : use pskb_trim_rcsum() instead of calling this directly
+ */
+int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len)
+{
+	if (skb->ip_summed == CHECKSUM_COMPLETE) {
+		int delta = skb->len - len;
+
+		skb->csum = csum_sub(skb->csum,
+				     skb_checksum(skb, len, delta, 0));
+	}
+	return __pskb_trim(skb, len);
+}
+EXPORT_SYMBOL(pskb_trim_rcsum_slow);
+
 /**
  *	__pskb_pull_tail - advance tail of skb header
  *	@skb: buffer to reallocate
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 23/30] ipv6: defrag: drop non-last frags smaller than min mtu
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet, Florian Westphal, Peter Oskolkov
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Florian Westphal <fw@strlen.de>

don't bother with pathological cases, they only waste cycles.
IPv6 requires a minimum MTU of 1280 so we should never see fragments
smaller than this (except last frag).

v3: don't use awkward "-offset + len"
v2: drop IPv4 part, which added same check w. IPV4_MIN_MTU (68).
    There were concerns that there could be even smaller frags
    generated by intermediate nodes, e.g. on radio networks.

Cc: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 0ed4229b08c13c84a3c301a08defdc9e7f4467e6)
---
 net/ipv6/netfilter/nf_conntrack_reasm.c | 4 ++++
 net/ipv6/reassembly.c                   | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index a1dc0d6a5949..1d2f07cde01a 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -565,6 +565,10 @@ int nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user)
 	hdr = ipv6_hdr(skb);
 	fhdr = (struct frag_hdr *)skb_transport_header(skb);
 
+	if (skb->len - skb_network_offset(skb) < IPV6_MIN_MTU &&
+	    fhdr->frag_off & htons(IP6_MF))
+		return -EINVAL;
+
 	skb_orphan(skb);
 	fq = fq_find(net, fhdr->identification, user, hdr,
 		     skb->dev ? skb->dev->ifindex : 0);
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index e1c5fa5e3873..afaad60dc2ac 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -522,6 +522,10 @@ static int ipv6_frag_rcv(struct sk_buff *skb)
 		return 1;
 	}
 
+	if (skb->len - skb_network_offset(skb) < IPV6_MIN_MTU &&
+	    fhdr->frag_off & htons(IP6_MF))
+		goto fail_hdr;
+
 	iif = skb->dev ? skb->dev->ifindex : 0;
 	fq = fq_find(net, fhdr->identification, hdr, iif);
 	if (fq) {
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 20/30] ip: discard IPv4 datagrams with overlapping segments.
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet, Peter Oskolkov, Florian Westphal
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Peter Oskolkov <posk@google.com>

This behavior is required in IPv6, and there is little need
to tolerate overlapping fragments in IPv4. This change
simplifies the code and eliminates potential DDoS attack vectors.

Tested: ran ip_defrag selftest (not yet available uptream).

Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 7969e5c40dfd04799d4341f1b7cd266b6e47f227)
---
 include/uapi/linux/snmp.h |  1 +
 net/ipv4/ip_fragment.c    | 75 ++++++++++-----------------------------
 net/ipv4/proc.c           |  1 +
 3 files changed, 21 insertions(+), 56 deletions(-)

diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index 0d941cdd8e8c..f5d753e60836 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -56,6 +56,7 @@ enum
 	IPSTATS_MIB_ECT1PKTS,			/* InECT1Pkts */
 	IPSTATS_MIB_ECT0PKTS,			/* InECT0Pkts */
 	IPSTATS_MIB_CEPKTS,			/* InCEPkts */
+	IPSTATS_MIB_REASM_OVERLAPS,		/* ReasmOverlaps */
 	__IPSTATS_MIB_MAX
 };
 
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index d14d741fb05e..960bf5eab59f 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -277,6 +277,7 @@ static int ip_frag_reinit(struct ipq *qp)
 /* Add new segment to existing queue. */
 static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 {
+	struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
 	struct sk_buff *prev, *next;
 	struct net_device *dev;
 	unsigned int fragsize;
@@ -357,65 +358,23 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 	}
 
 found:
-	/* We found where to put this one.  Check for overlap with
-	 * preceding fragment, and, if needed, align things so that
-	 * any overlaps are eliminated.
+	/* RFC5722, Section 4, amended by Errata ID : 3089
+	 *                          When reassembling an IPv6 datagram, if
+	 *   one or more its constituent fragments is determined to be an
+	 *   overlapping fragment, the entire datagram (and any constituent
+	 *   fragments) MUST be silently discarded.
+	 *
+	 * We do the same here for IPv4.
 	 */
-	if (prev) {
-		int i = (prev->ip_defrag_offset + prev->len) - offset;
 
-		if (i > 0) {
-			offset += i;
-			err = -EINVAL;
-			if (end <= offset)
-				goto err;
-			err = -ENOMEM;
-			if (!pskb_pull(skb, i))
-				goto err;
-			if (skb->ip_summed != CHECKSUM_UNNECESSARY)
-				skb->ip_summed = CHECKSUM_NONE;
-		}
-	}
+	/* Is there an overlap with the previous fragment? */
+	if (prev &&
+	    (prev->ip_defrag_offset + prev->len) > offset)
+		goto discard_qp;
 
-	err = -ENOMEM;
-
-	while (next && next->ip_defrag_offset < end) {
-		int i = end - next->ip_defrag_offset; /* overlap is 'i' bytes */
-
-		if (i < next->len) {
-			int delta = -next->truesize;
-
-			/* Eat head of the next overlapped fragment
-			 * and leave the loop. The next ones cannot overlap.
-			 */
-			if (!pskb_pull(next, i))
-				goto err;
-			delta += next->truesize;
-			if (delta)
-				add_frag_mem_limit(qp->q.net, delta);
-			next->ip_defrag_offset += i;
-			qp->q.meat -= i;
-			if (next->ip_summed != CHECKSUM_UNNECESSARY)
-				next->ip_summed = CHECKSUM_NONE;
-			break;
-		} else {
-			struct sk_buff *free_it = next;
-
-			/* Old fragment is completely overridden with
-			 * new one drop it.
-			 */
-			next = next->next;
-
-			if (prev)
-				prev->next = next;
-			else
-				qp->q.fragments = next;
-
-			qp->q.meat -= free_it->len;
-			sub_frag_mem_limit(qp->q.net, free_it->truesize);
-			kfree_skb(free_it);
-		}
-	}
+	/* Is there an overlap with the next fragment? */
+	if (next && next->ip_defrag_offset < end)
+		goto discard_qp;
 
 	/* Note : skb->ip_defrag_offset and skb->dev share the same location */
 	dev = skb->dev;
@@ -463,6 +422,10 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 	skb_dst_drop(skb);
 	return -EINPROGRESS;
 
+discard_qp:
+	inet_frag_kill(&qp->q);
+	err = -EINVAL;
+	__IP_INC_STATS(net, IPSTATS_MIB_REASM_OVERLAPS);
 err:
 	kfree_skb(skb);
 	return err;
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 8fbd5633e544..3fbf688a1943 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -132,6 +132,7 @@ static const struct snmp_mib snmp4_ipextstats_list[] = {
 	SNMP_MIB_ITEM("InECT1Pkts", IPSTATS_MIB_ECT1PKTS),
 	SNMP_MIB_ITEM("InECT0Pkts", IPSTATS_MIB_ECT0PKTS),
 	SNMP_MIB_ITEM("InCEPkts", IPSTATS_MIB_CEPKTS),
+	SNMP_MIB_ITEM("ReasmOverlaps", IPSTATS_MIB_REASM_OVERLAPS),
 	SNMP_MIB_SENTINEL
 };
 
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 19/30] inet: frags: fix ip6frag_low_thresh boundary
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

Giving an integer to proc_doulongvec_minmax() is dangerous on 64bit arches,
since linker might place next to it a non zero value preventing a change
to ip6frag_low_thresh.

ip6frag_low_thresh is not used anymore in the kernel, but we do not
want to prematuraly break user scripts wanting to change it.

Since specifying a minimal value of 0 for proc_doulongvec_minmax()
is moot, let's remove these zero values in all defrag units.

Fixes: 6e00f7dd5e4e ("ipv6: frags: fix /proc/sys/net/ipv6/ip6frag_low_thresh")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 3d23401283e80ceb03f765842787e0e79ff598b7)
---
 net/ieee802154/6lowpan/reassembly.c     | 2 --
 net/ipv4/ip_fragment.c                  | 5 ++---
 net/ipv6/netfilter/nf_conntrack_reasm.c | 2 --
 net/ipv6/reassembly.c                   | 4 +---
 4 files changed, 3 insertions(+), 10 deletions(-)

diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c
index 44f148a6bb57..1790b65944b3 100644
--- a/net/ieee802154/6lowpan/reassembly.c
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -411,7 +411,6 @@ int lowpan_frag_rcv(struct sk_buff *skb, u8 frag_type)
 }
 
 #ifdef CONFIG_SYSCTL
-static long zero;
 
 static struct ctl_table lowpan_frags_ns_ctl_table[] = {
 	{
@@ -428,7 +427,6 @@ static struct ctl_table lowpan_frags_ns_ctl_table[] = {
 		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
 		.proc_handler	= proc_doulongvec_minmax,
-		.extra1		= &zero,
 		.extra2		= &init_net.ieee802154_lowpan.frags.high_thresh
 	},
 	{
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 5331a0d68374..d14d741fb05e 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -672,7 +672,7 @@ struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
 EXPORT_SYMBOL(ip_check_defrag);
 
 #ifdef CONFIG_SYSCTL
-static long zero;
+static int dist_min;
 
 static struct ctl_table ip4_frags_ns_ctl_table[] = {
 	{
@@ -689,7 +689,6 @@ static struct ctl_table ip4_frags_ns_ctl_table[] = {
 		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
 		.proc_handler	= proc_doulongvec_minmax,
-		.extra1		= &zero,
 		.extra2		= &init_net.ipv4.frags.high_thresh
 	},
 	{
@@ -705,7 +704,7 @@ static struct ctl_table ip4_frags_ns_ctl_table[] = {
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= &zero
+		.extra1		= &dist_min,
 	},
 	{ }
 };
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 6613f81e553a..a1dc0d6a5949 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -63,7 +63,6 @@ struct nf_ct_frag6_skb_cb
 static struct inet_frags nf_frags;
 
 #ifdef CONFIG_SYSCTL
-static long zero;
 
 static struct ctl_table nf_ct_frag6_sysctl_table[] = {
 	{
@@ -79,7 +78,6 @@ static struct ctl_table nf_ct_frag6_sysctl_table[] = {
 		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
 		.proc_handler	= proc_doulongvec_minmax,
-		.extra1		= &zero,
 		.extra2		= &init_net.nf_frag.frags.high_thresh
 	},
 	{
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 2127da130dc2..e1c5fa5e3873 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -554,7 +554,6 @@ static const struct inet6_protocol frag_protocol = {
 };
 
 #ifdef CONFIG_SYSCTL
-static int zero;
 
 static struct ctl_table ip6_frags_ns_ctl_table[] = {
 	{
@@ -570,8 +569,7 @@ static struct ctl_table ip6_frags_ns_ctl_table[] = {
 		.data		= &init_net.ipv6.frags.low_thresh,
 		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= &zero,
+		.proc_handler	= proc_doulongvec_minmax,
 		.extra2		= &init_net.ipv6.frags.high_thresh
 	},
 	{
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 18/30] inet: frags: get rid of ipfrag_skb_cb/FRAG_CB
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

ip_defrag uses skb->cb[] to store the fragment offset, and unfortunately
this integer is currently in a different cache line than skb->next,
meaning that we use two cache lines per skb when finding the insertion point.

By aliasing skb->ip_defrag_offset and skb->dev, we pack all the fields
in a single cache line and save precious memory bandwidth.

Note that after the fast path added by Changli Gao in commit
d6bebca92c66 ("fragment: add fast path for in-order fragments")
this change wont help the fast path, since we still need
to access prev->len (2nd cache line), but will show great
benefits when slow path is entered, since we perform
a linear scan of a potentially long list.

Also, note that this potential long list is an attack vector,
we might consider also using an rb-tree there eventually.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit bf66337140c64c27fa37222b7abca7e49d63fb57)
---
 include/linux/skbuff.h |  1 +
 net/ipv4/ip_fragment.c | 35 ++++++++++++++---------------------
 2 files changed, 15 insertions(+), 21 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 6dd77767fd5b..f4749678b7ee 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -678,6 +678,7 @@ struct sk_buff {
 		 * UDP receive path is one user.
 		 */
 		unsigned long		dev_scratch;
+		int			ip_defrag_offset;
 	};
 	/*
 	 * This is the control buffer. It is free to use for every
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 88fa8ffc5558..5331a0d68374 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -57,14 +57,6 @@
  */
 static const char ip_frag_cache_name[] = "ip4-frags";
 
-struct ipfrag_skb_cb
-{
-	struct inet_skb_parm	h;
-	int			offset;
-};
-
-#define FRAG_CB(skb)	((struct ipfrag_skb_cb *)((skb)->cb))
-
 /* Describe an entry in the "incomplete datagrams" queue. */
 struct ipq {
 	struct inet_frag_queue q;
@@ -353,13 +345,13 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 	 * this fragment, right?
 	 */
 	prev = qp->q.fragments_tail;
-	if (!prev || FRAG_CB(prev)->offset < offset) {
+	if (!prev || prev->ip_defrag_offset < offset) {
 		next = NULL;
 		goto found;
 	}
 	prev = NULL;
 	for (next = qp->q.fragments; next != NULL; next = next->next) {
-		if (FRAG_CB(next)->offset >= offset)
+		if (next->ip_defrag_offset >= offset)
 			break;	/* bingo! */
 		prev = next;
 	}
@@ -370,7 +362,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 	 * any overlaps are eliminated.
 	 */
 	if (prev) {
-		int i = (FRAG_CB(prev)->offset + prev->len) - offset;
+		int i = (prev->ip_defrag_offset + prev->len) - offset;
 
 		if (i > 0) {
 			offset += i;
@@ -387,8 +379,8 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 
 	err = -ENOMEM;
 
-	while (next && FRAG_CB(next)->offset < end) {
-		int i = end - FRAG_CB(next)->offset; /* overlap is 'i' bytes */
+	while (next && next->ip_defrag_offset < end) {
+		int i = end - next->ip_defrag_offset; /* overlap is 'i' bytes */
 
 		if (i < next->len) {
 			int delta = -next->truesize;
@@ -401,7 +393,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 			delta += next->truesize;
 			if (delta)
 				add_frag_mem_limit(qp->q.net, delta);
-			FRAG_CB(next)->offset += i;
+			next->ip_defrag_offset += i;
 			qp->q.meat -= i;
 			if (next->ip_summed != CHECKSUM_UNNECESSARY)
 				next->ip_summed = CHECKSUM_NONE;
@@ -425,7 +417,13 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 		}
 	}
 
-	FRAG_CB(skb)->offset = offset;
+	/* Note : skb->ip_defrag_offset and skb->dev share the same location */
+	dev = skb->dev;
+	if (dev)
+		qp->iif = dev->ifindex;
+	/* Makes sure compiler wont do silly aliasing games */
+	barrier();
+	skb->ip_defrag_offset = offset;
 
 	/* Insert this fragment in the chain of fragments. */
 	skb->next = next;
@@ -436,11 +434,6 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 	else
 		qp->q.fragments = skb;
 
-	dev = skb->dev;
-	if (dev) {
-		qp->iif = dev->ifindex;
-		skb->dev = NULL;
-	}
 	qp->q.stamp = skb->tstamp;
 	qp->q.meat += skb->len;
 	qp->ecn |= ecn;
@@ -516,7 +509,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 	}
 
 	WARN_ON(!head);
-	WARN_ON(FRAG_CB(head)->offset != 0);
+	WARN_ON(head->ip_defrag_offset != 0);
 
 	/* Allocate a new buffer for the datagram. */
 	ihlen = ip_hdrlen(head);
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 17/30] inet: frags: reorganize struct netns_frags
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

Put the read-mostly fields in a separate cache line
at the beginning of struct netns_frags, to reduce
false sharing noticed in inet_frag_kill()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit c2615cf5a761b32bf74e85bddc223dfff3d9b9f0)
---
 include/net/inet_frag.h | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index a52e7273e7a5..ed07e3786d98 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -5,16 +5,17 @@
 #include <linux/rhashtable.h>
 
 struct netns_frags {
-	struct rhashtable       rhashtable ____cacheline_aligned_in_smp;
-
-	/* Keep atomic mem on separate cachelines in structs that include it */
-	atomic_long_t		mem ____cacheline_aligned_in_smp;
 	/* sysctls */
 	long			high_thresh;
 	long			low_thresh;
 	int			timeout;
 	int			max_dist;
 	struct inet_frags	*f;
+
+	struct rhashtable       rhashtable ____cacheline_aligned_in_smp;
+
+	/* Keep atomic mem on separate cachelines in structs that include it */
+	atomic_long_t		mem ____cacheline_aligned_in_smp;
 };
 
 /**
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 15/30] ipv6: frags: rewrite ip6_expire_frag_queue()
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

Make it similar to IPv4 ip_expire(), and release the lock
before calling icmp functions.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 05c0b86b9696802fd0ce5676a92a63f1b455bdf3)
---
 net/ipv6/reassembly.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 905a8aee2671..2127da130dc2 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -92,7 +92,9 @@ EXPORT_SYMBOL(ip6_frag_init);
 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq)
 {
 	struct net_device *dev = NULL;
+	struct sk_buff *head;
 
+	rcu_read_lock();
 	spin_lock(&fq->q.lock);
 
 	if (fq->q.flags & INET_FRAG_COMPLETE)
@@ -100,28 +102,34 @@ void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq)
 
 	inet_frag_kill(&fq->q);
 
-	rcu_read_lock();
 	dev = dev_get_by_index_rcu(net, fq->iif);
 	if (!dev)
-		goto out_rcu_unlock;
+		goto out;
 
 	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
 	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
 
 	/* Don't send error if the first segment did not arrive. */
-	if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !fq->q.fragments)
-		goto out_rcu_unlock;
+	head = fq->q.fragments;
+	if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !head)
+		goto out;
 
 	/* But use as source device on which LAST ARRIVED
 	 * segment was received. And do not use fq->dev
 	 * pointer directly, device might already disappeared.
 	 */
-	fq->q.fragments->dev = dev;
-	icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
-out_rcu_unlock:
-	rcu_read_unlock();
+	head->dev = dev;
+	skb_get(head);
+	spin_unlock(&fq->q.lock);
+
+	icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
+	kfree_skb(head);
+	goto out_rcu_unlock;
+
 out:
 	spin_unlock(&fq->q.lock);
+out_rcu_unlock:
+	rcu_read_unlock();
 	inet_frag_put(&fq->q);
 }
 EXPORT_SYMBOL(ip6_expire_frag_queue);
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 14/30] inet: frags: do not clone skb in ip_expire()
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

An skb_clone() was added in commit ec4fbd64751d ("inet: frag: release
spinlock before calling icmp_send()")

While fixing the bug at that time, it also added a very high cost
for DDOS frags, as the ICMP rate limit is applied after this
expensive operation (skb_clone() + consume_skb(), implying memory
allocations, copy, and freeing)

We can use skb_get(head) here, all we want is to make sure skb wont
be freed by another cpu.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 1eec5d5670084ee644597bd26c25e22c69b9f748)
---
 net/ipv4/ip_fragment.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index dc3ed0ac4c58..88fa8ffc5558 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -143,8 +143,8 @@ static bool frag_expire_skip_icmp(u32 user)
 static void ip_expire(struct timer_list *t)
 {
 	struct inet_frag_queue *frag = from_timer(frag, t, timer);
-	struct sk_buff *clone, *head;
 	const struct iphdr *iph;
+	struct sk_buff *head;
 	struct net *net;
 	struct ipq *qp;
 	int err;
@@ -187,16 +187,12 @@ static void ip_expire(struct timer_list *t)
 	    (skb_rtable(head)->rt_type != RTN_LOCAL))
 		goto out;
 
-	clone = skb_clone(head, GFP_ATOMIC);
+	skb_get(head);
+	spin_unlock(&qp->q.lock);
+	icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
+	kfree_skb(head);
+	goto out_rcu_unlock;
 
-	/* Send an ICMP "Fragment Reassembly Timeout" message. */
-	if (clone) {
-		spin_unlock(&qp->q.lock);
-		icmp_send(clone, ICMP_TIME_EXCEEDED,
-			  ICMP_EXC_FRAGTIME, 0);
-		consume_skb(clone);
-		goto out_rcu_unlock;
-	}
 out:
 	spin_unlock(&qp->q.lock);
 out_rcu_unlock:
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 13/30] inet: frags: break the 2GB limit for frags storage
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

Some users are willing to provision huge amounts of memory to be able
to perform reassembly reasonnably well under pressure.

Current memory tracking is using one atomic_t and integers.

Switch to atomic_long_t so that 64bit arches can use more than 2GB,
without any cost for 32bit arches.

Note that this patch avoids an overflow error, if high_thresh was set
to ~2GB, since this test in inet_frag_alloc() was never true :

if (... || frag_mem_limit(nf) > nf->high_thresh)

Tested:

$ echo 16000000000 >/proc/sys/net/ipv4/ipfrag_high_thresh

<frag DDOS>

$ grep FRAG /proc/net/sockstat
FRAG: inuse 14705885 memory 16000002880

$ nstat -n ; sleep 1 ; nstat | grep Reas
IpReasmReqds                    3317150            0.0
IpReasmFails                    3317112            0.0

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 3e67f106f619dcfaf6f4e2039599bdb69848c714)
---
 Documentation/networking/ip-sysctl.txt  |  4 ++--
 include/net/inet_frag.h                 | 20 ++++++++++----------
 net/ieee802154/6lowpan/reassembly.c     | 10 +++++-----
 net/ipv4/ip_fragment.c                  | 10 +++++-----
 net/ipv4/proc.c                         |  2 +-
 net/ipv6/netfilter/nf_conntrack_reasm.c | 10 +++++-----
 net/ipv6/proc.c                         |  2 +-
 net/ipv6/reassembly.c                   |  6 +++---
 8 files changed, 32 insertions(+), 32 deletions(-)

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index f23582a3c661..a054b5ad410a 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -133,10 +133,10 @@ min_adv_mss - INTEGER
 
 IP Fragmentation:
 
-ipfrag_high_thresh - INTEGER
+ipfrag_high_thresh - LONG INTEGER
 	Maximum memory used to reassemble IP fragments.
 
-ipfrag_low_thresh - INTEGER
+ipfrag_low_thresh - LONG INTEGER
 	(Obsolete since linux-4.17)
 	Maximum memory used to reassemble IP fragments before the kernel
 	begins to remove incomplete fragment queues to free up resources.
diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index 95e353e3305b..a52e7273e7a5 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -8,11 +8,11 @@ struct netns_frags {
 	struct rhashtable       rhashtable ____cacheline_aligned_in_smp;
 
 	/* Keep atomic mem on separate cachelines in structs that include it */
-	atomic_t		mem ____cacheline_aligned_in_smp;
+	atomic_long_t		mem ____cacheline_aligned_in_smp;
 	/* sysctls */
+	long			high_thresh;
+	long			low_thresh;
 	int			timeout;
-	int			high_thresh;
-	int			low_thresh;
 	int			max_dist;
 	struct inet_frags	*f;
 };
@@ -102,7 +102,7 @@ void inet_frags_fini(struct inet_frags *);
 
 static inline int inet_frags_init_net(struct netns_frags *nf)
 {
-	atomic_set(&nf->mem, 0);
+	atomic_long_set(&nf->mem, 0);
 	return rhashtable_init(&nf->rhashtable, &nf->f->rhash_params);
 }
 void inet_frags_exit_net(struct netns_frags *nf);
@@ -119,19 +119,19 @@ static inline void inet_frag_put(struct inet_frag_queue *q)
 
 /* Memory Tracking Functions. */
 
-static inline int frag_mem_limit(struct netns_frags *nf)
+static inline long frag_mem_limit(const struct netns_frags *nf)
 {
-	return atomic_read(&nf->mem);
+	return atomic_long_read(&nf->mem);
 }
 
-static inline void sub_frag_mem_limit(struct netns_frags *nf, int i)
+static inline void sub_frag_mem_limit(struct netns_frags *nf, long val)
 {
-	atomic_sub(i, &nf->mem);
+	atomic_long_sub(val, &nf->mem);
 }
 
-static inline void add_frag_mem_limit(struct netns_frags *nf, int i)
+static inline void add_frag_mem_limit(struct netns_frags *nf, long val)
 {
-	atomic_add(i, &nf->mem);
+	atomic_long_add(val, &nf->mem);
 }
 
 /* RFC 3168 support :
diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c
index 1aec71a3f904..44f148a6bb57 100644
--- a/net/ieee802154/6lowpan/reassembly.c
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -411,23 +411,23 @@ int lowpan_frag_rcv(struct sk_buff *skb, u8 frag_type)
 }
 
 #ifdef CONFIG_SYSCTL
-static int zero;
+static long zero;
 
 static struct ctl_table lowpan_frags_ns_ctl_table[] = {
 	{
 		.procname	= "6lowpanfrag_high_thresh",
 		.data		= &init_net.ieee802154_lowpan.frags.high_thresh,
-		.maxlen		= sizeof(int),
+		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
+		.proc_handler	= proc_doulongvec_minmax,
 		.extra1		= &init_net.ieee802154_lowpan.frags.low_thresh
 	},
 	{
 		.procname	= "6lowpanfrag_low_thresh",
 		.data		= &init_net.ieee802154_lowpan.frags.low_thresh,
-		.maxlen		= sizeof(int),
+		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
+		.proc_handler	= proc_doulongvec_minmax,
 		.extra1		= &zero,
 		.extra2		= &init_net.ieee802154_lowpan.frags.high_thresh
 	},
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 38cbf56bb48e..dc3ed0ac4c58 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -683,23 +683,23 @@ struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
 EXPORT_SYMBOL(ip_check_defrag);
 
 #ifdef CONFIG_SYSCTL
-static int zero;
+static long zero;
 
 static struct ctl_table ip4_frags_ns_ctl_table[] = {
 	{
 		.procname	= "ipfrag_high_thresh",
 		.data		= &init_net.ipv4.frags.high_thresh,
-		.maxlen		= sizeof(int),
+		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
+		.proc_handler	= proc_doulongvec_minmax,
 		.extra1		= &init_net.ipv4.frags.low_thresh
 	},
 	{
 		.procname	= "ipfrag_low_thresh",
 		.data		= &init_net.ipv4.frags.low_thresh,
-		.maxlen		= sizeof(int),
+		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
+		.proc_handler	= proc_doulongvec_minmax,
 		.extra1		= &zero,
 		.extra2		= &init_net.ipv4.frags.high_thresh
 	},
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 01a337c3a36b..8fbd5633e544 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -71,7 +71,7 @@ static int sockstat_seq_show(struct seq_file *seq, void *v)
 		   sock_prot_inuse_get(net, &udplite_prot));
 	seq_printf(seq, "RAW: inuse %d\n",
 		   sock_prot_inuse_get(net, &raw_prot));
-	seq_printf(seq,  "FRAG: inuse %u memory %u\n",
+	seq_printf(seq,  "FRAG: inuse %u memory %lu\n",
 		   atomic_read(&net->ipv4.frags.rhashtable.nelems),
 		   frag_mem_limit(&net->ipv4.frags));
 	return 0;
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 54ce1d2a9a9d..6613f81e553a 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -63,7 +63,7 @@ struct nf_ct_frag6_skb_cb
 static struct inet_frags nf_frags;
 
 #ifdef CONFIG_SYSCTL
-static int zero;
+static long zero;
 
 static struct ctl_table nf_ct_frag6_sysctl_table[] = {
 	{
@@ -76,18 +76,18 @@ static struct ctl_table nf_ct_frag6_sysctl_table[] = {
 	{
 		.procname	= "nf_conntrack_frag6_low_thresh",
 		.data		= &init_net.nf_frag.frags.low_thresh,
-		.maxlen		= sizeof(unsigned int),
+		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
+		.proc_handler	= proc_doulongvec_minmax,
 		.extra1		= &zero,
 		.extra2		= &init_net.nf_frag.frags.high_thresh
 	},
 	{
 		.procname	= "nf_conntrack_frag6_high_thresh",
 		.data		= &init_net.nf_frag.frags.high_thresh,
-		.maxlen		= sizeof(unsigned int),
+		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
+		.proc_handler	= proc_doulongvec_minmax,
 		.extra1		= &init_net.nf_frag.frags.low_thresh
 	},
 	{ }
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index 5704ec3d3178..dc04c024986c 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -47,7 +47,7 @@ static int sockstat6_seq_show(struct seq_file *seq, void *v)
 			sock_prot_inuse_get(net, &udplitev6_prot));
 	seq_printf(seq, "RAW6: inuse %d\n",
 		       sock_prot_inuse_get(net, &rawv6_prot));
-	seq_printf(seq, "FRAG6: inuse %u memory %u\n",
+	seq_printf(seq, "FRAG6: inuse %u memory %lu\n",
 		   atomic_read(&net->ipv6.frags.rhashtable.nelems),
 		   frag_mem_limit(&net->ipv6.frags));
 	return 0;
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 2a77fda5e3bc..905a8aee2671 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -552,15 +552,15 @@ static struct ctl_table ip6_frags_ns_ctl_table[] = {
 	{
 		.procname	= "ip6frag_high_thresh",
 		.data		= &init_net.ipv6.frags.high_thresh,
-		.maxlen		= sizeof(int),
+		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
+		.proc_handler	= proc_doulongvec_minmax,
 		.extra1		= &init_net.ipv6.frags.low_thresh
 	},
 	{
 		.procname	= "ip6frag_low_thresh",
 		.data		= &init_net.ipv6.frags.low_thresh,
-		.maxlen		= sizeof(int),
+		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= &zero,
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 09/30] inet: frags: use rhashtables for reassembly units
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh
  Cc: netdev, stable, edumazet, Kirill Tkhai, Herbert Xu,
	Florian Westphal, Jesper Dangaard Brouer, Alexander Aring,
	Stefan Schmidt
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

Some applications still rely on IP fragmentation, and to be fair linux
reassembly unit is not working under any serious load.

It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!)

A work queue is supposed to garbage collect items when host is under memory
pressure, and doing a hash rebuild, changing seed used in hash computations.

This work queue blocks softirqs for up to 25 ms when doing a hash rebuild,
occurring every 5 seconds if host is under fire.

Then there is the problem of sharing this hash table for all netns.

It is time to switch to rhashtables, and allocate one of them per netns
to speedup netns dismantle, since this is a critical metric these days.

Lookup is now using RCU. A followup patch will even remove
the refcount hold/release left from prior implementation and save
a couple of atomic operations.

Before this patch, 16 cpus (16 RX queue NIC) could not handle more
than 1 Mpps frags DDOS.

After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB
of storage for the fragments (exact number depends on frags being evicted
after timeout)

$ grep FRAG /proc/net/sockstat
FRAG: inuse 1966916 memory 2140004608

A followup patch will change the limits for 64bit arches.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Florian Westphal <fw@strlen.de>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Alexander Aring <alex.aring@gmail.com>
Cc: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 648700f76b03b7e8149d13cc2bdb3355035258a9)
---
 Documentation/networking/ip-sysctl.txt  |   7 +-
 include/net/inet_frag.h                 |  81 +++---
 include/net/ipv6.h                      |  16 +-
 net/ieee802154/6lowpan/6lowpan_i.h      |  26 +-
 net/ieee802154/6lowpan/reassembly.c     |  91 +++----
 net/ipv4/inet_fragment.c                | 346 +++++-------------------
 net/ipv4/ip_fragment.c                  | 112 ++++----
 net/ipv6/netfilter/nf_conntrack_reasm.c |  51 +---
 net/ipv6/reassembly.c                   | 110 ++++----
 9 files changed, 266 insertions(+), 574 deletions(-)

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index d499676890d8..f23582a3c661 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -134,13 +134,10 @@ min_adv_mss - INTEGER
 IP Fragmentation:
 
 ipfrag_high_thresh - INTEGER
-	Maximum memory used to reassemble IP fragments. When
-	ipfrag_high_thresh bytes of memory is allocated for this purpose,
-	the fragment handler will toss packets until ipfrag_low_thresh
-	is reached. This also serves as a maximum limit to namespaces
-	different from the initial one.
+	Maximum memory used to reassemble IP fragments.
 
 ipfrag_low_thresh - INTEGER
+	(Obsolete since linux-4.17)
 	Maximum memory used to reassemble IP fragments before the kernel
 	begins to remove incomplete fragment queues to free up resources.
 	The kernel still accepts new fragments for defragmentation.
diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index 69e531ed8189..3fec0d3a0d01 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -2,7 +2,11 @@
 #ifndef __NET_FRAG_H__
 #define __NET_FRAG_H__
 
+#include <linux/rhashtable.h>
+
 struct netns_frags {
+	struct rhashtable       rhashtable ____cacheline_aligned_in_smp;
+
 	/* Keep atomic mem on separate cachelines in structs that include it */
 	atomic_t		mem ____cacheline_aligned_in_smp;
 	/* sysctls */
@@ -26,12 +30,30 @@ enum {
 	INET_FRAG_COMPLETE	= BIT(2),
 };
 
+struct frag_v4_compare_key {
+	__be32		saddr;
+	__be32		daddr;
+	u32		user;
+	u32		vif;
+	__be16		id;
+	u16		protocol;
+};
+
+struct frag_v6_compare_key {
+	struct in6_addr	saddr;
+	struct in6_addr	daddr;
+	u32		user;
+	__be32		id;
+	u32		iif;
+};
+
 /**
  * struct inet_frag_queue - fragment queue
  *
- * @lock: spinlock protecting the queue
+ * @node: rhash node
+ * @key: keys identifying this frag.
  * @timer: queue expiration timer
- * @list: hash bucket list
+ * @lock: spinlock protecting this frag
  * @refcnt: reference count of the queue
  * @fragments: received fragments head
  * @fragments_tail: received fragments tail
@@ -41,12 +63,16 @@ enum {
  * @flags: fragment queue flags
  * @max_size: maximum received fragment size
  * @net: namespace that this frag belongs to
- * @list_evictor: list of queues to forcefully evict (e.g. due to low memory)
+ * @rcu: rcu head for freeing deferall
  */
 struct inet_frag_queue {
-	spinlock_t		lock;
+	struct rhash_head	node;
+	union {
+		struct frag_v4_compare_key v4;
+		struct frag_v6_compare_key v6;
+	} key;
 	struct timer_list	timer;
-	struct hlist_node	list;
+	spinlock_t		lock;
 	refcount_t		refcnt;
 	struct sk_buff		*fragments;
 	struct sk_buff		*fragments_tail;
@@ -55,51 +81,20 @@ struct inet_frag_queue {
 	int			meat;
 	__u8			flags;
 	u16			max_size;
-	struct netns_frags	*net;
-	struct hlist_node	list_evictor;
-};
-
-#define INETFRAGS_HASHSZ	1024
-
-/* averaged:
- * max_depth = default ipfrag_high_thresh / INETFRAGS_HASHSZ /
- *	       rounded up (SKB_TRUELEN(0) + sizeof(struct ipq or
- *	       struct frag_queue))
- */
-#define INETFRAGS_MAXDEPTH	128
-
-struct inet_frag_bucket {
-	struct hlist_head	chain;
-	spinlock_t		chain_lock;
+	struct netns_frags      *net;
+	struct rcu_head		rcu;
 };
 
 struct inet_frags {
-	struct inet_frag_bucket	hash[INETFRAGS_HASHSZ];
-
-	struct work_struct	frags_work;
-	unsigned int next_bucket;
-	unsigned long last_rebuild_jiffies;
-	bool rebuild;
-
-	/* The first call to hashfn is responsible to initialize
-	 * rnd. This is best done with net_get_random_once.
-	 *
-	 * rnd_seqlock is used to let hash insertion detect
-	 * when it needs to re-lookup the hash chain to use.
-	 */
-	u32			rnd;
-	seqlock_t		rnd_seqlock;
 	unsigned int		qsize;
 
-	unsigned int		(*hashfn)(const struct inet_frag_queue *);
-	bool			(*match)(const struct inet_frag_queue *q,
-					 const void *arg);
 	void			(*constructor)(struct inet_frag_queue *q,
 					       const void *arg);
 	void			(*destructor)(struct inet_frag_queue *);
 	void			(*frag_expire)(struct timer_list *t);
 	struct kmem_cache	*frags_cachep;
 	const char		*frags_cache_name;
+	struct rhashtable_params rhash_params;
 };
 
 int inet_frags_init(struct inet_frags *);
@@ -108,15 +103,13 @@ void inet_frags_fini(struct inet_frags *);
 static inline int inet_frags_init_net(struct netns_frags *nf)
 {
 	atomic_set(&nf->mem, 0);
-	return 0;
+	return rhashtable_init(&nf->rhashtable, &nf->f->rhash_params);
 }
 void inet_frags_exit_net(struct netns_frags *nf);
 
 void inet_frag_kill(struct inet_frag_queue *q);
 void inet_frag_destroy(struct inet_frag_queue *q);
-struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
-		struct inet_frags *f, void *key, unsigned int hash);
-
+struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, void *key);
 void inet_frag_maybe_warn_overflow(struct inet_frag_queue *q,
 				   const char *prefix);
 
@@ -128,7 +121,7 @@ static inline void inet_frag_put(struct inet_frag_queue *q)
 
 static inline bool inet_frag_evicting(struct inet_frag_queue *q)
 {
-	return !hlist_unhashed(&q->list_evictor);
+	return false;
 }
 
 /* Memory Tracking Functions. */
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index ff8407b19d05..a271611d341d 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -531,17 +531,8 @@ enum ip6_defrag_users {
 	__IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 };
 
-struct ip6_create_arg {
-	__be32 id;
-	u32 user;
-	const struct in6_addr *src;
-	const struct in6_addr *dst;
-	int iif;
-	u8 ecn;
-};
-
 void ip6_frag_init(struct inet_frag_queue *q, const void *a);
-bool ip6_frag_match(const struct inet_frag_queue *q, const void *a);
+extern const struct rhashtable_params ip6_rhash_params;
 
 /*
  *	Equivalent of ipv4 struct ip
@@ -549,11 +540,6 @@ bool ip6_frag_match(const struct inet_frag_queue *q, const void *a);
 struct frag_queue {
 	struct inet_frag_queue	q;
 
-	__be32			id;		/* fragment id		*/
-	u32			user;
-	struct in6_addr		saddr;
-	struct in6_addr		daddr;
-
 	int			iif;
 	unsigned int		csum;
 	__u16			nhoffset;
diff --git a/net/ieee802154/6lowpan/6lowpan_i.h b/net/ieee802154/6lowpan/6lowpan_i.h
index d8de3bcfb103..b8d95cb71c25 100644
--- a/net/ieee802154/6lowpan/6lowpan_i.h
+++ b/net/ieee802154/6lowpan/6lowpan_i.h
@@ -17,37 +17,19 @@ typedef unsigned __bitwise lowpan_rx_result;
 #define LOWPAN_DISPATCH_FRAG1           0xc0
 #define LOWPAN_DISPATCH_FRAGN           0xe0
 
-struct lowpan_create_arg {
+struct frag_lowpan_compare_key {
 	u16 tag;
 	u16 d_size;
-	const struct ieee802154_addr *src;
-	const struct ieee802154_addr *dst;
+	const struct ieee802154_addr src;
+	const struct ieee802154_addr dst;
 };
 
-/* Equivalent of ipv4 struct ip
+/* Equivalent of ipv4 struct ipq
  */
 struct lowpan_frag_queue {
 	struct inet_frag_queue	q;
-
-	u16			tag;
-	u16			d_size;
-	struct ieee802154_addr	saddr;
-	struct ieee802154_addr	daddr;
 };
 
-static inline u32 ieee802154_addr_hash(const struct ieee802154_addr *a)
-{
-	switch (a->mode) {
-	case IEEE802154_ADDR_LONG:
-		return (((__force u64)a->extended_addr) >> 32) ^
-			(((__force u64)a->extended_addr) & 0xffffffff);
-	case IEEE802154_ADDR_SHORT:
-		return (__force u32)(a->short_addr + (a->pan_id << 16));
-	default:
-		return 0;
-	}
-}
-
 int lowpan_frag_rcv(struct sk_buff *skb, const u8 frag_type);
 void lowpan_net_frag_exit(void);
 int lowpan_net_frag_init(void);
diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c
index ddada12a044d..0fa0121f85d4 100644
--- a/net/ieee802154/6lowpan/reassembly.c
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -37,47 +37,15 @@ static struct inet_frags lowpan_frags;
 static int lowpan_frag_reasm(struct lowpan_frag_queue *fq,
 			     struct sk_buff *prev, struct net_device *ldev);
 
-static unsigned int lowpan_hash_frag(u16 tag, u16 d_size,
-				     const struct ieee802154_addr *saddr,
-				     const struct ieee802154_addr *daddr)
-{
-	net_get_random_once(&lowpan_frags.rnd, sizeof(lowpan_frags.rnd));
-	return jhash_3words(ieee802154_addr_hash(saddr),
-			    ieee802154_addr_hash(daddr),
-			    (__force u32)(tag + (d_size << 16)),
-			    lowpan_frags.rnd);
-}
-
-static unsigned int lowpan_hashfn(const struct inet_frag_queue *q)
-{
-	const struct lowpan_frag_queue *fq;
-
-	fq = container_of(q, struct lowpan_frag_queue, q);
-	return lowpan_hash_frag(fq->tag, fq->d_size, &fq->saddr, &fq->daddr);
-}
-
-static bool lowpan_frag_match(const struct inet_frag_queue *q, const void *a)
-{
-	const struct lowpan_frag_queue *fq;
-	const struct lowpan_create_arg *arg = a;
-
-	fq = container_of(q, struct lowpan_frag_queue, q);
-	return	fq->tag == arg->tag && fq->d_size == arg->d_size &&
-		ieee802154_addr_equal(&fq->saddr, arg->src) &&
-		ieee802154_addr_equal(&fq->daddr, arg->dst);
-}
-
 static void lowpan_frag_init(struct inet_frag_queue *q, const void *a)
 {
-	const struct lowpan_create_arg *arg = a;
+	const struct frag_lowpan_compare_key *key = a;
 	struct lowpan_frag_queue *fq;
 
 	fq = container_of(q, struct lowpan_frag_queue, q);
 
-	fq->tag = arg->tag;
-	fq->d_size = arg->d_size;
-	fq->saddr = *arg->src;
-	fq->daddr = *arg->dst;
+	BUILD_BUG_ON(sizeof(*key) > sizeof(q->key));
+	memcpy(&q->key, key, sizeof(*key));
 }
 
 static void lowpan_frag_expire(struct timer_list *t)
@@ -105,21 +73,17 @@ fq_find(struct net *net, const struct lowpan_802154_cb *cb,
 	const struct ieee802154_addr *src,
 	const struct ieee802154_addr *dst)
 {
-	struct inet_frag_queue *q;
-	struct lowpan_create_arg arg;
-	unsigned int hash;
 	struct netns_ieee802154_lowpan *ieee802154_lowpan =
 		net_ieee802154_lowpan(net);
+	struct frag_lowpan_compare_key key = {
+		.tag = cb->d_tag,
+		.d_size = cb->d_size,
+		.src = *src,
+		.dst = *dst,
+	};
+	struct inet_frag_queue *q;
 
-	arg.tag = cb->d_tag;
-	arg.d_size = cb->d_size;
-	arg.src = src;
-	arg.dst = dst;
-
-	hash = lowpan_hash_frag(cb->d_tag, cb->d_size, src, dst);
-
-	q = inet_frag_find(&ieee802154_lowpan->frags,
-			   &lowpan_frags, &arg, hash);
+	q = inet_frag_find(&ieee802154_lowpan->frags, &key);
 	if (IS_ERR_OR_NULL(q)) {
 		inet_frag_maybe_warn_overflow(q, pr_fmt());
 		return NULL;
@@ -611,17 +575,46 @@ static struct pernet_operations lowpan_frags_ops = {
 	.exit = lowpan_frags_exit_net,
 };
 
+static u32 lowpan_key_hashfn(const void *data, u32 len, u32 seed)
+{
+	return jhash2(data,
+		      sizeof(struct frag_lowpan_compare_key) / sizeof(u32), seed);
+}
+
+static u32 lowpan_obj_hashfn(const void *data, u32 len, u32 seed)
+{
+	const struct inet_frag_queue *fq = data;
+
+	return jhash2((const u32 *)&fq->key,
+		      sizeof(struct frag_lowpan_compare_key) / sizeof(u32), seed);
+}
+
+static int lowpan_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
+{
+	const struct frag_lowpan_compare_key *key = arg->key;
+	const struct inet_frag_queue *fq = ptr;
+
+	return !!memcmp(&fq->key, key, sizeof(*key));
+}
+
+static const struct rhashtable_params lowpan_rhash_params = {
+	.head_offset		= offsetof(struct inet_frag_queue, node),
+	.hashfn			= lowpan_key_hashfn,
+	.obj_hashfn		= lowpan_obj_hashfn,
+	.obj_cmpfn		= lowpan_obj_cmpfn,
+	.automatic_shrinking	= true,
+};
+
 int __init lowpan_net_frag_init(void)
 {
 	int ret;
 
-	lowpan_frags.hashfn = lowpan_hashfn;
 	lowpan_frags.constructor = lowpan_frag_init;
 	lowpan_frags.destructor = NULL;
 	lowpan_frags.qsize = sizeof(struct frag_queue);
-	lowpan_frags.match = lowpan_frag_match;
 	lowpan_frags.frag_expire = lowpan_frag_expire;
 	lowpan_frags.frags_cache_name = lowpan_frags_cache_name;
+	lowpan_frags.rhash_params = lowpan_rhash_params;
 	ret = inet_frags_init(&lowpan_frags);
 	if (ret)
 		goto out;
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 97e747b1e9a0..ebb8f411e0db 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -25,12 +25,6 @@
 #include <net/inet_frag.h>
 #include <net/inet_ecn.h>
 
-#define INETFRAGS_EVICT_BUCKETS   128
-#define INETFRAGS_EVICT_MAX	  512
-
-/* don't rebuild inetfrag table with new secret more often than this */
-#define INETFRAGS_MIN_REBUILD_INTERVAL (5 * HZ)
-
 /* Given the OR values of all fragments, apply RFC 3168 5.3 requirements
  * Value : 0xff if frame should be dropped.
  *         0 or INET_ECN_CE value, to be ORed in to final iph->tos field
@@ -52,157 +46,8 @@ const u8 ip_frag_ecn_table[16] = {
 };
 EXPORT_SYMBOL(ip_frag_ecn_table);
 
-static unsigned int
-inet_frag_hashfn(const struct inet_frags *f, const struct inet_frag_queue *q)
-{
-	return f->hashfn(q) & (INETFRAGS_HASHSZ - 1);
-}
-
-static bool inet_frag_may_rebuild(struct inet_frags *f)
-{
-	return time_after(jiffies,
-	       f->last_rebuild_jiffies + INETFRAGS_MIN_REBUILD_INTERVAL);
-}
-
-static void inet_frag_secret_rebuild(struct inet_frags *f)
-{
-	int i;
-
-	write_seqlock_bh(&f->rnd_seqlock);
-
-	if (!inet_frag_may_rebuild(f))
-		goto out;
-
-	get_random_bytes(&f->rnd, sizeof(u32));
-
-	for (i = 0; i < INETFRAGS_HASHSZ; i++) {
-		struct inet_frag_bucket *hb;
-		struct inet_frag_queue *q;
-		struct hlist_node *n;
-
-		hb = &f->hash[i];
-		spin_lock(&hb->chain_lock);
-
-		hlist_for_each_entry_safe(q, n, &hb->chain, list) {
-			unsigned int hval = inet_frag_hashfn(f, q);
-
-			if (hval != i) {
-				struct inet_frag_bucket *hb_dest;
-
-				hlist_del(&q->list);
-
-				/* Relink to new hash chain. */
-				hb_dest = &f->hash[hval];
-
-				/* This is the only place where we take
-				 * another chain_lock while already holding
-				 * one.  As this will not run concurrently,
-				 * we cannot deadlock on hb_dest lock below, if its
-				 * already locked it will be released soon since
-				 * other caller cannot be waiting for hb lock
-				 * that we've taken above.
-				 */
-				spin_lock_nested(&hb_dest->chain_lock,
-						 SINGLE_DEPTH_NESTING);
-				hlist_add_head(&q->list, &hb_dest->chain);
-				spin_unlock(&hb_dest->chain_lock);
-			}
-		}
-		spin_unlock(&hb->chain_lock);
-	}
-
-	f->rebuild = false;
-	f->last_rebuild_jiffies = jiffies;
-out:
-	write_sequnlock_bh(&f->rnd_seqlock);
-}
-
-static bool inet_fragq_should_evict(const struct inet_frag_queue *q)
-{
-	if (!hlist_unhashed(&q->list_evictor))
-		return false;
-
-	return q->net->low_thresh == 0 ||
-	       frag_mem_limit(q->net) >= q->net->low_thresh;
-}
-
-static unsigned int
-inet_evict_bucket(struct inet_frags *f, struct inet_frag_bucket *hb)
-{
-	struct inet_frag_queue *fq;
-	struct hlist_node *n;
-	unsigned int evicted = 0;
-	HLIST_HEAD(expired);
-
-	spin_lock(&hb->chain_lock);
-
-	hlist_for_each_entry_safe(fq, n, &hb->chain, list) {
-		if (!inet_fragq_should_evict(fq))
-			continue;
-
-		if (!del_timer(&fq->timer))
-			continue;
-
-		hlist_add_head(&fq->list_evictor, &expired);
-		++evicted;
-	}
-
-	spin_unlock(&hb->chain_lock);
-
-	hlist_for_each_entry_safe(fq, n, &expired, list_evictor)
-		f->frag_expire(&fq->timer);
-
-	return evicted;
-}
-
-static void inet_frag_worker(struct work_struct *work)
-{
-	unsigned int budget = INETFRAGS_EVICT_BUCKETS;
-	unsigned int i, evicted = 0;
-	struct inet_frags *f;
-
-	f = container_of(work, struct inet_frags, frags_work);
-
-	BUILD_BUG_ON(INETFRAGS_EVICT_BUCKETS >= INETFRAGS_HASHSZ);
-
-	local_bh_disable();
-
-	for (i = ACCESS_ONCE(f->next_bucket); budget; --budget) {
-		evicted += inet_evict_bucket(f, &f->hash[i]);
-		i = (i + 1) & (INETFRAGS_HASHSZ - 1);
-		if (evicted > INETFRAGS_EVICT_MAX)
-			break;
-	}
-
-	f->next_bucket = i;
-
-	local_bh_enable();
-
-	if (f->rebuild && inet_frag_may_rebuild(f))
-		inet_frag_secret_rebuild(f);
-}
-
-static void inet_frag_schedule_worker(struct inet_frags *f)
-{
-	if (unlikely(!work_pending(&f->frags_work)))
-		schedule_work(&f->frags_work);
-}
-
 int inet_frags_init(struct inet_frags *f)
 {
-	int i;
-
-	INIT_WORK(&f->frags_work, inet_frag_worker);
-
-	for (i = 0; i < INETFRAGS_HASHSZ; i++) {
-		struct inet_frag_bucket *hb = &f->hash[i];
-
-		spin_lock_init(&hb->chain_lock);
-		INIT_HLIST_HEAD(&hb->chain);
-	}
-
-	seqlock_init(&f->rnd_seqlock);
-	f->last_rebuild_jiffies = 0;
 	f->frags_cachep = kmem_cache_create(f->frags_cache_name, f->qsize, 0, 0,
 					    NULL);
 	if (!f->frags_cachep)
@@ -214,66 +59,42 @@ EXPORT_SYMBOL(inet_frags_init);
 
 void inet_frags_fini(struct inet_frags *f)
 {
-	cancel_work_sync(&f->frags_work);
+	/* We must wait that all inet_frag_destroy_rcu() have completed. */
+	rcu_barrier();
+
 	kmem_cache_destroy(f->frags_cachep);
+	f->frags_cachep = NULL;
 }
 EXPORT_SYMBOL(inet_frags_fini);
 
-void inet_frags_exit_net(struct netns_frags *nf)
-{
-	struct inet_frags *f =nf->f;
-	unsigned int seq;
-	int i;
-
-	nf->low_thresh = 0;
-
-evict_again:
-	local_bh_disable();
-	seq = read_seqbegin(&f->rnd_seqlock);
-
-	for (i = 0; i < INETFRAGS_HASHSZ ; i++)
-		inet_evict_bucket(f, &f->hash[i]);
-
-	local_bh_enable();
-	cond_resched();
-
-	if (read_seqretry(&f->rnd_seqlock, seq) ||
-	    sum_frag_mem_limit(nf))
-		goto evict_again;
-}
-EXPORT_SYMBOL(inet_frags_exit_net);
-
-static struct inet_frag_bucket *
-get_frag_bucket_locked(struct inet_frag_queue *fq, struct inet_frags *f)
-__acquires(hb->chain_lock)
+static void inet_frags_free_cb(void *ptr, void *arg)
 {
-	struct inet_frag_bucket *hb;
-	unsigned int seq, hash;
-
- restart:
-	seq = read_seqbegin(&f->rnd_seqlock);
+	struct inet_frag_queue *fq = ptr;
 
-	hash = inet_frag_hashfn(f, fq);
-	hb = &f->hash[hash];
+	/* If we can not cancel the timer, it means this frag_queue
+	 * is already disappearing, we have nothing to do.
+	 * Otherwise, we own a refcount until the end of this function.
+	 */
+	if (!del_timer(&fq->timer))
+		return;
 
-	spin_lock(&hb->chain_lock);
-	if (read_seqretry(&f->rnd_seqlock, seq)) {
-		spin_unlock(&hb->chain_lock);
-		goto restart;
+	spin_lock_bh(&fq->lock);
+	if (!(fq->flags & INET_FRAG_COMPLETE)) {
+		fq->flags |= INET_FRAG_COMPLETE;
+		refcount_dec(&fq->refcnt);
 	}
+	spin_unlock_bh(&fq->lock);
 
-	return hb;
+	inet_frag_put(fq);
 }
 
-static inline void fq_unlink(struct inet_frag_queue *fq)
+void inet_frags_exit_net(struct netns_frags *nf)
 {
-	struct inet_frag_bucket *hb;
+	nf->low_thresh = 0; /* prevent creation of new frags */
 
-	hb = get_frag_bucket_locked(fq, fq->net->f);
-	hlist_del(&fq->list);
-	fq->flags |= INET_FRAG_COMPLETE;
-	spin_unlock(&hb->chain_lock);
+	rhashtable_free_and_destroy(&nf->rhashtable, inet_frags_free_cb, NULL);
 }
+EXPORT_SYMBOL(inet_frags_exit_net);
 
 void inet_frag_kill(struct inet_frag_queue *fq)
 {
@@ -281,12 +102,26 @@ void inet_frag_kill(struct inet_frag_queue *fq)
 		refcount_dec(&fq->refcnt);
 
 	if (!(fq->flags & INET_FRAG_COMPLETE)) {
-		fq_unlink(fq);
+		struct netns_frags *nf = fq->net;
+
+		fq->flags |= INET_FRAG_COMPLETE;
+		rhashtable_remove_fast(&nf->rhashtable, &fq->node, nf->f->rhash_params);
 		refcount_dec(&fq->refcnt);
 	}
 }
 EXPORT_SYMBOL(inet_frag_kill);
 
+static void inet_frag_destroy_rcu(struct rcu_head *head)
+{
+	struct inet_frag_queue *q = container_of(head, struct inet_frag_queue,
+						 rcu);
+	struct inet_frags *f = q->net->f;
+
+	if (f->destructor)
+		f->destructor(q);
+	kmem_cache_free(f->frags_cachep, q);
+}
+
 void inet_frag_destroy(struct inet_frag_queue *q)
 {
 	struct sk_buff *fp;
@@ -310,55 +145,21 @@ void inet_frag_destroy(struct inet_frag_queue *q)
 	}
 	sum = sum_truesize + f->qsize;
 
-	if (f->destructor)
-		f->destructor(q);
-	kmem_cache_free(f->frags_cachep, q);
+	call_rcu(&q->rcu, inet_frag_destroy_rcu);
 
 	sub_frag_mem_limit(nf, sum);
 }
 EXPORT_SYMBOL(inet_frag_destroy);
 
-static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf,
-						struct inet_frag_queue *qp_in,
-						struct inet_frags *f,
-						void *arg)
-{
-	struct inet_frag_bucket *hb = get_frag_bucket_locked(qp_in, f);
-	struct inet_frag_queue *qp;
-
-#ifdef CONFIG_SMP
-	/* With SMP race we have to recheck hash table, because
-	 * such entry could have been created on other cpu before
-	 * we acquired hash bucket lock.
-	 */
-	hlist_for_each_entry(qp, &hb->chain, list) {
-		if (qp->net == nf && f->match(qp, arg)) {
-			refcount_inc(&qp->refcnt);
-			spin_unlock(&hb->chain_lock);
-			qp_in->flags |= INET_FRAG_COMPLETE;
-			inet_frag_put(qp_in);
-			return qp;
-		}
-	}
-#endif
-	qp = qp_in;
-	if (!mod_timer(&qp->timer, jiffies + nf->timeout))
-		refcount_inc(&qp->refcnt);
-
-	refcount_inc(&qp->refcnt);
-	hlist_add_head(&qp->list, &hb->chain);
-
-	spin_unlock(&hb->chain_lock);
-
-	return qp;
-}
-
 static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
 					       struct inet_frags *f,
 					       void *arg)
 {
 	struct inet_frag_queue *q;
 
+	if (!nf->high_thresh || frag_mem_limit(nf) > nf->high_thresh)
+		return NULL;
+
 	q = kmem_cache_zalloc(f->frags_cachep, GFP_ATOMIC);
 	if (!q)
 		return NULL;
@@ -369,64 +170,52 @@ static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
 
 	timer_setup(&q->timer, f->frag_expire, 0);
 	spin_lock_init(&q->lock);
-	refcount_set(&q->refcnt, 1);
+	refcount_set(&q->refcnt, 3);
 
 	return q;
 }
 
 static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf,
-						struct inet_frags *f,
 						void *arg)
 {
+	struct inet_frags *f = nf->f;
 	struct inet_frag_queue *q;
+	int err;
 
 	q = inet_frag_alloc(nf, f, arg);
 	if (!q)
 		return NULL;
 
-	return inet_frag_intern(nf, q, f, arg);
-}
+	mod_timer(&q->timer, jiffies + nf->timeout);
 
-struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
-				       struct inet_frags *f, void *key,
-				       unsigned int hash)
-{
-	struct inet_frag_bucket *hb;
-	struct inet_frag_queue *q;
-	int depth = 0;
-
-	if (!nf->high_thresh || frag_mem_limit(nf) > nf->high_thresh) {
-		inet_frag_schedule_worker(f);
+	err = rhashtable_insert_fast(&nf->rhashtable, &q->node,
+				     f->rhash_params);
+	if (err < 0) {
+		q->flags |= INET_FRAG_COMPLETE;
+		inet_frag_kill(q);
+		inet_frag_destroy(q);
 		return NULL;
 	}
+	return q;
+}
 
-	if (frag_mem_limit(nf) > nf->low_thresh)
-		inet_frag_schedule_worker(f);
-
-	hash &= (INETFRAGS_HASHSZ - 1);
-	hb = &f->hash[hash];
-
-	spin_lock(&hb->chain_lock);
-	hlist_for_each_entry(q, &hb->chain, list) {
-		if (q->net == nf && f->match(q, key)) {
-			refcount_inc(&q->refcnt);
-			spin_unlock(&hb->chain_lock);
-			return q;
-		}
-		depth++;
-	}
-	spin_unlock(&hb->chain_lock);
+/* TODO : call from rcu_read_lock() and no longer use refcount_inc_not_zero() */
+struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, void *key)
+{
+	struct inet_frag_queue *fq;
 
-	if (depth <= INETFRAGS_MAXDEPTH)
-		return inet_frag_create(nf, f, key);
+	rcu_read_lock();
 
-	if (inet_frag_may_rebuild(f)) {
-		if (!f->rebuild)
-			f->rebuild = true;
-		inet_frag_schedule_worker(f);
+	fq = rhashtable_lookup(&nf->rhashtable, key, nf->f->rhash_params);
+	if (fq) {
+		if (!refcount_inc_not_zero(&fq->refcnt))
+			fq = NULL;
+		rcu_read_unlock();
+		return fq;
 	}
+	rcu_read_unlock();
 
-	return ERR_PTR(-ENOBUFS);
+	return inet_frag_create(nf, key);
 }
 EXPORT_SYMBOL(inet_frag_find);
 
@@ -434,8 +223,7 @@ void inet_frag_maybe_warn_overflow(struct inet_frag_queue *q,
 				   const char *prefix)
 {
 	static const char msg[] = "inet_frag_find: Fragment hash bucket"
-		" list length grew over limit " __stringify(INETFRAGS_MAXDEPTH)
-		". Dropping fragment.\n";
+		" list length grew over limit. Dropping fragment.\n";
 
 	if (PTR_ERR(q) == -ENOBUFS)
 		net_dbg_ratelimited("%s%s", prefix, msg);
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 5171c8cc0eb6..1d3b82e96c45 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -69,15 +69,9 @@ struct ipfrag_skb_cb
 struct ipq {
 	struct inet_frag_queue q;
 
-	u32		user;
-	__be32		saddr;
-	__be32		daddr;
-	__be16		id;
-	u8		protocol;
 	u8		ecn; /* RFC3168 support */
 	u16		max_df_size; /* largest frag with DF set seen */
 	int             iif;
-	int             vif;   /* L3 master device index */
 	unsigned int    rid;
 	struct inet_peer *peer;
 };
@@ -97,41 +91,6 @@ int ip_frag_mem(struct net *net)
 static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 			 struct net_device *dev);
 
-struct ip4_create_arg {
-	struct iphdr *iph;
-	u32 user;
-	int vif;
-};
-
-static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot)
-{
-	net_get_random_once(&ip4_frags.rnd, sizeof(ip4_frags.rnd));
-	return jhash_3words((__force u32)id << 16 | prot,
-			    (__force u32)saddr, (__force u32)daddr,
-			    ip4_frags.rnd);
-}
-
-static unsigned int ip4_hashfn(const struct inet_frag_queue *q)
-{
-	const struct ipq *ipq;
-
-	ipq = container_of(q, struct ipq, q);
-	return ipqhashfn(ipq->id, ipq->saddr, ipq->daddr, ipq->protocol);
-}
-
-static bool ip4_frag_match(const struct inet_frag_queue *q, const void *a)
-{
-	const struct ipq *qp;
-	const struct ip4_create_arg *arg = a;
-
-	qp = container_of(q, struct ipq, q);
-	return	qp->id == arg->iph->id &&
-		qp->saddr == arg->iph->saddr &&
-		qp->daddr == arg->iph->daddr &&
-		qp->protocol == arg->iph->protocol &&
-		qp->user == arg->user &&
-		qp->vif == arg->vif;
-}
 
 static void ip4_frag_init(struct inet_frag_queue *q, const void *a)
 {
@@ -140,17 +99,12 @@ static void ip4_frag_init(struct inet_frag_queue *q, const void *a)
 					       frags);
 	struct net *net = container_of(ipv4, struct net, ipv4);
 
-	const struct ip4_create_arg *arg = a;
+	const struct frag_v4_compare_key *key = a;
 
-	qp->protocol = arg->iph->protocol;
-	qp->id = arg->iph->id;
-	qp->ecn = ip4_frag_ecn(arg->iph->tos);
-	qp->saddr = arg->iph->saddr;
-	qp->daddr = arg->iph->daddr;
-	qp->vif = arg->vif;
-	qp->user = arg->user;
+	q->key.v4 = *key;
+	qp->ecn = 0;
 	qp->peer = q->net->max_dist ?
-		inet_getpeer_v4(net->ipv4.peers, arg->iph->saddr, arg->vif, 1) :
+		inet_getpeer_v4(net->ipv4.peers, key->saddr, key->vif, 1) :
 		NULL;
 }
 
@@ -234,7 +188,7 @@ static void ip_expire(struct timer_list *t)
 		/* Only an end host needs to send an ICMP
 		 * "Fragment Reassembly Timeout" message, per RFC792.
 		 */
-		if (frag_expire_skip_icmp(qp->user) &&
+		if (frag_expire_skip_icmp(qp->q.key.v4.user) &&
 		    (skb_rtable(head)->rt_type != RTN_LOCAL))
 			goto out;
 
@@ -262,17 +216,17 @@ static void ip_expire(struct timer_list *t)
 static struct ipq *ip_find(struct net *net, struct iphdr *iph,
 			   u32 user, int vif)
 {
+	struct frag_v4_compare_key key = {
+		.saddr = iph->saddr,
+		.daddr = iph->daddr,
+		.user = user,
+		.vif = vif,
+		.id = iph->id,
+		.protocol = iph->protocol,
+	};
 	struct inet_frag_queue *q;
-	struct ip4_create_arg arg;
-	unsigned int hash;
-
-	arg.iph = iph;
-	arg.user = user;
-	arg.vif = vif;
 
-	hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol);
-
-	q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash);
+	q = inet_frag_find(&net->ipv4.frags, &key);
 	if (IS_ERR_OR_NULL(q)) {
 		inet_frag_maybe_warn_overflow(q, pr_fmt());
 		return NULL;
@@ -661,7 +615,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 	err = -ENOMEM;
 	goto out_fail;
 out_oversize:
-	net_info_ratelimited("Oversized IP packet from %pI4\n", &qp->saddr);
+	net_info_ratelimited("Oversized IP packet from %pI4\n", &qp->q.key.v4.saddr);
 out_fail:
 	__IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
 	return err;
@@ -899,15 +853,47 @@ static struct pernet_operations ip4_frags_ops = {
 	.exit = ipv4_frags_exit_net,
 };
 
+
+static u32 ip4_key_hashfn(const void *data, u32 len, u32 seed)
+{
+	return jhash2(data,
+		      sizeof(struct frag_v4_compare_key) / sizeof(u32), seed);
+}
+
+static u32 ip4_obj_hashfn(const void *data, u32 len, u32 seed)
+{
+	const struct inet_frag_queue *fq = data;
+
+	return jhash2((const u32 *)&fq->key.v4,
+		      sizeof(struct frag_v4_compare_key) / sizeof(u32), seed);
+}
+
+static int ip4_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
+{
+	const struct frag_v4_compare_key *key = arg->key;
+	const struct inet_frag_queue *fq = ptr;
+
+	return !!memcmp(&fq->key, key, sizeof(*key));
+}
+
+static const struct rhashtable_params ip4_rhash_params = {
+	.head_offset		= offsetof(struct inet_frag_queue, node),
+	.key_offset		= offsetof(struct inet_frag_queue, key),
+	.key_len		= sizeof(struct frag_v4_compare_key),
+	.hashfn			= ip4_key_hashfn,
+	.obj_hashfn		= ip4_obj_hashfn,
+	.obj_cmpfn		= ip4_obj_cmpfn,
+	.automatic_shrinking	= true,
+};
+
 void __init ipfrag_init(void)
 {
-	ip4_frags.hashfn = ip4_hashfn;
 	ip4_frags.constructor = ip4_frag_init;
 	ip4_frags.destructor = ip4_frag_free;
 	ip4_frags.qsize = sizeof(struct ipq);
-	ip4_frags.match = ip4_frag_match;
 	ip4_frags.frag_expire = ip_expire;
 	ip4_frags.frags_cache_name = ip_frag_cache_name;
+	ip4_frags.rhash_params = ip4_rhash_params;
 	if (inet_frags_init(&ip4_frags))
 		panic("IP: failed to allocate ip4_frags cache\n");
 	ip4_frags_ctl_register();
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index bc776ef392ea..8b12431ae296 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -152,23 +152,6 @@ static inline u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h)
 	return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK);
 }
 
-static unsigned int nf_hash_frag(__be32 id, const struct in6_addr *saddr,
-				 const struct in6_addr *daddr)
-{
-	net_get_random_once(&nf_frags.rnd, sizeof(nf_frags.rnd));
-	return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr),
-			    (__force u32)id, nf_frags.rnd);
-}
-
-
-static unsigned int nf_hashfn(const struct inet_frag_queue *q)
-{
-	const struct frag_queue *nq;
-
-	nq = container_of(q, struct frag_queue, q);
-	return nf_hash_frag(nq->id, &nq->saddr, &nq->daddr);
-}
-
 static void nf_ct_frag6_expire(struct timer_list *t)
 {
 	struct inet_frag_queue *frag = from_timer(frag, t, timer);
@@ -182,26 +165,19 @@ static void nf_ct_frag6_expire(struct timer_list *t)
 }
 
 /* Creation primitives. */
-static inline struct frag_queue *fq_find(struct net *net, __be32 id,
-					 u32 user, struct in6_addr *src,
-					 struct in6_addr *dst, int iif, u8 ecn)
+static struct frag_queue *fq_find(struct net *net, __be32 id, u32 user,
+				  const struct ipv6hdr *hdr, int iif)
 {
+	struct frag_v6_compare_key key = {
+		.id = id,
+		.saddr = hdr->saddr,
+		.daddr = hdr->daddr,
+		.user = user,
+		.iif = iif,
+	};
 	struct inet_frag_queue *q;
-	struct ip6_create_arg arg;
-	unsigned int hash;
-
-	arg.id = id;
-	arg.user = user;
-	arg.src = src;
-	arg.dst = dst;
-	arg.iif = iif;
-	arg.ecn = ecn;
-
-	local_bh_disable();
-	hash = nf_hash_frag(id, src, dst);
 
-	q = inet_frag_find(&net->nf_frag.frags, &nf_frags, &arg, hash);
-	local_bh_enable();
+	q = inet_frag_find(&net->nf_frag.frags, &key);
 	if (IS_ERR_OR_NULL(q)) {
 		inet_frag_maybe_warn_overflow(q, pr_fmt());
 		return NULL;
@@ -593,8 +569,8 @@ int nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user)
 	fhdr = (struct frag_hdr *)skb_transport_header(skb);
 
 	skb_orphan(skb);
-	fq = fq_find(net, fhdr->identification, user, &hdr->saddr, &hdr->daddr,
-		     skb->dev ? skb->dev->ifindex : 0, ip6_frag_ecn(hdr));
+	fq = fq_find(net, fhdr->identification, user, hdr,
+		     skb->dev ? skb->dev->ifindex : 0);
 	if (fq == NULL) {
 		pr_debug("Can't find and can't create new queue\n");
 		return -ENOMEM;
@@ -662,13 +638,12 @@ int nf_ct_frag6_init(void)
 {
 	int ret = 0;
 
-	nf_frags.hashfn = nf_hashfn;
 	nf_frags.constructor = ip6_frag_init;
 	nf_frags.destructor = NULL;
 	nf_frags.qsize = sizeof(struct frag_queue);
-	nf_frags.match = ip6_frag_match;
 	nf_frags.frag_expire = nf_ct_frag6_expire;
 	nf_frags.frags_cache_name = nf_frags_cache_name;
+	nf_frags.rhash_params = ip6_rhash_params;
 	ret = inet_frags_init(&nf_frags);
 	if (ret)
 		goto out;
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index f0071b113a92..3fc853e4492a 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -79,52 +79,13 @@ static struct inet_frags ip6_frags;
 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 			  struct net_device *dev);
 
-/*
- * callers should be careful not to use the hash value outside the ipfrag_lock
- * as doing so could race with ipfrag_hash_rnd being recalculated.
- */
-static unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
-				    const struct in6_addr *daddr)
-{
-	net_get_random_once(&ip6_frags.rnd, sizeof(ip6_frags.rnd));
-	return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr),
-			    (__force u32)id, ip6_frags.rnd);
-}
-
-static unsigned int ip6_hashfn(const struct inet_frag_queue *q)
-{
-	const struct frag_queue *fq;
-
-	fq = container_of(q, struct frag_queue, q);
-	return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr);
-}
-
-bool ip6_frag_match(const struct inet_frag_queue *q, const void *a)
-{
-	const struct frag_queue *fq;
-	const struct ip6_create_arg *arg = a;
-
-	fq = container_of(q, struct frag_queue, q);
-	return	fq->id == arg->id &&
-		fq->user == arg->user &&
-		ipv6_addr_equal(&fq->saddr, arg->src) &&
-		ipv6_addr_equal(&fq->daddr, arg->dst) &&
-		(arg->iif == fq->iif ||
-		 !(ipv6_addr_type(arg->dst) & (IPV6_ADDR_MULTICAST |
-					       IPV6_ADDR_LINKLOCAL)));
-}
-EXPORT_SYMBOL(ip6_frag_match);
-
 void ip6_frag_init(struct inet_frag_queue *q, const void *a)
 {
 	struct frag_queue *fq = container_of(q, struct frag_queue, q);
-	const struct ip6_create_arg *arg = a;
+	const struct frag_v6_compare_key *key = a;
 
-	fq->id = arg->id;
-	fq->user = arg->user;
-	fq->saddr = *arg->src;
-	fq->daddr = *arg->dst;
-	fq->ecn = arg->ecn;
+	q->key.v6 = *key;
+	fq->ecn = 0;
 }
 EXPORT_SYMBOL(ip6_frag_init);
 
@@ -182,23 +143,22 @@ static void ip6_frag_expire(struct timer_list *t)
 }
 
 static struct frag_queue *
-fq_find(struct net *net, __be32 id, const struct in6_addr *src,
-	const struct in6_addr *dst, int iif, u8 ecn)
+fq_find(struct net *net, __be32 id, const struct ipv6hdr *hdr, int iif)
 {
+	struct frag_v6_compare_key key = {
+		.id = id,
+		.saddr = hdr->saddr,
+		.daddr = hdr->daddr,
+		.user = IP6_DEFRAG_LOCAL_DELIVER,
+		.iif = iif,
+	};
 	struct inet_frag_queue *q;
-	struct ip6_create_arg arg;
-	unsigned int hash;
-
-	arg.id = id;
-	arg.user = IP6_DEFRAG_LOCAL_DELIVER;
-	arg.src = src;
-	arg.dst = dst;
-	arg.iif = iif;
-	arg.ecn = ecn;
 
-	hash = inet6_hash_frag(id, src, dst);
+	if (!(ipv6_addr_type(&hdr->daddr) & (IPV6_ADDR_MULTICAST |
+					    IPV6_ADDR_LINKLOCAL)))
+		key.iif = 0;
 
-	q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);
+	q = inet_frag_find(&net->ipv6.frags, &key);
 	if (IS_ERR_OR_NULL(q)) {
 		inet_frag_maybe_warn_overflow(q, pr_fmt());
 		return NULL;
@@ -530,6 +490,7 @@ static int ipv6_frag_rcv(struct sk_buff *skb)
 	struct frag_queue *fq;
 	const struct ipv6hdr *hdr = ipv6_hdr(skb);
 	struct net *net = dev_net(skb_dst(skb)->dev);
+	int iif;
 
 	if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED)
 		goto fail_hdr;
@@ -558,13 +519,14 @@ static int ipv6_frag_rcv(struct sk_buff *skb)
 		return 1;
 	}
 
-	fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr,
-		     skb->dev ? skb->dev->ifindex : 0, ip6_frag_ecn(hdr));
+	iif = skb->dev ? skb->dev->ifindex : 0;
+	fq = fq_find(net, fhdr->identification, hdr, iif);
 	if (fq) {
 		int ret;
 
 		spin_lock(&fq->q.lock);
 
+		fq->iif = iif;
 		ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
 
 		spin_unlock(&fq->q.lock);
@@ -738,17 +700,47 @@ static struct pernet_operations ip6_frags_ops = {
 	.exit = ipv6_frags_exit_net,
 };
 
+static u32 ip6_key_hashfn(const void *data, u32 len, u32 seed)
+{
+	return jhash2(data,
+		      sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
+}
+
+static u32 ip6_obj_hashfn(const void *data, u32 len, u32 seed)
+{
+	const struct inet_frag_queue *fq = data;
+
+	return jhash2((const u32 *)&fq->key.v6,
+		      sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
+}
+
+static int ip6_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
+{
+	const struct frag_v6_compare_key *key = arg->key;
+	const struct inet_frag_queue *fq = ptr;
+
+	return !!memcmp(&fq->key, key, sizeof(*key));
+}
+
+const struct rhashtable_params ip6_rhash_params = {
+	.head_offset		= offsetof(struct inet_frag_queue, node),
+	.hashfn			= ip6_key_hashfn,
+	.obj_hashfn		= ip6_obj_hashfn,
+	.obj_cmpfn		= ip6_obj_cmpfn,
+	.automatic_shrinking	= true,
+};
+EXPORT_SYMBOL(ip6_rhash_params);
+
 int __init ipv6_frag_init(void)
 {
 	int ret;
 
-	ip6_frags.hashfn = ip6_hashfn;
 	ip6_frags.constructor = ip6_frag_init;
 	ip6_frags.destructor = NULL;
 	ip6_frags.qsize = sizeof(struct frag_queue);
-	ip6_frags.match = ip6_frag_match;
 	ip6_frags.frag_expire = ip6_frag_expire;
 	ip6_frags.frags_cache_name = ip6_frag_cache_name;
+	ip6_frags.rhash_params = ip6_rhash_params;
 	ret = inet_frags_init(&ip6_frags);
 	if (ret)
 		goto out;
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 10/30] inet: frags: remove some helpers
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

Remove sum_frag_mem_limit(), ip_frag_mem() & ip6_frag_mem()

Also since we use rhashtable we can bring back the number of fragments
in "grep FRAG /proc/net/sockstat /proc/net/sockstat6" that was
removed in commit 434d305405ab ("inet: frag: don't account number
of fragment queues")

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 6befe4a78b1553edb6eed3a78b4bcd9748526672)
---
 include/net/inet_frag.h | 5 -----
 include/net/ip.h        | 1 -
 include/net/ipv6.h      | 7 -------
 net/ipv4/ip_fragment.c  | 5 -----
 net/ipv4/proc.c         | 6 +++---
 net/ipv6/proc.c         | 5 +++--
 6 files changed, 6 insertions(+), 23 deletions(-)

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index 3fec0d3a0d01..4b5449df0aad 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -141,11 +141,6 @@ static inline void add_frag_mem_limit(struct netns_frags *nf, int i)
 	atomic_add(i, &nf->mem);
 }
 
-static inline int sum_frag_mem_limit(struct netns_frags *nf)
-{
-	return atomic_read(&nf->mem);
-}
-
 /* RFC 3168 support :
  * We want to check ECN values of all fragments, do detect invalid combinations.
  * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
diff --git a/include/net/ip.h b/include/net/ip.h
index 81da1123fc8e..7c430343176a 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -570,7 +570,6 @@ static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *s
 	return skb;
 }
 #endif
-int ip_frag_mem(struct net *net);
 
 /*
  *	Functions provided by ip_forward.c
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index a271611d341d..fa87a62e9bd3 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -331,13 +331,6 @@ static inline bool ipv6_accept_ra(struct inet6_dev *idev)
 	    idev->cnf.accept_ra;
 }
 
-#if IS_ENABLED(CONFIG_IPV6)
-static inline int ip6_frag_mem(struct net *net)
-{
-	return sum_frag_mem_limit(&net->ipv6.frags);
-}
-#endif
-
 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 1d3b82e96c45..94451fad9994 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -83,11 +83,6 @@ static u8 ip4_frag_ecn(u8 tos)
 
 static struct inet_frags ip4_frags;
 
-int ip_frag_mem(struct net *net)
-{
-	return sum_frag_mem_limit(&net->ipv4.frags);
-}
-
 static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 			 struct net_device *dev);
 
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 127153f1ed8a..01a337c3a36b 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -54,7 +54,6 @@
 static int sockstat_seq_show(struct seq_file *seq, void *v)
 {
 	struct net *net = seq->private;
-	unsigned int frag_mem;
 	int orphans, sockets;
 
 	orphans = percpu_counter_sum_positive(&tcp_orphan_count);
@@ -72,8 +71,9 @@ static int sockstat_seq_show(struct seq_file *seq, void *v)
 		   sock_prot_inuse_get(net, &udplite_prot));
 	seq_printf(seq, "RAW: inuse %d\n",
 		   sock_prot_inuse_get(net, &raw_prot));
-	frag_mem = ip_frag_mem(net);
-	seq_printf(seq,  "FRAG: inuse %u memory %u\n", !!frag_mem, frag_mem);
+	seq_printf(seq,  "FRAG: inuse %u memory %u\n",
+		   atomic_read(&net->ipv4.frags.rhashtable.nelems),
+		   frag_mem_limit(&net->ipv4.frags));
 	return 0;
 }
 
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index e88bcb8ff0fd..5704ec3d3178 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -38,7 +38,6 @@
 static int sockstat6_seq_show(struct seq_file *seq, void *v)
 {
 	struct net *net = seq->private;
-	unsigned int frag_mem = ip6_frag_mem(net);
 
 	seq_printf(seq, "TCP6: inuse %d\n",
 		       sock_prot_inuse_get(net, &tcpv6_prot));
@@ -48,7 +47,9 @@ static int sockstat6_seq_show(struct seq_file *seq, void *v)
 			sock_prot_inuse_get(net, &udplitev6_prot));
 	seq_printf(seq, "RAW6: inuse %d\n",
 		       sock_prot_inuse_get(net, &rawv6_prot));
-	seq_printf(seq, "FRAG6: inuse %u memory %u\n", !!frag_mem, frag_mem);
+	seq_printf(seq, "FRAG6: inuse %u memory %u\n",
+		   atomic_read(&net->ipv6.frags.rhashtable.nelems),
+		   frag_mem_limit(&net->ipv6.frags));
 	return 0;
 }
 
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 06/30] inet: frags: refactor lowpan_net_frag_init()
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

We want to call lowpan_net_frag_init() earlier.
Similar to commit "inet: frags: refactor ipv6_frag_init()"

This is a prereq to "inet: frags: use rhashtables for reassembly units"

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 807f1844df4ac23594268fa9f41902d0549e92aa)
---
 net/ieee802154/6lowpan/reassembly.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c
index 6badc055555b..ddada12a044d 100644
--- a/net/ieee802154/6lowpan/reassembly.c
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -615,14 +615,6 @@ int __init lowpan_net_frag_init(void)
 {
 	int ret;
 
-	ret = lowpan_frags_sysctl_register();
-	if (ret)
-		return ret;
-
-	ret = register_pernet_subsys(&lowpan_frags_ops);
-	if (ret)
-		goto err_pernet;
-
 	lowpan_frags.hashfn = lowpan_hashfn;
 	lowpan_frags.constructor = lowpan_frag_init;
 	lowpan_frags.destructor = NULL;
@@ -632,11 +624,21 @@ int __init lowpan_net_frag_init(void)
 	lowpan_frags.frags_cache_name = lowpan_frags_cache_name;
 	ret = inet_frags_init(&lowpan_frags);
 	if (ret)
-		goto err_pernet;
+		goto out;
 
+	ret = lowpan_frags_sysctl_register();
+	if (ret)
+		goto err_sysctl;
+
+	ret = register_pernet_subsys(&lowpan_frags_ops);
+	if (ret)
+		goto err_pernet;
+out:
 	return ret;
 err_pernet:
 	lowpan_frags_sysctl_unregister();
+err_sysctl:
+	inet_frags_fini(&lowpan_frags);
 	return ret;
 }
 
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 05/30] inet: frags: refactor ipv6_frag_init()
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

We want to call inet_frags_init() earlier.

This is a prereq to "inet: frags: use rhashtables for reassembly units"

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 5b975bab23615cd0fdf67af6c9298eb01c4b9f61)
---
 net/ipv6/reassembly.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index b85ef051b75c..42b6b2ba447a 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -746,10 +746,21 @@ int __init ipv6_frag_init(void)
 {
 	int ret;
 
-	ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
+	ip6_frags.hashfn = ip6_hashfn;
+	ip6_frags.constructor = ip6_frag_init;
+	ip6_frags.destructor = NULL;
+	ip6_frags.qsize = sizeof(struct frag_queue);
+	ip6_frags.match = ip6_frag_match;
+	ip6_frags.frag_expire = ip6_frag_expire;
+	ip6_frags.frags_cache_name = ip6_frag_cache_name;
+	ret = inet_frags_init(&ip6_frags);
 	if (ret)
 		goto out;
 
+	ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
+	if (ret)
+		goto err_protocol;
+
 	ret = ip6_frags_sysctl_register();
 	if (ret)
 		goto err_sysctl;
@@ -758,16 +769,6 @@ int __init ipv6_frag_init(void)
 	if (ret)
 		goto err_pernet;
 
-	ip6_frags.hashfn = ip6_hashfn;
-	ip6_frags.constructor = ip6_frag_init;
-	ip6_frags.destructor = NULL;
-	ip6_frags.qsize = sizeof(struct frag_queue);
-	ip6_frags.match = ip6_frag_match;
-	ip6_frags.frag_expire = ip6_frag_expire;
-	ip6_frags.frags_cache_name = ip6_frag_cache_name;
-	ret = inet_frags_init(&ip6_frags);
-	if (ret)
-		goto err_pernet;
 out:
 	return ret;
 
@@ -775,6 +776,8 @@ int __init ipv6_frag_init(void)
 	ip6_frags_sysctl_unregister();
 err_sysctl:
 	inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
+err_protocol:
+	inet_frags_fini(&ip6_frags);
 	goto out;
 }
 
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 04/30] inet: frags: Convert timers to use timer_setup()
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh
  Cc: netdev, stable, edumazet, Kees Cook, Alexander Aring,
	Stefan Schmidt, Alexey Kuznetsov, Hideaki YOSHIFUJI,
	Pablo Neira Ayuso, Jozsef Kadlecsik, Florian Westphal, linux-wpan,
	netfilter-devel, coreteam
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Kees Cook <keescook@chromium.org>

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Alexander Aring <alex.aring@gmail.com>
Cc: Stefan Schmidt <stefan@osg.samsung.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Cc: Florian Westphal <fw@strlen.de>
Cc: linux-wpan@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: netfilter-devel@vger.kernel.org
Cc: coreteam@netfilter.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Stefan Schmidt <stefan@osg.samsung.com> # for ieee802154
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 78802011fbe34331bdef6f2dfb1634011f0e4c32)
---
 include/net/inet_frag.h                 | 2 +-
 net/ieee802154/6lowpan/reassembly.c     | 5 +++--
 net/ipv4/inet_fragment.c                | 4 ++--
 net/ipv4/ip_fragment.c                  | 5 +++--
 net/ipv6/netfilter/nf_conntrack_reasm.c | 5 +++--
 net/ipv6/reassembly.c                   | 5 +++--
 6 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index fd338293a095..69e531ed8189 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -97,7 +97,7 @@ struct inet_frags {
 	void			(*constructor)(struct inet_frag_queue *q,
 					       const void *arg);
 	void			(*destructor)(struct inet_frag_queue *);
-	void			(*frag_expire)(unsigned long data);
+	void			(*frag_expire)(struct timer_list *t);
 	struct kmem_cache	*frags_cachep;
 	const char		*frags_cache_name;
 };
diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c
index 9ccb8458b5c3..6badc055555b 100644
--- a/net/ieee802154/6lowpan/reassembly.c
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -80,12 +80,13 @@ static void lowpan_frag_init(struct inet_frag_queue *q, const void *a)
 	fq->daddr = *arg->dst;
 }
 
-static void lowpan_frag_expire(unsigned long data)
+static void lowpan_frag_expire(struct timer_list *t)
 {
+	struct inet_frag_queue *frag = from_timer(frag, t, timer);
 	struct frag_queue *fq;
 	struct net *net;
 
-	fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
+	fq = container_of(frag, struct frag_queue, q);
 	net = container_of(fq->q.net, struct net, ieee802154_lowpan.frags);
 
 	spin_lock(&fq->q.lock);
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 4b44f973c37f..97e747b1e9a0 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -150,7 +150,7 @@ inet_evict_bucket(struct inet_frags *f, struct inet_frag_bucket *hb)
 	spin_unlock(&hb->chain_lock);
 
 	hlist_for_each_entry_safe(fq, n, &expired, list_evictor)
-		f->frag_expire((unsigned long) fq);
+		f->frag_expire(&fq->timer);
 
 	return evicted;
 }
@@ -367,7 +367,7 @@ static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
 	f->constructor(q, arg);
 	add_frag_mem_limit(nf, f->qsize);
 
-	setup_timer(&q->timer, f->frag_expire, (unsigned long)q);
+	timer_setup(&q->timer, f->frag_expire, 0);
 	spin_lock_init(&q->lock);
 	refcount_set(&q->refcnt, 1);
 
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 9d0b08c8ee00..5171c8cc0eb6 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -191,12 +191,13 @@ static bool frag_expire_skip_icmp(u32 user)
 /*
  * Oops, a fragment queue timed out.  Kill it and send an ICMP reply.
  */
-static void ip_expire(unsigned long arg)
+static void ip_expire(struct timer_list *t)
 {
+	struct inet_frag_queue *frag = from_timer(frag, t, timer);
 	struct ipq *qp;
 	struct net *net;
 
-	qp = container_of((struct inet_frag_queue *) arg, struct ipq, q);
+	qp = container_of(frag, struct ipq, q);
 	net = container_of(qp->q.net, struct net, ipv4.frags);
 
 	rcu_read_lock();
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 7ea2b4490672..bc776ef392ea 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -169,12 +169,13 @@ static unsigned int nf_hashfn(const struct inet_frag_queue *q)
 	return nf_hash_frag(nq->id, &nq->saddr, &nq->daddr);
 }
 
-static void nf_ct_frag6_expire(unsigned long data)
+static void nf_ct_frag6_expire(struct timer_list *t)
 {
+	struct inet_frag_queue *frag = from_timer(frag, t, timer);
 	struct frag_queue *fq;
 	struct net *net;
 
-	fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
+	fq = container_of(frag, struct frag_queue, q);
 	net = container_of(fq->q.net, struct net, nf_frag.frags);
 
 	ip6_expire_frag_queue(net, fq);
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 26f737c3fc7b..b85ef051b75c 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -169,12 +169,13 @@ void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq)
 }
 EXPORT_SYMBOL(ip6_expire_frag_queue);
 
-static void ip6_frag_expire(unsigned long data)
+static void ip6_frag_expire(struct timer_list *t)
 {
+	struct inet_frag_queue *frag = from_timer(frag, t, timer);
 	struct frag_queue *fq;
 	struct net *net;
 
-	fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
+	fq = container_of(frag, struct frag_queue, q);
 	net = container_of(fq->q.net, struct net, ipv6.frags);
 
 	ip6_expire_frag_queue(net, fq);
-- 
2.18.0

^ permalink raw reply related

* [PATCH v3 03/30] inet: frags: refactor ipfrag_init()
From: Stephen Hemminger @ 2018-09-13 14:58 UTC (permalink / raw)
  To: davem, gregkh; +Cc: netdev, stable, edumazet
In-Reply-To: <20180913145902.17531-1-sthemmin@microsoft.com>

From: Eric Dumazet <edumazet@google.com>

We need to call inet_frags_init() before register_pernet_subsys(),
as a prereq for following patch ("inet: frags: use rhashtables for reassembly units")

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 483a6e4fa055123142d8956866fe2aa9c98d546d)
---
 net/ipv4/ip_fragment.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index c32718b00761..9d0b08c8ee00 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -900,8 +900,6 @@ static struct pernet_operations ip4_frags_ops = {
 
 void __init ipfrag_init(void)
 {
-	ip4_frags_ctl_register();
-	register_pernet_subsys(&ip4_frags_ops);
 	ip4_frags.hashfn = ip4_hashfn;
 	ip4_frags.constructor = ip4_frag_init;
 	ip4_frags.destructor = ip4_frag_free;
@@ -911,4 +909,6 @@ void __init ipfrag_init(void)
 	ip4_frags.frags_cache_name = ip_frag_cache_name;
 	if (inet_frags_init(&ip4_frags))
 		panic("IP: failed to allocate ip4_frags cache\n");
+	ip4_frags_ctl_register();
+	register_pernet_subsys(&ip4_frags_ops);
 }
-- 
2.18.0

^ permalink raw reply related

* Re: [PATCH net-next] virtio_net: ethtool tx napi configuration
From: Willem de Bruijn @ 2018-09-13 14:58 UTC (permalink / raw)
  To: Jason Wang
  Cc: f.fainelli, Network Development, David Miller, caleb.raitto,
	Michael S. Tsirkin, Jon Olson (Google Drive), Willem de Bruijn
In-Reply-To: <4a3d69be-8651-e36d-bc14-5a3f1f23d155@redhat.com>

On Thu, Sep 13, 2018 at 5:02 AM Jason Wang <jasowang@redhat.com> wrote:
>
>
>
> On 2018年09月13日 07:27, Willem de Bruijn wrote:
> > On Wed, Sep 12, 2018 at 3:11 PM Willem de Bruijn
> > <willemdebruijn.kernel@gmail.com> wrote:
> >> On Wed, Sep 12, 2018 at 2:16 PM Florian Fainelli <f.fainelli@gmail.com> wrote:
> >>>
> >>>
> >>> On 9/12/2018 11:07 AM, Willem de Bruijn wrote:
> >>>> On Wed, Sep 12, 2018 at 1:42 PM Florian Fainelli <f.fainelli@gmail.com> wrote:
> >>>>>
> >>>>>
> >>>>> On 9/9/2018 3:44 PM, Willem de Bruijn wrote:
> >>>>>> From: Willem de Bruijn <willemb@google.com>
> >>>>>>
> >>>>>> Implement ethtool .set_coalesce (-C) and .get_coalesce (-c) handlers.
> >>>>>> Interrupt moderation is currently not supported, so these accept and
> >>>>>> display the default settings of 0 usec and 1 frame.
> >>>>>>
> >>>>>> Toggle tx napi through a bit in tx-frames. So as to not interfere
> >>>>>> with possible future interrupt moderation, use bit 10, well outside
> >>>>>> the reasonable range of real interrupt moderation values.
> >>>>>>
> >>>>>> Changes are not atomic. The tx IRQ, napi BH and transmit path must
> >>>>>> be quiesced when switching modes. Only allow changing this setting
> >>>>>> when the device is down.
> >>>>> Humm, would not a private ethtool flag to switch TX NAPI on/off be more
> >>>>> appropriate rather than use the coalescing configuration API here?
> >>>> What do you mean by private ethtool flag? A new field in ethtool
> >>>> --features (-k)?
> >>> I meant using ethtool_drvinfo::n_priv_flags, ETH_SS_PRIV_FLAGS and then
> >>> ETHTOOL_GFPFLAGS and ETHTOOL_SPFLAGS to control the toggling of that
> >>> private flag. mlx5 has a number of privates flags for instance.
> >> Interesting, thanks! I was not at all aware of those ethtool flags.
> >> Am having a look. It definitely looks promising.
> > Okay, I made that change. That is indeed much cleaner, thanks.
> > Let me send the patch, initially as RFC.
> >
> > I've observed one issue where if we toggle the flag before bringing
> > up the device, it hits a kernel BUG at include/linux/netdevice.h:515
> >
> >          BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
>
> This reminds me that we need to check netif_running() before trying to
> enable and disable tx napi in ethtool_set_coalesce().

The first iteration of my patch checked IFF_UP and effectively
only allowed the change when not running. What do you mean
by need to check?

And to respond to the other follow-up notes at once:

> Consider we may have interrupt moderation in the future, I tend to use
> set_coalesce. Otherwise we may need two steps to enable moderation:
>
> - tx-napi on
> - set_coalesce

FWIW, I don't care strongly whether we do this through coalesce or priv_flags.

>> +                     if (!napi_weight)
>> +                             virtqueue_enable_cb(vi->sq[i].vq);
>
> I don't get why we need to disable enable cb here.

To avoid entering no-napi mode with too few descriptors to
make progress and no way to get out of that state. This is a
pretty crude attempt at handling that, admittedly.

^ permalink raw reply


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