Vijay reported that a loop as simple as ...
while true; do
tc qdisc add dev foo root handle 1: prio
tc filter add dev foo parent 1: u32 match u32 0 0 flowid 1
tc qdisc del dev foo root
rmmod cls_u32
done
... will panic the kernel. Moreover, he bisected the change
apparently introducing it to 78fd1d0ab0 ("netlink: Re-add
locking to netlink_lookup() and seq walker").
The removal of synchronize_net() from the netlink socket
triggering the qdisc to be removed, seems to have uncovered
an RCU resp. module reference count race from the tc API.
Given that RCU conversion was done after e341694e3e ("netlink:
Convert netlink_lookup() to use RCU protected hash table")
which added the synchronize_net() originally, occasion of
hitting the bug was less likely (not impossible though):
When qdiscs that i) support attaching classifiers and,
ii) have at least one of them attached, get deleted, they
invoke tcf_destroy_chain(), and thus call into ->destroy()
handler from a classifier module.
After RCU conversion, all classifier that have an internal
prio list, unlink them and initiate freeing via call_rcu()
deferral.
Meanhile, tcf_destroy() releases already reference to the
tp->ops->owner module before the queued RCU callback handler
has been invoked.
Subsequent rmmod on the classifier module is then not prevented
since all module references are already dropped.
By the time, the kernel invokes the RCU callback handler from
the module, that function address is then invalid.
One way to fix it would be to add an rcu_barrier() to
unregister_tcf_proto_ops() to wait for all pending call_rcu()s
to complete.
synchronize_rcu() is not appropriate as under heavy RCU
callback load, registered call_rcu()s could be deferred
longer than a grace period. In case we don't have any pending
call_rcu()s, the barrier is allowed to return immediately.
Since we came here via unregister_tcf_proto_ops(), there
are no users of a given classifier anymore. Further nested
call_rcu()s pointing into the module space are not being
done anywhere.
Only cls_bpf_delete_prog() may schedule a work item, to
unlock pages eventually, but that is not in the range/context
of cls_bpf anymore.
Fixes: 25d8c0d55f ("net: rcu-ify tcf_proto")
Fixes: 9888faefe1 ("net: sched: cls_basic use RCU")
Reported-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.r.fastabend@intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Tested-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In WRED mode, the backlog for a single virtual queue (VQ) should not be
used to determine queue behavior; instead the backlog is summed across
all VQs. This sum is currently used when calculating the average queue
lengths. It also needs to be used when determining if the queue's hard
limit has been reached, or when reporting each VQ's backlog via netlink.
q->backlog will only be used if the queue switches out of WRED mode.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
When tcf_destroy() returns true, tp could be already destroyed,
we should not use tp->next after that.
For long term, we probably should move tp list to list_head.
Fixes: 1e052be69d ("net_sched: destroy proto tp when all filters are gone")
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Under presence of TSO/GSO/GRO packets, codel at low rates can be quite
useless. In following example, not a single packet was ever dropped,
while average delay in codel queue is ~100 ms !
qdisc codel 0: parent 1:12 limit 16000p target 5.0ms interval 100.0ms
Sent 134376498 bytes 88797 pkt (dropped 0, overlimits 0 requeues 0)
backlog 13626b 3p requeues 0
count 0 lastcount 0 ldelay 96.9ms drop_next 0us
maxpacket 9084 ecn_mark 0 drop_overlimit 0
This comes from a confusion of what should be the minimal backlog. It is
pretty clear it is not 64KB or whatever max GSO packet ever reached the
qdisc.
codel intent was to use MTU of the device.
After the fix, we finally drop some packets, and rtt/cwnd of my single
TCP flow are meeting our expectations.
qdisc codel 0: parent 1:12 limit 16000p target 5.0ms interval 100.0ms
Sent 102798497 bytes 67912 pkt (dropped 1365, overlimits 0 requeues 0)
backlog 6056b 3p requeues 0
count 1 lastcount 1 ldelay 36.3ms drop_next 0us
maxpacket 10598 ecn_mark 0 drop_overlimit 0
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kathleen Nichols <nichols@pollere.com>
Cc: Dave Taht <dave.taht@gmail.com>
Cc: Van Jacobson <vanj@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This action is meant to be passive, i.e. we should not alter
skb->nfct: If nfct is present just leave it alone.
Compile tested only.
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When you redirect a VLAN device to any device, you end up with
crap in af_packet on the xmit path because hard_header_len is
not equal to skb->mac_len. So the redirected packet contains
four extra bytes at the start which then gets interpreted as
part of the MAC address.
This patch fixes this by only pushing skb->mac_len. We also
need to fix ifb because it tries to undo the pushing done by
act_mirred.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the short-term solution, lets fix bpf helper functions to use
skb->mac_header relative offsets instead of skb->data in order to
get the same eBPF programs with cls_bpf and act_bpf work on ingress
and egress qdisc path. We need to ensure that mac_header is set
before calling into programs. This is effectively the first option
from below referenced discussion.
More long term solution for LD_ABS|LD_IND instructions will be more
intrusive but also more beneficial than this, and implemented later
as it's too risky at this point in time.
I.e., we plan to look into the option of moving skb_pull() out of
eth_type_trans() and into netif_receive_skb() as has been suggested
as second option. Meanwhile, this solution ensures ingress can be
used with eBPF, too, and that we won't run into ABI troubles later.
For dealing with negative offsets inside eBPF helper functions,
we've implemented bpf_skb_clone_unwritable() to test for unwriteable
headers.
Reference: http://thread.gmane.org/gmane.linux.network/359129/focus=359694
Fixes: 608cd71a9c ("tc: bpf: generalize pedit action")
Fixes: 91bc4822c3 ("tc: bpf: add checksum helpers")
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The dwmac-socfpga.c conflict was a case of a bug fix overlapping
changes in net-next to handle an error pointer differently.
Signed-off-by: David S. Miller <davem@davemloft.net>
Even if we make use of classifier and actions from the egress
path, we're going into handle_ing() executing additional code
on a per-packet cost for ingress qdisc, just to realize that
nothing is attached on ingress.
Instead, this can just be blinded out as a no-op entirely with
the use of a static key. On input fast-path, we already make
use of static keys in various places, e.g. skb time stamping,
in RPS, etc. It makes sense to not waste time when we're assured
that no ingress qdisc is attached anywhere.
Enabling/disabling of that code path is being done via two
helpers, namely net_{inc,dec}_ingress_queue(), that are being
invoked under RTNL mutex when a ingress qdisc is being either
initialized or destructed.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes byte backlog accounting for the first of two chained netem instances.
Bytes backlog reported now corresponds to the number of queued packets.
When two netem instances are chained, for instance to apply rate and queue
limitation followed by packet delay, the number of backlogged bytes reported
by the first netem instance is wrong. It reports the sum of bytes in the queues
of the first and second netem. The first netem reports the correct number of
backlogged packets but not bytes. This is shown in the example below.
Consider a chain of two netem schedulers created using the following commands:
$ tc -s qdisc replace dev veth2 root handle 1:0 netem rate 10000kbit limit 100
$ tc -s qdisc add dev veth2 parent 1:0 handle 2: netem delay 50ms
Start an iperf session to send packets out on the specified interface and
monitor the backlog using tc:
$ tc -s qdisc show dev veth2
Output using unpatched netem:
qdisc netem 1: root refcnt 2 limit 100 rate 10000Kbit
Sent 98422639 bytes 65434 pkt (dropped 123, overlimits 0 requeues 0)
backlog 172694b 73p requeues 0
qdisc netem 2: parent 1: limit 1000 delay 50.0ms
Sent 98422639 bytes 65434 pkt (dropped 0, overlimits 0 requeues 0)
backlog 63588b 42p requeues 0
The interface used to produce this output has an MTU of 1500. The output for
backlogged bytes behind netem 1 is 172694b. This value is not correct. Consider
the total number of sent bytes and packets. By dividing the number of sent
bytes by the number of sent packets, we get an average packet size of ~=1504.
If we divide the number of backlogged bytes by packets, we get ~=2365. This is
due to the first netem incorrectly counting the 63588b which are in netem 2's
queue as being in its own queue. To verify this is the case, we subtract them
from the reported value and divide by the number of packets as follows:
172694 - 63588 = 109106 bytes actualled backlogged in netem 1
109106 / 73 packets ~= 1494 bytes (which matches our MTU)
The root cause is that the byte accounting is not done at the
same time with packet accounting. The solution is to update the backlog value
every time the packet queue is updated.
Signed-off-by: Joseph D Beshay <joseph.beshay@utdallas.edu>
Acked-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Correct spelling of locally.
Also remove extra space before tab character in struct fq_flow.
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This work extends the "classic" BPF programmable tc action by extending
its scope also to native eBPF code!
Together with commit e2e9b6541d ("cls_bpf: add initial eBPF support
for programmable classifiers") this adds the facility to implement fully
flexible classifier and actions for tc that can be implemented in a C
subset in user space, "safely" loaded into the kernel, and being run in
native speed when JITed.
Also, since eBPF maps can be shared between eBPF programs, it offers the
possibility that cls_bpf and act_bpf can share data 1) between themselves
and 2) between user space applications. That means that, f.e. customized
runtime statistics can be collected in user space, but also more importantly
classifier and action behaviour could be altered based on map input from
the user space application.
For the remaining details on the workflow and integration, see the cls_bpf
commit e2e9b6541d. Preliminary iproute2 part can be found under [1].
[1] http://git.breakpoint.cc/cgit/dborkman/iproute2.git/log/?h=ebpf-act
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/emulex/benet/be_main.c
net/core/sysctl_net_core.c
net/ipv4/inet_diag.c
The be_main.c conflict resolution was really tricky. The conflict
hunks generated by GIT were very unhelpful, to say the least. It
split functions in half and moved them around, when the real actual
conflict only existed solely inside of one function, that being
be_map_pci_bars().
So instead, to resolve this, I checked out be_main.c from the top
of net-next, then I applied the be_main.c changes from 'net' since
the last time I merged. And this worked beautifully.
The inet_diag.c and sysctl_net_core.c conflicts were simple
overlapping changes, and were easily to resolve.
Signed-off-by: David S. Miller <davem@davemloft.net>
Revisiting commit d23b8ad8ab ("tc: add BPF based action") with regards
to eBPF support, I was thinking that it might be better to improve
return semantics from a BPF program invoked through BPF_PROG_RUN().
Currently, in case filter_res is 0, we overwrite the default action
opcode with TC_ACT_SHOT. A default action opcode configured through tc's
m_bpf can be: TC_ACT_RECLASSIFY, TC_ACT_PIPE, TC_ACT_SHOT, TC_ACT_UNSPEC,
TC_ACT_OK.
In cls_bpf, we have the possibility to overwrite the default class
associated with the classifier in case filter_res is _not_ 0xffffffff
(-1).
That allows us to fold multiple [e]BPF programs into a single one, where
they would otherwise need to be defined as a separate classifier with
its own classid, needlessly redoing parsing work, etc.
Similarly, we could do better in act_bpf: Since above TC_ACT* opcodes
are exported to UAPI anyway, we reuse them for return-code-to-tc-opcode
mapping, where we would allow above possibilities. Thus, like in cls_bpf,
a filter_res of 0xffffffff (-1) means that the configured _default_ action
is used. Any unkown return code from the BPF program would fail in
tcf_bpf() with TC_ACT_UNSPEC.
Should we one day want to make use of TC_ACT_STOLEN or TC_ACT_QUEUED,
which both have the same semantics, we have the option to either use
that as a default action (filter_res of 0xffffffff) or non-default BPF
return code.
All that will allow us to transparently use tcf_bpf() for both BPF
flavours.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, it is possible in cls_bpf to access eBPF maps only under
rcu_read_lock_bh() variants: while on ingress side, that is, handle_ing(),
the classifier would be called from __netif_receive_skb_core() under
rcu_read_lock(); on egress side, however, it's rcu_read_lock_bh() via
__dev_queue_xmit().
This rcu/rcu_bh mix doesn't work together with eBPF maps as they require
soley to be called under rcu_read_lock(). eBPF maps could also be shared
among various other eBPF programs (possibly even with other eBPF program
types, f.e. tracing) and user space processes, so any context is assumed.
Therefore, a possible fix for cls_bpf is to wrap/nest eBPF program
invocation under non-bh RCU lock variant.
Fixes: e2e9b6541d ("cls_bpf: add initial eBPF support for programmable classifiers")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We dynamically allocate divisor+1 entries for ->ht[] in tc_u_hnode:
ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
So ->ht is supposed to be the last field of this struct, however
this is broken, since an rcu head is appended after it.
Fixes: 1ce87720d4 ("net: sched: make cls_u32 lockless")
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Kernel automatically creates a tp for each
(kind, protocol, priority) tuple, which has handle 0,
when we add a new filter, but it still is left there
after we remove our own, unless we don't specify the
handle (literally means all the filters under
the tuple). For example this one is left:
# tc filter show dev eth0
filter parent 8001: protocol arp pref 49152 basic
The user-space is hard to clean up these for kernel
because filters like u32 are organized in a complex way.
So kernel is responsible to remove it after all filters
are gone. Each type of filter has its own way to
store the filters, so each type has to provide its
way to check if all filters are gone.
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim<jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/rocker/rocker.c
The rocker commit was two overlapping changes, one to rename
the ->vport member to ->pport, and another making the bitmask
expression use '1ULL' instead of plain '1'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
1) If an IPVS tunnel is created with a mixed-family destination
address, it cannot be removed. Fix from Alexey Andriyanov.
2) Fix module refcount underflow in netfilter's nft_compat, from Pablo
Neira Ayuso.
3) Generic statistics infrastructure can reference variables sitting on
a released function stack, therefore use dynamic allocation always.
Fix from Ignacy Gawędzki.
4) skb_copy_bits() return value test is inverted in ip_check_defrag().
5) Fix network namespace exit in openvswitch, we have to release all of
the per-net vports. From Pravin B Shelar.
6) Fix signedness bug in CAIF's cfpkt_iterate(), from Dan Carpenter.
7) Fix rhashtable grow/shrink behavior, only expand during inserts and
shrink during deletes. From Daniel Borkmann.
8) Netdevice names with semicolons should never be allowed, because
they serve as a separator. From Matthew Thode.
9) Use {,__}set_current_state() where appropriate, from Fabian
Frederick.
10) Revert byte queue limits support in r8169 driver, it's causing
regressions we can't figure out.
11) tcp_should_expand_sndbuf() erroneously uses tp->packets_out to
measure packets in flight, properly use tcp_packets_in_flight()
instead. From Neal Cardwell.
12) Fix accidental removal of support for bluetooth in CSR based Intel
wireless cards. From Marcel Holtmann.
13) We accidently added a behavioral change between native and compat
tasks, wrt testing the MSG_CMSG_COMPAT bit. Just ignore it if the
user happened to set it in a native binary as that was always the
behavior we had. From Catalin Marinas.
14) Check genlmsg_unicast() return valud in hwsim netlink tx frame
handling, from Bob Copeland.
15) Fix stale ->radar_required setting in mac80211 that can prevent
starting new scans, from Eliad Peller.
16) Fix memory leak in nl80211 monitor, from Johannes Berg.
17) Fix race in TX index handling in xen-netback, from David Vrabel.
18) Don't enable interrupts in amx-xgbe driver until all software et al.
state is ready for the interrupt handler to run. From Thomas
Lendacky.
19) Add missing netlink_ns_capable() checks to rtnl_newlink(), from Eric
W Biederman.
20) The amount of header space needed in macvtap was not calculated
properly, fix it otherwise we splat past the beginning of the
packet. From Eric Dumazet.
21) Fix bcmgenet TCP TX perf regression, from Jaedon Shin.
22) Don't raw initialize or mod timers, use setup_timer() and
mod_timer() instead. From Vaishali Thakkar.
23) Fix software maintained statistics in bcmgenet and systemport
drivers, from Florian Fainelli.
24) DMA descriptor updates in sh_eth need proper memory barriers, from
Ben Hutchings.
25) Don't do UDP Fragmentation Offload on RAW sockets, from Michal
Kubecek.
26) Openvswitch's non-masked set actions aren't constructed properly
into netlink messages, fix from Joe Stringer.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (116 commits)
openvswitch: Fix serialization of non-masked set actions.
gianfar: Reduce logging noise seen due to phy polling if link is down
ibmveth: Add function to enable live MAC address changes
net: bridge: add compile-time assert for cb struct size
udp: only allow UFO for packets from SOCK_DGRAM sockets
sh_eth: Really fix padding of short frames on TX
Revert "sh_eth: Enable Rx descriptor word 0 shift for r8a7790"
sh_eth: Fix RX recovery on R-Car in case of RX ring underrun
sh_eth: Ensure proper ordering of descriptor active bit write/read
net/mlx4_en: Disbale GRO for incoming loopback/selftest packets
net/mlx4_core: Fix wrong mask and error flow for the update-qp command
net: systemport: fix software maintained statistics
net: bcmgenet: fix software maintained statistics
rxrpc: don't multiply with HZ twice
rxrpc: terminate retrans loop when sending of skb fails
net/hsr: Fix NULL pointer dereference and refcnt bugs when deleting a HSR interface.
net: pasemi: Use setup_timer and mod_timer
net: stmmac: Use setup_timer and mod_timer
net: 8390: axnet_cs: Use setup_timer and mod_timer
net: 8390: pcnet_cs: Use setup_timer and mod_timer
...
This work extends the "classic" BPF programmable tc classifier by
extending its scope also to native eBPF code!
This allows for user space to implement own custom, 'safe' C like
classifiers (or whatever other frontend language LLVM et al may
provide in future), that can then be compiled with the LLVM eBPF
backend to an eBPF elf file. The result of this can be loaded into
the kernel via iproute2's tc. In the kernel, they can be JITed on
major archs and thus run in native performance.
Simple, minimal toy example to demonstrate the workflow:
#include <linux/ip.h>
#include <linux/if_ether.h>
#include <linux/bpf.h>
#include "tc_bpf_api.h"
__section("classify")
int cls_main(struct sk_buff *skb)
{
return (0x800 << 16) | load_byte(skb, ETH_HLEN + __builtin_offsetof(struct iphdr, tos));
}
char __license[] __section("license") = "GPL";
The classifier can then be compiled into eBPF opcodes and loaded
via tc, for example:
clang -O2 -emit-llvm -c cls.c -o - | llc -march=bpf -filetype=obj -o cls.o
tc filter add dev em1 parent 1: bpf cls.o [...]
As it has been demonstrated, the scope can even reach up to a fully
fledged flow dissector (similarly as in samples/bpf/sockex2_kern.c).
For tc, maps are allowed to be used, but from kernel context only,
in other words, eBPF code can keep state across filter invocations.
In future, we perhaps may reattach from a different application to
those maps e.g., to read out collected statistics/state.
Similarly as in socket filters, we may extend functionality for eBPF
classifiers over time depending on the use cases. For that purpose,
cls_bpf programs are using BPF_PROG_TYPE_SCHED_CLS program type, so
we can allow additional functions/accessors (e.g. an ABI compatible
offset translation to skb fields/metadata). For an initial cls_bpf
support, we allow the same set of helper functions as eBPF socket
filters, but we could diverge at some point in time w/o problem.
I was wondering whether cls_bpf and act_bpf could share C programs,
I can imagine that at some point, we introduce i) further common
handlers for both (or even beyond their scope), and/or if truly needed
ii) some restricted function space for each of them. Both can be
abstracted easily through struct bpf_verifier_ops in future.
The context of cls_bpf versus act_bpf is slightly different though:
a cls_bpf program will return a specific classid whereas act_bpf a
drop/non-drop return code, latter may also in future mangle skbs.
That said, we can surely have a "classify" and "action" section in
a single object file, or considered mentioned constraint add a
possibility of a shared section.
The workflow for getting native eBPF running from tc [1] is as
follows: for f_bpf, I've added a slightly modified ELF parser code
from Alexei's kernel sample, which reads out the LLVM compiled
object, sets up maps (and dynamically fixes up map fds) if any, and
loads the eBPF instructions all centrally through the bpf syscall.
The resulting fd from the loaded program itself is being passed down
to cls_bpf, which looks up struct bpf_prog from the fd store, and
holds reference, so that it stays available also after tc program
lifetime. On tc filter destruction, it will then drop its reference.
Moreover, I've also added the optional possibility to annotate an
eBPF filter with a name (e.g. path to object file, or something
else if preferred) so that when tc dumps currently installed filters,
some more context can be given to an admin for a given instance (as
opposed to just the file descriptor number).
Last but not least, bpf_prog_get() and bpf_prog_put() needed to be
exported, so that eBPF can be used from cls_bpf built as a module.
Thanks to 60a3b2253c ("net: bpf: make eBPF interpreter images
read-only") I think this is of no concern since anything wanting to
alter eBPF opcode after verification stage would crash the kernel.
[1] http://git.breakpoint.cc/cgit/dborkman/iproute2.git/log/?h=ebpf
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Although it is clear that textsearch state is intentionally passed to
skb_find_text() as uninitialized argument, it was never used by the
callers. Therefore, we can simplify skb_find_text() by making it
local variable.
Signed-off-by: Bojan Prtvar <prtvar.b@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In tcf_em_validate(), after calling request_module() to load the
kind-specific module, set em->ops to NULL before returning -EAGAIN, so
that module_put() is not called again by tcf_em_tree_destroy().
Signed-off-by: Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr>
Acked-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull kconfig updates from Michal Marek:
"Yann E Morin was supposed to take over kconfig maintainership, but
this hasn't happened. So I'm sending a few kconfig patches that I
collected:
- Fix for missing va_end in kconfig
- merge_config.sh displays used if given too few arguments
- s/boolean/bool/ in Kconfig files for consistency, with the plan to
only support bool in the future"
* 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kconfig: use va_end to match corresponding va_start
merge_config.sh: Display usage if given too few arguments
kconfig: use bool instead of boolean for type definition attributes
Conflicts:
drivers/net/vxlan.c
drivers/vhost/net.c
include/linux/if_vlan.h
net/core/dev.c
The net/core/dev.c conflict was the overlap of one commit marking an
existing function static whilst another was adding a new function.
In the include/linux/if_vlan.h case, the type used for a local
variable was changed in 'net', whereas the function got rewritten
to fix a stacked vlan bug in 'net-next'.
In drivers/vhost/net.c, Al Viro's iov_iter conversions in 'net-next'
overlapped with an endainness fix for VHOST 1.0 in 'net'.
In drivers/net/vxlan.c, vxlan_find_vni() added a 'flags' parameter
in 'net-next' whereas in 'net' there was a bug fix to pass in the
correct network namespace pointer in calls to this function.
Signed-off-by: David S. Miller <davem@davemloft.net>
FQ has a fast path for skb attached to a socket, as it does not
have to compute a flow hash. But for other packets, FQ being non
stochastic means that hosts exposed to random Internet traffic
can allocate million of flows structure (104 bytes each) pretty
easily. Not only host can OOM, but lookup in RB trees can take
too much cpu and memory resources.
This patch adds a new attribute, orphan_mask, that is adding
possibility of having a stochastic hash for orphaned skb.
Its default value is 1024 slots, to mimic SFQ behavior.
Note: This does not apply to locally generated TCP traffic,
and no locally generated traffic will share a flow structure
with another perfect or stochastic flow.
This patch also handles the specific case of SYNACK messages:
They are attached to the listener socket, and therefore all map
to a single hash bucket. If listener have set SO_MAX_PACING_RATE,
hoping to have new accepted socket inherit this rate, SYNACK
might be paced and even dropped.
This is very similar to an internal patch Google have used more
than one year.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we added pacing to TCP, we decided to let sch_fq take care
of actual pacing.
All TCP had to do was to compute sk->pacing_rate using simple formula:
sk->pacing_rate = 2 * cwnd * mss / rtt
It works well for senders (bulk flows), but not very well for receivers
or even RPC :
cwnd on the receiver can be less than 10, rtt can be around 100ms, so we
can end up pacing ACK packets, slowing down the sender.
Really, only the sender should pace, according to its own logic.
Instead of adding a new bit in skb, or call yet another flow
dissection, we tweak skb->truesize to a small value (2), and
we instruct sch_fq to use new helper and not pace pure ack.
Note this also helps TCP small queue, as ack packets present
in qdisc/NIC do not prevent sending a data packet (RPC workload)
This helps to reduce tx completion overhead, ack packets can use regular
sock_wfree() instead of tcp_wfree() which is a bit more expensive.
This has no impact in the case packets are sent to loopback interface,
as we do not coalesce ack packets (were we would detect skb->truesize
lie)
In case netem (with a delay) is used, skb_orphan_partial() also sets
skb->truesize to 1.
This patch is a combination of two patches we used for about one year at
Google.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In tcf_exts_dump_stats(), ensure that exts->actions is not empty before
accessing the first element of that list and calling tcf_action_copy_stats()
on it. This fixes some random segvs when adding filters of type "basic" with
no particular action.
This also fixes the dumping of those "no-action" filters, which more often
than not made calls to tcf_action_copy_stats() fail and consequently netlink
attributes added by the caller to be removed by a call to nla_nest_cancel().
Fixes: 33be627159 ("net_sched: act: use standard struct list_head")
Signed-off-by: Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr>
Acked-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Configuring fq with quantum 0 hangs the system, presumably because of a
non-interruptible infinite loop. Either way quantum 0 does not make sense.
Reproduce with:
sudo tc qdisc add dev lo root fq quantum 0 initial_quantum 0
ping 127.0.0.1
Signed-off-by: Kenneth Klette Jonassen <kennetkl@ifi.uio.no>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TIME_WAIT sockets are not owning any skb.
ip_send_unicast_reply() and tcp_v6_send_response() both use
regular sockets.
We can safely remove a test in sch_fq and save one cache line miss,
as sk_state is far away from sk_pacing_rate.
Tested at Google for about one year.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
NET_ACT_CONNMARK fails to build if NF_CONNTRACK_MARK is disabled,
and d7924450e1 ("act_connmark: Add missing dependency on
NF_CONNTRACK_MARK") fixed that case, but missed the cased where
NF_CONNTRACK is a loadable module.
This adds the second dependency to ensure that NET_ACT_CONNMARK
can only be built-in if NF_CONNTRACK is also part of the kernel
rather than a loadable module.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
arch/arm/boot/dts/imx6sx-sdb.dts
net/sched/cls_bpf.c
Two simple sets of overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Similarly as in cls_bpf, also this code needs to reject mismatches.
Reference: http://article.gmane.org/gmane.linux.network/347406
Fixes: d23b8ad8ab ("tc: add BPF based action")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As soon as we've found a matching handle in basic_get(), we can
return it. There's no need to continue walking until the end of
a filter chain, since they are unique anyway.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Cc: Thomas Graf <tgraf@suug.ch>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
When creating a bpf classifier in tc with priority collisions and
invoking automatic unique handle assignment, cls_bpf_grab_new_handle()
will return a wrong handle id which in fact is non-unique. Usually
altering of specific filters is being addressed over major id, but
in case of collisions we result in a filter chain, where handle ids
address individual cls_bpf_progs inside the classifier.
Issue is, in cls_bpf_grab_new_handle() we probe for head->hgen handle
in cls_bpf_get() and in case we found a free handle, we're supposed
to use exactly head->hgen. In case of insufficient numbers of handles,
we bail out later as handle id 0 is not allowed.
Fixes: 7d1d65cb84 ("net: sched: cls_bpf: add BPF-based classifier")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In cls_bpf_modify_existing(), we read out the number of filter blocks,
do some sanity checks, allocate a block on that size, and copy over the
BPF instruction blob from user space, then pass everything through the
classic BPF checker prior to installation of the classifier.
We should reject mismatches here, there are 2 scenarios: the number of
filter blocks could be smaller than the provided instruction blob, so
we do a partial copy of the BPF program, and thus the instructions will
either be rejected from the verifier or a valid BPF program will be run;
in the other case, we'll end up copying more than we're supposed to,
and most likely the trailing garbage will be rejected by the verifier
as well (i.e. we need to fit instruction pattern, ret {A,K} needs to be
last instruction, load/stores must be correct, etc); in case not, we
would leak memory when dumping back instruction patterns. The code should
have only used nla_len() as Dave noted to avoid this from the beginning.
Anyway, lets fix it by rejecting such load attempts.
Fixes: 7d1d65cb84 ("net: sched: cls_bpf: add BPF-based classifier")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Depending on NETFILTER is not sufficient to ensure the presence of the
'mark' field in nf_conn, also needs to depend on NF_CONNTRACK_MARK.
Fixes: 22a5dc ("net: sched: Introduce connmark action")
Cc: Felix Fietkau <nbd@openwrt.org>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This tc action allows you to retrieve the connection tracking mark
This action has been used heavily by openwrt for a few years now.
There are known limitations currently:
doesn't work for initial packets, since we only query the ct table.
Fine given use case is for returning packets
no implicit defrag.
frags should be rare so fix later..
won't work for more complex tasks, e.g. lookup of other extensions
since we have no means to store results
we still have a 2nd lookup later on via normal conntrack path.
This shouldn't break anything though since skb->nfct isn't altered.
V2:
remove unnecessary braces (Jiri)
change the action identifier to 14 (Jiri)
Fix some stylistic issues caught by checkpatch
V3:
Move module params to bottom (Cong)
Get rid of tcf_hashinfo_init and friends and conform to newer API (Cong)
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It was suggested by DaveM to change the name as "len" might indicate
unit bytes.
Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This action provides a possibility to exec custom BPF code.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
The same macros are used for rx as well. So rename it.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
tc code implicitly considers skb->protocol even in case of accelerated
vlan paths and expects vlan protocol type here. However, on rx path,
if the vlan header was already stripped, skb->protocol contains value
of next header. Similar situation is on tx path.
So for skbs that use skb->vlan_tci for tagging, use skb->vlan_proto instead.
Reported-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove the function teql_neigh_release() that is not used anywhere.
This was partially found by using a static code analysis program called cppcheck.
Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
Support for keyword 'boolean' will be dropped later on.
No functional change.
Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com
Signed-off-by: Christoph Jaeger <cj@linux.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Conflicts:
drivers/net/ethernet/amd/xgbe/xgbe-desc.c
drivers/net/ethernet/renesas/sh_eth.c
Overlapping changes in both conflict cases.
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 46e5da40ae (net: qdisc: use rcu prefix and silence
sparse warnings) triggers a spurious warning:
net/sched/sch_fq_codel.c:97 suspicious rcu_dereference_check() usage!
The code should be using the _bh variant of rcu_dereference.
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Reviewed-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is never called and implementations are void. So just remove it.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann