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  1. 27 5月, 2020 2 次提交
    • G
      cls_flower: Support filtering on multiple MPLS Label Stack Entries · 61aec25a
      由 Guillaume Nault 提交于 
      With struct flow_dissector_key_mpls now recording the first
FLOW_DIS_MPLS_MAX labels, we can extend Flower to filter on any of
these LSEs independently.

In order to avoid creating new netlink attributes for every possible
depth, let's define a new TCA_FLOWER_KEY_MPLS_OPTS nested attribute
that contains the list of LSEs to match. Each LSE is represented by
another attribute, TCA_FLOWER_KEY_MPLS_OPTS_LSE, which then contains
the attributes representing the depth and the MPLS fields to match at
this depth (label, TTL, etc.).

For each MPLS field, the mask is always set to all-ones, as this is
what the original API did. We could allow user configurable masks in
the future if there is demand for more flexibility.

The new API also allows to only specify an LSE depth. In that case,
Flower only verifies that the MPLS label stack depth is greater or
equal to the provided depth (that is, an LSE exists at this depth).

Filters that only match on one (or more) fields of the first LSE are
dumped using the old netlink attributes, to avoid confusing user space
programs that don't understand the new API.
Signed-off-by: NGuillaume Nault <gnault@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      61aec25a
    • G
      flow_dissector: Parse multiple MPLS Label Stack Entries · 58cff782
      由 Guillaume Nault 提交于 
      The current MPLS dissector only parses the first MPLS Label Stack
Entry (second LSE can be parsed too, but only to set a key_id).

This patch adds the possibility to parse several LSEs by making
__skb_flow_dissect_mpls() return FLOW_DISSECT_RET_PROTO_AGAIN as long
as the Bottom Of Stack bit hasn't been seen, up to a maximum of
FLOW_DIS_MPLS_MAX entries.

FLOW_DIS_MPLS_MAX is arbitrarily set to 7. This should be enough for
many practical purposes, without wasting too much space.

To record the parsed values, flow_dissector_key_mpls is modified to
store an array of stack entries, instead of just the values of the
first one. A bit field, "used_lses", is also added to keep track of
the LSEs that have been set. The objective is to avoid defining a
new FLOW_DISSECTOR_KEY_MPLS_XX for each level of the MPLS stack.

TC flower is adapted for the new struct flow_dissector_key_mpls layout.
Matching on several MPLS Label Stack Entries will be added in the next
patch.

The NFP and MLX5 drivers are also adapted: nfp_flower_compile_mac() and
mlx5's parse_tunnel() now verify that the rule only uses the first LSE
and fail if it doesn't.

Finally, the behaviour of the FLOW_DISSECTOR_KEY_MPLS_ENTROPY key is
slightly modified. Instead of recording the first Entropy Label, it
now records the last one. This shouldn't have any consequences since
there doesn't seem to have any user of FLOW_DISSECTOR_KEY_MPLS_ENTROPY
in the tree. We'd probably better do a hash of all parsed MPLS labels
instead (excluding reserved labels) anyway. That'd give better entropy
and would probably also simplify the code. But that's not the purpose
of this patch, so I'm keeping that as a future possible improvement.
Signed-off-by: NGuillaume Nault <gnault@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      58cff782
  3. 16 5月, 2020 1 次提交
  5. 31 3月, 2020 1 次提交
    • J
      net: sched: expose HW stats types per action used by drivers · 93a129eb
      由 Jiri Pirko 提交于 
      It may be up to the driver (in case ANY HW stats is passed) to select
which type of HW stats he is going to use. Add an infrastructure to
expose this information to user.

$ tc filter add dev enp3s0np1 ingress proto ip handle 1 pref 1 flower dst_ip 192.168.1.1 action drop
$ tc -s filter show dev enp3s0np1 ingress
filter protocol ip pref 1 flower chain 0
filter protocol ip pref 1 flower chain 0 handle 0x1
  eth_type ipv4
  dst_ip 192.168.1.1
  in_hw in_hw_count 2
        action order 1: gact action drop
         random type none pass val 0
         index 1 ref 1 bind 1 installed 10 sec used 10 sec
        Action statistics:
        Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
        backlog 0b 0p requeues 0
        used_hw_stats immediate     <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      93a129eb
  7. 27 3月, 2020 3 次提交
  9. 18 2月, 2020 2 次提交
  11. 14 2月, 2020 1 次提交
  13. 27 1月, 2020 1 次提交
    • C
      net_sched: fix ops->bind_class() implementations · 2e24cd75
      由 Cong Wang 提交于 
      The current implementations of ops->bind_class() are merely
searching for classid and updating class in the struct tcf_result,
without invoking either of cl_ops->bind_tcf() or
cl_ops->unbind_tcf(). This breaks the design of them as qdisc's
like cbq use them to count filters too. This is why syzbot triggered
the warning in cbq_destroy_class().

In order to fix this, we have to call cl_ops->bind_tcf() and
cl_ops->unbind_tcf() like the filter binding path. This patch does
so by refactoring out two helper functions __tcf_bind_filter()
and __tcf_unbind_filter(), which are lockless and accept a Qdisc
pointer, then teaching each implementation to call them correctly.

Note, we merely pass the Qdisc pointer as an opaque pointer to
each filter, they only need to pass it down to the helper
functions without understanding it at all.

Fixes: 07d79fc7 ("net_sched: add reverse binding for tc class")
Reported-and-tested-by: syzbot+0a0596220218fcb603a8@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+63bdb6006961d8c917c6@syzkaller.appspotmail.com
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2e24cd75
  15. 31 12月, 2019 1 次提交
    • D
      net/sched: add delete_empty() to filters and use it in cls_flower · a5b72a08
      由 Davide Caratti 提交于 
      Revert "net/sched: cls_u32: fix refcount leak in the error path of
u32_change()", and fix the u32 refcount leak in a more generic way that
preserves the semantic of rule dumping.
On tc filters that don't support lockless insertion/removal, there is no
need to guard against concurrent insertion when a removal is in progress.
Therefore, for most of them we can avoid a full walk() when deleting, and
just decrease the refcount, like it was done on older Linux kernels.
This fixes situations where walk() was wrongly detecting a non-empty
filter, like it happened with cls_u32 in the error path of change(), thus
leading to failures in the following tdc selftests:

 6aa7: (filter, u32) Add/Replace u32 with source match and invalid indev
 6658: (filter, u32) Add/Replace u32 with custom hash table and invalid handle
 74c2: (filter, u32) Add/Replace u32 filter with invalid hash table id

On cls_flower, and on (future) lockless filters, this check is necessary:
move all the check_empty() logic in a callback so that each filter
can have its own implementation. For cls_flower, it's sufficient to check
if no IDRs have been allocated.

This reverts commit 275c44aa.

Changes since v1:
 - document the need for delete_empty() when TCF_PROTO_OPS_DOIT_UNLOCKED
   is used, thanks to Vlad Buslov
 - implement delete_empty() without doing fl_walk(), thanks to Vlad Buslov
 - squash revert and new fix in a single patch, to be nice with bisect
   tests that run tdc on u32 filter, thanks to Dave Miller

Fixes: 275c44aa ("net/sched: cls_u32: fix refcount leak in the error path of u32_change()")
Fixes: 6676d5e4 ("net: sched: set dedicated tcf_walker flag when tp is empty")
Suggested-by: NJamal Hadi Salim <jhs@mojatatu.com>
Suggested-by: NVlad Buslov <vladbu@mellanox.com>
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Reviewed-by: NVlad Buslov <vladbu@mellanox.com>
Tested-by: NJamal Hadi Salim <jhs@mojatatu.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a5b72a08
  17. 10 12月, 2019 1 次提交
  19. 04 12月, 2019 1 次提交
    • Y
      cls_flower: Fix the behavior using port ranges with hw-offload · 8ffb055b
      由 Yoshiki Komachi 提交于 
      The recent commit 5c72299f ("net: sched: cls_flower: Classify
packets using port ranges") had added filtering based on port ranges
to tc flower. However the commit missed necessary changes in hw-offload
code, so the feature gave rise to generating incorrect offloaded flow
keys in NIC.

One more detailed example is below:

$ tc qdisc add dev eth0 ingress
$ tc filter add dev eth0 ingress protocol ip flower ip_proto tcp \
  dst_port 100-200 action drop

With the setup above, an exact match filter with dst_port == 0 will be
installed in NIC by hw-offload. IOW, the NIC will have a rule which is
equivalent to the following one.

$ tc qdisc add dev eth0 ingress
$ tc filter add dev eth0 ingress protocol ip flower ip_proto tcp \
  dst_port 0 action drop

The behavior was caused by the flow dissector which extracts packet
data into the flow key in the tc flower. More specifically, regardless
of exact match or specified port ranges, fl_init_dissector() set the
FLOW_DISSECTOR_KEY_PORTS flag in struct flow_dissector to extract port
numbers from skb in skb_flow_dissect() called by fl_classify(). Note
that device drivers received the same struct flow_dissector object as
used in skb_flow_dissect(). Thus, offloaded drivers could not identify
which of these is used because the FLOW_DISSECTOR_KEY_PORTS flag was
set to struct flow_dissector in either case.

This patch adds the new FLOW_DISSECTOR_KEY_PORTS_RANGE flag and the new
tp_range field in struct fl_flow_key to recognize which filters are applied
to offloaded drivers. At this point, when filters based on port ranges
passed to drivers, drivers return the EOPNOTSUPP error because they do
not support the feature (the newly created FLOW_DISSECTOR_KEY_PORTS_RANGE
flag).

Fixes: 5c72299f ("net: sched: cls_flower: Classify packets using port ranges")
Signed-off-by: NYoshiki Komachi <komachi.yoshiki@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8ffb055b
  21. 22 11月, 2019 2 次提交
    • X
      net: sched: allow flower to match erspan options · 79b1011c
      由 Xin Long 提交于 
      This patch is to allow matching options in erspan.

The options can be described in the form:
VER:INDEX:DIR:HWID/VER:INDEX_MASK:DIR_MASK:HWID_MASK.
When ver is set to 1, index will be applied while dir
and hwid will be ignored, and when ver is set to 2,
dir and hwid will be used while index will be ignored.

Different from geneve, only one option can be set. And
also, geneve options, vxlan options or erspan options
can't be set at the same time.

  # ip link add name erspan1 type erspan external
  # tc qdisc add dev erspan1 ingress
  # tc filter add dev erspan1 protocol ip parent ffff: \
      flower \
        enc_src_ip 10.0.99.192 \
        enc_dst_ip 10.0.99.193 \
        enc_key_id 11 \
        erspan_opts 1:12:0:0/1:ffff:0:0 \
        ip_proto udp \
        action mirred egress redirect dev eth0

v1->v2:
  - improve some err msgs of extack.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      79b1011c
    • X
      net: sched: allow flower to match vxlan options · d8f9dfae
      由 Xin Long 提交于 
      This patch is to allow matching gbp option in vxlan.

The options can be described in the form GBP/GBP_MASK,
where GBP is represented as a 32bit hexadecimal value.
Different from geneve, only one option can be set. And
also, geneve options and vxlan options can't be set at
the same time.

  # ip link add name vxlan0 type vxlan dstport 0 external
  # tc qdisc add dev vxlan0 ingress
  # tc filter add dev vxlan0 protocol ip parent ffff: \
      flower \
        enc_src_ip 10.0.99.192 \
        enc_dst_ip 10.0.99.193 \
        enc_key_id 11 \
        vxlan_opts 01020304/ffffffff \
        ip_proto udp \
        action mirred egress redirect dev eth0

v1->v2:
  - add .strict_start_type for enc_opts_policy as Jakub noticed.
  - use Duplicate instead of Wrong in err msg for extack as Jakub
    suggested.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d8f9dfae
  23. 27 8月, 2019 5 次提交
    • V
      net: sched: flower: don't take rtnl lock for cls hw offloads API · 918190f5
      由 Vlad Buslov 提交于 
      Don't manually take rtnl lock in flower classifier before calling cls
hardware offloads API. Instead, pass rtnl lock status via 'rtnl_held'
parameter.
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      918190f5
    • V
      net: sched: take reference to action dev before calling offloads · 5a6ff4b1
      由 Vlad Buslov 提交于 
      In order to remove dependency on rtnl lock when calling hardware offload
API, take reference to action mirred dev when initializing flow_action
structure in tc_setup_flow_action(). Implement function
tc_cleanup_flow_action(), use it to release the device after hardware
offload API is done using it.
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5a6ff4b1
    • V
      net: sched: take rtnl lock in tc_setup_flow_action() · 9838b20a
      由 Vlad Buslov 提交于 
      In order to allow using new flow_action infrastructure from unlocked
classifiers, modify tc_setup_flow_action() to accept new 'rtnl_held'
argument. Take rtnl lock before accessing tc_action data. This is necessary
to protect from concurrent action replace.
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9838b20a
    • V
      net: sched: notify classifier on successful offload add/delete · a449a3e7
      由 Vlad Buslov 提交于 
      To remove dependency on rtnl lock, extend classifier ops with new
ops->hw_add() and ops->hw_del() callbacks. Call them from cls API while
holding cb_lock every time filter if successfully added to or deleted from
hardware.

Implement the new API in flower classifier. Use it to manage hw_filters
list under cb_lock protection, instead of relying on rtnl lock to
synchronize with concurrent fl_reoffload() call.
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a449a3e7
    • V
      net: sched: refactor block offloads counter usage · 40119211
      由 Vlad Buslov 提交于 
      Without rtnl lock protection filters can no longer safely manage block
offloads counter themselves. Refactor cls API to protect block offloadcnt
with tcf_block->cb_lock that is already used to protect driver callback
list and nooffloaddevcnt counter. The counter can be modified by concurrent
tasks by new functions that execute block callbacks (which is safe with
previous patch that changed its type to atomic_t), however, block
bind/unbind code that checks the counter value takes cb_lock in write mode
to exclude any concurrent modifications. This approach prevents race
conditions between bind/unbind and callback execution code but allows for
concurrency for tc rule update path.

Move block offload counter, filter in hardware counter and filter flags
management from classifiers into cls hardware offloads API. Make functions
tcf_block_offload_{inc|dec}() and tc_cls_offload_cnt_update() to be cls API
private. Implement following new cls API to be used instead:

  tc_setup_cb_add() - non-destructive filter add. If filter that wasn't
  already in hardware is successfully offloaded, increment block offloads
  counter, set filter in hardware counter and flag. On failure, previously
  offloaded filter is considered to be intact and offloads counter is not
  decremented.

  tc_setup_cb_replace() - destructive filter replace. Release existing
  filter block offload counter and reset its in hardware counter and flag.
  Set new filter in hardware counter and flag. On failure, previously
  offloaded filter is considered to be destroyed and offload counter is
  decremented.

  tc_setup_cb_destroy() - filter destroy. Unconditionally decrement block
  offloads counter.

  tc_setup_cb_reoffload() - reoffload filter to single cb. Execute cb() and
  call tc_cls_offload_cnt_update() if cb() didn't return an error.

Refactor all offload-capable classifiers to atomically offload filters to
hardware, change block offload counter, and set filter in hardware counter
and flag by means of the new cls API functions.
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      40119211
  25. 20 7月, 2019 1 次提交
  27. 10 7月, 2019 2 次提交
  29. 02 7月, 2019 1 次提交
  31. 19 6月, 2019 1 次提交
  33. 16 6月, 2019 1 次提交
  35. 15 6月, 2019 1 次提交
  37. 31 5月, 2019 1 次提交
  39. 08 5月, 2019 1 次提交
  41. 06 5月, 2019 1 次提交
  43. 28 4月, 2019 2 次提交
    • J
      netlink: make validation more configurable for future strictness · 8cb08174
      由 Johannes Berg 提交于 
      We currently have two levels of strict validation:

 1) liberal (default)
     - undefined (type >= max) & NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted
     - garbage at end of message accepted
 2) strict (opt-in)
     - NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted

Split out parsing strictness into four different options:
 * TRAILING     - check that there's no trailing data after parsing
                  attributes (in message or nested)
 * MAXTYPE      - reject attrs > max known type
 * UNSPEC       - reject attributes with NLA_UNSPEC policy entries
 * STRICT_ATTRS - strictly validate attribute size

The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().

Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.

We end up with the following renames:
 * nla_parse           -> nla_parse_deprecated
 * nla_parse_strict    -> nla_parse_deprecated_strict
 * nlmsg_parse         -> nlmsg_parse_deprecated
 * nlmsg_parse_strict  -> nlmsg_parse_deprecated_strict
 * nla_parse_nested    -> nla_parse_nested_deprecated
 * nla_validate_nested -> nla_validate_nested_deprecated

Using spatch, of course:
    @@
    expression TB, MAX, HEAD, LEN, POL, EXT;
    @@
    -nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
    +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression TB, MAX, NLA, POL, EXT;
    @@
    -nla_parse_nested(TB, MAX, NLA, POL, EXT)
    +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)

    @@
    expression START, MAX, POL, EXT;
    @@
    -nla_validate_nested(START, MAX, POL, EXT)
    +nla_validate_nested_deprecated(START, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, MAX, POL, EXT;
    @@
    -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
    +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)

For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.

Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.

Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.

In effect then, this adds fully strict validation for any new command.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8cb08174
    • M
      netlink: make nla_nest_start() add NLA_F_NESTED flag · ae0be8de
      由 Michal Kubecek 提交于 
      Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.

Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().

Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:

@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)

@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)
Signed-off-by: NMichal Kubecek <mkubecek@suse.cz>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ae0be8de
  45. 25 4月, 2019 1 次提交
    • V
      net: sched: flower: refactor reoffload for concurrent access · c049d56e
      由 Vlad Buslov 提交于 
      Recent changes that introduced unlocked flower did not properly account for
case when reoffload is initiated concurrently with filter updates. To fix
the issue, extend flower with 'hw_filters' list that is used to store
filters that don't have 'skip_hw' flag set. Filter is added to the list
when it is inserted to hardware and only removed from it after being
unoffloaded from all drivers that parent block is attached to. This ensures
that concurrent reoffload can still access filter that is being deleted and
prevents race condition when driver callback can be removed when filter is
no longer accessible trough idr, but is still present in hardware.

Refactor fl_change() to respect new filter reference counter and to release
filter reference with __fl_put() in case of error, instead of directly
deallocating filter memory. This allows for concurrent access to filter
from fl_reoffload() and protects it with reference counting. Refactor
fl_reoffload() to iterate over hw_filters list instead of idr. Implement
fl_get_next_hw_filter() helper function that is used to iterate over
hw_filters list with reference counting and skips filters that are being
concurrently deleted.

Fixes: 92149190 ("net: sched: flower: set unlocked flag for flower proto ops")
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Reviewed-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c049d56e
  47. 12 4月, 2019 2 次提交
    • V
      net: sched: flower: fix filter net reference counting · 9994677c
      由 Vlad Buslov 提交于 
      Fix net reference counting in fl_change() and remove redundant call to
tcf_exts_get_net() from __fl_delete(). __fl_put() already tries to get net
before releasing exts and deallocating a filter, so this code caused flower
classifier to obtain net twice per filter that is being deleted.

Implementation of __fl_delete() called tcf_exts_get_net() to pass its
result as 'async' flag to fl_mask_put(). However, 'async' flag is redundant
and only complicates fl_mask_put() implementation. This functionality seems
to be copied from filter cleanup code, where it was added by Cong with
following explanation:

    This patchset tries to fix the race between call_rcu() and
    cleanup_net() again. Without holding the netns refcnt the
    tc_action_net_exit() in netns workqueue could be called before
    filter destroy works in tc filter workqueue. This patchset
    moves the netns refcnt from tc actions to tcf_exts, without
    breaking per-netns tc actions.

This doesn't apply to flower mask, which doesn't call any tc action code
during cleanup. Simplify fl_mask_put() by removing the flag parameter and
always use tcf_queue_work() to free mask objects.

Fixes: 06177558 ("net: sched: flower: introduce reference counting for filters")
Fixes: 1f17f774 ("net: sched: flower: insert filter to ht before offloading it to hw")
Fixes: 05cd271f ("cls_flower: Support multiple masks per priority")
Reported-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9994677c
    • V
      net: sched: flower: use correct ht function to prevent duplicates · 9e35552a
      由 Vlad Buslov 提交于 
      Implementation of function rhashtable_insert_fast() check if its internal
helper function __rhashtable_insert_fast() returns non-NULL pointer and
seemingly return -EEXIST in such case. However, since
__rhashtable_insert_fast() is called with NULL key pointer, it never
actually checks for duplicates, which means that -EEXIST is never returned
to the user. Use rhashtable_lookup_insert_fast() hash table API instead. In
order to verify that it works as expected and prevent the problem from
happening in future, extend tc-tests with new test that verifies that no
new filters with existing key can be inserted to flower classifier.

Fixes: 1f17f774 ("net: sched: flower: insert filter to ht before offloading it to hw")
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9e35552a
  49. 08 4月, 2019 1 次提交
    • V
      net: sched: flower: insert filter to ht before offloading it to hw · 1f17f774
      由 Vlad Buslov 提交于 
      John reports:

Recent refactoring of fl_change aims to use the classifier spinlock to
avoid the need for rtnl lock. In doing so, the fl_hw_replace_filer()
function was moved to before the lock is taken. This can create problems
for drivers if duplicate filters are created (commmon in ovs tc offload
due to filters being triggered by user-space matches).

Drivers registered for such filters will now receive multiple copies of
the same rule, each with a different cookie value. This means that the
drivers would need to do a full match field lookup to determine
duplicates, repeating work that will happen in flower __fl_lookup().
Currently, drivers do not expect to receive duplicate filters.

To fix this, verify that filter with same key is not present in flower
classifier hash table and insert the new filter to the flower hash table
before offloading it to hardware. Implement helper function
fl_ht_insert_unique() to atomically verify/insert a filter.

This change makes filter visible to fast path at the beginning of
fl_change() function, which means it can no longer be freed directly in
case of error. Refactor fl_change() error handling code to deallocate the
filter with rcu timeout.

Fixes: 620da486 ("net: sched: flower: refactor fl_change")
Reported-by: NJohn Hurley <john.hurley@netronome.com>
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1f17f774
  51. 05 4月, 2019 1 次提交
  53. 22 3月, 2019 2 次提交