linux.git/net/ipv4/inetpeer.c, branch v4.15

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

2017-10-06T01:19:22+00:00

Just simple overlapping changes.

Signed-off-by: David S. Miller

inetpeer: speed up inetpeer_invalidate_tree()

2017-09-28T16:40:59+00:00

As measured in my prior patch ("sch_netem: faster rb tree removal"),
rbtree_postorder_for_each_entry_safe() is nice looking but much slower
than using rb_next() directly, except when tree is small enough
to fit in CPU caches (then the cost is the same)

From: Eric Dumazet 

Signed-off-by: David S. Miller

inetpeer: fix RCU lookup() again

2017-09-28T16:39:34+00:00

My prior fix was not complete, as we were dereferencing a pointer
three times per node, not twice as I initially thought.

Fixes: 4cc5b44b29a9 ("inetpeer: fix RCU lookup()")
Fixes: b145425f269a ("inetpeer: remove AVL implementation in favor of RB tree")
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

inetpeer: fix RCU lookup()

2017-09-02T00:33:17+00:00

Excess of seafood or something happened while I cooked the commit
adding RB tree to inetpeer.

Of course, RCU rules need to be respected or bad things can happen.

In this particular loop, we need to read *pp once per iteration, not
twice.

Fixes: b145425f269a ("inetpeer: remove AVL implementation in favor of RB tree")
Reported-by: John Sperbeck 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

inetpeer: remove AVL implementation in favor of RB tree

2017-07-17T15:59:01+00:00

As discussed in Faro during Netfilter Workshop 2017, RB trees can be
used with RCU, using a seqlock.

Note that net/rxrpc/conn_service.c is already using this.

This patch converts inetpeer from AVL tree to RB tree, since it allows
to remove private AVL implementation in favor of shared RB code.

$ size net/ipv4/inetpeer.before net/ipv4/inetpeer.after
   text    data     bss     dec     hex filename
   3195      40     128    3363     d23 net/ipv4/inetpeer.before
   1562      24       0    1586     632 net/ipv4/inetpeer.after

The same technique can be used to speed up
net/netfilter/nft_set_rbtree.c (removing rwlock contention in fast path)

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: convert inet_peer.refcnt from atomic_t to refcount_t

2017-07-01T14:39:07+00:00

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
This conversion requires overall +1 on the whole
refcounting scheme.

Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Signed-off-by: David S. Miller

net: Add helper function to compare inetpeer addresses

2015-08-28T20:32:36+00:00

tcp_metrics and inetpeer both have functions to compare inetpeer
addresses. Consolidate into 1 version.

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

inet: remove dead inetpeer sequence code

2014-09-08T23:42:42+00:00

inetpeer sequence numbers are no longer incremented, so no need to
check and flush the tree. The function that increments the sequence
number was already dead code and removed in in "ipv4: remove unused
function" (068a6e18). Remove the code that checks for a change, too.

Verifying that v4_seq and v6_seq are never incremented and thus that
flush_check compares bp->flush_seq to 0 is trivial.

The second part of the change removes flush_check completely even
though bp->flush_seq is exactly !0 once, at initialization. This
change is correct because the time this branch is true is when
bp->root == peer_avl_empty_rcu, in which the branch and
inetpeer_invalidate_tree are a NOOP.

Signed-off-by: Willem de Bruijn 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

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

2014-06-12T21:27:40+00:00

Pull networking updates from David Miller:

 1) Seccomp BPF filters can now be JIT'd, from Alexei Starovoitov.

 2) Multiqueue support in xen-netback and xen-netfront, from Andrew J
    Benniston.

 3) Allow tweaking of aggregation settings in cdc_ncm driver, from Bjørn
    Mork.

 4) BPF now has a "random" opcode, from Chema Gonzalez.

 5) Add more BPF documentation and improve test framework, from Daniel
    Borkmann.

 6) Support TCP fastopen over ipv6, from Daniel Lee.

 7) Add software TSO helper functions and use them to support software
    TSO in mvneta and mv643xx_eth drivers.  From Ezequiel Garcia.

 8) Support software TSO in fec driver too, from Nimrod Andy.

 9) Add Broadcom SYSTEMPORT driver, from Florian Fainelli.

10) Handle broadcasts more gracefully over macvlan when there are large
    numbers of interfaces configured, from Herbert Xu.

11) Allow more control over fwmark used for non-socket based responses,
    from Lorenzo Colitti.

12) Do TCP congestion window limiting based upon measurements, from Neal
    Cardwell.

13) Support busy polling in SCTP, from Neal Horman.

14) Allow RSS key to be configured via ethtool, from Venkata Duvvuru.

15) Bridge promisc mode handling improvements from Vlad Yasevich.

16) Don't use inetpeer entries to implement ID generation any more, it
    performs poorly, from Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1522 commits)
  rtnetlink: fix userspace API breakage for iproute2 < v3.9.0
  tcp: fixing TLP's FIN recovery
  net: fec: Add software TSO support
  net: fec: Add Scatter/gather support
  net: fec: Increase buffer descriptor entry number
  net: fec: Factorize feature setting
  net: fec: Enable IP header hardware checksum
  net: fec: Factorize the .xmit transmit function
  bridge: fix compile error when compiling without IPv6 support
  bridge: fix smatch warning / potential null pointer dereference
  via-rhine: fix full-duplex with autoneg disable
  bnx2x: Enlarge the dorq threshold for VFs
  bnx2x: Check for UNDI in uncommon branch
  bnx2x: Fix 1G-baseT link
  bnx2x: Fix link for KR with swapped polarity lane
  sctp: Fix sk_ack_backlog wrap-around problem
  net/core: Add VF link state control policy
  net/fsl: xgmac_mdio is dependent on OF_MDIO
  net/fsl: Make xgmac_mdio read error message useful
  net_sched: drr: warn when qdisc is not work conserving
  ...

inetpeer: get rid of ip_id_count

2014-06-02T18:00:41+00:00

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
   with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
   is about 20.

4) If server deals with many tcp flows, we have a high probability of
   not finding the inet_peer, allocating a fresh one, inserting it in
   the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller