Commit Graph

47355 Commits

Author SHA1 Message Date
Pavel Machek
198ec9ae05 Bluetooth: document config options
Kernel config options should include useful help text; I had to look
up the terms on wikipedia.

Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2017-08-08 16:02:13 +02:00
Xin Long
bfc6f8270f sctp: remove the typedef sctp_subtype_t
This patch is to remove the typedef sctp_subtype_t, and
replace with union sctp_subtype in the places where it's
using this typedef.

Note that it doesn't fix many indents although it should,
as sctp_disposition_t's removal would mess them up again.
So better to fix them when removing sctp_disposition_t in
later patch.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:33:42 -07:00
Xin Long
61f0eb0722 sctp: remove the typedef sctp_event_t
This patch is to remove the typedef sctp_event_t, and
replace with enum sctp_event in the places where it's
using this typedef.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:33:42 -07:00
Xin Long
19cd1592a2 sctp: remove the typedef sctp_event_timeout_t
This patch is to remove the typedef sctp_event_timeout_t, and
replace with enum sctp_event_timeout in the places where it's
using this typedef.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:33:42 -07:00
Xin Long
5210601945 sctp: remove the typedef sctp_state_t
This patch is to remove the typedef sctp_state_t, and
replace with enum sctp_state in the places where it's
using this typedef.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:33:42 -07:00
Xin Long
4785c7ae18 sctp: remove the typedef sctp_ierror_t
This patch is to remove the typedef sctp_ierror_t, and
replace with enum sctp_ierror in the places where it's
using this typedef.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:33:42 -07:00
Xin Long
86b36f2a9b sctp: remove the typedef sctp_xmit_t
This patch is to remove the typedef sctp_xmit_t, and
replace with enum sctp_xmit in the places where it's
using this typedef.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:33:42 -07:00
Xin Long
0ceaeebe28 sctp: remove the typedef sctp_transport_cmd_t
This patch is to remove the typedef sctp_transport_cmd_t, and
replace with enum sctp_transport_cmd in the places where it's
using this typedef.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:33:41 -07:00
Xin Long
1c662018d2 sctp: remove the typedef sctp_scope_t
This patch is to remove the typedef sctp_scope_t, and
replace with enum sctp_scope in the places where it's
using this typedef.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:33:41 -07:00
Xin Long
701ef3e6c7 sctp: remove the typedef sctp_scope_policy_t
This patch is to remove the typedef sctp_scope_policy_t and keep
it's members as an anonymous enum.

It is also to define SCTP_SCOPE_POLICY_MAX to replace the num 3
in sysctl.c to make codes clear.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:33:41 -07:00
Xin Long
125c298202 sctp: remove the typedef sctp_retransmit_reason_t
This patch is to remove the typedef sctp_retransmit_reason_t, and
replace with enum sctp_retransmit_reason in the places where it's
using this typedef.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:33:41 -07:00
Xin Long
233e7936c8 sctp: remove the typedef sctp_lower_cwnd_t
This patch is to remove the typedef sctp_lower_cwnd_t, and
replace with enum sctp_lower_cwnd in the places where it's
using this typedef.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:33:41 -07:00
Florian Fainelli
5f6b4e14ca net: dsa: User per-cpu 64-bit statistics
During testing with a background iperf pushing 1Gbit/sec worth of
traffic and having both ifconfig and ethtool collect statistics, we
could see quite frequent deadlocks. Convert the often accessed DSA slave
network devices statistics to per-cpu 64-bit statistics to remove these
deadlocks and provide fast efficient statistics updates.

Fixes: f613ed665b ("net: dsa: Add support for 64-bit statistics")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:26:47 -07:00
Yuchung Cheng
f1722a1be1 tcp: consolidate congestion control undo functions
Most TCP congestion controls are using identical logic to undo
cwnd except BBR. This patch consolidates these similar functions
to the one used currently by Reno and others.

Suggested-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:25:10 -07:00
Yuchung Cheng
4faf783998 tcp: fix cwnd undo in Reno and HTCP congestion controls
Using ssthresh to revert cwnd is less reliable when ssthresh is
bounded to 2 packets. This patch uses an existing variable in TCP
"prior_cwnd" that snapshots the cwnd right before entering fast
recovery and RTO recovery in Reno.  This fixes the issue discussed
in netdev thread: "A buggy behavior for Linux TCP Reno and HTCP"
https://www.spinics.net/lists/netdev/msg444955.html

Suggested-by: Neal Cardwell <ncardwell@google.com>
Reported-by: Wei Sun <unlcsewsun@gmail.com>
Signed-off-by: Yuchung Cheng <ncardwell@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 21:25:10 -07:00
Paolo Abeni
3bdefdf9d9 udp: no need to preserve skb->dst
__ip_options_echo() does not need anymore skb->dst, so we can
avoid explicitly preserving it for its own sake.

This is almost a revert of commit 0ddf3fb2c4 ("udp: preserve
skb->dst if required for IP options processing") plus some
lifting to fit later changes.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 20:51:12 -07:00
Paolo Abeni
61a1030bad Revert "ipv4: keep skb->dst around in presence of IP options"
ip_options_echo() does not use anymore the skb->dst and don't
need to keep the dst around for options's sake only.
This reverts commit 34b2cef20f.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 20:51:12 -07:00
Paolo Abeni
91ed1e666a ip/options: explicitly provide net ns to __ip_options_echo()
__ip_options_echo() uses the current network namespace, and
currently retrives it via skb->dst->dev.

This commit adds an explicit 'net' argument to __ip_options_echo()
and update all the call sites to provide it, usually via a simpler
sock_net().

After this change, __ip_options_echo() no more needs to access
skb->dst and we can drop a couple of hack to preserve such
info in the rx path.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 20:51:12 -07:00
Paolo Abeni
a1e155ece1 IP: do not modify ingress packet IP option in ip_options_echo()
While computing the response option set for LSRR, ip_options_echo()
also changes the ingress packet LSRR addresses list, setting
the last one to the dst specific address for the ingress packet
- via memset(start[ ...
The only visible effect of such change - beyond possibly damaging
shared/cloned skbs - is modifying the data carried by ICMP replies
changing the header information for reported the ingress packet,
which violates RFC1122 3.2.2.6.
All the others call sites just ignore the ingress packet IP options
after calling ip_options_echo()
Note that the last element in the LSRR option address list for the
reply packet will be properly set later in the ip output path
via ip_options_build().
This buggy memset() predates git history and apparently was present
into the initial ip_options_echo() implementation in linux 1.3.30 but
still looks wrong.

The removal of the fib_compute_spec_dst() call will help
completely dropping the skb->dst usage by __ip_options_echo() with a
later patch.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06 20:51:11 -07:00
Jiri Pirko
9b0d4446b5 net: sched: avoid atomic swap in tcf_exts_change
tcf_exts_change is always called on newly created exts, which are not used
on fastpath. Therefore, simple struct copy is enough.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
705c709126 net: sched: cls_u32: no need to call tcf_exts_change for newly allocated struct
As the n struct was allocated right before u32_set_parms call,
no need to use tcf_exts_change to do atomic change, and we can just
fill-up the unused exts struct directly by tcf_exts_validate.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
8c98d571bb net: sched: cls_route: no need to call tcf_exts_change for newly allocated struct
As the f struct was allocated right before route4_set_parms call,
no need to use tcf_exts_change to do atomic change, and we can just
fill-up the unused exts struct directly by tcf_exts_validate.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
c09fc2e11e net: sched: cls_flow: no need to call tcf_exts_change for newly allocated struct
As the fnew struct just was allocated, so no need to use tcf_exts_change
to do atomic change, and we can just fill-up the unused exts struct
directly by tcf_exts_validate.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
8cc6251381 net: sched: cls_cgroup: no need to call tcf_exts_change for newly allocated struct
As the new struct just was allocated, so no need to use tcf_exts_change
to do atomic change, and we can just fill-up the unused exts struct
directly by tcf_exts_validate.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
6839da326d net: sched: cls_bpf: no need to call tcf_exts_change for newly allocated struct
As the prog struct was allocated right before cls_bpf_set_parms call,
no need to use tcf_exts_change to do atomic change, and we can just
fill-up the unused exts struct directly by tcf_exts_validate.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
ff1f8ca080 net: sched: cls_basic: no need to call tcf_exts_change for newly allocated struct
As the f struct was allocated right before basic_set_parms call, no need
to use tcf_exts_change to do atomic change, and we can just fill-up
the unused exts struct directly by tcf_exts_validate.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
a74cb36980 net: sched: cls_matchall: no need to call tcf_exts_change for newly allocated struct
As the head struct was allocated right before mall_set_parms call,
no need to use tcf_exts_change to do atomic change, and we can just
fill-up the unused exts struct directly by tcf_exts_validate.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
94611bff6e net: sched: cls_fw: no need to call tcf_exts_change for newly allocated struct
As the f struct was allocated right before fw_set_parms call, no need
to use tcf_exts_change to do atomic change, and we can just fill-up
the unused exts struct directly by tcf_exts_validate.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
455075292b net: sched: cls_flower: no need to call tcf_exts_change for newly allocated struct
As the f struct was allocated right before fl_set_parms call, no need
to use tcf_exts_change to do atomic change, and we can just fill-up
the unused exts struct directly by tcf_exts_validate.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
1e5003af37 net: sched: cls_fw: rename fw_change_attrs function
Since the function name is misleading since it is not changing
anything, name it similarly to other cls.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
6a725c481d net: sched: cls_bpf: rename cls_bpf_modify_existing function
The name cls_bpf_modify_existing is highly misleading, as it indeed does
not modify anything existing. It does not modify at all.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
978dfd8d14 net: sched: use tcf_exts_has_actions instead of exts->nr_actions
For check in tcf_exts_dump use tcf_exts_has_actions helper instead
of exts->nr_actions for checking if there are any actions present.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:24 -07:00
Jiri Pirko
ec1a9cca0e net: sched: remove check for number of actions in tcf_exts_exec
Leave it to tcf_action_exec to return TC_ACT_OK in case there is no
action present.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:23 -07:00
Jiri Pirko
6fc6d06e53 net: sched: remove redundant helpers tcf_exts_is_predicative and tcf_exts_is_available
These two helpers are doing the same as tcf_exts_has_actions, so remove
them and use tcf_exts_has_actions instead.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:23 -07:00
Jiri Pirko
3bcc0cec81 net: sched: change names of action number helpers to be aligned with the rest
The rest of the helpers are named tcf_exts_*, so change the name of
the action number helpers to be aligned. While at it, change to inline
functions.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:23 -07:00
Jiri Pirko
4ebc1e3cfc net: sched: remove unneeded tcf_em_tree_change
Since tcf_em_tree_validate could be always called on a newly created
filter, there is no need for this change function.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:23 -07:00
Jiri Pirko
f7ebdff757 net: sched: sch_atm: use Qdisc_class_common structure
Even if it is only for classid now, use this common struct a be aligned
with the rest of the classful qdiscs.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 11:21:23 -07:00
Willem de Bruijn
f214f915e7 tcp: enable MSG_ZEROCOPY
Enable support for MSG_ZEROCOPY to the TCP stack. TSO and GSO are
both supported. Only data sent to remote destinations is sent without
copying. Packets looped onto a local destination have their payload
copied to avoid unbounded latency.

Tested:
  A 10x TCP_STREAM between two hosts showed a reduction in netserver
  process cycles by up to 70%, depending on packet size. Systemwide,
  savings are of course much less pronounced, at up to 20% best case.

  msg_zerocopy.sh 4 tcp:

  without zerocopy
    tx=121792 (7600 MB) txc=0 zc=n
    rx=60458 (7600 MB)

  with zerocopy
    tx=286257 (17863 MB) txc=286257 zc=y
    rx=140022 (17863 MB)

  This test opens a pair of sockets over veth, one one calls send with
  64KB and optionally MSG_ZEROCOPY and on the other reads the initial
  bytes. The receiver truncates, so this is strictly an upper bound on
  what is achievable. It is more representative of sending data out of
  a physical NIC (when payload is not touched, either).

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 21:37:30 -07:00
Willem de Bruijn
a91dbff551 sock: ulimit on MSG_ZEROCOPY pages
Bound the number of pages that a user may pin.

Follow the lead of perf tools to maintain a per-user bound on memory
locked pages commit 789f90fcf6 ("perf_counter: per user mlock gift")

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 21:37:30 -07:00
Willem de Bruijn
4ab6c99d99 sock: MSG_ZEROCOPY notification coalescing
In the simple case, each sendmsg() call generates data and eventually
a zerocopy ready notification N, where N indicates the Nth successful
invocation of sendmsg() with the MSG_ZEROCOPY flag on this socket.

TCP and corked sockets can cause send() calls to append new data to an
existing sk_buff and, thus, ubuf_info. In that case the notification
must hold a range. odify ubuf_info to store a inclusive range [N..N+m]
and add skb_zerocopy_realloc() to optionally extend an existing range.

Also coalesce notifications in this common case: if a notification
[1, 1] is about to be queued while [0, 0] is the queue tail, just modify
the head of the queue to read [0, 1].

Coalescing is limited to a few TSO frames worth of data to bound
notification latency.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 21:37:30 -07:00
Willem de Bruijn
1f8b977ab3 sock: enable MSG_ZEROCOPY
Prepare the datapath for refcounted ubuf_info. Clone ubuf_info with
skb_zerocopy_clone() wherever needed due to skb split, merge, resize
or clone.

Split skb_orphan_frags into two variants. The split, merge, .. paths
support reference counted zerocopy buffers, so do not do a deep copy.
Add skb_orphan_frags_rx for paths that may loop packets to receive
sockets. That is not allowed, as it may cause unbounded latency.
Deep copy all zerocopy copy buffers, ref-counted or not, in this path.

The exact locations to modify were chosen by exhaustively searching
through all code that might modify skb_frag references and/or the
the SKBTX_DEV_ZEROCOPY tx_flags bit.

The changes err on the safe side, in two ways.

(1) legacy ubuf_info paths virtio and tap are not modified. They keep
    a 1:1 ubuf_info to sk_buff relationship. Calls to skb_orphan_frags
    still call skb_copy_ubufs and thus copy frags in this case.

(2) not all copies deep in the stack are addressed yet. skb_shift,
    skb_split and skb_try_coalesce can be refined to avoid copying.
    These are not in the hot path and this patch is hairy enough as
    is, so that is left for future refinement.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 21:37:30 -07:00
Willem de Bruijn
76851d1212 sock: add SOCK_ZEROCOPY sockopt
The send call ignores unknown flags. Legacy applications may already
unwittingly pass MSG_ZEROCOPY. Continue to ignore this flag unless a
socket opts in to zerocopy.

Introduce socket option SO_ZEROCOPY to enable MSG_ZEROCOPY processing.
Processes can also query this socket option to detect kernel support
for the feature. Older kernels will return ENOPROTOOPT.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 21:37:29 -07:00
Willem de Bruijn
52267790ef sock: add MSG_ZEROCOPY
The kernel supports zerocopy sendmsg in virtio and tap. Expand the
infrastructure to support other socket types. Introduce a completion
notification channel over the socket error queue. Notifications are
returned with ee_origin SO_EE_ORIGIN_ZEROCOPY. ee_errno is 0 to avoid
blocking the send/recv path on receiving notifications.

Add reference counting, to support the skb split, merge, resize and
clone operations possible with SOCK_STREAM and other socket types.

The patch does not yet modify any datapaths.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 21:37:29 -07:00
Willem de Bruijn
3ece782693 sock: skb_copy_ubufs support for compound pages
Refine skb_copy_ubufs to support compound pages. With upcoming TCP
zerocopy sendmsg, such fragments may appear.

The existing code replaces each page one for one. Splitting each
compound page into an independent number of regular pages can result
in exceeding limit MAX_SKB_FRAGS if data is not exactly page aligned.

Instead, fill all destination pages but the last to PAGE_SIZE.
Split the existing alloc + copy loop into separate stages:
1. compute bytelength and minimum number of pages to store this.
2. allocate
3. copy, filling each page except the last to PAGE_SIZE bytes
4. update skb frag array

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 21:37:29 -07:00
Willem de Bruijn
98ba0bd550 sock: allocate skbs from optmem
Add sock_omalloc and sock_ofree to be able to allocate control skbs,
for instance for looping errors onto sk_error_queue.

The transmit budget (sk_wmem_alloc) is involved in transmit skb
shaping, most notably in TCP Small Queues. Using this budget for
control packets would impact transmission.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 21:37:29 -07:00
Ido Schimmel
a460aa8396 ipv6: fib: Add helpers to hold / drop a reference on rt6_info
Similar to commit 1c677b3d28 ("ipv4: fib: Add fib_info_hold() helper")
and commit b423cb1080 ("ipv4: fib: Export free_fib_info()") add an
helper to hold a reference on rt6_info and export rt6_release() to drop
it and potentially release the route.

This is needed so that drivers capable of FIB offload could hold a
reference on the route before queueing it for offload and drop it after
the route has been programmed to the device's tables.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 15:36:00 -07:00
Ido Schimmel
fc882fcff1 ipv6: Regenerate host route according to node pointer upon interface up
When an interface is brought back up, the kernel tries to restore the
host routes tied to its permanent addresses.

However, if the host route was removed from the FIB, then we need to
reinsert it. This is done by releasing the current dst and allocating a
new, so as to not reuse a dst with obsolete values.

Since this function is called under RTNL and using the same explanation
from the previous patch, we can test if the route is in the FIB by
checking its node pointer instead of its reference count.

Tested using the following script and Andrey's reproducer mentioned
in commit 8048ced9be ("net: ipv6: regenerate host route if moved to gc
list") and linked below:

$ ip link set dev lo up
$ ip link add dummy1 type dummy
$ ip -6 address add cafe::1/64 dev dummy1
$ ip link set dev lo down	# cafe::1/128 is removed
$ ip link set dev dummy1 up
$ ip link set dev lo up

The host route is correctly regenerated.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Link: http://lkml.kernel.org/r/CAAeHK+zSe82vc5gCRgr_EoUwiALPnWVdWJBPwJZBpbxYz=kGJw@mail.gmail.com
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 15:36:00 -07:00
Ido Schimmel
9217d8c2fe ipv6: Regenerate host route according to node pointer upon loopback up
When the loopback device is brought back up we need to check if the host
route attached to the address is still in the FIB and regenerate one in
case it's not.

Host routes using the loopback device are always inserted into and
removed from the FIB under RTNL (under which this function is called),
so we can test their node pointer instead of the reference count in
order to check if the route is in the FIB or not.

Tested using the following script from Nicolas mentioned in
commit a220445f9f ("ipv6: correctly add local routes when lo goes up"):

$ ip link add dummy1 type dummy
$ ip link set dummy1 up
$ ip link set lo down ; ip link set lo up

The host route is correctly regenerated.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 15:36:00 -07:00
Ido Schimmel
7483cea799 ipv6: fib: Unlink replaced routes from their nodes
When a route is deleted its node pointer is set to NULL to indicate it's
no longer linked to its node. Do the same for routes that are replaced.

This will later allow us to test if a route is still in the FIB by
checking its node pointer instead of its reference count.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 15:36:00 -07:00
Ido Schimmel
c5b12410fa ipv6: fib: Don't assume only nodes hold a reference on routes
The code currently assumes that only FIB nodes can hold a reference on
routes. Therefore, after fib6_purge_rt() has run and the route is no
longer present in any intermediate nodes, it's assumed that its
reference count would be 1 - taken by the node where it's currently
stored.

However, we're going to allow users other than the FIB to take a
reference on a route, so this assumption is no longer valid and the
BUG_ON() needs to be removed.

Note that purging only takes place if the initial reference count is
different than 1. I've left that check intact, as in the majority of
systems (where routes are only referenced by the FIB), it does actually
mean the route is present in intermediate nodes.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 15:36:00 -07:00