Once we realize tcp_rcv_synsent_state_process() does not use
its 'len' argument and we get rid of it, then it becomes clear
this argument is no longer used in tcp_rcv_state_process()
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

None of these functions need to change the socket, make it
const.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The oif has already been checked that it is non-zero; the 2 additional
checks on oif within that if (oif) {...} block are redundant.

CC: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This documents fact that listener lock might not be held
at the time SYNACK are sent.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is to document that socket lock might not be held at this point.

skb_set_owner_w() and ipv6_local_error() are using proper atomic ops
or spinlocks, so we promote the socket to non const when calling them.

netfilter hooks should never assume socket lock is held,
we also promote the socket to non const.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When TCP new listener is done, these functions will be called
without socket lock being held. Make sure they don't change
anything.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

socket is not modified, make it const so that callers can
do the same if they need.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ip6_dst_lookup_flow() and ip6_dst_lookup_tail() do not touch
socket, lets add a const qualifier.

This will permit the same change in inet6_csk_route_req()
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Soon, listener socket spinlock will no longer be held,
add const arguments to tcp_v[46]_init_req() to make clear these
functions can not mess socket fields.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently error log messages in ip6_tnl_err are printed at 'warn'
level. This is different to other tunnel types which don't print
any messages. These log messages don't provide any information that
couldn't be deduced with networking tools. Also it can be annoying
to have one end of the tunnel go down and have the logs fill with
pointless messages such as "Path to destination invalid or inactive!".

This patch reduces the log level of these messages to 'dbg' level to
bring the visible behaviour into line with other tunnel types.
Signed-off-by: NMatt Bennett <matt.bennett@alliedtelesis.co.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently error log messages in ip6gre_err are printed at 'warn'
level. This is different to most other tunnel types which don't
print any messages. These log messages don't provide any information
that couldn't be deduced with networking tools. Also it can be annoying
to have one end of the tunnel go down and have the logs fill with
pointless messages such as "Path to destination invalid or inactive!".

This patch reduces the log level of these messages to 'dbg' level to
bring the visible behaviour into line with other tunnel types.
Signed-off-by: NMatt Bennett <matt.bennett@alliedtelesis.co.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Neal suggested to move sk_txhash init into tcp_create_openreq_child(),
called both from IPv4 and IPv6.

This opportunity was missed in commit 58d607d3 ("tcp: provide
skb->hash to synack packets")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 12fd84f4 ("ipv6: Remove unused neigh argument for
icmp6_dst_alloc() and its callers."), the neigh parameter of ndisc_send_na
and ndisc_send_ns is unused.

CC: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In rt6_info_hash_nhsfn replace the custom hashing over flowi6 that is
using xor with a call to common function get_hash_from_flowi6.
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently SYN/ACK RTT is measured in jiffies. For LAN the SYN/ACK
RTT is often measured as 0ms or sometimes 1ms, which would affect
RTT estimation and min RTT samping used by some congestion control.

This patch improves SYN/ACK RTT to be usec resolution if platform
supports it. While the timestamping of SYN/ACK is done in request
sock, the RTT measurement is carefully arranged to avoid storing
another u64 timestamp in tcp_sock.

For regular handshake w/o SYNACK retransmission, the RTT is sampled
right after the child socket is created and right before the request
sock is released (tcp_check_req() in tcp_minisocks.c)

For Fast Open the child socket is already created when SYN/ACK was
sent, the RTT is sampled in tcp_rcv_state_process() after processing
the final ACK an right before the request socket is released.

If the SYN/ACK was retransmistted or SYN-cookie was used, we rely
on TCP timestamps to measure the RTT. The sample is taken at the
same place in tcp_rcv_state_process() after the timestamp values
are validated in tcp_validate_incoming(). Note that we do not store
TS echo value in request_sock for SYN-cookies, because the value
is already stored in tp->rx_opt used by tcp_ack_update_rtt().

One side benefit is that the RTT measurement now happens before
initializing congestion control (of the passive side). Therefore
the congestion control can use the SYN/ACK RTT.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Man page of ip-route(8) says following about route types:

  unreachable - these destinations are unreachable.  Packets are dis‐
  carded and the ICMP message host unreachable is generated.  The local
  senders get an EHOSTUNREACH error.

  blackhole - these destinations are unreachable.  Packets are dis‐
  carded silently.  The local senders get an EINVAL error.

  prohibit - these destinations are unreachable.  Packets are discarded
  and the ICMP message communication administratively prohibited is
  generated.  The local senders get an EACCES error.

In the inet6 address family, this was correct, except the local senders
got ENETUNREACH error instead of EHOSTUNREACH in case of unreachable route.
In the inet address family, all three route types generated ICMP message
net unreachable, and the local senders got ENETUNREACH error.

In both address families all three route types now behave consistently
with documentation.
Signed-off-by: NNikola Forró <nforro@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use nf_ct_net(ct) instead of guessing that the netdevice out can
reliably report the network namespace the conntrack operation is
happening in.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Instead of calling dev_net on a likley looking network device
pass state->net into nf_xfrm_me_harder.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Only pass the void *priv parameter out of the nf_hook_ops.  That is
all any of the functions are interested now, and by limiting what is
passed it becomes simpler to change implementation details.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

As gre does not have the srckey in the packet gre_pkt_to_tuple
needs to perform a lookup in it's per network namespace tables.

Pass in the proper network namespace to all pkt_to_tuple
implementations to ensure gre (and any similar protocols) can get this
right.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This allows them to stop guessing the network namespace with pick_net.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

As xt_action_param lives on the stack this does not bloat any
persistent data structures.

This is a first step in making netfilter code that needs to know
which network namespace it is executing in simpler.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

- Add nft_pktinfo.pf to replace ops->pf
- Add nft_pktinfo.hook to replace ops->hooknum

This simplifies the code, makes it more readable, and likely reduces
cache line misses.  Maintainability is enhanced as the details of
nft_hook_ops are of no concern to the recpients of nft_pktinfo.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The values of nf_hook_state.hook and nf_hook_ops.hooknum must be the
same by definition.

We are more likely to access the fields in nf_hook_state over the
fields in nf_hook_ops so with a little luck this results in
fewer cache line misses, and slightly more consistent code.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The values of ops->hooknum and state->hook are guaraneted to be equal
making the hook argument to ip6t_do_table, arp_do_table, and
ipt_do_table is unnecessary. Remove the unnecessary hook argument.

In the callers use state->hook instead of ops->hooknum for clarity and
to reduce the number of cachelines the callers touch.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

David Woodhouse reports skb_under_panic when we try to push ethernet
header to fragmented ipv6 skbs:

 skbuff: skb_under_panic: text:c1277f1e len:1294 put:14 head:dec98000
 data:dec97ffc tail:0xdec9850a end:0xdec98f40 dev:br-lan
[..]
ip6_finish_output2+0x196/0x4da

David further debugged this:
  [..] offending fragments were arriving here with skb_headroom(skb)==10.
  Which is reasonable, being the Solos ADSL card's header of 8 bytes
  followed by 2 bytes of PPP frame type.

The problem is that if netfilter ipv6 defragmentation is used, skb_cow()
in ip6_forward will only see reassembled skb.

Therefore, headroom is overestimated by 8 bytes (we pulled fragment
header) and we don't check the skbs in the frag_list either.

We can't do these checks in netfilter defrag since outdev isn't known yet.

Furthermore, existing tests in ip6_fragment did not consider the fragment
or ipv6 header size when checking headroom of the fraglist skbs.

While at it, also fix a skb leak on memory allocation -- ip6_fragment
must consume the skb.

I tested this e1000 driver hacked to not allocate additional headroom
(we end up in slowpath, since LL_RESERVED_SPACE is 16).

If 2 bytes of headroom are allocated, fastpath is taken (14 byte
ethernet header was pulled, so 16 byte headroom available in all
fragments).
Reported-by: NDavid Woodhouse <dwmw2@infradead.org>
Diagnosed-by: NDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Tested-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit b73c3d0e ("net: Save TX flow hash in sock and set in skbuf
on xmit"), Tom provided a l4 hash to most outgoing TCP packets.

We'd like to provide one as well for SYNACK packets, so that all packets
of a given flow share same txhash, to later enable bonding driver to
also use skb->hash to perform slave selection.

Note that a SYNACK retransmit shuffles the tx hash, as Tom did
in commit 265f94ff ("net: Recompute sk_txhash on negative routing
advice") for established sockets.

This has nice effect making TCP flows resilient to some kind of black
holes, even at connection establish phase.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Acked-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In code review it was noticed that I had failed to add some blank lines
in places where they are customarily used.  Taking a second look at the
code I have to agree blank lines would be nice so I have added them
here.
Reported-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is immediately motivated by the bridge code that chains functions that
call into netfilter.  Without passing net into the okfns the bridge code would
need to guess about the best expression for the network namespace to process
packets in.

As net is frequently one of the first things computed in continuation functions
after netfilter has done it's job passing in the desired network namespace is in
many cases a code simplification.

To support this change the function dst_output_okfn is introduced to
simplify passing dst_output as an okfn.  For the moment dst_output_okfn
just silently drops the struct net.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of saying "net = dev_net(state->in?state->in:state->out)"
just say "state->net".  As that information is now availabe,
much less confusing and much less error prone.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a network namespace parameter into the netfilter hooks.  At the
call site of the netfilter hooks the path a packet is taking through
the network stack is well known which allows the network namespace to
be easily and reliabily.

This allows the replacement of magic code like
"dev_net(state->in?:state->out)" that appears at the start of most
netfilter hooks with "state->net".

In almost all cases the network namespace passed in is derived
from the first network device passed in, guaranteeing those
paths will not see any changes in practice.

The exceptions are:
xfrm/xfrm_output.c:xfrm_output_resume()         xs_net(skb_dst(skb)->xfrm)
ipvs/ip_vs_xmit.c:ip_vs_nat_send_or_cont()      ip_vs_conn_net(cp)
ipvs/ip_vs_xmit.c:ip_vs_send_or_cont()          ip_vs_conn_net(cp)
ipv4/raw.c:raw_send_hdrinc()                    sock_net(sk)
ipv6/ip6_output.c:ip6_xmit()			sock_net(sk)
ipv6/ndisc.c:ndisc_send_skb()                   dev_net(skb->dev) not dev_net(dst->dev)
ipv6/raw.c:raw6_send_hdrinc()                   sock_net(sk)
br_netfilter_hooks.c:br_nf_pre_routing_finish() dev_net(skb->dev) before skb->dev is set to nf_bridge->physindev

In all cases these exceptions seem to be a better expression for the
network namespace the packet is being processed in then the historic
"dev_net(in?in:out)".  I am documenting them in case something odd
pops up and someone starts trying to track down what happened.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Keep net in a local variable so I can use it in NF_HOOK_COND
when I pass struct net to all of the netfilter hooks.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Avoid silly redundant code
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a sock paramter to dst_output making dst_output_sk superfluous.
Add a skb->sk parameter to all of the callers of dst_output
Have the callers of dst_output_sk call dst_output.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds NLM_F_REPLACE flag to ipv6 route replace notifications.
This makes nlm_flags in ipv6 replace notifications consistent
with ipv4.
Signed-off-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: NMichal Kubecek <mkubecek@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>