linux.git/net/ipv4, branch v4.3-rc2

tcp_cubic: better follow cubic curve after idle period

2015-09-10T17:58:33+00:00

Jana Iyengar found an interesting issue on CUBIC :

The epoch is only updated/reset initially and when experiencing losses.
The delta "t" of now - epoch_start can be arbitrary large after app idle
as well as the bic_target. Consequentially the slope (inverse of
ca->cnt) would be really large, and eventually ca->cnt would be
lower-bounded in the end to 2 to have delayed-ACK slow-start behavior.

This particularly shows up when slow_start_after_idle is disabled
as a dangerous cwnd inflation (1.5 x RTT) after few seconds of idle
time.

Jana initial fix was to reset epoch_start if app limited,
but Neal pointed out it would ask the CUBIC algorithm to recalculate the
curve so that we again start growing steeply upward from where cwnd is
now (as CUBIC does just after a loss). Ideally we'd want the cwnd growth
curve to be the same shape, just shifted later in time by the amount of
the idle period.

Reported-by: Jana Iyengar 
Signed-off-by: Eric Dumazet 
Signed-off-by: Yuchung Cheng 
Signed-off-by: Neal Cardwell 
Cc: Stephen Hemminger 
Cc: Sangtae Ha 
Cc: Lawrence Brakmo 
Signed-off-by: David S. Miller

tcp: generate CA_EVENT_TX_START on data frames

2015-09-10T17:58:33+00:00

Issuing a CC TX_START event on control frames like pure ACK
is a waste of time, as a CC should not care.

Following patch needs this change, as we want CUBIC to properly track
idle time at a low cost, with a single TX_START being generated.

Yuchung might slightly refine the condition triggering TX_START
on a followup patch.

Signed-off-by: Neal Cardwell 
Signed-off-by: Eric Dumazet 
Signed-off-by: Yuchung Cheng 
Cc: Jana Iyengar 
Cc: Stephen Hemminger 
Cc: Sangtae Ha 
Cc: Lawrence Brakmo 
Signed-off-by: David S. Miller

net: ipv6: use common fib_default_rule_pref

2015-09-09T21:19:50+00:00

This switches IPv6 policy routing to use the shared
fib_default_rule_pref() function of IPv4 and DECnet. It is also used in
multicast routing for IPv4 as well as IPv6.

The motivation for this patch is a complaint about iproute2 behaving
inconsistent between IPv4 and IPv6 when adding policy rules: Formerly,
IPv6 rules were assigned a fixed priority of 0x3FFF whereas for IPv4 the
assigned priority value was decreased with each rule added.

Since then all users of the default_pref field have been converted to
assign the generic function fib_default_rule_pref(), fib_nl_newrule()
may just use it directly instead. Therefore get rid of the function
pointer altogether and make fib_default_rule_pref() static, as it's not
used outside fib_rules.c anymore.

Signed-off-by: Phil Sutter 
Signed-off-by: David S. Miller

netfilter: nf_dup{4, 6}: fix build error when nf_conntrack disabled

2015-09-02T23:28:06+00:00

While testing various Kconfig options on another issue, I found that
the following one triggers as well on allmodconfig and nf_conntrack
disabled:

  net/ipv4/netfilter/nf_dup_ipv4.c: In function ‘nf_dup_ipv4’:
  net/ipv4/netfilter/nf_dup_ipv4.c:72:20: error: ‘nf_skb_duplicated’ undeclared (first use in this function)
    if (this_cpu_read(nf_skb_duplicated))
  [...]
  net/ipv6/netfilter/nf_dup_ipv6.c: In function ‘nf_dup_ipv6’:
  net/ipv6/netfilter/nf_dup_ipv6.c:66:20: error: ‘nf_skb_duplicated’ undeclared (first use in this function)
    if (this_cpu_read(nf_skb_duplicated))

Fix it by including directly the header where it is defined.

Fixes: bbde9fc1824a ("netfilter: factor out packet duplication for IPv4/IPv6")
Signed-off-by: Daniel Borkmann 
Signed-off-by: David S. Miller

net: Make table id type u32

2015-09-01T21:32:44+00:00

A number of VRF patches used 'int' for table id. It should be u32 to be
consistent with the rest of the stack.

Fixes:
4e3c89920cd3a ("net: Introduce VRF related flags and helpers")
15be405eb2ea9 ("net: Add inet_addr lookup by table")
30bbaa1950055 ("net: Fix up inet_addr_type checks")
021dd3b8a142d ("net: Add routes to the table associated with the device")
dc028da54ed35 ("inet: Move VRF table lookup to inlined function")
f6d3c19274c74 ("net: FIB tracepoints")

Signed-off-by: David Ahern 
Reviewed-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

tcp: use dctcp if enabled on the route to the initiator

2015-08-31T19:34:00+00:00

Currently, the following case doesn't use DCTCP, even if it should:
A responder has f.e. Cubic as system wide default, but for a specific
route to the initiating host, DCTCP is being set in RTAX_CC_ALGO. The
initiating host then uses DCTCP as congestion control, but since the
initiator sets ECT(0), tcp_ecn_create_request() doesn't set ecn_ok,
and we have to fall back to Reno after 3WHS completes.

We were thinking on how to solve this in a minimal, non-intrusive
way without bloating tcp_ecn_create_request() needlessly: lets cache
the CA ecn option flag in RTAX_FEATURES. In other words, when ECT(0)
is set on the SYN packet, set ecn_ok=1 iff route RTAX_FEATURES
contains the unexposed (internal-only) DST_FEATURE_ECN_CA. This allows
to only do a single metric feature lookup inside tcp_ecn_create_request().

Joint work with Florian Westphal.

Signed-off-by: Daniel Borkmann 
Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller

fib, fib6: reject invalid feature bits

2015-08-31T19:34:00+00:00

Feature bits that are invalid should not be accepted by the kernel,
only the lower 4 bits may be configured, but not the remaining ones.
Even from these 4, 2 of them are unused.

Signed-off-by: Daniel Borkmann 
Signed-off-by: David S. Miller

net: fib: move metrics parsing to a helper

2015-08-31T19:34:00+00:00

fib_create_info() is already quite large, so before adding more
code to the metrics section move that to a helper, similar to
ip6_convert_metrics.

Suggested-by: Daniel Borkmann 
Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller

ip-tunnel: Use API to access tunnel metadata options.

2015-08-31T19:28:56+00:00

Currently tun-info options pointer is used in few cases to
pass options around. But tunnel options can be accessed using
ip_tunnel_info_opts() API without using the pointer. Following
patch removes the redundant pointer and consistently make use
of API.

Signed-off-by: Pravin B Shelar 
Acked-by: Thomas Graf 
Reviewed-by: Jesse Gross 
Signed-off-by: David S. Miller

ipv4: fix 32b build

2015-08-31T18:32:41+00:00

Address remaining issue after 80ec192.

Signed-off-by: Madalin Bucur 
Signed-off-by: David S. Miller