linux.git/net/sctp/sysctl.c, branch v4.13

sctp: add get and set sockopt for reconf_enable

2017-03-13T06:22:24+00:00

This patchset is to add SCTP_RECONFIG_SUPPORTED sockopt, it would
set and get asoc reconf_enable value when asoc_id is set, or it
would set and get ep reconf_enalbe value if asoc_id is 0.

It is also to add sysctl interface for users to set the default
value for reconf_enable.

After this patch, stream reconf will work.

Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

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

2016-01-12T04:55:43+00:00

Conflicts:
	drivers/net/bonding/bond_main.c
	drivers/net/ethernet/mellanox/mlxsw/spectrum.h
	drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c

The bond_main.c and mellanox switch conflicts were cases of
overlapping changes.

Signed-off-by: David S. Miller

net: sctp: prevent writes to cookie_hmac_alg from accessing invalid memory

2016-01-10T23:01:01+00:00

proc_dostring() needs an initialized destination string, while the one
provided in proc_sctp_do_hmac_alg() contains stack garbage.

Thus, writing to cookie_hmac_alg would strlen() that garbage and end up
accessing invalid memory.

Fixes: 3c68198e7 ("sctp: Make hmac algorithm selection for cookie generation dynamic")
Signed-off-by: Sasha Levin 
Signed-off-by: David S. Miller

net: sctp: dynamically enable or disable pf state

2015-12-16T15:56:50+00:00

As we all know, the value of pf_retrans >= max_retrans_path can
disable pf state. The variables of pf_retrans and max_retrans_path
can be changed by the userspace application.

Sometimes the user expects to disable pf state while the 2
variables are changed to enable pf state. So it is necessary to
introduce a new variable to disable pf state.

According to the suggestions from Vlad Yasevich, extra1 and extra2
are removed. The initialization of pf_enable is added.

Acked-by: Vlad Yasevich 
Signed-off-by: Zhu Yanjun 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: avoid to repeatedly declare external variables

2015-03-25T15:40:16+00:00

Move the declaration for external variables to sctp.h file avoiding
to repeatedly declare them with extern keyword.

Signed-off-by: Ying Xue 
Signed-off-by: David S. Miller

net: sctp: only warn in proc_sctp_do_alpha_beta if write

2014-07-03T01:44:07+00:00

Only warn if the value is written to alpha or beta. We don't care
emitting a one-time warning when only reading it.

Reported-by: Jiri Pirko 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller

net: sctp: check proc_dointvec result in proc_sctp_do_auth

2014-06-20T04:30:19+00:00

When writing to the sysctl field net.sctp.auth_enable, it can well
be that the user buffer we handed over to proc_dointvec() via
proc_sctp_do_auth() handler contains something other than integers.

In that case, we would set an uninitialized 4-byte value from the
stack to net->sctp.auth_enable that can be leaked back when reading
the sysctl variable, and it can unintentionally turn auth_enable
on/off based on the stack content since auth_enable is interpreted
as a boolean.

Fix it up by making sure proc_dointvec() returned sucessfully.

Fixes: b14878ccb7fa ("net: sctp: cache auth_enable per endpoint")
Reported-by: Florian Westphal 
Signed-off-by: Daniel Borkmann 
Acked-by: Neil Horman 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller

net: sctp: propagate sysctl errors from proc_do* properly

2014-06-19T00:03:07+00:00

sysctl handler proc_sctp_do_hmac_alg(), proc_sctp_do_rto_min() and
proc_sctp_do_rto_max() do not properly reflect some error cases
when writing values via sysctl from internal proc functions such
as proc_dointvec() and proc_dostring().

In all these cases we pass the test for write != 0 and partially
do additional work just to notice that additional sanity checks
fail and we return with hard-coded -EINVAL while proc_do*
functions might also return different errors. So fix this up by
simply testing a successful return of proc_do* right after
calling it.

This also allows to propagate its return value onwards to the user.
While touching this, also fix up some minor style issues.

Fixes: 4f3fdf3bc59c ("sctp: add check rto_min and rto_max in sysctl")
Fixes: 3c68198e7511 ("sctp: Make hmac algorithm selection for cookie generation dynamic")
Signed-off-by: Daniel Borkmann 
Signed-off-by: David S. Miller

net: sctp: fix permissions for rto_alpha and rto_beta knobs

2014-06-15T08:17:32+00:00

Commit 3fd091e73b81 ("[SCTP]: Remove multiple levels of msecs
to jiffies conversions.") has silently changed permissions for
rto_alpha and rto_beta knobs from 0644 to 0444. The purpose of
this was to discourage users from tweaking rto_alpha and
rto_beta knobs in production environments since they are key
to correctly compute rtt/srtt.

RFC4960 under section 6.3.1. RTO Calculation says regarding
rto_alpha and rto_beta under rule C3 and C4:

  [...]
  C3)  When a new RTT measurement R' is made, set

       RTTVAR <- (1 - RTO.Beta) * RTTVAR + RTO.Beta * |SRTT - R'|

       and

       SRTT <- (1 - RTO.Alpha) * SRTT + RTO.Alpha * R'

       Note: The value of SRTT used in the update to RTTVAR
       is its value before updating SRTT itself using the
       second assignment. After the computation, update
       RTO <- SRTT + 4 * RTTVAR.

  C4)  When data is in flight and when allowed by rule C5
       below, a new RTT measurement MUST be made each round
       trip. Furthermore, new RTT measurements SHOULD be
       made no more than once per round trip for a given
       destination transport address. There are two reasons
       for this recommendation: First, it appears that
       measuring more frequently often does not in practice
       yield any significant benefit [ALLMAN99]; second,
       if measurements are made more often, then the values
       of RTO.Alpha and RTO.Beta in rule C3 above should be
       adjusted so that SRTT and RTTVAR still adjust to
       changes at roughly the same rate (in terms of how many
       round trips it takes them to reflect new values) as
       they would if making only one measurement per
       round-trip and using RTO.Alpha and RTO.Beta as given
       in rule C3. However, the exact nature of these
       adjustments remains a research issue.
  [...]

While it is discouraged to adjust rto_alpha and rto_beta
and not further specified how to adjust them, the RFC also
doesn't explicitly forbid it, but rather gives a RECOMMENDED
default value (rto_alpha=3, rto_beta=2). We have a couple
of users relying on the old permissions before they got
changed. That said, if someone really has the urge to adjust
them, we could allow it with a warning in the log.

Fixes: 3fd091e73b81 ("[SCTP]: Remove multiple levels of msecs to jiffies conversions.")
Signed-off-by: Daniel Borkmann 
Cc: Vlad Yasevich 
Signed-off-by: David S. Miller

sctp: add a checking for sctp_sysctl_net_register

2014-05-09T20:41:09+00:00

When register_net_sysctl failed, we should free the
sysctl_table.

Signed-off-by: Wang Weidong 
Signed-off-by: David S. Miller