On 01/07/2013 10:38 AM, Neil Horman wrote:
On Mon, Jan 07, 2013 at 04:15:24PM +0100, Florian Fainelli wrote:
Le 01/07/13 15:49, Neil Horman a écrit :
On Mon, Jan 07, 2013 at 02:25:39PM +0100, Florian Fainelli wrote:
Hello Neil,
Le 12/15/12 02:22, Neil Horman a écrit :
Recently I posted commit 3c68198e75 which made selection of the cookie hmac
algorithm selectable. This is all well and good, but Linus noted that it
changes the default config:
http://marc.info/?l=linux-netdev&m=135536629004808&w=2
I've modified the sctp Kconfig file to reflect the recommended way of making
this choice, using the thermal driver example specified, and brought the
defaults back into line with the way they were prior to my origional patch
Also, on Linus' suggestion, re-adding ability to select default 'none' hmac
algorithm, so we don't needlessly bloat the kernel by forcing a non-none
default. This also led me to note that we won't honor the default none
condition properly because of how sctp_net_init is encoded. Fix that up as
well.
Tested by myself (allbeit fairly quickly). All configuration combinations seems
to work soundly.
Signed-off-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
CC: David Miller <davem@xxxxxxxxxxxxx>
CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
CC: Vlad Yasevich <vyasevich@xxxxxxxxx>
CC: linux-sctp@xxxxxxxxxxxxxxx
---
net/sctp/Kconfig | 27 +++++++++++++++++++++++++--
net/sctp/protocol.c | 4 ++--
2 files changed, 27 insertions(+), 4 deletions(-)
diff --git a/net/sctp/Kconfig b/net/sctp/Kconfig
index a9edd2e..c262106 100644
--- a/net/sctp/Kconfig
+++ b/net/sctp/Kconfig
@@ -66,12 +66,36 @@ config SCTP_DBG_OBJCNT
'cat /proc/net/sctp/sctp_dbg_objcnt'
If unsure, say N
+choice
+ prompt "Default SCTP cookie HMAC encoding"
+ default SCTP_COOKIE_HMAC_MD5
Should not this be SCTP_DEFAULT_COOKIE_HMAC_MD5? I just tried to
update to 3.8-rc2, and I usually build my kernel-headers with:
yes '' | ARCH=foo make oldconfig
and this just kept asking me for this config symbol because none
could be provided.
--
Florian
No, the config mechanism is setup to offer the user the ability to choose a
default cookie hmac, alg, then optionally select any other hmac algs you would
like to be made available (in the event you want to change the default at run
time). When you select the default, it eables (via the select directive), the
corresponding SCTP_COOKIE_HMAC_* config option, which is used in the build, and
then prompts for the remaining values.
Ok for the explanation, but this still breaks an oldconfig because
we do not actually propose the user with a default choice:
choice[1-3?]: Default SCTP cookie HMAC encoding
1. Enable optional MD5 hmac cookie generation
(SCTP_DEFAULT_COOKIE_HMAC_MD5) (NEW)
2. Enable optional SHA1 hmac cookie generation
(SCTP_DEFAULT_COOKIE_HMAC_SHA1) (NEW)
3. Use no hmac alg in SCTP cookie generation
(SCTP_DEFAULT_COOKIE_HMAC_NONE) (NEW)
I do not see any difference in what I am proposed if the default
config symbol is SCTP_DEFAULT_COOKIE_HMAC_MD5, I can still
optionally choose SHA1 to be supported, and I do have a valid
default config for this choice. While if I keep SCTP_COOKIE_HMAC_MD5
No, thats the problem, your old config is no longer valid with this new Kconfig
file. Your config is telling the config utility that you want your default
Cookie hmac to be MD5, but you've explicitly told it (via your yes "" | make
oldconfig command), that you want SCTP_COOKIE_HMAC_MD5 to be disabled, so the
config utility is left with no choice to prompt you again for a default hmac,
which your command answers again by saying SCTP_DEFAULT_COOKIE_HMAC_MD5 (the
default choice of 1). Thats your loop, you keep telling the config utility that
you both want the default hmac to be md5, and that you don't want to allow md5
to be an available hmac alg.
Thats not a bug. I'm sorry if your old configuration needs manual updating, but
there are no guarantees that old configurations will 'just work' in perpituity.
Neil
Actually, I think we have a bug in the config. Look at the thermal
driver config again. It has:
choice
prompt "Default Thermal governor"
default THERMAL_DEFAULT_GOV_STEP_WISE
config THERMAL_DEFAULT_GOV_STEP_WISE
...
config THERMAL_DEFAULT_GOV_FAIR_SHARE
...
config THERMAL_DEFAULT_GOV_USER_SPACE
...
endchoice
SCTP has:
choice
prompt "Default SCTP cookie HMAC encoding"
default SCTP_COOKIE_HMAC_MD5
config SCTP_DEFAULT_COOKIE_HMAC_MD5
...
config SCTP_DEFAULT_COOKIE_HMAC_SHA1
...
config SCTP_DEFAULT_COOKIE_HMAC_NONE
...
endchoice
See the difference? The default value of the choice statement needs to
be one of the available choices.
-vlad
Neil
as the default I have to manually enter which option I want.
--
Florian
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