On Mon, Jan 07, 2013 at 10:32:01AM -0500, Vlad Yasevich wrote: > On 01/07/2013 09:49 AM, Neil Horman wrote: > >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. > > > > Neil > > Actually, I think it should be as Florian suggests. The default > value of the choice should be one of the values defined as part of > the choice (the SCTP_DEFAULT_COOKIE_*). Turning on appropriate > default would turn on appropriate cookie config > (SCTP_COOKIE_HMAC_*). > I absolutely disagree. > Would that save all the config trouble? > Yes, it would fix it as Florian has noted, but at the cost of silently modifying what the default hmac config vaule is. If you've expressly disabled SCTP_COOKIE_HMAC_MD5, and then blindly take the default choice in the SCTP_DEFAULT_COOKIE selection option (the default default as it were), using the approach your suggesting, then that will silently enable SCTP_COOKIE_HMAC_MD5 again, which may not be expected by users. If you expressly have a config option disabled in an old configuration, we should leave it there. We're doing the right thing now, IMO. When presented with a conflictly set of configuration options, the config utilty is (repeatedly) prompting us to resolve them. That seems like a much more reasonable approach to this, than silently changing pre-existing options so people can do the equivalent of just blindly pressing enter through the config process (which is all yes "" | make oldconfig is). This is a momentary hiccup, corrected by taking 30 seconds to make a manual config change (or by taking a second to understand what the config utility is tell us by prompting for a default choice repeatedly). Theres nothing to fix here. Neil > -vlad > > >Neil > > > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
