| Message ID | 5320BB4C.9060400@web.de |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Heiner Kallweit <heiner.kallweit@web.de> Date: Wed, 12 Mar 2014 20:53:48 +0100 > @@ -1103,8 +1103,11 @@ retry: > * Lifetime is greater than REGEN_ADVANCE time units. In particular, > * an implementation must not create a temporary address with a zero > * Preferred Lifetime. > + * Use age calculation as in addrconf_verify to avoid unnecessary > + * temporary addresses being generated. > */ > - if (tmp_prefered_lft <= regen_advance) { > + age = (now - ifp->tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ; > + if (tmp_prefered_lft <= regen_advance + age) { I think you must use tmp_tstamp here, we snapshot all of the values above into local variables while holding the lock so that we calculate a consistent set of values and tests. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
You're right. Fixed it and submitted v2 of patch. > From: Heiner Kallweit <heiner.kallweit@web.de> > Date: Wed, 12 Mar 2014 20:53:48 +0100 > >> @@ -1103,8 +1103,11 @@ retry: >> * Lifetime is greater than REGEN_ADVANCE time units. In particular, >> * an implementation must not create a temporary address with a zero >> * Preferred Lifetime. >> + * Use age calculation as in addrconf_verify to avoid unnecessary >> + * temporary addresses being generated. >> */ >> - if (tmp_prefered_lft <= regen_advance) { >> + age = (now - ifp->tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ; >> + if (tmp_prefered_lft <= regen_advance + age) { > I think you must use tmp_tstamp here, we snapshot all of the values > above into local variables while holding the lock so that we calculate > a consistent set of values and tests. > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index fdbfeca..bd64dbe 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -1103,8 +1103,11 @@ retry: * Lifetime is greater than REGEN_ADVANCE time units. In particular, * an implementation must not create a temporary address with a zero * Preferred Lifetime. + * Use age calculation as in addrconf_verify to avoid unnecessary + * temporary addresses being generated. */ - if (tmp_prefered_lft <= regen_advance) { + age = (now - ifp->tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ; + if (tmp_prefered_lft <= regen_advance + age) { in6_ifa_put(ifp); in6_dev_put(idev); ret = -1;
tmp_prefered_lft is an offset to ifp->tstamp, not now. Therefore age needs to be added to the condition. Age calculation in ipv6_create_tempaddr is different from the one in addrconf_verify and doesn't consider ADDRCONF_TIMER_FUZZ_MINUS. This can cause age in ipv6_create_tempaddr to be less than the one in addrconf_verify and therefore unnecessary temporary address to be generated. Use age calculation as in addrconf_modify to avoid this. Signed-off-by: Heiner Kallweit <heiner.kallweit@web.de> --- net/ipv6/addrconf.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)