From 4bed72e4f5502ea3322f0a00794815fa58951abe Mon Sep 17 00:00:00 2001 From: YOSHIFUJI Hideaki Date: Tue, 27 May 2008 17:37:49 +0900 Subject: [IPV6] ADDRCONF: Allow longer lifetime on 64bit archs. - Allow longer lifetimes (>= 0x7fffffff/HZ) on 64bit archs by using unsigned long. - Shadow this arithmetic overflow workaround by introducing helper functions: addrconf_timeout_fixup() and addrconf_finite_timeout(). Signed-off-by: YOSHIFUJI Hideaki --- include/net/addrconf.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'include/net/addrconf.h') diff --git a/include/net/addrconf.h b/include/net/addrconf.h index 0a2f0372df31..bbd3d583c6e6 100644 --- a/include/net/addrconf.h +++ b/include/net/addrconf.h @@ -94,6 +94,28 @@ extern void addrconf_join_solict(struct net_device *dev, extern void addrconf_leave_solict(struct inet6_dev *idev, struct in6_addr *addr); +static inline unsigned long addrconf_timeout_fixup(u32 timeout, + unsigned unit) +{ + if (timeout == 0xffffffff) + return ~0UL; + + /* + * Avoid arithmetic overflow. + * Assuming unit is constant and non-zero, this "if" statement + * will go away on 64bit archs. + */ + if (0xfffffffe > LONG_MAX / unit && timeout > LONG_MAX / unit) + return LONG_MAX / unit; + + return timeout; +} + +static inline int addrconf_finite_timeout(unsigned long timeout) +{ + return ~timeout; +} + /* * IPv6 Address Label subsystem (addrlabel.c) */ -- cgit v1.2.3