[PATCH 09/12] ipv6: use ktime_t for internal timestamps

From: Arnd Bergmann
Date: Wed Sep 30 2015 - 07:27:31 EST


The ipv6 mip6 implementation is one of only a few users of the
skb_get_timestamp() function in the kernel, which is both unsafe
on 32-bit architectures because of the 2038 overflow, and slightly
less efficient than the skb_get_ktime() based approach.

This converts the function call and the mip6_report_rate_limiter
structure that stores the time stamp, eliminating all uses of
timeval in the ipv6 code.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Alexey Kuznetsov <kuznet@xxxxxxxxxxxxx>
Cc: James Morris <jmorris@xxxxxxxxx>
Cc: Hideaki YOSHIFUJI <yoshfuji@xxxxxxxxxxxxxx>
Cc: Patrick McHardy <kaber@xxxxxxxxx>
---
net/ipv6/mip6.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/net/ipv6/mip6.c b/net/ipv6/mip6.c
index b9779d441b12..60c79a08e14a 100644
--- a/net/ipv6/mip6.c
+++ b/net/ipv6/mip6.c
@@ -118,7 +118,7 @@ static int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)

struct mip6_report_rate_limiter {
spinlock_t lock;
- struct timeval stamp;
+ ktime_t stamp;
int iif;
struct in6_addr src;
struct in6_addr dst;
@@ -184,20 +184,18 @@ static int mip6_destopt_output(struct xfrm_state *x, struct sk_buff *skb)
return 0;
}

-static inline int mip6_report_rl_allow(struct timeval *stamp,
+static inline int mip6_report_rl_allow(ktime_t stamp,
const struct in6_addr *dst,
const struct in6_addr *src, int iif)
{
int allow = 0;

spin_lock_bh(&mip6_report_rl.lock);
- if (mip6_report_rl.stamp.tv_sec != stamp->tv_sec ||
- mip6_report_rl.stamp.tv_usec != stamp->tv_usec ||
+ if (!ktime_equal(mip6_report_rl.stamp, stamp) ||
mip6_report_rl.iif != iif ||
!ipv6_addr_equal(&mip6_report_rl.src, src) ||
!ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
- mip6_report_rl.stamp.tv_sec = stamp->tv_sec;
- mip6_report_rl.stamp.tv_usec = stamp->tv_usec;
+ mip6_report_rl.stamp = stamp;
mip6_report_rl.iif = iif;
mip6_report_rl.src = *src;
mip6_report_rl.dst = *dst;
@@ -216,7 +214,7 @@ static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb,
struct ipv6_destopt_hao *hao = NULL;
struct xfrm_selector sel;
int offset;
- struct timeval stamp;
+ ktime_t stamp;
int err = 0;

if (unlikely(fl6->flowi6_proto == IPPROTO_MH &&
@@ -230,9 +228,9 @@ static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb,
(skb_network_header(skb) + offset);
}

- skb_get_timestamp(skb, &stamp);
+ stamp = skb_get_ktime(skb);

- if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
+ if (!mip6_report_rl_allow(stamp, &ipv6_hdr(skb)->daddr,
hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
opt->iif))
goto out;
--
2.1.0.rc2

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