[PATCH] kernel: sysctl: change ipfrag_high/low_thresh to CTL_ULONG

[PATCH] kernel: sysctl: change ipfrag_high/low_thresh to CTL_ULONG

[Kefeng Wang]

3e67f106f619 ("inet: frags: break the 2GB limit for frags storage"),
changes ipfrag_high/low_thread 'type' from int to long, using CTL_ULONG
instead of CTL_INT to keep consistent.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 kernel/sysctl_binary.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index 73c132095a7b..ef0687f40f87 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -410,8 +410,8 @@ static const struct bin_table bin_net_ipv4_table[] = {
 	{ CTL_INT,	NET_IPV4_ICMP_RATELIMIT,		"icmp_ratelimit" },
 	{ CTL_INT,	NET_IPV4_ICMP_RATEMASK,			"icmp_ratemask" },
 
-	{ CTL_INT,	NET_IPV4_IPFRAG_HIGH_THRESH,		"ipfrag_high_thresh" },
-	{ CTL_INT,	NET_IPV4_IPFRAG_LOW_THRESH,		"ipfrag_low_thresh" },
+	{ CTL_ULONG,	NET_IPV4_IPFRAG_HIGH_THRESH,		"ipfrag_high_thresh" },
+	{ CTL_ULONG,	NET_IPV4_IPFRAG_LOW_THRESH,		"ipfrag_low_thresh" },
 	{ CTL_INT,	NET_IPV4_IPFRAG_TIME,			"ipfrag_time" },
 
 	{ CTL_INT,	NET_IPV4_IPFRAG_SECRET_INTERVAL,	"ipfrag_secret_interval" },
-- 
2.20.1

Re: [PATCH] kernel: sysctl: change ipfrag_high/low_thresh to CTL_ULONG

[Eric Dumazet]

On Fri, May 24, 2019 at 7:30 AM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
>
> 3e67f106f619 ("inet: frags: break the 2GB limit for frags storage"),
> changes ipfrag_high/low_thread 'type' from int to long, using CTL_ULONG
> instead of CTL_INT to keep consistent.


What about  compatibility with existing applications ?
Will there sysctl() fail if they provide 32bit variable ?

/proc/sys/net  files are text files, but sysctl() system call has been
discouraged for more than a decade.

Re: [PATCH] kernel: sysctl: change ipfrag_high/low_thresh to CTL_ULONG

[Kefeng Wang]

On 2019/5/24 23:00, Eric Dumazet wrote:
> On Fri, May 24, 2019 at 7:30 AM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
>> 3e67f106f619 ("inet: frags: break the 2GB limit for frags storage"),
>> changes ipfrag_high/low_thread 'type' from int to long, using CTL_ULONG
>> instead of CTL_INT to keep consistent.
>
> What about  compatibility with existing applications ?
> Will there sysctl() fail if they provide 32bit variable ?
>
> /proc/sys/net  files are text files, but sysctl() system call has been
> discouraged for more than a decade.

The sysctl() system call is deprecated, so the main purpose of this patch is to keep consistent,

but it does set wrong value(eg, set 16000000000 to ipfrag_high_thresh) when use sysctl().


>
>