On Sun, Apr 10, 2022 at 02:54:38PM +0300, Серж ИвановЪ wrote:
> пт, 8 апр. 2022 г. в 17:55, Серж ИвановЪ <evasive.gy...@gmail.com>:
> > пт, 8 апр. 2022 г. в 17:46, Geert Stappers <stapp...@stappers.nl>:
> >> On Fri, Apr 08, 2022 at 04:34:11PM +0300, Серж ИвановЪ wrote:
> >> > I am talking about this part of code in src/dhcp.c
> >> > ```
> >> > struct ping_result *do_icmp_ping(time_t now, struct in_addr addr,
> >> > unsigned
> >> > int h
> >> > {
> >> > static struct ping_result dummy;
> >> > struct ping_result *r, *victim = NULL;
> >> > int count, max = (int)(0.6 * (((float)PING_CACHE_TIME)/
> >> > ((float)PING_WAIT)));
> >> > ```
> >> >
> >> > 0.6 should be configurable via compile-time constants, not hard-coded
> >>
> >> That should be expressed as a patch.
> >>
> From d93e601e5d02221ae8a82770aa8771c8c0700beb Mon Sep 17 00:00:00 2001
> From: s3rj1k <evasive.gy...@gmail.com>
> Date: Sun, 10 Apr 2022 14:40:27 +0300
> Subject: [PATCH] Add PING_CHECKS_THRESHOLD compile-time variable
>
> Signed-off-by: s3rj1k <evasive.gy...@gmail.com>
> ---
> src/config.h | 1 +
> src/dhcp.c | 4 ++--
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/src/config.h b/src/config.h
> index cd37900..75c5d05 100644
> --- a/src/config.h
> +++ b/src/config.h
> @@ -35,6 +35,7 @@
> #define MAXLEASES 1000 /* maximum number of DHCP leases */
> #define PING_WAIT 3 /* wait for ping address-in-use test */
> #define PING_CACHE_TIME 30 /* Ping test assumed to be valid this long. */
> +#define PING_CHECKS_THRESHOLD 60 /* threshold percent of possible ping
> checks in the last PING_CACHE_TIME */
> #define DECLINE_BACKOFF 600 /* disable DECLINEd static addresses for this
> long */
> #define DHCP_PACKET_MAX 16384 /* hard limit on DHCP packet size */
> #define SMALLDNAME 50 /* most domain names are smaller than this */
> diff --git a/src/dhcp.c b/src/dhcp.c
> index 6104c87..3187e3f 100644
> --- a/src/dhcp.c
> +++ b/src/dhcp.c
> @@ -723,14 +723,14 @@ struct ping_result *do_icmp_ping(time_t now, struct
> in_addr addr, unsigned int h
> {
> static struct ping_result dummy;
> struct ping_result *r, *victim = NULL;
> - int count, max = (int)(0.6 * (((float)PING_CACHE_TIME)/
> + int count, max = (int)(((float)PING_CHECKS_THRESHOLD / 100) *
> (((float)PING_CACHE_TIME)/
> ((float)PING_WAIT)));
>
> /* check if we failed to ping addr sometime in the last
> PING_CACHE_TIME seconds. If so, assume the same situation still exists.
> This avoids problems when a stupid client bangs
> on us repeatedly. As a final check, if we did more
> - than 60% of the possible ping checks in the last
> + than PING_CHECKS_THRESHOLD% of the possible ping checks in the last
FWIW: I can't tell if that 60% is very same as the 0.6,
but this patch does make that connection / relation.
> PING_CACHE_TIME, we are in high-load mode, so don't do any more. */
> for (count = 0, r = daemon->ping_results; r; r = r->next)
> if (difftime(now, r->time) > (float)PING_CACHE_TIME)
Groeten
Geert Stappers
--
Silence is hard to parse
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