Fix IGMP timer (#3476)

LWIP_RAND() return type is int, value returned is sometimes negative.
This causes timer to sometimes (often) go outside of max_time, which in turn causes IGMP snoopers or IGMP routers to drop the subscription
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Johan Ström 2021-11-19 22:47:54 +01:00 committed by GitHub
parent 77e5359087
commit f7b48b9214
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1 changed files with 1 additions and 1 deletions

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@ -731,7 +731,7 @@ igmp_start_timer(struct igmp_group *group, u8_t max_time)
if(max_time == 1) if(max_time == 1)
group->timer = 1; group->timer = 1;
else else
group->timer = (LWIP_RAND() % (max_time - 1)) + 1; group->timer = (u16_t) ((unsigned int)LWIP_RAND() % (max_time - 1)) + 1;
} }
/** /**