d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

bbr: Use arc4random_uniform from libkern.

Browse Source 
This unbreak LINT build

Reported by:	jenkins, melifaro
This commit is contained in:
Emmanuel Vadot 2020-05-23 19:52:20 +00:00
parent 4d2c2509f2
commit 77c68315f6
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=361422
1 changed files with 1 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
sys/netinet/tcp_stacks/bbr.c
View File

@ -43,6 +43,7 @@ __FBSDID("$FreeBSD$");
#include <sys/arb.h>
#include <sys/module.h>
#include <sys/kernel.h>
#include <sys/libkern.h>
#ifdef TCP_HHOOK
#include <sys/hhook.h>
#endif
@ -3097,43 +3098,6 @@ bbr_lt_bw_samp_done(struct tcp_bbr *bbr, uint64_t bw, uint32_t cts, uint32_t tim
bbr_log_type_ltbw(bbr, cts, 5, 0, (uint32_t)bw, 0, timin);
}
/*
* RRS: Copied from user space!
* Calculate a uniformly distributed random number less than upper_bound
* avoiding "modulo bias".
*
* Uniformity is achieved by generating new random numbers until the one
* returned is outside the range [0, 2**32 % upper_bound). This
* guarantees the selected random number will be inside
* [2**32 % upper_bound, 2**32) which maps back to [0, upper_bound)
* after reduction modulo upper_bound.
*/
static uint32_t
arc4random_uniform(uint32_t upper_bound)
{
uint32_t r, min;
if (upper_bound < 2)
return 0;
/* 2**32 % x == (2**32 - x) % x */
min = -upper_bound % upper_bound;
/*
* This could theoretically loop forever but each retry has
* p > 0.5 (worst case, usually far better) of selecting a
* number inside the range we need, so it should rarely need
* to re-roll.
*/
for (;;) {
r = arc4random();
if (r >= min)
break;
}
return r % upper_bound;
}
static void
bbr_randomize_extra_state_time(struct tcp_bbr *bbr)
{