git: 674956e19979 - main - sys/netinet/cc: Switch from deprecated random() to prng32()

From: Warner Losh <imp_at_FreeBSD.org>
Date: Thu, 23 May 2024 21:11:31 UTC
The branch main has been updated by imp:

URL: https://cgit.FreeBSD.org/src/commit/?id=674956e1997954e8478e68080061c0530b081515

commit 674956e1997954e8478e68080061c0530b081515
Author:     Henrich Hartzer <henrichhartzer@tuta.io>
AuthorDate: 2024-04-10 21:53:02 +0000
Commit:     Warner Losh <imp@FreeBSD.org>
CommitDate: 2024-05-23 21:10:09 +0000

    sys/netinet/cc: Switch from deprecated random() to prng32()
    
    Related: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277655
    
    Signed-off-by: henrichhartzer@tuta.io
    Reviewed by: imp, mav
    Pull Request: https://github.com/freebsd/freebsd-src/pull/1162
---
 sys/netinet/cc/cc_cdg.c | 8 +++++---
 sys/netinet/cc/cc_chd.c | 9 +++++----
 sys/netinet/cc/cc_hd.c  | 7 ++++---
 3 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/sys/netinet/cc/cc_cdg.c b/sys/netinet/cc/cc_cdg.c
index 1e9236f878d4..7ec9e8ca3ccc 100644
--- a/sys/netinet/cc/cc_cdg.c
+++ b/sys/netinet/cc/cc_cdg.c
@@ -57,6 +57,7 @@
 #include <sys/malloc.h>
 #include <sys/module.h>
 #include <sys/queue.h>
+#include <sys/prng.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
 #include <sys/sysctl.h>
@@ -507,7 +508,8 @@ cdg_cong_signal(struct cc_var *ccv, ccsignal_t signal_type)
 static inline int
 prob_backoff(long qtrend)
 {
-	int backoff, idx, p;
+	int backoff, idx;
+	uint32_t p;
 
 	backoff = (qtrend > ((MAXGRAD * V_cdg_exp_backoff_scale) << D_P_E));
 
@@ -519,8 +521,8 @@ prob_backoff(long qtrend)
 			idx = qtrend;
 
 		/* Backoff probability proportional to rate of queue growth. */
-		p = (INT_MAX / (1 << EXP_PREC)) * probexp[idx];
-		backoff = (random() < p);
+		p = (UINT32_MAX / (1 << EXP_PREC)) * probexp[idx];
+		backoff = (prng32() < p);
 	}
 
 	return (backoff);
diff --git a/sys/netinet/cc/cc_chd.c b/sys/netinet/cc/cc_chd.c
index 52048a7c05ae..92fcf68c41f1 100644
--- a/sys/netinet/cc/cc_chd.c
+++ b/sys/netinet/cc/cc_chd.c
@@ -58,6 +58,7 @@
 #include <sys/limits.h>
 #include <sys/malloc.h>
 #include <sys/module.h>
+#include <sys/prng.h>
 #include <sys/queue.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
@@ -85,8 +86,8 @@
  */
 #define	CC_CHD_DELAY	0x02000000
 
-/* Largest possible number returned by random(). */
-#define	RANDOM_MAX	INT_MAX
+/* Largest possible number returned by prng32(). */
+#define	RANDOM_MAX	UINT32_MAX
 
 static void	chd_ack_received(struct cc_var *ccv, ccsignal_t ack_type);
 static void	chd_cb_destroy(struct cc_var *ccv);
@@ -159,9 +160,9 @@ chd_window_decrease(struct cc_var *ccv)
 static __inline int
 should_backoff(int qdly, int maxqdly, struct chd *chd_data)
 {
-	unsigned long p, rand;
+	uint32_t rand, p;
 
-	rand = random();
+	rand = prng32();
 
 	if (qdly < V_chd_qthresh) {
 		chd_data->loss_compete = 0;
diff --git a/sys/netinet/cc/cc_hd.c b/sys/netinet/cc/cc_hd.c
index 82486563f97e..def1580d8ffb 100644
--- a/sys/netinet/cc/cc_hd.c
+++ b/sys/netinet/cc/cc_hd.c
@@ -59,6 +59,7 @@
 #include <sys/limits.h>
 #include <sys/malloc.h>
 #include <sys/module.h>
+#include <sys/prng.h>
 #include <sys/queue.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
@@ -77,8 +78,8 @@
 
 #include <netinet/khelp/h_ertt.h>
 
-/* Largest possible number returned by random(). */
-#define	RANDOM_MAX	INT_MAX
+/* Largest possible number returned by prng32(). */
+#define	RANDOM_MAX	UINT32_MAX
 
 static void	hd_ack_received(struct cc_var *ccv, ccsignal_t ack_type);
 static int	hd_mod_init(void);
@@ -128,7 +129,7 @@ should_backoff(int qdly, int maxqdly)
 			p = (RANDOM_MAX / 100) * V_hd_pmax;
 	}
 
-	return (random() < p);
+	return (prng32() < p);
 }
 
 /*