libspl: move random impl from libzpool

Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes #17861

lib/libspl/Makefile.am

@@ -27,6 +27,7 @@ libspl_la_SOURCES = \
 	%D%/mutex.c \
 	%D%/page.c \
 	%D%/procfs_list.c \
+	%D%/random.c \
 	%D%/rwlock.c \
 	%D%/strlcat.c \
 	%D%/strlcpy.c \

lib/libspl/libspl.c

@@ -32,6 +32,7 @@
 #include <unistd.h>
 #include <sys/misc.h>
 #include <sys/utsname.h>
+#include "libspl_impl.h"
 
 uint64_t physmem;
 struct utsname hw_utsname;
@@ -48,9 +49,12 @@ libspl_init(void)
 	physmem = sysconf(_SC_PHYS_PAGES);
 
 	VERIFY0(uname(&hw_utsname));
+
+	random_init();
 }
 
 void
 libspl_fini(void)
 {
+	random_fini();
 }

lib/libspl/libspl_impl.h

@@ -21,5 +21,12 @@
  * CDDL HEADER END
  */
 
+#ifndef _LIBSPL_IMPL_H
+#define	_LIBSPL_IMPL_H
 
 extern ssize_t getexecname_impl(char *execname);
+
+extern void random_init(void);
+extern void random_fini(void);
+
+#endif

lib/libspl/random.c

@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: CDDL-1.0
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2016 Actifio, Inc. All rights reserved.
+ * Copyright (c) 2025, Klara, Inc.
+ */
+
+#include <stdint.h>
+#include <fcntl.h>
+#include <assert.h>
+#include <sys/random.h>
+#include "libspl_impl.h"
+
+const char *random_path = "/dev/random";
+const char *urandom_path = "/dev/urandom";
+static int random_fd = -1, urandom_fd = -1;
+
+void
+random_init(void)
+{
+	VERIFY((random_fd = open(random_path, O_RDONLY | O_CLOEXEC)) != -1);
+	VERIFY((urandom_fd = open(urandom_path, O_RDONLY | O_CLOEXEC)) != -1);
+}
+
+void
+random_fini(void)
+{
+	close(random_fd);
+	close(urandom_fd);
+
+	random_fd = -1;
+	urandom_fd = -1;
+}
+
+static int
+random_get_bytes_common(uint8_t *ptr, size_t len, int fd)
+{
+	size_t resid = len;
+	ssize_t bytes;
+
+	ASSERT(fd != -1);
+
+	while (resid != 0) {
+		bytes = read(fd, ptr, resid);
+		ASSERT3S(bytes, >=, 0);
+		ptr += bytes;
+		resid -= bytes;
+	}
+
+	return (0);
+}
+
+int
+random_get_bytes(uint8_t *ptr, size_t len)
+{
+	return (random_get_bytes_common(ptr, len, random_fd));
+}
+
+int
+random_get_pseudo_bytes(uint8_t *ptr, size_t len)
+{
+	return (random_get_bytes_common(ptr, len, urandom_fd));
+}

lib/libzpool/kernel.c

@@ -342,57 +342,6 @@ lowbit64(uint64_t i)
 	return (__builtin_ffsll(i));
 }
 
-const char *random_path = "/dev/random";
-const char *urandom_path = "/dev/urandom";
-static int random_fd = -1, urandom_fd = -1;
-
-void
-random_init(void)
-{
-	VERIFY((random_fd = open(random_path, O_RDONLY | O_CLOEXEC)) != -1);
-	VERIFY((urandom_fd = open(urandom_path, O_RDONLY | O_CLOEXEC)) != -1);
-}
-
-void
-random_fini(void)
-{
-	close(random_fd);
-	close(urandom_fd);
-
-	random_fd = -1;
-	urandom_fd = -1;
-}
-
-static int
-random_get_bytes_common(uint8_t *ptr, size_t len, int fd)
-{
-	size_t resid = len;
-	ssize_t bytes;
-
-	ASSERT(fd != -1);
-
-	while (resid != 0) {
-		bytes = read(fd, ptr, resid);
-		ASSERT3S(bytes, >=, 0);
-		ptr += bytes;
-		resid -= bytes;
-	}
-
-	return (0);
-}
-
-int
-random_get_bytes(uint8_t *ptr, size_t len)
-{
-	return (random_get_bytes_common(ptr, len, random_fd));
-}
-
-int
-random_get_pseudo_bytes(uint8_t *ptr, size_t len)
-{
-	return (random_get_bytes_common(ptr, len, urandom_fd));
-}
-
 int
 ddi_strtoull(const char *str, char **nptr, int base, u_longlong_t *result)
 {
@@ -505,8 +454,6 @@ kernel_init(int mode)
 
 	hostid = (mode & SPA_MODE_WRITE) ? get_system_hostid() : 0;
 
-	random_init();
-
 	system_taskq_init();
 	icp_init();
 
@@ -531,8 +478,6 @@ kernel_fini(void)
 	icp_fini();
 	system_taskq_fini();
 
-	random_fini();
-
 	libspl_fini();
 }