https://github.com/c-ares/c-ares/commit/d8edb76bece36267c4c55355ae9c7009e131a0e0

From d8edb76bece36267c4c55355ae9c7009e131a0e0 Mon Sep 17 00:00:00 2001
From: Brad House <brad@brad-house.com>
Date: Sun, 17 Dec 2023 11:08:21 -0500
Subject: [PATCH] getrandom() may require sys/random.h on some systems

There is a reported build issue where getrandom() is detected
but compile fails due to a missing prototype. This commit attempts
to resolve that issue.

Fixes Bug: #665
Fix By: Brad House (@bradh352)
---
 CMakeLists.txt              | 2 ++
 configure.ac                | 1 +
 src/lib/ares_config.h.cmake | 3 +++
 src/lib/ares_rand.c         | 3 +++
 4 files changed, 9 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a8d3eed06..29f5d7ed3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -225,6 +225,7 @@ CHECK_INCLUDE_FILES (sys/select.h          HAVE_SYS_SELECT_H)
 CHECK_INCLUDE_FILES (sys/stat.h            HAVE_SYS_STAT_H)
 CHECK_INCLUDE_FILES (sys/time.h            HAVE_SYS_TIME_H)
 CHECK_INCLUDE_FILES (sys/uio.h             HAVE_SYS_UIO_H)
+CHECK_INCLUDE_FILES (sys/random.h          HAVE_SYS_RANDOM_H)
 CHECK_INCLUDE_FILES (ifaddrs.h             HAVE_IFADDRS_H)
 CHECK_INCLUDE_FILES (time.h                HAVE_TIME_H)
 CHECK_INCLUDE_FILES (dlfcn.h               HAVE_DLFCN_H)
@@ -323,6 +324,7 @@ CARES_EXTRAINCLUDE_IFSET (HAVE_SYS_SOCKIO_H	sys/sockio.h)
 CARES_EXTRAINCLUDE_IFSET (HAVE_SYS_TIME_H     sys/time.h)
 CARES_EXTRAINCLUDE_IFSET (HAVE_SYS_STAT_H     sys/stat.h)
 CARES_EXTRAINCLUDE_IFSET (HAVE_SYS_UIO_H      sys/uio.h)
+CARES_EXTRAINCLUDE_IFSET (HAVE_SYS_RANDOM_H   sys/random.h)
 CARES_EXTRAINCLUDE_IFSET (HAVE_TIME_H         time.h)
 CARES_EXTRAINCLUDE_IFSET (HAVE_FCNTL_H        fcntl.h)
 CARES_EXTRAINCLUDE_IFSET (HAVE_UNISTD_H       unistd.h)
diff --git a/configure.ac b/configure.ac
index 7a6b14092..e9c2534cd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -574,6 +574,7 @@ AC_CHECK_HEADERS(
        sys/ioctl.h \
        sys/param.h \
        sys/uio.h \
+       sys/random.h \
        assert.h \
        iphlpapi.h \
        netioapi.h \
diff --git a/src/lib/ares_config.h.cmake b/src/lib/ares_config.h.cmake
index c2974dced..3fb85d54f 100644
--- a/src/lib/ares_config.h.cmake
+++ b/src/lib/ares_config.h.cmake
@@ -320,6 +320,9 @@
 /* Define to 1 if you have the <sys/param.h> header file. */
 #cmakedefine HAVE_SYS_PARAM_H
 
+/* Define to 1 if you have the <sys/random.h> header file. */
+#cmakedefine HAVE_SYS_RANDOM_H
+
 /* Define to 1 if you have the <sys/select.h> header file. */
 #cmakedefine HAVE_SYS_SELECT_H
 
diff --git a/src/lib/ares_rand.c b/src/lib/ares_rand.c
index e6e35ef61..867ca3340 100644
--- a/src/lib/ares_rand.c
+++ b/src/lib/ares_rand.c
@@ -28,6 +28,9 @@
 #include "ares.h"
 #include "ares_private.h"
 #include <stdlib.h>
+#ifdef HAVE_SYS_RANDOM_H
+#  include <sys/random.h>
+#endif
 
 
 typedef enum {