From 5f6ccd5200b66235f82f76dae42abe731acf9ba3 Mon Sep 17 00:00:00 2001
From: Steven Seungcheol Lee <sc108.lee@samsung.com>
Date: Mon, 22 Nov 2021 17:34:58 +0900
Subject: [PATCH] nvme: fix fatal error for sys/random.h

fatal error: sys/random.h: No such file or directory
sys/random.h supported from glibc version 2.25
so add header file existence check
if there is no sys/random.h, try to read /dev/urandom or /dev/random

Signed-off-by: Steven Seungcheol Lee <sc108.lee@samsung.com>
[dwagner: cache errno value, close will overwrite it]
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 ccan/tools/configurator/configurator.c |  3 +++
 meson.build                            |  8 +++++++
 nvme.c                                 | 31 ++++++++++++++++++++++----
 3 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/ccan/tools/configurator/configurator.c b/ccan/tools/configurator/configurator.c
index 9487e694..0518c9b5 100644
--- a/ccan/tools/configurator/configurator.c
+++ b/ccan/tools/configurator/configurator.c
@@ -498,6 +498,9 @@ static const struct test base_tests[] = {
 	  "	return __builtin_cpu_supports(\"mmx\");\n"
 	  "}"
 	},
+	{ "HAVE_SYS_RANDOM", "<sys/random.h>",
+	  "OUTSIDE_MAIN", NULL, NULL,
+	  "#include <sys/random.h>\n" },
 };
 
 static void c12r_err(int eval, const char *fmt, ...)
diff --git a/meson.build b/meson.build
index 8efc8525..c81efe01 100644
--- a/meson.build
+++ b/meson.build
@@ -123,6 +123,14 @@ conf.set10(
     ),
     description: 'Is isblank() available?'
 )
+conf.set10(
+    'HAVE_SYS_RANDOM',
+    cc.compiles(
+        '''#include <sys/random.h>''',
+        name: 'sys/random.h'
+    ),
+    description: 'Is sys/random.h(getrandom) include-able?'
+)
 
 configure_file(
     output: 'config.h',
diff --git a/nvme.c b/nvme.c
index 6ebfa928..09cb2fd8 100644
--- a/nvme.c
+++ b/nvme.c
@@ -23,7 +23,7 @@
 /**
  * This program uses NVMe IOCTLs to run native nvme commands to a device.
  */
-
+#include "config.h"
 #include "nvme/tree.h"
 #include "nvme/types.h"
 #include <errno.h>
@@ -55,7 +55,10 @@
 #include <sys/mman.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <sys/random.h>
+
+#if HAVE_SYS_RANDOM
+	#include <sys/random.h>
+#endif
 
 #include "common.h"
 #include "nvme.h"
@@ -159,6 +162,26 @@ void *nvme_alloc(size_t len, bool *huge)
 }
 #endif
 
+static ssize_t getrandom_bytes(void *buf, size_t buflen)
+{
+#if !HAVE_SYS_RANDOM
+	return getrandom(buf, buflen, GRND_NONBLOCK);
+#else
+	ssize_t result;
+	int fd, err = 0;
+
+	fd = open("/dev/urandom", O_RDONLY);
+	if (fd < 0)
+		return fd;
+	result = read(fd, buf, buflen);
+	if (result < 0)
+		err = errno;
+	close(fd);
+	errno = err;
+	return result;
+#endif
+}
+
 static bool is_chardev(void)
 {
 	return S_ISCHR(nvme_stat.st_mode);
@@ -6757,8 +6780,8 @@ static int gen_dhchap_key(int argc, char **argv, struct command *command, struct
 	if (!raw_secret)
 		return -ENOMEM;
 	if (!cfg.secret) {
-		if (getrandom(raw_secret, cfg.key_len, GRND_NONBLOCK) < 0)
-			return errno;
+		if (getrandom_bytes(raw_secret, cfg.key_len) < 0)
+			return -errno;
 	} else {
 		int secret_len = 0, i;
 		unsigned int c;
-- 
2.50.1