From 18f1f8b7ca7e41f7cfad5fb737860affb3d51965 Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Sat, 15 Oct 2022 16:31:08 +0200
Subject: [PATCH] Add VERY HACKY rand() implementation.

---
 libs/libc/include/stdlib.h |  6 ++++++
 libs/libc/src/rand.cpp     | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)
 create mode 100644 libs/libc/src/rand.cpp

diff --git a/libs/libc/include/stdlib.h b/libs/libc/include/stdlib.h
index eee533e9..90a5ac48 100644
--- a/libs/libc/include/stdlib.h
+++ b/libs/libc/include/stdlib.h
@@ -50,6 +50,12 @@ extern "C"
      * is undefined behavior. */
     void free(void* ptr);
 
+    /* Returns a random number. */
+    int rand(void);
+
+    /* Does nothing. */
+    void srand(unsigned int seed);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libs/libc/src/rand.cpp b/libs/libc/src/rand.cpp
new file mode 100644
index 00000000..eea3ae4e
--- /dev/null
+++ b/libs/libc/src/rand.cpp
@@ -0,0 +1,37 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static FILE* randfp = nullptr;
+
+void close_randfp()
+{
+    fclose(randfp);
+}
+
+extern "C"
+{
+    int rand() // FIXME: This function is a dirty and extremely hacky way to get going, /dev/random should only be used
+               // for initial seeding, userspace should do their own random calculations.
+    {
+        if (!randfp)
+        {
+            randfp = fopen("/dev/random", "rw");
+            assert(randfp != nullptr);
+            atexit(close_randfp);
+        }
+        int result;
+        fread(&result, sizeof(result), 1, randfp);
+        if (ferror(randfp))
+        {
+            perror("read(randfp)");
+            abort();
+        }
+        return result;
+    }
+
+    void srand(unsigned int)
+    {
+        return;
+    }
+}
\ No newline at end of file