Migrate syscall for SYS_getrandom to C code

Author: 05nelsonm

library/crypto-rand/build.gradle.kts

@@ -71,16 +71,18 @@ kmpConfiguration {
                 .resolve("cinterop")
 
             val interopTaskInfo = targets.filterIsInstance<KotlinNativeTarget>().map { target ->
-                if (target.konanTarget.family == Family.ANDROID) {
-                    target.compilations["main"].cinterops.create("crypto_rand_sys") {
-                        definitionFile.set(cInteropDir.resolve("$name.def"))
-                        includeDirs(cInteropDir)
-                    }
+                val hasSysRandom = when (target.konanTarget.family) {
+                    Family.ANDROID, Family.LINUX -> "-D__CRYPTO_RAND_HAS_SYS_RANDOM__=1"
+                    else -> null
                 }
 
-                target.compilations["test"].cinterops.create("syscall") {
+                val taskName = target.compilations["main"].cinterops.create("crypto_rand_sys") {
                     definitionFile.set(cInteropDir.resolve("$name.def"))
-                }.interopProcessingTaskName to target.konanTarget
+                    includeDirs(cInteropDir)
+                    if (hasSysRandom != null) compilerOpts.add(hasSysRandom)
+                }.interopProcessingTaskName
+
+                Triple(taskName, target.konanTarget, hasSysRandom)
             }
 
             project.extensions.configure<CompileToBitcodeExtension>("cklib") {
@@ -97,11 +99,13 @@ kmpConfiguration {
 
                     val kt = KonanTarget.predefinedTargets[target]!!
 
-                    // Must add dependency on the test cinterop task to ensure
-                    // that Kotlin/Native dependencies get downloaded beforehand
-                    interopTaskInfo.forEach { (interopTaskName, konanTarget) ->
+                    interopTaskInfo.forEach { (interopTaskName, konanTarget, hasSysRandom) ->
                         if (kt != konanTarget) return@forEach
+
+                        // Must add dependency on the test cinterop task to ensure
+                        // that Kotlin/Native dependencies get downloaded beforehand
                         this.dependsOn(interopTaskName)
+                        if (hasSysRandom != null) compilerArgs.add(hasSysRandom)
                     }
                 }
             }

library/crypto-rand/src/androidNativeMain/kotlin/org/kotlincrypto/random/internal/AndroidNativePlatform.kt

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  **/
-@file:Suppress("KotlinRedundantDiagnosticSuppress", "NOTHING_TO_INLINE", "SpellCheckingInspection", "UnnecessaryOptInAnnotation")
+@file:Suppress("NOTHING_TO_INLINE", "RemoveRedundantCallsOfConversionMethods")
 
 package org.kotlincrypto.random.internal
 
@@ -24,20 +24,12 @@ import kotlin.contracts.ExperimentalContracts
 import kotlin.contracts.InvocationKind
 import kotlin.contracts.contract
 
-@Suppress("FunctionName")
-internal expect inline fun _SYS_getrandom(): Int
-
-@OptIn(ExperimentalForeignApi::class, UnsafeNumber::class)
-private inline fun getrandom2(buf: CPointer<ByteVar>, buflen: size_t, flags: u_int): Int {
-    return syscall(_SYS_getrandom().convert(), buf, buflen, flags).convert()
-}
-
 // getrandom(2) available for Linux Kernel 3.17+ (Android API 26+)
 @OptIn(ExperimentalForeignApi::class, UnsafeNumber::class)
 internal val HAS_GET_RANDOM: Boolean by lazy(LazyThreadSafetyMode.SYNCHRONIZED) {
     val buf = ByteArray(1)
     val result = buf.usePinned { pinned ->
-        getrandom2(pinned.addressOf(0), buf.size.convert(), 0x0001u /* GRND_NONBLOCK */)
+        __SYS_getrandom(__buf = pinned.addressOf(0), __len = buf.size.convert(), __is_nonblock = 1).toInt()
     }
     if (result >= 0) return@lazy true
 
@@ -54,7 +46,7 @@ internal val HAS_GET_RANDOM: Boolean by lazy(LazyThreadSafetyMode.SYNCHRONIZED)
 @OptIn(ExperimentalForeignApi::class, UnsafeNumber::class)
 internal actual fun ByteArray.cryptoRandFill() {
     if (HAS_GET_RANDOM) {
-        cryptoRandFill { ptr, len -> getrandom2(ptr, len.toULong().convert(), 0u) }
+        cryptoRandFill { ptr, len -> __SYS_getrandom(__buf = ptr, __len = len.convert(), __is_nonblock = 0).toInt() }
     } else {
         cryptoRandFillURandom()
     }

library/crypto-rand/src/androidNativeTest/kotlin/org/kotlincrypto/random/internal/CryptoRandAndroidNativeUnitTest.kt

@@ -16,12 +16,25 @@
 
 #include "crypto_rand_sys.h"
 
-#ifdef __ANDROID__
+#ifdef __CRYPTO_RAND_HAS_SYS_RANDOM__
 #include <sys/syscall.h>
+#include <unistd.h>
 
-int
-__SYS_getrandom()
+#if __has_include(<sys/random.h>)
+#include <sys/random.h>
+#endif // __has_include(<sys/random.h>)
+
+#ifndef GRND_NONBLOCK
+#define GRND_NONBLOCK 0x01
+#endif // GRND_NONBLOCK
+
+ssize_t
+__SYS_getrandom(void *__buf, size_t __len, int __is_nonblock)
 {
-  return SYS_getrandom;
+  unsigned int flags = 0;
+  if (__is_nonblock) {
+    flags = GRND_NONBLOCK;
+  }
+  return syscall(SYS_getrandom, __buf, __len, flags);
 }
-#endif /* !defined(__ANDROID__) */
+#endif // __CRYPTO_RAND_HAS_SYS_RANDOM__

library/crypto-rand/src/linuxAndroidMain/kotlin/org/kotlincrypto/random/internal/LinuxAndroidPlatform.kt

@@ -14,12 +14,18 @@
  * limitations under the License.
  **/
 
-/* https://youtrack.jetbrains.com/issue/KT-75722 */
 #ifndef CRYPTO_RAND_SYS_H
 #define CRYPTO_RAND_SYS_H
 
-#ifdef __ANDROID__
-int __SYS_getrandom();
-#endif /* !defined(__ANDROID__) */
+#ifdef __CRYPTO_RAND_HAS_SYS_RANDOM__
+#include <sys/types.h>
 
-#endif /* !defined(CRYPTO_RAND_SYS_H) */
+/**
+ * Performs syscall using SYS_getrandom and provided arguments.
+ *
+ * If __is_nonblock > 0, will use flag GRND_NONBLOCK, otherwise will use 0.
+ * */
+ssize_t __SYS_getrandom(void *__buf, size_t __len, int __is_nonblock);
+#endif // __CRYPTO_RAND_HAS_SYS_RANDOM__
+
+#endif // CRYPTO_RAND_SYS_H