Add comments and test for ioctl()

Author: catamorphism

libc-bottom-half/cloudlibc/src/libc/sys/ioctl/ioctl.c

@@ -57,7 +57,8 @@ int ioctl(int fildes, int request, ...) {
 				return -1;
 			}
 		}
-
+                // TODO: In particular, this doesn't support using FIONREAD
+                // with file descriptors
 		default:
 			errno = ENOPROTOOPT;
 			return -1;
@@ -111,11 +112,6 @@ int ioctl(int fildes, int request, ...) {
       return 0;
     }
     case FIONBIO: {
-#ifdef __wasilibc_use_wasip2
-      // wasip2 doesn't support setting the non-blocking flag
-      errno = ENOTSUP;
-      return -1;
-#else
       // Obtain the current file descriptor flags.
       __wasi_fdstat_t fds;
       __wasi_errno_t error = __wasi_fd_fdstat_get(fildes, &fds);
@@ -140,7 +136,6 @@ int ioctl(int fildes, int request, ...) {
         return -1;
       }
       return 0;
-#endif
     }
     default:
       // Invalid request.

test/src/misc/ioctl.c

@@ -0,0 +1,41 @@
+//! add-flags.py(RUN): --dir fs::/ --wasi=inherit-network=y
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#include "test.h"
+
+#define TEST(c) do { \
+	errno = 0; \
+	if (!(c)) \
+		t_error("%s failed (errno = %d)\n", #c, errno); \
+} while(0)
+
+int main(void)
+{
+        char tmp[] = "testsuite-XXXXXX";
+	int fd;
+        int nbytes = 0;
+        int flags = 0;
+        flags |= O_RDWR | O_CREAT | O_EXCL;
+
+	TEST((fd = open(tmp, flags, 0600)) > 2);
+        TEST(write(fd, "hello", 6)==6);
+
+#ifdef __wasilibc_use_wasip2
+        // Not supported on wasip2
+        TEST(ioctl(fd, FIONREAD, &nbytes)==-1);
+#else
+        // Always returns 0?
+        TEST(ioctl(fd, FIONREAD, &nbytes)==0);
+#endif
+        close(fd);
+        TEST(unlink(tmp)==0);
+
+	return t_status;
+}