Merge pull request #1535 from nanovms/fix/open-write-directory

Check for directory type on open and read syscalls

src/unix/syscall.c

@@ -276,6 +276,8 @@ sysreturn readv(int fd, struct iovec *iov, int iovcnt)
     if (!validate_iovec(iov, iovcnt, true))
         return -EFAULT;
     fdesc f = resolve_fd(current->p, fd);
+    if (fdesc_type(f) == FDESC_TYPE_DIRECTORY)
+        return -EISDIR;
     iov_op(f, false, iov, iovcnt, infinity, true, syscall_io_complete);
     return thread_maybe_sleep_uninterruptible(current);
 }
@@ -458,7 +460,8 @@ closure_function(2, 6, sysreturn, file_read,
                  void *, dest, u64, length, u64, offset_arg, thread, t, boolean, bh, io_completion, completion)
 {
     file f = bound(f);
-
+    if (fdesc_type(&f->f) == FDESC_TYPE_DIRECTORY)
+        return -EISDIR;
     boolean is_file_offset = offset_arg == infinity;
     u64 offset = is_file_offset ? f->offset : offset_arg;
     thread_log(t, "%s: f %p, dest %p, offset %ld (%s), length %ld, file length %ld",
@@ -764,11 +767,18 @@ sysreturn open_internal(filesystem fs, tuple cwd, const char *name, int flags,
     case O_RDWR:
         if (!(file_meta_perms(current->p, n) & ACCESS_PERM_WRITE))
             return -EACCES;
+        if (is_dir(n))
+            return -EISDIR;
         break;
     default:
         return -EINVAL;
     }
 
+    if ((flags & (O_CREAT|O_DIRECTORY)) == O_DIRECTORY && !is_dir(n)) {
+        thread_log(current, "\"%s\" opened with O_DIRECTORY but is not a directory", name);
+        return -ENOTDIR;
+    }
+
     u64 length = 0;
     fsfile fsf = 0;
 

src/unix/system_structs.h

@@ -93,6 +93,7 @@ typedef struct iovec {
 #define O_NOATIME       01000000
 #define O_CLOEXEC       02000000
 #define O_PATH         010000000
+#define O_TMPFILE     (020000000 | O_DIRECTORY)
 
 #define F_LINUX_SPECIFIC_BASE   0x400
 

src/x86_64/unix_machine.h

@@ -28,6 +28,7 @@ struct stat {
 } __attribute__((packed));
 
 #define O_DIRECT        00040000
+#define O_DIRECTORY     00200000
 #define O_NOFOLLOW      00400000
 
 #define MAP_32BIT           0x40

test/runtime/write.c

@@ -50,7 +50,43 @@ void basic_write_test()
 {
     char buf[BUFLEN];
     ssize_t rv;
-    int fd = open("hello", O_RDWR);
+    int fd = open("/", O_RDWR);
+    if (fd != -1 || errno != EISDIR) {
+        perror("open directory rdwr");
+        exit(EXIT_FAILURE);
+    }
+    fd = open("/", O_WRONLY);
+    if (fd != -1 || errno != EISDIR) {
+        perror("open directory wr");
+        exit(EXIT_FAILURE);
+    }
+    fd = open("/", O_RDONLY | O_DIRECTORY);
+    if (fd < 0) {
+        perror("open directory");
+        exit(EXIT_FAILURE);
+    }
+    close(fd);
+    fd = open("/", O_RDONLY);
+    if (fd < 0) {
+        perror("open directory rd");
+        exit(EXIT_FAILURE);
+    }
+    if (read(fd, buf, BUFLEN) != -1 || errno != EISDIR) {
+        perror("read directory");
+        exit(EXIT_FAILURE);
+    }
+    if (write(fd, buf, BUFLEN) != -1 || errno != EBADF) {
+        perror("write directory");
+        exit(EXIT_FAILURE);
+    }
+    close(fd);
+
+    fd = open("hello", O_RDWR | O_DIRECTORY);
+    if (fd != -1 || errno != ENOTDIR) {
+        perror("open file as directory");
+        exit(EXIT_FAILURE);
+    }
+    fd = open("hello", O_RDWR);
     if (fd < 0) {
         perror("open");
         exit(EXIT_FAILURE);