* io.c (ioctl_narg_len, linux_iocparm_len): reinstantiate linux

specific narg length calculation.
* test/ruby/test_io.rb (test_ioctl_linux2): add new test for old and
  unstructured ioctl.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@33839 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,10 @@
+Fri Nov 25 11:37:07 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* io.c (ioctl_narg_len, linux_iocparm_len): reinstantiate linux
+	  specific narg length calculation.
+	* test/ruby/test_io.rb (test_ioctl_linux2): add new test for old and
+	  unstructured ioctl.
+
 Fri Nov 25 10:39:14 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* Makefile.in (EXTLDFLAGS): export it.

io.c

@@ -7966,6 +7966,29 @@ do_ioctl(int fd, ioctl_req_t cmd, long narg)
     return retval;
 }
 
+#define DEFULT_IOCTL_NARG_LEN (256)
+
+#ifdef __linux__
+static long
+linux_iocparm_len(ioctl_req_t cmd)
+{
+    long len;
+
+    if ((cmd & 0xFFFF0000) == 0) {
+	/* legacy and unstructured ioctl number. */
+	return DEFULT_IOCTL_NARG_LEN;
+    }
+
+    len = _IOC_SIZE(cmd);
+
+    /* paranoia check for silly drivers which don't keep ioctl convention */
+    if (len < DEFULT_IOCTL_NARG_LEN)
+	len = DEFULT_IOCTL_NARG_LEN;
+
+    return len;
+}
+#endif
+
 static long
 ioctl_narg_len(ioctl_req_t cmd)
 {
@@ -7978,8 +8001,11 @@ ioctl_narg_len(ioctl_req_t cmd)
 #endif
 #ifdef IOCPARM_LEN
     len = IOCPARM_LEN(cmd);	/* on BSDish systems we're safe */
+#elif defined(__linux__)
+    len = linux_iocparm_len(cmd);
 #else
-    len = 256;		/* otherwise guess at what's safe */
+    /* otherwise guess at what's safe */
+    len = DEFULT_IOCTL_NARG_LEN;
 #endif
 
     return len;

test/ruby/test_io.rb

@@ -2123,6 +2123,19 @@ End
     assert_equal(File.size(__FILE__), buf.unpack('i!')[0])
   end
 
+  def test_ioctl_linux2
+    return if /linux/ !~ RUBY_PLATFORM
+    return if /^i?86|^x86_64/ !~ RUBY_PLATFORM
+
+    File.open('/dev/tty') { |f|
+      tiocgwinsz=0x5413
+      winsize=""
+      assert_nothing_raised {
+        f.ioctl(tiocgwinsz, winsize)
+      }
+    }
+  end
+
   def test_setpos
     mkcdtmpdir {
       File.open("tmp.txt", "w") {|f|