* miscfuncs.cc (check_iovec_for_read): Don't check buffer when zero length

iov_len.
(check_iovec_for_write): Ditto.
* fhandler.h (fhandler_base::readv): New method.
(fhandler_base::writev): Ditto.
* fhandler.cc (fhandler_base::readv): New method.
(fhandler_base::writev): Ditto.
* syscalls.cc (_read): Delegate to readv(2).
(_write): Ditto, mutatis mutandi.
(readv): Rewrite, based on the old _read code, to use the new
fhandler_base::readv method.  Improve access mode handling and ensure all calls
reach the final strace statement.
(writev): Ditto, mutatis mutandi.
* include/sys/uio.h (struct iovec): Change field types to match SUSv3.
* winsup.h (check_iovec_for_read): New function.
(check_iovec_for_write): Ditto.
* miscfuncs.cc (check_iovec_for_read): Ditto.
(check_iovec_for_write): Ditto.

8 files changed, 288 insertions, 130 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 3dfcf904d..1b2b73df1 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,27 @@
+2002-08-30  Christopher Faylor  <cgf@redhat.com>
+
+	* miscfuncs.cc (check_iovec_for_read): Don't check buffer when zero
+	length iov_len.
+	(check_iovec_for_write): Ditto.
+
+2002-08-27  Conrad Scott  <conrad.scott@dsl.pipex.com>
+
+	* fhandler.h (fhandler_base::readv): New method.
+	(fhandler_base::writev): Ditto.
+	* fhandler.cc (fhandler_base::readv): New method.
+	(fhandler_base::writev): Ditto.
+	* syscalls.cc (_read): Delegate to readv(2).
+	(_write): Ditto, mutatis mutandi.
+	(readv): Rewrite, based on the old _read code, to use the new
+	fhandler_base::readv method.  Improve access mode handling and ensure
+	all calls reach the final strace statement.
+	(writev): Ditto, mutatis mutandi.
+	* include/sys/uio.h (struct iovec): Change field types to match SUSv3.
+	* winsup.h (check_iovec_for_read): New function.
+	(check_iovec_for_write): Ditto.
+	* miscfuncs.cc (check_iovec_for_read): Ditto.
+	(check_iovec_for_write): Ditto.
+
 2002-08-30  Corinna Vinschen  <corinna@vinschen.de>
 
 	* cygwin.din: Add more prototypes for new wchar functions in newlib.
diff --git a/winsup/cygwin/fhandler.cc b/winsup/cygwin/fhandler.cc
index 591bc72f5..8ac42acdb 100644
--- a/winsup/cygwin/fhandler.cc
+++ b/winsup/cygwin/fhandler.cc
@@ -13,6 +13,7 @@ details. */
 #include <unistd.h>
 #include <stdlib.h>
 #include <sys/cygwin.h>
+#include <sys/uio.h>
 #include <signal.h>
 #include "cygerrno.h"
 #include "perprocess.h"
@@ -697,6 +698,109 @@ fhandler_base::write (const void *ptr, size_t len)
   return res;
 }
 
+ssize_t
+fhandler_base::readv (const struct iovec *const iov, const int iovcnt,
+		      ssize_t tot)
+{
+  assert (iov);
+  assert (iovcnt >= 1);
+
+  if (iovcnt == 1)
+    return read (iov->iov_base, iov->iov_len);
+
+  if (tot == -1)		// i.e. if not pre-calculated by the caller.
+    {
+      tot = 0;
+      const struct iovec *iovptr = iov + iovcnt;
+      do 
+	{
+	  iovptr -= 1;
+	  tot += iovptr->iov_len;
+	}
+      while (iovptr != iov);
+    }
+
+  assert (tot >= 0);
+
+  if (tot == 0)
+    return 0;
+
+  char *buf = (char *) alloca (tot);
+
+  if (!buf)
+    {
+      set_errno (ENOMEM);
+      return -1;
+    }
+
+  const ssize_t res = read (buf, tot);
+
+  const struct iovec *iovptr = iov;
+  int nbytes = res;
+
+  while (nbytes > 0)
+    {
+      const int frag = min (nbytes, (ssize_t) iovptr->iov_len);
+      memcpy (iovptr->iov_base, buf, frag);
+      buf += frag;
+      iovptr += 1;
+      nbytes -= frag;
+    }
+
+  return res;
+}
+
+ssize_t
+fhandler_base::writev (const struct iovec *const iov, const int iovcnt,
+		       ssize_t tot)
+{
+  assert (iov);
+  assert (iovcnt >= 1);
+
+  if (iovcnt == 1)
+    return write (iov->iov_base, iov->iov_len);
+
+  if (tot == -1)		// i.e. if not pre-calculated by the caller.
+    {
+      tot = 0;
+      const struct iovec *iovptr = iov + iovcnt;
+      do 
+	{
+	  iovptr -= 1;
+	  tot += iovptr->iov_len;
+	}
+      while (iovptr != iov);
+    }
+
+  assert (tot >= 0);
+
+  if (tot == 0)
+    return 0;
+
+  char *const buf = (char *) alloca (tot);
+
+  if (!buf)
+    {
+      set_errno (ENOMEM);
+      return -1;
+    }
+
+  char *bufptr = buf;
+  const struct iovec *iovptr = iov;
+  int nbytes = tot;
+
+  while (nbytes != 0)
+    {
+      const int frag = min (nbytes, (ssize_t) iovptr->iov_len);
+      memcpy (bufptr, iovptr->iov_base, frag);
+      bufptr += frag;
+      iovptr += 1;
+      nbytes -= frag;
+    }
+
+  return write (buf, tot);
+}
+
 __off64_t
 fhandler_base::lseek (__off64_t offset, int whence)
 {
diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index ec72091e3..a63c0514e 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -116,6 +116,7 @@ class path_conv;
 class fhandler_disk_file;
 typedef struct __DIR DIR;
 struct dirent;
+struct iovec;
 
 enum bg_check_types
 {
@@ -297,6 +298,8 @@ class fhandler_base
   virtual char const * ttyname () { return get_name(); }
   virtual int __stdcall read (void *ptr, size_t len) __attribute__ ((regparm (3)));
   virtual int write (const void *ptr, size_t len);
+  virtual ssize_t readv (const struct iovec *, int iovcnt, ssize_t tot = -1);
+  virtual ssize_t writev (const struct iovec *, int iovcnt, ssize_t tot = -1);
   virtual __off64_t lseek (__off64_t offset, int whence);
   virtual int lock (int, struct flock *);
   virtual void dump ();
diff --git a/winsup/cygwin/fhandler_socket.cc b/winsup/cygwin/fhandler_socket.cc
index 85b210752..94866e3fe 100644
--- a/winsup/cygwin/fhandler_socket.cc
+++ b/winsup/cygwin/fhandler_socket.cc
@@ -736,7 +736,9 @@ fhandler_socket::recvmsg (struct msghdr *msg, int flags)
   p = buf;
   while (nb > 0)
     {
-      ssize_t cnt = min(nb, iov->iov_len);
+      ssize_t cnt = iov->iov_len;
+      if (nb < cnt)
+	cnt = nb;
       memcpy (iov->iov_base, p, cnt);
       p += cnt;
       nb -= cnt;
diff --git a/winsup/cygwin/include/sys/uio.h b/winsup/cygwin/include/sys/uio.h
index d355ac5b6..e28f14e7e 100644
--- a/winsup/cygwin/include/sys/uio.h
+++ b/winsup/cygwin/include/sys/uio.h
@@ -1,6 +1,6 @@
 /* sys/uio.h
 
-   Copyright 1996, 2000, 2001 Red Hat, Inc.
+   Copyright 1996, 2000, 2001, 2002 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -24,9 +24,10 @@ __BEGIN_DECLS
  * Define the uio buffers used for writev, readv.
  */
 
-struct iovec {
-	caddr_t iov_base;
-	int iov_len;
+struct iovec
+{
+  void *iov_base;
+  size_t iov_len;
 };
 
 extern ssize_t readv __P ((int filedes, const struct iovec *vector, int count));
diff --git a/winsup/cygwin/miscfuncs.cc b/winsup/cygwin/miscfuncs.cc
index 0849da51c..a6fec0ddc 100644
--- a/winsup/cygwin/miscfuncs.cc
+++ b/winsup/cygwin/miscfuncs.cc
@@ -11,6 +11,9 @@ details. */
 #include "winsup.h"
 #include "cygerrno.h"
 #include <sys/errno.h>
+#include <sys/uio.h>
+#include <assert.h>
+#include <limits.h>
 #include <winbase.h>
 #include <winnls.h>
 
@@ -179,6 +182,76 @@ __check_invalid_read_ptr_errno (const void *s, unsigned sz)
   return set_errno (EFAULT);
 }
 
+ssize_t
+check_iovec_for_read (const struct iovec *iov, int iovcnt)
+{
+  if (iovcnt <= 0 || iovcnt > IOV_MAX)
+    {
+      set_errno (EINVAL);
+      return -1;
+    }
+
+  if (__check_invalid_read_ptr_errno (iov, iovcnt * sizeof (*iov)))
+    return -1;
+
+  size_t tot = 0;
+
+  while (iovcnt != 0)
+    {
+      if (iov->iov_len > SSIZE_MAX || (tot += iov->iov_len) > SSIZE_MAX)
+	{
+	  set_errno (EINVAL);
+	  return -1;
+	}
+
+      if (iov->iov_len
+	  && __check_null_invalid_struct_errno (iov->iov_base, iov->iov_len))
+	return -1;
+
+      iov += 1;
+      iovcnt -= 1;
+    }
+
+  assert (tot <= SSIZE_MAX);
+
+  return (ssize_t) tot;
+}
+
+ssize_t
+check_iovec_for_write (const struct iovec *iov, int iovcnt)
+{
+  if (iovcnt <= 0 || iovcnt > IOV_MAX)
+    {
+      set_errno (EINVAL);
+      return -1;
+    }
+
+  if (__check_invalid_read_ptr_errno (iov, iovcnt * sizeof (*iov)))
+    return -1;
+
+  size_t tot = 0;
+
+  while (iovcnt != 0)
+    {
+      if (iov->iov_len > SSIZE_MAX || (tot += iov->iov_len) > SSIZE_MAX)
+	{
+	  set_errno (EINVAL);
+	  return -1;
+	}
+
+      if (iov->iov_len
+	  && __check_invalid_read_ptr_errno (iov->iov_base, iov->iov_len))
+	return -1;
+
+      iov += 1;
+      iovcnt -= 1;
+    }
+
+  assert (tot <= SSIZE_MAX);
+
+  return (ssize_t) tot;
+}
+
 UINT
 get_cp ()
 {
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index f047cbd1c..657a40cfc 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -321,15 +321,42 @@ getsid (pid_t pid)
 extern "C" ssize_t
 _read (int fd, void *ptr, size_t len)
 {
-  if (len == 0)
-    return 0;
+  const struct iovec iov =
+    {
+      iov_base: ptr,
+      iov_len: len
+    };
 
-  if (__check_null_invalid_struct_errno (ptr, len))
-    return -1;
+  return readv (fd, &iov, 1);
+}
 
-  int res;
+extern "C" ssize_t
+_write (int fd, const void *ptr, size_t len)
+{
+  const struct iovec iov =
+    {
+      iov_base: (void *) ptr,	// const_cast
+      iov_len: len
+    };
+
+  return writev (fd, &iov, 1);
+}
+
+extern "C" ssize_t
+readv (int fd, const struct iovec *const iov, const int iovcnt)
+{
   extern int sigcatchers;
-  int e = get_errno ();
+  const int e = get_errno ();
+
+  int res = -1;
+
+  const ssize_t tot = check_iovec_for_read (iov, iovcnt);
+
+  if (tot <= 0)
+    {
+      res = tot;
+      goto done;
+    }
 
   while (1)
     {
@@ -337,13 +364,19 @@ _read (int fd, void *ptr, size_t len)
 
       cygheap_fdget cfd (fd);
       if (cfd < 0)
-	return -1;
+	break;
+
+      if ((cfd->get_flags () & O_ACCMODE) == O_WRONLY)
+	{
+	  set_errno (EBADF);
+	  break;
+	}
 
       DWORD wait = cfd->is_nonblocking () ? 0 : INFINITE;
 
       /* Could block, so let user know we at least got here.  */
-      syscall_printf ("read (%d, %p, %d) %sblocking, sigcatchers %d",
-		      fd, ptr, len, wait ? "" : "non", sigcatchers);
+      syscall_printf ("readv (%d, %p, %d) %sblocking, sigcatchers %d",
+		      fd, iov, iovcnt, wait ? "" : "non", sigcatchers);
 
       if (wait && (!cfd->is_slow () || cfd->get_r_no_interrupt ()))
 	debug_printf ("no need to call ready_for_read\n");
@@ -357,177 +390,91 @@ _read (int fd, void *ptr, size_t len)
 	 ensure that an fd, closed in another thread, aborts I/O
 	 operations. */
       if (!cfd.isopen ())
-	return -1;
+	break;
 
       /* Check to see if this is a background read from a "tty",
 	 sending a SIGTTIN, if appropriate */
       res = cfd->bg_check (SIGTTIN);
 
       if (!cfd.isopen ())
-	return -1;
+	{
+	  res = -1;
+	  break;
+	}
 
       if (res > bg_eof)
 	{
 	  myself->process_state |= PID_TTYIN;
 	  if (!cfd.isopen ())
-	    return -1;
-	  res = cfd->read (ptr, len);
+	    {
+	      res = -1;
+	      break;
+	    }
+	  res = cfd->readv (iov, iovcnt, tot);
 	  myself->process_state &= ~PID_TTYIN;
 	}
 
     out:
-
-      if (res && get_errno () == EACCES &&
-	  !(cfd->get_flags () & (O_RDONLY | O_RDWR)))
-	{
-	  set_errno (EBADF);
-	  break;
-	}
-
       if (res >= 0 || get_errno () != EINTR || !thisframe.call_signal_handler ())
 	break;
       set_errno (e);
     }
 
-  syscall_printf ("%d = read (%d, %p, %d), errno %d", res, fd, ptr, len,
+done:
+  syscall_printf ("%d = readv (%d, %p, %d), errno %d", res, fd, iov, iovcnt,
 		  get_errno ());
   MALLOC_CHECK;
   return res;
 }
 
 extern "C" ssize_t
-_write (int fd, const void *ptr, size_t len)
+writev (const int fd, const struct iovec *const iov, const int iovcnt)
 {
   int res = -1;
+  const ssize_t tot = check_iovec_for_write (iov, iovcnt);
 
   sigframe thisframe (mainthread);
   cygheap_fdget cfd (fd);
   if (cfd < 0)
     goto done;
 
-  /* No further action required for len == 0 */
-  if (len == 0)
+  if (tot <= 0)
     {
-      res = 0;
+      res = tot;
       goto done;
     }
 
-  if (len && __check_invalid_read_ptr_errno (ptr, len))
-    goto done;
+  if ((cfd->get_flags () & O_ACCMODE) == O_RDONLY)
+    {
+      set_errno (EBADF);
+      goto done;
+    }
 
   /* Could block, so let user know we at least got here.  */
   if (fd == 1 || fd == 2)
-    paranoid_printf ("write (%d, %p, %d)", fd, ptr, len);
+    paranoid_printf ("writev (%d, %p, %d)", fd, iov, iovcnt);
   else
-    syscall_printf  ("write (%d, %p, %d)", fd, ptr, len);
+    syscall_printf  ("writev (%d, %p, %d)", fd, iov, iovcnt);
 
   res = cfd->bg_check (SIGTTOU);
 
   if (res > bg_eof)
     {
       myself->process_state |= PID_TTYOU;
-      res = cfd->write (ptr, len);
+      res = cfd->writev (iov, iovcnt, tot);
       myself->process_state &= ~PID_TTYOU;
-      if (res && get_errno () == EACCES &&
-	  !(cfd->get_flags () & (O_WRONLY | O_RDWR)))
-	set_errno (EBADF);
     }
 
 done:
   if (fd == 1 || fd == 2)
-    paranoid_printf ("%d = write (%d, %p, %d)", res, fd, ptr, len);
+    paranoid_printf ("%d = write (%d, %p, %d), errno %d",
+		     res, fd, iov, iovcnt, get_errno ());
   else
-    syscall_printf ("%d = write (%d, %p, %d)", res, fd, ptr, len);
-
-  return (ssize_t) res;
-}
-
-/*
- * FIXME - should really move this interface into fhandler, and implement
- * write in terms of it. There are devices in Win32 that could do this with
- * overlapped I/O much more efficiently - we should eventually use
- * these.
- */
-
-extern "C" ssize_t
-writev (int fd, const struct iovec *iov, int iovcnt)
-{
-  int i;
-  ssize_t len, total;
-  char *base;
-
-  if (iovcnt < 1 || iovcnt > IOV_MAX)
-    {
-      set_errno (EINVAL);
-      return -1;
-    }
+    syscall_printf ("%d = write (%d, %p, %d), errno %d",
+		    res, fd, iov, iovcnt, get_errno ());
 
-  /* Ensure that the sum of the iov_len values is less than
-     SSIZE_MAX (per spec), if so, we must fail with no output (per spec).
-  */
-  total = 0;
-  for (i = 0; i < iovcnt; ++i)
-    {
-    total += iov[i].iov_len;
-    if (total > SSIZE_MAX)
-      {
-      set_errno (EINVAL);
-      return -1;
-      }
-    }
-  /* Now write the data */
-  for (i = 0, total = 0; i < iovcnt; i++, iov++)
-    {
-      len = iov->iov_len;
-      base = iov->iov_base;
-      while (len > 0)
-	{
-	  register int nbytes;
-	  nbytes = write (fd, base, len);
-	  if (nbytes < 0 && total == 0)
-	    return -1;
-	  if (nbytes <= 0)
-	    return total;
-	  len -= nbytes;
-	  total += nbytes;
-	  base += nbytes;
-	}
-    }
-  return total;
-}
-
-/*
- * FIXME - should really move this interface into fhandler, and implement
- * read in terms of it. There are devices in Win32 that could do this with
- * overlapped I/O much more efficiently - we should eventually use
- * these.
- */
-
-extern "C" ssize_t
-readv (int fd, const struct iovec *iov, int iovcnt)
-{
-  int i;
-  ssize_t len, total;
-  char *base;
-
-  for (i = 0, total = 0; i < iovcnt; i++, iov++)
-    {
-      len = iov->iov_len;
-      base = iov->iov_base;
-      while (len > 0)
-	{
-	  register int nbytes;
-	  nbytes = read (fd, base, len);
-	  if (nbytes < 0 && total == 0)
-	    return -1;
-	  if (nbytes <= 0)
-	    return total;
-	  len -= nbytes;
-	  total += nbytes;
-	  base += nbytes;
-	}
-    }
-  return total;
+  MALLOC_CHECK;
+  return res;
 }
 
 /* _open */
diff --git a/winsup/cygwin/winsup.h b/winsup/cygwin/winsup.h
index 0739cb4dc..9e39728cc 100644
--- a/winsup/cygwin/winsup.h
+++ b/winsup/cygwin/winsup.h
@@ -221,6 +221,10 @@ int __stdcall __check_invalid_read_ptr_errno (const void *s, unsigned sz) __attr
 #define check_null_invalid_struct_errno(s) \
   __check_null_invalid_struct_errno ((s), sizeof (*(s)))
 
+struct iovec;
+ssize_t check_iovec_for_read (const struct iovec *, int) __attribute__ ((regparm(2)));
+ssize_t check_iovec_for_write (const struct iovec *, int) __attribute__ ((regparm(2)));
+
 #define set_winsock_errno() __set_winsock_errno (__FUNCTION__, __LINE__)
 void __set_winsock_errno (const char *fn, int ln) __attribute__ ((regparm(2)));