[NaCl SDK] nacl_io: Fix real_node when dealing with a windows terminal

native_client_sdk/src/libraries/nacl_io/passthroughfs/real_node.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "nacl_io/passthroughfs/real_node.h"
 
 #include <errno.h>
+#include <string.h>
 
 #include "nacl_io/kernel_handle.h"
 #include "nacl_io/kernel_wrap_real.h"
+#include "nacl_io/log.h"
 
 namespace nacl_io {
 RealNode::RealNode(Filesystem* filesystem, int real_fd, bool close_on_destroy)
   : Node(filesystem),
     real_fd_(real_fd),
     close_on_destroy_(close_on_destroy)
 {
 }
 
 void RealNode::Destroy() {
   if (close_on_destroy_)
     _real_close(real_fd_);
   real_fd_ = -1;
 }
 
 // Normal read/write operations on a file
 Error RealNode::Read(const HandleAttr& attr,
                    void* buf,
                    size_t count,
                    int* out_bytes) {
+  int err;
   *out_bytes = 0;
 
-  int64_t new_offset;
-  int err = _real_lseek(real_fd_, attr.offs, 0, &new_offset);
-  if (err && err != ESPIPE)
-    return err;
+  if (IsaFile()) {
+    int64_t new_offset;
+    err = _real_lseek(real_fd_, attr.offs, SEEK_SET, &new_offset);
+    if (err) {
+      LOG_ERROR("_real_lseek failed: %s\n", strerror(err));

[binji, 2014/10/08 01:26:13]

these could get noisy. Though I guess read/write/lseek don't typically fail.

[Sam Clegg, 2014/10/08 02:01:02]

Changed to LOG_WARN which are not compiled in by default ever for debug builds.

+      return err;
+    }
+  }
 
   size_t nread;
   err = _real_read(real_fd_, buf, count, &nread);
-  if (err)
+  if (err) {
+    LOG_ERROR("_real_read failed: %s\n", strerror(err));
     return err;
+  }
 
   *out_bytes = static_cast<int>(nread);
   return 0;
 }
 
 Error RealNode::Write(const HandleAttr& attr,
                       const void* buf,
                       size_t count,
                       int* out_bytes) {
-  //nacl_io_log("Real::Write\n");
   int err;
   *out_bytes = 0;
 
-  int64_t new_offset;
-  err = _real_lseek(real_fd_, attr.offs, 0, &new_offset);
-  if (err && err != ESPIPE)
-    return err;
+  if (IsaFile()) {
+    int64_t new_offset;
+    err = _real_lseek(real_fd_, attr.offs, SEEK_SET, &new_offset);
+    if (err) {
+      LOG_ERROR("_real_lseek failed: %s\n", strerror(err));
+      return err;
+    }
+  }
 
   size_t nwrote;
   err = _real_write(real_fd_, buf, count, &nwrote);
-  if (err)
+  if (err) {
+    LOG_ERROR("_real_write failed: %d\n", err);

[binji, 2014/10/08 01:26:13]

strerror

[Sam Clegg, 2014/10/08 02:01:02]

Done.

     return err;
+  }
 
   *out_bytes = static_cast<int>(nwrote);
   return 0;
 }
 
 Error RealNode::FTruncate(off_t size) {
   // TODO(binji): what to do here?
   return ENOSYS;
 }
 
 Error RealNode::GetDents(size_t offs,
                          struct dirent* pdir,
                          size_t count,
                          int* out_bytes) {
   size_t nread;
   int err = _real_getdents(real_fd_, pdir, count, &nread);
   if (err)
     return err;
   return nread;
 }
 
 Error RealNode::GetStat(struct stat* stat) {
   int err = _real_fstat(real_fd_, stat);
   if (err)
     return err;
+  // On windows, fstat() of stdin/stdout/stderr returns all zeros
+  // for the permission bits. This can cause problems down the
+  // line.  For example, CanOpen() will fail.
+  // TODO(sbc): Fix this within sel_ldr instead.
+  if (S_ISCHR(stat->st_mode) && (stat->st_mode & S_IRWXU) == 0)

[binji, 2014/10/08 01:26:13]

Maybe put this in a Windows-only ifdef?

[Sam Clegg, 2014/10/08 02:01:02]

No, its the windows version of sel_ldr that is returning this info, so we can't
distinguish it at compile time or at run time :(

[binji, 2014/10/08 18:22:24]

Oh, I see.

+    stat->st_mode |= S_IRWXU;
   return 0;
 }
 
 Error RealNode::Isatty() {
 #ifdef __GLIBC__
   // isatty is not yet hooked up to the IRT interface under glibc.
   return ENOTTY;
 #else
   int result = 0;
   int err = _real_isatty(real_fd_, &result);
@@ skipping 10 matching lines @@
                      size_t offset,
                      void** out_addr) {
   *out_addr = addr;
   int err = _real_mmap(out_addr, length, prot, flags, real_fd_, offset);
   if (err)
     return err;
   return 0;
 }
 
 }