1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef LIBRARIES_NACL_IO_MOUNT_NODE_H_
6#define LIBRARIES_NACL_IO_MOUNT_NODE_H_
7
8#include <stdarg.h>
9#include <string>
10
11#include "nacl_io/error.h"
12#include "nacl_io/event_listener.h"
13#include "nacl_io/osdirent.h"
14#include "nacl_io/osstat.h"
15#include "nacl_io/ostermios.h"
16
17#include "sdk_util/ref_object.h"
18#include "sdk_util/scoped_ref.h"
19#include "sdk_util/simple_lock.h"
20
21#define S_IRALL (S_IRUSR | S_IRGRP | S_IROTH)
22#define S_IWALL (S_IWUSR | S_IWGRP | S_IWOTH)
23#define S_IXALL (S_IXUSR | S_IXGRP | S_IXOTH)
24
25namespace nacl_io {
26
27class Mount;
28class MountNode;
29struct HandleAttr;
30
31typedef sdk_util::ScopedRef<MountNode> ScopedMountNode;
32
33// NOTE: The KernelProxy is the only class that should be setting errno. All
34// other classes should return Error (as defined by nacl_io/error.h).
35class MountNode : public sdk_util::RefObject {
36 protected:
37  explicit MountNode(Mount* mount);
38  virtual ~MountNode();
39
40 protected:
41  virtual Error Init(int open_flags);
42  virtual void Destroy();
43
44 public:
45  // Return true if the node permissions match the given open mode.
46  virtual bool CanOpen(int open_flags);
47
48  // Returns the emitter for this Node if it has one, if not, assume this
49  // object can not block.
50  virtual EventEmitter* GetEventEmitter();
51  virtual uint32_t GetEventStatus();
52
53  // Normal OS operations on a node (file), can be called by the kernel
54  // directly so it must lock and unlock appropriately.  These functions
55  // must not be called by the mount.
56  virtual Error FSync();
57  // It is expected that the derived MountNode will fill with 0 when growing
58  // the file.
59  virtual Error FTruncate(off_t length);
60  // Assume that |out_bytes| is non-NULL.
61  virtual Error GetDents(size_t offs,
62                         struct dirent* pdir,
63                         size_t count,
64                         int* out_bytes);
65  // Assume that |stat| is non-NULL.
66  virtual Error GetStat(struct stat* stat);
67  // Assume that |arg| is non-NULL.
68  Error Ioctl(int request, ...);
69  virtual Error VIoctl(int request, va_list args);
70  // Assume that |buf| and |out_bytes| are non-NULL.
71  virtual Error Read(const HandleAttr& attr,
72                     void* buf,
73                     size_t count,
74                     int* out_bytes);
75  // Assume that |buf| and |out_bytes| are non-NULL.
76  virtual Error Write(const HandleAttr& attr,
77                      const void* buf,
78                      size_t count,
79                      int* out_bytes);
80  // Assume that |addr| and |out_addr| are non-NULL.
81  virtual Error MMap(void* addr,
82                     size_t length,
83                     int prot,
84                     int flags,
85                     size_t offset,
86                     void** out_addr);
87  virtual Error Tcflush(int queue_selector);
88  virtual Error Tcgetattr(struct termios* termios_p);
89  virtual Error Tcsetattr(int optional_actions,
90                          const struct termios *termios_p);
91
92  virtual int GetLinks();
93  virtual int GetMode();
94  virtual int GetType();
95  virtual void SetType(int type);
96  // Assume that |out_size| is non-NULL.
97  virtual Error GetSize(size_t* out_size);
98  virtual bool IsaDir();
99  virtual bool IsaFile();
100  virtual bool IsaSock();
101  virtual bool IsaTTY();
102
103  // Number of children for this node (directory)
104  virtual int ChildCount();
105
106 protected:
107  // Directory operations on the node are done by the Mount. The mount's lock
108  // must be held while these calls are made.
109
110  // Adds or removes a directory entry updating the link numbers and refcount
111  // Assumes that |node| is non-NULL.
112  virtual Error AddChild(const std::string& name, const ScopedMountNode& node);
113  virtual Error RemoveChild(const std::string& name);
114
115  // Find a child and return it without updating the refcount
116  // Assumes that |out_node| is non-NULL.
117  virtual Error FindChild(const std::string& name, ScopedMountNode* out_node);
118
119  // Update the link count
120  virtual void Link();
121  virtual void Unlink();
122
123 protected:
124  struct stat stat_;
125  sdk_util::SimpleLock node_lock_;
126
127  // We use a pointer directly to avoid cycles in the ref count.
128  // TODO(noelallen) We should change this so it's unnecessary for the node
129  // to track it's parent.  When a node is unlinked, the mount should do
130  // any cleanup it needs.
131  Mount* mount_;
132
133  friend class Mount;
134  friend class MountDev;
135  friend class MountFuse;
136  friend class MountHtml5Fs;
137  friend class MountHttp;
138  friend class MountMem;
139  friend class MountNodeDir;
140};
141
142}  // namespace nacl_io
143
144#endif  // LIBRARIES_NACL_IO_MOUNT_NODE_H_
145