15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2011 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef IPC_FILE_DESCRIPTOR_SET_POSIX_H_ 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define IPC_FILE_DESCRIPTOR_SET_POSIX_H_ 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <vector> 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/basictypes.h" 111320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci#include "base/files/file.h" 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/memory/ref_counted.h" 131320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci#include "base/memory/scoped_vector.h" 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "ipc/ipc_export.h" 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ----------------------------------------------------------------------------- 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// A FileDescriptorSet is an ordered set of POSIX file descriptors. These are 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// associated with IPC messages so that descriptors can be transmitted over a 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// UNIX domain socket. 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ----------------------------------------------------------------------------- 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class IPC_EXPORT FileDescriptorSet 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) : public base::RefCountedThreadSafe<FileDescriptorSet> { 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) FileDescriptorSet(); 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This is the maximum number of descriptors per message. We need to know this 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // because the control message kernel interface has to be given a buffer which 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // is large enough to store all the descriptor numbers. Otherwise the kernel 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // tells us that it truncated the control data and the extra descriptors are 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // lost. 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // In debugging mode, it's a fatal error to try and add more than this number 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // of descriptors to a FileDescriptorSet. 34424c4d7b64af9d0d8fd9624f381f469654d5e3d2Torne (Richard Coles) static const size_t kMaxDescriptorsPerMessage = 7; 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Interfaces for building during message serialisation... 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Add a descriptor to the end of the set. Returns false iff the set is full. 401320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci bool AddToBorrow(base::PlatformFile fd); 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Add a descriptor to the end of the set and automatically close it after 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // transmission. Returns false iff the set is full. 431320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci bool AddToOwn(base::ScopedFD fd); 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Interfaces for accessing during message deserialisation... 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Return the number of descriptors 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned size() const { return descriptors_.size(); } 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Return true if no unconsumed descriptors remain 541320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci bool empty() const { return 0 == size(); } 551320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // Take the nth descriptor from the beginning of the set, 561320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // transferring the ownership of the descriptor taken. Code using this 571320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // /must/ access the descriptors in order, and must do it at most once. 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This interface is designed for the deserialising code as it doesn't 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // support close flags. 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // returns: file descriptor, or -1 on error 621320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci base::PlatformFile TakeDescriptorAt(unsigned n); 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Interfaces for transmission... 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Fill an array with file descriptors without 'consuming' them. CommitAll 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // must be called after these descriptors have been transmitted. 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // buffer: (output) a buffer of, at least, size() integers. 731320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci void PeekDescriptors(base::PlatformFile* buffer) const; 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This must be called after transmitting the descriptors returned by 751320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // PeekDescriptors. It marks all the descriptors as consumed and closes those 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // which are auto-close. 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void CommitAll(); 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Returns true if any contained file descriptors appear to be handles to a 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // directory. 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool ContainsDirectoryDescriptor() const; 814e180b6a0b4720a9b8e9e959a882386f690f08ffTorne (Richard Coles) // Fetch all filedescriptors with the "auto close" property. 824e180b6a0b4720a9b8e9e959a882386f690f08ffTorne (Richard Coles) // Used instead of CommitAll() when closing must be handled manually. 831320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci void ReleaseFDsToClose(std::vector<base::PlatformFile>* fds); 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Interfaces for receiving... 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Set the contents of the set from the given buffer. This set must be empty 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // before calling. The auto-close flag is set on all the descriptors so that 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // unconsumed descriptors are closed on destruction. 941320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci void AddDescriptorsToOwn(const base::PlatformFile* buffer, unsigned count); 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) friend class base::RefCountedThreadSafe<FileDescriptorSet>; 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ~FileDescriptorSet(); 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // A vector of descriptors and close flags. If this message is sent, then 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // these descriptors are sent as control data. After sending, any descriptors 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // with a true flag are closed. If this message has been received, then these 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // are the descriptors which were received and all close flags are true. 1071320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci std::vector<base::PlatformFile> descriptors_; 1081320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci ScopedVector<base::ScopedFD> owned_descriptors_; 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This contains the index of the next descriptor which should be consumed. 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // It's used in a couple of ways. Firstly, at destruction we can check that 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // all the descriptors have been read (with GetNthDescriptor). Secondly, we 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // can check that they are read in order. 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mutable unsigned consumed_descriptor_highwater_; 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(FileDescriptorSet); 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // IPC_FILE_DESCRIPTOR_SET_POSIX_H_ 120