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" 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/file_descriptor_posix.h" 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/memory/ref_counted.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "ipc/ipc_export.h" 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ----------------------------------------------------------------------------- 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// A FileDescriptorSet is an ordered set of POSIX file descriptors. These are 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// associated with IPC messages so that descriptors can be transmitted over a 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// UNIX domain socket. 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ----------------------------------------------------------------------------- 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class IPC_EXPORT FileDescriptorSet 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) : public base::RefCountedThreadSafe<FileDescriptorSet> { 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) FileDescriptorSet(); 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This is the maximum number of descriptors per message. We need to know this 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // because the control message kernel interface has to be given a buffer which 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // is large enough to store all the descriptor numbers. Otherwise the kernel 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // tells us that it truncated the control data and the extra descriptors are 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // lost. 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // In debugging mode, it's a fatal error to try and add more than this number 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // of descriptors to a FileDescriptorSet. 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static const size_t kMaxDescriptorsPerMessage = 5; 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Interfaces for building during message serialisation... 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Add a descriptor to the end of the set. Returns false iff the set is full. 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool Add(int fd); 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Add a descriptor to the end of the set and automatically close it after 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // transmission. Returns false iff the set is full. 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool AddAndAutoClose(int fd); 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Interfaces for accessing during message deserialisation... 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Return the number of descriptors 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned size() const { return descriptors_.size(); } 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Return true if no unconsumed descriptors remain 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool empty() const { return descriptors_.empty(); } 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Fetch the nth descriptor from the beginning of the set. Code using this 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // /must/ access the descriptors in order, except that it may wrap from the 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // end to index 0 again. 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This interface is designed for the deserialising code as it doesn't 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // support close flags. 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // returns: file descriptor, or -1 on error 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int GetDescriptorAt(unsigned n) const; 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Interfaces for transmission... 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Fill an array with file descriptors without 'consuming' them. CommitAll 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // must be called after these descriptors have been transmitted. 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // buffer: (output) a buffer of, at least, size() integers. 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void GetDescriptors(int* buffer) const; 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This must be called after transmitting the descriptors returned by 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // GetDescriptors. It marks all the descriptors as consumed and closes those 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // which are auto-close. 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void CommitAll(); 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Returns true if any contained file descriptors appear to be handles to a 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // directory. 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool ContainsDirectoryDescriptor() const; 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Interfaces for receiving... 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Set the contents of the set from the given buffer. This set must be empty 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // before calling. The auto-close flag is set on all the descriptors so that 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // unconsumed descriptors are closed on destruction. 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void SetDescriptors(const int* buffer, unsigned count); 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // --------------------------------------------------------------------------- 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) friend class base::RefCountedThreadSafe<FileDescriptorSet>; 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ~FileDescriptorSet(); 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // A vector of descriptors and close flags. If this message is sent, then 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // these descriptors are sent as control data. After sending, any descriptors 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // with a true flag are closed. If this message has been received, then these 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // are the descriptors which were received and all close flags are true. 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) std::vector<base::FileDescriptor> descriptors_; 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This contains the index of the next descriptor which should be consumed. 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // It's used in a couple of ways. Firstly, at destruction we can check that 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // all the descriptors have been read (with GetNthDescriptor). Secondly, we 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // can check that they are read in order. 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mutable unsigned consumed_descriptor_highwater_; 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(FileDescriptorSet); 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // IPC_FILE_DESCRIPTOR_SET_POSIX_H_ 115