| // Copyright 2011 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef IPC_IPC_MESSAGE_ATTACHMENT_SET_H_ |
| #define IPC_IPC_MESSAGE_ATTACHMENT_SET_H_ |
| |
| #include <stddef.h> |
| |
| #include <vector> |
| |
| #include "base/memory/ref_counted.h" |
| #include "build/build_config.h" |
| #include "ipc/ipc_message_support_export.h" |
| |
| namespace IPC { |
| |
| class MessageAttachment; |
| |
| // ----------------------------------------------------------------------------- |
| // A MessageAttachmentSet is an ordered set of MessageAttachment objects |
| // associated with an IPC message. All attachments are wrapped in a mojo handle |
| // if necessary and sent over the mojo message pipe. |
| // |
| // For ChannelNacl under SFI NaCl, only Type::PLATFORM_FILE is supported. In |
| // that case, the FD is sent over socket. |
| // ----------------------------------------------------------------------------- |
| class IPC_MESSAGE_SUPPORT_EXPORT MessageAttachmentSet |
| : public base::RefCountedThreadSafe<MessageAttachmentSet> { |
| public: |
| MessageAttachmentSet(); |
| |
| MessageAttachmentSet(const MessageAttachmentSet&) = delete; |
| MessageAttachmentSet& operator=(const MessageAttachmentSet&) = delete; |
| |
| // Return the number of attachments |
| unsigned size() const; |
| |
| // Return true if no unconsumed descriptors remain |
| bool empty() const { return attachments_.empty(); } |
| |
| // Returns whether the attachment was successfully added. |
| // |index| is an output variable. On success, it contains the index of the |
| // newly added attachment. |
| bool AddAttachment(scoped_refptr<MessageAttachment> attachment, |
| size_t* index); |
| |
| // Similar to the above method, but without output variables. |
| bool AddAttachment(scoped_refptr<MessageAttachment> attachment); |
| |
| // Take the nth from the beginning of the vector, Code using this /must/ |
| // access the attachments in order, and must do it at most once. |
| // |
| // This interface is designed for the deserialising code as it doesn't |
| // support close flags. |
| // returns: an attachment, or nullptr on error |
| scoped_refptr<MessageAttachment> GetAttachmentAt(unsigned index); |
| |
| // Marks all the descriptors as consumed and closes those which are |
| // auto-close. |
| void CommitAllDescriptors(); |
| |
| #if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) |
| // This is the maximum number of descriptors per message. We need to know this |
| // because the control message kernel interface has to be given a buffer which |
| // is large enough to store all the descriptor numbers. Otherwise the kernel |
| // tells us that it truncated the control data and the extra descriptors are |
| // lost. |
| // |
| // In debugging mode, it's a fatal error to try and add more than this number |
| // of descriptors to a MessageAttachmentSet. |
| static const size_t kMaxDescriptorsPerMessage = 7; |
| #endif // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) |
| |
| // --------------------------------------------------------------------------- |
| |
| private: |
| friend class base::RefCountedThreadSafe<MessageAttachmentSet>; |
| |
| ~MessageAttachmentSet(); |
| |
| // Return the number of file descriptors |
| unsigned num_descriptors() const; |
| |
| std::vector<scoped_refptr<MessageAttachment>> attachments_; |
| |
| // This contains the index of the next descriptor which should be consumed. |
| // It's used in a couple of ways. Firstly, at destruction we can check that |
| // all the descriptors have been read (with GetNthDescriptor). Secondly, we |
| // can check that they are read in order. |
| unsigned consumed_descriptor_highwater_; |
| }; |
| |
| } // namespace IPC |
| |
| #endif // IPC_IPC_MESSAGE_ATTACHMENT_SET_H_ |