1 // Copyright 2014 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 MOJO_EDK_EMBEDDER_PLATFORM_CHANNEL_UTILS_POSIX_H_ 6 #define MOJO_EDK_EMBEDDER_PLATFORM_CHANNEL_UTILS_POSIX_H_ 7 8 #include <stddef.h> 9 #include <sys/types.h> // For |ssize_t|. 10 11 #include <deque> 12 #include <memory> 13 14 #include "mojo/edk/embedder/platform_handle.h" 15 #include "mojo/edk/system/system_impl_export.h" 16 17 struct iovec; // Declared in <sys/uio.h>. 18 19 namespace mojo { 20 namespace edk { 21 22 // The maximum number of handles that can be sent "at once" using 23 // |PlatformChannelSendmsgWithHandles()|. This must be less than the Linux 24 // kernel's SCM_MAX_FD which is 253. 25 const size_t kPlatformChannelMaxNumHandles = 128; 26 27 // Use these to write to a socket created using |PlatformChannelPair| (or 28 // equivalent). These are like |write()| and |writev()|, but handle |EINTR| and 29 // never raise |SIGPIPE|. (Note: On Mac, the suppression of |SIGPIPE| is set up 30 // by |PlatformChannelPair|.) 31 MOJO_SYSTEM_IMPL_EXPORT ssize_t 32 PlatformChannelWrite(PlatformHandle h, const void* bytes, size_t num_bytes); 33 MOJO_SYSTEM_IMPL_EXPORT ssize_t 34 PlatformChannelWritev(PlatformHandle h, struct iovec* iov, size_t num_iov); 35 36 // Writes data, and the given set of |PlatformHandle|s (i.e., file descriptors) 37 // over the Unix domain socket given by |h| (e.g., created using 38 // |PlatformChannelPair()|). All the handles must be valid, and there must be at 39 // least one and at most |kPlatformChannelMaxNumHandles| handles. The return 40 // value is as for |sendmsg()|, namely -1 on failure and otherwise the number of 41 // bytes of data sent on success (note that this may not be all the data 42 // specified by |iov|). (The handles are not closed, regardless of success or 43 // failure.) 44 MOJO_SYSTEM_IMPL_EXPORT ssize_t 45 PlatformChannelSendmsgWithHandles(PlatformHandle h, 46 struct iovec* iov, 47 size_t num_iov, 48 PlatformHandle* platform_handles, 49 size_t num_platform_handles); 50 51 // TODO(vtl): Remove this once I've switched things over to 52 // |PlatformChannelSendmsgWithHandles()|. 53 // Sends |PlatformHandle|s (i.e., file descriptors) over the Unix domain socket 54 // (e.g., created using PlatformChannelPair|). (These will be sent in a single 55 // message having one null byte of data and one control message header with all 56 // the file descriptors.) All of the handles must be valid, and there must be at 57 // most |kPlatformChannelMaxNumHandles| (and at least one handle). Returns true 58 // on success, in which case it closes all the handles. 59 MOJO_SYSTEM_IMPL_EXPORT bool PlatformChannelSendHandles(PlatformHandle h, 60 PlatformHandle* handles, 61 size_t num_handles); 62 63 // Wrapper around |recvmsg()|, which will extract any attached file descriptors 64 // (in the control message) to |PlatformHandle|s (and append them to 65 // |platform_handles|). (This also handles |EINTR|.) 66 MOJO_SYSTEM_IMPL_EXPORT ssize_t 67 PlatformChannelRecvmsg(PlatformHandle h, 68 void* buf, 69 size_t num_bytes, 70 std::deque<PlatformHandle>* platform_handles, 71 bool block = false); 72 73 } // namespace edk 74 } // namespace mojo 75 76 #endif // MOJO_EDK_EMBEDDER_PLATFORM_CHANNEL_UTILS_POSIX_H_ 77