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 class ScopedPlatformHandle; 22 23 // The maximum number of handles that can be sent "at once" using 24 // |PlatformChannelSendmsgWithHandles()|. This must be less than the Linux 25 // kernel's SCM_MAX_FD which is 253. 26 const size_t kPlatformChannelMaxNumHandles = 128; 27 28 // Use these to write to a socket created using |PlatformChannelPair| (or 29 // equivalent). These are like |write()| and |writev()|, but handle |EINTR| and 30 // never raise |SIGPIPE|. (Note: On Mac, the suppression of |SIGPIPE| is set up 31 // by |PlatformChannelPair|.) 32 MOJO_SYSTEM_IMPL_EXPORT ssize_t 33 PlatformChannelWrite(PlatformHandle h, const void* bytes, size_t num_bytes); 34 MOJO_SYSTEM_IMPL_EXPORT ssize_t 35 PlatformChannelWritev(PlatformHandle h, struct iovec* iov, size_t num_iov); 36 37 // Writes data, and the given set of |PlatformHandle|s (i.e., file descriptors) 38 // over the Unix domain socket given by |h| (e.g., created using 39 // |PlatformChannelPair()|). All the handles must be valid, and there must be at 40 // least one and at most |kPlatformChannelMaxNumHandles| handles. The return 41 // value is as for |sendmsg()|, namely -1 on failure and otherwise the number of 42 // bytes of data sent on success (note that this may not be all the data 43 // specified by |iov|). (The handles are not closed, regardless of success or 44 // failure.) 45 MOJO_SYSTEM_IMPL_EXPORT ssize_t 46 PlatformChannelSendmsgWithHandles(PlatformHandle h, 47 struct iovec* iov, 48 size_t num_iov, 49 PlatformHandle* platform_handles, 50 size_t num_platform_handles); 51 52 // TODO(vtl): Remove this once I've switched things over to 53 // |PlatformChannelSendmsgWithHandles()|. 54 // Sends |PlatformHandle|s (i.e., file descriptors) over the Unix domain socket 55 // (e.g., created using PlatformChannelPair|). (These will be sent in a single 56 // message having one null byte of data and one control message header with all 57 // the file descriptors.) All of the handles must be valid, and there must be at 58 // most |kPlatformChannelMaxNumHandles| (and at least one handle). Returns true 59 // on success, in which case it closes all the handles. 60 MOJO_SYSTEM_IMPL_EXPORT bool PlatformChannelSendHandles(PlatformHandle h, 61 PlatformHandle* handles, 62 size_t num_handles); 63 64 // Wrapper around |recvmsg()|, which will extract any attached file descriptors 65 // (in the control message) to |PlatformHandle|s (and append them to 66 // |platform_handles|). (This also handles |EINTR|.) 67 MOJO_SYSTEM_IMPL_EXPORT ssize_t 68 PlatformChannelRecvmsg(PlatformHandle h, 69 void* buf, 70 size_t num_bytes, 71 std::deque<PlatformHandle>* platform_handles, 72 bool block = false); 73 74 // Returns false if |server_handle| encounters an unrecoverable error. 75 // Returns true if it's valid to keep listening on |server_handle|. In this 76 // case, it's possible that a connection wasn't successfully established; then, 77 // |connection_handle| will be invalid. If |check_peer_user| is True, the 78 // connection will be rejected if the peer is running as a different user. 79 MOJO_SYSTEM_IMPL_EXPORT bool ServerAcceptConnection( 80 PlatformHandle server_handle, 81 ScopedPlatformHandle* connection_handle, 82 bool check_peer_user = true); 83 84 } // namespace edk 85 } // namespace mojo 86 87 #endif // MOJO_EDK_EMBEDDER_PLATFORM_CHANNEL_UTILS_POSIX_H_ 88