ext/common/MessageChannel.h in passenger-jmazzi-2.2.9 vs ext/common/MessageChannel.h in passenger-jmazzi-2.2.10

@@ -317,16 +317,28 @@
 	/**
 	 * Pass a file descriptor. This only works if the underlying file
 	 * descriptor is a Unix socket.
 	 *
 	 * @param fileDescriptor The file descriptor to pass.
+	 * @param negotiate See Ruby's MessageChannel#send_io method's comments.
 	 * @throws SystemException Something went wrong during file descriptor passing.
 	 * @throws boost::thread_interrupted
 	 * @pre <tt>fileDescriptor >= 0</tt>
 	 * @see readFileDescriptor()
 	 */
-	void writeFileDescriptor(int fileDescriptor) {
+	void writeFileDescriptor(int fileDescriptor, bool negotiate = true) {
+		// See message_channel.rb for more info about negotiation.
+		if (negotiate) {
+			vector<string> args;
+			
+			if (!read(args)) {
+				throw IOException("Unexpected end of stream encountered while pre-negotiating a file descriptor");
+			} else if (args.size() != 1 || args[0] != "pass IO") {
+				throw IOException("FD passing pre-negotiation message expected.");
+			}
+		}
+		
 		struct msghdr msg;
 		struct iovec vec;
 		char dummy[1];
 		#if defined(__APPLE__) || defined(__SOLARIS__) || defined(__arm__)
 			struct {
@@ -366,10 +378,20 @@
 		
 		ret = syscalls::sendmsg(fd, &msg, 0);
 		if (ret == -1) {
 			throw SystemException("Cannot send file descriptor with sendmsg()", errno);
 		}
+		
+		if (negotiate) {
+			vector<string> args;
+			
+			if (!read(args)) {
+				throw IOException("Unexpected end of stream encountered while post-negotiating a file descriptor");
+			} else if (args.size() != 1 || args[0] != "got IO") {
+				throw IOException("FD passing post-negotiation message expected.");
+			}
+		}
 	}
 	
 	/**
 	 * Read an array message from the underlying file descriptor.
 	 *
@@ -490,19 +512,25 @@
 	
 	/**
 	 * Receive a file descriptor, which had been passed over the underlying
 	 * file descriptor.
 	 *
+	 * @param negotiate See Ruby's MessageChannel#send_io method's comments.
 	 * @return The passed file descriptor.
 	 * @throws SystemException If something went wrong during the
 	 *            receiving of a file descriptor. Perhaps the underlying
 	 *            file descriptor isn't a Unix socket.
 	 * @throws IOException Whatever was received doesn't seem to be a
 	 *            file descriptor.
 	 * @throws boost::thread_interrupted
 	 */
-	int readFileDescriptor() {
+	int readFileDescriptor(bool negotiate = true) {
+		// See message_channel.rb for more info about negotiation.
+		if (negotiate) {
+			write("pass IO", NULL);
+		}
+		
 		struct msghdr msg;
 		struct iovec vec;
 		char dummy[1];
 		#if defined(__APPLE__) || defined(__SOLARIS__) || defined(__arm__)
 			// File descriptor passing macros (CMSG_*) seem to be broken
@@ -536,19 +564,35 @@
 		if (ret == -1) {
 			throw SystemException("Cannot read file descriptor with recvmsg()", errno);
 		}
 		
 		control_header = CMSG_FIRSTHDR(&msg);
+		if (control_header == NULL) {
+			throw IOException("No valid file descriptor received.");
+		}
 		if (control_header->cmsg_len   != EXPECTED_CMSG_LEN
 		 || control_header->cmsg_level != SOL_SOCKET
 		 || control_header->cmsg_type  != SCM_RIGHTS) {
 			throw IOException("No valid file descriptor received.");
 		}
+		
 		#if defined(__APPLE__) || defined(__SOLARIS__) || defined(__arm__)
-			return control_data.fd;
+			int fd = control_data.fd;
 		#else
-			return *((int *) CMSG_DATA(control_header));
+			int fd = *((int *) CMSG_DATA(control_header));
 		#endif
+		
+		if (negotiate) {
+			try {
+				write("got IO", NULL);
+			} catch (...) {
+				this_thread::disable_syscall_interruption dsi;
+				syscalls::close(fd);
+				throw;
+			}
+		}
+		
+		return fd;
 	}
 	
 	/**
 	 * Set the timeout value for reading data from this channel.
 	 * If no data can be read within the timeout period, then a