Revert "Revert "Qemu-pipe: refactor qemu_pipe.h into libqemu_pipe""
This reverts commit 63ef9ff5fa4b1e68029a54bb60c97b99bdf5defc.
diff --git a/qemu_pipe/qemu_pipe.cpp b/qemu_pipe/qemu_pipe.cpp
new file mode 100644
index 0000000..a4529de
--- /dev/null
+++ b/qemu_pipe/qemu_pipe.cpp
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "qemu_pipe.h"
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+
+
+// Define QEMU_PIPE_DEBUG if you want to print error messages when an error
+// occurs during pipe operations. The macro should simply take a printf-style
+// formatting string followed by optional arguments.
+#ifndef QEMU_PIPE_DEBUG
+# define QEMU_PIPE_DEBUG(...) (void)0
+#endif
+
+// Try to open a new Qemu fast-pipe. This function returns a file descriptor
+// that can be used to communicate with a named service managed by the
+// emulator.
+//
+// This file descriptor can be used as a standard pipe/socket descriptor.
+//
+// 'pipeName' is the name of the emulator service you want to connect to,
+// and must begin with 'pipe:' (e.g. 'pipe:camera' or 'pipe:opengles').
+//
+// On success, return a valid file descriptor, or -1/errno on failure. E.g.:
+//
+// EINVAL -> unknown/unsupported pipeName
+// ENOSYS -> fast pipes not available in this system.
+//
+// ENOSYS should never happen, except if you're trying to run within a
+// misconfigured emulator.
+//
+// You should be able to open several pipes to the same pipe service,
+// except for a few special cases (e.g. GSM modem), where EBUSY will be
+// returned if more than one client tries to connect to it.
+int qemu_pipe_open(const char* pipeName) {
+ // Sanity check.
+ if (!pipeName || memcmp(pipeName, "pipe:", 5) != 0) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ int fd = TEMP_FAILURE_RETRY(open("/dev/qemu_pipe", O_RDWR));
+ if (fd < 0) {
+ QEMU_PIPE_DEBUG("%s: Could not open /dev/qemu_pipe: %s", __FUNCTION__,
+ strerror(errno));
+ return -1;
+ }
+
+ // Write the pipe name, *including* the trailing zero which is necessary.
+ size_t pipeNameLen = strlen(pipeName);
+ ssize_t ret = TEMP_FAILURE_RETRY(write(fd, pipeName, pipeNameLen + 1U));
+ if (ret != (ssize_t)pipeNameLen + 1) {
+ QEMU_PIPE_DEBUG("%s: Could not connect to %s pipe service: %s",
+ __FUNCTION__, pipeName, strerror(errno));
+ if (ret == 0) {
+ errno = ECONNRESET;
+ } else if (ret > 0) {
+ errno = EINVAL;
+ }
+ return -1;
+ }
+ return fd;
+}
+
+// Send a framed message |buff| of |len| bytes through the |fd| descriptor.
+// This really adds a 4-hexchar prefix describing the payload size.
+// Returns 0 on success, and -1 on error.
+int qemu_pipe_frame_send(int fd, const void* buff, size_t len) {
+ char header[5];
+ snprintf(header, sizeof(header), "%04zx", len);
+ ssize_t ret = TEMP_FAILURE_RETRY(write(fd, header, 4));
+ if (ret != 4) {
+ QEMU_PIPE_DEBUG("Can't write qemud frame header: %s", strerror(errno));
+ return -1;
+ }
+ ret = TEMP_FAILURE_RETRY(write(fd, buff, len));
+ if (ret != (ssize_t)len) {
+ QEMU_PIPE_DEBUG("Can't write qemud frame payload: %s", strerror(errno));
+ return -1;
+ }
+ return 0;
+}
+
+// Read a frame message from |fd|, and store it into |buff| of |len| bytes.
+// If the framed message is larger than |len|, then this returns -1 and the
+// content is lost. Otherwise, this returns the size of the message. NOTE:
+// empty messages are possible in a framed wire protocol and do not mean
+// end-of-stream.
+int qemu_pipe_frame_recv(int fd, void* buff, size_t len) {
+ char header[5];
+ ssize_t ret = TEMP_FAILURE_RETRY(read(fd, header, 4));
+ if (ret != 4) {
+ QEMU_PIPE_DEBUG("Can't read qemud frame header: %s", strerror(errno));
+ return -1;
+ }
+ header[4] = '\0';
+ size_t size;
+ if (sscanf(header, "%04zx", &size) != 1) {
+ QEMU_PIPE_DEBUG("Malformed qemud frame header: [%.*s]", 4, header);
+ return -1;
+ }
+ if (size > len) {
+ QEMU_PIPE_DEBUG("Oversized qemud frame (% bytes, expected <= %)", size,
+ len);
+ return -1;
+ }
+ ret = TEMP_FAILURE_RETRY(read(fd, buff, size));
+ if (ret != (ssize_t)size) {
+ QEMU_PIPE_DEBUG("Could not read qemud frame payload: %s",
+ strerror(errno));
+ return -1;
+ }
+ return size;
+}