Revert "Revert "Qemu: make the qemu_pipe_open back compatible""
This reverts commit 79b30058992ddf678a261a59172a009d6a0db0ed.
diff --git a/qemu_pipe/qemu_pipe.cpp b/qemu_pipe/qemu_pipe.cpp
index ca3b795..beeccb0 100644
--- a/qemu_pipe/qemu_pipe.cpp
+++ b/qemu_pipe/qemu_pipe.cpp
@@ -34,29 +34,9 @@
# 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) {
+ if (!pipeName) {
errno = EINVAL;
return -1;
}
@@ -70,18 +50,24 @@
// Write the pipe name, *including* the trailing zero which is necessary.
size_t pipeNameLen = strlen(pipeName);
- if (!WriteFully(fd, pipeName, pipeNameLen + 1U)) {
- QEMU_PIPE_DEBUG("%s: Could not connect to %s pipe service: %s",
- __FUNCTION__, pipeName, strerror(errno));
- close(fd);
- return -1;
+ if (WriteFully(fd, pipeName, pipeNameLen + 1U)) {
+ return fd;
}
- return fd;
+
+ // now, add 'pipe:' prefix and try again
+ // Note: host side will wait for the trailing '\0' to start
+ // service lookup.
+ const char pipe_prefix[] = "pipe:";
+ if (WriteFully(fd, pipe_prefix, strlen(pipe_prefix)) &&
+ WriteFully(fd, pipeName, pipeNameLen + 1U)) {
+ return fd;
+ }
+ QEMU_PIPE_DEBUG("%s: Could not write to %s pipe service: %s",
+ __FUNCTION__, pipeName, strerror(errno));
+ close(fd);
+ return -1;
}
-// 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);
@@ -96,11 +82,6 @@
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];
if (!ReadFully(fd, header, 4)) {