gltrace: Use Unix Domain Socket rather than INET Socket

Export trace information via abstract Unix Domain Socket (UDS).
This allows tracing of applications without INTERNET permission,
and should be faster as well.

Change-Id: Iabb67fcc2bc2484afd8128af07dca723b81c52c6

Author: vsiva

opengl/libs/GLES_trace/src/gltrace_eglapi.cpp

@@ -77,12 +77,10 @@ static void *commandReceiveTask(void *arg) {
 }
 
 void GLTrace_start() {
-    char value[PROPERTY_VALUE_MAX];
+    char udsName[PROPERTY_VALUE_MAX];
 
-    property_get("debug.egl.debug_port", value, "5039");
-    const unsigned short port = (unsigned short)atoi(value);
-
-    int clientSocket = gltrace::acceptClientConnection(port);
+    property_get("debug.egl.debug_portname", udsName, "gltrace");
+    int clientSocket = gltrace::acceptClientConnection(udsName);
     if (clientSocket < 0) {
         ALOGE("Error creating GLTrace server socket. Quitting application.");
         exit(-1);

opengl/libs/GLES_trace/src/gltrace_transport.cpp

@@ -17,9 +17,10 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#include <unistd.h>
 #include <sys/socket.h>
+#include <sys/un.h>
 #include <netinet/in.h>
-#include <arpa/inet.h>
 
 #include <cutils/log.h>
 
@@ -28,22 +29,24 @@
 namespace android {
 namespace gltrace {
 
-int acceptClientConnection(int serverPort) {
-    int serverSocket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+int acceptClientConnection(char *sockname) {
+    int serverSocket = socket(AF_LOCAL, SOCK_STREAM, 0);
     if (serverSocket < 0) {
         ALOGE("Error (%d) while creating socket. Check if app has network permissions.",
                                                                             serverSocket);
         return -1;
     }
 
-    struct sockaddr_in server, client;
+    struct sockaddr_un server, client;
 
-    server.sin_family = AF_INET;
-    server.sin_addr.s_addr = htonl(INADDR_ANY);
-    server.sin_port = htons(serverPort);
+    memset(&server, 0, sizeof server);
+    server.sun_family = AF_UNIX;
+    // the first byte of sun_path should be '\0' for abstract namespace
+    strcpy(server.sun_path + 1, sockname);
 
-    socklen_t sockaddr_len = sizeof(sockaddr_in);
-    if (bind(serverSocket, (struct sockaddr *) &server, sizeof(server)) < 0) {
+    // note that sockaddr_len should be set to the exact size of the buffer that is used.
+    socklen_t sockaddr_len = sizeof(server.sun_family) + strlen(sockname) + 1;
+    if (bind(serverSocket, (struct sockaddr *) &server, sockaddr_len) < 0) {
         close(serverSocket);
         ALOGE("Failed to bind the server socket");
         return -1;
@@ -55,7 +58,7 @@ int acceptClientConnection(int serverPort) {
         return -1;
     }
 
-    ALOGD("gltrace::waitForClientConnection: server listening @ port %d", serverPort);
+    ALOGD("gltrace::waitForClientConnection: server listening @ path %s", sockname);
 
     int clientSocket = accept(serverSocket, (struct sockaddr *)&client, &sockaddr_len);
     if (clientSocket < 0) {
@@ -64,7 +67,7 @@ int acceptClientConnection(int serverPort) {
         return -1;
     }
 
-    ALOGD("gltrace::waitForClientConnection: client connected: %s", inet_ntoa(client.sin_addr));
+    ALOGD("gltrace::waitForClientConnection: client connected.");
 
     // do not accept any more incoming connections
     close(serverSocket);

opengl/libs/GLES_trace/src/gltrace_transport.h

@@ -76,10 +76,11 @@ class BufferedOutputStream {
 };
 
 /**
- * Utility method: start a server at @serverPort, and wait for a client
- * connection. Returns the connected client socket on success, or -1 on failure.
+ * Utility method: start a server listening at @sockName (unix domain socket,
+ * abstract namespace path), and wait for a client connection.
+ * Returns the connected client socket on success, or -1 on failure.
  */
-int acceptClientConnection(int serverPort);
+int acceptClientConnection(char *sockName);
 
 };
 };