adb: run reverse_service() in main thread.

reverse_service() calls handle_forward_request(), which calls
functions in fdevent.cpp. fdevent functions is only supposed
to be called in the main thread.
Add check in fdevent.cpp to make sure all operations come from
main thread.

Bug: 25355808
Change-Id: Iceb9273f3056acc0713eaafe086ac950ca80ff4f

1 files changed, 12 insertions, 17 deletions

diff --git a/services.cpp b/services.cpp
index e24b470..19a6726 100644
--- a/services.cpp
+++ b/services.cpp
@@ -184,15 +184,18 @@ void reboot_service(int fd, void* arg)
     adb_close(fd);
 }
 
-void reverse_service(int fd, void* arg)
-{
-    const char* command = reinterpret_cast<const char*>(arg);
-
-    if (handle_forward_request(command, kTransportAny, NULL, fd) < 0) {
-        SendFail(fd, "not a reverse forwarding command");
+int reverse_service(const char* command) {
+    int s[2];
+    if (adb_socketpair(s)) {
+        PLOG(ERROR) << "cannot create service socket pair.";
+        return -1;
     }
-    free(arg);
-    adb_close(fd);
+    VLOG(SERVICES) << "service socketpair: " << s[0] << ", " << s[1];
+    if (handle_forward_request(command, kTransportAny, nullptr, s[1]) < 0) {
+        SendFail(s[1], "not a reverse forwarding command");
+    }
+    adb_close(s[1]);
+    return s[0];
 }
 
 // Shell service string can look like:
@@ -335,15 +338,7 @@ int service_to_fd(const char* name, const atransport* transport) {
     } else if(!strncmp(name, "usb:", 4)) {
         ret = create_service_thread(restart_usb_service, NULL);
     } else if (!strncmp(name, "reverse:", 8)) {
-        char* cookie = strdup(name + 8);
-        if (cookie == NULL) {
-            ret = -1;
-        } else {
-            ret = create_service_thread(reverse_service, cookie);
-            if (ret < 0) {
-                free(cookie);
-            }
-        }
+        ret = reverse_service(name + 8);
     } else if(!strncmp(name, "disable-verity:", 15)) {
         ret = create_service_thread(set_verity_enabled_state_service, (void*)0);
     } else if(!strncmp(name, "enable-verity:", 15)) {