Introduce owned_fd

native/src/base/misc.hpp

@@ -11,11 +11,10 @@
 #include "xwrap.hpp"
 
 #define DISALLOW_COPY_AND_MOVE(clazz) \
-clazz(const clazz &) = delete;        \
+clazz(const clazz&) = delete;        \
 clazz(clazz &&) = delete;
 
 #define ALLOW_MOVE_ONLY(clazz) \
-clazz() = default;             \
 clazz(const clazz&) = delete;  \
 clazz(clazz &&o) { swap(o); }  \
 clazz& operator=(clazz &&o) { swap(o); return *this; }
@@ -211,6 +210,7 @@ class byte_channel;
 struct heap_data : public byte_data {
     ALLOW_MOVE_ONLY(heap_data)
 
+    heap_data() = default;
     explicit heap_data(size_t sz) : byte_data(calloc(sz, 1), sz) {}
     ~heap_data() { free(_buf); }
 
@@ -218,6 +218,21 @@ struct heap_data : public byte_data {
     friend byte_channel;
 };
 
+struct owned_fd {
+    ALLOW_MOVE_ONLY(owned_fd)
+
+    owned_fd() : fd(-1) {}
+    owned_fd(int fd) : fd(fd) {}
+    ~owned_fd() { close(fd); fd = -1; }
+
+    operator int() { return fd; }
+    int release() { int f = fd; fd = -1; return f; }
+    void swap(owned_fd &owned) { std::swap(fd, owned.fd); }
+
+private:
+    int fd;
+};
+
 rust::Vec<size_t> mut_u8_patch(
         rust::Slice<uint8_t> buf,
         rust::Slice<const uint8_t> from,

native/src/core/daemon.cpp

@@ -211,7 +211,7 @@ static bool is_client(pid_t pid) {
 }
 
 static void handle_request(pollfd *pfd) {
-    int client = xaccept4(pfd->fd, nullptr, nullptr, SOCK_CLOEXEC);
+    owned_fd client = xaccept4(pfd->fd, nullptr, nullptr, SOCK_CLOEXEC);
 
     // Verify client credentials
     sock_cred cred;
@@ -221,7 +221,7 @@ static void handle_request(pollfd *pfd) {
 
     if (!get_client_cred(client, &cred)) {
         // Client died
-        goto done;
+        return;
     }
     is_root = cred.uid == AID_ROOT;
     is_zygote = cred.context == "u:r:zygote:s0";
@@ -229,7 +229,7 @@ static void handle_request(pollfd *pfd) {
     if (!is_root && !is_zygote && !is_client(cred.pid)) {
         // Unsupported client state
         write_int(client, MainResponse::ACCESS_DENIED);
-        goto done;
+        return;
     }
 
     code = read_int(client);
@@ -237,7 +237,7 @@ static void handle_request(pollfd *pfd) {
         code == MainRequest::_SYNC_BARRIER_ ||
         code == MainRequest::_STAGE_BARRIER_) {
         // Unknown request code
-        goto done;
+        return;
     }
 
     // Check client permissions
@@ -251,20 +251,20 @@ static void handle_request(pollfd *pfd) {
     case MainRequest::STOP_DAEMON:
         if (!is_root) {
             write_int(client, MainResponse::ROOT_REQUIRED);
-            goto done;
+            return;
         }
         break;
     case MainRequest::REMOVE_MODULES:
         if (!is_root && cred.uid != AID_SHELL) {
             write_int(client, MainResponse::ACCESS_DENIED);
-            goto done;
+            return;
         }
         break;
     case MainRequest::ZYGISK:
         if (!is_zygote) {
             // Invalid client context
             write_int(client, MainResponse::ACCESS_DENIED);
-            goto done;
+            return;
         }
         break;
     default:
@@ -275,16 +275,11 @@ static void handle_request(pollfd *pfd) {
 
     if (code < MainRequest::_SYNC_BARRIER_) {
         handle_request_sync(client, code);
-        goto done;
     } else if (code < MainRequest::_STAGE_BARRIER_) {
-        exec_task([=] { handle_request_async(client, code, cred); });
+        exec_task([=, fd = client.release()] { handle_request_async(fd, code, cred); });
     } else {
-        exec_task([=] { boot_stage_handler(client, code); });
+        exec_task([=, fd = client.release()] { boot_stage_handler(fd, code); });
     }
-    return;
-
-done:
-    close(client);
 }
 
 static void switch_cgroup(const char *cgroup, int pid) {