From 005f602d2323741f287d6f6b02c9333f964593bd Mon Sep 17 00:00:00 2001
From: shihchienc <shihchienc@google.com>
Date: Wed, 31 Jan 2024 07:37:55 +0000
Subject: [PATCH] [Thread] Wait until socket created to create interface

Bug: 313425570
Test: build pass & manual test
Change-Id: I4704178519ed032ad352a3ab252e80478c179574
---
 .../aidl/default/socket_interface.cpp         | 66 +++++++++++++++++++
 .../aidl/default/socket_interface.hpp         | 24 +++++++
 2 files changed, 90 insertions(+)

diff --git a/threadnetwork/aidl/default/socket_interface.cpp b/threadnetwork/aidl/default/socket_interface.cpp
index e42f03db7f..a8b434af07 100644
--- a/threadnetwork/aidl/default/socket_interface.cpp
+++ b/threadnetwork/aidl/default/socket_interface.cpp
@@ -24,14 +24,18 @@
 
 #include <errno.h>
 #include <openthread/logging.h>
+#include <sys/inotify.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/un.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include <string>
+
 #include "common/code_utils.hpp"
 #include "openthread/openthread-system.h"
+#include "platform-posix.h"
 
 namespace aidl {
 namespace android {
@@ -54,6 +58,8 @@ otError SocketInterface::Init(ReceiveFrameCallback aCallback, void* aCallbackCon
 
     VerifyOrExit(mSockFd == -1, error = OT_ERROR_ALREADY);
 
+    WaitForSocketFileCreated(mRadioUrl.GetPath());
+
     mSockFd = OpenFile(mRadioUrl);
     VerifyOrExit(mSockFd != -1, error = OT_ERROR_FAILED);
 
@@ -125,6 +131,66 @@ exit:
     return;
 }
 
+void SocketInterface::WaitForSocketFileCreated(const char* aPath) {
+    int inotifyFd;
+    int wd;
+    int lastSlashIdx;
+    std::string folderPath;
+    std::string socketPath(aPath);
+
+    VerifyOrExit(!IsSocketFileExisted(aPath));
+
+    inotifyFd = inotify_init();
+    VerifyOrDie(inotifyFd != -1, OT_EXIT_ERROR_ERRNO);
+
+    lastSlashIdx = socketPath.find_last_of('/');
+    VerifyOrDie(lastSlashIdx != std::string::npos, OT_EXIT_ERROR_ERRNO);
+
+    folderPath = socketPath.substr(0, lastSlashIdx);
+    wd = inotify_add_watch(inotifyFd, folderPath.c_str(), IN_CREATE);
+    VerifyOrDie(wd != -1, OT_EXIT_ERROR_ERRNO);
+
+    otLogInfoPlat("Waiting for socket file %s be created...", aPath);
+
+    while (true) {
+        fd_set fds;
+        FD_ZERO(&fds);
+        FD_SET(inotifyFd, &fds);
+        struct timeval timeout = {kMaxSelectTimeMs / MS_PER_S,
+                                  (kMaxSelectTimeMs % MS_PER_S) * MS_PER_S};
+
+        int rval = select(inotifyFd + 1, &fds, nullptr, nullptr, &timeout);
+        VerifyOrDie(rval >= 0, OT_EXIT_ERROR_ERRNO);
+
+        if (rval == 0 && IsSocketFileExisted(aPath)) {
+            break;
+        }
+
+        if (FD_ISSET(inotifyFd, &fds)) {
+            char buffer[sizeof(struct inotify_event)];
+            ssize_t bytesRead = read(inotifyFd, buffer, sizeof(buffer));
+
+            VerifyOrDie(bytesRead >= 0, OT_EXIT_ERROR_ERRNO);
+
+            struct inotify_event* event = reinterpret_cast<struct inotify_event*>(buffer);
+            if ((event->mask & IN_CREATE) && IsSocketFileExisted(aPath)) {
+                break;
+            }
+        }
+    }
+
+    close(inotifyFd);
+
+exit:
+    otLogInfoPlat("Socket file: %s is created", aPath);
+    return;
+}
+
+bool SocketInterface::IsSocketFileExisted(const char* aPath) {
+    struct stat st;
+    return stat(aPath, &st) == 0 && S_ISSOCK(st.st_mode);
+}
+
 }  // namespace threadnetwork
 }  // namespace hardware
 }  // namespace android
diff --git a/threadnetwork/aidl/default/socket_interface.hpp b/threadnetwork/aidl/default/socket_interface.hpp
index 5c679cd899..23940f5fda 100644
--- a/threadnetwork/aidl/default/socket_interface.hpp
+++ b/threadnetwork/aidl/default/socket_interface.hpp
@@ -140,6 +140,30 @@ class SocketInterface : public ot::Spinel::SpinelInterface {
      */
     void CloseFile(void);
 
+    /**
+     * Check if socket file is created.
+     *
+     * @param[in] aPath  Socket file path name.
+     *
+     * @retval TRUE The required socket file is created.
+     * @retval FALSE The required socket file is not created.
+     *
+     */
+    bool IsSocketFileExisted(const char* aPath);
+
+    /**
+     * Wait until the socket file is created.
+     *
+     * @param[in] aPath  Socket file path name.
+     *
+     */
+    void WaitForSocketFileCreated(const char* aPath);
+
+    enum {
+        kMaxSelectTimeMs = 2000,  ///< Maximum wait time in Milliseconds for file
+                                  ///< descriptor to become available.
+    };
+
     ReceiveFrameCallback mReceiveFrameCallback;
     void* mReceiveFrameContext;
     RxFrameBuffer* mReceiveFrameBuffer;