fix(Server): Handle "socket already exists" more gracefully

whisperity · May 7, 2022 · 8ff2c80 · 8ff2c80
1 parent 5705478
commit 8ff2c80
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Showing 2 changed files with 78 additions and 63 deletions.
diff --git a/src/client/Main.cpp b/src/client/Main.cpp
@@ -226,33 +226,33 @@ int main(Options& Opts)
   {
     ScopeGuard TerminalSetup{[&Term, &Client] { Term.setupClient(Client); },
                              [&Term] { Term.releaseClient(); }};
-    ScopeGuard Signal{
-      [&Term] {
-        SignalHandling& Sig = SignalHandling::get();
-        Sig.registerObject(SignalHandling::ModuleObjName, "Client");
-        Sig.registerObject(TerminalObjName, &Term);
-        Sig.registerCallback(SIGWINCH, &windowSizeChange);
-        Sig.enable();
-
-        // Override the SIGABRT handler with a custom one that
-        // resets the terminal during a crash.
-        Sig.registerCallback(SIGILL, &coreDumped);
-        Sig.registerCallback(SIGABRT, &coreDumped);
-        Sig.registerCallback(SIGSEGV, &coreDumped);
-        Sig.registerCallback(SIGSYS, &coreDumped);
-        Sig.registerCallback(SIGSTKFLT, &coreDumped);
-      },
-      [] {
-        SignalHandling& Sig = SignalHandling::get();
-        Sig.defaultCallback(SIGWINCH);
-        Sig.deleteObject(TerminalObjName);
-
-        Sig.clearOneCallback(SIGILL);
-        Sig.clearOneCallback(SIGABRT);
-        Sig.clearOneCallback(SIGSEGV);
-        Sig.clearOneCallback(SIGSYS);
-        Sig.clearOneCallback(SIGSTKFLT);
-      }};
+    ScopeGuard Signal{[&Term] {
+                        SignalHandling& Sig = SignalHandling::get();
+                        Sig.registerObject(SignalHandling::ModuleObjName,
+                                           "Client");
+                        Sig.registerObject(TerminalObjName, &Term);
+                        Sig.registerCallback(SIGWINCH, &windowSizeChange);
+                        Sig.enable();
+
+                        // Override the SIGABRT handler with a custom one that
+                        // resets the terminal during a crash.
+                        Sig.registerCallback(SIGILL, &coreDumped);
+                        Sig.registerCallback(SIGABRT, &coreDumped);
+                        Sig.registerCallback(SIGSEGV, &coreDumped);
+                        Sig.registerCallback(SIGSYS, &coreDumped);
+                        Sig.registerCallback(SIGSTKFLT, &coreDumped);
+                      },
+                      [] {
+                        SignalHandling& Sig = SignalHandling::get();
+                        Sig.defaultCallback(SIGWINCH);
+                        Sig.deleteObject(TerminalObjName);
+
+                        Sig.clearOneCallback(SIGILL);
+                        Sig.clearOneCallback(SIGABRT);
+                        Sig.clearOneCallback(SIGSEGV);
+                        Sig.clearOneCallback(SIGSYS);
+                        Sig.clearOneCallback(SIGSTKFLT);
+                      }};
 
     LOG(trace) << "Starting client...";
 

diff --git a/src/server/Main.cpp b/src/server/Main.cpp
@@ -77,11 +77,9 @@ constexpr char ServerObjName[] = "Server";
 void serverShutdown(SignalHandling::Signal SigNum,
                     ::siginfo_t* Info,
                     const SignalHandling* Handling);
-
 void childExited(SignalHandling::Signal SigNum,
                  ::siginfo_t* Info,
                  const SignalHandling* Handling);
-
 void coreDumped(SignalHandling::Signal SigNum,
                 ::siginfo_t* Info,
                 const SignalHandling* Handling);
@@ -90,41 +88,58 @@ void coreDumped(SignalHandling::Signal SigNum,
 
 int main(Options& Opts)
 {
-  Socket ServerSock = Socket::create(*Opts.SocketPath);
-  Server S = Server(std::move(ServerSock));
+  std::optional<Socket> ServerSock;
+  try
+  {
+    ServerSock.emplace(Socket::create(*Opts.SocketPath));
+  }
+  catch (const std::system_error& SE)
+  {
+    LOG(fatal) << "Creating the socket '" << *Opts.SocketPath << "' failed:\n\t"
+               << SE.what();
+    if (SE.code() == std::errc::address_in_use)
+      LOG(info) << "If you are sure another server is not running, delete the "
+                   "file and restart the server.";
+    return EXIT_SystemError;
+  }
+
+  Server S = Server(std::move(*ServerSock));
   S.setExitIfNoMoreSessions(Opts.ExitOnLastSessionTerminate);
-  ScopeGuard Signal{
-    [&S] {
-      SignalHandling& Sig = SignalHandling::get();
-      Sig.registerObject(SignalHandling::ModuleObjName, "Server");
-      Sig.registerObject(ServerObjName, &S);
-      Sig.registerCallback(SIGINT, &serverShutdown);
-      Sig.registerCallback(SIGTERM, &serverShutdown);
-      Sig.registerCallback(SIGCHLD, &childExited);
-      Sig.ignore(SIGPIPE);
-      Sig.enable();
-
-      // Override the SIGABRT handler with a custom one that kills the server.
-      Sig.registerCallback(SIGILL, &coreDumped);
-      Sig.registerCallback(SIGABRT, &coreDumped);
-      Sig.registerCallback(SIGSEGV, &coreDumped);
-      Sig.registerCallback(SIGSYS, &coreDumped);
-      Sig.registerCallback(SIGSTKFLT, &coreDumped);
-    },
-    [] {
-      SignalHandling& Sig = SignalHandling::get();
-      Sig.unignore(SIGPIPE);
-      Sig.defaultCallback(SIGCHLD);
-      Sig.defaultCallback(SIGTERM);
-      Sig.defaultCallback(SIGINT);
-      Sig.deleteObject(ServerObjName);
-
-      Sig.clearOneCallback(SIGILL);
-      Sig.clearOneCallback(SIGABRT);
-      Sig.clearOneCallback(SIGSEGV);
-      Sig.clearOneCallback(SIGSYS);
-      Sig.clearOneCallback(SIGSTKFLT);
-    }};
+  ScopeGuard Signal{[&S] {
+                      SignalHandling& Sig = SignalHandling::get();
+                      Sig.registerObject(SignalHandling::ModuleObjName,
+                                         "Server");
+                      Sig.registerObject(ServerObjName, &S);
+                      Sig.registerCallback(SIGHUP, &serverShutdown);
+                      Sig.registerCallback(SIGINT, &serverShutdown);
+                      Sig.registerCallback(SIGTERM, &serverShutdown);
+                      Sig.registerCallback(SIGCHLD, &childExited);
+                      Sig.ignore(SIGPIPE);
+                      Sig.enable();
+
+                      // Override the SIGABRT handler with a custom one that
+                      // kills the server.
+                      Sig.registerCallback(SIGILL, &coreDumped);
+                      Sig.registerCallback(SIGABRT, &coreDumped);
+                      Sig.registerCallback(SIGSEGV, &coreDumped);
+                      Sig.registerCallback(SIGSYS, &coreDumped);
+                      Sig.registerCallback(SIGSTKFLT, &coreDumped);
+                    },
+                    [] {
+                      SignalHandling& Sig = SignalHandling::get();
+                      Sig.unignore(SIGPIPE);
+                      Sig.defaultCallback(SIGCHLD);
+                      Sig.defaultCallback(SIGTERM);
+                      Sig.defaultCallback(SIGINT);
+                      Sig.defaultCallback(SIGHUP);
+                      Sig.deleteObject(ServerObjName);
+
+                      Sig.clearOneCallback(SIGILL);
+                      Sig.clearOneCallback(SIGABRT);
+                      Sig.clearOneCallback(SIGSEGV);
+                      Sig.clearOneCallback(SIGSYS);
+                      Sig.clearOneCallback(SIGSTKFLT);
+                    }};
 
   LOG(info) << "Starting Monomux Server";
   if (Opts.Background)