Support systemd socket activation

CMakeLists.txt

@@ -36,6 +36,7 @@ find_package(GnuTLS)
 find_package(Threads)
 find_package(X11)
 find_package(OpenSSL)
+find_package(PkgConfig)
 find_library(LIBGCRYPT_LIBRARIES gcrypt)
 
 # Check whether the version of libjpeg we found was libjpeg-turbo and print a
@@ -102,6 +103,17 @@ if(PNG_FOUND)
 endif(PNG_FOUND)
 option(LIBVNCSERVER_ALLOW24BPP "Allow 24 bpp" ON)
 
+pkg_check_modules(SYSTEMD "libsystemd")
+if(SYSTEMD_FOUND)
+  option(LIBVNCSERVER_WITH_SYSTEMD "Build with systemd socket activation support" ON)
+endif(SYSTEMD_FOUND)
+
+if(LIBVNCSERVER_WITH_SYSTEMD)
+  add_definitions(-DLIBVNCSERVER_WITH_SYSTEMD)
+  include_directories(${SYSTEMD_INCLUDE_DIRS})
+  set(ADDITIONAL_LIBS ${ADDITIONAL_LIBS} ${SYSTEMD_LIBRARIES})
+endif(LIBVNCSERVER_WITH_SYSTEMD)
+
 if(GNUTLS_FOUND)
   set(LIBVNCSERVER_WITH_CLIENT_TLS 1)
   option(LIBVNCSERVER_WITH_WEBSOCKETS "Build with websockets support (gnutls)" ON)

configure.ac

@@ -68,6 +68,9 @@ if test ! -z "$with_ffmpeg"; then
 fi
 AM_CONDITIONAL(HAVE_MP3LAME, test "$HAVE_MP3LAME" = "true")
 
+PKG_CHECK_MODULES([LIBSYSTEMD], [libsystemd], [with_systemd=1], [with_systemd=0])
+AM_CONDITIONAL([WITH_SYSTEMD], [test $with_systemd -eq 1])
+
 # Seem to need this dummy here to induce the 'checking for egrep... grep -E', etc.
 # before it seemed to be inside the with_jpeg conditional. 
 AC_CHECK_HEADER(thenonexistentheader.h, HAVE_THENONEXISTENTHEADER_H="true")

libvncserver/Makefile.am

@@ -59,6 +59,12 @@ LIB_SRCS = main.c rfbserver.c rfbregion.c auth.c sockets.c $(WEBSOCKETSSRCS) \
 libvncserver_la_SOURCES=$(LIB_SRCS)
 libvncserver_la_LIBADD=$(WEBSOCKETSSSLLIBS)
 
+if WITH_SYSTEMD
+AM_CPPFLAGS += -DLIBVNCSERVER_WITH_SYSTEMD
+libvncserver_la_CFLAGS = $(LIBSYSTEMD_CFLAGS)
+libvncserver_la_LIBADD += $(LIBSYSTEMD_LIBS)
+endif
+
 lib_LTLIBRARIES=libvncserver.la
 libvncserver_la_LDFLAGS = -version-info 1:0:0
 

libvncserver/sockets.c

@@ -77,6 +77,10 @@
 #include "rfbssl.h"
 #endif
 
+#ifdef LIBVNCSERVER_WITH_SYSTEMD
+#include <systemd/sd-daemon.h>
+#endif
+
 #if defined(__linux__) && defined(NEED_TIMEVAL)
 struct timeval 
 {
@@ -122,6 +126,54 @@ int deny_severity=LOG_WARNING;
 int rfbMaxClientWait = 20000;   /* time (ms) after which we decide client has
                                    gone away - needed to stop us hanging */
 
+static rfbBool
+rfbNewConnectionFromSock(rfbScreenInfoPtr rfbScreen, int sock)
+{
+    const int one = 1;
+#ifdef LIBVNCSERVER_IPv6
+    struct sockaddr_storage addr;
+#else
+    struct sockaddr_in addr;
+#endif
+    socklen_t addrlen = sizeof(addr);
+
+    getpeername(sock, (struct sockaddr *)&addr, &addrlen);
+
+    if(!rfbSetNonBlocking(sock)) {
+      rfbLogPerror("rfbCheckFds: setnonblock");
+      closesocket(sock);
+      return FALSE;
+    }
+
+    if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
+		   (char *)&one, sizeof(one)) < 0) {
+      rfbLogPerror("rfbCheckFds: setsockopt failed: can't set TCP_NODELAY flag, non TCP socket?");
+    }
+
+#ifdef USE_LIBWRAP
+    if(!hosts_ctl("vnc",STRING_UNKNOWN,inet_ntoa(addr.sin_addr),
+		  STRING_UNKNOWN)) {
+      rfbLog("Rejected connection from client %s\n",
+	     inet_ntoa(addr.sin_addr));
+      closesocket(sock);
+      return FALSE;
+    }
+#endif
+
+#ifdef LIBVNCSERVER_IPv6
+    char host[1024];
+    if(getnameinfo((struct sockaddr*)&addr, addrlen, host, sizeof(host), NULL, 0, NI_NUMERICHOST) != 0) {
+      rfbLogPerror("rfbProcessNewConnection: error in getnameinfo");
+    }
+    rfbLog("Got connection from client %s\n", host);
+#else
+    rfbLog("Got connection from client %s\n", inet_ntoa(addr.sin_addr));
+#endif
+
+    rfbNewClient(rfbScreen,sock);
+    return TRUE;
+}
+
 /*
  * rfbInitSockets sets up the TCP and UDP sockets to listen for RFB
  * connections.  It does nothing if called again.
@@ -138,6 +190,20 @@ rfbInitSockets(rfbScreenInfoPtr rfbScreen)
 
     rfbScreen->socketState = RFB_SOCKET_READY;
 
+#ifdef LIBVNCSERVER_WITH_SYSTEMD
+    if (sd_listen_fds(0) == 1)
+    {
+        int sock = SD_LISTEN_FDS_START + 0;
+        if (sd_is_socket(sock, AF_UNSPEC, 0, 0))
+            rfbNewConnectionFromSock(rfbScreen, sock);
+        else if (sd_is_socket(sock, AF_UNSPEC, 0, 1))
+            rfbProcessNewConnection(rfbScreen);
+        return;
+    }
+    else
+        rfbLog("Unable to establish connection with systemd socket\n");
+#endif
+
     if (rfbScreen->inetdSock != -1) {
 	const int one = 1;
 
@@ -411,14 +477,7 @@ rfbCheckFds(rfbScreenInfoPtr rfbScreen,long usec)
 rfbBool
 rfbProcessNewConnection(rfbScreenInfoPtr rfbScreen)
 {
-    const int one = 1;
     int sock = -1;
-#ifdef LIBVNCSERVER_IPv6
-    struct sockaddr_storage addr;
-#else
-    struct sockaddr_in addr;
-#endif
-    socklen_t addrlen = sizeof(addr);
     fd_set listen_fds; 
     int chosen_listen_sock = -1;
 
@@ -439,47 +498,12 @@ rfbProcessNewConnection(rfbScreenInfoPtr rfbScreen)
     if (rfbScreen->listen6Sock >= 0 && FD_ISSET(rfbScreen->listen6Sock, &listen_fds))
       chosen_listen_sock = rfbScreen->listen6Sock;
 
-    if ((sock = accept(chosen_listen_sock,
-		       (struct sockaddr *)&addr, &addrlen)) < 0) {
+    if ((sock = accept(chosen_listen_sock, NULL, NULL)) < 0) {
       rfbLogPerror("rfbCheckFds: accept");
       return FALSE;
     }
 
-    if(!rfbSetNonBlocking(sock)) {
-      closesocket(sock);
-      return FALSE;
-    }
-
-    if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
-		   (char *)&one, sizeof(one)) < 0) {
-      rfbLogPerror("rfbCheckFds: setsockopt failed: can't set TCP_NODELAY flag, non TCP socket?");
-    }
-
-#ifdef USE_LIBWRAP
-    if(!hosts_ctl("vnc",STRING_UNKNOWN,inet_ntoa(addr.sin_addr),
-		  STRING_UNKNOWN)) {
-      rfbLog("Rejected connection from client %s\n",
-	     inet_ntoa(addr.sin_addr));
-      closesocket(sock);
-      return FALSE;
-    }
-#endif
-
-#ifdef LIBVNCSERVER_IPv6
-    {
-        char host[1024];
-        if(getnameinfo((struct sockaddr*)&addr, addrlen, host, sizeof(host), NULL, 0, NI_NUMERICHOST) != 0) {
-            rfbLogPerror("rfbProcessNewConnection: error in getnameinfo");
-        }
-        rfbLog("Got connection from client %s\n", host);
-    }
-#else
-    rfbLog("Got connection from client %s\n", inet_ntoa(addr.sin_addr));
-#endif
-
-    rfbNewClient(rfbScreen,sock);
-
-    return TRUE;
+    return rfbNewConnectionFromSock(rfbScreen, sock);
 }