spice: client: add checks to see if it is safe to use XShem.

Beacuse that XShem internal checks wont fail when using the spice client
from remote, we are adding check on the socket family to see if it is
unix domain socket and fail in case it is not.

Signed-off-by: Izik Eidus <ieidus@redhat.com>

3 files changed, 25 insertions, 3 deletions

diff --git a/client/x11/platform.cpp b/client/x11/platform.cpp
index 1ac45ef8..d13c9fe6 100644
--- a/client/x11/platform.cpp
+++ b/client/x11/platform.cpp
@@ -26,7 +26,9 @@
 #include <X11/extensions/render.h>
 #include <X11/extensions/XKB.h>
 #include <X11/extensions/Xrender.h>
+#include <X11/extensions/XShm.h>
 #include <unistd.h>
+#include <sys/socket.h>
 #include <sys/epoll.h>
 #include <sys/resource.h>
 #include <sys/types.h>
@@ -63,6 +65,7 @@
 #endif
 
 static Display* x_display = NULL;
+static bool x_shm_avail = false;
 static XVisualInfo **vinfo = NULL;
 static GLXFBConfig **fb_config = NULL;
 static XIM x_input_method = NULL;
@@ -185,6 +188,11 @@ Display* XPlatform::get_display()
     return x_display;
 }
 
+bool XPlatform::is_x_shm_avail()
+{
+    return x_shm_avail;
+}
+
 XVisualInfo** XPlatform::get_vinfo()
 {
     return vinfo;
@@ -2095,6 +2103,9 @@ void Platform::init()
 {
     int err, ev;
     int threads_enable;
+    int connection_fd;
+    socklen_t sock_len;
+    struct sockaddr sock_addr;
 
     DBG(0, "");
 
@@ -2107,6 +2118,12 @@ void Platform::init()
         THROW("open X display failed");
     }
 
+    connection_fd = ConnectionNumber(x_display);
+    if (!getsockname(connection_fd, &sock_addr, &sock_len) &&
+        XShmQueryExtension(x_display) && sock_addr.sa_family == AF_UNIX ) {
+        x_shm_avail = true;
+    }
+
     vinfo = new XVisualInfo *[ScreenCount(x_display)];
     memset(vinfo, 0, sizeof(XVisualInfo *) * ScreenCount(x_display));
     fb_config = new GLXFBConfig *[ScreenCount(x_display)];
diff --git a/client/x11/red_pixmap_cairo.cpp b/client/x11/red_pixmap_cairo.cpp
index d15c35c3..795c8a0d 100644
--- a/client/x11/red_pixmap_cairo.cpp
+++ b/client/x11/red_pixmap_cairo.cpp
@@ -36,6 +36,7 @@ RedPixmapCairo::RedPixmapCairo(int width, int height, RedPixmap::Format format,
     XShmSegmentInfo *shminfo = NULL;
     _data = NULL;
     XVisualInfo *vinfo = NULL;
+    bool using_shm = false;
 
 
     try {
@@ -45,7 +46,9 @@ RedPixmapCairo::RedPixmapCairo(int width, int height, RedPixmap::Format format,
             vinfo = XPlatform::get_vinfo()[win->get_screen_num()];
         }
 
-        if (vinfo && XShmQueryExtension(XPlatform::get_display())) {
+        using_shm = vinfo && XPlatform::is_x_shm_avail();
+
+        if (using_shm) {
             int depth;
 
             switch (format) {
@@ -146,14 +149,14 @@ RedPixmapCairo::RedPixmapCairo(int width, int height, RedPixmap::Format format,
         if (cairo_status(cairo) != CAIRO_STATUS_SUCCESS) {
             THROW("cairo create failed failed");
         }
-        if (!(vinfo && XShmQueryExtension(XPlatform::get_display()))) {
+        if (!using_shm) {
             ((PixelsSource_p*)get_opaque())->pixmap.cairo_surf = cairo_surf;
         } else {
             ((PixelsSource_p*)get_opaque())->x_shm_drawable.cairo_surf = cairo_surf;
         }
         ((RedDrawable_p*)get_opaque())->cairo = cairo;
     } catch (...) {
-        if (vinfo && XShmQueryExtension(XPlatform::get_display())) {
+        if (using_shm) {
             if (image) {
                 XDestroyImage(image);
             }
diff --git a/client/x11/x_platform.h b/client/x11/x_platform.h
index 3d3fd8f9..8423e667 100644
--- a/client/x11/x_platform.h
+++ b/client/x11/x_platform.h
@@ -31,6 +31,8 @@ public:
 
     static void on_focus_in();
     static void on_focus_out();
+
+    static bool is_x_shm_avail();
 };
 
 #endif