xfree86: add new key MatchSeat to xorg.conf sections "Device", "Screen", and "ServerLayout"

This patch introduces a new key MatchSeat in xorg.conf (also applies to
any .conf file in xorg.conf.d). It will allow targeting a given
"Device", "Screen", and/or "ServerLayout" section to a particular
seat only (specified by option "-seat" in X server command line),
so that other seats won't be affected.

Without this patch, one needs to write a separate xorg.conf.custom
file and pass it to X server via "-config" option, if one wants that
these settings only apply for the right seat. However, in some cases,
this solution is undesirable or even impossible (e.g. when using GDM,
which doesn't allow X server command line customization).

Example file (/etc/X11/xorg.conf.d/seat1.conf), which would be ignored
by X server unless it was started with "-seat seat1" option:

Section "Device"
    Identifier "card0"
    Driver "nvidia"
    Option "NoLogo" "True"
    MatchSeat "seat1"
EndSection

Signed-off-by: Oleg Samarin <osamarin68@gmail.com>
Signed-off-by: Laércio de Sousa <lbsousajr@gmail.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

hw/xfree86/common/xf86Config.c

@@ -232,6 +232,17 @@ xf86ValidateFontPath(char *path)
     return tmp_path;
 }
 
+#define FIND_SUITABLE(pointertype, listhead, ptr)                               \
+    {                                                                           \
+        pointertype l, p;                                                       \
+                                                                                \
+        for (l = listhead, p = NULL; !p && l; l = (pointertype) l->list.next) { \
+            if (! l->match_seat || SeatId && xf86nameCompare(l->match_seat, SeatId) == 0) \
+                p = l;                                                          \
+        }                                                                       \
+        ptr = p;                                                                \
+    }
+
 /*
  * use the datastructure that the parser provides and pick out the parts
  * that we need at this point
@@ -1580,8 +1591,11 @@ configLayout(serverLayoutPtr servlayoutp, XF86ConfLayoutPtr conf_layout,
      * config file, or - if it is NULL - configScreen autogenerates one for
      * us */
     if (!count) {
+        XF86ConfScreenPtr screen;
+
+        FIND_SUITABLE (XF86ConfScreenPtr, xf86configptr->conf_screen_lst, screen);
         slp[0].screen = xnfcalloc(1, sizeof(confScreenRec));
-        if (!configScreen(slp[0].screen, xf86configptr->conf_screen_lst,
+        if (!configScreen(slp[0].screen, screen,
                           0, X_CONFIG)) {
             free(slp[0].screen);
             free(slp);
@@ -1821,7 +1835,7 @@ configScreen(confScreenPtr screenp, XF86ConfScreenPtr conf_screen, int scrnum,
      * set it to NULL so that the section can be autoconfigured later */
     screenp->device = xnfcalloc(1, sizeof(GDevRec));
     if ((!conf_screen->scrn_device) && (xf86configptr->conf_device_lst)) {
-        conf_screen->scrn_device = xf86configptr->conf_device_lst;
+        FIND_SUITABLE (XF86ConfDevicePtr, xf86configptr->conf_device_lst, conf_screen->scrn_device);
         xf86Msg(X_DEFAULT, "No device specified for screen \"%s\".\n"
                 "\tUsing the first device section listed.\n", screenp->id);
     }
@@ -2429,14 +2443,19 @@ xf86HandleConfigFile(Bool autoconfig)
      */
 
     /* First check if a layout section is present, and if it is valid. */
+    XF86ConfLayoutPtr layout;
+
+    FIND_SUITABLE(XF86ConfLayoutPtr, xf86configptr->conf_layout_lst, layout);
+    if (layout == NULL || xf86ScreenName != NULL) {
+        XF86ConfScreenPtr screen;
 
-    if (xf86configptr->conf_layout_lst == NULL || xf86ScreenName != NULL) {
         if (xf86ScreenName == NULL) {
             xf86Msg(X_DEFAULT,
                     "No Layout section.  Using the first Screen section.\n");
         }
+        FIND_SUITABLE (XF86ConfScreenPtr, xf86configptr->conf_screen_lst, screen);
         if (!configImpliedLayout(&xf86ConfigLayout,
-                                 xf86configptr->conf_screen_lst,
+                                 screen,
                                  xf86configptr)) {
             xf86Msg(X_ERROR, "Unable to determine the screen layout\n");
             return CONFIG_PARSE_ERROR;
@@ -2451,16 +2470,13 @@ xf86HandleConfigFile(Bool autoconfig)
             if (optlist && xf86FindOption(optlist, "defaultserverlayout"))
                 dfltlayout =
                     xf86SetStrOption(optlist, "defaultserverlayout", NULL);
-            if (!configLayout
+            if (!configLayout(&xf86ConfigLayout, layout, dfltlayout)) {
-                (&xf86ConfigLayout, xf86configptr->conf_layout_lst,
-                 dfltlayout)) {
                 xf86Msg(X_ERROR, "Unable to determine the screen layout\n");
                 return CONFIG_PARSE_ERROR;
             }
         }
         else {
-            if (!configLayout(&xf86ConfigLayout, xf86configptr->conf_layout_lst,
+            if (!configLayout(&xf86ConfigLayout, layout, NULL)) {
-                              NULL)) {
                 xf86Msg(X_ERROR, "Unable to determine the screen layout\n");
                 return CONFIG_PARSE_ERROR;
             }

hw/xfree86/parser/Device.c

@@ -71,6 +71,7 @@ xf86ConfigSymTabRec DeviceTab[] = {
     {RAMDAC, "ramdac"},
     {DACSPEED, "dacspeed"},
     {CLOCKS, "clocks"},
+    {MATCHSEAT, "matchseat"},
     {OPTION, "option"},
     {VIDEORAM, "videoram"},
     {BIOSBASE, "biosbase"},
@@ -216,6 +217,11 @@ xf86parseDeviceSection(void)
                 Error(NUMBER_MSG, "TextClockFreq");
             ptr->dev_textclockfreq = (int) (xf86_lex_val.realnum * 1000.0 + 0.5);
             break;
+        case MATCHSEAT:
+            if (xf86getSubToken(&(ptr->dev_comment)) != STRING)
+                Error(QUOTE_MSG, "MatchSeat");
+            ptr->match_seat = xf86_lex_val.str;
+            break;
         case OPTION:
             ptr->dev_option_lst = xf86parseOption(ptr->dev_option_lst);
             break;

hw/xfree86/parser/Layout.c

@@ -70,6 +70,7 @@ static xf86ConfigSymTabRec LayoutTab[] = {
     {ENDSECTION, "endsection"},
     {SCREEN, "screen"},
     {IDENTIFIER, "identifier"},
+    {MATCHSEAT, "matchseat"},
     {INACTIVE, "inactive"},
     {INPUTDEVICE, "inputdevice"},
     {OPTION, "option"},
@@ -109,6 +110,11 @@ xf86parseLayoutSection(void)
             ptr->lay_identifier = xf86_lex_val.str;
             has_ident = TRUE;
             break;
+        case MATCHSEAT:
+            if (xf86getSubToken(&(ptr->lay_comment)) != STRING)
+                Error(QUOTE_MSG, "MatchSeat");
+            ptr->match_seat = xf86_lex_val.str;
+            break;
         case INACTIVE:
         {
             XF86ConfInactivePtr iptr;

hw/xfree86/parser/Screen.c

@@ -198,6 +198,7 @@ xf86parseDisplaySubSection(void)
 static xf86ConfigSymTabRec ScreenTab[] = {
     {ENDSECTION, "endsection"},
     {IDENTIFIER, "identifier"},
+    {MATCHSEAT, "matchseat"},
     {OBSDRIVER, "driver"},
     {MDEVICE, "device"},
     {MONITOR, "monitor"},
@@ -236,6 +237,11 @@ xf86parseScreenSection(void)
                 Error(ONLY_ONE_MSG, "Identifier or Driver");
             has_ident = TRUE;
             break;
+        case MATCHSEAT:
+            if (xf86getSubToken(&(ptr->scrn_comment)) != STRING)
+                Error(QUOTE_MSG, "MatchSeat");
+            ptr->match_seat = xf86_lex_val.str;
+            break;
         case OBSDRIVER:
             if (xf86getSubToken(&(ptr->scrn_comment)) != STRING)
                 Error(QUOTE_MSG, "Driver");

hw/xfree86/parser/xf86Parser.h

@@ -224,6 +224,7 @@ typedef struct {
     int dev_screen;
     XF86OptionPtr dev_option_lst;
     char *dev_comment;
+    char *match_seat;
 } XF86ConfDeviceRec, *XF86ConfDevicePtr;
 
 typedef struct {
@@ -275,6 +276,7 @@ typedef struct {
     XF86OptionPtr scrn_option_lst;
     char *scrn_comment;
     int scrn_virtualX, scrn_virtualY;
+    char *match_seat;
 } XF86ConfScreenRec, *XF86ConfScreenPtr;
 
 typedef struct {
@@ -366,6 +368,7 @@ typedef struct {
     XF86ConfInactivePtr lay_inactive_lst;
     XF86ConfInputrefPtr lay_input_lst;
     XF86OptionPtr lay_option_lst;
+    char *match_seat;
     char *lay_comment;
 } XF86ConfLayoutRec, *XF86ConfLayoutPtr;
 

hw/xfree86/parser/xf86tokens.h

@@ -87,6 +87,7 @@ typedef enum {
     VENDOR,
     DASH,
     COMMA,
+    MATCHSEAT,
     OPTION,
     COMMENT,