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-rw-r--r--nx-X11/programs/Xserver/hw/nxagent/Display.c142
1 files changed, 118 insertions, 24 deletions
diff --git a/nx-X11/programs/Xserver/hw/nxagent/Display.c b/nx-X11/programs/Xserver/hw/nxagent/Display.c
index ea58437ea..aa8ab26d1 100644
--- a/nx-X11/programs/Xserver/hw/nxagent/Display.c
+++ b/nx-X11/programs/Xserver/hw/nxagent/Display.c
@@ -45,6 +45,7 @@ is" without express or implied warranty.
#include <unistd.h>
#include <time.h>
#include <errno.h>
+#include <stdbool.h>
#include <nx-X11/X.h>
#include <nx-X11/Xproto.h>
@@ -178,7 +179,7 @@ static void nxagentInitDepths(void);
static void nxagentInitPixmapFormats(void);
static int nxagentCheckForDefaultDepthCompatibility(void);
-static int nxagentCheckForDepthsCompatibility(int flexibility);
+static int nxagentCheckForDepthsCompatibility(void);
static int nxagentCheckForPixmapFormatsCompatibility(void);
static int nxagentInitAndCheckVisuals(int flexibility);
static int nxagentCheckForColormapsCompatibility(int flexibility);
@@ -2240,69 +2241,162 @@ static int nxagentCheckForDefaultDepthCompatibility()
}
}
-static int nxagentCheckForDepthsCompatibility(int flexibility)
+static int nxagentCheckForDepthsCompatibility()
{
- int i, j;
- int matched;
- int compatible;
+ /*
+ * Depending on the (reconnect) tolerance checks value, this
+ * function checks stricter or looser:
+ * - Strict means that the number of old and new depths must
+ * match exactly and every old depth value must be
+ * available in the new depth array.
+ * - Safe means that the number of depths might diverge,
+ * but all former depth must also be included in the
+ * new depth array. This is recommended, because
+ * it allows clients with more depths to still
+ * connect, but not lose functionality.
+ * - Risky means that the new depths array is allowed to be
+ * smaller than the old depths array, but at least
+ * one depth value must be included in both.
+ * This is potentially unsafe.
+ * - Bypass or higher means that all of these checks are
+ * essentially deactivated. This is a very bad idea.
+ */
+
+ const unsigned int tolerance = nxagentOption(ReconnectTolerance);
+
+ if (ToleranceChecksBypass <= tolerance)
+ {
+ #ifdef WARNING
+ fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! Not proceeding with any checks, "
+ "because tolerance [%u] higher than or equal [%u]. Number of newly available depths "
+ "is [%d], number of old depths is [%d].\n", tolerance, ToleranceChecksBypass,
+ nxagentNumDepths, nxagentNumDepthsRecBackup);
+ #endif
+
+ return 1;
+ }
- if (nxagentNumDepths != nxagentNumDepthsRecBackup)
+ if ((ToleranceChecksStrict == tolerance) && (nxagentNumDepths != nxagentNumDepthsRecBackup))
{
#ifdef WARNING
- fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! Number of new available depths [%d] "
- "doesn't match with old depths [%d].\n", nxagentNumDepths,
- nxagentNumDepthsRecBackup);
+ fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! No tolerance allowed and "
+ "number of new available depths [%d] doesn't match with number of old "
+ "depths [%d].\n", nxagentNumDepths,
+ nxagentNumDepthsRecBackup);
#endif
return 0;
}
- compatible = 1;
+ if ((ToleranceChecksSafe == tolerance) && (nxagentNumDepths < nxagentNumDepthsRecBackup))
+ {
+ #ifdef WARNING
+ fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! Tolerance [%u] not "
+ "high enough and number of new available depths [%d] "
+ "lower than number of old depths [%d].\n", tolerance,
+ nxagentNumDepths, nxagentNumDepthsRecBackup);
+ #endif
+
+ return 0;
+ }
+
+ /*
+ * By now the tolerance is either:
+ * - Strict and both depth numbers match
+ * - Safe and:
+ * o the number of old and new depths matches exactly, or
+ * o the number of old depths is lower than the number
+ * of new depths
+ * - Risky
+ */
+
+ bool compatible = true;
+ bool one_match = false;
+ bool matched = false;
+ int total_matches = 0;
- for (i = 0; i < nxagentNumDepths; i++)
+ /*
+ * FIXME: within this loop, we try to match all "new" depths
+ * against the "old" depths. Depending upon the flexibility
+ * value, either all "new" depths must have a corresponding
+ * counterpart in the "old" array, or at least one value
+ * must be included in both.
+ * Is this safe enough though?
+ * Shouldn't we better try to match entries in the "old"
+ * depths array against the "new" depths array, such that
+ * we know that all "old" values are covered by "new"
+ * values? Or is it more important that "new" values are
+ * covered by "old" ones, with potentially more "old"
+ * values lingering around that cannot be displayed by the
+ * connected client?
+ *
+ * This section probably needs a revisit at some point in time.
+ */
+ for (int i = 0; i < nxagentNumDepths; ++i)
{
- matched = 0;
+ matched = false;
- for (j = 0; j < nxagentNumDepthsRecBackup; j++)
+ for (int j = 0; j < nxagentNumDepthsRecBackup; ++j)
{
if (nxagentDepths[i] == nxagentDepthsRecBackup[j])
{
- matched = 1;
+ matched = true;
+ one_match = true;
+ ++total_matches;
break;
}
}
- if (matched == 0)
+ if ((ToleranceChecksRisky > tolerance) && (!matched))
{
#ifdef WARNING
- fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! Failed to match available depth [%d].\n",
- nxagentDepths[i]);
+ fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! Tolerance [%u] too low and "
+ "failed to match available depth [%d].\n", tolerance, nxagentDepths[i]);
#endif
- compatible = 0;
+ compatible = false;
break;
}
}
+ /*
+ * At Risky tolerance, only one match is necessary to be "compatible".
+ */
+ if (ToleranceChecksRisky == tolerance)
+ {
+ compatible = one_match;
+ }
- if (compatible == 1)
+ int ret = (!(!compatible));
+
+ if (compatible)
{
#ifdef TEST
fprintf(stderr, "nxagentCheckForDepthsCompatibility: Internal depths match with "
- "remote depths.\n");
+ "remote depths at tolerance [%u].\n", tolerance);
#endif
+
+ if (total_matches != nxagentNumDepths)
+ {
+ #ifdef WARNING
+ fprintf(stderr, "nxagentCheckForDepthsCompatibility: only some [%d] of the new depths [%d] "
+ "match with old depths [%d] at tolerance [%u].\n", total_matches, nxagentNumDepths,
+ nxagentNumDepthsRecBackup, tolerance);
+ #endif
+ }
}
else
{
#ifdef WARNING
- fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! New available depths don't match with "
- "old depths.\n");
+ fprintf(stderr, "nxagentCheckForDepthsCompatibility: WARNING! New available depths [%d] don't match "
+ "with old depths [%d] at tolerance [%u]. Only [%d] depth values matched.\n",
+ nxagentNumDepths, nxagentNumDepthsRecBackup, tolerance, total_matches);
#endif
}
- return compatible;
+ return (ret);
}
static int nxagentCheckForPixmapFormatsCompatibility()
@@ -2633,7 +2727,7 @@ Bool nxagentReconnectDisplay(void *p0)
reconnectDisplayState = GOT_DEPTH_LIST;
- if (nxagentCheckForDepthsCompatibility(flexibility) == 0)
+ if (nxagentCheckForDepthsCompatibility() == 0)
{
nxagentSetReconnectError(FAILED_RESUME_DEPTHS_ALERT,
"Couldn't restore all the required depths.");