From 728e8c27a9fad3acb359d587e48298c88c18aa15 Mon Sep 17 00:00:00 2001
From: Robert Spalek <robert@ucw.cz>
Date: Mon, 14 Jun 2004 17:21:50 +0000
Subject: [PATCH] tested the wrapper guarding the safe decompression

---
 lib/lizard-test.c | 47 ++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 40 insertions(+), 7 deletions(-)

diff --git a/lib/lizard-test.c b/lib/lizard-test.c
index 38a76c56..2c5c1494 100644
--- a/lib/lizard-test.c
+++ b/lib/lizard-test.c
@@ -6,8 +6,9 @@
 #include <stdlib.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <sys/user.h>
 
-static char *options = CF_SHORT_OPTS "cdt";
+static char *options = CF_SHORT_OPTS "cdtx";
 static char *help = "\
 Usage: lizard-test <options> input-file [output-file]\n\
 \n\
@@ -16,6 +17,7 @@ CF_USAGE
 "-c\t\tCompress (default)\n\
 -d\t\tDecompress\n\
 -t\t\tCompress, decompress, and compare (in memory only)\n\
+-x, -xx, -xxx\tMake the test crash by underestimating the output buffer\n\
 ";
 
 static void NONRET
@@ -30,6 +32,7 @@ main(int argc, char **argv)
 {
   int opt;
   uns action = 'c';
+  uns crash = 0;
   log_init(argv[0]);
   while ((opt = cf_getopt(argc, argv, options, CF_NO_LONG_OPTS, NULL)) >= 0)
     switch (opt)
@@ -39,6 +42,9 @@ main(int argc, char **argv)
       case 't':
 	action = opt;
 	break;
+      case 'x':
+	crash++;
+	break;
       default:
 	usage();
     }
@@ -47,7 +53,7 @@ main(int argc, char **argv)
     usage();
 
   void *mi, *mo;
-  uns li, lo;
+  int li, lo;
 
   struct stat st;
   stat(argv[optind], &st);
@@ -89,16 +95,43 @@ main(int argc, char **argv)
   }
   else
   {
-    void *mv;
-    uns lv;
-    mv = xmalloc(li);
-    lv = lizard_decompress(mo, mv);
+    struct lizard_buffer *buf = lizard_alloc(li);
+    uns exp_len = li;
+    if (crash==1)
+    {
+      if (exp_len >= PAGE_SIZE)
+	exp_len -= PAGE_SIZE;
+      else
+	exp_len = 0;
+      printf("Setting shorter output buffer to %d: ", exp_len);
+      fflush(stdout);
+    }
+    int lv = lizard_decompress_safe(mo, buf, exp_len);
     printf("-> %d ", lv);
     fflush(stdout);
-    if (lv != li || memcmp(mi, mv, lv))
+    if (crash >= 2)
+    {
+      uns guarded_pos = (lv + PAGE_SIZE-1)/PAGE_SIZE * PAGE_SIZE;
+      printf("Reading from guarded memory: %d\n", ((byte *) (buf->ptr)) [guarded_pos]);
+      if (crash == 2)
+      {
+	printf("Writing to guarded memory: ");
+	fflush(stdout);
+	((byte *) (buf->ptr)) [guarded_pos] = 0;
+	printf("succeeded\n");
+      }
+      if (crash == 3)
+      {
+	printf("Reading behind guarded memory: ");
+	fflush(stdout);
+	printf("%d\n", ((byte *) (buf->ptr)) [guarded_pos + PAGE_SIZE] = 0);
+      }
+    }
+    if (lv != li || memcmp(mi, buf->ptr, li))
       printf("WRONG");
     else
       printf("OK");
+    lizard_free(buf);
   }
   printf("\n");
 }
-- 
2.39.5