Changeset cf74c60a8f0eedfcc9fae71cfa789e16ce382092

Timestamp:

06/23/2008 10:38:48 PM (2 months ago)

Author:

mitchell <mitchell@frost.(none)>

git-committer:

mitchell <mitchell@frost.(none)> 1214285928 -0400

git-parent:

[c97cbe81a1d91cffd70753dae8bbff4898fb4736]

git-author:

mitchell <mitchell@frost.(none)> 1214285928 -0400

Message:

Check for buffer overflow before writing to lb so there's no segfaulting.
For now I'm ceasing callbacks when buffer overflows occur. In the future I'll
probably add a Ruby exception that will be thrown and can be caught to notify
the user of the file that wasn't parsed correctly.

Files:

• ext/ohcount_native/language_breakdown.c (modified) (3 diffs)
• ext/ohcount_native/language_breakdown.h (modified) (1 diff)
• ext/ohcount_native/ragel_parser.c (modified) (1 diff)

ext/ohcount_native/language_breakdown.c

@@ -23 +23 @@
-  lb->comment[0] = 0;
-  lb->blank_count = 0;
+  lb->buffer_size = buffer_size;
-}
-
@@ -56 +57 @@
- * copies the passed in string (via delimiters) to the code buffer
- *
+ * Returns 1 on success, 0 on buffer overflow. Buffer overflows typically occur
+ * for language syntax errors (e.g. unclosed strings or block comments) or
+ * parser errors.
- */
-void
+int
-  from = first_non_blank(from, to);
+  if (lb->code_cur + (to - from) > lb->code + lb->buffer_size)
+    return 0; // overflow error
-  strncpy(lb->code_cur, from, to - from);
-  lb->code_cur += to - from;
-  *lb->code_cur = 0;
+  return 1;
-}
-
@@ -69 +76 @@
- * copies the passed in string (via delimiters) to the comment buffer
- *
+ * Returns 1 on success, 0 on buffer overflow. Buffer overflows typically occur
+ * for language syntax errors (e.g. unclosed strings or block comments) or
+ * parser errors.
- */
-void
+int
-  from = first_non_blank(from, to);
+  if (lb->comment_cur + (to - from) > lb->comment + lb->buffer_size)
+    return 0; // overflow error
-  strncpy(lb->comment_cur, from, to - from);
-  lb->comment_cur += to - from;
-  *lb->comment_cur = 0;
+  return 1;
-}

ext/ohcount_native/language_breakdown.h

@@ -15 +15 @@
-  char *comment_cur;
-  int blank_count;
+  int buffer_size;
-} LanguageBreakdown;
-
-void language_breakdown_initialize(LanguageBreakdown *lb, char *name, int buffer_size);
-void
-void
+int
+int
-
-void language_breakdown_free(LanguageBreakdown *lb);

ext/ohcount_native/ragel_parser.c

@@ -196 +196 @@
- * @param e The end position of the entity relative to the start of the buffer
- *   (non-inclusive).
+ * TODO: instead of ignoring syntax errors that cause buffer overflows, consider
+ *   raising Ruby exceptions to catch and notify the user of.
- */
-void ragel_parser_callback(const char *lang, const char *entity, int s, int e) {
-  LanguageBreakdown *lb = get_language_breakdown((char *) lang);
-  if (strcmp(entity, "lcode") == 0) {
-language_breakdown_copy_code(lb, parse_buffer + s, parse_buffer + e);
-
+if (language_breakdown_copy_code(lb, parse_buffer + s, parse_buffer + e))
+  
-  } else if (strcmp(entity, "lcomment") == 0) {
-language_breakdown_copy_comment(lb, parse_buffer + s, parse_buffer + e);
-
+if (language_breakdown_copy_comment(lb, parse_buffer + s, parse_buffer + e))
+  
-  } else if (strcmp(entity, "lblank") == 0) {
-    lb->blank_count++;