Merge branch 'maint-0.2.9'

1 files changed, 85 insertions, 36 deletions

diff --git a/src/or/routerparse.c b/src/or/routerparse.c
index 58b9a22438..22c9a61080 100644
--- a/src/or/routerparse.c
+++ b/src/or/routerparse.c
@@ -4785,40 +4785,78 @@ microdescs_parse_from_string(const char *s, const char *eos,
   return result;
 }
 
-/** Parse the Tor version of the platform string <b>platform</b>,
- * and compare it to the version in <b>cutoff</b>. Return 1 if
- * the router is at least as new as the cutoff, else return 0.
+/** Extract a Tor version from a <b>platform</b> line from a router
+ * descriptor, and place the result in <b>router_version</b>.
+ *
+ * Return 1 on success, -1 on parsing failure, and 0 if the
+ * platform line does not indicate some version of Tor.
+ *
+ * If <b>strict</b> is non-zero, finding any weird version components
+ * (like negative numbers) counts as a parsing failure.
  */
 int
-tor_version_as_new_as(const char *platform, const char *cutoff)
+tor_version_parse_platform(const char *platform,
+                           tor_version_t *router_version,
+                           int strict)
 {
-  tor_version_t cutoff_version, router_version;
-  char *s, *s2, *start;
   char tmp[128];
+  char *s, *s2, *start;
 
-  tor_assert(platform);
-
-  if (tor_version_parse(cutoff, &cutoff_version)<0) {
-    log_warn(LD_BUG,"cutoff version '%s' unparseable.",cutoff);
+  if (strcmpstart(platform,"Tor ")) /* nonstandard Tor; say 0. */
     return 0;
-  }
-  if (strcmpstart(platform,"Tor ")) /* nonstandard Tor; be safe and say yes */
-    return 1;
 
   start = (char *)eat_whitespace(platform+3);
-  if (!*start) return 0;
+  if (!*start) return -1;
   s = (char *)find_whitespace(start); /* also finds '\0', which is fine */
   s2 = (char*)eat_whitespace(s);
   if (!strcmpstart(s2, "(r") || !strcmpstart(s2, "(git-"))
     s = (char*)find_whitespace(s2);
 
   if ((size_t)(s-start+1) >= sizeof(tmp)) /* too big, no */
-    return 0;
+    return -1;
   strlcpy(tmp, start, s-start+1);
 
-  if (tor_version_parse(tmp, &router_version)<0) {
+  if (tor_version_parse(tmp, router_version)<0) {
     log_info(LD_DIR,"Router version '%s' unparseable.",tmp);
-    return 1; /* be safe and say yes */
+    return -1;
+  }
+
+  if (strict) {
+    if (router_version->major < 0 ||
+        router_version->minor < 0 ||
+        router_version->minor < 0 ||
+        router_version->patchlevel < 0 ||
+        router_version->svn_revision < 0) {
+      return -1;
+    }
+  }
+
+  return 1;
+}
+
+/** Parse the Tor version of the platform string <b>platform</b>,
+ * and compare it to the version in <b>cutoff</b>. Return 1 if
+ * the router is at least as new as the cutoff, else return 0.
+ */
+int
+tor_version_as_new_as(const char *platform, const char *cutoff)
+{
+  tor_version_t cutoff_version, router_version;
+  int r;
+  tor_assert(platform);
+
+  if (tor_version_parse(cutoff, &cutoff_version)<0) {
+    log_warn(LD_BUG,"cutoff version '%s' unparseable.",cutoff);
+    return 0;
+  }
+
+  r = tor_version_parse_platform(platform, &router_version, 0);
+  if (r == 0) {
+    /* nonstandard Tor; be safe and say yes */
+    return 1;
+  } else if (r < 0) {
+    /* unparseable version; be safe and say yes. */
+    return 1;
   }
 
   /* Here's why we don't need to do any special handling for svn revisions:
@@ -4945,26 +4983,37 @@ tor_version_compare(tor_version_t *a, tor_version_t *b)
   int i;
   tor_assert(a);
   tor_assert(b);
-  if ((i = a->major - b->major))
-    return i;
-  else if ((i = a->minor - b->minor))
-    return i;
-  else if ((i = a->micro - b->micro))
-    return i;
-  else if ((i = a->status - b->status))
-    return i;
-  else if ((i = a->patchlevel - b->patchlevel))
-    return i;
-  else if ((i = strcmp(a->status_tag, b->status_tag)))
-    return i;
-  else if ((i = a->svn_revision - b->svn_revision))
-    return i;
-  else if ((i = a->git_tag_len - b->git_tag_len))
-    return i;
-  else if (a->git_tag_len)
-    return fast_memcmp(a->git_tag, b->git_tag, a->git_tag_len);
+
+  /* We take this approach to comparison to ensure the same (bogus!) behavior
+   * on all inputs as we would have seen before bug #21278 was fixed. The
+   * only important difference here is that this method doesn't cause
+   * a signed integer underflow.
+   */
+#define CMP(field) do {                               \
+    unsigned aval = (unsigned) a->field;              \
+    unsigned bval = (unsigned) b->field;              \
+    int result = (int) (aval - bval);                 \
+    if (result < 0)                                   \
+      return -1;                                      \
+    else if (result > 0)                              \
+      return 1;                                       \
+  } while (0)
+
+  CMP(major);
+  CMP(minor);
+  CMP(micro);
+  CMP(status);
+  CMP(patchlevel);
+  if ((i = strcmp(a->status_tag, b->status_tag)))
+     return i;
+  CMP(svn_revision);
+  CMP(git_tag_len);
+  if (a->git_tag_len)
+     return fast_memcmp(a->git_tag, b->git_tag, a->git_tag_len);
   else
-    return 0;
+     return 0;
+
+#undef CMP
 }
 
 /** Return true iff versions <b>a</b> and <b>b</b> belong to the same series.