[or-cvs] r12952: Fix several remotely triggerable asserts based on DirPort re (in tor/trunk: . src/or)

[arma at seul.org]

Author: arma
Date: 2007-12-24 06:25:45 -0500 (Mon, 24 Dec 2007)
New Revision: 12952

Modified:
   tor/trunk/ChangeLog
   tor/trunk/src/or/dirserv.c
Log:
Fix several remotely triggerable asserts based on DirPort requests
for a v2 or v3 networkstatus object before we were prepared. This
was particularly bad for 0.2.0.13 and later bridge relays, who
would never have a v2 networkstatus and would thus always crash
when used. Bugfixes on 0.2.0.x.

Estimate the v3 networkstatus size more accurately, rather than
estimating it at zero bytes and giving it artificially high priority 
compared to other directory requests. Bugfix on 0.2.0.x.


Modified: tor/trunk/ChangeLog
===================================================================
--- tor/trunk/ChangeLog	2007-12-24 11:18:05 UTC (rev 12951)
+++ tor/trunk/ChangeLog	2007-12-24 11:25:45 UTC (rev 12952)
@@ -1,4 +1,14 @@
-Changes in version 0.2.0.15-alpha - 2008-01-??
+Changes in version 0.2.0.15-alpha - 2007-12-??
+  o Major bugfixes:
+    - Fix several remotely triggerable asserts based on DirPort requests
+      for a v2 or v3 networkstatus object before we were prepared. This
+      was particularly bad for 0.2.0.13 and later bridge relays, who
+      would never have a v2 networkstatus and would thus always crash
+      when used. Bugfixes on 0.2.0.x.
+    - Estimate the v3 networkstatus size more accurately, rather than
+      estimating it at zero bytes and giving it artificially high priority
+      compared to other directory requests. Bugfix on 0.2.0.x.
+
   o Minor bugfixes:
     - Fix configure.in logic for cross-compilation.
     - When we load a bridge descriptor from the cache, and it was

Modified: tor/trunk/src/or/dirserv.c
===================================================================
--- tor/trunk/src/or/dirserv.c	2007-12-24 11:18:05 UTC (rev 12951)
+++ tor/trunk/src/or/dirserv.c	2007-12-24 11:25:45 UTC (rev 12952)
@@ -2757,6 +2757,24 @@
     ctr = (ctr + 1) % 128;
 }
 
+
+/** Given a fingerprint <b>fp</b> which is either set if we're looking
+ * for a v2 status, or zeroes if we're looking for a v3 status, return
+ * a pointer to the appropriate cached dir object, or NULL if there isn't
+ * one available. */
+static cached_dir_t *
+lookup_cached_dir_by_fp(const char *fp)
+{
+  cached_dir_t *d = NULL;
+  if (tor_digest_is_zero(fp) && cached_v3_networkstatus)
+    d = cached_v3_networkstatus;
+  else if (router_digest_is_me(fp) && the_v2_networkstatus)
+    d = the_v2_networkstatus;
+  else if (cached_v2_networkstatus)
+    d = digestmap_get(cached_v2_networkstatus, fp);
+  return d;
+}
+
 /** Remove from <b>fps</b> every networkstatus key where both
  * a) we have a networkstatus document and
  * b) it is not newer than <b>cutoff</b>.
@@ -2769,13 +2787,7 @@
   int found_any = 0;
   SMARTLIST_FOREACH(fps, char *, digest,
   {
-    cached_dir_t *d;
-    if (router_digest_is_me(digest) && the_v2_networkstatus)
-      d = the_v2_networkstatus;
-    else if (tor_digest_is_zero(digest) && cached_v3_networkstatus)
-      d = cached_v3_networkstatus;
-    else
-      d = digestmap_get(cached_v2_networkstatus, digest);
+    cached_dir_t *d = lookup_cached_dir_by_fp(digest);
     if (!d)
       continue;
     found_any = 1;
@@ -2864,8 +2876,8 @@
       result /= 2; /* observed compressability is between 35 and 55%. */
   } else {
     result = 0;
-    SMARTLIST_FOREACH(fps, const char *, d, {
-        cached_dir_t *dir = digestmap_get(cached_v2_networkstatus, d);
+    SMARTLIST_FOREACH(fps, const char *, digest, {
+        cached_dir_t *dir = lookup_cached_dir_by_fp(digest);
         if (dir)
           result += compressed ? dir->dir_z_len : dir->dir_len;
       });
@@ -3019,13 +3031,7 @@
                smartlist_len(conn->fingerprint_stack)) {
       /* Add another networkstatus; start serving it. */
       char *fp = smartlist_pop_last(conn->fingerprint_stack);
-      cached_dir_t *d;
-      if (tor_digest_is_zero(fp))
-        d = cached_v3_networkstatus;
-      else if (router_digest_is_me(fp))
-        d = the_v2_networkstatus;
-      else
-        d = digestmap_get(cached_v2_networkstatus, fp);
+      cached_dir_t *d = lookup_cached_dir_by_fp(fp);
       tor_free(fp);
       if (d) {
         ++d->refcnt;