1 files changed, 51 insertions, 22 deletions

diff --git a/src/or/addressmap.c b/src/or/addressmap.c
index 33fd7e0f4a..7f861e4d24 100644
--- a/src/or/addressmap.c
+++ b/src/or/addressmap.c
@@ -1,7 +1,7 @@
 /* Copyright (c) 2001 Matej Pfajfar.
  * Copyright (c) 2001-2004, Roger Dingledine.
  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2016, The Tor Project, Inc. */
+ * Copyright (c) 2007-2017, The Tor Project, Inc. */
 /* See LICENSE for licensing information */
 
 /**
@@ -21,9 +21,10 @@
 #include "config.h"
 #include "connection_edge.h"
 #include "control.h"
+#include "crypto_rand.h"
 #include "dns.h"
-#include "routerset.h"
 #include "nodelist.h"
+#include "routerset.h"
 
 /** A client-side struct to remember requests to rewrite addresses
  * to new addresses. These structs are stored in the hash table
@@ -90,34 +91,47 @@ addressmap_init(void)
   virtaddress_reversemap = strmap_new();
 }
 
+#define addressmap_ent_free(ent)                                        \
+  FREE_AND_NULL(addressmap_entry_t, addressmap_ent_free_, (ent))
+
 /** Free the memory associated with the addressmap entry <b>_ent</b>. */
 static void
-addressmap_ent_free(void *_ent)
+addressmap_ent_free_(addressmap_entry_t *ent)
 {
-  addressmap_entry_t *ent;
-  if (!_ent)
+  if (!ent)
     return;
 
-  ent = _ent;
   tor_free(ent->new_address);
   tor_free(ent);
 }
 
+static void
+addressmap_ent_free_void(void *ent)
+{
+  addressmap_ent_free_(ent);
+}
+
+#define addressmap_virtaddress_ent_free(ent)                            \
+  FREE_AND_NULL(virtaddress_entry_t, addressmap_virtaddress_ent_free_, (ent))
+
 /** Free storage held by a virtaddress_entry_t* entry in <b>_ent</b>. */
 static void
-addressmap_virtaddress_ent_free(void *_ent)
+addressmap_virtaddress_ent_free_(virtaddress_entry_t *ent)
 {
-  virtaddress_entry_t *ent;
-  if (!_ent)
+  if (!ent)
     return;
-
-  ent = _ent;
   tor_free(ent->ipv4_address);
   tor_free(ent->ipv6_address);
   tor_free(ent->hostname_address);
   tor_free(ent);
 }
 
+static void
+addressmap_virtaddress_ent_free_void(void *ent)
+{
+  addressmap_virtaddress_ent_free_(ent);
+}
+
 /** Remove <b>address</b> (which must map to <b>ent</b>) from the
  * virtual address map. */
 static void
@@ -213,8 +227,8 @@ addressmap_clear_excluded_trackexithosts(const or_options_t *options)
     while (dot > target && *dot != '.')
       dot--;
     if (*dot == '.') dot++;
-    nodename = tor_strndup(dot, len-5-(dot-target));;
-    node = node_get_by_nickname(nodename, 0);
+    nodename = tor_strndup(dot, len-5-(dot-target));
+    node = node_get_by_nickname(nodename, NNF_NO_WARN_UNNAMED);
     tor_free(nodename);
     if (!node ||
         (allow_nodes && !routerset_contains_node(allow_nodes, node)) ||
@@ -311,10 +325,10 @@ addressmap_clean(time_t now)
 void
 addressmap_free_all(void)
 {
-  strmap_free(addressmap, addressmap_ent_free);
+  strmap_free(addressmap, addressmap_ent_free_void);
   addressmap = NULL;
 
-  strmap_free(virtaddress_reversemap, addressmap_virtaddress_ent_free);
+  strmap_free(virtaddress_reversemap, addressmap_virtaddress_ent_free_void);
   virtaddress_reversemap = NULL;
 }
 
@@ -376,29 +390,38 @@ addressmap_rewrite(char *address, size_t maxlen,
   char *addr_orig = tor_strdup(address);
   char *log_addr_orig = NULL;
 
+  /* We use a loop here to limit the total number of rewrites we do,
+   * so that we can't hit an infinite loop. */
   for (rewrites = 0; rewrites < 16; rewrites++) {
     int exact_match = 0;
     log_addr_orig = tor_strdup(escaped_safe_str_client(address));
 
+    /* First check to see if there's an exact match for this address */
     ent = strmap_get(addressmap, address);
 
     if (!ent || !ent->new_address) {
+      /* And if we don't have an exact match, try to check whether
+       * we have a pattern-based match.
+       */
       ent = addressmap_match_superdomains(address);
     } else {
       if (ent->src_wildcard && !ent->dst_wildcard &&
           !strcasecmp(address, ent->new_address)) {
-        /* This is a rule like *.example.com example.com, and we just got
-         * "example.com" */
+        /* This is a rule like "rewrite *.example.com to example.com", and we
+         * just got "example.com". Instead of calling it an infinite loop,
+         * call it complete. */
         goto done;
       }
-
       exact_match = 1;
     }
 
     if (!ent || !ent->new_address) {
+      /* We still have no match at all.  We're done! */
       goto done;
     }
 
+    /* Check wither the flags we were passed tell us not to use this
+     * mapping. */
     switch (ent->source) {
       case ADDRMAPSRC_DNS:
         {
@@ -431,6 +454,8 @@ addressmap_rewrite(char *address, size_t maxlen,
         goto done;
     }
 
+    /* Now fill in the address with the new address. That might be via
+     * appending some new stuff to the end, or via just replacing it. */
     if (ent->dst_wildcard && !exact_match) {
       strlcat(address, ".", maxlen);
       strlcat(address, ent->new_address, maxlen);
@@ -438,6 +463,7 @@ addressmap_rewrite(char *address, size_t maxlen,
       strlcpy(address, ent->new_address, maxlen);
     }
 
+    /* Is this now a .exit address?  If so, remember where we got it.*/
     if (!strcmpend(address, ".exit") &&
         strcmpend(addr_orig, ".exit") &&
         exit_source == ADDRMAPSRC_NONE) {
@@ -529,7 +555,7 @@ addressmap_have_mapping(const char *address, int update_expiry)
  * (virtual address mapping) from the controller.)
  *
  * <b>new_address</b> should be a newly dup'ed string, which we'll use or
- * free as appropriate. We will leave address alone.
+ * free as appropriate. We will leave <b>address</b> alone.
  *
  * If <b>wildcard_addr</b> is true, then the mapping will match any address
  * equal to <b>address</b>, or any address ending with a period followed by
@@ -542,7 +568,6 @@ addressmap_have_mapping(const char *address, int update_expiry)
  * <b>wildcard_new_addr</b>, remove any mappings that exist from
  * <b>address</b>.
  *
- *
  * It is an error to set <b>wildcard_new_addr</b> if <b>wildcard_addr</b> is
  * not set. */
 void
@@ -802,7 +827,7 @@ parse_virtual_addr_network(const char *val, sa_family_t family,
                    ipv6?"IPv6":"");
     return -1;
   }
-#endif
+#endif /* 0 */
 
   if (bits > max_prefix_bits) {
     if (msg)
@@ -935,9 +960,11 @@ addressmap_get_virtual_address(int type)
         char tmp[TOR_ADDR_BUF_LEN];
         tor_addr_to_str(tmp, &addr, sizeof(tmp), 0);
         if (strmap_get(addressmap, tmp)) {
+          // LCOV_EXCL_START
           log_warn(LD_BUG, "%s wasn't in the addressmap, but %s was.",
                    buf, tmp);
           continue;
+          // LCOV_EXCL_STOP
         }
 
         return tor_strdup(buf);
@@ -946,8 +973,10 @@ addressmap_get_virtual_address(int type)
     log_warn(LD_CONFIG, "Ran out of virtual addresses!");
     return NULL;
   } else {
+    // LCOV_EXCL_START
     log_warn(LD_BUG, "Called with unsupported address type (%d)", type);
     return NULL;
+    // LCOV_EXCL_STOP
   }
 }
 
@@ -1032,7 +1061,7 @@ addressmap_register_virtual_address(int type, char *new_address)
              safe_str_client(*addrp),
              safe_str_client(new_address));
   }
-#endif
+#endif /* 0 */
 
   return *addrp;
 }