Generate 18.0.0.0/8 address policy format in descs when we can; warn when the mask is not reducible to a bit-prefix.

svn:r5991

doc/TODO

@@ -73,8 +73,12 @@ R - Add config options to not publish and not fetch rend descs.
 R - let controlport be configurable on other interfaces
 R - look into "uncounting" bytes spent on local connections. so
     we can bandwidthrate but still have fast downloads.
-N - make clients understand "private:*" in exit policies, even though
-    we don't generate it yet.
+N . Clean and future-proof exit policy formats a bit.
+    o Likewise accept, but don't generate /bits formats (unless they're
+      accepted in 0.0.9 and later).
+    o Warn when we see a netmask that isn't a prefix.
+    - Make clients understand "private:*" in exit policies, even though
+      we don't generate it yet.
 
 N - Display the reasons in 'destroy' and 'truncated' cells under some
     circumstances?

src/common/util.c

@@ -1420,6 +1420,20 @@ parse_addr_port(const char *addrport, char **address, uint32_t *addr,
   return ok ? 0 : -1;
 }
 
+/** If <b>mask</b> is an address mask for a bit-prefix, return the number of
+ * bits.  Otherwise, return -1. */
+int
+addr_mask_get_bits(uint32_t mask)
+{
+  int i;
+  for (i=0; i<=32; ++i) {
+    if (mask == ~((1<<(32-i))-1)) {
+      return i;
+    }
+  }
+  return -1;
+}
+
 /** Parse a string <b>s</b> in the format of
  * (IP(/mask|/mask-bits)?|*):(*|port(-maxport)?), setting the various
  * *out pointers as appropriate.  Return 0 on success, -1 on failure.

src/common/util.h

@@ -168,6 +168,7 @@ int parse_addr_port(const char *addrport, char **address, uint32_t *addr,
 int parse_addr_and_port_range(const char *s, uint32_t *addr_out,
                               uint32_t *mask_out, uint16_t *port_min_out,
                               uint16_t *port_max_out);
+int addr_mask_get_bits(uint32_t mask);
 #define INET_NTOA_BUF_LEN 16
 int tor_inet_ntoa(struct in_addr *in, char *buf, size_t buf_len);
 char *tor_dup_addr(uint32_t addr);

src/or/config.c

@@ -3150,6 +3150,10 @@ config_parse_addr_policy(config_line_t *cfg,
       debug(LD_CONFIG,"Adding new entry '%s'",ent);
       *nextp = router_parse_addr_policy_from_string(ent, assume_action);
       if (*nextp) {
+        if (addr_mask_get_bits((*nextp)->msk)<0) {
+          warn(LD_CONFIG, "Address policy element '%s' can't be expressed "
+               "as a bit prefix.", ent);
+        }
         nextp = &((*nextp)->next);
       } else {
         warn(LD_CONFIG,"Malformed policy '%s'.", ent);

src/or/router.c

@@ -1111,13 +1111,18 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router,
       return -1;
     written += result;
     if (tmpe->msk != 0xFFFFFFFFu && tmpe->msk != 0) {
-      /* Write "/255.255.0.0" */
-      in.s_addr = htonl(tmpe->msk);
-      tor_inet_ntoa(&in, addrbuf, sizeof(addrbuf));
-      result = tor_snprintf(s+written, maxlen-written, "/%s", addrbuf);
-      if (result<0)
-        return -1;
-      written += result;
+      int n_bits = addr_mask_get_bits(tmpe->msk);
+      if (n_bits >= 0) {
+        if (tor_snprintf(s+written, maxlen-written, "/%d", n_bits)<0)
+          return -1;
+      } else {
+        /* Write "/255.255.0.0" */
+        in.s_addr = htonl(tmpe->msk);
+        tor_inet_ntoa(&in, addrbuf, sizeof(addrbuf));
+        if (tor_snprintf(s+written, maxlen-written, "/%s", addrbuf)<0)
+          return -1;
+      }
+      written += strlen(s+written);
     }
     if (tmpe->prt_min <= 1 && tmpe->prt_max == 65535) {
       /* There is no port set; write ":*" */