Update comments about ExitPolicy parsing

Fix incomplete and incorrect comments.

Comment changes only.

src/common/address.h

@@ -227,6 +227,9 @@ int tor_addr_parse_PTR_name(tor_addr_t *result, const char *address,
 
 int tor_addr_port_lookup(const char *s, tor_addr_t *addr_out,
                         uint16_t *port_out);
+/* Does the address * yield an AF_UNSPEC wildcard address (1) and do we
+ * allow *4 and *6 for IPv4 and IPv6 wildcards, respectively;
+ * or does the address * yield IPv4 wildcard address (0).  */
 #define TAPMP_EXTENDED_STAR 1
 int tor_addr_parse_mask_ports(const char *s, unsigned flags,
                               tor_addr_t *addr_out, maskbits_t *mask_out,

src/or/policies.c

@@ -152,7 +152,7 @@ policy_expand_unspec(smartlist_t **policy)
 }
 
 /**
- * Given a linked list of config lines containing "allow" and "deny"
+ * Given a linked list of config lines containing "accept[6]" and "reject[6]"
  * tokens, parse them and append the result to <b>dest</b>. Return -1
  * if any tokens are malformed (and don't append any), else return 0.
  *

src/or/routerparse.c

@@ -3676,10 +3676,14 @@ router_parse_addr_policy_item_from_string,(const char *s, int assume_action))
   directory_token_t *tok = NULL;
   const char *cp, *eos;
   /* Longest possible policy is
-   * "accept6 ffff:ffff:..255/ffff:...255:10000-65535",
+   * "accept6 ffff:ffff:..255/128:10000-65535",
-   * which contains 2 max-length IPv6 addresses, plus 21 characters.
+   * which contains a max-length IPv6 address, plus 24 characters.
    * But note that there can be an arbitrary amount of space between the
-   * accept and the address:mask/port element. */
+   * accept and the address:mask/port element.
+   * We don't need to multiply TOR_ADDR_BUF_LEN by 2, as there is only one
+   * IPv6 address. But making the buffer shorter might cause valid long lines,
+   * which parsed in previous versions, to fail to parse in new versions.
+   * (These lines would have to have excessive amounts of whitespace.) */
   char line[TOR_ADDR_BUF_LEN*2 + 32];
   addr_policy_t *r;
   memarea_t *area = NULL;