r17391@pc-10-8-1-079: nickm | 2008-07-25 17:11:17 +0200

 Tor_addr_compare did a semantic comparison, such that ::1.2.3.4 and 1.2.3.4 were "equal".  we sometimes need an exact comparison.  Add a feature to do that.


svn:r16210

src/common/address.c

@@ -649,11 +649,13 @@ tor_addr_copy(tor_addr_t *dest, const tor_addr_t *src)
  * preceeds addr2, and greater than 0 otherwise.
  *
  * Different address families (IPv4 vs IPv6) are always considered unequal.
+ *   NOT QUITE XXXX DOCDOC.
  */
 int
-tor_addr_compare(const tor_addr_t *addr1, const tor_addr_t *addr2)
+tor_addr_compare(const tor_addr_t *addr1, const tor_addr_t *addr2,
+                 tor_addr_comparison_t how)
 {
-  return tor_addr_compare_masked(addr1, addr2, 128);
+  return tor_addr_compare_masked(addr1, addr2, 128, how);
 }
 
 /** As tor_addr_compare(), but only looks at the first <b>mask</b> bits of
@@ -663,7 +665,7 @@ tor_addr_compare(const tor_addr_t *addr1, const tor_addr_t *addr2)
  */
 int
 tor_addr_compare_masked(const tor_addr_t *addr1, const tor_addr_t *addr2,
-                        maskbits_t mbits)
+                        maskbits_t mbits, tor_addr_comparison_t how)
 {
   uint32_t ip4a=0, ip4b=0;
   sa_family_t v_family[2];
@@ -672,6 +674,28 @@ tor_addr_compare_masked(const tor_addr_t *addr1, const tor_addr_t *addr2,
 
   tor_assert(addr1 && addr2);
 
+  if (how == CMP_EXACT) {
+    int r = ((int)addr2->family) - ((int)addr1->family);
+    if (r) return r;
+    switch (addr1->family) {
+      case AF_UNSPEC:
+        return 0; /* All unspecified addresses are equal */
+      case AF_INET: {
+        uint32_t a1 = ntohl(addr1->addr.in_addr.s_addr);
+        uint32_t a2 = ntohl(addr2->addr.in_addr.s_addr);
+        return (a1 < a2) ? -1 : (a1 == a2) ? 0 : 1;
+      }
+      case AF_INET6: {
+        uint32_t *a1 = S6_ADDR32(addr1->addr.in6_addr);
+        uint32_t *a2 = S6_ADDR32(addr2->addr.in6_addr);
+        return memcmp(a1, a2, 16);
+      }
+      default:
+        tor_fragile_assert();
+        return 0;
+    }
+  }
+
   /* XXXX021 this code doesn't handle mask bits right it's using v4-mapped v6
    * addresses.  If I ask whether ::ffff:1.2.3.4 and ::ffff:1.2.7.8 are the
    * same in the first 16 bits, it will say "yes."  That's not so intuitive.

src/common/address.h

@@ -81,11 +81,19 @@ tor_addr_to_in(const tor_addr_t *a)
 
 int tor_addr_lookup(const char *name, uint16_t family, tor_addr_t *addr_out);
 char *tor_dup_addr(const tor_addr_t *addr) ATTR_MALLOC;
-
 int get_interface_address6(int severity, sa_family_t family, tor_addr_t *addr);
-int tor_addr_compare(const tor_addr_t *addr1, const tor_addr_t *addr2);
+
+/** DOCDOC */
+typedef enum {
+  CMP_EXACT,
+  CMP_SEMANTIC,
+} tor_addr_comparison_t;
+
+int tor_addr_compare(const tor_addr_t *addr1, const tor_addr_t *addr2,
+                     tor_addr_comparison_t how);
 int tor_addr_compare_masked(const tor_addr_t *addr1, const tor_addr_t *addr2,
-                            maskbits_t mask);
+                            maskbits_t mask, tor_addr_comparison_t how);
+
 unsigned int tor_addr_hash(const tor_addr_t *addr);
 int tor_addr_is_v4(const tor_addr_t *addr);
 int tor_addr_is_internal(const tor_addr_t *ip, int for_listening) ATTR_PURE;

src/or/policies.c

@@ -409,7 +409,7 @@ cmp_single_addr_policy(addr_policy_t *a, addr_policy_t *b)
     return r;
   if ((r=((int)a->is_private - (int)b->is_private)))
     return r;
-  if ((r=tor_addr_compare(&a->addr, &b->addr)))
+  if ((r=tor_addr_compare(&a->addr, &b->addr, CMP_EXACT)))
     return r;
   if ((r=((int)a->maskbits - (int)b->maskbits)))
     return r;
@@ -558,7 +558,8 @@ compare_addr_to_addr_policy(uint32_t _addr, uint16_t port,
       }
     } else {
       /* Address is known */
-      if (!tor_addr_compare_masked(&addr, &tmpe->addr, tmpe->maskbits)) {
+      if (!tor_addr_compare_masked(&addr, &tmpe->addr, tmpe->maskbits,
+                                   CMP_SEMANTIC)) {
         if (port >= tmpe->prt_min && port <= tmpe->prt_max) {
           /* Exact match for the policy */
           match = 1;
@@ -601,7 +602,7 @@ addr_policy_covers(addr_policy_t *a, addr_policy_t *b)
     /* a has more fixed bits than b; it can't possibly cover b. */
     return 0;
   }
-  if (tor_addr_compare_masked(&a->addr, &b->addr, a->maskbits)) {
+  if (tor_addr_compare_masked(&a->addr, &b->addr, a->maskbits, CMP_SEMANTIC)) {
     /* There's a fixed bit in a that's set differently in b. */
     return 0;
   }
@@ -624,7 +625,7 @@ addr_policy_intersects(addr_policy_t *a, addr_policy_t *b)
     minbits = a->maskbits;
   else
     minbits = b->maskbits;
-  if (tor_addr_compare_masked(&a->addr, &b->addr, minbits))
+  if (tor_addr_compare_masked(&a->addr, &b->addr, minbits, CMP_SEMANTIC))
     return 0;
   if (a->prt_max < b->prt_min || b->prt_max < a->prt_min)
     return 0;

src/or/test.c

@@ -1272,7 +1272,7 @@ _test_eq_ip6(struct in6_addr *a, struct in6_addr *b, const char *e1,
     test_eq(tor_inet_pton(AF_INET6, a, &t1.addr.in6_addr), 1);    \
     test_eq(tor_inet_pton(AF_INET6, b, &t2.addr.in6_addr), 1);    \
     t1.family = t2.family = AF_INET6;                             \
-    r = tor_addr_compare(&t1,&t2);                                \
+    r = tor_addr_compare(&t1,&t2,CMP_SEMANTIC);                   \
     if (!(r op 0))                                                \
       test_fail_msg("failed: tor_addr_compare("a","b") "#op" 0"); \
   STMT_END
@@ -1284,7 +1284,7 @@ _test_eq_ip6(struct in6_addr *a, struct in6_addr *b, const char *e1,
     test_eq(tor_inet_pton(AF_INET6, a, &t1.addr.in6_addr), 1);    \
     test_eq(tor_inet_pton(AF_INET6, b, &t2.addr.in6_addr), 1);    \
     t1.family = t2.family = AF_INET6;                             \
-    r = tor_addr_compare_masked(&t1,&t2,m);                       \
+    r = tor_addr_compare_masked(&t1,&t2,m,CMP_SEMANTIC);          \
     if (!(r op 0))                                                \
       test_fail_msg("failed: tor_addr_compare_masked("a","b","#m") "#op" 0"); \
   STMT_END
@@ -1445,10 +1445,10 @@ test_util_ip6_helpers(void)
   test_addr_compare("0::ffff:5.2.2.1", <, "::ffff:6.0.0.0"); /* XXXX wrong. */
   tor_addr_parse_mask_ports("[::ffff:2.3.4.5]", &t1, NULL, NULL, NULL);
   tor_addr_parse_mask_ports("2.3.4.5", &t2, NULL, NULL, NULL);
-  test_assert(tor_addr_compare(&t1, &t2) == 0);
+  test_assert(tor_addr_compare(&t1, &t2, CMP_SEMANTIC) == 0);
   tor_addr_parse_mask_ports("[::ffff:2.3.4.4]", &t1, NULL, NULL, NULL);
   tor_addr_parse_mask_ports("2.3.4.5", &t2, NULL, NULL, NULL);
-  test_assert(tor_addr_compare(&t1, &t2) < 0);
+  test_assert(tor_addr_compare(&t1, &t2, CMP_SEMANTIC) < 0);
 
   /* test compare_masked */
   test_addr_compare_masked("ffff::", ==, "ffff::0", 128);
@@ -3282,7 +3282,7 @@ test_policies(void)
   test_assert(p != NULL);
   test_eq(ADDR_POLICY_REJECT, p->policy_type);
   tor_addr_from_ipv4h(&tar, 0xc0a80000u);
-  test_eq(0, tor_addr_compare(&p->addr, &tar));
+  test_eq(0, tor_addr_compare(&p->addr, &tar, CMP_EXACT));
   test_eq(16, p->maskbits);
   test_eq(1, p->prt_min);
   test_eq(65535, p->prt_max);