hs: Add service-side circuitmap API.

Now we have separate getters and setters for service-side and relay-side. I
took this approach over adding arguments to the already existing methods to
have more explicit type-checking, and also because some functions would grow
too large and dirty.

This commit also fixes every callsite to use the new function names which
modifies the legacy HS (v2) and the prop224 (v3) code.

Signed-off-by: David Goulet <dgoulet@torproject.org>

1 files changed, 196 insertions, 54 deletions

diff --git a/src/or/hs_circuitmap.c b/src/or/hs_circuitmap.c
index 4d5c89307b..ea66fb5194 100644
--- a/src/or/hs_circuitmap.c
+++ b/src/or/hs_circuitmap.c
@@ -4,8 +4,9 @@
 /**
  * \file hs_circuitmap.c
  *
- * \brief Manage the hidden service circuitmap: A hash table that maps binary
- *  tokens to introduction and rendezvous circuits.
+ * \brief Hidden service circuitmap: A hash table that maps binary tokens to
+ *  introduction and rendezvous circuits; it's used both by relays acting as
+ *  intro points and rendezvous points, and also by hidden services themselves.
  **/
 
 #define HS_CIRCUITMAP_PRIVATE
@@ -177,15 +178,17 @@ hs_circuitmap_register_circuit(circuit_t *circ,
   hs_circuitmap_register_impl(circ, hs_token);
 }
 
-/* Query circuitmap for circuit with <b>token</b> of size <b>token_len</b>.
- * Only returns a circuit with purpose equal to the <b>wanted_circ_purpose</b>
- * parameter and if it is NOT marked for close. Return NULL if no such circuit
- * is found. */
+/* Helper function for hs_circuitmap_get_origin_circuit() and
+ * hs_circuitmap_get_or_circuit(). Because only circuit_t are indexed in the
+ * circuitmap, this function returns object type so the specialized functions
+ * using this helper can upcast it to the right type.
+ *
+ * Return NULL if not such circuit is found. */
 static circuit_t *
-hs_circuitmap_get_circuit(hs_token_type_t type,
-                          size_t token_len,
-                          const uint8_t *token,
-                          uint8_t wanted_circ_purpose)
+hs_circuitmap_get_circuit_impl(hs_token_type_t type,
+                               size_t token_len,
+                               const uint8_t *token,
+                               uint8_t wanted_circ_purpose)
 {
   circuit_t *found_circ = NULL;
 
@@ -209,38 +212,46 @@ hs_circuitmap_get_circuit(hs_token_type_t type,
   return found_circ;
 }
 
-/************** Public circuitmap API ****************************************/
-
-/* Public function: Return v3 introduction circuit with <b>auth_key</b>. Return
- * NULL if no such circuit is found in the circuitmap. */
-or_circuit_t *
-hs_circuitmap_get_intro_circ_v3(const ed25519_public_key_t *auth_key)
+/* Helper function: Query circuitmap for origin circuit with <b>token</b> of
+ * size <b>token_len</b> and <b>type</b>.  Only returns a circuit with purpose
+ * equal to the <b>wanted_circ_purpose</b> parameter and if it is NOT marked
+ * for close. Return NULL if no such circuit is found. */
+static origin_circuit_t *
+hs_circuitmap_get_origin_circuit(hs_token_type_t type,
+                                 size_t token_len,
+                                 const uint8_t *token,
+                                 uint8_t wanted_circ_purpose)
 {
   circuit_t *circ;
-  tor_assert(auth_key);
+  tor_assert(token);
+  tor_assert(CIRCUIT_PURPOSE_IS_ORIGIN(wanted_circ_purpose));
 
-  circ = hs_circuitmap_get_circuit(HS_TOKEN_INTRO_V3,
-                                   ED25519_PUBKEY_LEN, auth_key->pubkey,
-                                   CIRCUIT_PURPOSE_INTRO_POINT);
+  circ = hs_circuitmap_get_circuit_impl(type, token_len, token,
+                                        wanted_circ_purpose);
   if (!circ) {
     return NULL;
   }
 
-  tor_assert(CIRCUIT_IS_ORCIRC(circ));
-  return TO_OR_CIRCUIT(circ);
+  tor_assert(CIRCUIT_IS_ORIGIN(circ));
+  return TO_ORIGIN_CIRCUIT(circ);
 }
 
-/* Public function: Return v2 introduction circuit with <b>digest</b>. Return
- * NULL if no such circuit is found in the circuitmap. */
-or_circuit_t *
-hs_circuitmap_get_intro_circ_v2(const uint8_t *digest)
+/* Helper function: Query circuitmap for OR circuit with <b>token</b> of size
+ * <b>token_len</b> and <b>type</b>.  Only returns a circuit with purpose equal
+ * to the <b>wanted_circ_purpose</b> parameter and if it is NOT marked for
+ * close. Return NULL if no such circuit is found. */
+static or_circuit_t *
+hs_circuitmap_get_or_circuit(hs_token_type_t type,
+                             size_t token_len,
+                             const uint8_t *token,
+                             uint8_t wanted_circ_purpose)
 {
   circuit_t *circ;
-  tor_assert(digest);
+  tor_assert(token);
+  tor_assert(!CIRCUIT_PURPOSE_IS_ORIGIN(wanted_circ_purpose));
 
-  circ = hs_circuitmap_get_circuit(HS_TOKEN_INTRO_V2,
-                                   REND_TOKEN_LEN, digest,
-                                   CIRCUIT_PURPOSE_INTRO_POINT);
+  circ = hs_circuitmap_get_circuit_impl(type, token_len, token,
+                                        wanted_circ_purpose);
   if (!circ) {
     return NULL;
   }
@@ -249,58 +260,189 @@ hs_circuitmap_get_intro_circ_v2(const uint8_t *digest)
   return TO_OR_CIRCUIT(circ);
 }
 
-/* Public function: Return rendezvous circuit with rendezvous
- * <b>cookie</b>. Return NULL if no such circuit is found in the circuitmap. */
+/************** Public circuitmap API ****************************************/
+
+/**** Public relay-side getters: */
+
+/* Public function: Return a v3 introduction circuit to this relay with
+ * <b>auth_key</b>. Return NULL if no such circuit is found in the
+ * circuitmap. */
 or_circuit_t *
-hs_circuitmap_get_rend_circ(const uint8_t *cookie)
+hs_circuitmap_get_intro_circ_v3_relay_side(
+                                          const ed25519_public_key_t *auth_key)
 {
-  circuit_t *circ;
-  tor_assert(cookie);
+  return hs_circuitmap_get_or_circuit(HS_TOKEN_INTRO_V3_RELAY_SIDE,
+                                      ED25519_PUBKEY_LEN, auth_key->pubkey,
+                                      CIRCUIT_PURPOSE_INTRO_POINT);
+}
 
-  circ = hs_circuitmap_get_circuit(HS_TOKEN_REND,
-                                   REND_TOKEN_LEN, cookie,
-                                   CIRCUIT_PURPOSE_REND_POINT_WAITING);
-  if (!circ) {
-    return NULL;
-  }
+/* Public function: Return v2 introduction circuit to this relay with
+ * <b>digest</b>. Return NULL if no such circuit is found in the circuitmap. */
+or_circuit_t *
+hs_circuitmap_get_intro_circ_v2_relay_side(const uint8_t *digest)
+{
+  return hs_circuitmap_get_or_circuit(HS_TOKEN_INTRO_V2_RELAY_SIDE,
+                                      REND_TOKEN_LEN, digest,
+                                      CIRCUIT_PURPOSE_INTRO_POINT);
+}
 
-  tor_assert(CIRCUIT_IS_ORCIRC(circ));
-  return TO_OR_CIRCUIT(circ);
+/* Public function: Return rendezvous circuit to this relay with rendezvous
+ * <b>cookie</b>. Return NULL if no such circuit is found in the circuitmap. */
+or_circuit_t *
+hs_circuitmap_get_rend_circ_relay_side(const uint8_t *cookie)
+{
+  return hs_circuitmap_get_or_circuit(HS_TOKEN_REND_RELAY_SIDE,
+                                      REND_TOKEN_LEN, cookie,
+                                      CIRCUIT_PURPOSE_REND_POINT_WAITING);
 }
 
+/** Public relay-side setters: */
+
 /* Public function: Register rendezvous circuit with key <b>cookie</b> to the
  * circuitmap. */
 void
-hs_circuitmap_register_rend_circ(or_circuit_t *circ, const uint8_t *cookie)
+hs_circuitmap_register_rend_circ_relay_side(or_circuit_t *circ,
+                                            const uint8_t *cookie)
 {
   hs_circuitmap_register_circuit(TO_CIRCUIT(circ),
-                                 HS_TOKEN_REND,
+                                 HS_TOKEN_REND_RELAY_SIDE,
                                  REND_TOKEN_LEN, cookie);
 }
+/* Public function: Register v2 intro circuit with key <b>digest</b> to the
+ * circuitmap. */
+void
+hs_circuitmap_register_intro_circ_v2_relay_side(or_circuit_t *circ,
+                                                const uint8_t *digest)
+{
+  hs_circuitmap_register_circuit(TO_CIRCUIT(circ),
+                                 HS_TOKEN_INTRO_V2_RELAY_SIDE,
+                                 REND_TOKEN_LEN, digest);
+}
+
+/* Public function: Register v3 intro circuit with key <b>auth_key</b> to the
+ * circuitmap. */
+void
+hs_circuitmap_register_intro_circ_v3_relay_side(or_circuit_t *circ,
+                                          const ed25519_public_key_t *auth_key)
+{
+  hs_circuitmap_register_circuit(TO_CIRCUIT(circ),
+                                 HS_TOKEN_INTRO_V3_RELAY_SIDE,
+                                 ED25519_PUBKEY_LEN, auth_key->pubkey);
+}
+
+/**** Public servide-side getters: */
+
+/* Public function: Return v3 introduction circuit with <b>auth_key</b>
+ * originating from this hidden service. Return NULL if no such circuit is
+ * found in the circuitmap. */
+origin_circuit_t *
+hs_circuitmap_get_intro_circ_v3_service_side(const
+                                             ed25519_public_key_t *auth_key)
+{
+  origin_circuit_t *circ = NULL;
+
+  /* Check first for established intro circuits */
+  circ = hs_circuitmap_get_origin_circuit(HS_TOKEN_INTRO_V3_SERVICE_SIDE,
+                                          ED25519_PUBKEY_LEN, auth_key->pubkey,
+                                          CIRCUIT_PURPOSE_S_INTRO);
+  if (circ) {
+    return circ;
+  }
+
+  /* ...if nothing found, check for pending intro circs */
+  circ = hs_circuitmap_get_origin_circuit(HS_TOKEN_INTRO_V3_SERVICE_SIDE,
+                                          ED25519_PUBKEY_LEN, auth_key->pubkey,
+                                          CIRCUIT_PURPOSE_S_ESTABLISH_INTRO);
+
+  return circ;
+}
+
+/* Public function: Return v2 introduction circuit originating from this hidden
+ * service with <b>digest</b>. Return NULL if no such circuit is found in the
+ * circuitmap. */
+origin_circuit_t *
+hs_circuitmap_get_intro_circ_v2_service_side(const uint8_t *digest)
+{
+  origin_circuit_t *circ = NULL;
+
+  /* Check first for established intro circuits */
+  circ = hs_circuitmap_get_origin_circuit(HS_TOKEN_INTRO_V2_SERVICE_SIDE,
+                                          REND_TOKEN_LEN, digest,
+                                          CIRCUIT_PURPOSE_S_INTRO);
+  if (circ) {
+    return circ;
+  }
+
+  /* ...if nothing found, check for pending intro circs */
+  circ = hs_circuitmap_get_origin_circuit(HS_TOKEN_INTRO_V2_SERVICE_SIDE,
+                                          REND_TOKEN_LEN, digest,
+                                          CIRCUIT_PURPOSE_S_ESTABLISH_INTRO);
+
+  return circ;
+}
+
+/* Public function: Return rendezvous circuit originating from this hidden
+ * service with rendezvous <b>cookie</b>. Return NULL if no such circuit is
+ * found in the circuitmap. */
+origin_circuit_t *
+hs_circuitmap_get_rend_circ_service_side(const uint8_t *cookie)
+{
+  origin_circuit_t *circ = NULL;
+
+  /* Try to check if we have a connecting circuit. */
+  circ = hs_circuitmap_get_origin_circuit(HS_TOKEN_REND_SERVICE_SIDE,
+                                          REND_TOKEN_LEN, cookie,
+                                          CIRCUIT_PURPOSE_S_CONNECT_REND);
+  if (circ) {
+    return circ;
+  }
+
+  /* Then try for connected circuit. */
+  circ = hs_circuitmap_get_origin_circuit(HS_TOKEN_REND_SERVICE_SIDE,
+                                          REND_TOKEN_LEN, cookie,
+                                          CIRCUIT_PURPOSE_S_REND_JOINED);
+  return circ;
+}
+
+/**** Public servide-side setters: */
 
 /* Public function: Register v2 intro circuit with key <b>digest</b> to the
  * circuitmap. */
 void
-hs_circuitmap_register_intro_circ_v2(or_circuit_t *circ, const uint8_t *digest)
+hs_circuitmap_register_intro_circ_v2_service_side(origin_circuit_t *circ,
+                                                  const uint8_t *digest)
 {
   hs_circuitmap_register_circuit(TO_CIRCUIT(circ),
-                                 HS_TOKEN_INTRO_V2,
+                                 HS_TOKEN_INTRO_V2_SERVICE_SIDE,
                                  REND_TOKEN_LEN, digest);
 }
 
 /* Public function: Register v3 intro circuit with key <b>auth_key</b> to the
  * circuitmap. */
 void
-hs_circuitmap_register_intro_circ_v3(or_circuit_t *circ,
-                                     const ed25519_public_key_t *auth_key)
+hs_circuitmap_register_intro_circ_v3_service_side(origin_circuit_t *circ,
+                                          const ed25519_public_key_t *auth_key)
 {
   hs_circuitmap_register_circuit(TO_CIRCUIT(circ),
-                                 HS_TOKEN_INTRO_V3,
+                                 HS_TOKEN_INTRO_V3_SERVICE_SIDE,
                                  ED25519_PUBKEY_LEN, auth_key->pubkey);
 }
 
-/** Remove this circuit from the HS circuitmap. Clear its HS token, and remove
- *  it from the hashtable. */
+/* Public function: Register rendezvous circuit with key <b>cookie</b> to the
+ * circuitmap. */
+void
+hs_circuitmap_register_rend_circ_service_side(origin_circuit_t *circ,
+                                              const uint8_t *cookie)
+{
+  hs_circuitmap_register_circuit(TO_CIRCUIT(circ),
+                                 HS_TOKEN_REND_SERVICE_SIDE,
+                                 REND_TOKEN_LEN, cookie);
+}
+
+/**** Misc public functions: */
+
+/** Public function: Remove this circuit from the HS circuitmap. Clear its HS
+ *  token, and remove it from the hashtable. */
 void
 hs_circuitmap_remove_circuit(circuit_t *circ)
 {
@@ -326,7 +468,7 @@ hs_circuitmap_remove_circuit(circuit_t *circ)
   circ->hs_token = NULL;
 }
 
-/* Initialize the global HS circuitmap. */
+/* Public function: Initialize the global HS circuitmap. */
 void
 hs_circuitmap_init(void)
 {
@@ -336,7 +478,7 @@ hs_circuitmap_init(void)
   HT_INIT(hs_circuitmap_ht, the_hs_circuitmap);
 }
 
-/* Free all memory allocated by the global HS circuitmap. */
+/* Public function: Free all memory allocated by the global HS circuitmap. */
 void
 hs_circuitmap_free_all(void)
 {