Control: add HS_DESC_CONTENT event

As defined in section 4.1.26 in the control-spec.txt, this new event replies
the content of a successfully fetched HS descriptor. This also adds a unit
test for the controller event.

Signed-off-by: David Goulet <dgoulet@ev0ke.net>

3 files changed, 50 insertions, 1 deletions

diff --git a/src/or/control.c b/src/or/control.c
index 1bc833371d..e7d8b5cdef 100644
--- a/src/or/control.c
+++ b/src/or/control.c
@@ -943,6 +943,7 @@ static const struct control_event_t control_event_table[] = {
   { EVENT_CIRC_BANDWIDTH_USED, "CIRC_BW" },
   { EVENT_TRANSPORT_LAUNCHED, "TRANSPORT_LAUNCHED" },
   { EVENT_HS_DESC, "HS_DESC" },
+  { EVENT_HS_DESC_CONTENT, "HS_DESC_CONTENT" },
   { 0, NULL },
 };
 
@@ -5414,6 +5415,36 @@ control_event_hs_descriptor_failed(const rend_data_t *rend_query,
                                           id_digest, reason);
 }
 
+/** send HS_DESC_CONTENT event after completion of a successful fetch from
+ * hs directory. */
+void
+control_event_hs_descriptor_content(const char *onion_address,
+                                    const char *desc_id,
+                                    const char *hsdir_id_digest,
+                                    const char *content)
+{
+  static const char *event_name = "HS_DESC_CONTENT";
+  char *esc_content = NULL;
+
+  if (!onion_address || !desc_id || !hsdir_id_digest || !content) {
+    log_warn(LD_BUG, "Called with onion_address==%p, desc_id==%p, "
+             "hsdir_id_digest==%p, content==%p", onion_address, desc_id,
+             hsdir_id_digest, content);
+    return;
+  }
+
+  write_escaped_data(content, strlen(content), &esc_content);
+
+  send_control_event(EVENT_HS_DESC_CONTENT, ALL_FORMATS,
+                     "650 %s %s %s %s\r\n%s",
+                     event_name,
+                     onion_address,
+                     desc_id,
+                     node_describe_longname_by_id(hsdir_id_digest),
+                     esc_content);
+  tor_free(esc_content);
+}
+
 /** Free any leftover allocated memory of the control.c subsystem. */
 void
 control_free_all(void)
diff --git a/src/or/control.h b/src/or/control.h
index dbb80b1f20..ae49284965 100644
--- a/src/or/control.h
+++ b/src/or/control.h
@@ -115,6 +115,10 @@ void control_event_hs_descriptor_received(const rend_data_t *rend_query,
 void control_event_hs_descriptor_failed(const rend_data_t *rend_query,
                                         const char *hs_dir,
                                         const char *reason);
+void control_event_hs_descriptor_content(const char *onion_address,
+                                         const char *desc_id,
+                                         const char *hsdir_fp,
+                                         const char *content);
 
 void control_free_all(void);
 
@@ -158,7 +162,8 @@ void control_free_all(void);
 #define EVENT_CIRC_BANDWIDTH_USED     0x001D
 #define EVENT_TRANSPORT_LAUNCHED      0x0020
 #define EVENT_HS_DESC                 0x0021
-#define EVENT_MAX_                    0x0021
+#define EVENT_HS_DESC_CONTENT         0x0022
+#define EVENT_MAX_                    0x0022
 
 /* sizeof(control_connection_t.event_mask) in bits, currently a uint64_t */
 #define EVENT_CAPACITY_               0x0040
diff --git a/src/or/directory.c b/src/or/directory.c
index d2b6b86f6d..b6b0a5d7e0 100644
--- a/src/or/directory.c
+++ b/src/or/directory.c
@@ -2102,6 +2102,11 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
       control_event_hs_descriptor_failed(conn->rend_data, \
                                          conn->identity_digest, \
                                          reason) )
+    #define SEND_HS_DESC_FAILED_CONTENT() ( \
+      control_event_hs_descriptor_content(conn->rend_data->onion_address, \
+                                          conn->requested_resource, \
+                                          conn->identity_digest, \
+                                          "") )
     tor_assert(conn->rend_data);
     log_info(LD_REND,"Received rendezvous descriptor (size %d, status %d "
              "(%s))",
@@ -2117,6 +2122,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
             /* We'll retry when connection_about_to_close_connection()
              * cleans this dir conn up. */
             SEND_HS_DESC_FAILED_EVENT("BAD_DESC");
+            SEND_HS_DESC_FAILED_CONTENT();
             break;
           case RCS_OKAY:
           default:
@@ -2125,6 +2131,10 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
                      "descriptor.");
             control_event_hs_descriptor_received(conn->rend_data,
                                                  conn->identity_digest);
+            control_event_hs_descriptor_content(conn->rend_data->onion_address,
+                                                conn->requested_resource,
+                                                conn->identity_digest,
+                                                body);
             conn->base_.purpose = DIR_PURPOSE_HAS_FETCHED_RENDDESC_V2;
             rend_client_desc_trynow(conn->rend_data->onion_address);
             break;
@@ -2136,6 +2146,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
         log_info(LD_REND,"Fetching v2 rendezvous descriptor failed: "
                          "Retrying at another directory.");
         SEND_HS_DESC_FAILED_EVENT("NOT_FOUND");
+        SEND_HS_DESC_FAILED_CONTENT();
         break;
       case 400:
         log_warn(LD_REND, "Fetching v2 rendezvous descriptor failed: "
@@ -2143,6 +2154,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
                  "v2 rendezvous query? Retrying at another directory.",
                  escaped(reason));
         SEND_HS_DESC_FAILED_EVENT("QUERY_REJECTED");
+        SEND_HS_DESC_FAILED_CONTENT();
         break;
       default:
         log_warn(LD_REND, "Fetching v2 rendezvous descriptor failed: "
@@ -2152,6 +2164,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
                  status_code, escaped(reason), conn->base_.address,
                  conn->base_.port);
         SEND_HS_DESC_FAILED_EVENT("UNEXPECTED");
+        SEND_HS_DESC_FAILED_CONTENT();
         break;
     }
   }