Add: GETINFO support for dumping microdesc consensus

test: case to check GETINFO consensus commands are functional.
fix: code structure
update: changes with human readable description
fix: command naming convention
add: test case checks if consensus body is returned
fix: potential memory leak
test: memory leak trace

changes/ticket31684

@@ -1,2 +1,2 @@
   o Minor features (onion services):
-    - GETINFO dir/status-vote/current/consensus-microdesc dumps microdesc consensus. Closes ticket 31684.
+    - Implement a new GETINFO command to fetch consensus. Closes ticket 31684.

src/feature/control/control_getinfo.c

@@ -326,46 +326,30 @@ getinfo_helper_current_time(control_connection_t *control_conn,
 }
 
 /**
- * Switch between microdesc vs networkstatus descriptor dumps
- * Assumes that question would be either:
- * - dir/status-vote/current/consensus-microdesc
- * or
- * - dir/status-vote/current/consensus
+ * Helps to access directory information for a given
+ * type of consensus.
  */
 STATIC int
-getinfo_helper_current_consensus(const char* question,
-                          char** answer,
-                          const char** errmsg)
+getinfo_helper_current_consensus(const char* flavor_name,
+                                 char** answer,
+                                 const char** errmsg)
 {
-  // Ensures question contains a request for
-  // ns or microdesc consensus
-  if (
-      strcmp(question, "dir/status-vote/current/consensus") &&
-      strcmp(question, "dir/status-vote/current/consensus-microdesc")) {
-    return 0;
-  }
-
-  const char* consensus_type = !strcmp(
-     question, "dir/status-vote/current/consensus-microdesc"
-  ) ? "microdesc" : "ns";
-
   if (we_want_to_fetch_flavor(get_options(), FLAV_NS)) {
-    const cached_dir_t *consensus = dirserv_get_consensus(consensus_type);
-    if (consensus) {
+    const cached_dir_t *consensus = dirserv_get_consensus(flavor_name);
+    if (consensus)
       *answer = tor_strdup(consensus->dir);
-    }
   }
   if (!*answer) { /* try loading it from disk */
-    tor_mmap_t *mapped = networkstatus_map_cached_consensus(consensus_type);
+    tor_mmap_t *mapped = networkstatus_map_cached_consensus(flavor_name);
     if (mapped) {
       *answer = tor_memdup_nulterm(mapped->data, mapped->size);
       tor_munmap_file(mapped);
     }
     if (!*answer) { /* generate an error */
       *errmsg = "Could not open cached consensus. "
         "Make sure FetchUselessDescriptors is set to 1.";
-       return -1;
-   }
+      return -1;
+    }
   }
   return 0;
 }
@@ -622,16 +606,16 @@ getinfo_helper_dir(control_connection_t *control_conn,
     smartlist_free(descs);
   } else if (!strcmpstart(question, "dir/status/")) {
     *answer = tor_strdup("");
-  } else if (-1 == getinfo_helper_current_consensus(
-                                                    question,
-                                                    answer,
-                                                    errmsg))
-  {
-    /**
-     * answer is set by getinfo_helper_current_consensus
-     * if the question matches
-     */
-    return -1;
+  } else if (!strcmp(question, "dir/status-vote/current/consensus")) {
+    if (getinfo_helper_current_consensus("ns", answer, errmsg) == -1) {
+      return -1;
+    }
+  } else if (!strcmp(question,
+                     "dir/status-vote/current/consensus-microdesc")) {
+    if (getinfo_helper_current_consensus("microdesc",
+                                         answer, errmsg) == -1) {
+        return -1;
+      }
   } else if (!strcmp(question, "network-status")) { /* v1 */
     static int network_status_warned = 0;
     if (!network_status_warned) {

src/feature/control/control_getinfo.h

@@ -49,7 +49,8 @@ STATIC int getinfo_helper_downloads(
     const char *question, char **answer,
     const char **errmsg);
 STATIC int getinfo_helper_current_consensus(
-    const char *question, char **answer,
+    const char* flavor_name,
+    char **answer,
     const char **errmsg);
 STATIC int getinfo_helper_dir(
     control_connection_t *control_conn,

src/feature/dircache/dirserv.c

@@ -259,8 +259,9 @@ dirserv_set_cached_consensus_networkstatus(const char *networkstatus,
 
 /** Return the latest downloaded consensus networkstatus in encoded, signed,
  * optionally compressed format, suitable for sending to clients. */
-cached_dir_t *
-dirserv_get_consensus(const char *flavor_name)
+MOCK_IMPL(cached_dir_t *,
+          dirserv_get_consensus,
+          (const char *flavor_name))
 {
   if (!cached_consensuses)
     return NULL;

src/feature/dircache/dirserv.h

@@ -82,7 +82,7 @@ int directory_permits_begindir_requests(const or_options_t *options);
 int directory_too_idle_to_fetch_descriptors(const or_options_t *options,
                                             time_t now);
 
-cached_dir_t *dirserv_get_consensus(const char *flavor_name);
+MOCK_DECL(cached_dir_t *, dirserv_get_consensus, (const char *flavor_name));
 void dirserv_set_cached_consensus_networkstatus(const char *consensus,
                                               size_t consensus_len,
                                               const char *flavor_name,

src/feature/nodelist/networkstatus.c

@@ -216,10 +216,11 @@ networkstatus_reset_download_failures(void)
 }
 
 /** Return the filename used to cache the consensus of a given flavor */
-static char *
-networkstatus_get_cache_fname(int flav,
-                              const char *flavorname,
-                              int unverified_consensus)
+MOCK_IMPL(char *,
+          networkstatus_get_cache_fname,
+          (int flav,
+          const char *flavorname,
+          int unverified_consensus))
 {
   char buf[128];
   const char *prefix;

src/feature/nodelist/networkstatus.h

@@ -16,7 +16,12 @@
 
 void networkstatus_reset_warnings(void);
 void networkstatus_reset_download_failures(void);
-tor_mmap_t *networkstatus_map_cached_consensus(const char *flavorname);
+MOCK_DECL(char *,
+          networkstatus_get_cache_fname,
+          (int flav,
+           const char *flavorname,
+           int unverified_consensus));
+tor_mmap_t * networkstatus_map_cached_consensus(const char *flavorname);
 int router_reload_consensus_networkstatus(void);
 void routerstatus_free_(routerstatus_t *rs);
 #define routerstatus_free(rs) \

src/lib/fs/mmap.c

@@ -42,8 +42,7 @@
  * failure, return NULL. Sets errno properly, using ERANGE to mean
  * "empty file". Must only be called on trusted Tor-owned files, as changing
  * the underlying file's size causes unspecified behavior. */
-tor_mmap_t *
-tor_mmap_file(const char *filename)
+MOCK_IMPL(tor_mmap_t *, tor_mmap_file, (const char *filename))
 {
   int fd; /* router file */
   char *string;
@@ -111,8 +110,7 @@ tor_mmap_file(const char *filename)
 }
 /** Release storage held for a memory mapping; returns 0 on success,
  * or -1 on failure (and logs a warning). */
-int
-tor_munmap_file(tor_mmap_t *handle)
+MOCK_IMPL(int, tor_munmap_file, (tor_mmap_t *handle))
 {
   int res;
 
@@ -132,8 +130,8 @@ tor_munmap_file(tor_mmap_t *handle)
   return res;
 }
 #elif defined(_WIN32)
-tor_mmap_t *
-tor_mmap_file(const char *filename)
+
+MOCK_IMPL(tor_mmap_t *, tor_mmap_file, (const char *filename))
 {
   TCHAR tfilename[MAX_PATH]= {0};
   tor_mmap_t *res = tor_malloc_zero(sizeof(tor_mmap_t));
@@ -213,8 +211,7 @@ tor_mmap_file(const char *filename)
 }
 
 /* Unmap the file, and return 0 for success or -1 for failure */
-int
-tor_munmap_file(tor_mmap_t *handle)
+MOCK_IMPL(int, tor_munmap_file, (tor_mmap_t *handle))
 {
   if (handle == NULL)
     return 0;

src/lib/fs/mmap.h

@@ -13,6 +13,7 @@
 #define TOR_MMAP_H
 
 #include "lib/cc/compat_compiler.h"
+#include "lib/testsupport/testsupport.h"
 #include <stddef.h>
 
 #ifdef _WIN32
@@ -35,7 +36,7 @@ typedef struct tor_mmap_t {
 
 } tor_mmap_t;
 
-tor_mmap_t *tor_mmap_file(const char *filename);
-int tor_munmap_file(tor_mmap_t *handle);
+MOCK_DECL(tor_mmap_t *, tor_mmap_file, (const char *filename));
+MOCK_DECL(int, tor_munmap_file, (tor_mmap_t *handle));
 
 #endif /* !defined(TOR_MMAP_H) */

src/test/test_controller.c

@@ -27,6 +27,7 @@
 #include "feature/dirclient/download_status_st.h"
 #include "feature/nodelist/microdesc_st.h"
 #include "feature/nodelist/node_st.h"
+#include "feature/dircache/dirserv.c"
 
 typedef struct {
   const char *input;
@@ -756,6 +757,7 @@ static download_status_t descbr_digest_2_dl;
 static const char *descbr_expected_list =
     "616408544C7345822696074A1A3DFA16AB381CBD\n"
     "06E8067246967265DBCB6641631B530EFEC12DC3\n";
+
 /*
  * Flag to make all descbr queries fail, to simulate not being
  * configured such that such queries make sense.
@@ -1689,6 +1691,114 @@ test_download_status_bridge(void *arg)
   return;
 }
 
+cached_dir_t *
+mock_dirserv_get_consensus(const char *flavor_name);
+
+cached_dir_t *
+mock_dirserv_get_consensus(const char *flavor_name)
+{
+  const char* string = NULL;
+  if (!strcmp(flavor_name, "microdesc")) {
+    string = "mock_microdesc_consensus";
+  } else if (!strcmp(flavor_name, "ns")) {
+    string = "mock_ns_consensus";
+  }
+  return new_cached_dir(tor_memdup_nulterm(string,
+                        strlen(string)),
+                        time(NULL));
+}
+
+char *
+mock_networkstatus_get_cache_fname(int flav,
+                                   const char *flavor_name,
+                                   int unverified_consensus);
+
+char *
+mock_networkstatus_get_cache_fname(int flav,
+                                   const char *flavor_name,
+                                   int unverified_consensus)
+{
+  flav = flav & 1;
+  unverified_consensus = unverified_consensus & 1;
+  return tor_strdup(flavor_name);
+}
+
+tor_mmap_t *
+mock_tor_mmap_file(const char* filename);
+
+tor_mmap_t *
+mock_tor_mmap_file(const char* filename)
+{
+  tor_mmap_t *res;
+  res = tor_malloc_zero(sizeof(tor_mmap_t));
+  if (!strcmp(filename, "ns")) {
+    res->data = "mock_ns_consensus";
+  }
+  if (!strcmp(filename, "microdesc")) {
+    res->data = "mock_microdesc_consensus";
+  }
+  res->size = strlen(res->data);
+  return res;
+}
+
+int
+mock_tor_munmap_file(tor_mmap_t *handle);
+
+int
+mock_tor_munmap_file(tor_mmap_t *handle)
+{
+  tor_free(handle);
+  return 0;
+}
+
+static void
+test_getinfo_helper_dir(void *arg)
+{
+  /* We just need one of these to pass, it doesn't matter what's in it */
+  control_connection_t dummy;
+  /* Get results out */
+  char *answer = NULL;
+  const char *errmsg = NULL;
+
+  (void)arg;
+
+  setup_bridge_mocks();
+  MOCK(tor_mmap_file, mock_tor_mmap_file);
+  MOCK(tor_munmap_file, mock_tor_munmap_file);
+  MOCK(networkstatus_get_cache_fname,
+       mock_networkstatus_get_cache_fname);
+  MOCK(networkstatus_get_cache_fname,
+       mock_networkstatus_get_cache_fname);
+  MOCK(dirserv_get_consensus,
+       mock_dirserv_get_consensus);
+
+  getinfo_helper_dir(&dummy,
+                     "dir/status-vote/current/consensus",
+                     &answer,
+                     &errmsg);
+  tt_str_op(answer, OP_EQ, "mock_ns_consensus");
+  tt_ptr_op(errmsg, OP_EQ, NULL);
+  tor_free(answer);
+  errmsg = NULL;
+
+  getinfo_helper_dir(&dummy,
+                     "dir/status-vote/current/consensus-microdesc",
+                     &answer,
+                     &errmsg);
+  tt_str_op(answer, OP_EQ, "mock_microdesc_consensus");
+  tt_ptr_op(errmsg, OP_EQ, NULL);
+  errmsg = NULL;
+
+ done:
+  clear_bridge_mocks();
+  tor_free(answer);
+  UNMOCK(tor_mmap_file);
+  UNMOCK(tor_munmap_file);
+  UNMOCK(networkstatus_get_cache_fname);
+  UNMOCK(dirserv_get_consensus);
+  return;
+}
+
 /** Set timeval to a mock date and time. This is necessary
  * to make tor_gettimeofday() mockable. */
 static void
@@ -1734,13 +1844,12 @@ test_current_time(void *arg)
   tt_ptr_op(answer, OP_NE, NULL);
   tt_ptr_op(errmsg, OP_EQ, NULL);
   tt_str_op(answer, OP_EQ, timebuf);
-  tor_free(answer);
   errmsg = NULL;
+  answer = NULL;
 
  done:
   UNMOCK(tor_gettimeofday);
   tor_free(answer);
-
   return;
 }
 
@@ -1838,6 +1947,8 @@ struct testcase_t controller_tests[] = {
     NULL },
   { "download_status_consensus", test_download_status_consensus, 0, NULL,
     NULL },
+  {"getinfo_helper_dir", test_getinfo_helper_dir, 0, NULL,
+   NULL },
   { "download_status_cert", test_download_status_cert, 0, NULL,
     NULL },
   { "download_status_desc", test_download_status_desc, 0, NULL, NULL },