Add: GETINFO support for dumping microdesc consensus

test: check if GETINFO commands return expected consensus data..
docs: function docs easier to understand
update: Code simplification and refactoring change

changes/ticket31684

@@ -1,2 +1,5 @@
   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 microdesc consensus. Closes ticket 31684.
+
+  o Code simplification and refactoring (onion services):
+    - Create a helper function that can fetch network status or microdesc consensuses.

src/feature/control/control_getinfo.c

@@ -325,47 +325,32 @@ getinfo_helper_current_time(control_connection_t *control_conn,
   return 0;
 }
 
-/**
- * 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
- */
+/** Fetch network-status or micro-descriptor
+ * returns: 0 on success -1 on error. */
 STATIC int
-getinfo_helper_current_consensus(const char* question,
-                          char** answer,
-                          const char** errmsg)
+getinfo_helper_current_consensus(int flavor,
+                                 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 (we_want_to_fetch_flavor(get_options(), flavor)) {
+    /** Check from the cache */
+    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 +607,21 @@ 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")) {
+    int consensus_result = getinfo_helper_current_consensus(FLAV_NS,
+                                                            "ns",
+                                                            answer, errmsg);
+    if (consensus_result == -1) {
+      return -1;
+    }
+  } else if (!strcmp(question,
+                     "dir/status-vote/current/consensus-microdesc")) {
+    int consensus_result = getinfo_helper_current_consensus(FLAV_MICRODESC,
+                                                            "microdesc",
+                                                            answer, errmsg);
+    if (consensus_result == -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 +49,9 @@ STATIC int getinfo_helper_downloads(
     const char *question, char **answer,
     const char **errmsg);
 STATIC int getinfo_helper_current_consensus(
-    const char *question, char **answer,
+    int flavor,
+    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;
@@ -856,8 +857,9 @@ router_get_consensus_status_by_id(const char *digest)
  *
  * For certificate fetches, use we_want_to_fetch_unknown_auth_certs, and
  * for serving fetched documents, use directory_caches_dir_info. */
-int
-we_want_to_fetch_flavor(const or_options_t *options, int flavor)
+MOCK_IMPL(int,
+          we_want_to_fetch_flavor,
+          (const or_options_t *options, int flavor))
 {
   if (flavor < 0 || flavor > N_CONSENSUS_FLAVORS) {
     /* This flavor is crazy; we don't want it */

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) \
@@ -71,7 +76,9 @@ const routerstatus_t *router_get_consensus_status_by_descriptor_digest(
 MOCK_DECL(routerstatus_t *,
           router_get_mutable_consensus_status_by_descriptor_digest,
           (networkstatus_t *consensus, const char *digest));
-int we_want_to_fetch_flavor(const or_options_t *options, int flavor);
+MOCK_DECL(int,
+          we_want_to_fetch_flavor,
+          (const or_options_t *options, int flavor));
 int we_want_to_fetch_unknown_auth_certs(const or_options_t *options);
 void networkstatus_consensus_download_failed(int status_code,
                                              const char *flavname);

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) */