Control: command to lookup cached HS descriptor

This adds the key "hs/client/desc/id/<ADDR>" to the GETINFO command used to
lookup the given onion address in the client hs descriptor cache.

If found, prints it formatted as specified in section 1.3 of rend-spec.txt.

Fixes #14845

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

diff --git a/src/or/control.c b/src/or/control.c
index 064b745c9f898abcaa12f14c4b727293bccf1f04..8d899dc9f747d1ac67758f9430911aab84e6ad7f 100644 (file)
--- a/src/or/control.c
+++ b/src/or/control.c
@@ -41,6 +41,8 @@
 #include "router.h"
 #include "routerlist.h"
 #include "routerparse.h"
+#include "rendclient.h"
+#include "rendcommon.h"
 
 #ifndef _WIN32
 #include <pwd.h>
@@ -1713,6 +1715,25 @@ getinfo_helper_dir(control_connection_t *control_conn,
     *answer = smartlist_join_strings(sl, "", 0, NULL);
     SMARTLIST_FOREACH(sl, char *, c, tor_free(c));
     smartlist_free(sl);
+  } else if (!strcmpstart(question, "hs/client/desc/id/")) {
+    char *msg;
+    rend_cache_entry_t *e = NULL;
+
+    question += strlen("hs/client/desc/id/");
+    if (strlen(question) != REND_SERVICE_ID_LEN_BASE32) {
+      tor_asprintf(&msg, "\"%s\" invalid address.", question);
+      *errmsg = msg;
+      return -1;
+    }
+
+    if (rend_cache_lookup_entry(question, -1, &e) > 0) {
+      /* Descriptor found in cache */
+      *answer = tor_strdup(e->desc);
+    } else {
+      tor_asprintf(&msg, "\"%s\" not found in cache.", question);
+      *errmsg = msg;
+      return -1;
+    }
   } else if (!strcmpstart(question, "md/id/")) {
     const node_t *node = node_get_by_hex_id(question+strlen("md/id/"));
     const microdesc_t *md = NULL;
@@ -2176,6 +2197,8 @@ static const getinfo_item_t getinfo_items[] = {
   PREFIX("md/id/", dir, "Microdescriptors by ID"),
   PREFIX("md/name/", dir, "Microdescriptors by name"),
   PREFIX("extra-info/digest/", dir, "Extra-info documents by digest."),
+  PREFIX("hs/client/desc/id", dir,
+         "Hidden Service descriptor in client's cache by onion."),
   PREFIX("net/listeners/", listeners, "Bound addresses by type"),
   ITEM("ns/all", networkstatus,
        "Brief summary of router status (v2 directory format)"),