Added metadata query of debuginfod servers

Debuginfod servers can be queried by source path and will return JSON
arrays of all the known metadata.

Signed-off-by: Ryan Goldberg <rgoldber@redhat.com>

16 files changed, 960 insertions, 334 deletions

diff --git a/ChangeLog b/ChangeLog
index 7bbb2c0f..efce0716 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2022-10-06  Ryan Goldberg <rgoldber@redhat.com>
+
+	* configure.ac (HAVE_JSON_C): Defined iff libjson-c
+	is found, and debuginfod metadata querying is thus enabled.
+
 2022-10-20  Mark Wielaard  <mark@klomp.org>
 
 	* Makefile.am (rpm): Remove --sign.
diff --git a/configure.ac b/configure.ac
index 1084b469..6077d52a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -600,6 +600,11 @@ case "$ac_cv_search__obstack_free" in
 esac
 AC_SUBST([obstack_LIBS])
 
+AC_CHECK_LIB(json-c, json_object_array_add, [
+  AC_DEFINE([HAVE_JSON_C], [1], [Define if json-c is on the machine])
+  AC_SUBST(jsonc_LIBS, '-ljson-c')
+])
+
 dnl The directories with content.
 
 dnl Documentation.
diff --git a/debuginfod/ChangeLog b/debuginfod/ChangeLog
index 1df903fe..79f827d9 100644
--- a/debuginfod/ChangeLog
+++ b/debuginfod/ChangeLog
@@ -1,3 +1,27 @@
+2022-10-06  Ryan Goldberg <rgoldber@redhat.com>
+
+	* Makefile.am (debuginfod_LDADD): Add jsonc_LIBS.
+	(libdebuginfod_so_LDLIBS): Likewise.
+	* debuginfod-find.c (main): Add command line interface for
+	metadata query by path.
+	* debuginfod.h.in: Added debuginfod_find_metadata.
+	* debuginfod.cxx (add_client_federation_headers): New function
+	created from existing code to remove code duplication.
+	(handle_buildid_match): Calls new add_client_federation_headers
+	function.
+	(handle_metadata): New function which queries local DB and
+	upstream for metadata.
+	(handler_cb): New accepted url type, /metadata.
+	* debuginfod-client.c (struct handle_data): New fields: metadata,
+	metadata_size, to store incoming metadata.
+	(metadata_callback): New function called by curl upon reciving
+	metedata
+	(init_server_urls, init_handle, perform_queries) : New functions created from
+	existing code within debuginfod_query_server to reduce code duplication.
+	(debuginfod_query_server_by_buildid): debuginfod_query_server renamed, and above
+	functions used in place of identical previously inline code.
+	(debuginfod_find_metadata): New function.
+
 2022-10-18  Daniel Thornburgh <dthorn@google.com>
 
   * debuginfod-client.c (debuginfod_query_server): Add DEBUGINFOD_HEADERS_FILE
diff --git a/debuginfod/Makefile.am b/debuginfod/Makefile.am
index 435cb8a6..3d6bc26e 100644
--- a/debuginfod/Makefile.am
+++ b/debuginfod/Makefile.am
@@ -70,7 +70,7 @@ bin_PROGRAMS += debuginfod-find
 endif
 
 debuginfod_SOURCES = debuginfod.cxx
-debuginfod_LDADD = $(libdw) $(libelf) $(libeu) $(libdebuginfod) $(argp_LDADD) $(fts_LIBS) $(libmicrohttpd_LIBS) $(sqlite3_LIBS) $(libarchive_LIBS) -lpthread -ldl
+debuginfod_LDADD = $(libdw) $(libelf) $(libeu) $(libdebuginfod) $(argp_LDADD) $(fts_LIBS) $(libmicrohttpd_LIBS) $(sqlite3_LIBS) $(libarchive_LIBS) $(jsonc_LIBS) $(libcurl_LIBS) -lpthread -ldl
 
 debuginfod_find_SOURCES = debuginfod-find.c
 debuginfod_find_LDADD = $(libdw) $(libelf) $(libeu) $(libdebuginfod) $(argp_LDADD) $(fts_LIBS)
@@ -97,7 +97,7 @@ libdebuginfod_so_LIBS = libdebuginfod_pic.a
 if DUMMY_LIBDEBUGINFOD
 libdebuginfod_so_LDLIBS =
 else
-libdebuginfod_so_LDLIBS = -lpthread $(libcurl_LIBS) $(fts_LIBS)
+libdebuginfod_so_LDLIBS = -lpthread $(libcurl_LIBS) $(fts_LIBS) $(jsonc_LIBS)
 endif
 $(LIBDEBUGINFOD_SONAME): $(srcdir)/libdebuginfod.map $(libdebuginfod_so_LIBS)
 	$(AM_V_CCLD)$(LINK) $(dso_LDFLAGS) -o $@ \
diff --git a/debuginfod/debuginfod-client.c b/debuginfod/debuginfod-client.c
index 716cb769..2be9a07e 100644
--- a/debuginfod/debuginfod-client.c
+++ b/debuginfod/debuginfod-client.c
@@ -56,6 +56,8 @@ int debuginfod_find_executable (debuginfod_client *c, const unsigned char *b,
                                 int s, char **p) { return -ENOSYS; }
 int debuginfod_find_source (debuginfod_client *c, const unsigned char *b,
                             int s, const char *f, char **p)  { return -ENOSYS; }
+int debuginfod_find_metadata (debuginfod_client *c,
+                                const char* p, char** m) { return -ENOSYS; }
 void debuginfod_set_progressfn(debuginfod_client *c,
 			       debuginfod_progressfn_t fn) { }
 void debuginfod_set_verbose_fd(debuginfod_client *c, int fd) { }
@@ -103,6 +105,10 @@ void debuginfod_end (debuginfod_client *c) { }
 
 #include <pthread.h>
 
+#ifdef HAVE_JSON_C
+  #include <json-c/json.h>
+#endif
+
 static pthread_once_t init_control = PTHREAD_ONCE_INIT;
 
 static void
@@ -201,6 +207,9 @@ struct handle_data
   /* Response http headers for this client handle, sent from the server */
   char *response_data;
   size_t response_data_size;
+  /* Response metadata values for this client handle, sent from the server */
+  char *metadata;
+  size_t metadata_size;
 };
 
 static size_t
@@ -555,18 +564,9 @@ header_callback (char * buffer, size_t size, size_t numitems, void * userdata)
   }
   /* Temporary buffer for realloc */
   char *temp = NULL;
-  if (data->response_data == NULL)
-    {
-      temp = malloc(numitems);
-      if (temp == NULL)
-        return 0;
-    }
-  else
-    {
-      temp = realloc(data->response_data, data->response_data_size + numitems);
-      if (temp == NULL)
-        return 0;
-    }
+  temp = realloc(data->response_data, data->response_data_size + numitems);
+  if (temp == NULL)
+    return 0;
 
   memcpy(temp + data->response_data_size, buffer, numitems-1);
   data->response_data = temp;
@@ -576,13 +576,345 @@ header_callback (char * buffer, size_t size, size_t numitems, void * userdata)
   return numitems;
 }
 
+#ifdef HAVE_JSON_C
+static size_t
+metadata_callback (char * buffer, size_t size, size_t numitems, void * userdata)
+{
+  if (size != 1)
+    return 0;
+  /* Temporary buffer for realloc */
+  char *temp = NULL;
+  struct handle_data *data = (struct handle_data *) userdata;
+  temp = realloc(data->metadata, data->metadata_size + numitems + 1);
+  if (temp == NULL)
+    return 0;
+
+  memcpy(temp + data->metadata_size, buffer, numitems);
+  data->metadata = temp;
+  data->metadata_size += numitems;
+  data->metadata[data->metadata_size] = '\0';
+  return numitems;
+}
+#endif
+
+
+/* This function takes a copy of DEBUGINFOD_URLS, server_urls, and seperates it into an
+ * array of urls to query. The url_subdir is either 'buildid' or 'metadata', corresponding
+ * to the query type. Returns 0 on success and -Posix error on faliure.
+ */
+int
+init_server_urls(char* url_subdir, char *server_urls, char ***server_url_list, int *num_urls, int vfd)
+{
+  /* Initialize the memory to zero */
+  char *strtok_saveptr;
+  char *server_url = strtok_r(server_urls, url_delim, &strtok_saveptr);
+  /* Count number of URLs.  */
+  int n = 0;
+  assert(0 == strcmp(url_subdir, "buildid") || 0 == strcmp(url_subdir, "metadata"));
+
+  /* PR 27983: If the url is already set to be used use, skip it */
+  while (server_url != NULL)
+  {
+    int r;
+    char *tmp_url;
+    if (strlen(server_url) > 1 && server_url[strlen(server_url)-1] == '/')
+      r = asprintf(&tmp_url, "%s%s", server_url, url_subdir);
+    else
+      r = asprintf(&tmp_url, "%s/%s", server_url, url_subdir);
+
+    if (r == -1)
+      {
+        return -ENOMEM;
+      }
+    int url_index;
+    for (url_index = 0; url_index < n; ++url_index)
+      {
+        if(strcmp(tmp_url, (*server_url_list)[url_index]) == 0)
+          {
+            url_index = -1;
+            break;
+          }
+      }
+    if (url_index == -1)
+      {
+        if (vfd >= 0)
+          dprintf(vfd, "duplicate url: %s, skipping\n", tmp_url);
+        free(tmp_url);
+      }
+    else
+      {
+        n++;
+        char ** realloc_ptr;
+        realloc_ptr = reallocarray(*server_url_list, n,
+                                        sizeof(char*));
+        if (realloc_ptr == NULL)
+          {
+            free (tmp_url);
+            return -ENOMEM;
+          }
+        *server_url_list = realloc_ptr;
+        (*server_url_list)[n-1] = tmp_url;
+      }
+    server_url = strtok_r(NULL, url_delim, &strtok_saveptr);
+  }
+  *num_urls = n;
+  return 0;
+}
+
+/* Some boilerplate for checking curl_easy_setopt.  */
+#define curl_easy_setopt_ck(H,O,P) do {			\
+      CURLcode curl_res = curl_easy_setopt (H,O,P);	\
+      if (curl_res != CURLE_OK)				\
+	    {						\
+	      if (vfd >= 0)					\
+	        dprintf (vfd,				\
+            "Bad curl_easy_setopt: %s\n",	\
+		      curl_easy_strerror(curl_res));	\
+	      return -EINVAL;					\
+	    }						\
+      } while (0)
+
+
+/*
+ * This function initializes a CURL handle. It takes optional callbacks for the write
+ * function and the header function, which if defined will use userdata of type struct handle_data*.
+ * Specifically the data[i] within an array of struct handle_data's.
+ * Returns 0 on success and -Posix error on faliure.
+ */
+int
+init_handle(debuginfod_client *client,
+  size_t (*w_callback)(char *buffer,size_t size,size_t nitems,void *userdata),
+  size_t (*h_callback)(char *buffer,size_t size,size_t nitems,void *userdata),
+  struct handle_data *data, int i, long timeout,
+  int vfd)
+{
+  data->handle = curl_easy_init();
+  if (data->handle == NULL)
+  {
+    return -ENETUNREACH;
+  }
+
+  if (vfd >= 0)
+    dprintf (vfd, "url %d %s\n", i, data->url);
+
+  /* Only allow http:// + https:// + file:// so we aren't being
+    redirected to some unsupported protocol.  */
+  curl_easy_setopt_ck(data->handle, CURLOPT_PROTOCOLS,
+    (CURLPROTO_HTTP | CURLPROTO_HTTPS | CURLPROTO_FILE));
+  curl_easy_setopt_ck(data->handle, CURLOPT_URL, data->url);
+  if (vfd >= 0)
+    curl_easy_setopt_ck(data->handle, CURLOPT_ERRORBUFFER,
+      data->errbuf);
+  if(w_callback) {
+    curl_easy_setopt_ck(data->handle,
+      CURLOPT_WRITEFUNCTION, w_callback);
+    curl_easy_setopt_ck(data->handle, CURLOPT_WRITEDATA, data);
+  }
+  if (timeout > 0)
+  {
+    /* Make sure there is at least some progress,
+      try to get at least 100K per timeout seconds.  */
+    curl_easy_setopt_ck (data->handle, CURLOPT_LOW_SPEED_TIME,
+            timeout);
+    curl_easy_setopt_ck (data->handle, CURLOPT_LOW_SPEED_LIMIT,
+            100 * 1024L);
+  }
+  data->response_data = NULL;
+  data->response_data_size = 0;
+  curl_easy_setopt_ck(data->handle, CURLOPT_FILETIME, (long) 1);
+  curl_easy_setopt_ck(data->handle, CURLOPT_FOLLOWLOCATION, (long) 1);
+  curl_easy_setopt_ck(data->handle, CURLOPT_FAILONERROR, (long) 1);
+  curl_easy_setopt_ck(data->handle, CURLOPT_NOSIGNAL, (long) 1);
+  if(h_callback){
+    curl_easy_setopt_ck(data->handle,
+      CURLOPT_HEADERFUNCTION, h_callback);
+    curl_easy_setopt_ck(data->handle, CURLOPT_HEADERDATA, data);
+  }
+  #if LIBCURL_VERSION_NUM >= 0x072a00 /* 7.42.0 */
+  curl_easy_setopt_ck(data->handle, CURLOPT_PATH_AS_IS, (long) 1);
+  #else
+  /* On old curl; no big deal, canonicalization here is almost the
+      same, except perhaps for ? # type decorations at the tail. */
+  #endif
+  curl_easy_setopt_ck(data->handle, CURLOPT_AUTOREFERER, (long) 1);
+  curl_easy_setopt_ck(data->handle, CURLOPT_ACCEPT_ENCODING, "");
+  curl_easy_setopt_ck(data->handle, CURLOPT_HTTPHEADER, client->headers);
+
+  return 0;
+}
+
+
+/*
+ * This function busy-waits on one or more curl queries to complete. This can
+ * be controled via only_one, which, if true, will find the first winner and exit
+ * once found. If positive maxtime and maxsize dictate the maximum allowed wait times
+ * and download sizes respectivly. Returns 0 on success and -Posix error on faliure.
+ */
+int
+perform_queries(CURLM *curlm, CURL **target_handle, struct handle_data *data, debuginfod_client *c,
+  int num_urls, long maxtime, long maxsize, bool only_one, int vfd)
+{
+  int still_running = -1;
+  long loops = 0;
+  int committed_to = -1;
+  bool verbose_reported = false;
+  struct timespec start_time, cur_time;
+  if (c->winning_headers != NULL)
+    {
+      free (c->winning_headers);
+      c->winning_headers = NULL;
+    }
+  if ( maxtime > 0 && clock_gettime(CLOCK_MONOTONIC_RAW, &start_time) == -1)
+  {
+    return errno;
+  }
+  long delta = 0;
+  do
+  {
+    /* Check to see how long querying is taking. */
+    if (maxtime > 0)
+    {
+      if (clock_gettime(CLOCK_MONOTONIC_RAW, &cur_time) == -1)
+      {
+        return errno;
+      }
+      delta = cur_time.tv_sec - start_time.tv_sec;
+      if ( delta >  maxtime)
+      {
+        dprintf(vfd, "Timeout with max time=%lds and transfer time=%lds\n", maxtime, delta );
+        return -ETIME;
+      }
+    }
+    /* Wait 1 second, the minimum DEBUGINFOD_TIMEOUT.  */
+    curl_multi_wait(curlm, NULL, 0, 1000, NULL);
+    CURLMcode curlm_res = curl_multi_perform(curlm, &still_running);
+
+    if(only_one){
+      /* If the target file has been found, abort the other queries.  */
+      if (target_handle && *target_handle != NULL)
+      {
+        for (int i = 0; i < num_urls; i++)
+          if (data[i].handle != *target_handle)
+            curl_multi_remove_handle(curlm, data[i].handle);
+          else
+          {
+            committed_to = i;
+            if (c->winning_headers == NULL)
+            {
+              c->winning_headers = data[committed_to].response_data;
+              if (vfd >= 0 && c->winning_headers != NULL)
+                dprintf(vfd, "\n%s", c->winning_headers);
+              data[committed_to].response_data = NULL;
+              data[committed_to].response_data_size = 0;
+            }
+          }
+      }
+
+      if (vfd >= 0 && !verbose_reported && committed_to >= 0)
+      {
+        bool pnl = (c->default_progressfn_printed_p && vfd == STDERR_FILENO);
+        dprintf (vfd, "%scommitted to url %d\n", pnl ? "\n" : "",
+          committed_to);
+        if (pnl)
+          c->default_progressfn_printed_p = 0;
+        verbose_reported = true;
+      }
+    }
+
+    if (curlm_res != CURLM_OK)
+    {
+      switch (curlm_res)
+      {
+      case CURLM_CALL_MULTI_PERFORM: continue;
+      case CURLM_OUT_OF_MEMORY: return -ENOMEM;
+      default: return -ENETUNREACH;
+      }
+    }
+
+    long dl_size = 0;
+    if(only_one && target_handle){ // Only bother with progress functions if we're retrieving exactly 1 file
+      if (*target_handle && (c->progressfn || maxsize > 0))
+      {
+        /* Get size of file being downloaded. NB: If going through
+            deflate-compressing proxies, this number is likely to be
+            unavailable, so -1 may show. */
+        CURLcode curl_res;
+#ifdef CURLINFO_CONTENT_LENGTH_DOWNLOAD_T
+        curl_off_t cl;
+        curl_res = curl_easy_getinfo(*target_handle,
+                                      CURLINFO_CONTENT_LENGTH_DOWNLOAD_T,
+                                      &cl);
+        if (curl_res == CURLE_OK && cl >= 0)
+          dl_size = (cl > LONG_MAX ? LONG_MAX : (long)cl);
+#else
+        double cl;
+        curl_res = curl_easy_getinfo(*target_handle,
+                                      CURLINFO_CONTENT_LENGTH_DOWNLOAD,
+                                      &cl);
+        if (curl_res == CURLE_OK)
+          dl_size = (cl >= (double)(LONG_MAX+1UL) ? LONG_MAX : (long)cl);
+#endif
+        /* If Content-Length is -1, try to get the size from
+            X-Debuginfod-Size */
+        if (dl_size == -1 && c->winning_headers != NULL)
+        {
+          long xdl;
+          char *hdr = strcasestr(c->winning_headers, "x-debuginfod-size");
+
+          if (hdr != NULL
+              && sscanf(hdr, "x-debuginfod-size: %ld", &xdl) == 1)
+            dl_size = xdl;
+        }
+      }
+
+      if (c->progressfn) /* inform/check progress callback */
+      {
+        loops ++;
+        long pa = loops; /* default param for progress callback */
+        if (*target_handle) /* we've committed to a server; report its download progress */
+        {
+          CURLcode curl_res;
+#ifdef CURLINFO_SIZE_DOWNLOAD_T
+          curl_off_t dl;
+          curl_res = curl_easy_getinfo(*target_handle,
+                                        CURLINFO_SIZE_DOWNLOAD_T,
+                                        &dl);
+          if (curl_res == 0 && dl >= 0)
+            pa = (dl > LONG_MAX ? LONG_MAX : (long)dl);
+#else
+          double dl;
+          curl_res = curl_easy_getinfo(*target_handle,
+                                        CURLINFO_SIZE_DOWNLOAD,
+                                        &dl);
+          if (curl_res == 0)
+            pa = (dl >= (double)(LONG_MAX+1UL) ? LONG_MAX : (long)dl);
+#endif
+
+        }
+
+        if ((*c->progressfn) (c, pa, dl_size))
+          break;
+      }
+    }
+    /* Check to see if we are downloading something which exceeds maxsize, if set.*/
+    if (target_handle && *target_handle && dl_size > maxsize && maxsize > 0)
+    {
+      if (vfd >=0)
+        dprintf(vfd, "Content-Length too large.\n");
+      return -EFBIG;
+    }
+  } while (still_running);
+  return 0;
+}
+
+
 /* Query each of the server URLs found in $DEBUGINFOD_URLS for the file
    with the specified build-id, type (debuginfo, executable or source)
    and filename. filename may be NULL. If found, return a file
    descriptor for the target, otherwise return an error code.
 */
 static int
-debuginfod_query_server (debuginfod_client *c,
+debuginfod_query_server_by_buildid (debuginfod_client *c,
 			 const unsigned char *build_id,
                          int build_id_len,
                          const char *type,
@@ -601,7 +933,7 @@ debuginfod_query_server (debuginfod_client *c,
   char suffix[PATH_MAX + 1]; /* +1 for zero terminator.  */
   char build_id_bytes[MAX_BUILD_ID_BYTES * 2 + 1];
   int vfd = c->verbose_fd;
-  int rc;
+  int rc, r;
 
   if (vfd >= 0)
     {
@@ -915,60 +1247,14 @@ debuginfod_query_server (debuginfod_client *c,
       goto out0;
     }
 
-  /* Initialize the memory to zero */
-  char *strtok_saveptr;
   char **server_url_list = NULL;
-  char *server_url = strtok_r(server_urls, url_delim, &strtok_saveptr);
-  /* Count number of URLs.  */
-  int num_urls = 0;
-
-  while (server_url != NULL)
-    {
-      /* PR 27983: If the url is already set to be used use, skip it */
-      char *slashbuildid;
-      if (strlen(server_url) > 1 && server_url[strlen(server_url)-1] == '/')
-        slashbuildid = "buildid";
-      else
-        slashbuildid = "/buildid";
-
-      char *tmp_url;
-      if (asprintf(&tmp_url, "%s%s", server_url, slashbuildid) == -1)
-        {
-          rc = -ENOMEM;
-          goto out1;
-        }
-      int url_index;
-      for (url_index = 0; url_index < num_urls; ++url_index)
-        {
-          if(strcmp(tmp_url, server_url_list[url_index]) == 0)
-            {
-              url_index = -1;
-              break;
-            }
-        }
-      if (url_index == -1)
-        {
-          if (vfd >= 0)
-            dprintf(vfd, "duplicate url: %s, skipping\n", tmp_url);
-          free(tmp_url);
-        }
-      else
-        {
-          num_urls++;
-          char ** realloc_ptr;
-          realloc_ptr = reallocarray(server_url_list, num_urls,
-                                         sizeof(char*));
-          if (realloc_ptr == NULL)
-            {
-              free (tmp_url);
-              rc = -ENOMEM;
-              goto out1;
-            }
-          server_url_list = realloc_ptr;
-          server_url_list[num_urls-1] = tmp_url;
-        }
-      server_url = strtok_r(NULL, url_delim, &strtok_saveptr);
-    }
+  char *server_url;
+  int num_urls;
+  r = init_server_urls("buildid", server_urls, &server_url_list, &num_urls, vfd);
+  if(0 != r){
+    rc = r;
+    goto out1;
+  }
 
   int retry_limit = default_retry_limit;
   const char* retry_limit_envvar = getenv(DEBUGINFOD_RETRY_LIMIT_ENV_VAR);
@@ -1038,13 +1324,6 @@ debuginfod_query_server (debuginfod_client *c,
 
       data[i].fd = fd;
       data[i].target_handle = &target_handle;
-      data[i].handle = curl_easy_init();
-      if (data[i].handle == NULL)
-        {
-          if (filename) curl_free (escaped_string);
-          rc = -ENETUNREACH;
-          goto out2;
-        }
       data[i].client = c;
 
       if (filename) /* must start with / */
@@ -1055,220 +1334,30 @@ debuginfod_query_server (debuginfod_client *c,
         }
       else
         snprintf(data[i].url, PATH_MAX, "%s/%s/%s", server_url, build_id_bytes, type);
-      if (vfd >= 0)
-	dprintf (vfd, "url %d %s\n", i, data[i].url);
 
-      /* Some boilerplate for checking curl_easy_setopt.  */
-#define curl_easy_setopt_ck(H,O,P) do {			\
-      CURLcode curl_res = curl_easy_setopt (H,O,P);	\
-      if (curl_res != CURLE_OK)				\
-	{						\
-	  if (vfd >= 0)					\
-	    dprintf (vfd,				\
-	             "Bad curl_easy_setopt: %s\n",	\
-		     curl_easy_strerror(curl_res));	\
-	  rc = -EINVAL;					\
-	  goto out2;					\
-	}						\
-      } while (0)
-
-      /* Only allow http:// + https:// + file:// so we aren't being
-	 redirected to some unsupported protocol.  */
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_PROTOCOLS,
-			  (CURLPROTO_HTTP | CURLPROTO_HTTPS | CURLPROTO_FILE));
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_URL, data[i].url);
-      if (vfd >= 0)
-	curl_easy_setopt_ck(data[i].handle, CURLOPT_ERRORBUFFER,
-			    data[i].errbuf);
-      curl_easy_setopt_ck(data[i].handle,
-			  CURLOPT_WRITEFUNCTION,
-			  debuginfod_write_callback);
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_WRITEDATA, (void*)&data[i]);
-      if (timeout > 0)
-	{
-	  /* Make sure there is at least some progress,
-	     try to get at least 100K per timeout seconds.  */
-	  curl_easy_setopt_ck (data[i].handle, CURLOPT_LOW_SPEED_TIME,
-			       timeout);
-	  curl_easy_setopt_ck (data[i].handle, CURLOPT_LOW_SPEED_LIMIT,
-			       100 * 1024L);
-	}
-      data[i].response_data = NULL;
-      data[i].response_data_size = 0;
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_FILETIME, (long) 1);
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_FOLLOWLOCATION, (long) 1);
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_FAILONERROR, (long) 1);
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_NOSIGNAL, (long) 1);
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_HEADERFUNCTION,
-			  header_callback);
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_HEADERDATA,
-			  (void *) &(data[i]));
-#if LIBCURL_VERSION_NUM >= 0x072a00 /* 7.42.0 */
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_PATH_AS_IS, (long) 1);
-#else
-      /* On old curl; no big deal, canonicalization here is almost the
-         same, except perhaps for ? # type decorations at the tail. */
-#endif
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_AUTOREFERER, (long) 1);
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_ACCEPT_ENCODING, "");
-      curl_easy_setopt_ck(data[i].handle, CURLOPT_HTTPHEADER, c->headers);
+      r = init_handle(c, debuginfod_write_callback, header_callback,
+        data+i,i, timeout, vfd);
+      if(0 != r){
+        rc = r;
+        if(filename) curl_free (escaped_string);
+        goto out2;
+      }
 
       curl_multi_add_handle(curlm, data[i].handle);
     }
 
   if (filename) curl_free(escaped_string);
+
   /* Query servers in parallel.  */
   if (vfd >= 0)
     dprintf (vfd, "query %d urls in parallel\n", num_urls);
-  int still_running;
-  long loops = 0;
-  int committed_to = -1;
-  bool verbose_reported = false;
-  struct timespec start_time, cur_time;
 
-  free (c->winning_headers);
-  c->winning_headers = NULL;
-  if ( maxtime > 0 && clock_gettime(CLOCK_MONOTONIC_RAW, &start_time) == -1)
+  r = perform_queries(curlm, &target_handle,data,c, num_urls, maxtime, maxsize, true,  vfd);
+  if (0 != r)
     {
-      rc = -errno;
+      rc = r;
       goto out2;
     }
-  long delta = 0;
-  do
-    {
-      /* Check to see how long querying is taking. */
-      if (maxtime > 0)
-        {
-          if (clock_gettime(CLOCK_MONOTONIC_RAW, &cur_time) == -1)
-            {
-              rc = -errno;
-              goto out2;
-            }
-          delta = cur_time.tv_sec - start_time.tv_sec;
-          if ( delta >  maxtime)
-            {
-              dprintf(vfd, "Timeout with max time=%lds and transfer time=%lds\n", maxtime, delta );
-              rc = -ETIME;
-              goto out2;
-            }
-        }
-      /* Wait 1 second, the minimum DEBUGINFOD_TIMEOUT.  */
-      curl_multi_wait(curlm, NULL, 0, 1000, NULL);
-      CURLMcode curlm_res = curl_multi_perform(curlm, &still_running);
-
-      /* If the target file has been found, abort the other queries.  */
-      if (target_handle != NULL)
-	{
-	  for (int i = 0; i < num_urls; i++)
-	    if (data[i].handle != target_handle)
-	      curl_multi_remove_handle(curlm, data[i].handle);
-	    else
-              {
-	        committed_to = i;
-                if (c->winning_headers == NULL)
-                  {
-                    c->winning_headers = data[committed_to].response_data;
-                    data[committed_to].response_data = NULL;
-                    data[committed_to].response_data_size = 0;
-                  }
-
-              }
-	}
-
-      if (vfd >= 0 && !verbose_reported && committed_to >= 0)
-	{
-	  bool pnl = (c->default_progressfn_printed_p && vfd == STDERR_FILENO);
-	  dprintf (vfd, "%scommitted to url %d\n", pnl ? "\n" : "",
-		   committed_to);
-	  if (pnl)
-	    c->default_progressfn_printed_p = 0;
-	  verbose_reported = true;
-	}
-
-      if (curlm_res != CURLM_OK)
-        {
-          switch (curlm_res)
-            {
-            case CURLM_CALL_MULTI_PERFORM: continue;
-            case CURLM_OUT_OF_MEMORY: rc = -ENOMEM; break;
-            default: rc = -ENETUNREACH; break;
-            }
-          goto out2;
-        }
-
-      long dl_size = 0;
-      if (target_handle && (c->progressfn || maxsize > 0))
-        {
-          /* Get size of file being downloaded. NB: If going through
-             deflate-compressing proxies, this number is likely to be
-             unavailable, so -1 may show. */
-          CURLcode curl_res;
-#ifdef CURLINFO_CONTENT_LENGTH_DOWNLOAD_T
-          curl_off_t cl;
-          curl_res = curl_easy_getinfo(target_handle,
-                                       CURLINFO_CONTENT_LENGTH_DOWNLOAD_T,
-                                       &cl);
-          if (curl_res == CURLE_OK && cl >= 0)
-            dl_size = (cl > LONG_MAX ? LONG_MAX : (long)cl);
-#else
-          double cl;
-          curl_res = curl_easy_getinfo(target_handle,
-                                       CURLINFO_CONTENT_LENGTH_DOWNLOAD,
-                                       &cl);
-          if (curl_res == CURLE_OK)
-            dl_size = (cl >= (double)(LONG_MAX+1UL) ? LONG_MAX : (long)cl);
-#endif
-          /* If Content-Length is -1, try to get the size from
-             X-Debuginfod-Size */
-          if (dl_size == -1 && c->winning_headers != NULL)
-            {
-              long xdl;
-              char *hdr = strcasestr(c->winning_headers, "x-debuginfod-size");
-
-              if (hdr != NULL
-                  && sscanf(hdr, "x-debuginfod-size: %ld", &xdl) == 1)
-                dl_size = xdl;
-            }
-        }
-
-      if (c->progressfn) /* inform/check progress callback */
-        {
-          loops ++;
-          long pa = loops; /* default param for progress callback */
-          if (target_handle) /* we've committed to a server; report its download progress */
-            {
-              CURLcode curl_res;
-#ifdef CURLINFO_SIZE_DOWNLOAD_T
-              curl_off_t dl;
-              curl_res = curl_easy_getinfo(target_handle,
-                                           CURLINFO_SIZE_DOWNLOAD_T,
-                                           &dl);
-              if (curl_res == 0 && dl >= 0)
-                pa = (dl > LONG_MAX ? LONG_MAX : (long)dl);
-#else
-              double dl;
-              curl_res = curl_easy_getinfo(target_handle,
-                                           CURLINFO_SIZE_DOWNLOAD,
-                                           &dl);
-              if (curl_res == 0)
-                pa = (dl >= (double)(LONG_MAX+1UL) ? LONG_MAX : (long)dl);
-#endif
-
-            }
-
-          if ((*c->progressfn) (c, pa, dl_size))
-            break;
-        }
-
-      /* Check to see if we are downloading something which exceeds maxsize, if set.*/
-      if (target_handle && dl_size > maxsize && maxsize > 0)
-        {
-          if (vfd >=0)
-            dprintf(vfd, "Content-Length too large.\n");
-          rc = -EFBIG;
-          goto out2;
-        }
-    } while (still_running);
 
   /* Check whether a query was successful. If so, assign its handle
      to verified_handle.  */
@@ -1625,7 +1714,7 @@ debuginfod_find_debuginfo (debuginfod_client *client,
 			   const unsigned char *build_id, int build_id_len,
                            char **path)
 {
-  return debuginfod_query_server(client, build_id, build_id_len,
+  return debuginfod_query_server_by_buildid(client, build_id, build_id_len,
                                  "debuginfo", NULL, path);
 }
 
@@ -1636,7 +1725,7 @@ debuginfod_find_executable(debuginfod_client *client,
 			   const unsigned char *build_id, int build_id_len,
                            char **path)
 {
-  return debuginfod_query_server(client, build_id, build_id_len,
+  return debuginfod_query_server_by_buildid(client, build_id, build_id_len,
                                  "executable", NULL, path);
 }
 
@@ -1645,10 +1734,210 @@ int debuginfod_find_source(debuginfod_client *client,
 			   const unsigned char *build_id, int build_id_len,
                            const char *filename, char **path)
 {
-  return debuginfod_query_server(client, build_id, build_id_len,
+  return debuginfod_query_server_by_buildid(client, build_id, build_id_len,
                                  "source", filename, path);
 }
 
+int debuginfod_find_metadata (debuginfod_client *client,
+			    const char* path, char** metadata)
+{
+  (void) client;
+  (void) path;
+  if(NULL == metadata) return EPERM;
+  *metadata = strdup("[ ]"); // An empty JSON array
+#ifdef HAVE_JSON_C
+  char *server_urls;
+  char *urls_envvar;
+  json_object *json_metadata = json_object_new_array();
+  int rc = 0, r;
+  int vfd = client->verbose_fd;
+
+  if(NULL == json_metadata){
+    rc = -ENOMEM;
+    goto out;
+  }
+
+  if(NULL == path){
+    rc = -ENOSYS;
+    goto out;
+  }
+
+  if (vfd >= 0)
+    dprintf (vfd, "debuginfod_find_metadata %s\n", path);
+
+  /* Without query-able URL, we can stop here*/
+  urls_envvar = getenv(DEBUGINFOD_URLS_ENV_VAR);
+  if (vfd >= 0)
+    dprintf (vfd, "server urls \"%s\"\n",
+      urls_envvar != NULL ? urls_envvar : "");
+  if (urls_envvar == NULL || urls_envvar[0] == '\0')
+  {
+    rc = -ENOSYS;
+    goto out;
+  }
+
+  /* Clear the client of previous urls*/
+  free (client->url);
+  client->url = NULL;
+
+  long maxtime = 0;
+  const char *maxtime_envvar;
+  maxtime_envvar = getenv(DEBUGINFOD_MAXTIME_ENV_VAR);
+  if (maxtime_envvar != NULL)
+    maxtime = atol (maxtime_envvar);
+  if (maxtime && vfd >= 0)
+    dprintf(vfd, "using max time %lds\n", maxtime);
+
+  long timeout = default_timeout;
+  const char* timeout_envvar = getenv(DEBUGINFOD_TIMEOUT_ENV_VAR);
+  if (timeout_envvar != NULL)
+    timeout = atoi (timeout_envvar);
+  if (vfd >= 0)
+    dprintf (vfd, "using timeout %ld\n", timeout);
+
+  add_default_headers(client);
+
+  /* make a copy of the envvar so it can be safely modified.  */
+  server_urls = strdup(urls_envvar);
+  if (server_urls == NULL)
+  {
+    rc = -ENOMEM;
+    goto out;
+  }
+  /* thereafter, goto out1 on error*/
+
+  char **server_url_list = NULL;
+  char *server_url;
+  int num_urls;
+  r = init_server_urls("metadata", server_urls, &server_url_list, &num_urls, vfd);
+  if(0 != r){
+    rc = r;
+    goto out1;
+  }
+
+  CURLM *curlm = client->server_mhandle;
+  assert (curlm != NULL);
+
+  CURL *target_handle = NULL;
+  struct handle_data *data = malloc(sizeof(struct handle_data) * num_urls);
+  if (data == NULL)
+  {
+    rc = -ENOMEM;
+    goto out1;
+  }
+
+  /* thereafter, goto out2 on error.  */
+
+
+  /* Initialize handle_data  */
+  for (int i = 0; i < num_urls; i++)
+  {
+    if ((server_url = server_url_list[i]) == NULL)
+      break;
+    if (vfd >= 0)
+      dprintf (vfd, "init server %d %s\n", i, server_url);
+
+    data[i].errbuf[0] = '\0';
+    data[i].target_handle = &target_handle;
+    data[i].client = client;
+    data[i].metadata = NULL;
+    data[i].metadata_size = 0;
+
+    // At the moment only glob path querying is supported, but leave room for
+    // future expansion
+    const char *key = "glob";
+    snprintf(data[i].url, PATH_MAX, "%s?%s=%s", server_url, key, path);
+    r = init_handle(client, metadata_callback, header_callback,
+      data+i, i, timeout, vfd);
+    if(0 != r){
+      rc = r;
+      goto out2;
+    }
+    curl_multi_add_handle(curlm, data[i].handle);
+  }
+
+  /* Query servers */
+  if (vfd >= 0)
+      dprintf (vfd, "Starting %d queries\n",num_urls);
+  r = perform_queries(curlm, NULL, data, client, num_urls, maxtime, 0, false, vfd);
+  if(0 != r){
+    rc = r;
+    goto out2;
+  }
+
+  /* NOTE: We don't check the return codes of the curl messages since
+     a metadata query failing silently is just fine. We want to know what's
+     available from servers which can be connected with no issues.
+     If running with additional verbosity, the failure will be noted in stderr */
+
+  /* Building the new json array from all the upstream data
+    and cleanup while at it
+  */
+  for (int i = 0; i < num_urls; i++)
+  {
+    curl_multi_remove_handle(curlm, data[i].handle); /* ok to repeat */
+    if(NULL == data[i].metadata)
+    {
+      if (vfd >= 0)
+        dprintf (vfd, "Query to %s failed with error message:\n\t\"%s\"\n",
+          data[i].url, data[i].errbuf);
+      continue;
+    }
+    json_object *upstream_metadata = json_tokener_parse(data[i].metadata);
+    if(NULL == upstream_metadata) continue;
+    // Combine the upstream metadata into the json array
+    for (int j = 0, n = json_object_array_length(upstream_metadata); j < n; j++) {
+        json_object *entry = json_object_array_get_idx(upstream_metadata, j);
+        json_object_get(entry); // increment reference count
+        json_object_array_add(json_metadata, entry);
+    }
+    json_object_put(upstream_metadata);
+
+    curl_easy_cleanup (data[i].handle);
+    free (data[i].response_data);
+    free (data[i].metadata);
+  }
+
+  free(*metadata);
+  *metadata = strdup(json_object_to_json_string_ext(json_metadata, JSON_C_TO_STRING_PRETTY));
+
+  free (data);
+  goto out1;
+
+/* error exits */
+out2:
+  /* remove all handles from multi */
+  for (int i = 0; i < num_urls; i++)
+  {
+    if (data[i].handle != NULL)
+    {
+      curl_multi_remove_handle(curlm, data[i].handle); /* ok to repeat */
+      curl_easy_cleanup (data[i].handle);
+      free (data[i].response_data);
+      free (data[i].metadata);
+    }
+  }
+  free(data);
+
+out1:
+  for (int i = 0; i < num_urls; ++i)
+    free(server_url_list[i]);
+  free(server_url_list);
+  free (server_urls);
+
+/* general purpose exit */
+out:
+  json_object_put(json_metadata);
+  /* Reset sent headers */
+  curl_slist_free_all (client->headers);
+  client->headers = NULL;
+  client->user_agent_set_p = 0;
+
+  return rc;
+#else
+  return -ENOSYS;
+#endif
+}
 
 /* Add an outgoing HTTP header.  */
 int debuginfod_add_http_header (debuginfod_client *client, const char* header)
diff --git a/debuginfod/debuginfod-find.c b/debuginfod/debuginfod-find.c
index 778fb09b..ecaf954e 100644
--- a/debuginfod/debuginfod-find.c
+++ b/debuginfod/debuginfod-find.c
@@ -31,6 +31,9 @@
 #include <gelf.h>
 #include <libdwelf.h>
 
+#ifdef HAVE_JSON_C
+  #include <json-c/json.h>
+#endif
 
 /* Name and version of program.  */
 ARGP_PROGRAM_VERSION_HOOK_DEF = print_version;
@@ -48,7 +51,8 @@ static const char args_doc[] = N_("debuginfo BUILDID\n"
                                   "executable BUILDID\n"
                                   "executable PATH\n"
                                   "source BUILDID /FILENAME\n"
-                                  "source PATH /FILENAME\n");
+                                  "source PATH /FILENAME\n"
+                                  "metadata GLOB");
 
 
 /* Definitions of arguments for argp functions.  */
@@ -140,6 +144,33 @@ main(int argc, char** argv)
       return 1;
     }
 
+  if(strcmp(argv[remaining], "metadata") == 0){
+    #ifdef HAVE_JSON_C
+      if (remaining+1 == argc)
+      {
+        fprintf(stderr, "If FILETYPE is \"metadata\" then GLOB must be given\n");
+        return 1;
+      }
+
+      char* metadata;
+      int rc = debuginfod_find_metadata (client, argv[remaining+1], &metadata);
+
+      if (rc < 0)
+      {
+        fprintf(stderr, "Server query failed: %s\n", strerror(-rc));
+        return 1;
+      }
+      // Output the metadata to stdout
+      printf("%s\n", metadata);
+      free(metadata);
+      return 0;
+    #else
+      fprintf(stderr, "If FILETYPE is \"metadata\" then libjson-c must be available\n");
+      return 1;
+    #endif
+
+  }
+
   /* If we were passed an ELF file name in the BUILDID slot, look in there. */
   unsigned char* build_id = (unsigned char*) argv[remaining+1];
   int build_id_len = 0; /* assume text */
diff --git a/debuginfod/debuginfod.cxx b/debuginfod/debuginfod.cxx
index 9dc4836b..b9cf15ed 100644
--- a/debuginfod/debuginfod.cxx
+++ b/debuginfod/debuginfod.cxx
@@ -115,6 +115,9 @@ using namespace std;
 #define tid() pthread_self()
 #endif
 
+#ifdef HAVE_JSON_C
+  #include <json-c/json.h>
+#endif
 
 inline bool
 string_endswith(const string& haystack, const string& needle)
@@ -1824,6 +1827,58 @@ handle_buildid_r_match (bool internal_req_p,
   return r;
 }
 
+void
+add_client_federation_headers(debuginfod_client *client, MHD_Connection* conn){
+  // Transcribe incoming User-Agent:
+  string ua = MHD_lookup_connection_value (conn, MHD_HEADER_KIND, "User-Agent") ?: "";
+  string ua_complete = string("User-Agent: ") + ua;
+  debuginfod_add_http_header (client, ua_complete.c_str());
+
+  // Compute larger XFF:, for avoiding info loss during
+  // federation, and for future cyclicity detection.
+  string xff = MHD_lookup_connection_value (conn, MHD_HEADER_KIND, "X-Forwarded-For") ?: "";
+  if (xff != "")
+    xff += string(", "); // comma separated list
+
+  unsigned int xff_count = 0;
+  for (auto&& i : xff){
+    if (i == ',') xff_count++;
+  }
+
+  // if X-Forwarded-For: exceeds N hops,
+  // do not delegate a local lookup miss to upstream debuginfods.
+  if (xff_count >= forwarded_ttl_limit)
+    throw reportable_exception(MHD_HTTP_NOT_FOUND, "not found, --forwared-ttl-limit reached \
+and will not query the upstream servers");
+
+  // Compute the client's numeric IP address only - so can't merge with conninfo()
+  const union MHD_ConnectionInfo *u = MHD_get_connection_info (conn,
+                                                                MHD_CONNECTION_INFO_CLIENT_ADDRESS);
+  struct sockaddr *so = u ? u->client_addr : 0;
+  char hostname[256] = ""; // RFC1035
+  if (so && so->sa_family == AF_INET) {
+    (void) getnameinfo (so, sizeof (struct sockaddr_in), hostname, sizeof (hostname), NULL, 0,
+                        NI_NUMERICHOST);
+  } else if (so && so->sa_family == AF_INET6) {
+    struct sockaddr_in6* addr6 = (struct sockaddr_in6*) so;
+    if (IN6_IS_ADDR_V4MAPPED(&addr6->sin6_addr)) {
+      struct sockaddr_in addr4;
+      memset (&addr4, 0, sizeof(addr4));
+      addr4.sin_family = AF_INET;
+      addr4.sin_port = addr6->sin6_port;
+      memcpy (&addr4.sin_addr.s_addr, addr6->sin6_addr.s6_addr+12, sizeof(addr4.sin_addr.s_addr));
+      (void) getnameinfo ((struct sockaddr*) &addr4, sizeof (addr4),
+                          hostname, sizeof (hostname), NULL, 0,
+                          NI_NUMERICHOST);
+    } else {
+      (void) getnameinfo (so, sizeof (struct sockaddr_in6), hostname, sizeof (hostname), NULL, 0,
+                          NI_NUMERICHOST);
+    }
+  }
+
+  string xff_complete = string("X-Forwarded-For: ")+xff+string(hostname);
+  debuginfod_add_http_header (client, xff_complete.c_str());
+}
 
 static struct MHD_Response*
 handle_buildid_match (bool internal_req_p,
@@ -2010,57 +2065,7 @@ handle_buildid (MHD_Connection* conn,
       debuginfod_set_progressfn (client, & debuginfod_find_progress);
 
       if (conn)
-        {
-          // Transcribe incoming User-Agent:
-          string ua = MHD_lookup_connection_value (conn, MHD_HEADER_KIND, "User-Agent") ?: "";
-          string ua_complete = string("User-Agent: ") + ua;
-          debuginfod_add_http_header (client, ua_complete.c_str());
-
-          // Compute larger XFF:, for avoiding info loss during
-          // federation, and for future cyclicity detection.
-          string xff = MHD_lookup_connection_value (conn, MHD_HEADER_KIND, "X-Forwarded-For") ?: "";
-          if (xff != "")
-            xff += string(", "); // comma separated list
-
-          unsigned int xff_count = 0;
-          for (auto&& i : xff){
-            if (i == ',') xff_count++;
-          }
-
-          // if X-Forwarded-For: exceeds N hops,
-          // do not delegate a local lookup miss to upstream debuginfods.
-          if (xff_count >= forwarded_ttl_limit)
-            throw reportable_exception(MHD_HTTP_NOT_FOUND, "not found, --forwared-ttl-limit reached \
-and will not query the upstream servers");
-
-          // Compute the client's numeric IP address only - so can't merge with conninfo()
-          const union MHD_ConnectionInfo *u = MHD_get_connection_info (conn,
-                                                                       MHD_CONNECTION_INFO_CLIENT_ADDRESS);
-          struct sockaddr *so = u ? u->client_addr : 0;
-          char hostname[256] = ""; // RFC1035
-          if (so && so->sa_family == AF_INET) {
-            (void) getnameinfo (so, sizeof (struct sockaddr_in), hostname, sizeof (hostname), NULL, 0,
-                                NI_NUMERICHOST);
-          } else if (so && so->sa_family == AF_INET6) {
-            struct sockaddr_in6* addr6 = (struct sockaddr_in6*) so;
-            if (IN6_IS_ADDR_V4MAPPED(&addr6->sin6_addr)) {
-              struct sockaddr_in addr4;
-              memset (&addr4, 0, sizeof(addr4));
-              addr4.sin_family = AF_INET;
-              addr4.sin_port = addr6->sin6_port;
-              memcpy (&addr4.sin_addr.s_addr, addr6->sin6_addr.s6_addr+12, sizeof(addr4.sin_addr.s_addr));
-              (void) getnameinfo ((struct sockaddr*) &addr4, sizeof (addr4),
-                                  hostname, sizeof (hostname), NULL, 0,
-                                  NI_NUMERICHOST);
-            } else {
-              (void) getnameinfo (so, sizeof (struct sockaddr_in6), hostname, sizeof (hostname), NULL, 0,
-                                  NI_NUMERICHOST);
-            }
-          }
-          
-          string xff_complete = string("X-Forwarded-For: ")+xff+string(hostname);
-          debuginfod_add_http_header (client, xff_complete.c_str());
-        }
+        add_client_federation_headers(client, conn);
 
       if (artifacttype == "debuginfo")
 	fd = debuginfod_find_debuginfo (client,
@@ -2273,6 +2278,110 @@ handle_metrics (off_t* size)
 }
 
 static struct MHD_Response*
+handle_metadata (MHD_Connection* conn,
+                string path, off_t* size)
+{
+  MHD_Response* r;
+  (void) conn;
+  (void) path;
+  (void) size;
+  #ifdef HAVE_JSON_C
+  sqlite3 *thisdb = dbq;
+
+  json_object *metadata = json_object_new_array();
+  // Query locally for matching e, d and s files
+  if(metadata){
+    sqlite_ps *pp = new sqlite_ps (thisdb, "mhd-query-m",
+    "select * from \n"
+    "(\n"
+      "select \"e\" as atype, mtime, buildid, sourcetype, source0, source1, null as artifactsrc, null as source0ref "
+      "from " BUILDIDS "_query_e "
+      "union all \n"
+      "select \"d\" as atype, mtime, buildid, sourcetype, source0, source1, null as artifactsrc, null as source0ref "
+      "from " BUILDIDS "_query_d "
+      "union all \n"
+      "select \"s\" as atype, mtime, buildid, sourcetype, source0, source1, artifactsrc, source0ref "
+      "from " BUILDIDS "_query_s "
+      "\n"
+    ")\n"
+    "where source1 glob ? ");
+
+    pp->reset();
+    pp->bind(1, path);
+
+    unique_ptr<sqlite_ps> ps_closer(pp); // release pp if exception or return
+
+    // consume all the rows
+    int rc;
+    while (SQLITE_DONE != (rc = pp->step()))
+    {
+      if (rc != SQLITE_ROW) throw sqlite_exception(rc, "step");
+
+      auto get_column_str = [pp](int idx) { return string((const char*) sqlite3_column_text (*pp, idx) ?: ""); };
+
+      string atype       = get_column_str(0);
+      string mtime       = to_string(sqlite3_column_int64 (*pp, 1));
+      string buildid     = get_column_str(2);
+      string stype       = get_column_str(3);
+      string source0     = get_column_str(4);
+      string source1     = get_column_str(5);
+      string artifactsrc = get_column_str(6);
+      string source0ref  = get_column_str(7);
+
+      json_object *entry = json_object_new_object();
+      auto add_entry_metadata = [entry](const char* key, string value) { if(value != "") json_object_object_add(entry, key, json_object_new_string(value.c_str())); };
+
+      add_entry_metadata("atype", atype);
+      add_entry_metadata("mtime", mtime);
+      add_entry_metadata("buildid", buildid);
+      add_entry_metadata("stype", stype);
+      add_entry_metadata("source0", source0);
+      add_entry_metadata("source1", source1);
+      add_entry_metadata("artifactsrc", artifactsrc);
+      add_entry_metadata("source0ref", source0ref);
+
+      json_object_array_add(metadata, json_object_get(entry)); // Increase ref count to switch its ownership
+      json_object_put(entry);
+    }
+    pp->reset();
+  }
+  // Query upstream as well
+  debuginfod_client *client = debuginfod_pool_begin();
+  if (metadata && client != NULL)
+  {
+    add_client_federation_headers(client, conn);
+
+    char * upstream_metadata;
+    if(0 == debuginfod_find_metadata(client, path.c_str(), &upstream_metadata)){
+      json_object *upstream_metadata_json = json_tokener_parse(upstream_metadata);
+      if(NULL != upstream_metadata_json)
+        for (int i = 0, n = json_object_array_length(upstream_metadata_json); i < n; i++) {
+            json_object *entry = json_object_array_get_idx(upstream_metadata_json, i);
+            json_object_get(entry); // increment reference count
+            json_object_array_add(metadata, entry);
+        }
+      json_object_put(upstream_metadata_json);
+      free(upstream_metadata);
+    }
+    debuginfod_pool_end (client);
+  }
+
+  const char* metadata_str = (metadata != NULL) ?
+    json_object_to_json_string(metadata) : "[ ]" ;
+  r = MHD_create_response_from_buffer (strlen(metadata_str),
+                                       (void*) metadata_str,
+                                       MHD_RESPMEM_MUST_COPY);
+  *size = strlen(metadata_str);
+  json_object_put(metadata);
+  #else
+    throw reportable_exception("webapi error, metadata querying not supported by server");
+  #endif
+  if(r)
+    add_mhd_response_header(r, "Content-Type", "application/json");
+  return r;
+}
+
+static struct MHD_Response*
 handle_root (off_t* size)
 {
   static string version = "debuginfod (" + string (PACKAGE_NAME) + ") "
@@ -2406,6 +2515,23 @@ handler_cb (void * /*cls*/,
           inc_metric("http_requests_total", "type", artifacttype);
           r = handle_metrics(& http_size);
         }
+      else if (url1 == "/metadata")
+        {
+          tmp_inc_metric m ("thread_busy", "role", "http-metadata");
+
+          // At the moment only glob path querying is supported, but leave room for
+          // future expansion
+          const char *key = "glob";
+
+          const char* path = MHD_lookup_connection_value(connection, MHD_GET_ARGUMENT_KIND, key);
+          if (NULL == path)
+            throw reportable_exception("/metadata webapi error, need glob");
+
+          artifacttype = "metadata";
+          inc_metric("http_requests_total", "type", artifacttype);
+          r = handle_metadata(connection, path, &http_size);
+
+        }
       else if (url1 == "/")
         {
           artifacttype = "/";
diff --git a/debuginfod/debuginfod.h.in b/debuginfod/debuginfod.h.in
index 7d8e4972..076f8869 100644
--- a/debuginfod/debuginfod.h.in
+++ b/debuginfod/debuginfod.h.in
@@ -79,6 +79,16 @@ int debuginfod_find_source (debuginfod_client *client,
                             const char *filename,
                             char **path);
 
+/*  Query the urls contained in $DEBUGINFOD_URLS for metadata
+    with paths matching the given, glob-supporting path.
+
+   If successful, return 0, otherwise return a posix error code.
+   If successful, set *metadata to a malloc'd json array
+   with each entry being a json object of metadata for 1 file.
+   Caller must free() it later. metadata MUST be non-NULL */
+int debuginfod_find_metadata (debuginfod_client *client,
+			    const char* path, char** metadata);
+
 typedef int (*debuginfod_progressfn_t)(debuginfod_client *c, long a, long b);
 void debuginfod_set_progressfn(debuginfod_client *c,
 			       debuginfod_progressfn_t fn);
diff --git a/doc/ChangeLog b/doc/ChangeLog
index 269ed06e..7f852824 100644
--- a/doc/ChangeLog
+++ b/doc/ChangeLog
@@ -1,3 +1,10 @@
+2022-10-06  Ryan Goldberg <rgoldber@redhat.com>
+
+	* debuginfod-find.1: Document metadata query commandline API.
+	* debuginfod_find_debuginfo.1: Document metadata queryC API.
+	* debuginfod_find_metadata.3: New file.
+	* Makefile.am (notrans_dist_*_man3): Add it.
+
 2022-10-28  Arsen Arsenović  <arsen@aarsen.me>
 
 	* readelf.1: Document the --syms alias.
diff --git a/doc/Makefile.am b/doc/Makefile.am
index db2506fd..64ffdaa2 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -38,6 +38,7 @@ notrans_dist_man3_MANS += debuginfod_end.3
 notrans_dist_man3_MANS += debuginfod_find_debuginfo.3
 notrans_dist_man3_MANS += debuginfod_find_executable.3
 notrans_dist_man3_MANS += debuginfod_find_source.3
+notrans_dist_man3_MANS += debuginfod_find_metadata.3
 notrans_dist_man3_MANS += debuginfod_get_user_data.3
 notrans_dist_man3_MANS += debuginfod_get_url.3
 notrans_dist_man3_MANS += debuginfod_set_progressfn.3
diff --git a/doc/debuginfod-find.1 b/doc/debuginfod-find.1
index 957ec7e7..caea2462 100644
--- a/doc/debuginfod-find.1
+++ b/doc/debuginfod-find.1
@@ -29,6 +29,8 @@ debuginfod-find \- request debuginfo-related data
 .B debuginfod-find [\fIOPTION\fP]... source \fIBUILDID\fP \fI/FILENAME\fP
 .br
 .B debuginfod-find [\fIOPTION\fP]... source \fIPATH\fP \fI/FILENAME\fP
+.br
+.B debuginfod-find [\fIOPTION\fP]... metadata \fIGLOB\fP
 
 .SH DESCRIPTION
 \fBdebuginfod-find\fP queries one or more \fBdebuginfod\fP servers for
@@ -106,6 +108,21 @@ l l.
 \../bar/foo.c AT_comp_dir=/zoo/	source BUILDID /zoo//../bar/foo.c
 .TE
 
+.SS metadata \fIGLOB\fP
+
+If the given path, which may be globbed, is known to the server,
+this request will result in a json string being written to
+\fBstdout\fP. The result will consist of a json array, with one
+json object for each matching file's metadata. The result can be piped
+into \fBjq\fP for easy processing. On failure, an empty array is written
+as the output. Unlike finding by buildid no new file will be created or cached.
+
+For a given file's metadata, the result is guaranteed to contain, \fBatype\fP
+(the atrifact type), \fBbuildid\fP, \fBmtime\fP (time of last data modification,
+seconds since Epoch), \fBstype\fP (the sourcetype), \fBsource0\fP (the path to
+the file in the local filesystem), \fBsource1\fP (the path which is being globbed against).
+Extra fields and duplicated metadata may appear.
+
 .SH "OPTIONS"
 
 .TP
diff --git a/doc/debuginfod_find_debuginfo.3 b/doc/debuginfod_find_debuginfo.3
index 3dd83240..a7e8016c 100644
--- a/doc/debuginfod_find_debuginfo.3
+++ b/doc/debuginfod_find_debuginfo.3
@@ -43,6 +43,9 @@ LOOKUP FUNCTIONS
 .BI "                           int " build_id_len ","
 .BI "                           const char *" filename ","
 .BI "                           char ** " path ");"
+.BI "int debuginfod_find_metadata(debuginfod_client *" client ","
+.BI "                           const char *" path ","
+.BI "                           char** " metadata ");"
 
 OPTIONAL FUNCTIONS
 
@@ -109,6 +112,12 @@ A \fBclient\fP handle should be used from only one thread at a time.
 A handle may be reused for a series of lookups, which can improve
 performance due to retention of connections and caches.
 
+.BR debuginfod_find_metadata (),
+likewise queries the debuginfod server URLs contained in
+.BR $DEBUGINFOD_URLS
+but instead retrieves metadata. The given \fIpath\fP may contained
+the standard glob characters.
+
 .SH "RETURN VALUE"
 
 \fBdebuginfod_begin\fP returns the \fBdebuginfod_client\fP handle to
@@ -118,7 +127,11 @@ use with all other calls.  On error \fBNULL\fP will be returned and
 If a find family function is successful, the resulting file is saved
 to the client cache and a file descriptor to that file is returned.
 The caller needs to \fBclose\fP() this descriptor.  Otherwise, a
-negative error code is returned.
+negative error code is returned. The one excpetion is \fBdebuginfod_find_metadata\fP
+which likewise returns negative error codes, but on success returns 0
+and sets \fI*metadata\fP to a string-form json array of the found matching
+metadata. This should be freed by the caller. See \fIdebuginfod-find(1)\fP for 
+more information on the metadata being returned.
 
 .SH "OPTIONAL FUNCTIONS"
 
diff --git a/doc/debuginfod_find_metadata.3 b/doc/debuginfod_find_metadata.3
new file mode 100644
index 00000000..16279936
--- /dev/null
+++ b/doc/debuginfod_find_metadata.3
@@ -0,0 +1 @@
+.so man3/debuginfod_find_debuginfo.3
diff --git a/tests/ChangeLog b/tests/ChangeLog
index a240a705..79aae920 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,9 @@
+2022-10-06  Ryan Goldberg <rgoldber@redhat.com>
+
+	* run-debuginfod-find-metadata.sh: New test.
+	* Makefile.am (TESTS): Add run-debuginfod-find-metadata.sh.
+	(EXTRA_DIST): Likewise.
+
 2022-09-20  Yonggang Luo  <luoyonggang@gmail.com>
 
 	* Makefile.am (EXTRA_DIST): Remove debuginfod-rpms/hello2.spec.
diff --git a/tests/Makefile.am b/tests/Makefile.am
index ced4a826..aaa5d35a 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -247,7 +247,8 @@ TESTS += run-debuginfod-dlopen.sh \
          run-debuginfod-x-forwarded-for.sh \
          run-debuginfod-response-headers.sh \
          run-debuginfod-extraction-passive.sh \
-	 run-debuginfod-webapi-concurrency.sh
+	 run-debuginfod-webapi-concurrency.sh \
+	 run-debuginfod-find-metadata.sh
 endif
 if !OLD_LIBMICROHTTPD
 # Will crash on too old libmicrohttpd
@@ -554,6 +555,7 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh run-ar.sh \
 	     run-debuginfod-response-headers.sh \
              run-debuginfod-extraction-passive.sh \
              run-debuginfod-webapi-concurrency.sh \
+			 run-debuginfod-find-metadata.sh \
 	     debuginfod-rpms/fedora30/hello2-1.0-2.src.rpm \
 	     debuginfod-rpms/fedora30/hello2-1.0-2.x86_64.rpm \
 	     debuginfod-rpms/fedora30/hello2-debuginfo-1.0-2.x86_64.rpm \
diff --git a/tests/run-debuginfod-find-metadata.sh b/tests/run-debuginfod-find-metadata.sh
new file mode 100755
index 00000000..18c57067
--- /dev/null
+++ b/tests/run-debuginfod-find-metadata.sh
@@ -0,0 +1,89 @@
+#!/usr/bin/env bash
+#
+# Copyright (C) 2019-2021 Red Hat, Inc.
+# This file is part of elfutils.
+#
+# This file is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# elfutils is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. $srcdir/debuginfod-subr.sh
+
+# for test case debugging, uncomment:
+set -x
+unset VALGRIND_CMD
+
+type curl 2>/dev/null || { echo "need curl"; exit 77; }
+type jq 2>/dev/null || { echo "need jq"; exit 77; }
+
+pkg-config json-c libcurl || { echo "one or more libraries are missing (libjson-c, libcurl)"; exit 77; }
+
+DB=${PWD}/.debuginfod_tmp.sqlite
+export DEBUGINFOD_CACHE_PATH=${PWD}/.client_cache
+tempfiles $DB ${DB}_2
+
+# This variable is essential and ensures no time-race for claiming ports occurs
+# set base to a unique multiple of 100 not used in any other 'run-debuginfod-*' test
+base=13100
+get_ports
+mkdir R D
+cp -rvp ${abs_srcdir}/debuginfod-rpms/rhel7 R
+cp -rvp ${abs_srcdir}/debuginfod-debs/*deb D
+
+env LD_LIBRARY_PATH=$ldpath DEBUGINFOD_URLS= ${abs_builddir}/../debuginfod/debuginfod $VERBOSE -R \
+    -d $DB -p $PORT1 -t0 -g0 R > vlog$PORT1 2>&1 &
+PID1=$!
+tempfiles vlog$PORT1
+errfiles vlog$PORT1
+
+wait_ready $PORT1 'ready' 1
+wait_ready $PORT1 'thread_work_total{role="traverse"}' 1
+wait_ready $PORT1 'thread_work_pending{role="scan"}' 0
+wait_ready $PORT1 'thread_busy{role="scan"}' 0
+
+env LD_LIBRARY_PATH=$ldpath DEBUGINFOD_URLS="http://127.0.0.1:$PORT1 https://bad/url.web" ${abs_builddir}/../debuginfod/debuginfod $VERBOSE -U \
+    -d ${DB}_2 -p $PORT2 -t0 -g0 D > vlog$PORT2 2>&1 &
+PID2=$!
+tempfiles vlog$PORT2
+errfiles vlog$PORT2
+
+wait_ready $PORT2 'ready' 1
+wait_ready $PORT2 'thread_work_total{role="traverse"}' 1
+wait_ready $PORT2 'thread_work_pending{role="scan"}' 0
+wait_ready $PORT2 'thread_busy{role="scan"}' 0
+
+# have clients contact the new server
+export DEBUGINFOD_URLS=http://127.0.0.1:$PORT2
+
+tempfiles json.txt
+# Check that we find 11 files(which means that the local and upstream correctly reply to the query)
+N_FOUND=`env LD_LIBRARY_PATH=$ldpath ${abs_builddir}/../debuginfod/debuginfod-find metadata "/?sr*" | jq '. | length'`
+test $N_FOUND -eq 11
+
+# Query via the webapi as well
+MTIME=$(stat -c %Y D/hithere_1.0-1_amd64.deb)
+EXPECTED='[ { "atype": "e", "buildid": "f17a29b5a25bd4960531d82aa6b07c8abe84fa66", "mtime": "'$MTIME'", "stype": "R", "source0": "'$PWD'/D/hithere_1.0-1_amd64.deb", "source1": "/usr/bin/hithere"} ]'
+test `curl http://127.0.0.1:$PORT2/metadata?glob=/usr/bin/*hi* | jq ". == $EXPECTED" ` = 'true'
+
+# An empty array is returned on server error or if the file DNE
+test `env LD_LIBRARY_PATH=$ldpath ${abs_builddir}/../debuginfod/debuginfod-find metadata "/this/isnt/there" | jq ". == [ ]" ` = 'true'
+
+kill $PID1
+kill $PID2
+wait $PID1
+wait $PID2
+PID1=0
+PID2=0
+
+test `env LD_LIBRARY_PATH=$ldpath ${abs_builddir}/../debuginfod/debuginfod-find metadata "/usr/bin/hithere" | jq ". == [ ]" ` = 'true'
+
+exit 0