commit d8bad02afc7b7f30402b4e0e458df874a6d600da
Author: Mark Wielaard <mark@klomp.org>
Date:   Mon Dec 9 19:38:19 2019 +0100

    debuginfod: Check the DEBUGINFOD_URLS environment variable early in client.
    
    If the debuginfod-client isn't configured we should do as little
    as possible. Simply return early with ENOSYS if no servers are
    configured. This means we won't check
    
    This does change the behavior of the debuginfod_find calls slightly.
    Previously we would setup and check the cache if the given build-id
    was valid. Which might have provided a result if an earlier client
    had run with the same cache and valid server URLs which knew about
    that particular build-id. Now we don't return any cached results
    unless at least one server is configured.
    
    This prevents selinux errors when the library is used in a confined
    setup.
    
    Signed-off-by: Mark Wielaard <mark@klomp.org>

diff --git a/debuginfod/debuginfod-client.c b/debuginfod/debuginfod-client.c
index 302ea2dc..ab7b4e13 100644
--- a/debuginfod/debuginfod-client.c
+++ b/debuginfod/debuginfod-client.c
@@ -301,6 +301,16 @@ debuginfod_query_server (debuginfod_client *c,
   char target_cache_tmppath[PATH_MAX*5];
   char suffix[PATH_MAX*2];
   char build_id_bytes[MAX_BUILD_ID_BYTES * 2 + 1];
+  int rc;
+
+  /* Is there any server we can query?  If not, don't do any work,
+     just return with ENOSYS.  Don't even access the cache.  */
+  urls_envvar = getenv(server_urls_envvar);
+  if (urls_envvar == NULL || urls_envvar[0] == '\0')
+    {
+      rc = -ENOSYS;
+      goto out;
+    }
 
   /* Copy lowercase hex representation of build_id into buf.  */
   if ((build_id_len >= MAX_BUILD_ID_BYTES) ||
@@ -373,7 +383,7 @@ debuginfod_query_server (debuginfod_client *c,
   /* XXX combine these */
   snprintf(interval_path, sizeof(interval_path), "%s/%s", cache_path, cache_clean_interval_filename);
   snprintf(maxage_path, sizeof(maxage_path), "%s/%s", cache_path, cache_max_unused_age_filename);
-  int rc = debuginfod_init_cache(cache_path, interval_path, maxage_path);
+  rc = debuginfod_init_cache(cache_path, interval_path, maxage_path);
   if (rc != 0)
     goto out;
   rc = debuginfod_clean_cache(c, cache_path, interval_path, maxage_path);
@@ -390,14 +400,6 @@ debuginfod_query_server (debuginfod_client *c,
       return fd;
     }
 
-
-  urls_envvar = getenv(server_urls_envvar);
-  if (urls_envvar == NULL || urls_envvar[0] == '\0')
-    {
-      rc = -ENOSYS;
-      goto out;
-    }
-
   if (getenv(server_timeout_envvar))
     server_timeout = atoi (getenv(server_timeout_envvar));