Re: v5 [PATCH 6/6] nsswitch: use new internal API (callers)

[DJ Delorie <dj@redhat.com>]

Andreas Schwab <schwab@linux-m68k.org> writes:
> This makes nss_compat non-functional.

Since you have a way to test it, and have not included a reproducer,
could you please test this patch?

Thanks!

From 85b77876abf0d98eb57bf692499fd1f229459f72 Mon Sep 17 00:00:00 2001
From: DJ Delorie <dj@redhat.com>
Date: Mon, 15 Feb 2021 21:34:23 -0500
Subject: nss: fix nss_database_lookup2's alternate handling [27416]


diff --git a/nss/nsswitch.c b/nss/nsswitch.c
index 46f232d720..6d4aa3b019 100644
--- a/nss/nsswitch.c
+++ b/nss/nsswitch.c
@@ -76,24 +76,25 @@ __nss_database_lookup2 (const char *database, const char *alternate_name,
 
   for (database_id = 0; database_names[database_id]; database_id++)
     if (strcmp (database_names[database_id], database) == 0)
-	break;
+      /* If *NI is NULL, the database was not mentioned in nsswitch.conf.
+	 If *NI is not NULL, but *NI->module is NULL, the database was in
+	 nsswitch.conf but listed no actions.  We test for the former.  */
+      if (__nss_database_get (database_id, ni) && *ni != NULL)
+	return 0;
 
-  if (database_names[database_id] == NULL)
-    return -1;
+  /* Primary name not found, try alternate.  */
+  for (database_id = 0; database_names[database_id]; database_id++)
+    if (strcmp (database_names[database_id], alternate_name) == 0)
+      if (__nss_database_get (database_id, ni) && *ni != NULL)
+	return 0;
 
-  /* If *NI is NULL, the database was not mentioned in nsswitch.conf.
-     If *NI is not NULL, but *NI->module is NULL, the database was in
-     nsswitch.conf but listed no actions.  We test for the former.  */
-  if (__nss_database_get (database_id, ni) && *ni != NULL)
-    {
-      /* Success.  */
-      return 0;
-    }
-  else
-    {
-      /* Failure.  */
-      return -1;
-    }
+  /* Neither found, use default config.  */
+  *ni = __nss_action_parse (defconfig);
+  if (*ni != NULL)
+    return 0;
+
+  /* Failure.  */
+  return -1;
 }
 libc_hidden_def (__nss_database_lookup2)