From 61fd63d70578043de9f3bff1c3267c499dbf50a0 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn@samba.org>
Date: Wed, 10 Nov 2021 12:06:51 +0100
Subject: [PATCH] auth:creds: Guess the username first via getpwuid(my_id)

If we have a container, we often don't have USER or LOGNAME set.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14883

Tested-by: Anoop C S <anoopcs@samba.org>
Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
(cherry picked from commit c28be4067463e582e378df402f812e510883d606)
---
 auth/credentials/credentials.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/auth/credentials/credentials.c b/auth/credentials/credentials.c
index 02a3cf3b354..c5a6ba6940c 100644
--- a/auth/credentials/credentials.c
+++ b/auth/credentials/credentials.c
@@ -30,6 +30,7 @@
 #include "tevent.h"
 #include "param/param.h"
 #include "system/filesys.h"
+#include "system/passwd.h"
 
 /**
  * Create a new credentials structure
@@ -1159,6 +1160,7 @@ _PUBLIC_ bool cli_credentials_guess(struct cli_credentials *cred,
 {
 	const char *error_string;
 	const char *env = NULL;
+	struct passwd *pwd = NULL;
 	bool ok;
 
 	if (lp_ctx != NULL) {
@@ -1168,6 +1170,17 @@ _PUBLIC_ bool cli_credentials_guess(struct cli_credentials *cred,
 		}
 	}
 
+	pwd = getpwuid(getuid());
+	if (pwd != NULL) {
+		size_t len = strlen(pwd->pw_name);
+
+		if (len > 0 && len <= 1024) {
+			(void)cli_credentials_parse_string(cred,
+							   pwd->pw_name,
+							   CRED_GUESS_ENV);
+		}
+	}
+
 	env = getenv("LOGNAME");
 	if (env != NULL) {
 		size_t len = strlen(env);
-- 
2.33.1