From 7b465135217327d4941462c652d92762c639577d Mon Sep 17 00:00:00 2001
From: Yoni Couriel <yonic@google.com>
Date: Wed, 26 Jun 2024 11:30:11 +0300
Subject: [PATCH] Added NETCONFIG override by environment variable.

The NETCONFIG location can be overidden by setting the "NETCONFIG_OVERRIDE" environment variable.
This can facilitate unit testing.
---
 ntirpc/netconfig.h |  3 +++
 src/getnetconfig.c | 11 +++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/ntirpc/netconfig.h b/ntirpc/netconfig.h
index d250090cd5..296ba4827b 100644
--- a/ntirpc/netconfig.h
+++ b/ntirpc/netconfig.h
@@ -12,6 +12,9 @@
 #endif
 #define NETPATH	  "NETPATH"
 
+/* Environment variable to override the location of NETCONFIG */
+#define ENV_NETCONFIG_OVERRIDE "NETCONFIG_OVERRIDE"
+
 struct netconfig {
 	char *nc_netid;		/* Network ID */
 	unsigned long nc_semantics;	/* Semantics (see below) */
diff --git a/src/getnetconfig.c b/src/getnetconfig.c
index 3e22437325..b4e1f52457 100644
--- a/src/getnetconfig.c
+++ b/src/getnetconfig.c
@@ -162,6 +162,13 @@ __nc_error(void)
 	return (nc_addr);
 }
 
+static inline const char* getnetconfig_path(void)
+{
+	/* Overriding netconfig path is used for unit testing */
+	const char *const override = getenv(ENV_NETCONFIG_OVERRIDE);
+	return override != NULL ? override : NETCONFIG;
+}
+
 #define nc_error        (*(__nc_error()))
 /*
  * A call to setnetconfig() establishes a /etc/netconfig "session".  A session
@@ -196,7 +203,7 @@ setnetconfig(void)
 	ni.ref++;
 
 	if (!nc_file) {
-		nc_file = fopen(NETCONFIG, "r");
+		nc_file = fopen(getnetconfig_path(), "r");
 		if (!nc_file) {
 			ni.ref--;
 			mutex_unlock(&nc_mtx);
@@ -436,7 +443,7 @@ getnetconfigent(const char *netid)
 		}
 	}
 
-	file = fopen(NETCONFIG, "r");
+	file = fopen(getnetconfig_path(), "r");
 	if (!file) {
 		nc_error = NC_NONETCONFIG;
 		mutex_unlock(&nc_mtx);