From bc3b6846356532d0bcab88d97b0b84def32be7b1 Mon Sep 17 00:00:00 2001
From: Vincent Jardin <vjardin@free.fr>
Date: Sun, 1 Dec 2024 17:01:30 +0100
Subject: [PATCH] hostname: add conf hostname=

If the configuration provides a hostname, let's use it instead of the
local hostname.
---
 src/pam_radius_auth.c | 21 +++++++++++++++++++--
 src/pam_radius_auth.h |  2 ++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/pam_radius_auth.c b/src/pam_radius_auth.c
index 443c526..649020b 100644
--- a/src/pam_radius_auth.c
+++ b/src/pam_radius_auth.c
@@ -163,6 +163,19 @@ static int _pam_parse(int argc, CONST char **argv, radius_conf_t *conf)
 			ctrl |= PAM_DEBUG_ARG;
 			conf->debug = TRUE;
 
+		} else if (!strncmp(*argv, "hostname=", 9)) {
+			if (!strncmp(conf->hostname, (char*)*argv+9, MAXHOSTNAME)) {
+				_pam_log(LOG_WARNING, "ignoring duplicate '%s'", *argv);
+			} else {
+				/* truncate excessive hostnames to (MAXHOSTNAME -1) length */
+				if (strlen((char*)*argv+9) >= (MAXHOSTNAME - 1)) {
+					*((char*)*argv+9 + (MAXHOSTNAME - 1)) = 0;
+				}
+				/* set the new hostname */
+				memset(conf->hostname, 0, sizeof(conf->hostname));
+				snprintf(conf->hostname, MAXHOSTNAME, "%s", (char*)*argv+9);
+			}
+
 		} else if (!strncmp(arg, "prompt=", 7)) {
 			if (!strncmp(conf->prompt, (arg+7), MAXPROMPT)) {
 				_pam_log(LOG_WARNING, "ignoring duplicate '%s'", arg);
@@ -957,10 +970,14 @@ static int initialize(radius_conf_t *conf, int accounting)
  */
 static void build_radius_packet(AUTH_HDR *request, CONST char *user, CONST char *password, radius_conf_t *conf)
 {
-	char hostname[256];
+	char hostname[MAXHOSTNAME];
 
 	hostname[0] = '\0';
-	gethostname(hostname, sizeof(hostname) - 1);
+	if (conf->hostname[0] != '\0') {
+		strcpy(hostname, conf->hostname);
+	} else {
+		gethostname(hostname, sizeof(hostname) - 1);
+	}
 
 	/*
 	 *	For Access-Request, create a random authentication
diff --git a/src/pam_radius_auth.h b/src/pam_radius_auth.h
index acecb4d..6fa9b6a 100644
--- a/src/pam_radius_auth.h
+++ b/src/pam_radius_auth.h
@@ -58,6 +58,7 @@
 #define MAXPROMPT 33               /* max prompt length, including '\0' */
 #define DEFAULT_PROMPT "Password"  /* default prompt, without the ': '  */
 
+#define MAXHOSTNAME 65
 
 /*************************************************************************
  * Platform specific defines
@@ -190,6 +191,7 @@ typedef struct radius_conf_t {
 	int privilege_level;
 	int require_message_authenticator;
 	uint8_t *message_authenticator;
+	char hostname[MAXHOSTNAME];
 } radius_conf_t;
 
 #endif /* PAM_RADIUS_H */