From 7a27ce3077d2fa42c87bfa5f0cc0ad770ad25883 Mon Sep 17 00:00:00 2001
From: david reid <zathrasorama@gmail.com>
Date: Fri, 25 Aug 2017 23:17:17 +0100
Subject: [PATCH] Add the ability to set the group to run as.

---
 minidlna.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/minidlna.c b/minidlna.c
index 10b4806..48e56ff 100644
--- a/minidlna.c
+++ b/minidlna.c
@@ -68,6 +68,7 @@
 #include <limits.h>
 #include <libgen.h>
 #include <pwd.h>
+#include <grp.h>
 
 #include "config.h"
 
@@ -510,6 +511,7 @@ init(int argc, char **argv)
 	int ifaces = 0;
 	media_types types;
 	uid_t uid = 0;
+	gid_t gid = 0;
 
 	/* first check if "-f" option is used */
 	for (i=2; i<argc; i++)
@@ -857,7 +859,7 @@ init(int argc, char **argv)
 		case 'R':
 			snprintf(buf, sizeof(buf), "rm -rf %s/files.db %s/art_cache", db_path, db_path);
 			if (system(buf) != 0)
-				DPRINTF(E_FATAL, L_GENERAL, "Failed to clean old file cache. EXITING\n");
+				DPRINTF(E_FATAL, L_GENERAL, "Failed to clean old file cache %s. EXITING\n", db_path);
 			break;
 		case 'u':
 			if (i+1 != argc)
@@ -876,6 +878,22 @@ init(int argc, char **argv)
 			else
 				DPRINTF(E_FATAL, L_GENERAL, "Option -%c takes one argument.\n", argv[i][1]);
 			break;
+		case 'g':
+			if (i+1 != argc)
+			{
+				i++;
+				gid = strtoul(argv[i], &string, 0);
+				if (*string)
+				{
+					/* Symbolic group given, not GID. */
+					struct group *grp = getgrnam(argv[i]);
+					if (!grp)
+						DPRINTF(E_FATAL, L_GENERAL, "Bad group '%s'.\n", argv[i]);
+					gid = grp->gr_gid;
+				}
+			}
+			else
+				DPRINTF(E_FATAL, L_GENERAL, "Option -%c takes one argument.\n", argv[i][1]);
 			break;
 #ifdef __linux__
 		case 'S':
@@ -896,7 +914,7 @@ init(int argc, char **argv)
 	{
 		printf("Usage:\n\t"
 			"%s [-d] [-v] [-f config_file] [-p port]\n"
-			"\t\t[-i network_interface] [-u uid_to_run_as]\n"
+			"\t\t[-i network_interface] [-u uid_to_run_as] [-g group_to_run_as]\n"
 			"\t\t[-t notify_interval] [-P pid_filename]\n"
 			"\t\t[-s serial] [-m model_number]\n"
 #ifdef __linux__
@@ -997,6 +1015,10 @@ init(int argc, char **argv)
 				db_path, uid, strerror(errno));
 	}
 
+	if (gid > 0 && setgid(gid) == -1)
+		DPRINTF(E_FATAL, L_GENERAL, "Failed to switch to gid '%d'. [%s] EXITING.\n",
+			gid, strerror(errno));
+
 	if (uid > 0 && setuid(uid) == -1)
 		DPRINTF(E_FATAL, L_GENERAL, "Failed to switch to uid '%d'. [%s] EXITING.\n",
 			uid, strerror(errno));