Patch: privilege drop

Source:
https://github.com/djpohly/dwl/compare/main...DanielMowitz:privilege-drop.patch

1 files changed, 15 insertions, 6 deletions

diff --git a/dwl.c b/dwl.c
index 73d3c00..95850d6 100644
--- a/dwl.c
+++ b/dwl.c
@@ -8,6 +8,7 @@
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/types.h>
 #include <sys/wait.h>
 #include <time.h>
 #include <unistd.h>
@@ -322,7 +323,7 @@ static void requestdecorationmode(struct wl_listener *listener, void *data);
 static void requeststartdrag(struct wl_listener *listener, void *data);
 static void requestmonstate(struct wl_listener *listener, void *data);
 static void resize(Client *c, struct wlr_box geo, int interact);
-static void run(char *startup_cmd);
+static void run(char *startup_cmd, uid_t uid);
 static void setcursor(struct wl_listener *listener, void *data);
 static void setcursorshape(struct wl_listener *listener, void *data);
 static void setfloating(Client *c, int floating);
@@ -2188,7 +2189,7 @@ resize(Client *c, struct wlr_box geo, int interact)
 }
 
 void
-run(char *startup_cmd)
+run(char *startup_cmd, uid_t uid)
 {
 	/* Add a Unix socket to the Wayland display. */
 	const char *socket = wl_display_add_socket_auto(dpy);
@@ -2201,6 +2202,11 @@ run(char *startup_cmd)
 	if (!wlr_backend_start(backend))
 		die("startup: backend_start");
 
+	/* In case the option is passed, drop priviledges to desired uid */
+	if (uid > 0)
+		setuid(uid);
+
+
 	/* Now that the socket exists and the backend is started, run the startup command */
 	if (startup_cmd) {
 		int piperw[2];
@@ -3172,10 +3178,13 @@ int
 main(int argc, char *argv[])
 {
 	char *startup_cmd = NULL;
+	uid_t uid = 0;
 	int c;
 
-	while ((c = getopt(argc, argv, "s:hdv")) != -1) {
-		if (c == 's')
+	while ((c = getopt(argc, argv, "u:s:hdv")) != -1) {
+		if (c == 'u')
+			uid = atoi(optarg);
+    else if (c == 's')
 			startup_cmd = optarg;
 		else if (c == 'd')
 			log_level = WLR_DEBUG;
@@ -3191,10 +3200,10 @@ main(int argc, char *argv[])
 	if (!getenv("XDG_RUNTIME_DIR"))
 		die("XDG_RUNTIME_DIR must be set");
 	setup();
-	run(startup_cmd);
+	run(startup_cmd, uid);
 	cleanup();
 	return EXIT_SUCCESS;
 
 usage:
-	die("Usage: %s [-v] [-d] [-s startup command]", argv[0]);
+	die("Usage: %s [-v] [-u uid] [-d] [-s startup command]", argv[0]);
 }