From 7c9e476867bc4271919dfc367514be0033426344 Mon Sep 17 00:00:00 2001
From: "B. Watson" <yalhcru@gmail.com>
Date: Mon, 18 May 2020 04:16:34 -0400
Subject: exit if event_dir gets deleted out from under us

---
 jsmond.c | 90 ++++++++++++++++++++++++++++++++++++++--------------------------
 1 file changed, 53 insertions(+), 37 deletions(-)

(limited to 'jsmond.c')

diff --git a/jsmond.c b/jsmond.c
index b0d6d6d..d5e2606 100644
--- a/jsmond.c
+++ b/jsmond.c
@@ -47,13 +47,14 @@ int button = -1;                 /* -b */
 char *event_dir = EVENTDIR;      /* -d */
 char *js_node_name = JSNODE;     /* -j */
 int autodiscover = 1; /* cleared if user supplies joydev args */
-fake_mode_t fake_mode = fm_auto_keycode;  /* -b, -m */
+fake_mode_t fake_mode = fm_auto_keycode;  /* -k, -b, -m */
 
 /* joystick stuff */
 char *joynames[MAX_STICKS + 1];
 int last_joyname = 0;
 int joyfds[MAX_STICKS + 1];
 
+/* executable name, for warnings/errors */
 const char *self;
 
 /* X stuff */
@@ -64,6 +65,7 @@ int inotify_fd, watch_fd;
 char inotify_buf[sizeof(struct inotify_event) + NAME_MAX + 1];
 struct inotify_event *inotify_ev = (struct inotify_event *)inotify_buf;
 
+/* not going to include pages of usage info duplicating the man page */
 void usage(void) {
 	printf("jsmond v" VERSION " by B. Watson, WTFPL\n");
 	printf("Usage: %s [-i interval] [-b button | -k keycode] [-j name]\n", self);
@@ -160,7 +162,8 @@ void send_fake_motion(void) {
 			0,
 			0,
 			0,
-			oldx, oldy);
+			oldx,
+			oldy);
 	XSync(xdisp, 0);
 }
 
@@ -204,15 +207,6 @@ void open_joysticks(void) {
 	if(debug) fprintf(stderr, "opened %d devices\n", fdcount);
 }
 
-void init_joysticks(void) {
-	int i;
-
-	for(i = 0; i < MAX_STICKS; i++)
-		joyfds[i] = -1;
-
-	open_joysticks();
-}
-
 void check_inotify() {
 	int res;
 
@@ -222,15 +216,21 @@ void check_inotify() {
 		if(debug) {
 			fprintf(stderr, "read %d bytes from inotify_fd\n", res);
 			if(!inotify_ev->len) {
-				fprintf(stderr, "got event with no name: %x\n", inotify_ev->mask);
+				fprintf(stderr, "got event with no name: 0x%x\n", inotify_ev->mask);
 			} else {
-				fprintf(stderr, "got event with name %s: %x\n", inotify_ev->name, inotify_ev->mask);
+				fprintf(stderr, "got event with name %s: 0x%x\n", inotify_ev->name, inotify_ev->mask);
 			}
 		}
+		if(inotify_ev->mask & IN_DELETE_SELF) {
+			/* not much we can do to recover from this */
+			die("someone deleted our device directory!");
+		}
 		usleep(EVENT_DELAY); /* might not need, be paranoid */
 		open_joysticks();
 	} else {
 		if(errno != EAGAIN) {
+			/* not sure what could cause this, so no idea how/if we
+			   recover from it */
 			fprintf(stderr, "%s: failed to read from inotify_fd: %s\n",
 					self, strerror(errno));
 			exit(1);
@@ -346,7 +346,11 @@ void parse_args(int argc, char **argv) {
 	if(argc > 1 && strcmp(argv[1], "--help") == 0) usage();
 
 	while(++argv, --argc) {
-		if(argv[0][0] == '-') {
+		if(argv[0][0] != '-') {
+			/* no dash, treat as a joystick device */
+			add_joystick_name(*argv);
+			autodiscover = 0;
+		} else {
 			if(argv[0][1] && argv[0][2])
 				die("spaces required between options and arguments, please");
 			nextarg = argv[1];
@@ -408,9 +412,6 @@ void parse_args(int argc, char **argv) {
 					die("unrecognized argument, try --help");
 					break;
 			}
-		} else {
-			add_joystick_name(*argv);
-			autodiscover = 0;
 		}
 	}
 }
@@ -459,26 +460,7 @@ void daemonize(void) {
 	chdir("/");
 }
 
-void init_inotify(void) {
-	inotify_fd = inotify_init1(IN_NONBLOCK);
-	if(inotify_fd < 0) {
-		fprintf(stderr, "%s: inotify_init1() failed: %s",
-				self, strerror(errno));
-		exit(1);
-	}
-
-	if(debug) fprintf(stderr, "inotify_init1() returned %d\n", inotify_fd);
-
-	watch_fd = inotify_add_watch(inotify_fd, event_dir, IN_CREATE | IN_DELETE);
-	if(watch_fd < 0) {
-		fprintf(stderr, "%s: inotify_add_watch() failed: %s",
-				self, strerror(errno));
-		exit(1);
-	}
-
-	if(debug) fprintf(stderr, "inotify_add_watch() on %s returned %d\n", event_dir, inotify_fd);
-}
-
+/* helpers for init_* functions */
 void connect_to_x(void) {
 	int ignoreme;
 
@@ -529,6 +511,40 @@ void find_keycode() {
 	}
 }
 
+/* init_* functions. these are only called once each, from main() */
+void init_joysticks(void) {
+	int i;
+
+	for(i = 0; i < MAX_STICKS; i++)
+		joyfds[i] = -1;
+
+	open_joysticks();
+}
+
+void init_inotify(void) {
+	inotify_fd = inotify_init1(IN_NONBLOCK);
+	if(inotify_fd < 0) {
+		fprintf(stderr, "%s: inotify_init1() failed: %s",
+				self, strerror(errno));
+		exit(1);
+	}
+
+	if(debug) fprintf(stderr, "inotify_init1() returned %d\n", inotify_fd);
+
+	watch_fd = inotify_add_watch(
+			inotify_fd,
+			event_dir,
+			IN_CREATE | IN_DELETE | IN_DELETE_SELF);
+
+	if(watch_fd < 0) {
+		fprintf(stderr, "%s: inotify_add_watch(\"%s\") failed: %s\n",
+				self, event_dir, strerror(errno));
+		exit(1);
+	}
+
+	if(debug) fprintf(stderr, "inotify_add_watch() on %s returned %d\n", event_dir, inotify_fd);
+}
+
 void init_x(void) {
 	connect_to_x();
 
-- 
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