From 56bd57b5582ea4bbf3cf6f1a50457e64a4e295e8 Mon Sep 17 00:00:00 2001
From: Mattias Andrée <maandree@kth.se>
Date: Sat, 30 Jul 2022 17:00:08 +0200
Subject: Minor improvements
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Mattias Andrée <maandree@kth.se>
---
 libgamepad_list_superdevices.c | 48 ++++++++++++++++++++++++++++++++++++------
 1 file changed, 42 insertions(+), 6 deletions(-)

(limited to 'libgamepad_list_superdevices.c')

diff --git a/libgamepad_list_superdevices.c b/libgamepad_list_superdevices.c
index f8c7c4d..57068cb 100644
--- a/libgamepad_list_superdevices.c
+++ b/libgamepad_list_superdevices.c
@@ -5,7 +5,9 @@
 int
 libgamepad_list_superdevices(char ***devicesp, size_t *ndevicesp)
 {
-	char path[PATH_MAX], target[PATH_MAX]; /* TODO do not use PATH_MAX */
+	char *path, *target;
+	size_t path_size, target_size = 256;
+	const size_t path_size_base = sizeof("/sys/class/input//device/device");
 	int dirfd;
 	DIR *dir;
 	struct dirent *f;
@@ -28,18 +30,48 @@ libgamepad_list_superdevices(char ***devicesp, size_t *ndevicesp)
 		return -1;
 	}
 
+	path_size = path_size_base + 255;
+	path_size = path_size > sizeof("/dev/fd/") + 3 * sizeof(int) ? path_size : sizeof("/dev/fd/") + 3 * sizeof(int);
+	path = malloc(path_size);
+	if (!path)
+		goto fail;
+
+	target = malloc(target_size);
+	if (!target)
+		goto fail;
+
 	while (errno = 0, (f = readdir(dir))) {
 		if (!strncmp(f->d_name, "event", 5) && isdigit(f->d_name[5])) {
+			if (path_size_base + strlen(f->d_name) > path_size) {
+				path_size = path_size_base + strlen(f->d_name);
+				new = realloc(path, path_size);
+				if (!new)
+					goto fail;
+				path = new;
+			}
 			stpcpy(stpcpy(stpcpy(path, "/sys/class/input/"), f->d_name), "/device/device");
 			dirfd = open(path, O_PATH);
 			if (dirfd < 0)
 				continue;
+
 			sprintf(path, "/dev/fd/%i", dirfd);
-			r = readlink(path, target, sizeof(target) - 1);
-			close(dirfd);
-			if (r < 0)
-				continue;
-			target[r] = '\0';
+			for (;;) {
+				r = readlink(path, target, target_size);
+				if (r < 0) {
+					close(dirfd);
+					goto next;
+				}
+				if ((size_t)r < target_size) {
+					close(dirfd);
+					target[r] = '\0';
+					break;
+				}
+				new = realloc(target, target_size += 256);
+				if (!new)
+					goto fail;
+				target = new;
+			}
+
 			if (paths)
 				for (i = 0; i < n; i++)
 					if (!strcmp(paths[i], target))
@@ -61,6 +93,8 @@ libgamepad_list_superdevices(char ***devicesp, size_t *ndevicesp)
 
 	if (errno)
 		goto fail;
+	free(path);
+	free(target);
 	closedir(dir);
 
 	errno = saved_errno;
@@ -72,6 +106,8 @@ fail:
 	for (i = 0; i < n; i++)
 		free(paths[i]);
 	free(paths);
+	free(path);
+	free(target);
 	closedir(dir);
 	return -1;
 }
-- 
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