libudev: monitor - replace far too expensive snprintf() with strlcpy()

diff --git a/udev/lib/libudev-monitor.c b/udev/lib/libudev-monitor.c
index 7f7f8460c26f1046554408f469a28c024203ce8a..9f139170421bc21f75956a40e62bd92cd32f3c16 100644 (file)
--- a/udev/lib/libudev-monitor.c
+++ b/udev/lib/libudev-monitor.c
@@ -384,19 +384,37 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi
        struct udev_list_entry *list_entry;
        char buf[4096];
        size_t bufpos;
+       size_t len;
        ssize_t count;
 
        action = udev_device_get_action(udev_device);
        if (action == NULL)
                return -EINVAL;
-       bufpos = snprintf(buf, sizeof(buf), "%s@%s", action, udev_device_get_devpath(udev_device));
-       bufpos++;
+
+       bufpos = util_strlcpy(buf, action, sizeof(buf));
+       len = util_strlcpy(&buf[bufpos], "@", sizeof(buf)-bufpos);
+       if (len >= sizeof(buf)-bufpos)
+               return -1;
+       bufpos += len;
+       len = util_strlcpy(&buf[bufpos], udev_device_get_devpath(udev_device), sizeof(buf)-bufpos);
+       if (len+1 >= sizeof(buf)-bufpos)
+               return -1;
+       bufpos += len+1;
        udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
-               bufpos += snprintf(&buf[bufpos], sizeof(buf) - bufpos, "%s=%s",
-                                  udev_list_entry_get_name(list_entry),
-                                  udev_list_entry_get_value(list_entry));
-               bufpos++;
+               len = util_strlcpy(&buf[bufpos], udev_list_entry_get_name(list_entry), sizeof(buf)-bufpos);
+               if (len >= sizeof(buf)-bufpos)
+                       return -1;
+               bufpos += len;
+               len = util_strlcpy(&buf[bufpos], "=", sizeof(buf)-bufpos);
+               if (len >= sizeof(buf)-bufpos)
+                       return -1;
+               bufpos += len;
+               len = util_strlcpy(&buf[bufpos], udev_list_entry_get_value(list_entry), sizeof(buf)-bufpos);
+               if (len+1 >= sizeof(buf)-bufpos)
+                       return -1;
+               bufpos += len+1;
        }
+
        count = sendto(udev_monitor->sock,
                       &buf, bufpos, 0,
                       (struct sockaddr *)&udev_monitor->sun, udev_monitor->addrlen);