libudev: resolve ifindex in udev_device_new_from_id_filename()

diff --git a/libudev/libudev-device.c b/libudev/libudev-device.c
index 8b8507c3a415dc32c5c79a06fd4805e6aa6ce887..c78cf9b7a05753d8c9948c4b95a6dd5dcab9dfdc 100644 (file)
--- a/libudev/libudev-device.c
+++ b/libudev/libudev-device.c
@@ -19,7 +19,11 @@
 #include <dirent.h>
 #include <fcntl.h>
 #include <ctype.h>
+#include <net/if.h>
 #include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <linux/sockios.h>
 
 #include "libudev.h"
 #include "libudev-private.h"
@@ -497,6 +501,35 @@ struct udev_device *udev_device_new_from_id_filename(struct udev *udev, char *id
                if (sscanf(id, "%c%i:%i", &type, &maj, &min) != 3)
                        return NULL;
                return udev_device_new_from_devnum(udev, type, makedev(maj, min));
+       case 'n': {
+               int sk;
+               struct ifreq ifr;
+               struct udev_device *dev;
+               int ifindex;
+
+               ifindex = strtoul(&id[1], NULL, 10);
+               if (ifindex <= 0)
+                       return NULL;
+
+               sk = socket(PF_INET, SOCK_DGRAM, 0);
+               if (sk < 0)
+                       return NULL;
+               memset(&ifr, 0x00, sizeof(struct ifreq));
+               ifr.ifr_ifindex = ifindex;
+               if (ioctl(sk, SIOCGIFNAME, &ifr) != 0) {
+                       close(sk);
+                       return NULL;
+               }
+               close(sk);
+
+               dev = udev_device_new_from_subsystem_sysname(udev, "net", ifr.ifr_name);
+               if (dev == NULL)
+                       return NULL;
+               if (udev_device_get_ifindex(dev) == ifindex)
+                       return dev;
+               udev_device_unref(dev);
+               return NULL;
+       }
        case '+':
                util_strscpy(subsys, sizeof(subsys), &id[1]);
                sysname = strchr(subsys, ':');