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Diffstat (limited to 'src/udev/udev-builtin-net_id.c')
-rw-r--r--src/udev/udev-builtin-net_id.c28
1 files changed, 20 insertions, 8 deletions
diff --git a/src/udev/udev-builtin-net_id.c b/src/udev/udev-builtin-net_id.c
index bc6ca212db..fd84e6e24f 100644
--- a/src/udev/udev-builtin-net_id.c
+++ b/src/udev/udev-builtin-net_id.c
@@ -18,18 +18,27 @@
***/
/*
- * prefixes:
+ * predictable network interface device names based on:
+ * - firmware/bios-provided index numbers for on-board devices
+ * - firmware-provided pci-express hotplug slot index number
+ * - physical/geographical location of the hardware
+ * - the interface's MAC address
+ *
+ * two character prefixes based on the type of interface:
* en -- ethernet
* wl -- wlan
* ww -- wwan
*
- * types:
- * o<index> -- on-board device index
- * s<slot>[f<function>] -- hotplug slot number
+ * type of names:
+ * o<index> -- on-board device index number
+ * s<slot>[f<function>] -- hotplug slot index number
* x<MAC> -- MAC address
- * p<bus>s<slot>[f<function>] -- PCI/physical location
+ * p<bus>s<slot>[f<function>] -- PCI geographical location
+ *
+ * All multi-function devices will carry the [f<function>] number in the
+ * device name, including the function 0 device.
*
- * example:
+ * examples:
* ID_NET_NAME_ONBOARD=eno1
* ID_NET_NAME_SLOT=ens1
* ID_NET_NAME_SLOT=ens2f0
@@ -82,6 +91,7 @@ static int dev_pci_onboard(struct udev_device *dev, struct udev_device *parent,
return 0;
}
+/* read the 256 bytes PCI configuration space to check for multi-function */
static bool is_pci_singlefunction(struct udev_device *dev) {
char filename[256];
FILE *f;
@@ -215,8 +225,10 @@ static int dev_mac(struct udev_device *dev, const char *prefix, bool test) {
return -EINVAL;
/* add IEEE Organizationally Unique Identifier */
- snprintf(str, sizeof(str), "OUI:%X%X%X", a1, a2, a3);
- udev_builtin_hwdb_lookup(dev, str, test);
+ if (a1 + a2 + a3 > 0) {
+ snprintf(str, sizeof(str), "OUI:%02X%02X%02X", a1, a2, a3);
+ udev_builtin_hwdb_lookup(dev, str, test);
+ }
snprintf(str, sizeof(str), "%sx%02x%02x%02x%02x%02x%02x", prefix, a1, a2, a3, a4, a5, a6);
return udev_builtin_add_property(dev, test, "ID_NET_NAME_MAC", str);