From 08f8572347ca597147ab761d425e4480885e1995 Mon Sep 17 00:00:00 2001

From: Hendrik Brueckner <brueckner@redhat.com>

Date: Thu, 9 Jan 2014 11:28:12 +0100

Subject: [PATCH] udev/net_id: Introduce predictable network names for Linux on

 System z

Use the bus-ID to create predicatable devices names for network interfaces

on Linux on System z instances.  The bus-ID identifies a device in the s390

channel subsystem.

Network interfaces of device type Ethernet are named as:

    enccw0.0.1234    (13 characters)

up to

    enccwff.7.ffff   (14 characters)

CTC network devices of device type SLIP, use a different prefix as follows:

    slccw0.0.1234    (13 characters)

See also Red Hat Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=870859

[tomegun: typical problem of netdevs switching names between reboots.]

Conflicts:

	src/udev/udev-builtin-net_id.c

---

 src/udev/udev-builtin-net_id.c | 64 ++++++++++++++++++++++++++++++++++++++++--

 1 file changed, 62 insertions(+), 2 deletions(-)

diff --git a/src/udev/udev-builtin-net_id.c b/src/udev/udev-builtin-net_id.c

index 9ae8f08..d9de46d 100644

--- a/src/udev/udev-builtin-net_id.c

+++ b/src/udev/udev-builtin-net_id.c

@@ -28,6 +28,7 @@

  *

  * Two character prefixes based on the type of interface:

  *   en -- ethernet

+ *   sl -- serial line IP (slip)

  *   wl -- wlan

  *   ww -- wwan

  *

@@ -101,6 +102,7 @@ enum netname_type{

         NET_PCI,

         NET_USB,

         NET_BCMA,

+        NET_CCWGROUP,

 };

 struct netnames {

@@ -118,6 +120,8 @@ struct netnames {

         char usb_ports[IFNAMSIZ];

         char bcma_core[IFNAMSIZ];

+

+        char ccw_core[IFNAMSIZ];

 };

 /* retrieve on-board index number and label from firmware */

@@ -351,6 +355,44 @@ static int names_bcma(struct udev_device *dev, struct netnames *names) {

         return 0;

 }

+static int names_ccw(struct  udev_device *dev, struct netnames *names) {

+        struct udev_device *cdev;

+        const char *bus_id;

+        size_t bus_id_len;

+        int rc;

+

+        /* Retrieve the associated CCW device */

+        cdev = udev_device_get_parent(dev);

+        if (!cdev)

+                return -ENOENT;

+

+        /* Network devices are always grouped CCW devices */

+        if (!streq_ptr("ccwgroup", udev_device_get_subsystem(cdev)))

+                return -ENOENT;

+

+        /* Retrieve bus-ID of the grouped CCW device.  The bus-ID uniquely

+         * identifies the network device on the Linux on System z channel

+         * subsystem.  Note that the bus-ID contains lowercase characters.

+         */

+        bus_id = udev_device_get_sysname(cdev);

+        if (!bus_id)

+                return -ENOENT;

+

+        /* Check the length of the bus-ID.  Rely on that the kernel provides

+         * a correct bus-ID; alternatively, improve this check and parse and

+         * verify each bus-ID part...

+         */

+        bus_id_len = strlen(bus_id);

+        if (!bus_id_len || bus_id_len < 8 || bus_id_len > 9)

+                return -EINVAL;

+

+        /* Store the CCW bus-ID for use as network device name */

+        rc = snprintf(names->ccw_core, sizeof(names->ccw_core), "ccw%s", bus_id);

+        if (rc >= 0 && rc < (int)sizeof(names->ccw_core))

+                names->type = NET_CCWGROUP;

+        return 0;

+}

+

 static int names_mac(struct udev_device *dev, struct netnames *names) {

         const char *s;

         unsigned int i;

@@ -409,13 +451,21 @@ static int builtin_net_id(struct udev_device *dev, int argc, char *argv[], bool

         struct netnames names = {};

         int err;

-        /* handle only ARPHRD_ETHER devices */

+        /* handle only ARPHRD_ETHER and ARPHRD_SLIP devices */

         s = udev_device_get_sysattr_value(dev, "type");

         if (!s)

                 return EXIT_FAILURE;

         i = strtoul(s, NULL, 0);

-        if (i != 1)

+        switch (i) {

+        case 1: /* ARPHRD_ETHER */

+                prefix = "en";

+                break;

+        case 256: /* ARPHRD_SLIP */

+                prefix = "sl";

+                break;

+        default:

                 return 0;

+        }

         /* skip stacked devices, like VLANs, ... */

         s = udev_device_get_sysattr_value(dev, "ifindex");

@@ -447,6 +497,16 @@ static int builtin_net_id(struct udev_device *dev, int argc, char *argv[], bool

                 ieee_oui(dev, &names, test);

         }

+        /* get path names for Linux on System z network devices */

+        err = names_ccw(dev, &names);

+        if (err >= 0 && names.type == NET_CCWGROUP) {

+                char str[IFNAMSIZ];

+

+                if (snprintf(str, sizeof(str), "%s%s", prefix, names.ccw_core) < (int)sizeof(str))

+                        udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);

+                goto out;

+        }

+

         /* get PCI based path names, we compose only PCI based paths */

         err = names_pci(dev, &names);

         if (err < 0)