From 08f8572347ca597147ab761d425e4480885e1995 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner 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)