From 033998c21f01e7b7d91e4aa51a358f8016f3740a Mon Sep 17 00:00:00 2001 From: Viktor Mihajlovski Date: Tue, 27 Apr 2021 15:25:16 +0200 Subject: [PATCH] udev: allow onboard index up to 65535 The maximum allowed value of the sysfs device index entry was limited to 16383 (2^14-1) to avoid the generation of unreasonable onboard interface names. For s390 the index can assume a value of up to 65535 (2^16-1) which is now allowed depending on the new naming flag NAMING_16BIT_INDEX. Larger index values are considered unreasonable and remain to be ignored. Related: #1939914 (cherry picked from commit 5a7eb46c0206411d380543021291b4bca0b6f59f) --- man/systemd.net-naming-scheme.xml | 7 ++++++- src/udev/udev-builtin-net_id.c | 22 +++++++++++++++------- 2 files changed, 21 insertions(+), 8 deletions(-) diff --git a/man/systemd.net-naming-scheme.xml b/man/systemd.net-naming-scheme.xml index e42c93eaad..a567483995 100644 --- a/man/systemd.net-naming-scheme.xml +++ b/man/systemd.net-naming-scheme.xml @@ -320,7 +320,12 @@ of the function_id device attribute. This attribute is now used to build the ID_NET_NAME_SLOT. Before that, all slot names were parsed as decimal numbers, which could either result in an incorrect value of the ID_NET_NAME_SLOT - property or none at all. + property or none at all. + + Some firmware and hypervisor implementations report unreasonable high numbers for the onboard + index. To prevent the generation of bogus onbard interface names, index numbers greater than 16381 + (2^14-1) were ignored. For s390 PCI devices index values up to 65535 (2^16-1) are valid. To account + for that, the limit is increased to now 65535. Note that latest may be used to denote the latest scheme known to this diff --git a/src/udev/udev-builtin-net_id.c b/src/udev/udev-builtin-net_id.c index ba7638fcb8..df84acf27c 100644 --- a/src/udev/udev-builtin-net_id.c +++ b/src/udev/udev-builtin-net_id.c @@ -104,7 +104,8 @@ #include "udev.h" #include "udev-util.h" -#define ONBOARD_INDEX_MAX (16*1024-1) +#define ONBOARD_14BIT_INDEX_MAX ((1U << 14) - 1) +#define ONBOARD_16BIT_INDEX_MAX ((1U << 16) - 1) /* So here's the deal: net_id is supposed to be an excercise in providing stable names for network devices. However, we * also want to keep updating the naming scheme used in future versions of net_id. These two goals of course are @@ -127,6 +128,7 @@ typedef enum NamingSchemeFlags { NAMING_NPAR_ARI = 1 << 1, /* Use NPAR "ARI", see 6bc04997b6eab35d1cb9fa73889892702c27be09 */ NAMING_BRIDGE_NO_SLOT = 1 << 9, /* Don't use PCI hotplug slot information if the corresponding device is a PCI bridge */ NAMING_SLOT_FUNCTION_ID = 1 << 10, /* Use function_id if present to identify PCI hotplug slots */ + NAMING_16BIT_INDEX = 1 << 11, /* Allow full 16-bit for the onboard index */ /* And now the masks that combine the features above */ NAMING_V238 = 0, @@ -138,7 +140,7 @@ typedef enum NamingSchemeFlags { NAMING_RHEL_8_4 = NAMING_V239|NAMING_BRIDGE_NO_SLOT, NAMING_RHEL_8_5 = NAMING_RHEL_8_4, NAMING_RHEL_8_6 = NAMING_RHEL_8_4, - NAMING_RHEL_8_7 = NAMING_RHEL_8_4|NAMING_SLOT_FUNCTION_ID, + NAMING_RHEL_8_7 = NAMING_RHEL_8_4|NAMING_SLOT_FUNCTION_ID|NAMING_16BIT_INDEX, _NAMING_SCHEME_FLAGS_INVALID = -1, } NamingSchemeFlags; @@ -326,6 +328,16 @@ out_unref: return r; } +static bool is_valid_onboard_index(unsigned long idx) { + /* Some BIOSes report rubbish indexes that are excessively high (2^24-1 is an index VMware likes to + * report for example). Let's define a cut-off where we don't consider the index reliable anymore. We + * pick some arbitrary cut-off, which is somewhere beyond the realistic number of physical network + * interface a system might have. Ideally the kernel would already filter this crap for us, but it + * doesn't currently. The initial cut-off value (2^14-1) was too conservative for s390 PCI which + * allows for index values up 2^16-1 which is now enabled with the NAMING_16BIT_INDEX naming flag. */ + return idx <= (naming_scheme_has(NAMING_16BIT_INDEX) ? ONBOARD_16BIT_INDEX_MAX : ONBOARD_14BIT_INDEX_MAX); +} + /* retrieve on-board index number and label from firmware */ static int dev_pci_onboard(struct udev_device *dev, struct netnames *names) { unsigned dev_port = 0; @@ -346,11 +358,7 @@ static int dev_pci_onboard(struct udev_device *dev, struct netnames *names) { if (idx <= 0) return -EINVAL; - /* Some BIOSes report rubbish indexes that are excessively high (2^24-1 is an index VMware likes to report for - * example). Let's define a cut-off where we don't consider the index reliable anymore. We pick some arbitrary - * cut-off, which is somewhere beyond the realistic number of physical network interface a system might - * have. Ideally the kernel would already filter his crap for us, but it doesn't currently. */ - if (idx > ONBOARD_INDEX_MAX) + if (!is_valid_onboard_index(idx)) return -ENOENT; /* kernel provided port index for multiple ports on a single PCI function */