From 5a7eb46c0206411d380543021291b4bca0b6f59f 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. --- man/systemd.net-naming-scheme.xml | 7 ++++++- src/shared/netif-naming-scheme.h | 3 ++- src/udev/udev-builtin-net_id.c | 20 +++++++++++++------- 3 files changed, 21 insertions(+), 9 deletions(-) diff --git a/man/systemd.net-naming-scheme.xml b/man/systemd.net-naming-scheme.xml index fe044d236ab..bc1ff7876d9 100644 --- a/man/systemd.net-naming-scheme.xml +++ b/man/systemd.net-naming-scheme.xml @@ -376,7 +376,12 @@ 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. diff --git a/src/shared/netif-naming-scheme.h b/src/shared/netif-naming-scheme.h index f719744d568..c0f94d0407c 100644 --- a/src/shared/netif-naming-scheme.h +++ b/src/shared/netif-naming-scheme.h @@ -33,6 +33,7 @@ typedef enum NamingSchemeFlags { NAMING_NSPAWN_LONG_HASH = 1 << 8, /* Shorten nspawn interfaces by including 24bit hash, instead of simple truncation */ 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, @@ -42,7 +43,7 @@ typedef enum NamingSchemeFlags { NAMING_V243 = NAMING_V241 | NAMING_NETDEVSIM | NAMING_LABEL_NOPREFIX, NAMING_V245 = NAMING_V243 | NAMING_NSPAWN_LONG_HASH, NAMING_V247 = NAMING_V245 | NAMING_BRIDGE_NO_SLOT, - NAMING_V249 = NAMING_V247 | NAMING_SLOT_FUNCTION_ID, + NAMING_V249 = NAMING_V247 | NAMING_SLOT_FUNCTION_ID | NAMING_16BIT_INDEX, _NAMING_SCHEME_FLAGS_INVALID = -EINVAL, } NamingSchemeFlags; diff --git a/src/udev/udev-builtin-net_id.c b/src/udev/udev-builtin-net_id.c index 088bfe38d9e..33601151a6f 100644 --- a/src/udev/udev-builtin-net_id.c +++ b/src/udev/udev-builtin-net_id.c @@ -37,7 +37,8 @@ #include "strxcpyx.h" #include "udev-builtin.h" -#define ONBOARD_INDEX_MAX (16*1024-1) +#define ONBOARD_14BIT_INDEX_MAX ((1U << 14) - 1) +#define ONBOARD_16BIT_INDEX_MAX ((1U << 16) - 1) enum netname_type{ NET_UNDEF, @@ -162,6 +163,16 @@ static int get_virtfn_info(sd_device *dev, struct netnames *names, struct virtfn return 0; } +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(sd_device *dev, struct netnames *names) { unsigned long idx, dev_port = 0; @@ -184,12 +195,7 @@ static int dev_pci_onboard(sd_device *dev, struct netnames *names) { if (idx == 0 && !naming_scheme_has(NAMING_ZERO_ACPI_INDEX)) 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 this 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 */