From fc53809803cd2bc2434e312b19a18fa36776da12 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 12 Jun 2024 05:50:40 +0200 Subject: Adding upstream version 256. Signed-off-by: Daniel Baumann --- src/shared/netif-util.c | 90 ++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 82 insertions(+), 8 deletions(-) (limited to 'src/shared/netif-util.c') diff --git a/src/shared/netif-util.c b/src/shared/netif-util.c index f56c564..8adc2c8 100644 --- a/src/shared/netif-util.c +++ b/src/shared/netif-util.c @@ -5,13 +5,17 @@ #include "arphrd-util.h" #include "device-util.h" +#include "hexdecoct.h" #include "log-link.h" #include "memory-util.h" +#include "netif-naming-scheme.h" #include "netif-util.h" #include "siphash24.h" #include "sparse-endian.h" #include "strv.h" +#define SHORTEN_IFNAME_HASH_KEY SD_ID128_MAKE(e1,90,a4,04,a8,ef,4b,51,8c,cc,c3,3a,9f,11,fc,a2) + bool netif_has_carrier(uint8_t operstate, unsigned flags) { /* see Documentation/networking/operstates.txt in the kernel sources */ @@ -32,14 +36,8 @@ int net_get_type_string(sd_device *device, uint16_t iftype, char **ret) { if (device && sd_device_get_devtype(device, &t) >= 0 && - !isempty(t)) { - p = strdup(t); - if (!p) - return -ENOMEM; - - *ret = p; - return 0; - } + !isempty(t)) + return strdup_to(ret, t); t = arphrd_to_name(iftype); if (!t) @@ -204,3 +202,79 @@ int net_verify_hardware_address( return 0; } + +int net_generate_mac( + const char *machine_name, + struct ether_addr *mac, + sd_id128_t hash_key, + uint64_t idx) { + + uint64_t result; + size_t l, sz; + uint8_t *v, *i; + int r; + + l = strlen(machine_name); + sz = sizeof(sd_id128_t) + l; + if (idx > 0) + sz += sizeof(idx); + + v = newa(uint8_t, sz); + + /* fetch some persistent data unique to the host */ + r = sd_id128_get_machine((sd_id128_t*) v); + if (r < 0) + return r; + + /* combine with some data unique (on this host) to this + * container instance */ + i = mempcpy(v + sizeof(sd_id128_t), machine_name, l); + if (idx > 0) { + idx = htole64(idx); + memcpy(i, &idx, sizeof(idx)); + } + + /* Let's hash the host machine ID plus the container name. We + * use a fixed, but originally randomly created hash key here. */ + result = htole64(siphash24(v, sz, hash_key.bytes)); + + assert_cc(ETH_ALEN <= sizeof(result)); + memcpy(mac->ether_addr_octet, &result, ETH_ALEN); + + ether_addr_mark_random(mac); + + return 0; +} + +int net_shorten_ifname(char *ifname, bool check_naming_scheme) { + char new_ifname[IFNAMSIZ]; + + assert(ifname); + + if (strlen(ifname) < IFNAMSIZ) /* Name is short enough */ + return 0; + + if (!check_naming_scheme || naming_scheme_has(NAMING_NSPAWN_LONG_HASH)) { + uint64_t h; + + /* Calculate 64-bit hash value */ + h = siphash24(ifname, strlen(ifname), SHORTEN_IFNAME_HASH_KEY.bytes); + + /* Set the final four bytes (i.e. 32-bit) to the lower 24bit of the hash, encoded in url-safe base64 */ + memcpy(new_ifname, ifname, IFNAMSIZ - 5); + new_ifname[IFNAMSIZ - 5] = urlsafe_base64char(h >> 18); + new_ifname[IFNAMSIZ - 4] = urlsafe_base64char(h >> 12); + new_ifname[IFNAMSIZ - 3] = urlsafe_base64char(h >> 6); + new_ifname[IFNAMSIZ - 2] = urlsafe_base64char(h); + } else + /* On old nspawn versions we just truncated the name, provide compatibility */ + memcpy(new_ifname, ifname, IFNAMSIZ-1); + + new_ifname[IFNAMSIZ - 1] = 0; + + /* Log the incident to make it more discoverable */ + log_warning("Network interface name '%s' has been changed to '%s' to fit length constraints.", ifname, new_ifname); + + strcpy(ifname, new_ifname); + return 1; +} -- cgit v1.2.3