/*** This file is part of systemd. Copyright (C) 2015 Tom Gundersen <teg@jklmen> systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include "libudev.h" #include "sd-id128.h" #include "dhcp-identifier.h" #include "dhcp6-protocol.h" #include "network-internal.h" #include "siphash24.h" #include "sparse-endian.h" #include "udev-util.h" #include "virt.h" #define SYSTEMD_PEN 43793 #define HASH_KEY SD_ID128_MAKE(80,11,8c,c2,fe,4a,03,ee,3e,d6,0c,6f,36,39,14,09) int dhcp_identifier_set_duid_en(struct duid *duid, size_t *len) { sd_id128_t machine_id; uint64_t hash; int r; assert(duid); assert(len); r = sd_id128_get_machine(&machine_id); if (r < 0) return r; unaligned_write_be16(&duid->type, DUID_TYPE_EN); unaligned_write_be32(&duid->en.pen, SYSTEMD_PEN); *len = sizeof(duid->type) + sizeof(duid->en); /* a bit of snake-oil perhaps, but no need to expose the machine-id directly; duid->en.id might not be aligned, so we need to copy */ hash = htole64(siphash24(&machine_id, sizeof(machine_id), HASH_KEY.bytes)); memcpy(duid->en.id, &hash, sizeof(duid->en.id)); return 0; } int dhcp_identifier_set_iaid(int ifindex, uint8_t *mac, size_t mac_len, void *_id) { /* name is a pointer to memory in the udev_device struct, so must have the same scope */ _cleanup_udev_device_unref_ struct udev_device *device = NULL; const char *name = NULL; uint64_t id; if (detect_container() <= 0) { /* not in a container, udev will be around */ _cleanup_udev_unref_ struct udev *udev; char ifindex_str[2 + DECIMAL_STR_MAX(int)]; udev = udev_new(); if (!udev) return -ENOMEM; sprintf(ifindex_str, "n%d", ifindex); device = udev_device_new_from_device_id(udev, ifindex_str); if (device) { if (udev_device_get_is_initialized(device) <= 0) /* not yet ready */ return -EBUSY; name = net_get_name(device); } } if (name) id = siphash24(name, strlen(name), HASH_KEY.bytes); else /* fall back to MAC address if no predictable name available */ id = siphash24(mac, mac_len, HASH_KEY.bytes); id = htole64(id); /* fold into 32 bits */ unaligned_write_be32(_id, (id & 0xffffffff) ^ (id >> 32)); return 0; }