Line data    Source code

       1             : /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
       2             : 
       3             : /***
       4             :   This file is part of systemd.
       5             : 
       6             :   Copyright (C) 2015 Tom Gundersen <teg@jklmen>
       7             : 
       8             :   systemd is free software; you can redistribute it and/or modify it
       9             :   under the terms of the GNU Lesser General Public License as published by
      10             :   the Free Software Foundation; either version 2.1 of the License, or
      11             :   (at your option) any later version.
      12             : 
      13             :   systemd is distributed in the hope that it will be useful, but
      14             :   WITHOUT ANY WARRANTY; without even the implied warranty of
      15             :   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
      16             :   Lesser General Public License for more details.
      17             : 
      18             :   You should have received a copy of the GNU Lesser General Public License
      19             :   along with systemd; If not, see <http://www.gnu.org/licenses/>.
      20             : ***/
      21             : 
      22             : 
      23             : #include "sd-id128.h"
      24             : #include "libudev.h"
      25             : #include "udev-util.h"
      26             : 
      27             : #include "virt.h"
      28             : #include "sparse-endian.h"
      29             : #include "siphash24.h"
      30             : 
      31             : #include "dhcp6-protocol.h"
      32             : #include "dhcp-identifier.h"
      33             : #include "network-internal.h"
      34             : 
      35             : #define SYSTEMD_PEN 43793
      36             : #define HASH_KEY SD_ID128_MAKE(80,11,8c,c2,fe,4a,03,ee,3e,d6,0c,6f,36,39,14,09)
      37             : 
      38           6 : int dhcp_identifier_set_duid_en(struct duid *duid, size_t *len) {
      39             :         sd_id128_t machine_id;
      40             :         int r;
      41             : 
      42           6 :         assert(duid);
      43           6 :         assert(len);
      44             : 
      45           6 :         r = sd_id128_get_machine(&machine_id);
      46           6 :         if (r < 0)
      47           0 :                 return r;
      48             : 
      49           6 :         unaligned_write_be16(&duid->type, DHCP6_DUID_EN);
      50           6 :         unaligned_write_be32(&duid->en.pen, SYSTEMD_PEN);
      51             : 
      52           6 :         *len = sizeof(duid->type) + sizeof(duid->en);
      53             : 
      54             :         /* a bit of snake-oil perhaps, but no need to expose the machine-id
      55             :            directly */
      56           6 :         siphash24(duid->en.id, &machine_id, sizeof(machine_id), HASH_KEY.bytes);
      57             : 
      58           6 :         return 0;
      59             : }
      60             : 
      61             : 
      62           6 : int dhcp_identifier_set_iaid(int ifindex, uint8_t *mac, size_t mac_len, void *_id) {
      63             :         /* name is a pointer to memory in the udev_device struct, so must
      64             :            have the same scope */
      65          12 :         _cleanup_udev_device_unref_ struct udev_device *device = NULL;
      66           6 :         const char *name = NULL;
      67             :         uint64_t id;
      68             : 
      69           6 :         if (detect_container(NULL) <= 0) {
      70             :                 /* not in a container, udev will be around */
      71           5 :                 _cleanup_udev_unref_ struct udev *udev;
      72             :                 char ifindex_str[2 + DECIMAL_STR_MAX(int)];
      73             : 
      74           5 :                 udev = udev_new();
      75           5 :                 if (!udev)
      76           0 :                         return -ENOMEM;
      77             : 
      78           5 :                 sprintf(ifindex_str, "n%d", ifindex);
      79           5 :                 device = udev_device_new_from_device_id(udev, ifindex_str);
      80           5 :                 if (device) {
      81           0 :                         if (udev_device_get_is_initialized(device) <= 0)
      82             :                                 /* not yet ready */
      83           0 :                                 return -EBUSY;
      84             : 
      85           0 :                         name = net_get_name(device);
      86             :                 }
      87             :         }
      88             : 
      89           6 :         if (name)
      90           0 :                 siphash24((uint8_t*)&id, name, strlen(name), HASH_KEY.bytes);
      91             :         else
      92             :                 /* fall back to MAC address if no predictable name available */
      93           6 :                 siphash24((uint8_t*)&id, mac, mac_len, HASH_KEY.bytes);
      94             : 
      95             :         /* fold into 32 bits */
      96           6 :         unaligned_write_be32(_id, (id & 0xffffffff) ^ (id >> 32));
      97             : 
      98           6 :         return 0;
      99             : }