src/networkd/address.h

   1 /*#############################################################################
   2 #                                                                             #
   3 # IPFire.org - A linux based firewall                                         #
   4 # Copyright (C) 2023 IPFire Network Development Team                          #
   5 #                                                                             #
   6 # This program is free software: you can redistribute it and/or modify        #
   7 # it under the terms of the GNU General Public License as published by        #
   8 # the Free Software Foundation, either version 3 of the License, or           #
   9 # (at your option) any later version.                                         #
  10 #                                                                             #
  11 # This program is distributed in the hope that it will be useful,             #
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of              #
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
  14 # GNU General Public License for more details.                                #
  15 #                                                                             #
  16 # You should have received a copy of the GNU General Public License           #
  17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
  18 #                                                                             #
  19 #############################################################################*/
  20
  21 #ifndef NETWORKD_ADDRESS_H
  22 #define NETWORKD_ADDRESS_H
  23
  24 #include <errno.h>
  25 #include <netinet/ether.h>
  26 #include <string.h>
  27 #include <sys/random.h>
  28
  29 #include "logging.h"
  30
  31 typedef struct ether_addr nw_address_t;
  32
  33 enum {
  34         NW_ADDRESS_MULTICAST        = (1 << 0),
  35         NW_ADDRESS_SOFTWAREASSIGNED = (1 << 1),
  36 };
  37
  38 static inline int nw_address_from_string(nw_address_t* addr, const char* s) {
  39         if (!s)
  40                 return -EINVAL;
  41
  42         struct ether_addr* p = ether_aton_r(s, addr);
  43         if (!p)
  44                 return -errno;
  45
  46         return 0;
  47 }
  48
  49 static inline char* nw_address_to_string(const nw_address_t* addr) {
  50         char buffer[20];
  51
  52         char* p = ether_ntoa_r(addr, buffer);
  53         if (!p)
  54                 return NULL;
  55
  56         return strdup(buffer);
  57 }
  58
  59 static inline int nw_address_generate(nw_address_t* addr) {
  60         ssize_t bytes = getrandom(addr, sizeof(*addr), 0);
  61         if (bytes < 0) {
  62                 ERROR("getrandom() failed: %m\n");
  63                 return 1;
  64         }
  65
  66         // Check if we filled the entire buffer
  67         if (bytes < (ssize_t)sizeof(*addr)) {
  68                 ERROR("Could not gather enough randomness\n");
  69                 return 1;
  70         }
  71
  72         // Clear the multicast bit
  73         addr->ether_addr_octet[0] &= ~NW_ADDRESS_MULTICAST;
  74
  75         // Set the software-generated bit
  76         addr->ether_addr_octet[0] |= NW_ADDRESS_SOFTWAREASSIGNED;
  77
  78         return 0;
  79 }
  80
  81 static inline int nw_address_is_multicast(const nw_address_t* addr) {
  82         return (addr->ether_addr_octet[0] & NW_ADDRESS_MULTICAST);
  83 }
  84
  85 #endif /* NETWORKD_ADDRESS_H */