src/vendorcode/google/chromeos/vpd_mac.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright 2014 Google Inc.
   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; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <boot/coreboot_tables.h>
  17 #include <console/console.h>
  18 #include <string.h>
  19
  20 #include <vendorcode/google/chromeos/cros_vpd.h>
  21
  22 /*
  23  * Decode string representation of the MAC address (a string of 12 hex
  24  * symbols) into binary. 'key_name' is the name of the VPD field, it's used if
  25  * it is necessary to report an input data format problem.
  26  */
  27 static void decode_mac(struct mac_address *mac,
  28                        const char *mac_addr_str,
  29                        const char *key_name)
  30 {
  31         int i;
  32
  33         for (i = 0; i < sizeof(mac->mac_addr); i++) {
  34                 int j;
  35                 uint8_t n = 0;
  36
  37                 for (j = 0; j < 2; j++) {
  38                         char c = mac_addr_str[i * 2 + j];
  39
  40                         if (isxdigit(c)) {
  41                                 if (isdigit(c))
  42                                         c -= '0';
  43                                 else
  44                                         c = tolower(c) - 'a' + 10;
  45                         } else {
  46                                 printk(BIOS_ERR, "%s: non hexadecimal symbol "
  47                                        "%#2.2x in the VPD field %s:%s\n",
  48                                        __func__, (uint8_t)c, key_name,
  49                                        mac_addr_str);
  50                                 c = 0;
  51                         }
  52                         n <<= 4;
  53                         n |= c;
  54                 }
  55                 mac->mac_addr[i] = n;
  56         }
  57 }
  58
  59 void lb_table_add_macs_from_vpd(struct lb_header *header)
  60 {
  61         /*
  62          * Mac addresses in the VPD can be stored in two groups, for ethernet
  63          * and WiFi, with keys 'ethernet_macX and wifi_macX.
  64          */
  65         const char *mac_addr_key_bases[] = {"ethernet_mac0", "wifi_mac0"};
  66         char mac_addr_key[20]; /* large enough for either key */
  67         char mac_addr_str[13]; /* 12 symbols and the trailing zero. */
  68         int i, count;
  69         struct lb_macs *macs = NULL;
  70
  71         /* Make sure the copy is always zero terminated. */
  72         mac_addr_key[sizeof(mac_addr_key) - 1] = '\0';
  73
  74         count = 0;
  75         for (i = 0; i < ARRAY_SIZE(mac_addr_key_bases); i++) {
  76                 int index_of_index;
  77
  78                 strncpy(mac_addr_key, mac_addr_key_bases[i],
  79                         sizeof(mac_addr_key) - 1);
  80                 index_of_index = strlen(mac_addr_key) - 1;
  81
  82                 do {
  83                         /*
  84                          * If there are no more MAC addresses of this template
  85                          * in the VPD - move on.
  86                          */
  87                         if (!cros_vpd_gets(mac_addr_key, mac_addr_str,
  88                                            sizeof(mac_addr_str)))
  89                                 break;
  90
  91                         if (!macs) {
  92                                 macs = (struct lb_macs *)lb_new_record(header);
  93                                 macs->tag = LB_TAG_MAC_ADDRS;
  94                         }
  95
  96                         decode_mac(macs->mac_addrs + count,
  97                                    mac_addr_str,
  98                                    mac_addr_key);
  99
 100                         count++;
 101                         mac_addr_key[index_of_index]++;
 102                 } while (count < 10);
 103         }
 104         if (!count)
 105                 return; /* No MAC addresses in the VPD. */
 106
 107         macs->count = count;
 108         macs->size = sizeof(*macs) + count * sizeof(struct mac_address);
 109 }