net/dhcpv6.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Copyright (C) Microsoft Corporation
   4  * Author: Sean Edmond <seanedmond@microsoft.com>
   5  *
   6  */
   7
   8 #ifndef __DHCP6_H__
   9 #define __DHCP6_H__
  10
  11 /* Message types */
  12 #define DHCP6_MSG_SOLICIT       1
  13 #define DHCP6_MSG_ADVERTISE     2
  14 #define DHCP6_MSG_REQUEST       3
  15 #define DHCP6_MSG_REPLY         7
  16
  17 /* Option Codes */
  18 #define DHCP6_OPTION_CLIENTID           1
  19 #define DHCP6_OPTION_SERVERID           2
  20 #define DHCP6_OPTION_IA_NA              3
  21 #define DHCP6_OPTION_IA_TA              4
  22 #define DHCP6_OPTION_IAADDR             5
  23 #define DHCP6_OPTION_ORO                6
  24 #define DHCP6_OPTION_PREFERENCE         7
  25 #define DHCP6_OPTION_ELAPSED_TIME       8
  26 #define DHCP6_OPTION_STATUS_CODE        13
  27 #define DHCP6_OPTION_OPT_BOOTFILE_URL   59
  28 #define DHCP6_OPTION_OPT_BOOTFILE_PARAM 60
  29 #define DHCP6_OPTION_SOL_MAX_RT         82
  30 #define DHCP6_OPTION_CLIENT_ARCH_TYPE   61
  31 #define DHCP6_OPTION_VENDOR_CLASS       16
  32 #define DHCP6_OPTION_NII                62
  33
  34 /* DUID */
  35 #define DUID_TYPE_LL            3
  36 #define DUID_HW_TYPE_ENET       1
  37 #define DUID_LL_SIZE            (sizeof(struct dhcp6_option_duid_ll) + ETH_ALEN)
  38 #define DUID_MAX_SIZE           DUID_LL_SIZE /* only supports DUID-LL currently */
  39
  40 /* vendor-class-data to send in vendor clas option */
  41 #define DHCP6_VCI_STRING        "U-Boot"
  42
  43 #define DHCP6_MULTICAST_ADDR    "ff02::1:2"     /* DHCP multicast address */
  44
  45 /* DHCP6 States supported */
  46 enum dhcp6_state {
  47         DHCP6_INIT,
  48         DHCP6_SOLICIT,
  49         DHCP6_REQUEST,
  50         DHCP6_DONE,
  51         DHCP6_FAIL,
  52 };
  53
  54 /* DHCP6 Status codes */
  55 enum dhcp6_status {
  56         DHCP6_SUCCESS = 0,
  57         DHCP6_UNSPEC_FAIL = 1,
  58         DHCP6_NO_ADDRS_AVAIL = 2,
  59         DHCP6_NO_BINDING = 3,
  60         DHCP6_NOT_ON_LINK = 4,
  61         DHCP6_USE_MULTICAST = 5,
  62         DHCP6_NO_PREFIX_AVAIL = 6,
  63 };
  64
  65 /* DHCP6 message header format */
  66 struct dhcp6_hdr {
  67         unsigned int msg_type : 8;      /* message type */
  68         unsigned int trans_id : 24;     /* transaction ID */
  69 } __packed;
  70
  71 /* DHCP6 option header format */
  72 struct dhcp6_option_hdr {
  73         __be16  option_id;      /* option id */
  74         __be16  option_len;     /* Option length */
  75         u8      option_data[0]; /* Option data */
  76 } __packed;
  77
  78 /* DHCP6_OPTION_CLIENTID option (DUID-LL) */
  79 struct dhcp6_option_duid_ll {
  80         __be16  duid_type;
  81         __be16  hw_type;
  82         u8      ll_addr[0];
  83 } __packed;
  84
  85 /* DHCP6_OPTION_ELAPSED_TIME option */
  86 struct dhcp6_option_elapsed_time {
  87         __be16  elapsed_time;
  88 } __packed;
  89
  90 /* DHCP6_OPTION_IA_TA option */
  91 struct dhcp6_option_ia_ta {
  92         __be32  iaid;
  93         u8      ia_ta_options[0];
  94 } __packed;
  95
  96 /* DHCP6_OPTION_IA_NA option */
  97 struct dhcp6_option_ia_na {
  98         __be32  iaid;
  99         __be32  t1;
 100         __be32  t2;
 101         u8      ia_na_options[0];
 102 } __packed;
 103
 104 /* OPTION_ORO option */
 105 struct dhcp6_option_oro  {
 106         __be16  req_option_code[0];
 107 } __packed;
 108
 109 /* DHCP6_OPTION_CLIENT_ARCH_TYPE option */
 110 struct dhcp6_option_client_arch {
 111         __be16  arch_type[0];
 112 } __packed;
 113
 114 /* vendor-class-data inside OPTION_VENDOR_CLASS option */
 115 struct vendor_class_data {
 116         __be16  vendor_class_len;
 117         u8      opaque_data[0];
 118 } __packed;
 119
 120 /* DHCP6_OPTION_VENDOR_CLASS option */
 121 struct dhcp6_option_vendor_class {
 122         __be32                          enterprise_number;
 123         struct vendor_class_data        vendor_class_data[0];
 124 } __packed;
 125
 126 /**
 127  * struct dhcp6_rx_pkt_status - Structure that holds status
 128  *                              from a received message
 129  * @client_id_match: Client ID was found and matches DUID sent
 130  * @server_id_found: Server ID was found in the message
 131  * @server_uid_ptr: Pointer to received server ID
 132  * @server_uid_size: Size of received server ID
 133  * @ia_addr_found: IA addr option was found in received message
 134  * @ia_addr_ipv6: The IPv6 address received in IA
 135  * @ia_status_code: Status code received in the IA
 136  * @status_code: Top-level status code received
 137  * @preference: Preference code received
 138  */
 139 struct dhcp6_rx_pkt_status {
 140         bool                    client_id_match;
 141         bool                    server_id_found;
 142         uchar                   *server_uid_ptr;
 143         u16                     server_uid_size;
 144         bool                    ia_addr_found;
 145         struct in6_addr         ia_addr_ipv6;
 146         enum dhcp6_status       ia_status_code;
 147         enum dhcp6_status       status_code;
 148         u8                      preference;
 149 };
 150
 151 /**
 152  * struct dhcp6_server_uid - Structure that holds the server UID
 153  *                             received from an ADVERTISE and saved
 154  *                             given the server selection criteria.
 155  * @uid_ptr: Dynamically allocated and copied server UID
 156  * @uid_size: Size of the server UID in uid_ptr (in bytes)
 157  * @preference: Preference code associated with this server UID
 158  */
 159 struct dhcp6_server_uid {
 160         uchar   *uid_ptr;
 161         u16     uid_size;
 162         u8      preference;
 163 };
 164
 165 /**
 166  * struct dhcp6_sm_params - Structure that holds DHCP6
 167  *                          state machine parameters
 168  * @curr_state: current DHCP6 state
 169  * @next_state: next DHCP6 state
 170  * @dhcp6_start_ms: timestamp DHCP6 start
 171  * @dhcp6_retry_start_ms: timestamp of current TX message start
 172  * @dhcp6_retry_ms: timestamp of last retransmission
 173  * @retry_cnt: retry count
 174  * @trans_id: transaction ID
 175  * @ia_id: transmitted IA ID
 176  * @irt_ms: Initial retransmission time (in ms)
 177  * @mrt_ms: Maximum retransmission time (in ms)
 178  * @mrc: Maximum retransmission count
 179  * @mrd_ms: Maximum retransmission duration (in ms)
 180  * @rt_ms: retransmission timeout (is ms)
 181  * @rt_prev_ms: previous retransmission timeout
 182  * @rx_status: Status from received message
 183  * @server_uid: Saved Server UID for selected server
 184  * @duid: pointer to transmitted Client DUID
 185  */
 186 struct dhcp6_sm_params {
 187         enum dhcp6_state                curr_state;
 188         enum dhcp6_state                next_state;
 189         ulong                           dhcp6_start_ms;
 190         ulong                           dhcp6_retry_start_ms;
 191         ulong                           dhcp6_retry_ms;
 192         u32                             retry_cnt;
 193         u32                             trans_id;
 194         u32                             ia_id;
 195         int                             irt_ms;
 196         int                             mrt_ms;
 197         int                             mrc;
 198         int                             mrd_ms;
 199         int                             rt_ms;
 200         int                             rt_prev_ms;
 201         struct dhcp6_rx_pkt_status      rx_status;
 202         struct dhcp6_server_uid         server_uid;
 203         char                            duid[DUID_MAX_SIZE];
 204 };
 205
 206 /* Starts a DHCPv6 4-message exchange as a DHCPv6 client. On successful exchange,
 207  * the DHCPv6 state machine will transition from internal states:
 208  *      DHCP6_INIT->DHCP6_SOLICIT->DHCP6_REQUEST->DHCP6_DONE
 209  *
 210  * Transmitted SOLICIT and REQUEST packets will set/request the minimum required
 211  * DHCPv6 options to PXE boot.
 212  *
 213  * After a successful exchange, the DHCPv6 assigned address will be set in net_ip6
 214  *
 215  * Additionally, the following will be set after receiving these options:
 216  * DHCP6_OPTION_OPT_BOOTFILE_URL (option 59) -> net_server_ip6, net_boot_file_name
 217  * DHCP6_OPTION_OPT_BOOTFILE_PARAM (option 60) - > pxelinux_configfile
 218  *
 219  * Illustration of a 4-message exchange with 2 servers (copied from
 220  * https://www.rfc-editor.org/rfc/rfc8415):
 221  *
 222  *               Server                          Server
 223  *           (not selected)      Client        (selected)
 224  *
 225  *                 v               v               v
 226  *                 |               |               |
 227  *                 |     Begins initialization     |
 228  *                 |               |               |
 229  *    start of     | _____________/|\_____________ |
 230  *    4-message    |/ Solicit      | Solicit      \|
 231  *    exchange     |               |               |
 232  *             Determines          |          Determines
 233  *            configuration        |         configuration
 234  *                 |               |               |
 235  *                 |\              |  ____________/|
 236  *                 | \________     | /Advertise    |
 237  *                 | Advertise\    |/              |
 238  *                 |           \   |               |
 239  *                 |      Collects Advertises      |
 240  *                 |             \ |               |
 241  *                 |     Selects configuration     |
 242  *                 |               |               |
 243  *                 | _____________/|\_____________ |
 244  *                 |/ Request      |  Request     \|
 245  *                 |               |               |
 246  *                 |               |     Commits configuration
 247  *                 |               |               |
 248  *    end of       |               | _____________/|
 249  *    4-message    |               |/ Reply        |
 250  *    exchange     |               |               |
 251  *                 |    Initialization complete    |
 252  *                 |               |               |
 253  */
 254 void dhcp6_start(void);
 255
 256 #endif /* __DHCP6_H__ */