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 */
46enum dhcp6_state {
47	DHCP6_INIT,
48	DHCP6_SOLICIT,
49	DHCP6_REQUEST,
50	DHCP6_DONE,
51	DHCP6_FAIL,
52};
53
54/* DHCP6 Status codes */
55enum 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 */
66struct 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 */
72struct 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) */
79struct 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 */
86struct dhcp6_option_elapsed_time {
87	__be16	elapsed_time;
88} __packed;
89
90/* DHCP6_OPTION_IA_TA option */
91struct dhcp6_option_ia_ta {
92	__be32	iaid;
93	u8	ia_ta_options[0];
94} __packed;
95
96/* DHCP6_OPTION_IA_NA option */
97struct 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 */
105struct dhcp6_option_oro  {
106	__be16	req_option_code[0];
107} __packed;
108
109/* DHCP6_OPTION_CLIENT_ARCH_TYPE option */
110struct dhcp6_option_client_arch {
111	__be16	arch_type[0];
112} __packed;
113
114/* vendor-class-data inside OPTION_VENDOR_CLASS option */
115struct vendor_class_data {
116	__be16	vendor_class_len;
117	u8	opaque_data[0];
118} __packed;
119
120/* DHCP6_OPTION_VENDOR_CLASS option */
121struct 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 */
139struct 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 */
159struct 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 */
186struct 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 */
254void dhcp6_start(void);
255
256#endif /* __DHCP6_H__ */
257