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1 /**
2  * @file
3  * DHCP protocol definitions
4  */
5 
6 /*
7  * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net>
8  * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without modification,
12  * are permitted provided that the following conditions are met:
13  *
14  * 1. Redistributions of source code must retain the above copyright notice,
15  *    this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright notice,
17  *    this list of conditions and the following disclaimer in the documentation
18  *    and/or other materials provided with the distribution.
19  * 3. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
25  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
27  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
30  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
31  * OF SUCH DAMAGE.
32  *
33  * This file is part of the lwIP TCP/IP stack.
34  *
35  * Author: Leon Woestenberg <leon.woestenberg@gmx.net>
36  *
37  */
38 #ifndef LWIP_HDR_PROT_DHCP_H
39 #define LWIP_HDR_PROT_DHCP_H
40 
41 #include "lwip/opt.h"
42 
43 #if defined (__cplusplus) && __cplusplus
44 extern "C" {
45 #endif
46 
47 #define DHCP_RELAY_PORT   LWIP_IANA_PORT_DHCP_SERVER
48 
49 /* DHCP message item offsets and length */
50 #define DHCP_CHADDR_LEN   16U
51 #define DHCP_SNAME_OFS    44U
52 #define DHCP_SNAME_LEN    64U
53 #define DHCP_FILE_OFS     108U
54 #define DHCP_FILE_LEN     128U
55 #define DHCP_MSG_LEN      236U
56 #define DHCP_OPTIONS_OFS  (DHCP_MSG_LEN + 4U) /* 4 byte: cookie */
57 
58 #ifdef PACK_STRUCT_USE_INCLUDES
59 #  include "arch/bpstruct.h"
60 #endif
61 PACK_STRUCT_BEGIN
62 /* minimum set of fields of any DHCP message */
63 struct dhcp_msg {
64   PACK_STRUCT_FLD_8(u8_t op);
65   PACK_STRUCT_FLD_8(u8_t htype);
66   PACK_STRUCT_FLD_8(u8_t hlen);
67   PACK_STRUCT_FLD_8(u8_t hops);
68   PACK_STRUCT_FIELD(u32_t xid);
69   PACK_STRUCT_FIELD(u16_t secs);
70   PACK_STRUCT_FIELD(u16_t flags);
71   PACK_STRUCT_FLD_S(ip4_addr_p_t ciaddr);
72   PACK_STRUCT_FLD_S(ip4_addr_p_t yiaddr);
73   PACK_STRUCT_FLD_S(ip4_addr_p_t siaddr);
74   PACK_STRUCT_FLD_S(ip4_addr_p_t giaddr);
75   PACK_STRUCT_FLD_8(u8_t chaddr[DHCP_CHADDR_LEN]);
76   PACK_STRUCT_FLD_8(u8_t sname[DHCP_SNAME_LEN]);
77   PACK_STRUCT_FLD_8(u8_t file[DHCP_FILE_LEN]);
78   PACK_STRUCT_FIELD(u32_t cookie);
79 
80 #define DHCP_MIN_OPTIONS_LEN 68U
81 
82 /* Max length of the vendor class identifier information string can be stored */
83 #define DHCP_VCI_MAX_LEN 32U
84 
85 #if (LWIP_NETIF_HOSTNAME && LWIP_DHCP_VENDOR_CLASS_IDENTIFIER)
86 #define DHCP_MIN_OPTIONS_BUFFER_LEN ((DHCP_MIN_OPTIONS_LEN) + \
87                                      (NETIF_HOSTNAME_MAX_LEN) + \
88                                      (DHCP_VCI_MAX_LEN) + \
89                                      4U)
90 #elif LWIP_NETIF_HOSTNAME
91   /* Minimum option buffer length include:
92      minimum option len + 2 bytes of type/length + max hostname len + 2 bytes padding */
93 #define DHCP_MIN_OPTIONS_BUFFER_LEN ((DHCP_MIN_OPTIONS_LEN) + \
94                                      (NETIF_HOSTNAME_MAX_LEN) + \
95                                      4U)
96 #elif LWIP_DHCP_VENDOR_CLASS_IDENTIFIER
97 #define DHCP_MIN_OPTIONS_BUFFER_LEN ((DHCP_MIN_OPTIONS_LEN) + \
98                                      (DHCP_VCI_MAX_LEN) + \
99                                      4U)
100 #else
101 #define DHCP_MIN_OPTIONS_BUFFER_LEN (DHCP_MIN_OPTIONS_LEN)
102 #endif
103 
104 /** make sure user does not configure this too small */
105 #if ((defined(DHCP_OPTIONS_LEN)) && (DHCP_OPTIONS_LEN < DHCP_MIN_OPTIONS_BUFFER_LEN))
106 #  undef DHCP_OPTIONS_LEN
107 #endif
108 /* allow this to be configured in lwipopts.h, but not too small */
109 #if (!defined(DHCP_OPTIONS_LEN))
110 /* set this to be sufficient for your options in outgoing DHCP msgs */
111 #define DHCP_OPTIONS_LEN DHCP_MIN_OPTIONS_BUFFER_LEN
112 #endif
113   PACK_STRUCT_FLD_8(u8_t options[DHCP_OPTIONS_LEN]);
114 } PACK_STRUCT_STRUCT;
115 PACK_STRUCT_END
116 #ifdef PACK_STRUCT_USE_INCLUDES
117 #  include "arch/epstruct.h"
118 #endif
119 
120 /* DHCP client states */
121 typedef enum {
122   DHCP_STATE_OFF             = 0,
123   DHCP_STATE_REQUESTING      = 1,
124   DHCP_STATE_INIT            = 2,
125   DHCP_STATE_REBOOTING       = 3,
126   DHCP_STATE_REBINDING       = 4,
127   DHCP_STATE_RENEWING        = 5,
128   DHCP_STATE_SELECTING       = 6,
129   DHCP_STATE_INFORMING       = 7,
130   DHCP_STATE_CHECKING        = 8,
131   DHCP_STATE_PERMANENT       = 9,  /* not yet implemented */
132   DHCP_STATE_BOUND           = 10,
133   DHCP_STATE_RELEASING       = 11, /* not yet implemented */
134   DHCP_STATE_BACKING_OFF     = 12
135 } dhcp_state_enum_t;
136 
137 /* DHCP op codes */
138 #define DHCP_BOOTREQUEST            1
139 #define DHCP_BOOTREPLY              2
140 
141 /* DHCP message types */
142 #define DHCP_DISCOVER               1
143 #define DHCP_OFFER                  2
144 #define DHCP_REQUEST                3
145 #define DHCP_DECLINE                4
146 #define DHCP_ACK                    5
147 #define DHCP_NAK                    6
148 #define DHCP_RELEASE                7
149 #define DHCP_INFORM                 8
150 
151 #define DHCP_MAGIC_COOKIE           0x63825363UL
152 
153 /* This is a list of options for BOOTP and DHCP, see RFC 2132 for descriptions */
154 
155 /* BootP options */
156 #define DHCP_OPTION_PAD             0
157 #define DHCP_OPTION_SUBNET_MASK     1 /* RFC 2132 3.3 */
158 #define DHCP_OPTION_SUBNET_MASK_SIZE 4
159 #define DHCP_OPTION_ROUTER          3
160 #define DHCP_OPTION_ROUTER_LEN      4
161 #define DHCP_OPTION_DNS_SERVER      6
162 #define DHCP_OPTION_HOSTNAME        12
163 #define DHCP_OPTION_IP_TTL          23
164 #define DHCP_OPTION_MTU             26
165 #define DHCP_OPTION_BROADCAST       28
166 #define DHCP_OPTION_TCP_TTL         37
167 #define DHCP_OPTION_NTP             42
168 #define DHCP_OPTION_END             255
169 
170 /* DHCP options */
171 #define DHCP_OPTION_REQUESTED_IP    50 /* RFC 2132 9.1, requested IP address */
172 #define DHCP_OPTION_LEASE_TIME      51 /* RFC 2132 9.2, time in seconds, in 4 bytes */
173 #define DHCP_OPTION_LEASE_TIME_SIZE 4
174 #define DHCP_OPTION_OVERLOAD        52 /* RFC2132 9.3, use file and/or sname field for options */
175 
176 #define DHCP_OPTION_MESSAGE_TYPE    53 /* RFC 2132 9.6, important for DHCP */
177 #define DHCP_OPTION_MESSAGE_TYPE_LEN 1
178 
179 #define DHCP_OPTION_SERVER_ID       54 /* RFC 2132 9.7, server IP address */
180 #define DHCP_OPTION_SERVER_ID_LEN 4
181 #define DHCP_OPTION_PARAMETER_REQUEST_LIST  55 /* RFC 2132 9.8, requested option types */
182 
183 #define DHCP_OPTION_MAX_MSG_SIZE    57 /* RFC 2132 9.10, message size accepted >= 576 */
184 #define DHCP_OPTION_MAX_MSG_SIZE_LEN 2
185 
186 #define DHCP_OPTION_T1              58 /* T1 renewal time */
187 #define DHCP_OPTION_T1_LEN          4
188 #define DHCP_OPTION_T2              59 /* T2 rebinding time */
189 #define DHCP_OPTION_T2_LEN          4
190 #define DHCP_OPTION_VCI             60
191 #define DHCP_OPTION_CLIENT_ID       61
192 #define DHCP_OPTION_CLIENT_ID_LEN   7
193 #define DHCP_OPTION_TFTP_SERVERNAME 66
194 #define DHCP_OPTION_BOOTFILE        67
195 
196 #define DHCP_OPTION_AGENT_INFO      82
197 #define DHCP_OPTION_AGENT_INFO_CID   1
198 #define DHCP_OPTION_AGENT_INFO_RID   2
199 
200 #define GEN_FLG(name) (1U << (DHCP_OPTION_##name - 32))
201 
202 
203 /* possible combinations of overloading the file and sname fields with options */
204 #define DHCP_OVERLOAD_NONE          0
205 #define DHCP_OVERLOAD_FILE          1
206 #define DHCP_OVERLOAD_SNAME         2
207 #define DHCP_OVERLOAD_SNAME_FILE    3
208 
209 #if defined (__cplusplus) && __cplusplus
210 }
211 #endif
212 
213 #endif /* LWIP_HDR_PROT_DHCP_H */
214