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1/* vi: set sw=4 ts=4: */
2/*
3 * Russ Dill <Russ.Dill@asu.edu> September 2001
4 * Rewritten by Vladimir Oleynik <dzo@simtreas.ru> (C) 2003
5 *
6 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
7 */
8#ifndef UDHCP_COMMON_H
9#define UDHCP_COMMON_H 1
10
11#include "libbb.h"
12#include <netinet/udp.h>
13#include <netinet/ip.h>
14
15PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
16
17extern const uint8_t MAC_BCAST_ADDR[6] ALIGN2; /* six all-ones */
18
19
20/*** DHCP packet ***/
21
22/* DHCP protocol. See RFC 2131 */
23#define DHCP_MAGIC 0x63825363
24#define DHCP_OPTIONS_BUFSIZE 308
25#define BOOTREQUEST 1
26#define BOOTREPLY 2
27
28//TODO: rename ciaddr/yiaddr/chaddr
29struct dhcp_packet {
30 uint8_t op; /* BOOTREQUEST or BOOTREPLY */
31 uint8_t htype; /* hardware address type. 1 = 10mb ethernet */
32 uint8_t hlen; /* hardware address length */
33 uint8_t hops; /* used by relay agents only */
34 uint32_t xid; /* unique id */
35 uint16_t secs; /* elapsed since client began acquisition/renewal */
36 uint16_t flags; /* only one flag so far: */
37#define BROADCAST_FLAG 0x8000 /* "I need broadcast replies" */
38 uint32_t ciaddr; /* client IP (if client is in BOUND, RENEW or REBINDING state) */
39 uint32_t yiaddr; /* 'your' (client) IP address */
40 /* IP address of next server to use in bootstrap, returned in DHCPOFFER, DHCPACK by server */
41 uint32_t siaddr_nip;
42 uint32_t gateway_nip; /* relay agent IP address */
43 uint8_t chaddr[16]; /* link-layer client hardware address (MAC) */
44 uint8_t sname[64]; /* server host name (ASCIZ) */
45 uint8_t file[128]; /* boot file name (ASCIZ) */
46 uint32_t cookie; /* fixed first four option bytes (99,130,83,99 dec) */
47 uint8_t options[DHCP_OPTIONS_BUFSIZE + CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS];
48} PACKED;
49#define DHCP_PKT_SNAME_LEN 64
50#define DHCP_PKT_FILE_LEN 128
51#define DHCP_PKT_SNAME_LEN_STR "64"
52#define DHCP_PKT_FILE_LEN_STR "128"
53
54struct ip_udp_dhcp_packet {
55 struct iphdr ip;
56 struct udphdr udp;
57 struct dhcp_packet data;
58} PACKED;
59
60struct udp_dhcp_packet {
61 struct udphdr udp;
62 struct dhcp_packet data;
63} PACKED;
64
65enum {
66 IP_UDP_DHCP_SIZE = sizeof(struct ip_udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
67 UDP_DHCP_SIZE = sizeof(struct udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
68 DHCP_SIZE = sizeof(struct dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
69};
70
71/* Let's see whether compiler understood us right */
72struct BUG_bad_sizeof_struct_ip_udp_dhcp_packet {
73 char c[IP_UDP_DHCP_SIZE == 576 ? 1 : -1];
74};
75
76
77/*** Options ***/
78
79enum {
80 OPTION_IP = 1,
81 OPTION_IP_PAIR,
82 OPTION_STRING,
83 /* Opts of STRING_HOST type will be sanitized before they are passed
84 * to udhcpc script's environment: */
85 OPTION_STRING_HOST,
86// OPTION_BOOLEAN,
87 OPTION_U8,
88 OPTION_U16,
89// OPTION_S16,
90 OPTION_U32,
91 OPTION_S32,
92 OPTION_BIN,
93 OPTION_STATIC_ROUTES,
94 OPTION_6RD,
95#if ENABLE_FEATURE_UDHCP_RFC3397
96 OPTION_DNS_STRING, /* RFC1035 compressed domain name list */
97 OPTION_SIP_SERVERS,
98#endif
99
100 OPTION_TYPE_MASK = 0x0f,
101 /* Client requests this option by default */
102 OPTION_REQ = 0x10,
103 /* There can be a list of 1 or more of these */
104 OPTION_LIST = 0x20,
105};
106
107/* DHCP option codes (partial list). See RFC 2132 and
108 * http://www.iana.org/assignments/bootp-dhcp-parameters/
109 * Commented out options are handled by common option machinery,
110 * uncommented ones have special cases (grep for them to see).
111 */
112#define DHCP_PADDING 0x00
113#define DHCP_SUBNET 0x01
114//#define DHCP_TIME_OFFSET 0x02 /* (localtime - UTC_time) in seconds. signed */
115//#define DHCP_ROUTER 0x03
116//#define DHCP_TIME_SERVER 0x04 /* RFC 868 time server (32-bit, 0 = 1.1.1900) */
117//#define DHCP_NAME_SERVER 0x05 /* IEN 116 _really_ ancient kind of NS */
118//#define DHCP_DNS_SERVER 0x06
119//#define DHCP_LOG_SERVER 0x07 /* port 704 UDP log (not syslog)
120//#define DHCP_COOKIE_SERVER 0x08 /* "quote of the day" server */
121//#define DHCP_LPR_SERVER 0x09
122#define DHCP_HOST_NAME 0x0c /* either client informs server or server gives name to client */
123//#define DHCP_BOOT_SIZE 0x0d
124//#define DHCP_DOMAIN_NAME 0x0f /* server gives domain suffix */
125//#define DHCP_SWAP_SERVER 0x10
126//#define DHCP_ROOT_PATH 0x11
127//#define DHCP_IP_TTL 0x17
128//#define DHCP_MTU 0x1a
129//#define DHCP_BROADCAST 0x1c
130//#define DHCP_ROUTES 0x21
131//#define DHCP_NIS_DOMAIN 0x28
132//#define DHCP_NIS_SERVER 0x29
133//#define DHCP_NTP_SERVER 0x2a
134//#define DHCP_WINS_SERVER 0x2c
135#define DHCP_REQUESTED_IP 0x32 /* sent by client if specific IP is wanted */
136#define DHCP_LEASE_TIME 0x33
137#define DHCP_OPTION_OVERLOAD 0x34
138#define DHCP_MESSAGE_TYPE 0x35
139#define DHCP_SERVER_ID 0x36 /* by default server's IP */
140#define DHCP_PARAM_REQ 0x37 /* list of options client wants */
141//#define DHCP_ERR_MESSAGE 0x38 /* error message when sending NAK etc */
142#define DHCP_MAX_SIZE 0x39
143#define DHCP_VENDOR 0x3c /* client's vendor (a string) */
144#define DHCP_CLIENT_ID 0x3d /* by default client's MAC addr, but may be arbitrarily long */
145//#define DHCP_TFTP_SERVER_NAME 0x42 /* same as 'sname' field */
146//#define DHCP_BOOT_FILE 0x43 /* same as 'file' field */
147//#define DHCP_USER_CLASS 0x4d /* RFC 3004. set of LASCII strings. "I am a printer" etc */
148#define DHCP_FQDN 0x51 /* client asks to update DNS to map its FQDN to its new IP */
149//#define DHCP_DOMAIN_SEARCH 0x77 /* RFC 3397. set of ASCIZ string, DNS-style compressed */
150//#define DHCP_SIP_SERVERS 0x78 /* RFC 3361. flag byte, then: 0: domain names, 1: IP addrs */
151//#define DHCP_STATIC_ROUTES 0x79 /* RFC 3442. (mask,ip,router) tuples */
152//#define DHCP_VLAN_ID 0x84 /* 802.1P VLAN ID */
153//#define DHCP_VLAN_PRIORITY 0x85 /* 802.1Q VLAN priority */
154//#define DHCP_PXE_CONF_FILE 0xd1 /* RFC 5071 Configuration File */
155//#define DHCP_MS_STATIC_ROUTES 0xf9 /* Microsoft's pre-RFC 3442 code for 0x79? */
156//#define DHCP_WPAD 0xfc /* MSIE's Web Proxy Autodiscovery Protocol */
157#define DHCP_END 0xff
158
159/* Offsets in option byte sequence */
160#define OPT_CODE 0
161#define OPT_LEN 1
162#define OPT_DATA 2
163/* Bits in "overload" option */
164#define OPTION_FIELD 0
165#define FILE_FIELD 1
166#define SNAME_FIELD 2
167
168/* DHCP_MESSAGE_TYPE values */
169#define DHCPDISCOVER 1 /* client -> server */
170#define DHCPOFFER 2 /* client <- server */
171#define DHCPREQUEST 3 /* client -> server */
172#define DHCPDECLINE 4 /* client -> server */
173#define DHCPACK 5 /* client <- server */
174#define DHCPNAK 6 /* client <- server */
175#define DHCPRELEASE 7 /* client -> server */
176#define DHCPINFORM 8 /* client -> server */
177#define DHCP_MINTYPE DHCPDISCOVER
178#define DHCP_MAXTYPE DHCPINFORM
179
180struct dhcp_optflag {
181 uint8_t flags;
182 uint8_t code;
183};
184
185struct option_set {
186 uint8_t *data;
187 struct option_set *next;
188};
189
190extern const struct dhcp_optflag dhcp_optflags[];
191extern const char dhcp_option_strings[] ALIGN1;
192extern const uint8_t dhcp_option_lengths[] ALIGN1;
193
194unsigned FAST_FUNC udhcp_option_idx(const char *name);
195
196uint8_t *udhcp_get_option(struct dhcp_packet *packet, int code) FAST_FUNC;
197int udhcp_end_option(uint8_t *optionptr) FAST_FUNC;
198void udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt) FAST_FUNC;
199void udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data) FAST_FUNC;
200#if ENABLE_FEATURE_UDHCP_RFC3397
201char *dname_dec(const uint8_t *cstr, int clen, const char *pre) FAST_FUNC;
202uint8_t *dname_enc(const uint8_t *cstr, int clen, const char *src, int *retlen) FAST_FUNC;
203#endif
204struct option_set *udhcp_find_option(struct option_set *opt_list, uint8_t code) FAST_FUNC;
205
206
207// RFC 2131 Table 5: Fields and options used by DHCP clients
208//
209// Fields 'hops', 'yiaddr', 'siaddr', 'giaddr' are always zero
210//
211// Field DHCPDISCOVER DHCPINFORM DHCPREQUEST DHCPDECLINE DHCPRELEASE
212// ----- ------------ ------------ ----------- ----------- -----------
213// 'xid' selected by client selected by client 'xid' from server selected by client selected by client
214// DHCPOFFER message
215// 'secs' 0 or seconds since 0 or seconds since 0 or seconds since 0 0
216// DHCP process started DHCP process started DHCP process started
217// 'flags' Set 'BROADCAST' Set 'BROADCAST' Set 'BROADCAST' 0 0
218// flag if client flag if client flag if client
219// requires broadcast requires broadcast requires broadcast
220// reply reply reply
221// 'ciaddr' 0 client's IP 0 or client's IP 0 client's IP
222// (BOUND/RENEW/REBIND)
223// 'chaddr' client's MAC client's MAC client's MAC client's MAC client's MAC
224// 'sname' options or sname options or sname options or sname (unused) (unused)
225// 'file' options or file options or file options or file (unused) (unused)
226// 'options' options options options message type opt message type opt
227//
228// Option DHCPDISCOVER DHCPINFORM DHCPREQUEST DHCPDECLINE DHCPRELEASE
229// ------ ------------ ---------- ----------- ----------- -----------
230// Requested IP address MAY MUST NOT MUST (in MUST MUST NOT
231// SELECTING or
232// INIT-REBOOT)
233// MUST NOT (in
234// BOUND or
235// RENEWING)
236// IP address lease time MAY MUST NOT MAY MUST NOT MUST NOT
237// Use 'file'/'sname' fields MAY MAY MAY MAY MAY
238// Client identifier MAY MAY MAY MAY MAY
239// Vendor class identifier MAY MAY MAY MUST NOT MUST NOT
240// Server identifier MUST NOT MUST NOT MUST (after MUST MUST
241// SELECTING)
242// MUST NOT (after
243// INIT-REBOOT,
244// BOUND, RENEWING
245// or REBINDING)
246// Parameter request list MAY MAY MAY MUST NOT MUST NOT
247// Maximum message size MAY MAY MAY MUST NOT MUST NOT
248// Message SHOULD NOT SHOULD NOT SHOULD NOT SHOULD SHOULD
249// Site-specific MAY MAY MAY MUST NOT MUST NOT
250// All others MAY MAY MAY MUST NOT MUST NOT
251
252
253/*** Logging ***/
254
255#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
256# define IF_UDHCP_VERBOSE(...) __VA_ARGS__
257extern unsigned dhcp_verbose;
258# define log1(...) do { if (dhcp_verbose >= 1) bb_info_msg(__VA_ARGS__); } while (0)
259# if CONFIG_UDHCP_DEBUG >= 2
260void udhcp_dump_packet(struct dhcp_packet *packet) FAST_FUNC;
261# define log2(...) do { if (dhcp_verbose >= 2) bb_info_msg(__VA_ARGS__); } while (0)
262# else
263# define udhcp_dump_packet(...) ((void)0)
264# define log2(...) ((void)0)
265# endif
266# if CONFIG_UDHCP_DEBUG >= 3
267# define log3(...) do { if (dhcp_verbose >= 3) bb_info_msg(__VA_ARGS__); } while (0)
268# else
269# define log3(...) ((void)0)
270# endif
271#else
272# define IF_UDHCP_VERBOSE(...)
273# define udhcp_dump_packet(...) ((void)0)
274# define log1(...) ((void)0)
275# define log2(...) ((void)0)
276# define log3(...) ((void)0)
277#endif
278
279
280/*** Other shared functions ***/
281
282/* 2nd param is "uint32_t*" */
283int FAST_FUNC udhcp_str2nip(const char *str, void *arg);
284/* 2nd param is "struct option_set**" */
285int FAST_FUNC udhcp_str2optset(const char *str, void *arg);
286
287void udhcp_init_header(struct dhcp_packet *packet, char type) FAST_FUNC;
288
289int udhcp_recv_kernel_packet(struct dhcp_packet *packet, int fd) FAST_FUNC;
290
291int udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
292 uint32_t source_nip, int source_port,
293 uint32_t dest_nip, int dest_port, const uint8_t *dest_arp,
294 int ifindex) FAST_FUNC;
295
296int udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
297 uint32_t source_nip, int source_port,
298 uint32_t dest_nip, int dest_port) FAST_FUNC;
299
300void udhcp_sp_setup(void) FAST_FUNC;
301int udhcp_sp_fd_set(fd_set *rfds, int extra_fd) FAST_FUNC;
302int udhcp_sp_read(const fd_set *rfds) FAST_FUNC;
303
304int udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uint8_t *mac) FAST_FUNC;
305
306int udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf) FAST_FUNC;
307
308/* Returns 1 if no reply received */
309int arpping(uint32_t test_nip,
310 const uint8_t *safe_mac,
311 uint32_t from_ip,
312 uint8_t *from_mac,
313 const char *interface) FAST_FUNC;
314
315/* note: ip is a pointer to an IPv6 in network order, possibly misaliged */
316int sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip) FAST_FUNC;
317
318POP_SAVED_FUNCTION_VISIBILITY
319
320#endif
321
generated by cgit at 2024-05-15 06:55:57 (GMT)