blob: a526494d7c5df0e75b27d3a975e393b485c88744
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 "common_bufsiz.h" |
13 | #include <netinet/udp.h> |
14 | #include <netinet/ip.h> |
15 | |
16 | PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN |
17 | |
18 | extern const uint8_t MAC_BCAST_ADDR[6] ALIGN2; /* six all-ones */ |
19 | |
20 | |
21 | /*** DHCP packet ***/ |
22 | |
23 | /* DHCP protocol. See RFC 2131 */ |
24 | #define DHCP_MAGIC 0x63825363 |
25 | #define DHCP_OPTIONS_BUFSIZE 308 |
26 | #define BOOTREQUEST 1 |
27 | #define BOOTREPLY 2 |
28 | |
29 | //TODO: rename ciaddr/yiaddr/chaddr |
30 | struct dhcp_packet { |
31 | uint8_t op; /* BOOTREQUEST or BOOTREPLY */ |
32 | uint8_t htype; /* hardware address type. 1 = 10mb ethernet */ |
33 | uint8_t hlen; /* hardware address length */ |
34 | uint8_t hops; /* used by relay agents only */ |
35 | uint32_t xid; /* unique id */ |
36 | uint16_t secs; /* elapsed since client began acquisition/renewal */ |
37 | uint16_t flags; /* only one flag so far: */ |
38 | #define BROADCAST_FLAG 0x8000 /* "I need broadcast replies" */ |
39 | uint32_t ciaddr; /* client IP (if client is in BOUND, RENEW or REBINDING state) */ |
40 | uint32_t yiaddr; /* 'your' (client) IP address */ |
41 | /* IP address of next server to use in bootstrap, returned in DHCPOFFER, DHCPACK by server */ |
42 | uint32_t siaddr_nip; |
43 | uint32_t gateway_nip; /* relay agent IP address */ |
44 | uint8_t chaddr[16]; /* link-layer client hardware address (MAC) */ |
45 | uint8_t sname[64]; /* server host name (ASCIZ) */ |
46 | uint8_t file[128]; /* boot file name (ASCIZ) */ |
47 | uint32_t cookie; /* fixed first four option bytes (99,130,83,99 dec) */ |
48 | uint8_t options[DHCP_OPTIONS_BUFSIZE + CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS]; |
49 | } PACKED; |
50 | #define DHCP_PKT_SNAME_LEN 64 |
51 | #define DHCP_PKT_FILE_LEN 128 |
52 | #define DHCP_PKT_SNAME_LEN_STR "64" |
53 | #define DHCP_PKT_FILE_LEN_STR "128" |
54 | |
55 | struct ip_udp_dhcp_packet { |
56 | struct iphdr ip; |
57 | struct udphdr udp; |
58 | struct dhcp_packet data; |
59 | } PACKED; |
60 | |
61 | struct udp_dhcp_packet { |
62 | struct udphdr udp; |
63 | struct dhcp_packet data; |
64 | } PACKED; |
65 | |
66 | enum { |
67 | IP_UDP_DHCP_SIZE = sizeof(struct ip_udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, |
68 | UDP_DHCP_SIZE = sizeof(struct udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, |
69 | DHCP_SIZE = sizeof(struct dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, |
70 | }; |
71 | |
72 | /* Let's see whether compiler understood us right */ |
73 | struct BUG_bad_sizeof_struct_ip_udp_dhcp_packet { |
74 | char c[IP_UDP_DHCP_SIZE == 576 ? 1 : -1]; |
75 | }; |
76 | |
77 | |
78 | /*** Options ***/ |
79 | |
80 | enum { |
81 | OPTION_IP = 1, |
82 | OPTION_IP_PAIR, |
83 | OPTION_STRING, |
84 | /* Opts of STRING_HOST type will be sanitized before they are passed |
85 | * to udhcpc script's environment: */ |
86 | OPTION_STRING_HOST, |
87 | // OPTION_BOOLEAN, |
88 | OPTION_U8, |
89 | OPTION_U16, |
90 | // OPTION_S16, |
91 | OPTION_U32, |
92 | OPTION_S32, |
93 | OPTION_BIN, |
94 | OPTION_STATIC_ROUTES, |
95 | OPTION_6RD, |
96 | #if ENABLE_FEATURE_UDHCP_RFC3397 |
97 | OPTION_DNS_STRING, /* RFC1035 compressed domain name list */ |
98 | OPTION_SIP_SERVERS, |
99 | #endif |
100 | |
101 | OPTION_TYPE_MASK = 0x0f, |
102 | /* Client requests this option by default */ |
103 | OPTION_REQ = 0x10, |
104 | /* There can be a list of 1 or more of these */ |
105 | OPTION_LIST = 0x20, |
106 | }; |
107 | |
108 | /* DHCP option codes (partial list). See RFC 2132 and |
109 | * http://www.iana.org/assignments/bootp-dhcp-parameters/ |
110 | * Commented out options are handled by common option machinery, |
111 | * uncommented ones have special cases (grep for them to see). |
112 | */ |
113 | #define DHCP_PADDING 0x00 |
114 | #define DHCP_SUBNET 0x01 |
115 | //#define DHCP_TIME_OFFSET 0x02 /* (localtime - UTC_time) in seconds. signed */ |
116 | //#define DHCP_ROUTER 0x03 |
117 | //#define DHCP_TIME_SERVER 0x04 /* RFC 868 time server (32-bit, 0 = 1.1.1900) */ |
118 | //#define DHCP_NAME_SERVER 0x05 /* IEN 116 _really_ ancient kind of NS */ |
119 | //#define DHCP_DNS_SERVER 0x06 |
120 | //#define DHCP_LOG_SERVER 0x07 /* port 704 UDP log (not syslog) |
121 | //#define DHCP_COOKIE_SERVER 0x08 /* "quote of the day" server */ |
122 | //#define DHCP_LPR_SERVER 0x09 |
123 | #define DHCP_HOST_NAME 0x0c /* either client informs server or server gives name to client */ |
124 | //#define DHCP_BOOT_SIZE 0x0d |
125 | //#define DHCP_DOMAIN_NAME 0x0f /* server gives domain suffix */ |
126 | //#define DHCP_SWAP_SERVER 0x10 |
127 | //#define DHCP_ROOT_PATH 0x11 |
128 | //#define DHCP_IP_TTL 0x17 |
129 | //#define DHCP_MTU 0x1a |
130 | //#define DHCP_BROADCAST 0x1c |
131 | //#define DHCP_ROUTES 0x21 |
132 | //#define DHCP_NIS_DOMAIN 0x28 |
133 | //#define DHCP_NIS_SERVER 0x29 |
134 | //#define DHCP_NTP_SERVER 0x2a |
135 | //#define DHCP_WINS_SERVER 0x2c |
136 | #define DHCP_REQUESTED_IP 0x32 /* sent by client if specific IP is wanted */ |
137 | #define DHCP_LEASE_TIME 0x33 |
138 | #define DHCP_OPTION_OVERLOAD 0x34 |
139 | #define DHCP_MESSAGE_TYPE 0x35 |
140 | #define DHCP_SERVER_ID 0x36 /* by default server's IP */ |
141 | #define DHCP_PARAM_REQ 0x37 /* list of options client wants */ |
142 | //#define DHCP_ERR_MESSAGE 0x38 /* error message when sending NAK etc */ |
143 | #define DHCP_MAX_SIZE 0x39 |
144 | #define DHCP_VENDOR 0x3c /* client's vendor (a string) */ |
145 | #define DHCP_CLIENT_ID 0x3d /* by default client's MAC addr, but may be arbitrarily long */ |
146 | //#define DHCP_TFTP_SERVER_NAME 0x42 /* same as 'sname' field */ |
147 | //#define DHCP_BOOT_FILE 0x43 /* same as 'file' field */ |
148 | //#define DHCP_USER_CLASS 0x4d /* RFC 3004. set of LASCII strings. "I am a printer" etc */ |
149 | #define DHCP_FQDN 0x51 /* client asks to update DNS to map its FQDN to its new IP */ |
150 | //#define DHCP_DOMAIN_SEARCH 0x77 /* RFC 3397. set of ASCIZ string, DNS-style compressed */ |
151 | //#define DHCP_SIP_SERVERS 0x78 /* RFC 3361. flag byte, then: 0: domain names, 1: IP addrs */ |
152 | //#define DHCP_STATIC_ROUTES 0x79 /* RFC 3442. (mask,ip,router) tuples */ |
153 | //#define DHCP_VLAN_ID 0x84 /* 802.1P VLAN ID */ |
154 | //#define DHCP_VLAN_PRIORITY 0x85 /* 802.1Q VLAN priority */ |
155 | //#define DHCP_PXE_CONF_FILE 0xd1 /* RFC 5071 Configuration File */ |
156 | //#define DHCP_PXE_PATH_PREFIX 0xd2 /* RFC 5071 Configuration File */ |
157 | //#define DHCP_MS_STATIC_ROUTES 0xf9 /* Microsoft's pre-RFC 3442 code for 0x79? */ |
158 | //#define DHCP_WPAD 0xfc /* MSIE's Web Proxy Autodiscovery Protocol */ |
159 | #define DHCP_END 0xff |
160 | |
161 | /* Offsets in option byte sequence */ |
162 | #define OPT_CODE 0 |
163 | #define OPT_LEN 1 |
164 | #define OPT_DATA 2 |
165 | /* Bits in "overload" option */ |
166 | #define OPTION_FIELD 0 |
167 | #define FILE_FIELD 1 |
168 | #define SNAME_FIELD 2 |
169 | |
170 | /* DHCP_MESSAGE_TYPE values */ |
171 | #define DHCPDISCOVER 1 /* client -> server */ |
172 | #define DHCPOFFER 2 /* client <- server */ |
173 | #define DHCPREQUEST 3 /* client -> server */ |
174 | #define DHCPDECLINE 4 /* client -> server */ |
175 | #define DHCPACK 5 /* client <- server */ |
176 | #define DHCPNAK 6 /* client <- server */ |
177 | #define DHCPRELEASE 7 /* client -> server */ |
178 | #define DHCPINFORM 8 /* client -> server */ |
179 | #define DHCP_MINTYPE DHCPDISCOVER |
180 | #define DHCP_MAXTYPE DHCPINFORM |
181 | |
182 | struct dhcp_optflag { |
183 | uint8_t flags; |
184 | uint8_t code; |
185 | }; |
186 | |
187 | struct option_set { |
188 | uint8_t *data; |
189 | struct option_set *next; |
190 | }; |
191 | |
192 | extern const struct dhcp_optflag dhcp_optflags[]; |
193 | extern const char dhcp_option_strings[] ALIGN1; |
194 | extern const uint8_t dhcp_option_lengths[] ALIGN1; |
195 | |
196 | unsigned FAST_FUNC udhcp_option_idx(const char *name); |
197 | |
198 | uint8_t *udhcp_get_option(struct dhcp_packet *packet, int code) FAST_FUNC; |
199 | int udhcp_end_option(uint8_t *optionptr) FAST_FUNC; |
200 | void udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt) FAST_FUNC; |
201 | void udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data) FAST_FUNC; |
202 | #if ENABLE_FEATURE_UDHCP_RFC3397 |
203 | char *dname_dec(const uint8_t *cstr, int clen, const char *pre) FAST_FUNC; |
204 | uint8_t *dname_enc(const uint8_t *cstr, int clen, const char *src, int *retlen) FAST_FUNC; |
205 | #endif |
206 | struct option_set *udhcp_find_option(struct option_set *opt_list, uint8_t code) FAST_FUNC; |
207 | |
208 | |
209 | // RFC 2131 Table 5: Fields and options used by DHCP clients |
210 | // |
211 | // Fields 'hops', 'yiaddr', 'siaddr', 'giaddr' are always zero |
212 | // |
213 | // Field DHCPDISCOVER DHCPINFORM DHCPREQUEST DHCPDECLINE DHCPRELEASE |
214 | // ----- ------------ ------------ ----------- ----------- ----------- |
215 | // 'xid' selected by client selected by client 'xid' from server selected by client selected by client |
216 | // DHCPOFFER message |
217 | // 'secs' 0 or seconds since 0 or seconds since 0 or seconds since 0 0 |
218 | // DHCP process started DHCP process started DHCP process started |
219 | // 'flags' Set 'BROADCAST' Set 'BROADCAST' Set 'BROADCAST' 0 0 |
220 | // flag if client flag if client flag if client |
221 | // requires broadcast requires broadcast requires broadcast |
222 | // reply reply reply |
223 | // 'ciaddr' 0 client's IP 0 or client's IP 0 client's IP |
224 | // (BOUND/RENEW/REBIND) |
225 | // 'chaddr' client's MAC client's MAC client's MAC client's MAC client's MAC |
226 | // 'sname' options or sname options or sname options or sname (unused) (unused) |
227 | // 'file' options or file options or file options or file (unused) (unused) |
228 | // 'options' options options options message type opt message type opt |
229 | // |
230 | // Option DHCPDISCOVER DHCPINFORM DHCPREQUEST DHCPDECLINE DHCPRELEASE |
231 | // ------ ------------ ---------- ----------- ----------- ----------- |
232 | // Requested IP address MAY MUST NOT MUST (in MUST MUST NOT |
233 | // SELECTING or |
234 | // INIT-REBOOT) |
235 | // MUST NOT (in |
236 | // BOUND or |
237 | // RENEWING) |
238 | // IP address lease time MAY MUST NOT MAY MUST NOT MUST NOT |
239 | // Use 'file'/'sname' fields MAY MAY MAY MAY MAY |
240 | // Client identifier MAY MAY MAY MAY MAY |
241 | // Vendor class identifier MAY MAY MAY MUST NOT MUST NOT |
242 | // Server identifier MUST NOT MUST NOT MUST (after MUST MUST |
243 | // SELECTING) |
244 | // MUST NOT (after |
245 | // INIT-REBOOT, |
246 | // BOUND, RENEWING |
247 | // or REBINDING) |
248 | // Parameter request list MAY MAY MAY MUST NOT MUST NOT |
249 | // Maximum message size MAY MAY MAY MUST NOT MUST NOT |
250 | // Message SHOULD NOT SHOULD NOT SHOULD NOT SHOULD SHOULD |
251 | // Site-specific MAY MAY MAY MUST NOT MUST NOT |
252 | // All others MAY MAY MAY MUST NOT MUST NOT |
253 | |
254 | |
255 | /*** Logging ***/ |
256 | |
257 | #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1 |
258 | # define IF_UDHCP_VERBOSE(...) __VA_ARGS__ |
259 | extern unsigned dhcp_verbose; |
260 | # define log1(...) do { if (dhcp_verbose >= 1) bb_error_msg(__VA_ARGS__); } while (0) |
261 | # if CONFIG_UDHCP_DEBUG >= 2 |
262 | void udhcp_dump_packet(struct dhcp_packet *packet) FAST_FUNC; |
263 | # define log2(...) do { if (dhcp_verbose >= 2) bb_error_msg(__VA_ARGS__); } while (0) |
264 | # else |
265 | # define udhcp_dump_packet(...) ((void)0) |
266 | # define log2(...) ((void)0) |
267 | # endif |
268 | # if CONFIG_UDHCP_DEBUG >= 3 |
269 | # define log3(...) do { if (dhcp_verbose >= 3) bb_error_msg(__VA_ARGS__); } while (0) |
270 | # else |
271 | # define log3(...) ((void)0) |
272 | # endif |
273 | #else |
274 | # define IF_UDHCP_VERBOSE(...) |
275 | # define udhcp_dump_packet(...) ((void)0) |
276 | # define log1(...) ((void)0) |
277 | # define log2(...) ((void)0) |
278 | # define log3(...) ((void)0) |
279 | #endif |
280 | |
281 | |
282 | /*** Other shared functions ***/ |
283 | |
284 | /* 2nd param is "uint32_t*" */ |
285 | int FAST_FUNC udhcp_str2nip(const char *str, void *arg); |
286 | /* 2nd param is "struct option_set**" */ |
287 | int FAST_FUNC udhcp_str2optset(const char *str, void *arg); |
288 | |
289 | void udhcp_init_header(struct dhcp_packet *packet, char type) FAST_FUNC; |
290 | |
291 | int udhcp_recv_kernel_packet(struct dhcp_packet *packet, int fd) FAST_FUNC; |
292 | |
293 | int udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt, |
294 | uint32_t source_nip, int source_port, |
295 | uint32_t dest_nip, int dest_port, const uint8_t *dest_arp, |
296 | int ifindex) FAST_FUNC; |
297 | |
298 | int udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt, |
299 | uint32_t source_nip, int source_port, |
300 | uint32_t dest_nip, int dest_port) FAST_FUNC; |
301 | |
302 | void udhcp_sp_setup(void) FAST_FUNC; |
303 | int udhcp_sp_fd_set(fd_set *rfds, int extra_fd) FAST_FUNC; |
304 | int udhcp_sp_read(const fd_set *rfds) FAST_FUNC; |
305 | |
306 | int udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uint8_t *mac) FAST_FUNC; |
307 | |
308 | int udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf) FAST_FUNC; |
309 | |
310 | /* Returns 1 if no reply received */ |
311 | int arpping(uint32_t test_nip, |
312 | const uint8_t *safe_mac, |
313 | uint32_t from_ip, |
314 | uint8_t *from_mac, |
315 | const char *interface, |
316 | unsigned timeo) FAST_FUNC; |
317 | |
318 | /* note: ip is a pointer to an IPv6 in network order, possibly misaliged */ |
319 | int sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip) FAST_FUNC; |
320 | |
321 | POP_SAVED_FUNCTION_VISIBILITY |
322 | |
323 | #endif |
324 |