xref: /titanic_41/usr/src/cmd/cmd-inet/sbin/dhcpagent/states.h (revision a1196271e1d6e6ce9cc40c8b94f5b659935e82bc)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #ifndef	STATES_H
27 #define	STATES_H
28 
29 #include <sys/types.h>
30 #include <netinet/in.h>
31 #include <netinet/dhcp.h>
32 #include <libinetutil.h>
33 
34 #include "common.h"
35 #include "ipc_action.h"
36 #include "async.h"
37 #include "packet.h"
38 #include "util.h"
39 
40 /*
41  * interfaces for state transition/action functions.  these functions
42  * can be found in suitably named .c files, such as inform.c, select.c,
43  * renew.c, etc.
44  */
45 
46 #ifdef	__cplusplus
47 extern "C" {
48 #endif
49 
50 /*
51  * DHCP state machine representation: includes all of the information used for
52  * a state machine instance.  For IPv4, this represents a single logical
53  * interface and (usually) a leased address.  For IPv6, it represents a
54  * DUID+IAID combination.  Note that if multiple DUID+IAID instances are one
55  * day allowed per interface, this will need to become a list.
56  */
57 struct dhcp_smach_s {
58 	dhcp_smach_t	*dsm_next;	/* Note: must be first */
59 	dhcp_smach_t	*dsm_prev;
60 
61 	/*
62 	 * The name of the state machine.  This is currently just a pointer to
63 	 * the controlling LIF's name, but could be otherwise.
64 	 */
65 	const char	*dsm_name;
66 	dhcp_lif_t	*dsm_lif;	/* Controlling LIF */
67 	uint_t		dsm_hold_count;	/* reference count */
68 
69 	dhcp_lease_t	*dsm_leases;	/* List of leases */
70 	uint_t		dsm_lif_wait;	/* LIFs waiting on DAD */
71 	uint_t		dsm_lif_down;	/* LIFs failed */
72 
73 	/*
74 	 * each state machine can have at most one pending asynchronous
75 	 * action, which is represented in a `struct async_action'.
76 	 * if that asynchronous action was a result of a user request,
77 	 * then the `struct ipc_action' is used to hold information
78 	 * about the user request.  these structures are opaque to
79 	 * users of the ifslist, and the functional interfaces
80 	 * provided in async.[ch] and ipc_action.[ch] should be used
81 	 * to maintain them.
82 	 */
83 
84 	ipc_action_t	dsm_ia;
85 	async_action_t	dsm_async;
86 
87 	uchar_t		*dsm_cid;	/* client id */
88 	uchar_t		dsm_cidlen;	/* client id len */
89 
90 	/*
91 	 * current state of the machine
92 	 */
93 
94 	DHCPSTATE	dsm_state;
95 	boolean_t	dsm_droprelease;  /* soon to call finished_smach */
96 
97 	uint16_t	dsm_dflags;	/* DHCP_IF_* (shared with IPC) */
98 
99 	uint16_t	*dsm_prl;	/* if non-NULL, param request list */
100 	uint_t		dsm_prllen;	/* param request list len */
101 	uint16_t	*dsm_pil;	/* if non-NULL, param ignore list */
102 	uint_t		dsm_pillen;	/* param ignore list len */
103 
104 	uint_t		dsm_nrouters;	/* the number of default routers */
105 	struct in_addr	*dsm_routers;	/* an array of default routers */
106 
107 	in6_addr_t	dsm_server;	/* our DHCP server */
108 	uchar_t		*dsm_serverid;	/* server DUID for v6 */
109 	uint_t		dsm_serveridlen; /* DUID length */
110 
111 	/*
112 	 * We retain the very first ack obtained on the state machine to
113 	 * provide access to options which were originally assigned by
114 	 * the server but may not have been included in subsequent
115 	 * acks, as there are servers which do this and customers have
116 	 * had unsatisfactory results when using our agent with them.
117 	 * ipc_event() in agent.c provides a fallback to the original
118 	 * ack when the current ack doesn't have the information
119 	 * requested.
120 	 *
121 	 * Note that neither of these is actually a list of packets.  There's
122 	 * exactly one packet here, so use free_pkt_entry.
123 	 */
124 	PKT_LIST	*dsm_ack;
125 	PKT_LIST	*dsm_orig_ack;
126 
127 	/*
128 	 * other miscellaneous variables set or needed in the process
129 	 * of acquiring a lease.
130 	 */
131 
132 	int		dsm_offer_wait;	/* seconds between sending offers */
133 	iu_timer_id_t	dsm_offer_timer; /* timer associated with offer wait */
134 
135 	/*
136 	 * time we sent the DISCOVER relative to dsm_neg_hrtime, so that the
137 	 * REQUEST can have the same pkt->secs.
138 	 */
139 
140 	uint16_t	dsm_disc_secs;
141 
142 	/*
143 	 * this is a chain of packets which have been received on this
144 	 * state machine over some interval of time.  the packets may have
145 	 * to meet some criteria in order to be put on this list.  in
146 	 * general, packets are put on this list through recv_pkt()
147 	 */
148 
149 	PKT_LIST	*dsm_recv_pkt_list;
150 
151 	/*
152 	 * these three fields are initially zero, and get incremented
153 	 * as the ifslist goes from INIT -> BOUND.  if and when the
154 	 * ifslist moves to the RENEWING state, these fields are
155 	 * reset, so they always either indicate the number of packets
156 	 * sent, received, and declined while obtaining the current
157 	 * lease (if BOUND), or the number of packets sent, received,
158 	 * and declined while attempting to obtain a future lease
159 	 * (if any other state).
160 	 */
161 
162 	uint32_t	dsm_sent;
163 	uint32_t	dsm_received;
164 	uint32_t	dsm_bad_offers;
165 
166 	/*
167 	 * dsm_send_pkt.pkt is dynamically allocated to be as big a
168 	 * packet as we can send out on this state machine.  the remainder
169 	 * of this information is needed to make it easy to handle
170 	 * retransmissions.  note that other than dsm_bad_offers, all
171 	 * of these fields are maintained internally in send_pkt(),
172 	 * and consequently should never need to be modified by any
173 	 * other functions.
174 	 */
175 
176 	dhcp_pkt_t	dsm_send_pkt;
177 	union {
178 		struct sockaddr_in v4;
179 		struct sockaddr_in6 v6;
180 	} dsm_send_dest;
181 
182 	/*
183 	 * For v4, dsm_send_tcenter is used to track the central timer value in
184 	 * milliseconds (4000, 8000, 16000, 32000, 64000), and dsm_send_timeout
185 	 * is that value plus the +/- 1000 millisecond fuzz.
186 	 *
187 	 * For v6, dsm_send_tcenter is the MRT (maximum retransmit timer)
188 	 * value, and dsm_send_timeout must be set to the IRT (initial
189 	 * retransmit timer) value by the sender.
190 	 */
191 	uint_t		dsm_send_timeout;
192 	uint_t		dsm_send_tcenter;
193 	stop_func_t	*dsm_send_stop_func;
194 	uint32_t	dsm_packet_sent;
195 	iu_timer_id_t	dsm_retrans_timer;
196 
197 	/*
198 	 * The host name we've been asked to request is remembered
199 	 * here between the DISCOVER and the REQUEST.  (v4 only)
200 	 */
201 	char		*dsm_reqhost;
202 
203 	/*
204 	 * V4 and V6 use slightly different timers.  For v4, we must count
205 	 * seconds from the point where we first try to configure the
206 	 * interface.  For v6, only seconds while performing a transaction
207 	 * matter.
208 	 *
209 	 * In v4, `dsm_neg_hrtime' represents the time since DHCP started
210 	 * configuring the interface, and is used for computing the pkt->secs
211 	 * field in v4.  In v6, it represents the time since the current
212 	 * transaction (if any) was started, and is used for the ELAPSED_TIME
213 	 * option.
214 	 *
215 	 * `dsm_newstart_monosec' represents the time the ACKed REQUEST was
216 	 * sent, which represents the start time of a new batch of leases.
217 	 * When the lease time actually begins (and thus becomes current),
218 	 * `dsm_curstart_monosec' is set to `dsm_newstart_monosec'.
219 	 */
220 	hrtime_t	dsm_neg_hrtime;
221 	monosec_t	dsm_newstart_monosec;
222 	monosec_t	dsm_curstart_monosec;
223 
224 	int		dsm_script_fd;
225 	pid_t		dsm_script_pid;
226 	pid_t		dsm_script_helper_pid;
227 	const char	*dsm_script_event;
228 	iu_event_id_t	dsm_script_event_id;
229 	void		*dsm_callback_arg;
230 	script_callback_t *dsm_script_callback;
231 
232 	iu_timer_id_t	dsm_start_timer;
233 };
234 
235 #define	dsm_isv6	dsm_lif->lif_pif->pif_isv6
236 #define	dsm_hwtype	dsm_lif->lif_pif->pif_hwtype
237 
238 struct dhcp_lease_s {
239 	dhcp_lease_t	*dl_next;	/* Note: must be first */
240 	dhcp_lease_t	*dl_prev;
241 
242 	dhcp_smach_t	*dl_smach;	/* back pointer to state machine */
243 	dhcp_lif_t	*dl_lifs;	/* LIFs configured by this lease */
244 	uint_t		dl_nlifs;	/* Number of configured LIFs */
245 	uint_t		dl_hold_count;	/* reference counter */
246 	boolean_t	dl_removed;	/* Set if removed from list */
247 	boolean_t	dl_stale;	/* not updated by Renew/bind */
248 
249 	/*
250 	 * the following fields are set when a lease is acquired, and
251 	 * may be updated over the lifetime of the lease.  they are
252 	 * all reset by reset_smach().
253 	 */
254 
255 	dhcp_timer_t	dl_t1;		/* relative renewal start time, hbo */
256 	dhcp_timer_t	dl_t2;		/* relative rebinding start time, hbo */
257 };
258 
259 /* The IU event callback functions */
260 iu_eh_callback_t	dhcp_acknak_global;
261 iu_eh_callback_t	dhcp_packet_lif;
262 
263 /* Common state-machine related routines throughout dhcpagent */
264 boolean_t	dhcp_adopt(void);
265 void		dhcp_adopt_complete(dhcp_smach_t *);
266 boolean_t	dhcp_bound(dhcp_smach_t *, PKT_LIST *);
267 void		dhcp_bound_complete(dhcp_smach_t *);
268 int		dhcp_drop(dhcp_smach_t *, void *);
269 void		dhcp_deprecate(iu_tq_t *, void *);
270 void		dhcp_expire(iu_tq_t *, void *);
271 boolean_t	dhcp_extending(dhcp_smach_t *);
272 void		dhcp_inform(dhcp_smach_t *);
273 void		dhcp_init_reboot(dhcp_smach_t *);
274 void		dhcp_rebind(iu_tq_t *, void *);
275 int		dhcp_release(dhcp_smach_t *, void *);
276 void		dhcp_renew(iu_tq_t *, void *);
277 void		dhcp_requesting(iu_tq_t *, void *);
278 void		dhcp_restart(dhcp_smach_t *);
279 void		dhcp_selecting(dhcp_smach_t *);
280 boolean_t	set_start_timer(dhcp_smach_t *);
281 void		send_declines(dhcp_smach_t *);
282 void		send_v6_request(dhcp_smach_t *);
283 boolean_t	save_server_id(dhcp_smach_t *, PKT_LIST *);
284 void		server_unicast_option(dhcp_smach_t *, PKT_LIST *);
285 
286 /* State machine support functions in states.c */
287 dhcp_smach_t	*insert_smach(dhcp_lif_t *, int *);
288 void		hold_smach(dhcp_smach_t *);
289 void		release_smach(dhcp_smach_t *);
290 void		remove_smach(dhcp_smach_t *);
291 dhcp_smach_t	*next_smach(dhcp_smach_t *, boolean_t);
292 dhcp_smach_t	*primary_smach(boolean_t);
293 dhcp_smach_t	*info_primary_smach(boolean_t);
294 void		make_primary(dhcp_smach_t *);
295 dhcp_smach_t	*lookup_smach(const char *, boolean_t);
296 dhcp_smach_t	*lookup_smach_by_uindex(uint16_t, dhcp_smach_t *, boolean_t);
297 dhcp_smach_t	*lookup_smach_by_xid(uint32_t, dhcp_smach_t *, boolean_t);
298 dhcp_smach_t	*lookup_smach_by_event(iu_event_id_t);
299 void		finished_smach(dhcp_smach_t *, int);
300 boolean_t	set_smach_state(dhcp_smach_t *, DHCPSTATE);
301 int		get_smach_cid(dhcp_smach_t *);
302 boolean_t	verify_smach(dhcp_smach_t *);
303 uint_t		smach_count(void);
304 void		reset_smach(dhcp_smach_t *);
305 void		refresh_smachs(iu_eh_t *, int, void *);
306 void		refresh_smach(dhcp_smach_t *);
307 void		nuke_smach_list(void);
308 boolean_t	schedule_smach_timer(dhcp_smach_t *, int, uint32_t,
309 		    iu_tq_callback_t *);
310 void		cancel_offer_timer(dhcp_smach_t *);
311 void		cancel_smach_timers(dhcp_smach_t *);
312 void		discard_default_routes(dhcp_smach_t *);
313 void		remove_default_routes(dhcp_smach_t *);
314 boolean_t	is_bound_state(DHCPSTATE);
315 
316 /* Lease-related support functions in states.c */
317 dhcp_lease_t	*insert_lease(dhcp_smach_t *);
318 void		hold_lease(dhcp_lease_t *);
319 void		release_lease(dhcp_lease_t *);
320 void		remove_lease(dhcp_lease_t *);
321 void		deprecate_leases(dhcp_smach_t *);
322 void		cancel_lease_timers(dhcp_lease_t *);
323 boolean_t	schedule_lease_timer(dhcp_lease_t *, dhcp_timer_t *,
324 		    iu_tq_callback_t *);
325 
326 #ifdef	__cplusplus
327 }
328 #endif
329 
330 #endif	/* STATES_H */
331