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 * Copyright (c) 2016-2017, Chris Fraire <cfraire@me.com>.
25 *
26 * INIT_REBOOT state of the DHCP client state machine.
27 */
28
29 #include <sys/types.h>
30 #include <stdio.h>
31 #include <sys/socket.h>
32 #include <netinet/in.h>
33 #include <netinet/dhcp.h>
34 #include <netinet/udp.h>
35 #include <netinet/ip_var.h>
36 #include <netinet/udp_var.h>
37 #include <dhcpmsg.h>
38 #include <string.h>
39
40 #include "agent.h"
41 #include "packet.h"
42 #include "states.h"
43 #include "util.h"
44 #include "interface.h"
45 #include "defaults.h"
46
47 static stop_func_t stop_init_reboot;
48
49 /*
50 * dhcp_init_reboot_v4(): attempts to reuse a cached configuration for a state
51 * machine.
52 *
53 * input: dhcp_smach_t *: the state machine to examine for reuse
54 * output: void
55 */
56
57 static void
dhcp_init_reboot_v4(dhcp_smach_t * dsmp)58 dhcp_init_reboot_v4(dhcp_smach_t *dsmp)
59 {
60 dhcp_pkt_t *dpkt;
61
62 /*
63 * assemble DHCPREQUEST message. The max dhcp message size
64 * option is set to the interface max, minus the size of the udp and
65 * ip headers.
66 */
67
68 dpkt = init_pkt(dsmp, REQUEST);
69 (void) add_pkt_opt32(dpkt, CD_REQUESTED_IP_ADDR,
70 dsmp->dsm_ack->pkt->yiaddr.s_addr);
71
72 (void) add_pkt_opt32(dpkt, CD_LEASE_TIME, htonl(DHCP_PERM));
73 (void) add_pkt_opt16(dpkt, CD_MAX_DHCP_SIZE,
74 htons(dsmp->dsm_lif->lif_pif->pif_max - sizeof (struct udpiphdr)));
75
76 if (class_id_len != 0)
77 (void) add_pkt_opt(dpkt, CD_CLASS_ID, class_id, class_id_len);
78 (void) add_pkt_prl(dpkt, dsmp);
79
80 if (!dhcp_add_fqdn_opt(dpkt, dsmp))
81 (void) dhcp_add_hostname_opt(dpkt, dsmp);
82
83 (void) add_pkt_opt(dpkt, CD_END, NULL, 0);
84
85 (void) send_pkt(dsmp, dpkt, htonl(INADDR_BROADCAST), stop_init_reboot);
86 }
87
88
89 /*
90 * dhcp_init_reboot_v6(): attempts to reuse a cached configuration for a state
91 * machine. Create a Confirm message and multicast it
92 * out.
93 *
94 * input: dhcp_smach_t *: the state machine to examine for reuse
95 * output: void
96 */
97
98 static void
dhcp_init_reboot_v6(dhcp_smach_t * dsmp)99 dhcp_init_reboot_v6(dhcp_smach_t *dsmp)
100 {
101 dhcp_pkt_t *dpkt;
102 dhcpv6_option_t *d6o, *d6so, *popt;
103 uint_t olen, solen;
104 dhcpv6_ia_na_t d6in;
105 dhcpv6_iaaddr_t d6ia;
106 char *obase;
107
108 /*
109 * Assemble a Confirm message based on the current ack.
110 */
111
112 dpkt = init_pkt(dsmp, DHCPV6_MSG_CONFIRM);
113
114 /*
115 * Loop over and copy IA_NAs and IAADDRs we have in our last ack. This
116 * is what we'll be requesting.
117 */
118 d6o = NULL;
119 while ((d6o = dhcpv6_pkt_option(dsmp->dsm_ack, d6o, DHCPV6_OPT_IA_NA,
120 &olen)) != NULL) {
121
122 /*
123 * Copy in IA_NA option from the ack. Note that we use zero
124 * for all timers in accordance with RFC 3315. (It would make
125 * some sense to say what we think the current timers are as
126 * a hint to the server, but the RFC doesn't agree.)
127 */
128 if (olen < sizeof (dhcpv6_ia_na_t))
129 continue;
130 (void) memcpy(&d6in, d6o, sizeof (d6in));
131 d6in.d6in_t1 = 0;
132 d6in.d6in_t2 = 0;
133 popt = add_pkt_opt(dpkt, DHCPV6_OPT_IA_NA,
134 (char *)&d6in + sizeof (*d6o),
135 sizeof (d6in) - sizeof (*d6o));
136 if (popt == NULL)
137 goto failure;
138
139 /*
140 * Now loop over the IAADDR suboptions and add those.
141 */
142 obase = (char *)d6o + sizeof (dhcpv6_ia_na_t);
143 olen -= sizeof (dhcpv6_ia_na_t);
144 d6so = NULL;
145 while ((d6so = dhcpv6_find_option(obase, olen, d6so,
146 DHCPV6_OPT_IAADDR, &solen)) != NULL) {
147 if (solen < sizeof (dhcpv6_iaaddr_t))
148 continue;
149 (void) memcpy(&d6ia, d6so, sizeof (d6ia));
150 d6ia.d6ia_preflife = 0;
151 d6ia.d6ia_vallife = 0;
152 if (add_pkt_subopt(dpkt, popt, DHCPV6_OPT_IAADDR,
153 (char *)&d6ia + sizeof (*d6so),
154 sizeof (d6ia) - sizeof (*d6so)) == NULL)
155 goto failure;
156 }
157 }
158
159 /* Add required Option Request option */
160 (void) add_pkt_prl(dpkt, dsmp);
161
162 (void) send_pkt_v6(dsmp, dpkt, ipv6_all_dhcp_relay_and_servers,
163 stop_init_reboot, DHCPV6_CNF_TIMEOUT, DHCPV6_CNF_MAX_RT);
164
165 return;
166
167 failure:
168 if (!set_start_timer(dsmp))
169 dhcp_selecting(dsmp);
170 }
171
172 /*
173 * dhcp_init_reboot(): attempts to reuse a cached configuration for a state
174 * machine.
175 *
176 * input: dhcp_smach_t *: the state machine to examine for reuse
177 * output: void
178 */
179
180 void
dhcp_init_reboot(dhcp_smach_t * dsmp)181 dhcp_init_reboot(dhcp_smach_t *dsmp)
182 {
183 dhcpmsg(MSG_VERBOSE, "%s has cached configuration - entering "
184 "INIT_REBOOT", dsmp->dsm_name);
185
186 if (!set_smach_state(dsmp, INIT_REBOOT)) {
187 dhcpmsg(MSG_ERROR, "dhcp_init_reboot: cannot register to "
188 "collect ACK/NAK packets, reverting to INIT on %s",
189 dsmp->dsm_name);
190
191 dsmp->dsm_dflags |= DHCP_IF_FAILED;
192 (void) set_smach_state(dsmp, INIT);
193 ipc_action_finish(dsmp, DHCP_IPC_E_MEMORY);
194 return;
195 }
196
197 if (dsmp->dsm_isv6)
198 dhcp_init_reboot_v6(dsmp);
199 else
200 dhcp_init_reboot_v4(dsmp);
201 }
202
203 /*
204 * stop_init_reboot(): decides when to stop retransmitting REQUESTs
205 *
206 * input: dhcp_smach_t *: the state machine sending the REQUESTs
207 * unsigned int: the number of REQUESTs sent so far
208 * output: boolean_t: B_TRUE if retransmissions should stop
209 */
210
211 static boolean_t
stop_init_reboot(dhcp_smach_t * dsmp,unsigned int n_requests)212 stop_init_reboot(dhcp_smach_t *dsmp, unsigned int n_requests)
213 {
214 if (dsmp->dsm_isv6) {
215 uint_t nowabs, maxabs;
216
217 nowabs = NSEC2MSEC(gethrtime());
218 maxabs = NSEC2MSEC(dsmp->dsm_neg_hrtime) + DHCPV6_CNF_MAX_RD;
219 if (nowabs < maxabs) {
220 /* Cap the timer based on the maximum */
221 if (nowabs + dsmp->dsm_send_timeout > maxabs)
222 dsmp->dsm_send_timeout = maxabs - nowabs;
223 return (B_FALSE);
224 }
225 } else {
226 if (n_requests < DHCP_MAX_REQUESTS)
227 return (B_FALSE);
228 }
229
230 if (df_get_bool(dsmp->dsm_name, dsmp->dsm_isv6,
231 DF_VERIFIED_LEASE_ONLY)) {
232 dhcpmsg(MSG_INFO,
233 "unable to verify existing lease on %s; restarting",
234 dsmp->dsm_name);
235 dhcp_selecting(dsmp);
236 return (B_TRUE);
237 }
238
239 if (dsmp->dsm_isv6) {
240 dhcpmsg(MSG_INFO, "no Reply to Confirm, using remainder of "
241 "existing lease on %s", dsmp->dsm_name);
242 } else {
243 dhcpmsg(MSG_INFO, "no ACK/NAK to INIT_REBOOT REQUEST, "
244 "using remainder of existing lease on %s", dsmp->dsm_name);
245 }
246
247 /*
248 * We already stuck our old ack in dsmp->dsm_ack and relativized the
249 * packet times, so we can just pretend that the server sent it to us
250 * and move to bound. If that fails, fall back to selecting.
251 */
252
253 if (dhcp_bound(dsmp, NULL)) {
254 if (dsmp->dsm_isv6) {
255 if (!save_server_id(dsmp, dsmp->dsm_ack))
256 goto failure;
257 server_unicast_option(dsmp, dsmp->dsm_ack);
258 }
259 } else {
260 failure:
261 dhcpmsg(MSG_INFO, "unable to use saved lease on %s; restarting",
262 dsmp->dsm_name);
263 dhcp_selecting(dsmp);
264 }
265
266 return (B_TRUE);
267 }
268