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 * INIT_REBOOT state of the DHCP client state machine.
26 */
27
28 #include <sys/types.h>
29 #include <stdio.h>
30 #include <limits.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 const char *reqhost;
62 char hostfile[PATH_MAX + 1];
63
64 /*
65 * assemble DHCPREQUEST message. The max dhcp message size
66 * option is set to the interface max, minus the size of the udp and
67 * ip headers.
68 */
69
70 dpkt = init_pkt(dsmp, REQUEST);
71 (void) add_pkt_opt32(dpkt, CD_REQUESTED_IP_ADDR,
72 dsmp->dsm_ack->pkt->yiaddr.s_addr);
73
74 (void) add_pkt_opt32(dpkt, CD_LEASE_TIME, htonl(DHCP_PERM));
75 (void) add_pkt_opt16(dpkt, CD_MAX_DHCP_SIZE,
76 htons(dsmp->dsm_lif->lif_pif->pif_max - sizeof (struct udpiphdr)));
77
78 if (class_id_len != 0)
79 (void) add_pkt_opt(dpkt, CD_CLASS_ID, class_id, class_id_len);
80 (void) add_pkt_prl(dpkt, dsmp);
81
82 /*
83 * Set CD_HOSTNAME option if REQUEST_HOSTNAME is set and a hostname
84 * is found in /etc/hostname.<ifname>
85 */
86 if (df_get_bool(dsmp->dsm_name, dsmp->dsm_isv6, DF_REQUEST_HOSTNAME)) {
87 (void) snprintf(hostfile, sizeof (hostfile), "/etc/hostname.%s",
88 dsmp->dsm_name);
89
90 if ((reqhost = iffile_to_hostname(hostfile)) != NULL) {
91 dhcpmsg(MSG_DEBUG, "dhcp_selecting: host %s", reqhost);
92 if ((dsmp->dsm_reqhost = strdup(reqhost)) != NULL)
93 (void) add_pkt_opt(dpkt, CD_HOSTNAME,
94 dsmp->dsm_reqhost,
95 strlen(dsmp->dsm_reqhost));
96 else
97 dhcpmsg(MSG_WARNING, "dhcp_selecting: cannot"
98 " allocate memory for host name option");
99 } else {
100 dhcpmsg(MSG_DEBUG,
101 "dhcp_selecting: no hostname for %s",
102 dsmp->dsm_name);
103 }
104 }
105
106 (void) add_pkt_opt(dpkt, CD_END, NULL, 0);
107
108 (void) send_pkt(dsmp, dpkt, htonl(INADDR_BROADCAST), stop_init_reboot);
109 }
110
111
112 /*
113 * dhcp_init_reboot_v6(): attempts to reuse a cached configuration for a state
114 * machine. Create a Confirm message and multicast it
115 * out.
116 *
117 * input: dhcp_smach_t *: the state machine to examine for reuse
118 * output: void
119 */
120
121 static void
dhcp_init_reboot_v6(dhcp_smach_t * dsmp)122 dhcp_init_reboot_v6(dhcp_smach_t *dsmp)
123 {
124 dhcp_pkt_t *dpkt;
125 dhcpv6_option_t *d6o, *d6so, *popt;
126 uint_t olen, solen;
127 dhcpv6_ia_na_t d6in;
128 dhcpv6_iaaddr_t d6ia;
129 char *obase;
130
131 /*
132 * Assemble a Confirm message based on the current ack.
133 */
134
135 dpkt = init_pkt(dsmp, DHCPV6_MSG_CONFIRM);
136
137 /*
138 * Loop over and copy IA_NAs and IAADDRs we have in our last ack. This
139 * is what we'll be requesting.
140 */
141 d6o = NULL;
142 while ((d6o = dhcpv6_pkt_option(dsmp->dsm_ack, d6o, DHCPV6_OPT_IA_NA,
143 &olen)) != NULL) {
144
145 /*
146 * Copy in IA_NA option from the ack. Note that we use zero
147 * for all timers in accordance with RFC 3315. (It would make
148 * some sense to say what we think the current timers are as
149 * a hint to the server, but the RFC doesn't agree.)
150 */
151 if (olen < sizeof (dhcpv6_ia_na_t))
152 continue;
153 (void) memcpy(&d6in, d6o, sizeof (d6in));
154 d6in.d6in_t1 = 0;
155 d6in.d6in_t2 = 0;
156 popt = add_pkt_opt(dpkt, DHCPV6_OPT_IA_NA,
157 (char *)&d6in + sizeof (*d6o),
158 sizeof (d6in) - sizeof (*d6o));
159 if (popt == NULL)
160 goto failure;
161
162 /*
163 * Now loop over the IAADDR suboptions and add those.
164 */
165 obase = (char *)d6o + sizeof (dhcpv6_ia_na_t);
166 olen -= sizeof (dhcpv6_ia_na_t);
167 d6so = NULL;
168 while ((d6so = dhcpv6_find_option(obase, olen, d6so,
169 DHCPV6_OPT_IAADDR, &solen)) != NULL) {
170 if (solen < sizeof (dhcpv6_iaaddr_t))
171 continue;
172 (void) memcpy(&d6ia, d6so, sizeof (d6ia));
173 d6ia.d6ia_preflife = 0;
174 d6ia.d6ia_vallife = 0;
175 if (add_pkt_subopt(dpkt, popt, DHCPV6_OPT_IAADDR,
176 (char *)&d6ia + sizeof (*d6so),
177 sizeof (d6ia) - sizeof (*d6so)) == NULL)
178 goto failure;
179 }
180 }
181
182 /* Add required Option Request option */
183 (void) add_pkt_prl(dpkt, dsmp);
184
185 (void) send_pkt_v6(dsmp, dpkt, ipv6_all_dhcp_relay_and_servers,
186 stop_init_reboot, DHCPV6_CNF_TIMEOUT, DHCPV6_CNF_MAX_RT);
187
188 return;
189
190 failure:
191 if (!set_start_timer(dsmp))
192 dhcp_selecting(dsmp);
193 }
194
195 /*
196 * dhcp_init_reboot(): attempts to reuse a cached configuration for a state
197 * machine.
198 *
199 * input: dhcp_smach_t *: the state machine to examine for reuse
200 * output: void
201 */
202
203 void
dhcp_init_reboot(dhcp_smach_t * dsmp)204 dhcp_init_reboot(dhcp_smach_t *dsmp)
205 {
206 dhcpmsg(MSG_VERBOSE, "%s has cached configuration - entering "
207 "INIT_REBOOT", dsmp->dsm_name);
208
209 if (!set_smach_state(dsmp, INIT_REBOOT)) {
210 dhcpmsg(MSG_ERROR, "dhcp_init_reboot: cannot register to "
211 "collect ACK/NAK packets, reverting to INIT on %s",
212 dsmp->dsm_name);
213
214 dsmp->dsm_dflags |= DHCP_IF_FAILED;
215 (void) set_smach_state(dsmp, INIT);
216 ipc_action_finish(dsmp, DHCP_IPC_E_MEMORY);
217 return;
218 }
219
220 if (dsmp->dsm_isv6)
221 dhcp_init_reboot_v6(dsmp);
222 else
223 dhcp_init_reboot_v4(dsmp);
224 }
225
226 /*
227 * stop_init_reboot(): decides when to stop retransmitting REQUESTs
228 *
229 * input: dhcp_smach_t *: the state machine sending the REQUESTs
230 * unsigned int: the number of REQUESTs sent so far
231 * output: boolean_t: B_TRUE if retransmissions should stop
232 */
233
234 static boolean_t
stop_init_reboot(dhcp_smach_t * dsmp,unsigned int n_requests)235 stop_init_reboot(dhcp_smach_t *dsmp, unsigned int n_requests)
236 {
237 if (dsmp->dsm_isv6) {
238 uint_t nowabs, maxabs;
239
240 nowabs = NSEC2MSEC(gethrtime());
241 maxabs = NSEC2MSEC(dsmp->dsm_neg_hrtime) + DHCPV6_CNF_MAX_RD;
242 if (nowabs < maxabs) {
243 /* Cap the timer based on the maximum */
244 if (nowabs + dsmp->dsm_send_timeout > maxabs)
245 dsmp->dsm_send_timeout = maxabs - nowabs;
246 return (B_FALSE);
247 }
248 } else {
249 if (n_requests < DHCP_MAX_REQUESTS)
250 return (B_FALSE);
251 }
252
253 if (df_get_bool(dsmp->dsm_name, dsmp->dsm_isv6,
254 DF_VERIFIED_LEASE_ONLY)) {
255 dhcpmsg(MSG_INFO,
256 "unable to verify existing lease on %s; restarting",
257 dsmp->dsm_name);
258 dhcp_selecting(dsmp);
259 return (B_TRUE);
260 }
261
262 if (dsmp->dsm_isv6) {
263 dhcpmsg(MSG_INFO, "no Reply to Confirm, using remainder of "
264 "existing lease on %s", dsmp->dsm_name);
265 } else {
266 dhcpmsg(MSG_INFO, "no ACK/NAK to INIT_REBOOT REQUEST, "
267 "using remainder of existing lease on %s", dsmp->dsm_name);
268 }
269
270 /*
271 * We already stuck our old ack in dsmp->dsm_ack and relativized the
272 * packet times, so we can just pretend that the server sent it to us
273 * and move to bound. If that fails, fall back to selecting.
274 */
275
276 if (dhcp_bound(dsmp, NULL)) {
277 if (dsmp->dsm_isv6) {
278 if (!save_server_id(dsmp, dsmp->dsm_ack))
279 goto failure;
280 server_unicast_option(dsmp, dsmp->dsm_ack);
281 }
282 } else {
283 failure:
284 dhcpmsg(MSG_INFO, "unable to use saved lease on %s; restarting",
285 dsmp->dsm_name);
286 dhcp_selecting(dsmp);
287 }
288
289 return (B_TRUE);
290 }
291