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 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 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 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 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