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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 * 26 * SELECTING state of the client state machine. 27 */ 28 29 #pragma ident "%Z%%M% %I% %E% SMI" 30 31 #include <sys/types.h> 32 #include <stdlib.h> 33 #include <stdio.h> 34 #include <strings.h> 35 #include <time.h> 36 #include <limits.h> 37 #include <netinet/in.h> 38 #include <sys/socket.h> 39 #include <net/route.h> 40 #include <net/if.h> 41 #include <netinet/dhcp.h> 42 #include <netinet/udp.h> 43 #include <netinet/ip_var.h> 44 #include <netinet/udp_var.h> 45 #include <stropts.h> /* FLUSHR/FLUSHW */ 46 #include <dhcpmsg.h> 47 48 #include "states.h" 49 #include "agent.h" 50 #include "util.h" 51 #include "interface.h" 52 #include "packet.h" 53 #include "defaults.h" 54 55 static iu_eh_callback_t dhcp_collect_offers; 56 static stop_func_t stop_selecting; 57 58 /* 59 * dhcp_start(): starts DHCP on an interface 60 * 61 * input: iu_tq_t *: unused 62 * void *: the interface to start DHCP on 63 * output: void 64 */ 65 66 /* ARGSUSED */ 67 void 68 dhcp_start(iu_tq_t *tqp, void *arg) 69 { 70 struct ifslist *ifsp = (struct ifslist *)arg; 71 72 if (check_ifs(ifsp) == 0) { 73 (void) release_ifs(ifsp); 74 return; 75 } 76 77 dhcpmsg(MSG_VERBOSE, "starting DHCP on %s", ifsp->if_name); 78 dhcp_selecting(ifsp); 79 } 80 81 /* 82 * dhcp_selecting(): sends a DISCOVER and sets up reception for an OFFER 83 * 84 * input: struct ifslist *: the interface to send the DISCOVER on, ... 85 * output: void 86 */ 87 88 void 89 dhcp_selecting(struct ifslist *ifsp) 90 { 91 dhcp_pkt_t *dpkt; 92 const char *reqhost; 93 char hostfile[PATH_MAX + 1]; 94 95 /* 96 * we first set up to collect OFFER packets as they arrive. 97 * we then send out DISCOVER probes. then we wait at a 98 * user-tunable number of seconds before seeing if OFFERs have 99 * come in response to our DISCOVER. if none have come in, we 100 * continue to wait, sending out our DISCOVER probes with 101 * exponential backoff. if an OFFER is never received, we 102 * will wait forever (note that since we're event-driven 103 * though, we're still able to service other interfaces.) 104 * 105 * note that we do an reset_ifs() here because we may be 106 * landing in dhcp_selecting() as a result of restarting DHCP, 107 * so the ifs may not be fresh. 108 */ 109 110 reset_ifs(ifsp); 111 ifsp->if_state = SELECTING; 112 113 if ((ifsp->if_offer_id = iu_register_event(eh, ifsp->if_dlpi_fd, POLLIN, 114 dhcp_collect_offers, ifsp)) == -1) { 115 116 dhcpmsg(MSG_ERROR, "dhcp_selecting: cannot register to collect " 117 "OFFER packets, reverting to INIT on %s", 118 ifsp->if_name); 119 120 ifsp->if_state = INIT; 121 ifsp->if_dflags |= DHCP_IF_FAILED; 122 ipc_action_finish(ifsp, DHCP_IPC_E_MEMORY); 123 async_finish(ifsp); 124 return; 125 } else 126 hold_ifs(ifsp); 127 128 129 if (iu_schedule_timer(tq, ifsp->if_offer_wait, dhcp_requesting, 130 ifsp) == -1) { 131 132 dhcpmsg(MSG_ERROR, "dhcp_selecting: cannot schedule to read " 133 "OFFER packets"); 134 135 if (iu_unregister_event(eh, ifsp->if_offer_id, NULL) != 0) { 136 ifsp->if_offer_id = -1; 137 (void) release_ifs(ifsp); 138 } 139 140 ifsp->if_state = INIT; 141 ifsp->if_dflags |= DHCP_IF_FAILED; 142 ipc_action_finish(ifsp, DHCP_IPC_E_MEMORY); 143 async_finish(ifsp); 144 return; 145 } else 146 hold_ifs(ifsp); 147 148 /* 149 * Assemble DHCPDISCOVER message. The max dhcp message size 150 * option is set to the interface max, minus the size of the udp and 151 * ip headers. 152 */ 153 154 dpkt = init_pkt(ifsp, DISCOVER); 155 156 add_pkt_opt16(dpkt, CD_MAX_DHCP_SIZE, htons(ifsp->if_max - 157 sizeof (struct udpiphdr))); 158 add_pkt_opt32(dpkt, CD_LEASE_TIME, htonl(DHCP_PERM)); 159 160 add_pkt_opt(dpkt, CD_CLASS_ID, class_id, class_id_len); 161 add_pkt_opt(dpkt, CD_REQUEST_LIST, ifsp->if_prl, ifsp->if_prllen); 162 163 if (df_get_bool(ifsp->if_name, DF_REQUEST_HOSTNAME)) { 164 dhcpmsg(MSG_DEBUG, "dhcp_selecting: DF_REQUEST_HOSTNAME"); 165 (void) snprintf(hostfile, sizeof (hostfile), "/etc/hostname.%s", 166 ifsp->if_name); 167 168 if ((reqhost = iffile_to_hostname(hostfile)) != NULL) { 169 dhcpmsg(MSG_DEBUG, "dhcp_selecting: host %s", reqhost); 170 if ((ifsp->if_reqhost = strdup(reqhost)) != NULL) 171 add_pkt_opt(dpkt, CD_HOSTNAME, ifsp->if_reqhost, 172 strlen(ifsp->if_reqhost)); 173 else 174 dhcpmsg(MSG_WARNING, "dhcp_selecting: cannot" 175 " allocate memory for host name option"); 176 } 177 } 178 add_pkt_opt(dpkt, CD_END, NULL, 0); 179 180 (void) send_pkt(ifsp, dpkt, htonl(INADDR_BROADCAST), stop_selecting); 181 } 182 183 /* 184 * dhcp_collect_offers(): collects incoming OFFERs to a DISCOVER 185 * 186 * input: iu_eh_t *: unused 187 * int: the file descriptor the OFFER arrived on 188 * short: unused 189 * iu_event_id_t: the id of this event callback with the handler 190 * void *: the interface that received the OFFER 191 * output: void 192 */ 193 194 /* ARGSUSED */ 195 static void 196 dhcp_collect_offers(iu_eh_t *eh, int fd, short events, iu_event_id_t id, 197 void *arg) 198 { 199 struct ifslist *ifsp = (struct ifslist *)arg; 200 201 if (verify_ifs(ifsp) == 0) { 202 (void) ioctl(fd, I_FLUSH, FLUSHR|FLUSHW); 203 return; 204 } 205 206 /* 207 * DHCP_PUNTYPED messages are BOOTP server responses. 208 */ 209 210 (void) recv_pkt(ifsp, fd, DHCP_POFFER|DHCP_PUNTYPED, B_TRUE); 211 } 212 213 /* 214 * stop_selecting(): decides when to stop retransmitting DISCOVERs (never) 215 * 216 * input: struct ifslist *: the interface DISCOVERs are being sent on 217 * unsigned int: the number of DISCOVERs sent so far 218 * output: boolean_t: B_TRUE if retransmissions should stop 219 */ 220 221 /* ARGSUSED */ 222 static boolean_t 223 stop_selecting(struct ifslist *ifsp, unsigned int n_discovers) 224 { 225 return (B_FALSE); 226 } 227