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 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 * 25 * SELECTING state of the client state machine. 26 */ 27 28 #pragma ident "%Z%%M% %I% %E% SMI" 29 30 #include <sys/types.h> 31 #include <stdlib.h> 32 #include <stdio.h> 33 #include <strings.h> 34 #include <time.h> 35 #include <limits.h> 36 #include <netinet/in.h> 37 #include <sys/socket.h> 38 #include <net/route.h> 39 #include <net/if.h> 40 #include <netinet/dhcp.h> 41 #include <netinet/udp.h> 42 #include <netinet/ip_var.h> 43 #include <netinet/udp_var.h> 44 #include <stropts.h> /* FLUSHR/FLUSHW */ 45 #include <dhcpmsg.h> 46 47 #include "states.h" 48 #include "agent.h" 49 #include "util.h" 50 #include "interface.h" 51 #include "packet.h" 52 #include "defaults.h" 53 54 static iu_eh_callback_t dhcp_collect_offers; 55 static stop_func_t stop_selecting; 56 57 /* 58 * dhcp_start(): starts DHCP on an interface 59 * 60 * input: iu_tq_t *: unused 61 * void *: the interface to start DHCP on 62 * output: void 63 */ 64 65 /* ARGSUSED */ 66 void 67 dhcp_start(iu_tq_t *tqp, void *arg) 68 { 69 struct ifslist *ifsp = (struct ifslist *)arg; 70 71 if (check_ifs(ifsp) == 0) { 72 (void) release_ifs(ifsp); 73 return; 74 } 75 76 dhcpmsg(MSG_VERBOSE, "starting DHCP on %s", ifsp->if_name); 77 dhcp_selecting(ifsp); 78 } 79 80 /* 81 * dhcp_selecting(): sends a DISCOVER and sets up reception for an OFFER 82 * 83 * input: struct ifslist *: the interface to send the DISCOVER on, ... 84 * output: void 85 */ 86 87 void 88 dhcp_selecting(struct ifslist *ifsp) 89 { 90 dhcp_pkt_t *dpkt; 91 const char *reqhost; 92 char hostfile[PATH_MAX + 1]; 93 94 /* 95 * we first set up to collect OFFER packets as they arrive. 96 * we then send out DISCOVER probes. then we wait at a 97 * user-tunable number of seconds before seeing if OFFERs have 98 * come in response to our DISCOVER. if none have come in, we 99 * continue to wait, sending out our DISCOVER probes with 100 * exponential backoff. if an OFFER is never received, we 101 * will wait forever (note that since we're event-driven 102 * though, we're still able to service other interfaces.) 103 * 104 * note that we do an reset_ifs() here because we may be 105 * landing in dhcp_selecting() as a result of restarting DHCP, 106 * so the ifs may not be fresh. 107 */ 108 109 reset_ifs(ifsp); 110 ifsp->if_state = SELECTING; 111 112 if ((ifsp->if_offer_id = iu_register_event(eh, ifsp->if_dlpi_fd, POLLIN, 113 dhcp_collect_offers, ifsp)) == -1) { 114 115 dhcpmsg(MSG_ERROR, "dhcp_selecting: cannot register to collect " 116 "OFFER packets, reverting to INIT on %s", 117 ifsp->if_name); 118 119 ifsp->if_state = INIT; 120 ifsp->if_dflags |= DHCP_IF_FAILED; 121 ipc_action_finish(ifsp, DHCP_IPC_E_MEMORY); 122 async_finish(ifsp); 123 return; 124 } else 125 hold_ifs(ifsp); 126 127 128 if ((ifsp->if_offer_timer = iu_schedule_timer(tq, 129 ifsp->if_offer_wait, dhcp_requesting, ifsp)) == -1) { 130 131 dhcpmsg(MSG_ERROR, "dhcp_selecting: cannot schedule to read " 132 "OFFER packets"); 133 134 if (iu_unregister_event(eh, ifsp->if_offer_id, NULL) != 0) { 135 ifsp->if_offer_id = -1; 136 (void) release_ifs(ifsp); 137 } 138 139 ifsp->if_state = INIT; 140 ifsp->if_dflags |= DHCP_IF_FAILED; 141 ipc_action_finish(ifsp, DHCP_IPC_E_MEMORY); 142 async_finish(ifsp); 143 return; 144 } else 145 hold_ifs(ifsp); 146 147 /* 148 * Assemble DHCPDISCOVER message. The max dhcp message size 149 * option is set to the interface max, minus the size of the udp and 150 * ip headers. 151 */ 152 153 dpkt = init_pkt(ifsp, DISCOVER); 154 155 add_pkt_opt16(dpkt, CD_MAX_DHCP_SIZE, htons(ifsp->if_max - 156 sizeof (struct udpiphdr))); 157 add_pkt_opt32(dpkt, CD_LEASE_TIME, htonl(DHCP_PERM)); 158 159 add_pkt_opt(dpkt, CD_CLASS_ID, class_id, class_id_len); 160 add_pkt_opt(dpkt, CD_REQUEST_LIST, ifsp->if_prl, ifsp->if_prllen); 161 162 if (df_get_bool(ifsp->if_name, DF_REQUEST_HOSTNAME)) { 163 dhcpmsg(MSG_DEBUG, "dhcp_selecting: DF_REQUEST_HOSTNAME"); 164 (void) snprintf(hostfile, sizeof (hostfile), "/etc/hostname.%s", 165 ifsp->if_name); 166 167 if ((reqhost = iffile_to_hostname(hostfile)) != NULL) { 168 dhcpmsg(MSG_DEBUG, "dhcp_selecting: host %s", reqhost); 169 if ((ifsp->if_reqhost = strdup(reqhost)) != NULL) 170 add_pkt_opt(dpkt, CD_HOSTNAME, ifsp->if_reqhost, 171 strlen(ifsp->if_reqhost)); 172 else 173 dhcpmsg(MSG_WARNING, "dhcp_selecting: cannot" 174 " allocate memory for host name option"); 175 } 176 } 177 add_pkt_opt(dpkt, CD_END, NULL, 0); 178 179 (void) send_pkt(ifsp, dpkt, htonl(INADDR_BROADCAST), stop_selecting); 180 } 181 182 /* 183 * dhcp_collect_offers(): collects incoming OFFERs to a DISCOVER 184 * 185 * input: iu_eh_t *: unused 186 * int: the file descriptor the OFFER arrived on 187 * short: unused 188 * iu_event_id_t: the id of this event callback with the handler 189 * void *: the interface that received the OFFER 190 * output: void 191 */ 192 193 /* ARGSUSED */ 194 static void 195 dhcp_collect_offers(iu_eh_t *eh, int fd, short events, iu_event_id_t id, 196 void *arg) 197 { 198 struct ifslist *ifsp = (struct ifslist *)arg; 199 200 if (verify_ifs(ifsp) == 0) { 201 (void) ioctl(fd, I_FLUSH, FLUSHR|FLUSHW); 202 return; 203 } 204 205 /* 206 * DHCP_PUNTYPED messages are BOOTP server responses. 207 */ 208 209 (void) recv_pkt(ifsp, fd, DHCP_POFFER|DHCP_PUNTYPED, B_TRUE); 210 } 211 212 /* 213 * stop_selecting(): decides when to stop retransmitting DISCOVERs (never) 214 * 215 * input: struct ifslist *: the interface DISCOVERs are being sent on 216 * unsigned int: the number of DISCOVERs sent so far 217 * output: boolean_t: B_TRUE if retransmissions should stop 218 */ 219 220 /* ARGSUSED */ 221 static boolean_t 222 stop_selecting(struct ifslist *ifsp, unsigned int n_discovers) 223 { 224 return (B_FALSE); 225 } 226