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 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #ifndef INTERFACE_H 28 #define INTERFACE_H 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 /* 33 * interface.[ch] encapsulate all of the agent's knowledge of network 34 * interfaces from the DHCP agent's perspective. see interface.c 35 * for documentation on how to use the exported functions. note that 36 * there are not functional interfaces for manipulating all of the fields 37 * in an ifslist -- please read the comments in the ifslist structure 38 * definition below for the rules on accessing various fields. 39 */ 40 41 #ifdef __cplusplus 42 extern "C" { 43 #endif 44 45 #include <netinet/in.h> 46 #include <sys/socket.h> 47 #include <net/if.h> /* IFNAMSIZ */ 48 #include <sys/types.h> 49 #include <netinet/dhcp.h> 50 #include <dhcpagent_ipc.h> 51 #include <libinetutil.h> 52 53 #include "async.h" 54 #include "agent.h" 55 #include "dlpi_io.h" 56 #include "ipc_action.h" 57 #include "packet.h" 58 #include "util.h" 59 60 enum { DHCP_T1_TIMER, DHCP_T2_TIMER, DHCP_LEASE_TIMER }; 61 62 typedef int script_callback_t (struct ifslist *, const char *); 63 64 struct ifslist { 65 66 /* 67 * ifslist chain pointers, maintained by insert_ifs() / 68 * remove_ifs(). 69 */ 70 71 struct ifslist *next; 72 struct ifslist *prev; 73 74 /* 75 * hold count on this ifslist, maintained by hold_ifs() / 76 * release_ifs() -- see below for a discussion of ifs memory 77 * management. 78 */ 79 80 uchar_t if_hold_count; 81 82 /* 83 * each interface can have at most one pending asynchronous 84 * action, which is represented in a `struct async_action'. 85 * if that asynchronous action was a result of a user request, 86 * then the `struct ipc_action' is used to hold information 87 * about the user request. these structures are opaque to 88 * users of the ifslist, and the functional interfaces 89 * provided in async.[ch] and ipc_action.[ch] should be used 90 * to maintain them. 91 */ 92 93 struct ipc_action if_ia; 94 struct async_action if_async; 95 96 /* 97 * current state of the interface 98 */ 99 100 DHCPSTATE if_state; 101 102 /* 103 * flags specific to DHCP (see dhcpagent_ipc.h) 104 */ 105 106 uint16_t if_dflags; 107 108 /* 109 * general interface information -- this information is initialized 110 * in insert_ifs() and does not change over the lifetime of the 111 * interface. 112 */ 113 114 char if_name[IFNAMSIZ]; 115 116 uint16_t if_max; /* largest DHCP packet on this if */ 117 uint16_t if_min; /* minimum mtu size on this if */ 118 uint16_t if_opt; /* amount of space for options in PKT */ 119 120 uchar_t *if_hwaddr; /* our link-layer address */ 121 uchar_t if_hwlen; /* our link-layer address len */ 122 uchar_t if_hwtype; /* type of link-layer */ 123 124 uchar_t *if_cid; /* client id, if set in defaults file */ 125 uchar_t if_cidlen; /* client id len */ 126 127 uchar_t *if_prl; /* if non-NULL, param request list */ 128 uchar_t if_prllen; /* param request list len */ 129 130 /* 131 * the destination address is the broadcast address of 132 * the interface, in DLPI terms (which means it 133 * includes both a link-layer broadcast address and a 134 * sap, and the order isn't consistent.) fun, huh? 135 * blame AT&T. we store it as a token like this 136 * because it's generally how we need to use it. we 137 * can pull it apart using the saplen and sap_before 138 * fields below. 139 */ 140 141 uchar_t *if_daddr; /* our destination address */ 142 uchar_t if_dlen; /* our destination address len */ 143 144 uchar_t if_saplen; /* the SAP len */ 145 uchar_t if_sap_before; /* does SAP come before address? */ 146 147 /* 148 * network descriptors; one is used for the DLPI 149 * traffic before we have our IP address configured; 150 * the other two are used afterwards. there have to 151 * be two socket descriptors since: 152 * 153 * o we need one to be bound to IPPORT_BOOTPC and 154 * and INADDR_BROADCAST, so it can receive all 155 * broadcast traffic. this is if_sock_fd. it 156 * is also used as a general descriptor to perform 157 * socket-related ioctls on, like SIOCGIFFLAGS. 158 * 159 * o we need another to be bound to IPPORT_BOOTPC and 160 * the IP address given to us by the DHCP server, 161 * so we can guarantee the IP address of outgoing 162 * packets when multihomed. (the problem being that 163 * if a packet goes out with the wrong IP address, 164 * then the server's response will come back on the 165 * wrong interface). this is if_sock_ip_fd. 166 * 167 * note that if_sock_fd is created in init_ifs() but 168 * not bound until dhcp_bound(); this is because we 169 * cannot even bind to the broadcast address until we 170 * have an IP address. 171 * 172 * if_sock_ip_fd isn't created until dhcp_bound(), 173 * since we don't need it until then and we can't 174 * bind it until after we have an IP address anyway. 175 * 176 * both socket descriptors are closed in reset_ifs(). 177 */ 178 179 int if_dlpi_fd; 180 int if_sock_fd; 181 int if_sock_ip_fd; 182 183 /* 184 * the following fields are set when a lease is acquired, and 185 * may be updated over the lifetime of the lease. they are 186 * all reset by reset_ifs(). 187 */ 188 189 iu_timer_id_t if_timer[3]; /* T1, T2, and LEASE timers */ 190 191 lease_t if_t1; /* relative renewal start time, hbo */ 192 lease_t if_t2; /* relative rebinding start time, hbo */ 193 lease_t if_lease; /* relative expire time, hbo */ 194 195 unsigned int if_nrouters; /* the number of default routers */ 196 struct in_addr *if_routers; /* an array of default routers */ 197 struct in_addr if_server; /* our DHCP server, nbo */ 198 199 /* 200 * while in any states except ADOPTING, INIT, INFORMATION and 201 * INFORM_SENT, the following three fields are equal to what 202 * we believe the current address, netmask, and broadcast 203 * address on the interface to be. this is so we can detect 204 * if the user changes them and abandon the interface. 205 */ 206 207 struct in_addr if_addr; /* our IP address, nbo */ 208 struct in_addr if_netmask; /* our netmask, nbo */ 209 struct in_addr if_broadcast; /* our broadcast address, nbo */ 210 211 PKT_LIST *if_ack; /* ACK from the server */ 212 213 /* 214 * We retain the very first ack obtained on the interface to 215 * provide access to options which were originally assigned by 216 * the server but may not have been included in subsequent 217 * acks, as there are servers which do this and customers have 218 * had unsatisfactory results when using our agent with them. 219 * ipc_event() in agent.c provides a fallback to the original 220 * ack when the current ack doesn't have the information 221 * requested. 222 */ 223 224 PKT_LIST *if_orig_ack; 225 226 /* 227 * other miscellaneous variables set or needed in the process 228 * of acquiring a lease. 229 */ 230 231 int if_offer_wait; /* seconds between offers */ 232 iu_event_id_t if_offer_id; /* event offer id */ 233 iu_event_id_t if_acknak_id; /* event acknak id */ 234 iu_event_id_t if_acknak_bcast_id; 235 236 /* 237 * `if_neg_monosec' represents the time since lease 238 * acquisition or renewal began, and is used for 239 * computing the pkt->secs field. `if_newstart_monosec' 240 * represents the time the ACKed REQUEST was sent, 241 * which represents the start time of a new lease. 242 * when the lease actually begins (and thus becomes 243 * current), `if_curstart_monosec' is set to 244 * `if_newstart_monosec'. 245 */ 246 247 monosec_t if_neg_monosec; 248 monosec_t if_newstart_monosec; 249 monosec_t if_curstart_monosec; 250 251 /* 252 * time we sent the DISCOVER relative to if_neg_monosec, 253 * so that the REQUEST can have the same pkt->secs. 254 */ 255 256 uint16_t if_disc_secs; 257 258 /* 259 * the host name we've been asked to request is remembered 260 * here between the DISCOVER and the REQUEST 261 */ 262 char *if_reqhost; 263 264 /* 265 * this is a chain of packets which have been received on this 266 * interface over some interval of time. the packets may have 267 * to meet some criteria in order to be put on this list. in 268 * general, packets are put on this list through recv_pkt() 269 */ 270 271 PKT_LIST *if_recv_pkt_list; 272 273 /* 274 * these three fields are initially zero, and get incremented 275 * as the ifslist goes from INIT -> BOUND. if and when the 276 * ifslist moves to the RENEWING state, these fields are 277 * reset, so they always either indicate the number of packets 278 * sent, received, and declined while obtaining the current 279 * lease (if BOUND), or the number of packets sent, received, 280 * and declined while attempting to obtain a future lease 281 * (if any other state). 282 */ 283 284 uint32_t if_sent; 285 uint32_t if_received; 286 uint32_t if_bad_offers; 287 288 /* 289 * if_send_pkt.pkt is dynamically allocated to be as big a 290 * packet as we can send out on this interface. the remainder 291 * of this information is needed to make it easy to handle 292 * retransmissions. note that other than if_bad_offers, all 293 * of these fields are maintained internally in send_pkt(), 294 * and consequently should never need to be modified by any 295 * other functions. 296 */ 297 298 dhcp_pkt_t if_send_pkt; 299 uint32_t if_send_timeout; 300 struct sockaddr_in if_send_dest; 301 stop_func_t *if_send_stop_func; 302 uint32_t if_packet_sent; 303 iu_timer_id_t if_retrans_timer; 304 305 int if_script_fd; 306 pid_t if_script_pid; 307 pid_t if_script_helper_pid; 308 const char *if_script_event; 309 iu_event_id_t if_script_event_id; 310 const char *if_callback_msg; 311 script_callback_t *if_script_callback; 312 }; 313 314 /* 315 * a word on memory management and ifslists: 316 * 317 * since ifslists are often passed as context to callback functions, 318 * they cannot be freed when the interface they represent is dropped 319 * or released (or when those callbacks finally go off, they will be 320 * hosed). to handle this situation, ifslists are reference counted. 321 * here are the rules for managing ifslists: 322 * 323 * an ifslist is created through insert_ifs(). along with 324 * initializing the ifslist, this puts a hold on the ifslist through 325 * hold_ifs(). 326 * 327 * whenever an ifslist is released or dropped (implicitly or 328 * explicitly), remove_ifs() is called, which sets the DHCP_IF_REMOVED 329 * flag and removes the interface from the internal list of managed 330 * interfaces. lastly, remove_ifs() calls release_ifs() to remove the 331 * hold acquired in insert_ifs(). if this decrements the hold count 332 * on the interface to zero, then free_ifs() is called. if there are 333 * holds other than the hold acquired in insert_ifs(), the hold count 334 * will still be > 0, and the interface will remain allocated (though 335 * dormant). 336 * 337 * whenever a callback is scheduled against an ifslist, another hold 338 * must be put on the ifslist through hold_ifs(). 339 * 340 * whenever a callback is called back against an ifslist, 341 * release_ifs() must be called to decrement the hold count, which may 342 * end up freeing the ifslist if the hold count becomes zero. 343 * 344 * if release_ifs() returns 0, then there are no remaining holds 345 * against this ifslist, and the ifslist in fact no longer exists. 346 * 347 * since some callbacks may take a long time to get called back (such 348 * as timeout callbacks for lease expiration, etc), it is sometimes 349 * more appropriate to cancel the callbacks and call release_ifs() if 350 * the cancellation succeeds. this is done in remove_ifs() for the 351 * lease, t1, and t2 callbacks. 352 * 353 * in general, a callback should also call verify_ifs() when it gets 354 * called back in addition to release_ifs(), to make sure that the 355 * interface is still in fact under the dhcpagent's control. to make 356 * coding simpler, there is a third function, check_ifs(), which 357 * performs both the release_ifs() and the verify_ifs(). in addition, 358 * if check_ifs() detects that the callback has the last hold against 359 * a given interface, it informs it instead of performing the final 360 * release, and thus allows it to clean up appropriately before 361 * performing the final release. 362 */ 363 364 int canonize_ifs(struct ifslist *); 365 int check_ifs(struct ifslist *); 366 void hold_ifs(struct ifslist *); 367 struct ifslist *insert_ifs(const char *, boolean_t, int *); 368 struct ifslist *lookup_ifs(const char *); 369 struct ifslist *lookup_ifs_by_xid(uint32_t); 370 void nuke_ifslist(boolean_t); 371 void refresh_ifslist(iu_eh_t *, int, void *); 372 int release_ifs(struct ifslist *); 373 void remove_ifs(struct ifslist *); 374 void reset_ifs(struct ifslist *); 375 int verify_ifs(struct ifslist *); 376 unsigned int ifs_count(void); 377 void cancel_ifs_timers(struct ifslist *); 378 int schedule_ifs_timer(struct ifslist *, int, uint32_t, 379 iu_tq_callback_t *); 380 381 #ifdef __cplusplus 382 } 383 #endif 384 385 #endif /* INTERFACE_H */ 386