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/contrib/bind9/lib/irs/getaddrinfo.c

https://bitbucket.org/freebsd/freebsd-head/
C | 1295 lines | 930 code | 131 blank | 234 comment | 333 complexity | 7a55969e5562264c1c13f2ee3c517d7a MD5 | raw file
   1/*
   2 * Copyright (C) 2009  Internet Systems Consortium, Inc. ("ISC")
   3 *
   4 * Permission to use, copy, modify, and/or distribute this software for any
   5 * purpose with or without fee is hereby granted, provided that the above
   6 * copyright notice and this permission notice appear in all copies.
   7 *
   8 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
   9 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  10 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  11 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  12 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  13 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  14 * PERFORMANCE OF THIS SOFTWARE.
  15 */
  16
  17/* $Id: getaddrinfo.c,v 1.3 2009/09/02 23:48:02 tbox Exp $ */
  18
  19/*! \file */
  20
  21/**
  22 *    getaddrinfo() is used to get a list of IP addresses and port
  23 *    numbers for host hostname and service servname as defined in RFC3493.
  24 *    hostname and servname are pointers to null-terminated strings
  25 *    or NULL. hostname is either a host name or a numeric host address
  26 *    string: a dotted decimal IPv4 address or an IPv6 address. servname is
  27 *    either a decimal port number or a service name as listed in
  28 *    /etc/services.
  29 *
  30 *    If the operating system does not provide a struct addrinfo, the
  31 *    following structure is used:
  32 *
  33 * \code
  34 * struct  addrinfo {
  35 *         int             ai_flags;       // AI_PASSIVE, AI_CANONNAME
  36 *         int             ai_family;      // PF_xxx
  37 *         int             ai_socktype;    // SOCK_xxx
  38 *         int             ai_protocol;    // 0 or IPPROTO_xxx for IPv4 and IPv6
  39 *         size_t          ai_addrlen;     // length of ai_addr
  40 *         char            *ai_canonname;  // canonical name for hostname
  41 *         struct sockaddr *ai_addr;       // binary address
  42 *         struct addrinfo *ai_next;       // next structure in linked list
  43 * };
  44 * \endcode
  45 *
  46 *
  47 *    hints is an optional pointer to a struct addrinfo. This structure can
  48 *    be used to provide hints concerning the type of socket that the caller
  49 *    supports or wishes to use. The caller can supply the following
  50 *    structure elements in *hints:
  51 *
  52 * <ul>
  53 *    <li>ai_family:
  54 *           The protocol family that should be used. When ai_family is set
  55 *           to PF_UNSPEC, it means the caller will accept any protocol
  56 *           family supported by the operating system.</li>
  57 *
  58 *    <li>ai_socktype:
  59 *           denotes the type of socket -- SOCK_STREAM, SOCK_DGRAM or
  60 *           SOCK_RAW -- that is wanted. When ai_socktype is zero the caller
  61 *           will accept any socket type.</li>
  62 *
  63 *    <li>ai_protocol:
  64 *           indicates which transport protocol is wanted: IPPROTO_UDP or
  65 *           IPPROTO_TCP. If ai_protocol is zero the caller will accept any
  66 *           protocol.</li>
  67 *
  68 *    <li>ai_flags:
  69 *           Flag bits. If the AI_CANONNAME bit is set, a successful call to
  70 *           getaddrinfo() will return a null-terminated string
  71 *           containing the canonical name of the specified hostname in
  72 *           ai_canonname of the first addrinfo structure returned. Setting
  73 *           the AI_PASSIVE bit indicates that the returned socket address
  74 *           structure is intended for used in a call to bind(2). In this
  75 *           case, if the hostname argument is a NULL pointer, then the IP
  76 *           address portion of the socket address structure will be set to
  77 *           INADDR_ANY for an IPv4 address or IN6ADDR_ANY_INIT for an IPv6
  78 *           address.<br /><br />
  79 *
  80 *           When ai_flags does not set the AI_PASSIVE bit, the returned
  81 *           socket address structure will be ready for use in a call to
  82 *           connect(2) for a connection-oriented protocol or connect(2),
  83 *           sendto(2), or sendmsg(2) if a connectionless protocol was
  84 *           chosen. The IP address portion of the socket address structure
  85 *           will be set to the loopback address if hostname is a NULL
  86 *           pointer and AI_PASSIVE is not set in ai_flags.<br /><br />
  87 *
  88 *           If ai_flags is set to AI_NUMERICHOST it indicates that hostname
  89 *           should be treated as a numeric string defining an IPv4 or IPv6
  90 *           address and no name resolution should be attempted.
  91 * </li></ul>
  92 *
  93 *    All other elements of the struct addrinfo passed via hints must be
  94 *    zero.
  95 *
  96 *    A hints of NULL is treated as if the caller provided a struct addrinfo
  97 *    initialized to zero with ai_familyset to PF_UNSPEC.
  98 *
  99 *    After a successful call to getaddrinfo(), *res is a pointer to a
 100 *    linked list of one or more addrinfo structures. Each struct addrinfo
 101 *    in this list cn be processed by following the ai_next pointer, until a
 102 *    NULL pointer is encountered. The three members ai_family, ai_socktype,
 103 *    and ai_protocol in each returned addrinfo structure contain the
 104 *    corresponding arguments for a call to socket(2). For each addrinfo
 105 *    structure in the list, the ai_addr member points to a filled-in socket
 106 *    address structure of length ai_addrlen.
 107 *
 108 *    All of the information returned by getaddrinfo() is dynamically
 109 *    allocated: the addrinfo structures, and the socket address structures
 110 *    and canonical host name strings pointed to by the addrinfostructures.
 111 *    Memory allocated for the dynamically allocated structures created by a
 112 *    successful call to getaddrinfo() is released by freeaddrinfo().
 113 *    ai is a pointer to a struct addrinfo created by a call to getaddrinfo().
 114 *
 115 * \section irsreturn RETURN VALUES
 116 *
 117 *    getaddrinfo() returns zero on success or one of the error codes
 118 *    listed in gai_strerror() if an error occurs. If both hostname and
 119 *    servname are NULL getaddrinfo() returns #EAI_NONAME.
 120 *
 121 * \section irssee SEE ALSO
 122 *
 123 *    getaddrinfo(), freeaddrinfo(),
 124 *    gai_strerror(), RFC3493, getservbyname(3), connect(2),
 125 *    sendto(2), sendmsg(2), socket(2).
 126 */
 127
 128#include <config.h>
 129
 130#include <stdlib.h>
 131#include <string.h>
 132#include <errno.h>
 133
 134#include <isc/app.h>
 135#include <isc/buffer.h>
 136#include <isc/lib.h>
 137#include <isc/mem.h>
 138#include <isc/sockaddr.h>
 139#include <isc/util.h>
 140
 141#include <dns/client.h>
 142#include <dns/fixedname.h>
 143#include <dns/name.h>
 144#include <dns/rdata.h>
 145#include <dns/rdataset.h>
 146#include <dns/rdatastruct.h>
 147#include <dns/rdatatype.h>
 148#include <dns/result.h>
 149
 150#include <irs/context.h>
 151#include <irs/netdb.h>
 152#include <irs/resconf.h>
 153
 154#define SA(addr)	((struct sockaddr *)(addr))
 155#define SIN(addr)	((struct sockaddr_in *)(addr))
 156#define SIN6(addr)	((struct sockaddr_in6 *)(addr))
 157#define SLOCAL(addr)	((struct sockaddr_un *)(addr))
 158
 159/*! \struct addrinfo
 160 */
 161static struct addrinfo
 162	*ai_concat(struct addrinfo *ai1, struct addrinfo *ai2),
 163	*ai_reverse(struct addrinfo *oai),
 164	*ai_clone(struct addrinfo *oai, int family),
 165	*ai_alloc(int family, int addrlen);
 166#ifdef AF_LOCAL
 167static int get_local(const char *name, int socktype, struct addrinfo **res);
 168#endif
 169
 170static int
 171resolve_name(int family, const char *hostname, int flags,
 172	     struct addrinfo **aip, int socktype, int port);
 173
 174static int add_ipv4(const char *hostname, int flags, struct addrinfo **aip,
 175		    int socktype, int port);
 176static int add_ipv6(const char *hostname, int flags, struct addrinfo **aip,
 177		    int socktype, int port);
 178static void set_order(int, int (**)(const char *, int, struct addrinfo **,
 179				    int, int));
 180
 181#define FOUND_IPV4	0x1
 182#define FOUND_IPV6	0x2
 183#define FOUND_MAX	2
 184
 185#define ISC_AI_MASK (AI_PASSIVE|AI_CANONNAME|AI_NUMERICHOST)
 186/*%
 187 * Get a list of IP addresses and port numbers for host hostname and
 188 * service servname.
 189 */
 190int
 191getaddrinfo(const char *hostname, const char *servname,
 192	    const struct addrinfo *hints, struct addrinfo **res)
 193{
 194	struct servent *sp;
 195	const char *proto;
 196	int family, socktype, flags, protocol;
 197	struct addrinfo *ai, *ai_list;
 198	int err = 0;
 199	int port, i;
 200	int (*net_order[FOUND_MAX+1])(const char *, int, struct addrinfo **,
 201				      int, int);
 202
 203	if (hostname == NULL && servname == NULL)
 204		return (EAI_NONAME);
 205
 206	proto = NULL;
 207	if (hints != NULL) {
 208		if ((hints->ai_flags & ~(ISC_AI_MASK)) != 0)
 209			return (EAI_BADFLAGS);
 210		if (hints->ai_addrlen || hints->ai_canonname ||
 211		    hints->ai_addr || hints->ai_next) {
 212			errno = EINVAL;
 213			return (EAI_SYSTEM);
 214		}
 215		family = hints->ai_family;
 216		socktype = hints->ai_socktype;
 217		protocol = hints->ai_protocol;
 218		flags = hints->ai_flags;
 219		switch (family) {
 220		case AF_UNSPEC:
 221			switch (hints->ai_socktype) {
 222			case SOCK_STREAM:
 223				proto = "tcp";
 224				break;
 225			case SOCK_DGRAM:
 226				proto = "udp";
 227				break;
 228			}
 229			break;
 230		case AF_INET:
 231		case AF_INET6:
 232			switch (hints->ai_socktype) {
 233			case 0:
 234				break;
 235			case SOCK_STREAM:
 236				proto = "tcp";
 237				break;
 238			case SOCK_DGRAM:
 239				proto = "udp";
 240				break;
 241			case SOCK_RAW:
 242				break;
 243			default:
 244				return (EAI_SOCKTYPE);
 245			}
 246			break;
 247#ifdef	AF_LOCAL
 248		case AF_LOCAL:
 249			switch (hints->ai_socktype) {
 250			case 0:
 251				break;
 252			case SOCK_STREAM:
 253				break;
 254			case SOCK_DGRAM:
 255				break;
 256			default:
 257				return (EAI_SOCKTYPE);
 258			}
 259			break;
 260#endif
 261		default:
 262			return (EAI_FAMILY);
 263		}
 264	} else {
 265		protocol = 0;
 266		family = 0;
 267		socktype = 0;
 268		flags = 0;
 269	}
 270
 271#ifdef	AF_LOCAL
 272	/*!
 273	 * First, deal with AF_LOCAL.  If the family was not set,
 274	 * then assume AF_LOCAL if the first character of the
 275	 * hostname/servname is '/'.
 276	 */
 277
 278	if (hostname != NULL &&
 279	    (family == AF_LOCAL || (family == 0 && *hostname == '/')))
 280		return (get_local(hostname, socktype, res));
 281
 282	if (servname != NULL &&
 283	    (family == AF_LOCAL || (family == 0 && *servname == '/')))
 284		return (get_local(servname, socktype, res));
 285#endif
 286
 287	/*
 288	 * Ok, only AF_INET and AF_INET6 left.
 289	 */
 290	ai_list = NULL;
 291
 292	/*
 293	 * First, look up the service name (port) if it was
 294	 * requested.  If the socket type wasn't specified, then
 295	 * try and figure it out.
 296	 */
 297	if (servname != NULL) {
 298		char *e;
 299
 300		port = strtol(servname, &e, 10);
 301		if (*e == '\0') {
 302			if (socktype == 0)
 303				return (EAI_SOCKTYPE);
 304			if (port < 0 || port > 65535)
 305				return (EAI_SERVICE);
 306			port = htons((unsigned short) port);
 307		} else {
 308			sp = getservbyname(servname, proto);
 309			if (sp == NULL)
 310				return (EAI_SERVICE);
 311			port = sp->s_port;
 312			if (socktype == 0) {
 313				if (strcmp(sp->s_proto, "tcp") == 0)
 314					socktype = SOCK_STREAM;
 315				else if (strcmp(sp->s_proto, "udp") == 0)
 316					socktype = SOCK_DGRAM;
 317			}
 318		}
 319	} else
 320		port = 0;
 321
 322	/*
 323	 * Next, deal with just a service name, and no hostname.
 324	 * (we verified that one of them was non-null up above).
 325	 */
 326	if (hostname == NULL && (flags & AI_PASSIVE) != 0) {
 327		if (family == AF_INET || family == 0) {
 328			ai = ai_alloc(AF_INET, sizeof(struct sockaddr_in));
 329			if (ai == NULL)
 330				return (EAI_MEMORY);
 331			ai->ai_socktype = socktype;
 332			ai->ai_protocol = protocol;
 333			SIN(ai->ai_addr)->sin_port = port;
 334			ai->ai_next = ai_list;
 335			ai_list = ai;
 336		}
 337
 338		if (family == AF_INET6 || family == 0) {
 339			ai = ai_alloc(AF_INET6, sizeof(struct sockaddr_in6));
 340			if (ai == NULL) {
 341				freeaddrinfo(ai_list);
 342				return (EAI_MEMORY);
 343			}
 344			ai->ai_socktype = socktype;
 345			ai->ai_protocol = protocol;
 346			SIN6(ai->ai_addr)->sin6_port = port;
 347			ai->ai_next = ai_list;
 348			ai_list = ai;
 349		}
 350
 351		*res = ai_list;
 352		return (0);
 353	}
 354
 355	/*
 356	 * If the family isn't specified or AI_NUMERICHOST specified, check
 357	 * first to see if it is a numeric address.
 358	 * Though the gethostbyname2() routine will recognize numeric addresses,
 359	 * it will only recognize the format that it is being called for.  Thus,
 360	 * a numeric AF_INET address will be treated by the AF_INET6 call as
 361	 * a domain name, and vice versa.  Checking for both numerics here
 362	 * avoids that.
 363	 */
 364	if (hostname != NULL &&
 365	    (family == 0 || (flags & AI_NUMERICHOST) != 0)) {
 366		char abuf[sizeof(struct in6_addr)];
 367		char nbuf[NI_MAXHOST];
 368		int addrsize, addroff;
 369#ifdef IRS_HAVE_SIN6_SCOPE_ID
 370		char *p, *ep;
 371		char ntmp[NI_MAXHOST];
 372		isc_uint32_t scopeid;
 373#endif
 374
 375#ifdef IRS_HAVE_SIN6_SCOPE_ID
 376		/*
 377		 * Scope identifier portion.
 378		 */
 379		ntmp[0] = '\0';
 380		if (strchr(hostname, '%') != NULL) {
 381			strncpy(ntmp, hostname, sizeof(ntmp) - 1);
 382			ntmp[sizeof(ntmp) - 1] = '\0';
 383			p = strchr(ntmp, '%');
 384			ep = NULL;
 385
 386			/*
 387			 * Vendors may want to support non-numeric
 388			 * scopeid around here.
 389			 */
 390
 391			if (p != NULL)
 392				scopeid = (isc_uint32_t)strtoul(p + 1,
 393								&ep, 10);
 394			if (p != NULL && ep != NULL && ep[0] == '\0')
 395				*p = '\0';
 396			else {
 397				ntmp[0] = '\0';
 398				scopeid = 0;
 399			}
 400		} else
 401			scopeid = 0;
 402#endif
 403
 404		if (inet_pton(AF_INET, hostname, (struct in_addr *)abuf)
 405		    == 1) {
 406			if (family == AF_INET6) {
 407				/*
 408				 * Convert to a V4 mapped address.
 409				 */
 410				struct in6_addr *a6 = (struct in6_addr *)abuf;
 411				memcpy(&a6->s6_addr[12], &a6->s6_addr[0], 4);
 412				memset(&a6->s6_addr[10], 0xff, 2);
 413				memset(&a6->s6_addr[0], 0, 10);
 414				goto inet6_addr;
 415			}
 416			addrsize = sizeof(struct in_addr);
 417			addroff = (char *)(&SIN(0)->sin_addr) - (char *)0;
 418			family = AF_INET;
 419			goto common;
 420#ifdef IRS_HAVE_SIN6_SCOPE_ID
 421		} else if (ntmp[0] != '\0' &&
 422			   inet_pton(AF_INET6, ntmp, abuf) == 1) {
 423			if (family && family != AF_INET6)
 424				return (EAI_NONAME);
 425			addrsize = sizeof(struct in6_addr);
 426			addroff = (char *)(&SIN6(0)->sin6_addr) - (char *)0;
 427			family = AF_INET6;
 428			goto common;
 429#endif
 430		} else if (inet_pton(AF_INET6, hostname, abuf) == 1) {
 431			if (family != 0 && family != AF_INET6)
 432				return (EAI_NONAME);
 433		inet6_addr:
 434			addrsize = sizeof(struct in6_addr);
 435			addroff = (char *)(&SIN6(0)->sin6_addr) - (char *)0;
 436			family = AF_INET6;
 437
 438		common:
 439			ai = ai_alloc(family,
 440				      ((family == AF_INET6) ?
 441				       sizeof(struct sockaddr_in6) :
 442				       sizeof(struct sockaddr_in)));
 443			if (ai == NULL)
 444				return (EAI_MEMORY);
 445			ai_list = ai;
 446			ai->ai_socktype = socktype;
 447			SIN(ai->ai_addr)->sin_port = port;
 448			memcpy((char *)ai->ai_addr + addroff, abuf, addrsize);
 449			if ((flags & AI_CANONNAME) != 0) {
 450#ifdef IRS_HAVE_SIN6_SCOPE_ID
 451				if (ai->ai_family == AF_INET6)
 452					SIN6(ai->ai_addr)->sin6_scope_id =
 453						scopeid;
 454#endif
 455				if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
 456						nbuf, sizeof(nbuf), NULL, 0,
 457						NI_NUMERICHOST) == 0) {
 458					ai->ai_canonname = strdup(nbuf);
 459					if (ai->ai_canonname == NULL) {
 460						freeaddrinfo(ai);
 461						return (EAI_MEMORY);
 462					}
 463				} else {
 464					/* XXX raise error? */
 465					ai->ai_canonname = NULL;
 466				}
 467			}
 468			goto done;
 469		} else if ((flags & AI_NUMERICHOST) != 0) {
 470			return (EAI_NONAME);
 471		}
 472	}
 473
 474	if (hostname == NULL && (flags & AI_PASSIVE) == 0) {
 475		set_order(family, net_order);
 476		for (i = 0; i < FOUND_MAX; i++) {
 477			if (net_order[i] == NULL)
 478				break;
 479			err = (net_order[i])(hostname, flags, &ai_list,
 480					     socktype, port);
 481			if (err != 0) {
 482				if (ai_list != NULL)
 483					freeaddrinfo(ai_list);
 484				break;
 485			}
 486		}
 487	} else
 488		err = resolve_name(family, hostname, flags, &ai_list,
 489				   socktype, port);
 490
 491	if (ai_list == NULL) {
 492		if (err == 0)
 493			err = EAI_NONAME;
 494		return (err);
 495	}
 496
 497done:
 498	ai_list = ai_reverse(ai_list);
 499
 500	*res = ai_list;
 501	return (0);
 502}
 503
 504typedef struct gai_restrans {
 505	dns_clientrestrans_t	*xid;
 506	isc_boolean_t		is_inprogress;
 507	int			error;
 508	struct addrinfo		ai_sentinel;
 509	struct gai_resstate	*resstate;
 510} gai_restrans_t;
 511
 512typedef struct gai_resstate {
 513	isc_mem_t			*mctx;
 514	struct gai_statehead		*head;
 515	dns_fixedname_t			fixedname;
 516	dns_name_t			*qname;
 517	gai_restrans_t			*trans4;
 518	gai_restrans_t			*trans6;
 519	ISC_LINK(struct gai_resstate)	link;
 520} gai_resstate_t;
 521
 522typedef struct gai_statehead {
 523	int				ai_family;
 524	int				ai_flags;
 525	int				ai_socktype;
 526	int				ai_port;
 527	isc_appctx_t			*actx;
 528	dns_client_t			*dnsclient;
 529	ISC_LIST(struct gai_resstate)	resstates;
 530	unsigned int			activestates;
 531} gai_statehead_t;
 532
 533static isc_result_t
 534make_resstate(isc_mem_t *mctx, gai_statehead_t *head, const char *hostname,
 535	      const char *domain, gai_resstate_t **statep)
 536{
 537	isc_result_t result;
 538	gai_resstate_t *state;
 539	dns_fixedname_t fixeddomain;
 540	dns_name_t *qdomain;
 541	size_t namelen;
 542	isc_buffer_t b;
 543	isc_boolean_t need_v4 = ISC_FALSE;
 544	isc_boolean_t need_v6 = ISC_FALSE;
 545
 546	state = isc_mem_get(mctx, sizeof(*state));
 547	if (state == NULL)
 548		return (ISC_R_NOMEMORY);
 549
 550	/* Construct base domain name */
 551	namelen = strlen(domain);
 552	isc_buffer_init(&b, domain, namelen);
 553	isc_buffer_add(&b, namelen);
 554	dns_fixedname_init(&fixeddomain);
 555	qdomain = dns_fixedname_name(&fixeddomain);
 556	result = dns_name_fromtext(qdomain, &b, dns_rootname, 0, NULL);
 557	if (result != ISC_R_SUCCESS) {
 558		isc_mem_put(mctx, state, sizeof(*state));
 559		return (result);
 560	}
 561
 562	/* Construct query name */
 563	namelen = strlen(hostname);
 564	isc_buffer_init(&b, hostname, namelen);
 565	isc_buffer_add(&b, namelen);
 566	dns_fixedname_init(&state->fixedname);
 567	state->qname = dns_fixedname_name(&state->fixedname);
 568	result = dns_name_fromtext(state->qname, &b, qdomain, 0, NULL);
 569	if (result != ISC_R_SUCCESS) {
 570		isc_mem_put(mctx, state, sizeof(*state));
 571		return (result);
 572	}
 573
 574	if (head->ai_family == AF_UNSPEC || head->ai_family == AF_INET)
 575		need_v4 = ISC_TRUE;
 576	if (head->ai_family == AF_UNSPEC || head->ai_family == AF_INET6)
 577		need_v6 = ISC_TRUE;
 578
 579	state->trans6 = NULL;
 580	state->trans4 = NULL;
 581	if (need_v4) {
 582		state->trans4 = isc_mem_get(mctx, sizeof(gai_restrans_t));
 583		if (state->trans4 == NULL) {
 584			isc_mem_put(mctx, state, sizeof(*state));
 585			return (ISC_R_NOMEMORY);
 586		}
 587		state->trans4->error = 0;
 588		state->trans4->xid = NULL;
 589		state->trans4->resstate = state;
 590		state->trans4->is_inprogress = ISC_TRUE;
 591		state->trans4->ai_sentinel.ai_next = NULL;
 592	}
 593	if (need_v6) {
 594		state->trans6 = isc_mem_get(mctx, sizeof(gai_restrans_t));
 595		if (state->trans6 == NULL) {
 596			if (state->trans4 != NULL)
 597				isc_mem_put(mctx, state->trans4,
 598					    sizeof(*state->trans4));
 599			isc_mem_put(mctx, state, sizeof(*state));
 600			return (ISC_R_NOMEMORY);
 601		}
 602		state->trans6->error = 0;
 603		state->trans6->xid = NULL;
 604		state->trans6->resstate = state;
 605		state->trans6->is_inprogress = ISC_TRUE;
 606		state->trans6->ai_sentinel.ai_next = NULL;
 607	}
 608
 609	state->mctx = mctx;
 610	state->head = head;
 611	ISC_LINK_INIT(state, link);
 612
 613	*statep = state;
 614
 615	return (ISC_R_SUCCESS);
 616}
 617
 618static isc_result_t
 619make_resstates(isc_mem_t *mctx, const char *hostname, gai_statehead_t *head,
 620	       irs_resconf_t *resconf)
 621{
 622	isc_result_t result;
 623	irs_resconf_searchlist_t *searchlist;
 624	irs_resconf_search_t *searchent;
 625	gai_resstate_t *resstate, *resstate0;
 626
 627	resstate0 = NULL;
 628	result = make_resstate(mctx, head, hostname, ".", &resstate0);
 629	if (result != ISC_R_SUCCESS)
 630		return (result);
 631
 632	searchlist = irs_resconf_getsearchlist(resconf);
 633	for (searchent = ISC_LIST_HEAD(*searchlist); searchent != NULL;
 634	     searchent = ISC_LIST_NEXT(searchent, link)) {
 635		resstate = NULL;
 636		result = make_resstate(mctx, head, hostname,
 637				       (const char *)searchent->domain,
 638				       &resstate);
 639		if (result != ISC_R_SUCCESS)
 640			break;
 641
 642		ISC_LIST_APPEND(head->resstates, resstate, link);
 643		head->activestates++;
 644	}
 645
 646	/*
 647	 * Insert the original hostname either at the head or the tail of the
 648	 * state list, depending on the number of labels contained in the
 649	 * original name and the 'ndots' configuration parameter.
 650	 */
 651	if (dns_name_countlabels(resstate0->qname) >
 652	    irs_resconf_getndots(resconf) + 1) {
 653		ISC_LIST_PREPEND(head->resstates, resstate0, link);
 654	} else
 655		ISC_LIST_APPEND(head->resstates, resstate0, link);
 656	head->activestates++;
 657
 658	if (result != ISC_R_SUCCESS) {
 659		while ((resstate = ISC_LIST_HEAD(head->resstates)) != NULL) {
 660			ISC_LIST_UNLINK(head->resstates, resstate, link);
 661			if (resstate->trans4 != NULL) {
 662				isc_mem_put(mctx, resstate->trans4,
 663					    sizeof(*resstate->trans4));
 664			}
 665			if (resstate->trans6 != NULL) {
 666				isc_mem_put(mctx, resstate->trans6,
 667					    sizeof(*resstate->trans6));
 668			}
 669
 670			isc_mem_put(mctx, resstate, sizeof(*resstate));
 671		}
 672	}
 673
 674	return (result);
 675}
 676
 677static void
 678process_answer(isc_task_t *task, isc_event_t *event) {
 679	int error = 0, family;
 680	gai_restrans_t *trans = event->ev_arg;
 681	gai_resstate_t *resstate;
 682	dns_clientresevent_t *rev = (dns_clientresevent_t *)event;
 683	dns_rdatatype_t qtype;
 684	dns_name_t *name;
 685
 686	REQUIRE(trans != NULL);
 687	resstate = trans->resstate;
 688	REQUIRE(resstate != NULL);
 689	REQUIRE(task != NULL);
 690
 691	if (trans == resstate->trans4) {
 692		family = AF_INET;
 693		qtype = dns_rdatatype_a;
 694	} else {
 695		INSIST(trans == resstate->trans6);
 696		family = AF_INET6;
 697		qtype = dns_rdatatype_aaaa;
 698	}
 699
 700	INSIST(trans->is_inprogress);
 701	trans->is_inprogress = ISC_FALSE;
 702
 703	switch (rev->result) {
 704	case ISC_R_SUCCESS:
 705	case DNS_R_NCACHENXDOMAIN: /* treat this as a fatal error? */
 706	case DNS_R_NCACHENXRRSET:
 707		break;
 708	default:
 709		switch (rev->vresult) {
 710		case DNS_R_SIGINVALID:
 711		case DNS_R_SIGEXPIRED:
 712		case DNS_R_SIGFUTURE:
 713		case DNS_R_KEYUNAUTHORIZED:
 714		case DNS_R_MUSTBESECURE:
 715		case DNS_R_COVERINGNSEC:
 716		case DNS_R_NOTAUTHORITATIVE:
 717		case DNS_R_NOVALIDKEY:
 718		case DNS_R_NOVALIDDS:
 719		case DNS_R_NOVALIDSIG:
 720			error = EAI_INSECUREDATA;
 721			break;
 722		default:
 723			error = EAI_FAIL;
 724		}
 725		goto done;
 726	}
 727
 728	/* Parse the response and construct the addrinfo chain */
 729	for (name = ISC_LIST_HEAD(rev->answerlist); name != NULL;
 730	     name = ISC_LIST_NEXT(name, link)) {
 731		isc_result_t result;
 732		dns_rdataset_t *rdataset;
 733		isc_buffer_t b;
 734		isc_region_t r;
 735		char t[1024];
 736
 737		for (rdataset = ISC_LIST_HEAD(name->list);
 738		     rdataset != NULL;
 739		     rdataset = ISC_LIST_NEXT(rdataset, link)) {
 740			if (!dns_rdataset_isassociated(rdataset))
 741				continue;
 742			if (rdataset->type != qtype)
 743				continue;
 744
 745			if ((resstate->head->ai_flags & AI_CANONNAME) != 0) {
 746				isc_buffer_init(&b, t, sizeof(t));
 747				result = dns_name_totext(name, ISC_TRUE, &b);
 748				if (result != ISC_R_SUCCESS) {
 749					error = EAI_FAIL;
 750					goto done;
 751				}
 752				isc_buffer_putuint8(&b, '\0');
 753				isc_buffer_usedregion(&b, &r);
 754			}
 755
 756			for (result = dns_rdataset_first(rdataset);
 757			     result == ISC_R_SUCCESS;
 758			     result = dns_rdataset_next(rdataset)) {
 759				struct addrinfo *ai;
 760				dns_rdata_t rdata;
 761				dns_rdata_in_a_t rdata_a;
 762				dns_rdata_in_aaaa_t rdata_aaaa;
 763
 764				ai = ai_alloc(family,
 765					      ((family == AF_INET6) ?
 766					       sizeof(struct sockaddr_in6) :
 767					       sizeof(struct sockaddr_in)));
 768				if (ai == NULL) {
 769					error = EAI_MEMORY;
 770					goto done;
 771				}
 772				ai->ai_socktype = resstate->head->ai_socktype;
 773				ai->ai_next = trans->ai_sentinel.ai_next;
 774				trans->ai_sentinel.ai_next = ai;
 775
 776				/*
 777				 * Set AF-specific parameters
 778				 * (IPv4/v6 address/port)
 779				 */
 780				dns_rdata_init(&rdata);
 781				switch (family) {
 782				case AF_INET:
 783					dns_rdataset_current(rdataset, &rdata);
 784					dns_rdata_tostruct(&rdata, &rdata_a,
 785							   NULL);
 786
 787					SIN(ai->ai_addr)->sin_port =
 788						resstate->head->ai_port;
 789					memcpy(&SIN(ai->ai_addr)->sin_addr,
 790					       &rdata_a.in_addr, 4);
 791					dns_rdata_freestruct(&rdata_a);
 792					break;
 793				case AF_INET6:
 794					dns_rdataset_current(rdataset, &rdata);
 795					dns_rdata_tostruct(&rdata, &rdata_aaaa,
 796							   NULL);
 797					SIN6(ai->ai_addr)->sin6_port =
 798						resstate->head->ai_port;
 799					memcpy(&SIN6(ai->ai_addr)->sin6_addr,
 800					       &rdata_aaaa.in6_addr, 16);
 801					dns_rdata_freestruct(&rdata_aaaa);
 802					break;
 803				}
 804
 805				if ((resstate->head->ai_flags & AI_CANONNAME)
 806				    != 0) {
 807					ai->ai_canonname =
 808						strdup((const char *)r.base);
 809					if (ai->ai_canonname == NULL) {
 810						error = EAI_MEMORY;
 811						goto done;
 812					}
 813				}
 814			}
 815		}
 816	}
 817
 818 done:
 819	dns_client_freeresanswer(resstate->head->dnsclient, &rev->answerlist);
 820	dns_client_destroyrestrans(&trans->xid);
 821
 822	isc_event_free(&event);
 823
 824	/* Make sure that error == 0 iff we have a non-empty list */
 825	if (error == 0) {
 826		if (trans->ai_sentinel.ai_next == NULL)
 827			error = EAI_NONAME;
 828	} else {
 829		if (trans->ai_sentinel.ai_next != NULL) {
 830			freeaddrinfo(trans->ai_sentinel.ai_next);
 831			trans->ai_sentinel.ai_next = NULL;
 832		}
 833	}
 834	trans->error = error;
 835
 836	/* Check whether we are done */
 837	if ((resstate->trans4 == NULL || !resstate->trans4->is_inprogress) &&
 838	    (resstate->trans6 == NULL || !resstate->trans6->is_inprogress)) {
 839		/*
 840		 * We're done for this state.  If there is no other outstanding
 841		 * state, we can exit.
 842		 */
 843		resstate->head->activestates--;
 844		if (resstate->head->activestates == 0) {
 845			isc_app_ctxsuspend(resstate->head->actx);
 846			return;
 847		}
 848
 849		/*
 850		 * There are outstanding states, but if we are at the head
 851		 * of the state list (i.e., at the highest search priority)
 852		 * and have any answer, we can stop now by canceling the
 853		 * others.
 854		 */
 855		if (resstate == ISC_LIST_HEAD(resstate->head->resstates)) {
 856			if ((resstate->trans4 != NULL &&
 857			     resstate->trans4->ai_sentinel.ai_next != NULL) ||
 858			    (resstate->trans6 != NULL &&
 859			     resstate->trans6->ai_sentinel.ai_next != NULL)) {
 860				gai_resstate_t *rest;
 861
 862				for (rest = ISC_LIST_NEXT(resstate, link);
 863				     rest != NULL;
 864				     rest = ISC_LIST_NEXT(rest, link)) {
 865					if (rest->trans4 != NULL &&
 866					    rest->trans4->xid != NULL)
 867						dns_client_cancelresolve(
 868							rest->trans4->xid);
 869					if (rest->trans6 != NULL &&
 870					    rest->trans6->xid != NULL)
 871						dns_client_cancelresolve(
 872							rest->trans6->xid);
 873				}
 874			} else {
 875				/*
 876				 * This search fails, so we move to the tail
 877				 * of the list so that the next entry will
 878				 * have the highest priority.
 879				 */
 880				ISC_LIST_UNLINK(resstate->head->resstates,
 881						resstate, link);
 882				ISC_LIST_APPEND(resstate->head->resstates,
 883						resstate, link);
 884			}
 885		}
 886	}
 887}
 888
 889static int
 890resolve_name(int family, const char *hostname, int flags,
 891	     struct addrinfo **aip, int socktype, int port)
 892{
 893	isc_result_t result;
 894	irs_context_t *irsctx;
 895	irs_resconf_t *conf;
 896	isc_mem_t *mctx;
 897	isc_appctx_t *actx;
 898	isc_task_t *task;
 899	int terror = 0;
 900	int error = 0;
 901	dns_client_t *client;
 902	gai_resstate_t *resstate;
 903	gai_statehead_t head;
 904	isc_boolean_t all_fail = ISC_TRUE;
 905
 906	/* get IRS context and the associated parameters */
 907	irsctx = NULL;
 908	result = irs_context_get(&irsctx);
 909	if (result != ISC_R_SUCCESS)
 910		return (EAI_FAIL);
 911	actx = irs_context_getappctx(irsctx);
 912
 913	mctx = irs_context_getmctx(irsctx);
 914	task = irs_context_gettask(irsctx);
 915	conf = irs_context_getresconf(irsctx);
 916	client = irs_context_getdnsclient(irsctx);
 917
 918	/* construct resolution states */
 919	head.activestates = 0;
 920	head.ai_family = family;
 921	head.ai_socktype = socktype;
 922	head.ai_flags = flags;
 923	head.ai_port = port;
 924	head.actx = actx;
 925	head.dnsclient = client;
 926	ISC_LIST_INIT(head.resstates);
 927	result = make_resstates(mctx, hostname, &head, conf);
 928	if (result != ISC_R_SUCCESS)
 929		return (EAI_FAIL);
 930
 931	for (resstate = ISC_LIST_HEAD(head.resstates);
 932	     resstate != NULL; resstate = ISC_LIST_NEXT(resstate, link)) {
 933		if (resstate->trans4 != NULL) {
 934			result = dns_client_startresolve(client,
 935							 resstate->qname,
 936							 dns_rdataclass_in,
 937							 dns_rdatatype_a,
 938							 0, task,
 939							 process_answer,
 940							 resstate->trans4,
 941							 &resstate->trans4->xid);
 942			if (result == ISC_R_SUCCESS) {
 943				resstate->trans4->is_inprogress = ISC_TRUE;
 944				all_fail = ISC_FALSE;
 945			} else
 946				resstate->trans4->is_inprogress = ISC_FALSE;
 947		}
 948		if (resstate->trans6 != NULL) {
 949			result = dns_client_startresolve(client,
 950							 resstate->qname,
 951							 dns_rdataclass_in,
 952							 dns_rdatatype_aaaa,
 953							 0, task,
 954							 process_answer,
 955							 resstate->trans6,
 956							 &resstate->trans6->xid);
 957			if (result == ISC_R_SUCCESS) {
 958				resstate->trans6->is_inprogress = ISC_TRUE;
 959				all_fail = ISC_FALSE;
 960			} else
 961				resstate->trans6->is_inprogress= ISC_FALSE;
 962		}
 963	}
 964	if (!all_fail) {
 965		/* Start all the events */
 966		isc_app_ctxrun(actx);
 967	} else
 968		error = EAI_FAIL;
 969
 970	/* Cleanup */
 971	while ((resstate = ISC_LIST_HEAD(head.resstates)) != NULL) {
 972		int terror4 = 0, terror6 = 0;
 973
 974		ISC_LIST_UNLINK(head.resstates, resstate, link);
 975
 976		if (*aip == NULL) {
 977			struct addrinfo *sentinel4 = NULL;
 978			struct addrinfo *sentinel6 = NULL;
 979
 980			if (resstate->trans4 != NULL) {
 981				sentinel4 =
 982					resstate->trans4->ai_sentinel.ai_next;
 983				resstate->trans4->ai_sentinel.ai_next = NULL;
 984			}
 985			if (resstate->trans6 != NULL) {
 986				sentinel6 =
 987					resstate->trans6->ai_sentinel.ai_next;
 988				resstate->trans6->ai_sentinel.ai_next = NULL;
 989			}
 990			*aip = ai_concat(sentinel4, sentinel6);
 991		}
 992
 993		if (resstate->trans4 != NULL) {
 994			INSIST(resstate->trans4->xid == NULL);
 995			terror4 = resstate->trans4->error;
 996			isc_mem_put(mctx, resstate->trans4,
 997				    sizeof(*resstate->trans4));
 998		}
 999		if (resstate->trans6 != NULL) {
1000			INSIST(resstate->trans6->xid == NULL);
1001			terror6 = resstate->trans6->error;
1002			isc_mem_put(mctx, resstate->trans6,
1003				    sizeof(*resstate->trans6));
1004		}
1005
1006		/*
1007		 * If the entire lookup fails, we need to choose an appropriate
1008		 * error code from individual codes.  We'll try to provide as
1009		 * specific a code as possible.  In general, we are going to
1010		 * find an error code other than EAI_NONAME (which is too
1011		 * generic and may actually not be problematic in some cases).
1012		 * EAI_NONAME will be set below if no better code is found.
1013		 */
1014		if (terror == 0 || terror == EAI_NONAME) {
1015			if (terror4 != 0 && terror4 != EAI_NONAME)
1016				terror = terror4;
1017			else if (terror6 != 0 && terror6 != EAI_NONAME)
1018				terror = terror6;
1019		}
1020
1021		isc_mem_put(mctx, resstate, sizeof(*resstate));
1022	}
1023
1024	if (*aip == NULL) {
1025		error = terror;
1026		if (error == 0)
1027			error = EAI_NONAME;
1028	}
1029
1030#if 1	/*  XXX: enabled for finding leaks.  should be cleaned up later. */
1031	isc_app_ctxfinish(actx);
1032	irs_context_destroy(&irsctx);
1033#endif
1034
1035	return (error);
1036}
1037
1038static char *
1039irs_strsep(char **stringp, const char *delim) {
1040	char *string = *stringp;
1041	char *s;
1042	const char *d;
1043	char sc, dc;
1044
1045	if (string == NULL)
1046		return (NULL);
1047
1048	for (s = string; *s != '\0'; s++) {
1049		sc = *s;
1050		for (d = delim; (dc = *d) != '\0'; d++)
1051			if (sc == dc) {
1052				*s++ = '\0';
1053				*stringp = s;
1054				return (string);
1055			}
1056	}
1057	*stringp = NULL;
1058	return (string);
1059}
1060
1061static void
1062set_order(int family, int (**net_order)(const char *, int, struct addrinfo **,
1063					int, int))
1064{
1065	char *order, *tok;
1066	int found;
1067
1068	if (family) {
1069		switch (family) {
1070		case AF_INET:
1071			*net_order++ = add_ipv4;
1072			break;
1073		case AF_INET6:
1074			*net_order++ = add_ipv6;
1075			break;
1076		}
1077	} else {
1078		order = getenv("NET_ORDER");
1079		found = 0;
1080		while (order != NULL) {
1081			/*
1082			 * We ignore any unknown names.
1083			 */
1084			tok = irs_strsep(&order, ":");
1085			if (strcasecmp(tok, "inet6") == 0) {
1086				if ((found & FOUND_IPV6) == 0)
1087					*net_order++ = add_ipv6;
1088				found |= FOUND_IPV6;
1089			} else if (strcasecmp(tok, "inet") == 0 ||
1090			    strcasecmp(tok, "inet4") == 0) {
1091				if ((found & FOUND_IPV4) == 0)
1092					*net_order++ = add_ipv4;
1093				found |= FOUND_IPV4;
1094			}
1095		}
1096
1097		/*
1098		 * Add in anything that we didn't find.
1099		 */
1100		if ((found & FOUND_IPV4) == 0)
1101			*net_order++ = add_ipv4;
1102		if ((found & FOUND_IPV6) == 0)
1103			*net_order++ = add_ipv6;
1104	}
1105	*net_order = NULL;
1106	return;
1107}
1108
1109static char v4_loop[4] = { 127, 0, 0, 1 };
1110
1111static int
1112add_ipv4(const char *hostname, int flags, struct addrinfo **aip,
1113	 int socktype, int port)
1114{
1115	struct addrinfo *ai;
1116
1117	UNUSED(hostname);
1118	UNUSED(flags);
1119
1120	ai = ai_clone(*aip, AF_INET); /* don't use ai_clone() */
1121	if (ai == NULL) {
1122		freeaddrinfo(*aip);
1123		return (EAI_MEMORY);
1124	}
1125
1126	*aip = ai;
1127	ai->ai_socktype = socktype;
1128	SIN(ai->ai_addr)->sin_port = port;
1129	memcpy(&SIN(ai->ai_addr)->sin_addr, v4_loop, 4);
1130
1131	return (0);
1132}
1133
1134static char v6_loop[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 };
1135
1136static int
1137add_ipv6(const char *hostname, int flags, struct addrinfo **aip,
1138	 int socktype, int port)
1139{
1140	struct addrinfo *ai;
1141
1142	UNUSED(hostname);
1143	UNUSED(flags);
1144
1145	ai = ai_clone(*aip, AF_INET6); /* don't use ai_clone() */
1146	if (ai == NULL) {
1147		freeaddrinfo(*aip);
1148		return (EAI_MEMORY);
1149	}
1150
1151	*aip = ai;
1152	ai->ai_socktype = socktype;
1153	SIN6(ai->ai_addr)->sin6_port = port;
1154	memcpy(&SIN6(ai->ai_addr)->sin6_addr, v6_loop, 16);
1155
1156	return (0);
1157}
1158
1159/*% Free address info. */
1160void
1161freeaddrinfo(struct addrinfo *ai) {
1162	struct addrinfo *ai_next;
1163
1164	while (ai != NULL) {
1165		ai_next = ai->ai_next;
1166		if (ai->ai_addr != NULL)
1167			free(ai->ai_addr);
1168		if (ai->ai_canonname)
1169			free(ai->ai_canonname);
1170		free(ai);
1171		ai = ai_next;
1172	}
1173}
1174
1175#ifdef AF_LOCAL
1176static int
1177get_local(const char *name, int socktype, struct addrinfo **res) {
1178	struct addrinfo *ai;
1179	struct sockaddr_un *slocal;
1180
1181	if (socktype == 0)
1182		return (EAI_SOCKTYPE);
1183
1184	ai = ai_alloc(AF_LOCAL, sizeof(*slocal));
1185	if (ai == NULL)
1186		return (EAI_MEMORY);
1187
1188	slocal = SLOCAL(ai->ai_addr);
1189	strncpy(slocal->sun_path, name, sizeof(slocal->sun_path));
1190
1191	ai->ai_socktype = socktype;
1192	/*
1193	 * ai->ai_flags, ai->ai_protocol, ai->ai_canonname,
1194	 * and ai->ai_next were initialized to zero.
1195	 */
1196
1197	*res = ai;
1198	return (0);
1199}
1200#endif
1201
1202/*!
1203 * Allocate an addrinfo structure, and a sockaddr structure
1204 * of the specificed length.  We initialize:
1205 *	ai_addrlen
1206 *	ai_family
1207 *	ai_addr
1208 *	ai_addr->sa_family
1209 *	ai_addr->sa_len	(IRS_PLATFORM_HAVESALEN)
1210 * and everything else is initialized to zero.
1211 */
1212static struct addrinfo *
1213ai_alloc(int family, int addrlen) {
1214	struct addrinfo *ai;
1215
1216	ai = (struct addrinfo *)calloc(1, sizeof(*ai));
1217	if (ai == NULL)
1218		return (NULL);
1219
1220	ai->ai_addr = SA(calloc(1, addrlen));
1221	if (ai->ai_addr == NULL) {
1222		free(ai);
1223		return (NULL);
1224	}
1225	ai->ai_addrlen = addrlen;
1226	ai->ai_family = family;
1227	ai->ai_addr->sa_family = family;
1228#ifdef IRS_PLATFORM_HAVESALEN
1229	ai->ai_addr->sa_len = addrlen;
1230#endif
1231	return (ai);
1232}
1233
1234static struct addrinfo *
1235ai_clone(struct addrinfo *oai, int family) {
1236	struct addrinfo *ai;
1237
1238	ai = ai_alloc(family, ((family == AF_INET6) ?
1239	    sizeof(struct sockaddr_in6) : sizeof(struct sockaddr_in)));
1240
1241	if (ai == NULL) {
1242		if (oai != NULL)
1243			freeaddrinfo(oai);
1244		return (NULL);
1245	}
1246	if (oai == NULL)
1247		return (ai);
1248
1249	ai->ai_flags = oai->ai_flags;
1250	ai->ai_socktype = oai->ai_socktype;
1251	ai->ai_protocol = oai->ai_protocol;
1252	ai->ai_canonname = NULL;
1253	ai->ai_next = oai;
1254	return (ai);
1255}
1256
1257static struct addrinfo *
1258ai_reverse(struct addrinfo *oai) {
1259	struct addrinfo *nai, *tai;
1260
1261	nai = NULL;
1262
1263	while (oai != NULL) {
1264		/*
1265		 * Grab one off the old list.
1266		 */
1267		tai = oai;
1268		oai = oai->ai_next;
1269		/*
1270		 * Put it on the front of the new list.
1271		 */
1272		tai->ai_next = nai;
1273		nai = tai;
1274	}
1275	return (nai);
1276}
1277
1278
1279static struct addrinfo *
1280ai_concat(struct addrinfo *ai1, struct addrinfo *ai2) {
1281	struct addrinfo *ai_tmp;
1282
1283	if (ai1 == NULL)
1284		return (ai2);
1285	else if (ai2 == NULL)
1286		return (ai1);
1287
1288	for (ai_tmp = ai1; ai_tmp != NULL && ai_tmp->ai_next != NULL;
1289	     ai_tmp = ai_tmp->ai_next)
1290		;
1291
1292	ai_tmp->ai_next = ai2;
1293
1294	return (ai1);
1295}