1/* 2 * Copyright (C) 2004, 2005, 2007, 2009, 2013 Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (C) 2000-2003 Internet Software Consortium. 4 * 5 * Permission to use, copy, modify, and/or distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 15 * PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18/* $Id: byaddr.c,v 1.41 2009/09/02 23:48:02 tbox Exp $ */ 19 20/*! \file */ 21 22#include <config.h> 23 24#include <isc/mem.h> 25#include <isc/netaddr.h> 26#include <isc/print.h> 27#include <isc/string.h> /* Required for HP/UX (and others?) */ 28#include <isc/task.h> 29#include <isc/util.h> 30 31#include <dns/byaddr.h> 32#include <dns/db.h> 33#include <dns/events.h> 34#include <dns/lookup.h> 35#include <dns/rdata.h> 36#include <dns/rdataset.h> 37#include <dns/rdatastruct.h> 38#include <dns/resolver.h> 39#include <dns/result.h> 40#include <dns/view.h> 41 42/* 43 * XXXRTH We could use a static event... 44 */ 45 46static char hex_digits[] = { 47 '0', '1', '2', '3', '4', '5', '6', '7', 48 '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' 49}; 50 51isc_result_t 52dns_byaddr_createptrname(isc_netaddr_t *address, isc_boolean_t nibble, 53 dns_name_t *name) 54{ 55 /* 56 * We dropped bitstring labels, so all lookups will use nibbles. 57 */ 58 UNUSED(nibble); 59 60 return (dns_byaddr_createptrname2(address, 61 DNS_BYADDROPT_IPV6INT, name)); 62} 63 64isc_result_t 65dns_byaddr_createptrname2(isc_netaddr_t *address, unsigned int options, 66 dns_name_t *name) 67{ 68 char textname[128]; 69 unsigned char *bytes; 70 int i; 71 char *cp; 72 isc_buffer_t buffer; 73 unsigned int len; 74 75 REQUIRE(address != NULL); 76 77 /* 78 * We create the text representation and then convert to a 79 * dns_name_t. This is not maximally efficient, but it keeps all 80 * of the knowledge of wire format in the dns_name_ routines. 81 */ 82 83 bytes = (unsigned char *)(&address->type); 84 if (address->family == AF_INET) { 85 (void)snprintf(textname, sizeof(textname), 86 "%u.%u.%u.%u.in-addr.arpa.", 87 (bytes[3] & 0xff), 88 (bytes[2] & 0xff), 89 (bytes[1] & 0xff), 90 (bytes[0] & 0xff)); 91 } else if (address->family == AF_INET6) { 92 cp = textname; 93 for (i = 15; i >= 0; i--) { 94 *cp++ = hex_digits[bytes[i] & 0x0f]; 95 *cp++ = '.'; 96 *cp++ = hex_digits[(bytes[i] >> 4) & 0x0f]; 97 *cp++ = '.'; 98 } 99 if ((options & DNS_BYADDROPT_IPV6INT) != 0) 100 strcpy(cp, "ip6.int."); 101 else 102 strcpy(cp, "ip6.arpa."); 103 } else 104 return (ISC_R_NOTIMPLEMENTED); 105 106 len = (unsigned int)strlen(textname); 107 isc_buffer_init(&buffer, textname, len); 108 isc_buffer_add(&buffer, len); 109 return (dns_name_fromtext(name, &buffer, dns_rootname, 0, NULL)); 110} 111 112#ifdef BIND9 113struct dns_byaddr { 114 /* Unlocked. */ 115 unsigned int magic; 116 isc_mem_t * mctx; 117 isc_mutex_t lock; 118 dns_fixedname_t name; 119 /* Locked by lock. */ 120 unsigned int options; 121 dns_lookup_t * lookup; 122 isc_task_t * task; 123 dns_byaddrevent_t * event; 124 isc_boolean_t canceled; 125}; 126 127#define BYADDR_MAGIC ISC_MAGIC('B', 'y', 'A', 'd') 128#define VALID_BYADDR(b) ISC_MAGIC_VALID(b, BYADDR_MAGIC) 129 130#define MAX_RESTARTS 16 131 132static inline isc_result_t 133copy_ptr_targets(dns_byaddr_t *byaddr, dns_rdataset_t *rdataset) { 134 isc_result_t result; 135 dns_name_t *name; 136 dns_rdata_t rdata = DNS_RDATA_INIT; 137 138 /* 139 * The caller must be holding the byaddr's lock. 140 */ 141 142 result = dns_rdataset_first(rdataset); 143 while (result == ISC_R_SUCCESS) { 144 dns_rdata_ptr_t ptr; 145 dns_rdataset_current(rdataset, &rdata); 146 result = dns_rdata_tostruct(&rdata, &ptr, NULL); 147 if (result != ISC_R_SUCCESS) 148 return (result); 149 name = isc_mem_get(byaddr->mctx, sizeof(*name)); 150 if (name == NULL) { 151 dns_rdata_freestruct(&ptr); 152 return (ISC_R_NOMEMORY); 153 } 154 dns_name_init(name, NULL); 155 result = dns_name_dup(&ptr.ptr, byaddr->mctx, name); 156 dns_rdata_freestruct(&ptr); 157 if (result != ISC_R_SUCCESS) { 158 isc_mem_put(byaddr->mctx, name, sizeof(*name)); 159 return (ISC_R_NOMEMORY); 160 } 161 ISC_LIST_APPEND(byaddr->event->names, name, link); 162 dns_rdata_reset(&rdata); 163 result = dns_rdataset_next(rdataset); 164 } 165 if (result == ISC_R_NOMORE) 166 result = ISC_R_SUCCESS; 167 168 return (result); 169} 170 171static void 172lookup_done(isc_task_t *task, isc_event_t *event) { 173 dns_byaddr_t *byaddr = event->ev_arg; 174 dns_lookupevent_t *levent; 175 isc_result_t result; 176 177 REQUIRE(event->ev_type == DNS_EVENT_LOOKUPDONE); 178 REQUIRE(VALID_BYADDR(byaddr)); 179 REQUIRE(byaddr->task == task); 180 181 UNUSED(task); 182 183 levent = (dns_lookupevent_t *)event; 184 185 if (levent->result == ISC_R_SUCCESS) { 186 result = copy_ptr_targets(byaddr, levent->rdataset); 187 byaddr->event->result = result; 188 } else 189 byaddr->event->result = levent->result; 190 isc_event_free(&event); 191 isc_task_sendanddetach(&byaddr->task, (isc_event_t **)&byaddr->event); 192} 193 194static void 195bevent_destroy(isc_event_t *event) { 196 dns_byaddrevent_t *bevent; 197 dns_name_t *name, *next_name; 198 isc_mem_t *mctx; 199 200 REQUIRE(event->ev_type == DNS_EVENT_BYADDRDONE); 201 mctx = event->ev_destroy_arg; 202 bevent = (dns_byaddrevent_t *)event; 203 204 for (name = ISC_LIST_HEAD(bevent->names); 205 name != NULL; 206 name = next_name) { 207 next_name = ISC_LIST_NEXT(name, link); 208 ISC_LIST_UNLINK(bevent->names, name, link); 209 dns_name_free(name, mctx); 210 isc_mem_put(mctx, name, sizeof(*name)); 211 } 212 isc_mem_put(mctx, event, event->ev_size); 213} 214 215isc_result_t 216dns_byaddr_create(isc_mem_t *mctx, isc_netaddr_t *address, dns_view_t *view, 217 unsigned int options, isc_task_t *task, 218 isc_taskaction_t action, void *arg, dns_byaddr_t **byaddrp) 219{ 220 isc_result_t result; 221 dns_byaddr_t *byaddr; 222 isc_event_t *ievent; 223 224 byaddr = isc_mem_get(mctx, sizeof(*byaddr)); 225 if (byaddr == NULL) 226 return (ISC_R_NOMEMORY); 227 byaddr->mctx = NULL; 228 isc_mem_attach(mctx, &byaddr->mctx); 229 byaddr->options = options; 230 231 byaddr->event = isc_mem_get(mctx, sizeof(*byaddr->event)); 232 if (byaddr->event == NULL) { 233 result = ISC_R_NOMEMORY; 234 goto cleanup_byaddr; 235 } 236 ISC_EVENT_INIT(byaddr->event, sizeof(*byaddr->event), 0, NULL, 237 DNS_EVENT_BYADDRDONE, action, arg, byaddr, 238 bevent_destroy, mctx); 239 byaddr->event->result = ISC_R_FAILURE; 240 ISC_LIST_INIT(byaddr->event->names); 241 242 byaddr->task = NULL; 243 isc_task_attach(task, &byaddr->task); 244 245 result = isc_mutex_init(&byaddr->lock); 246 if (result != ISC_R_SUCCESS) 247 goto cleanup_event; 248 249 dns_fixedname_init(&byaddr->name); 250 251 result = dns_byaddr_createptrname2(address, options, 252 dns_fixedname_name(&byaddr->name)); 253 if (result != ISC_R_SUCCESS) 254 goto cleanup_lock; 255 256 byaddr->lookup = NULL; 257 result = dns_lookup_create(mctx, dns_fixedname_name(&byaddr->name), 258 dns_rdatatype_ptr, view, 0, task, 259 lookup_done, byaddr, &byaddr->lookup); 260 if (result != ISC_R_SUCCESS) 261 goto cleanup_lock; 262 263 byaddr->canceled = ISC_FALSE; 264 byaddr->magic = BYADDR_MAGIC; 265 266 *byaddrp = byaddr; 267 268 return (ISC_R_SUCCESS); 269 270 cleanup_lock: 271 DESTROYLOCK(&byaddr->lock); 272 273 cleanup_event: 274 ievent = (isc_event_t *)byaddr->event; 275 isc_event_free(&ievent); 276 byaddr->event = NULL; 277 278 isc_task_detach(&byaddr->task); 279 280 cleanup_byaddr: 281 isc_mem_putanddetach(&mctx, byaddr, sizeof(*byaddr)); 282 283 return (result); 284} 285 286void 287dns_byaddr_cancel(dns_byaddr_t *byaddr) { 288 REQUIRE(VALID_BYADDR(byaddr)); 289 290 LOCK(&byaddr->lock); 291 292 if (!byaddr->canceled) { 293 byaddr->canceled = ISC_TRUE; 294 if (byaddr->lookup != NULL) 295 dns_lookup_cancel(byaddr->lookup); 296 } 297 298 UNLOCK(&byaddr->lock); 299} 300 301void 302dns_byaddr_destroy(dns_byaddr_t **byaddrp) { 303 dns_byaddr_t *byaddr; 304 305 REQUIRE(byaddrp != NULL); 306 byaddr = *byaddrp; 307 REQUIRE(VALID_BYADDR(byaddr)); 308 REQUIRE(byaddr->event == NULL); 309 REQUIRE(byaddr->task == NULL); 310 dns_lookup_destroy(&byaddr->lookup); 311 312 DESTROYLOCK(&byaddr->lock); 313 byaddr->magic = 0; 314 isc_mem_putanddetach(&byaddr->mctx, byaddr, sizeof(*byaddr)); 315 316 *byaddrp = NULL; 317} 318#endif /* BIND9 */ 319