1 /* $NetBSD: getrrset.c,v 1.6 2014/12/10 04:38:02 christos Exp $ */ 2 3 /* 4 * Copyright (C) 2004, 2005, 2007, 2012, 2014 Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (C) 2000-2003 Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and/or distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 13 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 17 * PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 /* Id: getrrset.c,v 1.18 2007/06/19 23:47:22 tbox Exp */ 21 22 /*! \file */ 23 24 /** 25 * DESCRIPTION 26 * 27 * lwres_getrrsetbyname() gets a set of resource records associated with 28 * a hostname, class, and type. hostname is a pointer a to 29 * null-terminated string. The flags field is currently unused and must 30 * be zero. 31 * 32 * After a successful call to lwres_getrrsetbyname(), *res is a pointer 33 * to an #rrsetinfo structure, containing a list of one or more #rdatainfo 34 * structures containing resource records and potentially another list of 35 * rdatainfo structures containing SIG resource records associated with 36 * those records. The members #rri_rdclass and #rri_rdtype are copied from 37 * the parameters. #rri_ttl and #rri_name are properties of the obtained 38 * rrset. The resource records contained in #rri_rdatas and #rri_sigs are 39 * in uncompressed DNS wire format. Properties of the rdataset are 40 * represented in the #rri_flags bitfield. If the #RRSET_VALIDATED bit is 41 * set, the data has been DNSSEC validated and the signatures verified. 42 * 43 * All of the information returned by lwres_getrrsetbyname() is 44 * dynamically allocated: the rrsetinfo and rdatainfo structures, and the 45 * canonical host name strings pointed to by the rrsetinfostructure. 46 * Memory allocated for the dynamically allocated structures created by a 47 * successful call to lwres_getrrsetbyname() is released by 48 * lwres_freerrset(). rrset is a pointer to a struct rrset created by a 49 * call to lwres_getrrsetbyname(). 50 * 51 * The following structures are used: 52 * 53 * \code 54 * struct rdatainfo { 55 * unsigned int rdi_length; // length of data 56 * unsigned char *rdi_data; // record data 57 * }; 58 * 59 * struct rrsetinfo { 60 * unsigned int rri_flags; // RRSET_VALIDATED... 61 * unsigned int rri_rdclass; // class number 62 * unsigned int rri_rdtype; // RR type number 63 * unsigned int rri_ttl; // time to live 64 * unsigned int rri_nrdatas; // size of rdatas array 65 * unsigned int rri_nsigs; // size of sigs array 66 * char *rri_name; // canonical name 67 * struct rdatainfo *rri_rdatas; // individual records 68 * struct rdatainfo *rri_sigs; // individual signatures 69 * }; 70 * \endcode 71 * 72 * \section getrrset_return Return Values 73 * 74 * lwres_getrrsetbyname() returns zero on success, and one of the 75 * following error codes if an error occurred: 76 * 77 * \li #ERRSET_NONAME: the name does not exist 78 * 79 * \li #ERRSET_NODATA: 80 * the name exists, but does not have data of the desired type 81 * 82 * \li #ERRSET_NOMEMORY: 83 * memory could not be allocated 84 * 85 * \li #ERRSET_INVAL: 86 * a parameter is invalid 87 * 88 * \li #ERRSET_FAIL: 89 * other failure 90 */ 91 92 #include <config.h> 93 94 #include <string.h> 95 #include <errno.h> 96 #include <stdlib.h> 97 98 #include <lwres/lwres.h> 99 #include <lwres/net.h> 100 #include <lwres/netdb.h> /* XXX #include <netdb.h> */ 101 102 #include "assert_p.h" 103 104 /*! 105 * Structure to map results 106 */ 107 static unsigned int 108 lwresult_to_result(lwres_result_t lwresult) { 109 switch (lwresult) { 110 case LWRES_R_SUCCESS: return (ERRSET_SUCCESS); 111 case LWRES_R_NOMEMORY: return (ERRSET_NOMEMORY); 112 case LWRES_R_NOTFOUND: return (ERRSET_NONAME); 113 case LWRES_R_TYPENOTFOUND: return (ERRSET_NODATA); 114 default: return (ERRSET_FAIL); 115 } 116 } 117 118 /*@{*/ 119 /*! 120 * malloc / calloc functions that guarantee to only 121 * return NULL if there is an error, like they used 122 * to before the ANSI C committee broke them. 123 */ 124 125 static void * 126 sane_malloc(size_t size) { 127 if (size == 0U) 128 size = 1; 129 return (malloc(size)); 130 } 131 132 static void * 133 sane_calloc(size_t number, size_t size) { 134 size_t len = number * size; 135 void *mem = sane_malloc(len); 136 if (mem != NULL) 137 memset(mem, 0, len); 138 return (mem); 139 } 140 /*@}*/ 141 142 /*% Returns a set of resource records associated with a hostname, class, and type. hostname is a pointer a to null-terminated string. */ 143 int 144 lwres_getrrsetbyname(const char *hostname, unsigned int rdclass, 145 unsigned int rdtype, unsigned int flags, 146 struct rrsetinfo **res) 147 { 148 lwres_context_t *lwrctx = NULL; 149 lwres_result_t lwresult; 150 lwres_grbnresponse_t *response = NULL; 151 struct rrsetinfo *rrset = NULL; 152 unsigned int i; 153 unsigned int lwflags; 154 unsigned int result; 155 156 if (rdclass > 0xffff || rdtype > 0xffff) { 157 result = ERRSET_INVAL; 158 goto fail; 159 } 160 161 /* 162 * Don't allow queries of class or type ANY 163 */ 164 if (rdclass == 0xff || rdtype == 0xff) { 165 result = ERRSET_INVAL; 166 goto fail; 167 } 168 169 lwresult = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0); 170 if (lwresult != LWRES_R_SUCCESS) { 171 result = lwresult_to_result(lwresult); 172 goto fail; 173 } 174 (void) lwres_conf_parse(lwrctx, lwres_resolv_conf); 175 176 /* 177 * If any input flags were defined, lwflags would be set here 178 * based on them 179 */ 180 UNUSED(flags); 181 lwflags = 0; 182 183 lwresult = lwres_getrdatabyname(lwrctx, hostname, 184 (lwres_uint16_t)rdclass, 185 (lwres_uint16_t)rdtype, 186 lwflags, &response); 187 if (lwresult != LWRES_R_SUCCESS) { 188 result = lwresult_to_result(lwresult); 189 goto fail; 190 } 191 192 rrset = sane_malloc(sizeof(struct rrsetinfo)); 193 if (rrset == NULL) { 194 result = ERRSET_NOMEMORY; 195 goto fail; 196 } 197 rrset->rri_name = NULL; 198 rrset->rri_rdclass = response->rdclass; 199 rrset->rri_rdtype = response->rdtype; 200 rrset->rri_ttl = response->ttl; 201 rrset->rri_flags = 0; 202 rrset->rri_nrdatas = 0; 203 rrset->rri_rdatas = NULL; 204 rrset->rri_nsigs = 0; 205 rrset->rri_sigs = NULL; 206 207 rrset->rri_name = sane_malloc(response->realnamelen + 1); 208 if (rrset->rri_name == NULL) { 209 result = ERRSET_NOMEMORY; 210 goto fail; 211 } 212 strncpy(rrset->rri_name, response->realname, response->realnamelen); 213 rrset->rri_name[response->realnamelen] = 0; 214 215 if ((response->flags & LWRDATA_VALIDATED) != 0) 216 rrset->rri_flags |= RRSET_VALIDATED; 217 218 rrset->rri_nrdatas = response->nrdatas; 219 rrset->rri_rdatas = sane_calloc(rrset->rri_nrdatas, 220 sizeof(struct rdatainfo)); 221 if (rrset->rri_rdatas == NULL) { 222 result = ERRSET_NOMEMORY; 223 goto fail; 224 } 225 for (i = 0; i < rrset->rri_nrdatas; i++) { 226 rrset->rri_rdatas[i].rdi_length = response->rdatalen[i]; 227 rrset->rri_rdatas[i].rdi_data = 228 sane_malloc(rrset->rri_rdatas[i].rdi_length); 229 if (rrset->rri_rdatas[i].rdi_data == NULL) { 230 result = ERRSET_NOMEMORY; 231 goto fail; 232 } 233 memmove(rrset->rri_rdatas[i].rdi_data, response->rdatas[i], 234 rrset->rri_rdatas[i].rdi_length); 235 } 236 rrset->rri_nsigs = response->nsigs; 237 rrset->rri_sigs = sane_calloc(rrset->rri_nsigs, 238 sizeof(struct rdatainfo)); 239 if (rrset->rri_sigs == NULL) { 240 result = ERRSET_NOMEMORY; 241 goto fail; 242 } 243 for (i = 0; i < rrset->rri_nsigs; i++) { 244 rrset->rri_sigs[i].rdi_length = response->siglen[i]; 245 rrset->rri_sigs[i].rdi_data = 246 sane_malloc(rrset->rri_sigs[i].rdi_length); 247 if (rrset->rri_sigs[i].rdi_data == NULL) { 248 result = ERRSET_NOMEMORY; 249 goto fail; 250 } 251 memmove(rrset->rri_sigs[i].rdi_data, response->sigs[i], 252 rrset->rri_sigs[i].rdi_length); 253 } 254 255 lwres_grbnresponse_free(lwrctx, &response); 256 lwres_conf_clear(lwrctx); 257 lwres_context_destroy(&lwrctx); 258 *res = rrset; 259 return (ERRSET_SUCCESS); 260 fail: 261 if (rrset != NULL) 262 lwres_freerrset(rrset); 263 if (response != NULL) 264 lwres_grbnresponse_free(lwrctx, &response); 265 if (lwrctx != NULL) { 266 lwres_conf_clear(lwrctx); 267 lwres_context_destroy(&lwrctx); 268 } 269 return (result); 270 } 271 272 /*% Releases memory allocated for the dynamically allocated structures created by a successful call to lwres_getrrsetbyname(). */ 273 void 274 lwres_freerrset(struct rrsetinfo *rrset) { 275 unsigned int i; 276 if (rrset->rri_rdatas != NULL) { 277 for (i = 0; i < rrset->rri_nrdatas; i++) { 278 if (rrset->rri_rdatas[i].rdi_data == NULL) 279 break; 280 free(rrset->rri_rdatas[i].rdi_data); 281 } 282 free(rrset->rri_rdatas); 283 } 284 if (rrset->rri_sigs != NULL) { 285 for (i = 0; i < rrset->rri_nsigs; i++) { 286 if (rrset->rri_sigs[i].rdi_data == NULL) 287 break; 288 free(rrset->rri_sigs[i].rdi_data); 289 } 290 free(rrset->rri_sigs); 291 } 292 free(rrset->rri_name); 293 free(rrset); 294 } 295