contrib/ldns/higher.c

   1 /*
   2  * higher.c
   3  *
   4  * Specify some higher level functions that would
   5  * be useful to would be developers
   6  *
   7  * a Net::DNS like library for C
   8  *
   9  * (c) NLnet Labs, 2004-2006
  10  *
  11  * See the file LICENSE for the license
  12  */
  13
  14 #include <ldns/config.h>
  15
  16 #include <ldns/ldns.h>
  17
  18 #ifdef HAVE_SSL
  19 #include <openssl/ssl.h>
  20 #include <openssl/sha.h>
  21 #endif /* HAVE_SSL */
  22
  23 ldns_rr_list *
  24 ldns_get_rr_list_addr_by_name(ldns_resolver *res, const ldns_rdf *name,
  25                 ldns_rr_class c, uint16_t flags)
  26 {
  27         ldns_pkt *pkt;
  28         ldns_rr_list *aaaa;
  29         ldns_rr_list *a;
  30         ldns_rr_list *result = NULL;
  31         ldns_rr_list *hostsfilenames;
  32         size_t i;
  33         uint8_t ip6;
  34
  35         a = NULL;
  36         aaaa = NULL;
  37         result = NULL;
  38
  39         if (!res) {
  40                 return NULL;
  41         }
  42         if (ldns_rdf_get_type(name) != LDNS_RDF_TYPE_DNAME) {
  43                 return NULL;
  44         }
  45
  46         ip6 = ldns_resolver_ip6(res); /* we use INET_ANY here, save
  47                                          what was there */
  48
  49         ldns_resolver_set_ip6(res, LDNS_RESOLV_INETANY);
  50
  51         hostsfilenames = ldns_get_rr_list_hosts_frm_file(NULL);
  52         for (i = 0; i < ldns_rr_list_rr_count(hostsfilenames); i++) {
  53                 if (ldns_rdf_compare(name,
  54                                         ldns_rr_owner(ldns_rr_list_rr(hostsfilenames,
  55                                                         i))) == 0) {
  56                         if (!result) {
  57                                 result = ldns_rr_list_new();
  58                         }
  59                         ldns_rr_list_push_rr(result,
  60                                         ldns_rr_clone(ldns_rr_list_rr(hostsfilenames, i)));
  61                 }
  62         }
  63         ldns_rr_list_deep_free(hostsfilenames);
  64
  65         if (result) {
  66                 return result;
  67         }
  68
  69         /* add the RD flags, because we want an answer */
  70         pkt = ldns_resolver_query(res, name, LDNS_RR_TYPE_AAAA, c, flags | LDNS_RD);
  71         if (pkt) {
  72                 /* extract the data we need */
  73                 aaaa = ldns_pkt_rr_list_by_type(pkt, LDNS_RR_TYPE_AAAA,
  74                         LDNS_SECTION_ANSWER);
  75                 ldns_pkt_free(pkt);
  76         }
  77
  78         pkt = ldns_resolver_query(res, name, LDNS_RR_TYPE_A, c, flags | LDNS_RD);
  79         if (pkt) {
  80                 /* extract the data we need */
  81                 a = ldns_pkt_rr_list_by_type(pkt, LDNS_RR_TYPE_A, LDNS_SECTION_ANSWER);
  82                 ldns_pkt_free(pkt);
  83         }
  84         ldns_resolver_set_ip6(res, ip6);
  85
  86         if (aaaa && a) {
  87                 result = ldns_rr_list_cat_clone(aaaa, a);
  88                 ldns_rr_list_deep_free(aaaa);
  89                 ldns_rr_list_deep_free(a);
  90                 return result;
  91         }
  92
  93         if (aaaa) {
  94                 result = ldns_rr_list_clone(aaaa);
  95         }
  96
  97         if (a) {
  98                 result = ldns_rr_list_clone(a);
  99         }
 100
 101         ldns_rr_list_deep_free(aaaa);
 102         ldns_rr_list_deep_free(a);
 103         return result;
 104 }
 105
 106 ldns_rr_list *
 107 ldns_get_rr_list_name_by_addr(ldns_resolver *res, const ldns_rdf *addr,
 108                 ldns_rr_class c, uint16_t flags)
 109 {
 110         ldns_pkt *pkt;
 111         ldns_rr_list *names;
 112         ldns_rdf *name;
 113
 114         names = NULL;
 115
 116         if (!res || !addr) {
 117                 return NULL;
 118         }
 119
 120         if (ldns_rdf_get_type(addr) != LDNS_RDF_TYPE_A &&
 121                         ldns_rdf_get_type(addr) != LDNS_RDF_TYPE_AAAA) {
 122                 return NULL;
 123         }
 124
 125         name = ldns_rdf_address_reverse(addr);
 126
 127         /* add the RD flags, because we want an answer */
 128         pkt = ldns_resolver_query(res, name, LDNS_RR_TYPE_PTR, c, flags | LDNS_RD);
 129         ldns_rdf_deep_free(name);
 130         if (pkt) {
 131                 /* extract the data we need */
 132                 names = ldns_pkt_rr_list_by_type(pkt,
 133                                 LDNS_RR_TYPE_PTR, LDNS_SECTION_ANSWER);
 134                 ldns_pkt_free(pkt);
 135         }
 136         return names;
 137 }
 138
 139 /* read a line, put it in a buffer, parse the buffer */
 140 ldns_rr_list *
 141 ldns_get_rr_list_hosts_frm_fp(FILE *fp)
 142 {
 143         return ldns_get_rr_list_hosts_frm_fp_l(fp, NULL);
 144 }
 145
 146 ldns_rr_list *
 147 ldns_get_rr_list_hosts_frm_fp_l(FILE *fp, int *line_nr)
 148 {
 149         ssize_t i, j;
 150         size_t cnt;
 151         char *line;
 152         char *word;
 153         char *addr;
 154         char *rr_str;
 155         ldns_buffer *linebuf;
 156         ldns_rr *rr;
 157         ldns_rr_list *list;
 158         ldns_rdf *tmp;
 159         bool ip6;
 160         ldns_status parse_result;
 161
 162         line = LDNS_XMALLOC(char, LDNS_MAX_LINELEN + 1);
 163         word = LDNS_XMALLOC(char, LDNS_MAX_LINELEN + 1);
 164         addr = LDNS_XMALLOC(char, LDNS_MAX_LINELEN + 1);
 165         rr_str = LDNS_XMALLOC(char, LDNS_MAX_LINELEN + 1);
 166         ip6 = false;
 167         list = ldns_rr_list_new();
 168         rr = NULL;
 169         if(!line || !word || !addr || !rr_str || !list) {
 170                 LDNS_FREE(line);
 171                 LDNS_FREE(word);
 172                 LDNS_FREE(addr);
 173                 LDNS_FREE(rr_str);
 174                 ldns_rr_list_free(list);
 175                 return NULL;
 176         }
 177
 178         for(i = ldns_fget_token_l(fp, line, "\n", LDNS_MAX_LINELEN, line_nr);
 179                         i > 0; i = ldns_fget_token_l(fp, line, "\n", LDNS_MAX_LINELEN, line_nr)) {
 180                 /* # is comment */
 181                 if (line[0] == '#') {
 182                         continue;
 183                 }
 184                 /* put it in a buffer for further processing */
 185                 linebuf = LDNS_MALLOC(ldns_buffer);
 186                 if(!linebuf) {
 187                         LDNS_FREE(line);
 188                         LDNS_FREE(word);
 189                         LDNS_FREE(addr);
 190                         LDNS_FREE(rr_str);
 191                         ldns_rr_list_deep_free(list);
 192                         return NULL;
 193                 }
 194
 195                 ldns_buffer_new_frm_data(linebuf, line, (size_t) i);
 196                 for(cnt = 0, j = ldns_bget_token(linebuf, word, LDNS_PARSE_NO_NL, LDNS_MAX_LINELEN);
 197                                 j > 0;
 198                                 j = ldns_bget_token(linebuf, word, LDNS_PARSE_NO_NL, LDNS_MAX_LINELEN), cnt++) {
 199                         if (cnt == 0) {
 200                                 /* the address */
 201                                 if ((tmp = ldns_rdf_new_frm_str(LDNS_RDF_TYPE_AAAA,
 202                                                                 word))) {
 203                                         /* ip6 */
 204                                         ldns_rdf_deep_free(tmp);
 205                                         ip6 = true;
 206                                 } else {
 207                                         if ((tmp = ldns_rdf_new_frm_str(LDNS_RDF_TYPE_A,
 208                                                                         word))) {
 209                                                 /* ip4 */
 210                                                 ldns_rdf_deep_free(tmp);
 211                                                 ip6 = false;
 212                                         } else {
 213                                                 /* kaput */
 214                                                 break;
 215                                         }
 216                                 }
 217                                 (void)strlcpy(addr, word, LDNS_MAX_LINELEN+1);
 218                         } else {
 219                                 /* Stop parsing line when a comment begins. */
 220                                 if (word[0] == '#')
 221                                         break;
 222                                 /* la al la la */
 223                                 if (ip6) {
 224                                         snprintf(rr_str, LDNS_MAX_LINELEN,
 225                                                 "%s IN AAAA %s", word, addr);
 226                                 } else {
 227                                         snprintf(rr_str, LDNS_MAX_LINELEN,
 228                                                 "%s IN A %s", word, addr);
 229                                 }
 230                                 parse_result = ldns_rr_new_frm_str(&rr, rr_str, 0, NULL, NULL);
 231                                 if (parse_result == LDNS_STATUS_OK && ldns_rr_owner(rr) && ldns_rr_rd_count(rr) > 0) {
 232                                         ldns_rr_list_push_rr(list, ldns_rr_clone(rr));
 233                                         ldns_rr_free(rr);
 234                                 }
 235                         }
 236                 }
 237                 ldns_buffer_free(linebuf);
 238         }
 239         LDNS_FREE(line);
 240         LDNS_FREE(word);
 241         LDNS_FREE(addr);
 242         LDNS_FREE(rr_str);
 243         return list;
 244 }
 245
 246 ldns_rr_list *
 247 ldns_get_rr_list_hosts_frm_file(char *filename)
 248 {
 249         ldns_rr_list *names;
 250         FILE *fp;
 251
 252         if (!filename) {
 253                 fp = fopen(LDNS_RESOLV_HOSTS, "r");
 254
 255         } else {
 256                 fp = fopen(filename, "r");
 257         }
 258         if (!fp) {
 259                 return NULL;
 260         }
 261
 262         names = ldns_get_rr_list_hosts_frm_fp(fp);
 263         fclose(fp);
 264         return names;
 265 }
 266
 267 uint16_t
 268 ldns_getaddrinfo(ldns_resolver *res, const ldns_rdf *node,
 269                 ldns_rr_class c, ldns_rr_list **ret)
 270 {
 271         ldns_rdf_type t;
 272         uint16_t names_found;
 273         ldns_resolver *r;
 274         ldns_status s;
 275
 276         t = ldns_rdf_get_type(node);
 277         names_found = 0;
 278         r = res;
 279
 280         if (res == NULL) {
 281                 /* prepare a new resolver, using /etc/resolv.conf as a guide  */
 282                 s = ldns_resolver_new_frm_file(&r, NULL);
 283                 if (s != LDNS_STATUS_OK) {
 284                         return 0;
 285                 }
 286         }
 287
 288         if (t == LDNS_RDF_TYPE_DNAME) {
 289                 /* we're asked to query for a name */
 290                 *ret = ldns_get_rr_list_addr_by_name(r, node, c, 0);
 291                 names_found = ldns_rr_list_rr_count(*ret);
 292         }
 293
 294         if (t == LDNS_RDF_TYPE_A || t == LDNS_RDF_TYPE_AAAA) {
 295                 /* an address */
 296                 *ret = ldns_get_rr_list_name_by_addr(r, node, c, 0);
 297                 names_found = ldns_rr_list_rr_count(*ret);
 298         }
 299
 300         if (res == NULL) {
 301                 ldns_resolver_deep_free(r);
 302         }
 303
 304         return names_found;
 305 }
 306
 307 bool
 308 ldns_nsec_type_check(const ldns_rr *nsec, ldns_rr_type t)
 309 {
 310         switch (ldns_rr_get_type(nsec)) {
 311         case LDNS_RR_TYPE_NSEC  : if (ldns_rr_rd_count(nsec) < 2) {
 312                                           return false;
 313                                   }
 314                                   return ldns_nsec_bitmap_covers_type(
 315                                                   ldns_rr_rdf(nsec, 1), t);
 316
 317         case LDNS_RR_TYPE_NSEC3 : if (ldns_rr_rd_count(nsec) < 6) {
 318                                           return false;
 319                                   }
 320                                   return ldns_nsec_bitmap_covers_type(
 321                                                   ldns_rr_rdf(nsec, 5), t);
 322
 323         default                 : return false;
 324         }
 325 }
 326
 327 void
 328 ldns_print_rr_rdf(FILE *fp, ldns_rr *r, int rdfnum, ...)
 329 {
 330         int16_t rdf;
 331         ldns_rdf *rd;
 332         va_list va_rdf;
 333         va_start(va_rdf, rdfnum);
 334
 335         for (rdf = (int16_t)rdfnum; rdf != -1; rdf = (int16_t)va_arg(va_rdf, int))
 336         {
 337                 rd = ldns_rr_rdf(r, rdf);
 338                 if (!rd) {
 339                         continue;
 340                 } else {
 341                         ldns_rdf_print(fp, rd);
 342                         fprintf(fp, " "); /* not sure if we want to do this */
 343                 }
 344         }
 345         va_end(va_rdf);
 346 }
 347