helpers/external_acl/kerberos_ldap_group/support_resolv.cc

   1 /*
   2  * -----------------------------------------------------------------------------
   3  *
   4  * Author: Markus Moeller (markus_moeller at compuserve.com)
   5  *
   6  * Copyright (C) 2007 Markus Moeller. All rights reserved.
   7  *
   8  *   This program is free software; you can redistribute it and/or modify
   9  *   it under the terms of the GNU General Public License as published by
  10  *   the Free Software Foundation; either version 2 of the License, or
  11  *   (at your option) any later version.
  12  *
  13  *   This program is distributed in the hope that it will be useful,
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *   GNU General Public License for more details.
  17  *
  18  *   You should have received a copy of the GNU General Public License
  19  *   along with this program; if not, write to the Free Software
  20  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
  21  *
  22  * -----------------------------------------------------------------------------
  23  */
  24
  25 #include "config.h"
  26 #include "util.h"
  27
  28 #ifdef HAVE_LDAP
  29
  30 #include "support.h"
  31 #ifdef HAVE_ERRNO_H
  32 #include <errno.h>
  33 #endif
  34 #ifdef HAVE_NETDB_H
  35 #include <netdb.h>
  36 #endif
  37 #ifdef HAVE_NETINET_IN_H
  38 #include <netinet/in.h>
  39 #endif
  40 #ifdef HAVE_RESOLV_H
  41 #include <resolv.h>
  42 #endif
  43 #ifdef HAVE_ARPA_NAMESER_H
  44 #include <arpa/nameser.h>
  45 #endif
  46
  47 void nsError(int nserror, char *server);
  48 static int compare_hosts(struct hstruct *h1, struct hstruct *h2);
  49 static void swap(struct hstruct *a, struct hstruct *b);
  50 static void sort(struct hstruct *array, int nitems, int (*cmp) (struct hstruct *, struct hstruct *), int begin, int end);
  51 static void msort(struct hstruct *array, size_t nitems, int (*cmp) (struct hstruct *, struct hstruct *));
  52
  53 /*
  54  * See http://www.ietf.org/rfc/rfc1035.txt
  55  */
  56 /*
  57  * See http://www.ietf.org/rfc/rfc2782.txt
  58  *
  59  */
  60 void
  61 nsError(int nserror, char *service)
  62 {
  63     switch (nserror) {
  64     case HOST_NOT_FOUND:
  65         error((char *) "%s| %s: ERROR: res_search: Unknown service record: %s\n", LogTime(), PROGRAM, service);
  66         break;
  67     case NO_DATA:
  68         error((char *) "%s| %s: ERROR: res_search: No SRV record for %s\n", LogTime(), PROGRAM, service);
  69         break;
  70     case TRY_AGAIN:
  71         error((char *) "%s| %s: ERROR: res_search: No response for SRV query\n", LogTime(), PROGRAM);
  72         break;
  73     default:
  74         error((char *) "%s| %s: ERROR: res_search: Unexpected error: %s\n", LogTime(), PROGRAM, strerror(nserror));
  75     }
  76 }
  77
  78 static void
  79 swap(struct hstruct *a, struct hstruct *b)
  80 {
  81     struct hstruct c;
  82
  83     c.host = a->host;
  84     c.priority = a->priority;
  85     c.weight = a->weight;
  86     a->priority = b->priority;
  87     a->weight = b->weight;
  88     b->host = c.host;
  89     b->priority = c.priority;
  90     b->weight = c.weight;
  91 }
  92
  93 static void
  94 sort(struct hstruct *array, int nitems, int (*cmp) (struct hstruct *, struct hstruct *), int begin, int end)
  95 {
  96     if (end > begin) {
  97         int pivot = begin;
  98         int l = begin + 1;
  99         int r = end;
 100         while (l < r) {
 101             if (cmp(&array[l], &array[pivot]) <= 0) {
 102                 l += 1;
 103             } else {
 104                 r -= 1;
 105                 swap(&array[l], &array[r]);
 106             }
 107         }
 108         l -= 1;
 109         swap(&array[begin], &array[l]);
 110         sort(array, nitems, cmp, begin, l);
 111         sort(array, nitems, cmp, r, end);
 112     }
 113 }
 114
 115 static void
 116 msort(struct hstruct *array, size_t nitems, int (*cmp) (struct hstruct *, struct hstruct *))
 117 {
 118     sort(array, nitems, cmp, 0, nitems - 1);
 119 }
 120
 121 static int
 122 compare_hosts(struct hstruct *host1, struct hstruct *host2)
 123 {
 124     /*
 125      *
 126      * The comparison function must return an integer less than,  equal  to,
 127      * or  greater  than  zero  if  the  first  argument is considered to be
 128      * respectively less than, equal to, or greater than the second.
 129      */
 130     if ((host1->priority < host2->priority) && (host1->priority != -1))
 131         return -1;
 132     if ((host1->priority < host2->priority) && (host1->priority == -1))
 133         return 1;
 134     if ((host1->priority > host2->priority) && (host2->priority != -1))
 135         return 1;
 136     if ((host1->priority > host2->priority) && (host2->priority == -1))
 137         return -1;
 138     if (host1->priority == host2->priority) {
 139         if (host1->weight > host2->weight)
 140             return -1;
 141         if (host1->weight < host2->weight)
 142             return 1;
 143     }
 144     return 0;
 145 }
 146
 147 int
 148 free_hostname_list(struct hstruct **hlist, int nhosts)
 149 {
 150     struct hstruct *hp = NULL;
 151     int i;
 152
 153     hp = *hlist;
 154     for (i = 0; i < nhosts; i++) {
 155         if (hp[i].host)
 156             xfree(hp[i].host);
 157         hp[i].host = NULL;
 158     }
 159
 160
 161     if (hp)
 162         xfree(hp);
 163     hp = NULL;
 164     *hlist = hp;
 165     return 0;
 166 }
 167
 168 int
 169 get_hostname_list(struct main_args *margs, struct hstruct **hlist, int nhosts, char *name)
 170 {
 171     /*
 172      * char host[sysconf(_SC_HOST_NAME_MAX)];
 173      */
 174     char host[1024];
 175     struct addrinfo *hres = NULL, *hres_list;
 176     int rc, count;
 177     struct hstruct *hp = NULL;
 178
 179     if (!name)
 180         return (nhosts);
 181
 182     hp = *hlist;
 183     rc = getaddrinfo((const char *) name, NULL, NULL, &hres);
 184     if (rc != 0) {
 185         error((char *) "%s| %s: ERROR: Error while resolving hostname with getaddrinfo: %s\n", LogTime(), PROGRAM, gai_strerror(rc));
 186         return (nhosts);
 187     }
 188     hres_list = hres;
 189     count = 0;
 190     while (hres_list) {
 191         count++;
 192         hres_list = hres_list->ai_next;
 193     }
 194     hres_list = hres;
 195     count = 0;
 196     while (hres_list) {
 197         rc = getnameinfo(hres_list->ai_addr, hres_list->ai_addrlen, host, sizeof(host), NULL, 0, 0);
 198         if (rc != 0) {
 199             error((char *) "%s| %s: ERROR: Error while resolving ip address with getnameinfo: %s\n", LogTime(), PROGRAM, gai_strerror(rc));
 200             freeaddrinfo(hres);
 201             *hlist = hp;
 202             return (nhosts);
 203         }
 204         count++;
 205         debug((char *) "%s| %s: DEBUG: Resolved address %d of %s to %s\n", LogTime(), PROGRAM, count, name, host);
 206
 207         hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 208         hp[nhosts].host = xstrdup(host);
 209         hp[nhosts].port = -1;
 210         hp[nhosts].priority = -1;
 211         hp[nhosts].weight = -1;
 212         nhosts++;
 213
 214         hres_list = hres_list->ai_next;
 215     }
 216
 217     freeaddrinfo(hres);
 218     *hlist = hp;
 219     return (nhosts);
 220 }
 221
 222 int
 223 get_ldap_hostname_list(struct main_args *margs, struct hstruct **hlist, int nh, char *domain)
 224 {
 225
 226     /*
 227      * char name[sysconf(_SC_HOST_NAME_MAX)];
 228      */
 229     char name[1024];
 230     char host[NS_MAXDNAME];
 231     char *service;
 232     struct hstruct *hp = NULL;
 233     int nhosts = 0;
 234     int size;
 235     int type, rdlength;
 236     int priority, weight, port;
 237     int len, olen;
 238     int i, j, k;
 239     u_char *buffer;
 240     u_char *p;
 241
 242     if (margs->ssl) {
 243         service = (char *) xmalloc(strlen("_ldaps._tcp.") + strlen(domain) + 1);
 244         strcpy(service, "_ldaps._tcp.");
 245     } else {
 246         service = (char *) xmalloc(strlen("_ldap._tcp.") + strlen(domain) + 1);
 247         strcpy(service, "_ldap._tcp.");
 248     }
 249     strcat(service, domain);
 250
 251 #ifndef PACKETSZ_MULT
 252     /*
 253      * It seems Solaris doesn't give back the real length back when res_search uses a to small buffer
 254      * Set a bigger one here
 255      */
 256 #define PACKETSZ_MULT 10
 257 #endif
 258
 259     hp = *hlist;
 260     buffer = (u_char *) xmalloc(PACKETSZ_MULT * NS_PACKETSZ);
 261     if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, PACKETSZ_MULT * NS_PACKETSZ)) < 0) {
 262         error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 263         nsError(h_errno, service);
 264         if (margs->ssl) {
 265             xfree(service);
 266             service = (char *) xmalloc(strlen("_ldap._tcp.") + strlen(domain) + 1);
 267             strcpy(service, "_ldap._tcp.");
 268             strcat(service, domain);
 269             if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, PACKETSZ_MULT * NS_PACKETSZ)) < 0) {
 270                 error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 271                 nsError(h_errno, service);
 272                 goto cleanup;
 273             }
 274         } else {
 275             goto cleanup;
 276         }
 277     }
 278     if (len > PACKETSZ_MULT * NS_PACKETSZ) {
 279         olen = len;
 280         buffer = (u_char *) xrealloc(buffer, len);
 281         if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, len)) < 0) {
 282             error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 283             nsError(h_errno, service);
 284             goto cleanup;
 285         }
 286         if (len > olen) {
 287             error((char *) "%s| %s: ERROR: Reply to big: buffer: %d reply length: %d\n", LogTime(), PROGRAM, olen, len);
 288             goto cleanup;
 289         }
 290     }
 291     p = buffer;
 292     p += 6 * NS_INT16SZ;        /* Header(6*16bit) = id + flags + 4*section count */
 293     if (p > buffer + len) {
 294         error((char *) "%s| %s: ERROR: Message to small: %d < header size\n", LogTime(), PROGRAM, len);
 295         goto cleanup;
 296     }
 297     if ((size = dn_expand(buffer, buffer + len, p, name, sysconf(_SC_HOST_NAME_MAX))) < 0) {
 298         error((char *) "%s| %s: ERROR: Error while expanding query name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 299         goto cleanup;
 300     }
 301     p += size;                  /* Query name */
 302     p += 2 * NS_INT16SZ;        /* Query type + class (2*16bit) */
 303     if (p > buffer + len) {
 304         error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class \n", LogTime(), PROGRAM, len);
 305         goto cleanup;
 306     }
 307     while (p < buffer + len) {
 308         if ((size = dn_expand(buffer, buffer + len, p, name, sysconf(_SC_HOST_NAME_MAX))) < 0) {
 309             error((char *) "%s| %s: ERROR: Error while expanding answer name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 310             goto cleanup;
 311         }
 312         p += size;              /* Resource Record name */
 313         if (p > buffer + len) {
 314             error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class + answer name\n", LogTime(), PROGRAM, len);
 315             goto cleanup;
 316         }
 317         NS_GET16(type, p);      /* RR type (16bit) */
 318         p += NS_INT16SZ + NS_INT32SZ;   /* RR class + ttl (16bit+32bit) */
 319         if (p > buffer + len) {
 320             error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class + answer name + RR type,class,ttl\n", LogTime(), PROGRAM, len);
 321             goto cleanup;
 322         }
 323         NS_GET16(rdlength, p);  /* RR data length (16bit) */
 324
 325         if (type == ns_t_srv) { /* SRV record */
 326             if (p > buffer + len) {
 327                 error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class + answer name + RR type,class,ttl + RR data length\n", LogTime(), PROGRAM, len);
 328                 goto cleanup;
 329             }
 330             NS_GET16(priority, p);      /* Priority (16bit) */
 331             if (p > buffer + len) {
 332                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority\n", LogTime(), PROGRAM, len);
 333                 goto cleanup;
 334             }
 335             NS_GET16(weight, p);        /* Weight (16bit) */
 336             if (p > buffer + len) {
 337                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight\n", LogTime(), PROGRAM, len);
 338                 goto cleanup;
 339             }
 340             NS_GET16(port, p);  /* Port (16bit) */
 341             if (p > buffer + len) {
 342                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight + port\n", LogTime(), PROGRAM, len);
 343                 goto cleanup;
 344             }
 345             if ((size = dn_expand(buffer, buffer + len, p, host, NS_MAXDNAME)) < 0) {
 346                 error((char *) "%s| %s: ERROR: Error while expanding SRV RR name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 347                 goto cleanup;
 348             }
 349             debug((char *) "%s| %s: DEBUG: Resolved SRV %s record to %s\n", LogTime(), PROGRAM, service, host);
 350             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nh + 1));
 351             hp[nh].host = xstrdup(host);
 352             hp[nh].port = port;
 353             hp[nh].priority = priority;
 354             hp[nh].weight = weight;
 355             nh++;
 356             p += size;
 357         } else {
 358             p += rdlength;
 359         }
 360         if (p > buffer + len) {
 361             error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight + port + name\n", LogTime(), PROGRAM, len);
 362             goto cleanup;
 363         }
 364     }
 365     if (p != buffer + len) {
 366 #if (SIZEOF_LONG == 8)
 367         error("%s| %s: ERROR: Inconsistence message length: %ld!=0\n", LogTime(), PROGRAM, buffer + len - p);
 368 #else
 369         error((char *) "%s| %s: ERROR: Inconsistence message length: %d!=0\n", LogTime(), PROGRAM, buffer + len - p);
 370 #endif
 371         goto cleanup;
 372     }
 373     nhosts = get_hostname_list(margs, &hp, nh, domain);
 374
 375     /* Remove duplicates */
 376     for (i = 0; i < nhosts; i++) {
 377         for (j = i + 1; j < nhosts; j++) {
 378             if (!strcasecmp(hp[i].host, hp[j].host)) {
 379                 if (hp[i].port == hp[j].port ||
 380                         (hp[i].port == -1 && hp[j].port == 389) ||
 381                         (hp[i].port == 389 && hp[j].port == -1)) {
 382                     xfree(hp[j].host);
 383                     for (k = j + 1; k < nhosts; k++) {
 384                         hp[k - 1].host = hp[k].host;
 385                         hp[k - 1].port = hp[k].port;
 386                         hp[k - 1].priority = hp[k].priority;
 387                         hp[k - 1].weight = hp[k].weight;
 388                     }
 389                     j--;
 390                     nhosts--;
 391                     hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 392                 }
 393             }
 394         }
 395     }
 396
 397     /* Sort by Priority / Weight */
 398     msort(hp, nhosts, compare_hosts);
 399
 400     if (debug_enabled) {
 401         debug((char *) "%s| %s: DEBUG: Sorted ldap server names for domain %s:\n", LogTime(), PROGRAM, domain);
 402         for (i = 0; i < nhosts; i++) {
 403             debug((char *) "%s| %s: DEBUG: Host: %s Port: %d Priority: %d Weight: %d\n", LogTime(), PROGRAM, hp[i].host, hp[i].port, hp[i].priority, hp[i].weight);
 404         }
 405     }
 406     if (buffer)
 407         xfree(buffer);
 408     if (service)
 409         xfree(service);
 410     *hlist = hp;
 411     return (nhosts);
 412
 413 cleanup:
 414     if (buffer)
 415         xfree(buffer);
 416     if (service)
 417         xfree(service);
 418     *hlist = hp;
 419     return (nhosts);
 420 }
 421 #endif