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 "squid.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->host = b->host;
  87     a->priority = b->priority;
  88     a->weight = b->weight;
  89     b->host = c.host;
  90     b->priority = c.priority;
  91     b->weight = c.weight;
  92 }
  93
  94 static void
  95 sort(struct hstruct *array, int nitems, int (*cmp) (struct hstruct *, struct hstruct *), int begin, int end)
  96 {
  97     if (end > begin) {
  98         int pivot = begin;
  99         int l = begin + 1;
 100         int r = end;
 101         while (l < r) {
 102             if (cmp(&array[l], &array[pivot]) <= 0) {
 103                 l += 1;
 104             } else {
 105                 r -= 1;
 106                 swap(&array[l], &array[r]);
 107             }
 108         }
 109         l -= 1;
 110         swap(&array[begin], &array[l]);
 111         sort(array, nitems, cmp, begin, l);
 112         sort(array, nitems, cmp, r, end);
 113     }
 114 }
 115
 116 static void
 117 msort(struct hstruct *array, size_t nitems, int (*cmp) (struct hstruct *, struct hstruct *))
 118 {
 119     sort(array, nitems, cmp, 0, nitems - 1);
 120 }
 121
 122 static int
 123 compare_hosts(struct hstruct *host1, struct hstruct *host2)
 124 {
 125     /*
 126      *
 127      * The comparison function must return an integer less than,  equal  to,
 128      * or  greater  than  zero  if  the  first  argument is considered to be
 129      * respectively less than, equal to, or greater than the second.
 130      */
 131     if ((host1->priority < host2->priority) && (host1->priority != -1))
 132         return -1;
 133     if ((host1->priority < host2->priority) && (host1->priority == -1))
 134         return 1;
 135     if ((host1->priority > host2->priority) && (host2->priority != -1))
 136         return 1;
 137     if ((host1->priority > host2->priority) && (host2->priority == -1))
 138         return -1;
 139     if (host1->priority == host2->priority) {
 140         if (host1->weight > host2->weight)
 141             return -1;
 142         if (host1->weight < host2->weight)
 143             return 1;
 144     }
 145     return 0;
 146 }
 147
 148 int
 149 free_hostname_list(struct hstruct **hlist, int nhosts)
 150 {
 151     struct hstruct *hp = NULL;
 152     int i;
 153
 154     hp = *hlist;
 155     for (i = 0; i < nhosts; ++i) {
 156         if (hp[i].host)
 157             xfree(hp[i].host);
 158         hp[i].host = NULL;
 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 = NULL;
 232     struct hstruct *hp = NULL;
 233     struct lsstruct *ls = NULL;
 234     int nhosts = 0;
 235     int size;
 236     int type, rdlength;
 237     int priority, weight, port;
 238     int len, olen;
 239     int i, j, k;
 240     u_char *buffer = NULL;
 241     u_char *p;
 242
 243     ls = margs->lservs;
 244     while (ls) {
 245         debug((char *) "%s| %s: DEBUG: Ldap server loop: lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain?ls->domain:"NULL");
 246         if (ls->domain && !strcasecmp(ls->domain, domain)) {
 247             debug((char *) "%s| %s: DEBUG: Found lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain);
 248             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 249             hp[nhosts].host = strdup(ls->lserver);
 250             hp[nhosts].port = -1;
 251             hp[nhosts].priority = -2;
 252             hp[nhosts].weight = -2;
 253             ++nhosts;
 254         } else if ( !ls->domain || !strcasecmp(ls->domain, "") ) {
 255             debug((char *) "%s| %s: DEBUG: Found lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain?ls->domain:"NULL");
 256             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 257             hp[nhosts].host = strdup(ls->lserver);
 258             hp[nhosts].port = -1;
 259             hp[nhosts].priority = -2;
 260             hp[nhosts].weight = -2;
 261             ++nhosts;
 262
 263         }
 264         ls = ls->next;
 265     }
 266     /* found ldap servers in predefined list -> exit */
 267     if (nhosts > 0)
 268         goto cleanup;
 269
 270     if (margs->ssl) {
 271         service = (char *) xmalloc(strlen("_ldaps._tcp.") + strlen(domain) + 1);
 272         strcpy(service, "_ldaps._tcp.");
 273     } else {
 274         service = (char *) xmalloc(strlen("_ldap._tcp.") + strlen(domain) + 1);
 275         strcpy(service, "_ldap._tcp.");
 276     }
 277     strcat(service, domain);
 278
 279 #ifndef PACKETSZ_MULT
 280     /*
 281      * It seems Solaris doesn't give back the real length back when res_search uses a to small buffer
 282      * Set a bigger one here
 283      */
 284 #define PACKETSZ_MULT 10
 285 #endif
 286
 287     hp = *hlist;
 288     buffer = (u_char *) xmalloc(PACKETSZ_MULT * NS_PACKETSZ);
 289     if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, PACKETSZ_MULT * NS_PACKETSZ)) < 0) {
 290         error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 291         nsError(h_errno, service);
 292         if (margs->ssl) {
 293             xfree(service);
 294             service = (char *) xmalloc(strlen("_ldap._tcp.") + strlen(domain) + 1);
 295             strcpy(service, "_ldap._tcp.");
 296             strcat(service, domain);
 297             if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, PACKETSZ_MULT * NS_PACKETSZ)) < 0) {
 298                 error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 299                 nsError(h_errno, service);
 300                 goto cleanup;
 301             }
 302         } else {
 303             goto cleanup;
 304         }
 305     }
 306     if (len > PACKETSZ_MULT * NS_PACKETSZ) {
 307         olen = len;
 308         buffer = (u_char *) xrealloc(buffer, len);
 309         if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, len)) < 0) {
 310             error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 311             nsError(h_errno, service);
 312             goto cleanup;
 313         }
 314         if (len > olen) {
 315             error((char *) "%s| %s: ERROR: Reply to big: buffer: %d reply length: %d\n", LogTime(), PROGRAM, olen, len);
 316             goto cleanup;
 317         }
 318     }
 319     p = buffer;
 320     p += 6 * NS_INT16SZ;        /* Header(6*16bit) = id + flags + 4*section count */
 321     if (p > buffer + len) {
 322         error((char *) "%s| %s: ERROR: Message to small: %d < header size\n", LogTime(), PROGRAM, len);
 323         goto cleanup;
 324     }
 325     if ((size = dn_expand(buffer, buffer + len, p, name, sysconf(_SC_HOST_NAME_MAX))) < 0) {
 326         error((char *) "%s| %s: ERROR: Error while expanding query name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 327         goto cleanup;
 328     }
 329     p += size;                  /* Query name */
 330     p += 2 * NS_INT16SZ;        /* Query type + class (2*16bit) */
 331     if (p > buffer + len) {
 332         error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class \n", LogTime(), PROGRAM, len);
 333         goto cleanup;
 334     }
 335     while (p < buffer + len) {
 336         if ((size = dn_expand(buffer, buffer + len, p, name, sysconf(_SC_HOST_NAME_MAX))) < 0) {
 337             error((char *) "%s| %s: ERROR: Error while expanding answer name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 338             goto cleanup;
 339         }
 340         p += size;              /* Resource Record name */
 341         if (p > buffer + len) {
 342             error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class + answer name\n", LogTime(), PROGRAM, len);
 343             goto cleanup;
 344         }
 345         NS_GET16(type, p);      /* RR type (16bit) */
 346         p += NS_INT16SZ + NS_INT32SZ;   /* RR class + ttl (16bit+32bit) */
 347         if (p > buffer + len) {
 348             error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class + answer name + RR type,class,ttl\n", LogTime(), PROGRAM, len);
 349             goto cleanup;
 350         }
 351         NS_GET16(rdlength, p);  /* RR data length (16bit) */
 352
 353         if (type == ns_t_srv) { /* SRV record */
 354             if (p > buffer + len) {
 355                 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);
 356                 goto cleanup;
 357             }
 358             NS_GET16(priority, p);      /* Priority (16bit) */
 359             if (p > buffer + len) {
 360                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority\n", LogTime(), PROGRAM, len);
 361                 goto cleanup;
 362             }
 363             NS_GET16(weight, p);        /* Weight (16bit) */
 364             if (p > buffer + len) {
 365                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight\n", LogTime(), PROGRAM, len);
 366                 goto cleanup;
 367             }
 368             NS_GET16(port, p);  /* Port (16bit) */
 369             if (p > buffer + len) {
 370                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight + port\n", LogTime(), PROGRAM, len);
 371                 goto cleanup;
 372             }
 373             if ((size = dn_expand(buffer, buffer + len, p, host, NS_MAXDNAME)) < 0) {
 374                 error((char *) "%s| %s: ERROR: Error while expanding SRV RR name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 375                 goto cleanup;
 376             }
 377             debug((char *) "%s| %s: DEBUG: Resolved SRV %s record to %s\n", LogTime(), PROGRAM, service, host);
 378             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nh + 1));
 379             hp[nh].host = xstrdup(host);
 380             hp[nh].port = port;
 381             hp[nh].priority = priority;
 382             hp[nh].weight = weight;
 383             ++nh;
 384             p += size;
 385         } else {
 386             p += rdlength;
 387         }
 388         if (p > buffer + len) {
 389             error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight + port + name\n", LogTime(), PROGRAM, len);
 390             goto cleanup;
 391         }
 392     }
 393     if (p != buffer + len) {
 394 #if (SIZEOF_LONG == 8)
 395         error("%s| %s: ERROR: Inconsistence message length: %ld!=0\n", LogTime(), PROGRAM, buffer + len - p);
 396 #else
 397         error((char *) "%s| %s: ERROR: Inconsistence message length: %d!=0\n", LogTime(), PROGRAM, buffer + len - p);
 398 #endif
 399         goto cleanup;
 400     }
 401
 402 cleanup:
 403     nhosts = get_hostname_list(margs, &hp, nh, domain);
 404
 405     debug("%s| %s: DEBUG: Adding %s to list\n", LogTime(), PROGRAM, domain);
 406
 407     hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 408     hp[nhosts].host = strdup(domain);
 409     hp[nhosts].port = -1;
 410     hp[nhosts].priority = -2;
 411     hp[nhosts].weight = -2;
 412     ++nhosts;
 413
 414     /* Remove duplicates */
 415     for (i = 0; i < nhosts; ++i) {
 416         for (j = i + 1; j < nhosts; ++j) {
 417             if (!strcasecmp(hp[i].host, hp[j].host)) {
 418                 if (hp[i].port == hp[j].port ||
 419                         (hp[i].port == -1 && hp[j].port == 389) ||
 420                         (hp[i].port == 389 && hp[j].port == -1)) {
 421                     xfree(hp[j].host);
 422                     for (k = j + 1; k < nhosts; ++k) {
 423                         hp[k - 1].host = hp[k].host;
 424                         hp[k - 1].port = hp[k].port;
 425                         hp[k - 1].priority = hp[k].priority;
 426                         hp[k - 1].weight = hp[k].weight;
 427                     }
 428                     --j;
 429                     --nhosts;
 430                     hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 431                 }
 432             }
 433         }
 434     }
 435
 436     /* Sort by Priority / Weight */
 437     msort(hp, nhosts, compare_hosts);
 438
 439     if (debug_enabled) {
 440         debug((char *) "%s| %s: DEBUG: Sorted ldap server names for domain %s:\n", LogTime(), PROGRAM, domain);
 441         for (i = 0; i < nhosts; ++i) {
 442             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);
 443         }
 444     }
 445     if (buffer)
 446         xfree(buffer);
 447     if (service)
 448         xfree(service);
 449     *hlist = hp;
 450     return (nhosts);
 451 }
 452 #endif