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 l = begin + 1;
  99         int r = end;
 100         while (l < r) {
 101             int pivot = begin;
 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, (int)nitems, cmp, 0, (int)(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 size_t
 149 free_hostname_list(struct hstruct **hlist, size_t nhosts)
 150 {
 151     struct hstruct *hp = NULL;
 152     size_t i;
 153
 154     hp = *hlist;
 155     for (i = 0; i < nhosts; ++i) {
 156         xfree(hp[i].host);
 157     }
 158
 159     safe_free(hp);
 160     *hlist = hp;
 161     return 0;
 162 }
 163
 164 size_t
 165 get_hostname_list(struct hstruct **hlist, size_t nhosts, char *name)
 166 {
 167     struct addrinfo *hres = NULL, *hres_list;
 168     int rc, count;
 169     struct hstruct *hp = NULL;
 170
 171     if (!name)
 172         return (nhosts);
 173
 174     hp = *hlist;
 175     rc = getaddrinfo((const char *) name, NULL, NULL, &hres);
 176     if (rc != 0) {
 177         error((char *) "%s| %s: ERROR: Error while resolving hostname with getaddrinfo: %s\n", LogTime(), PROGRAM, gai_strerror(rc));
 178         return (nhosts);
 179     }
 180     hres_list = hres;
 181     count = 0;
 182     while (hres_list) {
 183         ++count;
 184         hres_list = hres_list->ai_next;
 185     }
 186     hres_list = hres;
 187     count = 0;
 188     while (hres_list) {
 189         /*
 190          * char host[sysconf(_SC_HOST_NAME_MAX)];
 191          */
 192         char host[1024];
 193         rc = getnameinfo(hres_list->ai_addr, hres_list->ai_addrlen, host, sizeof(host), NULL, 0, 0);
 194         if (rc != 0) {
 195             error((char *) "%s| %s: ERROR: Error while resolving ip address with getnameinfo: %s\n", LogTime(), PROGRAM, gai_strerror(rc));
 196             freeaddrinfo(hres);
 197             *hlist = hp;
 198             return (nhosts);
 199         }
 200         ++count;
 201         debug((char *) "%s| %s: DEBUG: Resolved address %d of %s to %s\n", LogTime(), PROGRAM, count, name, host);
 202
 203         hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 204         hp[nhosts].host = xstrdup(host);
 205         hp[nhosts].port = -1;
 206         hp[nhosts].priority = -1;
 207         hp[nhosts].weight = -1;
 208         ++nhosts;
 209
 210         hres_list = hres_list->ai_next;
 211     }
 212
 213     freeaddrinfo(hres);
 214     *hlist = hp;
 215     return (nhosts);
 216 }
 217
 218 size_t
 219 get_ldap_hostname_list(struct main_args *margs, struct hstruct **hlist, size_t nh, char *domain)
 220 {
 221
 222     /*
 223      * char name[sysconf(_SC_HOST_NAME_MAX)];
 224      */
 225     char name[1024];
 226     char *service = NULL;
 227     struct hstruct *hp = NULL;
 228     struct lsstruct *ls = NULL;
 229     size_t nhosts = 0;
 230     int size;
 231     int len, olen;
 232     size_t i, j, k;
 233     u_char *buffer = NULL;
 234     u_char *p;
 235
 236     ls = margs->lservs;
 237     while (ls) {
 238         debug((char *) "%s| %s: DEBUG: Ldap server loop: lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain?ls->domain:"NULL");
 239         if (ls->domain && !strcasecmp(ls->domain, domain)) {
 240             debug((char *) "%s| %s: DEBUG: Found lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain);
 241             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 242             hp[nhosts].host = xstrdup(ls->lserver);
 243             hp[nhosts].port = -1;
 244             hp[nhosts].priority = -2;
 245             hp[nhosts].weight = -2;
 246             ++nhosts;
 247         } else if ( !ls->domain || !strcasecmp(ls->domain, "") ) {
 248             debug((char *) "%s| %s: DEBUG: Found lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain?ls->domain:"NULL");
 249             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 250             hp[nhosts].host = xstrdup(ls->lserver);
 251             hp[nhosts].port = -1;
 252             hp[nhosts].priority = -2;
 253             hp[nhosts].weight = -2;
 254             ++nhosts;
 255
 256         }
 257         ls = ls->next;
 258     }
 259     /* found ldap servers in predefined list -> exit */
 260     if (nhosts > 0)
 261         goto cleanup;
 262
 263     if (margs->ssl) {
 264         service = (char *) xmalloc(strlen("_ldaps._tcp.") + strlen(domain) + 1);
 265         strcpy(service, "_ldaps._tcp.");
 266     } else {
 267         service = (char *) xmalloc(strlen("_ldap._tcp.") + strlen(domain) + 1);
 268         strcpy(service, "_ldap._tcp.");
 269     }
 270     strcat(service, domain);
 271
 272 #ifndef PACKETSZ_MULT
 273     /*
 274      * It seems Solaris doesn't give back the real length back when res_search uses a to small buffer
 275      * Set a bigger one here
 276      */
 277 #define PACKETSZ_MULT 10
 278 #endif
 279
 280     hp = *hlist;
 281     buffer = (u_char *) xmalloc(PACKETSZ_MULT * NS_PACKETSZ);
 282     if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, PACKETSZ_MULT * NS_PACKETSZ)) < 0) {
 283         error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 284         nsError(h_errno, service);
 285         if (margs->ssl) {
 286             xfree(service);
 287             service = (char *) xmalloc(strlen("_ldap._tcp.") + strlen(domain) + 1);
 288             strcpy(service, "_ldap._tcp.");
 289             strcat(service, domain);
 290             if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, PACKETSZ_MULT * NS_PACKETSZ)) < 0) {
 291                 error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 292                 nsError(h_errno, service);
 293                 goto finalise;
 294             }
 295         } else {
 296             goto finalise;
 297         }
 298     }
 299     if (len > PACKETSZ_MULT * NS_PACKETSZ) {
 300         olen = len;
 301         buffer = (u_char *) xrealloc(buffer, (size_t)len);
 302         if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, len)) < 0) {
 303             error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 304             nsError(h_errno, service);
 305             goto finalise;
 306         }
 307         if (len > olen) {
 308             error((char *) "%s| %s: ERROR: Reply to big: buffer: %d reply length: %d\n", LogTime(), PROGRAM, olen, len);
 309             goto finalise;
 310         }
 311     }
 312     p = buffer;
 313     p += 6 * NS_INT16SZ;        /* Header(6*16bit) = id + flags + 4*section count */
 314     if (p > buffer + len) {
 315         error((char *) "%s| %s: ERROR: Message to small: %d < header size\n", LogTime(), PROGRAM, len);
 316         goto finalise;
 317     }
 318     if ((size = dn_expand(buffer, buffer + len, p, name, sizeof(name))) < 0) {
 319         error((char *) "%s| %s: ERROR: Error while expanding query name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 320         goto finalise;
 321     }
 322     p += size;                  /* Query name */
 323     p += 2 * NS_INT16SZ;        /* Query type + class (2*16bit) */
 324     if (p > buffer + len) {
 325         error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class \n", LogTime(), PROGRAM, len);
 326         goto finalise;
 327     }
 328     while (p < buffer + len) {
 329         int type, rdlength;
 330         if ((size = dn_expand(buffer, buffer + len, p, name, sizeof(name))) < 0) {
 331             error((char *) "%s| %s: ERROR: Error while expanding answer name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 332             goto finalise;
 333         }
 334         p += size;              /* Resource Record name */
 335         if (p > buffer + len) {
 336             error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class + answer name\n", LogTime(), PROGRAM, len);
 337             goto finalise;
 338         }
 339         NS_GET16(type, p);      /* RR type (16bit) */
 340         p += NS_INT16SZ + NS_INT32SZ;   /* RR class + ttl (16bit+32bit) */
 341         if (p > buffer + len) {
 342             error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class + answer name + RR type,class,ttl\n", LogTime(), PROGRAM, len);
 343             goto finalise;
 344         }
 345         NS_GET16(rdlength, p);  /* RR data length (16bit) */
 346
 347         if (type == ns_t_srv) { /* SRV record */
 348             int priority, weight, port;
 349             char host[NS_MAXDNAME];
 350             if (p > buffer + len) {
 351                 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);
 352                 goto finalise;
 353             }
 354             NS_GET16(priority, p);      /* Priority (16bit) */
 355             if (p > buffer + len) {
 356                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority\n", LogTime(), PROGRAM, len);
 357                 goto finalise;
 358             }
 359             NS_GET16(weight, p);        /* Weight (16bit) */
 360             if (p > buffer + len) {
 361                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight\n", LogTime(), PROGRAM, len);
 362                 goto finalise;
 363             }
 364             NS_GET16(port, p);  /* Port (16bit) */
 365             if (p > buffer + len) {
 366                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight + port\n", LogTime(), PROGRAM, len);
 367                 goto finalise;
 368             }
 369             if ((size = dn_expand(buffer, buffer + len, p, host, NS_MAXDNAME)) < 0) {
 370                 error((char *) "%s| %s: ERROR: Error while expanding SRV RR name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 371                 goto finalise;
 372             }
 373             debug((char *) "%s| %s: DEBUG: Resolved SRV %s record to %s\n", LogTime(), PROGRAM, service, host);
 374             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nh + 1));
 375             hp[nh].host = xstrdup(host);
 376             hp[nh].port = port;
 377             hp[nh].priority = priority;
 378             hp[nh].weight = weight;
 379             ++nh;
 380             p += size;
 381         } else {
 382             p += rdlength;
 383         }
 384         if (p > buffer + len) {
 385             error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight + port + name\n", LogTime(), PROGRAM, len);
 386             goto finalise;
 387         }
 388     }
 389     if (p != buffer + len) {
 390 #if (SIZEOF_LONG == 8)
 391         error("%s| %s: ERROR: Inconsistence message length: %ld!=0\n", LogTime(), PROGRAM, buffer + len - p);
 392 #else
 393         error((char *) "%s| %s: ERROR: Inconsistence message length: %d!=0\n", LogTime(), PROGRAM, buffer + len - p);
 394 #endif
 395         goto finalise;
 396     }
 397
 398 finalise:
 399     nhosts = get_hostname_list(&hp, nh, domain);
 400
 401     debug("%s| %s: DEBUG: Adding %s to list\n", LogTime(), PROGRAM, domain);
 402
 403     hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 404     hp[nhosts].host = xstrdup(domain);
 405     hp[nhosts].port = -1;
 406     hp[nhosts].priority = -2;
 407     hp[nhosts].weight = -2;
 408     ++nhosts;
 409
 410 cleanup:
 411     /* Remove duplicates */
 412     for (i = 0; i < nhosts; ++i) {
 413         for (j = i + 1; j < nhosts; ++j) {
 414             if (!strcasecmp(hp[i].host, hp[j].host)) {
 415                 if (hp[i].port == hp[j].port ||
 416                         (hp[i].port == -1 && hp[j].port == 389) ||
 417                         (hp[i].port == 389 && hp[j].port == -1)) {
 418                     xfree(hp[j].host);
 419                     for (k = j + 1; k < nhosts; ++k) {
 420                         hp[k - 1].host = hp[k].host;
 421                         hp[k - 1].port = hp[k].port;
 422                         hp[k - 1].priority = hp[k].priority;
 423                         hp[k - 1].weight = hp[k].weight;
 424                     }
 425                     --j;
 426                     --nhosts;
 427                     hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 428                 }
 429             }
 430         }
 431     }
 432
 433     /* Sort by Priority / Weight */
 434     msort(hp, (size_t)nhosts, compare_hosts);
 435
 436     if (debug_enabled) {
 437         debug((char *) "%s| %s: DEBUG: Sorted ldap server names for domain %s:\n", LogTime(), PROGRAM, domain);
 438         for (i = 0; i < nhosts; ++i) {
 439             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);
 440         }
 441     }
 442     xfree(buffer);
 443     xfree(service);
 444     *hlist = hp;
 445     return (nhosts);
 446 }
 447 #endif