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
 162     if (hp)
 163         xfree(hp);
 164     hp = NULL;
 165     *hlist = hp;
 166     return 0;
 167 }
 168
 169 int
 170 get_hostname_list(struct main_args *margs, struct hstruct **hlist, int nhosts, char *name)
 171 {
 172     /*
 173      * char host[sysconf(_SC_HOST_NAME_MAX)];
 174      */
 175     char host[1024];
 176     struct addrinfo *hres = NULL, *hres_list;
 177     int rc, count;
 178     struct hstruct *hp = NULL;
 179
 180     if (!name)
 181         return (nhosts);
 182
 183     hp = *hlist;
 184     rc = getaddrinfo((const char *) name, NULL, NULL, &hres);
 185     if (rc != 0) {
 186         error((char *) "%s| %s: ERROR: Error while resolving hostname with getaddrinfo: %s\n", LogTime(), PROGRAM, gai_strerror(rc));
 187         return (nhosts);
 188     }
 189     hres_list = hres;
 190     count = 0;
 191     while (hres_list) {
 192         count++;
 193         hres_list = hres_list->ai_next;
 194     }
 195     hres_list = hres;
 196     count = 0;
 197     while (hres_list) {
 198         rc = getnameinfo(hres_list->ai_addr, hres_list->ai_addrlen, host, sizeof(host), NULL, 0, 0);
 199         if (rc != 0) {
 200             error((char *) "%s| %s: ERROR: Error while resolving ip address with getnameinfo: %s\n", LogTime(), PROGRAM, gai_strerror(rc));
 201             freeaddrinfo(hres);
 202             *hlist = hp;
 203             return (nhosts);
 204         }
 205         count++;
 206         debug((char *) "%s| %s: DEBUG: Resolved address %d of %s to %s\n", LogTime(), PROGRAM, count, name, host);
 207
 208         hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 209         hp[nhosts].host = xstrdup(host);
 210         hp[nhosts].port = -1;
 211         hp[nhosts].priority = -1;
 212         hp[nhosts].weight = -1;
 213         nhosts++;
 214
 215         hres_list = hres_list->ai_next;
 216     }
 217
 218     freeaddrinfo(hres);
 219     *hlist = hp;
 220     return (nhosts);
 221 }
 222
 223 int
 224 get_ldap_hostname_list(struct main_args *margs, struct hstruct **hlist, int nh, char *domain)
 225 {
 226
 227     /*
 228      * char name[sysconf(_SC_HOST_NAME_MAX)];
 229      */
 230     char name[1024];
 231     char host[NS_MAXDNAME];
 232     char *service = NULL;
 233     struct hstruct *hp = NULL;
 234     struct lsstruct *ls = NULL;
 235     int nhosts = 0;
 236     int size;
 237     int type, rdlength;
 238     int priority, weight, port;
 239     int len, olen;
 240     int i, j, k;
 241     u_char *buffer = NULL;
 242     u_char *p;
 243
 244     ls = margs->lservs;
 245     while (ls) {
 246         debug((char *) "%s| %s: DEBUG: Ldap server loop: lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain?ls->domain:"NULL");
 247         if (ls->domain && !strcasecmp(ls->domain, domain)) {
 248             debug((char *) "%s| %s: DEBUG: Found lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain);
 249             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 250             hp[nhosts].host = strdup(ls->lserver);
 251             hp[nhosts].port = -1;
 252             hp[nhosts].priority = -2;
 253             hp[nhosts].weight = -2;
 254             nhosts++;
 255         } else if ( !ls->domain || !strcasecmp(ls->domain, "") ) {
 256             debug((char *) "%s| %s: DEBUG: Found lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain?ls->domain:"NULL");
 257             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 258             hp[nhosts].host = strdup(ls->lserver);
 259             hp[nhosts].port = -1;
 260             hp[nhosts].priority = -2;
 261             hp[nhosts].weight = -2;
 262             nhosts++;
 263
 264         }
 265         ls = ls->next;
 266     }
 267     /* found ldap servers in predefined list -> exit */
 268     if (nhosts > 0)
 269         goto cleanup;
 270
 271     if (margs->ssl) {
 272         service = (char *) xmalloc(strlen("_ldaps._tcp.") + strlen(domain) + 1);
 273         strcpy(service, "_ldaps._tcp.");
 274     } else {
 275         service = (char *) xmalloc(strlen("_ldap._tcp.") + strlen(domain) + 1);
 276         strcpy(service, "_ldap._tcp.");
 277     }
 278     strcat(service, domain);
 279
 280 #ifndef PACKETSZ_MULT
 281     /*
 282      * It seems Solaris doesn't give back the real length back when res_search uses a to small buffer
 283      * Set a bigger one here
 284      */
 285 #define PACKETSZ_MULT 10
 286 #endif
 287
 288     hp = *hlist;
 289     buffer = (u_char *) xmalloc(PACKETSZ_MULT * NS_PACKETSZ);
 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         if (margs->ssl) {
 294             xfree(service);
 295             service = (char *) xmalloc(strlen("_ldap._tcp.") + strlen(domain) + 1);
 296             strcpy(service, "_ldap._tcp.");
 297             strcat(service, domain);
 298             if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, PACKETSZ_MULT * NS_PACKETSZ)) < 0) {
 299                 error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 300                 nsError(h_errno, service);
 301                 goto cleanup;
 302             }
 303         } else {
 304             goto cleanup;
 305         }
 306     }
 307     if (len > PACKETSZ_MULT * NS_PACKETSZ) {
 308         olen = len;
 309         buffer = (u_char *) xrealloc(buffer, len);
 310         if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, len)) < 0) {
 311             error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 312             nsError(h_errno, service);
 313             goto cleanup;
 314         }
 315         if (len > olen) {
 316             error((char *) "%s| %s: ERROR: Reply to big: buffer: %d reply length: %d\n", LogTime(), PROGRAM, olen, len);
 317             goto cleanup;
 318         }
 319     }
 320     p = buffer;
 321     p += 6 * NS_INT16SZ;        /* Header(6*16bit) = id + flags + 4*section count */
 322     if (p > buffer + len) {
 323         error((char *) "%s| %s: ERROR: Message to small: %d < header size\n", LogTime(), PROGRAM, len);
 324         goto cleanup;
 325     }
 326     if ((size = dn_expand(buffer, buffer + len, p, name, sysconf(_SC_HOST_NAME_MAX))) < 0) {
 327         error((char *) "%s| %s: ERROR: Error while expanding query name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 328         goto cleanup;
 329     }
 330     p += size;                  /* Query name */
 331     p += 2 * NS_INT16SZ;        /* Query type + class (2*16bit) */
 332     if (p > buffer + len) {
 333         error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class \n", LogTime(), PROGRAM, len);
 334         goto cleanup;
 335     }
 336     while (p < buffer + len) {
 337         if ((size = dn_expand(buffer, buffer + len, p, name, sysconf(_SC_HOST_NAME_MAX))) < 0) {
 338             error((char *) "%s| %s: ERROR: Error while expanding answer name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 339             goto cleanup;
 340         }
 341         p += size;              /* Resource Record name */
 342         if (p > buffer + len) {
 343             error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class + answer name\n", LogTime(), PROGRAM, len);
 344             goto cleanup;
 345         }
 346         NS_GET16(type, p);      /* RR type (16bit) */
 347         p += NS_INT16SZ + NS_INT32SZ;   /* RR class + ttl (16bit+32bit) */
 348         if (p > buffer + len) {
 349             error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class + answer name + RR type,class,ttl\n", LogTime(), PROGRAM, len);
 350             goto cleanup;
 351         }
 352         NS_GET16(rdlength, p);  /* RR data length (16bit) */
 353
 354         if (type == ns_t_srv) { /* SRV record */
 355             if (p > buffer + len) {
 356                 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);
 357                 goto cleanup;
 358             }
 359             NS_GET16(priority, p);      /* Priority (16bit) */
 360             if (p > buffer + len) {
 361                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority\n", LogTime(), PROGRAM, len);
 362                 goto cleanup;
 363             }
 364             NS_GET16(weight, p);        /* Weight (16bit) */
 365             if (p > buffer + len) {
 366                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight\n", LogTime(), PROGRAM, len);
 367                 goto cleanup;
 368             }
 369             NS_GET16(port, p);  /* Port (16bit) */
 370             if (p > buffer + len) {
 371                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight + port\n", LogTime(), PROGRAM, len);
 372                 goto cleanup;
 373             }
 374             if ((size = dn_expand(buffer, buffer + len, p, host, NS_MAXDNAME)) < 0) {
 375                 error((char *) "%s| %s: ERROR: Error while expanding SRV RR name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 376                 goto cleanup;
 377             }
 378             debug((char *) "%s| %s: DEBUG: Resolved SRV %s record to %s\n", LogTime(), PROGRAM, service, host);
 379             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nh + 1));
 380             hp[nh].host = xstrdup(host);
 381             hp[nh].port = port;
 382             hp[nh].priority = priority;
 383             hp[nh].weight = weight;
 384             nh++;
 385             p += size;
 386         } else {
 387             p += rdlength;
 388         }
 389         if (p > buffer + len) {
 390             error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight + port + name\n", LogTime(), PROGRAM, len);
 391             goto cleanup;
 392         }
 393     }
 394     if (p != buffer + len) {
 395 #if (SIZEOF_LONG == 8)
 396         error("%s| %s: ERROR: Inconsistence message length: %ld!=0\n", LogTime(), PROGRAM, buffer + len - p);
 397 #else
 398         error((char *) "%s| %s: ERROR: Inconsistence message length: %d!=0\n", LogTime(), PROGRAM, buffer + len - p);
 399 #endif
 400         goto cleanup;
 401     }
 402
 403 cleanup:
 404     nhosts = get_hostname_list(margs, &hp, nh, domain);
 405
 406     debug("%s| %s: DEBUG: Adding %s to list\n", LogTime(), PROGRAM, domain);
 407
 408     hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 409     hp[nhosts].host = strdup(domain);
 410     hp[nhosts].port = -1;
 411     hp[nhosts].priority = -2;
 412     hp[nhosts].weight = -2;
 413     nhosts++;
 414
 415     /* Remove duplicates */
 416     for (i = 0; i < nhosts; i++) {
 417         for (j = i + 1; j < nhosts; j++) {
 418             if (!strcasecmp(hp[i].host, hp[j].host)) {
 419                 if (hp[i].port == hp[j].port ||
 420                         (hp[i].port == -1 && hp[j].port == 389) ||
 421                         (hp[i].port == 389 && hp[j].port == -1)) {
 422                     xfree(hp[j].host);
 423                     for (k = j + 1; k < nhosts; k++) {
 424                         hp[k - 1].host = hp[k].host;
 425                         hp[k - 1].port = hp[k].port;
 426                         hp[k - 1].priority = hp[k].priority;
 427                         hp[k - 1].weight = hp[k].weight;
 428                     }
 429                     j--;
 430                     nhosts--;
 431                     hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 432                 }
 433             }
 434         }
 435     }
 436
 437     /* Sort by Priority / Weight */
 438     msort(hp, nhosts, compare_hosts);
 439
 440     if (debug_enabled) {
 441         debug((char *) "%s| %s: DEBUG: Sorted ldap server names for domain %s:\n", LogTime(), PROGRAM, domain);
 442         for (i = 0; i < nhosts; i++) {
 443             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);
 444         }
 445     }
 446     if (buffer)
 447         xfree(buffer);
 448     if (service)
 449         xfree(service);
 450     *hlist = hp;
 451     return (nhosts);
 452 }
 453 #endif