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 #if HAVE_LDAP
  29
  30 #include "support.h"
  31 #include <cerrno>
  32 #if HAVE_NETDB_H
  33 #include <netdb.h>
  34 #endif
  35 #if HAVE_NETINET_IN_H
  36 #include <netinet/in.h>
  37 #endif
  38 #if HAVE_RESOLV_H
  39 #include <resolv.h>
  40 #endif
  41 #if HAVE_ARPA_NAMESER_H
  42 #include <arpa/nameser.h>
  43 #endif
  44
  45 void nsError(int nserror, char *server);
  46 static int compare_hosts(struct hstruct *h1, struct hstruct *h2);
  47 static void swap(struct hstruct *a, struct hstruct *b);
  48 static void sort(struct hstruct *array, int nitems, int (*cmp) (struct hstruct *, struct hstruct *), int begin, int end);
  49 static void msort(struct hstruct *array, size_t nitems, int (*cmp) (struct hstruct *, struct hstruct *));
  50
  51 /*
  52  * See http://www.ietf.org/rfc/rfc1035.txt
  53  */
  54 /*
  55  * See http://www.ietf.org/rfc/rfc2782.txt
  56  *
  57  */
  58 void
  59 nsError(int nserror, char *service)
  60 {
  61     switch (nserror) {
  62     case HOST_NOT_FOUND:
  63         error((char *) "%s| %s: ERROR: res_search: Unknown service record: %s\n", LogTime(), PROGRAM, service);
  64         break;
  65     case NO_DATA:
  66         error((char *) "%s| %s: ERROR: res_search: No SRV record for %s\n", LogTime(), PROGRAM, service);
  67         break;
  68     case TRY_AGAIN:
  69         error((char *) "%s| %s: ERROR: res_search: No response for SRV query\n", LogTime(), PROGRAM);
  70         break;
  71     default:
  72         error((char *) "%s| %s: ERROR: res_search: Unexpected error: %s\n", LogTime(), PROGRAM, strerror(nserror));
  73     }
  74 }
  75
  76 static void
  77 swap(struct hstruct *a, struct hstruct *b)
  78 {
  79     struct hstruct c;
  80
  81     c.host = a->host;
  82     c.priority = a->priority;
  83     c.weight = a->weight;
  84     a->host = b->host;
  85     a->priority = b->priority;
  86     a->weight = b->weight;
  87     b->host = c.host;
  88     b->priority = c.priority;
  89     b->weight = c.weight;
  90 }
  91
  92 static void
  93 sort(struct hstruct *array, int nitems, int (*cmp) (struct hstruct *, struct hstruct *), int begin, int end)
  94 {
  95     if (end > begin) {
  96         int l = begin + 1;
  97         int r = end;
  98         while (l < r) {
  99             int pivot = begin;
 100             if (cmp(&array[l], &array[pivot]) <= 0) {
 101                 l += 1;
 102             } else {
 103                 r -= 1;
 104                 swap(&array[l], &array[r]);
 105             }
 106         }
 107         l -= 1;
 108         swap(&array[begin], &array[l]);
 109         sort(array, nitems, cmp, begin, l);
 110         sort(array, nitems, cmp, r, end);
 111     }
 112 }
 113
 114 static void
 115 msort(struct hstruct *array, size_t nitems, int (*cmp) (struct hstruct *, struct hstruct *))
 116 {
 117     sort(array, (int)nitems, cmp, 0, (int)(nitems - 1));
 118 }
 119
 120 static int
 121 compare_hosts(struct hstruct *host1, struct hstruct *host2)
 122 {
 123     /*
 124      *
 125      * The comparison function must return an integer less than,  equal  to,
 126      * or  greater  than  zero  if  the  first  argument is considered to be
 127      * respectively less than, equal to, or greater than the second.
 128      */
 129     if ((host1->priority < host2->priority) && (host1->priority != -1))
 130         return -1;
 131     if ((host1->priority < host2->priority) && (host1->priority == -1))
 132         return 1;
 133     if ((host1->priority > host2->priority) && (host2->priority != -1))
 134         return 1;
 135     if ((host1->priority > host2->priority) && (host2->priority == -1))
 136         return -1;
 137     if (host1->priority == host2->priority) {
 138         if (host1->weight > host2->weight)
 139             return -1;
 140         if (host1->weight < host2->weight)
 141             return 1;
 142     }
 143     return 0;
 144 }
 145
 146 size_t
 147 free_hostname_list(struct hstruct **hlist, size_t nhosts)
 148 {
 149     struct hstruct *hp = NULL;
 150     size_t i;
 151
 152     hp = *hlist;
 153     for (i = 0; i < nhosts; ++i) {
 154         xfree(hp[i].host);
 155     }
 156
 157     safe_free(hp);
 158     *hlist = hp;
 159     return 0;
 160 }
 161
 162 size_t
 163 get_hostname_list(struct hstruct **hlist, size_t nhosts, char *name)
 164 {
 165     struct addrinfo *hres = NULL, *hres_list;
 166     int rc, count;
 167     struct hstruct *hp = NULL;
 168
 169     if (!name)
 170         return (nhosts);
 171
 172     hp = *hlist;
 173     rc = getaddrinfo((const char *) name, NULL, NULL, &hres);
 174     if (rc != 0) {
 175         error((char *) "%s| %s: ERROR: Error while resolving hostname with getaddrinfo: %s\n", LogTime(), PROGRAM, gai_strerror(rc));
 176         return (nhosts);
 177     }
 178     hres_list = hres;
 179     count = 0;
 180     while (hres_list) {
 181         ++count;
 182         hres_list = hres_list->ai_next;
 183     }
 184     hres_list = hres;
 185     count = 0;
 186     while (hres_list) {
 187         /*
 188          * char host[sysconf(_SC_HOST_NAME_MAX)];
 189          */
 190         char host[1024];
 191         rc = getnameinfo(hres_list->ai_addr, hres_list->ai_addrlen, host, sizeof(host), NULL, 0, 0);
 192         if (rc != 0) {
 193             error((char *) "%s| %s: ERROR: Error while resolving ip address with getnameinfo: %s\n", LogTime(), PROGRAM, gai_strerror(rc));
 194             freeaddrinfo(hres);
 195             *hlist = hp;
 196             return (nhosts);
 197         }
 198         ++count;
 199         debug((char *) "%s| %s: DEBUG: Resolved address %d of %s to %s\n", LogTime(), PROGRAM, count, name, host);
 200
 201         hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 202         hp[nhosts].host = xstrdup(host);
 203         hp[nhosts].port = -1;
 204         hp[nhosts].priority = -1;
 205         hp[nhosts].weight = -1;
 206         ++nhosts;
 207
 208         hres_list = hres_list->ai_next;
 209     }
 210
 211     freeaddrinfo(hres);
 212     *hlist = hp;
 213     return (nhosts);
 214 }
 215
 216 size_t
 217 get_ldap_hostname_list(struct main_args *margs, struct hstruct **hlist, size_t nh, char *domain)
 218 {
 219
 220     /*
 221      * char name[sysconf(_SC_HOST_NAME_MAX)];
 222      */
 223     char name[1024];
 224     char *service = NULL;
 225     struct hstruct *hp = NULL;
 226     struct lsstruct *ls = NULL;
 227     size_t nhosts = 0;
 228     int size;
 229     int len, olen;
 230     size_t i, j, k;
 231     u_char *buffer = NULL;
 232     u_char *p;
 233
 234     ls = margs->lservs;
 235     while (ls) {
 236         debug((char *) "%s| %s: DEBUG: Ldap server loop: lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain?ls->domain:"NULL");
 237         if (ls->domain && !strcasecmp(ls->domain, domain)) {
 238             debug((char *) "%s| %s: DEBUG: Found lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain);
 239             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 240             hp[nhosts].host = xstrdup(ls->lserver);
 241             hp[nhosts].port = -1;
 242             hp[nhosts].priority = -2;
 243             hp[nhosts].weight = -2;
 244             ++nhosts;
 245         } else if ( !ls->domain || !strcasecmp(ls->domain, "") ) {
 246             debug((char *) "%s| %s: DEBUG: Found lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain?ls->domain:"NULL");
 247             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 248             hp[nhosts].host = xstrdup(ls->lserver);
 249             hp[nhosts].port = -1;
 250             hp[nhosts].priority = -2;
 251             hp[nhosts].weight = -2;
 252             ++nhosts;
 253
 254         }
 255         ls = ls->next;
 256     }
 257     /* found ldap servers in predefined list -> exit */
 258     if (nhosts > 0)
 259         goto cleanup;
 260
 261     if (margs->ssl) {
 262         service = (char *) xmalloc(strlen("_ldaps._tcp.") + strlen(domain) + 1);
 263         strcpy(service, "_ldaps._tcp.");
 264     } else {
 265         service = (char *) xmalloc(strlen("_ldap._tcp.") + strlen(domain) + 1);
 266         strcpy(service, "_ldap._tcp.");
 267     }
 268     strcat(service, domain);
 269
 270 #ifndef PACKETSZ_MULT
 271     /*
 272      * It seems Solaris doesn't give back the real length back when res_search uses a to small buffer
 273      * Set a bigger one here
 274      */
 275 #define PACKETSZ_MULT 10
 276 #endif
 277
 278     hp = *hlist;
 279     buffer = (u_char *) xmalloc(PACKETSZ_MULT * NS_PACKETSZ);
 280     if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, PACKETSZ_MULT * NS_PACKETSZ)) < 0) {
 281         error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 282         nsError(h_errno, service);
 283         if (margs->ssl) {
 284             xfree(service);
 285             service = (char *) xmalloc(strlen("_ldap._tcp.") + strlen(domain) + 1);
 286             strcpy(service, "_ldap._tcp.");
 287             strcat(service, domain);
 288             if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, PACKETSZ_MULT * NS_PACKETSZ)) < 0) {
 289                 error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 290                 nsError(h_errno, service);
 291                 goto finalise;
 292             }
 293         } else {
 294             goto finalise;
 295         }
 296     }
 297     if (len > PACKETSZ_MULT * NS_PACKETSZ) {
 298         olen = len;
 299         buffer = (u_char *) xrealloc(buffer, (size_t)len);
 300         if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, len)) < 0) {
 301             error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 302             nsError(h_errno, service);
 303             goto finalise;
 304         }
 305         if (len > olen) {
 306             error((char *) "%s| %s: ERROR: Reply to big: buffer: %d reply length: %d\n", LogTime(), PROGRAM, olen, len);
 307             goto finalise;
 308         }
 309     }
 310     p = buffer;
 311     p += 6 * NS_INT16SZ;        /* Header(6*16bit) = id + flags + 4*section count */
 312     if (p > buffer + len) {
 313         error((char *) "%s| %s: ERROR: Message to small: %d < header size\n", LogTime(), PROGRAM, len);
 314         goto finalise;
 315     }
 316     if ((size = dn_expand(buffer, buffer + len, p, name, sizeof(name))) < 0) {
 317         error((char *) "%s| %s: ERROR: Error while expanding query name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 318         goto finalise;
 319     }
 320     p += size;                  /* Query name */
 321     p += 2 * NS_INT16SZ;        /* Query type + class (2*16bit) */
 322     if (p > buffer + len) {
 323         error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class \n", LogTime(), PROGRAM, len);
 324         goto finalise;
 325     }
 326     while (p < buffer + len) {
 327         int type, rdlength;
 328         if ((size = dn_expand(buffer, buffer + len, p, name, sizeof(name))) < 0) {
 329             error((char *) "%s| %s: ERROR: Error while expanding answer name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 330             goto finalise;
 331         }
 332         p += size;              /* Resource Record name */
 333         if (p > buffer + len) {
 334             error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class + answer name\n", LogTime(), PROGRAM, len);
 335             goto finalise;
 336         }
 337         NS_GET16(type, p);      /* RR type (16bit) */
 338         p += NS_INT16SZ + NS_INT32SZ;   /* RR class + ttl (16bit+32bit) */
 339         if (p > buffer + len) {
 340             error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class + answer name + RR type,class,ttl\n", LogTime(), PROGRAM, len);
 341             goto finalise;
 342         }
 343         NS_GET16(rdlength, p);  /* RR data length (16bit) */
 344
 345         if (type == ns_t_srv) { /* SRV record */
 346             int priority, weight, port;
 347             char host[NS_MAXDNAME];
 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 + RR data length\n", LogTime(), PROGRAM, len);
 350                 goto finalise;
 351             }
 352             NS_GET16(priority, p);      /* Priority (16bit) */
 353             if (p > buffer + len) {
 354                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority\n", LogTime(), PROGRAM, len);
 355                 goto finalise;
 356             }
 357             NS_GET16(weight, p);        /* Weight (16bit) */
 358             if (p > buffer + len) {
 359                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight\n", LogTime(), PROGRAM, len);
 360                 goto finalise;
 361             }
 362             NS_GET16(port, p);  /* Port (16bit) */
 363             if (p > buffer + len) {
 364                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight + port\n", LogTime(), PROGRAM, len);
 365                 goto finalise;
 366             }
 367             if ((size = dn_expand(buffer, buffer + len, p, host, NS_MAXDNAME)) < 0) {
 368                 error((char *) "%s| %s: ERROR: Error while expanding SRV RR name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 369                 goto finalise;
 370             }
 371             debug((char *) "%s| %s: DEBUG: Resolved SRV %s record to %s\n", LogTime(), PROGRAM, service, host);
 372             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nh + 1));
 373             hp[nh].host = xstrdup(host);
 374             hp[nh].port = port;
 375             hp[nh].priority = priority;
 376             hp[nh].weight = weight;
 377             ++nh;
 378             p += size;
 379         } else {
 380             p += rdlength;
 381         }
 382         if (p > buffer + len) {
 383             error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight + port + name\n", LogTime(), PROGRAM, len);
 384             goto finalise;
 385         }
 386     }
 387     if (p != buffer + len) {
 388 #if (SIZEOF_LONG == 8)
 389         error("%s| %s: ERROR: Inconsistence message length: %ld!=0\n", LogTime(), PROGRAM, buffer + len - p);
 390 #else
 391         error((char *) "%s| %s: ERROR: Inconsistence message length: %d!=0\n", LogTime(), PROGRAM, buffer + len - p);
 392 #endif
 393         goto finalise;
 394     }
 395
 396 finalise:
 397     nhosts = get_hostname_list(&hp, nh, domain);
 398
 399     debug("%s| %s: DEBUG: Adding %s to list\n", LogTime(), PROGRAM, domain);
 400
 401     hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 402     hp[nhosts].host = xstrdup(domain);
 403     hp[nhosts].port = -1;
 404     hp[nhosts].priority = -2;
 405     hp[nhosts].weight = -2;
 406     ++nhosts;
 407
 408 cleanup:
 409     /* Remove duplicates */
 410     for (i = 0; i < nhosts; ++i) {
 411         for (j = i + 1; j < nhosts; ++j) {
 412             if (!strcasecmp(hp[i].host, hp[j].host)) {
 413                 if (hp[i].port == hp[j].port ||
 414                         (hp[i].port == -1 && hp[j].port == 389) ||
 415                         (hp[i].port == 389 && hp[j].port == -1)) {
 416                     xfree(hp[j].host);
 417                     for (k = j + 1; k < nhosts; ++k) {
 418                         hp[k - 1].host = hp[k].host;
 419                         hp[k - 1].port = hp[k].port;
 420                         hp[k - 1].priority = hp[k].priority;
 421                         hp[k - 1].weight = hp[k].weight;
 422                     }
 423                     --j;
 424                     --nhosts;
 425                     hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 426                 }
 427             }
 428         }
 429     }
 430
 431     /* Sort by Priority / Weight */
 432     msort(hp, (size_t)nhosts, compare_hosts);
 433
 434     if (debug_enabled) {
 435         debug((char *) "%s| %s: DEBUG: Sorted ldap server names for domain %s:\n", LogTime(), PROGRAM, domain);
 436         for (i = 0; i < nhosts; ++i) {
 437             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);
 438         }
 439     }
 440     xfree(buffer);
 441     xfree(service);
 442     *hlist = hp;
 443     return (nhosts);
 444 }
 445 #endif