src/acl/external/kerberos_ldap_group/support_resolv.cc

   1 /*
   2  * Copyright (C) 1996-2021 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /*
  10  * -----------------------------------------------------------------------------
  11  *
  12  * Author: Markus Moeller (markus_moeller at compuserve.com)
  13  *
  14  * Copyright (C) 2007 Markus Moeller. All rights reserved.
  15  *
  16  *   This program is free software; you can redistribute it and/or modify
  17  *   it under the terms of the GNU General Public License as published by
  18  *   the Free Software Foundation; either version 2 of the License, or
  19  *   (at your option) any later version.
  20  *
  21  *   This program is distributed in the hope that it will be useful,
  22  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *   GNU General Public License for more details.
  25  *
  26  *   You should have received a copy of the GNU General Public License
  27  *   along with this program; if not, write to the Free Software
  28  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
  29  *
  30  * -----------------------------------------------------------------------------
  31  */
  32
  33 #include "squid.h"
  34 #include "util.h"
  35
  36 #if HAVE_LDAP
  37
  38 #include "support.h"
  39 #include <cerrno>
  40 #if HAVE_NETDB_H
  41 #include <netdb.h>
  42 #endif
  43 #if HAVE_NETINET_IN_H
  44 #include <netinet/in.h>
  45 #endif
  46 #if HAVE_RESOLV_H
  47 #include <resolv.h>
  48 #endif
  49 #if HAVE_ARPA_NAMESER_H
  50 #include <arpa/nameser.h>
  51 #endif
  52
  53 void nsError(int nserror, char *server);
  54 static int compare_hosts(struct hstruct *h1, struct hstruct *h2);
  55 static void swap(struct hstruct *a, struct hstruct *b);
  56 static void sort(struct hstruct *array, int nitems, int (*cmp) (struct hstruct *, struct hstruct *), int begin, int end);
  57 static void msort(struct hstruct *array, size_t nitems, int (*cmp) (struct hstruct *, struct hstruct *));
  58
  59 /*
  60  * See http://www.ietf.org/rfc/rfc1035.txt
  61  */
  62 /*
  63  * See http://www.ietf.org/rfc/rfc2782.txt
  64  *
  65  */
  66 void
  67 nsError(int nserror, char *service)
  68 {
  69     switch (nserror) {
  70     case HOST_NOT_FOUND:
  71         error((char *) "%s| %s: ERROR: res_search: Unknown service record: %s\n", LogTime(), PROGRAM, service);
  72         break;
  73     case NO_DATA:
  74         error((char *) "%s| %s: ERROR: res_search: No SRV record for %s\n", LogTime(), PROGRAM, service);
  75         break;
  76     case TRY_AGAIN:
  77         error((char *) "%s| %s: ERROR: res_search: No response for SRV query\n", LogTime(), PROGRAM);
  78         break;
  79     default:
  80         error((char *) "%s| %s: ERROR: res_search: Unexpected error: %s\n", LogTime(), PROGRAM, strerror(nserror));
  81     }
  82 }
  83
  84 static void
  85 swap(struct hstruct *a, struct hstruct *b)
  86 {
  87     struct hstruct c;
  88
  89     c.host = a->host;
  90     c.priority = a->priority;
  91     c.weight = a->weight;
  92     a->host = b->host;
  93     a->priority = b->priority;
  94     a->weight = b->weight;
  95     b->host = c.host;
  96     b->priority = c.priority;
  97     b->weight = c.weight;
  98 }
  99
 100 static void
 101 sort(struct hstruct *array, int nitems, int (*cmp) (struct hstruct *, struct hstruct *), int begin, int end)
 102 {
 103     if (end > begin) {
 104         int l = begin + 1;
 105         int r = end;
 106         while (l < r) {
 107             int pivot = begin;
 108             if (cmp(&array[l], &array[pivot]) <= 0) {
 109                 l += 1;
 110             } else {
 111                 r -= 1;
 112                 swap(&array[l], &array[r]);
 113             }
 114         }
 115         l -= 1;
 116         swap(&array[begin], &array[l]);
 117         sort(array, nitems, cmp, begin, l);
 118         sort(array, nitems, cmp, r, end);
 119     }
 120 }
 121
 122 static void
 123 msort(struct hstruct *array, size_t nitems, int (*cmp) (struct hstruct *, struct hstruct *))
 124 {
 125     sort(array, (int)nitems, cmp, 0, (int)(nitems - 1));
 126 }
 127
 128 static int
 129 compare_hosts(struct hstruct *host1, struct hstruct *host2)
 130 {
 131     /*
 132      *
 133      * The comparison function must return an integer less than,  equal  to,
 134      * or  greater  than  zero  if  the  first  argument is considered to be
 135      * respectively less than, equal to, or greater than the second.
 136      */
 137     if ((host1->priority < host2->priority) && (host1->priority != -1))
 138         return -1;
 139     if ((host1->priority < host2->priority) && (host1->priority == -1))
 140         return 1;
 141     if ((host1->priority > host2->priority) && (host2->priority != -1))
 142         return 1;
 143     if ((host1->priority > host2->priority) && (host2->priority == -1))
 144         return -1;
 145     if (host1->priority == host2->priority) {
 146         if (host1->weight > host2->weight)
 147             return -1;
 148         if (host1->weight < host2->weight)
 149             return 1;
 150     }
 151     return 0;
 152 }
 153
 154 size_t
 155 free_hostname_list(struct hstruct **hlist, size_t nhosts)
 156 {
 157     struct hstruct *hp = NULL;
 158     size_t i;
 159
 160     hp = *hlist;
 161     for (i = 0; i < nhosts; ++i) {
 162         xfree(hp[i].host);
 163     }
 164
 165     safe_free(hp);
 166     *hlist = hp;
 167     return 0;
 168 }
 169
 170 size_t
 171 get_hostname_list(struct hstruct **hlist, size_t nhosts, char *name)
 172 {
 173     struct addrinfo *hres = NULL, *hres_list;
 174     int rc, count;
 175     struct hstruct *hp = NULL;
 176
 177     if (!name)
 178         return (nhosts);
 179
 180     hp = *hlist;
 181     rc = getaddrinfo((const char *) name, NULL, NULL, &hres);
 182     if (rc != 0) {
 183         error((char *) "%s| %s: ERROR: Error while resolving hostname with getaddrinfo: %s\n", LogTime(), PROGRAM, gai_strerror(rc));
 184         return (nhosts);
 185     }
 186     hres_list = hres;
 187     count = 0;
 188     while (hres_list) {
 189         ++count;
 190         hres_list = hres_list->ai_next;
 191     }
 192     hres_list = hres;
 193     count = 0;
 194     while (hres_list) {
 195         /*
 196          * char host[sysconf(_SC_HOST_NAME_MAX)];
 197          */
 198         char host[1024];
 199         rc = getnameinfo(hres_list->ai_addr, hres_list->ai_addrlen, host, sizeof(host), NULL, 0, 0);
 200         if (rc != 0) {
 201             error((char *) "%s| %s: ERROR: Error while resolving ip address with getnameinfo: %s\n", LogTime(), PROGRAM, gai_strerror(rc));
 202             freeaddrinfo(hres);
 203             *hlist = hp;
 204             return (nhosts);
 205         }
 206         ++count;
 207         debug((char *) "%s| %s: DEBUG: Resolved address %d of %s to %s\n", LogTime(), PROGRAM, count, name, host);
 208
 209         hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 210         hp[nhosts].host = xstrdup(host);
 211         hp[nhosts].port = -1;
 212         hp[nhosts].priority = -1;
 213         hp[nhosts].weight = -1;
 214         ++nhosts;
 215
 216         hres_list = hres_list->ai_next;
 217     }
 218
 219     freeaddrinfo(hres);
 220     *hlist = hp;
 221     return (nhosts);
 222 }
 223
 224 size_t
 225 get_ldap_hostname_list(struct main_args *margs, struct hstruct **hlist, size_t nh, char *domain)
 226 {
 227
 228     /*
 229      * char name[sysconf(_SC_HOST_NAME_MAX)];
 230      */
 231     char name[1024];
 232     char *service = NULL;
 233     struct hstruct *hp = NULL;
 234     struct lsstruct *ls = NULL;
 235     size_t nhosts = 0;
 236     int size;
 237     int len, olen;
 238     size_t i, j, k;
 239     u_char *buffer = NULL;
 240     u_char *p;
 241
 242     ls = margs->lservs;
 243     while (ls) {
 244         debug((char *) "%s| %s: DEBUG: Ldap server loop: lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain?ls->domain:"NULL");
 245         if (ls->domain && !strcasecmp(ls->domain, domain)) {
 246             debug((char *) "%s| %s: DEBUG: Found lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain);
 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         } else if ( !ls->domain || !strcasecmp(ls->domain, "") ) {
 254             debug((char *) "%s| %s: DEBUG: Found lserver@domain %s@%s\n", LogTime(), PROGRAM, ls->lserver, ls->domain?ls->domain:"NULL");
 255             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 256             hp[nhosts].host = xstrdup(ls->lserver);
 257             hp[nhosts].port = -1;
 258             hp[nhosts].priority = -2;
 259             hp[nhosts].weight = -2;
 260             ++nhosts;
 261
 262         }
 263         ls = ls->next;
 264     }
 265     /* found ldap servers in predefined list -> exit */
 266     if (nhosts > 0)
 267         goto cleanup;
 268
 269     if (margs->ssl) {
 270         service = (char *) xmalloc(strlen("_ldaps._tcp.") + strlen(domain) + 1);
 271         strcpy(service, "_ldaps._tcp.");
 272     } else {
 273         service = (char *) xmalloc(strlen("_ldap._tcp.") + strlen(domain) + 1);
 274         strcpy(service, "_ldap._tcp.");
 275     }
 276     strcat(service, domain);
 277
 278 #ifndef PACKETSZ_MULT
 279     /*
 280      * It seems Solaris doesn't give back the real length back when res_search uses a to small buffer
 281      * Set a bigger one here
 282      */
 283 #define PACKETSZ_MULT 10
 284 #endif
 285
 286     hp = *hlist;
 287     buffer = (u_char *) xmalloc(PACKETSZ_MULT * NS_PACKETSZ);
 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         if (margs->ssl) {
 292             xfree(service);
 293             service = (char *) xmalloc(strlen("_ldap._tcp.") + strlen(domain) + 1);
 294             strcpy(service, "_ldap._tcp.");
 295             strcat(service, domain);
 296             if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, PACKETSZ_MULT * NS_PACKETSZ)) < 0) {
 297                 error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 298                 nsError(h_errno, service);
 299                 goto finalise;
 300             }
 301         } else {
 302             goto finalise;
 303         }
 304     }
 305     if (len > PACKETSZ_MULT * NS_PACKETSZ) {
 306         olen = len;
 307         buffer = (u_char *) xrealloc(buffer, (size_t)len);
 308         if ((len = res_search(service, ns_c_in, ns_t_srv, (u_char *) buffer, len)) < 0) {
 309             error((char *) "%s| %s: ERROR: Error while resolving service record %s with res_search\n", LogTime(), PROGRAM, service);
 310             nsError(h_errno, service);
 311             goto finalise;
 312         }
 313         if (len > olen) {
 314             error((char *) "%s| %s: ERROR: Reply to big: buffer: %d reply length: %d\n", LogTime(), PROGRAM, olen, len);
 315             goto finalise;
 316         }
 317     }
 318     p = buffer;
 319     p += 6 * NS_INT16SZ;    /* Header(6*16bit) = id + flags + 4*section count */
 320     if (p > buffer + len) {
 321         error((char *) "%s| %s: ERROR: Message to small: %d < header size\n", LogTime(), PROGRAM, len);
 322         goto finalise;
 323     }
 324     if ((size = dn_expand(buffer, buffer + len, p, name, sizeof(name))) < 0) {
 325         error((char *) "%s| %s: ERROR: Error while expanding query name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 326         goto finalise;
 327     }
 328     p += size;          /* Query name */
 329     p += 2 * NS_INT16SZ;    /* Query type + class (2*16bit) */
 330     if (p > buffer + len) {
 331         error((char *) "%s| %s: ERROR: Message to small: %d < header + query name,type,class \n", LogTime(), PROGRAM, len);
 332         goto finalise;
 333     }
 334     while (p < buffer + len) {
 335         int type, rdlength;
 336         if ((size = dn_expand(buffer, buffer + len, p, name, sizeof(name))) < 0) {
 337             error((char *) "%s| %s: ERROR: Error while expanding answer name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 338             goto finalise;
 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 finalise;
 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 finalise;
 350         }
 351         NS_GET16(rdlength, p);  /* RR data length (16bit) */
 352
 353         if (type == ns_t_srv) { /* SRV record */
 354             int priority, weight, port;
 355             char host[NS_MAXDNAME];
 356             if (p > buffer + len) {
 357                 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);
 358                 goto finalise;
 359             }
 360             NS_GET16(priority, p);  /* Priority (16bit) */
 361             if (p > buffer + len) {
 362                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority\n", LogTime(), PROGRAM, len);
 363                 goto finalise;
 364             }
 365             NS_GET16(weight, p);    /* Weight (16bit) */
 366             if (p > buffer + len) {
 367                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight\n", LogTime(), PROGRAM, len);
 368                 goto finalise;
 369             }
 370             NS_GET16(port, p);  /* Port (16bit) */
 371             if (p > buffer + len) {
 372                 error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight + port\n", LogTime(), PROGRAM, len);
 373                 goto finalise;
 374             }
 375             if ((size = dn_expand(buffer, buffer + len, p, host, NS_MAXDNAME)) < 0) {
 376                 error((char *) "%s| %s: ERROR: Error while expanding SRV RR name with dn_expand:  %s\n", LogTime(), PROGRAM, strerror(errno));
 377                 goto finalise;
 378             }
 379             debug((char *) "%s| %s: DEBUG: Resolved SRV %s record to %s\n", LogTime(), PROGRAM, service, host);
 380             hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nh + 1));
 381             hp[nh].host = xstrdup(host);
 382             hp[nh].port = port;
 383             hp[nh].priority = priority;
 384             hp[nh].weight = weight;
 385             ++nh;
 386             p += size;
 387         } else {
 388             p += rdlength;
 389         }
 390         if (p > buffer + len) {
 391             error((char *) "%s| %s: ERROR: Message to small: %d <  SRV RR + priority + weight + port + name\n", LogTime(), PROGRAM, len);
 392             goto finalise;
 393         }
 394     }
 395     if (p != buffer + len) {
 396 #if (SIZEOF_LONG == 8)
 397         error("%s| %s: ERROR: Inconsistence message length: %ld!=0\n", LogTime(), PROGRAM, buffer + len - p);
 398 #else
 399         error((char *) "%s| %s: ERROR: Inconsistence message length: %d!=0\n", LogTime(), PROGRAM, buffer + len - p);
 400 #endif
 401         goto finalise;
 402     }
 403
 404 finalise:
 405     nhosts = get_hostname_list(&hp, nh, domain);
 406
 407     debug("%s| %s: DEBUG: Adding %s to list\n", LogTime(), PROGRAM, domain);
 408
 409     hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 410     hp[nhosts].host = xstrdup(domain);
 411     hp[nhosts].port = -1;
 412     hp[nhosts].priority = -2;
 413     hp[nhosts].weight = -2;
 414     ++nhosts;
 415
 416 cleanup:
 417     /* Remove duplicates */
 418     for (i = 0; i < nhosts; ++i) {
 419         for (j = i + 1; j < nhosts; ++j) {
 420             if (!strcasecmp(hp[i].host, hp[j].host)) {
 421                 if (hp[i].port == hp[j].port ||
 422                         (hp[i].port == -1 && hp[j].port == 389) ||
 423                         (hp[i].port == 389 && hp[j].port == -1)) {
 424                     xfree(hp[j].host);
 425                     for (k = j + 1; k < nhosts; ++k) {
 426                         hp[k - 1].host = hp[k].host;
 427                         hp[k - 1].port = hp[k].port;
 428                         hp[k - 1].priority = hp[k].priority;
 429                         hp[k - 1].weight = hp[k].weight;
 430                     }
 431                     --j;
 432                     --nhosts;
 433                     hp = (struct hstruct *) xrealloc(hp, sizeof(struct hstruct) * (nhosts + 1));
 434                 }
 435             }
 436         }
 437     }
 438
 439     /* Sort by Priority / Weight */
 440     msort(hp, (size_t)nhosts, compare_hosts);
 441
 442     if (debug_enabled) {
 443         debug((char *) "%s| %s: DEBUG: Sorted ldap server names for domain %s:\n", LogTime(), PROGRAM, domain);
 444         for (i = 0; i < nhosts; ++i) {
 445             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);
 446         }
 447     }
 448     xfree(buffer);
 449     xfree(service);
 450     *hlist = hp;
 451     return (nhosts);
 452 }
 453 #endif
 454