src/acl/Ip.cc

   1 /*
   2  * $Id$
   3  *
   4  * DEBUG: section 28    Access Control
   5  * AUTHOR: Duane Wessels
   6  *
   7  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   8  * ----------------------------------------------------------
   9  *
  10  *  Squid is the result of efforts by numerous individuals from
  11  *  the Internet community; see the CONTRIBUTORS file for full
  12  *  details.   Many organizations have provided support for Squid's
  13  *  development; see the SPONSORS file for full details.  Squid is
  14  *  Copyrighted (C) 2001 by the Regents of the University of
  15  *  California; see the COPYRIGHT file for full details.  Squid
  16  *  incorporates software developed and/or copyrighted by other
  17  *  sources; see the CREDITS file for full details.
  18  *
  19  *  This program is free software; you can redistribute it and/or modify
  20  *  it under the terms of the GNU General Public License as published by
  21  *  the Free Software Foundation; either version 2 of the License, or
  22  *  (at your option) any later version.
  23  *
  24  *  This program is distributed in the hope that it will be useful,
  25  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  *  GNU General Public License for more details.
  28  *
  29  *  You should have received a copy of the GNU General Public License
  30  *  along with this program; if not, write to the Free Software
  31  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  32  *
  33  * Copyright (c) 2003, Robert Collins <robertc@squid-cache.org>
  34  */
  35
  36 #include "squid.h"
  37 #include "acl/Ip.h"
  38 #include "acl/Checklist.h"
  39 #include "MemBuf.h"
  40 #include "wordlist.h"
  41
  42 void *
  43 ACLIP::operator new (size_t byteCount)
  44 {
  45     fatal ("ACLIP::operator new: unused");
  46     return (void *)1;
  47 }
  48
  49 void
  50 ACLIP::operator delete (void *address)
  51 {
  52     fatal ("ACLIP::operator delete: unused");
  53 }
  54
  55 /**
  56  * Writes an IP ACL data into a buffer, then copies the buffer into the wordlist given
  57  *
  58  \param ip      ACL data structure to display
  59  \param state   wordlist structure which is being generated
  60  */
  61 void
  62 ACLIP::DumpIpListWalkee(acl_ip_data * const & ip, void *state)
  63 {
  64     char tmpbuf[ ((MAX_IPSTRLEN*2)+6) ]; // space for 2 IPs and a CIDR mask(3) and seperators(3).
  65     MemBuf mb;
  66     wordlist **W = static_cast<wordlist **>(state);
  67     tmpbuf[0] = '\0';
  68
  69     mb.init();
  70     assert(mb.max_capacity > 0 && 1==1 );
  71
  72     ip->toStr(tmpbuf, sizeof(tmpbuf) );
  73     assert(mb.max_capacity > 0 && 2==2 );
  74     mb.append(tmpbuf, strlen(tmpbuf) );
  75     assert(mb.max_capacity > 0 && 3==3);
  76     wordlistAdd(W, mb.buf);
  77     mb.clean();
  78 }
  79
  80 /**
  81  * print/format an acl_ip_data structure for debugging output.
  82  *
  83  \param buf     string buffer to write to
  84  \param len     size of the buffer available
  85  */
  86 void
  87 acl_ip_data::toStr(char *buf, int len) const
  88 {
  89     char *b1 = buf;
  90     char *b2 = NULL;
  91     char *b3 = NULL;
  92     int rlen = 0;
  93
  94     addr1.NtoA(b1, len - rlen );
  95     rlen = strlen(buf);
  96     b2 = buf + rlen;
  97
  98     if (!addr2.IsAnyAddr()) {
  99         b2[0] = '-';
 100         rlen++;
 101         addr2.NtoA(&(b2[1]), len - rlen );
 102         rlen = strlen(buf);
 103     } else
 104         b2[0] = '\0';
 105
 106     b3 = buf + rlen;
 107
 108     if (!mask.IsNoAddr()) {
 109         b3[0] = '/';
 110         rlen++;
 111 #if USE_IPV6
 112         snprintf(&(b3[1]), (len-rlen), "%u", mask.GetCIDR() - (addr1.IsIPv4()?96:0) );
 113 #else
 114         snprintf(&(b3[1]), (len-rlen), "%u", mask.GetCIDR() );
 115 #endif
 116     } else
 117         b3[0] = '\0';
 118 }
 119
 120 /*
 121  * aclIpAddrNetworkCompare - The guts of the comparison for IP ACLs
 122  * matching checks.  The first argument (p) is a "host" address,
 123  * i.e.  the IP address of a cache client.  The second argument (q)
 124  * is an entry in some address-based access control element.  This
 125  * function is called via ACLIP::match() and the splay library.
 126  */
 127 int
 128 aclIpAddrNetworkCompare(acl_ip_data * const &p, acl_ip_data * const &q)
 129 {
 130     IpAddress A = p->addr1;
 131
 132     /* apply netmask */
 133     A.ApplyMask(q->mask);
 134
 135     debugs(28,9, "aclIpAddrNetworkCompare: compare: " << p->addr1 << "/" << q->mask << " (" << A << ")  vs " <<
 136            q->addr1 << "-" << q->addr2 << "/" << q->mask);
 137
 138     if (q->addr2.IsAnyAddr()) {       /* single address check */
 139
 140         return A.matchIPAddr( q->addr1 );
 141
 142     } else {                   /* range address check */
 143
 144         if ( (A >= q->addr1) && (A <= q->addr2) )
 145             return 0; /* valid. inside range. */
 146         else
 147             return A.matchIPAddr( q->addr1 ); /* outside of range, 'less than' */
 148     }
 149 }
 150
 151
 152 /*
 153  * acl_ip_data::NetworkCompare - Compare two acl_ip_data entries.  Strictly
 154  * used by the splay insertion routine.  It emits a warning if it
 155  * detects a "collision" or overlap that would confuse the splay
 156  * sorting algorithm.  Much like aclDomainCompare.
 157  * The first argument (p) is a "host" address, i.e. the IP address of a cache client.
 158  * The second argument (b) is a "network" address that might have a subnet and/or range.
 159  * We mask the host address bits with the network subnet mask.
 160  */
 161 int
 162 acl_ip_data::NetworkCompare(acl_ip_data * const & a, acl_ip_data * const &b)
 163 {
 164     int ret;
 165     bool bina = true;
 166     ret = aclIpAddrNetworkCompare(b, a);
 167
 168     if (ret != 0) {
 169         bina = false;
 170         ret = aclIpAddrNetworkCompare(a, b);
 171     }
 172
 173     if (ret == 0) {
 174         char buf_n1[3*(MAX_IPSTRLEN+1)];
 175         char buf_n2[3*(MAX_IPSTRLEN+1)];
 176         if (bina) {
 177             b->toStr(buf_n1, 3*(MAX_IPSTRLEN+1));
 178             a->toStr(buf_n2, 3*(MAX_IPSTRLEN+1));
 179         } else {
 180             a->toStr(buf_n1, 3*(MAX_IPSTRLEN+1));
 181             b->toStr(buf_n2, 3*(MAX_IPSTRLEN+1));
 182         }
 183         debugs(28, 0, "WARNING: (" << (bina?'B':'A') << ") '" << buf_n1 << "' is a subnetwork of (" << (bina?'A':'B') << ") '" << buf_n2 << "'");
 184         debugs(28, 0, "WARNING: because of this '" << (bina?buf_n2:buf_n1) << "' is ignored to keep splay tree searching predictable");
 185         debugs(28, 0, "WARNING: You should probably remove '" << buf_n1 << "' from the ACL named '" << AclMatchedName << "'");
 186     }
 187
 188     return ret;
 189 }
 190
 191 /**
 192  * Decode an ascii representation (asc) of a IP netmask address or CIDR,
 193  * and place resulting information in mask.
 194  * This function should NOT be called if 'asc' is a hostname!
 195  */
 196 bool
 197 acl_ip_data::DecodeMask(const char *asc, IpAddress &mask, int ctype)
 198 {
 199     char junk;
 200     int a1 = 0;
 201
 202     /* default is a mask that doesn't change any IP */
 203     mask.SetNoAddr();
 204
 205     if (!asc || !*asc) {
 206         return true;
 207     }
 208
 209     /* An int mask 128, 32 */
 210     if ((sscanf(asc, "%d%c", &a1, &junk)==1) &&
 211             (a1 <= 128) && (a1  >= 0)
 212        ) {
 213         return mask.ApplyMask(a1, ctype);
 214     }
 215
 216     /* dotted notation */
 217     /* assignment returns true if asc contained an IP address as text */
 218     if ((mask = asc)) {
 219         /* HACK: IPv4 netmasks don't cleanly map to IPv6 masks. */
 220         debugs(28, DBG_CRITICAL, "WARNING: Netmasks are deprecated. Please use CIDR masks instead.");
 221         if (mask.IsIPv4()) {
 222             /* locate what CIDR mask was _probably_ meant to be in its native protocol format. */
 223             /* this will completely crap out with a security fail-open if the admin is playing mask tricks */
 224             /* however, thats their fault, and we do warn. see bug 2601 for the effects if we don't do this. */
 225             unsigned int m = mask.GetCIDR();
 226 #if USE_IPV6
 227             debugs(28, DBG_CRITICAL, "WARNING: IPv4 netmasks are particularly nasty when used to compare IPv6 to IPv4 ranges.");
 228 #endif
 229             debugs(28, DBG_CRITICAL, "WARNING: For now we will assume you meant to write /" << m);
 230             /* reset the mask completely, and crop to the CIDR boundary back properly. */
 231             mask.SetNoAddr();
 232             return mask.ApplyMask(m,AF_INET);
 233         }
 234         return true;
 235     }
 236
 237     return false;
 238 }
 239
 240 /* Handle either type of address, IPv6 will be discarded with a warning if disabled */
 241 #define SCAN_ACL1_6       "%[0123456789ABCDEFabcdef:]-%[0123456789ABCDEFabcdef:]/%[0123456789]"
 242 #define SCAN_ACL2_6       "%[0123456789ABCDEFabcdef:]-%[0123456789ABCDEFabcdef:]%c"
 243 #define SCAN_ACL3_6       "%[0123456789ABCDEFabcdef:]/%[0123456789]"
 244 #define SCAN_ACL4_6       "%[0123456789ABCDEFabcdef:]/%c"
 245 /* We DO need to know which is which though, for proper CIDR masking. */
 246 #define SCAN_ACL1_4       "%[0123456789.]-%[0123456789.]/%[0123456789.]"
 247 #define SCAN_ACL2_4       "%[0123456789.]-%[0123456789.]%c"
 248 #define SCAN_ACL3_4       "%[0123456789.]/%[0123456789.]"
 249 #define SCAN_ACL4_4       "%[0123456789.]/%c"
 250
 251 acl_ip_data *
 252 acl_ip_data::FactoryParse(const char *t)
 253 {
 254     LOCAL_ARRAY(char, addr1, 256);
 255     LOCAL_ARRAY(char, addr2, 256);
 256     LOCAL_ARRAY(char, mask, 256);
 257     acl_ip_data *r = NULL;
 258     acl_ip_data **Q = NULL;
 259     IpAddress temp;
 260     char c;
 261     unsigned int changed;
 262     acl_ip_data *q = new acl_ip_data;
 263     int iptype = AF_UNSPEC;
 264
 265     debugs(28, 5, "aclIpParseIpData: " << t);
 266
 267     /* Special ACL RHS "all" matches entire Internet */
 268     if (strcasecmp(t, "all") == 0) {
 269         debugs(28, 9, "aclIpParseIpData: magic 'all' found.");
 270         q->addr1.SetAnyAddr();
 271         q->addr2.SetEmpty();
 272         q->mask.SetAnyAddr();
 273         return q;
 274     }
 275
 276 #if USE_IPV6
 277     /* Special ACL RHS "ipv6" matches IPv6-Unicast Internet */
 278     if (strcasecmp(t, "ipv6") == 0) {
 279         debugs(28, 9, "aclIpParseIpData: magic 'ipv6' found.");
 280         r = q; // save head of the list for result.
 281
 282         /* 0000::/4 is a mix of localhost and obsolete IPv4-mapping space. Not valid outside this host. */
 283
 284         /* Future global unicast space: 1000::/4 */
 285         q->addr1 = "1000::";
 286         q->mask.SetNoAddr();
 287         q->mask.ApplyMask(4, AF_INET6);
 288
 289         /* Current global unicast space: 2000::/4 = (2000::/4 - 3000::/4) */
 290         q->next = new acl_ip_data;
 291         q = q->next;
 292         q->addr1 = "2000::";
 293         q->mask.SetNoAddr();
 294         q->mask.ApplyMask(3, AF_INET6);
 295
 296         /* Future global unicast space: 4000::/2 = (4000::/4 - 7000::/4) */
 297         q->next = new acl_ip_data;
 298         q = q->next;
 299         q->addr1 = "4000::";
 300         q->mask.SetNoAddr();
 301         q->mask.ApplyMask(2, AF_INET6);
 302
 303         /* Future global unicast space: 8000::/2 = (8000::/4 - B000::/4) */
 304         q->next = new acl_ip_data;
 305         q = q->next;
 306         q->addr1 = "8000::";
 307         q->mask.SetNoAddr();
 308         q->mask.ApplyMask(2, AF_INET6);
 309
 310         /* Future global unicast space: C000::/3 = (C000::/4 - D000::/4) */
 311         q->next = new acl_ip_data;
 312         q = q->next;
 313         q->addr1 = "C000::";
 314         q->mask.SetNoAddr();
 315         q->mask.ApplyMask(3, AF_INET6);
 316
 317         /* Future global unicast space: E000::/4 */
 318         q->next = new acl_ip_data;
 319         q = q->next;
 320         q->addr1 = "E000::";
 321         q->mask.SetNoAddr();
 322         q->mask.ApplyMask(4, AF_INET6);
 323
 324         /* F000::/4 is mostly reserved non-unicast. With some exceptions ... */
 325
 326         /* RFC 4193 Unique-Local unicast space: FC00::/7 */
 327         q->next = new acl_ip_data;
 328         q = q->next;
 329         q->addr1 = "FC00::";
 330         q->mask.SetNoAddr();
 331         q->mask.ApplyMask(7, AF_INET6);
 332
 333         /* Link-Local unicast space: FE80::/10 */
 334         q->next = new acl_ip_data;
 335         q = q->next;
 336         q->addr1 = "FE80::";
 337         q->mask.SetNoAddr();
 338         q->mask.ApplyMask(10, AF_INET6);
 339
 340         return r;
 341     }
 342 #endif
 343
 344 // IPv4
 345     if (sscanf(t, SCAN_ACL1_4, addr1, addr2, mask) == 3) {
 346         debugs(28, 9, "aclIpParseIpData: '" << t << "' matched: SCAN1-v4: " << SCAN_ACL1_4);
 347         iptype=AF_INET;
 348     } else if (sscanf(t, SCAN_ACL2_4, addr1, addr2, &c) >= 2) {
 349         debugs(28, 9, "aclIpParseIpData: '" << t << "' matched: SCAN2-v4: " << SCAN_ACL2_4);
 350         mask[0] = '\0';
 351         iptype=AF_INET;
 352     } else if (sscanf(t, SCAN_ACL3_4, addr1, mask) == 2) {
 353         debugs(28, 9, "aclIpParseIpData: '" << t << "' matched: SCAN3-v4: " << SCAN_ACL3_4);
 354         addr2[0] = '\0';
 355         iptype=AF_INET;
 356     } else if (sscanf(t, SCAN_ACL4_4, addr1,&c) == 2) {
 357         debugs(28, 9, "aclIpParseIpData: '" << t << "' matched: SCAN4-v4: " << SCAN_ACL4_4);
 358         addr2[0] = '\0';
 359         mask[0] = '\0';
 360         iptype=AF_INET;
 361
 362 // IPv6
 363     } else if (sscanf(t, SCAN_ACL1_6, addr1, addr2, mask) == 3) {
 364         debugs(28, 9, "aclIpParseIpData: '" << t << "' matched: SCAN1-v6: " << SCAN_ACL1_6);
 365         iptype=AF_INET6;
 366     } else if (sscanf(t, SCAN_ACL2_6, addr1, addr2, &c) >= 2) {
 367         debugs(28, 9, "aclIpParseIpData: '" << t << "' matched: SCAN2-v6: " << SCAN_ACL2_6);
 368         mask[0] = '\0';
 369         iptype=AF_INET6;
 370     } else if (sscanf(t, SCAN_ACL3_6, addr1, mask) == 2) {
 371         debugs(28, 9, "aclIpParseIpData: '" << t << "' matched: SCAN3-v6: " << SCAN_ACL3_6);
 372         addr2[0] = '\0';
 373         iptype=AF_INET6;
 374     } else if (sscanf(t, SCAN_ACL4_6, addr1, mask) == 2) {
 375         debugs(28, 9, "aclIpParseIpData: '" << t << "' matched: SCAN4-v6: " << SCAN_ACL4_6);
 376         addr2[0] = '\0';
 377         iptype=AF_INET6;
 378
 379 // Neither
 380     } else if (sscanf(t, "%[^/]/%s", addr1, mask) == 2) {
 381         debugs(28, 9, "aclIpParseIpData: '" << t << "' matched: non-IP pattern: %[^/]/%s");
 382         addr2[0] = '\0';
 383     } else if (sscanf(t, "%s", addr1) == 1) {
 384         /*
 385          * Note, must use plain xgetaddrinfo() here because at startup
 386          * ipcache hasn't been initialized
 387          * TODO: offload this to one of the IpAddress lookups.
 388          */
 389
 390         debugs(28, 5, "aclIpParseIpData: Lookup Host/IP " << addr1);
 391         struct addrinfo *hp = NULL, *x = NULL;
 392         struct addrinfo hints;
 393         IpAddress *prev_addr = NULL;
 394
 395         memset(&hints, 0, sizeof(struct addrinfo));
 396
 397         if ( iptype != AF_UNSPEC ) {
 398             hints.ai_flags |= AI_NUMERICHOST;
 399         }
 400
 401 #if 0 && USE_IPV6 && !IPV6_SPECIAL_SPLITSTACK
 402         hints.ai_flags |= AI_V4MAPPED | AI_ALL;
 403 #endif
 404
 405         int errcode = xgetaddrinfo(addr1,NULL,&hints,&hp);
 406         if (hp == NULL) {
 407             debugs(28, 0, "aclIpParseIpData: Bad host/IP: '" << addr1 <<
 408                    "' in '" << t << "', flags=" << hints.ai_flags <<
 409                    " : (" << errcode << ") " << xgai_strerror(errcode) );
 410             self_destruct();
 411             return NULL;
 412         }
 413
 414         Q = &q;
 415
 416         for (x = hp; x != NULL;) {
 417             if ((r = *Q) == NULL)
 418                 r = *Q = new acl_ip_data;
 419
 420             /* getaddrinfo given a host has a nasty tendency to return duplicate addr's */
 421             /* BUT sorted fortunately, so we can drop most of them easily */
 422             r->addr1 = *x;
 423             x = x->ai_next;
 424             if ( prev_addr && r->addr1 == *prev_addr) {
 425                 debugs(28, 3, "aclIpParseIpData: Duplicate host/IP: '" << r->addr1 << "' dropped.");
 426                 delete r;
 427                 *Q = NULL;
 428                 continue;
 429             } else
 430                 prev_addr = &r->addr1;
 431
 432             debugs(28, 3, "aclIpParseIpData: Located host/IP: '" << r->addr1 << "'");
 433
 434             r->addr2.SetAnyAddr();
 435             r->mask.SetNoAddr();
 436
 437             Q = &r->next;
 438
 439             debugs(28, 3, "" << addr1 << " --> " << r->addr1 );
 440         }
 441
 442         if (*Q != NULL) {
 443             debugs(28, 0, "aclIpParseIpData: Bad host/IP: '" << t << "'");
 444             self_destruct();
 445             return NULL;
 446         }
 447
 448         xfreeaddrinfo(hp);
 449
 450         return q;
 451     }
 452
 453 #if !USE_IPV6
 454     /* ignore IPv6 addresses when built with IPv4-only */
 455     if ( iptype == AF_INET6 ) {
 456         debugs(28, 0, "aclIpParseIpData: IPv6 has not been enabled. build with '--enable-ipv6'");
 457         return NULL;
 458     }
 459 #endif
 460
 461     /* Decode addr1 */
 462     if (!*addr1 || !(q->addr1 = addr1)) {
 463         debugs(28, 0, "aclIpParseIpData: unknown first address in '" << t << "'");
 464         delete q;
 465         self_destruct();
 466         return NULL;
 467     }
 468
 469     /* Decode addr2 */
 470     if (!*addr2)
 471         q->addr2.SetAnyAddr();
 472     else if (!(q->addr2=addr2) ) {
 473         debugs(28, 0, "aclIpParseIpData: unknown second address in '" << t << "'");
 474         delete q;
 475         self_destruct();
 476         return NULL;
 477     }
 478
 479     /* Decode mask (NULL or empty means a exact host mask) */
 480     if (!DecodeMask(mask, q->mask, iptype)) {
 481         debugs(28, 0, "aclParseIpData: unknown netmask '" << mask << "' in '" << t << "'");
 482         delete q;
 483         self_destruct();
 484         return NULL;
 485     }
 486
 487     changed = 0;
 488     changed += q->addr1.ApplyMask(q->mask);
 489     changed += q->addr2.ApplyMask(q->mask);
 490
 491     if (changed)
 492         debugs(28, 0, "aclIpParseIpData: WARNING: Netmask masks away part of the specified IP in '" << t << "'");
 493
 494     debugs(28,9, HERE << "Parsed: " << q->addr1 << "-" << q->addr2 << "/" << q->mask << "(/" << q->mask.GetCIDR() <<")");
 495
 496     /* 1.2.3.4/255.255.255.0  --> 1.2.3.0 */
 497     /* Same as IPv6 (not so trivial to depict) */
 498     return q;
 499 }
 500
 501 void
 502 ACLIP::parse()
 503 {
 504     char *t = NULL;
 505
 506     while ((t = strtokFile())) {
 507         acl_ip_data *q = acl_ip_data::FactoryParse(t);
 508
 509         while (q != NULL) {
 510             /* pop each result off the list and add it to the data tree individually */
 511             acl_ip_data *next = q->next;
 512             q->next = NULL;
 513             data = data->insert(q, acl_ip_data::NetworkCompare);
 514             q = next;
 515         }
 516     }
 517 }
 518
 519 ACLIP::~ACLIP()
 520 {
 521     if (data)
 522         data->destroy(IPSplay::DefaultFree);
 523 }
 524
 525 wordlist *
 526 ACLIP::dump() const
 527 {
 528     wordlist *w = NULL;
 529     data->walk (DumpIpListWalkee, &w);
 530     return w;
 531 }
 532
 533 bool
 534 ACLIP::empty () const
 535 {
 536     return data->empty();
 537 }
 538
 539 int
 540 ACLIP::match(IpAddress &clientip)
 541 {
 542     static acl_ip_data ClientAddress;
 543     /*
 544      * aclIpAddrNetworkCompare() takes two acl_ip_data pointers as
 545      * arguments, so we must create a fake one for the client's IP
 546      * address. Since we are scanning for a single IP mask and addr2
 547      * MUST be set to empty.
 548      */
 549     ClientAddress.addr1 = clientip;
 550     ClientAddress.addr2.SetEmpty();
 551     ClientAddress.mask.SetEmpty();
 552
 553     data = data->splay(&ClientAddress, aclIpAddrNetworkCompare);
 554     debugs(28, 3, "aclIpMatchIp: '" << clientip << "' " << (splayLastResult ? "NOT found" : "found"));
 555     return !splayLastResult;
 556 }
 557
 558 acl_ip_data::acl_ip_data () :addr1(), addr2(), mask(), next (NULL) {}
 559
 560 acl_ip_data::acl_ip_data (IpAddress const &anAddress1, IpAddress const &anAddress2, IpAddress const &aMask, acl_ip_data *aNext) : addr1(anAddress1), addr2(anAddress2), mask(aMask), next(aNext) {}