qcsrc/server/ipban.qc

   1 #include "ipban.qh"
   2
   3 #include <common/constants.qh>
   4 #include <common/stats.qh>
   5 #include <common/util.qh>
   6 #include <common/weapons/_all.qh>
   7 #include <server/autocvars.qh>
   8 #include <server/command/banning.qh>
   9 #include <server/main.qh>
  10
  11 /*
  12  * Protocol of online ban list:
  13  *
  14  * - Reporting a ban:
  15  *     GET g_ban_sync_uri?action=ban&hostname=...&ip=xxx.xxx.xxx&duration=nnnn&reason=...................
  16  *     (IP 1, 2, 3, or 4 octets, 3 octets for example is a /24 mask)
  17  * - Removing a ban:
  18  *     GET g_ban_sync_uri?action=unban&hostname=...&ip=xxx.xxx.xxx
  19  * - Querying the ban list
  20  *     GET g_ban_sync_uri?action=list&hostname=...&servers=xxx.xxx.xxx.xxx;xxx.xxx.xxx.xxx;...
  21  *
  22  *     shows the bans from the listed servers, and possibly others.
  23  *     Format of a ban is ASCII plain text, four lines per ban, delimited by
  24  *     newline ONLY (no carriage return):
  25  *
  26  *     IP address (also 1, 2, 3, or 4 octets, delimited by dot)
  27  *     time left in seconds
  28  *     reason of the ban
  29  *     server IP that registered the ban
  30  */
  31
  32 #define MAX_IPBAN_URIS (URI_GET_IPBAN_END - URI_GET_IPBAN + 1)
  33
  34 void OnlineBanList_SendBan(string ip, float bantime, string reason)
  35 {
  36         string uri;
  37         float i, n;
  38
  39         uri = strcat(     "action=ban&hostname=", uri_escape(autocvar_hostname));
  40         uri = strcat(uri, "&ip=", uri_escape(ip));
  41         uri = strcat(uri, "&duration=", ftos(bantime));
  42         uri = strcat(uri, "&reason=", uri_escape(reason));
  43
  44         n = tokenize_console(autocvar_g_ban_sync_uri);
  45         if(n >= MAX_IPBAN_URIS)
  46                 n = MAX_IPBAN_URIS;
  47         for(i = 0; i < n; ++i)
  48         {
  49                 if(strstrofs(argv(i), "?", 0) >= 0)
  50                         uri_get(strcat(argv(i), "&", uri), URI_GET_DISCARD); // 0 = "discard" callback target
  51                 else
  52                         uri_get(strcat(argv(i), "?", uri), URI_GET_DISCARD); // 0 = "discard" callback target
  53         }
  54 }
  55
  56 void OnlineBanList_SendUnban(string ip)
  57 {
  58         string uri;
  59         float i, n;
  60
  61         uri = strcat(     "action=unban&hostname=", uri_escape(autocvar_hostname));
  62         uri = strcat(uri, "&ip=", uri_escape(ip));
  63
  64         n = tokenize_console(autocvar_g_ban_sync_uri);
  65         if(n >= MAX_IPBAN_URIS)
  66                 n = MAX_IPBAN_URIS;
  67         for(i = 0; i < n; ++i)
  68         {
  69                 if(strstrofs(argv(i), "?", 0) >= 0)
  70                         uri_get(strcat(argv(i), "&", uri), URI_GET_DISCARD); // 0 = "discard" callback target
  71                 else
  72                         uri_get(strcat(argv(i), "?", uri), URI_GET_DISCARD); // 0 = "discard" callback target
  73         }
  74 }
  75
  76 string OnlineBanList_Servers;
  77 float OnlineBanList_Timeout;
  78 float OnlineBanList_RequestWaiting[MAX_IPBAN_URIS];
  79
  80 void OnlineBanList_URI_Get_Callback(float id, float status, string data)
  81 {
  82         float n, i, j, l;
  83         string ip;
  84         float timeleft;
  85         string reason;
  86         string serverip;
  87         float syncinterval;
  88         string uri;
  89
  90         id -= URI_GET_IPBAN;
  91
  92         if(id >= MAX_IPBAN_URIS)
  93         {
  94                 LOG_INFO("Received ban list for invalid ID");
  95                 return;
  96         }
  97
  98         tokenize_console(autocvar_g_ban_sync_uri);
  99         uri = argv(id);
 100
 101         string prelude = strcat("Received ban list from ", uri, ": ");
 102
 103         if(OnlineBanList_RequestWaiting[id] == 0)
 104         {
 105                 LOG_INFO(prelude, "rejected (unexpected)");
 106                 return;
 107         }
 108
 109         OnlineBanList_RequestWaiting[id] = 0;
 110
 111         if(time > OnlineBanList_Timeout)
 112         {
 113                 LOG_INFO(prelude, "rejected (too late)");
 114                 return;
 115         }
 116
 117         syncinterval = autocvar_g_ban_sync_interval;
 118         if(syncinterval == 0)
 119         {
 120                 LOG_INFO(prelude, "rejected (syncing disabled)");
 121                 return;
 122         }
 123         if(syncinterval > 0)
 124                 syncinterval *= 60;
 125
 126         if(status != 0)
 127         {
 128                 LOG_INFO(prelude, "error: status is ", ftos(status));
 129                 return;
 130         }
 131
 132         if(substring(data, 0, 1) == "<")
 133         {
 134                 LOG_INFO(prelude, "error: received HTML instead of a ban list");
 135                 return;
 136         }
 137
 138         if(strstrofs(data, "\r", 0) != -1)
 139         {
 140                 LOG_INFO(prelude, "error: received carriage returns");
 141                 return;
 142         }
 143
 144         if(data == "")
 145                 n = 0;
 146         else
 147                 n = tokenizebyseparator(data, "\n");
 148
 149         if((n % 4) != 0)
 150         {
 151                 LOG_INFO(prelude, "error: received invalid item count: ", ftos(n));
 152                 return;
 153         }
 154
 155         LOG_INFO(prelude, "OK, ", ftos(n / 4), " items");
 156
 157         for(i = 0; i < n; i += 4)
 158         {
 159                 ip = argv(i);
 160                 timeleft = stof(argv(i + 1));
 161                 reason = argv(i + 2);
 162                 serverip = argv(i + 3);
 163
 164                 LOG_TRACE("received ban list item ", ftos(i / 4), ": ip=", ip);
 165                 LOG_TRACE(" timeleft=", ftos(timeleft), " reason=", reason);
 166                 LOG_TRACE(" serverip=", serverip);
 167
 168                 timeleft -= 1.5 * autocvar_g_ban_sync_timeout;
 169                 if(timeleft < 0)
 170                         continue;
 171
 172                 l = strlen(ip);
 173                 if(l != 44) // length 44 is a cryptographic ID
 174                 {
 175                         for(j = 0; j < l; ++j)
 176                                 if(strstrofs("0123456789.", substring(ip, j, 1), 0) == -1)
 177                                 {
 178                                         LOG_INFO("Invalid character ", substring(ip, j, 1), " in IP address ", ip, ". Skipping this ban.");
 179                                         goto skip;
 180                                 }
 181                 }
 182
 183                 if(autocvar_g_ban_sync_trusted_servers_verify)
 184                         if((strstrofs(strcat(";", OnlineBanList_Servers, ";"), strcat(";", serverip, ";"), 0) == -1))
 185                                 continue;
 186
 187                 if(syncinterval > 0)
 188                         timeleft = min(syncinterval + (OnlineBanList_Timeout - time) + 5, timeleft);
 189                         // the ban will be prolonged on the next sync
 190                         // or expire 5 seconds after the next timeout
 191                 Ban_Insert(ip, timeleft, strcat("ban synced from ", serverip, " at ", uri), 0);
 192                 LOG_INFO("Ban list syncing: accepted ban of ", ip, " by ", serverip, " at ", uri, ": ", reason);
 193
 194 LABEL(skip)
 195         }
 196 }
 197
 198 void OnlineBanList_Think(entity this)
 199 {
 200         int argc;
 201         string uri;
 202         float i, n;
 203
 204         if(autocvar_g_ban_sync_uri == "")
 205         {
 206                 delete(this);
 207                 return;
 208         }
 209         if(autocvar_g_ban_sync_interval == 0) // < 0 is okay, it means "sync on level start only"
 210         {
 211                 delete(this);
 212                 return;
 213         }
 214         argc = tokenize_console(autocvar_g_ban_sync_trusted_servers);
 215         if(argc == 0)
 216         {
 217                 delete(this);
 218                 return;
 219         }
 220
 221         string s = argv(0); for(i = 1; i < argc; ++i) s = strcat(s, ";", argv(i));
 222         strcpy(OnlineBanList_Servers, s);
 223
 224         uri = strcat(     "action=list&hostname=", uri_escape(autocvar_hostname));
 225         uri = strcat(uri, "&servers=", uri_escape(OnlineBanList_Servers));
 226
 227         OnlineBanList_Timeout = time + autocvar_g_ban_sync_timeout;
 228
 229         n = tokenize_console(autocvar_g_ban_sync_uri);
 230         if(n >= MAX_IPBAN_URIS)
 231                 n = MAX_IPBAN_URIS;
 232         for(i = 0; i < n; ++i)
 233         {
 234                 if(OnlineBanList_RequestWaiting[i])
 235                         continue;
 236                 OnlineBanList_RequestWaiting[i] = 1;
 237                 if(strstrofs(argv(i), "?", 0) >= 0)
 238                         uri_get(strcat(argv(i), "&", uri), URI_GET_IPBAN + i); // 1000 = "banlist" callback target
 239                 else
 240                         uri_get(strcat(argv(i), "?", uri), URI_GET_IPBAN + i); // 1000 = "banlist" callback target
 241         }
 242
 243         if(autocvar_g_ban_sync_interval <= 0)
 244         {
 245                 delete(this);
 246                 return;
 247         }
 248
 249         this.nextthink = time + max(60, autocvar_g_ban_sync_interval * 60);
 250 }
 251
 252 const float BAN_MAX = 256;
 253 float ban_loaded;
 254 string ban_ip[BAN_MAX];
 255 float ban_expire[BAN_MAX];
 256 float ban_count;
 257
 258 string ban_ip1;
 259 string ban_ip2;
 260 string ban_ip3;
 261 string ban_ip4;
 262 string ban_idfp;
 263
 264 void Ban_SaveBans()
 265 {
 266         string out;
 267         float i;
 268
 269         if(!ban_loaded)
 270                 return;
 271
 272         // version of list
 273         out = "1";
 274         for(i = 0; i < ban_count; ++i)
 275         {
 276                 if(time > ban_expire[i])
 277                         continue;
 278                 out = strcat(out, " ", ban_ip[i]);
 279                 out = strcat(out, " ", ftos(ban_expire[i] - time));
 280         }
 281         if(strlen(out) <= 1) // no real entries
 282                 cvar_set("g_banned_list", "");
 283         else
 284                 cvar_set("g_banned_list", out);
 285 }
 286
 287 float Ban_Delete(float i)
 288 {
 289         if(i < 0)
 290                 return false;
 291         if(i >= ban_count)
 292                 return false;
 293         if(ban_expire[i] == 0)
 294                 return false;
 295         if(ban_expire[i] > 0)
 296         {
 297                 OnlineBanList_SendUnban(ban_ip[i]);
 298                 strunzone(ban_ip[i]);
 299         }
 300         ban_expire[i] = 0;
 301         ban_ip[i] = "";
 302         Ban_SaveBans();
 303         return true;
 304 }
 305
 306 void Ban_LoadBans()
 307 {
 308         float i, n;
 309         for(i = 0; i < ban_count; ++i)
 310                 Ban_Delete(i);
 311         ban_count = 0;
 312         ban_loaded = true;
 313         n = tokenize_console(autocvar_g_banned_list);
 314         if(stof(argv(0)) == 1)
 315         {
 316                 ban_count = (n - 1) / 2;
 317                 for(i = 0; i < ban_count; ++i)
 318                 {
 319                         ban_ip[i] = strzone(argv(2*i+1));
 320                         ban_expire[i] = time + stof(argv(2*i+2));
 321                 }
 322         }
 323
 324         entity e = new(bansyncer);
 325         setthink(e, OnlineBanList_Think);
 326         e.nextthink = time + 1;
 327 }
 328
 329 void Ban_View()
 330 {
 331         float i, n;
 332         string msg;
 333
 334         LOG_INFO("^2Listing all existing active bans:");
 335
 336         n = 0;
 337         for(i = 0; i < ban_count; ++i)
 338         {
 339                 if(time > ban_expire[i])
 340                         continue;
 341
 342                 ++n; // total number of existing bans
 343
 344                 msg = strcat("#", ftos(i), ": ");
 345                 msg = strcat(msg, ban_ip[i], " is still banned for ");
 346                 msg = strcat(msg, ftos(ban_expire[i] - time), " seconds");
 347
 348                 LOG_INFO("  ", msg);
 349         }
 350
 351         LOG_INFO("^2Done listing all active (", ftos(n), ") bans.");
 352 }
 353
 354 float Ban_GetClientIP(entity client)
 355 {
 356         // we can't use tokenizing here, as this is called during ban list parsing
 357         float i1, i2, i3, i4;
 358         string s;
 359
 360         if(client.crypto_idfp_signed)
 361                 ban_idfp = client.crypto_idfp;
 362         else
 363                 ban_idfp = string_null;
 364
 365         s = client.netaddress;
 366
 367         i1 = strstrofs(s, ".", 0);
 368         if(i1 < 0)
 369                 goto ipv6;
 370         i2 = strstrofs(s, ".", i1 + 1);
 371         if(i2 < 0)
 372                 return false;
 373         i3 = strstrofs(s, ".", i2 + 1);
 374         if(i3 < 0)
 375                 return false;
 376         i4 = strstrofs(s, ".", i3 + 1);
 377         if(i4 >= 0)
 378                 s = substring(s, 0, i4);
 379
 380         ban_ip1 = substring(s, 0, i1); // 8
 381         ban_ip2 = substring(s, 0, i2); // 16
 382         ban_ip3 = substring(s, 0, i3); // 24
 383         ban_ip4 = strcat1(s); // 32
 384         return true;
 385
 386 LABEL(ipv6)
 387         i1 = strstrofs(s, ":", 0);
 388         if(i1 < 0)
 389                 return false;
 390         i1 = strstrofs(s, ":", i1 + 1);
 391         if(i1 < 0)
 392                 return false;
 393         i2 = strstrofs(s, ":", i1 + 1);
 394         if(i2 < 0)
 395                 return false;
 396         i3 = strstrofs(s, ":", i2 + 1);
 397         if(i3 < 0)
 398                 return false;
 399
 400         ban_ip1 = strcat(substring(s, 0, i1), "::/32"); // 32
 401         ban_ip2 = strcat(substring(s, 0, i2), "::/48"); // 48
 402         ban_ip4 = strcat(substring(s, 0, i3), "::/64"); // 64
 403
 404         if(i3 - i2 > 3) // means there is more than 2 digits and a : in the range
 405                 ban_ip3 = strcat(substring(s, 0, i2), ":", substring(s, i2 + 1, i3 - i2 - 3), "00::/56");
 406         else
 407                 ban_ip3 = strcat(substring(s, 0, i2), ":0::/56");
 408
 409         return true;
 410 }
 411
 412 float Ban_IsClientBanned(entity client, float idx)
 413 {
 414         float i, b, e, ipbanned;
 415         if(!ban_loaded)
 416                 Ban_LoadBans();
 417         if(!Ban_GetClientIP(client))
 418                 return false;
 419         if(idx < 0)
 420         {
 421                 b = 0;
 422                 e = ban_count;
 423         }
 424         else
 425         {
 426                 b = idx;
 427                 e = idx + 1;
 428         }
 429         ipbanned = false;
 430         for(i = b; i < e; ++i)
 431         {
 432                 string s;
 433                 if(time > ban_expire[i])
 434                         continue;
 435                 s = ban_ip[i];
 436                 if(ban_ip1 == s) ipbanned = true;
 437                 if(ban_ip2 == s) ipbanned = true;
 438                 if(ban_ip3 == s) ipbanned = true;
 439                 if(ban_ip4 == s) ipbanned = true;
 440                 if(ban_idfp == s) return true;
 441         }
 442         if(ipbanned)
 443         {
 444                 if(!autocvar_g_banned_list_idmode)
 445                         return true;
 446                 if (!ban_idfp)
 447                         return true;
 448         }
 449         return false;
 450 }
 451
 452 bool Ban_MaybeEnforceBan(entity client)
 453 {
 454         if (Ban_IsClientBanned(client, -1))
 455         {
 456                 if (!client.crypto_idfp)
 457                         LOG_INFOF("^1NOTE:^7 banned client %s just tried to enter\n",
 458                                 client.netaddress);
 459                 else
 460                         LOG_INFOF("^1NOTE:^7 banned client %s (%s) just tried to enter\n",
 461                                 client.netaddress, client.crypto_idfp);
 462
 463                 if(autocvar_g_ban_telluser)
 464                         sprint(client, "You are banned from this server.\n");
 465                 dropclient(client);
 466                 return true;
 467         }
 468         return false;
 469 }
 470
 471 .bool ban_checked;
 472 bool Ban_MaybeEnforceBanOnce(entity client)
 473 {
 474         if (client.ban_checked) return false;
 475         client.ban_checked = true;
 476         return Ban_MaybeEnforceBan(client);
 477 }
 478
 479 string Ban_Enforce(float j, string reason)
 480 {
 481         string s;
 482
 483         // Enforce our new ban
 484         s = "";
 485         FOREACH_CLIENTSLOT(IS_REAL_CLIENT(it),
 486         {
 487                 if(Ban_IsClientBanned(it, j))
 488                 {
 489                         if(reason != "")
 490                         {
 491                                 if(s == "")
 492                                         reason = strcat(reason, ": affects ");
 493                                 else
 494                                         reason = strcat(reason, ", ");
 495                                 reason = strcat(reason, it.netname);
 496                         }
 497                         s = strcat(s, "^1NOTE:^7 banned client ", it.netname, "^7 has to go\n");
 498                         dropclient(it);
 499                 }
 500         });
 501         bprint(s);
 502
 503         return reason;
 504 }
 505
 506 float Ban_Insert(string ip, float bantime, string reason, float dosync)
 507 {
 508         float i;
 509         float j;
 510         float bestscore;
 511
 512         // already banned?
 513         for(i = 0; i < ban_count; ++i)
 514                 if(ban_ip[i] == ip)
 515                 {
 516                         // prolong the ban
 517                         if(time + bantime > ban_expire[i])
 518                         {
 519                                 ban_expire[i] = time + bantime;
 520                                 LOG_TRACE(ip, "'s ban has been prolonged to ", ftos(bantime), " seconds from now");
 521                         }
 522                         else
 523                                 LOG_TRACE(ip, "'s ban is still active until ", ftos(ban_expire[i] - time), " seconds from now");
 524
 525                         // and enforce
 526                         reason = Ban_Enforce(i, reason);
 527
 528                         // and abort
 529                         if(dosync)
 530                                 if(reason != "")
 531                                         if(substring(reason, 0, 1) != "~") // like IRC: unauthenticated banner
 532                                                 OnlineBanList_SendBan(ip, bantime, reason);
 533
 534                         return false;
 535                 }
 536
 537         // do we have a free slot?
 538         for(i = 0; i < ban_count; ++i)
 539                 if(time > ban_expire[i])
 540                         break;
 541         // no free slot? Then look for the one who would get unbanned next
 542         if(i >= BAN_MAX)
 543         {
 544                 i = 0;
 545                 bestscore = ban_expire[i];
 546                 for(j = 1; j < ban_count; ++j)
 547                 {
 548                         if(ban_expire[j] < bestscore)
 549                         {
 550                                 i = j;
 551                                 bestscore = ban_expire[i];
 552                         }
 553                 }
 554         }
 555         // if we replace someone, will we be banned longer than him (so long-term
 556         // bans never get overridden by short-term bans)
 557         if(i < ban_count)
 558         if(ban_expire[i] > time + bantime)
 559         {
 560                 LOG_INFO(ip, " could not get banned due to no free ban slot");
 561                 return false;
 562         }
 563         // okay, insert our new victim as i
 564         Ban_Delete(i);
 565         LOG_TRACE(ip, " has been banned for ", ftos(bantime), " seconds");
 566         ban_expire[i] = time + bantime;
 567         ban_ip[i] = strzone(ip);
 568         ban_count = max(ban_count, i + 1);
 569
 570         Ban_SaveBans();
 571
 572         reason = Ban_Enforce(i, reason);
 573
 574         // and abort
 575         if(dosync)
 576                 if(reason != "")
 577                         if(substring(reason, 0, 1) != "~") // like IRC: unauthenticated banner
 578                                 OnlineBanList_SendBan(ip, bantime, reason);
 579
 580         return true;
 581 }
 582
 583 void Ban_KickBanClient(entity client, float bantime, float masksize, string reason)
 584 {
 585         string ip, id;
 586         if(!Ban_GetClientIP(client))
 587         {
 588                 sprint(client, strcat("Kickbanned: ", reason, "\n"));
 589                 dropclient(client);
 590                 return;
 591         }
 592
 593         // who to ban?
 594         switch(masksize)
 595         {
 596                 case 1:
 597                         ip = strcat1(ban_ip1);
 598                         break;
 599                 case 2:
 600                         ip = strcat1(ban_ip2);
 601                         break;
 602                 case 3:
 603                         ip = strcat1(ban_ip3);
 604                         break;
 605                 case 4:
 606                 default:
 607                         ip = strcat1(ban_ip4);
 608                         break;
 609         }
 610         if(ban_idfp)
 611                 id = strcat1(ban_idfp);
 612         else
 613                 id = string_null;
 614
 615         Ban_Insert(ip, bantime, reason, 1);
 616         if(id)
 617                 Ban_Insert(id, bantime, reason, 1);
 618         /*
 619          * not needed, as we enforce the ban in Ban_Insert anyway
 620         // and kick him
 621         sprint(client, strcat("Kickbanned: ", reason, "\n"));
 622         dropclient(client);
 623          */
 624 }