1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299
|
Network Working Group P. Deutsch
Request for Comments: 1835 BUNYIP INFORMATION SYSTEMS, Inc.
Category: Standards Track R. Schoultz
KTHNOC
P. Faltstrom
BUNYIP INFORMATION SYSTEMS, Inc.
C. Weider
BUNYIP INFORMATION SYSTEMS, Inc.
August 1995
Architecture of the WHOIS++ service
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Abstract
This document describes WHOIS++, an extension to the trivial WHOIS
service described in RFC 954 to permit WHOIS-like servers to make
available more structured information to the Internet. We describe
an extension to the simple WHOIS data model and query protocol and a
companion extensible, distributed indexing service. A number of
options have also been added such as the use of multiple languages
and character sets, more advanced search expressions, structured data
and a number of other useful features. An optional authentication
mechanism for protecting all or part of the associated WHOIS++
information database from unauthorized access is also described.
Table of Contents
Part I - WHOIS++ Overview ................................. 3
1.1. Purpose and Motivation .............................. 3
1.2. Basic Information Model ............................. 4
1.2.1. Changes to the current WHOIS Model ................ 5
1.2.2. Registering WHOIS++ servers ....................... 5
1.2.3. The WHOIS++ Search Selection Mechanism ............ 7
1.2.4. The WHOIS++ Architecture .......................... 7
1.3. Indexing in WHOIS++ ................................. 8
1.4. Getting Help ........................................ 9
1.4.1. Minimum HELP Required ............................. 9
1.5. Options and Constraints ............................. 10
1.6. Formatting Responses ................................ 10
Deutsch, et al Standards Track [Page 1]
RFC 1835 Architecture of the WHOIS++ service August 1995
1.7. Reporting Warnings and Errors ....................... 11
1.8. Privacy and Security Issues ......................... 11
Part II - WHOIS++ Implementation .......................... 12
2.1. The WHOIS++ interaction model ....................... 12
2.2. The WHOIS++ Command set ............................. 12
2.2.1. System Commands ................................... 13
2.2.1.1. The COMMANDS command ............................ 14
2.2.1.2. The CONSTRAINTS command ......................... 15
2.2.1.3. The DESCRIBE command ............................ 15
2.2.1.4. The HELP command ................................ 15
2.2.1.5. The LIST command ................................ 15
2.2.1.6. The POLLED-BY command ........................... 15
2.2.1.7. The POLLED-FOR command .......................... 16
2.2.1.8. The SHOW command ................................ 16
2.2.1.9. The VERSION command ............................. 16
2.2.2. The Search Command ................................ 16
2.2.2.1. Format of a Search Term ......................... 17
2.2.2.2. Format of a Search String ....................... 18
2.3. WHOIS++ Constraints ................................. 19
2.3.1. Required Constraints .............................. 20
2.3.2. Optional CONSTRAINTS .............................. 21
2.3.2.1. The SEARCH Constraint ........................... 22
2.3.2.2. The FORMAT Constraint ........................... 22
2.3.2.3. The MAXFULL Constraint .......................... 22
2.3.2.4. The MAXHITS Constraint .......................... 23
2.3.2.5. The CASE Constraint ............................. 23
2.3.2.6. The AUTHENTICATE Constraint ..................... 23
2.3.2.7. The NAME Constraint ............................. 23
2.3.2.8. The PASSWORD Constraint ......................... 23
2.3.2.9. The LANGUAGE Constraint ......................... 23
2.3.2.10. The INCHARSET Constraint ....................... 24
2.3.2.11. The IGNORE Constraint .......................... 24
2.3.2.12. The INCLUDE Constraint ......................... 24
2.4. Server Response Modes ............................... 24
2.4.1. Default Responses ................................. 25
2.4.2. Format of Responses ............................... 25
2.4.3. Syntax of a Formatted Response .................... 26
2.4.3.1. A FULL format response .......................... 26
2.4.3.2. ABRIDGED Format Response ........................ 27
2.4.3.3. HANDLE Format Response .......................... 27
2.4.3.4. SUMMARY Format Response ......................... 27
2.4.3.5. SERVERS-TO-ASK Response ......................... 28
2.4.4. System Generated Messages ......................... 28
2.5. Compatibility with Older WHOIS Servers .............. 29
3. Miscellaneous ......................................... 29
3.1. Acknowledgements .................................... 29
3.2. References .......................................... 29
3.3. Authors' Addresses .................................. 30
Deutsch, et al Standards Track [Page 2]
RFC 1835 Architecture of the WHOIS++ service August 1995
Appendix A - Some Sample Queries .......................... 31
Appendix B - Some sample responses ........................ 31
Appendix C - Sample responses to system commands .......... 33
Appendix D - Sample whois++ session ....................... 35
Appendix E - System messages .............................. 36
Appendix F - The WHOIS++ BNF Grammar ...................... 38
Appendix G - Description of Regular expressions ........... 40
1. Part I - WHOIS++ Overview
1.1. Purpose and Motivation
The current NIC WHOIS service [HARR85] is used to provide a very
limited directory service, serving information about a small number
of Internet users registered with the DDN NIC. Over time the basic
service has been expanded to serve additional information and similar
services have also been set up on other hosts. Unfortunately, these
additions and extensions have been done in an ad hoc and
uncoordinated manner.
The basic WHOIS information model represents each individual record
as a Rolodex-like collection of text. Each record has a unique
identifier (or handle), but otherwise is assumed to have little
structure. The current service allows users to issue searches for
individual strings within individual records, as well as searches for
individual record handles using a very simple query-response
protocol.
Despite its utility, the current NIC WHOIS service cannot function as
a general White Pages service for the entire Internet. Given the
inability of a single server to offer guaranteed response or
reliability, the huge volume of traffic that a full scale directory
service will generate and the potentially huge number of users of
such a service, such a trivial architecture is obviously unsuitable
for the current Internet's needs for information services.
This document describes the architecture and protocol for WHOIS++, a
simple, distributed and extensible information lookup service based
upon a small set of extensions to the original WHOIS information
model. These extensions allow the new service to address the
community's needs for a simple directory service, yet the extensible
architecture is expected to also allow it to find application in a
number of other information service areas.
Added features include an extension to the trivial WHOIS data model
and query protocol and a companion extensible, distributed indexing
service. A number of other options have also been added, like boolean
operators, more powerful search constraints and search methods, and
Deutsch, et al Standards Track [Page 3]
RFC 1835 Architecture of the WHOIS++ service August 1995
most specificly structured the data to make both the client and the
server part of the dialogue more stringent and parseable. An optional
authentication mechanism for protecting all or parts of the
associated WHOIS++ information database from unauthorized access is
also briefly described.
The basic architecture of WHOIS++ allows distributed maintenance of
the directory contents and the use of the WHOIS++ indexing service
for locating additional WHOIS++ servers. Although a general overview
of this service is included for completeness, the indexing extensions
are described in a separate paper.
1.2. Basic Information Model
The WHOIS++ service is centered in a recommendation to structure user
information around a series of standardized information templates.
Such templates consist of ordered sets of data elements (or
attribute-value pairs).
It is intended that adding such structured templates to a server and
subsequently identifying and searching them be simple tasks. The
creation and use of customized templates should also be possible with
little effort, although their use should be discouraged where
appropriate standardized templates exist.
We also offer methods to allow the user to constrain searches to
desired attributes or template types, in addition to the existing
commands for specifying handles or simple strings.
It is expected that the minimalist approach we have taken will find
application where the high cost of configuring and operating
traditional White Pages services can not currently be justified.
Also note that the architecture makes no assumptions about the search
and retrieval mechanisms used within individual servers. Operators
are free to use dedicated database formats, fast indexing software or
even provide gateways to other directory services to store and
retrieve information, if desired.
The WHOIS++ server simply functions as a known front end, offering a
simple data model and communicating through a well known port and
query protocol. The format of both queries and replies has been
structured to allow the use of client software for generating
searches and displaying the results. At the same time, some effort
has been made to keep responses at least to some degree readible by
humans, to ensure low entry cost and to ease debugging.
Deutsch, et al Standards Track [Page 4]
RFC 1835 Architecture of the WHOIS++ service August 1995
The actual implemention details of an individual WHOIS++ search
engine are left to the imagination of the implementor and it is hoped
that the simple, extensible approach taken will encourage
experimentation and the development of improved search engines.
1.2.1. Changes to the current WHOIS Model
The current WHOIS service is based upon an extremely simple data
model. The NIC WHOIS database consists of a series of individual
records, each of which is identified by a single unique identifer
(the "handle"). Each record contains one or more lines of
information. Currently, there is no structure or implicit ordering of
this information, although by implication each record is concerned
with information about a single user or service.
We have implemented two basic changes to this model. First, we have
structured the information within the database as collections of data
elements, or simple attribute/value pairs. Each individual record
contains a specified ordered set of these data elements.
Secondly, we have introduced typing of the database records. In
effect, each record is based upon one of a specified set of
templates, each containing a finite and specified number of data
elements. This allow users to easily limit searches to specific
collections of information, such as information about users,
services, abstracts of papers, descriptions of software, and so on.
As a final extension, we require that each individual WHOIS++
database on the Internet be assigned a unique handle, analogous to
the handle associated with each database record.
The WHOIS++ database structure is shown in Fig. 1.
1.2.2. Registering WHOIS++ servers
We propose that individual database handles be registered through the
Internet Assigned Numbers Authority (the IANA), ensuring their
uniqueness. This will allow us to specify each WHOIS++ entry on the
Internet as a unique pair consisting of a server handle and a record
handle.
A unique registered handle is preferable to using the host's IP
address, since it is conceivable that the WHOIS++ server for a
particular domain may move over time. If we preserve the unique
WHOIS++ handle in such cases we have the option of using it for
resource discovery and networked information retrieval (see [IIIR]
for a discussion of resource and discovery and support issues).
Deutsch, et al Standards Track [Page 5]
RFC 1835 Architecture of the WHOIS++ service August 1995
There are many ways of guaranteeing uniqueness of server handles; we
will discuss them in a separate paper.
We believe that organizing information around a series of such
templates will make it easier for administrators to gather and
maintain this information and thus encourage them to make such
information available. At the same time, as users become more
familiar with the data elements available within specific templates
they will be better able to specify their searches, leading to a more
useful service.
______________________________________________________________________
| |
| + Single unique WHOIS++ database handle |
| |
| _______ _______ _______ |
| handle3 |.. .. | handle6 |.. .. | handle9 |.. .. | |
| _______ | _______ | _______ | |
| handle2 |.. .. | handle5 |.. .. | handle8 |.. .. | |
| _______ | _______ | _______ | |
| handle1 |.. .. | handle4 |.. .. | handle7 |.. .. | |
| |.. .. | |.. .. | |.. .. | |
| ------- ------- ------- |
| Template Template Template |
| Type 1 Type 2 Type 3 |
| |
| |
| |
| |
| Fig.1 - Structure of a WHOIS++ database. |
| |
| Notes: - Entire database is identified by a single unique WHOIS |
| handle. |
| - Each record has a single unique handle and a specific set |
| of attributes, determined by the template type used. |
| - Each value associated with an attribute can be any ASCII |
| string up to a specified length. |
|______________________________________________________________________|
Deutsch, et al Standards Track [Page 6]
RFC 1835 Architecture of the WHOIS++ service August 1995
1.2.3. The WHOIS++ Search Selection Mechanism
The WHOIS++ search mechanism is intended to be extremely simple. A
search command consists of one or more search terms, with an optional
set of global constraints (specifiers that modify or control a
search).
Search terms allow the user to specify template type, attribute,
value or handle that any record returns must satisfy. Each search
term can have an optional set of local constraints that apply to only
that term.
A WHOIS++ database may be seen as a single rolodex-like collection of
typed records. Each term specifies a further constraint that the
selected set of output records must satisfy. Each term may thus be
thought of as performing a subtractive selection, in the sense that
any record that does not fulfil the term is discarded from the result
set. Boolean searches are possible by the use of AND, OR, NOT and
parenthesis.
1.2.4. The WHOIS++ Architecture
The WHOIS++ directory service has an architecture which is separated
into two components; the base level server, which is described in
this paper, and a indexing server. A single physical server can act
as both a base level server and an indexing server.
A base level server is one which contains only filled templates. An
indexing server is one which contains forward knowledge (q.v.) and
pointers to other indexing servers or base level servers.
Deutsch, et al Standards Track [Page 7]
RFC 1835 Architecture of the WHOIS++ service August 1995
1.3. Indexing in WHOIS++
Indexing in WHOIS++ is used to tie together many base level servers
and index servers into a unified directory service.
Each base level server and index server which wishes to participate
in the unified directory service must generate "forward knowledge"
for the entries it contains. One type of forward knowledge is the
"centroid".
An example of a centroid is as follows: if a whois++ server contained
exactly three records, as follows:
Record 1 Record 2
Template: Person Template: Person
First-Name: John First-Name: Joe
Last-Name: Smith Last-Name: Smith
Favourite-Drink: Labatt Beer Favourite-Drink: Molson Beer
Record 3
Template: Domain
Domain-Name: foo.edu
Contact-Name: Mike Foobar
the centroid for this server would be
Template: Person
First-Name: Joe
John
Last-Name: Smith
Favourite-Drink:Beer
Labatt
Molson
Template: Domain
Domain-Name: foo.edu
Contact-Name: Mike
Foobar
An index server would then collect this centroid for this server as
forward knowledge.
Index servers can collect forward knowledge for any servers it
wishes. In effect, all of the servers that the index server knows
about can be searched with a single query to the index server; the
index server holds the forward knowledge along with pointers to the
servers it indexes, and can refer the query to servers which might
hold information which satisfies the query.
Deutsch, et al Standards Track [Page 8]
RFC 1835 Architecture of the WHOIS++ service August 1995
Implementors of this protocol are strongly encouraged to incorporate
centroid generation abilities into their servers.
-------------------------------------------------------------------
____ ____
top level | | | |
whois index | | | |
servers ---- ----
____ ____
first level | | | |
whois index | | | |
servers ---- ----
____ ____ ____
individual | | | | | |
whois servers | | | | | |
---- ---- ----
Fig. 2 - Indexing system architecture.
-------------------------------------------------------------------
1.4. Getting Help
Another extension to the basic WHOIS service is the requirement that
all servers support at least a minimal set of help commands, allowing
users to find out information about both the individual server and
the entire WHOIS++ service itself. This is done in the context of the
new extended information model by defining two specific template
formats and requiring each server to offer at least one example of
each record using these formats. The operator of each WHOIS service
is therefor expected to have, as a minimum, a single example of
SERVICES and HELP records, which can be accessed through appropriate
commands.
1.4.1. Minimum HELP Required
Executing the command:
DESCRIBE
gives a brief information about the WHOIS++ server.
Deutsch, et al Standards Track [Page 9]
RFC 1835 Architecture of the WHOIS++ service August 1995
Executing the command:
HELP
gives a brief description of the WHOIS++ service itself.
The text of both required helped records should contain pointers to
additional help subjects that are available.
Executing the command:
HELP <searchstring>
may give information on any topic.
1.5. Options and Constraints
The WHOIS++ service is based upon a minimal core set of commands and
controlling constraints. A small set of additional optional commands
and constraints can be supported. These would allow users to perform
such tasks as provide security options, modify the information
contents of a server or add multilingual support. The required set of
WHOIS++ commands are summarized in section 2.2. WHOIS++ constraints
are described in section 2.3. Optional constraints are described in
section 2.3.2.
1.6. Formatting Responses
The output returned by a WHOIS++ server is structured to allow
machine parsing and automated handling. Of particular interest in the
ability to return summary information about a search (without having
to return the entire results).
All output of searches will be returned in one of five output
formats, which will be one of FULL, ABRIDGED, HANDLE, SUMMARY or
SERVER-TO-ASK. Note that a conforming server is only required to
support the first four formats.
When available, SERVER-TO-ASK format is used to indicate that a
search cannot be completed but that one or more alternative WHOIS++
servers may be able to perform the search.
Details of each output format are specified in section 2.4.
Deutsch, et al Standards Track [Page 10]
RFC 1835 Architecture of the WHOIS++ service August 1995
1.7. Reporting Warnings and Errors
The formatted response of WHOIS++ commands allows the encoding of
warning or error messages to simplify parsing and machine handling.
The syntax of output formats are described in detail in section 2.4,
and details of WHOIS++ warnings and error conditions are given in
Appendix E.
All system messages are numerical, but can be tagged with text. It is
the clients decision if the text is presented to the user.
1.8. Privacy and Security Issues
The basic WHOIS++ service was conceived as a simple, unauthenticated
information lookup service, but there are occasions when
authentication mechanisms are required. To handle such cases, an
optional mechanism is provided for authenticating each WHOIS++
transaction.
The current identified authentication mechanism is PASSWORD, which
uses simple password authentication. Any other scheme name used must
begin with the characters "X-" and should thus be regarded as
experimental and non-standard.
Note that the WHOIS++ authentication mechanism does not dictate the
actual authentication scheme used, it merely provides a framework for
indicating that a particular transaction is to be authenticated, and
the appropriate mechanisms to use. This mechanism is extensible and
individual implementors are free to add additional mechanisms.
This document includes a very simple authentication scheme where a
combination of username and password is sent together with the search
string so the server can verify that the user have access to the
information. Note that this is NOT by any means a method recommended
to secure the data itself because both password and information are
tranferred unencrypted over the network.
Given the unauthenticated nature that default services like white
pages services are, it is easy to either forget the implications of
this and just show all data to the public Internet, or think that
Internet is so dangerous that information is hidden from the Internet
so the whole idea of a global white pages service is lost. Therefore
the type of authentication scheme selected and the public nature of
the Internet environment must still be taken into consideration when
assessing the security and authentication of the information served.
A more detailed exposition on security is outside the scope of this
document.
Deutsch, et al Standards Track [Page 11]
RFC 1835 Architecture of the WHOIS++ service August 1995
2. Part II - WHOIS++ Implementation
2.1. The WHOIS++ interaction model
A WHOIS++ server will normally listen for a TCP connections on the
allocated WHOIS++ port (although a WHOIS++ server can be accessed
over any TCP connection). Once a connection is established, the
server issues a banner message, and listens for input. The command
specified in this input is processed and the results returned
including an ending system message. If the optional HOLD constraint
has not been specified the connection is then terminated.
If the server supports the optional HOLD constraint, and this
constraint is specified as part of any command, the server continues
to listen on the connection for another line of input. This cycle
continues as long as the sender continues to append the required HOLD
constraint to each subsequent command.
At the same time, each server is permitted to set an optional timeout
value (which should be indicated in the response to the CONSTRAINTS
command). If set, the server is free to terminate an idle connection
at any time after this delay has passed with no input from the
client. If the server terminates the connection due to timeout, it
will be indicated by the system message. The timeout value is not
changeable by the client.
2.2. The WHOIS++ Command set
There are two types of WHOIS++ commands - system commands and the
WHOIS++ search command.
The WHOIS++ command set consists of a core set of required systems
commands, a single required search command and an set of optional
system commands which support features that are not required by all
servers. The set of required WHOIS++ system commands are listed in
Table I. Details of the allowable search terms for the search command
are included in Table II.
Each WHOIS++ command also allows the use of one or more controlling
constraints, when selected can be used to override defaults or
otherwise modify server behavior. There is a core set of constraints
that must be supported by all conforming servers. These include
SEARCH (which controls the type of search performed), FORMAT (which
determines the output format used) and MAXHITS (which determines the
maximum number of matches that a search can return).
These required constraints are summarized in Table III.
Deutsch, et al Standards Track [Page 12]
RFC 1835 Architecture of the WHOIS++ service August 1995
An additional set of optional constraints are used to provide support
for different character sets, indicate the need and type of
authentication to perform on a transaction, and permit multiple
transactions during a single communications session. These optional
constraints are listed in Table IV.
It is possible, using the required COMMANDS and CONSTRAINTS system
commands, to query any WHOIS++ server for its list of supported
commands and constraints.
2.2.1. System Commands
System commands are commands to the server for information or to
control its operation. These include commands to list the template
types available from individual servers, to obtain a single blank
template of any available type, and commands to obtain the list of
valid commands and constraints supported on a server.
There are also commands to obtain the current version of the WHOIS++
protocol supported, to access a simple help subsystem, to obtain a
brief description of the service (which is intended, among other
things, to support the automated registration of the service by
yellow pages directory services). All of these commands are required
from a conforming WHOIS++ server.
Deutsch, et al Standards Track [Page 13]
RFC 1835 Architecture of the WHOIS++ service August 1995
------------------------------------------------------------------------
Short Long Form Functionality
----- --------- -------------
COMMANDS [ ':' HOLD ] list valid WHOIS++ commands
supported by this server
CONSTRAINTS [ ':' HOLD ] List valid constraints
supported by this server
DESCRIBE [ ':' HOLD ] Describe this server,
formating the response
using a standard
"Services" template
'?' HELP [<string> [':' <cnstrnts>]] System help, using a "Help"
template
LIST [':' <cnstrnts>] List templates supported
by this system
POLLED-BY [ ':' HOLD ] List indexing servers
that are know to track
this server
POLLED-FOR [ ':' HOLD ] List information about
what this server is
tracking for
SHOW <string> [':' <cnstrnts>] Show contents of templates
specified
VERSION [ ':' HOLD ] return current version of
the protocol supported.
Table I - Required WHOIS++ SYSTEM commands.
------------------------------------------------------------------------
Below follows a descriptions for each command. Examples of responses
to each command is in Appendix C.
2.2.1.1. The COMMANDS command
The COMMANDS command returns a list of commands that the server
supports. The response is formatted as a FULL response.
Deutsch, et al Standards Track [Page 14]
RFC 1835 Architecture of the WHOIS++ service August 1995
2.2.1.2. The CONSTRAINTS command
The CONSTRAINTS command returns a list of constraints and the values
of those that the server supports. The response is formatted as a
FULL response, where every constraint is represented as a separate
record. The template name for these records is CONSTRAINT. No
attention is paid to handles. Each record has, as a minimum, the
following two fields:
- "Constraint", which contains the attribute name described -
"Default", which shows the default value for this constraint.
If the client is permitted to change the value of the constraint,
there is also:
- "Range" field, which contains a list of values that this
server supports, as a comma separated list; Or, if the range
is numerical, as a pair of numbers separated with a hyphen.
2.2.1.3. The DESCRIBE command
The DESCRIBE command gives a brief description about the server in a
"Services" template. The result is formatted as a FULL response.
2.2.1.4. The HELP command
The HELP command takes an optional argument as subject to get help
for.
2.2.1.5. The LIST command
The LIST command returns the name of the templates available on the
server. The answer is formatted FULL format response.
2.2.1.6. The POLLED-BY command
The POLLED-BY command returns a list of servers and the templates and
attribute names that those server polled as centroids from this
server. The format is in FULL format with two attributes, Template
and Field. Each of these is a list of names of the templates or
fields polled. An empty result means either that the server is not
polled by anyone, or that it doesn't support indexing.
Deutsch, et al Standards Track [Page 15]
RFC 1835 Architecture of the WHOIS++ service August 1995
2.2.1.7. The POLLED-FOR command
The POLLED-FOR command returns a list of servers that this server has
polled, and the template and attribute names for each of those. The
answer is in FULL format with two attributes, Template and Field. An
empty result means either that the server is not polling anyone, or
that it doesn't support indexing.
2.2.1.8. The SHOW command
The SHOW command takes a template name as argument and returns
information about a specific template, formatted as a FULL response.
The answer is formatted as a blank template with the requested name.
2.2.1.9. The VERSION command
The output format is a FULL response containg a record with template
name VERSION. The record must have attribute name "Version", which
value is "1.0" for this version of the protocol. The record may also
have the additional fields "Program-Name" and "Program-Version" which
gives information about the server implementation if the server so
desires.
2.2.2. The Search Command
A search command consists of one or more search terms, which might
each have local constraints, followed by an optional colon with a set
of global search constraints.
Each attribute value in the WHOIS++ database is divided into one or
more words separated by whitespace. Each search term operates on
every word in the attribute value.
Two or more search terms may be combined with boolean operators AND,
OR or NOT (other than the implied AND between terms). The operator
AND has higher precedence than the operator OR, but this can be
changed by the use of parentheses.
Search constraints that apply to every search term are specified as
global constraints. Local constraints override global constraints for
the search term they are bound to. The search terms and the global
constraints are separated with a colon (':'). Additional global
constraints are appended to the end of the search command delimited
with a semicolon ';'.
If different search constraints can not be fulfilled, or the
combination of different search constraints is uncombinable, the
server may choose to ignore some constraints, but still do the search
Deutsch, et al Standards Track [Page 16]
RFC 1835 Architecture of the WHOIS++ service August 1995
and return some records.
The set of required constraints are summarized in Table III. The set
of optional constraints are summarized in Table IV.
As an option, the server may accept specifications for attributes for
either inclusion or exclusion from a reply. Thus, users could specify
-only- those attributes to return, or specific attributes to filter
out, thus creating custom views.
2.2.2.1. Format of a Search Term
Each search term consists of one of the following:
1) A search string, followed by an optional semicolon and set of
semicolon-separated local constraints.
2) A search term specifier (as listed in Table II), followed by a
'=', followed by a search string, an optional semicolon and a
set of semicolon-separate local constraints.
3) An abbreviated search term specifier, followed by a search
string, followed by an optional semicolon and set of
semicolon-separated local constraints.
4) A combination of attribute name, followed by '=', followed by
a search string, followed by an optional semicolon and set of
semicolon-separate local constraints.
If no term identifier is provided, then the search will be applied to
attribute values only. This corresponds to an identifier of VALUE.
If a SEARCH-ALL specifier is used then the search will be applied to
all template names, handles, attribute names and attribute values.
When the user specifies the search term using the form:
"<attribute_name> = <value>"
this is considered to be an ATTRIBUTE-VALUE search.
For discussion of the system reply format, and selecting the
appropriate reply format, see section 2.4.
Deutsch, et al Standards Track [Page 17]
RFC 1835 Architecture of the WHOIS++ service August 1995
-------------------------------------------------------------------
Valid specifiers:
-----------------
Name Functionality
---- -------------
ATTRIBUTE-VALUE [ ';' <constrnt>]* allows combining
attribute and value
specifiers in one term.
HANDLE [ ';' <constrnt>]* Confine search to handles.
SEARCH-ALL [ ';' <constrnt>]* Search everything.
TEMPLATE [ ';' <constrnt>]* Confine search to
template names.
VALUE [ ';' <constrnt>]* Confine search to attribute
values. This is the default.
(Note: The name HANDLE can be replaced with the shortname '!')
Acceptable forms of a search specifier:
---------------------------------------
1) <searchstring> [';' <constraint>]*
2) <specifier> = <searchstring> [';' <constraint>]*
3) <shortspecifier> <searchstring> [';' <constraint>]*
4) <attribute_name> = <searchstring> [';' <constraint>]*
(Note: A <constraint> is a name of a valid local constraint.)
Table II - Valid search command term specifiers.
-------------------------------------------------------------------
2.2.2.2. Format of a Search String
Special characters that need to be quoted are preceeded by a
backslash, '\'.
Special characters are space ' ', tab, equal sign '=', comma ',',
colon ':', backslash '\', semicolon ';', asterisk '*', period '.',
parenthesis '()', square brackets '[]', dollar sign '$' and
circumflex '^'.
Deutsch, et al Standards Track [Page 18]
RFC 1835 Architecture of the WHOIS++ service August 1995
If the search term is given in some other character set than ISO-
8859-1, it must be specified by the constraint INCHARSET.
2.3. WHOIS++ Constraints
Constraints are intended to be hints or recommendations to the server
about how to process a command. They may also be used to override
default behaviour, such as requesting that a server not drop the
connection after performing a command.
Thus, a user might specify a search constraint as "SEARCH=exact",
which means that the search engine is to perform an exact match
search. It might also specify "LANGUAGE=Fr", which implies that the
server should use French in fuzzy matches. It might also be able to
issue system messages in French.
In general, contraints take the form "<constraintname>=<value>", with
<value> being one of a specified set of valid values. The notable
exception is "HOLD", which takes no argument.
All constraints can be used as a global constraint, but only a few
can be used as local. See tables IV and V for information of which
constraints can be local.
The CONSTRAINTS system command is used to list the search constraints
supported by an individual server.
If a server cannot satisfy the specified constraint there will be a
mechanism for informing the user in the reply, using system messages.
In such cases, the search is still performed, with the the server
ignoring unsupported constraints.
Deutsch, et al Standards Track [Page 19]
RFC 1835 Architecture of the WHOIS++ service August 1995
2.3.1. Required Constraints
The following CONSTRAINTS must be supported in all conforming WHOIS++
servers.
------------------------------------------------------------------
Format LOCAL/GLOBAL
------ -------------
SEARCH= {exact | lstring } LOCAL/GLOBAL
FORMAT= {full | abridged | handle | summary } GLOBAL
MAXHITS= { 1-<max-allowed> } GLOBAL
Table III - Required WHOIS++ constraints.
------------------------------------------------------------------
Deutsch, et al Standards Track [Page 20]
RFC 1835 Architecture of the WHOIS++ service August 1995
2.3.2. Optional CONSTRAINTS
The following CONSTRAINTS and constraint values are not required of a
conforming WHOIS++ server, but may be supported. If supported, their
names and supported values must be returned in the response to the
CONSTRAINTS command.
---------------------------------------------------------------------
Format LOCAL/GLOBAL
------ -------------
SEARCH= { regex | fuzzy | substring | <X-format> } LOCAL/GLOBAL
CASE= { ignore | consider } LOCAL/GLOBAL
FORMAT= { server-to-ask | <X-format> } GLOBAL
MAXFULL= { 1-<max-allowed> } GLOBAL
AUTHENTICATE= password GLOBAL
NAME= <string> GLOBAL
PASSWORD= <string> GLOBAL
INCHARSET= { us-ascii | iso-8859-* } GLOBAL
LANGUAGE= <As defined in ISO 639:1988> GLOBAL
HOLD GLOBAL
IGNORE= {attributelist} GLOBAL
INCLUDE= {attributelist} GLOBAL
Table IV - Optional WHOIS++ constraints.
----------------------------------------------------------------------
Deutsch, et al Standards Track [Page 21]
RFC 1835 Architecture of the WHOIS++ service August 1995
2.3.2.1. The SEARCH Constraint
The SEARCH constraint is used for specifying the method that is to be
used for the search. The default method is "exact". Following is a
definition of each search method.
exact The search will succeed for a word that exactly
matches the search string.
substring The search will succeed for a word that matches
a part of a word.
regex The search will succeed for a word when a regular
expression matches the searched data. Regular
expression is built up by using constructions of
'*', '.', '^', '$', and '[]'. For use of
regular expressions see Appendix G.
fuzzy The search will succeed for words that matches the
search string by using an algorithm designed to catch
closely related names with different spelling, e.g.
names with the same pronounciation. The server
chooses which algorithm to use, but it may vary
depending on template name, attribute name and
language used (see Constraint Language above).
lstring The search will succed for words that begins
with the search string.
2.3.2.2. The FORMAT Constraint
The FORMAT constraint describes what format the result will be in.
Default format is FULL. For a description of each format, see Server
Response Modes below.
2.3.2.3. The MAXFULL Constraint
The MAXFULL constraint sets the limit of the number of matching
records the server allows before it enforces SUMMARY responses. The
client may attempt to override this value by specifying another value
to that constraint. Example: If, for privacy reasons, the server will
return the response in SUMMARY format if the number of hits exceeds
2, the MAXFULL constraint is set to 2 by the server.
Regardless of what format the client did or did not ask for, the
server will change the response format to SUMMARY when the number of
matching records equals or exceeds this value.
Deutsch, et al Standards Track [Page 22]
RFC 1835 Architecture of the WHOIS++ service August 1995
2.3.2.4. The MAXHITS Constraint
The MAXHITS constraint sets the maximum number of records the client
can get in a search respone.
2.3.2.5. The CASE Constraint
The CASE constraint defines if the search should be done case
sensistive or not. Default value is to have case ignored.
2.3.2.6. The AUTHENTICATE Constraint
The AUTHENTICATE constraint describes which authentication method to
use when executing the search. By using a specific authentication
method, some other constraints might be needed which is specified by
the authentication method.
The only authentication method described in this document is
"password", if used, also the two other constraints "name" and
"password" need to be set.
2.3.2.7. The NAME Constraint
The NAME constraint is only used together with some authentication
method named by the constraint "authenticate". The only use described
in this document is by sending a username as a string of characters
which together with the string given as an argument to the "password"
constraint is sent to the server. The server can use that pair of
strings to do a simple authentication check, similar to the UNIX
login program.
2.3.2.8. The PASSWORD Constraint
The PASSWORD constraint is only used together with some
authentication method named by the constraint "authenticate". The
only use described in this document is by sending a password as a
string of characters which together with the string given as an
argument to the "name" constraint is sent to the server. The server
can use that pair of strings to do a simple authentication check,
similar tothe UNIX login program.
2.3.2.9. The LANGUAGE Constraint
The LANGUAGE constraints can be used as an extra information to the
fuzzy matching search method, and it might also be used to tell the
server to give the system responses in another language, although
this ability should be handled by the client. The language code
defined in RFC 1766 [ALVE95] can be used as a value for the language
Deutsch, et al Standards Track [Page 23]
RFC 1835 Architecture of the WHOIS++ service August 1995
constraint. In these, the case of the letters are insignigicant.
2.3.2.10. The INCHARSET Constraint
The INCHARSET constraint tells the server in which character set the
search string itself is given in. The default character set is ISO-
8859-1.
2.3.2.11. The IGNORE Constraint
The IGNORE constraint specifies which attributes to NOT include in
the result. All other attributes will be included (as if named
explicitly by the "include" constraint).
If an attribute is named both with the "include" and "ignore"
constraint, the attribute is to be included in the result, but the
system message must be "% 205 Requested constraint not fulfilled".
2.3.2.12. The INCLUDE Constraint
The INCLUDE constraint specifies which attributes to include in the
result. All other attributes will be excluded (as if named explicitly
by the "ignore" constraint).
If an attribute is named both with the "include" and "ignore"
constraint, the attribute is to be included in the result, but the
system message must be "% 205 Requested constraint not fulfilled".
2.4. Server Response Modes
There are currently a total of five different response modes possible
for WHOIS++ servers. These are FULL, ABRIDGED, HANDLE, SUMMARY and
SERVER-TO-ASK. The syntax of each output format is specified in more
detail in the following section.
1) A FULL format response provides the complete contents of a
template matching the specified query, including the template
type, the server handle and an optional record handle.
2) An ABRIDGED format response provides a brief summary, including
(as a minimum) the server handle, the corresponding record handle
and relevant information for that template.
3) A HANDLE format response returns a line with information about
the server handle and record handle for a record that matched
the specified query.
Deutsch, et al Standards Track [Page 24]
RFC 1835 Architecture of the WHOIS++ service August 1995
4) A SUMMARY response provides only a brief summary of information
the number of matches and the list of template types in which the
matches occured.
5) A SERVER-TO-ASK response only returns pointers to other index
servers which might possibly be able to answer the specified
query.
The server may respond with a null answer and may also respond with a
null answer together with a correct system message to indicate that
the query was too complex.
2.4.1. Default Responses
By default, a WHOIS++ server will provide FULL responses. This may be
changed by the client with the use of the global constraint "format".
The server is allowed to provide response in SUMMARY format if the
number of hits exceeds the value of the global constraint "maxfull".
The server will not respond with more matches than the value
specified with the global constraint "maxhits"; Not in any response
format. If the number of matches exceeds this value, the server will
issues the system message 110 (maxhits value exceeded), but will
still show the responses, up to the number of the "maxhits"
constraint value. This mechanism will allow the server to hide the
number of possible matches to a search command.
The server response modes are summarized in Table V.
2.4.2. Format of Responses
Each response consists of a numerical system generated message, which
can be tagged with text, followed by an optional formatted response
message, followed by a second system generated messages.
That is:
'%' <system messages> <nl>
[ <formatted response> ]
'%' <system messages> <nl>
If there are no matches to a query, the system is not required to
generate any output as a formatted response, although it must still
generate system messages.
Deutsch, et al Standards Track [Page 25]
RFC 1835 Architecture of the WHOIS++ service August 1995
For information about the format for system messages, see Appendix E.
2.4.3. Syntax of a Formatted Response
All formatted responses except for the HANDLE response, consists of a
response-specific START line, followed by an optional response-
specific data section, followed by a TERMINATION line. The HANDLE
response is different in that it only consists of a START line. It
is permissible to insert any number of lines consisting solely of
newlines within a formatted response to improve readibility.
Each line shall be limited to no more than 81 characters, including
the terminating newline. If a line (including the required leading
single space) would exceed 81 characters, it is to be broken into
lines of no more than 81 characters, with each continuation line
beginning with a "+" character in the first column instead of the
leading character.
If an attribute value in a data section includes a line break, the
line break must be replaced by a CR/LF pair and the following line
begin with a "-" character in the first column, instead of the
leading character. The attribute name is not repeated on consecutive
lines.
A TERMINATION line consists of a line with a '#' in the first column,
followed by one white space character (SPACE or TAB), followed by the
keyword END, followed by zero or more characters, followed by a
newline.
A response-specific section will be one of the following:
1) FULL Format Response
2) ABRIDGED Format Response
3) HANDLE Format Response
4) SUMMARY Format Response
5) SERVER-TO-ASK Format Response
The details of each are specified in the following sections:
2.4.3.1. A FULL format response
A FULL format response consists of a series of responses, each
consisting of a START line, followed by the complete template
information for the matching record and a TERMINATION line.
Each START line consists of a '#' in the first column, followed by
one white space character, the word "FULL", a white space character,
the name of the corresponding template type, one white space
Deutsch, et al Standards Track [Page 26]
RFC 1835 Architecture of the WHOIS++ service August 1995
character, the server handle, a white space character, an optional
handle for the record, and a terminating newline.
The template information for the record will be returned as a series
of lines consisting of a single space, followed by the corresponding
line of the record.
The line of the record shall consist of a single space and the
attribute name followed by a ':', a single space, the value of that
attribute, and a newline.
2.4.3.2. ABRIDGED Format Response
Each ABRIDGED format response consists of a START line, a single line
excerpt of the template information from each matching record and a
TERMINATION line. The excerpt information shall include information
that is relevant to the template type.
The START line consists of a '#' in the first column, followed by one
white space character, the word "ABRIDGED", a white space character,
the name of the corresponding template type, a white space character,
the server handle, a white space character, the handle for the
record, and a terminating newline.
The abridged template information will be returned as a line,
consisting of a single space, followed by the abridged line of the
record and a newline pair.
2.4.3.3. HANDLE Format Response
A HANDLE response consists of a single START line, which shall start
with a '#' in the first column, followed by one white space
character, the word "HANDLE", a white space character, the name of
the corresponding template, a white space character, the handle for
the server, a white space character, the handle for that record, and
a terminating newline.
2.4.3.4. SUMMARY Format Response
A SUMMARY format response consists of a single set of responses,
consisting of a line listing the number of matches to the specified
query, followed by a list of all template types which satisfied the
query at least once.
The START line shall begin with a '#' in the first column, be
followed by one white space character, the word "SUMMARY", a white
space character, the handle for the server, and a terminating
newline.
Deutsch, et al Standards Track [Page 27]
RFC 1835 Architecture of the WHOIS++ service August 1995
All following lines until the TERMINATION line starts with a leading
space. The first line shall begin with the string "matches: ", be
followed by a space and the number of responses to the query and
terminated by a newline. The second line shall begin with the string
"templates: ", be followed by a newline separated list of the name of
the template types which matched the query. Each line following the
first which include the text "templates:" must begin with a '-'
instead of a space.
2.4.3.5. SERVER-TO-ASK Response
A SERVER-TO-ASK response consists of information to the client about
a server to contact next to resolve a query. If the server has
pointers to more than one server, it will present additional SERVER-
TO-ASK responses.
The SERVER-TO-ASK response will consist of a START line and a number
of lines with attribute-value pairs, separated by CRLF. Each line is
indented with one space. The end of a SERVER-TO-ASK response is
indicated with a TERMINATION line.
Each START line consists of a '#' in the first column, followed by
one white space character, the word "SERVER-TO-ASK", a white space
character, the handle of the server and a terminating newline.
1. "Server-Handle" - The server handle of the server pointed at.
(req.)
2. "Host-Name" - A cached host named for the server pointed at. (opt.)
3. "Host-Port" - A cached port number for the server pointed at.
(opt.)
Other attributes may be present, depending on the index server.
2.4.4. System Generated Messages
All system generated messages must begin with a '%' as the first
character, a space as the second one, followed by a three digit
number, a space and an optional text message. The total length of the
line must be no more than 81 characters long, including the
terminating CR LF pair. There is no limit to the number of system
messages that may be generated.
The format for multiline replies requires that every line, except the
last, begin with "%", followed by space, the reply code, a hyphen,
and an optional text. The last line will begin with "%", followed by
space, the reply code, a space and some optional text.
Deutsch, et al Standards Track [Page 28]
RFC 1835 Architecture of the WHOIS++ service August 1995
System generated messages displayed before or after the formatted
response section are expected to refer to operation of the system or
refer to the entire query. System generated messages within the
output of an individual record during a FULL reponse are expected to
refer to that record only, and could (for example) be used to
indicate problems with that record of the response. See Appendix E
for a description of system messages.
2.5. Compatibility with Older WHOIS Servers
Note that this format, although potentially more verbose, is still in
a human readible form. Responses from older systems that do not
follow this format are still conformant, since their responses would
be interpreted as being equivalent to optional text messages, without
a formatted response. Clients written to this specification would
display the responses as a advisory text message, where it would
still be readible by the user.
3. Miscellaneous
3.1. Acknowledgements
The WHOIS++ effort began as an intensive brainstorming session at the
24th IETF, in Boston Massachusetts. Present at the birth, and
contributing ideas through this early phase, were (alphabetically)
Peter Deutsch, Alan Emtage, Jim Fullton, Joan Gargano, Brad
Passwaters, Simon Spero, and Chris Weider. Others who have since
helped shape this document with feedback and suggestions include
Roxana Bradescu, Patrik Faltstrom, Kevin Gamiel, Dan Kegel, Michael
Mealling, Mark Prior and Rickard Schoultz.
3.2 References
[ALVE95] Alvestrand H., "Tags for the Identification of
Languages", RFC 1766, UNINETT, March 1995.
[HARR85] Harrenstein K., Stahl M., and E. Feinler,
"NICNAME/WHOIS", RFC 954, SRI, October 1985.
[IIIR] Weider C., and P. Deutsch, "A Vision of an
Integrated Internet Information Service", RFC 1727
Bunyip Information Systems, Inc., December 1994.
[POST82] Postel J., "Simple Mail Transfer Protocol", STD 10,
RFC 821, USC/Information Sciences Institute,
August 1982.
Deutsch, et al Standards Track [Page 29]
RFC 1835 Architecture of the WHOIS++ service August 1995
3.3. Authors' Addresses
Peter Deutsch
BUNYIP INFORMATION SYSTEMS, Inc.
310 St-Catherine St West,
Suite 202,
Montreal, Quebec H2X 2A1
CANADA
EMail: peterd@bunyip.com
Rickard Schoultz
KTHNOC, SUNET/NORDUnet/Ebone Operations Centre
100 44 STOCKHOLM
SWEDEN
EMail: schoultz@sunet.se
Patrik Faltstrom
BUNYIP INFORMATION SYSTEMS, Inc.
310 St-Catherine St West,
Suite 202,
Montreal, Quebec H2X 2A1
CANADA
EMail: paf@bunyip.com
Chris Weider
BUNYIP INFORMATION SYSTEMS, Inc.
2001 S. Huron Parkway, #12
Ann Arbor, MI 48104
USA
EMail: clw@bunyip.com
Deutsch, et al Standards Track [Page 30]
RFC 1835 Architecture of the WHOIS++ service August 1995
Appendix A - Some Sample Queries
author=chris and template=user
The result will consist of all records where attribute "author"
matches "chris" with case ignored. Only USER templates will be
searched. An example of a matching record is "Author=Chris Weider".
This is the typical case of search.
schoultz and rick;search=lstring
The result will consist of all records which have one attribute value
matching "schoultz" exactly and one having "rick" as leading
substring, both with case ignored. One example is "Name=Rickard
choultz".
value=phone;search=substring
The result will consist of all records which have attribute values
matching *phone*, for example the record "Name=Acme telephone inc.",
but will not match the attribute name "phone". (Since "value" term
specifier is the default, the search term could be "phone" as well as
"value=phone".)
search-all=Peter ; search=substring;case=consider
The result will consist of all records which have attribute names,
template names or attribute values matching "Peter" with respect to
case. One example is "Friend-Of-Peter: Yes".
ucdavis;search=substring and (gargano or joan):include=name,email
This search command will find records which have records containing
the words "gargano" or "joan" somewhere in the record, and has the
word "ucdavis" somewhere in a word. The result will only show the
"name" and "email" fields.
Appendix B - Some sample responses
1) FULL format responses:
# FULL USER SERVERHANDLE1 PD45
Name: Peter Deutsch
email: peterd@bunyip.com
# END
# FULL USER SERVERHANDLE1 AE1
Name: Alan Emtage
email: bajan@bunyip.com
Deutsch, et al Standards Track [Page 31]
RFC 1835 Architecture of the WHOIS++ service August 1995
# END
# FULL USER SERVERHANDLE1 NW1
Name: Nick West
Favourite-Bicycle-Forward-Wheel-Brand: New Bicy
+cles Acme Inc.
email: nick@bicycle.acme.com
My-favourite-song: Happy birthday to you!
-Happy birthday to you!
-Happy birthday dear Nick!
-Happy birthday to you.
# END
# FULL SERVICES SERVERHANDLE1 WWW1
Type: World Wide Web
Location: the world
# END
--------------------
2) An ABRIDGED format response:
# ABRIDGED USER SERVERHANDLE1 PD45
Peter Deutsch peterd@bunyip.com
# END
# ABRIDGED USER SERVERHANDLE1 AE1
Alan Emtage bajan@bunyip.com
# END
# ABRIDGED USER SERVERHANDLE1 WWW1
World Wide Web the world
# END
--------------------
3) HANDLE format responses:
# HANDLE USER SERVERHANDLE1 PD45
# HANDLE USER SERVERHANDLE1 AE1
# HANDLE SERVICES SERVERHANDLE1 WWW1
--------------------
Deutsch, et al Standards Track [Page 32]
RFC 1835 Architecture of the WHOIS++ service August 1995
4) A SUMMARY HANDLE format response:
# SUMMARY SERVERHANDLE1
Matches: 175
Templates: User
- Services
- Abstracts
# END
Appendix C - Sample responses to system commands
C.1 Response to the LIST command
# FULL LIST SERVERHANDLE1
Templates: USER
-SERVICES
-HELP
# END
C.2 Response to the SHOW command
This example shows the result after issuing "show user":
# FULL USER SERVERHANDLE1
Name:
Email:
Work-Phone:
Organization-Name:
City:
Country:
# END
C.3 Response to the POLLED-BY command
# FULL POLLED-BY SERVERHANDLE1
Server-handle: serverhandle2
Cached-Host-Name: sunic.sunet.se
Cached-Host-Port: 7070
Template: USER
Field: ALL
# END
# FULL POLLED-BY SERVERHANDLE1
Server-handle: serverhandle3
Cached-Host-Name: kth.se
Cached-Host-Port: 7070
Template: ALL
Deutsch, et al Standards Track [Page 33]
RFC 1835 Architecture of the WHOIS++ service August 1995
Field: Name,Email
# END
C.4 Response to the POLLED-FOR command
# FULL POLLED-FOR SERVERHANDLE1
Server-Handle: serverhandle5
Template: ALL
Field: Name,Address,Job-Title,Organization-Name,
+Organization-Address,Organization-Name
# END
# FULL POLLED-FOR SERVERHANDLE1
Server-Handle: serverhandle4
Template: USER
Field: ALL
# END
C.5 Response to the VERSION command
# FULL VERSION BUNYIP.COM
Version: 1.0
Program-Name: kth-whoisd
Program-Version: 2.0
# END
C.6 Response to the CONSTRAINTS command
# FULL CONSTRAINT COMEDIA.SE
Constraint: format
Default: full
Range: full,abridged,summary,handle
# END
# FULL CONSTRAINT COMEDIA.SE
Constraint: maxhits
Default: 200
Range: 1-1000
# END
# FULL CONSTRAINT COMEDIA.SE
Constraint: search
Default: exact
Range: exact,substring,lstring
# END
# FULL CONSTRAINT COMEDIA.SE
Constraint: maxfull
Default: 20
Deutsch, et al Standards Track [Page 34]
RFC 1835 Architecture of the WHOIS++ service August 1995
# END
C.3 Response to the COMMANDS command
# FULL COMMANDS SERVERHANDLE1
Commands: commands
-constraints
-describe
-help
-list
-polled-by
-polled-for
-show
-version
# END
Appendix D - Sample whois++ session
Below is an example of a session between a client and a server. The
angle brackets to the left is not part of the communication, but is
just put there to denonte the direction of the communication between
the server or the client. Text appended to '>' means messages from
the server and '<' from the client.
Client connects to the server
>% 220-Welcome to
>% 220-the whois++ server
>% 220 at ACME inc.
<name=Nick:hold
>% 200 Command okay
>
># FULL USER ACME.COM NW1
> name: Nick West
> email: nick@acme.com
># END
># SERVER-TO-ASK ACME.COM
> Server-Handle: SUNETSE01
> Host-Name: whois.sunet.se
> Host-Port: 7070
># END
># SERVER-TO-ASK ACME.COM
> Server-Handle: KTHSE01
># END
>% 226 Tranfer complete
<version
>% 200 Command okay
># FULL VERSION ACME.COM
Deutsch, et al Standards Track [Page 35]
RFC 1835 Architecture of the WHOIS++ service August 1995
> Version: 1.0
># END
>% 226 Tranfer complete
>% 203 Bye
Server closes the connection
In the example above, the client connected to a whois++ server and
queried for all records where the attribute "name" equals "Nick", and
asked the server not to close the connection after the response by
using the global constraint "HOLD".
The server responds with one record and a pointer to two other
servers that either holds records or pointers to other servers.
The client continues with asking for the servers version number
without using the HOLD constraint. After responding with protocol
version, the server closes the connection.
Note that each response from the server begins system message 200
(Command OK), and ends with system message 226 (Transfer Complete).
Appendix E - System messages
A system message begins with a '%', followed by a space and a three
digit number, a space, and an optional text message. The line message
must be no more than 81 characters long, including the terminating CR
LF pair. There is no limit to the number of system messages that may
be generated.
A multiline system message have a hyphen instead of a space in column
6, immediately after the numeric response code in all lines, except
the last one, where the space is used.
Example 1
% 200 Command okay
Example 2
% 220-Welcome to
% 220-the whois++ server
% 220 at ACME inc.
The client is not expected to parse the text part of the response
message except when receiving reply 600, in which case the text part
is the name of a character set that will be used by the server in the
rest of the response. The valid values for characters sets is
specified in the "characterset" list in the BNF listing in Appendix
Deutsch, et al Standards Track [Page 36]
RFC 1835 Architecture of the WHOIS++ service August 1995
F.
The theory of reply codes is described in Appendix E in STD 10, RFC
821 [POST82].
------------------------------------------------------------------------
List of system response codes
------------------------------
110 Too many hits The number of matches exceeded
the value specified by the
maxhits constraint. Server
will still reply with as many
records as "maxhits" allows.
111 Requested constraint not supported One or more constraints in
query is not implemented, but
the search is still done.
112 Requested constraint not fullfilled One or more constraints in
query has unacceptable value
and was therefore not used,
but the search is still done.
200 Command Ok Command accepted and executed.
The client must wait for a
transaction end system message.
201 Command Completed successfully Command accepted and executed.
203 Bye Server is closing connection
220 Service Ready Greeting message. Server is
accepting commands.
226 Transaction complete End of data. All responses to
query are sent.
430 Authentication needed Client requested information
that needs authentication.
500 Syntax error
502 Search expression too complicated This message is sent when the
server is not able to resolve
a query (i.e. when a client
sent a regular expression that
Deutsch, et al Standards Track [Page 37]
RFC 1835 Architecture of the WHOIS++ service August 1995
is too deeply nested).
530 Authentication failed The authentication phase
failed.
600 <token> Subsequent attribute values
are encoded in the charater
set specified by <token>.
Table V - System response codes
------------------------------------------------------------------------
Appendix F - The WHOIS++ BNF Grammar
whois-command = ( system-command [":" "hold"]
/ terms [":" globalcnstrnts] ) NL
system-command = "constraints"
/ "describe"
/ "commands"
/ "polled-by"
/ "polled-for"
/ "version"
/ "list"
/ "show" [1*SP string]
/ "help" [1*SP string]
/ "?" [string]
terms = and-expr *("or" and-expr)
and-expr = not-expr *("and" not-expr)
not-expr = ["not"] (term / ( "(" terms ")" ))
term = generalterm / specificterm
/ shorthandle / combinedterm
generalterm = string *(";" localcnstrnt)
specificterm = specificname "=" string
*(";" localcnstrnt)
specificname = "handle" / "value"
shorthandle = "!" string *(";" localcnstrnt)
Deutsch, et al Standards Track [Page 38]
RFC 1835 Architecture of the WHOIS++ service August 1995
combinedterm = string "=" string *(";" localcnstrnt)
globalcnstrnts = globalcnstrnt *(";" globalcnstrnt)
globalcnstrnt = localcnstrnt
/ "format" "=" format
/ "maxfull" "=" 1*digit
/ "maxhits" "=" 1*digit
/ opt-globalcnst
opt-globalcnst = "hold"
/ "authenticate" "=" auth-method
/ "name" "=" string
/ "password" "=" string
/ "language" "=" language
/ "incharset" "=" characterset
/ "ignore" "=" string
/ "include" "=" string
format = "full" / "abridged" / "handle" / "summary"
/ "server-to-ask"
language = <The language code defined in RFC1766 [ALVE95]>
characterset = "us-ascii" / "iso-8859-1" / "iso-8859-2" /
"iso-8859-3" / "iso-8859-4" / "iso-8859-5" /
"iso-8859-6" / "iso-8859-7" / "iso-8859-8" /
"iso-8859-9" / "iso-8859-10" / "utf-8" /
charset-value
charset-value = 1*char
localcnstrnt = "search" "=" searchvalue /
"case" "=" casevalue
searchvalue = "exact" / "substring" / "regex" / "fuzzy"
/ "lstring"
casevalue = "ignore" / "consider"
auth-method = "password"
string = 0*char
char = "\" specialchar
/ <Characters 0-255 (decimal) except specialchar>
Deutsch, et al Standards Track [Page 39]
RFC 1835 Architecture of the WHOIS++ service August 1995
specialchar = " " / <tab> / "=" / "," / ":" / ";" / "\" /
"*" / "." / "(" / ")" / "[" / "]" / "^" /
"$" / "!" / "?"
digit = "0" / "1" / "2" / "3" / "4" /
"5" / "6" / "7" / "8" / "9"
NL = <CR LF (decimal 13 10)>
NOTE: Significant blanks must be escaped. The following
characters, when significant to the query, may be preceded
and/or followed by a single blank:
: ; , ( ) = !
Appendix G - Description of Regular expressions
The regular expressions described in this section is the same as used
in many other applications and operating systems. It is though very
simple and does not include logical operators AND and OR.
Searches using regular expressions are always using substring
matching except when the regular expression contains the characters
'^' or '$'.
Character Function
--------- --------
<any except those listed in this table> Matches itself
. Matches any character
a* Matches zero or more 'a'
[ab] Matches 'a' or 'b'
[a-c] Matches 'a', 'b' or 'c'
^ Matches beginning of
a token
$ Matches end of a token
Deutsch, et al Standards Track [Page 40]
RFC 1835 Architecture of the WHOIS++ service August 1995
Examples
---------
String Matches Matches not
------- ------- -----------
hello xhelloy heello
h.llo hello helio
h.*o hello helloa
h[a-f]llo hello hgllo
^he.* hello ehello
.*lo$ hello helloo
Deutsch, et al Standards Track [Page 41]
|