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Diffstat (limited to 'contrib/ip_cloaking.c')
| -rw-r--r-- | contrib/ip_cloaking.c | 476 |
1 files changed, 476 insertions, 0 deletions
diff --git a/contrib/ip_cloaking.c b/contrib/ip_cloaking.c new file mode 100644 index 0000000..2b2cf48 --- /dev/null +++ b/contrib/ip_cloaking.c @@ -0,0 +1,476 @@ +/* MODULE CONFIGURATION FOLLOWS -- please read!! */ + +/* Change these numbers to something else. Please + * make sure that they match on ALL servers + * to avoid problems! + */ +#define KEY 23857 +#define KEY2 38447 +#define KEY3 64709 + +/* END OF MODULE CONFIGURATION */ + +/* + * ircd-hybrid: an advanced Internet Relay Chat Daemon (ircd). + * ip_cloaking.c: Provides hostname (partial) cloaking for clients. + * + * Copyright (c) 2005 by the past and present ircd coders, and others. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at you option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILILTY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have recieved a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 + * USA + * + * $Id$ + */ + +/* + * Originally re-written from AustNet's VirtualWorld Code. + * Virtual World written by Roger 'RogerY' Yerramesetti <rogery@austnet.org> + * + * Re-written using the crc32 encryption implementation by //ylo based on the original + * implementation by Gary S. Brown. + * + * HiddenHost implementation based on the code from Unreal IRCd by + * RaYmAn, NiQuiL, narf, Griever (great thinking) eternal, bball, JK.@ roxnet.org + * + * Additional ideas and code by ShadowMaster, [-Th3Dud3-] (RageIRCd), Solaris @ Demonkarma.net, + * Alan 'knight-' LeVee of the ChatJunkies IRC Network and doughk_ff7. + */ + +#include "stdinc.h" +#include "whowas.h" +#include "channel_mode.h" +#include "client.h" +#include "hash.h" +#include "hook.h" +#include "irc_string.h" +#include "ircd.h" +#include "ircd_defs.h" +#include "numeric.h" +#include "s_serv.h" +#include "s_user.h" +#include "send.h" +#include "conf.h" +#include "modules.h" +#include "memory.h" +#include "log.h" +#include "sprintf_irc.h" +#include "userhost.h" + +static unsigned int umode_vhost = 0; +static int vhost_ipv6_err; +static dlink_node *prev_enter_umode; +static dlink_node *prev_umode; +static void *reset_ipv6err_flag(va_list); +static void *h_set_user_mode(va_list); + +/* + * The implementation originally comes from Gary S. Brown. The tables + * are a direct transplant of his original concept and have been + * changed for randomization purposes. Minor changes were also made + * to the crc32-function by //ylo. + * + * knight- + */ + +/* ============================================================= + * COPYRIGHT (C) 1986 Gary S. Brown. You may use this program, or + * code or tables extracted from it, as desired without restriction. + * + * First, the polynomial itself and its stable of feedback terms. The + * polynomial is: + * + * X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0 + * + * Note that we take it "backwards" and put the highest-order term in + * the lowest-order bit. The X^32 term is "implied"; the LSB is the + * X^31 term, etc. The X^0 term (usually shown as "+1") results in + * the MSB being 1. + * + * Note that the usual hardware shift register implementation, which + * is what we're using (we're merely optimizing it by doing eight-bit + * chunks at a time) shifts bits into the lowest-order term. In our + * implementation, that means shifting towards the right. Why do we + * do it this way? Because the calculated CRC must be transmitted in + * order from highest-order term to lowest-order term. UARTs transmit + * characters in order from LSB to MSB. By storing the CRC this way, + * we and it to the UART in the order low-byte to high-byte; the UART + * sends each low-bit to high-bit; and the result is transmission bit + * by bit from highest-order to lowest-order term without requiring any + * bit shuffling on our part. Reception works similarly. + * + * The feedback term table consists of 256, 32-bit entries. Notes: + * + * The table can be generated at runtime if desired; code to do so + * is shown later. It might not be obvious, but the feedback terms + * simply represent the results of eight shift/xor operations for + * all combinations of data and CRC register values. + * + * The values must be right shifted by eight bits by the "updcrc" + * logic; the shift must be unsigned (bring in zeroes). On some hardware + * you could probably optimize the shift in assembler by using byte-swap + * instructions. + * + * polynomial $edb88320 + * + * -------------------------------------------------------------------- + */ + +static unsigned long crc32_tab[] = { + 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, + 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, + 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, + 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, + 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L, + 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, + 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, + 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, + 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, + 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL, + 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, + 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, + 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, + 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, + 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, + 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L, + 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, + 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, + 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, + 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, + 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, + 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, + 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L, + 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, + 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, + 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, + 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, + 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, + 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L, + 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, + 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, + 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, + 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, + 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL, + 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, + 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, + 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, + 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, + 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, + 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L, + 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, + 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, + 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, + 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, + 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, + 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, + 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, + 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, + 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, + 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, + 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, + 0x2d02ef8dL +}; + +static unsigned long +crc32(const char *s, unsigned int len) +{ + unsigned int i; + unsigned long crc32val = 0; + + for (i = 0; i < len; i++) + crc32val = crc32_tab[(crc32val ^ s[i]) & 0xff] ^ (crc32val >> 8); + + return crc32val; +} + +/* + * str2arr() + * + * converts IPv4 address segments into arrays + * for encryption + * + * inputs - address parvs, strings and deliminator + * outputs - array + * side effects - not IPv6 friendly + */ +static int +str2arr(char **pparv, char *string, const char *delim) +{ + char *tok; + int pparc = 0; + + /* Diane had suggested to use this method rather than while() -- knight */ + for (tok = strtok(string, delim); tok != NULL; tok = strtok(NULL, delim)) + { + pparv[pparc++] = tok; + } + + return pparc; +} + +/* + * make_virthost() + * + * curr = current hostname/ip + * host = current host socket + * new = encrypted hostname/ip + */ +static void +make_virthost(char *curr, char *host, char *new) +{ + char mask[HOSTLEN + 1]; + char *parv[HOSTLEN + 1], *parv2[HOSTLEN + 1], s[HOSTLEN + 1], s2[HOSTLEN + 1]; + int parc = 0, parc2 = 0, len = 0; + unsigned long hash[8]; + + strlcpy(s2, curr, HOSTLEN + 1); + strlcpy(s, host, HOSTLEN + 1); + + parc = str2arr(parv, s, "."); + parc2 = str2arr(parv2, s2, "."); + + if (!parc2) + return; + + hash[0] = ((crc32 (parv[3], strlen (parv[3])) + KEY) ^ KEY2) ^ KEY3; + hash[1] = ((KEY2 ^ crc32 (parv[2], strlen (parv[2]))) + KEY3) ^ KEY; + hash[2] = ((crc32 (parv[1], strlen (parv[1])) + KEY3) ^ KEY) ^ KEY2; + hash[3] = ((KEY3 ^ crc32 (parv[0], strlen (parv[0]))) + KEY2) ^ KEY; + + hash[0] <<= 2; + hash[0] >>= 2; + hash[0] &= 0x3FFFFFFF; + hash[0] &= 0xFFFFFFFF; + hash[1] <<= 2; + hash[1] >>= 2; + hash[1] &= 0x7FFFFFFF; + hash[1] &= 0x3FFFFFFF; + hash[2] <<= 2; + hash[2] >>= 2; + hash[2] &= 0x7FFFFFFF; + hash[2] &= 0xFFFFFFFF; + hash[3] <<= 2; + hash[3] >>= 2; + hash[3] &= 0x3FFFFFFF; + hash[3] &= 0x7FFFFFFF; + + /* IPv4 */ + if (parc2 == 4 || parc2 < 2) + { + len = strlen (parv2[3]); + + if (strchr("0123456789", parv2[3][len - 1]) || parc2 < 2) + { + ircsprintf(mask, "%s.%s.%s.%lx", + parv2[parc2 - 4], parv2[parc2 - 3], + parv2[parc2 - 2], hash[3]); + } + else + { + /* isp.tld */ + ircsprintf(mask, "%lx-%lx.%s.%s", + hash[0], hash[3], parv2[parc2 - 2], parv2[parc2 - 1]); + } + } + else + { + if (parc2 >= 4) + { + /* isp.sub.tld or district.isp.tld */ + ircsprintf(mask, "%lx-%lx.%s.%s.%s", + hash[3], hash[1], parv2[parc2 - 3], parv2[parc2 - 2], + parv2[parc2 - 1]); + } + else + { + /* isp.tld */ + ircsprintf(mask, "%lx-%lx.%s.%s", + hash[0], hash[3], parv2[parc2 - 2], parv2[parc2 - 1]); + } + + if (parc2 >= 5) + { + /* zone.district.isp.tld or district.isp.sub.tld */ + ircsprintf(mask, "%lx-%lx.%s.%s.%s.%s", + hash[1], hash[0], parv2[parc2 - 4], parv2[parc2 - 3], + parv2[parc2 - 2], parv2[parc2 - 1]); + } + else + { + /* isp.tld */ + ircsprintf(mask, "%lx-%lx.%s.%s", + hash[0], hash[3], parv2[parc2 - 2], parv2[parc2 - 1]); + } + } + + strlcpy(new, mask, HOSTLEN + 1); +} + +/* + * set_vhost() + * + * inputs - pointer to given client to set IP cloak. + * outputs - NONE + * side effects - NONE + */ +static void +set_vhost(struct Client *client_p, struct Client *source_p, + struct Client *target_p) +{ + target_p->umodes |= umode_vhost; + + if (IsUserHostIp(target_p)) + delete_user_host(target_p->username, target_p->host, !MyConnect(target_p)); + + SetIPSpoof(target_p); + make_virthost(target_p->host, target_p->sockhost, target_p->host); + + add_user_host(target_p->username, target_p->host, !MyConnect(target_p)); + SetUserHost(target_p); + + clear_ban_cache_client(target_p); + + if (IsClient(target_p)) + sendto_server(client_p, CAP_ENCAP, NOCAPS, + ":%s ENCAP * CHGHOST %s %s", + me.name, target_p->name, target_p->host); + + sendto_one(target_p, form_str(RPL_HOSTHIDDEN), + me.name, target_p->name, target_p->host); +} + +static void * +reset_ipv6err_flag(va_list args) +{ + struct Client *client_p = va_arg(args, struct Client *); + struct Client *source_p = va_arg(args, struct Client *); + + vhost_ipv6_err = 0; + + return pass_callback(prev_enter_umode, client_p, source_p); +} + +static void * +h_set_user_mode(va_list args) +{ + struct Client *client_p = va_arg(args, struct Client *); + struct Client *target_p = va_arg(args, struct Client *); + int what = va_arg(args, int); + unsigned int flag = va_arg(args, unsigned int); + + if (flag == umode_vhost) + { + if (what == MODE_ADD) + { + /* Automatically break if any of these conditions are met. -- knight- */ + if (!MyConnect(target_p)) + return NULL; + + if (IsIPSpoof(target_p)) + return NULL; + + /* + * IPv6 could potentially core the server if a user connected via IPv6 sets +h + * so we need to check and break before that happens. -- knight- + */ +#ifdef IPV6 + if (target_p->localClient->aftype == AF_INET6) + { + if (!vhost_ipv6_err) + { + sendto_one(target_p, ":%s NOTICE %s :*** Sorry, IP cloaking " + "does not support IPv6 users!", me.name, target_p->name); + vhost_ipv6_err = 1; + } + } + else +#endif + set_vhost(client_p, target_p, target_p); + } + + return NULL; + } + + return pass_callback(prev_umode, client_p, target_p, what, flag); +} + +static void +module_init(void) +{ + if (!user_modes['h']) + { + unsigned int all_umodes = 0, i; + + for (i = 0; i < 128; i++) + all_umodes |= user_modes[i]; + + for (umode_vhost = 1; umode_vhost && (all_umodes & umode_vhost); + umode_vhost <<= 1); + + if (!umode_vhost) + { + ilog(LOG_TYPE_IRCD, "You have more than 32 usermodes, " + "IP cloaking not installed"); + sendto_realops_flags(UMODE_ALL, L_ALL, SEND_NOTICE, + "You have more than " + "32 usermodes, IP cloaking not installed"); + return; + } + + user_modes['h'] = umode_vhost; + assemble_umode_buffer(); + } + else + { + ilog(LOG_TYPE_IRCD, "Usermode +h already in use, IP cloaking not installed"); + sendto_realops_flags(UMODE_ALL, L_ALL, SEND_NOTICE, + "Usermode +h already in use, " + "IP cloaking not installed"); + return; + } + + prev_enter_umode = install_hook(entering_umode_cb, reset_ipv6err_flag); + prev_umode = install_hook(umode_cb, h_set_user_mode); +} + +static void +module_exit(void) +{ + if (umode_vhost) + { + dlink_node *ptr; + + DLINK_FOREACH(ptr, local_client_list.head) + { + struct Client *cptr = ptr->data; + cptr->umodes &= ~umode_vhost; + } + + user_modes['h'] = 0; + assemble_umode_buffer(); + + uninstall_hook(entering_umode_cb, reset_ipv6err_flag); + uninstall_hook(umode_cb, h_set_user_mode); + } +} + +struct module module_entry = { + .node = { NULL, NULL, NULL }, + .name = NULL, + .version = "$Revision$", + .handle = NULL, + .modinit = module_init, + .modexit = module_exit, + .flags = 0 +}; |