/* 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 * * 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 };