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/* |
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* ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd). |
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* access.c: Common code for user@host access control blocks. |
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* |
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* Copyright (C) 2006 by the Hybrid Development Team. |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
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* USA |
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* |
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* $Id$ |
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*/ |
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|
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#include "stdinc.h" |
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#include "conf/conf.h" |
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|
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struct AccessConf *atable[ATABLE_SIZE] = {0}; |
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struct Callback *cb_expire_confs = NULL; |
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|
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static ACB_FREE_HANDLER *acb_types[MAX_ACB_TYPES] = {0}; |
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static dlink_node *hreset; |
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|
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/* |
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* hash_ipv4() |
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* |
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* Hash algorithm for IPv4. |
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* |
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* inputs: the IP address |
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* output: hash value |
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*/ |
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static unsigned int |
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hash_ipv4(const struct irc_ssaddr *addr, int bits) |
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{ |
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if (bits != 0) |
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{ |
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const struct sockaddr_in *v4 = (const struct sockaddr_in *) addr; |
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unsigned int av = ntohl(v4->sin_addr.s_addr) & ~((1 << (32 - bits)) - 1); |
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|
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return (av ^ (av >> 12) ^ (av >> 24)) % ATABLE_SIZE; |
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} |
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|
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return 0; |
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} |
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|
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/* |
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* hash_ipv6() |
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* |
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* Hash algorithm for IPv6. |
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* |
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* inputs: the IP address |
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* output: hash value |
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*/ |
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#ifdef IPV6 |
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static unsigned int |
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hash_ipv6(const struct irc_ssaddr *addr, int bits) |
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{ |
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const struct sockaddr_in6 *v6 = (const struct sockaddr_in6 *) addr; |
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unsigned int av = 0, n; |
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|
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for (n = 0; n < 16; n++) |
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if (bits >= 8) |
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{ |
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av ^= v6->sin6_addr.s6_addr[n]; |
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bits -= 8; |
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} |
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else |
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{ |
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if (bits > 0) |
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av ^= v6->sin6_addr.s6_addr[n] & ~((1 << (8 - bits)) - 1); |
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break; |
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} |
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|
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return av % ATABLE_SIZE; |
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} |
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#endif |
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|
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/* |
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* hash_text() |
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* |
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* Hash algorithm for DNS names. |
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* |
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* inputs: the start of text to hash |
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* output: hash value |
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*/ |
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static unsigned int |
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hash_text(const char *p) |
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{ |
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unsigned int av = 0; |
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|
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for (; *p; p++) |
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av = (av << 4) - (av + ToLower(*p)); |
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|
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return av % ATABLE_SIZE; |
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} |
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|
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/* |
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* hash_hostmask() |
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* |
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* Calculates the hash value for a given hostmask. |
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* |
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* inputs: |
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* p - the hostname to hash |
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* addr - where to store mask info |
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* output: hash value |
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*/ |
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static unsigned int |
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hash_hostmask(const char *p, struct irc_ssaddr *addr) |
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{ |
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int bits; |
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unsigned int hv; |
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const char *seg; |
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|
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switch (parse_netmask(p, addr, &bits)) |
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{ |
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case HM_IPV4: |
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hv = hash_ipv4(addr, bits - bits % 8); |
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break; |
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#ifdef IPV6 |
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case HM_IPV6: |
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hv = hash_ipv6(addr, bits - bits % 16); |
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break; |
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#endif |
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default: |
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// |
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// Choose the longest domain substring which contains no wildcards. |
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// This way hash value will be as precise as possible. |
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// |
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for (seg = p; *p; p++) |
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if (*p == '.' && !seg) |
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seg = p + 1; |
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else if (IsMWildChar(*p)) |
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seg = NULL; |
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|
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hv = seg ? hash_text(seg) : 0; |
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} |
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|
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addr->ss_port = (in_port_t) bits; |
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|
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return hv; |
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} |
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|
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/* |
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* add_access_conf() |
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* |
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* Adds an AccessConf entry to the hash table. |
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* |
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* inputs: pointer to AccessConf struct |
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* output: none |
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*/ |
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void |
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add_access_conf(struct AccessConf *conf) |
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{ |
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unsigned int hv = hash_hostmask(conf->host, &conf->ip); |
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static uint64_t curprec = ~0; |
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|
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conf->precedence = curprec--; |
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conf->hnext = atable[hv]; |
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atable[hv] = conf; |
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} |
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|
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/* |
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* destroy_access_conf() |
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* |
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* Deletes an AccessConf entry from the hash table and frees its memory. |
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* |
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* inputs: pointer to AccessConf struct |
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* output: none |
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*/ |
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void |
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destroy_access_conf(struct AccessConf *conf) |
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{ |
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struct irc_ssaddr addr; |
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unsigned int hv = hash_hostmask(conf->host, &addr); |
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struct AccessConf *prev; |
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|
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if (conf == atable[hv]) |
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atable[hv] = conf->hnext; |
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else |
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{ |
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for (prev = atable[hv]; prev->hnext != conf; prev = prev->hnext) |
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; // let it core if not found |
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prev->hnext = conf->hnext; |
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} |
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|
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acb_types[conf->type](conf); |
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} |
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|
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/* |
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* acb_generic_free() |
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* |
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* Generic free procedure for ACB's. |
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* |
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* inputs: pointer to AccessConf struct |
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* output: none |
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*/ |
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void |
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acb_generic_free(struct AccessConf *conf) |
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{ |
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MyFree(conf->user); |
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MyFree(conf->host); |
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MyFree(conf); |
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} |
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|
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/* |
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* enum_access_confs() |
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* |
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* Enumerates all AccessConfs. Calls the supplied routine on each one, |
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* if 1 is returned then this one is deleted and freed. |
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* Any number of AccessConfs can be deleted by this function. |
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* |
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* inputs: pointer to checking routine |
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* output: none |
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*/ |
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void |
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enum_access_confs(ACB_EXAMINE_HANDLER *examine, void *param) |
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{ |
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unsigned int hv; |
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struct AccessConf *prev, *conf; |
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|
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for (hv = 0; hv < ATABLE_SIZE; hv++) |
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for (prev = NULL, conf = atable[hv]; conf != NULL; |
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conf = (prev ? prev->hnext : atable[hv])) |
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{ |
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if (examine(conf, param)) |
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{ |
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if (prev != NULL) |
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prev->hnext = conf->hnext; |
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else |
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atable[hv] = conf->hnext; |
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|
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acb_types[conf->type](conf); |
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} |
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else |
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prev = conf; |
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} |
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} |
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|
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static int is_acb_permanent(struct AccessConf *conf, void *unused) |
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{ |
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return !conf->expires; |
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} |
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|
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static int is_acb_expired(struct AccessConf *conf, void *unused) |
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{ |
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return conf->expires && conf->expires <= CurrentTime; |
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} |
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|
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static int is_acb_orphaned(struct AccessConf *conf, void *unused) |
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{ |
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return !acb_types[conf->type]; |
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} |
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|
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/* |
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* register_acb_type() |
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* |
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* Allocates a unique value for AccessConf.type field to be used by modules. |
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* |
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* inputs: pointer to routine which frees a conf entry of this type |
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* output: requested value |
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*/ |
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int |
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register_acb_type(void *fh) |
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{ |
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int i; |
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|
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for (i = 0; i < MAX_ACB_TYPES; i++) |
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if (acb_types[i] == NULL) |
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{ |
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acb_types[i] = (ACB_FREE_HANDLER *) fh; |
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return i; |
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} |
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|
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return -1; |
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} |
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|
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/* |
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* unregister_acb_type() |
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* |
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* Deallocates an AccessConf.type specifier. |
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* |
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* inputs: type value |
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* output: none |
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*/ |
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void |
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unregister_acb_type(int id) |
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{ |
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acb_types[id] = NULL; |
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enum_access_confs(is_acb_orphaned, NULL); |
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} |
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|
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/* |
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* reset_access() |
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* |
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* Deletes all non-expiring ACB's before a rehash. |
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* |
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* inputs: none |
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* output: none |
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*/ |
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static void * |
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reset_access(va_list args) |
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{ |
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enum_access_confs(is_acb_permanent, NULL); |
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return pass_callback(hreset); |
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} |
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|
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/* |
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* find_access_conf() |
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* |
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* Looks for an access conf matching given criteria. |
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* |
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* inputs: |
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* type - only check confs of this type |
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* user - if non-NULL, limit to confs matching given username |
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* host - limit to confs matching given hostname... |
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* ip - ...or IP address (either host or ip must be non-NULL) |
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* func - function which verifies additional criteria, can be NULL |
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* output: pointer to struct AccessConf or NULL if not found |
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*/ |
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struct AccessConf * |
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find_access_conf(int type, const char *user, const char *host, |
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const struct irc_ssaddr *ip, ACB_EXAMINE_HANDLER *func, |
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void *param) |
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{ |
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struct AccessConf *conf, *best = NULL; |
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int bits; |
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|
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if (ip != NULL) |
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if (ip->ss.sin_family == AF_INET) |
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for (bits = 32; bits >= 0; bits -= 8) |
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for (conf = atable[hash_ipv4(ip, bits)]; conf; conf = conf->hnext) |
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if ((best == NULL || conf->precedence > best->precedence) && |
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conf->type == type && match_ipv4(ip, &conf->ip, conf->ip.ss_port) |
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&& (EmptyString(user) || match(conf->user, user)) && |
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(!func || func(conf, param))) |
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best = conf; |
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#ifdef IPV6 |
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else if (ip->ss.sin_family == AF_INET6) |
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for (bits = 128; bits >= 0; bits -= 16) |
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for (conf = atable[hash_ipv6(ip, bits)]; conf; conf = conf->hnext) |
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if ((best == NULL || conf->precedence > best->precedence) && |
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conf->type == type && match_ipv6(ip, &conf->ip, conf->ip.ss_port) |
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&& (EmptyString(user) || match(conf->user, user)) && |
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(!func || func(conf, param))) |
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best = conf; |
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#endif |
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|
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if (host != NULL) |
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while (1) |
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{ |
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for (conf = atable[hash_text(host)]; conf; conf = conf->hnext) |
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if ((best == NULL || conf->precedence > best->precedence) && |
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conf->type == type && match(conf->host, host) && |
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(EmptyString(user) || match(conf->user, user)) && |
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(!func || func(conf, param))) |
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best = conf; |
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|
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if (*host) |
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do { |
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if (*host++ == '.') |
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break; |
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} |
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while (*host); |
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else |
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break; |
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} |
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|
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return best; |
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} |
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|
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/* |
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* expire_confs() |
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* |
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* Called periodically to remove expired conf entries. |
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* |
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* inputs: none |
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* output: none |
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*/ |
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static void |
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expire_confs(void *unused) |
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{ |
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enum_access_confs(is_acb_expired, NULL); |
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execute_callback(cb_expire_confs); |
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} |
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|
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/* |
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* init_access() |
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* |
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* Initializes ACB's support. |
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* |
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* inputs: none |
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* output: none |
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*/ |
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void |
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init_access(void) |
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{ |
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hreset = install_hook(reset_conf, reset_access); |
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|
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cb_expire_confs = register_callback(NULL, NULL); |
| 410 |
eventAddIsh("expire_confs", expire_confs, NULL, EXPIRE_FREQUENCY); |
| 411 |
} |
