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/* |
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* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd) |
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* |
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* Copyright (c) 1997-2020 ircd-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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 |
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* USA |
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*/ |
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|
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/*! \file ipcache.c |
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* \brief Routines to count connections from particular IP addresses. |
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* \version $Id$ |
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*/ |
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|
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#include "stdinc.h" |
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#include "list.h" |
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#include "ipcache.h" |
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#include "event.h" |
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#include "memory.h" |
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#include "conf.h" |
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#include "ircd.h" |
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#include "patricia.h" |
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|
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|
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static dlink_list ipcache_list; |
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static patricia_tree_t *ipcache_trie_v6; |
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static patricia_tree_t *ipcache_trie_v4; |
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|
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|
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static void * |
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ipcache_get_trie(void *addr) |
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{ |
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if (((struct sockaddr *)addr)->sa_family == AF_INET6) |
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return ipcache_trie_v6; |
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else |
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return ipcache_trie_v4; |
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} |
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|
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/* ipcache_find_or_add_address() |
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* |
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* inputs - pointer to struct irc_ssaddr |
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* output - pointer to a struct ip_entry |
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* side effects - |
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* |
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* If the ip # was not found, a new struct ip_entry is created, and the ip |
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* count set to 0. |
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*/ |
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struct ip_entry * |
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ipcache_record_find_or_add(void *addr) |
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{ |
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patricia_tree_t *ptrie = ipcache_get_trie(addr); |
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patricia_node_t *pnode = patricia_make_and_lookup_addr(ptrie, addr, 0); |
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|
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if (pnode->data) /* Deliberate crash if 'pnode' is NULL */ |
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return pnode->data; /* Already added to the trie */ |
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|
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struct ip_entry *iptr = xcalloc(sizeof(*iptr)); |
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iptr->trie_pointer = ptrie; |
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dlinkAdd(pnode, &iptr->node, &ipcache_list); |
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|
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PATRICIA_DATA_SET(pnode, iptr); |
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|
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return iptr; |
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} |
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|
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static void |
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ipcache_record_delete(patricia_node_t *pnode) |
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{ |
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struct ip_entry *iptr = PATRICIA_DATA_GET(pnode, struct ip_entry); |
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|
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if (iptr->count_local == 0 && iptr->count_remote == 0 && |
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(event_base->time.sec_monotonic - iptr->last_attempt) >= ConfigGeneral.throttle_time) |
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{ |
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patricia_remove(iptr->trie_pointer, pnode); |
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|
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dlinkDelete(&iptr->node, &ipcache_list); |
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xfree(iptr); |
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} |
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} |
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|
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/* ipcache_remove_addres() |
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* |
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* inputs - unsigned long IP address value |
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* output - NONE |
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* side effects - The ip address given, is looked up in ip hash table |
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* and number of ip#'s for that ip decremented. |
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* If ip # count reaches 0 and has expired, |
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* the struct ip_entry is returned to the ip_entry_heap |
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*/ |
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void |
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ipcache_record_remove(void *addr, bool local) |
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{ |
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patricia_node_t *pnode = patricia_try_search_exact_addr(ipcache_get_trie(addr), addr, 0); |
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|
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if (pnode == NULL) |
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return; |
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|
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struct ip_entry *iptr = PATRICIA_DATA_GET(pnode, struct ip_entry); |
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assert(iptr->count_local > 0 || iptr->count_remote > 0); |
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|
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if (local == true) |
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--iptr->count_local; |
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else |
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--iptr->count_remote; |
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|
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ipcache_record_delete(pnode); |
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} |
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|
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/* ipcache_remove_expired_entries() |
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* |
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* input - NONE |
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* output - NONE |
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* side effects - free up all ip entries with no connections |
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*/ |
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static void |
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ipcache_remove_expired_records(void *unused) |
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{ |
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dlink_node *node, *node_next; |
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|
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DLINK_FOREACH_SAFE(node, node_next, ipcache_list.head) |
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ipcache_record_delete(node->data); |
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} |
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|
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/* ipcache_get_stats() |
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* |
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* inputs - pointer to counter of number of ips hashed |
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* - pointer to memory used for ip hash |
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* output - returned via pointers input |
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* side effects - NONE |
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* |
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* number of hashed ip #'s is counted up, plus the amount of memory |
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* used in the hash. |
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*/ |
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void |
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ipcache_get_stats(unsigned int *const number_ips_stored, size_t *const mem_ips_stored) |
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{ |
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/* TBD: inaccurate for now as it does only count the amount of memory for struct ip_entry items */ |
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(*number_ips_stored) = dlink_list_length(&ipcache_list); |
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(*mem_ips_stored) = dlink_list_length(&ipcache_list) * sizeof(struct ip_entry); |
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} |
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|
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void |
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ipcache_init(void) |
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{ |
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static struct event event_expire_ipcache = |
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{ |
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.name = "ipcache_remove_expired_records", |
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.handler = ipcache_remove_expired_records, |
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.when = 123 |
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}; |
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|
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ipcache_trie_v6 = patricia_new(128); |
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ipcache_trie_v4 = patricia_new( 32); |
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|
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event_add(&event_expire_ipcache, NULL); |
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} |
