trunk/src/ipcache.c

/*
 *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
 *
 *  Copyright (c) 1997-2014 ircd-hybrid development team
 *
 *  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 your 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
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received 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
 */

/*! \file ipcache.c
 * \brief Routines to count connections from particular IP addresses.
 * \version $Id$
 */

#include "stdinc.h"
#include "list.h"
#include "ipcache.h"
#include "event.h"
#include "mempool.h"
#include "conf.h"
#include "ircd.h"


static dlink_list ip_hash_table[IP_HASH_SIZE];
static mp_pool_t *ip_entry_pool;


/* ipcache_hash_address()
 *
 * input        - pointer to an irc_inaddr
 * output       - integer value used as index into hash table
 * side effects - hopefully, none
 */
static uint32_t
ipcache_hash_address(const struct irc_ssaddr *addr)
{
  if (addr->ss.ss_family == AF_INET)
  {
    const struct sockaddr_in *v4 = (const struct sockaddr_in *)addr;
    uint32_t hash = 0, ip = ntohl(v4->sin_addr.s_addr);

    hash = ((ip >> 12) + ip) & (IP_HASH_SIZE - 1);
    return hash;
  }
#ifdef IPV6
  else
  {
    const struct sockaddr_in6 *v6 = (const struct sockaddr_in6 *)addr;
    uint32_t hash = 0, *ip = (uint32_t *)&v6->sin6_addr.s6_addr;

    hash  = ip[0] ^ ip[3];
    hash ^= hash >> 16;
    hash ^= hash >> 8;
    hash  = hash & (IP_HASH_SIZE - 1);
    return hash;
  }
#else
  return 0;
#endif
}

/* ipcache_find_or_add_address()
 *
 * inputs       - pointer to struct irc_ssaddr
 * output       - pointer to a struct ip_entry
 * side effects -
 *
 * If the ip # was not found, a new struct ip_entry is created, and the ip
 * count set to 0.
 */
struct ip_entry *
ipcache_find_or_add_address(struct irc_ssaddr *addr)
{
  dlink_node *ptr = NULL;
  struct ip_entry *iptr = NULL;
  uint32_t hash_index = ipcache_hash_address(addr);
  struct sockaddr_in *v4 = (struct sockaddr_in *)addr, *ptr_v4;
#ifdef IPV6
  struct sockaddr_in6 *v6 = (struct sockaddr_in6 *)addr, *ptr_v6;
#endif

  DLINK_FOREACH(ptr, ip_hash_table[hash_index].head)
  {
    iptr = ptr->data;
#ifdef IPV6
    if (iptr->ip.ss.ss_family != addr->ss.ss_family)
      continue;

    if (addr->ss.ss_family == AF_INET6)
    {
      ptr_v6 = (struct sockaddr_in6 *)&iptr->ip;
      if (!memcmp(&v6->sin6_addr, &ptr_v6->sin6_addr, sizeof(struct in6_addr)))
        return iptr;  /* Found entry already in hash, return it. */
    }
    else
#endif
    {
      ptr_v4 = (struct sockaddr_in *)&iptr->ip;
      if (!memcmp(&v4->sin_addr, &ptr_v4->sin_addr, sizeof(struct in_addr)))
        return iptr;  /* Found entry already in hash, return it. */
    }
  }

  iptr = mp_pool_get(ip_entry_pool);
  memcpy(&iptr->ip, addr, sizeof(struct irc_ssaddr));

  dlinkAdd(iptr, &iptr->node, &ip_hash_table[hash_index]);

  return iptr;
}

/* ipcache_remove_addres()
 *
 * inputs        - unsigned long IP address value
 * output        - NONE
 * side effects  - The ip address given, is looked up in ip hash table
 *                 and number of ip#'s for that ip decremented.
 *                 If ip # count reaches 0 and has expired,
 *                 the struct ip_entry is returned to the ip_entry_heap
 */
void
ipcache_remove_address(struct irc_ssaddr *addr)
{
  dlink_node *ptr = NULL;
  uint32_t hash_index = ipcache_hash_address(addr);
  struct sockaddr_in *v4 = (struct sockaddr_in *)addr, *ptr_v4;
#ifdef IPV6
  struct sockaddr_in6 *v6 = (struct sockaddr_in6 *)addr, *ptr_v6;
#endif

  DLINK_FOREACH(ptr, ip_hash_table[hash_index].head)
  {
    struct ip_entry *iptr = ptr->data;
#ifdef IPV6
    if (iptr->ip.ss.ss_family != addr->ss.ss_family)
      continue;

    if (addr->ss.ss_family == AF_INET6)
    {
      ptr_v6 = (struct sockaddr_in6 *)&iptr->ip;
      if (memcmp(&v6->sin6_addr, &ptr_v6->sin6_addr, sizeof(struct in6_addr)))
        continue;
    }
    else
#endif
    {
      ptr_v4 = (struct sockaddr_in *)&iptr->ip;
      if (memcmp(&v4->sin_addr, &ptr_v4->sin_addr, sizeof(struct in_addr)))
        continue;
    }

    assert(iptr->count > 0);

    if (--iptr->count == 0 &&
        (CurrentTime - iptr->last_attempt) >= ConfigGeneral.throttle_time)
    {
      dlinkDelete(&iptr->node, &ip_hash_table[hash_index]);
      mp_pool_release(iptr);
      return;
    }
  }
}

/* ipcache_remove_expired_entries()
 *
 * input        - NONE
 * output       - NONE
 * side effects - free up all ip entries with no connections
 */
static void
ipcache_remove_expired_entries(void *unused)
{
  dlink_node *ptr = NULL, *ptr_next = NULL;

  for (unsigned int i = 0; i < IP_HASH_SIZE; ++i)
  {
    DLINK_FOREACH_SAFE(ptr, ptr_next, ip_hash_table[i].head)
    {
      struct ip_entry *iptr = ptr->data;

      if (iptr->count == 0 &&
          (CurrentTime - iptr->last_attempt) >= ConfigGeneral.throttle_time)
      {
        dlinkDelete(&iptr->node, &ip_hash_table[i]);
        mp_pool_release(iptr);
      }
    }
  }
}

/* ipcache_get_stats()
 *
 * inputs        - pointer to counter of number of ips hashed
 *               - pointer to memory used for ip hash
 * output        - returned via pointers input
 * side effects  - NONE
 *
 * number of hashed ip #'s is counted up, plus the amount of memory
 * used in the hash.
 */
void
ipcache_get_stats(unsigned int *const number_ips_stored, uint64_t *const mem_ips_stored)
{
  for (unsigned int i = 0; i < IP_HASH_SIZE; ++i)
    *number_ips_stored += dlink_list_length(&ip_hash_table[i]);
  *mem_ips_stored = *number_ips_stored * sizeof(struct ip_entry);
}

void
ipcache_init(void)
{
  static struct event event_expire_ipcache =
  {
    .name = "ipcache_remove_expired_entries",
    .handler = ipcache_remove_expired_entries,
    .when = 123
  };

  event_add(&event_expire_ipcache, NULL);
  ip_entry_pool = mp_pool_new(sizeof(struct ip_entry), MP_CHUNK_SIZE_IP_ENTRY);
}
Revision:	4367
Committed:	Sun Aug 3 10:33:39 2014 UTC (11 years ago) by michael
Content type:	text/x-csrc
File size:	6398 byte(s)
Log Message:	- ipcache.c: minor cleanup
#	Content
1	/*
2	* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3	*
4	* Copyright (c) 1997-2014 ircd-hybrid development team
5	*
6	* This program is free software; you can redistribute it and/or modify
7	* it under the terms of the GNU General Public License as published by
8	* the Free Software Foundation; either version 2 of the License, or
9	* (at your option) any later version.
10	*
11	* This program is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.
15	*
16	* You should have received a copy of the GNU General Public License
17	* along with this program; if not, write to the Free Software
18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
19	* USA
20	*/
21
22	/*! \file ipcache.c
23	* \brief Routines to count connections from particular IP addresses.
24	* \version $Id$
25	*/
26
27	#include "stdinc.h"
28	#include "list.h"
29	#include "ipcache.h"
30	#include "event.h"
31	#include "mempool.h"
32	#include "conf.h"
33	#include "ircd.h"
34
35
36	static dlink_list ip_hash_table[IP_HASH_SIZE];
37	static mp_pool_t *ip_entry_pool;
38
39
40
41	/* ipcache_hash_address()
42	*
43	* input - pointer to an irc_inaddr
44	* output - integer value used as index into hash table
45	* side effects - hopefully, none
46	*/
47	static uint32_t
48	ipcache_hash_address(const struct irc_ssaddr *addr)
49	{
50	if (addr->ss.ss_family == AF_INET)
51	{
52	const struct sockaddr_in v4 = (const struct sockaddr_in )addr;
53	uint32_t hash = 0, ip = ntohl(v4->sin_addr.s_addr);
54
55	hash = ((ip >> 12) + ip) & (IP_HASH_SIZE - 1);
56	return hash;
57	}
58	#ifdef IPV6
59	else
60	{
61	const struct sockaddr_in6 v6 = (const struct sockaddr_in6 )addr;
62	uint32_t hash = 0, ip = (uint32_t )&v6->sin6_addr.s6_addr;
63
64	hash = ip[0] ^ ip[3];
65	hash ^= hash >> 16;
66	hash ^= hash >> 8;
67	hash = hash & (IP_HASH_SIZE - 1);
68	return hash;
69	}
70	#else
71	return 0;
72	#endif
73	}
74
75	/* ipcache_find_or_add_address()
76	*
77	* inputs - pointer to struct irc_ssaddr
78	* output - pointer to a struct ip_entry
79	* side effects -
80	*
81	* If the ip # was not found, a new struct ip_entry is created, and the ip
82	* count set to 0.
83	*/
84	struct ip_entry *
85	ipcache_find_or_add_address(struct irc_ssaddr *addr)
86	{
87	dlink_node *ptr = NULL;
88	struct ip_entry *iptr = NULL;
89	uint32_t hash_index = ipcache_hash_address(addr);
90	struct sockaddr_in v4 = (struct sockaddr_in )addr, *ptr_v4;
91	#ifdef IPV6
92	struct sockaddr_in6 v6 = (struct sockaddr_in6 )addr, *ptr_v6;
93	#endif
94
95	DLINK_FOREACH(ptr, ip_hash_table[hash_index].head)
96	{
97	iptr = ptr->data;
98	#ifdef IPV6
99	if (iptr->ip.ss.ss_family != addr->ss.ss_family)
100	continue;
101
102	if (addr->ss.ss_family == AF_INET6)
103	{
104	ptr_v6 = (struct sockaddr_in6 *)&iptr->ip;
105	if (!memcmp(&v6->sin6_addr, &ptr_v6->sin6_addr, sizeof(struct in6_addr)))
106	return iptr; /* Found entry already in hash, return it. */
107	}
108	else
109	#endif
110	{
111	ptr_v4 = (struct sockaddr_in *)&iptr->ip;
112	if (!memcmp(&v4->sin_addr, &ptr_v4->sin_addr, sizeof(struct in_addr)))
113	return iptr; /* Found entry already in hash, return it. */
114	}
115	}
116
117	iptr = mp_pool_get(ip_entry_pool);
118	memcpy(&iptr->ip, addr, sizeof(struct irc_ssaddr));
119
120	dlinkAdd(iptr, &iptr->node, &ip_hash_table[hash_index]);
121
122	return iptr;
123	}
124
125	/* ipcache_remove_addres()
126	*
127	* inputs - unsigned long IP address value
128	* output - NONE
129	* side effects - The ip address given, is looked up in ip hash table
130	* and number of ip#'s for that ip decremented.
131	* If ip # count reaches 0 and has expired,
132	* the struct ip_entry is returned to the ip_entry_heap
133	*/
134	void
135	ipcache_remove_address(struct irc_ssaddr *addr)
136	{
137	dlink_node *ptr = NULL;
138	uint32_t hash_index = ipcache_hash_address(addr);
139	struct sockaddr_in v4 = (struct sockaddr_in )addr, *ptr_v4;
140	#ifdef IPV6
141	struct sockaddr_in6 v6 = (struct sockaddr_in6 )addr, *ptr_v6;
142	#endif
143
144	DLINK_FOREACH(ptr, ip_hash_table[hash_index].head)
145	{
146	struct ip_entry *iptr = ptr->data;
147	#ifdef IPV6
148	if (iptr->ip.ss.ss_family != addr->ss.ss_family)
149	continue;
150
151	if (addr->ss.ss_family == AF_INET6)
152	{
153	ptr_v6 = (struct sockaddr_in6 *)&iptr->ip;
154	if (memcmp(&v6->sin6_addr, &ptr_v6->sin6_addr, sizeof(struct in6_addr)))
155	continue;
156	}
157	else
158	#endif
159	{
160	ptr_v4 = (struct sockaddr_in *)&iptr->ip;
161	if (memcmp(&v4->sin_addr, &ptr_v4->sin_addr, sizeof(struct in_addr)))
162	continue;
163	}
164
165	assert(iptr->count > 0);
166
167	if (--iptr->count == 0 &&
168	(CurrentTime - iptr->last_attempt) >= ConfigGeneral.throttle_time)
169	{
170	dlinkDelete(&iptr->node, &ip_hash_table[hash_index]);
171	mp_pool_release(iptr);
172	return;
173	}
174	}
175	}
176
177	/* ipcache_remove_expired_entries()
178	*
179	* input - NONE
180	* output - NONE
181	* side effects - free up all ip entries with no connections
182	*/
183	static void
184	ipcache_remove_expired_entries(void *unused)
185	{
186	dlink_node ptr = NULL, ptr_next = NULL;
187
188	for (unsigned int i = 0; i < IP_HASH_SIZE; ++i)
189	{
190	DLINK_FOREACH_SAFE(ptr, ptr_next, ip_hash_table[i].head)
191	{
192	struct ip_entry *iptr = ptr->data;
193
194	if (iptr->count == 0 &&
195	(CurrentTime - iptr->last_attempt) >= ConfigGeneral.throttle_time)
196	{
197	dlinkDelete(&iptr->node, &ip_hash_table[i]);
198	mp_pool_release(iptr);
199	}
200	}
201	}
202	}
203
204	/* ipcache_get_stats()
205	*
206	* inputs - pointer to counter of number of ips hashed
207	* - pointer to memory used for ip hash
208	* output - returned via pointers input
209	* side effects - NONE
210	*
211	* number of hashed ip #'s is counted up, plus the amount of memory
212	* used in the hash.
213	*/
214	void
215	ipcache_get_stats(unsigned int const number_ips_stored, uint64_t const mem_ips_stored)
216	{
217	for (unsigned int i = 0; i < IP_HASH_SIZE; ++i)
218	*number_ips_stored += dlink_list_length(&ip_hash_table[i]);
219	mem_ips_stored = number_ips_stored * sizeof(struct ip_entry);
220	}
221
222	void
223	ipcache_init(void)
224	{
225	static struct event event_expire_ipcache =
226	{
227	.name = "ipcache_remove_expired_entries",
228	.handler = ipcache_remove_expired_entries,
229	.when = 123
230	};
231
232	event_add(&event_expire_ipcache, NULL);
233	ip_entry_pool = mp_pool_new(sizeof(struct ip_entry), MP_CHUNK_SIZE_IP_ENTRY);
234	}