trunk/src/ipcache.c

/*
 *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
 *
 *  Copyright (c) 1997-2018 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 *  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 "memory.h"
#include "conf.h"
#include "ircd.h"


static dlink_list ip_hash_table[IP_HASH_SIZE];


/* 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 *const 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;
  }
  else
  {
    const struct sockaddr_in6 *const v6 = (const struct sockaddr_in6 *)addr;
    uint32_t hash = 0, *const 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;
  }
}

/* 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(const struct irc_ssaddr *addr)
{
  dlink_node *node;
  const uint32_t hash_index = ipcache_hash_address(addr);
  const struct sockaddr_in *v4 = (const struct sockaddr_in *)addr, *ptr_v4;
  const struct sockaddr_in6 *v6 = (const struct sockaddr_in6 *)addr, *ptr_v6;

  DLINK_FOREACH(node, ip_hash_table[hash_index].head)
  {
    struct ip_entry *iptr = node->data;

    if (iptr->ip.ss.ss_family != addr->ss.ss_family)
      continue;

    if (addr->ss.ss_family == AF_INET6)
    {
      ptr_v6 = (const 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
    {
      ptr_v4 = (const 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. */
    }
  }

  struct ip_entry *iptr = xcalloc(sizeof(*iptr));
  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(const struct irc_ssaddr *addr)
{
  dlink_node *node;
  const uint32_t hash_index = ipcache_hash_address(addr);
  const struct sockaddr_in *v4 = (const struct sockaddr_in *)addr, *ptr_v4;
  const struct sockaddr_in6 *v6 = (const struct sockaddr_in6 *)addr, *ptr_v6;

  DLINK_FOREACH(node, ip_hash_table[hash_index].head)
  {
    struct ip_entry *iptr = node->data;

    if (iptr->ip.ss.ss_family != addr->ss.ss_family)
      continue;

    if (addr->ss.ss_family == AF_INET6)
    {
      ptr_v6 = (const struct sockaddr_in6 *)&iptr->ip;
      if (memcmp(&v6->sin6_addr, &ptr_v6->sin6_addr, sizeof(struct in6_addr)))
        continue;
    }
    else
    {
      ptr_v4 = (const 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]);
      xfree(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 *node, *node_next;

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

      if (iptr->count == 0 &&
          (CurrentTime - iptr->last_attempt) >= ConfigGeneral.throttle_time)
      {
        dlinkDelete(&iptr->node, &ip_hash_table[i]);
        xfree(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, size_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);
}
Revision:	8385
Committed:	Fri Mar 16 20:09:55 2018 UTC (7 years, 5 months ago) by michael
Content type:	text/x-csrc
File size:	6249 byte(s)
Log Message:	- Rip out mempool
#	User	Rev	Content
1	michael	4325	/*
2			* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3			*
4	michael	8279	* Copyright (c) 1997-2018 ircd-hybrid development team
5	michael	4325	*
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	michael	4565	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
19	michael	4325	* USA
20			*/
21
22			/*! \file ipcache.c
23			* \brief Routines to count connections from particular IP addresses.
24	michael	4327	* \version $Id$
25	michael	4325	*/
26
27			#include "stdinc.h"
28			#include "list.h"
29			#include "ipcache.h"
30			#include "event.h"
31	michael	8385	#include "memory.h"
32	michael	4325	#include "conf.h"
33			#include "ircd.h"
34
35
36			static dlink_list ip_hash_table[IP_HASH_SIZE];
37
38
39			/* ipcache_hash_address()
40			*
41			* input - pointer to an irc_inaddr
42			* output - integer value used as index into hash table
43			* side effects - hopefully, none
44			*/
45			static uint32_t
46			ipcache_hash_address(const struct irc_ssaddr *addr)
47			{
48			if (addr->ss.ss_family == AF_INET)
49			{
50	michael	4977	const struct sockaddr_in const v4 = (const struct sockaddr_in )addr;
51	michael	4325	uint32_t hash = 0, ip = ntohl(v4->sin_addr.s_addr);
52
53			hash = ((ip >> 12) + ip) & (IP_HASH_SIZE - 1);
54			return hash;
55			}
56			else
57			{
58	michael	4977	const struct sockaddr_in6 const v6 = (const struct sockaddr_in6 )addr;
59			uint32_t hash = 0, const ip = (uint32_t )&v6->sin6_addr.s6_addr;
60	michael	4325
61			hash = ip[0] ^ ip[3];
62			hash ^= hash >> 16;
63			hash ^= hash >> 8;
64			hash = hash & (IP_HASH_SIZE - 1);
65			return hash;
66			}
67			}
68
69			/* ipcache_find_or_add_address()
70			*
71			* inputs - pointer to struct irc_ssaddr
72			* output - pointer to a struct ip_entry
73			* side effects -
74			*
75			* If the ip # was not found, a new struct ip_entry is created, and the ip
76			* count set to 0.
77			*/
78			struct ip_entry *
79	michael	6651	ipcache_find_or_add_address(const struct irc_ssaddr *addr)
80	michael	4325	{
81	michael	8349	dlink_node *node;
82	michael	4977	const uint32_t hash_index = ipcache_hash_address(addr);
83	michael	6651	const struct sockaddr_in v4 = (const struct sockaddr_in )addr, *ptr_v4;
84			const struct sockaddr_in6 v6 = (const struct sockaddr_in6 )addr, *ptr_v6;
85	michael	4325
86	michael	4800	DLINK_FOREACH(node, ip_hash_table[hash_index].head)
87	michael	4325	{
88	michael	8349	struct ip_entry *iptr = node->data;
89	michael	4415
90	michael	4325	if (iptr->ip.ss.ss_family != addr->ss.ss_family)
91			continue;
92
93			if (addr->ss.ss_family == AF_INET6)
94			{
95	michael	6651	ptr_v6 = (const struct sockaddr_in6 *)&iptr->ip;
96	michael	4367	if (!memcmp(&v6->sin6_addr, &ptr_v6->sin6_addr, sizeof(struct in6_addr)))
97			return iptr; /* Found entry already in hash, return it. */
98	michael	4325	}
99			else
100			{
101	michael	6651	ptr_v4 = (const struct sockaddr_in *)&iptr->ip;
102	michael	4367	if (!memcmp(&v4->sin_addr, &ptr_v4->sin_addr, sizeof(struct in_addr)))
103			return iptr; /* Found entry already in hash, return it. */
104	michael	4325	}
105			}
106
107	michael	8385	struct ip_entry iptr = xcalloc(sizeof(iptr));
108	michael	4325	memcpy(&iptr->ip, addr, sizeof(struct irc_ssaddr));
109
110			dlinkAdd(iptr, &iptr->node, &ip_hash_table[hash_index]);
111
112			return iptr;
113			}
114
115			/* ipcache_remove_addres()
116			*
117			* inputs - unsigned long IP address value
118			* output - NONE
119			* side effects - The ip address given, is looked up in ip hash table
120			* and number of ip#'s for that ip decremented.
121			* If ip # count reaches 0 and has expired,
122			* the struct ip_entry is returned to the ip_entry_heap
123			*/
124			void
125	michael	6651	ipcache_remove_address(const struct irc_ssaddr *addr)
126	michael	4325	{
127	michael	8349	dlink_node *node;
128	michael	4977	const uint32_t hash_index = ipcache_hash_address(addr);
129	michael	6651	const struct sockaddr_in v4 = (const struct sockaddr_in )addr, *ptr_v4;
130			const struct sockaddr_in6 v6 = (const struct sockaddr_in6 )addr, *ptr_v6;
131	michael	4325
132	michael	4800	DLINK_FOREACH(node, ip_hash_table[hash_index].head)
133	michael	4325	{
134	michael	4800	struct ip_entry *iptr = node->data;
135	michael	4415
136	michael	4325	if (iptr->ip.ss.ss_family != addr->ss.ss_family)
137			continue;
138	michael	4367
139	michael	4325	if (addr->ss.ss_family == AF_INET6)
140			{
141	michael	6651	ptr_v6 = (const struct sockaddr_in6 *)&iptr->ip;
142	michael	4367	if (memcmp(&v6->sin6_addr, &ptr_v6->sin6_addr, sizeof(struct in6_addr)))
143			continue;
144	michael	4325	}
145			else
146			{
147	michael	6651	ptr_v4 = (const struct sockaddr_in *)&iptr->ip;
148	michael	4367	if (memcmp(&v4->sin_addr, &ptr_v4->sin_addr, sizeof(struct in_addr)))
149			continue;
150	michael	4325	}
151
152			assert(iptr->count > 0);
153
154			if (--iptr->count == 0 &&
155	michael	4340	(CurrentTime - iptr->last_attempt) >= ConfigGeneral.throttle_time)
156	michael	4325	{
157			dlinkDelete(&iptr->node, &ip_hash_table[hash_index]);
158	michael	8385	xfree(iptr);
159	michael	4325	return;
160			}
161			}
162			}
163
164			/* ipcache_remove_expired_entries()
165			*
166			* input - NONE
167			* output - NONE
168			* side effects - free up all ip entries with no connections
169			*/
170			static void
171			ipcache_remove_expired_entries(void *unused)
172			{
173	michael	8349	dlink_node node, node_next;
174	michael	4325
175			for (unsigned int i = 0; i < IP_HASH_SIZE; ++i)
176			{
177	michael	4800	DLINK_FOREACH_SAFE(node, node_next, ip_hash_table[i].head)
178	michael	4325	{
179	michael	4800	struct ip_entry *iptr = node->data;
180	michael	4325
181			if (iptr->count == 0 &&
182	michael	4340	(CurrentTime - iptr->last_attempt) >= ConfigGeneral.throttle_time)
183	michael	4325	{
184			dlinkDelete(&iptr->node, &ip_hash_table[i]);
185	michael	8385	xfree(iptr);
186	michael	4325	}
187			}
188			}
189			}
190
191			/* ipcache_get_stats()
192			*
193			* inputs - pointer to counter of number of ips hashed
194			* - pointer to memory used for ip hash
195			* output - returned via pointers input
196			* side effects - NONE
197			*
198			* number of hashed ip #'s is counted up, plus the amount of memory
199			* used in the hash.
200			*/
201			void
202	michael	6719	ipcache_get_stats(unsigned int const number_ips_stored, size_t const mem_ips_stored)
203	michael	4325	{
204			for (unsigned int i = 0; i < IP_HASH_SIZE; ++i)
205			*number_ips_stored += dlink_list_length(&ip_hash_table[i]);
206			mem_ips_stored = number_ips_stored * sizeof(struct ip_entry);
207			}
208
209			void
210			ipcache_init(void)
211			{
212			static struct event event_expire_ipcache =
213			{
214			.name = "ipcache_remove_expired_entries",
215			.handler = ipcache_remove_expired_entries,
216			.when = 123
217			};
218
219			event_add(&event_expire_ipcache, NULL);
220			}