* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- * $Id$
- *
- *
- * This file should be edited in a window with a width of 141 characters
- * ick
*/
+/** @file
+ * @brief Code to count users connected from particular IP addresses.
+ * @version $Id$
+ */
+#include "config.h"
+
#include "IPcheck.h"
#include "client.h"
#include "ircd.h"
-#include "numnicks.h" /* NumNick, NumServ (GODMODE) */
+#include "match.h"
+#include "msg.h"
#include "ircd_alloc.h"
-#include "s_bsd.h" /* SetIPChecked */
+#include "ircd_events.h"
+#include "ircd_features.h"
+#include "ircd_log.h"
+#include "ircd_string.h" /* ircd_ntoa */
#include "s_debug.h" /* Debug */
#include "s_user.h" /* TARGET_DELAY */
#include "send.h"
-#include <assert.h>
-#include <stdio.h> /* NULL ... bleah */
-
+/* #include <assert.h> -- Now using assert in ircd_log.h */
+#include <string.h>
+/** Stores free target information for a particular user. */
struct IPTargetEntry {
- int count;
- unsigned char targets[MAXTARGETS];
+ unsigned int count; /**< Number of free targets targets. */
+ unsigned char targets[MAXTARGETS]; /**< Array of recent targets. */
};
+/** Stores recent information about a particular IP address. */
struct IPRegistryEntry {
- struct IPRegistryEntry* next;
- struct IPTargetEntry* target;
- unsigned int addr;
- unsigned short last_connect;
- unsigned char connected;
- unsigned char attempts;
+ struct IPRegistryEntry* next; /**< Next entry in the hash chain. */
+ struct IPTargetEntry* target; /**< Recent targets, if any. */
+ struct irc_in_addr addr; /**< IP address for this user. */
+ int last_connect; /**< Last connection attempt timestamp. */
+ unsigned short connected; /**< Number of currently connected clients. */
+ unsigned char attempts; /**< Number of recent connection attempts. */
};
-/*
- * Hash table for IPv4 address registry
- *
- * Hash table size must be a power of 2
- * Use 64K hash table to conserve memory
- */
+/** Size of hash table (must be a power of two). */
#define IP_REGISTRY_TABLE_SIZE 0x10000
-#define MASK_16 0xffff
-
-#define NOW ((unsigned short)(CurrentTime & MASK_16))
+/** Report current time for tracking in IPRegistryEntry::last_connect. */
+#define NOW ((unsigned short)(CurrentTime & 0xffff))
+/** Time from \a x until now, in seconds. */
#define CONNECTED_SINCE(x) (NOW - (x))
-#define IPCHECK_CLONE_LIMIT 2
-#define IPCHECK_CLONE_PERIOD 20
-#define IPCHECK_CLONE_DELAY 600
-
+/** Macro for easy access to configured IPcheck clone limit. */
+#define IPCHECK_CLONE_LIMIT feature_int(FEAT_IPCHECK_CLONE_LIMIT)
+/** Macro for easy access to configured IPcheck clone period. */
+#define IPCHECK_CLONE_PERIOD feature_int(FEAT_IPCHECK_CLONE_PERIOD)
+/** Macro for easy access to configured IPcheck clone delay. */
+#define IPCHECK_CLONE_DELAY feature_int(FEAT_IPCHECK_CLONE_DELAY)
+/** Hash table for storing IPRegistryEntry entries. */
static struct IPRegistryEntry* hashTable[IP_REGISTRY_TABLE_SIZE];
-static struct IPRegistryEntry* freeList = 0;
+/** List of allocated but unused IPRegistryEntry structs. */
+static struct IPRegistryEntry* freeList;
+/** Periodic timer to look for too-old registry entries. */
+static struct Timer expireTimer;
+
+/** Convert IP addresses to canonical form for comparison. IPv4
+ * addresses are translated into 6to4 form; IPv6 addresses are left
+ * alone.
+ * @param[out] out Receives canonical format for address.
+ * @param[in] in IP address to canonicalize.
+ */
+static void ip_registry_canonicalize(struct irc_in_addr *out, const struct irc_in_addr *in)
+{
+ if (irc_in_addr_is_ipv4(in)) {
+ out->in6_16[0] = htons(0x2002);
+ out->in6_16[1] = in->in6_16[6];
+ out->in6_16[2] = in->in6_16[7];
+ out->in6_16[3] = out->in6_16[4] = out->in6_16[5] = 0;
+ out->in6_16[6] = out->in6_16[7] = 0;
+ } else
+ memcpy(out, in, sizeof(*out));
+}
-static unsigned int ip_registry_hash(unsigned int ip)
+/** Calculate hash value for an IP address.
+ * @param[in] ip Address to hash; must be in canonical form.
+ * @return Hash value for address.
+ */
+static unsigned int ip_registry_hash(const struct irc_in_addr *ip)
{
- return ((ip >> 16) ^ ip) & (IP_REGISTRY_TABLE_SIZE - 1);
+ unsigned int res;
+ /* Only use the first 64 bits of address, since the last 64 bits
+ * tend to be under user control. */
+ res = ip->in6_16[0] ^ ip->in6_16[1] ^ ip->in6_16[2] ^ ip->in6_16[3];
+ return res & (IP_REGISTRY_TABLE_SIZE - 1);
}
-static struct IPRegistryEntry* ip_registry_find(unsigned int ip)
+/** Find an IP registry entry if one exists for the IP address.
+ * If \a ip looks like an IPv6 address, only consider the first 64 bits
+ * of the address. Otherwise, only consider the final 32 bits.
+ * @param[in] ip IP address to search for.
+ * @return Matching registry entry, or NULL if none exists.
+ */
+static struct IPRegistryEntry* ip_registry_find(const struct irc_in_addr *ip)
{
- struct IPRegistryEntry* entry = hashTable[ip_registry_hash(ip)];
+ struct irc_in_addr canon;
+ struct IPRegistryEntry* entry;
+ ip_registry_canonicalize(&canon, ip);
+ entry = hashTable[ip_registry_hash(&canon)];
for ( ; entry; entry = entry->next) {
- if (entry->addr == ip)
+ int bits = (canon.in6_16[0] == htons(0x2002)) ? 48 : 64;
+ if (ipmask_check(&canon, &entry->addr, bits))
break;
}
return entry;
}
+/** Add an IP registry entry to the hash table.
+ * @param[in] entry Registry entry to add.
+ */
static void ip_registry_add(struct IPRegistryEntry* entry)
{
- unsigned int bucket = ip_registry_hash(entry->addr);
+ unsigned int bucket = ip_registry_hash(&entry->addr);
entry->next = hashTable[bucket];
hashTable[bucket] = entry;
}
-
+
+/** Remove an IP registry entry from the hash table.
+ * @param[in] entry Registry entry to add.
+ */
static void ip_registry_remove(struct IPRegistryEntry* entry)
{
- unsigned int bucket = ip_registry_hash(entry->addr);
+ unsigned int bucket = ip_registry_hash(&entry->addr);
if (hashTable[bucket] == entry)
hashTable[bucket] = entry->next;
else {
}
}
}
-
-static struct IPRegistryEntry* ip_registry_new_entry()
+
+/** Allocate a new IP registry entry.
+ * For members that have a sensible default value, that is used.
+ * @return Newly allocated registry entry.
+ */
+static struct IPRegistryEntry* ip_registry_new_entry(void)
{
struct IPRegistryEntry* entry = freeList;
if (entry)
return entry;
}
+/** Deallocate memory for \a entry.
+ * The entry itself is prepended to #freeList.
+ * @param[in] entry IP registry entry to release.
+ */
static void ip_registry_delete_entry(struct IPRegistryEntry* entry)
{
if (entry->target)
freeList = entry;
}
+/** Update free target count for \a entry.
+ * @param[in,out] entry IP registry entry to update.
+ */
static unsigned int ip_registry_update_free_targets(struct IPRegistryEntry* entry)
{
unsigned int free_targets = STARTTARGETS;
return free_targets;
}
+/** Check whether all or part of \a entry needs to be expired.
+ * If the entry is at least 600 seconds stale, free the entire thing.
+ * If it is at least 120 seconds stale, expire its free targets list.
+ * @param[in] entry Registry entry to check for expiration.
+ */
static void ip_registry_expire_entry(struct IPRegistryEntry* entry)
{
/*
/*
* expired
*/
+ Debug((DEBUG_DNS, "IPcheck expiring registry for %s (no clients connected).", ircd_ntoa(&entry->addr)));
ip_registry_remove(entry);
ip_registry_delete_entry(entry);
}
}
}
-/*
- * ip_registry_expire
+/** Periodic timer callback to check for expired registry entries.
+ * @param[in] ev Timer event (ignored).
*/
-static void ip_registry_expire()
+static void ip_registry_expire(struct Event* ev)
{
int i;
struct IPRegistryEntry* entry;
struct IPRegistryEntry* entry_next;
+ assert(ET_EXPIRE == ev_type(ev));
+ assert(0 != ev_timer(ev));
+
for (i = 0; i < IP_REGISTRY_TABLE_SIZE; ++i) {
for (entry = hashTable[i]; entry; entry = entry_next) {
entry_next = entry->next;
}
}
-/*
- * IPcheck_local_connect
- *
- * Event:
- * A new connection was accept()-ed with IP number `cptr->ip.s_addr'.
- *
- * Action:
- * Update the IPcheck registry.
- * Return:
- * 1 : You're allowed to connect.
- * 0 : You're not allowed to connect.
- *
- * Throttling:
- *
- * A connection should be rejected when a connection from the same IP number was
- * received IPCHECK_CLONE_LIMIT times before this connect attempt, with
- * reconnect intervals of IPCHECK_CLONE_PERIOD seconds or less.
- *
- * Free target inheritance:
- *
- * When the client is accepted, then the number of Free Targets
- * of the cptr is set to the value stored in the found IPregistry
- * structure, or left at STARTTARGETS. This can be done by changing
- * cptr->nexttarget to be `now - (TARGET_DELAY * (FREE_TARGETS - 1))',
- * where FREE_TARGETS may range from 0 till STARTTARGETS.
+/** Initialize the IPcheck subsystem. */
+void IPcheck_init(void)
+{
+ timer_add(timer_init(&expireTimer), ip_registry_expire, 0, TT_PERIODIC, 60);
+}
+
+/** Check whether a new connection from a local client should be allowed.
+ * A connection is rejected if someone from the "same" address (see
+ * ip_registry_find()) connects IPCHECK_CLONE_LIMIT times, each time
+ * separated by no more than IPCHECK_CLONE_PERIOD seconds.
+ * @param[in] addr Address of client.
+ * @param[out] next_target_out Receives time to grant another free target.
+ * @return Non-zero if the connection is permitted, zero if denied.
*/
-int ip_registry_check_local(unsigned int addr, time_t* next_target_out)
+int ip_registry_check_local(const struct irc_in_addr *addr, time_t* next_target_out)
{
struct IPRegistryEntry* entry = ip_registry_find(addr);
unsigned int free_targets = STARTTARGETS;
-
+
if (0 == entry) {
entry = ip_registry_new_entry();
- entry->addr = addr; /* The IP number of registry entry */
+ ip_registry_canonicalize(&entry->addr, addr);
ip_registry_add(entry);
+ Debug((DEBUG_DNS, "IPcheck added new registry for local connection from %s.", ircd_ntoa(&entry->addr)));
return 1;
}
- /* Note that this also connects server connects.
+ /* Note that this also counts server connects.
* It is hard and not interesting, to change that.
- *
- * Don't allow more then 255 connects from one IP number, ever
+ * Refuse connection if it would overflow the counter.
*/
if (0 == ++entry->connected)
+ {
+ entry->connected--;
+ Debug((DEBUG_DNS, "IPcheck refusing local connection from %s: counter overflow.", ircd_ntoa(&entry->addr)));
return 0;
+ }
if (CONNECTED_SINCE(entry->last_connect) > IPCHECK_CLONE_PERIOD)
entry->attempts = 0;
if (next_target_out)
*next_target_out = CurrentTime - (TARGET_DELAY * free_targets - 1);
}
- else if ((CurrentTime - me.since) > IPCHECK_CLONE_DELAY) {
- /*
+ else if ((CurrentTime - cli_since(&me)) > IPCHECK_CLONE_DELAY) {
+ /*
* Don't refuse connection when we just rebooted the server
*/
-#ifdef NOTHROTTLE
- return 1;
-#else
+#ifndef NOTHROTTLE
+ assert(entry->connected > 0);
+ --entry->connected;
+ Debug((DEBUG_DNS, "IPcheck refusing local connection from %s: too fast.", ircd_ntoa(&entry->addr)));
return 0;
-#endif
+#endif
}
+ Debug((DEBUG_DNS, "IPcheck accepting local connection from %s.", ircd_ntoa(&entry->addr)));
return 1;
}
-/*
- * IPcheck_remote_connect
- *
- * Event:
- * A remote client connected to Undernet, with IP number `cptr->ip.s_addr'
- * and hostname `hostname'.
- *
- * Action:
- * Update the IPcheck registry.
- * Return 0 on failure, 1 on success.
+/** Check whether a connection from a remote client should be allowed.
+ * This is much more relaxed than ip_registry_check_local(): The only
+ * cause for rejection is when the IPRegistryEntry::connected counter
+ * would overflow.
+ * @param[in] cptr Client that has connected.
+ * @param[in] is_burst Non-zero if client was introduced during a burst.
+ * @return Non-zero if the client should be accepted, zero if they must be killed.
*/
int ip_registry_check_remote(struct Client* cptr, int is_burst)
{
- struct IPRegistryEntry* entry = ip_registry_find(cptr->ip.s_addr);
+ struct IPRegistryEntry* entry;
/*
* Mark that we did add/update an IPregistry entry
*/
SetIPChecked(cptr);
+ if (!irc_in_addr_valid(&cli_ip(cptr))) {
+ Debug((DEBUG_DNS, "IPcheck accepting remote connection from invalid %s.", ircd_ntoa(&cli_ip(cptr))));
+ return 1;
+ }
+ entry = ip_registry_find(&cli_ip(cptr));
if (0 == entry) {
entry = ip_registry_new_entry();
- entry->addr = cptr->ip.s_addr;
+ ip_registry_canonicalize(&entry->addr, &cli_ip(cptr));
if (is_burst)
entry->attempts = 0;
ip_registry_add(entry);
+ Debug((DEBUG_DNS, "IPcheck added new registry for remote connection from %s.", ircd_ntoa(&entry->addr)));
+ return 1;
}
- else {
- if (0 == ++entry->connected) {
- /*
- * Don't allow more then 255 connects from one IP number, ever
+ /* Avoid overflowing the connection counter. */
+ if (0 == ++entry->connected) {
+ Debug((DEBUG_DNS, "IPcheck refusing remote connection from %s: counter overflow.", ircd_ntoa(&entry->addr)));
+ return 0;
+ }
+ if (CONNECTED_SINCE(entry->last_connect) > IPCHECK_CLONE_PERIOD)
+ entry->attempts = 0;
+ if (!is_burst) {
+ if (0 == ++entry->attempts) {
+ /*
+ * Check for overflow
*/
- return 0;
- }
- if (CONNECTED_SINCE(entry->last_connect) > IPCHECK_CLONE_PERIOD)
- entry->attempts = 0;
- if (!is_burst) {
- if (0 == ++entry->attempts) {
- /*
- * Check for overflow
- */
- --entry->attempts;
- }
- ip_registry_update_free_targets(entry);
- entry->last_connect = NOW;
+ --entry->attempts;
}
+ ip_registry_update_free_targets(entry);
+ entry->last_connect = NOW;
}
+ Debug((DEBUG_DNS, "IPcheck counting remote connection from %s.", ircd_ntoa(&entry->addr)));
return 1;
}
-/*
- * IPcheck_connect_fail
- *
- * Event:
- * This local client failed to connect due to legal reasons.
- *
- * Action:
- * Neutralize the effect of calling IPcheck_local_connect, in such
- * a way that the client won't be penalized when trying to reconnect
- * again.
+/** Handle a client being rejected during connection through no fault
+ * of their own. This "undoes" the effect of ip_registry_check_local()
+ * so the client's address is not penalized for the failure.
+ * @param[in] addr Address of rejected client.
+ * @param[in] disconnect If true, also count the client as disconnecting.
*/
-void ip_registry_connect_fail(unsigned int addr)
+void ip_registry_connect_fail(const struct irc_in_addr *addr, int disconnect)
{
struct IPRegistryEntry* entry = ip_registry_find(addr);
- if (entry)
- --entry->attempts;
+ if (entry) {
+ if (0 == --entry->attempts) {
+ Debug((DEBUG_DNS, "IPcheck noting local connection failure for %s.", ircd_ntoa(&entry->addr)));
+ ++entry->attempts;
+ }
+ if (disconnect) {
+ assert(entry->connected > 0);
+ entry->connected--;
+ }
+ }
}
-/*
- * IPcheck_connect_succeeded
- *
- * Event:
- * A client succeeded to finish the registration.
- *
- * Finish IPcheck registration of a successfully, locally connected client.
+/** Handle a client that has successfully connected.
+ * This copies free target information to \a cptr from his address's
+ * registry entry and sends him a NOTICE describing the parameters for
+ * the entry.
+ * @param[in,out] cptr Client that has successfully connected.
*/
void ip_registry_connect_succeeded(struct Client *cptr)
{
const char* tr = "";
unsigned int free_targets = STARTTARGETS;
- struct IPRegistryEntry* entry = ip_registry_find(cptr->ip.s_addr);
+ struct IPRegistryEntry* entry = ip_registry_find(&cli_ip(cptr));
- if (!entry) {
- Debug((DEBUG_ERROR, "Missing registry entry for: %s", cptr->sock_ip));
- return;
- }
+ assert(entry);
if (entry->target) {
- memcpy(cptr->targets, entry->target->targets, MAXTARGETS);
+ memcpy(cli_targets(cptr), entry->target->targets, MAXTARGETS);
free_targets = entry->target->count;
tr = " tr";
}
- sendto_one(cptr, ":%s NOTICE %s :on %u ca %u(%u) ft %u(%u)%s",
- me.name, cptr->name, entry->connected, entry->attempts,
- IPCHECK_CLONE_LIMIT, free_targets, STARTTARGETS, tr);
+ Debug((DEBUG_DNS, "IPcheck noting local connection success for %s.", ircd_ntoa(&entry->addr)));
+ sendcmdto_one(&me, CMD_NOTICE, cptr, "%C :on %u ca %u(%u) ft %u(%u)%s",
+ cptr, entry->connected, entry->attempts, IPCHECK_CLONE_LIMIT,
+ free_targets, STARTTARGETS, tr);
}
-/*
- * IPcheck_disconnect
- *
- * Event:
- * A local client disconnected or a remote client left Undernet.
- *
- * Action:
- * Update the IPcheck registry.
- * Remove all expired IPregistry structures from the hash bucket
- * that belongs to this clients IP number.
+/** Handle a client that decided to disconnect (or was killed after
+ * completing his connection). This updates the free target
+ * information for his IP registry entry.
+ * @param[in] cptr Client that has exited.
*/
void ip_registry_disconnect(struct Client *cptr)
{
- struct IPRegistryEntry* entry = ip_registry_find(cptr->ip.s_addr);
- if (0 == entry) {
- /*
- * trying to find an entry for a server causes this to happen,
- * servers should never have FLAGS_IPCHECK set
- */
+ struct IPRegistryEntry* entry = ip_registry_find(&cli_ip(cptr));
+ if (!irc_in_addr_valid(&cli_ip(cptr))) {
+ Debug((DEBUG_DNS, "IPcheck noting dicconnect from invalid %s.", ircd_ntoa(&cli_ip(cptr))));
return;
}
+ assert(entry);
+ assert(entry->connected > 0);
+ Debug((DEBUG_DNS, "IPcheck noting disconnect from %s.", ircd_ntoa(&entry->addr)));
/*
* If this was the last one, set `last_connect' to disconnect time (used for expiration)
*/
if (0 == --entry->connected) {
if (CONNECTED_SINCE(entry->last_connect) > IPCHECK_CLONE_LIMIT * IPCHECK_CLONE_PERIOD) {
/*
- * Otherwise we'd penetalize for this old value if the client reconnects within 20 seconds
+ * Otherwise we'd penalize for this old value if the client reconnects within 20 seconds
*/
entry->attempts = 0;
}
}
assert(0 != entry->target);
- memcpy(entry->target->targets, cptr->targets, MAXTARGETS);
+ memcpy(entry->target->targets, cli_targets(cptr), MAXTARGETS);
/*
* This calculation can be pretty unfair towards large multi-user hosts, but
* there is "nothing" we can do without also allowing spam bots to send more
- * messages or by drastically increasing the ammount of memory used in the IPregistry.
+ * messages or by drastically increasing the amount of memory used in the IPregistry.
*
* The problem is that when a client disconnects, leaving no free targets, then
* the next client from that IP number has to pay for it (getting no free targets).
* ALL should get no free targets when reconnecting. We'd need to store an entry
* per client (instead of per IP number) to avoid this.
*/
- if (cptr->nexttarget < CurrentTime) {
+ if (cli_nexttarget(cptr) < CurrentTime) {
/*
* Number of free targets
*/
- free_targets = (CurrentTime - cptr->nexttarget) / TARGET_DELAY + 1;
+ free_targets = (CurrentTime - cli_nexttarget(cptr)) / TARGET_DELAY + 1;
}
else
free_targets = 0;
/*
* Add bonus, this is pretty fuzzy, but it will help in some cases.
*/
- if ((CurrentTime - cptr->firsttime) > 600)
+ if ((CurrentTime - cli_firsttime(cptr)) > 600)
/*
* Was longer then 10 minutes online?
*/
- free_targets += (CurrentTime - cptr->firsttime - 600) / TARGET_DELAY;
+ free_targets += (CurrentTime - cli_firsttime(cptr) - 600) / TARGET_DELAY;
/*
- * Finally, store smallest value for Judgement Day
+ * Finally, store smallest value for Judgment Day
*/
if (free_targets < entry->target->count)
entry->target->count = free_targets;
}
}
-/*
- * IPcheck_nr
- *
- * Returns number of clients with the same IP number
+/** Find number of clients from a particular IP address.
+ * @param[in] addr Address to look up.
+ * @return Number of clients known to be connected from that address.
*/
-int ip_registry_count(unsigned int addr)
+int ip_registry_count(const struct irc_in_addr *addr)
{
struct IPRegistryEntry* entry = ip_registry_find(addr);
return (entry) ? entry->connected : 0;
}
-/*
- * IPcheck_local_connect
- *
- * Event:
- * A new connection was accept()-ed with IP number `cptr->ip.s_addr'.
- *
- * Action:
- * Update the IPcheck registry.
- * Return:
- * 1 : You're allowed to connect.
- * 0 : You're not allowed to connect.
- *
- * Throttling:
- *
- * A connection should be rejected when a connection from the same IP number was
- * received IPCHECK_CLONE_LIMIT times before this connect attempt, with
- * reconnect intervals of IPCHECK_CLONE_PERIOD seconds or less.
- *
- * Free target inheritance:
- *
- * When the client is accepted, then the number of Free Targets
- * of the cptr is set to the value stored in the found IPregistry
- * structure, or left at STARTTARGETS. This can be done by changing
- * cptr->nexttarget to be `now - (TARGET_DELAY * (FREE_TARGETS - 1))',
- * where FREE_TARGETS may range from 0 till STARTTARGETS.
+/** Check whether a client is allowed to connect locally.
+ * @param[in] a Address of client.
+ * @param[out] next_target_out Receives time to grant another free target.
+ * @return Non-zero if the connection is permitted, zero if denied.
*/
-int IPcheck_local_connect(struct in_addr a, time_t* next_target_out)
+int IPcheck_local_connect(const struct irc_in_addr *a, time_t* next_target_out)
{
assert(0 != next_target_out);
- return ip_registry_check_local(a.s_addr, next_target_out);
+ return ip_registry_check_local(a, next_target_out);
}
-/*
- * IPcheck_remote_connect
- *
- * Event:
- * A remote client connected to Undernet, with IP number `cptr->ip.s_addr'
- * and hostname `hostname'.
- *
- * Action:
- * Update the IPcheck registry.
- * Return 0 on failure, 1 on success.
+/** Check whether a client is allowed to connect remotely.
+ * @param[in] cptr Client that has connected.
+ * @param[in] is_burst Non-zero if client was introduced during a burst.
+ * @return Non-zero if the client should be accepted, zero if they must be killed.
*/
-int IPcheck_remote_connect(struct Client *cptr, const char *hostname, int is_burst)
+int IPcheck_remote_connect(struct Client *cptr, int is_burst)
{
assert(0 != cptr);
+ assert(!IsIPChecked(cptr));
return ip_registry_check_remote(cptr, is_burst);
}
-/*
- * IPcheck_connect_fail
- *
- * Event:
- * This local client failed to connect due to legal reasons.
- *
- * Action:
- * Neutralize the effect of calling IPcheck_local_connect, in such
- * a way that the client won't be penalized when trying to reconnect
- * again.
+/** Handle a client being rejected during connection through no fault
+ * of their own. This "undoes" the effect of ip_registry_check_local()
+ * so the client's address is not penalized for the failure.
+ * @param[in] cptr Client who has been rejected.
+ * @param[in] disconnect If true, also count the client as disconnecting.
*/
-void IPcheck_connect_fail(struct in_addr a)
+void IPcheck_connect_fail(const struct Client *cptr, int disconnect)
{
- ip_registry_connect_fail(a.s_addr);
+ assert(IsIPChecked(cptr));
+ ip_registry_connect_fail(&cli_ip(cptr), disconnect);
}
-/*
- * IPcheck_connect_succeeded
- *
- * Event:
- * A client succeeded to finish the registration.
- *
- * Finish IPcheck registration of a successfully, locally connected client.
+/** Handle a client that has successfully connected.
+ * This copies free target information to \a cptr from his address's
+ * registry entry and sends him a NOTICE describing the parameters for
+ * the entry.
+ * @param[in,out] cptr Client that has successfully connected.
*/
void IPcheck_connect_succeeded(struct Client *cptr)
{
assert(0 != cptr);
+ assert(IsIPChecked(cptr));
ip_registry_connect_succeeded(cptr);
}
-/*
- * IPcheck_disconnect
- *
- * Event:
- * A local client disconnected or a remote client left Undernet.
- *
- * Action:
- * Update the IPcheck registry.
- * Remove all expired IPregistry structures from the hash bucket
- * that belongs to this clients IP number.
+/** Handle a client that decided to disconnect (or was killed after
+ * completing his connection). This updates the free target
+ * information for his IP registry entry.
+ * @param[in] cptr Client that has exited.
*/
void IPcheck_disconnect(struct Client *cptr)
{
assert(0 != cptr);
+ assert(IsIPChecked(cptr));
ip_registry_disconnect(cptr);
}
-/*
- * IPcheck_nr
- *
- * Returns number of clients with the same IP number
+/** Find number of clones of a client.
+ * @param[in] cptr Client whose address to look up.
+ * @return Number of clients known to be connected from that address.
*/
unsigned short IPcheck_nr(struct Client *cptr)
{
assert(0 != cptr);
- return ip_registry_count(cptr->ip.s_addr);
+ return ip_registry_count(&cli_ip(cptr));
}
-
-void IPcheck_expire()
-{
- static time_t next_expire = 0;
- if (next_expire < CurrentTime) {
- ip_registry_expire();
- next_expire = CurrentTime + 60;
- }
-}
-
-#if 0
-struct IPregistry_vector {
- unsigned short length;
- unsigned short allocated_length;
- struct IPregistry *vector;
-};
-
-#define HASHTABSIZE 0x2000 /* Must be power of 2 */
-static struct IPregistry_vector IPregistry_hashtable[HASHTABSIZE];
-
-/*
- * Calculate a `hash' value between 0 and HASHTABSIZE, from the internet address `in_addr'.
- * Apply it immedeately to the table, effectively hiding the table itself.
- */
-#define CALCULATE_HASH(in_addr) \
- struct IPregistry_vector *hash; \
- do { unsigned int ip = (in_addr).s_addr; \
- hash = &IPregistry_hashtable[((ip >> 14) + (ip >> 7) + ip) & (HASHTABSIZE - 1)]; } while(0)
-
-/*
- * Fit `now' in an unsigned short, the advantage is that we use less memory
- * `struct IPregistry::last_connect' can be smaller while the only disadvantage
- * is that if someone reconnects after exactly 18 hours and 12 minutes, and NOBODY with the
- * same _hash_ value for this IP-number did disconnect in the meantime, then the server
- * will think he reconnected immedeately. In other words: No disadvantage at all.
- */
-#define BITMASK 0xffff /* Same number of bits as `struct IPregistry::last_connect' */
-#define HAS_TARGETS_MAGIC 15
-#define HAS_TARGETS(entry) ((entry)->free_targets == HAS_TARGETS_MAGIC)
-
-#if STARTTARGETS >= HAS_TARGETS_MAGIC
-#error "That doesn't fit in 4 bits, does it?"
-#endif
-
-/* IP(entry) returns the `struct in_addr' of the IPregistry. */
-#define IP(entry) (HAS_TARGETS(entry) ? (entry)->ip_targets.ptr->ip : (entry)->ip_targets.ip)
-#define FREE_TARGETS(entry) (HAS_TARGETS(entry) ? (entry)->ip_targets.ptr->free_targets : (entry)->free_targets)
-
-static unsigned short count = 10000, average_length = 4;
-
-static struct IPregistry *IPregistry_add(struct IPregistry_vector *iprv)
-{
- assert(0 != iprv);
- if (iprv->length == iprv->allocated_length)
- {
- iprv->allocated_length += 4;
- if (iprv->vector) {
- iprv->vector =
- (struct IPregistry*) MyRealloc(iprv->vector,
- iprv->allocated_length * sizeof(struct IPregistry));
- }
- else {
- iprv->vector =
- (struct IPregistry*) MyMalloc(
- iprv->allocated_length * sizeof(struct IPregistry));
- }
- }
- return &iprv->vector[iprv->length++];
-}
-
-static struct IPregistry *IPregistry_find(struct IPregistry_vector *iprv,
- struct in_addr ip)
-{
- if (iprv->length > 0)
- {
- struct IPregistry *i, *end = &iprv->vector[iprv->length];
- for (i = &iprv->vector[0]; i < end; ++i)
- if (IP(i).s_addr == ip.s_addr)
- return i;
- }
- return NULL;
-}
-
-static struct IPregistry *IPregistry_find_with_expire(struct IPregistry_vector
- *iprv, struct in_addr ip)
-{
- struct IPregistry *last;
- struct IPregistry *curr;
- struct IPregistry *retval = NULL;
-
- /*
- * if the vector is empty, IPcheck_disconnect will cause the server
- * to core when NDEBUG is defined
- */
- if (iprv->length < 1)
- return retval;
-
- last = &iprv->vector[iprv->length - 1];
-
- for (curr = &iprv->vector[0]; curr < last;)
- {
- if (IP(curr).s_addr == ip.s_addr)
- /* `curr' is element we looked for */
- retval = curr;
- else if (curr->connected == 0)
- {
- if (CONNECTED_SINCE(curr) > 600U) /* Don't touch this number, it has statistical significance */
- {
- /* `curr' expired */
- if (HAS_TARGETS(curr))
- MyFree(curr->ip_targets.ptr);
- *curr = *last--;
- iprv->length--;
- if (--count == 0)
- {
- /* Make ever 10000 disconnects an estimation of the average vector length */
- count = 10000;
- average_length =
- (UserStats.clients + UserStats.unknowns + UserStats.local_servers) / HASHTABSIZE;
- }
- /* Now check the new element (last) that was moved to this position */
- continue;
- }
- else if (CONNECTED_SINCE(curr) > 120U && HAS_TARGETS(curr))
- {
- /* Expire storage of targets */
- struct in_addr ip1 = curr->ip_targets.ptr->ip;
- curr->free_targets = curr->ip_targets.ptr->free_targets;
- MyFree(curr->ip_targets.ptr);
- curr->ip_targets.ip = ip1;
- }
- }
- /* Did not expire, check next element */
- ++curr;
- }
- /* Now check the last element in the list (curr == last) */
- if (IP(curr).s_addr == ip.s_addr)
- /* `curr' is element we looked for */
- retval = curr;
- else if (curr->connected == 0)
- {
- if (CONNECTED_SINCE(curr) > 600U) /* Don't touch this number, it has statistical significance */
- {
- /* `curr' expired */
- if (HAS_TARGETS(curr))
- MyFree(curr->ip_targets.ptr);
- iprv->length--;
- if (--count == 0)
- {
- /* Make ever 10000 disconnects an estimation of the average vector length */
- count = 10000;
- average_length =
- (UserStats.clients + UserStats.unknowns + UserStats.local_servers) / HASHTABSIZE;
- }
- }
- else if (CONNECTED_SINCE(curr) > 120U && HAS_TARGETS(curr))
- {
- /* Expire storage of targets */
- struct in_addr ip1 = curr->ip_targets.ptr->ip;
- curr->free_targets = curr->ip_targets.ptr->free_targets;
- MyFree(curr->ip_targets.ptr);
- curr->ip_targets.ip = ip1;
- }
- }
- /* Do we need to shrink the vector? */
- if (iprv->allocated_length > average_length
- && iprv->allocated_length - iprv->length >= 4)
- {
- struct IPregistry *newpos;
- iprv->allocated_length = iprv->length;
- newpos =
- (struct IPregistry *)MyRealloc(iprv->vector,
- iprv->allocated_length * sizeof(struct IPregistry));
- if (newpos != iprv->vector) /* Is this ever true? */
- {
- retval =
- (struct IPregistry *)((char *)retval + ((char *)newpos -
- (char *)iprv->vector));
- iprv->vector = newpos;
- }
- }
- return retval;
-}
-
-static void reset_connect_time(struct IPregistry *entry)
-{
- unsigned int previous_free_targets;
-
- /* Apply aging */
- previous_free_targets =
- FREE_TARGETS(entry) + CONNECTED_SINCE(entry) / TARGET_DELAY;
- if (previous_free_targets > STARTTARGETS)
- previous_free_targets = STARTTARGETS;
- if (HAS_TARGETS(entry))
- entry->ip_targets.ptr->free_targets = previous_free_targets;
- else
- entry->free_targets = previous_free_targets;
-
- entry->last_connect = NOW;
-}
-
-/*
- * IPcheck_local_connect
- *
- * Event:
- * A new connection was accept()-ed with IP number `cptr->ip.s_addr'.
- *
- * Action:
- * Update the IPcheck registry.
- * Return:
- * 1 : You're allowed to connect.
- * 0 : You're not allowed to connect.
- *
- * Throttling:
- *
- * A connection should be rejected when a connection from the same IP number was
- * received IPCHECK_CLONE_LIMIT times before this connect attempt, with
- * reconnect intervals of IPCHECK_CLONE_PERIOD seconds or less.
- *
- * Free target inheritance:
- *
- * When the client is accepted, then the number of Free Targets
- * of the cptr is set to the value stored in the found IPregistry
- * structure, or left at STARTTARGETS. This can be done by changing
- * cptr->nexttarget to be `now - (TARGET_DELAY * (FREE_TARGETS - 1))',
- * where FREE_TARGETS may range from 0 till STARTTARGETS.
- */
-int IPcheck_local_connect(struct in_addr a, time_t* next_target_out)
-{
- struct IPregistry *entry;
- CALCULATE_HASH(a);
- assert(0 != next_target_out);
-
- if (!(entry = IPregistry_find(hash, a)))
- {
- entry = IPregistry_add(hash);
- entry->ip_targets.ip = a; /* The IP number of registry entry */
- entry->last_connect = NOW; /* Seconds since last connect attempt */
- entry->connected = 1; /* connected clients for this IP */
- entry->connect_attempts = 1; /* Number attempts for this IP */
- entry->free_targets = STARTTARGETS; /* free targets a client gets */
- return 1;
- }
- /* Note that this also connects server connects.
- * It is hard and not interesting, to change that.
- *
- * Don't allow more then 255 connects from one IP number, ever
- */
- if (0 == ++entry->connected)
- return 0;
-
- if (CONNECTED_SINCE(entry) > IPCHECK_CLONE_PERIOD)
- entry->connect_attempts = 0;
-
- reset_connect_time(entry);
-
- if (0 == ++entry->connect_attempts) /* Check for overflow */
- --entry->connect_attempts;
-
- if (entry->connect_attempts <= IPCHECK_CLONE_LIMIT)
- *next_target_out = CurrentTime - (TARGET_DELAY * (FREE_TARGETS(entry) - 1));
-
- /* Don't refuse connection when we just rebooted the server */
- else if (CurrentTime - me.since > IPCHECK_CLONE_DELAY)
-#ifndef NOTHROTTLE
- return 0;
-#else
- return 1;
-#endif
- return 1;
-}
-
-/*
- * IPcheck_remote_connect
- *
- * Event:
- * A remote client connected to Undernet, with IP number `cptr->ip.s_addr'
- * and hostname `hostname'.
- *
- * Action:
- * Update the IPcheck registry.
- * Return -1 on failure, 0 on success.
- */
-int IPcheck_remote_connect(struct Client *cptr, const char *hostname,
- int is_burst)
-{
- struct IPregistry *entry;
- CALCULATE_HASH(cptr->ip);
- SetIPChecked(cptr); /* Mark that we did add/update an IPregistry entry */
- if (!(entry = IPregistry_find(hash, cptr->ip)))
- {
- entry = IPregistry_add(hash);
- entry->ip_targets.ip = cptr->ip; /* The IP number of registry entry */
- entry->last_connect = NOW; /* Seconds since last connect (attempt) */
- entry->connected = 1; /* Number of currently connected clients with this IP number */
- entry->connect_attempts = is_burst ? 1 : 0; /* Number of clients that connected with this IP number */
- entry->free_targets = STARTTARGETS; /* Number of free targets that a client gets on connect */
- }
- else
- {
-#ifdef GODMODE
- sendto_one(cptr,
- "%s NOTICE %s%s :I saw your face before my friend (connected: %u; connect_attempts %u; free_targets %u)",
- NumServ(&me), NumNick(cptr), entry->connected, entry->connect_attempts,
- FREE_TARGETS(entry));
-#endif
- if (++(entry->connected) == 0) /* Don't allow more then 255 connects from one IP number, ever */
- return -1;
- if (CONNECTED_SINCE(entry) > IPCHECK_CLONE_PERIOD)
- entry->connect_attempts = 0;
- if (!is_burst)
- {
- if (++(entry->connect_attempts) == 0) /* Check for overflow */
- --(entry->connect_attempts);
- reset_connect_time(entry);
- }
- }
- return 0;
-}
-
-/*
- * IPcheck_connect_fail
- *
- * Event:
- * This local client failed to connect due to legal reasons.
- *
- * Action:
- * Neutralize the effect of calling IPcheck_local_connect, in such
- * a way that the client won't be penalized when trying to reconnect
- * again.
- */
-void IPcheck_connect_fail(struct in_addr a)
-{
- struct IPregistry *entry;
- CALCULATE_HASH(a);
- if ((entry = IPregistry_find(hash, a)))
- --entry->connect_attempts;
-}
-
-/*
- * IPcheck_connect_succeeded
- *
- * Event:
- * A client succeeded to finish the registration.
- *
- * Finish IPcheck registration of a successfully, locally connected client.
- */
-void IPcheck_connect_succeeded(struct Client *cptr)
-{
- struct IPregistry *entry;
- const char *tr = "";
- CALCULATE_HASH(cptr->ip);
- entry = IPregistry_find(hash, cptr->ip);
- if (HAS_TARGETS(entry))
- {
- memcpy(cptr->targets, entry->ip_targets.ptr->targets, MAXTARGETS);
- tr = " tr";
- }
- sendto_one(cptr, ":%s NOTICE %s :on %u ca %u(%u) ft %u(%u)%s",
- me.name, cptr->name, entry->connected, entry->connect_attempts,
- IPCHECK_CLONE_LIMIT, FREE_TARGETS(entry), STARTTARGETS, tr);
-}
-
-/*
- * IPcheck_disconnect
- *
- * Event:
- * A local client disconnected or a remote client left Undernet.
- *
- * Action:
- * Update the IPcheck registry.
- * Remove all expired IPregistry structures from the hash bucket
- * that belongs to this clients IP number.
- */
-void IPcheck_disconnect(struct Client *cptr)
-{
- struct IPregistry *entry;
- CALCULATE_HASH(cptr->ip);
- entry = IPregistry_find_with_expire(hash, cptr->ip);
- if (0 == entry) {
- /*
- * trying to find an entry for a server causes this to happen,
- * servers should never have FLAGS_IPCHECK set
- */
- assert(0 != entry);
- return;
- }
- /*
- * If this was the last one, set `last_connect' to disconnect time (used for expiration)
- */
- if (--(entry->connected) == 0) {
- if (CONNECTED_SINCE(entry) > IPCHECK_CLONE_LIMIT * IPCHECK_CLONE_PERIOD)
- /*
- * Otherwise we'd penetalize for this old value if the client reconnects within 20 seconds
- */
- entry->connect_attempts = 0;
- reset_connect_time(entry);
- }
- if (MyConnect(cptr)) {
- unsigned int inheritance;
- /*
- * Copy the clients targets
- */
- if (HAS_TARGETS(entry)) {
- entry->free_targets = entry->ip_targets.ptr->free_targets;
- MyFree(entry->ip_targets.ptr);
- }
- entry->ip_targets.ptr =
- (struct ip_targets_st*) MyMalloc(sizeof(struct ip_targets_st));
-
- assert(0 != entry->ip_targets.ptr);
- entry->ip_targets.ptr->ip = cptr->ip;
- entry->ip_targets.ptr->free_targets = entry->free_targets;
- entry->free_targets = HAS_TARGETS_MAGIC;
- memcpy(entry->ip_targets.ptr->targets, cptr->targets, MAXTARGETS);
- /*
- * This calculation can be pretty unfair towards large multi-user hosts, but
- * there is "nothing" we can do without also allowing spam bots to send more
- * messages or by drastically increasing the ammount of memory used in the IPregistry.
- *
- * The problem is that when a client disconnects, leaving no free targets, then
- * the next client from that IP number has to pay for it (getting no free targets).
- * But ALSO the next client, and the next client, and the next client etc - until
- * another client disconnects that DOES leave free targets. The reason for this
- * is that if there are 10 SPAM bots, and they all disconnect at once, then they
- * ALL should get no free targets when reconnecting. We'd need to store an entry
- * per client (instead of per IP number) to avoid this.
- */
- if (cptr->nexttarget <= CurrentTime)
- /*
- * Number of free targets
- */
- inheritance = (CurrentTime - cptr->nexttarget) / TARGET_DELAY + 1;
- else
- inheritance = 0;
- /*
- * Add bonus, this is pretty fuzzy, but it will help in some cases.
- */
- if (CurrentTime - cptr->firsttime > 600)
- /*
- * Was longer then 10 minutes online?
- */
- inheritance += (CurrentTime - cptr->firsttime - 600) / TARGET_DELAY;
- /*
- * Finally, store smallest value for Judgement Day
- */
- if (inheritance < entry->ip_targets.ptr->free_targets)
- entry->ip_targets.ptr->free_targets = inheritance;
- }
-}
-
-/*
- * IPcheck_nr
- *
- * Returns number of clients with the same IP number
- */
-unsigned short IPcheck_nr(struct Client *cptr)
-{
- struct IPregistry *entry;
- CALCULATE_HASH(cptr->ip);
- entry = IPregistry_find(hash, cptr->ip);
- return (entry ? entry->connected : 0);
-}
-#endif
projects / ircu2.10.12-pk.git / blobdiff