*
* $Id$
*
- *
- * This file should be edited in a window with a width of 141 characters
- * ick
*/
+
+/*----------------------------------------------------------------------------
+ * Platform Includes
+ *--------------------------------------------------------------------------*/
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+
+/*----------------------------------------------------------------------------
+ * Application Includes
+ *--------------------------------------------------------------------------*/
#include "IPcheck.h"
#include "client.h"
#include "ircd.h"
-#include "numnicks.h" /* NumNick, NumServ (GODMODE) */
+#include "numnicks.h"
#include "ircd_alloc.h"
-#include "s_bsd.h" /* SetIPChecked */
-#include "s_debug.h" /* Debug */
-#include "s_user.h" /* TARGET_DELAY */
+#include "msg.h"
+#include "s_bsd.h"
+#include "s_debug.h"
+#include "s_user.h"
#include "send.h"
-#include <assert.h>
-#include <stdio.h> /* NULL ... bleah */
-
-struct IPTargetEntry {
+/*----------------------------------------------------------------------------
+ * Data Structures (should be moved to IPcheck.h)
+ *--------------------------------------------------------------------------*/
+typedef struct IPTargetEntry {
int count;
unsigned char targets[MAXTARGETS];
-};
+} iptarget_entry_t;
-struct IPRegistryEntry {
- struct IPRegistryEntry* next;
- struct IPTargetEntry* target;
+typedef struct IPRegistryEntry {
+ struct IPRegistryEntry *next;
+ struct IPTargetEntry *target;
unsigned int addr;
- unsigned short last_connect;
+ time_t last_connect;
unsigned char connected;
unsigned char attempts;
-};
+} ip_reg_entry_t;
+
/*
* Hash table for IPv4 address registry
* Hash table size must be a power of 2
* Use 64K hash table to conserve memory
*/
+/*----------------------------------------------------------------------------
+ * Compile-time Configuration
+ *--------------------------------------------------------------------------*/
#define IP_REGISTRY_TABLE_SIZE 0x10000
#define MASK_16 0xffff
-#define NOW ((unsigned short)(CurrentTime & MASK_16))
-#define CONNECTED_SINCE(x) (NOW - (x))
-
#define IPCHECK_CLONE_LIMIT 2
#define IPCHECK_CLONE_PERIOD 20
-#define IPCHECK_CLONE_DELAY 600
+#define IPCHECK_CLONE_DELAY 600
-static struct IPRegistryEntry* hashTable[IP_REGISTRY_TABLE_SIZE];
-static struct IPRegistryEntry* freeList = 0;
+/*----------------------------------------------------------------------------
+ * Handy Macros
+ *--------------------------------------------------------------------------*/
+#define NOW (CurrentTime)
+#define CONNECTED_SINCE(x) (NOW - (x->last_connect))
-static unsigned int ip_registry_hash(unsigned int ip)
-{
+
+/*----------------------------------------------------------------------------
+ * Global Data (ugly!)
+ *--------------------------------------------------------------------------*/
+static ip_reg_entry_t *hashTable[IP_REGISTRY_TABLE_SIZE];
+static ip_reg_entry_t *freeList = 0;
+
+
+/*----------------------------------------------------------------------------
+ * ip_registry_hash: Create a hash key for an IP registry entry and return
+ * the value. (Is unsigned int really a good type to give
+ * to the IP argument? Ugly. This should probably be a
+ * struct in_addr. This is asking for trouble. --ZS)
+ *--------------------------------------------------------------------------*/
+static unsigned int ip_registry_hash(unsigned int ip) {
return ((ip >> 16) ^ ip) & (IP_REGISTRY_TABLE_SIZE - 1);
}
-static struct IPRegistryEntry* ip_registry_find(unsigned int ip)
-{
- struct IPRegistryEntry* entry = hashTable[ip_registry_hash(ip)];
- for ( ; entry; entry = entry->next) {
+
+/*----------------------------------------------------------------------------
+ * ip_registry_find: Find a given IP registry entry and return it.
+ *--------------------------------------------------------------------------*/
+static ip_reg_entry_t *ip_registry_find(unsigned int ip) {
+ ip_reg_entry_t *entry;
+
+ for (entry = hashTable[ip_registry_hash(ip)]; entry; entry = entry->next) {
if (entry->addr == ip)
break;
}
+
return entry;
}
-static void ip_registry_add(struct IPRegistryEntry* entry)
-{
+
+/*----------------------------------------------------------------------------
+ * ip_registry_add: Add an entry to the IP registry
+ *--------------------------------------------------------------------------*/
+static void ip_registry_add(ip_reg_entry_t *entry) {
unsigned int bucket = ip_registry_hash(entry->addr);
+
entry->next = hashTable[bucket];
hashTable[bucket] = entry;
}
-static void ip_registry_remove(struct IPRegistryEntry* entry)
-{
+
+/*----------------------------------------------------------------------------
+ * ip_registry_remove: Remove an entry from the IP registry
+ *--------------------------------------------------------------------------*/
+static void ip_registry_remove(ip_reg_entry_t *entry) {
unsigned int bucket = ip_registry_hash(entry->addr);
+
if (hashTable[bucket] == entry)
hashTable[bucket] = entry->next;
else {
- struct IPRegistryEntry* prev = hashTable[bucket];
- for ( ; prev; prev = prev->next) {
+ ip_reg_entry_t *prev;
+
+ for (prev = hashTable[bucket]; prev; prev = prev->next) {
if (prev->next == entry) {
prev->next = entry->next;
break;
}
}
-static struct IPRegistryEntry* ip_registry_new_entry()
-{
- struct IPRegistryEntry* entry = freeList;
+
+/*----------------------------------------------------------------------------
+ * ip_registry_new_entry(): Creates and initializes an IP Registry entry.
+ * NOW ALSO ADDS IT TO THE LIST! --ZS
+ *--------------------------------------------------------------------------*/
+static ip_reg_entry_t *ip_registry_new_entry(unsigned int addr, int attempt) {
+ ip_reg_entry_t *entry = freeList;
+
if (entry)
freeList = entry->next;
else
- entry = (struct IPRegistryEntry*) MyMalloc(sizeof(struct IPRegistryEntry));
+ entry = (ip_reg_entry_t *)MyMalloc(sizeof(ip_reg_entry_t));
assert(0 != entry);
- memset(entry, 0, sizeof(struct IPRegistryEntry));
+
+ memset(entry, 0, sizeof(ip_reg_entry_t));
entry->last_connect = NOW; /* Seconds since last connect attempt */
entry->connected = 1; /* connected clients for this IP */
- entry->attempts = 1; /* Number attempts for this IP */
+ entry->attempts = attempt; /* Number attempts for this IP */
+ entry->addr = addr; /* Entry's IP Address */
+
+ ip_registry_add(entry);
+
return entry;
}
-static void ip_registry_delete_entry(struct IPRegistryEntry* entry)
-{
+
+/*----------------------------------------------------------------------------
+ * ip_registry_delete_entry: Frees an entry and adds the structure to a list
+ * of free structures. (We should probably reclaim
+ * the freelist every once in a while! This is
+ * potentially a way to DoS the server... -ZS)
+ *--------------------------------------------------------------------------*/
+static void ip_registry_delete_entry(ip_reg_entry_t *entry) {
if (entry->target)
MyFree(entry->target);
+
entry->next = freeList;
freeList = entry;
}
-static unsigned int ip_registry_update_free_targets(struct IPRegistryEntry* entry)
-{
+
+/*----------------------------------------------------------------------------
+ * ip_registry_update_free_targets:
+ *--------------------------------------------------------------------------*/
+static unsigned int ip_registry_update_free_targets(ip_reg_entry_t *entry) {
unsigned int free_targets = STARTTARGETS;
if (entry->target) {
- free_targets = entry->target->count + (CONNECTED_SINCE(entry->last_connect) / TARGET_DELAY);
+ free_targets = (entry->target->count +
+ (CONNECTED_SINCE(entry) / TARGET_DELAY));
+
if (free_targets > STARTTARGETS)
free_targets = STARTTARGETS;
+
entry->target->count = free_targets;
}
+
return free_targets;
}
-static void ip_registry_expire_entry(struct IPRegistryEntry* entry)
-{
+
+/*----------------------------------------------------------------------------
+ * ip_registry_expire_entry: expire an IP entry if it needs to be. If an
+ * entry isn't expired, then also check the target
+ * list to see if it needs to be expired.
+ *--------------------------------------------------------------------------*/
+static void ip_registry_expire_entry(ip_reg_entry_t *entry) {
/*
* Don't touch this number, it has statistical significance
* XXX - blah blah blah
+ * ZS - Just -what- statistical significance does it -have-?
*/
- if (CONNECTED_SINCE(entry->last_connect) > 600) {
- /*
- * expired
- */
+ if (CONNECTED_SINCE(entry) > 600) {
ip_registry_remove(entry);
ip_registry_delete_entry(entry);
- }
- else if (CONNECTED_SINCE(entry->last_connect) > 120 && 0 != entry->target) {
- /*
- * Expire storage of targets
- */
+ } else if (CONNECTED_SINCE(entry) > 120 && 0 != entry->target) {
MyFree(entry->target);
entry->target = 0;
}
}
-/*
- * ip_registry_expire
- */
-static void ip_registry_expire()
-{
+
+/*----------------------------------------------------------------------------
+ * ip_registry_expire: Expire all of the needed entries in the hash table
+ *--------------------------------------------------------------------------*/
+void ip_registry_expire(void) {
+ ip_reg_entry_t *entry;
+ ip_reg_entry_t *entry_next;
+ static time_t next_expire = 0;
int i;
- struct IPRegistryEntry* entry;
- struct IPRegistryEntry* entry_next;
+
+ /* Only do this if we're ready to */
+ if (next_expire >= CurrentTime)
+ return;
for (i = 0; i < IP_REGISTRY_TABLE_SIZE; ++i) {
for (entry = hashTable[i]; entry; entry = entry_next) {
ip_registry_expire_entry(entry);
}
}
+
+ next_expire = CurrentTime + 60;
}
-/*
+
+/*----------------------------------------------------------------------------
* IPcheck_local_connect
*
* Event:
*
* 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.
+ * 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:
*
* 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 ip_registry_check_local(unsigned int addr, time_t* next_target_out)
+ *--------------------------------------------------------------------------*/
+int ip_registry_check_local(unsigned int addr, time_t *next_target_out)
{
- struct IPRegistryEntry* entry = ip_registry_find(addr);
+ ip_reg_entry_t *entry = ip_registry_find(addr);
unsigned int free_targets = STARTTARGETS;
+ assert(0 != next_target_out);
+
if (0 == entry) {
- entry = ip_registry_new_entry();
- entry->addr = addr; /* The IP number of registry entry */
- ip_registry_add(entry);
+ entry = ip_registry_new_entry(addr, 1);
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
- */
+
+ /* Do not allow more than 255 connects from a single IP, EVER. */
if (0 == ++entry->connected)
return 0;
- if (CONNECTED_SINCE(entry->last_connect) > IPCHECK_CLONE_PERIOD)
+ /* If our threshhold has elapsed, reset the counter so we don't throttle */
+ if (CONNECTED_SINCE(entry) > IPCHECK_CLONE_PERIOD)
entry->attempts = 0;
+ else if (0 == ++entry->attempts)
+ --entry->attempts; /* Disallow overflow */
- free_targets = ip_registry_update_free_targets(entry);
entry->last_connect = NOW;
+ free_targets = ip_registry_update_free_targets(entry);
- if (0 == ++entry->attempts) /* Check for overflow */
- --entry->attempts;
-
- if (entry->attempts < IPCHECK_CLONE_LIMIT) {
- if (next_target_out)
+ if (entry->attempts < IPCHECK_CLONE_LIMIT && next_target_out)
*next_target_out = CurrentTime - (TARGET_DELAY * free_targets - 1);
- }
else if ((CurrentTime - me.since) > IPCHECK_CLONE_DELAY) {
- /*
- * Don't refuse connection when we just rebooted the server
- */
#ifdef NOTHROTTLE
return 1;
#else
+ --entry->connected;
return 0;
#endif
}
+
return 1;
}
-/*
+
+/*----------------------------------------------------------------------------
+ * ip_registry_local_connect
+ *
+ * Does anything that needs to be done once we actually have a client
+ * structure to play with on a local connection that passed the IPcheck test.
+ *--------------------------------------------------------------------------*/
+void ip_registry_local_connect(struct Client *cptr) {
+ assert(0 != cptr);
+ SetIPChecked(cptr);
+}
+
+
+/*----------------------------------------------------------------------------
* IPcheck_remote_connect
*
* Event:
* Action:
* Update the IPcheck registry.
* Return 0 on failure, 1 on success.
- */
-int ip_registry_check_remote(struct Client* cptr, int is_burst)
-{
- struct IPRegistryEntry* entry = ip_registry_find(cptr->ip.s_addr);
+ *--------------------------------------------------------------------------*/
+int ip_registry_check_remote(struct Client* cptr, int is_burst) {
+ ip_reg_entry_t *entry;
+
+ assert(cptr);
+
+ entry = ip_registry_find(cptr->ip.s_addr);
- /*
- * Mark that we did add/update an IPregistry entry
- */
SetIPChecked(cptr);
- if (0 == entry) {
- entry = ip_registry_new_entry();
- entry->addr = cptr->ip.s_addr;
- if (is_burst)
- entry->attempts = 0;
- ip_registry_add(entry);
- }
+
+ if (0 == entry)
+ entry = ip_registry_new_entry(cptr->ip.s_addr, (is_burst ? 0 : 1));
else {
- if (0 == ++entry->connected) {
- /*
- * Don't allow more then 255 connects from one IP number, ever
- */
+ /* NEVER more than 255 connections. */
+ if (0 == ++entry->connected)
return 0;
- }
- if (CONNECTED_SINCE(entry->last_connect) > IPCHECK_CLONE_PERIOD)
+
+ /* Make sure we don't bounce if our threshhold has expired */
+ if (CONNECTED_SINCE(entry) > IPCHECK_CLONE_PERIOD)
entry->attempts = 0;
+
+ /* If we're not part of a burst, go ahead and process the rest */
if (!is_burst) {
- if (0 == ++entry->attempts) {
- /*
- * Check for overflow
- */
- --entry->attempts;
- }
+ if (0 == ++entry->attempts)
+ --entry->attempts; /* Overflows are bad, mmmkay? */
ip_registry_update_free_targets(entry);
entry->last_connect = NOW;
}
}
+
return 1;
}
-/*
+/*----------------------------------------------------------------------------
* IPcheck_connect_fail
*
* Event:
* 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 ip_registry_connect_fail(unsigned int addr)
-{
- struct IPRegistryEntry* entry = ip_registry_find(addr);
+ *--------------------------------------------------------------------------*/
+void ip_registry_connect_fail(unsigned int addr) {
+ ip_reg_entry_t *entry = ip_registry_find(addr);
+
if (entry)
--entry->attempts;
}
-/*
+
+/*----------------------------------------------------------------------------
* IPcheck_connect_succeeded
*
* Event:
* A client succeeded to finish the registration.
*
* Finish IPcheck registration of a successfully, locally connected client.
- */
-void ip_registry_connect_succeeded(struct Client *cptr)
-{
- const char* tr = "";
+ *--------------------------------------------------------------------------*/
+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);
+ ip_reg_entry_t *entry;
+
+ assert(cptr);
+
+ entry = ip_registry_find(cptr->ip.s_addr);
if (!entry) {
Debug((DEBUG_ERROR, "Missing registry entry for: %s", cptr->sock_ip));
return;
}
+
if (entry->target) {
memcpy(cptr->targets, 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);
+
+ 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:
* Update the IPcheck registry.
* Remove all expired IPregistry structures from the hash bucket
* that belongs to this clients IP number.
- */
-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
- */
+ *--------------------------------------------------------------------------*/
+void ip_registry_disconnect(struct Client *cptr) {
+ ip_reg_entry_t *entry;
+
+ assert(0 != cptr);
+
+ if (!IsIPChecked(cptr))
return;
- }
+
+ entry = ip_registry_find(cptr->ip.s_addr);
+
+ /* Entry is probably a server if this happens. */
+ if (0 == entry)
+ return;
+
+
/*
- * If this was the last one, set `last_connect' to disconnect time (used for expiration)
+ * If this was the last one, set `last_connect' to disconnect time
+ * (used for expiration) Note that we reset attempts here as well if our
+ * threshhold hasn't been crossed.
*/
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
- */
+ if (CONNECTED_SINCE(entry) > IPCHECK_CLONE_LIMIT * IPCHECK_CLONE_PERIOD)
entry->attempts = 0;
- }
ip_registry_update_free_targets(entry);
entry->last_connect = NOW;
}
+
+
if (MyConnect(cptr)) {
unsigned int free_targets;
- /*
- * Copy the clients targets
- */
+
if (0 == entry->target) {
- entry->target = (struct IPTargetEntry*) MyMalloc(sizeof(struct IPTargetEntry));
+ entry->target = (iptarget_entry_t *)MyMalloc(sizeof(iptarget_entry_t));
+ assert(0 != entry->target);
entry->target->count = STARTTARGETS;
}
- assert(0 != entry->target);
-
memcpy(entry->target->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.
+ * 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
+ * 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)
free_targets = (CurrentTime - cptr->nexttarget) / TARGET_DELAY + 1;
- }
else
free_targets = 0;
- /*
- * Add bonus, this is pretty fuzzy, but it will help in some cases.
- */
+
+ /* Add bonus, this is pretty fuzzy, but it will help in some cases. */
if ((CurrentTime - cptr->firsttime) > 600)
- /*
- * Was longer then 10 minutes online?
- */
free_targets += (CurrentTime - cptr->firsttime - 600) / TARGET_DELAY;
- /*
- * Finally, store smallest value for Judgement Day
- */
+
+ /* Finally, store smallest value for Judgement Day */
if (free_targets < entry->target->count)
entry->target->count = free_targets;
}
}
-/*
+/*----------------------------------------------------------------------------
* IPcheck_nr
*
* Returns number of clients with the same IP number
- */
-int ip_registry_count(unsigned int addr)
-{
- struct IPRegistryEntry* entry = ip_registry_find(addr);
+ *--------------------------------------------------------------------------*/
+int ip_registry_count(unsigned int addr) {
+ ip_reg_entry_t *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.
- */
-int IPcheck_local_connect(struct in_addr a, time_t* next_target_out)
-{
- assert(0 != next_target_out);
- return ip_registry_check_local(a.s_addr, 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.
- */
-int IPcheck_remote_connect(struct Client *cptr, int is_burst)
-{
- assert(0 != 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.
- */
-void IPcheck_connect_fail(struct in_addr a)
-{
- ip_registry_connect_fail(a.s_addr);
-}
-
-/*
- * 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)
-{
- assert(0 != 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.
- */
-void IPcheck_disconnect(struct Client *cptr)
-{
- assert(0 != cptr);
- ip_registry_disconnect(cptr);
-}
-
-/*
- * IPcheck_nr
- *
- * Returns number of clients with the same IP number
- */
-unsigned short IPcheck_nr(struct Client *cptr)
-{
- assert(0 != cptr);
- return ip_registry_count(cptr->ip.s_addr);
-}
-
-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