* 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.
- *
- * $Id$
- *
*/
+/** @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"
-#include "ircd_alloc.h"
+#include "match.h"
#include "msg.h"
-#include "s_bsd.h"
-#include "s_debug.h"
-#include "s_user.h"
+#include "ircd_alloc.h"
+#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 <arpa/inet.h>
-#include <stdio.h>
+/* #include <assert.h> -- Now using assert in ircd_log.h */
#include <string.h>
-#if 1
-#warning Nick collisions are horribly broken in
-#warning this version, and its known to core on
-#warning a whim. If your even concidering
-#warning running this on something resembling a
-#warning production network, dont bother, its
-#warning not worth your time. To those of you
-#warning who grabbed the latest CVS version to
-#warning bug test it, thanks, but I recommend
-#warning you stick to previous versions for the
-#warning time being.
-#error --- Broken code ---
-#endif
-
+/** 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;
- time_t 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
- */
-/*----------------------------------------------------------------------------
- * Compile-time Configuration
- *--------------------------------------------------------------------------*/
+/** Size of hash table (must be a power of two). */
#define IP_REGISTRY_TABLE_SIZE 0x10000
-#define MASK_16 0xffff
-
-/* We allow 6 connections in 60 seconds */
-#define IPCHECK_CLONE_LIMIT 6
-#define IPCHECK_CLONE_PERIOD 60
-#define IPCHECK_CLONE_DELAY 600
-
-
-/*----------------------------------------------------------------------------
- * Handy Macros
- *--------------------------------------------------------------------------*/
-#define NOW (CurrentTime)
-#define CONNECTED_SINCE(x) (NOW - (x->last_connect))
-
-
-/*----------------------------------------------------------------------------
- * Global Data (ugly!)
- *--------------------------------------------------------------------------*/
-static struct IPRegistryEntry *hashTable[IP_REGISTRY_TABLE_SIZE];
-static struct IPRegistryEntry *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)
+/** 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))
+
+/** 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];
+/** 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)
{
- return ((ip >> 16) ^ ip) & (IP_REGISTRY_TABLE_SIZE - 1);
+ 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));
}
-
-/*----------------------------------------------------------------------------
- * ip_registry_find: Find a given IP registry entry and return it.
- *--------------------------------------------------------------------------*/
-static struct IPRegistryEntry *ip_registry_find(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)
{
- struct IPRegistryEntry *entry = NULL;
+ 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);
+}
- for (entry = hashTable[ip_registry_hash(ip)]; entry; entry = entry->next) {
- if (entry->addr == ip)
- return entry;
+/** 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 irc_in_addr canon;
+ struct IPRegistryEntry* entry;
+ ip_registry_canonicalize(&canon, ip);
+ entry = hashTable[ip_registry_hash(&canon)];
+ for ( ; entry; entry = entry->next) {
+ int bits = (canon.in6_16[0] == htons(0x2002)) ? 48 : 64;
+ if (ipmask_check(&canon, &entry->addr, bits))
+ break;
}
-
- return NULL;
+ return entry;
}
-
-/*----------------------------------------------------------------------------
- * ip_registry_add: Add an entry to the IP registry
- *--------------------------------------------------------------------------*/
-static void ip_registry_add(struct IPRegistryEntry *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;
}
-
-/*----------------------------------------------------------------------------
- * ip_registry_remove: Remove an entry from the IP registry
- *--------------------------------------------------------------------------*/
-static void ip_registry_remove(struct IPRegistryEntry* 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 {
- struct IPRegistryEntry *prev;
-
- for (prev = hashTable[bucket]; prev; prev = prev->next) {
+ struct IPRegistryEntry* prev = hashTable[bucket];
+ for ( ; prev; prev = prev->next) {
if (prev->next == entry) {
prev->next = entry->next;
break;
}
}
}
-
-/*----------------------------------------------------------------------------
- * ip_registry_new_entry(): Creates and initializes an IP Registry entry.
- * NOW ALSO ADDS IT TO THE LIST! --ZS
- *--------------------------------------------------------------------------*/
-static struct IPRegistryEntry *ip_registry_new_entry(unsigned int addr, int attempt)
+/** 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)
freeList = entry->next;
else
- entry = (struct IPRegistryEntry *)MyMalloc(sizeof(struct IPRegistryEntry));
+ entry = (struct IPRegistryEntry*) MyMalloc(sizeof(struct IPRegistryEntry));
assert(0 != entry);
-
memset(entry, 0, sizeof(struct IPRegistryEntry));
entry->last_connect = NOW; /* Seconds since last connect attempt */
entry->connected = 1; /* connected clients for this IP */
- entry->attempts = attempt; /* Number attempts for this IP */
- entry->addr = addr; /* Entry's IP Address */
-
- ip_registry_add(entry);
-
+ entry->attempts = 1; /* Number attempts for this IP */
return 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(struct IPRegistryEntry *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)
MyFree(entry->target);
-
entry->next = freeList;
freeList = entry;
}
-
-/*----------------------------------------------------------------------------
- * ip_registry_update_free_targets:
- *--------------------------------------------------------------------------*/
-static unsigned int ip_registry_update_free_targets(struct IPRegistryEntry *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;
if (entry->target) {
- free_targets = (entry->target->count +
- (CONNECTED_SINCE(entry) / TARGET_DELAY));
-
+ free_targets = entry->target->count + (CONNECTED_SINCE(entry->last_connect) / TARGET_DELAY);
if (free_targets > STARTTARGETS)
free_targets = STARTTARGETS;
-
entry->target->count = free_targets;
}
-
return free_targets;
}
-
-/*----------------------------------------------------------------------------
- * 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(struct IPRegistryEntry *entry)
+/** 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)
{
/*
* Don't touch this number, it has statistical significance
* XXX - blah blah blah
- * ZS - Just -what- statistical significance does it -have-?
- * Iso - Noone knows, we've just been told not to touch it.
*/
- if (CONNECTED_SINCE(entry) > 120 && 0 != entry->target) {
- MyFree(entry->target);
- entry->target = 0;
- }
- if (CONNECTED_SINCE(entry) > 600) {
+ if (CONNECTED_SINCE(entry->last_connect) > 600) {
+ /*
+ * 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);
}
+ else if (CONNECTED_SINCE(entry->last_connect) > 120 && 0 != entry->target) {
+ /*
+ * Expire storage of targets
+ */
+ MyFree(entry->target);
+ entry->target = 0;
+ }
}
-
-/*----------------------------------------------------------------------------
- * ip_registry_expire: Expire all of the needed entries in the hash table
- *--------------------------------------------------------------------------*/
-void ip_registry_expire(void)
+/** Periodic timer callback to check for expired registry entries.
+ * @param[in] ev Timer event (ignored).
+ */
+static void ip_registry_expire(struct Event* ev)
{
- struct IPRegistryEntry *entry;
- struct IPRegistryEntry *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;
+ 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) {
ip_registry_expire_entry(entry);
}
}
-
- next_expire = CurrentTime + 60;
}
+/** Initialize the IPcheck subsystem. */
+void IPcheck_init(void)
+{
+ timer_add(timer_init(&expireTimer), ip_registry_expire, 0, TT_PERIODIC, 60);
+}
-/*----------------------------------------------------------------------------
- *
- * 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 ip_registry_check_local(unsigned int addr, time_t *next_target_out)
+/** 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(const struct irc_in_addr *addr, time_t* next_target_out)
{
- struct IPRegistryEntry *entry = ip_registry_find(addr);
+ struct IPRegistryEntry* entry = ip_registry_find(addr);
unsigned int free_targets = STARTTARGETS;
-
- assert(0 != next_target_out);
- /* If they've never connected before, let them on */
if (0 == entry) {
- Debug((DEBUG_DEBUG,"IPcheck: Local user allowed - unseen"));
- entry = ip_registry_new_entry(addr, 1);
+ entry = ip_registry_new_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;
}
-
- /* Keep track of how many people have connected */
- entry->connected++;
-
- /* Do not allow more than 250 connects from a single IP, EVER. */
- if (250 <= entry->connected) {
- Debug((DEBUG_DEBUG,"IPcheck: Local user disallowed - Too many connections"));
+ /* Note that this also counts server connects.
+ * It is hard and not interesting, to change that.
+ * 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 our threshhold has elapsed, reset the counter so we don't throttle,
- * IPCHECK_CLONE_LIMIT connections every IPCHECK_CLONE_PERIOD
- */
- if (CONNECTED_SINCE(entry) > IPCHECK_CLONE_PERIOD) {
+ if (CONNECTED_SINCE(entry->last_connect) > IPCHECK_CLONE_PERIOD)
entry->attempts = 0;
- entry->last_connect = NOW;
- }
-
- /* Count the number of recent attempts */
- entry->attempts++;
-
- if (250 <= entry->attempts)
- --entry->attempts; /* Disallow overflow */
-
free_targets = ip_registry_update_free_targets(entry);
+ entry->last_connect = NOW;
+
+ if (0 == ++entry->attempts) /* Check for overflow */
+ --entry->attempts;
- /* Have they connected less than IPCHECK_CLONE_LIMIT times && next_target_out */
- if (entry->attempts < IPCHECK_CLONE_LIMIT && next_target_out) {
+ if (entry->attempts < IPCHECK_CLONE_LIMIT) {
+ if (next_target_out)
*next_target_out = CurrentTime - (TARGET_DELAY * free_targets - 1);
- entry->last_connect = NOW;
- Debug((DEBUG_DEBUG,"IPcheck: Local user allowed"));
- return 1;
}
-
- /* If the server is younger than IPCHECK_CLONE_DELAY then the person
- * is allowed on.
- */
- if ((CurrentTime - me.since) < IPCHECK_CLONE_DELAY) {
- Debug((DEBUG_DEBUG,"IPcheck: Local user allowed during server startup"));
- return 1;
+ else if ((CurrentTime - cli_since(&me)) > IPCHECK_CLONE_DELAY) {
+ /*
+ * Don't refuse connection when we just rebooted the server
+ */
+#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
}
-
- /* Otherwise they're throttled */
- entry->connected--;
- Debug((DEBUG_DEBUG,"IPcheck: Throttling local user"));
- return 0;
+ Debug((DEBUG_DNS, "IPcheck accepting local connection from %s.", ircd_ntoa(&entry->addr)));
+ return 1;
}
-
-/*----------------------------------------------------------------------------
- * ip_registry_remote_connect
- *
- * Does anything that needs to be done once we actually have a client
- * structure to play with on a remote connection.
- * returns:
- * 1 - allowed to connect
- * 0 - disallowed.
- *--------------------------------------------------------------------------*/
-int ip_registry_remote_connect(struct Client *cptr)
+/** 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);
- assert(0 != cptr);
+ struct IPRegistryEntry* entry;
- /* If they've never connected before, let them on */
+ /*
+ * 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(cptr->ip.s_addr, 1);
- SetIPChecked(cptr);
- Debug((DEBUG_DEBUG,"IPcheck: First remote connection. connected=%i",entry->connected));
+ entry = ip_registry_new_entry();
+ 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;
}
-
- /* Keep track of how many people have connected */
- entry->connected++;
- SetIPChecked(cptr);
-
- /* Do not allow more than 250 connections from one IP.
- * This can happen by having 128 clients on one server, and 128 on another
- * and then the servers joining after a netsplit
- */
- if (250 <= entry->connected) {
- sendto_ops("IPcheck Ghost! [%s]",inet_ntoa(cptr->ip));
- Debug((DEBUG_DEBUG,"IPcheck: Too many connected from IP: %i",entry->connected));
+ /* 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;
}
-
- Debug((DEBUG_DEBUG,"IPcheck: %i people connected",entry->connected));
-
- /* They are allowed to connect */
+ 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;
+ }
+ Debug((DEBUG_DNS, "IPcheck counting remote connection from %s.", ircd_ntoa(&entry->addr)));
return 1;
}
-/*----------------------------------------------------------------------------
- * IPcheck_connect_succeeded
- *
- * Event:
- * A client succeeded to finish the registration.
- *
- * Finish IPcheck registration of a successfully, locally connected client.
- *--------------------------------------------------------------------------*/
+/** 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(const struct irc_in_addr *addr, int disconnect)
+{
+ struct IPRegistryEntry* entry = ip_registry_find(addr);
+ 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--;
+ }
+ }
+}
+
+/** 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;
-
- assert(cptr);
-
- entry = ip_registry_find(cptr->ip.s_addr);
-
+ struct IPRegistryEntry* entry = ip_registry_find(&cli_ip(cptr));
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";
}
-
- sendcmdto_one(&me, CMD_NOTICE, cptr, "%C :connected %u attempts %u/%u free targets %u/%u%s"
- " IPcheck: %s",
+ 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,
- ((entry->target) ? " [Inherited Targets]" : ""),
- ((CurrentTime - me.since) < IPCHECK_CLONE_DELAY) ? "Disabled" : "Enabled");
-
- SetIPChecked(cptr);
+ free_targets, STARTTARGETS, tr);
}
-
-/*----------------------------------------------------------------------------
- * IPcheck_disconnect
- *
- * Event:
- * A local client disconnected.
- *
- * Action:
- * Update the IPcheck registry.
- * Remove all expired IPregistry structures from the hash bucket
- * that belongs to this clients IP number.
- *--------------------------------------------------------------------------*/
-void ip_registry_local_disconnect(struct Client *cptr)
+/** 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;
- unsigned int free_targets;
-
- assert(0 != cptr);
-
- entry = ip_registry_find(cptr->ip.s_addr);
-
- /* Servers might not be in IPcheck because we connected to them, not visa
- * versa.
- * We can't use IsServer() here, because it might be in the 'unregistered'
- * state.
- */
- if (0 != cptr->serv && !entry) {
- Debug((DEBUG_DEBUG,"IPcheck: Server ignored"));
- return;
+ 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;
}
- Debug((DEBUG_DEBUG,"IPcheck: Local Disconnect"));
-
- assert(IsIPChecked(cptr));
-
assert(entry);
-
assert(entry->connected > 0);
-
- if (entry->connected > 0) {
- entry->connected--;
- }
-
+ 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) Note that we reset attempts here as well if our
- * threshhold hasn't been crossed.
+ * If this was the last one, set `last_connect' to disconnect time (used for expiration)
*/
- if (0 == entry->connected) {
+ if (0 == --entry->connected) {
+ if (CONNECTED_SINCE(entry->last_connect) > IPCHECK_CLONE_LIMIT * IPCHECK_CLONE_PERIOD) {
+ /*
+ * Otherwise we'd penalize for this old value if the client reconnects within 20 seconds
+ */
+ entry->attempts = 0;
+ }
ip_registry_update_free_targets(entry);
entry->last_connect = NOW;
}
-
- assert(MyConnect(cptr));
-
- if (0 == entry->target) {
- entry->target = (struct IPTargetEntry *)MyMalloc(sizeof(struct IPTargetEntry));
+ 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->count = STARTTARGETS;
+ }
assert(0 != entry->target);
- entry->target->count = STARTTARGETS;
- }
- 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.
- *
- * 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, if you've been connected for more than 10 minutes you
- * get a free target every TARGET_DELAY seconds.
- * this is pretty fuzzy, but it will help in some cases.
- */
- if ((CurrentTime - cptr->firsttime) > 600)
- free_targets += (CurrentTime - cptr->firsttime - 600) / TARGET_DELAY;
+ 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 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).
+ * 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 (cli_nexttarget(cptr) < CurrentTime) {
+ /*
+ * Number of free targets
+ */
+ 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 - cli_firsttime(cptr)) > 600)
+ /*
+ * Was longer then 10 minutes online?
+ */
+ free_targets += (CurrentTime - cli_firsttime(cptr) - 600) / TARGET_DELAY;
+ /*
+ * Finally, store smallest value for Judgment Day
+ */
+ if (free_targets < entry->target->count)
+ entry->target->count = free_targets;
+ }
+}
- /* Finally, store smallest value for Judgement Day */
- if (free_targets < entry->target->count)
- entry->target->count = free_targets;
-
+/** 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(const struct irc_in_addr *addr)
+{
+ struct IPRegistryEntry* entry = ip_registry_find(addr);
+ return (entry) ? entry->connected : 0;
}
-/*----------------------------------------------------------------------------
- * ip_registry_remote_disconnect
- *
- * Event:
- * A remote client disconnected.
- *
- * Action:
- * Update the IPcheck registry.
- * Remove all expired IPregistry structures from the hash bucket
- * that belongs to this clients IP number.
- *--------------------------------------------------------------------------*/
-void ip_registry_remote_disconnect(struct Client *cptr)
+/** 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(const struct irc_in_addr *a, time_t* next_target_out)
{
- struct IPRegistryEntry *entry;
+ assert(0 != next_target_out);
+ return ip_registry_check_local(a, next_target_out);
+}
+/** 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, int is_burst)
+{
assert(0 != cptr);
+ assert(!IsIPChecked(cptr));
+ return ip_registry_check_remote(cptr, is_burst);
+}
- entry = ip_registry_find(cptr->ip.s_addr);
-
- assert(entry);
-
- assert(entry->connected > 0);
- Debug((DEBUG_DEBUG,"IPcheck: Remote Disconnect"));
+/** 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(const struct Client *cptr, int disconnect)
+{
+ assert(IsIPChecked(cptr));
+ ip_registry_connect_fail(&cli_ip(cptr), disconnect);
+}
- if (entry->connected > 0) {
- entry->connected--;
- }
+/** 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);
+}
- /*
- * 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) {
- ip_registry_update_free_targets(entry);
- entry->last_connect=NOW;
- }
+/** 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
- *--------------------------------------------------------------------------*/
-int ip_registry_count(unsigned int addr)
+/** 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)
{
- struct IPRegistryEntry *entry = ip_registry_find(addr);
- return (entry) ? entry->connected : 0;
+ assert(0 != cptr);
+ return ip_registry_count(&cli_ip(cptr));
}
projects / ircu2.10.12-pk.git / blobdiff