* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
+/** @file
+ * @brief Code to count users connected from particular IP addresses.
+ * @version $Id$
+ */
+#include "config.h"
-/* This file should be edited in a window with a width of 141 characters */
-
-#include "sys.h"
-#include <netinet/in.h>
-#include "h.h"
#include "IPcheck.h"
-#include "querycmds.h"
-#include "struct.h"
-#include "s_user.h"
-#include "s_bsd.h"
-#include "struct.h"
-#ifdef GODMODE
-#include "numnicks.h"
-#endif
+#include "client.h"
+#include "ircd.h"
+#include "match.h"
+#include "msg.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"
-RCSTAG_CC("$Id$");
+/* #include <assert.h> -- Now using assert in ircd_log.h */
+#include <string.h>
-extern aClient me;
-extern time_t now;
-
-/*
- * IP number and last targets of a user that just disconnected.
- * Used to allow a user that shortly disconnected to rejoin
- * the channels he/she was on.
- */
-struct ip_targets_st {
- struct in_addr ip;
- unsigned char free_targets;
- unsigned char targets[MAXTARGETS];
+/** Stores free target information for a particular user. */
+struct IPTargetEntry {
+ unsigned int count; /**< Number of free targets targets. */
+ unsigned char targets[MAXTARGETS]; /**< Array of recent targets. */
};
-/* We keep one IPregistry for each IP number (for both, remote and local clients) */
-struct IPregistry {
- union {
- struct in_addr ip; /* The IP number of the registry entry. */
- struct ip_targets_st *ptr; /* The IP number of the registry entry, and a list of targets */
- } ip_targets;
- unsigned int last_connect:16; /* Time of last connect (attempt), see BITMASK below,
- or time of last disconnect when `connected' is zero. */
- unsigned int connected:8; /* Used for IP# throttling: Number of currently on-line clients with this IP number */
- unsigned int connect_attempts:4; /* Used for connect speed throttling: Number of clients that connected with this IP number
- or `15' when then real value is >= 15. This value is only valid when the last connect
- was less then IPCHECK_CLONE_PERIOD seconds ago, it should considered to be 0 otherwise. */
- unsigned int free_targets:4; /* Number of free targets that the next local client will inherit on connect,
- or HAS_TARGETS_MAGIC when ip_targets.ptr is a pointer to a ip_targets_st. */
+/** Stores recent information about a particular IP address. */
+struct IPRegistryEntry {
+ 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. */
};
-struct IPregistry_vector {
- unsigned short length;
- unsigned short allocated_length;
- struct IPregistry *vector;
-};
+/** Size of hash table (must be a power of two). */
+#define IP_REGISTRY_TABLE_SIZE 0x10000
+/** 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 HASHTABSIZE 0x2000 /* Must be power of 2 */
-static struct IPregistry_vector IPregistry_hashtable[HASHTABSIZE];
+/** 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)
-/*
- * 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.
+/** 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.
*/
-#define CALCULATE_HASH(in_addr) \
- struct IPregistry_vector *hash; \
- do { register unsigned int ip = (in_addr).s_addr; \
- hash = &IPregistry_hashtable[((ip >> 14) + (ip >> 7) + ip) & (HASHTABSIZE - 1)]; } while(0)
+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));
+}
-/*
- * 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.
+/** Calculate hash value for an IP address.
+ * @param[in] ip Address to hash; must be in canonical form.
+ * @return Hash value for address.
*/
-#define BITMASK 0xffff /* Same number of bits as `struct IPregistry::last_connect' */
-#define NOW ((unsigned short)(now & BITMASK))
-#define CONNECTED_SINCE(x) ((unsigned short)((now & BITMASK) - (x)->last_connect))
+static unsigned int ip_registry_hash(const struct irc_in_addr *ip)
+{
+ 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);
+}
-#define IPCHECK_CLONE_LIMIT 2
-#define IPCHECK_CLONE_PERIOD 20
-#define IPCHECK_CLONE_DELAY 600
+/** 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 entry;
+}
-#define HAS_TARGETS_MAGIC 15
-#define HAS_TARGETS(entry) ((entry)->free_targets == HAS_TARGETS_MAGIC)
+/** 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);
+ entry->next = hashTable[bucket];
+ hashTable[bucket] = entry;
+}
-#if STARTTARGETS >= HAS_TARGETS_MAGIC
-#error "That doesn't fit in 4 bits, does it?"
-#endif
+/** 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);
+ if (hashTable[bucket] == entry)
+ hashTable[bucket] = entry->next;
+ else {
+ struct IPRegistryEntry* prev = hashTable[bucket];
+ for ( ; prev; prev = prev->next) {
+ if (prev->next == entry) {
+ prev->next = entry->next;
+ break;
+ }
+ }
+ }
+}
-/* 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)
+/** 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));
-static unsigned short count = 10000, average_length = 4;
+ 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 = 1; /* Number attempts for this IP */
+ return entry;
+}
-static struct IPregistry *IPregistry_add(struct IPregistry_vector *iprv)
+/** 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 (iprv->length == iprv->allocated_length)
- {
- iprv->allocated_length += 4;
- iprv->vector =
- (struct IPregistry *)RunRealloc(iprv->vector,
- iprv->allocated_length * sizeof(struct IPregistry));
- }
- return &iprv->vector[iprv->length++];
+ if (entry->target)
+ MyFree(entry->target);
+ entry->next = freeList;
+ freeList = entry;
}
-static struct IPregistry *IPregistry_find(struct IPregistry_vector *iprv,
- struct in_addr ip)
+/** 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)
{
- 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;
+ unsigned int free_targets = STARTTARGETS;
+
+ if (entry->target) {
+ 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 NULL;
+ return free_targets;
}
-static struct IPregistry *IPregistry_find_with_expire(struct IPregistry_vector
- *iprv, struct in_addr ip)
+/** 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)
{
- struct IPregistry *last = &iprv->vector[iprv->length - 1]; /* length always > 0 because searched element always exists */
- struct IPregistry *curr;
- struct IPregistry *retval = NULL; /* Core dump if we find nothing :/ - can be removed when code is stable */
-
- 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))
- RunFree(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 =
- (nrof.clients + nrof.unknowns + nrof.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;
- RunFree(curr->ip_targets.ptr);
- curr->ip_targets.ip = ip1;
- }
- }
- /* Did not expire, check next element */
- ++curr;
+ /*
+ * Don't touch this number, it has statistical significance
+ * XXX - blah blah blah
+ */
+ 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);
}
- /* 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))
- RunFree(curr->ip_targets.ptr);
- iprv->length--;
- if (--count == 0)
- {
- /* Make ever 10000 disconnects an estimation of the average vector length */
- count = 10000;
- average_length =
- (nrof.clients + nrof.unknowns + nrof.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;
- RunFree(curr->ip_targets.ptr);
- curr->ip_targets.ip = ip1;
- }
+ else if (CONNECTED_SINCE(entry->last_connect) > 120 && 0 != entry->target) {
+ /*
+ * Expire storage of targets
+ */
+ MyFree(entry->target);
+ entry->target = 0;
}
- /* 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 *)RunRealloc(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;
+}
+
+/** Periodic timer callback to check for expired registry entries.
+ * @param[in] ev Timer event (ignored).
+ */
+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;
+ if (0 == entry->connected)
+ ip_registry_expire_entry(entry);
}
}
- return retval;
}
-static void reset_connect_time(struct IPregistry *entry)
+/** Initialize the IPcheck subsystem. */
+void IPcheck_init(void)
{
- 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;
+ timer_add(timer_init(&expireTimer), ip_registry_expire, 0, TT_PERIODIC, 60);
}
-/*
- * IPcheck_local_connect
- *
- * Event:
- * A new connection was accept()-ed with IP number `cptr->ip.s_addr'.
- *
- * Action:
- * Update the IPcheck registry.
- * Return < 0 if the connection should be rejected, otherwise 0.
- * -1 : Throttled
- * -2 : Too many connections from your host
- *
- * 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 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 IPcheck_local_connect(aClient *cptr)
+int ip_registry_check_local(const struct irc_in_addr *addr, time_t* next_target_out)
{
- 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)))
+ struct IPRegistryEntry* entry = ip_registry_find(addr);
+ unsigned int free_targets = STARTTARGETS;
+
+ if (0 == entry) {
+ 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;
+ }
+ /* 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 = 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 = 1; /* Number of clients that connected with this IP number */
- entry->free_targets = STARTTARGETS; /* Number of free targets that a client gets on connect */
+ entry->connected--;
+ Debug((DEBUG_DNS, "IPcheck refusing local connection from %s: counter overflow.", ircd_ntoa(&entry->addr)));
return 0;
}
-#ifdef GODMODE
- sendto_one(cptr,
- "ERROR :I saw your face before my friend (connected: %u; connect_attempts %u; free_targets %u)",
- entry->connected, entry->connect_attempts, FREE_TARGETS(entry));
-#endif
- /* Note that this also connects server connects. It is hard and not interesting, to change that. */
- if (++(entry->connected) == 0) /* Don't allow more then 255 connects from one IP number, ever */
- return -2;
- if (CONNECTED_SINCE(entry) > IPCHECK_CLONE_PERIOD)
- entry->connect_attempts = 0;
- reset_connect_time(entry);
- if (++(entry->connect_attempts) == 0) /* Check for overflow */
- --(entry->connect_attempts);
- if (entry->connect_attempts <= IPCHECK_CLONE_LIMIT)
- cptr->nexttarget = now - (TARGET_DELAY * (FREE_TARGETS(entry) - 1));
-#ifdef DEBUGMODE
- else
-#else
- else if (now - me.since > IPCHECK_CLONE_DELAY) /* Don't refuse connection when we just rebooted the server */
+
+ if (CONNECTED_SINCE(entry->last_connect) > IPCHECK_CLONE_PERIOD)
+ entry->attempts = 0;
+
+ free_targets = ip_registry_update_free_targets(entry);
+ entry->last_connect = NOW;
+
+ if (0 == ++entry->attempts) /* Check for overflow */
+ --entry->attempts;
+
+ if (entry->attempts < IPCHECK_CLONE_LIMIT) {
+ if (next_target_out)
+ *next_target_out = CurrentTime - (TARGET_DELAY * free_targets - 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
- return -1;
- return 0;
+ }
+ 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 -1 on failure, 0 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 IPcheck_remote_connect(aClient *cptr, const char *UNUSED(hostname),
- int is_burst)
+int ip_registry_check_remote(struct Client* cptr, 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 */
+ 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;
}
- 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);
+ entry = ip_registry_find(&cli_ip(cptr));
+ if (0 == entry) {
+ 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;
+ }
+ /* 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
+ */
+ --entry->attempts;
}
+ ip_registry_update_free_targets(entry);
+ entry->last_connect = NOW;
}
- return 0;
+ 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 IPcheck_connect_fail(aClient *cptr)
+void ip_registry_connect_fail(const struct irc_in_addr *addr, int disconnect)
{
- struct IPregistry *entry;
- CALCULATE_HASH(cptr->ip);
- entry = IPregistry_find(hash, cptr->ip);
- entry->connect_attempts--;
+ 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--;
+ }
+ }
}
-/*
- * 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(aClient *cptr)
+void ip_registry_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);
+ const char* tr = "";
+ unsigned int free_targets = STARTTARGETS;
+ struct IPRegistryEntry* entry = ip_registry_find(&cli_ip(cptr));
+
+ assert(entry);
+ if (entry->target) {
+ 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->connect_attempts,
- IPCHECK_CLONE_LIMIT, FREE_TARGETS(entry), 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 IPcheck_disconnect(aClient *cptr)
+void ip_registry_disconnect(struct Client *cptr)
{
- struct IPregistry *entry;
- CALCULATE_HASH(cptr->ip);
- entry = IPregistry_find_with_expire(hash, cptr->ip);
- if (--(entry->connected) == 0) /* If this was the last one, set `last_connect' to disconnect time (used for expiration) */
- {
- if (CONNECTED_SINCE(entry) > IPCHECK_CLONE_LIMIT * IPCHECK_CLONE_PERIOD)
- entry->connect_attempts = 0; /* Otherwise we'd penetalize for this old value if the client reconnects within 20 seconds */
- reset_connect_time(entry);
+ 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;
}
- if (MyConnect(cptr))
- {
- unsigned int inheritance;
- /* Copy the clients targets */
- if (HAS_TARGETS(entry))
- {
- entry->free_targets = entry->ip_targets.ptr->free_targets;
- RunFree(entry->ip_targets.ptr);
+ 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 penalize for this old value if the client reconnects within 20 seconds
+ */
+ entry->attempts = 0;
}
- entry->ip_targets.ptr =
- (struct ip_targets_st *)RunMalloc(sizeof(struct ip_targets_st));
- 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);
+ 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->count = STARTTARGETS;
+ }
+ assert(0 != entry->target);
+
+ 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 <= now)
- inheritance = (now - cptr->nexttarget) / TARGET_DELAY + 1; /* Number of free targets */
+ if (cli_nexttarget(cptr) < CurrentTime) {
+ /*
+ * Number of free targets
+ */
+ free_targets = (CurrentTime - cli_nexttarget(cptr)) / TARGET_DELAY + 1;
+ }
else
- inheritance = 0;
- /* Add bonus, this is pretty fuzzy, but it will help in some cases. */
- if (now - cptr->firsttime > 600) /* Was longer then 10 minutes online? */
- inheritance += (now - 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;
+ 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;
}
}
-/*
- * 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(const struct irc_in_addr *addr)
+{
+ struct IPRegistryEntry* entry = ip_registry_find(addr);
+ return (entry) ? entry->connected : 0;
+}
+
+/** 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)
+{
+ 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);
+}
+
+/** 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);
+}
+
+/** 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);
+}
+
+/** 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);
+}
+
+/** 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(aClient *cptr)
+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);
+ assert(0 != cptr);
+ return ip_registry_count(&cli_ip(cptr));
}
projects / ircu2.10.12-pk.git / blobdiff