/*
* ircd-ratbox: A slightly useful ircd.
* hash.c: Maintains hashtables.
*
* Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
* Copyright (C) 1996-2002 Hybrid Development Team
* Copyright (C) 2002-2005 ircd-ratbox development team
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*
* $Id: hash.c 3177 2007-02-01 00:19:14Z jilles $
*/
#include "stdinc.h"
#include "ircd_defs.h"
#include "s_conf.h"
#include "channel.h"
#include "client.h"
#include "common.h"
#include "hash.h"
#include "match.h"
#include "ircd.h"
#include "numeric.h"
#include "send.h"
#include "msg.h"
#include "cache.h"
#include "s_newconf.h"
#define hash_cli_fd(x) (x % CLI_FD_MAX)
static rb_dlink_list clientbyfdTable[U_MAX];
rb_dlink_list *clientTable;
rb_dlink_list *channelTable;
rb_dlink_list *idTable;
rb_dlink_list *resvTable;
rb_dlink_list *hostTable;
/*
* look in whowas.c for the missing ...[WW_MAX]; entry
*/
/*
* Hashing.
*
* The server uses a chained hash table to provide quick and efficient
* hash table maintenance (providing the hash function works evenly over
* the input range). The hash table is thus not susceptible to problems
* of filling all the buckets or the need to rehash.
* It is expected that the hash table would look something like this
* during use:
* +-----+ +-----+ +-----+ +-----+
* ---| 224 |----| 225 |----| 226 |---| 227 |---
* +-----+ +-----+ +-----+ +-----+
* | | |
* +-----+ +-----+ +-----+
* | A | | C | | D |
* +-----+ +-----+ +-----+
* |
* +-----+
* | B |
* +-----+
*
* A - GOPbot, B - chang, C - hanuaway, D - *.mu.OZ.AU
*
* The order shown above is just one instant of the server.
*
*
* The hash functions currently used are based Fowler/Noll/Vo hashes
* which work amazingly well and have a extremely low collision rate
* For more info see http://www.isthe.com/chongo/tech/comp/fnv/index.html
*
*
*/
/* init_hash()
*
* clears the various hashtables
*/
void
init_hash(void)
{
clientTable = rb_malloc(sizeof(rb_dlink_list) * U_MAX);
idTable = rb_malloc(sizeof(rb_dlink_list) * U_MAX);
channelTable = rb_malloc(sizeof(rb_dlink_list) * CH_MAX);
hostTable = rb_malloc(sizeof(rb_dlink_list) * HOST_MAX);
resvTable = rb_malloc(sizeof(rb_dlink_list) * R_MAX);
}
#ifndef RICER_HASHING
u_int32_t
fnv_hash_upper(const unsigned char *s, int bits)
{
u_int32_t h = FNV1_32_INIT;
while (*s)
{
h ^= ToUpper(*s++);
h += (h<<1) + (h<<4) + (h<<7) + (h << 8) + (h << 24);
}
if (bits < 32)
h = ((h >> bits) ^ h) & ((1<<bits)-1);
return h;
}
u_int32_t
fnv_hash(const unsigned char *s, int bits)
{
u_int32_t h = FNV1_32_INIT;
while (*s)
{
h ^= *s++;
h += (h<<1) + (h<<4) + (h<<7) + (h << 8) + (h << 24);
}
if (bits < 32)
h = ((h >> bits) ^ h) & ((1<<bits)-1);
return h;
}
u_int32_t
fnv_hash_len(const unsigned char *s, int bits, int len)
{
u_int32_t h = FNV1_32_INIT;
const unsigned char *x = s + len;
while (*s && s < x)
{
h ^= *s++;
h += (h<<1) + (h<<4) + (h<<7) + (h << 8) + (h << 24);
}
if (bits < 32)
h = ((h >> bits) ^ h) & ((1<<bits)-1);
return h;
}
u_int32_t
fnv_hash_upper_len(const unsigned char *s, int bits, int len)
{
u_int32_t h = FNV1_32_INIT;
const unsigned char *x = s + len;
while (*s && s < x)
{
h ^= ToUpper(*s++);
h += (h<<1) + (h<<4) + (h<<7) + (h << 8) + (h << 24);
}
if (bits < 32)
h = ((h >> bits) ^ h) & ((1<<bits)-1);
return h;
}
#endif
/* hash_nick()
*
* hashes a nickname, first converting to lowercase
*/
static u_int32_t
hash_nick(const char *name)
{
return fnv_hash_upper((const unsigned char *) name, U_MAX_BITS);
}
/* hash_id()
*
* hashes an id, case is kept
*/
static u_int32_t
hash_id(const char *name)
{
return fnv_hash((const unsigned char *) name, U_MAX_BITS);
}
/* hash_channel()
*
* hashes a channel name, based on first 30 chars only for efficiency
*/
static u_int32_t
hash_channel(const char *name)
{
return fnv_hash_upper_len((const unsigned char *) name, CH_MAX_BITS, 30);
}
/* hash_hostname()
*
* hashes a hostname, based on first 30 chars only, as thats likely to
* be more dynamic than rest.
*/
static u_int32_t
hash_hostname(const char *name)
{
return fnv_hash_upper_len((const unsigned char *) name, HOST_MAX_BITS, 30);
}
/* hash_resv()
*
* hashes a resv channel name, based on first 30 chars only
*/
static u_int32_t
hash_resv(const char *name)
{
return fnv_hash_upper_len((const unsigned char *) name, R_MAX_BITS, 30);
}
/* add_to_id_hash()
*
* adds an entry to the id hash table
*/
void
add_to_id_hash(const char *name, struct Client *client_p)
{
unsigned int hashv;
if(EmptyString(name) || (client_p == NULL))
return;
hashv = hash_id(name);
rb_dlinkAddAlloc(client_p, &idTable[hashv]);
}
/* add_to_client_hash()
*
* adds an entry (client/server) to the client hash table
*/
void
add_to_client_hash(const char *name, struct Client *client_p)
{
unsigned int hashv;
s_assert(name != NULL);
s_assert(client_p != NULL);
if(EmptyString(name) || (client_p == NULL))
return;
hashv = hash_nick(name);
rb_dlinkAddAlloc(client_p, &clientTable[hashv]);
}
/* add_to_hostname_hash()
*
* adds a client entry to the hostname hash table
*/
void
add_to_hostname_hash(const char *hostname, struct Client *client_p)
{
unsigned int hashv;
s_assert(hostname != NULL);
s_assert(client_p != NULL);
if(EmptyString(hostname) || (client_p == NULL))
return;
hashv = hash_hostname(hostname);
rb_dlinkAddAlloc(client_p, &hostTable[hashv]);
}
/* add_to_resv_hash()
*
* adds a resv channel entry to the resv hash table
*/
void
add_to_resv_hash(const char *name, struct ConfItem *aconf)
{
unsigned int hashv;
s_assert(!EmptyString(name));
s_assert(aconf != NULL);
if(EmptyString(name) || aconf == NULL)
return;
hashv = hash_resv(name);
rb_dlinkAddAlloc(aconf, &resvTable[hashv]);
}
/* del_from_id_hash()
*
* removes an id from the id hash table
*/
void
del_from_id_hash(const char *id, struct Client *client_p)
{
unsigned int hashv;
s_assert(id != NULL);
s_assert(client_p != NULL);
if(EmptyString(id) || client_p == NULL)
return;
hashv = hash_id(id);
rb_dlinkFindDestroy(client_p, &idTable[hashv]);
}
/* del_from_client_hash()
*
* removes a client/server from the client hash table
*/
void
del_from_client_hash(const char *name, struct Client *client_p)
{
unsigned int hashv;
/* no s_asserts, this can happen when removing a client that
* is unregistered.
*/
if(EmptyString(name) || client_p == NULL)
return;
hashv = hash_nick(name);
rb_dlinkFindDestroy(client_p, &clientTable[hashv]);
}
/* del_from_channel_hash()
*
* removes a channel from the channel hash table
*/
void
del_from_channel_hash(const char *name, struct Channel *chptr)
{
unsigned int hashv;
s_assert(name != NULL);
s_assert(chptr != NULL);
if(EmptyString(name) || chptr == NULL)
return;
hashv = hash_channel(name);
rb_dlinkFindDestroy(chptr, &channelTable[hashv]);
}
/* del_from_hostname_hash()
*
* removes a client entry from the hostname hash table
*/
void
del_from_hostname_hash(const char *hostname, struct Client *client_p)
{
unsigned int hashv;
if(hostname == NULL || client_p == NULL)
return;
hashv = hash_hostname(hostname);
rb_dlinkFindDestroy(client_p, &hostTable[hashv]);
}
/* del_from_resv_hash()
*
* removes a resv entry from the resv hash table
*/
void
del_from_resv_hash(const char *name, struct ConfItem *aconf)
{
unsigned int hashv;
s_assert(name != NULL);
s_assert(aconf != NULL);
if(EmptyString(name) || aconf == NULL)
return;
hashv = hash_resv(name);
rb_dlinkFindDestroy(aconf, &resvTable[hashv]);
}
/* find_id()
*
* finds a client entry from the id hash table
*/
struct Client *
find_id(const char *name)
{
struct Client *target_p;
rb_dlink_node *ptr;
unsigned int hashv;
if(EmptyString(name))
return NULL;
hashv = hash_id(name);
RB_DLINK_FOREACH(ptr, idTable[hashv].head)
{
target_p = ptr->data;
if(strcmp(name, target_p->id) == 0)
return target_p;
}
return NULL;
}
/* find_client()
*
* finds a client/server entry from the client hash table
*/
struct Client *
find_client(const char *name)
{
struct Client *target_p;
rb_dlink_node *ptr;
unsigned int hashv;
s_assert(name != NULL);
if(EmptyString(name))
return NULL;
/* hunting for an id, not a nick */
if(IsDigit(*name))
return (find_id(name));
hashv = hash_nick(name);
RB_DLINK_FOREACH(ptr, clientTable[hashv].head)
{
target_p = ptr->data;
if(irccmp(name, target_p->name) == 0)
return target_p;
}
return NULL;
}
/* find_named_client()
*
* finds a client/server entry from the client hash table
*/
struct Client *
find_named_client(const char *name)
{
struct Client *target_p;
rb_dlink_node *ptr;
unsigned int hashv;
s_assert(name != NULL);
if(EmptyString(name))
return NULL;
hashv = hash_nick(name);
RB_DLINK_FOREACH(ptr, clientTable[hashv].head)
{
target_p = ptr->data;
if(irccmp(name, target_p->name) == 0)
return target_p;
}
return NULL;
}
/* find_server()
*
* finds a server from the client hash table
*/
struct Client *
find_server(struct Client *source_p, const char *name)
{
struct Client *target_p;
rb_dlink_node *ptr;
unsigned int hashv;
if(EmptyString(name))
return NULL;
if((source_p == NULL || !MyClient(source_p)) &&
IsDigit(*name) && strlen(name) == 3)
{
target_p = find_id(name);
return(target_p);
}
hashv = hash_nick(name);
RB_DLINK_FOREACH(ptr, clientTable[hashv].head)
{
target_p = ptr->data;
if((IsServer(target_p) || IsMe(target_p)) &&
irccmp(name, target_p->name) == 0)
return target_p;
}
return NULL;
}
/* find_hostname()
*
* finds a hostname rb_dlink list from the hostname hash table.
* we return the full rb_dlink list, because you can have multiple
* entries with the same hostname
*/
rb_dlink_node *
find_hostname(const char *hostname)
{
unsigned int hashv;
if(EmptyString(hostname))
return NULL;
hashv = hash_hostname(hostname);
return hostTable[hashv].head;
}
/* find_channel()
*
* finds a channel from the channel hash table
*/
struct Channel *
find_channel(const char *name)
{
struct Channel *chptr;
rb_dlink_node *ptr;
unsigned int hashv;
s_assert(name != NULL);
if(EmptyString(name))
return NULL;
hashv = hash_channel(name);
RB_DLINK_FOREACH(ptr, channelTable[hashv].head)
{
chptr = ptr->data;
if(irccmp(name, chptr->chname) == 0)
return chptr;
}
return NULL;
}
/*
* get_or_create_channel
* inputs - client pointer
* - channel name
* - pointer to int flag whether channel was newly created or not
* output - returns channel block or NULL if illegal name
* - also modifies *isnew
*
* Get Channel block for chname (and allocate a new channel
* block, if it didn't exist before).
*/
struct Channel *
get_or_create_channel(struct Client *client_p, const char *chname, int *isnew)
{
struct Channel *chptr;
rb_dlink_node *ptr;
unsigned int hashv;
int len;
const char *s = chname;
if(EmptyString(s))
return NULL;
len = strlen(s);
if(len > CHANNELLEN)
{
char *t;
if(IsServer(client_p))
{
sendto_realops_snomask(SNO_DEBUG, L_ALL,
"*** Long channel name from %s (%d > %d): %s",
client_p->name, len, CHANNELLEN, s);
}
len = CHANNELLEN;
t = LOCAL_COPY(s);
*(t + CHANNELLEN) = '\0';
s = t;
}
hashv = hash_channel(s);
RB_DLINK_FOREACH(ptr, channelTable[hashv].head)
{
chptr = ptr->data;
if(irccmp(s, chptr->chname) == 0)
{
if(isnew != NULL)
*isnew = 0;
return chptr;
}
}
if(isnew != NULL)
*isnew = 1;
chptr = allocate_channel(s);
rb_dlinkAdd(chptr, &chptr->node, &global_channel_list);
chptr->channelts = rb_current_time(); /* doesn't hurt to set it here */
rb_dlinkAddAlloc(chptr, &channelTable[hashv]);
return chptr;
}
/* hash_find_resv()
*
* hunts for a resv entry in the resv hash table
*/
struct ConfItem *
hash_find_resv(const char *name)
{
struct ConfItem *aconf;
rb_dlink_node *ptr;
unsigned int hashv;
s_assert(name != NULL);
if(EmptyString(name))
return NULL;
hashv = hash_resv(name);
RB_DLINK_FOREACH(ptr, resvTable[hashv].head)
{
aconf = ptr->data;
if(!irccmp(name, aconf->name))
{
aconf->port++;
return aconf;
}
}
return NULL;
}
void
clear_resv_hash(void)
{
struct ConfItem *aconf;
rb_dlink_node *ptr;
rb_dlink_node *next_ptr;
int i;
HASH_WALK_SAFE(i, R_MAX, ptr, next_ptr, resvTable)
{
aconf = ptr->data;
/* skip temp resvs */
if(aconf->hold)
continue;
free_conf(ptr->data);
rb_dlinkDestroy(ptr, &resvTable[i]);
}
HASH_WALK_END
}
void
add_to_cli_fd_hash(struct Client *client_p)
{
rb_dlinkAddAlloc(client_p, &clientbyfdTable[hash_cli_fd(rb_get_fd(client_p->localClient->F))]);
}
void
del_from_cli_fd_hash(struct Client *client_p)
{
unsigned int hashv;
hashv = hash_cli_fd(rb_get_fd(client_p->localClient->F));
rb_dlinkFindDestroy(client_p, &clientbyfdTable[hashv]);
}
struct Client *
find_cli_fd_hash(int fd)
{
struct Client *target_p;
rb_dlink_node *ptr;
unsigned int hashv;
hashv = hash_cli_fd(fd);
RB_DLINK_FOREACH(ptr, clientbyfdTable[hashv].head)
{
target_p = ptr->data;
if(rb_get_fd(target_p->localClient->F) == fd)
return target_p;
}
return NULL;
}
static void
output_hash(struct Client *source_p, const char *name, int length, int *counts, int deepest)
{
unsigned long total = 0;
int i;
char buf[128];
sendto_one_numeric(source_p, RPL_STATSDEBUG,
"B :%s Hash Statistics", name);
snprintf(buf, sizeof buf, "%.3f%%",
(float) ((counts[0]*100) / (float) length));
sendto_one_numeric(source_p, RPL_STATSDEBUG,
"B :Size: %d Empty: %d (%s)",
length, counts[0], buf);
for(i = 1; i < 11; i++)
{
total += (counts[i] * i);
}
/* dont want to divide by 0! --fl */
if(counts[0] != length)
{
snprintf(buf, sizeof buf, "%.3f/%.3f",
(float) (total / (length - counts[0])),
(float) (total / length));
sendto_one_numeric(source_p, RPL_STATSDEBUG,
"B :Average depth: %s Highest depth: %d",
buf, deepest);
}
for(i = 0; i < 11; i++)
{
sendto_one_numeric(source_p, RPL_STATSDEBUG,
"B :Nodes with %d entries: %d",
i, counts[i]);
}
}
static void
count_hash(struct Client *source_p, rb_dlink_list *table, int length, const char *name)
{
int counts[11];
int deepest = 0;
int i;
memset(counts, 0, sizeof(counts));
for(i = 0; i < length; i++)
{
if(rb_dlink_list_length(&table[i]) >= 10)
counts[10]++;
else
counts[rb_dlink_list_length(&table[i])]++;
if(rb_dlink_list_length(&table[i]) > deepest)
deepest = rb_dlink_list_length(&table[i]);
}
output_hash(source_p, name, length, counts, deepest);
}
void
hash_stats(struct Client *source_p)
{
count_hash(source_p, channelTable, CH_MAX, "Channel");
sendto_one_numeric(source_p, RPL_STATSDEBUG, "B :--");
count_hash(source_p, clientTable, U_MAX, "Client");
sendto_one_numeric(source_p, RPL_STATSDEBUG, "B :--");
count_hash(source_p, idTable, U_MAX, "ID");
sendto_one_numeric(source_p, RPL_STATSDEBUG, "B :--");
count_hash(source_p, hostTable, HOST_MAX, "Hostname");
}