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ircu2/ircd/numnicks.c

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/*
* IRC - Internet Relay Chat, ircd/channel.c
* Copyright (C) 1996 Carlo Wood (I wish this was C++ - this sucks :/)
*
* 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/** @file
* @brief Implementation of numeric nickname operations.
* @version $Id: numnicks.c 1398 2005-05-08 00:56:05Z entrope $
*/
#include "config.h"
#include "numnicks.h"
#include "client.h"
#include "ircd.h"
#include "ircd_alloc.h"
#include "ircd_log.h"
#include "ircd_string.h"
#include "match.h"
#include "s_bsd.h"
#include "s_debug.h"
#include "s_misc.h"
#include "struct.h"
/* #include <assert.h> -- Now using assert in ircd_log.h */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/** @page numnicks Numeric Nicks
* %Numeric nicks (numnicks) are new as of version ircu2.10.00beta1.
*
* The idea is as follows:
* In most messages (for protocol 10+) the original nick will be
* replaced by a 5 character string: YYXXX
* Where 'YY' represents the server, and 'XXX' the nick on that server.
*
* 'YYXXX' should not interfere with the input parser, and therefore is
* not allowed to contain spaces or a ':'.
* Also, 'YY' can't start with a '+' because of m_server().
*
* We keep the characters printable for debugging reasons too.
*
* The 'XXX' value can be larger then the maximum number of clients
* per server, we use a mask (Server::nn_mask) to get the real
* client numeric. The overhead is used to have some redundancy so
* just-disconnected-client aren't confused with just-connected ones.
*/
/* These must be the same on ALL servers ! Do not change ! */
/** Number of bits encoded in one numnick character. */
#define NUMNICKLOG 6
/** Bitmask to select value of next numnick character. */
#define NUMNICKMASK 63 /* (NUMNICKBASE-1) */
/** Number of servers representable in a numnick. */
#define NN_MAX_SERVER 4096 /* (NUMNICKBASE * NUMNICKBASE) */
/** Number of clients representable in a numnick. */
#define NN_MAX_CLIENT 262144 /* NUMNICKBASE ^ 3 */
/*
* The internal counter for the 'XX' of local clients
*/
/** Maximum used server numnick, plus one. */
static unsigned int lastNNServer = 0;
/** Array of servers indexed by numnick. */
static struct Client* server_list[NN_MAX_SERVER];
/* *INDENT-OFF* */
/**
* Converts a numeric to the corresponding character.
* The following characters are currently known to be forbidden:
*
* '\\0' : Because we use '\\0' as end of line.
*
* ' ' : Because parse_*() uses this as parameter separator.
*
* ':' : Because parse_server() uses this to detect if a prefix is a
* numeric or a name.
*
* '+' : Because m_nick() uses this to determine if parv[6] is a
* umode or not.
*
* '&', '#', '$', '@' and '%' :
* Because m_message() matches these characters to detect special cases.
*/
static const char convert2y[] = {
'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
'w','x','y','z','0','1','2','3','4','5','6','7','8','9','[',']'
};
/** Converts a character to its (base64) numnick value. */
static const unsigned int convert2n[] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
52,53,54,55,56,57,58,59,60,61, 0, 0, 0, 0, 0, 0,
0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,
15,16,17,18,19,20,21,22,23,24,25,62, 0,63, 0, 0,
0,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,
41,42,43,44,45,46,47,48,49,50,51, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
/* *INDENT-ON* */
/** Convert a string to its value as a numnick.
* @param[in] s Numnick string to decode.
* @return %Numeric nickname value.
*/
unsigned int base64toint(const char* s)
{
unsigned int i = convert2n[(unsigned char) *s++];
while (*s) {
i <<= NUMNICKLOG;
i += convert2n[(unsigned char) *s++];
}
return i;
}
/** Encode a number as a numnick.
* @param[out] buf Output buffer.
* @param[in] v Value to encode.
* @param[in] count Number of numnick digits to write to \a buf.
*/
const char* inttobase64(char* buf, unsigned int v, unsigned int count)
{
buf[count] = '\0';
while (count > 0) {
buf[--count] = convert2y[(v & NUMNICKMASK)];
v >>= NUMNICKLOG;
}
return buf;
}
/** Look up a server by numnick string.
* See @ref numnicks for more details.
* @param[in] numeric %Numeric nickname of server (may contain trailing junk).
* @return %Server with that numnick (or NULL).
*/
static struct Client* FindXNServer(const char* numeric)
{
char buf[3];
buf[0] = *numeric++;
buf[1] = *numeric;
buf[2] = '\0';
Debug((DEBUG_DEBUG, "FindXNServer: %s(%d)", buf, base64toint(buf)));
return server_list[base64toint(buf)];
}
/** Look up a server by numnick string.
* See @ref numnicks for more details.
* @param[in] numeric %Numeric nickname of server.
* @return %Server with that numnick (or NULL).
*/
struct Client* FindNServer(const char* numeric)
{
unsigned int len = strlen(numeric);
if (len < 3) {
Debug((DEBUG_DEBUG, "FindNServer: %s(%d)", numeric, base64toint(numeric)));
return server_list[base64toint(numeric)];
}
else if (len == 3) {
Debug((DEBUG_DEBUG, "FindNServer: %c(%d)", *numeric,
convert2n[(unsigned char) *numeric]));
return server_list[convert2n[(unsigned char) *numeric]];
}
return FindXNServer(numeric);
}
/** Look up a user by numnick string.
* See @ref numnicks for more details.
* @param[in] yxx %Numeric nickname of user.
* @return %User with that numnick (or NULL).
*/
struct Client* findNUser(const char* yxx)
{
struct Client* server = 0;
if (5 == strlen(yxx)) {
if (0 != (server = FindXNServer(yxx))) {
Debug((DEBUG_DEBUG, "findNUser: %s(%d)", yxx,
base64toint(yxx + 2) & cli_serv(server)->nn_mask));
return cli_serv(server)->client_list[base64toint(yxx + 2) & cli_serv(server)->nn_mask];
}
}
else if (0 != (server = FindNServer(yxx))) {
Debug((DEBUG_DEBUG, "findNUser: %s(%d)",
yxx, base64toint(yxx + 1) & cli_serv(server)->nn_mask));
return cli_serv(server)->client_list[base64toint(yxx + 1) & cli_serv(server)->nn_mask];
}
return 0;
}
/** Remove a client from a server's user array.
* @param[in] server %Server that owns the user to remove.
* @param[in] yxx Numnick of client to remove.
*/
void RemoveYXXClient(struct Client* server, const char* yxx)
{
assert(0 != server);
assert(0 != yxx);
if (*yxx) {
Debug((DEBUG_DEBUG, "RemoveYXXClient: %s(%d)", yxx,
base64toint(yxx) & cli_serv(server)->nn_mask));
cli_serv(server)->client_list[base64toint(yxx) & cli_serv(server)->nn_mask] = 0;
}
}
/** Set a server's numeric nick.
* @param[in] cptr %Client that announced the server (ignored).
* @param[in,out] server %Server that is being assigned a numnick.
* @param[in] yxx %Numeric nickname for server.
*/
void SetServerYXX(struct Client* cptr, struct Client* server, const char* yxx)
{
unsigned int index;
if (5 == strlen(yxx)) {
ircd_strncpy(cli_yxx(server), yxx, 3);
ircd_strncpy(cli_serv(server)->nn_capacity, yxx + 2, 4);
}
else {
(cli_yxx(server))[0] = yxx[0];
cli_serv(server)->nn_capacity[0] = yxx[1];
cli_serv(server)->nn_capacity[1] = yxx[2];
}
cli_serv(server)->nn_mask = base64toint(cli_serv(server)->nn_capacity);
index = base64toint(cli_yxx(server));
if (index >= lastNNServer)
lastNNServer = index + 1;
server_list[index] = server;
/* Note, exit_one_client uses the fact that `client_list' != NULL to
* determine that SetServerYXX has been called - and then calls
* ClearServerYXX. However, freeing the allocation happens in free_client() */
cli_serv(server)->client_list =
(struct Client**) MyCalloc(cli_serv(server)->nn_mask + 1, sizeof(struct Client*));
}
/** Set a server's capacity.
* @param[in] c %Server whose capacity is being set.
* @param[in] capacity Maximum number of clients the server supports.
*/
void SetYXXCapacity(struct Client* c, unsigned int capacity)
{
unsigned int max_clients = 16;
/*
* Calculate mask to be used for the maximum number of clients
*/
while (max_clients < capacity)
max_clients <<= 1;
/*
* Sanity checks
*/
if (max_clients > NN_MAX_CLIENT) {
fprintf(stderr, "MAXCLIENTS (or MAXCONNECTIONS) is (at least) %d "
"too large ! Please decrease this value.\n",
max_clients - NN_MAX_CLIENT);
exit(-1);
}
--max_clients;
inttobase64(cli_serv(c)->nn_capacity, max_clients, 3);
cli_serv(c)->nn_mask = max_clients; /* Our Numeric Nick mask */
cli_serv(c)->client_list = (struct Client**) MyCalloc(max_clients + 1,
sizeof(struct Client*));
server_list[base64toint(cli_yxx(c))] = c;
}
/** Set a server's numeric nick.
* See @ref numnicks for more details.
* @param[in] c %Server that is being assigned a numnick.
* @param[in] numeric Numnick value for server.
*/
void SetYXXServerName(struct Client* c, unsigned int numeric)
{
assert(0 != c);
assert(numeric < NN_MAX_SERVER);
inttobase64(cli_yxx(c), numeric, 2);
if (numeric >= lastNNServer)
lastNNServer = numeric + 1;
server_list[numeric] = c;
}
/** Unassign a server's numnick.
* @param[in] server %Server that should be removed from the numnick table.
*/
void ClearServerYXX(const struct Client *server)
{
unsigned int index = base64toint(cli_yxx(server));
if (server_list[index] == server) /* Sanity check */
server_list[index] = 0;
}
/** Register numeric of new (remote) client.
* See @ref numnicks for more details.
* Add it to the appropriate client_list.
* @param[in] acptr %User being registered.
* @param[in] yxx User's numnick.
*/
void SetRemoteNumNick(struct Client* acptr, const char *yxx)
{
struct Client** acptrp;
struct Client* server = cli_user(acptr)->server;
if (5 == strlen(yxx)) {
/* Security fix: Replace strcpy cu ircd_strncpy pentru protectie buffer overflow */
ircd_strncpy(cli_yxx(acptr), yxx + 2, sizeof(cli_yxx(acptr)));
}
else {
(cli_yxx(acptr))[0] = *++yxx;
(cli_yxx(acptr))[1] = *++yxx;
(cli_yxx(acptr))[2] = 0;
}
Debug((DEBUG_DEBUG, "SetRemoteNumNick: %s(%d)", cli_yxx(acptr),
base64toint(cli_yxx(acptr)) & cli_serv(server)->nn_mask));
acptrp = &(cli_serv(server))->client_list[base64toint(cli_yxx(acptr)) & cli_serv(server)->nn_mask];
if (*acptrp) {
/*
* this exits the old client in the array, not the client
* that is being set
*/
exit_client(cli_from(acptr), *acptrp, server, "Numeric nick collision (Ghost)");
}
*acptrp = acptr;
}
/** Register numeric of new (local) client.
* See @ref numnicks for more details.
* Assign a numnick and add it to our client_list.
* @param[in] cptr %User being registered.
*/
int SetLocalNumNick(struct Client *cptr)
{
static unsigned int last_nn = 0;
struct Client** client_list = cli_serv(&me)->client_list;
unsigned int mask = cli_serv(&me)->nn_mask;
unsigned int count = 0;
assert(cli_user(cptr)->server == &me);
while (client_list[last_nn & mask]) {
if (++count == NN_MAX_CLIENT) {
assert(count < NN_MAX_CLIENT);
return 0;
}
if (++last_nn == NN_MAX_CLIENT)
last_nn = 0;
}
client_list[last_nn & mask] = cptr; /* Reserve the numeric ! */
inttobase64(cli_yxx(cptr), last_nn, 3);
if (++last_nn == NN_MAX_CLIENT)
last_nn = 0;
return 1;
}
/** Mark servers whose name matches the given (compiled) mask by
* setting their FLAG_MAP flag.
* @param[in] cmask Compiled mask for server names.
* @param[in] minlen Minimum match length for \a cmask.
* @return Number of servers marked.
*/
int markMatchexServer(const char *cmask, int minlen)
{
int cnt = 0;
int i;
struct Client *acptr;
for (i = 0; i < lastNNServer; i++) {
if ((acptr = server_list[i]))
{
if (matchexec(cli_name(acptr), cmask, minlen))
ClrFlag(acptr, FLAG_MAP);
else
{
SetFlag(acptr, FLAG_MAP);
cnt++;
}
}
}
return cnt;
}
/** Find first server whose name matches the given mask.
* @param[in,out] mask %Server name mask (collapse()d in-place).
* @return Matching server with lowest numnick value (or NULL).
*/
struct Client* find_match_server(char *mask)
{
struct Client *acptr;
int i;
if (!(BadPtr(mask))) {
collapse(mask);
for (i = 0; i < lastNNServer; i++) {
if ((acptr = server_list[i]) && (!match(mask, cli_name(acptr))))
return acptr;
}
}
return 0;
}
/** Encode an IP address in the base64 used by numnicks.
* For IPv4 addresses (including IPv4-mapped and IPv4-compatible IPv6
* addresses), the 32-bit host address is encoded directly as six
* characters.
*
* For IPv6 addresses, each 16-bit address segment is encoded as three
* characters, but the longest run of zero segments is encoded using an
* underscore.
* @param[out] buf Output buffer to write to.
* @param[in] addr IP address to encode.
* @param[in] count Number of bytes writable to \a buf.
* @param[in] v6_ok If non-zero, peer understands base-64 encoded IPv6 addresses.
*/
const char* iptobase64(char* buf, const struct irc_in_addr* addr, unsigned int count, int v6_ok)
{
if (irc_in_addr_is_ipv4(addr)) {
assert(count >= 6);
inttobase64(buf, (ntohs(addr->in6_16[6]) << 16) | ntohs(addr->in6_16[7]), 6);
} else if (!v6_ok) {
assert(count >= 6);
if (addr->in6_16[0] == htons(0x2002))
inttobase64(buf, (ntohs(addr->in6_16[1]) << 16) | ntohs(addr->in6_16[2]), 6);
else if ((addr->in6_16[0] == htons(0x2001)) && (addr->in6_16[1] == 0))
inttobase64(buf, (ntohs(addr->in6_16[6] ^ 0xFFFF) << 16) | ntohs(addr->in6_16[7] ^ 0xFFFF), 6);
else {
/* Security fix: Replace strcpy cu memcpy pentru siguranță */
memcpy(buf, "AAAAAA", 7); /* Include null terminator */
}
} else {
unsigned int max_start, max_zeros, curr_zeros, zero, ii;
char *output = buf;
assert(count >= 25);
/* Can start by printing out the leading non-zero parts. */
for (ii = 0; (addr->in6_16[ii]) && (ii < 8); ++ii) {
inttobase64(output, ntohs(addr->in6_16[ii]), 3);
output += 3;
}
/* Find the longest run of zeros. */
for (max_start = zero = ii, max_zeros = curr_zeros = 0; ii < 8; ++ii) {
if (!addr->in6_16[ii])
curr_zeros++;
else if (curr_zeros > max_zeros) {
max_start = ii - curr_zeros;
max_zeros = curr_zeros;
curr_zeros = 0;
}
}
if (curr_zeros > max_zeros) {
max_start = ii - curr_zeros;
max_zeros = curr_zeros;
curr_zeros = 0;
}
/* Print the rest of the address */
for (ii = zero; ii < 8; ) {
if ((ii == max_start) && max_zeros) {
*output++ = '_';
ii += max_zeros;
} else {
inttobase64(output, ntohs(addr->in6_16[ii]), 3);
output += 3;
ii++;
}
}
*output = '\0';
}
return buf;
}
/** Decode an IP address from base64.
* @param[in] input Input buffer to decode.
* @param[out] addr IP address structure to populate.
*/
void base64toip(const char* input, struct irc_in_addr* addr)
{
memset(addr, 0, sizeof(*addr));
if (strlen(input) == 6) {
unsigned int in = base64toint(input);
/* An all-zero address should stay that way. */
if (in) {
addr->in6_16[5] = htons(65535);
addr->in6_16[6] = htons(in >> 16);
addr->in6_16[7] = htons(in & 65535);
}
} else {
unsigned int pos = 0;
do {
if (*input == '_') {
unsigned int left;
for (left = (25 - strlen(input)) / 3 - pos; left; left--)
addr->in6_16[pos++] = 0;
input++;
} else {
unsigned short accum = convert2n[(unsigned char)*input++];
accum = (accum << NUMNICKLOG) | convert2n[(unsigned char)*input++];
accum = (accum << NUMNICKLOG) | convert2n[(unsigned char)*input++];
addr->in6_16[pos++] = ntohs(accum);
}
} while (pos < 8);
}
}
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