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elemental-ircd/src/parse.c

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/*
* charybdis: an advanced ircd.
* parse.c: The message parser.
*
* 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
* Copyright (C) 2007 William Pitcock
*
* 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
*
*/
#include "stdinc.h"
#include "parse.h"
#include "client.h"
#include "channel.h"
#include "common.h"
#include "hash.h"
#include "match.h"
#include "ircd.h"
#include "numeric.h"
#include "logger.h"
#include "s_stats.h"
#include "send.h"
#include "msg.h"
#include "s_conf.h"
#include "s_serv.h"
#include "packet.h"
static struct Dictionary *cmd_dict = NULL;
struct Dictionary *alias_dict = NULL;
/* parv[0] is not used, and parv[LAST] == NULL */
static char *para[MAXPARA + 2];
static void cancel_clients(struct Client *, struct Client *, char *);
static void remove_unknown(struct Client *, char *, char *);
static void do_numeric(char[], struct Client *, struct Client *, int, char **);
static void do_alias(struct alias_entry *, struct Client *, char *);
static int handle_command(struct Message *, struct Client *, struct Client *, int, const char**);
static char buffer[1024];
/* turn a string into a parc/parv pair */
static inline int
string_to_array(char *string, char **parv)
{
char *p, *buf = string;
int x = 1;
parv[x] = NULL;
while (*buf == ' ') /* skip leading spaces */
buf++;
if(*buf == '\0') /* ignore all-space args */
return x;
do {
if(*buf == ':') { /* Last parameter */
buf++;
parv[x++] = buf;
parv[x] = NULL;
return x;
} else {
parv[x++] = buf;
parv[x] = NULL;
if((p = strchr(buf, ' ')) != NULL) {
*p++ = '\0';
buf = p;
} else
return x;
}
while (*buf == ' ')
buf++;
if(*buf == '\0')
return x;
}
/* we can go upto parv[MAXPARA], as parv[0] is skipped */
while (x < MAXPARA);
if(*p == ':')
p++;
parv[x++] = p;
parv[x] = NULL;
return x;
}
/* parse()
*
* given a raw buffer, parses it and generates parv and parc
*/
void
parse(struct Client *client_p, char *pbuffer, char *bufend)
{
struct Client *from = client_p;
char *sender;
char *ch;
char *s;
char *end;
int i = 1;
char *numeric = 0;
struct Message *mptr;
s_assert(MyConnect(client_p));
s_assert(client_p->localClient->F != NULL);
if(IsAnyDead(client_p))
return;
for (ch = pbuffer; *ch == ' '; ch++) /* skip spaces */
/* null statement */ ;
para[0] = from->name;
if(*ch == ':') {
ch++;
/* point sender to the sender param */
sender = ch;
if((s = strchr(ch, ' '))) {
*s = '\0';
s++;
ch = s;
}
if(*sender && IsServer(client_p)) {
from = find_client(sender);
/* didnt find any matching client, issue a kill */
if(from == NULL) {
ServerStats.is_unpf++;
remove_unknown(client_p, sender, pbuffer);
return;
}
para[0] = from->name;
/* fake direction, hmm. */
if(from->from != client_p) {
ServerStats.is_wrdi++;
cancel_clients(client_p, from, pbuffer);
return;
}
}
while (*ch == ' ')
ch++;
}
if(*ch == '\0') {
ServerStats.is_empt++;
return;
}
/* at this point there must be some sort of command parameter */
/*
* Extract the command code from the packet. Point s to the end
* of the command code and calculate the length using pointer
* arithmetic. Note: only need length for numerics and *all*
* numerics must have parameters and thus a space after the command
* code. -avalon
*/
/* EOB is 3 chars long but is not a numeric */
if(*(ch + 3) == ' ' && /* ok, lets see if its a possible numeric.. */
IsDigit(*ch) && IsDigit(*(ch + 1)) && IsDigit(*(ch + 2))) {
mptr = NULL;
numeric = ch;
ServerStats.is_num++;
s = ch + 3; /* I know this is ' ' from above if */
*s++ = '\0'; /* blow away the ' ', and point s to next part */
} else {
int ii = 0;
if((s = strchr(ch, ' ')))
*s++ = '\0';
mptr = irc_dictionary_retrieve(cmd_dict, ch);
/* no command or its encap only, error */
if(!mptr || !mptr->cmd) {
/*
* Note: Give error message *only* to recognized
* persons. It's a nightmare situation to have
* two programs sending "Unknown command"'s or
* equivalent to each other at full blast....
* If it has got to person state, it at least
* seems to be well behaving. Perhaps this message
* should never be generated, though... --msa
* Hm, when is the buffer empty -- if a command
* code has been found ?? -Armin
*/
if(pbuffer[0] != '\0') {
if (IsPerson(client_p)) {
struct alias_entry *aptr = irc_dictionary_retrieve(alias_dict, ch);
if (aptr != NULL) {
do_alias(aptr, client_p, s);
return;
}
}
if(IsPerson(from)) {
sendto_one(from, form_str(ERR_UNKNOWNCOMMAND),
me.name, from->name, ch);
}
}
ServerStats.is_unco++;
return;
}
ii = bufend - ((s) ? s : ch);
mptr->bytes += ii;
}
end = bufend - 1;
/* XXX this should be done before parse() is called */
if(*end == '\n')
*end-- = '\0';
if(*end == '\r')
*end = '\0';
if(s != NULL)
i = string_to_array(s, para);
if(mptr == NULL) {
do_numeric(numeric, client_p, from, i, para);
return;
}
if(handle_command(mptr, client_p, from, i, /* XXX discards const!!! */ (const char **)para) < -1) {
char *p;
for (p = pbuffer; p <= end; p += 8) {
/* HACK HACK */
/* Its expected this nasty code can be removed
* or rewritten later if still needed.
*/
if((unsigned long) (p + 8) > (unsigned long) end) {
for (; p <= end; p++) {
ilog(L_MAIN, "%02x |%c", p[0], p[0]);
}
} else
ilog(L_MAIN,
"%02x %02x %02x %02x %02x %02x %02x %02x |%c%c%c%c%c%c%c%c",
p[0], p[1], p[2], p[3], p[4], p[5],
p[6], p[7], p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
}
}
}
/*
* handle_command
*
* inputs - pointer to message block
* - pointer to client
* - pointer to client message is from
* - count of number of args
* - pointer to argv[] array
* output - -1 if error from server
* side effects -
*/
static int
handle_command(struct Message *mptr, struct Client *client_p,
struct Client *from, int i, const char** hpara)
{
struct MessageEntry ehandler;
MessageHandler handler = 0;
char squitreason[80];
if(IsAnyDead(client_p))
return -1;
if(IsServer(client_p))
mptr->rcount++;
mptr->count++;
/* New patch to avoid server flooding from unregistered connects
- Pie-Man 07/27/2000 */
if(!IsRegistered(client_p)) {
/* if its from a possible server connection
* ignore it.. more than likely its a header thats sneaked through
*/
if(IsAnyServer(client_p) && !(mptr->flags & MFLG_UNREG))
return (1);
}
ehandler = mptr->handlers[from->handler];
handler = ehandler.handler;
/* check right amount of params is passed... --is */
if(i < ehandler.min_para ||
(ehandler.min_para && EmptyString(hpara[ehandler.min_para - 1]))) {
if(!IsServer(client_p)) {
sendto_one(client_p, form_str(ERR_NEEDMOREPARAMS),
me.name,
EmptyString(client_p->name) ? "*" : client_p->name,
mptr->cmd);
if(MyClient(client_p))
return (1);
else
return (-1);
}
sendto_realops_snomask(SNO_GENERAL, L_ALL,
"Dropping server %s due to (invalid) command '%s'"
" with only %d arguments (expecting %d).",
client_p->name, mptr->cmd, i, ehandler.min_para);
ilog(L_SERVER,
"Insufficient parameters (%d < %d) for command '%s' from %s.",
i, ehandler.min_para, mptr->cmd, client_p->name);
snprintf(squitreason, sizeof squitreason,
"Insufficient parameters (%d < %d) for command '%s'",
i, ehandler.min_para, mptr->cmd);
exit_client(client_p, client_p, client_p, squitreason);
return (-1);
}
(*handler) (client_p, from, i, hpara);
return (1);
}
void
handle_encap(struct Client *client_p, struct Client *source_p,
const char *command, int parc, const char *parv[])
{
struct Message *mptr;
struct MessageEntry ehandler;
MessageHandler handler = 0;
parv[0] = source_p->name;
mptr = irc_dictionary_retrieve(cmd_dict, command);
if(mptr == NULL || mptr->cmd == NULL)
return;
ehandler = mptr->handlers[ENCAP_HANDLER];
handler = ehandler.handler;
if(parc < ehandler.min_para ||
(ehandler.min_para && EmptyString(parv[ehandler.min_para - 1])))
return;
(*handler) (client_p, source_p, parc, parv);
}
/*
* clear_hash_parse()
*
* inputs -
* output - NONE
* side effects - MUST MUST be called at startup ONCE before
* any other keyword hash routine is used.
*
*/
void
clear_hash_parse()
{
cmd_dict = irc_dictionary_create(strcasecmp);
}
/* mod_add_cmd
*
* inputs - command name
* - pointer to struct Message
* output - none
* side effects - load this one command name
* msg->count msg->bytes is modified in place, in
* modules address space. Might not want to do that...
*/
void
mod_add_cmd(struct Message *msg)
{
s_assert(msg != NULL);
if(msg == NULL)
return;
if (irc_dictionary_find(cmd_dict, msg->cmd) != NULL)
return;
msg->count = 0;
msg->rcount = 0;
msg->bytes = 0;
irc_dictionary_add(cmd_dict, msg->cmd, msg);
}
/* mod_del_cmd
*
* inputs - command name
* output - none
* side effects - unload this one command name
*/
void
mod_del_cmd(struct Message *msg)
{
s_assert(msg != NULL);
if(msg == NULL)
return;
irc_dictionary_delete(cmd_dict, msg->cmd);
}
/*
* report_messages
*
* inputs - pointer to client to report to
* output - NONE
* side effects - NONE
*/
void
report_messages(struct Client *source_p)
{
struct DictionaryIter iter;
struct Message *msg;
struct alias_entry *amsg;
DICTIONARY_FOREACH(msg, &iter, cmd_dict) {
s_assert(msg->cmd != NULL);
sendto_one_numeric(source_p, RPL_STATSCOMMANDS,
form_str(RPL_STATSCOMMANDS),
msg->cmd, msg->count,
msg->bytes, msg->rcount);
}
DICTIONARY_FOREACH(amsg, &iter, alias_dict) {
s_assert(amsg->name != NULL);
sendto_one_numeric(source_p, RPL_STATSCOMMANDS,
form_str(RPL_STATSCOMMANDS),
amsg->name, amsg->hits, 0, 0);
}
}
/* cancel_clients()
*
* inputs - client who sent us the message, client with fake
* direction, command
* outputs - a given warning about the fake direction
* side effects -
*/
static void
cancel_clients(struct Client *client_p, struct Client *source_p, char *cmd)
{
/* ok, fake prefix happens naturally during a burst on a nick
* collision with TS5, we cant kill them because one client has to
* survive, so we just send an error.
*/
if(IsServer(source_p) || IsMe(source_p)) {
sendto_realops_snomask(SNO_DEBUG, L_ALL,
"Message for %s[%s] from %s",
source_p->name, source_p->from->name,
client_p->name);
} else {
sendto_realops_snomask(SNO_DEBUG, L_ALL,
"Message for %s[%s@%s!%s] from %s (TS, ignored)",
source_p->name,
source_p->username,
source_p->host,
source_p->from->name,
client_p->name);
}
}
/* remove_unknown()
*
* inputs - client who gave us message, supposed sender, buffer
* output -
* side effects - kills issued for clients, squits for servers
*/
static void
remove_unknown(struct Client *client_p, char *lsender, char *lbuffer)
{
int slen = strlen(lsender);
char sid[4];
struct Client *server;
/* meepfoo is a nickname (ignore)
* #XXXXXXXX is a UID (KILL)
* #XX is a SID (SQUIT)
* meep.foo is a server (SQUIT)
*/
if((IsDigit(lsender[0]) && slen == 3) ||
(strchr(lsender, '.') != NULL)) {
sendto_realops_snomask(SNO_DEBUG, L_ALL,
"Unknown prefix (%s) from %s, Squitting %s",
lbuffer, client_p->name, lsender);
sendto_one(client_p,
":%s SQUIT %s :(Unknown prefix (%s) from %s)",
get_id(&me, client_p), lsender,
lbuffer, client_p->name);
} else if(!IsDigit(lsender[0]))
;
else if(slen != 9)
sendto_realops_snomask(SNO_DEBUG, L_ALL,
"Invalid prefix (%s) from %s",
lbuffer, client_p->name);
else {
memcpy(sid, lsender, 3);
sid[3] = '\0';
server = find_server(NULL, sid);
if (server != NULL && server->from == client_p)
sendto_one(client_p, ":%s KILL %s :%s (Unknown Client)",
get_id(&me, client_p), lsender, me.name);
}
}
/*
*
* parc number of arguments ('sender' counted as one!)
* parv[1]..parv[parc-1]
* pointers to additional parameters, this is a NULL
* terminated list (parv[parc] == NULL).
*
* *WARNING*
* Numerics are mostly error reports. If there is something
* wrong with the message, just *DROP* it! Don't even think of
* sending back a neat error message -- big danger of creating
* a ping pong error message...
*/
static void
do_numeric(char numeric[], struct Client *client_p, struct Client *source_p, int parc, char *parv[])
{
struct Client *target_p;
struct Channel *chptr;
if(parc < 2 || !IsServer(source_p))
return;
/* Remap low number numerics. */
if(numeric[0] == '0')
numeric[0] = '1';
/*
* Prepare the parameter portion of the message into 'buffer'.
* (Because the buffer is twice as large as the message buffer
* for the socket, no overflow can occur here... ...on current
* assumptions--bets are off, if these are changed --msa)
* Note: if buffer is non-empty, it will begin with SPACE.
*/
if(parc > 1) {
char *t = buffer; /* Current position within the buffer */
int i;
int tl; /* current length of presently being built string in t */
for (i = 2; i < (parc - 1); i++) {
tl = sprintf(t, " %s", parv[i]);
t += tl;
}
sprintf(t, " :%s", parv[parc - 1]);
}
if((target_p = find_client(parv[1])) != NULL) {
if(IsMe(target_p)) {
/*
* We shouldn't get numerics sent to us,
* any numerics we do get indicate a bug somewhere..
*/
/* ugh. this is here because of nick collisions. when two servers
* relink, they burst each other their nicks, then perform collides.
* if there is a nick collision, BOTH servers will kill their own
* nicks, and BOTH will kill the other servers nick, which wont exist,
* because it will have been already killed by the local server.
*
* unfortunately, as we cant guarantee other servers will do the
* "right thing" on a nick collision, we have to keep both kills.
* ergo we need to ignore ERR_NOSUCHNICK. --fl_
*/
/* quick comment. This _was_ tried. i.e. assume the other servers
* will do the "right thing" and kill a nick that is colliding.
* unfortunately, it did not work. --Dianora
*/
/* note, now we send PING on server connect, we can
* also get ERR_NOSUCHSERVER..
*/
if(atoi(numeric) != ERR_NOSUCHNICK &&
atoi(numeric) != ERR_NOSUCHSERVER)
sendto_realops_snomask(SNO_GENERAL, L_ADMIN,
"*** %s(via %s) sent a %s numeric to me: %s",
source_p->name,
client_p->name, numeric, buffer);
return;
} else if(target_p->from == client_p) {
/* This message changed direction (nick collision?)
* ignore it.
*/
return;
}
/* csircd will send out unknown umode flag for +a (admin), drop it here. */
if((atoi(numeric) == ERR_UMODEUNKNOWNFLAG) && MyClient(target_p))
return;
/* Fake it for server hiding, if its our client */
sendto_one(target_p, ":%s %s %s%s",
get_id(source_p, target_p), numeric,
get_id(target_p, target_p), buffer);
return;
} else if((chptr = find_channel(parv[1])) != NULL)
sendto_channel_flags(client_p, ALL_MEMBERS, source_p, chptr,
"%s %s%s",
numeric, chptr->chname, buffer);
}
static void do_alias(struct alias_entry *aptr, struct Client *source_p, char *text)
{
char *p;
struct Client *target_p;
if (!IsFloodDone(source_p) && source_p->localClient->receiveM > 20)
flood_endgrace(source_p);
p = strchr(aptr->target, '@');
if (p != NULL) {
/* user@server */
target_p = find_server(NULL, p + 1);
if (target_p != NULL && IsMe(target_p))
target_p = NULL;
} else {
/* nick, must be +S */
target_p = find_named_person(aptr->target);
if (target_p != NULL && !IsService(target_p))
target_p = NULL;
}
if (target_p == NULL) {
sendto_one_numeric(source_p, ERR_SERVICESDOWN, form_str(ERR_SERVICESDOWN), aptr->target);
return;
}
if (text != NULL && *text == ':')
text++;
if (text == NULL || *text == '\0') {
sendto_one(source_p, form_str(ERR_NOTEXTTOSEND), me.name, source_p->name);
return;
}
/* increment the hitcounter on this alias */
aptr->hits++;
sendto_one(target_p, ":%s PRIVMSG %s :%s",
get_id(source_p, target_p),
p != NULL ? aptr->target : get_id(target_p, target_p),
text);
}
int
m_not_oper(struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
{
sendto_one_numeric(source_p, ERR_NOPRIVILEGES, form_str(ERR_NOPRIVILEGES));
return 0;
}
int
m_unregistered(struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
{
/* bit of a hack.
* I don't =really= want to waste a bit in a flag
* number_of_nick_changes is only really valid after the client
* is fully registered..
*/
if(client_p->localClient->number_of_nick_changes == 0) {
sendto_one(client_p, form_str(ERR_NOTREGISTERED), me.name);
client_p->localClient->number_of_nick_changes++;
}
return 0;
}
int
m_registered(struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
{
sendto_one(client_p, form_str(ERR_ALREADYREGISTRED), me.name, source_p->name);
return 0;
}
int
m_ignore(struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
{
return 0;
}
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