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construct/ircd/parse.cc

519 lines
13 KiB
C++

/*
* 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) 2007-2016 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
*/
/*
make_index<Message>(),
{
[](mod &mod, const std::string &name)
{
auto &tab(get<Message>(mod, name));
mod_add_cmd(&tab);
},
[](mod &mod, const std::string &name)
{
auto &tab(get<Message>(mod, name));
mod_del_cmd(&tab);
}
}
*/
namespace ircd {
std::map<std::string, std::shared_ptr<alias_entry>, case_insensitive_less> alias_dict;
std::map<std::string, Message *, case_insensitive_less> cmd_dict;
static void cancel_clients(client::client *, client::client *);
static void remove_unknown(client::client *, const char *, char *);
static void do_numeric(int, client::client *, client::client *, int, const char **);
static int handle_command(struct Message *, struct MsgBuf *, client::client *, client::client *);
static char buffer[1024];
/* parse()
*
* given a raw buffer, parses it and generates parv and parc
*/
void
parse(client::client *client_p, char *pbuffer, char *bufend)
{
client::client *from = client_p;
char *end;
int res;
int numeric = 0;
struct Message *mptr;
struct MsgBuf msgbuf;
s_assert(my_connect(*client_p));
s_assert(client_p->localClient->F != NULL);
if(is_any_dead(*client_p))
return;
end = bufend - 1;
/* XXX this should be done before parse() is called */
if(*end == '\n')
*end-- = '\0';
if(*end == '\r')
*end = '\0';
res = msgbuf_parse(&msgbuf, pbuffer);
if (res)
{
ServerStats.is_empt++;
return;
}
if (msgbuf.origin != NULL && is_server(*client_p))
{
from = find_client(msgbuf.origin);
/* didnt find any matching client, issue a kill */
if(from == NULL)
{
ServerStats.is_unpf++;
remove_unknown(client_p, msgbuf.origin, pbuffer);
return;
}
/* fake direction, hmm. */
if(from->from != client_p)
{
ServerStats.is_wrdi++;
cancel_clients(client_p, from);
return;
}
}
if(rfc1459::is_digit(*msgbuf.cmd) && rfc1459::is_digit(*(msgbuf.cmd + 1)) && rfc1459::is_digit(*(msgbuf.cmd + 2)))
{
mptr = NULL;
numeric = atoi(msgbuf.cmd);
ServerStats.is_num++;
}
else
{
mptr = cmd_dict[msgbuf.cmd];
/* no command or its encap only, error */
if(!mptr || !mptr->cmd)
{
if(is_person(*from))
{
sendto_one(from, form_str(ERR_UNKNOWNCOMMAND),
me.name, from->name, msgbuf.cmd);
}
ServerStats.is_unco++;
return;
}
mptr->bytes += msgbuf.parselen;
}
if(mptr == NULL)
{
do_numeric(numeric, client_p, from, msgbuf.n_para, msgbuf.para);
return;
}
if(handle_command(mptr, &msgbuf, client_p, from) < -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((p + 8) > 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 message buffer
* - pointer to client
* - pointer to client message is from
* output - -1 if error from server
* side effects -
*/
static int
handle_command(struct Message *mptr, struct MsgBuf *msgbuf_p, client::client *client_p, client::client *from)
{
struct MessageEntry ehandler;
MessageHandler handler = 0;
char squitreason[80];
if(is_any_dead(*client_p))
return -1;
if(is_server(*client_p))
mptr->rcount++;
mptr->count++;
ehandler = mptr->handlers[from->handler];
handler = ehandler.handler;
/* check right amount of params is passed... --is */
if(msgbuf_p->n_para < ehandler.min_para ||
(ehandler.min_para && EmptyString(msgbuf_p->para[ehandler.min_para - 1])))
{
if(!is_server(*client_p))
{
sendto_one(client_p, form_str(ERR_NEEDMOREPARAMS),
me.name,
EmptyString(client_p->name) ? "*" : client_p->name,
mptr->cmd);
if(my(*client_p))
return (1);
else
return (-1);
}
sendto_realops_snomask(sno::GENERAL, L_ALL,
"Dropping server %s due to (invalid) command '%s'"
" with only %zu arguments (expecting %zu).",
client_p->name, mptr->cmd, msgbuf_p->n_para, ehandler.min_para);
ilog(L_SERVER,
"Insufficient parameters (%zu < %zu) for command '%s' from %s.",
msgbuf_p->n_para, ehandler.min_para, mptr->cmd, client_p->name);
snprintf(squitreason, sizeof squitreason,
"Insufficient parameters (%zu < %zu) for command '%s'",
msgbuf_p->n_para, ehandler.min_para, mptr->cmd);
exit_client(client_p, client_p, client_p, squitreason);
return (-1);
}
handler(msgbuf_p, *client_p, *from, msgbuf_p->n_para, msgbuf_p->para);
return (1);
}
void
handle_encap(struct MsgBuf *msgbuf_p, client::client *client_p, client::client *source_p,
const char *command, int parc, const char *parv[])
{
struct Message *mptr;
struct MessageEntry ehandler;
MessageHandler handler = 0;
mptr = cmd_dict[command];
if(mptr == NULL || mptr->cmd == NULL)
return;
ehandler = mptr->handlers[ENCAP_HANDLER];
handler = ehandler.handler;
if((size_t)parc < ehandler.min_para ||
(ehandler.min_para && EmptyString(parv[ehandler.min_para - 1])))
return;
handler(msgbuf_p, *client_p, *source_p, parc, parv);
}
/* 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 (cmd_dict[msg->cmd] != NULL)
{
s_assert(0);
return;
}
msg->count = 0;
msg->rcount = 0;
msg->bytes = 0;
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;
cmd_dict.erase(msg->cmd);
}
/* cancel_clients()
*
* inputs - client who sent us the message, client with fake
* direction
* outputs - a given warning about the fake direction
* side effects -
*/
static void
cancel_clients(client::client *client_p, client::client *source_p)
{
/* 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(is_server(*source_p) || is_me(*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(client::client *client_p, const char *lsender, char *lbuffer)
{
int slen = strlen(lsender);
char sid[4];
client::client *server;
/* meepfoo is a nickname (ignore)
* #XXXXXXXX is a UID (KILL)
* #XX is a SID (SQUIT)
* meep.foo is a server (SQUIT)
*/
if((rfc1459::is_digit(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(!rfc1459::is_digit(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(int numeric, client::client *client_p, client::client *source_p, int parc, const char *parv[])
{
client::client *target_p;
chan::chan *chptr;
if(parc < 2 || !is_server(*source_p))
return;
/* Remap low number numerics. */
if(numeric < 100)
numeric += 100;
/*
* 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(is_me(*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(numeric != ERR_NOSUCHNICK &&
numeric != ERR_NOSUCHSERVER)
sendto_realops_snomask(sno::GENERAL, L_ADMIN,
"*** %s(via %s) sent a %03d 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(numeric == ERR_UMODEUNKNOWNFLAG && my(*target_p))
return;
/* Fake it for server hiding, if its our client */
sendto_one(target_p, ":%s %03d %s%s",
get_id(source_p, target_p), numeric,
get_id(target_p, target_p), buffer);
return;
}
else if((chptr = chan::get(parv[1], std::nothrow)) != NULL)
sendto_channel_flags(client_p, chan::ALL_MEMBERS, source_p, chptr,
"%03d %s%s",
numeric, chptr->name.c_str(), buffer);
}
void
m_not_oper(struct MsgBuf *msgbuf_p, client::client &client, client::client &source, int parc, const char *parv[])
{
sendto_one_numeric(&source, ERR_NOPRIVILEGES, form_str(ERR_NOPRIVILEGES));
}
void
m_unregistered(struct MsgBuf *msgbuf_p, client::client &client, client::client &source, int parc, const char *parv[])
{
if(is_any_server(client))
return;
/* 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.localClient->number_of_nick_changes == 0)
{
sendto_one(&client, form_str(ERR_NOTREGISTERED), me.name);
client.localClient->number_of_nick_changes++;
}
}
void
m_registered(struct MsgBuf *msgbuf_p, client::client &client, client::client &source, int parc, const char *parv[])
{
sendto_one(&client, form_str(ERR_ALREADYREGISTRED), me.name, source.name);
}
void
m_ignore(struct MsgBuf *msgbuf_p, client::client &client, client::client &source, int parc, const char *parv[])
{
/* Does nothing */
}
} // namespace ircd