Update comments for parv[0] removal.

[irc/rqf/shadowircd.git] / src / parse.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 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
 *
 *  $Id: parse.c 3177 2007-02-01 00:19:14Z jilles $
 */

#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;

/*
 * NOTE: parse() should not be called recursively by other functions!
 */
static char *sender;

/* 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, parc and sender
 */
void
parse(struct Client *client_p, char *pbuffer, char *bufend)
{
        struct Client *from = client_p;
        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->fd >= 0);
        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);
                rb_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);

        /* 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]))
                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 = rb_sprintf(t, " %s", parv[i]);
                        t += tl;
                }
                rb_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;
}