/*
 *  ircd-ratbox: A slightly useful ircd.
 *  m_trace.c: Traces a path to a client/server.
 *
 *  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
 *
 */

#include "stdinc.h"
#include "class.h"
#include "hook.h"
#include "client.h"
#include "hash.h"
#include "common.h"
#include "hash.h"
#include "match.h"
#include "ircd.h"
#include "numeric.h"
#include "s_serv.h"
#include "s_conf.h"
#include "s_newconf.h"
#include "send.h"
#include "msg.h"
#include "parse.h"
#include "modules.h"

static int m_trace(struct Client *, struct Client *, int, const char **);

static void trace_spy(struct Client *, struct Client *);

struct Message trace_msgtab = {
    "TRACE", 0, 0, 0, MFLG_SLOW,
    {mg_unreg, {m_trace, 0}, {m_trace, 0}, mg_ignore, mg_ignore, {m_trace, 0}}
};

int doing_trace_hook;

mapi_clist_av1 trace_clist[] = { &trace_msgtab, NULL };
mapi_hlist_av1 trace_hlist[] = {
    { "doing_trace",	&doing_trace_hook },
    { NULL, NULL }
};
DECLARE_MODULE_AV1(trace, NULL, NULL, trace_clist, trace_hlist, NULL, "$Revision: 3183 $");

static void count_downlinks(struct Client *server_p, int *pservcount, int *pusercount);
static int report_this_status(struct Client *source_p, struct Client *target_p);

static const char *empty_sockhost = "255.255.255.255";

/*
 * m_trace
 *      parv[1] = servername
 */
static int
m_trace(struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
{
    struct Client *target_p = NULL;
    struct Class *cltmp;
    const char *tname;
    int doall = 0;
    int cnt = 0, wilds, dow;
    rb_dlink_node *ptr;

    if(parc > 1) {
        tname = parv[1];

        if(parc > 2) {
            if(hunt_server(client_p, source_p, ":%s TRACE %s :%s", 2, parc, parv) !=
               HUNTED_ISME)
                return 0;
        }
    } else
        tname = me.name;

    /* if we have 3 parameters, then the command is directed at us.  So
     * we shouldnt be forwarding it anywhere.
     */
    if(parc < 3) {
        switch (hunt_server(client_p, source_p, ":%s TRACE :%s", 1, parc, parv)) {
        case HUNTED_PASS: {	/* note: gets here only if parv[1] exists */
            struct Client *ac2ptr;

            if(MyClient(source_p))
                ac2ptr = find_named_client(tname);
            else
                ac2ptr = find_client(tname);

            if(ac2ptr == NULL) {
                RB_DLINK_FOREACH(ptr, global_serv_list.head) {
                    ac2ptr = ptr->data;

                    if(match(tname, ac2ptr->name))
                        break;
                    else
                        ac2ptr = NULL;
                }
            }

            /* giving this out with flattened links defeats the
             * object --fl
             */
            if(IsOper(source_p) || IsExemptShide(source_p) ||
               !ConfigServerHide.flatten_links)
                sendto_one_numeric(source_p, RPL_TRACELINK,
                                   form_str(RPL_TRACELINK),
                                   ircd_version,
                                   ac2ptr ? ac2ptr->name : tname,
                                   ac2ptr ? ac2ptr->from->name : "EEK!");

            return 0;
        }

        case HUNTED_ISME:
            break;

        default:
            return 0;
        }
    }

    if(match(tname, me.name)) {
        doall = 1;
    }
    /* if theyre tracing our SID, we need to move tname to our name so
     * we dont give the sid in ENDOFTRACE
     */
    else if(!MyClient(source_p) && !strcmp(tname, me.id)) {
        doall = 1;
        tname = me.name;
    }

    wilds = strchr(tname, '*') || strchr(tname, '?');
    dow = wilds || doall;

    /* specific trace */
    if(dow == 0) {
        if(MyClient(source_p) || parc > 2)
            target_p = find_named_person(tname);
        else
            target_p = find_person(tname);

        /* tname could be pointing to an ID at this point, so reset
         * it to target_p->name if we have a target --fl
         */
        if(target_p != NULL) {
            report_this_status(source_p, target_p);
            tname = target_p->name;
        }

        trace_spy(source_p, target_p);

        sendto_one_numeric(source_p, RPL_ENDOFTRACE,
                           form_str(RPL_ENDOFTRACE), tname);
        return 0;
    }

    trace_spy(source_p, NULL);

    /* give non-opers a limited trace output of themselves (if local),
     * opers and servers (if no shide) --fl
     */
    if(!IsOper(source_p)) {
        if(MyClient(source_p)) {
            if(doall || (wilds && match(tname, source_p->name)))
                report_this_status(source_p, source_p);
        }

        RB_DLINK_FOREACH(ptr, local_oper_list.head) {
            target_p = ptr->data;

            if(!doall && wilds && (match(tname, target_p->name) == 0))
                continue;

            report_this_status(source_p, target_p);
        }

        if (IsExemptShide(source_p) || !ConfigServerHide.flatten_links) {
            RB_DLINK_FOREACH(ptr, serv_list.head) {
                target_p = ptr->data;

                if(!doall && wilds && !match(tname, target_p->name))
                    continue;

                report_this_status(source_p, target_p);
            }
        }

        sendto_one_numeric(source_p, RPL_ENDOFTRACE,
                           form_str(RPL_ENDOFTRACE), tname);
        return 0;
    }

    /* source_p is opered */

    /* report all direct connections */
    RB_DLINK_FOREACH(ptr, lclient_list.head) {
        target_p = ptr->data;

        /* dont show invisible users to remote opers */
        if(IsInvisible(target_p) && dow && !MyConnect(source_p) && !IsOper(target_p))
            continue;

        if(!doall && wilds && !match(tname, target_p->name))
            continue;

        /* remote opers may not see invisible normal users */
        if(dow && !MyConnect(source_p) && !IsOper(target_p) &&
           IsInvisible(target_p))
            continue;

        cnt = report_this_status(source_p, target_p);
    }

    RB_DLINK_FOREACH(ptr, serv_list.head) {
        target_p = ptr->data;

        if(!doall && wilds && !match(tname, target_p->name))
            continue;

        cnt = report_this_status(source_p, target_p);
    }

    if(MyConnect(source_p)) {
        RB_DLINK_FOREACH(ptr, unknown_list.head) {
            target_p = ptr->data;

            if(!doall && wilds && !match(tname, target_p->name))
                continue;

            cnt = report_this_status(source_p, target_p);
        }
    }

    if(!cnt) {
        sendto_one_numeric(source_p, ERR_NOSUCHSERVER, form_str(ERR_NOSUCHSERVER),
                           tname);

        /* let the user have some idea that its at the end of the
         * trace
         */
        sendto_one_numeric(source_p, RPL_ENDOFTRACE,
                           form_str(RPL_ENDOFTRACE), tname);
        return 0;
    }

    if(doall) {
        RB_DLINK_FOREACH(ptr, class_list.head) {
            cltmp = ptr->data;

            if(CurrUsers(cltmp) > 0)
                sendto_one_numeric(source_p, RPL_TRACECLASS,
                                   form_str(RPL_TRACECLASS),
                                   ClassName(cltmp), CurrUsers(cltmp));
        }
    }

    sendto_one_numeric(source_p, RPL_ENDOFTRACE, form_str(RPL_ENDOFTRACE), tname);

    return 0;
}

/*
 * count_downlinks
 *
 * inputs	- pointer to server to count
 *		- pointers to server and user count
 * output	- NONE
 * side effects - server and user counts are added to given values
 */
static void
count_downlinks(struct Client *server_p, int *pservcount, int *pusercount)
{
    rb_dlink_node *ptr;

    (*pservcount)++;
    *pusercount += rb_dlink_list_length(&server_p->serv->users);
    RB_DLINK_FOREACH(ptr, server_p->serv->servers.head) {
        count_downlinks(ptr->data, pservcount, pusercount);
    }
}

/*
 * report_this_status
 *
 * inputs	- pointer to client to report to
 * 		- pointer to client to report about
 * output	- counter of number of hits
 * side effects - NONE
 */
static int
report_this_status(struct Client *source_p, struct Client *target_p)
{
    const char *name;
    const char *class_name;
    char ip[HOSTIPLEN];
    int cnt = 0;

    /* sanity check - should never happen */
    if(!MyConnect(target_p))
        return 0;

    rb_inet_ntop_sock((struct sockaddr *)&target_p->localClient->ip, ip, sizeof(ip));
    class_name = get_client_class(target_p);

    if(IsAnyServer(target_p))
        name = target_p->name;
    else
        name = get_client_name(target_p, HIDE_IP);

    switch (target_p->status) {
    case STAT_CONNECTING:
        sendto_one_numeric(source_p, RPL_TRACECONNECTING,
                           form_str(RPL_TRACECONNECTING),
                           class_name, name);
        cnt++;
        break;

    case STAT_HANDSHAKE:
        sendto_one_numeric(source_p, RPL_TRACEHANDSHAKE,
                           form_str(RPL_TRACEHANDSHAKE),
                           class_name, name);
        cnt++;
        break;

    case STAT_ME:
        break;

    case STAT_UNKNOWN:
        /* added time -Taner */
        sendto_one_numeric(source_p, RPL_TRACEUNKNOWN,
                           form_str(RPL_TRACEUNKNOWN),
                           class_name, name, ip,
                           rb_current_time() - target_p->localClient->firsttime);
        cnt++;
        break;

    case STAT_CLIENT: {
        int tnumeric;

        tnumeric = IsOper(target_p) ? RPL_TRACEOPERATOR : RPL_TRACEUSER;
        sendto_one_numeric(source_p, tnumeric, form_str(tnumeric),
                           class_name, name,
                           show_ip(source_p, target_p) ? ip : empty_sockhost,
                           rb_current_time() - target_p->localClient->lasttime,
                           rb_current_time() - target_p->localClient->last);

        cnt++;
    }
    break;

    case STAT_SERVER: {
        int usercount = 0;
        int servcount = 0;

        count_downlinks(target_p, &servcount, &usercount);

        sendto_one_numeric(source_p, RPL_TRACESERVER, form_str(RPL_TRACESERVER),
                           class_name, servcount, usercount, name,
                           *(target_p->serv->by) ? target_p->serv->by : "*", "*",
                           me.name, rb_current_time() - target_p->localClient->lasttime);
        cnt++;

    }
    break;

    default:		/* ...we actually shouldn't come here... --msa */
        sendto_one_numeric(source_p, RPL_TRACENEWTYPE,
                           form_str(RPL_TRACENEWTYPE),
                           me.name, source_p->name, name);
        cnt++;
        break;
    }

    return (cnt);
}

/* trace_spy()
 *
 * input        - pointer to client
 * output       - none
 * side effects - hook event doing_trace is called
 */
static void
trace_spy(struct Client *source_p, struct Client *target_p)
{
    hook_data_client hdata;

    hdata.client = source_p;
    hdata.target = target_p;

    call_hook(doing_trace_hook, &hdata);
}