dialback_in.c   [plain text]

/* --------------------------------------------------------------------------
 *
 * License
 *
 * The contents of this file are subject to the Jabber Open Source License
 * Version 1.0 (the "JOSL").  You may not copy or use this file, in either
 * source code or executable form, except in compliance with the JOSL. You
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 * Software distributed under the JOSL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the JOSL
 * for the specific language governing rights and limitations under the
 * JOSL.
 *
 * Copyrights
 * 
 * Portions created by or assigned to Jabber.com, Inc. are 
 * Copyright (c) 1999-2002 Jabber.com, Inc.  All Rights Reserved.  Contact
 * information for Jabber.com, Inc. is available at http://www.jabber.com/.
 *
 * Portions Copyright (c) 1998-1999 Jeremie Miller.
 * 
 * Acknowledgements
 * 
 * Special thanks to the Jabber Open Source Contributors for their
 * suggestions and support of Jabber.
 * 
 * Alternatively, the contents of this file may be used under the terms of the
 * GNU General Public License Version 2 or later (the "GPL"), in which case
 * the provisions of the GPL are applicable instead of those above.  If you
 * wish to allow use of your version of this file only under the terms of the
 * GPL and not to allow others to use your version of this file under the JOSL,
 * indicate your decision by deleting the provisions above and replace them
 * with the notice and other provisions required by the GPL.  If you do not
 * delete the provisions above, a recipient may use your version of this file
 * under either the JOSL or the GPL. 
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 * --------------------------------------------------------------------------*/

#include "dialback.h"

/* 
On incoming connections, it's our job to validate any packets we receive on this server

We'll get:
    <db:result to=B from=A>...</db:result>
We verify w/ the dialback process, then we'll send back:
    <db:result type="valid" to=A from=B/>

*/

/* db in connections */
typedef struct dbic_struct
{
    mio m;
    char *id;
    xmlnode results; /* contains all pending results we've sent out */
    db d;
} *dbic, _dbic;

/* clean up a hashtable entry containing this miod */
void dialback_in_dbic_cleanup(void *arg)
{
    dbic c = (dbic)arg;
    if(ghash_get(c->d->in_id,c->id) == c)
        ghash_remove(c->d->in_id,c->id);
}

/* nice new dbic */
dbic dialback_in_dbic_new(db d, mio m)
{
    dbic c;

    c = pmalloco(m->p, sizeof(_dbic));
    c->m = m;
    c->id = pstrdup(m->p,dialback_randstr());
    c->results = xmlnode_new_tag_pool(m->p,"r");
    c->d = d;
    pool_cleanup(m->p,dialback_in_dbic_cleanup, (void *)c);
    ghash_put(d->in_id, c->id, (void *)c);
    log_debug(ZONE,"created incoming connection %s from %s",c->id,m->ip);
    return c;
}

/* callback for mio for accepted sockets that are dialback */
void dialback_in_read_db(mio m, int flags, void *arg, xmlnode x)
{
    dbic c = (dbic)arg;
    miod md;
    jid key, from;
    xmlnode x2;

    if(flags != MIO_XML_NODE) return;

    log_debug(ZONE,"dbin read dialback: fd %d packet %s",m->fd, xmlnode2str(x));

    /* incoming verification request, check and respond */
    if(j_strcmp(xmlnode_get_name(x),"db:verify") == 0)
    {
        if(j_strcmp( xmlnode_get_data(x), dialback_merlin(xmlnode_pool(x), c->d->secret, xmlnode_get_attrib(x,"from"), xmlnode_get_attrib(x,"id"))) == 0)
            xmlnode_put_attrib(x,"type","valid");
        else
            xmlnode_put_attrib(x,"type","invalid");

        /* reformat the packet reply */
        jutil_tofrom(x);
        while((x2 = xmlnode_get_firstchild(x)) != NULL)
            xmlnode_hide(x2); /* hide the contents */
        mio_write(m, x, NULL, 0);
        return;
    }

    /* valid sender/recipient jids */
    if((from = jid_new(xmlnode_pool(x),xmlnode_get_attrib(x,"from"))) == NULL || (key = jid_new(xmlnode_pool(x),xmlnode_get_attrib(x,"to"))) == NULL)
    {
        mio_write(m, NULL, "<stream:error>Invalid Packets Recieved!</stream:error>", -1);
        mio_close(m);
        xmlnode_free(x);
        return;
    }

    /* make our special key */
    jid_set(key,from->server,JID_RESOURCE);
    jid_set(key,c->id,JID_USER); /* special user of the id attrib makes this key unique */

    /* incoming result, track it and forward on */
    if(j_strcmp(xmlnode_get_name(x),"db:result") == 0)
    {
        /* store the result in the connection, for later validation */
        xmlnode_put_attrib(xmlnode_insert_tag_node(c->results, x),"key",jid_full(key));

        /* send the verify back to them, on another outgoing trusted socket, via deliver (so it is real and goes through dnsrv and anything else) */
        x2 = xmlnode_new_tag_pool(xmlnode_pool(x),"db:verify");
        xmlnode_put_attrib(x2,"to",xmlnode_get_attrib(x,"from"));
        xmlnode_put_attrib(x2,"ofrom",xmlnode_get_attrib(x,"to"));
        xmlnode_put_attrib(x2,"from",c->d->i->id); /* so bounces come back to us to get tracked */
        xmlnode_put_attrib(x2,"id",c->id);
        xmlnode_insert_node(x2,xmlnode_get_firstchild(x)); /* copy in any children */
        deliver(dpacket_new(x2),c->d->i);

        return;
    }

    /* hmm, incoming packet on dialback line, there better be a valid entry for it or else! */
    md = ghash_get(c->d->in_ok_db, jid_full(key));
    if(md == NULL || md->m != m)
    { /* dude, what's your problem!  *click* */
        mio_write(m, NULL, "<stream:error>Invalid Packets Recieved!</stream:error>", -1);
        mio_close(m);
        xmlnode_free(x);
        return;
    }

    dialback_miod_read(md, x);
}


/* callback for mio for accepted sockets that are legacy */
void dialback_in_read_legacy(mio s, int flags, void *arg, xmlnode x)
{
    miod md = (miod)arg;

    if(flags != MIO_XML_NODE) return;

    dialback_miod_read(md, x);
}

/* callback for mio for accepted sockets */
void dialback_in_read(mio m, int flags, void *arg, xmlnode x)
{
    db d = (db)arg;
    xmlnode x2;
    miod md;
    jid key;
    char strid[10];
    dbic c;


    log_debug(ZONE,"dbin read: fd %d flag %d",m->fd, flags);

    if(flags != MIO_XML_ROOT)
        return;

    /* validate namespace */
    if(j_strcmp(xmlnode_get_attrib(x,"xmlns"),"jabber:server") != 0)
    {
        mio_write(m, NULL, "<stream:stream><stream:error>Invalid Stream Header!</stream:error>", -1);
        mio_close(m);
        xmlnode_free(x);
        return;
    }

    snprintf(strid, 9, "%X", m); /* for hashes for later */

    /* legacy, icky */
    if(xmlnode_get_attrib(x,"xmlns:db") == NULL)
    {
        key = jid_new(xmlnode_pool(x), xmlnode_get_attrib(x, "to"));
        mio_write(m,NULL, xstream_header_char(xstream_header("jabber:server", NULL, jid_full(key))), -1);
        if(d->legacy && key != NULL)
        {
            log_notice(d->i->id,"legacy server incoming connection to %s established from %s",key->server, m->ip);
            md = dialback_miod_new(d, m);
            jid_set(key,strid,JID_USER);
            dialback_miod_hash(md, d->in_ok_legacy, jid_user(key)); /* register 5A55BD@toname for tracking in the hash */
            mio_reset(m, dialback_in_read_legacy, (void *)md); /* set up legacy handler for all further packets */
            xmlnode_free(x);
            return;
        }
        mio_write(m, NULL, "<stream:error>Legacy Access Denied!</stream:error>", -1);
        mio_close(m);
        xmlnode_free(x);
        return;
    }

    /* dialback connection */
    c = dialback_in_dbic_new(d, m);

    /* write our header */
    x2 = xstream_header("jabber:server", NULL, xmlnode_get_attrib(x,"to"));
    xmlnode_put_attrib(x2,"xmlns:db","jabber:server:dialback"); /* flag ourselves as dialback capable */
    xmlnode_put_attrib(x2,"id",c->id); /* send random id as a challenge */
    mio_write(m,NULL, xstream_header_char(x2), -1);
    xmlnode_free(x2);
    xmlnode_free(x);

    /* reset to a dialback packet reader */
    mio_reset(m, dialback_in_read_db, (void *)c);
}

/* we take in db:valid packets that have been processed, and expect the to="" to be our name and from="" to be the remote name */
void dialback_in_verify(db d, xmlnode x)
{
    dbic c;
    xmlnode x2;
    jid key;

    log_debug(ZONE,"dbin validate: %s",xmlnode2str(x));

    /* check for the stored incoming connection first */
    if((c = ghash_get(d->in_id, xmlnode_get_attrib(x,"id"))) == NULL)
    {
        log_warn(d->i->id, "dropping broken dialback validating request: %s", xmlnode2str(x));
        xmlnode_free(x);
        return;
    }

    /* make a key of the sender/recipient addresses on the packet */
    key = jid_new(xmlnode_pool(x),xmlnode_get_attrib(x,"to"));
    jid_set(key,xmlnode_get_attrib(x,"from"),JID_RESOURCE);
    jid_set(key,c->id,JID_USER); /* special user of the id attrib makes this key unique */

    if((x2 = xmlnode_get_tag(c->results, spools(xmlnode_pool(x),"?key=",jid_full(key),xmlnode_pool(x)))) == NULL)
    {
        log_warn(d->i->id, "dropping broken dialback validating request: %s", xmlnode2str(x));
        xmlnode_free(x);
        return;
    }
    xmlnode_hide(x2);

    /* valid requests get the honour of being miod */
    if(j_strcmp(xmlnode_get_attrib(x,"type"),"valid") == 0)
        dialback_miod_hash(dialback_miod_new(c->d, c->m), c->d->in_ok_db, key);

    /* rewrite and send on to the socket */
    x2 = xmlnode_new_tag_pool(xmlnode_pool(x),"db:result");
    xmlnode_put_attrib(x2,"to",xmlnode_get_attrib(x,"from"));
    xmlnode_put_attrib(x2,"from",xmlnode_get_attrib(x,"to"));
    xmlnode_put_attrib(x2,"type",xmlnode_get_attrib(x,"type"));
    mio_write(c->m, x2, NULL, -1);

}