mod_roster.c

jabber server jabber server jabber server jabber server

/* --------------------------------------------------------------------------
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 * 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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 * Copyrights
 * 
 * Portions created by or assigned to Jabber.com, Inc. are 
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 * Portions Copyright (c) 1998-1999 Jeremie Miller.
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 * 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
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 * --------------------------------------------------------------------------*/
#include "jsm.h"

/**
 * @file mod_roster.c
 * @brief handle subscription state changes and the user's access to his roster
 *
 * The protocols implemented in this module are documented in XMPP IM.
 */

/**
 * get the roster of a user
 *
 * @param u for which user we want to get the roster
 * @return the user's roster
 */
xmlnode mod_roster_get(udata u) {
    xmlnode ret;

    log_debug2(ZONE, LOGT_ROSTER, "getting %s's roster", u->user);

    /* get the existing roster */
    ret = xdb_get(u->si->xc, u->id, NS_ROSTER);
    if (ret == NULL) {
	/* there isn't one, sucky, create a container node and let xdb manage it */
        log_debug2(ZONE, LOGT_ROSTER, "creating");
        ret = xmlnode_new_tag("query");
        xmlnode_put_attrib(ret, "xmlns", NS_ROSTER);
    }

    return ret;
}

/**
 * get a single item from the user's roster
 *
 * @param roster the complete roster from which the item should be gotten
 * @param id which item should be gotten
 * @param newflag where to store 1 if the item did not exist and has just been created
 * @return the roster item
 */
xmlnode mod_roster_get_item(xmlnode roster, jid id, int *newflag) {
    xmlnode ret;

    log_debug2(ZONE, LOGT_ROSTER, "getting item %s", jid_full(id));

    ret = jid_nodescan(id, roster);

    if (ret == NULL) {
	/* there isn't one, brew one up */
        log_debug2(ZONE, LOGT_ROSTER, "creating");
        ret = xmlnode_insert_tag(roster, "item");
        xmlnode_put_attrib(ret, "jid", jid_full(id));
        xmlnode_put_attrib(ret, "subscription", "none");
        *newflag = 1;
    }

    return ret;
}

/**
 * push a (changed) roster item to all sessions of a user
 *
 * @param user the user's data
 * @param item the (changed) roster item to be pushed
 */
void mod_roster_push(udata user, xmlnode item) {
    session cur;
    xmlnode packet, query;

    log_debug2(ZONE, LOGT_ROSTER, "pushing %s", xmlnode2str(item));

    if (xmlnode_get_attrib(item, "hidden") != NULL) return;

    /* create a jpacket roster item push */
    packet = xmlnode_new_tag("iq");
    xmlnode_put_attrib(packet, "type", "set");
    query = xmlnode_insert_tag(packet, "query");
    xmlnode_put_attrib(query, "xmlns", NS_ROSTER);
    xmlnode_insert_tag_node(query, item);
    xmlnode_hide_attrib(xmlnode_get_firstchild(query), "subscribe"); /* hide the server tirds */

    /* send a copy to all session that have a roster */
    for(cur = user->sessions; cur != NULL; cur = cur->next)
        if (cur->roster)
            js_session_to(cur, jpacket_new(xmlnode_dup(packet)));

    xmlnode_free(packet);
}

/**
 * helper function to update the subscription state in a roster item
 *
 * @param from if the is a subscription from the contact to the user's presence
 * @param to if the user is subscribed to the contact's presence
 * @param item the roster item in which the subscription state should be changed
 */
void mod_roster_set_s10n(int from, int to, xmlnode item) {
    xmlnode_put_attrib(item, "subscription", from ? (to ? "both" : "from") : (to ? "to" : "none"));
}

/**
 * force sending all presences of a user to a contact
 *
 * @param u the user's data
 * @param to to which contact the presence should be sent
 * @param uflag 1 for forcing offline presence, 0 else
 */
void mod_roster_pforce(udata u, jid to, int uflag)
{
    session s;
    xmlnode x;

    log_debug2(ZONE, LOGT_ROSTER, "brute forcing presence updates");

    /* loop through all the sessions */
    for(s = u->sessions; s != NULL; s = s->next) {
        if (uflag)
            x = jutil_presnew(JPACKET__UNAVAILABLE,NULL,NULL);
        else
            x = xmlnode_dup(s->presence);
        xmlnode_put_attrib(x,"to",jid_full(to));
        js_session_from(s,jpacket_new(x));
    }
}

/**
 * handle subscription packets sent by a user
 *
 * @param m the mapi instance containing the packet
 * @return always M_PASS
 */
mreturn mod_roster_out_s10n(mapi m) {
    xmlnode roster, item;
    int newflag=0, to=0, from=0, p_in=0, p_out=0, route=0, force_sent=0;
    jid curr;

    /* the packet needs a destination */
    if (m->packet->to == NULL)
	return M_PASS;

    /* don't handle subscription packets sent to the user itself */
    if (jid_cmpx(jid_user(m->s->id), m->packet->to, JID_USER|JID_SERVER) == 0)
	return M_PASS; /* vanity complex */

    log_debug2(ZONE, LOGT_ROSTER, "handling outgoing s10n");

    /* get the roster item */
    roster = mod_roster_get(m->user);
    item = mod_roster_get_item(roster, m->packet->to, &newflag);

    /* vars containing the old subscription state */
    if (j_strcmp(xmlnode_get_attrib(item, "subscription"),"to") == 0)
        to = 1;
    if (j_strcmp(xmlnode_get_attrib(item, "subscription"),"from") == 0)
        from = 1;
    if (j_strcmp(xmlnode_get_attrib(item, "subscription"),"both") == 0)
        to = from = 1;
    if (j_strcmp(xmlnode_get_attrib(item, "ask"), "subscribe") == 0)
	p_out = 1;
    if (xmlnode_get_attrib(item, "subscribe") != NULL)
	p_in = 1;

    /* ask='unsubscribe' can be in xdb from old data written by jabberd up to version 1.4.3 */
    if (j_strcmp(xmlnode_get_attrib(item, "ask"), "unsubscribe") == 0) {
	to = 0;
	xmlnode_put_attrib(item, "subscription", from ? "from" : "none");
    }

    /* if the packet is flagged with PACKET_FORCE_SENT_MAGIC we have to sent
     * it out without checking the previous subscription state. The packet
     * has been generated because a roster item has been removed, so we will
     * see a state of subscription "none" but we have to inform the other
     * server that the subscription has just been removed. */
    force_sent = m->packet->flag == PACKET_FORCE_SENT_MAGIC ? 1 : 0;

    switch(jpacket_subtype(m->packet)) {
	case JPACKET__SUBSCRIBE:
	    /* is the user already subscribed to this contact? */
	    if (!to) {
		/* no */
		xmlnode_put_attrib(item,"ask","subscribe");
		mod_roster_push(m->user, item);
	    }
	    /* always route the packet, the user might have rerequested auth
	     * because the contact's server is out of sync */
	    route = 1;
	    break;
	case JPACKET__SUBSCRIBED:
	    if (force_sent || (!from && p_in)) {
		/* XMPP IM, sect. 9 states "None + Pending In", "None + Pending Out/In", and "To + Pending In" */
		route = 1;
		mod_roster_set_s10n(1, to, item); /* update subscription */
		jid_append(js_trustees(m->user), m->packet->to); /* make them trusted now */
		xmlnode_hide_attrib(item, "subscribe"); /* reset "Pending In" */
		xmlnode_hide_attrib(item, "hidden"); /* make it visible on the user's roster */
		mod_roster_pforce(m->user, m->packet->to, 0); /* they are now subscribed to us, send them our presence */
		mod_roster_push(m->user, item); /* new roster to the user's other sessions */
	    } else {
		/* XMPP IM, sect. 9 other states */
		route = 0;
		/* no state change */
	    }
	    break;
	case JPACKET__UNSUBSCRIBE:
	    if (to) {
		/* changed behaviour since after version 1.4.3 ... we now immediatelly change to state "From" or "None"
		 * jabberd up to version 1.4.3 only set the flag ask="unsubscribe" and waited for an unsubscribed
		 * configirmation from the contact's server
		 */
		mod_roster_set_s10n(from, 0, item);
		xmlnode_hide_attrib(item, "ask"); /* reset Pending Out */
		mod_roster_push(m->user, item);
	    } else if (newflag) {
		/* the contact was not on the roster and should not become a roster item */
		xmlnode_hide(item);
	    }
	    /* always route the packet, the user might have unsubscribed a second time
	     * because the contact's server is out of sync */
	    route = 1;
	    break;
	case JPACKET__UNSUBSCRIBED:
	    if (!from && !p_in && !force_sent) {
		/* XMPP IM, sect. 9 states "None", "None + Pending Out", and "To" */
		route = 0;
		/* no state change */
	    } else {
		/* other states */
		route = 1;

		if (p_in) {
		    xmlnode_hide_attrib(item, "subscribe"); /* reset "Pending In" */
		}
		if (from) {
		    mod_roster_set_s10n(0, to, item); /* update subscription */
		    mod_roster_pforce(m->user, m->packet->to, 1); /* make us offline */
		    mod_roster_push(m->user, item);
		} else if (force_sent) {
		    mod_roster_pforce(m->user, m->packet->to, 1); /* make us offline */
		}
	    }

	    if ((!route || !from && !p_in && force_sent) && newflag || xmlnode_get_attrib(item, "hidden")) {
		/* the contact was not on the roster and should not become a roster item */
		xmlnode_hide(item);
	    }
	    break;
    }

    /* save the roster */
    /* XXX what do we do if the set fails?  hrmf... */
    xdb_set(m->si->xc, m->user->id, NS_ROSTER, roster);

    /* make sure it's sent from the *user*, not the resource */
    xmlnode_put_attrib(m->packet->x,"from",jid_full(jid_user(m->s->id)));
    jpacket_reset(m->packet);

    /* we don't need the roster anymore */
    xmlnode_free(roster);

    /* should the packet passed to the contact? */
    return route ? M_PASS : M_HANDLED;
}

/**