-/*
- * Handle XMPP presence exchanges
- *
- * Copyright (c) 2007-2021 by Art Cancro and citadel.org
- *
- * This program is open source 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 3 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 "sysdep.h"
-#include <stdlib.h>
-#include <unistd.h>
-#include <stdio.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <pwd.h>
-#include <errno.h>
-#include <sys/types.h>
-#include <assert.h>
-#include <time.h>
-#include <sys/wait.h>
-#include <string.h>
-#include <limits.h>
-#include <ctype.h>
-#include <expat.h>
-#include <libcitadel.h>
-#include "citadel.h"
-#include "server.h"
-#include "citserver.h"
-#include "support.h"
-#include "config.h"
-#include "internet_addressing.h"
-#include "ctdl_module.h"
-#include "serv_xmpp.h"
-
-
-/*
- * Indicate the presence of another user to the client
- * (used in several places)
- */
-void xmpp_indicate_presence(char *presence_jid) {
- char xmlbuf[256];
-
- syslog(LOG_DEBUG, "xmpp: indicating presence of <%s> to <%s>", presence_jid, XMPP->client_jid);
- cprintf("<presence from=\"%s\" ", xmlesc(xmlbuf, presence_jid, sizeof xmlbuf));
- cprintf("to=\"%s\"></presence>", xmlesc(xmlbuf, XMPP->client_jid, sizeof xmlbuf));
-}
-
-
-/*
- * Convenience function to determine whether any given session is 'visible' to any other given session,
- * and is capable of receiving instant messages from that session.
- */
-int xmpp_is_visible(struct CitContext *cptr, struct CitContext *to_whom) {
- int aide = (to_whom->user.axlevel >= AxAideU);
-
- if ( (cptr->logged_in)
- && (((cptr->cs_flags&CS_STEALTH)==0) || (aide)) /* aides see everyone */
- && (cptr->user.usernum != to_whom->user.usernum) /* don't show myself */
- && (cptr->can_receive_im) /* IM-capable session */
- ) {
- return(1);
- }
- else {
- return(0);
- }
-}
-
-
-/*
- * Initial dump of the entire wholist
- */
-void xmpp_wholist_presence_dump(void) {
- struct CitContext *cptr = NULL;
- int nContexts, i;
-
- cptr = CtdlGetContextArray(&nContexts);
- if (!cptr) {
- return;
- }
-
- for (i=0; i<nContexts; i++) {
- if (xmpp_is_visible(&cptr[i], CC)) {
- xmpp_indicate_presence(cptr[i].cs_principal_id);
- }
- }
- free(cptr);
-}
-
-
-/*
- * Function to remove a buddy subscription and delete from the roster
- * (used in several places)
- */
-void xmpp_destroy_buddy(char *presence_jid, int aggressively) {
- static int unsolicited_id = 1;
- char xmlbuf1[256];
- char xmlbuf2[256];
-
- if (!presence_jid) return;
- if (!XMPP) return;
- if (!XMPP->client_jid) return;
-
- /* Transmit non-presence information */
- cprintf("<presence type=\"unavailable\" from=\"%s\" to=\"%s\"></presence>",
- xmlesc(xmlbuf1, presence_jid, sizeof xmlbuf1),
- xmlesc(xmlbuf2, XMPP->client_jid, sizeof xmlbuf2)
- );
-
- /*
- * Setting the "aggressively" flag also sends an "unsubscribed" presence update.
- * We only ask for this when flushing the client side roster, because if we do it
- * in the middle of a session when another user logs off, some clients (Jitsi) interpret
- * it as a rejection of a subscription request.
- */
- if (aggressively) {
- cprintf("<presence type=\"unsubscribed\" from=\"%s\" to=\"%s\"></presence>",
- xmlesc(xmlbuf1, presence_jid, sizeof xmlbuf1),
- xmlesc(xmlbuf2, XMPP->client_jid, sizeof xmlbuf2)
- );
- }
-
- // note: we should implement xmpp_indicate_nonpresence so we can use it elsewhere
-
- /* Do an unsolicited roster update that deletes the contact. */
- cprintf("<iq from=\"%s\" to=\"%s\" id=\"unbuddy_%x\" type=\"result\">",
- xmlesc(xmlbuf1, CC->cs_principal_id, sizeof xmlbuf1),
- xmlesc(xmlbuf2, XMPP->client_jid, sizeof xmlbuf2),
- ++unsolicited_id
- );
- cprintf("<query xmlns=\"jabber:iq:roster\">");
- cprintf("<item jid=\"%s\" subscription=\"remove\">", xmlesc(xmlbuf1, presence_jid, sizeof xmlbuf1));
- cprintf("<group>%s</group>", xmlesc(xmlbuf1, CtdlGetConfigStr("c_humannode"), sizeof xmlbuf1));
- cprintf("</item>");
- cprintf("</query>"
- "</iq>"
- );
-}
-
-
-/*
- * When a user logs in or out of the local Citadel system, notify all XMPP sessions about it.
- * THIS FUNCTION HAS A BUG IN IT THAT ENUMERATES THE SESSIONS WRONG.
- */
-void xmpp_presence_notify(char *presence_jid, int event_type) {
- struct CitContext *cptr;
- static int unsolicited_id = 12345;
- int visible_sessions = 0;
- int nContexts, i;
- int which_cptr_is_relevant = (-1);
-
- if (IsEmptyStr(presence_jid)) return;
- if (CC->kill_me) return;
-
- cptr = CtdlGetContextArray(&nContexts);
- if (!cptr) {
- return;
- }
-
- /* Count the visible sessions for this user */
- for (i=0; i<nContexts; i++) {
- if ( (!strcasecmp(cptr[i].cs_principal_id, presence_jid))
- && (xmpp_is_visible(&cptr[i], CC))
- ) {
- ++visible_sessions;
- which_cptr_is_relevant = i;
- }
- }
-
- syslog(LOG_DEBUG, "xmpp: %d sessions for <%s> are now visible to session %d", visible_sessions, presence_jid, CC->cs_pid);
-
- if ( (event_type == XMPP_EVT_LOGIN) && (visible_sessions == 1) ) {
-
- syslog(LOG_DEBUG, "xmpp: telling session %d that <%s> logged in", CC->cs_pid, presence_jid);
-
- /* Do an unsolicited roster update that adds a new contact. */
- assert(which_cptr_is_relevant >= 0);
- cprintf("<iq id=\"unsolicited_%x\" type=\"result\">", ++unsolicited_id);
- cprintf("<query xmlns=\"jabber:iq:roster\">");
- xmpp_roster_item(&cptr[which_cptr_is_relevant]);
- cprintf("</query></iq>");
-
- /* Transmit presence information */
- xmpp_indicate_presence(presence_jid);
- }
-
- if (visible_sessions == 0) {
- syslog(LOG_DEBUG, "xmpp: telling session %d that <%s> logged out", CC->cs_pid, presence_jid);
- xmpp_destroy_buddy(presence_jid, 0); /* non aggressive presence update */
- }
-
- free(cptr);
-}
-
-
-void xmpp_fetch_mortuary_backend(long msgnum, void *userdata) {
- HashList *mortuary = (HashList *) userdata;
- struct CtdlMessage *msg;
- char *ptr = NULL;
- char *lasts = NULL;
-
- msg = CtdlFetchMessage(msgnum, 1);
- if (msg == NULL) {
- return;
- }
-
- /* now add anyone we find into the hashlist */
-
- /* skip past the headers */
- ptr = strstr(msg->cm_fields[eMesageText], "\n\n");
- if (ptr != NULL) {
- ptr += 2;
- }
- else {
- ptr = strstr(msg->cm_fields[eMesageText], "\n\r\n");
- if (ptr != NULL) {
- ptr += 3;
- }
- }
-
- /* the remaining lines are addresses */
- if (ptr != NULL) {
- ptr = strtok_r(ptr, "\n", &lasts);
- while (ptr != NULL) {
- char *pch = strdup(ptr);
- Put(mortuary, pch, strlen(pch), pch, NULL);
- ptr = strtok_r(NULL, "\n", &lasts);
- }
- }
-
- CM_Free(msg);
-}
-
-
-/*
- * Fetch the "mortuary" - a list of dead buddies which we keep around forever
- * so we can remove them from any client's roster that still has them listed
- */
-HashList *xmpp_fetch_mortuary(void) {
- HashList *mortuary = NewHash(1, NULL);
- if (!mortuary) {
- syslog(LOG_ALERT, "xmpp: NewHash() failed!");
- return(NULL);
- }
-
- if (CtdlGetRoom(&CC->room, USERCONFIGROOM) != 0) {
- /* no config room exists - no further processing is required. */
- return(mortuary);
- }
- CtdlForEachMessage(MSGS_LAST, 1, NULL, XMPPMORTUARY, NULL,
- xmpp_fetch_mortuary_backend, (void *)mortuary );
-
- return(mortuary);
-}
-
-
-/*
- * Fetch the "mortuary" - a list of dead buddies which we keep around forever
- * so we can remove them from any client's roster that still has them listed
- */
-void xmpp_store_mortuary(HashList *mortuary) {
- HashPos *HashPos;
- long len;
- void *Value;
- const char *Key;
- StrBuf *themsg;
-
- themsg = NewStrBuf();
- StrBufPrintf(themsg, "Content-type: " XMPPMORTUARY "\n"
- "Content-transfer-encoding: 7bit\n"
- "\n"
- );
-
- HashPos = GetNewHashPos(mortuary, 0);
- while (GetNextHashPos(mortuary, HashPos, &len, &Key, &Value) != 0) {
- StrBufAppendPrintf(themsg, "%s\n", (char *)Value);
- }
- DeleteHashPos(&HashPos);
-
- /* Delete the old mortuary */
- CtdlDeleteMessages(USERCONFIGROOM, NULL, 0, XMPPMORTUARY);
-
- /* And save the new one to disk */
- quickie_message(CC->user.fullname, NULL, NULL, USERCONFIGROOM, ChrPtr(themsg), 4, "XMPP Mortuary");
- FreeStrBuf(&themsg);
-}
-
-
-/*
- * Upon logout we make an attempt to delete the whole roster, in order to
- * try to keep "ghost" buddies from remaining in the client-side roster.
- *
- * Since the client is probably not still alive, also remember the current
- * roster for next time so we can delete dead buddies then.
- */
-void xmpp_massacre_roster(void) {
- struct CitContext *cptr;
- int nContexts, i;
- HashList *mortuary = xmpp_fetch_mortuary();
-
- cptr = CtdlGetContextArray(&nContexts);
- if (cptr) {
- for (i=0; i<nContexts; i++) {
- if (xmpp_is_visible(&cptr[i], CC)) {
- if (mortuary) {
- char *buddy = strdup(cptr[i].cs_principal_id);
- Put(mortuary, buddy, strlen(buddy), buddy, NULL);
- }
- }
- }
- free (cptr);
- }
-
- if (mortuary) {
- xmpp_store_mortuary(mortuary);
- DeleteHash(&mortuary);
- }
-}
-
-
-/*
- * Stupidly, XMPP does not specify a way to tell the client to flush its client-side roster
- * and prepare to receive a new one. So instead we remember every buddy we've ever told the
- * client about, and push delete operations out at the beginning of a session.
- *
- * We omit any users who happen to be online right now, but we still keep them in the mortuary,
- * which needs to be maintained as a list of every buddy the user has ever seen. We don't know
- * when they're connecting from the same client and when they're connecting from a different client,
- * so we have no guarantee of what is in the client side roster at connect time.
- */
-void xmpp_delete_old_buddies_who_no_longer_exist_from_the_client_roster(void) {
- long len;
- void *Value;
- const char *Key;
- struct CitContext *cptr;
- int nContexts, i;
- int online_now = 0;
- HashList *mortuary = xmpp_fetch_mortuary();
- HashPos *HashPos = GetNewHashPos(mortuary, 0);
-
- /* we need to omit anyone who is currently online */
- cptr = CtdlGetContextArray(&nContexts);
-
- /* go through the list of users in the mortuary... */
- while (GetNextHashPos(mortuary, HashPos, &len, &Key, &Value) != 0)
- {
-
- online_now = 0;
- if (cptr) for (i=0; i<nContexts; i++) {
- if (xmpp_is_visible(&cptr[i], CC)) {
- if (!strcasecmp(cptr[i].cs_principal_id, (char *)Value)) {
- online_now = 1;
- }
- }
- }
-
- if (!online_now) {
- xmpp_destroy_buddy((char *)Value, 1); /* aggressive presence update */
- }
-
- }
- DeleteHashPos(&HashPos);
- DeleteHash(&mortuary);
- free(cptr);
-}