c2s.c

这是一个完全开放的

/*
 * jabberd - Jabber Open Source Server
 * Copyright (c) 2002 Jeremie Miller, Thomas Muldowney,
 *                    Ryan Eatmon, Robert Norris
 *
 * 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, MA02111-1307USA
 */

#include "c2s.h"

static int _c2s_client_sx_callback(sx_t s, sx_event_t e, void *data, void *arg) {
    sess_t sess = (sess_t) arg;
    sx_buf_t buf = (sx_buf_t) data;
    int rlen, len, ns, elem, attr, i, r;
    sx_error_t *sxe;
    nad_t nad;
    char root[9];

    switch(e) {
        case event_WANT_READ:
            log_debug(ZONE, "want read");
            mio_read(sess->c2s->mio, sess->fd);
            break;

        case event_WANT_WRITE:
            log_debug(ZONE, "want write");
            mio_write(sess->c2s->mio, sess->fd);
            break;

        case event_READ:
            log_debug(ZONE, "reading from %d", sess->fd);

            /* check rate limits */
            if(sess->rate != NULL) {
                if(rate_check(sess->rate) == 0) {

                    /* inform the app if we haven't already */
                    if(!sess->rate_log) {
                        if(s->state >= state_STREAM && sess->jid != NULL)
                            log_write(sess->c2s->log, LOG_NOTICE, "[%d] [%s] is being byte rate limited", sess->fd, sess->jid);
                        else
                            log_write(sess->c2s->log, LOG_NOTICE, "[%d] [%s, port=%d] is being byte rate limited", sess->fd, sess->ip, sess->port);

                        sess->rate_log = 1;
                    }

                    log_debug(ZONE, "%d is throttled, delaying read", sess->fd);

                    buf->len = 0;
                    return 0;
                }

                /* find out how much we can have */
                rlen = rate_left(sess->rate);
                if(rlen > buf->len)
                    rlen = buf->len;
            }

            /* do the read */
            len = recv(sess->fd, buf->data, buf->len, 0);

            if(len < 0) {
                if(errno == EWOULDBLOCK || errno == EINTR || errno == EAGAIN) {
                    buf->len = 0;
                    return 0;
                }

                if(s->state >= state_STREAM && sess->jid != NULL)
                    log_write(sess->c2s->log, LOG_NOTICE, "[%d] [%s] read error: %s (%d)", sess->fd, jid_full(sess->jid), strerror(errno), errno);
                else
                    log_write(sess->c2s->log, LOG_NOTICE, "[%d] [%s, port=%d] read error: %s (%d)", sess->fd, sess->ip, sess->port, strerror(errno), errno);

                sx_kill(s);
                
                return -1;
            }

            else if(len == 0) {
                /* they went away */
                sx_kill(s);

                return -1;
            }

            log_debug(ZONE, "read %d bytes", len);

            buf->len = len;

            return len;

        case event_WRITE:
            log_debug(ZONE, "writing to %d", sess->fd);

            len = send(sess->fd, buf->data, buf->len, 0);
            if(len >= 0) {
                log_debug(ZONE, "%d bytes written", len);
                return len;
            }

            if(errno == EWOULDBLOCK || errno == EINTR || errno == EAGAIN)
                return 0;
            
            if(s->state >= state_OPEN && sess->jid != NULL)
                log_write(sess->c2s->log, LOG_NOTICE, "[%d] [%s] write error: %s (%d)", sess->fd, jid_full(sess->jid), strerror(errno), errno);
            else
                log_write(sess->c2s->log, LOG_NOTICE, "[%d] [%s. port=%d] write error: %s (%d)", sess->fd, sess->ip, sess->port, strerror(errno), errno);
        
            sx_kill(s);
        
            return -1;

        case event_ERROR:
            sxe = (sx_error_t *) data;
            if(sess->jid != NULL)
                log_write(sess->c2s->log, LOG_NOTICE, "[%d] [%s] error: %s (%s)", sess->fd, jid_full(sess->jid), sxe->generic, sxe->specific);
            else
                log_write(sess->c2s->log, LOG_NOTICE, "[%d] [%s, port=%d] error: %s (%s)", sess->fd, sess->ip, sess->port, sxe->generic, sxe->specific);

            break;
            
        case event_STREAM:

            if(s->req_to == NULL) {
                log_debug(ZONE, "no stream to provided, closing");
                sx_error(s, stream_err_HOST_UNKNOWN, "no 'to' attribute on stream header");
                sx_close(s);

                return 0;
            }

            /* setup the realm */
            sess->realm = xhash_get(sess->c2s->realms, s->req_to);

            if(sess->realm == NULL) {
                log_debug(ZONE, "no service available for requested domain '%s'", s->req_to);
                sx_error(s, stream_err_HOST_UNKNOWN, "service requested for unknown domain");
                sx_close(s);
                
                return 0;
            }

            if(xhash_get(sess->c2s->sm_avail, s->req_to) == NULL) {
                log_debug(ZONE, "sm for domain '%s' is not online", s->req_to);
                sx_error(s, stream_err_HOST_GONE, "session manager for requested domain is not available");
                sx_close(s);

                return 0;
            }

            break;

        case event_PACKET:
            nad = (nad_t) data;

            /* we only want (message|presence|iq) in jabber:client, everything else gets dropped */
            snprintf(root, 9, "%.*s", NAD_ENAME_L(nad, 0), NAD_ENAME(nad, 0));
            if(NAD_ENS(nad, 0) != nad_find_namespace(nad, 0, uri_CLIENT, NULL) ||
               (strcmp(root, "message") != 0 && strcmp(root, "presence") != 0 && strcmp(root, "iq") != 0)) {
                nad_free(nad);
                return 0;
            }

            /* pre-session requests */
            if(!sess->active && sess->sasl_authd && sess->result == NULL && strcmp(root, "iq") == 0 && nad_find_attr(nad, 0, -1, "type", "set") >= 0) {
                /* resource bind */
                if(!sess->bound && (ns = nad_find_scoped_namespace(nad, uri_BIND, NULL)) >= 0 && (elem = nad_find_elem(nad, 0, ns, "bind", 1)) >= 0) {
                    sess->jid = jid_new(sess->c2s->pc, sess->s->auth_id, 0);

                    /* get the resource */
                    elem = nad_find_elem(nad, elem, ns, "resource", 1);

                    /* user-specified resource */
                    if(elem >= 0) {
                        if(NAD_CDATA_L(nad, elem) == 0) {
                            log_debug(ZONE, "no resource specified on bind");
                            sx_nad_write(sess->s, stanza_error(nad, 0, stanza_err_BAD_REQUEST));

                            return 0;
                        }

                        snprintf(sess->jid->resource, sizeof(sess->jid->resource), "%.*s", NAD_CDATA_L(nad, elem), NAD_CDATA(nad, elem));
                        /* prep the resource */
                        if(jid_prep(sess->jid) != 0) {
                            jid_free(sess->jid);
                            sess->jid = NULL;

                            sx_nad_write(sess->s, stanza_error(nad, 0, stanza_err_BAD_REQUEST));
                            
                            return 0;
                        }

                        /* !!! xmpp-core-19 requires that the resource be unused, and that an
                         *     error be returned if its not. this is hard for us todo, and
                         *     might not be the right thing anyway (it basically gets rid
                         *     of the session replacement functionality, though that is not
                         *     as important now that resources can be generated). clarification
                         *     sought from the xmppwg */
                    }

                    /* generated resource */
                    else {
                        for(i = 0; i < 256; i++) {
                            r = (int) (36.0 * rand() / RAND_MAX);
                            sess->jid->resource[i] = (r >= 0 && r <= 0) ? (r + 48) : (r + 87);
                        }

                        shahash_r(sess->jid->resource, sess->jid->resource);

                        jid_prep(sess->jid);
                    }

                    log_write(sess->c2s->log, LOG_NOTICE, "[%d] bound: jid=%s", sess->s->tag, jid_full(sess->jid));

                    sess->bound = 1;

                    sess->result = nad_new(sess->s->nad_cache);

                    ns = nad_add_namespace(sess->result, uri_CLIENT, NULL);

                    nad_append_elem(sess->result, ns, "iq", 0);
                    nad_set_attr(sess->result, 0, -1, "type", "result", 6);

                    attr = nad_find_attr(nad, 0, -1, "id", NULL);
                    if(attr >= 0)
                        nad_set_attr(sess->result, 0, -1, "id", NAD_AVAL(nad, attr), NAD_AVAL_L(nad, attr));

                    ns = nad_add_namespace(sess->result, uri_BIND, NULL);

                    nad_append_elem(sess->result, ns, "bind", 1);
                    nad_append_elem(sess->result, ns, "jid", 2);
                    nad_append_cdata(sess->result, jid_full(sess->jid), strlen(jid_full(sess->jid)), 3);

                    sx_nad_write(sess->s, stanza_tofrom(sess->result, 0));

                    sess->result = NULL;

                    nad_free(nad);

                    return 0;
                }

                /* new-style session request */
                else if(sess->bound && (ns = nad_find_scoped_namespace(nad, uri_XSESSION, NULL)) >= 0 && (elem = nad_find_elem(nad, 0, ns, "session", 1)) >= 0) {
                    /* our local id */
                    sprintf(sess->c2s_id, "%d", sess->s->tag);

                    log_write(sess->c2s->log, LOG_NOTICE, "[%d] requesting session: jid=%s", sess->s->tag, jid_full(sess->jid));

                    /* build a result packet, we'll send this back to the client after we have a session for them */
                    sess->result = nad_new(sess->s->nad_cache);

                    ns = nad_add_namespace(sess->result, uri_CLIENT, NULL);

                    nad_append_elem(sess->result, ns, "iq", 0);
                    nad_set_attr(sess->result, 0, -1, "type", "result", 6);

                    attr = nad_find_attr(nad, 0, -1, "id", NULL);
                    if(attr >= 0)
                        nad_set_attr(sess->result, 0, -1, "id", NAD_AVAL(nad, attr), NAD_AVAL_L(nad, attr));

                    /* start a session with the sm */
                    sm_start(sess);

                    /* finished with the nad */
                    nad_free(nad);

                    /* handled */
                    return 0;
                }

                log_debug(ZONE, "unrecognised pre-session packet, bye");

                sx_error(s, stream_err_NOT_AUTHORIZED, NULL);
                sx_close(s);

                nad_free(nad);
                return 0;
            }

#ifdef HAVE_SSL
            /* drop packets if they have to starttls and they haven't */
            if((sess->s->flags & SX_SSL_STARTTLS_REQUIRE) && sess->s->ssf == 0) {
                nad_free(nad);
                return 0;
            }
#endif

            /* handle iq:auth packets */
            if(authreg_process(sess->c2s, sess, nad) == 0)
                return 0;

            /* drop it if no session */
            if(!sess->active) {
                log_debug(ZONE, "pre-session packet, bye");

                sx_error(s, stream_err_NOT_AUTHORIZED, NULL);
                sx_close(s);

                nad_free(nad);
                return 0;
            }

            /* pass it on to the session manager */
            sm_packet(sess, nad);

            break;
        
        case event_OPEN:

            /* only send a result and bring us online if this wasn't a sasl auth */
            if(strlen(s->auth_method) < 4 || strncmp("SASL", s->auth_method, 4) != 0) {
                /* return the auth result to the client */
                sx_nad_write(s, sess->result);
                sess->result = NULL;

                /* we're good to go */
                sess->active = 1;
            }

            /* they sasl auth'd, so we only want the new-style session start */
            else {
                log_write(sess->c2s->log, LOG_NOTICE, "[%d] SASL authentication succeeded: mechanism=%s; authzid=%s", sess->s->tag, &sess->s->auth_method[5], sess->s->auth_id);
                sess->sasl_authd = 1;
            }

            break;

        case event_CLOSED:
            mio_close(sess->c2s->mio, sess->fd);

            break;
    }

    return 0;
}

static int _c2s_client_accept_check(c2s_t c2s, int fd, char *ip) {
    rate_t rt;

    if(access_check(c2s->access, ip) == 0) {
        log_write(c2s->log, LOG_NOTICE, "[%d] [%s] access denied by configuration", fd, ip);
        return 1;
    }

    if(c2s->conn_rate_total != 0) {