2 * ip_conntrack_pptp.c - Version 3.0
4 * Connection tracking support for PPTP (Point to Point Tunneling Protocol).
5 * PPTP is a a protocol for creating virtual private networks.
6 * It is a specification defined by Microsoft and some vendors
7 * working with Microsoft. PPTP is built on top of a modified
8 * version of the Internet Generic Routing Encapsulation Protocol.
9 * GRE is defined in RFC 1701 and RFC 1702. Documentation of
10 * PPTP can be found in RFC 2637
12 * (C) 2000-2005 by Harald Welte <laforge@gnumonks.org>
14 * Development of this code funded by Astaro AG (http://www.astaro.com/)
17 * - We blindly assume that control connections are always
18 * established in PNS->PAC direction. This is a violation
20 * - We can only support one single call within each session
23 * - testing of incoming PPTP calls
26 * 2002-02-05 - Version 1.3
27 * - Call ip_conntrack_unexpect_related() from
28 * pptp_destroy_siblings() to destroy expectations in case
29 * CALL_DISCONNECT_NOTIFY or tcp fin packet was seen
30 * (Philip Craig <philipc@snapgear.com>)
31 * - Add Version information at module loadtime
32 * 2002-02-10 - Version 1.6
33 * - move to C99 style initializers
34 * - remove second expectation if first arrives
35 * 2004-10-22 - Version 2.0
36 * - merge Mandrake's 2.6.x port with recent 2.6.x API changes
37 * - fix lots of linear skb assumptions from Mandrake's port
38 * 2005-06-10 - Version 2.1
39 * - use ip_conntrack_expect_free() instead of kfree() on the
40 * expect's (which are from the slab for quite some time)
41 * 2005-06-10 - Version 3.0
42 * - port helper to post-2.6.11 API changes,
43 * funded by Oxcoda NetBox Blue (http://www.netboxblue.com/)
44 * 2005-07-30 - Version 3.1
45 * - port helper to 2.6.13 API changes
49 #include <linux/module.h>
50 #include <linux/netfilter.h>
52 #include <net/checksum.h>
55 #include <linux/netfilter_ipv4/ip_conntrack.h>
56 #include <linux/netfilter_ipv4/ip_conntrack_core.h>
57 #include <linux/netfilter_ipv4/ip_conntrack_helper.h>
58 #include <linux/netfilter_ipv4/ip_conntrack_proto_gre.h>
59 #include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
61 #define IP_CT_PPTP_VERSION "3.1"
63 MODULE_LICENSE("GPL");
64 MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
65 MODULE_DESCRIPTION("Netfilter connection tracking helper module for PPTP");
67 static DEFINE_SPINLOCK(ip_pptp_lock);
70 (*ip_nat_pptp_hook_outbound)(struct sk_buff **pskb,
71 struct ip_conntrack *ct,
72 enum ip_conntrack_info ctinfo,
73 struct PptpControlHeader *ctlh,
74 union pptp_ctrl_union *pptpReq);
77 (*ip_nat_pptp_hook_inbound)(struct sk_buff **pskb,
78 struct ip_conntrack *ct,
79 enum ip_conntrack_info ctinfo,
80 struct PptpControlHeader *ctlh,
81 union pptp_ctrl_union *pptpReq);
84 (*ip_nat_pptp_hook_exp_gre)(struct ip_conntrack_expect *expect_orig,
85 struct ip_conntrack_expect *expect_reply);
88 (*ip_nat_pptp_hook_expectfn)(struct ip_conntrack *ct,
89 struct ip_conntrack_expect *exp);
92 /* PptpControlMessageType names */
93 const char *pptp_msg_name[] = {
95 "START_SESSION_REQUEST",
96 "START_SESSION_REPLY",
97 "STOP_SESSION_REQUEST",
106 "CALL_CLEAR_REQUEST",
107 "CALL_DISCONNECT_NOTIFY",
111 EXPORT_SYMBOL(pptp_msg_name);
112 #define DEBUGP(format, args...) printk(KERN_DEBUG "%s:%s: " format, __FILE__, __FUNCTION__, ## args)
114 #define DEBUGP(format, args...)
118 #define MINS * 60 SECS
119 #define HOURS * 60 MINS
121 #define PPTP_GRE_TIMEOUT (10 MINS)
122 #define PPTP_GRE_STREAM_TIMEOUT (5 HOURS)
124 static void pptp_expectfn(struct ip_conntrack *ct,
125 struct ip_conntrack_expect *exp)
127 DEBUGP("increasing timeouts\n");
129 /* increase timeout of GRE data channel conntrack entry */
130 ct->proto.gre.timeout = PPTP_GRE_TIMEOUT;
131 ct->proto.gre.stream_timeout = PPTP_GRE_STREAM_TIMEOUT;
133 /* Can you see how rusty this code is, compared with the pre-2.6.11
134 * one? That's what happened to my shiny newnat of 2002 ;( -HW */
136 if (!ip_nat_pptp_hook_expectfn) {
137 struct ip_conntrack_tuple inv_t;
138 struct ip_conntrack_expect *exp_other;
140 /* obviously this tuple inversion only works until you do NAT */
141 invert_tuplepr(&inv_t, &exp->tuple);
142 DEBUGP("trying to unexpect other dir: ");
145 exp_other = ip_conntrack_expect_find(&inv_t);
147 /* delete other expectation. */
149 ip_conntrack_unexpect_related(exp_other);
150 ip_conntrack_expect_put(exp_other);
152 DEBUGP("not found\n");
155 /* we need more than simple inversion */
156 ip_nat_pptp_hook_expectfn(ct, exp);
160 static int destroy_sibling_or_exp(const struct ip_conntrack_tuple *t)
162 struct ip_conntrack_tuple_hash *h;
163 struct ip_conntrack_expect *exp;
165 DEBUGP("trying to timeout ct or exp for tuple ");
168 h = ip_conntrack_find_get(t, NULL);
170 struct ip_conntrack *sibling = tuplehash_to_ctrack(h);
171 DEBUGP("setting timeout of conntrack %p to 0\n", sibling);
172 sibling->proto.gre.timeout = 0;
173 sibling->proto.gre.stream_timeout = 0;
174 if (del_timer(&sibling->timeout))
175 sibling->timeout.function((unsigned long)sibling);
176 ip_conntrack_put(sibling);
179 exp = ip_conntrack_expect_find(t);
181 DEBUGP("unexpect_related of expect %p\n", exp);
182 ip_conntrack_unexpect_related(exp);
183 ip_conntrack_expect_put(exp);
192 /* timeout GRE data connections */
193 static void pptp_destroy_siblings(struct ip_conntrack *ct)
195 struct ip_conntrack_tuple t;
197 ip_ct_gre_keymap_destroy(ct);
198 /* Since ct->sibling_list has literally rusted away in 2.6.11,
199 * we now need another way to find out about our sibling
200 * contrack and expects... -HW */
202 /* try original (pns->pac) tuple */
203 memcpy(&t, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, sizeof(t));
204 t.dst.protonum = IPPROTO_GRE;
205 t.src.u.gre.key = ct->help.ct_pptp_info.pns_call_id;
206 t.dst.u.gre.key = ct->help.ct_pptp_info.pac_call_id;
208 if (!destroy_sibling_or_exp(&t))
209 DEBUGP("failed to timeout original pns->pac ct/exp\n");
211 /* try reply (pac->pns) tuple */
212 memcpy(&t, &ct->tuplehash[IP_CT_DIR_REPLY].tuple, sizeof(t));
213 t.dst.protonum = IPPROTO_GRE;
214 t.src.u.gre.key = ct->help.ct_pptp_info.pac_call_id;
215 t.dst.u.gre.key = ct->help.ct_pptp_info.pns_call_id;
217 if (!destroy_sibling_or_exp(&t))
218 DEBUGP("failed to timeout reply pac->pns ct/exp\n");
221 /* expect GRE connections (PNS->PAC and PAC->PNS direction) */
223 exp_gre(struct ip_conntrack *ct,
227 struct ip_conntrack_expect *exp_orig, *exp_reply;
230 exp_orig = ip_conntrack_expect_alloc(ct);
231 if (exp_orig == NULL)
234 exp_reply = ip_conntrack_expect_alloc(ct);
235 if (exp_reply == NULL)
238 /* original direction, PNS->PAC */
239 exp_orig->tuple.src.ip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
240 exp_orig->tuple.src.u.gre.key = peer_callid;
241 exp_orig->tuple.dst.ip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip;
242 exp_orig->tuple.dst.u.gre.key = callid;
243 exp_orig->tuple.dst.protonum = IPPROTO_GRE;
245 exp_orig->mask.src.ip = htonl(0xffffffff);
246 exp_orig->mask.src.u.all = 0;
247 exp_orig->mask.dst.u.gre.key = htons(0xffff);
248 exp_orig->mask.dst.ip = htonl(0xffffffff);
249 exp_orig->mask.dst.protonum = 0xff;
251 exp_orig->master = ct;
252 exp_orig->expectfn = pptp_expectfn;
255 /* both expectations are identical apart from tuple */
256 memcpy(exp_reply, exp_orig, sizeof(*exp_reply));
258 /* reply direction, PAC->PNS */
259 exp_reply->tuple.src.ip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip;
260 exp_reply->tuple.src.u.gre.key = callid;
261 exp_reply->tuple.dst.ip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
262 exp_reply->tuple.dst.u.gre.key = peer_callid;
263 exp_reply->tuple.dst.protonum = IPPROTO_GRE;
265 if (ip_nat_pptp_hook_exp_gre)
266 ip_nat_pptp_hook_exp_gre(exp_orig, exp_reply);
267 if (ip_conntrack_expect_related(exp_orig) != 0)
269 if (ip_conntrack_expect_related(exp_reply) != 0)
270 goto out_unexpect_orig;
272 /* Add GRE keymap entries */
273 if (ip_ct_gre_keymap_add(ct, &exp_orig->tuple, 0) != 0)
274 goto out_unexpect_both;
275 if (ip_ct_gre_keymap_add(ct, &exp_reply->tuple, 1) != 0) {
276 ip_ct_gre_keymap_destroy(ct);
277 goto out_unexpect_both;
282 ip_conntrack_expect_put(exp_reply);
284 ip_conntrack_expect_put(exp_orig);
289 ip_conntrack_unexpect_related(exp_reply);
291 ip_conntrack_unexpect_related(exp_orig);
296 pptp_inbound_pkt(struct sk_buff **pskb,
297 struct PptpControlHeader *ctlh,
298 union pptp_ctrl_union *pptpReq,
300 struct ip_conntrack *ct,
301 enum ip_conntrack_info ctinfo)
303 struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
305 __be16 cid = 0, pcid = 0;
307 msg = ntohs(ctlh->messageType);
308 DEBUGP("inbound control message %s\n", pptp_msg_name[msg]);
311 case PPTP_START_SESSION_REPLY:
312 /* server confirms new control session */
313 if (info->sstate < PPTP_SESSION_REQUESTED)
315 if (pptpReq->srep.resultCode == PPTP_START_OK)
316 info->sstate = PPTP_SESSION_CONFIRMED;
318 info->sstate = PPTP_SESSION_ERROR;
321 case PPTP_STOP_SESSION_REPLY:
322 /* server confirms end of control session */
323 if (info->sstate > PPTP_SESSION_STOPREQ)
325 if (pptpReq->strep.resultCode == PPTP_STOP_OK)
326 info->sstate = PPTP_SESSION_NONE;
328 info->sstate = PPTP_SESSION_ERROR;
331 case PPTP_OUT_CALL_REPLY:
332 /* server accepted call, we now expect GRE frames */
333 if (info->sstate != PPTP_SESSION_CONFIRMED)
335 if (info->cstate != PPTP_CALL_OUT_REQ &&
336 info->cstate != PPTP_CALL_OUT_CONF)
339 cid = pptpReq->ocack.callID;
340 pcid = pptpReq->ocack.peersCallID;
341 if (info->pns_call_id != pcid)
343 DEBUGP("%s, CID=%X, PCID=%X\n", pptp_msg_name[msg],
344 ntohs(cid), ntohs(pcid));
346 if (pptpReq->ocack.resultCode == PPTP_OUTCALL_CONNECT) {
347 info->cstate = PPTP_CALL_OUT_CONF;
348 info->pac_call_id = cid;
349 exp_gre(ct, cid, pcid);
351 info->cstate = PPTP_CALL_NONE;
354 case PPTP_IN_CALL_REQUEST:
355 /* server tells us about incoming call request */
356 if (info->sstate != PPTP_SESSION_CONFIRMED)
359 cid = pptpReq->icreq.callID;
360 DEBUGP("%s, CID=%X\n", pptp_msg_name[msg], ntohs(cid));
361 info->cstate = PPTP_CALL_IN_REQ;
362 info->pac_call_id = cid;
365 case PPTP_IN_CALL_CONNECT:
366 /* server tells us about incoming call established */
367 if (info->sstate != PPTP_SESSION_CONFIRMED)
369 if (info->cstate != PPTP_CALL_IN_REP &&
370 info->cstate != PPTP_CALL_IN_CONF)
373 pcid = pptpReq->iccon.peersCallID;
374 cid = info->pac_call_id;
376 if (info->pns_call_id != pcid)
379 DEBUGP("%s, PCID=%X\n", pptp_msg_name[msg], ntohs(pcid));
380 info->cstate = PPTP_CALL_IN_CONF;
382 /* we expect a GRE connection from PAC to PNS */
383 exp_gre(ct, cid, pcid);
386 case PPTP_CALL_DISCONNECT_NOTIFY:
387 /* server confirms disconnect */
388 cid = pptpReq->disc.callID;
389 DEBUGP("%s, CID=%X\n", pptp_msg_name[msg], ntohs(cid));
390 info->cstate = PPTP_CALL_NONE;
392 /* untrack this call id, unexpect GRE packets */
393 pptp_destroy_siblings(ct);
396 case PPTP_WAN_ERROR_NOTIFY:
397 case PPTP_ECHO_REQUEST:
398 case PPTP_ECHO_REPLY:
399 /* I don't have to explain these ;) */
405 if (ip_nat_pptp_hook_inbound)
406 return ip_nat_pptp_hook_inbound(pskb, ct, ctinfo, ctlh,
411 DEBUGP("invalid %s: type=%d cid=%u pcid=%u "
412 "cstate=%d sstate=%d pns_cid=%u pac_cid=%u\n",
413 msg <= PPTP_MSG_MAX ? pptp_msg_name[msg] : pptp_msg_name[0],
414 msg, ntohs(cid), ntohs(pcid), info->cstate, info->sstate,
415 ntohs(info->pns_call_id), ntohs(info->pac_call_id));
420 pptp_outbound_pkt(struct sk_buff **pskb,
421 struct PptpControlHeader *ctlh,
422 union pptp_ctrl_union *pptpReq,
424 struct ip_conntrack *ct,
425 enum ip_conntrack_info ctinfo)
427 struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
429 __be16 cid = 0, pcid = 0;
431 msg = ntohs(ctlh->messageType);
432 DEBUGP("outbound control message %s\n", pptp_msg_name[msg]);
435 case PPTP_START_SESSION_REQUEST:
436 /* client requests for new control session */
437 if (info->sstate != PPTP_SESSION_NONE)
439 info->sstate = PPTP_SESSION_REQUESTED;
441 case PPTP_STOP_SESSION_REQUEST:
442 /* client requests end of control session */
443 info->sstate = PPTP_SESSION_STOPREQ;
446 case PPTP_OUT_CALL_REQUEST:
447 /* client initiating connection to server */
448 if (info->sstate != PPTP_SESSION_CONFIRMED)
450 info->cstate = PPTP_CALL_OUT_REQ;
451 /* track PNS call id */
452 cid = pptpReq->ocreq.callID;
453 DEBUGP("%s, CID=%X\n", pptp_msg_name[msg], ntohs(cid));
454 info->pns_call_id = cid;
456 case PPTP_IN_CALL_REPLY:
457 /* client answers incoming call */
458 if (info->cstate != PPTP_CALL_IN_REQ &&
459 info->cstate != PPTP_CALL_IN_REP)
462 cid = pptpReq->icack.callID;
463 pcid = pptpReq->icack.peersCallID;
464 if (info->pac_call_id != pcid)
466 DEBUGP("%s, CID=%X PCID=%X\n", pptp_msg_name[msg],
467 ntohs(cid), ntohs(pcid));
469 if (pptpReq->icack.resultCode == PPTP_INCALL_ACCEPT) {
470 /* part two of the three-way handshake */
471 info->cstate = PPTP_CALL_IN_REP;
472 info->pns_call_id = cid;
474 info->cstate = PPTP_CALL_NONE;
477 case PPTP_CALL_CLEAR_REQUEST:
478 /* client requests hangup of call */
479 if (info->sstate != PPTP_SESSION_CONFIRMED)
481 /* FUTURE: iterate over all calls and check if
482 * call ID is valid. We don't do this without newnat,
483 * because we only know about last call */
484 info->cstate = PPTP_CALL_CLEAR_REQ;
486 case PPTP_SET_LINK_INFO:
487 case PPTP_ECHO_REQUEST:
488 case PPTP_ECHO_REPLY:
489 /* I don't have to explain these ;) */
495 if (ip_nat_pptp_hook_outbound)
496 return ip_nat_pptp_hook_outbound(pskb, ct, ctinfo, ctlh,
501 DEBUGP("invalid %s: type=%d cid=%u pcid=%u "
502 "cstate=%d sstate=%d pns_cid=%u pac_cid=%u\n",
503 msg <= PPTP_MSG_MAX ? pptp_msg_name[msg] : pptp_msg_name[0],
504 msg, ntohs(cid), ntohs(pcid), info->cstate, info->sstate,
505 ntohs(info->pns_call_id), ntohs(info->pac_call_id));
509 static const unsigned int pptp_msg_size[] = {
510 [PPTP_START_SESSION_REQUEST] = sizeof(struct PptpStartSessionRequest),
511 [PPTP_START_SESSION_REPLY] = sizeof(struct PptpStartSessionReply),
512 [PPTP_STOP_SESSION_REQUEST] = sizeof(struct PptpStopSessionRequest),
513 [PPTP_STOP_SESSION_REPLY] = sizeof(struct PptpStopSessionReply),
514 [PPTP_OUT_CALL_REQUEST] = sizeof(struct PptpOutCallRequest),
515 [PPTP_OUT_CALL_REPLY] = sizeof(struct PptpOutCallReply),
516 [PPTP_IN_CALL_REQUEST] = sizeof(struct PptpInCallRequest),
517 [PPTP_IN_CALL_REPLY] = sizeof(struct PptpInCallReply),
518 [PPTP_IN_CALL_CONNECT] = sizeof(struct PptpInCallConnected),
519 [PPTP_CALL_CLEAR_REQUEST] = sizeof(struct PptpClearCallRequest),
520 [PPTP_CALL_DISCONNECT_NOTIFY] = sizeof(struct PptpCallDisconnectNotify),
521 [PPTP_WAN_ERROR_NOTIFY] = sizeof(struct PptpWanErrorNotify),
522 [PPTP_SET_LINK_INFO] = sizeof(struct PptpSetLinkInfo),
525 /* track caller id inside control connection, call expect_related */
527 conntrack_pptp_help(struct sk_buff **pskb,
528 struct ip_conntrack *ct, enum ip_conntrack_info ctinfo)
531 int dir = CTINFO2DIR(ctinfo);
532 struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
533 struct tcphdr _tcph, *tcph;
534 struct pptp_pkt_hdr _pptph, *pptph;
535 struct PptpControlHeader _ctlh, *ctlh;
536 union pptp_ctrl_union _pptpReq, *pptpReq;
537 unsigned int tcplen = (*pskb)->len - (*pskb)->nh.iph->ihl * 4;
538 unsigned int datalen, reqlen, nexthdr_off;
539 int oldsstate, oldcstate;
543 /* don't do any tracking before tcp handshake complete */
544 if (ctinfo != IP_CT_ESTABLISHED
545 && ctinfo != IP_CT_ESTABLISHED+IP_CT_IS_REPLY) {
546 DEBUGP("ctinfo = %u, skipping\n", ctinfo);
550 nexthdr_off = (*pskb)->nh.iph->ihl*4;
551 tcph = skb_header_pointer(*pskb, nexthdr_off, sizeof(_tcph), &_tcph);
553 nexthdr_off += tcph->doff * 4;
554 datalen = tcplen - tcph->doff * 4;
556 pptph = skb_header_pointer(*pskb, nexthdr_off, sizeof(_pptph), &_pptph);
558 DEBUGP("no full PPTP header, can't track\n");
561 nexthdr_off += sizeof(_pptph);
562 datalen -= sizeof(_pptph);
564 /* if it's not a control message we can't do anything with it */
565 if (ntohs(pptph->packetType) != PPTP_PACKET_CONTROL ||
566 ntohl(pptph->magicCookie) != PPTP_MAGIC_COOKIE) {
567 DEBUGP("not a control packet\n");
571 ctlh = skb_header_pointer(*pskb, nexthdr_off, sizeof(_ctlh), &_ctlh);
574 nexthdr_off += sizeof(_ctlh);
575 datalen -= sizeof(_ctlh);
578 msg = ntohs(ctlh->messageType);
579 if (msg > 0 && msg <= PPTP_MSG_MAX && reqlen < pptp_msg_size[msg])
581 if (reqlen > sizeof(*pptpReq))
582 reqlen = sizeof(*pptpReq);
584 pptpReq = skb_header_pointer(*pskb, nexthdr_off, reqlen, &_pptpReq);
588 oldsstate = info->sstate;
589 oldcstate = info->cstate;
591 spin_lock_bh(&ip_pptp_lock);
593 /* FIXME: We just blindly assume that the control connection is always
594 * established from PNS->PAC. However, RFC makes no guarantee */
595 if (dir == IP_CT_DIR_ORIGINAL)
596 /* client -> server (PNS -> PAC) */
597 ret = pptp_outbound_pkt(pskb, ctlh, pptpReq, reqlen, ct,
600 /* server -> client (PAC -> PNS) */
601 ret = pptp_inbound_pkt(pskb, ctlh, pptpReq, reqlen, ct,
603 DEBUGP("sstate: %d->%d, cstate: %d->%d\n",
604 oldsstate, info->sstate, oldcstate, info->cstate);
605 spin_unlock_bh(&ip_pptp_lock);
610 /* control protocol helper */
611 static struct ip_conntrack_helper pptp = {
612 .list = { NULL, NULL },
617 .tuple = { .src = { .ip = 0,
618 .u = { .tcp = { .port =
619 __constant_htons(PPTP_CONTROL_PORT) } }
623 .protonum = IPPROTO_TCP
626 .mask = { .src = { .ip = 0,
627 .u = { .tcp = { .port = __constant_htons(0xffff) } }
634 .help = conntrack_pptp_help,
635 .destroy = pptp_destroy_siblings,
638 extern void ip_ct_proto_gre_fini(void);
639 extern int __init ip_ct_proto_gre_init(void);
641 /* ip_conntrack_pptp initialization */
642 static int __init ip_conntrack_helper_pptp_init(void)
646 retcode = ip_ct_proto_gre_init();
650 DEBUGP(" registering helper\n");
651 if ((retcode = ip_conntrack_helper_register(&pptp))) {
652 printk(KERN_ERR "Unable to register conntrack application "
653 "helper for pptp: %d\n", retcode);
654 ip_ct_proto_gre_fini();
658 printk("ip_conntrack_pptp version %s loaded\n", IP_CT_PPTP_VERSION);
662 static void __exit ip_conntrack_helper_pptp_fini(void)
664 ip_conntrack_helper_unregister(&pptp);
665 ip_ct_proto_gre_fini();
666 printk("ip_conntrack_pptp version %s unloaded\n", IP_CT_PPTP_VERSION);
669 module_init(ip_conntrack_helper_pptp_init);
670 module_exit(ip_conntrack_helper_pptp_fini);
672 EXPORT_SYMBOL(ip_nat_pptp_hook_outbound);
673 EXPORT_SYMBOL(ip_nat_pptp_hook_inbound);
674 EXPORT_SYMBOL(ip_nat_pptp_hook_exp_gre);
675 EXPORT_SYMBOL(ip_nat_pptp_hook_expectfn);