xref: /titanic_41/usr/src/uts/common/inet/sctp/sctp_shutdown.c (revision 49d3bc91e27cd871b950d56c01398fa2f2e12ab4)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 
26 #include <sys/types.h>
27 #include <sys/systm.h>
28 #include <sys/stream.h>
29 #include <sys/ddi.h>
30 #include <sys/sunddi.h>
31 #include <sys/strsubr.h>
32 #include <sys/strsun.h>
33 
34 #include <netinet/in.h>
35 #include <netinet/ip6.h>
36 
37 #include <inet/ipsec_impl.h>
38 #include <inet/common.h>
39 #include <inet/ip.h>
40 #include <inet/ip6.h>
41 #include <inet/mib2.h>
42 #include <inet/nd.h>
43 #include <inet/optcom.h>
44 #include <inet/sctp_ip.h>
45 #include <inet/ipclassifier.h>
46 #include "sctp_impl.h"
47 
48 void
49 sctp_send_shutdown(sctp_t *sctp, int rexmit)
50 {
51 	mblk_t *smp;
52 	mblk_t *sendmp;
53 	sctp_chunk_hdr_t *sch;
54 	uint32_t *ctsn;
55 	sctp_faddr_t *fp;
56 	sctp_stack_t	*sctps = sctp->sctp_sctps;
57 
58 	if (sctp->sctp_state != SCTPS_ESTABLISHED &&
59 	    sctp->sctp_state != SCTPS_SHUTDOWN_PENDING &&
60 	    sctp->sctp_state != SCTPS_SHUTDOWN_SENT) {
61 		return;
62 	}
63 
64 	if (sctp->sctp_state == SCTPS_ESTABLISHED) {
65 		sctp->sctp_state = SCTPS_SHUTDOWN_PENDING;
66 		/*
67 		 * We set an upper bound on how long we will
68 		 * wait for a shutdown-ack from the peer. This
69 		 * is to prevent the receiver from attempting
70 		 * to create a half-closed state indefinately.
71 		 * See archive from IETF TSVWG mailing list
72 		 * for June 2001 for more information.
73 		 * Since we will not be calculating RTTs after
74 		 * sending the shutdown, we can overload out_time
75 		 * to track how long we have waited.
76 		 */
77 		sctp->sctp_out_time = ddi_get_lbolt64();
78 	}
79 
80 	/*
81 	 * If there is unsent (or unacked) data, wait for it to get ack'd
82 	 */
83 	if (sctp->sctp_xmit_head != NULL || sctp->sctp_xmit_unsent != NULL) {
84 		return;
85 	}
86 
87 	/* rotate faddrs if we are retransmitting */
88 	if (!rexmit) {
89 		fp = sctp->sctp_current;
90 	} else {
91 		fp = sctp_rotate_faddr(sctp, sctp->sctp_shutdown_faddr);
92 	}
93 
94 	sctp->sctp_shutdown_faddr = fp;
95 
96 	/* Link in a SACK if resending the shutdown */
97 	if (sctp->sctp_state > SCTPS_SHUTDOWN_PENDING &&
98 	    (sendmp = sctp_make_sack(sctp, fp, NULL)) != NULL) {
99 
100 		smp = allocb(sizeof (*sch) + sizeof (*ctsn), BPRI_MED);
101 		if (smp == NULL) {
102 			freemsg(sendmp);
103 			goto done;
104 		}
105 		linkb(sendmp, smp);
106 
107 		sch = (sctp_chunk_hdr_t *)smp->b_rptr;
108 		smp->b_wptr = smp->b_rptr + sizeof (*sch) + sizeof (*ctsn);
109 	} else {
110 		sendmp = sctp_make_mp(sctp, fp,
111 		    sizeof (*sch) + sizeof (*ctsn));
112 		if (sendmp == NULL) {
113 			SCTP_KSTAT(sctps, sctp_send_shutdown_failed);
114 			goto done;
115 		}
116 		sch = (sctp_chunk_hdr_t *)sendmp->b_wptr;
117 		sendmp->b_wptr += sizeof (*sch) + sizeof (*ctsn);
118 
119 		/* shutdown w/o sack, update lastacked */
120 		sctp->sctp_lastacked = sctp->sctp_ftsn - 1;
121 	}
122 
123 	sch->sch_id = CHUNK_SHUTDOWN;
124 	sch->sch_flags = 0;
125 	sch->sch_len = htons(sizeof (*sch) + sizeof (*ctsn));
126 
127 	ctsn = (uint32_t *)(sch + 1);
128 	*ctsn = htonl(sctp->sctp_lastacked);
129 
130 	/* Link the shutdown chunk in after the IP/SCTP header */
131 
132 	BUMP_LOCAL(sctp->sctp_obchunks);
133 
134 	/* Send the shutdown and restart the timer */
135 	sctp_set_iplen(sctp, sendmp, fp->sf_ixa);
136 	(void) conn_ip_output(sendmp, fp->sf_ixa);
137 	BUMP_LOCAL(sctp->sctp_opkts);
138 
139 done:
140 	sctp->sctp_state = SCTPS_SHUTDOWN_SENT;
141 	SCTP_FADDR_TIMER_RESTART(sctp, sctp->sctp_current,
142 	    sctp->sctp_current->sf_rto);
143 }
144 
145 int
146 sctp_shutdown_received(sctp_t *sctp, sctp_chunk_hdr_t *sch, boolean_t crwsd,
147     boolean_t rexmit, sctp_faddr_t *fp)
148 {
149 	mblk_t *samp;
150 	uint32_t *tsn;
151 	int trysend = 0;
152 
153 	if (sctp->sctp_state != SCTPS_SHUTDOWN_ACK_SENT)
154 		sctp->sctp_state = SCTPS_SHUTDOWN_RECEIVED;
155 
156 	/* Extract and process the TSN in the shutdown chunk */
157 	if (sch != NULL) {
158 		tsn = (uint32_t *)(sch + 1);
159 		/* not already acked */
160 		if (!SEQ_LT(ntohl(*tsn), sctp->sctp_lastack_rxd))
161 			trysend = sctp_cumack(sctp, ntohl(*tsn), &samp);
162 	}
163 
164 	/* Don't allow sending new data */
165 	if (!SCTP_IS_DETACHED(sctp) && !sctp->sctp_ulp_discon_done) {
166 		sctp->sctp_ulp_opctl(sctp->sctp_ulpd, SOCK_OPCTL_SHUT_SEND, 0);
167 		sctp->sctp_ulp_discon_done = B_TRUE;
168 	}
169 
170 	/*
171 	 * If there is unsent or unacked data, try sending them out now.
172 	 * The other side should acknowledge them.  After we have flushed
173 	 * the transmit queue, we can complete the shutdown sequence.
174 	 */
175 	if (sctp->sctp_xmit_head != NULL || sctp->sctp_xmit_unsent != NULL)
176 		return (1);
177 
178 	if (fp == NULL) {
179 		/* rotate faddrs if we are retransmitting */
180 		if (!rexmit)
181 			fp = sctp->sctp_current;
182 		else
183 			fp = sctp_rotate_faddr(sctp, sctp->sctp_shutdown_faddr);
184 	}
185 
186 	sctp_send_shutdown_ack(sctp, fp, crwsd);
187 
188 	return (trysend);
189 }
190 
191 void
192 sctp_shutdown_complete(sctp_t *sctp)
193 {
194 	mblk_t *scmp;
195 	sctp_chunk_hdr_t *scch;
196 	sctp_stack_t	*sctps = sctp->sctp_sctps;
197 
198 	scmp = sctp_make_mp(sctp, sctp->sctp_current, sizeof (*scch));
199 	if (scmp == NULL) {
200 		/* XXX use timer approach */
201 		SCTP_KSTAT(sctps, sctp_send_shutdown_comp_failed);
202 		return;
203 	}
204 
205 	scch = (sctp_chunk_hdr_t *)scmp->b_wptr;
206 	scch->sch_id = CHUNK_SHUTDOWN_COMPLETE;
207 	scch->sch_flags = 0;
208 	scch->sch_len = htons(sizeof (*scch));
209 
210 	scmp->b_wptr += sizeof (*scch);
211 
212 	BUMP_LOCAL(sctp->sctp_obchunks);
213 
214 	sctp_set_iplen(sctp, scmp, sctp->sctp_current->sf_ixa);
215 	(void) conn_ip_output(scmp, sctp->sctp_current->sf_ixa);
216 	BUMP_LOCAL(sctp->sctp_opkts);
217 }
218 
219 /*
220  * Similar to sctp_shutdown_complete(), except that since this
221  * is out-of-the-blue, we can't use an sctp's association information,
222  * and instead must draw all necessary info from the incoming packet.
223  */
224 void
225 sctp_ootb_shutdown_ack(mblk_t *mp, uint_t ip_hdr_len, ip_recv_attr_t *ira,
226     ip_stack_t *ipst)
227 {
228 	boolean_t		isv4;
229 	ipha_t			*ipha = NULL;
230 	ip6_t			*ip6h = NULL;
231 	sctp_hdr_t		*insctph;
232 	sctp_chunk_hdr_t	*scch;
233 	int			i;
234 	uint16_t		port;
235 	mblk_t			*mp1;
236 	netstack_t		*ns = ipst->ips_netstack;
237 	sctp_stack_t		*sctps = ns->netstack_sctp;
238 	ip_xmit_attr_t		ixas;
239 
240 	bzero(&ixas, sizeof (ixas));
241 
242 	isv4 = (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION);
243 
244 	ASSERT(MBLKL(mp) >= sizeof (*insctph) + sizeof (*scch) +
245 	    (isv4 ? sizeof (ipha_t) : sizeof (ip6_t)));
246 
247 	/*
248 	 * Check to see if we can reuse the incoming mblk.  There should
249 	 * not be other reference. Since this packet comes from below,
250 	 * there should be enough header space to fill in what the lower
251 	 * layers want to add.
252 	 */
253 	if (DB_REF(mp) != 1) {
254 		mp1 = allocb(MBLKL(mp) + sctps->sctps_wroff_xtra, BPRI_MED);
255 		if (mp1 == NULL) {
256 			freeb(mp);
257 			return;
258 		}
259 		mp1->b_rptr += sctps->sctps_wroff_xtra;
260 		bcopy(mp->b_rptr, mp1->b_rptr, MBLKL(mp));
261 		freeb(mp);
262 		mp = mp1;
263 	} else {
264 		DB_CKSUMFLAGS(mp) = 0;
265 	}
266 
267 	ixas.ixa_pktlen = ip_hdr_len + sizeof (*insctph) + sizeof (*scch);
268 	ixas.ixa_ip_hdr_length = ip_hdr_len;
269 	mp->b_wptr = (mp->b_rptr + ixas.ixa_pktlen);
270 
271 	/*
272 	 * We follow the logic in tcp_xmit_early_reset() in that we skip
273 	 * reversing source route (i.e. replace all IP options with EOL).
274 	 */
275 	if (isv4) {
276 		ipaddr_t	v4addr;
277 
278 		ipha = (ipha_t *)mp->b_rptr;
279 		for (i = IP_SIMPLE_HDR_LENGTH; i < (int)ip_hdr_len; i++)
280 			mp->b_rptr[i] = IPOPT_EOL;
281 		/* Swap addresses */
282 		ipha->ipha_length = htons(ixas.ixa_pktlen);
283 		v4addr = ipha->ipha_src;
284 		ipha->ipha_src = ipha->ipha_dst;
285 		ipha->ipha_dst = v4addr;
286 		ipha->ipha_ident = 0;
287 		ipha->ipha_ttl = (uchar_t)sctps->sctps_ipv4_ttl;
288 
289 		ixas.ixa_flags = IXAF_BASIC_SIMPLE_V4;
290 	} else {
291 		in6_addr_t	v6addr;
292 
293 		ip6h = (ip6_t *)mp->b_rptr;
294 		/* Remove any extension headers assuming partial overlay */
295 		if (ip_hdr_len > IPV6_HDR_LEN) {
296 			uint8_t	*to;
297 
298 			to = mp->b_rptr + ip_hdr_len - IPV6_HDR_LEN;
299 			ovbcopy(ip6h, to, IPV6_HDR_LEN);
300 			mp->b_rptr += ip_hdr_len - IPV6_HDR_LEN;
301 			ip_hdr_len = IPV6_HDR_LEN;
302 			ip6h = (ip6_t *)mp->b_rptr;
303 			ip6h->ip6_nxt = IPPROTO_SCTP;
304 		}
305 		ip6h->ip6_plen = htons(ixas.ixa_pktlen - IPV6_HDR_LEN);
306 		v6addr = ip6h->ip6_src;
307 		ip6h->ip6_src = ip6h->ip6_dst;
308 		ip6h->ip6_dst = v6addr;
309 		ip6h->ip6_hops = (uchar_t)sctps->sctps_ipv6_hoplimit;
310 
311 		ixas.ixa_flags = IXAF_BASIC_SIMPLE_V6;
312 		if (IN6_IS_ADDR_LINKSCOPE(&ip6h->ip6_dst)) {
313 			ixas.ixa_flags |= IXAF_SCOPEID_SET;
314 			ixas.ixa_scopeid = ira->ira_ruifindex;
315 		}
316 	}
317 
318 	insctph = (sctp_hdr_t *)(mp->b_rptr + ip_hdr_len);
319 
320 	/* Swap ports.  Verification tag is reused. */
321 	port = insctph->sh_sport;
322 	insctph->sh_sport = insctph->sh_dport;
323 	insctph->sh_dport = port;
324 
325 	/* Lay in the shutdown complete chunk */
326 	scch = (sctp_chunk_hdr_t *)(insctph + 1);
327 	scch->sch_id = CHUNK_SHUTDOWN_COMPLETE;
328 	scch->sch_len = htons(sizeof (*scch));
329 	scch->sch_flags = 0;
330 
331 	/* Set the T-bit */
332 	SCTP_SET_TBIT(scch);
333 
334 	ixas.ixa_protocol = IPPROTO_SCTP;
335 	ixas.ixa_zoneid = ira->ira_zoneid;
336 	ixas.ixa_ipst = ipst;
337 	ixas.ixa_ifindex = 0;
338 
339 	if (ira->ira_flags & IRAF_IPSEC_SECURE) {
340 		/*
341 		 * Apply IPsec based on how IPsec was applied to
342 		 * the packet that was out of the blue.
343 		 */
344 		if (!ipsec_in_to_out(ira, &ixas, mp, ipha, ip6h)) {
345 			BUMP_MIB(&ipst->ips_ip_mib, ipIfStatsOutDiscards);
346 			/* Note: mp already consumed and ip_drop_packet done */
347 			return;
348 		}
349 	} else {
350 		/*
351 		 * This is in clear. The message we are building
352 		 * here should go out in clear, independent of our policy.
353 		 */
354 		ixas.ixa_flags |= IXAF_NO_IPSEC;
355 	}
356 
357 	(void) ip_output_simple(mp, &ixas);
358 	ixa_cleanup(&ixas);
359 }
360 
361 /*
362  * Called from sctp_input_data() and sctp_shutdown_received().
363  * Send a SHUTDOWN ACK chunk to the peer SCTP endpoint and change SCTP state.
364  * This should be done after all data (unacked and unsend) has been
365  * acknowledged.
366  */
367 void
368 sctp_send_shutdown_ack(sctp_t *sctp, sctp_faddr_t *fp, boolean_t crwsd)
369 {
370 	mblk_t *samp;
371 	sctp_chunk_hdr_t *sach;
372 	sctp_stack_t	*sctps = sctp->sctp_sctps;
373 
374 	ASSERT(sctp->sctp_xmit_unacked == NULL);
375 	ASSERT(sctp->sctp_lastack_rxd == (sctp->sctp_ltsn - 1));
376 	ASSERT(fp != NULL);
377 
378 	sctp->sctp_shutdown_faddr = fp;
379 
380 	samp = sctp_make_mp(sctp, fp, sizeof (*sach));
381 	if (samp == NULL) {
382 		SCTP_KSTAT(sctps, sctp_send_shutdown_ack_failed);
383 		goto dotimer;
384 	}
385 
386 	sach = (sctp_chunk_hdr_t *)samp->b_wptr;
387 	sach->sch_id = CHUNK_SHUTDOWN_ACK;
388 	sach->sch_flags = 0;
389 	sach->sch_len = htons(sizeof (*sach));
390 
391 	samp->b_wptr += sizeof (*sach);
392 	/*
393 	 * bundle a "cookie received while shutting down" error if
394 	 * the caller asks for it.
395 	 */
396 	if (crwsd) {
397 		mblk_t *errmp;
398 
399 		errmp = sctp_make_err(sctp, SCTP_ERR_COOKIE_SHUT, NULL, 0);
400 		if (errmp != NULL) {
401 			linkb(samp, errmp);
402 			BUMP_LOCAL(sctp->sctp_obchunks);
403 		}
404 	}
405 
406 	BUMP_LOCAL(sctp->sctp_obchunks);
407 
408 	sctp_set_iplen(sctp, samp, fp->sf_ixa);
409 	(void) conn_ip_output(samp, fp->sf_ixa);
410 	BUMP_LOCAL(sctp->sctp_opkts);
411 
412 dotimer:
413 	sctp->sctp_state = SCTPS_SHUTDOWN_ACK_SENT;
414 	SCTP_FADDR_TIMER_RESTART(sctp, fp, fp->sf_rto);
415 }
416