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/cmn_err.h>
30#include <sys/strsubr.h>
31
32#include <netinet/in.h>
33#include <netinet/ip6.h>
34
35#include <inet/common.h>
36#include <inet/ip.h>
37#include <inet/mib2.h>
38#include <inet/ipclassifier.h>
39#include "sctp_impl.h"
40
41void
42sctp_return_heartbeat(sctp_t *sctp, sctp_chunk_hdr_t *hbcp, mblk_t *mp)
43{
44	mblk_t *smp;
45	sctp_chunk_hdr_t *cp;
46	ipha_t *iniph;
47	ip6_t *inip6h;
48	int isv4;
49	in6_addr_t addr;
50	sctp_faddr_t *fp;
51	uint16_t len;
52	sctp_stack_t	*sctps = sctp->sctp_sctps;
53
54	BUMP_LOCAL(sctp->sctp_ibchunks);
55
56	/* Update the faddr for the src addr */
57	isv4 = (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION);
58	if (isv4) {
59		iniph = (ipha_t *)mp->b_rptr;
60		IN6_IPADDR_TO_V4MAPPED(iniph->ipha_src, &addr);
61	} else {
62		inip6h = (ip6_t *)mp->b_rptr;
63		addr = inip6h->ip6_src;
64	}
65	fp = sctp_lookup_faddr(sctp, &addr);
66	/* If the source address is bogus we silently drop the packet */
67	if (fp == NULL) {
68		dprint(1,
69		    ("sctp_return_heartbeat: %p bogus hb from %x:%x:%x:%x\n",
70		    (void *)sctp, SCTP_PRINTADDR(addr)));
71		SCTP_KSTAT(sctps, sctp_return_hb_failed);
72		return;
73	}
74	dprint(3, ("sctp_return_heartbeat: %p got hb from %x:%x:%x:%x\n",
75	    (void *)sctp, SCTP_PRINTADDR(addr)));
76
77	/*
78	 * XXX It's really tempting to reuse the heartbeat mblk. But
79	 * this complicates processing in sctp_dispatch (i.e. it will
80	 * screw up sctp_next_chunk since we will set the chunk
81	 * header's length into network byte-order), and if we ever
82	 * encounter a heartbeat bundled with other chunks...
83	 * So we take the slower-but-safe route.
84	 */
85	len = ntohs(hbcp->sch_len);
86
87	/* Create an IP header, returning to the src addr from the heartbt */
88	smp = sctp_make_mp(sctp, fp, len);
89	if (smp == NULL) {
90		SCTP_KSTAT(sctps, sctp_return_hb_failed);
91		return;
92	}
93
94	cp = (sctp_chunk_hdr_t *)smp->b_wptr;
95	cp->sch_id = CHUNK_HEARTBEAT_ACK;
96	cp->sch_flags = 0;
97	cp->sch_len = htons(len);
98
99	/* Copy the information field from the heartbeat */
100	bcopy((void *)(hbcp + 1), (void *)(cp + 1), len - sizeof (*cp));
101
102	smp->b_wptr += len;
103
104	BUMP_LOCAL(sctp->sctp_obchunks);
105
106	sctp_set_iplen(sctp, smp, fp->sf_ixa);
107	(void) conn_ip_output(smp, fp->sf_ixa);
108	BUMP_LOCAL(sctp->sctp_opkts);
109}
110
111/*
112 * The data section of the heartbeat contains a time field (lbolt64),
113 * a 64 bit secret, followed by the v6 (possible a v4mapped) address this
114 * heartbeat was sent to.  No byte-ordering is done, since the heartbeat
115 * is not interpreted by the peer.
116 */
117void
118sctp_send_heartbeat(sctp_t *sctp, sctp_faddr_t *fp)
119{
120	sctp_chunk_hdr_t *cp;
121	sctp_parm_hdr_t *hpp;
122	int64_t *t;
123	int64_t now;
124	in6_addr_t *a;
125	mblk_t *hbmp;
126	size_t hblen;
127	sctp_stack_t	*sctps = sctp->sctp_sctps;
128
129	dprint(3, ("sctp_send_heartbeat: to %x:%x:%x:%x from %x:%x:%x:%x\n",
130	    SCTP_PRINTADDR(fp->sf_faddr), SCTP_PRINTADDR(fp->sf_saddr)));
131
132	hblen = sizeof (*cp) +
133	    sizeof (*hpp) +
134	    sizeof (*t) +
135	    sizeof (fp->sf_hb_secret) +
136	    sizeof (fp->sf_faddr);
137	hbmp = sctp_make_mp(sctp, fp, hblen);
138	if (hbmp == NULL) {
139		SCTP_KSTAT(sctps, sctp_send_hb_failed);
140		return;
141	}
142
143	cp = (sctp_chunk_hdr_t *)hbmp->b_wptr;
144	cp->sch_id = CHUNK_HEARTBEAT;
145	cp->sch_flags = 0;
146	cp->sch_len = hblen;
147	cp->sch_len = htons(cp->sch_len);
148
149	hpp = (sctp_parm_hdr_t *)(cp + 1);
150	hpp->sph_type = htons(PARM_HBINFO);
151	hpp->sph_len = hblen - sizeof (*cp);
152	hpp->sph_len = htons(hpp->sph_len);
153
154	/*
155	 * Timestamp
156	 *
157	 * Copy the current time to the heartbeat and we can use it to
158	 * calculate the RTT when we get it back in the heartbeat ACK.
159	 */
160	now = ddi_get_lbolt64();
161	t = (int64_t *)(hpp + 1);
162	bcopy(&now, t, sizeof (now));
163
164	/*
165	 * Secret
166	 *
167	 * The per peer address secret is used to make sure that the heartbeat
168	 * ack is really in response to our heartbeat.  This prevents blind
169	 * spoofing of heartbeat ack to fake the validity of an address.
170	 */
171	t++;
172	bcopy(&fp->sf_hb_secret, t, sizeof (uint64_t));
173
174	/*
175	 * Peer address
176	 *
177	 * The peer address is used to associate the heartbeat ack with
178	 * the correct peer address.  The reason is that the peer is
179	 * multihomed so that it may not use the same address as source
180	 * in response to our heartbeat.
181	 */
182	a = (in6_addr_t *)(t + 1);
183	bcopy(&fp->sf_faddr, a, sizeof (*a));
184
185	hbmp->b_wptr += hblen;
186
187	/* Update the faddr's info */
188	fp->sf_lastactive = now;
189	fp->sf_hb_pending = B_TRUE;
190
191	BUMP_LOCAL(sctp->sctp_obchunks);
192	SCTPS_BUMP_MIB(sctps, sctpTimHeartBeatProbe);
193
194	sctp_set_iplen(sctp, hbmp, fp->sf_ixa);
195	(void) conn_ip_output(hbmp, fp->sf_ixa);
196	BUMP_LOCAL(sctp->sctp_opkts);
197}
198
199/*
200 * Call right after any address change to validate peer addresses.
201 */
202void
203sctp_validate_peer(sctp_t *sctp)
204{
205	sctp_faddr_t	*fp;
206	int		cnt;
207	int64_t		now;
208	int64_t		earliest_expiry;
209	sctp_stack_t	*sctps = sctp->sctp_sctps;
210
211	now = ddi_get_lbolt64();
212	earliest_expiry = 0;
213	cnt = sctps->sctps_maxburst;
214
215	/*
216	 * Loop thru the list looking for unconfirmed addresses and
217	 * send a heartbeat.  But we should only send at most sctp_maxburst
218	 * heartbeats.
219	 */
220	for (fp = sctp->sctp_faddrs; fp != NULL; fp = fp->sf_next) {
221		/* No need to validate unreachable address. */
222		if (fp->sf_state == SCTP_FADDRS_UNREACH)
223			continue;
224		if (fp->sf_state == SCTP_FADDRS_UNCONFIRMED) {
225			if (cnt-- > 0) {
226				fp->sf_hb_expiry = now + fp->sf_rto;
227				sctp_send_heartbeat(sctp, fp);
228			} else {
229				/*
230				 * If we cannot send now, be more aggressive
231				 * and try again about half of RTO.  Note that
232				 * all the unsent probes are set to expire at
233				 * the same time.
234				 */
235				fp->sf_hb_expiry = now +
236				    (sctp->sctp_rto_initial >> 1);
237			}
238		}
239		/* Find the earliest heartbeat expiry time for ALL fps. */
240		if (fp->sf_hb_interval != 0 && (earliest_expiry == 0 ||
241		    fp->sf_hb_expiry < earliest_expiry)) {
242			earliest_expiry = fp->sf_hb_expiry;
243		}
244	}
245	/* We use heartbeat timer for autoclose. */
246	if (sctp->sctp_autoclose != 0) {
247		int64_t expire;
248
249		expire = sctp->sctp_active + sctp->sctp_autoclose;
250		if (earliest_expiry == 0 || expire < earliest_expiry)
251			earliest_expiry = expire;
252	}
253
254	/*
255	 * Set the timer to fire for the earliest heartbeat unless
256	 * heartbeat is disabled for all addresses.
257	 */
258	if (earliest_expiry != 0) {
259		earliest_expiry -= now;
260		if (earliest_expiry < 0)
261			earliest_expiry = 1;
262		sctp_timer(sctp, sctp->sctp_heartbeat_mp, earliest_expiry);
263	}
264}
265
266/*
267 * Process an incoming heartbeat ack.  When sending a heartbeat, we
268 * put the timestamp, a secret and the peer address the heartbeat is
269 * sent in the data part of the heartbeat.  We will extract this info
270 * and verify that this heartbeat ack is valid.
271 */
272void
273sctp_process_heartbeat(sctp_t *sctp, sctp_chunk_hdr_t *cp)
274{
275	int64_t *sentp, sent;
276	uint64_t secret;
277	in6_addr_t addr;
278	sctp_faddr_t *fp;
279	sctp_parm_hdr_t *hpp;
280	int64_t now;
281
282	BUMP_LOCAL(sctp->sctp_ibchunks);
283
284	/* Sanity checks */
285	ASSERT(OK_32PTR(cp));
286	if (ntohs(cp->sch_len) < (sizeof (*cp) + sizeof (*hpp) +
287	    sizeof (sent) + sizeof (secret) + sizeof (addr))) {
288		/* drop it */
289		dprint(2, ("sctp_process_heartbeat: malformed ack %p\n",
290		    (void *)sctp));
291		return;
292	}
293
294	hpp = (sctp_parm_hdr_t *)(cp + 1);
295	if (ntohs(hpp->sph_type) != PARM_HBINFO ||
296	    ntohs(hpp->sph_len) != (ntohs(cp->sch_len) - sizeof (*cp))) {
297		dprint(2,
298		    ("sctp_process_heartbeat: malformed param in ack %p\n",
299		    (void *)sctp));
300		return;
301	}
302
303	/*
304	 * Pull out the time sent from the ack.
305	 * SCTP is 32-bit aligned, so copy 64 bit quantity.  Since we
306	 * put it in, it should be in our byte order.
307	 */
308	sentp = (int64_t *)(hpp + 1);
309	bcopy(sentp, &sent, sizeof (sent));
310
311	/* Grab the secret to make sure that this heartbeat is valid */
312	bcopy(++sentp, &secret, sizeof (secret));
313
314	/* Next, verify the address to make sure that it is the right one. */
315	bcopy(++sentp, &addr, sizeof (addr));
316	fp = sctp_lookup_faddr(sctp, &addr);
317	if (fp == NULL) {
318		dprint(2, ("sctp_process_heartbeat: invalid faddr (sctp=%p)\n",
319		    (void *)sctp));
320		return;
321	}
322	if (secret != fp->sf_hb_secret) {
323		dprint(2,
324		    ("sctp_process_heartbeat: invalid secret in ack %p\n",
325		    (void *)sctp));
326		return;
327	}
328
329	/* This address is now confirmed and alive. */
330	sctp_faddr_alive(sctp, fp);
331	now = ddi_get_lbolt64();
332	sctp_update_rtt(sctp, fp, now - sent);
333
334	/*
335	 * Note that the heartbeat timer should still be running, we don't
336	 * reset it to avoid going through the whole list of peer addresses
337	 * for each heartbeat ack as we probably are in interrupt context.
338	 */
339	fp->sf_hb_expiry = now + SET_HB_INTVL(fp);
340}
341