xref: /titanic_41/usr/src/uts/common/inet/sctp/sctp_heartbeat.c (revision 77c67f2fb257d2c7dfa00389cd9cd7dd5f99a920)
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 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/systm.h>
31 #include <sys/stream.h>
32 #include <sys/cmn_err.h>
33 #include <sys/strsubr.h>
34 
35 #include <netinet/in.h>
36 #include <netinet/ip6.h>
37 
38 #include <inet/common.h>
39 #include <inet/ip.h>
40 #include <inet/mib2.h>
41 #include "sctp_impl.h"
42 
43 void
44 sctp_return_heartbeat(sctp_t *sctp, sctp_chunk_hdr_t *hbcp, mblk_t *mp)
45 {
46 	mblk_t *smp;
47 	sctp_chunk_hdr_t *cp;
48 	ipha_t *iniph;
49 	ip6_t *inip6h;
50 	int isv4;
51 	in6_addr_t addr;
52 	sctp_faddr_t *fp;
53 	uint16_t len;
54 
55 	BUMP_LOCAL(sctp->sctp_ibchunks);
56 
57 	/* Update the faddr for the src addr */
58 	isv4 = (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION);
59 	if (isv4) {
60 		iniph = (ipha_t *)mp->b_rptr;
61 		IN6_IPADDR_TO_V4MAPPED(iniph->ipha_src, &addr);
62 	} else {
63 		inip6h = (ip6_t *)mp->b_rptr;
64 		addr = inip6h->ip6_src;
65 	}
66 	fp = sctp_lookup_faddr(sctp, &addr);
67 	ASSERT(fp != NULL);
68 
69 	dprint(3, ("sctp_return_heartbeat: %p got hb from %x:%x:%x:%x\n",
70 	    (void *)sctp, SCTP_PRINTADDR(addr)));
71 
72 	/*
73 	 * XXX It's really tempting to reuse the heartbeat mblk. But
74 	 * this complicates processing in sctp_dispatch (i.e. it will
75 	 * screw up sctp_next_chunk since we will set the chunk
76 	 * header's length into network byte-order), and if we ever
77 	 * encounter a heartbeat bundled with other chunks...
78 	 * So we take the slower-but-safe route.
79 	 */
80 	len = ntohs(hbcp->sch_len);
81 
82 	/* Create an IP header, returning to the src addr from the heartbt */
83 	smp = sctp_make_mp(sctp, fp, len);
84 	if (smp == NULL) {
85 		SCTP_KSTAT(sctp_return_hb_failed);
86 		return;
87 	}
88 
89 	cp = (sctp_chunk_hdr_t *)smp->b_wptr;
90 	cp->sch_id = CHUNK_HEARTBEAT_ACK;
91 	cp->sch_flags = 0;
92 	cp->sch_len = htons(len);
93 
94 	/* Copy the information field from the heartbeat */
95 	bcopy((void *)(hbcp + 1), (void *)(cp + 1), len - sizeof (*cp));
96 
97 	smp->b_wptr += len;
98 
99 	sctp_set_iplen(sctp, smp);
100 
101 	BUMP_LOCAL(sctp->sctp_obchunks);
102 	sctp_add_sendq(sctp, smp);
103 }
104 
105 /*
106  * The data section of the heartbeat contains a time field (lbolt64),
107  * a 64 bit secret, followed by the v6 (possible a v4mapped) address this
108  * heartbeat was sent to.  No byte-ordering is done, since the heartbeat
109  * is not interpreted by the peer.
110  */
111 void
112 sctp_send_heartbeat(sctp_t *sctp, sctp_faddr_t *fp)
113 {
114 	sctp_chunk_hdr_t *cp;
115 	sctp_parm_hdr_t *hpp;
116 	int64_t *t;
117 	int64_t now;
118 	in6_addr_t *a;
119 	mblk_t *hbmp;
120 	size_t hblen;
121 
122 	dprint(3, ("sctp_send_heartbeat: to %x:%x:%x:%x from %x:%x:%x:%x\n",
123 	    SCTP_PRINTADDR(fp->faddr), SCTP_PRINTADDR(fp->saddr)));
124 
125 	hblen = sizeof (*cp) +
126 		sizeof (*hpp) +
127 		sizeof (*t) +
128 		sizeof (fp->hb_secret) +
129 		sizeof (fp->faddr);
130 	hbmp = sctp_make_mp(sctp, fp, hblen);
131 	if (hbmp == NULL) {
132 		SCTP_KSTAT(sctp_send_hb_failed);
133 		return;
134 	}
135 
136 	cp = (sctp_chunk_hdr_t *)hbmp->b_wptr;
137 	cp->sch_id = CHUNK_HEARTBEAT;
138 	cp->sch_flags = 0;
139 	cp->sch_len = hblen;
140 	cp->sch_len = htons(cp->sch_len);
141 
142 	hpp = (sctp_parm_hdr_t *)(cp + 1);
143 	hpp->sph_type = htons(PARM_HBINFO);
144 	hpp->sph_len = hblen - sizeof (*cp);
145 	hpp->sph_len = htons(hpp->sph_len);
146 
147 	/*
148 	 * Timestamp
149 	 *
150 	 * Copy the current time to the heartbeat and we can use it to
151 	 * calculate the RTT when we get it back in the heartbeat ACK.
152 	 */
153 	now = lbolt64;
154 	t = (int64_t *)(hpp + 1);
155 	bcopy(&now, t, sizeof (now));
156 
157 	/*
158 	 * Secret
159 	 *
160 	 * The per peer address secret is used to make sure that the heartbeat
161 	 * ack is really in response to our heartbeat.  This prevents blind
162 	 * spoofing of heartbeat ack to fake the validity of an address.
163 	 */
164 	t++;
165 	bcopy(&fp->hb_secret, t, sizeof (uint64_t));
166 
167 	/*
168 	 * Peer address
169 	 *
170 	 * The peer address is used to associate the heartbeat ack with
171 	 * the correct peer address.  The reason is that the peer is
172 	 * multihomed so that it may not use the same address as source
173 	 * in response to our heartbeat.
174 	 */
175 	a = (in6_addr_t *)(t + 1);
176 	bcopy(&fp->faddr, a, sizeof (*a));
177 
178 	hbmp->b_wptr += hblen;
179 
180 	sctp_set_iplen(sctp, hbmp);
181 
182 	/* Update the faddr's info */
183 	fp->lastactive = now;
184 	fp->hb_pending = B_TRUE;
185 
186 	BUMP_LOCAL(sctp->sctp_obchunks);
187 	BUMP_MIB(&sctp_mib, sctpTimHeartBeatProbe);
188 
189 	sctp_add_sendq(sctp, hbmp);
190 }
191 
192 /*
193  * Call right after any address change to validate peer addresses.
194  */
195 void
196 sctp_validate_peer(sctp_t *sctp)
197 {
198 	sctp_faddr_t	*fp;
199 	int		cnt;
200 	int64_t		now;
201 	int64_t		earliest_expiry;
202 
203 	now = lbolt64;
204 	earliest_expiry = 0;
205 	cnt = sctp_maxburst;
206 
207 	/*
208 	 * Loop thru the list looking for unconfirmed addresses and
209 	 * send a heartbeat.  But we should only send at most sctp_maxburst
210 	 * heartbeats.
211 	 */
212 	for (fp = sctp->sctp_faddrs; fp != NULL; fp = fp->next) {
213 		/* No need to validate unreachable address. */
214 		if (fp->state == SCTP_FADDRS_UNREACH)
215 			continue;
216 		if (fp->state == SCTP_FADDRS_UNCONFIRMED) {
217 			if (cnt-- > 0) {
218 				fp->hb_expiry = now + fp->rto;
219 				sctp_send_heartbeat(sctp, fp);
220 			} else {
221 				/*
222 				 * If we cannot send now, be more aggressive
223 				 * and try again about half of RTO.  Note that
224 				 * all the unsent probes are set to expire at
225 				 * the same time.
226 				 */
227 				fp->hb_expiry = now +
228 				    (sctp->sctp_rto_initial >> 1);
229 			}
230 		}
231 		/* Find the earliest heartbeat expiry time for ALL fps. */
232 		if (fp->hb_interval != 0 && (earliest_expiry == 0 ||
233 		    fp->hb_expiry < earliest_expiry)) {
234 			earliest_expiry = fp->hb_expiry;
235 		}
236 	}
237 	/* We use heartbeat timer for autoclose. */
238 	if (sctp->sctp_autoclose != 0) {
239 		int64_t expire;
240 
241 		expire = sctp->sctp_active + sctp->sctp_autoclose;
242 		if (earliest_expiry == 0 || expire < earliest_expiry)
243 			earliest_expiry = expire;
244 	}
245 
246 	/*
247 	 * Set the timer to fire for the earliest heartbeat unless
248 	 * heartbeat is disabled for all addresses.
249 	 */
250 	if (earliest_expiry != 0) {
251 		earliest_expiry -= now;
252 		if (earliest_expiry < 0)
253 			earliest_expiry = 1;
254 		sctp_timer(sctp, sctp->sctp_heartbeat_mp, earliest_expiry);
255 	}
256 }
257 
258 /*
259  * Process an incoming heartbeat ack.  When sending a heartbeat, we
260  * put the timestamp, a secret and the peer address the heartbeat is
261  * sent in the data part of the heartbeat.  We will extract this info
262  * and verify that this heartbeat ack is valid.
263  */
264 void
265 sctp_process_heartbeat(sctp_t *sctp, sctp_chunk_hdr_t *cp)
266 {
267 	int64_t *sentp, sent;
268 	uint64_t secret;
269 	in6_addr_t addr;
270 	sctp_faddr_t *fp;
271 	sctp_parm_hdr_t *hpp;
272 	int64_t now;
273 
274 	BUMP_LOCAL(sctp->sctp_ibchunks);
275 
276 	/* Sanity checks */
277 	ASSERT(OK_32PTR(cp));
278 	if (ntohs(cp->sch_len) < (sizeof (*cp) + sizeof (*hpp) +
279 	    sizeof (sent) + sizeof (secret) + sizeof (addr))) {
280 		/* drop it */
281 		dprint(2, ("sctp_process_heartbeat: malformed ack %p\n",
282 		    (void *)sctp));
283 		return;
284 	}
285 
286 	hpp = (sctp_parm_hdr_t *)(cp + 1);
287 	if (ntohs(hpp->sph_type) != PARM_HBINFO ||
288 	    ntohs(hpp->sph_len) != (ntohs(cp->sch_len) - sizeof (*cp))) {
289 		dprint(2,
290 		    ("sctp_process_heartbeat: malformed param in ack %p\n",
291 		    (void *)sctp));
292 		return;
293 	}
294 
295 	/*
296 	 * Pull out the time sent from the ack.
297 	 * SCTP is 32-bit aligned, so copy 64 bit quantity.  Since we
298 	 * put it in, it should be in our byte order.
299 	 */
300 	sentp = (int64_t *)(hpp + 1);
301 	bcopy(sentp, &sent, sizeof (sent));
302 
303 	/* Grab the secret to make sure that this heartbeat is valid */
304 	bcopy(++sentp, &secret, sizeof (secret));
305 
306 	/* Next, verify the address to make sure that it is the right one. */
307 	bcopy(++sentp, &addr, sizeof (addr));
308 	fp = sctp_lookup_faddr(sctp, &addr);
309 	if (fp == NULL) {
310 		dprint(2, ("sctp_process_heartbeat: invalid faddr (sctp=%p)\n",
311 		    (void *)sctp));
312 		return;
313 	}
314 	if (secret != fp->hb_secret) {
315 		dprint(2,
316 		    ("sctp_process_heartbeat: invalid secret in ack %p\n",
317 		    (void *)sctp));
318 		return;
319 	}
320 
321 	/* This address is now confirmed and alive. */
322 	sctp_faddr_alive(sctp, fp);
323 	now = lbolt64;
324 	sctp_update_rtt(sctp, fp, now - sent);
325 
326 	/*
327 	 * Note that the heartbeat timer should still be running, we don't
328 	 * reset it to avoid going through the whole list of peer addresses
329 	 * for each heartbeat ack as we probably are in interrupt context.
330 	 */
331 	fp->hb_expiry = now + SET_HB_INTVL(fp);
332 }
333