xref: /titanic_41/usr/src/uts/common/inet/sctp/sctp_heartbeat.c (revision 96d9f183facd90dbbc2268c9a51689be0b6a0b46)
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 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <sys/types.h>
28 #include <sys/systm.h>
29 #include <sys/stream.h>
30 #include <sys/cmn_err.h>
31 #include <sys/strsubr.h>
32 
33 #include <netinet/in.h>
34 #include <netinet/ip6.h>
35 
36 #include <inet/common.h>
37 #include <inet/ip.h>
38 #include <inet/mib2.h>
39 #include <inet/ipclassifier.h>
40 #include "sctp_impl.h"
41 
42 void
43 sctp_return_heartbeat(sctp_t *sctp, sctp_chunk_hdr_t *hbcp, mblk_t *mp)
44 {
45 	mblk_t *smp;
46 	sctp_chunk_hdr_t *cp;
47 	ipha_t *iniph;
48 	ip6_t *inip6h;
49 	int isv4;
50 	in6_addr_t addr;
51 	sctp_faddr_t *fp;
52 	uint16_t len;
53 	sctp_stack_t	*sctps = sctp->sctp_sctps;
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 	/* If the source address is bogus we silently drop the packet */
68 	if (fp == NULL) {
69 		dprint(1,
70 		    ("sctp_return_heartbeat: %p bogus hb from %x:%x:%x:%x\n",
71 		    (void *)sctp, SCTP_PRINTADDR(addr)));
72 		SCTP_KSTAT(sctps, sctp_return_hb_failed);
73 		return;
74 	}
75 	dprint(3, ("sctp_return_heartbeat: %p got hb from %x:%x:%x:%x\n",
76 	    (void *)sctp, SCTP_PRINTADDR(addr)));
77 
78 	/*
79 	 * XXX It's really tempting to reuse the heartbeat mblk. But
80 	 * this complicates processing in sctp_dispatch (i.e. it will
81 	 * screw up sctp_next_chunk since we will set the chunk
82 	 * header's length into network byte-order), and if we ever
83 	 * encounter a heartbeat bundled with other chunks...
84 	 * So we take the slower-but-safe route.
85 	 */
86 	len = ntohs(hbcp->sch_len);
87 
88 	/* Create an IP header, returning to the src addr from the heartbt */
89 	smp = sctp_make_mp(sctp, fp, len);
90 	if (smp == NULL) {
91 		SCTP_KSTAT(sctps, sctp_return_hb_failed);
92 		return;
93 	}
94 
95 	cp = (sctp_chunk_hdr_t *)smp->b_wptr;
96 	cp->sch_id = CHUNK_HEARTBEAT_ACK;
97 	cp->sch_flags = 0;
98 	cp->sch_len = htons(len);
99 
100 	/* Copy the information field from the heartbeat */
101 	bcopy((void *)(hbcp + 1), (void *)(cp + 1), len - sizeof (*cp));
102 
103 	smp->b_wptr += len;
104 
105 	BUMP_LOCAL(sctp->sctp_obchunks);
106 
107 	sctp_set_iplen(sctp, smp, fp->ixa);
108 	(void) conn_ip_output(smp, fp->ixa);
109 	BUMP_LOCAL(sctp->sctp_opkts);
110 }
111 
112 /*
113  * The data section of the heartbeat contains a time field (lbolt64),
114  * a 64 bit secret, followed by the v6 (possible a v4mapped) address this
115  * heartbeat was sent to.  No byte-ordering is done, since the heartbeat
116  * is not interpreted by the peer.
117  */
118 void
119 sctp_send_heartbeat(sctp_t *sctp, sctp_faddr_t *fp)
120 {
121 	sctp_chunk_hdr_t *cp;
122 	sctp_parm_hdr_t *hpp;
123 	int64_t *t;
124 	int64_t now;
125 	in6_addr_t *a;
126 	mblk_t *hbmp;
127 	size_t hblen;
128 	sctp_stack_t	*sctps = sctp->sctp_sctps;
129 
130 	dprint(3, ("sctp_send_heartbeat: to %x:%x:%x:%x from %x:%x:%x:%x\n",
131 	    SCTP_PRINTADDR(fp->faddr), SCTP_PRINTADDR(fp->saddr)));
132 
133 	hblen = sizeof (*cp) +
134 	    sizeof (*hpp) +
135 	    sizeof (*t) +
136 	    sizeof (fp->hb_secret) +
137 	    sizeof (fp->faddr);
138 	hbmp = sctp_make_mp(sctp, fp, hblen);
139 	if (hbmp == NULL) {
140 		SCTP_KSTAT(sctps, sctp_send_hb_failed);
141 		return;
142 	}
143 
144 	cp = (sctp_chunk_hdr_t *)hbmp->b_wptr;
145 	cp->sch_id = CHUNK_HEARTBEAT;
146 	cp->sch_flags = 0;
147 	cp->sch_len = hblen;
148 	cp->sch_len = htons(cp->sch_len);
149 
150 	hpp = (sctp_parm_hdr_t *)(cp + 1);
151 	hpp->sph_type = htons(PARM_HBINFO);
152 	hpp->sph_len = hblen - sizeof (*cp);
153 	hpp->sph_len = htons(hpp->sph_len);
154 
155 	/*
156 	 * Timestamp
157 	 *
158 	 * Copy the current time to the heartbeat and we can use it to
159 	 * calculate the RTT when we get it back in the heartbeat ACK.
160 	 */
161 	now = ddi_get_lbolt64();
162 	t = (int64_t *)(hpp + 1);
163 	bcopy(&now, t, sizeof (now));
164 
165 	/*
166 	 * Secret
167 	 *
168 	 * The per peer address secret is used to make sure that the heartbeat
169 	 * ack is really in response to our heartbeat.  This prevents blind
170 	 * spoofing of heartbeat ack to fake the validity of an address.
171 	 */
172 	t++;
173 	bcopy(&fp->hb_secret, t, sizeof (uint64_t));
174 
175 	/*
176 	 * Peer address
177 	 *
178 	 * The peer address is used to associate the heartbeat ack with
179 	 * the correct peer address.  The reason is that the peer is
180 	 * multihomed so that it may not use the same address as source
181 	 * in response to our heartbeat.
182 	 */
183 	a = (in6_addr_t *)(t + 1);
184 	bcopy(&fp->faddr, a, sizeof (*a));
185 
186 	hbmp->b_wptr += hblen;
187 
188 	/* Update the faddr's info */
189 	fp->lastactive = now;
190 	fp->hb_pending = B_TRUE;
191 
192 	BUMP_LOCAL(sctp->sctp_obchunks);
193 	BUMP_MIB(&sctps->sctps_mib, sctpTimHeartBeatProbe);
194 
195 	sctp_set_iplen(sctp, hbmp, fp->ixa);
196 	(void) conn_ip_output(hbmp, fp->ixa);
197 	BUMP_LOCAL(sctp->sctp_opkts);
198 }
199 
200 /*
201  * Call right after any address change to validate peer addresses.
202  */
203 void
204 sctp_validate_peer(sctp_t *sctp)
205 {
206 	sctp_faddr_t	*fp;
207 	int		cnt;
208 	int64_t		now;
209 	int64_t		earliest_expiry;
210 	sctp_stack_t	*sctps = sctp->sctp_sctps;
211 
212 	now = ddi_get_lbolt64();
213 	earliest_expiry = 0;
214 	cnt = sctps->sctps_maxburst;
215 
216 	/*
217 	 * Loop thru the list looking for unconfirmed addresses and
218 	 * send a heartbeat.  But we should only send at most sctp_maxburst
219 	 * heartbeats.
220 	 */
221 	for (fp = sctp->sctp_faddrs; fp != NULL; fp = fp->next) {
222 		/* No need to validate unreachable address. */
223 		if (fp->state == SCTP_FADDRS_UNREACH)
224 			continue;
225 		if (fp->state == SCTP_FADDRS_UNCONFIRMED) {
226 			if (cnt-- > 0) {
227 				fp->hb_expiry = now + fp->rto;
228 				sctp_send_heartbeat(sctp, fp);
229 			} else {
230 				/*
231 				 * If we cannot send now, be more aggressive
232 				 * and try again about half of RTO.  Note that
233 				 * all the unsent probes are set to expire at
234 				 * the same time.
235 				 */
236 				fp->hb_expiry = now +
237 				    (sctp->sctp_rto_initial >> 1);
238 			}
239 		}
240 		/* Find the earliest heartbeat expiry time for ALL fps. */
241 		if (fp->hb_interval != 0 && (earliest_expiry == 0 ||
242 		    fp->hb_expiry < earliest_expiry)) {
243 			earliest_expiry = fp->hb_expiry;
244 		}
245 	}
246 	/* We use heartbeat timer for autoclose. */
247 	if (sctp->sctp_autoclose != 0) {
248 		int64_t expire;
249 
250 		expire = sctp->sctp_active + sctp->sctp_autoclose;
251 		if (earliest_expiry == 0 || expire < earliest_expiry)
252 			earliest_expiry = expire;
253 	}
254 
255 	/*
256 	 * Set the timer to fire for the earliest heartbeat unless
257 	 * heartbeat is disabled for all addresses.
258 	 */
259 	if (earliest_expiry != 0) {
260 		earliest_expiry -= now;
261 		if (earliest_expiry < 0)
262 			earliest_expiry = 1;
263 		sctp_timer(sctp, sctp->sctp_heartbeat_mp, earliest_expiry);
264 	}
265 }
266 
267 /*
268  * Process an incoming heartbeat ack.  When sending a heartbeat, we
269  * put the timestamp, a secret and the peer address the heartbeat is
270  * sent in the data part of the heartbeat.  We will extract this info
271  * and verify that this heartbeat ack is valid.
272  */
273 void
274 sctp_process_heartbeat(sctp_t *sctp, sctp_chunk_hdr_t *cp)
275 {
276 	int64_t *sentp, sent;
277 	uint64_t secret;
278 	in6_addr_t addr;
279 	sctp_faddr_t *fp;
280 	sctp_parm_hdr_t *hpp;
281 	int64_t now;
282 
283 	BUMP_LOCAL(sctp->sctp_ibchunks);
284 
285 	/* Sanity checks */
286 	ASSERT(OK_32PTR(cp));
287 	if (ntohs(cp->sch_len) < (sizeof (*cp) + sizeof (*hpp) +
288 	    sizeof (sent) + sizeof (secret) + sizeof (addr))) {
289 		/* drop it */
290 		dprint(2, ("sctp_process_heartbeat: malformed ack %p\n",
291 		    (void *)sctp));
292 		return;
293 	}
294 
295 	hpp = (sctp_parm_hdr_t *)(cp + 1);
296 	if (ntohs(hpp->sph_type) != PARM_HBINFO ||
297 	    ntohs(hpp->sph_len) != (ntohs(cp->sch_len) - sizeof (*cp))) {
298 		dprint(2,
299 		    ("sctp_process_heartbeat: malformed param in ack %p\n",
300 		    (void *)sctp));
301 		return;
302 	}
303 
304 	/*
305 	 * Pull out the time sent from the ack.
306 	 * SCTP is 32-bit aligned, so copy 64 bit quantity.  Since we
307 	 * put it in, it should be in our byte order.
308 	 */
309 	sentp = (int64_t *)(hpp + 1);
310 	bcopy(sentp, &sent, sizeof (sent));
311 
312 	/* Grab the secret to make sure that this heartbeat is valid */
313 	bcopy(++sentp, &secret, sizeof (secret));
314 
315 	/* Next, verify the address to make sure that it is the right one. */
316 	bcopy(++sentp, &addr, sizeof (addr));
317 	fp = sctp_lookup_faddr(sctp, &addr);
318 	if (fp == NULL) {
319 		dprint(2, ("sctp_process_heartbeat: invalid faddr (sctp=%p)\n",
320 		    (void *)sctp));
321 		return;
322 	}
323 	if (secret != fp->hb_secret) {
324 		dprint(2,
325 		    ("sctp_process_heartbeat: invalid secret in ack %p\n",
326 		    (void *)sctp));
327 		return;
328 	}
329 
330 	/* This address is now confirmed and alive. */
331 	sctp_faddr_alive(sctp, fp);
332 	now = ddi_get_lbolt64();
333 	sctp_update_rtt(sctp, fp, now - sent);
334 
335 	/*
336 	 * Note that the heartbeat timer should still be running, we don't
337 	 * reset it to avoid going through the whole list of peer addresses
338 	 * for each heartbeat ack as we probably are in interrupt context.
339 	 */
340 	fp->hb_expiry = now + SET_HB_INTVL(fp);
341 }
342