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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 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 	    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 		return;
86 	}
87 
88 	cp = (sctp_chunk_hdr_t *)smp->b_wptr;
89 	cp->sch_id = CHUNK_HEARTBEAT_ACK;
90 	cp->sch_flags = 0;
91 	cp->sch_len = htons(len);
92 
93 	/* Copy the information field from the heartbeat */
94 	bcopy((void *)(hbcp + 1), (void *)(cp + 1), len - sizeof (*cp));
95 
96 	smp->b_wptr += len;
97 
98 	sctp_set_iplen(sctp, smp);
99 
100 	BUMP_LOCAL(sctp->sctp_obchunks);
101 	sctp_add_sendq(sctp, smp);
102 }
103 
104 /*
105  * The data section of the heartbeat contains a time field (lbolt64),
106  * a 64 bit secret, followed by the v6 (possible a v4mapped) address this
107  * heartbeat was sent to.  No byte-ordering is done, since the heartbeat
108  * is not interpreted by the peer.
109  */
110 void
111 sctp_send_heartbeat(sctp_t *sctp, sctp_faddr_t *fp)
112 {
113 	sctp_chunk_hdr_t *cp;
114 	sctp_parm_hdr_t *hpp;
115 	int64_t *t;
116 	int64_t now;
117 	in6_addr_t *a;
118 	mblk_t *hbmp;
119 	size_t hblen;
120 
121 	dprint(3, ("sctp_send_heartbeat: to %x:%x:%x:%x from %x:%x:%x:%x\n",
122 	    SCTP_PRINTADDR(fp->faddr), SCTP_PRINTADDR(fp->saddr)));
123 
124 	hblen = sizeof (*cp) +
125 		sizeof (*hpp) +
126 		sizeof (*t) +
127 		sizeof (fp->hb_secret) +
128 		sizeof (fp->faddr);
129 	hbmp = sctp_make_mp(sctp, fp, hblen);
130 	if (hbmp == NULL)
131 		return;
132 
133 	cp = (sctp_chunk_hdr_t *)hbmp->b_wptr;
134 	cp->sch_id = CHUNK_HEARTBEAT;
135 	cp->sch_flags = 0;
136 	cp->sch_len = hblen;
137 	cp->sch_len = htons(cp->sch_len);
138 
139 	hpp = (sctp_parm_hdr_t *)(cp + 1);
140 	hpp->sph_type = htons(PARM_HBINFO);
141 	hpp->sph_len = hblen - sizeof (*cp);
142 	hpp->sph_len = htons(hpp->sph_len);
143 
144 	/*
145 	 * Timestamp
146 	 *
147 	 * Copy the current time to the heartbeat and we can use it to
148 	 * calculate the RTT when we get it back in the heartbeat ACK.
149 	 */
150 	now = lbolt64;
151 	t = (int64_t *)(hpp + 1);
152 	bcopy(&now, t, sizeof (now));
153 
154 	/*
155 	 * Secret
156 	 *
157 	 * The per peer address secret is used to make sure that the heartbeat
158 	 * ack is really in response to our heartbeat.  This prevents blind
159 	 * spoofing of heartbeat ack to fake the validity of an address.
160 	 */
161 	t++;
162 	bcopy(&fp->hb_secret, t, sizeof (uint64_t));
163 
164 	/*
165 	 * Peer address
166 	 *
167 	 * The peer address is used to associate the heartbeat ack with
168 	 * the correct peer address.  The reason is that the peer is
169 	 * multihomed so that it may not use the same address as source
170 	 * in response to our heartbeat.
171 	 */
172 	a = (in6_addr_t *)(t + 1);
173 	bcopy(&fp->faddr, a, sizeof (*a));
174 
175 	hbmp->b_wptr += hblen;
176 
177 	sctp_set_iplen(sctp, hbmp);
178 
179 	/* Update the faddr's info */
180 	fp->lastactive = now;
181 	fp->hb_pending = B_TRUE;
182 
183 	BUMP_LOCAL(sctp->sctp_obchunks);
184 	BUMP_MIB(&sctp_mib, sctpTimHeartBeatProbe);
185 
186 	sctp_add_sendq(sctp, hbmp);
187 }
188 
189 /*
190  * Call right after any address change to validate peer addresses.
191  */
192 void
193 sctp_validate_peer(sctp_t *sctp)
194 {
195 	sctp_faddr_t	*fp;
196 	int		cnt;
197 	int64_t		now;
198 	int64_t		earliest_expiry;
199 
200 	now = lbolt64;
201 	earliest_expiry = 0;
202 	cnt = sctp_maxburst;
203 
204 	/*
205 	 * Loop thru the list looking for unconfirmed addresses and
206 	 * send a heartbeat.  But we should only send at most sctp_maxburst
207 	 * heartbeats.
208 	 */
209 	for (fp = sctp->sctp_faddrs; fp != NULL; fp = fp->next) {
210 		/* No need to validate unreachable address. */
211 		if (fp->state == SCTP_FADDRS_UNREACH)
212 			continue;
213 		if (fp->state == SCTP_FADDRS_UNCONFIRMED) {
214 			if (cnt-- > 0) {
215 				fp->hb_expiry = now + fp->rto;
216 				sctp_send_heartbeat(sctp, fp);
217 			} else {
218 				/*
219 				 * If we cannot send now, be more aggressive
220 				 * and try again about half of RTO.  Note that
221 				 * all the unsent probes are set to expire at
222 				 * the same time.
223 				 */
224 				fp->hb_expiry = now +
225 				    (sctp->sctp_rto_initial >> 1);
226 			}
227 		}
228 		/* Find the earliest heartbeat expiry time for ALL fps. */
229 		if (fp->hb_interval != 0 && (earliest_expiry == 0 ||
230 		    fp->hb_expiry < earliest_expiry)) {
231 			earliest_expiry = fp->hb_expiry;
232 		}
233 	}
234 	/* We use heartbeat timer for autoclose. */
235 	if (sctp->sctp_autoclose != 0) {
236 		int64_t expire;
237 
238 		expire = sctp->sctp_active + sctp->sctp_autoclose;
239 		if (earliest_expiry == 0 || expire < earliest_expiry)
240 			earliest_expiry = expire;
241 	}
242 
243 	/*
244 	 * Set the timer to fire for the earliest heartbeat unless
245 	 * heartbeat is disabled for all addresses.
246 	 */
247 	if (earliest_expiry != 0) {
248 		earliest_expiry -= now;
249 		if (earliest_expiry < 0)
250 			earliest_expiry = 1;
251 		sctp_timer(sctp, sctp->sctp_heartbeat_mp, earliest_expiry);
252 	}
253 }
254 
255 /*
256  * Process an incoming heartbeat ack.  When sending a heartbeat, we
257  * put the timestamp, a secret and the peer address the heartbeat is
258  * sent in the data part of the heartbeat.  We will extract this info
259  * and verify that this heartbeat ack is valid.
260  */
261 void
262 sctp_process_heartbeat(sctp_t *sctp, sctp_chunk_hdr_t *cp)
263 {
264 	int64_t *sentp, sent;
265 	uint64_t secret;
266 	in6_addr_t addr;
267 	sctp_faddr_t *fp;
268 	sctp_parm_hdr_t *hpp;
269 	int64_t now;
270 
271 	BUMP_LOCAL(sctp->sctp_ibchunks);
272 
273 	/* Sanity checks */
274 	ASSERT(OK_32PTR(cp));
275 	if (ntohs(cp->sch_len) < (sizeof (*cp) + sizeof (*hpp) +
276 	    sizeof (sent) + sizeof (secret) + sizeof (addr))) {
277 		/* drop it */
278 		dprint(2, ("sctp_process_heartbeat: malformed ack %p\n",
279 		    sctp));
280 		return;
281 	}
282 
283 	hpp = (sctp_parm_hdr_t *)(cp + 1);
284 	if (ntohs(hpp->sph_type) != PARM_HBINFO ||
285 	    ntohs(hpp->sph_len) != (ntohs(cp->sch_len) - sizeof (*cp))) {
286 		dprint(2,
287 		    ("sctp_process_heartbeat: malformed param in ack %p\n",
288 		    sctp));
289 		return;
290 	}
291 
292 	/*
293 	 * Pull out the time sent from the ack.
294 	 * SCTP is 32-bit aligned, so copy 64 bit quantity.  Since we
295 	 * put it in, it should be in our byte order.
296 	 */
297 	sentp = (int64_t *)(hpp + 1);
298 	bcopy(sentp, &sent, sizeof (sent));
299 
300 	/* Grab the secret to make sure that this heartbeat is valid */
301 	bcopy(++sentp, &secret, sizeof (secret));
302 
303 	/* Next, verify the address to make sure that it is the right one. */
304 	bcopy(++sentp, &addr, sizeof (addr));
305 	fp = sctp_lookup_faddr(sctp, &addr);
306 	if (fp == NULL) {
307 		dprint(2, ("sctp_process_heartbeat: invalid faddr (sctp=%p)\n",
308 		    sctp));
309 		return;
310 	}
311 	if (secret != fp->hb_secret) {
312 		dprint(2,
313 		    ("sctp_process_heartbeat: invalid secret in ack %p\n",
314 		    sctp));
315 		return;
316 	}
317 
318 	/* This address is now confirmed and alive. */
319 	sctp_faddr_alive(sctp, fp);
320 	now = lbolt64;
321 	sctp_update_rtt(sctp, fp, now - sent);
322 
323 	/*
324 	 * Note that the heartbeat timer should still be running, we don't
325 	 * reset it to avoid going through the whole list of peer addresses
326 	 * for each heartbeat ack as we probably are in interrupt context.
327 	 */
328 	fp->hb_expiry = now + SET_HB_INTVL(fp);
329 }
330