xref: /titanic_41/usr/src/uts/common/inet/sctp/sctp_heartbeat.c (revision 6a634c9dca3093f3922e4b7ab826d7bdf17bf78e)
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 
41 void
sctp_return_heartbeat(sctp_t * sctp,sctp_chunk_hdr_t * hbcp,mblk_t * mp)42 sctp_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  */
117 void
sctp_send_heartbeat(sctp_t * sctp,sctp_faddr_t * fp)118 sctp_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  */
202 void
sctp_validate_peer(sctp_t * sctp)203 sctp_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  */
272 void
sctp_process_heartbeat(sctp_t * sctp,sctp_chunk_hdr_t * cp)273 sctp_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