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 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26/*
27 * This is used to support the hidden __sin6_src_id in the sockaddr_in6
28 * structure which is there to ensure that applications (such as UDP apps)
29 * which get an address from recvfrom and use that address in a sendto
30 * or connect will by default use the same source address in the "response"
31 * as the destination address in the "request" they received.
32 *
33 * This is built using some new functions (in IP - doing their own locking
34 * so they can be called from the transports) to map between integer IDs
35 * and in6_addr_t.
36 * The use applies to sockaddr_in6 - whether or not mapped addresses are used.
37 *
38 * This file contains the functions used by both IP and the transports
39 * to implement __sin6_src_id.
40 * The routines do their own locking since they are called from
41 * the transports (to map between a source id and an address)
42 * and from IP proper when IP addresses are added and removed.
43 *
44 * The routines handle both IPv4 and IPv6 with the IPv4 addresses represented
45 * as IPv4-mapped addresses.
46 */
47
48#include <sys/types.h>
49#include <sys/stream.h>
50#include <sys/dlpi.h>
51#include <sys/stropts.h>
52#include <sys/sysmacros.h>
53#include <sys/strsubr.h>
54#include <sys/strlog.h>
55#define	_SUN_TPI_VERSION 2
56#include <sys/tihdr.h>
57#include <sys/xti_inet.h>
58#include <sys/ddi.h>
59#include <sys/cmn_err.h>
60#include <sys/debug.h>
61#include <sys/modctl.h>
62#include <sys/atomic.h>
63#include <sys/zone.h>
64
65#include <sys/systm.h>
66#include <sys/param.h>
67#include <sys/kmem.h>
68#include <sys/callb.h>
69#include <sys/socket.h>
70#include <sys/vtrace.h>
71#include <sys/isa_defs.h>
72#include <sys/kmem.h>
73#include <net/if.h>
74#include <net/if_arp.h>
75#include <net/route.h>
76#include <sys/sockio.h>
77#include <netinet/in.h>
78#include <net/if_dl.h>
79
80#include <inet/common.h>
81#include <inet/mi.h>
82#include <inet/mib2.h>
83#include <inet/nd.h>
84#include <inet/arp.h>
85#include <inet/snmpcom.h>
86
87#include <netinet/igmp_var.h>
88#include <netinet/ip6.h>
89#include <netinet/icmp6.h>
90
91#include <inet/ip.h>
92#include <inet/ip6.h>
93#include <inet/tcp.h>
94#include <inet/ip_multi.h>
95#include <inet/ip_if.h>
96#include <inet/ip_ire.h>
97#include <inet/ip_rts.h>
98#include <inet/optcom.h>
99#include <inet/ip_ndp.h>
100#include <netinet/igmp.h>
101#include <netinet/ip_mroute.h>
102#include <inet/ipclassifier.h>
103
104#include <sys/kmem.h>
105
106static uint_t		srcid_nextid(ip_stack_t *);
107static srcid_map_t	**srcid_lookup_addr(const in6_addr_t *addr,
108    zoneid_t zoneid, ip_stack_t *);
109static srcid_map_t	**srcid_lookup_id(uint_t id, ip_stack_t *);
110
111
112/*
113 * Insert/add a new address to the map.
114 * Returns zero if ok; otherwise errno (e.g. for memory allocation failure).
115 */
116int
117ip_srcid_insert(const in6_addr_t *addr, zoneid_t zoneid, ip_stack_t *ipst)
118{
119	srcid_map_t	**smpp;
120#ifdef DEBUG
121	char		abuf[INET6_ADDRSTRLEN];
122
123	ip1dbg(("ip_srcid_insert(%s, %d)\n",
124	    inet_ntop(AF_INET6, addr, abuf, sizeof (abuf)), zoneid));
125#endif
126
127	rw_enter(&ipst->ips_srcid_lock, RW_WRITER);
128	smpp = srcid_lookup_addr(addr, zoneid, ipst);
129	if (*smpp != NULL) {
130		/* Already present - increment refcount */
131		(*smpp)->sm_refcnt++;
132		ASSERT((*smpp)->sm_refcnt != 0);	/* wraparound */
133		rw_exit(&ipst->ips_srcid_lock);
134		return (0);
135	}
136	/* Insert new */
137	*smpp = kmem_alloc(sizeof (srcid_map_t), KM_NOSLEEP);
138	if (*smpp == NULL) {
139		rw_exit(&ipst->ips_srcid_lock);
140		return (ENOMEM);
141	}
142	(*smpp)->sm_next = NULL;
143	(*smpp)->sm_addr = *addr;
144	(*smpp)->sm_srcid = srcid_nextid(ipst);
145	(*smpp)->sm_refcnt = 1;
146	(*smpp)->sm_zoneid = zoneid;
147
148	rw_exit(&ipst->ips_srcid_lock);
149	return (0);
150}
151
152/*
153 * Remove an new address from the map.
154 * Returns zero if ok; otherwise errno (e.g. for nonexistent address).
155 */
156int
157ip_srcid_remove(const in6_addr_t *addr, zoneid_t zoneid, ip_stack_t *ipst)
158{
159	srcid_map_t	**smpp;
160	srcid_map_t	*smp;
161#ifdef DEBUG
162	char		abuf[INET6_ADDRSTRLEN];
163
164	ip1dbg(("ip_srcid_remove(%s, %d)\n",
165	    inet_ntop(AF_INET6, addr, abuf, sizeof (abuf)), zoneid));
166#endif
167
168	rw_enter(&ipst->ips_srcid_lock, RW_WRITER);
169	smpp = srcid_lookup_addr(addr, zoneid, ipst);
170	smp = *smpp;
171	if (smp == NULL) {
172		/* Not preset */
173		rw_exit(&ipst->ips_srcid_lock);
174		return (ENOENT);
175	}
176
177	/* Decrement refcount */
178	ASSERT(smp->sm_refcnt != 0);
179	smp->sm_refcnt--;
180	if (smp->sm_refcnt != 0) {
181		rw_exit(&ipst->ips_srcid_lock);
182		return (0);
183	}
184	/* Remove entry */
185	*smpp = smp->sm_next;
186	rw_exit(&ipst->ips_srcid_lock);
187	smp->sm_next = NULL;
188	kmem_free(smp, sizeof (srcid_map_t));
189	return (0);
190}
191
192/*
193 * Map from an address to a source id.
194 * If the address is unknown return the unknown id (zero).
195 */
196uint_t
197ip_srcid_find_addr(const in6_addr_t *addr, zoneid_t zoneid,
198    netstack_t *ns)
199{
200	srcid_map_t	**smpp;
201	srcid_map_t	*smp;
202	uint_t		id;
203	ip_stack_t	*ipst = ns->netstack_ip;
204
205	rw_enter(&ipst->ips_srcid_lock, RW_READER);
206	smpp = srcid_lookup_addr(addr, zoneid, ipst);
207	smp = *smpp;
208	if (smp == NULL) {
209		char		abuf[INET6_ADDRSTRLEN];
210
211		/* Not present - could be broadcast or multicast address */
212		ip1dbg(("ip_srcid_find_addr: unknown %s in zone %d\n",
213		    inet_ntop(AF_INET6, addr, abuf, sizeof (abuf)), zoneid));
214		id = 0;
215	} else {
216		ASSERT(smp->sm_refcnt != 0);
217		id = smp->sm_srcid;
218	}
219	rw_exit(&ipst->ips_srcid_lock);
220	return (id);
221}
222
223/*
224 * Map from a source id to an address.
225 * If the id is unknown return the unspecified address.
226 */
227void
228ip_srcid_find_id(uint_t id, in6_addr_t *addr, zoneid_t zoneid,
229    netstack_t *ns)
230{
231	srcid_map_t	**smpp;
232	srcid_map_t	*smp;
233	ip_stack_t	*ipst = ns->netstack_ip;
234
235	rw_enter(&ipst->ips_srcid_lock, RW_READER);
236	smpp = srcid_lookup_id(id, ipst);
237	smp = *smpp;
238	if (smp == NULL || (smp->sm_zoneid != zoneid && zoneid != ALL_ZONES)) {
239		/* Not preset */
240		ip1dbg(("ip_srcid_find_id: unknown %u or in wrong zone\n", id));
241		*addr = ipv6_all_zeros;
242	} else {
243		ASSERT(smp->sm_refcnt != 0);
244		*addr = smp->sm_addr;
245	}
246	rw_exit(&ipst->ips_srcid_lock);
247}
248
249/* Assign the next available ID */
250static uint_t
251srcid_nextid(ip_stack_t *ipst)
252{
253	uint_t id;
254	srcid_map_t	**smpp;
255
256	ASSERT(rw_owner(&ipst->ips_srcid_lock) == curthread);
257
258	if (!ipst->ips_srcid_wrapped) {
259		id = ipst->ips_ip_src_id++;
260		if (ipst->ips_ip_src_id == 0)
261			ipst->ips_srcid_wrapped = B_TRUE;
262		return (id);
263	}
264	/* Once it wraps we search for an unused ID. */
265	for (id = 0; id < 0xffffffff; id++) {
266		smpp = srcid_lookup_id(id, ipst);
267		if (*smpp == NULL)
268			return (id);
269	}
270	panic("srcid_nextid: No free identifiers!");
271	/* NOTREACHED */
272}
273
274/*
275 * Lookup based on address.
276 * Always returns a non-null pointer.
277 * If found then *ptr will be the found object.
278 * Otherwise *ptr will be NULL and can be used to insert a new object.
279 */
280static srcid_map_t **
281srcid_lookup_addr(const in6_addr_t *addr, zoneid_t zoneid, ip_stack_t *ipst)
282{
283	srcid_map_t	**smpp;
284
285	ASSERT(RW_LOCK_HELD(&ipst->ips_srcid_lock));
286	smpp = &ipst->ips_srcid_head;
287	while (*smpp != NULL) {
288		if (IN6_ARE_ADDR_EQUAL(&(*smpp)->sm_addr, addr) &&
289		    (zoneid == (*smpp)->sm_zoneid || zoneid == ALL_ZONES))
290			return (smpp);
291		smpp = &(*smpp)->sm_next;
292	}
293	return (smpp);
294}
295
296/*
297 * Lookup based on address.
298 * Always returns a non-null pointer.
299 * If found then *ptr will be the found object.
300 * Otherwise *ptr will be NULL and can be used to insert a new object.
301 */
302static srcid_map_t **
303srcid_lookup_id(uint_t id, ip_stack_t *ipst)
304{
305	srcid_map_t	**smpp;
306
307	ASSERT(RW_LOCK_HELD(&ipst->ips_srcid_lock));
308	smpp = &ipst->ips_srcid_head;
309	while (*smpp != NULL) {
310		if ((*smpp)->sm_srcid == id)
311			return (smpp);
312		smpp = &(*smpp)->sm_next;
313	}
314	return (smpp);
315}
316