xref: /titanic_41/usr/src/uts/common/inet/ip/ip_srcid.c (revision 8b2cc8ac894f2d58f38cf2fb7c3ac778f4c57c09)
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 <net/pfkeyv2.h>
105 #include <inet/ipsec_info.h>
106 #include <inet/sadb.h>
107 #include <sys/kmem.h>
108 #include <inet/ipsec_impl.h>
109 #include <inet/tun.h>
110 
111 static uint_t		srcid_nextid(ip_stack_t *);
112 static srcid_map_t	**srcid_lookup_addr(const in6_addr_t *addr,
113     zoneid_t zoneid, ip_stack_t *);
114 static srcid_map_t	**srcid_lookup_id(uint_t id, ip_stack_t *);
115 
116 
117 /*
118  * Insert/add a new address to the map.
119  * Returns zero if ok; otherwise errno (e.g. for memory allocation failure).
120  */
121 int
122 ip_srcid_insert(const in6_addr_t *addr, zoneid_t zoneid, ip_stack_t *ipst)
123 {
124 	srcid_map_t	**smpp;
125 #ifdef DEBUG
126 	char		abuf[INET6_ADDRSTRLEN];
127 
128 	ip1dbg(("ip_srcid_insert(%s, %d)\n",
129 	    inet_ntop(AF_INET6, addr, abuf, sizeof (abuf)), zoneid));
130 #endif
131 
132 	rw_enter(&ipst->ips_srcid_lock, RW_WRITER);
133 	smpp = srcid_lookup_addr(addr, zoneid, ipst);
134 	if (*smpp != NULL) {
135 		/* Already present - increment refcount */
136 		(*smpp)->sm_refcnt++;
137 		ASSERT((*smpp)->sm_refcnt != 0);	/* wraparound */
138 		rw_exit(&ipst->ips_srcid_lock);
139 		return (0);
140 	}
141 	/* Insert new */
142 	*smpp = kmem_alloc(sizeof (srcid_map_t), KM_NOSLEEP);
143 	if (*smpp == NULL) {
144 		rw_exit(&ipst->ips_srcid_lock);
145 		return (ENOMEM);
146 	}
147 	(*smpp)->sm_next = NULL;
148 	(*smpp)->sm_addr = *addr;
149 	(*smpp)->sm_srcid = srcid_nextid(ipst);
150 	(*smpp)->sm_refcnt = 1;
151 	(*smpp)->sm_zoneid = zoneid;
152 
153 	rw_exit(&ipst->ips_srcid_lock);
154 	return (0);
155 }
156 
157 /*
158  * Remove an new address from the map.
159  * Returns zero if ok; otherwise errno (e.g. for nonexistent address).
160  */
161 int
162 ip_srcid_remove(const in6_addr_t *addr, zoneid_t zoneid, ip_stack_t *ipst)
163 {
164 	srcid_map_t	**smpp;
165 	srcid_map_t	*smp;
166 #ifdef DEBUG
167 	char		abuf[INET6_ADDRSTRLEN];
168 
169 	ip1dbg(("ip_srcid_remove(%s, %d)\n",
170 	    inet_ntop(AF_INET6, addr, abuf, sizeof (abuf)), zoneid));
171 #endif
172 
173 	rw_enter(&ipst->ips_srcid_lock, RW_WRITER);
174 	smpp = srcid_lookup_addr(addr, zoneid, ipst);
175 	smp = *smpp;
176 	if (smp == NULL) {
177 		/* Not preset */
178 		rw_exit(&ipst->ips_srcid_lock);
179 		return (ENOENT);
180 	}
181 
182 	/* Decrement refcount */
183 	ASSERT(smp->sm_refcnt != 0);
184 	smp->sm_refcnt--;
185 	if (smp->sm_refcnt != 0) {
186 		rw_exit(&ipst->ips_srcid_lock);
187 		return (0);
188 	}
189 	/* Remove entry */
190 	*smpp = smp->sm_next;
191 	rw_exit(&ipst->ips_srcid_lock);
192 	smp->sm_next = NULL;
193 	kmem_free(smp, sizeof (srcid_map_t));
194 	return (0);
195 }
196 
197 /*
198  * Map from an address to a source id.
199  * If the address is unknown return the unknown id (zero).
200  */
201 uint_t
202 ip_srcid_find_addr(const in6_addr_t *addr, zoneid_t zoneid,
203     netstack_t *ns)
204 {
205 	srcid_map_t	**smpp;
206 	srcid_map_t	*smp;
207 	uint_t		id;
208 	ip_stack_t	*ipst = ns->netstack_ip;
209 
210 	rw_enter(&ipst->ips_srcid_lock, RW_READER);
211 	smpp = srcid_lookup_addr(addr, zoneid, ipst);
212 	smp = *smpp;
213 	if (smp == NULL) {
214 		char		abuf[INET6_ADDRSTRLEN];
215 
216 		/* Not present - could be broadcast or multicast address */
217 		ip1dbg(("ip_srcid_find_addr: unknown %s in zone %d\n",
218 		    inet_ntop(AF_INET6, addr, abuf, sizeof (abuf)), zoneid));
219 		id = 0;
220 	} else {
221 		ASSERT(smp->sm_refcnt != 0);
222 		id = smp->sm_srcid;
223 	}
224 	rw_exit(&ipst->ips_srcid_lock);
225 	return (id);
226 }
227 
228 /*
229  * Map from a source id to an address.
230  * If the id is unknown return the unspecified address.
231  */
232 void
233 ip_srcid_find_id(uint_t id, in6_addr_t *addr, zoneid_t zoneid,
234     netstack_t *ns)
235 {
236 	srcid_map_t	**smpp;
237 	srcid_map_t	*smp;
238 	ip_stack_t	*ipst = ns->netstack_ip;
239 
240 	rw_enter(&ipst->ips_srcid_lock, RW_READER);
241 	smpp = srcid_lookup_id(id, ipst);
242 	smp = *smpp;
243 	if (smp == NULL || smp->sm_zoneid != zoneid) {
244 		/* Not preset */
245 		ip1dbg(("ip_srcid_find_id: unknown %u or in wrong zone\n", id));
246 		*addr = ipv6_all_zeros;
247 	} else {
248 		ASSERT(smp->sm_refcnt != 0);
249 		*addr = smp->sm_addr;
250 	}
251 	rw_exit(&ipst->ips_srcid_lock);
252 }
253 
254 /* Assign the next available ID */
255 static uint_t
256 srcid_nextid(ip_stack_t *ipst)
257 {
258 	uint_t id;
259 	srcid_map_t	**smpp;
260 
261 	ASSERT(rw_owner(&ipst->ips_srcid_lock) == curthread);
262 
263 	if (!ipst->ips_srcid_wrapped) {
264 		id = ipst->ips_ip_src_id++;
265 		if (ipst->ips_ip_src_id == 0)
266 			ipst->ips_srcid_wrapped = B_TRUE;
267 		return (id);
268 	}
269 	/* Once it wraps we search for an unused ID. */
270 	for (id = 0; id < 0xffffffff; id++) {
271 		smpp = srcid_lookup_id(id, ipst);
272 		if (*smpp == NULL)
273 			return (id);
274 	}
275 	panic("srcid_nextid: No free identifiers!");
276 	/* NOTREACHED */
277 }
278 
279 /*
280  * Lookup based on address.
281  * Always returns a non-null pointer.
282  * If found then *ptr will be the found object.
283  * Otherwise *ptr will be NULL and can be used to insert a new object.
284  */
285 static srcid_map_t **
286 srcid_lookup_addr(const in6_addr_t *addr, zoneid_t zoneid, ip_stack_t *ipst)
287 {
288 	srcid_map_t	**smpp;
289 
290 	ASSERT(RW_LOCK_HELD(&ipst->ips_srcid_lock));
291 	smpp = &ipst->ips_srcid_head;
292 	while (*smpp != NULL) {
293 		if (IN6_ARE_ADDR_EQUAL(&(*smpp)->sm_addr, addr) &&
294 		    zoneid == (*smpp)->sm_zoneid)
295 			return (smpp);
296 		smpp = &(*smpp)->sm_next;
297 	}
298 	return (smpp);
299 }
300 
301 /*
302  * Lookup based on address.
303  * Always returns a non-null pointer.
304  * If found then *ptr will be the found object.
305  * Otherwise *ptr will be NULL and can be used to insert a new object.
306  */
307 static srcid_map_t **
308 srcid_lookup_id(uint_t id, ip_stack_t *ipst)
309 {
310 	srcid_map_t	**smpp;
311 
312 	ASSERT(RW_LOCK_HELD(&ipst->ips_srcid_lock));
313 	smpp = &ipst->ips_srcid_head;
314 	while (*smpp != NULL) {
315 		if ((*smpp)->sm_srcid == id)
316 			return (smpp);
317 		smpp = &(*smpp)->sm_next;
318 	}
319 	return (smpp);
320 }
321