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1.1 root 1: /*
2: * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * Portions Copyright (c) 1999 Apple Computer, Inc. All Rights
7: * Reserved. This file contains Original Code and/or Modifications of
8: * Original Code as defined in and that are subject to the Apple Public
9: * Source License Version 1.1 (the "License"). You may not use this file
10: * except in compliance with the License. Please obtain a copy of the
11: * License at http://www.apple.com/publicsource and read it before using
12: * this file.
13: *
14: * The Original Code and all software distributed under the License are
15: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
16: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
17: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
18: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
19: * License for the specific language governing rights and limitations
20: * under the License.
21: *
22: * @APPLE_LICENSE_HEADER_END@
23: */
24:
25: /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
26: /*
27: * Copyright (c) 1988 Stephen Deering.
28: * Copyright (c) 1992, 1993
29: * The Regents of the University of California. All rights reserved.
30: *
31: * This code is derived from software contributed to Berkeley by
32: * Stephen Deering of Stanford University.
33: *
34: * Redistribution and use in source and binary forms, with or without
35: * modification, are permitted provided that the following conditions
36: * are met:
37: * 1. Redistributions of source code must retain the above copyright
38: * notice, this list of conditions and the following disclaimer.
39: * 2. Redistributions in binary form must reproduce the above copyright
40: * notice, this list of conditions and the following disclaimer in the
41: * documentation and/or other materials provided with the distribution.
42: * 3. All advertising materials mentioning features or use of this software
43: * must display the following acknowledgement:
44: * This product includes software developed by the University of
45: * California, Berkeley and its contributors.
46: * 4. Neither the name of the University nor the names of its contributors
47: * may be used to endorse or promote products derived from this software
48: * without specific prior written permission.
49: *
50: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60: * SUCH DAMAGE.
61: *
62: * @(#)igmp.c 8.2 (Berkeley) 5/3/95
63: */
64:
65: /* Internet Group Management Protocol (IGMP) routines. */
66:
67:
68: #include <sys/param.h>
69: #include <sys/mbuf.h>
70: #include <sys/socket.h>
71: #include <sys/protosw.h>
72:
73: #include <kernserv/machine/spl.h>
74:
75: #include <net/if.h>
76: #include <net/route.h>
77:
78: #include <netinet/in.h>
79: #include <netinet/in_var.h>
80: #include <netinet/in_systm.h>
81: #include <netinet/ip.h>
82: #include <netinet/ip_var.h>
83: #include <netinet/igmp.h>
84: #include <netinet/igmp_var.h>
85:
86: extern struct ifnet loif;
87:
88: struct igmpstat igmpstat;
89:
90: static int igmp_timers_are_running = 0;
91: static u_long igmp_all_hosts_group;
92:
93: static void igmp_sendreport __P((struct in_multi *));
94:
95: void
96: igmp_init()
97: {
98: /*
99: * To avoid byte-swapping the same value over and over again.
100: */
101: igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
102: }
103:
104: void
105: igmp_input(m, iphlen)
106: register struct mbuf *m;
107: register int iphlen;
108: {
109: register struct igmp *igmp;
110: register struct ip *ip;
111: register int igmplen;
112: register struct ifnet *ifp = m->m_pkthdr.rcvif;
113: register int minlen;
114: register struct in_multi *inm;
115: register struct in_ifaddr *ia;
116: struct in_multistep step;
117:
118: ++igmpstat.igps_rcv_total;
119:
120: ip = mtod(m, struct ip *);
121: igmplen = ip->ip_len;
122:
123: /*
124: * Validate lengths
125: */
126: if (igmplen < IGMP_MINLEN) {
127: ++igmpstat.igps_rcv_tooshort;
128: m_freem(m);
129: return;
130: }
131: minlen = iphlen + IGMP_MINLEN;
132: if ((m->m_flags & M_EXT || m->m_len < minlen) &&
133: (m = m_pullup(m, minlen)) == 0) {
134: ++igmpstat.igps_rcv_tooshort;
135: return;
136: }
137:
138: /*
139: * Validate checksum
140: */
141: m->m_data += iphlen;
142: m->m_len -= iphlen;
143: igmp = mtod(m, struct igmp *);
144: if (in_cksum(m, igmplen)) {
145: ++igmpstat.igps_rcv_badsum;
146: m_freem(m);
147: return;
148: }
149: m->m_data -= iphlen;
150: m->m_len += iphlen;
151: ip = mtod(m, struct ip *);
152:
153: switch (igmp->igmp_type) {
154:
155: case IGMP_HOST_MEMBERSHIP_QUERY:
156: ++igmpstat.igps_rcv_queries;
157:
158: if (ifp == &loif)
159: break;
160:
161: if (ip->ip_dst.s_addr != igmp_all_hosts_group) {
162: ++igmpstat.igps_rcv_badqueries;
163: m_freem(m);
164: return;
165: }
166:
167: /*
168: * Start the timers in all of our membership records for
169: * the interface on which the query arrived, except those
170: * that are already running and those that belong to the
171: * "all-hosts" group.
172: */
173: IN_FIRST_MULTI(step, inm);
174: while (inm != NULL) {
175: if (inm->inm_ifp == ifp && inm->inm_timer == 0 &&
176: inm->inm_addr.s_addr != igmp_all_hosts_group) {
177: inm->inm_timer =
178: IGMP_RANDOM_DELAY(inm->inm_addr);
179: igmp_timers_are_running = 1;
180: }
181: IN_NEXT_MULTI(step, inm);
182: }
183:
184: break;
185:
186: case IGMP_HOST_MEMBERSHIP_REPORT:
187: ++igmpstat.igps_rcv_reports;
188:
189: if (ifp == &loif)
190: break;
191:
192: if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr)) ||
193: igmp->igmp_group.s_addr != ip->ip_dst.s_addr) {
194: ++igmpstat.igps_rcv_badreports;
195: m_freem(m);
196: return;
197: }
198:
199: /*
200: * KLUDGE: if the IP source address of the report has an
201: * unspecified (i.e., zero) subnet number, as is allowed for
202: * a booting host, replace it with the correct subnet number
203: * so that a process-level multicast routing demon can
204: * determine which subnet it arrived from. This is necessary
205: * to compensate for the lack of any way for a process to
206: * determine the arrival interface of an incoming packet.
207: */
208: if ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0) {
209: IFP_TO_IA(ifp, ia);
210: if (ia) ip->ip_src.s_addr = htonl(ia->ia_subnet);
211: }
212:
213: /*
214: * If we belong to the group being reported, stop
215: * our timer for that group.
216: */
217: IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
218: if (inm != NULL) {
219: inm->inm_timer = 0;
220: ++igmpstat.igps_rcv_ourreports;
221: }
222:
223: break;
224: }
225:
226: /*
227: * Pass all valid IGMP packets up to any process(es) listening
228: * on a raw IGMP socket.
229: */
230: rip_input(m);
231: }
232:
233: void
234: igmp_joingroup(inm)
235: struct in_multi *inm;
236: {
237: register int s = splnet();
238:
239: if (inm->inm_addr.s_addr == igmp_all_hosts_group ||
240: inm->inm_ifp == &loif)
241: inm->inm_timer = 0;
242: else {
243: igmp_sendreport(inm);
244: inm->inm_timer = IGMP_RANDOM_DELAY(inm->inm_addr);
245: igmp_timers_are_running = 1;
246: }
247: splx(s);
248: }
249:
250: void
251: igmp_leavegroup(inm)
252: struct in_multi *inm;
253: {
254: /*
255: * No action required on leaving a group.
256: */
257: }
258:
259: void
260: igmp_fasttimo()
261: {
262: register struct in_multi *inm;
263: register int s;
264: struct in_multistep step;
265:
266: /*
267: * Quick check to see if any work needs to be done, in order
268: * to minimize the overhead of fasttimo processing.
269: */
270: if (!igmp_timers_are_running)
271: return;
272:
273: s = splnet();
274: igmp_timers_are_running = 0;
275: IN_FIRST_MULTI(step, inm);
276: while (inm != NULL) {
277: if (inm->inm_timer == 0) {
278: /* do nothing */
279: } else if (--inm->inm_timer == 0) {
280: igmp_sendreport(inm);
281: } else {
282: igmp_timers_are_running = 1;
283: }
284: IN_NEXT_MULTI(step, inm);
285: }
286: splx(s);
287: }
288:
289: static void
290: igmp_sendreport(inm)
291: register struct in_multi *inm;
292: {
293: register struct mbuf *m;
294: register struct igmp *igmp;
295: register struct ip *ip;
296: register struct ip_moptions *imo;
297: struct ip_moptions simo;
298:
299: MGETHDR(m, M_DONTWAIT, MT_HEADER);
300: if (m == NULL)
301: return;
302: /*
303: * Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN
304: * is smaller than mbuf size returned by MGETHDR.
305: */
306: m->m_data += max_linkhdr;
307: m->m_len = sizeof(struct ip) + IGMP_MINLEN;
308: m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;
309:
310: ip = mtod(m, struct ip *);
311: ip->ip_tos = 0;
312: ip->ip_len = sizeof(struct ip) + IGMP_MINLEN;
313: ip->ip_off = 0;
314: ip->ip_p = IPPROTO_IGMP;
315: ip->ip_src.s_addr = INADDR_ANY;
316: ip->ip_dst = inm->inm_addr;
317:
318: m->m_data += sizeof(struct ip);
319: m->m_len -= sizeof(struct ip);
320: igmp = mtod(m, struct igmp *);
321: igmp->igmp_type = IGMP_HOST_MEMBERSHIP_REPORT;
322: igmp->igmp_code = 0;
323: igmp->igmp_group = inm->inm_addr;
324: igmp->igmp_cksum = 0;
325: igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN);
326: m->m_data -= sizeof(struct ip);
327: m->m_len += sizeof(struct ip);
328:
329: imo = &simo;
330: bzero((caddr_t)imo, sizeof(*imo));
331: imo->imo_multicast_ifp = inm->inm_ifp;
332: imo->imo_multicast_ttl = 1;
333: /*
334: * Request loopback of the report if we are acting as a multicast
335: * router, so that the process-level routing demon can hear it.
336: */
337: #if MROUTING
338: {
339: extern struct socket *ip_mrouter;
340: imo->imo_multicast_loop = (ip_mrouter != NULL);
341: }
342: #endif
343: ip_output(m, NULL, NULL, 0, imo);
344:
345: ++igmpstat.igps_snd_reports;
346: }
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