[unix-history] / sys / netinet / igmp.c

/*
 * Copyright (c) 1988 Stephen Deering.
 * Copyright (c) 1992, 1993 Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Stephen Deering of Stanford University.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)igmp.c	7.2 (Berkeley) 10/11/92
 */

/* Internet Group Management Protocol (IGMP) routines. */

#ifdef MULTICAST

#include "param.h"
#include "mbuf.h"
#include "socket.h"
#include "protosw.h"

#include "net/if.h"
#include "net/route.h"

#include "in.h"
#include "in_var.h"
#include "in_systm.h"
#include "ip.h"
#include "ip_var.h"
#include "igmp.h"
#include "igmp_var.h"
#include "machine/cpufunc.h"

extern struct ifnet loif;

static int igmp_timers_are_running = 0;
static u_long igmp_all_hosts_group;

static void igmp_sendreport __P((struct in_multi *));

void
igmp_init()
{
	/*
	 * To avoid byte-swapping the same value over and over again.
	 */
	igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
}

void
igmp_input(m, iphlen)
	register struct mbuf *m;
	register int iphlen;
{
	register struct igmp *igmp;
	register struct ip *ip;
        register int igmplen;
	register struct ifnet *ifp = m->m_pkthdr.rcvif;
	register int minlen;
	register struct in_multi *inm;
	register struct in_ifaddr *ia;
	struct in_multistep step;

	++igmpstat.igps_rcv_total;

	ip = mtod(m, struct ip *);
	igmplen = ip->ip_len;

	/*
	 * Validate lengths
	 */
	if (igmplen < IGMP_MINLEN) {
		++igmpstat.igps_rcv_tooshort;
		m_freem(m);
		return;
	}
	minlen = iphlen + IGMP_MINLEN;
	if ((m->m_flags & M_EXT || m->m_len < minlen) &&
	    (m = m_pullup(m, minlen)) == 0) {
		++igmpstat.igps_rcv_tooshort;
		return;
	}

	/*
	 * Validate checksum
	 */
	m->m_data += iphlen;
	m->m_len -= iphlen;
	igmp = mtod(m, struct igmp *);
	if (in_cksum(m, igmplen)) {
		++igmpstat.igps_rcv_badsum;
		m_freem(m);
		return;
	}
	m->m_data -= iphlen;
	m->m_len += iphlen;
	ip = mtod(m, struct ip *);

	switch (igmp->igmp_type) {

	case IGMP_HOST_MEMBERSHIP_QUERY:
		++igmpstat.igps_rcv_queries;

		if (ifp == &loif)
			break;

		if (ip->ip_dst.s_addr != igmp_all_hosts_group) {
			++igmpstat.igps_rcv_badqueries;
			m_freem(m);
			return;
		}

		/*
		 * Start the timers in all of our membership records for
		 * the interface on which the query arrived, except those
		 * that are already running and those that belong to the
		 * "all-hosts" group.
		 */
		IN_FIRST_MULTI(step, inm);
		while (inm != NULL) {
			if (inm->inm_ifp == ifp && inm->inm_timer == 0 &&
			    inm->inm_addr.s_addr != igmp_all_hosts_group) {
				inm->inm_timer =
				    IGMP_RANDOM_DELAY(inm->inm_addr);
				igmp_timers_are_running = 1;
			}
			IN_NEXT_MULTI(step, inm);
		}

		break;

	case IGMP_HOST_MEMBERSHIP_REPORT:
		++igmpstat.igps_rcv_reports;

		if (ifp == &loif)
			break;

		if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr)) ||
		    igmp->igmp_group.s_addr != ip->ip_dst.s_addr) {
			++igmpstat.igps_rcv_badreports;
			m_freem(m);
			return;
		}

		/*
		 * KLUDGE: if the IP source address of the report has an
		 * unspecified (i.e., zero) subnet number, as is allowed for
		 * a booting host, replace it with the correct subnet number
		 * so that a process-level multicast routing demon can
		 * determine which subnet it arrived from.  This is necessary
		 * to compensate for the lack of any way for a process to
		 * determine the arrival interface of an incoming packet.
		 */
		if ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0) {
			IFP_TO_IA(ifp, ia);
			if (ia) ip->ip_src.s_addr = htonl(ia->ia_subnet);
		}

		/*
		 * If we belong to the group being reported, stop
		 * our timer for that group.
		 */
		IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
		if (inm != NULL) {
			inm->inm_timer = 0;
			++igmpstat.igps_rcv_ourreports;
		}

		break;
	}

	/*
	 * Pass all valid IGMP packets up to any process(es) listening
	 * on a raw IGMP socket.
	 */
	rip_input(m);
}

void
igmp_joingroup(inm)
	struct in_multi *inm;
{
	register int s = splnet();

	if (inm->inm_addr.s_addr == igmp_all_hosts_group ||
	    inm->inm_ifp == &loif)
		inm->inm_timer = 0;
	else {
		igmp_sendreport(inm);
		inm->inm_timer = IGMP_RANDOM_DELAY(inm->inm_addr);
		igmp_timers_are_running = 1;
	}
	splx(s);
}

void
igmp_leavegroup(inm)
	struct in_multi *inm;
{
	/*
	 * No action required on leaving a group.
	 */
}

void
igmp_fasttimo()
{
	register struct in_multi *inm;
	register int s;
	struct in_multistep step;

	/*
	 * Quick check to see if any work needs to be done, in order
	 * to minimize the overhead of fasttimo processing.
	 */
	if (!igmp_timers_are_running)
		return;

	s = splnet();
	igmp_timers_are_running = 0;
	IN_FIRST_MULTI(step, inm);
	while (inm != NULL) {
		if (inm->inm_timer == 0) {
			/* do nothing */
		} else if (--inm->inm_timer == 0) {
			igmp_sendreport(inm);
		} else {
			igmp_timers_are_running = 1;
		}
		IN_NEXT_MULTI(step, inm);
	}
	splx(s);
}

static void
igmp_sendreport(inm)
	register struct in_multi *inm;
{
	register struct mbuf *m;
	register struct igmp *igmp;
	register struct ip *ip;
	register struct ip_moptions *imo;
	struct ip_moptions simo;
	extern struct socket *ip_mrouter;

	MGETHDR(m, M_DONTWAIT, MT_HEADER);
	if (m == NULL)
		return;
	/*
	 * Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN
	 * is smaller than mbuf size returned by MGETHDR.
	 */
	m->m_data += max_linkhdr;
	m->m_len = sizeof(struct ip) + IGMP_MINLEN;
	m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;

	ip = mtod(m, struct ip *);
	ip->ip_tos = 0;
	ip->ip_len = sizeof(struct ip) + IGMP_MINLEN;
	ip->ip_off = 0;
	ip->ip_p = IPPROTO_IGMP;
	ip->ip_src.s_addr = INADDR_ANY;
	ip->ip_dst = inm->inm_addr;

	m->m_data += sizeof(struct ip);
	m->m_len -= sizeof(struct ip);
	igmp = mtod(m, struct igmp *);
	igmp->igmp_type = IGMP_HOST_MEMBERSHIP_REPORT;
	igmp->igmp_code = 0;
	igmp->igmp_group = inm->inm_addr;
	igmp->igmp_cksum = 0;
	igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN);
	m->m_data -= sizeof(struct ip);
	m->m_len += sizeof(struct ip);

	imo = &simo;
	bzero((caddr_t)imo, sizeof(*imo));
	imo->imo_multicast_ifp = inm->inm_ifp;
	imo->imo_multicast_ttl = 1;
	/*
	 * Request loopback of the report if we are acting as a multicast
	 * router, so that the process-level routing demon can hear it.
	 */
#ifdef MROUTING
	imo->imo_multicast_loop = (ip_mrouter != NULL);
#else
	imo->imo_multicast_loop = 0;
#endif

	ip_output(m, NULL, NULL, IP_MULTICASTOPTS, imo);

	++igmpstat.igps_snd_reports;
}
#endif
Commit	Line	Data
92b3ba47 JH	1	/*
	2	* Copyright (c) 1988 Stephen Deering.
	3	* Copyright (c) 1992, 1993 Regents of the University of California.
	4	* All rights reserved.
	5	*
	6	* This code is derived from software contributed to Berkeley by
	7	* Stephen Deering of Stanford University.
	8	*
	9	* Redistribution and use in source and binary forms, with or without
	10	* modification, are permitted provided that the following conditions
	11	* are met:
	12	* 1. Redistributions of source code must retain the above copyright
	13	* notice, this list of conditions and the following disclaimer.
	14	* 2. Redistributions in binary form must reproduce the above copyright
	15	* notice, this list of conditions and the following disclaimer in the
	16	* documentation and/or other materials provided with the distribution.
	17	* 3. All advertising materials mentioning features or use of this software
	18	* must display the following acknowledgement:
	19	* This product includes software developed by the University of
	20	* California, Berkeley and its contributors.
	21	* 4. Neither the name of the University nor the names of its contributors
	22	* may be used to endorse or promote products derived from this software
	23	* without specific prior written permission.
	24	*
	25	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	26	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	27	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	28	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	29	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	30	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	31	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	32	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	33	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	34	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	35	* SUCH DAMAGE.
	36	*
	37	* @(#)igmp.c 7.2 (Berkeley) 10/11/92
	38	*/
	39
	40	/* Internet Group Management Protocol (IGMP) routines. */
	41
	42	#ifdef MULTICAST
	43
6c21df3b JH	44	#include "param.h"
	45	#include "mbuf.h"
	46	#include "socket.h"
	47	#include "protosw.h"
92b3ba47	48
6c21df3b JH	49	#include "net/if.h"
6c21df3b JH	50	#include "net/route.h"
92b3ba47	51
6c21df3b JH	52	#include "in.h"
	53	#include "in_var.h"
	54	#include "in_systm.h"
	55	#include "ip.h"
	56	#include "ip_var.h"
	57	#include "igmp.h"
	58	#include "igmp_var.h"
	59	#include "machine/cpufunc.h"
92b3ba47 JH	60
	61	extern struct ifnet loif;
	62
	63	static int igmp_timers_are_running = 0;
	64	static u_long igmp_all_hosts_group;
	65
	66	static void igmp_sendreport __P((struct in_multi *));
	67
	68	void
	69	igmp_init()
	70	{
	71	/*
	72	* To avoid byte-swapping the same value over and over again.
	73	*/
	74	igmp_all_hosts_group = htonl(INADDR_ALLHOSTS_GROUP);
	75	}
	76
	77	void
	78	igmp_input(m, iphlen)
	79	register struct mbuf *m;
	80	register int iphlen;
	81	{
	82	register struct igmp *igmp;
	83	register struct ip *ip;
	84	register int igmplen;
	85	register struct ifnet *ifp = m->m_pkthdr.rcvif;
	86	register int minlen;
	87	register struct in_multi *inm;
	88	register struct in_ifaddr *ia;
	89	struct in_multistep step;
	90
	91	++igmpstat.igps_rcv_total;
	92
	93	ip = mtod(m, struct ip *);
	94	igmplen = ip->ip_len;
	95
	96	/*
	97	* Validate lengths
	98	*/
	99	if (igmplen < IGMP_MINLEN) {
	100	++igmpstat.igps_rcv_tooshort;
	101	m_freem(m);
	102	return;
	103	}
	104	minlen = iphlen + IGMP_MINLEN;
	105	if ((m->m_flags & M_EXT \|\| m->m_len < minlen) &&
	106	(m = m_pullup(m, minlen)) == 0) {
	107	++igmpstat.igps_rcv_tooshort;
	108	return;
	109	}
	110
	111	/*
	112	* Validate checksum
	113	*/
	114	m->m_data += iphlen;
	115	m->m_len -= iphlen;
	116	igmp = mtod(m, struct igmp *);
	117	if (in_cksum(m, igmplen)) {
	118	++igmpstat.igps_rcv_badsum;
	119	m_freem(m);
	120	return;
	121	}
	122	m->m_data -= iphlen;
	123	m->m_len += iphlen;
124	ip = mtod(m, struct ip *);
125
126	switch (igmp->igmp_type) {
127
128	case IGMP_HOST_MEMBERSHIP_QUERY:
129	++igmpstat.igps_rcv_queries;
130
131	if (ifp == &loif)
132	break;
133
134	if (ip->ip_dst.s_addr != igmp_all_hosts_group) {
135	++igmpstat.igps_rcv_badqueries;
136	m_freem(m);
137	return;
138	}
139
140	/*
141	* Start the timers in all of our membership records for
142	* the interface on which the query arrived, except those
143	* that are already running and those that belong to the
144	* "all-hosts" group.
145	*/
146	IN_FIRST_MULTI(step, inm);
147	while (inm != NULL) {
148	if (inm->inm_ifp == ifp && inm->inm_timer == 0 &&
149	inm->inm_addr.s_addr != igmp_all_hosts_group) {
150	inm->inm_timer =
151	IGMP_RANDOM_DELAY(inm->inm_addr);
152	igmp_timers_are_running = 1;
153	}
154	IN_NEXT_MULTI(step, inm);
155	}
156
157	break;
158
159	case IGMP_HOST_MEMBERSHIP_REPORT:
160	++igmpstat.igps_rcv_reports;
161
162	if (ifp == &loif)
163	break;
164
165	if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr)) \|\|
166	igmp->igmp_group.s_addr != ip->ip_dst.s_addr) {
167	++igmpstat.igps_rcv_badreports;
168	m_freem(m);
169	return;
170	}
171
172	/*
173	* KLUDGE: if the IP source address of the report has an
174	* unspecified (i.e., zero) subnet number, as is allowed for
175	* a booting host, replace it with the correct subnet number
176	* so that a process-level multicast routing demon can
177	* determine which subnet it arrived from. This is necessary
178	* to compensate for the lack of any way for a process to
179	* determine the arrival interface of an incoming packet.
180	*/
181	if ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) == 0) {
182	IFP_TO_IA(ifp, ia);
183	if (ia) ip->ip_src.s_addr = htonl(ia->ia_subnet);
184	}
185
186	/*
187	* If we belong to the group being reported, stop
188	* our timer for that group.
189	*/
190	IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
191	if (inm != NULL) {
192	inm->inm_timer = 0;
193	++igmpstat.igps_rcv_ourreports;
194	}
195
196	break;
197	}
198
199	/*
200	* Pass all valid IGMP packets up to any process(es) listening
201	* on a raw IGMP socket.
202	*/
203	rip_input(m);
204	}
205
206	void
207	igmp_joingroup(inm)
208	struct in_multi *inm;
209	{
210	register int s = splnet();
211
212	if (inm->inm_addr.s_addr == igmp_all_hosts_group \|\|
213	inm->inm_ifp == &loif)
214	inm->inm_timer = 0;
215	else {
216	igmp_sendreport(inm);
217	inm->inm_timer = IGMP_RANDOM_DELAY(inm->inm_addr);
218	igmp_timers_are_running = 1;
219	}
220	splx(s);
221	}
222
223	void
224	igmp_leavegroup(inm)
225	struct in_multi *inm;
226	{
227	/*
228	* No action required on leaving a group.
229	*/
230	}
231
232	void
233	igmp_fasttimo()
234	{
235	register struct in_multi *inm;
236	register int s;
237	struct in_multistep step;
238
239	/*
240	* Quick check to see if any work needs to be done, in order
241	* to minimize the overhead of fasttimo processing.
242	*/
243	if (!igmp_timers_are_running)
244	return;
245
246	s = splnet();
247	igmp_timers_are_running = 0;
248	IN_FIRST_MULTI(step, inm);
249	while (inm != NULL) {
250	if (inm->inm_timer == 0) {
251	/* do nothing */
252	} else if (--inm->inm_timer == 0) {
253	igmp_sendreport(inm);
254	} else {
255	igmp_timers_are_running = 1;
256	}
257	IN_NEXT_MULTI(step, inm);
258	}
259	splx(s);
260	}
261
262	static void
263	igmp_sendreport(inm)
264	register struct in_multi *inm;
265	{
266	register struct mbuf *m;
267	register struct igmp *igmp;
268	register struct ip *ip;
269	register struct ip_moptions *imo;
270	struct ip_moptions simo;
271	extern struct socket *ip_mrouter;
272
273	MGETHDR(m, M_DONTWAIT, MT_HEADER);
274	if (m == NULL)
275	return;
276	/*
277	* Assume max_linkhdr + sizeof(struct ip) + IGMP_MINLEN
278	* is smaller than mbuf size returned by MGETHDR.
279	*/
280	m->m_data += max_linkhdr;
281	m->m_len = sizeof(struct ip) + IGMP_MINLEN;
282	m->m_pkthdr.len = sizeof(struct ip) + IGMP_MINLEN;
283
284	ip = mtod(m, struct ip *);
285	ip->ip_tos = 0;
286	ip->ip_len = sizeof(struct ip) + IGMP_MINLEN;
287	ip->ip_off = 0;
288	ip->ip_p = IPPROTO_IGMP;
289	ip->ip_src.s_addr = INADDR_ANY;
290	ip->ip_dst = inm->inm_addr;
291
292	m->m_data += sizeof(struct ip);
293	m->m_len -= sizeof(struct ip);
294	igmp = mtod(m, struct igmp *);
295	igmp->igmp_type = IGMP_HOST_MEMBERSHIP_REPORT;
296	igmp->igmp_code = 0;
297	igmp->igmp_group = inm->inm_addr;
298	igmp->igmp_cksum = 0;
299	igmp->igmp_cksum = in_cksum(m, IGMP_MINLEN);
300	m->m_data -= sizeof(struct ip);
301	m->m_len += sizeof(struct ip);
302
303	imo = &simo;
304	bzero((caddr_t)imo, sizeof(*imo));
305	imo->imo_multicast_ifp = inm->inm_ifp;
306	imo->imo_multicast_ttl = 1;
307	/*
308	* Request loopback of the report if we are acting as a multicast
309	* router, so that the process-level routing demon can hear it.
310	*/
311	#ifdef MROUTING
312	imo->imo_multicast_loop = (ip_mrouter != NULL);
313	#else
314	imo->imo_multicast_loop = 0;
315	#endif
316
317	ip_output(m, NULL, NULL, IP_MULTICASTOPTS, imo);
318
319	++igmpstat.igps_snd_reports;
320	}
321	#endif