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in_mcast.c
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in_mcast.c
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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2007-2009 Bruce Simpson.
* Copyright (c) 2005 Robert N. M. Watson.
* All rights reserved.
*
* 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. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
/*
* IPv4 multicast socket, group, and socket option processing module.
*/
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
#include <sys/sysctl.h>
#include <sys/ktr.h>
#include <sys/taskqueue.h>
#include <sys/tree.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/route/nhop.h>
#include <net/vnet.h>
#include <net/ethernet.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_fib.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <net/if_private.h>
#include <netinet/ip_var.h>
#include <netinet/igmp_var.h>
#ifndef KTR_IGMPV3
#define KTR_IGMPV3 KTR_INET
#endif
#ifndef __SOCKUNION_DECLARED
union sockunion {
struct sockaddr_storage ss;
struct sockaddr sa;
struct sockaddr_dl sdl;
struct sockaddr_in sin;
};
typedef union sockunion sockunion_t;
#define __SOCKUNION_DECLARED
#endif /* __SOCKUNION_DECLARED */
static MALLOC_DEFINE(M_INMFILTER, "in_mfilter",
"IPv4 multicast PCB-layer source filter");
static MALLOC_DEFINE(M_IPMADDR, "in_multi", "IPv4 multicast group");
static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "IPv4 multicast options");
static MALLOC_DEFINE(M_IPMSOURCE, "ip_msource",
"IPv4 multicast IGMP-layer source filter");
/*
* Locking:
*
* - Lock order is: IN_MULTI_LOCK, INP_WLOCK, IN_MULTI_LIST_LOCK, IGMP_LOCK,
* IF_ADDR_LOCK.
* - The IF_ADDR_LOCK is implicitly taken by inm_lookup() earlier, however
* it can be taken by code in net/if.c also.
* - ip_moptions and in_mfilter are covered by the INP_WLOCK.
*
* struct in_multi is covered by IN_MULTI_LIST_LOCK. There isn't strictly
* any need for in_multi itself to be virtualized -- it is bound to an ifp
* anyway no matter what happens.
*/
struct mtx in_multi_list_mtx;
MTX_SYSINIT(in_multi_mtx, &in_multi_list_mtx, "in_multi_list_mtx", MTX_DEF);
struct mtx in_multi_free_mtx;
MTX_SYSINIT(in_multi_free_mtx, &in_multi_free_mtx, "in_multi_free_mtx", MTX_DEF);
struct sx in_multi_sx;
SX_SYSINIT(in_multi_sx, &in_multi_sx, "in_multi_sx");
/*
* Functions with non-static linkage defined in this file should be
* declared in in_var.h:
* imo_multi_filter()
* in_joingroup()
* in_joingroup_locked()
* in_leavegroup()
* in_leavegroup_locked()
* and ip_var.h:
* inp_freemoptions()
* inp_getmoptions()
* inp_setmoptions()
*/
static void imf_commit(struct in_mfilter *);
static int imf_get_source(struct in_mfilter *imf,
const struct sockaddr_in *psin,
struct in_msource **);
static struct in_msource *
imf_graft(struct in_mfilter *, const uint8_t,
const struct sockaddr_in *);
static void imf_leave(struct in_mfilter *);
static int imf_prune(struct in_mfilter *, const struct sockaddr_in *);
static void imf_purge(struct in_mfilter *);
static void imf_rollback(struct in_mfilter *);
static void imf_reap(struct in_mfilter *);
static struct in_mfilter *
imo_match_group(const struct ip_moptions *,
const struct ifnet *, const struct sockaddr *);
static struct in_msource *
imo_match_source(struct in_mfilter *, const struct sockaddr *);
static void ims_merge(struct ip_msource *ims,
const struct in_msource *lims, const int rollback);
static int in_getmulti(struct ifnet *, const struct in_addr *,
struct in_multi **);
static int inm_get_source(struct in_multi *inm, const in_addr_t haddr,
const int noalloc, struct ip_msource **pims);
#ifdef KTR
static int inm_is_ifp_detached(const struct in_multi *);
#endif
static int inm_merge(struct in_multi *, /*const*/ struct in_mfilter *);
static void inm_purge(struct in_multi *);
static void inm_reap(struct in_multi *);
static void inm_release(struct in_multi *);
static struct ip_moptions *
inp_findmoptions(struct inpcb *);
static int inp_get_source_filters(struct inpcb *, struct sockopt *);
static int inp_join_group(struct inpcb *, struct sockopt *);
static int inp_leave_group(struct inpcb *, struct sockopt *);
static struct ifnet *
inp_lookup_mcast_ifp(const struct inpcb *,
const struct sockaddr_in *, const struct in_addr);
static int inp_block_unblock_source(struct inpcb *, struct sockopt *);
static int inp_set_multicast_if(struct inpcb *, struct sockopt *);
static int inp_set_source_filters(struct inpcb *, struct sockopt *);
static int sysctl_ip_mcast_filters(SYSCTL_HANDLER_ARGS);
static SYSCTL_NODE(_net_inet_ip, OID_AUTO, mcast,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"IPv4 multicast");
static u_long in_mcast_maxgrpsrc = IP_MAX_GROUP_SRC_FILTER;
SYSCTL_ULONG(_net_inet_ip_mcast, OID_AUTO, maxgrpsrc,
CTLFLAG_RWTUN, &in_mcast_maxgrpsrc, 0,
"Max source filters per group");
static u_long in_mcast_maxsocksrc = IP_MAX_SOCK_SRC_FILTER;
SYSCTL_ULONG(_net_inet_ip_mcast, OID_AUTO, maxsocksrc,
CTLFLAG_RWTUN, &in_mcast_maxsocksrc, 0,
"Max source filters per socket");
int in_mcast_loop = IP_DEFAULT_MULTICAST_LOOP;
SYSCTL_INT(_net_inet_ip_mcast, OID_AUTO, loop, CTLFLAG_RWTUN,
&in_mcast_loop, 0, "Loopback multicast datagrams by default");
static SYSCTL_NODE(_net_inet_ip_mcast, OID_AUTO, filters,
CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_ip_mcast_filters,
"Per-interface stack-wide source filters");
#ifdef KTR
/*
* Inline function which wraps assertions for a valid ifp.
* The ifnet layer will set the ifma's ifp pointer to NULL if the ifp
* is detached.
*/
static int __inline
inm_is_ifp_detached(const struct in_multi *inm)
{
struct ifnet *ifp;
KASSERT(inm->inm_ifma != NULL, ("%s: no ifma", __func__));
ifp = inm->inm_ifma->ifma_ifp;
if (ifp != NULL) {
/*
* Sanity check that netinet's notion of ifp is the
* same as net's.
*/
KASSERT(inm->inm_ifp == ifp, ("%s: bad ifp", __func__));
}
return (ifp == NULL);
}
#endif
/*
* Interface detach can happen in a taskqueue thread context, so we must use a
* dedicated thread to avoid deadlocks when draining inm_release tasks.
*/
TASKQUEUE_DEFINE_THREAD(inm_free);
static struct in_multi_head inm_free_list = SLIST_HEAD_INITIALIZER();
static void inm_release_task(void *arg __unused, int pending __unused);
static struct task inm_free_task = TASK_INITIALIZER(0, inm_release_task, NULL);
void
inm_release_wait(void *arg __unused)
{
/*
* Make sure all pending multicast addresses are freed before
* the VNET or network device is destroyed:
*/
taskqueue_drain(taskqueue_inm_free, &inm_free_task);
}
#ifdef VIMAGE
/* XXX-BZ FIXME, see D24914. */
VNET_SYSUNINIT(inm_release_wait, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST, inm_release_wait, NULL);
#endif
void
inm_release_list_deferred(struct in_multi_head *inmh)
{
if (SLIST_EMPTY(inmh))
return;
mtx_lock(&in_multi_free_mtx);
SLIST_CONCAT(&inm_free_list, inmh, in_multi, inm_nrele);
mtx_unlock(&in_multi_free_mtx);
taskqueue_enqueue(taskqueue_inm_free, &inm_free_task);
}
void
inm_disconnect(struct in_multi *inm)
{
struct ifnet *ifp;
struct ifmultiaddr *ifma, *ll_ifma;
ifp = inm->inm_ifp;
IF_ADDR_WLOCK_ASSERT(ifp);
ifma = inm->inm_ifma;
if_ref(ifp);
if (ifma->ifma_flags & IFMA_F_ENQUEUED) {
CK_STAILQ_REMOVE(&ifp->if_multiaddrs, ifma, ifmultiaddr, ifma_link);
ifma->ifma_flags &= ~IFMA_F_ENQUEUED;
}
MCDPRINTF("removed ifma: %p from %s\n", ifma, ifp->if_xname);
if ((ll_ifma = ifma->ifma_llifma) != NULL) {
MPASS(ifma != ll_ifma);
ifma->ifma_llifma = NULL;
MPASS(ll_ifma->ifma_llifma == NULL);
MPASS(ll_ifma->ifma_ifp == ifp);
if (--ll_ifma->ifma_refcount == 0) {
if (ll_ifma->ifma_flags & IFMA_F_ENQUEUED) {
CK_STAILQ_REMOVE(&ifp->if_multiaddrs, ll_ifma, ifmultiaddr, ifma_link);
ll_ifma->ifma_flags &= ~IFMA_F_ENQUEUED;
}
MCDPRINTF("removed ll_ifma: %p from %s\n", ll_ifma, ifp->if_xname);
if_freemulti(ll_ifma);
}
}
}
void
inm_release_deferred(struct in_multi *inm)
{
struct in_multi_head tmp;
IN_MULTI_LIST_LOCK_ASSERT();
MPASS(inm->inm_refcount > 0);
if (--inm->inm_refcount == 0) {
SLIST_INIT(&tmp);
inm_disconnect(inm);
inm->inm_ifma->ifma_protospec = NULL;
SLIST_INSERT_HEAD(&tmp, inm, inm_nrele);
inm_release_list_deferred(&tmp);
}
}
static void
inm_release_task(void *arg __unused, int pending __unused)
{
struct in_multi_head inm_free_tmp;
struct in_multi *inm, *tinm;
SLIST_INIT(&inm_free_tmp);
mtx_lock(&in_multi_free_mtx);
SLIST_CONCAT(&inm_free_tmp, &inm_free_list, in_multi, inm_nrele);
mtx_unlock(&in_multi_free_mtx);
IN_MULTI_LOCK();
SLIST_FOREACH_SAFE(inm, &inm_free_tmp, inm_nrele, tinm) {
SLIST_REMOVE_HEAD(&inm_free_tmp, inm_nrele);
MPASS(inm);
inm_release(inm);
}
IN_MULTI_UNLOCK();
}
/*
* Initialize an in_mfilter structure to a known state at t0, t1
* with an empty source filter list.
*/
static __inline void
imf_init(struct in_mfilter *imf, const int st0, const int st1)
{
memset(imf, 0, sizeof(struct in_mfilter));
RB_INIT(&imf->imf_sources);
imf->imf_st[0] = st0;
imf->imf_st[1] = st1;
}
struct in_mfilter *
ip_mfilter_alloc(const int mflags, const int st0, const int st1)
{
struct in_mfilter *imf;
imf = malloc(sizeof(*imf), M_INMFILTER, mflags);
if (imf != NULL)
imf_init(imf, st0, st1);
return (imf);
}
void
ip_mfilter_free(struct in_mfilter *imf)
{
imf_purge(imf);
free(imf, M_INMFILTER);
}
/*
* Function for looking up an in_multi record for an IPv4 multicast address
* on a given interface. ifp must be valid. If no record found, return NULL.
* The IN_MULTI_LIST_LOCK and IF_ADDR_LOCK on ifp must be held.
*/
struct in_multi *
inm_lookup_locked(struct ifnet *ifp, const struct in_addr ina)
{
struct ifmultiaddr *ifma;
struct in_multi *inm;
IN_MULTI_LIST_LOCK_ASSERT();
IF_ADDR_LOCK_ASSERT(ifp);
CK_STAILQ_FOREACH(ifma, &((ifp)->if_multiaddrs), ifma_link) {
inm = inm_ifmultiaddr_get_inm(ifma);
if (inm == NULL)
continue;
if (inm->inm_addr.s_addr == ina.s_addr)
return (inm);
}
return (NULL);
}
/*
* Wrapper for inm_lookup_locked().
* The IF_ADDR_LOCK will be taken on ifp and released on return.
*/
struct in_multi *
inm_lookup(struct ifnet *ifp, const struct in_addr ina)
{
struct epoch_tracker et;
struct in_multi *inm;
IN_MULTI_LIST_LOCK_ASSERT();
NET_EPOCH_ENTER(et);
inm = inm_lookup_locked(ifp, ina);
NET_EPOCH_EXIT(et);
return (inm);
}
/*
* Find an IPv4 multicast group entry for this ip_moptions instance
* which matches the specified group, and optionally an interface.
* Return its index into the array, or -1 if not found.
*/
static struct in_mfilter *
imo_match_group(const struct ip_moptions *imo, const struct ifnet *ifp,
const struct sockaddr *group)
{
const struct sockaddr_in *gsin;
struct in_mfilter *imf;
struct in_multi *inm;
gsin = (const struct sockaddr_in *)group;
IP_MFILTER_FOREACH(imf, &imo->imo_head) {
inm = imf->imf_inm;
if (inm == NULL)
continue;
if ((ifp == NULL || (inm->inm_ifp == ifp)) &&
in_hosteq(inm->inm_addr, gsin->sin_addr)) {
break;
}
}
return (imf);
}
/*
* Find an IPv4 multicast source entry for this imo which matches
* the given group index for this socket, and source address.
*
* NOTE: This does not check if the entry is in-mode, merely if
* it exists, which may not be the desired behaviour.
*/
static struct in_msource *
imo_match_source(struct in_mfilter *imf, const struct sockaddr *src)
{
struct ip_msource find;
struct ip_msource *ims;
const sockunion_t *psa;
KASSERT(src->sa_family == AF_INET, ("%s: !AF_INET", __func__));
/* Source trees are keyed in host byte order. */
psa = (const sockunion_t *)src;
find.ims_haddr = ntohl(psa->sin.sin_addr.s_addr);
ims = RB_FIND(ip_msource_tree, &imf->imf_sources, &find);
return ((struct in_msource *)ims);
}
/*
* Perform filtering for multicast datagrams on a socket by group and source.
*
* Returns 0 if a datagram should be allowed through, or various error codes
* if the socket was not a member of the group, or the source was muted, etc.
*/
int
imo_multi_filter(const struct ip_moptions *imo, const struct ifnet *ifp,
const struct sockaddr *group, const struct sockaddr *src)
{
struct in_mfilter *imf;
struct in_msource *ims;
int mode;
KASSERT(ifp != NULL, ("%s: null ifp", __func__));
imf = imo_match_group(imo, ifp, group);
if (imf == NULL)
return (MCAST_NOTGMEMBER);
/*
* Check if the source was included in an (S,G) join.
* Allow reception on exclusive memberships by default,
* reject reception on inclusive memberships by default.
* Exclude source only if an in-mode exclude filter exists.
* Include source only if an in-mode include filter exists.
* NOTE: We are comparing group state here at IGMP t1 (now)
* with socket-layer t0 (since last downcall).
*/
mode = imf->imf_st[1];
ims = imo_match_source(imf, src);
if ((ims == NULL && mode == MCAST_INCLUDE) ||
(ims != NULL && ims->imsl_st[0] == MCAST_EXCLUDE))
return (MCAST_NOTSMEMBER);
return (MCAST_PASS);
}
/*
* Find and return a reference to an in_multi record for (ifp, group),
* and bump its reference count.
* If one does not exist, try to allocate it, and update link-layer multicast
* filters on ifp to listen for group.
* Assumes the IN_MULTI lock is held across the call.
* Return 0 if successful, otherwise return an appropriate error code.
*/
static int
in_getmulti(struct ifnet *ifp, const struct in_addr *group,
struct in_multi **pinm)
{
struct sockaddr_in gsin;
struct ifmultiaddr *ifma;
struct in_ifinfo *ii;
struct in_multi *inm;
int error;
IN_MULTI_LOCK_ASSERT();
ii = (struct in_ifinfo *)ifp->if_afdata[AF_INET];
IN_MULTI_LIST_LOCK();
inm = inm_lookup(ifp, *group);
if (inm != NULL) {
/*
* If we already joined this group, just bump the
* refcount and return it.
*/
KASSERT(inm->inm_refcount >= 1,
("%s: bad refcount %d", __func__, inm->inm_refcount));
inm_acquire_locked(inm);
*pinm = inm;
}
IN_MULTI_LIST_UNLOCK();
if (inm != NULL)
return (0);
memset(&gsin, 0, sizeof(gsin));
gsin.sin_family = AF_INET;
gsin.sin_len = sizeof(struct sockaddr_in);
gsin.sin_addr = *group;
/*
* Check if a link-layer group is already associated
* with this network-layer group on the given ifnet.
*/
error = if_addmulti(ifp, (struct sockaddr *)&gsin, &ifma);
if (error != 0)
return (error);
/* XXX ifma_protospec must be covered by IF_ADDR_LOCK */
IN_MULTI_LIST_LOCK();
IF_ADDR_WLOCK(ifp);
/*
* If something other than netinet is occupying the link-layer
* group, print a meaningful error message and back out of
* the allocation.
* Otherwise, bump the refcount on the existing network-layer
* group association and return it.
*/
if (ifma->ifma_protospec != NULL) {
inm = (struct in_multi *)ifma->ifma_protospec;
#ifdef INVARIANTS
KASSERT(ifma->ifma_addr != NULL, ("%s: no ifma_addr",
__func__));
KASSERT(ifma->ifma_addr->sa_family == AF_INET,
("%s: ifma not AF_INET", __func__));
KASSERT(inm != NULL, ("%s: no ifma_protospec", __func__));
if (inm->inm_ifma != ifma || inm->inm_ifp != ifp ||
!in_hosteq(inm->inm_addr, *group)) {
char addrbuf[INET_ADDRSTRLEN];
panic("%s: ifma %p is inconsistent with %p (%s)",
__func__, ifma, inm, inet_ntoa_r(*group, addrbuf));
}
#endif
inm_acquire_locked(inm);
*pinm = inm;
goto out_locked;
}
IF_ADDR_WLOCK_ASSERT(ifp);
/*
* A new in_multi record is needed; allocate and initialize it.
* We DO NOT perform an IGMP join as the in_ layer may need to
* push an initial source list down to IGMP to support SSM.
*
* The initial source filter state is INCLUDE, {} as per the RFC.
*/
inm = malloc(sizeof(*inm), M_IPMADDR, M_NOWAIT | M_ZERO);
if (inm == NULL) {
IF_ADDR_WUNLOCK(ifp);
IN_MULTI_LIST_UNLOCK();
if_delmulti_ifma(ifma);
return (ENOMEM);
}
inm->inm_addr = *group;
inm->inm_ifp = ifp;
inm->inm_igi = ii->ii_igmp;
inm->inm_ifma = ifma;
inm->inm_refcount = 1;
inm->inm_state = IGMP_NOT_MEMBER;
mbufq_init(&inm->inm_scq, IGMP_MAX_STATE_CHANGES);
inm->inm_st[0].iss_fmode = MCAST_UNDEFINED;
inm->inm_st[1].iss_fmode = MCAST_UNDEFINED;
RB_INIT(&inm->inm_srcs);
ifma->ifma_protospec = inm;
*pinm = inm;
out_locked:
IF_ADDR_WUNLOCK(ifp);
IN_MULTI_LIST_UNLOCK();
return (0);
}
/*
* Drop a reference to an in_multi record.
*
* If the refcount drops to 0, free the in_multi record and
* delete the underlying link-layer membership.
*/
static void
inm_release(struct in_multi *inm)
{
struct ifmultiaddr *ifma;
struct ifnet *ifp;
CTR2(KTR_IGMPV3, "%s: refcount is %d", __func__, inm->inm_refcount);
MPASS(inm->inm_refcount == 0);
CTR2(KTR_IGMPV3, "%s: freeing inm %p", __func__, inm);
ifma = inm->inm_ifma;
ifp = inm->inm_ifp;
/* XXX this access is not covered by IF_ADDR_LOCK */
CTR2(KTR_IGMPV3, "%s: purging ifma %p", __func__, ifma);
if (ifp != NULL) {
CURVNET_SET(ifp->if_vnet);
inm_purge(inm);
free(inm, M_IPMADDR);
if_delmulti_ifma_flags(ifma, 1);
CURVNET_RESTORE();
if_rele(ifp);
} else {
inm_purge(inm);
free(inm, M_IPMADDR);
if_delmulti_ifma_flags(ifma, 1);
}
}
/*
* Clear recorded source entries for a group.
* Used by the IGMP code. Caller must hold the IN_MULTI lock.
* FIXME: Should reap.
*/
void
inm_clear_recorded(struct in_multi *inm)
{
struct ip_msource *ims;
IN_MULTI_LIST_LOCK_ASSERT();
RB_FOREACH(ims, ip_msource_tree, &inm->inm_srcs) {
if (ims->ims_stp) {
ims->ims_stp = 0;
--inm->inm_st[1].iss_rec;
}
}
KASSERT(inm->inm_st[1].iss_rec == 0,
("%s: iss_rec %d not 0", __func__, inm->inm_st[1].iss_rec));
}
/*
* Record a source as pending for a Source-Group IGMPv3 query.
* This lives here as it modifies the shared tree.
*
* inm is the group descriptor.
* naddr is the address of the source to record in network-byte order.
*
* If the net.inet.igmp.sgalloc sysctl is non-zero, we will
* lazy-allocate a source node in response to an SG query.
* Otherwise, no allocation is performed. This saves some memory
* with the trade-off that the source will not be reported to the
* router if joined in the window between the query response and
* the group actually being joined on the local host.
*
* VIMAGE: XXX: Currently the igmp_sgalloc feature has been removed.
* This turns off the allocation of a recorded source entry if
* the group has not been joined.
*
* Return 0 if the source didn't exist or was already marked as recorded.
* Return 1 if the source was marked as recorded by this function.
* Return <0 if any error occurred (negated errno code).
*/
int
inm_record_source(struct in_multi *inm, const in_addr_t naddr)
{
struct ip_msource find;
struct ip_msource *ims, *nims;
IN_MULTI_LIST_LOCK_ASSERT();
find.ims_haddr = ntohl(naddr);
ims = RB_FIND(ip_msource_tree, &inm->inm_srcs, &find);
if (ims && ims->ims_stp)
return (0);
if (ims == NULL) {
if (inm->inm_nsrc == in_mcast_maxgrpsrc)
return (-ENOSPC);
nims = malloc(sizeof(struct ip_msource), M_IPMSOURCE,
M_NOWAIT | M_ZERO);
if (nims == NULL)
return (-ENOMEM);
nims->ims_haddr = find.ims_haddr;
RB_INSERT(ip_msource_tree, &inm->inm_srcs, nims);
++inm->inm_nsrc;
ims = nims;
}
/*
* Mark the source as recorded and update the recorded
* source count.
*/
++ims->ims_stp;
++inm->inm_st[1].iss_rec;
return (1);
}
/*
* Return a pointer to an in_msource owned by an in_mfilter,
* given its source address.
* Lazy-allocate if needed. If this is a new entry its filter state is
* undefined at t0.
*
* imf is the filter set being modified.
* haddr is the source address in *host* byte-order.
*
* SMPng: May be called with locks held; malloc must not block.
*/
static int
imf_get_source(struct in_mfilter *imf, const struct sockaddr_in *psin,
struct in_msource **plims)
{
struct ip_msource find;
struct ip_msource *ims, *nims;
struct in_msource *lims;
int error;
error = 0;
ims = NULL;
lims = NULL;
/* key is host byte order */
find.ims_haddr = ntohl(psin->sin_addr.s_addr);
ims = RB_FIND(ip_msource_tree, &imf->imf_sources, &find);
lims = (struct in_msource *)ims;
if (lims == NULL) {
if (imf->imf_nsrc == in_mcast_maxsocksrc)
return (ENOSPC);
nims = malloc(sizeof(struct in_msource), M_INMFILTER,
M_NOWAIT | M_ZERO);
if (nims == NULL)
return (ENOMEM);
lims = (struct in_msource *)nims;
lims->ims_haddr = find.ims_haddr;
lims->imsl_st[0] = MCAST_UNDEFINED;
RB_INSERT(ip_msource_tree, &imf->imf_sources, nims);
++imf->imf_nsrc;
}
*plims = lims;
return (error);
}
/*
* Graft a source entry into an existing socket-layer filter set,
* maintaining any required invariants and checking allocations.
*
* The source is marked as being in the new filter mode at t1.
*
* Return the pointer to the new node, otherwise return NULL.
*/
static struct in_msource *
imf_graft(struct in_mfilter *imf, const uint8_t st1,
const struct sockaddr_in *psin)
{
struct ip_msource *nims;
struct in_msource *lims;
nims = malloc(sizeof(struct in_msource), M_INMFILTER,
M_NOWAIT | M_ZERO);
if (nims == NULL)
return (NULL);
lims = (struct in_msource *)nims;
lims->ims_haddr = ntohl(psin->sin_addr.s_addr);
lims->imsl_st[0] = MCAST_UNDEFINED;
lims->imsl_st[1] = st1;
RB_INSERT(ip_msource_tree, &imf->imf_sources, nims);
++imf->imf_nsrc;
return (lims);
}
/*
* Prune a source entry from an existing socket-layer filter set,
* maintaining any required invariants and checking allocations.
*
* The source is marked as being left at t1, it is not freed.
*
* Return 0 if no error occurred, otherwise return an errno value.
*/
static int
imf_prune(struct in_mfilter *imf, const struct sockaddr_in *psin)
{
struct ip_msource find;
struct ip_msource *ims;
struct in_msource *lims;
/* key is host byte order */
find.ims_haddr = ntohl(psin->sin_addr.s_addr);
ims = RB_FIND(ip_msource_tree, &imf->imf_sources, &find);
if (ims == NULL)
return (ENOENT);
lims = (struct in_msource *)ims;
lims->imsl_st[1] = MCAST_UNDEFINED;
return (0);
}
/*
* Revert socket-layer filter set deltas at t1 to t0 state.
*/
static void
imf_rollback(struct in_mfilter *imf)
{
struct ip_msource *ims, *tims;
struct in_msource *lims;
RB_FOREACH_SAFE(ims, ip_msource_tree, &imf->imf_sources, tims) {
lims = (struct in_msource *)ims;
if (lims->imsl_st[0] == lims->imsl_st[1]) {
/* no change at t1 */
continue;
} else if (lims->imsl_st[0] != MCAST_UNDEFINED) {
/* revert change to existing source at t1 */
lims->imsl_st[1] = lims->imsl_st[0];
} else {
/* revert source added t1 */
CTR2(KTR_IGMPV3, "%s: free ims %p", __func__, ims);
RB_REMOVE(ip_msource_tree, &imf->imf_sources, ims);
free(ims, M_INMFILTER);
imf->imf_nsrc--;
}
}
imf->imf_st[1] = imf->imf_st[0];
}
/*
* Mark socket-layer filter set as INCLUDE {} at t1.
*/
static void
imf_leave(struct in_mfilter *imf)
{
struct ip_msource *ims;
struct in_msource *lims;
RB_FOREACH(ims, ip_msource_tree, &imf->imf_sources) {
lims = (struct in_msource *)ims;
lims->imsl_st[1] = MCAST_UNDEFINED;
}
imf->imf_st[1] = MCAST_INCLUDE;
}
/*
* Mark socket-layer filter set deltas as committed.
*/
static void
imf_commit(struct in_mfilter *imf)
{
struct ip_msource *ims;
struct in_msource *lims;
RB_FOREACH(ims, ip_msource_tree, &imf->imf_sources) {
lims = (struct in_msource *)ims;
lims->imsl_st[0] = lims->imsl_st[1];
}
imf->imf_st[0] = imf->imf_st[1];
}
/*
* Reap unreferenced sources from socket-layer filter set.
*/
static void
imf_reap(struct in_mfilter *imf)
{
struct ip_msource *ims, *tims;
struct in_msource *lims;
RB_FOREACH_SAFE(ims, ip_msource_tree, &imf->imf_sources, tims) {
lims = (struct in_msource *)ims;
if ((lims->imsl_st[0] == MCAST_UNDEFINED) &&
(lims->imsl_st[1] == MCAST_UNDEFINED)) {
CTR2(KTR_IGMPV3, "%s: free lims %p", __func__, ims);
RB_REMOVE(ip_msource_tree, &imf->imf_sources, ims);
free(ims, M_INMFILTER);
imf->imf_nsrc--;
}
}
}
/*
* Purge socket-layer filter set.
*/
static void
imf_purge(struct in_mfilter *imf)
{
struct ip_msource *ims, *tims;
RB_FOREACH_SAFE(ims, ip_msource_tree, &imf->imf_sources, tims) {
CTR2(KTR_IGMPV3, "%s: free ims %p", __func__, ims);
RB_REMOVE(ip_msource_tree, &imf->imf_sources, ims);
free(ims, M_INMFILTER);
imf->imf_nsrc--;
}
imf->imf_st[0] = imf->imf_st[1] = MCAST_UNDEFINED;
KASSERT(RB_EMPTY(&imf->imf_sources),
("%s: imf_sources not empty", __func__));
}
/*
* Look up a source filter entry for a multicast group.
*
* inm is the group descriptor to work with.
* haddr is the host-byte-order IPv4 address to look up.
* noalloc may be non-zero to suppress allocation of sources.
* *pims will be set to the address of the retrieved or allocated source.
*
* SMPng: NOTE: may be called with locks held.
* Return 0 if successful, otherwise return a non-zero error code.
*/
static int
inm_get_source(struct in_multi *inm, const in_addr_t haddr,
const int noalloc, struct ip_msource **pims)
{
struct ip_msource find;
struct ip_msource *ims, *nims;
find.ims_haddr = haddr;
ims = RB_FIND(ip_msource_tree, &inm->inm_srcs, &find);
if (ims == NULL && !noalloc) {
if (inm->inm_nsrc == in_mcast_maxgrpsrc)
return (ENOSPC);
nims = malloc(sizeof(struct ip_msource), M_IPMSOURCE,
M_NOWAIT | M_ZERO);
if (nims == NULL)
return (ENOMEM);
nims->ims_haddr = haddr;
RB_INSERT(ip_msource_tree, &inm->inm_srcs, nims);
++inm->inm_nsrc;
ims = nims;
#ifdef KTR
CTR3(KTR_IGMPV3, "%s: allocated 0x%08x as %p", __func__,
haddr, ims);
#endif
}
*pims = ims;
return (0);
}
/*
* Merge socket-layer source into IGMP-layer source.
* If rollback is non-zero, perform the inverse of the merge.
*/
static void
ims_merge(struct ip_msource *ims, const struct in_msource *lims,
const int rollback)
{
int n = rollback ? -1 : 1;
if (lims->imsl_st[0] == MCAST_EXCLUDE) {
CTR3(KTR_IGMPV3, "%s: t1 ex -= %d on 0x%08x",
__func__, n, ims->ims_haddr);
ims->ims_st[1].ex -= n;
} else if (lims->imsl_st[0] == MCAST_INCLUDE) {
CTR3(KTR_IGMPV3, "%s: t1 in -= %d on 0x%08x",
__func__, n, ims->ims_haddr);
ims->ims_st[1].in -= n;
}
if (lims->imsl_st[1] == MCAST_EXCLUDE) {
CTR3(KTR_IGMPV3, "%s: t1 ex += %d on 0x%08x",
__func__, n, ims->ims_haddr);
ims->ims_st[1].ex += n;
} else if (lims->imsl_st[1] == MCAST_INCLUDE) {
CTR3(KTR_IGMPV3, "%s: t1 in += %d on 0x%08x",
__func__, n, ims->ims_haddr);
ims->ims_st[1].in += n;
}
}
/*
* Atomically update the global in_multi state, when a membership's
* filter list is being updated in any way.
*
* imf is the per-inpcb-membership group filter pointer.
* A fake imf may be passed for in-kernel consumers.
*
* XXX This is a candidate for a set-symmetric-difference style loop
* which would eliminate the repeated lookup from root of ims nodes,