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freebsd-skq/sys/netinet/in_mcast.c
Julian Elischer 8b07e49a00 Add code to allow the system to handle multiple routing tables. 
This particular implementation is designed to be fully backwards compatible
and to be MFC-able to 7.x (and 6.x)

Currently the only protocol that can make use of the multiple tables is IPv4
Similar functionality exists in OpenBSD and Linux.

From my notes:

-----

  One thing where FreeBSD has been falling behind, and which by chance I
  have some time to work on is "policy based routing", which allows
  different
  packet streams to be routed by more than just the destination address.

  Constraints:
  ------------

  I want to make some form of this available in the 6.x tree
  (and by extension 7.x) , but FreeBSD in general needs it so I might as
  well do it in -current and back port the portions I need.

  One of the ways that this can be done is to have the ability to
  instantiate multiple kernel routing tables (which I will now
  refer to as "Forwarding Information Bases" or "FIBs" for political
  correctness reasons). Which FIB a particular packet uses to make
  the next hop decision can be decided by a number of mechanisms.
  The policies these mechanisms implement are the "Policies" referred
  to in "Policy based routing".

  One of the constraints I have if I try to back port this work to
  6.x is that it must be implemented as a EXTENSION to the existing
  ABIs in 6.x so that third party applications do not need to be
  recompiled in timespan of the branch.

  This first version will not have some of the bells and whistles that
  will come with later versions. It will, for example, be limited to 16
  tables in the first commit.
  Implementation method, Compatible version. (part 1)
  -------------------------------
  For this reason I have implemented a "sufficient subset" of a
  multiple routing table solution in Perforce, and back-ported it
  to 6.x. (also in Perforce though not  always caught up with what I
  have done in -current/P4). The subset allows a number of FIBs
  to be defined at compile time (8 is sufficient for my purposes in 6.x)
  and implements the changes needed to allow IPV4 to use them. I have not
  done the changes for ipv6 simply because I do not need it, and I do not
  have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it.

  Other protocol families are left untouched and should there be
  users with proprietary protocol families, they should continue to work
  and be oblivious to the existence of the extra FIBs.

  To understand how this is done, one must know that the current FIB
  code starts everything off with a single dimensional array of
  pointers to FIB head structures (One per protocol family), each of
  which in turn points to the trie of routes available to that family.

  The basic change in the ABI compatible version of the change is to
  extent that array to be a 2 dimensional array, so that
  instead of protocol family X looking at rt_tables[X] for the
  table it needs, it looks at rt_tables[Y][X] when for all
  protocol families except ipv4 Y is always 0.
  Code that is unaware of the change always just sees the first row
  of the table, which of course looks just like the one dimensional
  array that existed before.

  The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign()
  are all maintained, but refer only to the first row of the array,
  so that existing callers in proprietary protocols can continue to
  do the "right thing".
  Some new entry points are added, for the exclusive use of ipv4 code
  called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(),
  which have an extra argument which refers the code to the correct row.

  In addition, there are some new entry points (currently called
  rtalloc_fib() and friends) that check the Address family being
  looked up and call either rtalloc() (and friends) if the protocol
  is not IPv4 forcing the action to row 0 or to the appropriate row
  if it IS IPv4 (and that info is available). These are for calling
  from code that is not specific to any particular protocol. The way
  these are implemented would change in the non ABI preserving code
  to be added later.

  One feature of the first version of the code is that for ipv4,
  the interface routes show up automatically on all the FIBs, so
  that no matter what FIB you select you always have the basic
  direct attached hosts available to you. (rtinit() does this
  automatically).

  You CAN delete an interface route from one FIB should you want
  to but by default it's there. ARP information is also available
  in each FIB. It's assumed that the same machine would have the
  same MAC address, regardless of which FIB you are using to get
  to it.

  This brings us as to how the correct FIB is selected for an outgoing
  IPV4 packet.

  Firstly, all packets have a FIB associated with them. if nothing
  has been done to change it, it will be FIB 0. The FIB is changed
  in the following ways.

  Packets fall into one of a number of classes.

  1/ locally generated packets, coming from a socket/PCB.
     Such packets select a FIB from a number associated with the
     socket/PCB. This in turn is inherited from the process,
     but can be changed by a socket option. The process in turn
     inherits it on fork. I have written a utility call setfib
     that acts a bit like nice..

         setfib -3 ping target.example.com # will use fib 3 for ping.

     It is an obvious extension to make it a property of a jail
     but I have not done so. It can be achieved by combining the setfib and
     jail commands.

  2/ packets received on an interface for forwarding.
     By default these packets would use table 0,
     (or possibly a number settable in a sysctl(not yet)).
     but prior to routing the firewall can inspect them (see below).
     (possibly in the future you may be able to associate a FIB
     with packets received on an interface..  An ifconfig arg, but not yet.)

  3/ packets inspected by a packet classifier, which can arbitrarily
     associate a fib with it on a packet by packet basis.
     A fib assigned to a packet by a packet classifier
     (such as ipfw) would over-ride a fib associated by
     a more default source. (such as cases 1 or 2).

  4/ a tcp listen socket associated with a fib will generate
     accept sockets that are associated with that same fib.

  5/ Packets generated in response to some other packet (e.g. reset
     or icmp packets). These should use the FIB associated with the
     packet being reponded to.

  6/ Packets generated during encapsulation.
     gif, tun and other tunnel interfaces will encapsulate using the FIB
     that was in effect withthe proces that set up the tunnel.
     thus setfib 1 ifconfig gif0 [tunnel instructions]
     will set the fib for the tunnel to use to be fib 1.

  Routing messages would be associated with their
  process, and thus select one FIB or another.
  messages from the kernel would be associated with the fib they
  refer to and would only be received by a routing socket associated
  with that fib. (not yet implemented)

  In addition Netstat has been edited to be able to cope with the
  fact that the array is now 2 dimensional. (It looks in system
  memory using libkvm (!)). Old versions of netstat see only the first FIB.

  In addition two sysctls are added to give:
  a) the number of FIBs compiled in (active)
  b) the default FIB of the calling process.

  Early testing experience:
  -------------------------

  Basically our (IronPort's) appliance does this functionality already
  using ipfw fwd but that method has some drawbacks.

  For example,
  It can't fully simulate a routing table because it can't influence the
  socket's choice of local address when a connect() is done.

  Testing during the generating of these changes has been
  remarkably smooth so far. Multiple tables have co-existed
  with no notable side effects, and packets have been routes
  accordingly.

  ipfw has grown 2 new keywords:

  setfib N ip from anay to any
  count ip from any to any fib N

  In pf there seems to be a requirement to be able to give symbolic names to the
  fibs but I do not have that capacity. I am not sure if it is required.

  SCTP has interestingly enough built in support for this, called VRFs
  in Cisco parlance. it will be interesting to see how that handles it
  when it suddenly actually does something.

  Where to next:
  --------------------

  After committing the ABI compatible version and MFCing it, I'd
  like to proceed in a forward direction in -current. this will
  result in some roto-tilling in the routing code.

  Firstly: the current code's idea of having a separate tree per
  protocol family, all of the same format, and pointed to by the
  1 dimensional array is a bit silly. Especially when one considers that
  there is code that makes assumptions about every protocol having the
  same internal structures there. Some protocols don't WANT that
  sort of structure. (for example the whole idea of a netmask is foreign
  to appletalk). This needs to be made opaque to the external code.

  My suggested first change is to add routing method pointers to the
  'domain' structure, along with information pointing the data.
  instead of having an array of pointers to uniform structures,
  there would be an array pointing to the 'domain' structures
  for each protocol address domain (protocol family),
  and the methods this reached would be called. The methods would have
  an argument that gives FIB number, but the protocol would be free
  to ignore it.

  When the ABI can be changed it raises the possibilty of the
  addition of a fib entry into the "struct route". Currently,
  the structure contains the sockaddr of the desination, and the resulting
  fib entry. To make this work fully, one could add a fib number
  so that given an address and a fib, one can find the third element, the
  fib entry.

  Interaction with the ARP layer/ LL layer would need to be
  revisited as well. Qing Li has been working on this already.

  This work was sponsored by Ironport Systems/Cisco

Reviewed by:    several including rwatson, bz and mlair (parts each)
Obtained from:  Ironport systems/Cisco
2008-05-09 23:03:00 +00:00

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/*-
* Copyright (c) 2007 Bruce M. 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.
* Until further notice, this file requires INET to compile.
* TODO: Make this infrastructure independent of address family.
* TODO: Teach netinet6 to use this code.
* TODO: Hook up SSM logic to IGMPv3/MLDv2.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <netinet/igmp_var.h>
#ifndef __SOCKUNION_DECLARED
union sockunion {
struct sockaddr_storage ss;
struct sockaddr sa;
struct sockaddr_dl sdl;
struct sockaddr_in sin;
#ifdef INET6
struct sockaddr_in6 sin6;
#endif
};
typedef union sockunion sockunion_t;
#define __SOCKUNION_DECLARED
#endif /* __SOCKUNION_DECLARED */
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, "in_msource", "IPv4 multicast source filter");
/*
* The IPv4 multicast list (in_multihead and associated structures) are
* protected by the global in_multi_mtx. See in_var.h for more details. For
* now, in_multi_mtx is marked as recursible due to IGMP's calling back into
* ip_output() to send IGMP packets while holding the lock; this probably is
* not quite desirable.
*/
struct in_multihead in_multihead; /* XXX BSS initialization */
struct mtx in_multi_mtx;
MTX_SYSINIT(in_multi_mtx, &in_multi_mtx, "in_multi_mtx", MTX_DEF | MTX_RECURSE);
/*
* Functions with non-static linkage defined in this file should be
* declared in in_var.h:
* imo_match_group()
* imo_match_source()
* in_addmulti()
* in_delmulti()
* in_delmulti_locked()
* and ip_var.h:
* inp_freemoptions()
* inp_getmoptions()
* inp_setmoptions()
*/
static int imo_grow(struct ip_moptions *);
static int imo_join_source(struct ip_moptions *, size_t, sockunion_t *);
static int imo_leave_source(struct ip_moptions *, size_t, sockunion_t *);
static int inp_change_source_filter(struct inpcb *, struct sockopt *);
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 int inp_set_multicast_if(struct inpcb *, struct sockopt *);
static int inp_set_source_filters(struct inpcb *, struct sockopt *);
/*
* Resize the ip_moptions vector to the next power-of-two minus 1.
* May be called with locks held; do not sleep.
*/
static int
imo_grow(struct ip_moptions *imo)
{
struct in_multi **nmships;
struct in_multi **omships;
struct in_mfilter *nmfilters;
struct in_mfilter *omfilters;
size_t idx;
size_t newmax;
size_t oldmax;
nmships = NULL;
nmfilters = NULL;
omships = imo->imo_membership;
omfilters = imo->imo_mfilters;
oldmax = imo->imo_max_memberships;
newmax = ((oldmax + 1) * 2) - 1;
if (newmax <= IP_MAX_MEMBERSHIPS) {
nmships = (struct in_multi **)realloc(omships,
sizeof(struct in_multi *) * newmax, M_IPMOPTS, M_NOWAIT);
nmfilters = (struct in_mfilter *)realloc(omfilters,
sizeof(struct in_mfilter) * newmax, M_IPMSOURCE, M_NOWAIT);
if (nmships != NULL && nmfilters != NULL) {
/* Initialize newly allocated source filter heads. */
for (idx = oldmax; idx < newmax; idx++) {
nmfilters[idx].imf_fmode = MCAST_EXCLUDE;
nmfilters[idx].imf_nsources = 0;
TAILQ_INIT(&nmfilters[idx].imf_sources);
}
imo->imo_max_memberships = newmax;
imo->imo_membership = nmships;
imo->imo_mfilters = nmfilters;
}
}
if (nmships == NULL || nmfilters == NULL) {
if (nmships != NULL)
free(nmships, M_IPMOPTS);
if (nmfilters != NULL)
free(nmfilters, M_IPMSOURCE);
return (ETOOMANYREFS);
}
return (0);
}
/*
* Add a source to a multicast filter list.
* Assumes the associated inpcb is locked.
*/
static int
imo_join_source(struct ip_moptions *imo, size_t gidx, sockunion_t *src)
{
struct in_msource *ims, *nims;
struct in_mfilter *imf;
KASSERT(src->ss.ss_family == AF_INET, ("%s: !AF_INET", __func__));
KASSERT(imo->imo_mfilters != NULL,
("%s: imo_mfilters vector not allocated", __func__));
imf = &imo->imo_mfilters[gidx];
if (imf->imf_nsources == IP_MAX_SOURCE_FILTER)
return (ENOBUFS);
ims = imo_match_source(imo, gidx, &src->sa);
if (ims != NULL)
return (EADDRNOTAVAIL);
/* Do not sleep with inp lock held. */
MALLOC(nims, struct in_msource *, sizeof(struct in_msource),
M_IPMSOURCE, M_NOWAIT | M_ZERO);
if (nims == NULL)
return (ENOBUFS);
nims->ims_addr = src->ss;
TAILQ_INSERT_TAIL(&imf->imf_sources, nims, ims_next);
imf->imf_nsources++;
return (0);
}
static int
imo_leave_source(struct ip_moptions *imo, size_t gidx, sockunion_t *src)
{
struct in_msource *ims;
struct in_mfilter *imf;
KASSERT(src->ss.ss_family == AF_INET, ("%s: !AF_INET", __func__));
KASSERT(imo->imo_mfilters != NULL,
("%s: imo_mfilters vector not allocated", __func__));
imf = &imo->imo_mfilters[gidx];
if (imf->imf_nsources == IP_MAX_SOURCE_FILTER)
return (ENOBUFS);
ims = imo_match_source(imo, gidx, &src->sa);
if (ims == NULL)
return (EADDRNOTAVAIL);
TAILQ_REMOVE(&imf->imf_sources, ims, ims_next);
FREE(ims, M_IPMSOURCE);
imf->imf_nsources--;
return (0);
}
/*
* 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.
*/
size_t
imo_match_group(struct ip_moptions *imo, struct ifnet *ifp,
struct sockaddr *group)
{
sockunion_t *gsa;
struct in_multi **pinm;
int idx;
int nmships;
gsa = (sockunion_t *)group;
/* The imo_membership array may be lazy allocated. */
if (imo->imo_membership == NULL || imo->imo_num_memberships == 0)
return (-1);
nmships = imo->imo_num_memberships;
pinm = &imo->imo_membership[0];
for (idx = 0; idx < nmships; idx++, pinm++) {
if (*pinm == NULL)
continue;
#if 0
printf("%s: trying ifp = %p, inaddr = %s ", __func__,
ifp, inet_ntoa(gsa->sin.sin_addr));
printf("against %p, %s\n",
(*pinm)->inm_ifp, inet_ntoa((*pinm)->inm_addr));
#endif
if ((ifp == NULL || ((*pinm)->inm_ifp == ifp)) &&
(*pinm)->inm_addr.s_addr == gsa->sin.sin_addr.s_addr) {
break;
}
}
if (idx >= nmships)
idx = -1;
return (idx);
}
/*
* Find a multicast source entry for this imo which matches
* the given group index for this socket, and source address.
*/
struct in_msource *
imo_match_source(struct ip_moptions *imo, size_t gidx, struct sockaddr *src)
{
struct in_mfilter *imf;
struct in_msource *ims, *pims;
KASSERT(src->sa_family == AF_INET, ("%s: !AF_INET", __func__));
KASSERT(gidx != -1 && gidx < imo->imo_num_memberships,
("%s: invalid index %d\n", __func__, (int)gidx));
/* The imo_mfilters array may be lazy allocated. */
if (imo->imo_mfilters == NULL)
return (NULL);
pims = NULL;
imf = &imo->imo_mfilters[gidx];
TAILQ_FOREACH(ims, &imf->imf_sources, ims_next) {
/*
* Perform bitwise comparison of two IPv4 addresses.
* TODO: Do the same for IPv6.
* Do not use sa_equal() for this as it is not aware of
* deeper structure in sockaddr_in or sockaddr_in6.
*/
if (((struct sockaddr_in *)&ims->ims_addr)->sin_addr.s_addr ==
((struct sockaddr_in *)src)->sin_addr.s_addr) {
pims = ims;
break;
}
}
return (pims);
}
/*
* Join an IPv4 multicast group.
*/
struct in_multi *
in_addmulti(struct in_addr *ap, struct ifnet *ifp)
{
struct in_multi *inm;
inm = NULL;
IFF_LOCKGIANT(ifp);
IN_MULTI_LOCK();
IN_LOOKUP_MULTI(*ap, ifp, inm);
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->inm_refcount;
} else do {
sockunion_t gsa;
struct ifmultiaddr *ifma;
struct in_multi *ninm;
int error;
memset(&gsa, 0, sizeof(gsa));
gsa.sin.sin_family = AF_INET;
gsa.sin.sin_len = sizeof(struct sockaddr_in);
gsa.sin.sin_addr = *ap;
/*
* Check if a link-layer group is already associated
* with this network-layer group on the given ifnet.
* If so, bump the refcount on the existing network-layer
* group association and return it.
*/
error = if_addmulti(ifp, &gsa.sa, &ifma);
if (error)
break;
if (ifma->ifma_protospec != NULL) {
inm = (struct in_multi *)ifma->ifma_protospec;
#ifdef INVARIANTS
if (inm->inm_ifma != ifma || inm->inm_ifp != ifp ||
inm->inm_addr.s_addr != ap->s_addr)
panic("%s: ifma is inconsistent", __func__);
#endif
++inm->inm_refcount;
break;
}
/*
* A new membership is needed; construct it and
* perform the IGMP join.
*/
ninm = malloc(sizeof(*ninm), M_IPMADDR, M_NOWAIT | M_ZERO);
if (ninm == NULL) {
if_delmulti_ifma(ifma);
break;
}
ninm->inm_addr = *ap;
ninm->inm_ifp = ifp;
ninm->inm_ifma = ifma;
ninm->inm_refcount = 1;
ifma->ifma_protospec = ninm;
LIST_INSERT_HEAD(&in_multihead, ninm, inm_link);
igmp_joingroup(ninm);
inm = ninm;
} while (0);
IN_MULTI_UNLOCK();
IFF_UNLOCKGIANT(ifp);
return (inm);
}
/*
* Leave an IPv4 multicast group.
* It is OK to call this routine if the underlying ifnet went away.
*
* XXX: To deal with the ifp going away, we cheat; the link-layer code in net
* will set ifma_ifp to NULL when the associated ifnet instance is detached
* from the system.
*
* The only reason we need to violate layers and check ifma_ifp here at all
* is because certain hardware drivers still require Giant to be held,
* and it must always be taken before other locks.
*/
void
in_delmulti(struct in_multi *inm)
{
struct ifnet *ifp;
KASSERT(inm != NULL, ("%s: inm is NULL", __func__));
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__));
IFF_LOCKGIANT(ifp);
}
IN_MULTI_LOCK();
in_delmulti_locked(inm);
IN_MULTI_UNLOCK();
if (ifp != NULL)
IFF_UNLOCKGIANT(ifp);
}
/*
* Delete a multicast address record, with locks held.
*
* It is OK to call this routine if the ifp went away.
* Assumes that caller holds the IN_MULTI lock, and that
* Giant was taken before other locks if required by the hardware.
*/
void
in_delmulti_locked(struct in_multi *inm)
{
struct ifmultiaddr *ifma;
IN_MULTI_LOCK_ASSERT();
KASSERT(inm->inm_refcount >= 1, ("%s: freeing freed inm", __func__));
if (--inm->inm_refcount == 0) {
igmp_leavegroup(inm);
ifma = inm->inm_ifma;
#ifdef DIAGNOSTIC
if (bootverbose)
printf("%s: purging ifma %p\n", __func__, ifma);
#endif
KASSERT(ifma->ifma_protospec == inm,
("%s: ifma_protospec != inm", __func__));
ifma->ifma_protospec = NULL;
LIST_REMOVE(inm, inm_link);
free(inm, M_IPMADDR);
if_delmulti_ifma(ifma);
}
}
/*
* Block or unblock an ASM/SSM multicast source on an inpcb.
*/
static int
inp_change_source_filter(struct inpcb *inp, struct sockopt *sopt)
{
struct group_source_req gsr;
sockunion_t *gsa, *ssa;
struct ifnet *ifp;
struct in_mfilter *imf;
struct ip_moptions *imo;
struct in_msource *ims;
size_t idx;
int error;
int block;
ifp = NULL;
error = 0;
block = 0;
memset(&gsr, 0, sizeof(struct group_source_req));
gsa = (sockunion_t *)&gsr.gsr_group;
ssa = (sockunion_t *)&gsr.gsr_source;
switch (sopt->sopt_name) {
case IP_BLOCK_SOURCE:
case IP_UNBLOCK_SOURCE: {
struct ip_mreq_source mreqs;
error = sooptcopyin(sopt, &mreqs,
sizeof(struct ip_mreq_source),
sizeof(struct ip_mreq_source));
if (error)
return (error);
gsa->sin.sin_family = AF_INET;
gsa->sin.sin_len = sizeof(struct sockaddr_in);
gsa->sin.sin_addr = mreqs.imr_multiaddr;
ssa->sin.sin_family = AF_INET;
ssa->sin.sin_len = sizeof(struct sockaddr_in);
ssa->sin.sin_addr = mreqs.imr_sourceaddr;
if (mreqs.imr_interface.s_addr != INADDR_ANY)
INADDR_TO_IFP(mreqs.imr_interface, ifp);
if (sopt->sopt_name == IP_BLOCK_SOURCE)
block = 1;
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: imr_interface = %s, ifp = %p\n",
__func__, inet_ntoa(mreqs.imr_interface), ifp);
}
#endif
break;
}
case MCAST_BLOCK_SOURCE:
case MCAST_UNBLOCK_SOURCE:
error = sooptcopyin(sopt, &gsr,
sizeof(struct group_source_req),
sizeof(struct group_source_req));
if (error)
return (error);
if (gsa->sin.sin_family != AF_INET ||
gsa->sin.sin_len != sizeof(struct sockaddr_in))
return (EINVAL);
if (ssa->sin.sin_family != AF_INET ||
ssa->sin.sin_len != sizeof(struct sockaddr_in))
return (EINVAL);
if (gsr.gsr_interface == 0 || if_index < gsr.gsr_interface)
return (EADDRNOTAVAIL);
ifp = ifnet_byindex(gsr.gsr_interface);
if (sopt->sopt_name == MCAST_BLOCK_SOURCE)
block = 1;
break;
default:
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: unknown sopt_name %d\n", __func__,
sopt->sopt_name);
}
#endif
return (EOPNOTSUPP);
break;
}
/* XXX INET6 */
if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
return (EINVAL);
/*
* Check if we are actually a member of this group.
*/
imo = inp_findmoptions(inp);
idx = imo_match_group(imo, ifp, &gsa->sa);
if (idx == -1 || imo->imo_mfilters == NULL) {
error = EADDRNOTAVAIL;
goto out_locked;
}
KASSERT(imo->imo_mfilters != NULL,
("%s: imo_mfilters not allocated", __func__));
imf = &imo->imo_mfilters[idx];
/*
* SSM multicast truth table for block/unblock operations.
*
* Operation Filter Mode Entry exists? Action
*
* block exclude no add source to filter
* unblock include no add source to filter
* block include no EINVAL
* unblock exclude no EINVAL
* block exclude yes EADDRNOTAVAIL
* unblock include yes EADDRNOTAVAIL
* block include yes remove source from filter
* unblock exclude yes remove source from filter
*
* FreeBSD does not explicitly distinguish between ASM and SSM
* mode sockets; all sockets are assumed to have a filter list.
*/
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: imf_fmode is %s\n", __func__,
imf->imf_fmode == MCAST_INCLUDE ? "include" : "exclude");
}
#endif
ims = imo_match_source(imo, idx, &ssa->sa);
if (ims == NULL) {
if ((block == 1 && imf->imf_fmode == MCAST_EXCLUDE) ||
(block == 0 && imf->imf_fmode == MCAST_INCLUDE)) {
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: adding %s to filter list\n",
__func__, inet_ntoa(ssa->sin.sin_addr));
}
#endif
error = imo_join_source(imo, idx, ssa);
}
if ((block == 1 && imf->imf_fmode == MCAST_INCLUDE) ||
(block == 0 && imf->imf_fmode == MCAST_EXCLUDE)) {
/*
* If the socket is in inclusive mode:
* the source is already blocked as it has no entry.
* If the socket is in exclusive mode:
* the source is already unblocked as it has no entry.
*/
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: ims %p; %s already [un]blocked\n",
__func__, ims,
inet_ntoa(ssa->sin.sin_addr));
}
#endif
error = EINVAL;
}
} else {
if ((block == 1 && imf->imf_fmode == MCAST_EXCLUDE) ||
(block == 0 && imf->imf_fmode == MCAST_INCLUDE)) {
/*
* If the socket is in exclusive mode:
* the source is already blocked as it has an entry.
* If the socket is in inclusive mode:
* the source is already unblocked as it has an entry.
*/
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: ims %p; %s already [un]blocked\n",
__func__, ims,
inet_ntoa(ssa->sin.sin_addr));
}
#endif
error = EADDRNOTAVAIL;
}
if ((block == 1 && imf->imf_fmode == MCAST_INCLUDE) ||
(block == 0 && imf->imf_fmode == MCAST_EXCLUDE)) {
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: removing %s from filter list\n",
__func__, inet_ntoa(ssa->sin.sin_addr));
}
#endif
error = imo_leave_source(imo, idx, ssa);
}
}
out_locked:
INP_WUNLOCK(inp);
return (error);
}
/*
* Given an inpcb, return its multicast options structure pointer. Accepts
* an unlocked inpcb pointer, but will return it locked. May sleep.
*/
static struct ip_moptions *
inp_findmoptions(struct inpcb *inp)
{
struct ip_moptions *imo;
struct in_multi **immp;
struct in_mfilter *imfp;
size_t idx;
INP_WLOCK(inp);
if (inp->inp_moptions != NULL)
return (inp->inp_moptions);
INP_WUNLOCK(inp);
imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS,
M_WAITOK);
immp = (struct in_multi **)malloc(sizeof(*immp) * IP_MIN_MEMBERSHIPS,
M_IPMOPTS, M_WAITOK | M_ZERO);
imfp = (struct in_mfilter *)malloc(
sizeof(struct in_mfilter) * IP_MIN_MEMBERSHIPS,
M_IPMSOURCE, M_WAITOK);
imo->imo_multicast_ifp = NULL;
imo->imo_multicast_addr.s_addr = INADDR_ANY;
imo->imo_multicast_vif = -1;
imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
imo->imo_num_memberships = 0;
imo->imo_max_memberships = IP_MIN_MEMBERSHIPS;
imo->imo_membership = immp;
/* Initialize per-group source filters. */
for (idx = 0; idx < IP_MIN_MEMBERSHIPS; idx++) {
imfp[idx].imf_fmode = MCAST_EXCLUDE;
imfp[idx].imf_nsources = 0;
TAILQ_INIT(&imfp[idx].imf_sources);
}
imo->imo_mfilters = imfp;
INP_WLOCK(inp);
if (inp->inp_moptions != NULL) {
free(imfp, M_IPMSOURCE);
free(immp, M_IPMOPTS);
free(imo, M_IPMOPTS);
return (inp->inp_moptions);
}
inp->inp_moptions = imo;
return (imo);
}
/*
* Discard the IP multicast options (and source filters).
*/
void
inp_freemoptions(struct ip_moptions *imo)
{
struct in_mfilter *imf;
struct in_msource *ims, *tims;
size_t idx, nmships;
KASSERT(imo != NULL, ("%s: ip_moptions is NULL", __func__));
nmships = imo->imo_num_memberships;
for (idx = 0; idx < nmships; ++idx) {
in_delmulti(imo->imo_membership[idx]);
if (imo->imo_mfilters != NULL) {
imf = &imo->imo_mfilters[idx];
TAILQ_FOREACH_SAFE(ims, &imf->imf_sources,
ims_next, tims) {
TAILQ_REMOVE(&imf->imf_sources, ims, ims_next);
FREE(ims, M_IPMSOURCE);
imf->imf_nsources--;
}
KASSERT(imf->imf_nsources == 0,
("%s: did not free all imf_nsources", __func__));
}
}
if (imo->imo_mfilters != NULL)
free(imo->imo_mfilters, M_IPMSOURCE);
free(imo->imo_membership, M_IPMOPTS);
free(imo, M_IPMOPTS);
}
/*
* Atomically get source filters on a socket for an IPv4 multicast group.
* Called with INP lock held; returns with lock released.
*/
static int
inp_get_source_filters(struct inpcb *inp, struct sockopt *sopt)
{
struct __msfilterreq msfr;
sockunion_t *gsa;
struct ifnet *ifp;
struct ip_moptions *imo;
struct in_mfilter *imf;
struct in_msource *ims;
struct sockaddr_storage *ptss;
struct sockaddr_storage *tss;
int error;
size_t idx;
INP_WLOCK_ASSERT(inp);
imo = inp->inp_moptions;
KASSERT(imo != NULL, ("%s: null ip_moptions", __func__));
INP_WUNLOCK(inp);
error = sooptcopyin(sopt, &msfr, sizeof(struct __msfilterreq),
sizeof(struct __msfilterreq));
if (error)
return (error);
if (msfr.msfr_ifindex == 0 || if_index < msfr.msfr_ifindex)
return (EINVAL);
ifp = ifnet_byindex(msfr.msfr_ifindex);
if (ifp == NULL)
return (EINVAL);
INP_WLOCK(inp);
/*
* Lookup group on the socket.
*/
gsa = (sockunion_t *)&msfr.msfr_group;
idx = imo_match_group(imo, ifp, &gsa->sa);
if (idx == -1 || imo->imo_mfilters == NULL) {
INP_WUNLOCK(inp);
return (EADDRNOTAVAIL);
}
imf = &imo->imo_mfilters[idx];
msfr.msfr_fmode = imf->imf_fmode;
msfr.msfr_nsrcs = imf->imf_nsources;
/*
* If the user specified a buffer, copy out the source filter
* entries to userland gracefully.
* msfr.msfr_nsrcs is always set to the total number of filter
* entries which the kernel currently has for this group.
*/
tss = NULL;
if (msfr.msfr_srcs != NULL && msfr.msfr_nsrcs > 0) {
/*
* Make a copy of the source vector so that we do not
* thrash the inpcb lock whilst copying it out.
* We only copy out the number of entries which userland
* has asked for, but we always tell userland how big the
* buffer really needs to be.
*/
MALLOC(tss, struct sockaddr_storage *,
sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs,
M_TEMP, M_NOWAIT);
if (tss == NULL) {
error = ENOBUFS;
} else {
ptss = tss;
TAILQ_FOREACH(ims, &imf->imf_sources, ims_next) {
memcpy(ptss++, &ims->ims_addr,
sizeof(struct sockaddr_storage));
}
}
}
INP_WUNLOCK(inp);
if (tss != NULL) {
error = copyout(tss, msfr.msfr_srcs,
sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs);
FREE(tss, M_TEMP);
}
if (error)
return (error);
error = sooptcopyout(sopt, &msfr, sizeof(struct __msfilterreq));
return (error);
}
/*
* Return the IP multicast options in response to user getsockopt().
*/
int
inp_getmoptions(struct inpcb *inp, struct sockopt *sopt)
{
struct ip_mreqn mreqn;
struct ip_moptions *imo;
struct ifnet *ifp;
struct in_ifaddr *ia;
int error, optval;
u_char coptval;
INP_WLOCK(inp);
imo = inp->inp_moptions;
/*
* If socket is neither of type SOCK_RAW or SOCK_DGRAM,
* or is a divert socket, reject it.
*/
if (inp->inp_socket->so_proto->pr_protocol == IPPROTO_DIVERT ||
(inp->inp_socket->so_proto->pr_type != SOCK_RAW &&
inp->inp_socket->so_proto->pr_type != SOCK_DGRAM)) {
INP_WUNLOCK(inp);
return (EOPNOTSUPP);
}
error = 0;
switch (sopt->sopt_name) {
case IP_MULTICAST_VIF:
if (imo != NULL)
optval = imo->imo_multicast_vif;
else
optval = -1;
INP_WUNLOCK(inp);
error = sooptcopyout(sopt, &optval, sizeof(int));
break;
case IP_MULTICAST_IF:
memset(&mreqn, 0, sizeof(struct ip_mreqn));
if (imo != NULL) {
ifp = imo->imo_multicast_ifp;
if (imo->imo_multicast_addr.s_addr != INADDR_ANY) {
mreqn.imr_address = imo->imo_multicast_addr;
} else if (ifp != NULL) {
mreqn.imr_ifindex = ifp->if_index;
IFP_TO_IA(ifp, ia);
if (ia != NULL) {
mreqn.imr_address =
IA_SIN(ia)->sin_addr;
}
}
}
INP_WUNLOCK(inp);
if (sopt->sopt_valsize == sizeof(struct ip_mreqn)) {
error = sooptcopyout(sopt, &mreqn,
sizeof(struct ip_mreqn));
} else {
error = sooptcopyout(sopt, &mreqn.imr_address,
sizeof(struct in_addr));
}
break;
case IP_MULTICAST_TTL:
if (imo == 0)
optval = coptval = IP_DEFAULT_MULTICAST_TTL;
else
optval = coptval = imo->imo_multicast_ttl;
INP_WUNLOCK(inp);
if (sopt->sopt_valsize == sizeof(u_char))
error = sooptcopyout(sopt, &coptval, sizeof(u_char));
else
error = sooptcopyout(sopt, &optval, sizeof(int));
break;
case IP_MULTICAST_LOOP:
if (imo == 0)
optval = coptval = IP_DEFAULT_MULTICAST_LOOP;
else
optval = coptval = imo->imo_multicast_loop;
INP_WUNLOCK(inp);
if (sopt->sopt_valsize == sizeof(u_char))
error = sooptcopyout(sopt, &coptval, sizeof(u_char));
else
error = sooptcopyout(sopt, &optval, sizeof(int));
break;
case IP_MSFILTER:
if (imo == NULL) {
error = EADDRNOTAVAIL;
INP_WUNLOCK(inp);
} else {
error = inp_get_source_filters(inp, sopt);
}
break;
default:
INP_WUNLOCK(inp);
error = ENOPROTOOPT;
break;
}
INP_UNLOCK_ASSERT(inp);
return (error);
}
/*
* Join an IPv4 multicast group, possibly with a source.
*/
static int
inp_join_group(struct inpcb *inp, struct sockopt *sopt)
{
struct group_source_req gsr;
sockunion_t *gsa, *ssa;
struct ifnet *ifp;
struct in_mfilter *imf;
struct ip_moptions *imo;
struct in_multi *inm;
size_t idx;
int error;
ifp = NULL;
error = 0;
memset(&gsr, 0, sizeof(struct group_source_req));
gsa = (sockunion_t *)&gsr.gsr_group;
gsa->ss.ss_family = AF_UNSPEC;
ssa = (sockunion_t *)&gsr.gsr_source;
ssa->ss.ss_family = AF_UNSPEC;
switch (sopt->sopt_name) {
case IP_ADD_MEMBERSHIP:
case IP_ADD_SOURCE_MEMBERSHIP: {
struct ip_mreq_source mreqs;
if (sopt->sopt_name == IP_ADD_MEMBERSHIP) {
error = sooptcopyin(sopt, &mreqs,
sizeof(struct ip_mreq),
sizeof(struct ip_mreq));
/*
* Do argument switcharoo from ip_mreq into
* ip_mreq_source to avoid using two instances.
*/
mreqs.imr_interface = mreqs.imr_sourceaddr;
mreqs.imr_sourceaddr.s_addr = INADDR_ANY;
} else if (sopt->sopt_name == IP_ADD_SOURCE_MEMBERSHIP) {
error = sooptcopyin(sopt, &mreqs,
sizeof(struct ip_mreq_source),
sizeof(struct ip_mreq_source));
}
if (error)
return (error);
gsa->sin.sin_family = AF_INET;
gsa->sin.sin_len = sizeof(struct sockaddr_in);
gsa->sin.sin_addr = mreqs.imr_multiaddr;
if (sopt->sopt_name == IP_ADD_SOURCE_MEMBERSHIP) {
ssa->sin.sin_family = AF_INET;
ssa->sin.sin_len = sizeof(struct sockaddr_in);
ssa->sin.sin_addr = mreqs.imr_sourceaddr;
}
/*
* Obtain ifp. If no interface address was provided,
* use the interface of the route in the unicast FIB for
* the given multicast destination; usually, this is the
* default route.
* If this lookup fails, attempt to use the first non-loopback
* interface with multicast capability in the system as a
* last resort. The legacy IPv4 ASM API requires that we do
* this in order to allow groups to be joined when the routing
* table has not yet been populated during boot.
* If all of these conditions fail, return EADDRNOTAVAIL, and
* reject the IPv4 multicast join.
*/
if (mreqs.imr_interface.s_addr != INADDR_ANY) {
INADDR_TO_IFP(mreqs.imr_interface, ifp);
} else {
struct route ro;
ro.ro_rt = NULL;
*(struct sockaddr_in *)&ro.ro_dst = gsa->sin;
in_rtalloc_ign(&ro, RTF_CLONING,
inp->inp_inc.inc_fibnum);
if (ro.ro_rt != NULL) {
ifp = ro.ro_rt->rt_ifp;
KASSERT(ifp != NULL, ("%s: null ifp",
__func__));
RTFREE(ro.ro_rt);
} else {
struct in_ifaddr *ia;
struct ifnet *mfp = NULL;
TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link) {
mfp = ia->ia_ifp;
if (!(mfp->if_flags & IFF_LOOPBACK) &&
(mfp->if_flags & IFF_MULTICAST)) {
ifp = mfp;
break;
}
}
}
}
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: imr_interface = %s, ifp = %p\n",
__func__, inet_ntoa(mreqs.imr_interface), ifp);
}
#endif
break;
}
case MCAST_JOIN_GROUP:
case MCAST_JOIN_SOURCE_GROUP:
if (sopt->sopt_name == MCAST_JOIN_GROUP) {
error = sooptcopyin(sopt, &gsr,
sizeof(struct group_req),
sizeof(struct group_req));
} else if (sopt->sopt_name == MCAST_JOIN_SOURCE_GROUP) {
error = sooptcopyin(sopt, &gsr,
sizeof(struct group_source_req),
sizeof(struct group_source_req));
}
if (error)
return (error);
if (gsa->sin.sin_family != AF_INET ||
gsa->sin.sin_len != sizeof(struct sockaddr_in))
return (EINVAL);
/*
* Overwrite the port field if present, as the sockaddr
* being copied in may be matched with a binary comparison.
* XXX INET6
*/
gsa->sin.sin_port = 0;
if (sopt->sopt_name == MCAST_JOIN_SOURCE_GROUP) {
if (ssa->sin.sin_family != AF_INET ||
ssa->sin.sin_len != sizeof(struct sockaddr_in))
return (EINVAL);
ssa->sin.sin_port = 0;
}
/*
* Obtain the ifp.
*/
if (gsr.gsr_interface == 0 || if_index < gsr.gsr_interface)
return (EADDRNOTAVAIL);
ifp = ifnet_byindex(gsr.gsr_interface);
break;
default:
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: unknown sopt_name %d\n", __func__,
sopt->sopt_name);
}
#endif
return (EOPNOTSUPP);
break;
}
if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
return (EINVAL);
if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0)
return (EADDRNOTAVAIL);
/*
* Check if we already hold membership of this group for this inpcb.
* If so, we do not need to perform the initial join.
*/
imo = inp_findmoptions(inp);
idx = imo_match_group(imo, ifp, &gsa->sa);
if (idx != -1) {
if (ssa->ss.ss_family != AF_UNSPEC) {
/*
* Attempting to join an ASM group (when already
* an ASM or SSM member) is an error.
*/
error = EADDRNOTAVAIL;
} else {
imf = &imo->imo_mfilters[idx];
if (imf->imf_nsources == 0) {
/*
* Attempting to join an SSM group (when
* already an ASM member) is an error.
*/
error = EINVAL;
} else {
/*
* Attempting to join an SSM group (when
* already an SSM member) means "add this
* source to the inclusive filter list".
*/
error = imo_join_source(imo, idx, ssa);
}
}
goto out_locked;
}
/*
* Call imo_grow() to reallocate the membership and source filter
* vectors if they are full. If the size would exceed the hard limit,
* then we know we've really run out of entries. We keep the INP
* lock held to avoid introducing a race condition.
*/
if (imo->imo_num_memberships == imo->imo_max_memberships) {
error = imo_grow(imo);
if (error)
goto out_locked;
}
/*
* So far, so good: perform the layer 3 join, layer 2 join,
* and make an IGMP announcement if needed.
*/
inm = in_addmulti(&gsa->sin.sin_addr, ifp);
if (inm == NULL) {
error = ENOBUFS;
goto out_locked;
}
idx = imo->imo_num_memberships;
imo->imo_membership[idx] = inm;
imo->imo_num_memberships++;
KASSERT(imo->imo_mfilters != NULL,
("%s: imf_mfilters vector was not allocated", __func__));
imf = &imo->imo_mfilters[idx];
KASSERT(TAILQ_EMPTY(&imf->imf_sources),
("%s: imf_sources not empty", __func__));
/*
* If this is a new SSM group join (i.e. a source was specified
* with this group), add this source to the filter list.
*/
if (ssa->ss.ss_family != AF_UNSPEC) {
/*
* An initial SSM join implies that this socket's membership
* of the multicast group is now in inclusive mode.
*/
imf->imf_fmode = MCAST_INCLUDE;
error = imo_join_source(imo, idx, ssa);
if (error) {
/*
* Drop inp lock before calling in_delmulti(),
* to prevent a lock order reversal.
*/
--imo->imo_num_memberships;
INP_WUNLOCK(inp);
in_delmulti(inm);
return (error);
}
}
out_locked:
INP_WUNLOCK(inp);
return (error);
}
/*
* Leave an IPv4 multicast group on an inpcb, possibly with a source.
*/
static int
inp_leave_group(struct inpcb *inp, struct sockopt *sopt)
{
struct group_source_req gsr;
struct ip_mreq_source mreqs;
sockunion_t *gsa, *ssa;
struct ifnet *ifp;
struct in_mfilter *imf;
struct ip_moptions *imo;
struct in_msource *ims, *tims;
struct in_multi *inm;
size_t idx;
int error;
ifp = NULL;
error = 0;
memset(&gsr, 0, sizeof(struct group_source_req));
gsa = (sockunion_t *)&gsr.gsr_group;
gsa->ss.ss_family = AF_UNSPEC;
ssa = (sockunion_t *)&gsr.gsr_source;
ssa->ss.ss_family = AF_UNSPEC;
switch (sopt->sopt_name) {
case IP_DROP_MEMBERSHIP:
case IP_DROP_SOURCE_MEMBERSHIP:
if (sopt->sopt_name == IP_DROP_MEMBERSHIP) {
error = sooptcopyin(sopt, &mreqs,
sizeof(struct ip_mreq),
sizeof(struct ip_mreq));
/*
* Swap interface and sourceaddr arguments,
* as ip_mreq and ip_mreq_source are laid
* out differently.
*/
mreqs.imr_interface = mreqs.imr_sourceaddr;
mreqs.imr_sourceaddr.s_addr = INADDR_ANY;
} else if (sopt->sopt_name == IP_DROP_SOURCE_MEMBERSHIP) {
error = sooptcopyin(sopt, &mreqs,
sizeof(struct ip_mreq_source),
sizeof(struct ip_mreq_source));
}
if (error)
return (error);
gsa->sin.sin_family = AF_INET;
gsa->sin.sin_len = sizeof(struct sockaddr_in);
gsa->sin.sin_addr = mreqs.imr_multiaddr;
if (sopt->sopt_name == IP_DROP_SOURCE_MEMBERSHIP) {
ssa->sin.sin_family = AF_INET;
ssa->sin.sin_len = sizeof(struct sockaddr_in);
ssa->sin.sin_addr = mreqs.imr_sourceaddr;
}
if (gsa->sin.sin_addr.s_addr != INADDR_ANY)
INADDR_TO_IFP(mreqs.imr_interface, ifp);
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: imr_interface = %s, ifp = %p\n",
__func__, inet_ntoa(mreqs.imr_interface), ifp);
}
#endif
break;
case MCAST_LEAVE_GROUP:
case MCAST_LEAVE_SOURCE_GROUP:
if (sopt->sopt_name == MCAST_LEAVE_GROUP) {
error = sooptcopyin(sopt, &gsr,
sizeof(struct group_req),
sizeof(struct group_req));
} else if (sopt->sopt_name == MCAST_LEAVE_SOURCE_GROUP) {
error = sooptcopyin(sopt, &gsr,
sizeof(struct group_source_req),
sizeof(struct group_source_req));
}
if (error)
return (error);
if (gsa->sin.sin_family != AF_INET ||
gsa->sin.sin_len != sizeof(struct sockaddr_in))
return (EINVAL);
if (sopt->sopt_name == MCAST_LEAVE_SOURCE_GROUP) {
if (ssa->sin.sin_family != AF_INET ||
ssa->sin.sin_len != sizeof(struct sockaddr_in))
return (EINVAL);
}
if (gsr.gsr_interface == 0 || if_index < gsr.gsr_interface)
return (EADDRNOTAVAIL);
ifp = ifnet_byindex(gsr.gsr_interface);
break;
default:
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: unknown sopt_name %d\n", __func__,
sopt->sopt_name);
}
#endif
return (EOPNOTSUPP);
break;
}
if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
return (EINVAL);
/*
* Find the membership in the membership array.
*/
imo = inp_findmoptions(inp);
idx = imo_match_group(imo, ifp, &gsa->sa);
if (idx == -1) {
error = EADDRNOTAVAIL;
goto out_locked;
}
imf = &imo->imo_mfilters[idx];
/*
* If we were instructed only to leave a given source, do so.
*/
if (ssa->ss.ss_family != AF_UNSPEC) {
if (imf->imf_nsources == 0 ||
imf->imf_fmode == MCAST_EXCLUDE) {
/*
* Attempting to SSM leave an ASM group
* is an error; should use *_BLOCK_SOURCE instead.
* Attempting to SSM leave a source in a group when
* the socket is in 'exclude mode' is also an error.
*/
error = EINVAL;
} else {
error = imo_leave_source(imo, idx, ssa);
}
/*
* If an error occurred, or this source is not the last
* source in the group, do not leave the whole group.
*/
if (error || imf->imf_nsources > 0)
goto out_locked;
}
/*
* Give up the multicast address record to which the membership points.
*/
inm = imo->imo_membership[idx];
in_delmulti(inm);
/*
* Free any source filters for this group if they exist.
* Revert inpcb to the default MCAST_EXCLUDE state.
*/
if (imo->imo_mfilters != NULL) {
TAILQ_FOREACH_SAFE(ims, &imf->imf_sources, ims_next, tims) {
TAILQ_REMOVE(&imf->imf_sources, ims, ims_next);
FREE(ims, M_IPMSOURCE);
imf->imf_nsources--;
}
KASSERT(imf->imf_nsources == 0,
("%s: imf_nsources not 0", __func__));
KASSERT(TAILQ_EMPTY(&imf->imf_sources),
("%s: imf_sources not empty", __func__));
imf->imf_fmode = MCAST_EXCLUDE;
}
/*
* Remove the gap in the membership array.
*/
for (++idx; idx < imo->imo_num_memberships; ++idx)
imo->imo_membership[idx-1] = imo->imo_membership[idx];
imo->imo_num_memberships--;
out_locked:
INP_WUNLOCK(inp);
return (error);
}
/*
* Select the interface for transmitting IPv4 multicast datagrams.
*
* Either an instance of struct in_addr or an instance of struct ip_mreqn
* may be passed to this socket option. An address of INADDR_ANY or an
* interface index of 0 is used to remove a previous selection.
* When no interface is selected, one is chosen for every send.
*/
static int
inp_set_multicast_if(struct inpcb *inp, struct sockopt *sopt)
{
struct in_addr addr;
struct ip_mreqn mreqn;
struct ifnet *ifp;
struct ip_moptions *imo;
int error;
if (sopt->sopt_valsize == sizeof(struct ip_mreqn)) {
/*
* An interface index was specified using the
* Linux-derived ip_mreqn structure.
*/
error = sooptcopyin(sopt, &mreqn, sizeof(struct ip_mreqn),
sizeof(struct ip_mreqn));
if (error)
return (error);
if (mreqn.imr_ifindex < 0 || if_index < mreqn.imr_ifindex)
return (EINVAL);
if (mreqn.imr_ifindex == 0) {
ifp = NULL;
} else {
ifp = ifnet_byindex(mreqn.imr_ifindex);
if (ifp == NULL)
return (EADDRNOTAVAIL);
}
} else {
/*
* An interface was specified by IPv4 address.
* This is the traditional BSD usage.
*/
error = sooptcopyin(sopt, &addr, sizeof(struct in_addr),
sizeof(struct in_addr));
if (error)
return (error);
if (addr.s_addr == INADDR_ANY) {
ifp = NULL;
} else {
INADDR_TO_IFP(addr, ifp);
if (ifp == NULL)
return (EADDRNOTAVAIL);
}
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: ifp = %p, addr = %s\n",
__func__, ifp, inet_ntoa(addr)); /* XXX INET6 */
}
#endif
}
/* Reject interfaces which do not support multicast. */
if (ifp != NULL && (ifp->if_flags & IFF_MULTICAST) == 0)
return (EOPNOTSUPP);
imo = inp_findmoptions(inp);
imo->imo_multicast_ifp = ifp;
imo->imo_multicast_addr.s_addr = INADDR_ANY;
INP_WUNLOCK(inp);
return (0);
}
/*
* Atomically set source filters on a socket for an IPv4 multicast group.
*/
static int
inp_set_source_filters(struct inpcb *inp, struct sockopt *sopt)
{
struct __msfilterreq msfr;
sockunion_t *gsa;
struct ifnet *ifp;
struct in_mfilter *imf;
struct ip_moptions *imo;
struct in_msource *ims, *tims;
size_t idx;
int error;
error = sooptcopyin(sopt, &msfr, sizeof(struct __msfilterreq),
sizeof(struct __msfilterreq));
if (error)
return (error);
if (msfr.msfr_nsrcs > IP_MAX_SOURCE_FILTER ||
(msfr.msfr_fmode != MCAST_EXCLUDE &&
msfr.msfr_fmode != MCAST_INCLUDE))
return (EINVAL);
if (msfr.msfr_group.ss_family != AF_INET ||
msfr.msfr_group.ss_len != sizeof(struct sockaddr_in))
return (EINVAL);
gsa = (sockunion_t *)&msfr.msfr_group;
if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
return (EINVAL);
gsa->sin.sin_port = 0; /* ignore port */
if (msfr.msfr_ifindex == 0 || if_index < msfr.msfr_ifindex)
return (EADDRNOTAVAIL);
ifp = ifnet_byindex(msfr.msfr_ifindex);
if (ifp == NULL)
return (EADDRNOTAVAIL);
/*
* Take the INP lock.
* Check if this socket is a member of this group.
*/
imo = inp_findmoptions(inp);
idx = imo_match_group(imo, ifp, &gsa->sa);
if (idx == -1 || imo->imo_mfilters == NULL) {
error = EADDRNOTAVAIL;
goto out_locked;
}
imf = &imo->imo_mfilters[idx];
#ifdef DIAGNOSTIC
if (bootverbose)
printf("%s: clearing source list\n", __func__);
#endif
/*
* Remove any existing source filters.
*/
TAILQ_FOREACH_SAFE(ims, &imf->imf_sources, ims_next, tims) {
TAILQ_REMOVE(&imf->imf_sources, ims, ims_next);
FREE(ims, M_IPMSOURCE);
imf->imf_nsources--;
}
KASSERT(imf->imf_nsources == 0,
("%s: source list not cleared", __func__));
/*
* Apply any new source filters, if present.
*/
if (msfr.msfr_nsrcs > 0) {
struct in_msource **pnims;
struct in_msource *nims;
struct sockaddr_storage *kss;
struct sockaddr_storage *pkss;
sockunion_t *psu;
int i, j;
/*
* Drop the inp lock so we may sleep if we need to
* in order to satisfy a malloc request.
* We will re-take it before changing socket state.
*/
INP_WUNLOCK(inp);
#ifdef DIAGNOSTIC
if (bootverbose) {
printf("%s: loading %lu source list entries\n",
__func__, (unsigned long)msfr.msfr_nsrcs);
}
#endif
/*
* Make a copy of the user-space source vector so
* that we may copy them with a single copyin. This
* allows us to deal with page faults up-front.
*/
MALLOC(kss, struct sockaddr_storage *,
sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs,
M_TEMP, M_WAITOK);
error = copyin(msfr.msfr_srcs, kss,
sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs);
if (error) {
FREE(kss, M_TEMP);
return (error);
}
/*
* Perform argument checking on every sockaddr_storage
* structure in the vector provided to us. Overwrite
* fields which should not apply to source entries.
* TODO: Check for duplicate sources on this pass.
*/
psu = (sockunion_t *)kss;
for (i = 0; i < msfr.msfr_nsrcs; i++, psu++) {
switch (psu->ss.ss_family) {
case AF_INET:
if (psu->sin.sin_len !=
sizeof(struct sockaddr_in)) {
error = EINVAL;
} else {
psu->sin.sin_port = 0;
}
break;
#ifdef notyet
case AF_INET6;
if (psu->sin6.sin6_len !=
sizeof(struct sockaddr_in6)) {
error = EINVAL;
} else {
psu->sin6.sin6_port = 0;
psu->sin6.sin6_flowinfo = 0;
}
break;
#endif
default:
error = EAFNOSUPPORT;
break;
}
if (error)
break;
}
if (error) {
FREE(kss, M_TEMP);
return (error);
}
/*
* Allocate a block to track all the in_msource
* entries we are about to allocate, in case we
* abruptly need to free them.
*/
MALLOC(pnims, struct in_msource **,
sizeof(struct in_msource *) * msfr.msfr_nsrcs,
M_TEMP, M_WAITOK | M_ZERO);
/*
* Allocate up to nsrcs individual chunks.
* If we encounter an error, backtrack out of
* all allocations cleanly; updates must be atomic.
*/
pkss = kss;
nims = NULL;
for (i = 0; i < msfr.msfr_nsrcs; i++, pkss++) {
MALLOC(nims, struct in_msource *,
sizeof(struct in_msource) * msfr.msfr_nsrcs,
M_IPMSOURCE, M_WAITOK | M_ZERO);
pnims[i] = nims;
}
if (i < msfr.msfr_nsrcs) {
for (j = 0; j < i; j++) {
if (pnims[j] != NULL)
FREE(pnims[j], M_IPMSOURCE);
}
FREE(pnims, M_TEMP);
FREE(kss, M_TEMP);
return (ENOBUFS);
}
INP_UNLOCK_ASSERT(inp);
/*
* Finally, apply the filters to the socket.
* Re-take the inp lock; we are changing socket state.
*/
pkss = kss;
INP_WLOCK(inp);
for (i = 0; i < msfr.msfr_nsrcs; i++, pkss++) {
memcpy(&(pnims[i]->ims_addr), pkss,
sizeof(struct sockaddr_storage));
TAILQ_INSERT_TAIL(&imf->imf_sources, pnims[i],
ims_next);
imf->imf_nsources++;
}
FREE(pnims, M_TEMP);
FREE(kss, M_TEMP);
}
/*
* Update the filter mode on the socket before releasing the inpcb.
*/
INP_WLOCK_ASSERT(inp);
imf->imf_fmode = msfr.msfr_fmode;
out_locked:
INP_WUNLOCK(inp);
return (error);
}
/*
* Set the IP multicast options in response to user setsockopt().
*
* Many of the socket options handled in this function duplicate the
* functionality of socket options in the regular unicast API. However,
* it is not possible to merge the duplicate code, because the idempotence
* of the IPv4 multicast part of the BSD Sockets API must be preserved;
* the effects of these options must be treated as separate and distinct.
*/
int
inp_setmoptions(struct inpcb *inp, struct sockopt *sopt)
{
struct ip_moptions *imo;
int error;
error = 0;
/*
* If socket is neither of type SOCK_RAW or SOCK_DGRAM,
* or is a divert socket, reject it.
* XXX Unlocked read of inp_socket believed OK.
*/
if (inp->inp_socket->so_proto->pr_protocol == IPPROTO_DIVERT ||
(inp->inp_socket->so_proto->pr_type != SOCK_RAW &&
inp->inp_socket->so_proto->pr_type != SOCK_DGRAM))
return (EOPNOTSUPP);
switch (sopt->sopt_name) {
case IP_MULTICAST_VIF: {
int vifi;
/*
* Select a multicast VIF for transmission.
* Only useful if multicast forwarding is active.
*/
if (legal_vif_num == NULL) {
error = EOPNOTSUPP;
break;
}
error = sooptcopyin(sopt, &vifi, sizeof(int), sizeof(int));
if (error)
break;
if (!legal_vif_num(vifi) && (vifi != -1)) {
error = EINVAL;
break;
}
imo = inp_findmoptions(inp);
imo->imo_multicast_vif = vifi;
INP_WUNLOCK(inp);
break;
}
case IP_MULTICAST_IF:
error = inp_set_multicast_if(inp, sopt);
break;
case IP_MULTICAST_TTL: {
u_char ttl;
/*
* Set the IP time-to-live for outgoing multicast packets.
* The original multicast API required a char argument,
* which is inconsistent with the rest of the socket API.
* We allow either a char or an int.
*/
if (sopt->sopt_valsize == sizeof(u_char)) {
error = sooptcopyin(sopt, &ttl, sizeof(u_char),
sizeof(u_char));
if (error)
break;
} else {
u_int ittl;
error = sooptcopyin(sopt, &ittl, sizeof(u_int),
sizeof(u_int));
if (error)
break;
if (ittl > 255) {
error = EINVAL;
break;
}
ttl = (u_char)ittl;
}
imo = inp_findmoptions(inp);
imo->imo_multicast_ttl = ttl;
INP_WUNLOCK(inp);
break;
}
case IP_MULTICAST_LOOP: {
u_char loop;
/*
* Set the loopback flag for outgoing multicast packets.
* Must be zero or one. The original multicast API required a
* char argument, which is inconsistent with the rest
* of the socket API. We allow either a char or an int.
*/
if (sopt->sopt_valsize == sizeof(u_char)) {
error = sooptcopyin(sopt, &loop, sizeof(u_char),
sizeof(u_char));
if (error)
break;
} else {
u_int iloop;
error = sooptcopyin(sopt, &iloop, sizeof(u_int),
sizeof(u_int));
if (error)
break;
loop = (u_char)iloop;
}
imo = inp_findmoptions(inp);
imo->imo_multicast_loop = !!loop;
INP_WUNLOCK(inp);
break;
}
case IP_ADD_MEMBERSHIP:
case IP_ADD_SOURCE_MEMBERSHIP:
case MCAST_JOIN_GROUP:
case MCAST_JOIN_SOURCE_GROUP:
error = inp_join_group(inp, sopt);
break;
case IP_DROP_MEMBERSHIP:
case IP_DROP_SOURCE_MEMBERSHIP:
case MCAST_LEAVE_GROUP:
case MCAST_LEAVE_SOURCE_GROUP:
error = inp_leave_group(inp, sopt);
break;
case IP_BLOCK_SOURCE:
case IP_UNBLOCK_SOURCE:
case MCAST_BLOCK_SOURCE:
case MCAST_UNBLOCK_SOURCE:
error = inp_change_source_filter(inp, sopt);
break;
case IP_MSFILTER:
error = inp_set_source_filters(inp, sopt);
break;
default:
error = EOPNOTSUPP;
break;
}
INP_UNLOCK_ASSERT(inp);
return (error);
}
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