* Copyright (c) 1989 Stephen Deering
* Copyright (c) 1992, 1993
* The 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
* 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
* @(#)ip_mroute.c 8.2 (Berkeley) 11/15/93
* Procedures for the kernel part of DVMRP,
* a Distance-Vector Multicast Routing Protocol.
* Written by David Waitzman, BBN Labs, August 1988.
* Modified by Steve Deering, Stanford, February 1989.
int ip_mrtproto
; /* for netstat only */
#include <sys/socketvar.h>
#include <netinet/in_systm.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <netinet/igmp.h>
#include <netinet/igmp_var.h>
#include <netinet/ip_mroute.h>
static int ip_mrouter_init
__P((struct socket
*));
static int add_vif
__P((struct vifctl
*));
static int del_vif
__P((vifi_t
*vifip
));
static int add_lgrp
__P((struct lgrplctl
*));
static int del_lgrp
__P((struct lgrplctl
*));
static int grplst_member
__P((struct vif
*, struct in_addr
));
static u_long nethash
__P((struct in_addr in
));
static int add_mrt
__P((struct mrtctl
*));
static int del_mrt
__P((struct in_addr
*));
static struct mrt
*mrtfind
__P((struct in_addr
));
static void phyint_send
__P((struct mbuf
*, struct vif
*));
static void tunnel_send
__P((struct mbuf
*, struct vif
*));
#define INSIZ sizeof(struct in_addr)
#define same(a1, a2) (bcmp((caddr_t)(a1), (caddr_t)(a2), INSIZ) == 0)
#define satosin(sa) ((struct sockaddr_in *)(sa))
* Globals. All but ip_mrouter and ip_mrtproto could be static,
* except for netstat or debugging purposes.
struct socket
*ip_mrouter
= NULL
;
int ip_mrtproto
= IGMP_DVMRP
; /* for netstat only */
struct mrt
*mrttable
[MRTHASHSIZ
];
struct vif viftable
[MAXVIFS
];
static vifi_t numvifs
= 0;
static struct mrt
*cached_mrt
= NULL
;
static u_long cached_origin
;
static u_long cached_originmask
;
* Handle DVMRP setsockopt commands to modify the multicast routing tables.
ip_mrouter_cmd(cmd
, so
, m
)
register struct socket
*so
;
if (cmd
!= DVMRP_INIT
&& so
!= ip_mrouter
)
error
= ip_mrouter_init(so
);
error
= ip_mrouter_done();
if (m
== NULL
|| m
->m_len
< sizeof(struct vifctl
))
error
= add_vif(mtod(m
, struct vifctl
*));
if (m
== NULL
|| m
->m_len
< sizeof(short))
error
= del_vif(mtod(m
, vifi_t
*));
if (m
== NULL
|| m
->m_len
< sizeof(struct lgrplctl
))
error
= add_lgrp(mtod(m
, struct lgrplctl
*));
if (m
== NULL
|| m
->m_len
< sizeof(struct lgrplctl
))
error
= del_lgrp(mtod(m
, struct lgrplctl
*));
if (m
== NULL
|| m
->m_len
< sizeof(struct mrtctl
))
error
= add_mrt(mtod(m
, struct mrtctl
*));
if (m
== NULL
|| m
->m_len
< sizeof(struct in_addr
))
error
= del_mrt(mtod(m
, struct in_addr
*));
* Enable multicast routing
register struct socket
*so
;
if (so
->so_type
!= SOCK_RAW
||
so
->so_proto
->pr_protocol
!= IPPROTO_IGMP
)
* Disable multicast routing
register struct ifnet
*ifp
;
* For each phyint in use, free its local group list and
* disable promiscuous reception of all IP multicasts.
for (vifi
= 0; vifi
< numvifs
; vifi
++) {
if (viftable
[vifi
].v_lcl_addr
.s_addr
!= 0 &&
!(viftable
[vifi
].v_flags
& VIFF_TUNNEL
)) {
if (viftable
[vifi
].v_lcl_grps
)
free(viftable
[vifi
].v_lcl_grps
, M_MRTABLE
);
satosin(&ifr
.ifr_addr
)->sin_family
= AF_INET
;
satosin(&ifr
.ifr_addr
)->sin_addr
.s_addr
= INADDR_ANY
;
ifp
= viftable
[vifi
].v_ifp
;
(*ifp
->if_ioctl
)(ifp
, SIOCDELMULTI
, (caddr_t
)&ifr
);
bzero((caddr_t
)viftable
, sizeof(viftable
));
* Free any multicast route entries.
for (i
= 0; i
< MRTHASHSIZ
; i
++)
free(mrttable
[i
], M_MRTABLE
);
bzero((caddr_t
)mrttable
, sizeof(mrttable
));
* Add a vif to the vif table
register struct vifctl
*vifcp
;
register struct vif
*vifp
= viftable
+ vifcp
->vifc_vifi
;
register struct ifaddr
*ifa
;
register struct ifnet
*ifp
;
static struct sockaddr_in sin
= { sizeof(sin
), AF_INET
};
if (vifcp
->vifc_vifi
>= MAXVIFS
)
if (vifp
->v_lcl_addr
.s_addr
!= 0)
/* Find the interface with an address in AF_INET family */
sin
.sin_addr
= vifcp
->vifc_lcl_addr
;
ifa
= ifa_ifwithaddr((struct sockaddr
*)&sin
);
if (vifcp
->vifc_flags
& VIFF_TUNNEL
)
vifp
->v_rmt_addr
= vifcp
->vifc_rmt_addr
;
/* Make sure the interface supports multicast */
if ((ifp
->if_flags
& IFF_MULTICAST
) == 0) {
* Enable promiscuous reception of all IP multicasts
satosin(&ifr
.ifr_addr
)->sin_family
= AF_INET
;
satosin(&ifr
.ifr_addr
)->sin_addr
.s_addr
= INADDR_ANY
;
error
= (*ifp
->if_ioctl
)(ifp
, SIOCADDMULTI
, (caddr_t
)&ifr
);
vifp
->v_flags
= vifcp
->vifc_flags
;
vifp
->v_threshold
= vifcp
->vifc_threshold
;
vifp
->v_lcl_addr
= vifcp
->vifc_lcl_addr
;
vifp
->v_ifp
= ifa
->ifa_ifp
;
/* Adjust numvifs up if the vifi is higher than numvifs */
if (numvifs
<= vifcp
->vifc_vifi
)
numvifs
= vifcp
->vifc_vifi
+ 1;
* Delete a vif from the vif table
register struct vif
*vifp
= viftable
+ *vifip
;
register struct ifnet
*ifp
;
if (vifp
->v_lcl_addr
.s_addr
== 0)
if (!(vifp
->v_flags
& VIFF_TUNNEL
)) {
free(vifp
->v_lcl_grps
, M_MRTABLE
);
satosin(&ifr
.ifr_addr
)->sin_family
= AF_INET
;
satosin(&ifr
.ifr_addr
)->sin_addr
.s_addr
= INADDR_ANY
;
(*ifp
->if_ioctl
)(ifp
, SIOCDELMULTI
, (caddr_t
)&ifr
);
bzero((caddr_t
)vifp
, sizeof (*vifp
));
/* Adjust numvifs down */
for (i
= numvifs
- 1; i
>= 0; i
--)
if (viftable
[i
].v_lcl_addr
.s_addr
!= 0)
* Add the multicast group in the lgrpctl to the list of local multicast
* group memberships associated with the vif indexed by gcp->lgc_vifi.
register struct lgrplctl
*gcp
;
register struct vif
*vifp
;
if (gcp
->lgc_vifi
>= numvifs
)
vifp
= viftable
+ gcp
->lgc_vifi
;
if (vifp
->v_lcl_addr
.s_addr
== 0 || (vifp
->v_flags
& VIFF_TUNNEL
))
/* If not enough space in existing list, allocate a larger one */
if (vifp
->v_lcl_grps_n
+ 1 >= vifp
->v_lcl_grps_max
) {
register struct in_addr
*ip
;
num
= vifp
->v_lcl_grps_max
;
num
= 32; /* initial number */
num
+= num
; /* double last number */
ip
= (struct in_addr
*)malloc(num
* sizeof(*ip
),
bzero((caddr_t
)ip
, num
* sizeof(*ip
)); /* XXX paranoid */
bcopy((caddr_t
)vifp
->v_lcl_grps
, (caddr_t
)ip
,
vifp
->v_lcl_grps_n
* sizeof(*ip
));
vifp
->v_lcl_grps_max
= num
;
free(vifp
->v_lcl_grps
, M_MRTABLE
);
vifp
->v_lcl_grps
[vifp
->v_lcl_grps_n
++] = gcp
->lgc_gaddr
;
if (gcp
->lgc_gaddr
.s_addr
== vifp
->v_cached_group
)
vifp
->v_cached_result
= 1;
* Delete the the local multicast group associated with the vif
* indexed by gcp->lgc_vifi.
register struct lgrplctl
*gcp
;
register struct vif
*vifp
;
register int i
, error
, s
;
if (gcp
->lgc_vifi
>= numvifs
)
vifp
= viftable
+ gcp
->lgc_vifi
;
if (vifp
->v_lcl_addr
.s_addr
== 0 || (vifp
->v_flags
& VIFF_TUNNEL
))
if (gcp
->lgc_gaddr
.s_addr
== vifp
->v_cached_group
)
vifp
->v_cached_result
= 0;
for (i
= 0; i
< vifp
->v_lcl_grps_n
; ++i
)
if (same(&gcp
->lgc_gaddr
, &vifp
->v_lcl_grps
[i
])) {
bcopy((caddr_t
)&vifp
->v_lcl_grps
[i
+ 1],
(caddr_t
)&vifp
->v_lcl_grps
[i
],
(vifp
->v_lcl_grps_n
- i
) * sizeof(struct in_addr
));
* Return 1 if gaddr is a member of the local group list for vifp.
grplst_member(vifp
, gaddr
)
register struct vif
*vifp
;
mrtstat
.mrts_grp_lookups
++;
if (addr
== vifp
->v_cached_group
)
return (vifp
->v_cached_result
);
mrtstat
.mrts_grp_misses
++;
for (i
= 0; i
< vifp
->v_lcl_grps_n
; ++i
)
if (addr
== vifp
->v_lcl_grps
[i
].s_addr
) {
vifp
->v_cached_group
= addr
;
vifp
->v_cached_result
= 1;
vifp
->v_cached_group
= addr
;
vifp
->v_cached_result
= 0;
* A simple hash function: returns MRTHASHMOD of the low-order octet of
* the argument's network or subnet number.
register struct mrtctl
*mrtcp
;
if (rt
= mrtfind(mrtcp
->mrtc_origin
)) {
/* Just update the route */
rt
->mrt_parent
= mrtcp
->mrtc_parent
;
VIFM_COPY(mrtcp
->mrtc_children
, rt
->mrt_children
);
VIFM_COPY(mrtcp
->mrtc_leaves
, rt
->mrt_leaves
);
rt
= (struct mrt
*)malloc(sizeof(*rt
), M_MRTABLE
, M_NOWAIT
);
* insert new entry at head of hash chain
rt
->mrt_origin
= mrtcp
->mrtc_origin
;
rt
->mrt_originmask
= mrtcp
->mrtc_originmask
;
rt
->mrt_parent
= mrtcp
->mrtc_parent
;
VIFM_COPY(mrtcp
->mrtc_children
, rt
->mrt_children
);
VIFM_COPY(mrtcp
->mrtc_leaves
, rt
->mrt_leaves
);
hash
= nethash(mrtcp
->mrtc_origin
);
rt
->mrt_next
= mrttable
[hash
];
register struct in_addr
*origin
;
register struct mrt
*rt
, *prev_rt
;
register u_long hash
= nethash(*origin
);
for (prev_rt
= rt
= mrttable
[hash
]; rt
; prev_rt
= rt
, rt
= rt
->mrt_next
)
if (origin
->s_addr
== rt
->mrt_origin
.s_addr
)
mrttable
[hash
] = rt
->mrt_next
;
prev_rt
->mrt_next
= rt
->mrt_next
;
* Find a route for a given origin IP address.
mrtstat
.mrts_mrt_lookups
++;
if (cached_mrt
!= NULL
&&
(origin
.s_addr
& cached_originmask
) == cached_origin
)
mrtstat
.mrts_mrt_misses
++;
for (rt
= mrttable
[hash
]; rt
; rt
= rt
->mrt_next
)
if ((origin
.s_addr
& rt
->mrt_originmask
.s_addr
) ==
cached_origin
= rt
->mrt_origin
.s_addr
;
cached_originmask
= rt
->mrt_originmask
.s_addr
;
* IP multicast forwarding function. This function assumes that the packet
* pointed to by "ip" has arrived on (or is about to be sent to) the interface
* pointed to by "ifp", and the packet is to be relayed to other networks
* that have members of the packet's destination IP multicast group.
* The packet is returned unscathed to the caller, unless it is tunneled
* or erroneous, in which case a non-zero return value tells the caller to
#define IP_HDR_LEN 20 /* # bytes of fixed IP header (excluding options) */
#define TUNNEL_LEN 12 /* # bytes of IP option for tunnel encapsulation */
register struct ifnet
*ifp
;
register struct ip
*ip
= mtod(m
, struct ip
*);
register struct vif
*vifp
;
register u_char
*ipoptions
;
if (ip
->ip_hl
< (IP_HDR_LEN
+ TUNNEL_LEN
) >> 2 ||
(ipoptions
= (u_char
*)(ip
+ 1))[1] != IPOPT_LSRR
) {
* Packet arrived via a physical interface.
* Packet arrived through a tunnel.
* A tunneled packet has a single NOP option and a
* two-element loose-source-and-record-route (LSRR)
* option immediately following the fixed-size part of
* the IP header. At this point in processing, the IP
* header should contain the following IP addresses:
* original source - in the source address field
* destination group - in the destination address field
* remote tunnel end-point - in the first element of LSRR
* one of this host's addrs - in the second element of LSRR
* NOTE: RFC-1075 would have the original source and
* remote tunnel end-point addresses swapped. However,
* that could cause delivery of ICMP error messages to
* innocent applications on intermediate routing
* hosts! Therefore, we hereby change the spec.
* Verify that the tunnel options are well-formed.
if (ipoptions
[0] != IPOPT_NOP
||
ipoptions
[2] != 11 || /* LSRR option length */
ipoptions
[3] != 12 || /* LSRR address pointer */
(tunnel_src
= *(u_long
*)(&ipoptions
[4])) == 0) {
mrtstat
.mrts_bad_tunnel
++;
* Delete the tunnel options from the packet.
ovbcopy((caddr_t
)(ipoptions
+ TUNNEL_LEN
), (caddr_t
)ipoptions
,
(unsigned)(m
->m_len
- (IP_HDR_LEN
+ TUNNEL_LEN
)));
ip
->ip_len
-= TUNNEL_LEN
;
ip
->ip_hl
-= TUNNEL_LEN
>> 2;
* Don't forward a packet with time-to-live of zero or one,
* or a packet destined to a local-only group.
ntohl(ip
->ip_dst
.s_addr
) <= INADDR_MAX_LOCAL_GROUP
)
return ((int)tunnel_src
);
* Don't forward if we don't have a route for the packet's origin.
if (!(rt
= mrtfind(ip
->ip_src
))) {
return ((int)tunnel_src
);
* Don't forward if it didn't arrive from the parent vif for its origin.
if ((viftable
[vifi
].v_flags
& VIFF_TUNNEL
) ||
viftable
[vifi
].v_ifp
!= ifp
)
return ((int)tunnel_src
);
if (!(viftable
[vifi
].v_flags
& VIFF_TUNNEL
) ||
viftable
[vifi
].v_rmt_addr
.s_addr
!= tunnel_src
)
return ((int)tunnel_src
);
* For each vif, decide if a copy of the packet should be forwarded.
* - the ttl exceeds the vif's threshold AND
* - the vif is a child in the origin's route AND
* - ( the vif is not a leaf in the origin's route OR
* the destination group has members on the vif )
* (This might be speeded up with some sort of cache -- someday.)
for (vifp
= viftable
, vifi
= 0; vifi
< numvifs
; vifp
++, vifi
++) {
if (ip
->ip_ttl
> vifp
->v_threshold
&&
VIFM_ISSET(vifi
, rt
->mrt_children
) &&
(!VIFM_ISSET(vifi
, rt
->mrt_leaves
) ||
grplst_member(vifp
, ip
->ip_dst
))) {
if (vifp
->v_flags
& VIFF_TUNNEL
)
return ((int)tunnel_src
);
register struct vif
*vifp
;
register struct ip
*ip
= mtod(m
, struct ip
*);
register struct mbuf
*mb_copy
;
register struct ip_moptions
*imo
;
mb_copy
= m_copy(m
, 0, M_COPYALL
);
imo
->imo_multicast_ifp
= vifp
->v_ifp
;
imo
->imo_multicast_ttl
= ip
->ip_ttl
- 1;
imo
->imo_multicast_loop
= 1;
error
= ip_output(mb_copy
, NULL
, NULL
, IP_FORWARDING
, imo
);
register struct vif
*vifp
;
register struct ip
*ip
= mtod(m
, struct ip
*);
register struct mbuf
*mb_copy
, *mb_opts
;
register struct ip
*ip_copy
;
* Make sure that adding the tunnel options won't exceed the
* maximum allowed number of option bytes.
if (ip
->ip_hl
> (60 - TUNNEL_LEN
) >> 2) {
mrtstat
.mrts_cant_tunnel
++;
* Get a private copy of the IP header so that changes to some
* of the IP fields don't damage the original header, which is
* examined later in ip_input.c.
mb_copy
= m_copy(m
, IP_HDR_LEN
, M_COPYALL
);
MGETHDR(mb_opts
, M_DONTWAIT
, MT_HEADER
);
* Make mb_opts be the new head of the packet chain.
* Any options of the packet were left in the old packet chain head
mb_opts
->m_next
= mb_copy
;
mb_opts
->m_len
= IP_HDR_LEN
+ TUNNEL_LEN
;
mb_opts
->m_data
+= MSIZE
- mb_opts
->m_len
;
ip_copy
= mtod(mb_opts
, struct ip
*);
* Copy the base ip header to the new head mbuf.
ip_copy
->ip_dst
= vifp
->v_rmt_addr
; /* remote tunnel end-point */
* Adjust the ip header length to account for the tunnel options.
ip_copy
->ip_hl
+= TUNNEL_LEN
>> 2;
ip_copy
->ip_len
+= TUNNEL_LEN
;
* Add the NOP and LSRR after the base ip header
cp
= (u_char
*)(ip_copy
+ 1);
*cp
++ = 11; /* LSRR option length */
*cp
++ = 8; /* LSSR pointer to second element */
*(u_long
*)cp
= vifp
->v_lcl_addr
.s_addr
; /* local tunnel end-point */
*(u_long
*)cp
= ip
->ip_dst
.s_addr
; /* destination group */
error
= ip_output(mb_opts
, NULL
, NULL
, IP_FORWARDING
, NULL
);