/*
* The mrouted program is covered by the license in the accompanying file
* named "LICENSE". Use of the mrouted program represents acceptance of
* the terms and conditions listed in that file.
*
* The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
* Leland Stanford Junior University.
*/
#include "defs.h"
extern int cache_lifetime;
extern int max_prune_lifetime;
extern struct rtentry *routing_table;
extern int phys_vif;
/*
* dither cache lifetime to obtain a value between x and 2*x
*/
#define CACHE_LIFETIME(x) ((x) + (arc4random() % (x)))
#define CHK_GS(x, y) { \
switch(x) { \
case 2: \
case 4: \
case 8: \
case 16: \
case 32: \
case 64: \
case 128: \
/*case 256:*/ y = 1; \
break; \
default: y = 0; \
} \
}
struct gtable *kernel_table; /* ptr to list of kernel grp entries*/
static struct gtable *kernel_no_route; /* list of grp entries w/o routes */
struct gtable *gtp; /* pointer for kernel rt entries */
unsigned int kroutes; /* current number of cache entries */
/*
* Updates the ttl values for each vif.
*/
static void
prun_add_ttls(struct gtable *gt)
{
struct uvif *v;
vifi_t vifi;
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
if (VIFM_ISSET(vifi, gt->gt_grpmems))
gt->gt_ttls[vifi] = v->uv_threshold;
else
gt->gt_ttls[vifi] = 0;
}
}
/*
* checks for scoped multicast addresses
*/
#define GET_SCOPE(gt) { \
vifi_t _i; \
if ((ntohl((gt)->gt_mcastgrp) & 0xff000000) == 0xef000000) \
for (_i = 0; _i < numvifs; _i++) \
if (scoped_addr(_i, (gt)->gt_mcastgrp)) \
VIFM_SET(_i, (gt)->gt_scope); \
}
int
scoped_addr(vifi_t vifi, u_int32_t addr)
{
struct vif_acl *acl;
for (acl = uvifs[vifi].uv_acl; acl; acl = acl->acl_next)
if ((addr & acl->acl_mask) == acl->acl_addr)
return 1;
return 0;
}
/*
* Determine if mcastgrp has a listener on vifi
*/
int
grplst_mem(vifi_t vifi, u_int32_t mcastgrp)
{
struct listaddr *g;
struct uvif *v;
v = &uvifs[vifi];
for (g = v->uv_groups; g != NULL; g = g->al_next)
if (mcastgrp == g->al_addr)
return 1;
return 0;
}
/*
* Finds the group entry with the specified source and netmask.
* If netmask is 0, it uses the route's netmask.
*
* Returns TRUE if found a match, and the global variable gtp is left
* pointing to entry before the found entry.
* Returns FALSE if no exact match found, gtp is left pointing to before
* the entry in question belongs, or is NULL if the it belongs at the
* head of the list.
*/
int
find_src_grp(u_int32_t src, u_int32_t mask, u_int32_t grp)
{
struct gtable *gt;
/*
* Check if the neighbor supports pruning
*/
static int
pruning_neighbor(vifi_t vifi, u_int32_t addr)
{
struct listaddr *n = neighbor_info(vifi, addr);
int vers;
if (n == NULL)
return 0;
if (n->al_flags & NF_PRUNE)
return 1;
/*
* Versions from 3.0 to 3.4 relied on the version number to identify
* that they could handle pruning.
*/
vers = NBR_VERS(n);
return (vers >= 0x0300 && vers <= 0x0304);
}
/*
* Can the neighbor in question handle multicast traceroute?
*/
static int
can_mtrace(vifi_t vifi, u_int32_t addr)
{
struct listaddr *n = neighbor_info(vifi, addr);
int vers;
if (n == NULL)
return 0;
if (n->al_flags & NF_MTRACE)
return 1;
/*
* Versions 3.3 and 3.4 relied on the version number to identify
* that they could handle traceroute.
*/
vers = NBR_VERS(n);
return (vers >= 0x0303 && vers <= 0x0304);
}
/*
* Returns the prune entry of the router, or NULL if none exists
*/
static struct ptable *
find_prune_entry(u_int32_t vr, struct ptable *pt)
{
while (pt) {
if (pt->pt_router == vr)
return pt;
pt = pt->pt_next;
}
return NULL;
}
/*
* Send a prune message to the dominant router for
* this source.
*
* Record an entry that a prune was sent for this group
*/
static void
send_prune(struct gtable *gt)
{
struct ptable *pt;
char *p;
int i;
int datalen;
u_int32_t src;
u_int32_t dst;
u_int32_t tmp;
/* Don't process any prunes if router is not pruning */
if (pruning == 0)
return;
/* Can't process a prune if we don't have an associated route */
if (gt->gt_route == NULL)
return;
/* Don't send a prune to a non-pruning router */
if (!pruning_neighbor(gt->gt_route->rt_parent, gt->gt_route->rt_gateway))
return;
/*
* sends a prune message to the router upstream.
*/
src = uvifs[gt->gt_route->rt_parent].uv_lcl_addr;
dst = gt->gt_route->rt_gateway;
p = send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN;
datalen = 0;
/*
* If we have a graft pending, cancel graft retransmission
*/
gt->gt_grftsnt = 0;
for (i = 0; i < 4; i++)
*p++ = ((char *)&(gt->gt_route->rt_origin))[i];
for (i = 0; i < 4; i++)
*p++ = ((char *)&(gt->gt_mcastgrp))[i];
tmp = htonl(gt->gt_prsent_timer);
for (i = 0; i < 4; i++)
*p++ = ((char *)&(tmp))[i];
datalen += 12;
logit(LOG_DEBUG, 0, "sent prune for (%s %s)/%d on vif %d to %s",
inet_fmts(gt->gt_route->rt_origin, gt->gt_route->rt_originmask),
inet_fmt(gt->gt_mcastgrp),
gt->gt_prsent_timer, gt->gt_route->rt_parent,
inet_fmt(gt->gt_route->rt_gateway));
}
/*
* a prune was sent upstream
* so, a graft has to be sent to annul the prune
* set up a graft timer so that if an ack is not
* heard within that time, another graft request
* is sent out.
*/
static void
send_graft(struct gtable *gt)
{
char *p;
int i;
int datalen;
u_int32_t src;
u_int32_t dst;
/* Can't send a graft without an associated route */
if (gt->gt_route == NULL)
return;
p = send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN;
datalen = 0;
for (i = 0; i < 4; i++)
*p++ = ((char *)&(gt->gt_route->rt_origin))[i];
for (i = 0; i < 4; i++)
*p++ = ((char *)&(gt->gt_mcastgrp))[i];
datalen += 8;
if (datalen != 0) {
send_igmp(src, dst, IGMP_DVMRP, DVMRP_GRAFT,
htonl(MROUTED_LEVEL), datalen);
}
logit(LOG_DEBUG, 0, "sent graft for (%s %s) to %s on vif %d",
inet_fmts(gt->gt_route->rt_origin, gt->gt_route->rt_originmask),
inet_fmt(gt->gt_mcastgrp),
inet_fmt(gt->gt_route->rt_gateway),
gt->gt_route->rt_parent);
}
/*
* Send an ack that a graft was received
*/
static void
send_graft_ack(u_int32_t src, u_int32_t dst, u_int32_t origin, u_int32_t grp)
{
char *p;
int i;
int datalen;
p = send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN;
datalen = 0;
for (i = 0; i < 4; i++)
*p++ = ((char *)&(origin))[i];
for (i = 0; i < 4; i++)
*p++ = ((char *)&(grp))[i];
datalen += 8;
logit(LOG_DEBUG, 0, "sent graft ack for (%s, %s) to %s",
inet_fmt(origin), inet_fmt(grp),
inet_fmt(dst));
}
/*
* Update the kernel cache with all the routes hanging off the group entry
*/
static void
update_kernel(struct gtable *g)
{
struct stable *st;
for (st = g->gt_srctbl; st; st = st->st_next)
k_add_rg(st->st_origin, g);
}
/****************************************************************************
Functions that are used externally
****************************************************************************/
/*
* Find a specific group entry in the group table
*/
struct gtable *
find_grp(u_long grp)
{
struct gtable *gt;
for (gt = kernel_table; gt; gt = gt->gt_gnext) {
if (ntohl(grp) < ntohl(gt->gt_mcastgrp))
break;
if (gt->gt_mcastgrp == grp)
return gt;
}
return NULL;
}
/*
* Given a group entry and source, find the corresponding source table
* entry
*/
struct stable *
find_grp_src(struct gtable *gt, u_long src)
{
struct stable *st;
u_long grp = gt->gt_mcastgrp;
struct gtable *gtcurr;
for (gtcurr = gt; gtcurr->gt_mcastgrp == grp; gtcurr = gtcurr->gt_gnext) {
for (st = gtcurr->gt_srctbl; st; st = st->st_next)
if (st->st_origin == src)
return st;
}
return NULL;
}
/*
* Find next entry > specification
*
* gtpp: ordered by group
* stpp: ordered by source
*/
int
next_grp_src_mask(struct gtable **gtpp, struct stable **stpp, u_long grp,
u_long src, u_long mask)
{
struct gtable *gt, *gbest = NULL;
struct stable *st, *sbest = NULL;
/* Find first group entry >= grp spec */
(*gtpp) = kernel_table;
while ((*gtpp) && ntohl((*gtpp)->gt_mcastgrp) < ntohl(grp))
(*gtpp)=(*gtpp)->gt_gnext;
if (!(*gtpp))
return 0; /* no more groups */
for (gt = kernel_table; gt; gt=gt->gt_gnext) {
/* Since grps are ordered, we can stop when group changes from gbest */
if (gbest && gbest->gt_mcastgrp != gt->gt_mcastgrp)
break;
for (st = gt->gt_srctbl; st; st=st->st_next) {
/*
* Ensure that sg contains current information for the given group,source.
* This is fetched from the kernel as a unit so that counts for the entry
* are consistent, i.e. packet and byte counts for the same entry are
* read at the same time.
*/
void
refresh_sg(struct sioc_sg_req *sg, struct gtable *gt, struct stable *st)
{
static int lastq = -1;
/*
* Return pointer to a specific route entry. This must be a separate
* function from find_route() which modifies rtp.
*/
struct rtentry *
snmp_find_route(u_long src, u_long mask)
{
struct rtentry *rt;
for (rt = routing_table; rt; rt = rt->rt_next) {
if (src == rt->rt_origin && mask == rt->rt_originmask)
return rt;
}
return NULL;
}
/* Among all entries > spec, find "lowest" one in order */
for (rt = routing_table; rt; rt=rt->rt_next) {
if ((ntohl(rt->rt_origin) > ntohl(src)
|| (ntohl(rt->rt_origin) == ntohl(src)
&& ntohl(rt->rt_originmask) > ntohl(mask)))
&& (!rbest || (ntohl(rt->rt_origin) < ntohl(rbest->rt_origin))
|| (ntohl(rt->rt_origin) == ntohl(rbest->rt_origin)
&& ntohl(rt->rt_originmask) < ntohl(rbest->rt_originmask))))
rbest = rt;
}
(*rtpp) = rbest;
return (*rtpp)!=0;
}
/*
* Given a routing table entry, and a vifi, find the next vifi/entry
*
* vifi: vifi at which to start looking
*/
int
next_route_child(struct rtentry **rtpp, u_long src, u_long mask, vifi_t *vifi)
{
struct rtentry *rt;
/* Get (S,M) entry */
if (!((*rtpp) = snmp_find_route(src,mask)))
if (!next_route(rtpp, src, mask))
return 0;
/* Continue until we get one with a valid next vif */
do {
for (; (*rtpp)->rt_children && *vifi<numvifs; (*vifi)++)
if (VIFM_ISSET(*vifi, (*rtpp)->rt_children))
return 1;
*vifi = 0;
} while( next_route(rtpp, (*rtpp)->rt_origin, (*rtpp)->rt_originmask) );
return 0;
}
/*
* Given a routing table entry, and a vifi, find the next entry
* equal to or greater than those
*
* vifi: vifi at which to start looking
*/
int
next_child(struct gtable **gtpp, struct stable **stpp, u_long grp, u_long src,
u_long mask, vifi_t *vifi)
{
struct stable *st;
/* Get (G,S,M) entry */
if (mask!=0xFFFFFFFF
|| !((*gtpp) = find_grp(grp))
|| !((*stpp) = find_grp_src((*gtpp),src)))
if (!next_grp_src_mask(gtpp, stpp, grp, src, mask))
return 0;
/* Continue until we get one with a valid next vif */
do {
for (; (*gtpp)->gt_route->rt_children && *vifi<numvifs; (*vifi)++)
if (VIFM_ISSET(*vifi, (*gtpp)->gt_route->rt_children))
return 1;
*vifi = 0;
} while (next_grp_src_mask(gtpp, stpp, (*gtpp)->gt_mcastgrp,
(*stpp)->st_origin, 0xFFFFFFFF) );
r = determine_route(origin);
prev_gt = NULL;
if (r == NULL) {
/*
* Look for it on the no_route table; if it is found then
* it will be detected as a duplicate below.
*/
for (gt = kernel_no_route; gt; gt = gt->gt_next)
if (mcastgrp == gt->gt_mcastgrp &&
gt->gt_srctbl && gt->gt_srctbl->st_origin == origin)
break;
gtnp = &kernel_no_route;
} else {
gtnp = &r->rt_groups;
while ((gt = *gtnp) != NULL) {
if (gt->gt_mcastgrp >= mcastgrp)
break;
gtnp = >->gt_next;
prev_gt = gt;
}
}
if (gt == NULL || gt->gt_mcastgrp != mcastgrp) {
gt = (struct gtable *)malloc(sizeof(struct gtable));
if (gt == NULL) {
logit(LOG_ERR, 0, "ran out of memory");
return;
}
if (r != NULL) {
/* obtain the multicast group membership list */
for (i = 0; i < numvifs; i++) {
if (VIFM_ISSET(i, r->rt_children) &&
!(VIFM_ISSET(i, r->rt_leaves)))
VIFM_SET(i, gt->gt_grpmems);
stnp = >->gt_srctbl;
while ((st = *stnp) != NULL) {
if (ntohl(st->st_origin) >= ntohl(origin))
break;
stnp = &st->st_next;
}
if (st == NULL || st->st_origin != origin) {
st = (struct stable *)malloc(sizeof(struct stable));
if (st == NULL)
logit(LOG_ERR, 0, "ran out of memory");
st->st_origin = origin;
st->st_pktcnt = 0;
st->st_next = *stnp;
*stnp = st;
} else {
#ifdef DEBUG_MFC
md_log(MD_DUPE, origin, mcastgrp);
#endif
logit(LOG_WARNING, 0, "kernel entry already exists for (%s %s)",
inet_fmt(origin),
inet_fmt(mcastgrp));
/* XXX Doing this should cause no harm, and may ensure
* kernel<>mrouted synchronization */
k_add_rg(origin, gt);
return;
}
/* If there are no leaf vifs
* which have this group, then
* mark this src-grp as a prune candidate.
*/
if (!gt->gt_prsent_timer && !gt->gt_grpmems && r && r->rt_gateway)
send_prune(gt);
}
/*
* An mrouter has gone down and come up on an interface
* Forward on that interface immediately
*/
void
reset_neighbor_state(vifi_t vifi, u_int32_t addr)
{
struct rtentry *r;
struct gtable *g;
struct ptable *pt, **ptnp;
struct stable *st;
for (g = kernel_table; g; g = g->gt_gnext) {
r = g->gt_route;
/*
* If neighbor was the parent, remove the prune sent state
* and all of the source cache info so that prunes get
* regenerated.
*/
if (vifi == r->rt_parent) {
if (addr == r->rt_gateway) {
logit(LOG_DEBUG, 0, "reset_neighbor_state parent reset (%s %s)",
inet_fmts(r->rt_origin, r->rt_originmask),
inet_fmt(g->gt_mcastgrp));
g->gt_prsent_timer = 0;
g->gt_grftsnt = 0;
while ((st = g->gt_srctbl) != NULL) {
g->gt_srctbl = st->st_next;
k_del_rg(st->st_origin, g);
kroutes--;
free(st);
}
}
} else {
/*
* Neighbor was not the parent, send grafts to join the groups
*/
if (g->gt_prsent_timer) {
g->gt_grftsnt = 1;
send_graft(g);
g->gt_prsent_timer = 0;
}
/*
* Remove any prunes that this router has sent us.
*/
ptnp = &g->gt_pruntbl;
while ((pt = *ptnp) != NULL) {
if (pt->pt_vifi == vifi && pt->pt_router == addr) {
*ptnp = pt->pt_next;
free(pt);
} else
ptnp = &pt->pt_next;
}
/*
* And see if we want to forward again.
*/
if (!VIFM_ISSET(vifi, g->gt_grpmems)) {
if (VIFM_ISSET(vifi, r->rt_children) &&
!(VIFM_ISSET(vifi, r->rt_leaves)))
VIFM_SET(vifi, g->gt_grpmems);
if (VIFM_ISSET(vifi, r->rt_leaves) &&
grplst_mem(vifi, g->gt_mcastgrp))
VIFM_SET(vifi, g->gt_grpmems);
/*
* Dummy routine - someday this may be needed, so it is just there
*/
if (del_flag == DEL_RTE_GROUP) {
prev_g = (struct gtable *)&r->rt_groups;
for (g = r->rt_groups; g; g = g->gt_next) {
if (g->gt_mcastgrp == mcastgrp) {
logit(LOG_DEBUG, 0, "del_table_entry deleting (%s %s)",
inet_fmts(r->rt_origin, r->rt_originmask),
inet_fmt(g->gt_mcastgrp));
st = g->gt_srctbl;
while (st) {
if (k_del_rg(st->st_origin, g) < 0) {
logit(LOG_WARNING, errno,
"del_table_entry trying to delete (%s, %s)",
inet_fmt(st->st_origin),
inet_fmt(g->gt_mcastgrp));
}
kroutes--;
prev_st = st;
st = st->st_next;
free(prev_st);
}
g->gt_srctbl = NULL;
for (g = r->rt_groups; g; g = g->gt_next) {
pt = g->gt_pruntbl;
while (pt) {
prev_pt = pt->pt_next;
free(pt);
pt = prev_pt;
}
g->gt_pruntbl = NULL;
g->gt_grpmems = 0;
/* obtain the multicast group membership list */
for (i = 0; i < numvifs; i++) {
if (VIFM_ISSET(i, r->rt_children) &&
!(VIFM_ISSET(i, r->rt_leaves)))
VIFM_SET(i, g->gt_grpmems);
if (VIFM_ISSET(i, r->rt_leaves) && grplst_mem(i, g->gt_mcastgrp))
VIFM_SET(i, g->gt_grpmems);
}
if (VIFM_ISSET(r->rt_parent, g->gt_scope))
g->gt_scope = -1;
g->gt_grpmems &= ~g->gt_scope;
/* update ttls and add entry into kernel */
prun_add_ttls(g);
update_kernel(g);
#ifdef RSRR
/* Send route change notification to reservation protocol. */
rsrr_cache_send(g,1);
#endif /* RSRR */
/* Check if we want to prune this group */
if (!g->gt_prsent_timer && g->gt_grpmems == 0 && r->rt_gateway) {
g->gt_timer = CACHE_LIFETIME(cache_lifetime);
send_prune(g);
}
}
}
/*
* set the forwarding flag for all mcastgrps on this vifi
*/
void
update_lclgrp(vifi_t vifi, u_int32_t mcastgrp)
{
struct rtentry *r;
struct gtable *g;
logit(LOG_DEBUG, 0, "group %s joined on vif %d",
inet_fmt(mcastgrp), vifi);
for (g = kernel_table; g; g = g->gt_gnext) {
if (ntohl(mcastgrp) < ntohl(g->gt_mcastgrp))
break;
r = g->gt_route;
if (g->gt_mcastgrp == mcastgrp &&
VIFM_ISSET(vifi, r->rt_children)) {
VIFM_SET(vifi, g->gt_grpmems);
g->gt_grpmems &= ~g->gt_scope;
if (g->gt_grpmems == 0)
continue;
/*
* reset forwarding flag for all mcastgrps on this vifi
*/
void
delete_lclgrp(vifi_t vifi, u_int32_t mcastgrp)
{
struct rtentry *r;
struct gtable *g;
logit(LOG_DEBUG, 0, "group %s left on vif %d",
inet_fmt(mcastgrp), vifi);
for (g = kernel_table; g; g = g->gt_gnext) {
if (ntohl(mcastgrp) < ntohl(g->gt_mcastgrp))
break;
if (g->gt_mcastgrp == mcastgrp) {
int stop_sending = 1;
r = g->gt_route;
/*
* If this is not a leaf, then we have router neighbors on this
* vif. Only turn off forwarding if they have all pruned.
*/
if (!VIFM_ISSET(vifi, r->rt_leaves)) {
struct listaddr *vr;
for (vr = uvifs[vifi].uv_neighbors; vr; vr = vr->al_next)
if (find_prune_entry(vr->al_addr, g->gt_pruntbl) == NULL) {
stop_sending = 0;
break;
}
}
/*
* If there are no more members of this particular group,
* send prune upstream
*/
if (!g->gt_prsent_timer && g->gt_grpmems == 0 && r->rt_gateway)
send_prune(g);
}
}
}
}
/*
* Takes the prune message received and then strips it to
* determine the (src, grp) pair to be pruned.
*
* Adds the router to the (src, grp) entry then.
*
* Determines if further packets have to be sent down that vif
*
* Determines if a corresponding prune message has to be generated
*/
void
accept_prune(u_int32_t src, u_int32_t dst, char *p, int datalen)
{
u_int32_t prun_src;
u_int32_t prun_grp;
u_int32_t prun_tmr;
vifi_t vifi;
int i;
int stop_sending;
struct rtentry *r;
struct gtable *g;
struct ptable *pt;
struct listaddr *vr;
/* Don't process any prunes if router is not pruning */
if (pruning == 0)
return;
if ((vifi = find_vif(src, dst)) == NO_VIF) {
logit(LOG_INFO, 0,
"ignoring prune report from non-neighbor %s",
inet_fmt(src));
return;
}
/* Check if enough data is present */
if (datalen < 12)
{
logit(LOG_WARNING, 0,
"non-decipherable prune from %s",
inet_fmt(src));
return;
}
for (i = 0; i< 4; i++)
((char *)&prun_src)[i] = *p++;
for (i = 0; i< 4; i++)
((char *)&prun_grp)[i] = *p++;
for (i = 0; i< 4; i++)
((char *)&prun_tmr)[i] = *p++;
prun_tmr = ntohl(prun_tmr);
/*
* Find the subnet for the prune
*/
if (find_src_grp(prun_src, 0, prun_grp)) {
g = gtp ? gtp->gt_gnext : kernel_table;
r = g->gt_route;
if (!VIFM_ISSET(vifi, r->rt_children)) {
logit(LOG_WARNING, 0, "prune received from non-child %s for (%s %s)",
inet_fmt(src), inet_fmt(prun_src),
inet_fmt(prun_grp));
return;
}
if (VIFM_ISSET(vifi, g->gt_scope)) {
logit(LOG_WARNING, 0, "prune received from %s on scoped grp (%s %s)",
inet_fmt(src), inet_fmt(prun_src),
inet_fmt(prun_grp));
return;
}
if ((pt = find_prune_entry(src, g->gt_pruntbl)) != NULL) {
/*
* If it's about to expire, then it's only still around because
* of timer granularity, so don't warn about it.
*/
if (pt->pt_timer > 10) {
logit(LOG_WARNING, 0, "%s %d from %s for (%s %s)/%d %s %d %s %x",
"duplicate prune received on vif",
vifi, inet_fmt(src), inet_fmt(prun_src),
inet_fmt(prun_grp), prun_tmr,
"old timer:", pt->pt_timer, "cur gm:", g->gt_grpmems);
}
pt->pt_timer = prun_tmr;
} else {
/* allocate space for the prune structure */
pt = (struct ptable *)(malloc(sizeof(struct ptable)));
if (pt == NULL) {
logit(LOG_ERR, 0, "pt: ran out of memory");
return;
}
/* Refresh the group's lifetime */
g->gt_timer = CACHE_LIFETIME(cache_lifetime);
if ((u_int32_t)g->gt_timer < prun_tmr)
g->gt_timer = prun_tmr;
/*
* check if any more packets need to be sent on the
* vif which sent this message
*/
stop_sending = 1;
for (vr = uvifs[vifi].uv_neighbors; vr; vr = vr->al_next)
if (find_prune_entry(vr->al_addr, g->gt_pruntbl) == NULL) {
stop_sending = 0;
break;
}
/*
* check if all the child routers have expressed no interest
* in this group and if this group does not exist in the
* interface
* Send a prune message then upstream
*/
if (!g->gt_prsent_timer && g->gt_grpmems == 0 && r->rt_gateway) {
send_prune(g);
}
} else {
/*
* There is no kernel entry for this group. Therefore, we can
* simply ignore the prune, as we are not forwarding this traffic
* downstream.
*/
logit(LOG_DEBUG, 0, "%s (%s %s)/%d from %s",
"prune message received with no kernel entry for",
inet_fmt(prun_src), inet_fmt(prun_grp),
prun_tmr, inet_fmt(src));
return;
}
}
/*
* Checks if this mcastgrp is present in the kernel table
* If so and if a prune was sent, it sends a graft upwards
*/
void
chkgrp_graft(vifi_t vifi, u_int32_t mcastgrp)
{
struct rtentry *r;
struct gtable *g;
for (g = kernel_table; g; g = g->gt_gnext) {
if (ntohl(mcastgrp) < ntohl(g->gt_mcastgrp))
break;
r = g->gt_route;
if (g->gt_mcastgrp == mcastgrp && VIFM_ISSET(vifi, r->rt_children))
if (g->gt_prsent_timer) {
VIFM_SET(vifi, g->gt_grpmems);
/*
* If the vif that was joined was a scoped vif,
* ignore it ; don't graft back
*/
g->gt_grpmems &= ~g->gt_scope;
if (g->gt_grpmems == 0)
continue;
/* set the flag for graft retransmission */
g->gt_grftsnt = 1;
/* send graft upwards */
send_graft(g);
/* reset the prune timer and update cache timer*/
g->gt_prsent_timer = 0;
g->gt_timer = max_prune_lifetime;
/* determine the multicast group and src
*
* if it does, then determine if a prune was sent
* upstream.
* if prune sent upstream, send graft upstream and send
* ack downstream.
*
* if no prune sent upstream, change the forwarding bit
* for this interface and send ack downstream.
*
* if no entry exists for this group send ack downstream.
*/
void
accept_graft(u_int32_t src, u_int32_t dst, char *p, int datalen)
{
vifi_t vifi;
u_int32_t graft_src;
u_int32_t graft_grp;
int i;
struct rtentry *r;
struct gtable *g;
struct ptable *pt, **ptnp;
if ((vifi = find_vif(src, dst)) == NO_VIF) {
logit(LOG_INFO, 0,
"ignoring graft from non-neighbor %s",
inet_fmt(src));
return;
}
if (datalen < 8) {
logit(LOG_WARNING, 0,
"received non-decipherable graft from %s",
inet_fmt(src));
return;
}
for (i = 0; i< 4; i++)
((char *)&graft_src)[i] = *p++;
for (i = 0; i< 4; i++)
((char *)&graft_grp)[i] = *p++;
/*
* Find the subnet for the graft
*/
if (find_src_grp(graft_src, 0, graft_grp)) {
g = gtp ? gtp->gt_gnext : kernel_table;
r = g->gt_route;
if (VIFM_ISSET(vifi, g->gt_scope)) {
logit(LOG_WARNING, 0, "graft received from %s on scoped grp (%s %s)",
inet_fmt(src), inet_fmt(graft_src),
inet_fmt(graft_grp));
return;
}
if (g->gt_prsent_timer) {
/* set the flag for graft retransmission */
g->gt_grftsnt = 1;
/* send graft upwards */
send_graft(g);
/* reset the prune sent timer */
g->gt_prsent_timer = 0;
}
} else {
/*
* We have no state for the source and group in question.
* We can simply acknowledge the graft, since we know
* that we have no prune state, and grafts are requests
* to remove prune state.
*/
send_graft_ack(dst, src, graft_src, graft_grp);
logit(LOG_DEBUG, 0, "%s (%s %s) from %s",
"graft received with no kernel entry for",
inet_fmt(graft_src), inet_fmt(graft_grp),
inet_fmt(src));
return;
}
}
/*
* find out which group is involved first of all
* then determine if a graft was sent.
* if no graft sent, ignore the message
* if graft was sent and the ack is from the right
* source, remove the graft timer so that we don't
* have send a graft again
*/
void
accept_g_ack(u_int32_t src, u_int32_t dst, char *p, int datalen)
{
struct gtable *g;
vifi_t vifi;
u_int32_t grft_src;
u_int32_t grft_grp;
int i;
if ((vifi = find_vif(src, dst)) == NO_VIF) {
logit(LOG_INFO, 0,
"ignoring graft ack from non-neighbor %s",
inet_fmt(src));
return;
}
if (datalen < 0 || datalen > 8) {
logit(LOG_WARNING, 0,
"received non-decipherable graft ack from %s",
inet_fmt(src));
return;
}
for (i = 0; i< 4; i++)
((char *)&grft_src)[i] = *p++;
for (i = 0; i< 4; i++)
((char *)&grft_grp)[i] = *p++;
/*
* Find the subnet for the graft ack
*/
if (find_src_grp(grft_src, 0, grft_grp)) {
g = gtp ? gtp->gt_gnext : kernel_table;
g->gt_grftsnt = 0;
} else {
logit(LOG_WARNING, 0, "%s (%s, %s) from %s",
"rcvd graft ack with no kernel entry for",
inet_fmt(grft_src), inet_fmt(grft_grp),
inet_fmt(src));
return;
}
}
/*
* free all prune entries and kernel routes
* normally, this should inform the kernel that all of its routes
* are going away, but this is only called by restart(), which is
* about to call MRT_DONE which does that anyway.
*/
void
free_all_prunes(void)
{
struct rtentry *r;
struct gtable *g, *prev_g;
struct stable *s, *prev_s;
struct ptable *p, *prev_p;
for (r = routing_table; r; r = r->rt_next) {
g = r->rt_groups;
while (g) {
s = g->gt_srctbl;
while (s) {
prev_s = s;
s = s->st_next;
free(prev_s);
}
p = g->gt_pruntbl;
while (p) {
prev_p = p;
p = p->pt_next;
free(prev_p);
}
/*
* When a new route is created, search
* a) The less-specific part of the routing table
* b) The route-less kernel table
* for sources that the new route might want to handle.
*
* "Inheriting" these sources might be cleanest, but simply deleting
* them is easier, and letting the kernel re-request them.
*/
void
steal_sources(struct rtentry *rt)
{
struct rtentry *rp;
struct gtable *gt, **gtnp;
struct stable *st, **stnp;
for (rp = rt->rt_next; rp; rp = rp->rt_next) {
if ((rt->rt_origin & rp->rt_originmask) == rp->rt_origin) {
logit(LOG_DEBUG, 0, "Route for %s stealing sources from %s",
inet_fmts(rt->rt_origin, rt->rt_originmask),
inet_fmts(rp->rt_origin, rp->rt_originmask));
for (gt = rp->rt_groups; gt; gt = gt->gt_next) {
stnp = >->gt_srctbl;
while ((st = *stnp) != NULL) {
if ((st->st_origin & rt->rt_originmask) == rt->rt_origin) {
logit(LOG_DEBUG, 0, "%s stealing (%s %s) from %s",
inet_fmts(rt->rt_origin, rt->rt_originmask),
inet_fmt(st->st_origin),
inet_fmt(gt->gt_mcastgrp),
inet_fmts(rp->rt_origin, rp->rt_originmask));
if (k_del_rg(st->st_origin, gt) < 0) {
logit(LOG_WARNING, errno, "%s (%s, %s)",
"steal_sources trying to delete",
inet_fmt(st->st_origin),
inet_fmt(gt->gt_mcastgrp));
}
*stnp = st->st_next;
kroutes--;
free(st);
} else {
stnp = &st->st_next;
}
}
}
}
}
/*
* Advance the timers on all the cache entries.
* If there are any entries whose timers have expired,
* remove these entries from the kernel cache.
*/
void
age_table_entry(void)
{
struct rtentry *r;
struct gtable *gt, **gtnptr;
struct stable *st, **stnp;
struct ptable *pt, **ptnp;
struct sioc_sg_req sg_req;
logit(LOG_DEBUG, 0, "ageing entries");
gtnptr = &kernel_table;
while ((gt = *gtnptr) != NULL) {
r = gt->gt_route;
/* advance the timer for the kernel entry */
gt->gt_timer -= ROUTE_MAX_REPORT_DELAY;
/* decrement prune timer if need be */
if (gt->gt_prsent_timer > 0) {
gt->gt_prsent_timer -= ROUTE_MAX_REPORT_DELAY;
if (gt->gt_prsent_timer <= 0) {
logit(LOG_DEBUG, 0, "upstream prune tmo (%s %s)",
inet_fmts(r->rt_origin, r->rt_originmask),
inet_fmt(gt->gt_mcastgrp));
gt->gt_prsent_timer = -1;
}
}
/* retransmit graft if graft sent flag is still set */
if (gt->gt_grftsnt) {
int y;
CHK_GS(gt->gt_grftsnt++, y);
if (y)
send_graft(gt);
}
/*
* Age prunes
*
* If a prune expires, forward again on that vif.
*/
ptnp = >->gt_pruntbl;
while ((pt = *ptnp) != NULL) {
if ((pt->pt_timer -= ROUTE_MAX_REPORT_DELAY) <= 0) {
logit(LOG_DEBUG, 0, "expire prune (%s %s) from %s on vif %d",
inet_fmts(r->rt_origin, r->rt_originmask),
inet_fmt(gt->gt_mcastgrp),
inet_fmt(pt->pt_router),
pt->pt_vifi);
expire_prune(pt->pt_vifi, gt);
/* remove the router's prune entry and await new one */
*ptnp = pt->pt_next;
free(pt);
} else {
ptnp = &pt->pt_next;
}
}
/*
* If the cache entry has expired, delete source table entries for
* silent sources. If there are no source entries left, and there
* are no downstream prunes, then the entry is deleted.
* Otherwise, the cache entry's timer is refreshed.
*/
if (gt->gt_timer <= 0) {
/* Check for traffic before deleting source entries */
sg_req.grp.s_addr = gt->gt_mcastgrp;
stnp = >->gt_srctbl;
while ((st = *stnp) != NULL) {
sg_req.src.s_addr = st->st_origin;
if (ioctl(igmp_socket, SIOCGETSGCNT, (char *)&sg_req) < 0) {
logit(LOG_WARNING, errno, "%s (%s %s)",
"age_table_entry: SIOCGETSGCNT failing for",
inet_fmt(st->st_origin),
inet_fmt(gt->gt_mcastgrp));
/* Make sure it gets deleted below */
sg_req.pktcnt = st->st_pktcnt;
}
if (sg_req.pktcnt == st->st_pktcnt) {
*stnp = st->st_next;
logit(LOG_DEBUG, 0, "age_table_entry deleting (%s %s)",
inet_fmt(st->st_origin),
inet_fmt(gt->gt_mcastgrp));
if (k_del_rg(st->st_origin, gt) < 0) {
logit(LOG_WARNING, errno,
"age_table_entry trying to delete (%s %s)",
inet_fmt(st->st_origin),
inet_fmt(gt->gt_mcastgrp));
}
kroutes--;
free(st);
} else {
st->st_pktcnt = sg_req.pktcnt;
stnp = &st->st_next;
}
}
/*
* Retain the group entry if we have downstream prunes or if
* there is at least one source in the list that still has
* traffic, or if our upstream prune timer is running.
*/
if (gt->gt_pruntbl != NULL || gt->gt_srctbl != NULL ||
gt->gt_prsent_timer > 0) {
gt->gt_timer = CACHE_LIFETIME(cache_lifetime);
if (gt->gt_prsent_timer == -1) {
if (gt->gt_grpmems == 0)
send_prune(gt);
else
gt->gt_prsent_timer = 0;
}
gtnptr = >->gt_gnext;
continue;
}
/*
* When traversing the no_route table, the decision is much easier.
* Just delete it if it has timed out.
*/
gtnptr = &kernel_no_route;
while ((gt = *gtnptr) != NULL) {
/* advance the timer for the kernel entry */
gt->gt_timer -= ROUTE_MAX_REPORT_DELAY;
if (gt->gt_timer < 0) {
if (gt->gt_srctbl) {
if (k_del_rg(gt->gt_srctbl->st_origin, gt) < 0) {
logit(LOG_WARNING, errno, "%s (%s %s)",
"age_table_entry trying to delete no-route",
inet_fmt(gt->gt_srctbl->st_origin),
inet_fmt(gt->gt_mcastgrp));
}
free(gt->gt_srctbl);
}
*gtnptr = gt->gt_next;
if (gt->gt_next)
gt->gt_next->gt_prev = gt->gt_prev;
/*
* Modify the kernel to forward packets when one or multiple prunes that
* were received on the vif given by vifi, for the group given by gt,
* have expired.
*/
static void
expire_prune(vifi_t vifi, struct gtable *gt)
{
/*
* No need to send a graft, any prunes that we sent
* will expire before any prunes that we have received.
*/
if (gt->gt_prsent_timer > 0) {
logit(LOG_DEBUG, 0, "prune expired with %d left on %s",
gt->gt_prsent_timer, "prsent_timer");
gt->gt_prsent_timer = 0;
}
/* modify the kernel entry to forward packets */
if (!VIFM_ISSET(vifi, gt->gt_grpmems)) {
struct rtentry *rt = gt->gt_route;
VIFM_SET(vifi, gt->gt_grpmems);
logit(LOG_DEBUG, 0, "forw again (%s %s) gm:%x vif:%d",
inet_fmts(rt->rt_origin, rt->rt_originmask),
inet_fmt(gt->gt_mcastgrp), gt->gt_grpmems, vifi);
p = buf;
if (buf == buf1)
buf = buf2;
else
buf = buf1;
if (t < 120) {
s = 's';
} else if (t < 3600) {
t /= 60;
s = 'm';
} else if (t < 86400) {
t /= 3600;
s = 'h';
} else if (t < 864000) {
t /= 86400;
s = 'd';
} else {
t /= 604800;
s = 'w';
}
if (t > 999)
return "*** ";
snprintf(p, 5, "%3d%c", (int)t, s);
return p;
}
/*
* Print the contents of the cache table on file 'fp2'.
*/
void
dump_cache(FILE *fp2)
{
struct rtentry *r;
struct gtable *gt;
struct stable *st;
vifi_t i;
time_t thyme = time(0);
/* timestamp the request/response */
gettimeofday(&tp, 0);
/*
* Check if it is a query or a response
*/
if (datalen == QLEN) {
type = QUERY;
logit(LOG_DEBUG, 0, "Initial traceroute query rcvd from %s to %s",
inet_fmt(src), inet_fmt(dst));
}
else if ((datalen - QLEN) % RLEN == 0) {
type = RESP;
logit(LOG_DEBUG, 0, "In-transit traceroute query rcvd from %s to %s",
inet_fmt(src), inet_fmt(dst));
if (IN_MULTICAST(ntohl(dst))) {
logit(LOG_DEBUG, 0, "Dropping multicast response");
return;
}
}
else {
logit(LOG_WARNING, 0, "%s from %s to %s",
"Non decipherable traceroute request received",
inet_fmt(src), inet_fmt(dst));
return;
}
qry = (struct tr_query *)data;
/*
* if it is a packet with all reports filled, drop it
*/
if ((u_int)(rcount = (datalen - QLEN)/RLEN) == no) {
logit(LOG_DEBUG, 0, "packet with all reports filled in");
return;
}
/*
* Query type packet - check if rte exists
* Check if the query destination is a vif connected to me.
* and if so, whether I should start response back
*/
if (type == QUERY) {
if (oqid == qry->tr_qid) {
/*
* If the multicast router is a member of the group being
* queried, and the query is multicasted, then the router can
* receive multiple copies of the same query. If we have already
* replied to this traceroute, just ignore it this time.
*
* This is not a total solution, but since if this fails you
* only get N copies, N <= the number of interfaces on the router,
* it is not fatal.
*/
logit(LOG_DEBUG, 0, "ignoring duplicate traceroute packet");
return;
}
if (rt == NULL) {
logit(LOG_DEBUG, 0, "Mcast traceroute: no route entry %s",
inet_fmt(qry->tr_src));
if (IN_MULTICAST(ntohl(dst)))
return;
}
vifi = find_vif(qry->tr_dst, 0);
if (vifi == NO_VIF) {
/* The traceroute destination is not on one of my subnet vifs. */
logit(LOG_DEBUG, 0, "Destination %s not an interface",
inet_fmt(qry->tr_dst));
if (IN_MULTICAST(ntohl(dst)))
return;
errcode = TR_WRONG_IF;
} else if (rt != NULL && !VIFM_ISSET(vifi, rt->rt_children)) {
logit(LOG_DEBUG, 0,
"Destination %s not on forwarding tree for src %s",
inet_fmt(qry->tr_dst),
inet_fmt(qry->tr_src));
if (IN_MULTICAST(ntohl(dst)))
return;
errcode = TR_WRONG_IF;
}
}
else {
/*
* determine which interface the packet came in on
* RESP packets travel hop-by-hop so this either traversed
* a tunnel or came from a directly attached mrouter.
*/
if ((vifi = find_vif(src, dst)) == NO_VIF) {
logit(LOG_DEBUG, 0, "Wrong interface for packet");
errcode = TR_WRONG_IF;
}
}
/* Now that we've decided to send a response, save the qid */
oqid = qry->tr_qid;
/* copy the packet to the sending buffer */
p = send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN;
bcopy(data, p, datalen);
p += datalen;
/*
* If there is no room to insert our reply, coopt the previous hop
* error indication to relay this fact.
*/
if (p + sizeof(struct tr_resp) > send_buf + RECV_BUF_SIZE) {
resp = (struct tr_resp *)p - 1;
resp->tr_rflags = TR_NO_SPACE;
rt = NULL;
goto sendit;
}
/*
* fill in initial response fields
*/
resp = (struct tr_resp *)p;
bzero(resp, sizeof(struct tr_resp));
datalen += RLEN;
/*
* obtain # of packets out on interface
*/
v_req.vifi = vifi;
if (ioctl(igmp_socket, SIOCGETVIFCNT, (char *)&v_req) >= 0)
resp->tr_vifout = htonl(v_req.ocount);
/*
* fill in scoping & pruning information
*/
if (rt)
for (gt = rt->rt_groups; gt; gt = gt->gt_next) {
if (gt->gt_mcastgrp >= group)
break;
}
else
gt = NULL;
if (VIFM_ISSET(vifi, gt->gt_scope))
resp->tr_rflags = TR_SCOPED;
else if (gt->gt_prsent_timer)
resp->tr_rflags = TR_PRUNED;
else if (!VIFM_ISSET(vifi, gt->gt_grpmems)) {
if (VIFM_ISSET(vifi, rt->rt_children) &&
!VIFM_ISSET(vifi, rt->rt_leaves))
resp->tr_rflags = TR_OPRUNED;
else
resp->tr_rflags = TR_NO_FWD;
}
} else {
if (scoped_addr(vifi, group))
resp->tr_rflags = TR_SCOPED;
else if (rt && !VIFM_ISSET(vifi, rt->rt_children))
resp->tr_rflags = TR_NO_FWD;
}
/*
* if no rte exists, set NO_RTE error
*/
if (rt == NULL) {
src = dst; /* the dst address of resp. pkt */
resp->tr_inaddr = 0;
resp->tr_rflags = TR_NO_RTE;
resp->tr_rmtaddr = 0;
} else {
/* get # of packets in on interface */
v_req.vifi = rt->rt_parent;
if (ioctl(igmp_socket, SIOCGETVIFCNT, (char *)&v_req) >= 0)
resp->tr_vifin = htonl(v_req.icount);
MASK_TO_VAL(rt->rt_originmask, resp->tr_smask);
src = uvifs[rt->rt_parent].uv_lcl_addr;
resp->tr_inaddr = src;
resp->tr_rmtaddr = rt->rt_gateway;
if (!VIFM_ISSET(vifi, rt->rt_children)) {
logit(LOG_DEBUG, 0,
"Destination %s not on forwarding tree for src %s",
inet_fmt(qry->tr_dst),
inet_fmt(qry->tr_src));
resp->tr_rflags = TR_WRONG_IF;
}
if (rt->rt_metric >= UNREACHABLE) {
resp->tr_rflags = TR_NO_RTE;
/* Hack to send reply directly */
rt = NULL;
}
}
sendit:
/*
* if metric is 1 or no. of reports is 1, send response to requestor
* else send to upstream router. If the upstream router can't handle
* mtrace, set an error code and send to requestor anyway.
*/
logit(LOG_DEBUG, 0, "rcount:%d, no:%d", rcount, no);
if (IN_MULTICAST(ntohl(dst))) {
/*
* Send the reply on a known multicast capable vif.
* If we don't have one, we can't source any multicasts anyway.
*/
if (phys_vif != -1) {
logit(LOG_DEBUG, 0, "Sending reply to %s from %s",
inet_fmt(dst), inet_fmt(uvifs[phys_vif].uv_lcl_addr));
k_set_ttl(qry->tr_rttl);
send_igmp(uvifs[phys_vif].uv_lcl_addr, dst,
resptype, no, group,
datalen);
k_set_ttl(1);
} else
logit(LOG_INFO, 0, "No enabled phyints -- %s",
"dropping traceroute reply");
} else {
logit(LOG_DEBUG, 0, "Sending %s to %s from %s",
resptype == IGMP_MTRACE_REPLY ? "reply" : "request on",
inet_fmt(dst), inet_fmt(src));
send_igmp(src, dst,
resptype, no, group,
datalen);
}
return;
}
