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freebsd/usr.sbin/mrouted/route.c
Bill Fenner ec114097dd Merge conflicts from 3.9-beta3+IOS12. The conflicts were huge; cvs's 
merge algorithm failed on several files, and the translation of the
mrouted man page to mdoc didn't help...
1999-01-20 07:55:57 +00:00

1476 lines
40 KiB
C
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/*
* 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.
*
*
* route.c,v 3.8.4.41 1998/01/15 00:08:34 fenner Exp
*/
#ifndef lint
static const char rcsid[] =
"$Id: route.c,v 1.10 1998/01/16 07:17:45 charnier Exp $";
#endif /* not lint */
#include "defs.h"
/*
* This define statement saves a lot of space later
*/
#define RT_ADDR (struct rtentry *)&routing_table
/*
* Exported variables.
*/
int routes_changed; /* 1=>some routes have changed */
int delay_change_reports; /* 1=>postpone change reports */
/*
* The routing table is shared with prune.c , so must not be static.
*/
struct rtentry *routing_table; /* pointer to list of route entries */
/*
* Private variables.
*/
static struct rtentry *rtp; /* pointer to a route entry */
static struct rtentry *rt_end; /* pointer to last route entry */
unsigned int nroutes; /* current number of route entries */
/*
* Private functions.
*/
static int init_children_and_leaves __P((struct rtentry *r,
vifi_t parent, int first));
static int find_route __P((u_int32 origin, u_int32 mask));
static void create_route __P((u_int32 origin, u_int32 mask));
static void discard_route __P((struct rtentry *prev_r));
static int compare_rts __P((const void *rt1, const void *rt2));
static int report_chunk __P((int, struct rtentry *start_rt, vifi_t vifi,
u_int32 dst));
static void queue_blaster_report __P((vifi_t, u_int32, u_int32, char *,
int, u_int32));
static void process_blaster_report __P((void *));
#ifdef SNMP
#include <sys/types.h>
#include "snmp.h"
/*
* Return pointer to a specific route entry. This must be a separate
* function from find_route() which modifies rtp.
*/
struct rtentry *
snmp_find_route(src, mask)
register u_int32 src, mask;
{
register 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;
}
/*
* Find next route entry > specification
*/
int
next_route(rtpp, src, mask)
struct rtentry **rtpp;
u_int32 src;
u_int32 mask;
{
struct rtentry *rt, *rbest = 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
*/
int
next_route_child(rtpp, src, mask, vifi)
struct rtentry **rtpp;
u_int32 src;
u_int32 mask;
vifi_t *vifi; /* vif at which to start looking */
{
/* 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;
}
#endif
/*
* Initialize the routing table and associated variables.
*/
void
init_routes()
{
routing_table = NULL;
rt_end = RT_ADDR;
nroutes = 0;
routes_changed = FALSE;
delay_change_reports = FALSE;
}
/*
* Initialize the children bits for route 'r', along with the
* associated dominant and subordinate data structures.
* If first is set, initialize dominants, otherwise keep old
* dominants on non-parent interfaces.
* XXX Does this need a return value?
*/
static int
init_children_and_leaves(r, parent, first)
register struct rtentry *r;
register vifi_t parent;
int first;
{
register vifi_t vifi;
register struct uvif *v;
vifbitmap_t old_children;
nbrbitmap_t old_subords;
VIFM_COPY(r->rt_children, old_children);
NBRM_COPY(r->rt_subordinates, old_subords);
VIFM_CLRALL(r->rt_children);
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
if (first || vifi == parent)
r->rt_dominants [vifi] = 0;
if (vifi == parent || uvifs[vifi].uv_flags & VIFF_NOFLOOD ||
AVOID_TRANSIT(vifi, r) || (!first && r->rt_dominants[vifi]))
NBRM_CLRMASK(r->rt_subordinates, uvifs[vifi].uv_nbrmap);
else
NBRM_SETMASK(r->rt_subordinates, uvifs[vifi].uv_nbrmap);
if (vifi != parent && !(v->uv_flags & (VIFF_DOWN|VIFF_DISABLED)) &&
!(!first && r->rt_dominants[vifi])) {
VIFM_SET(vifi, r->rt_children);
}
}
return (!VIFM_SAME(r->rt_children, old_children) ||
!NBRM_SAME(r->rt_subordinates, old_subords));
}
/*
* A new vif has come up -- update the children bitmaps in all route
* entries to take that into account.
*/
void
add_vif_to_routes(vifi)
register vifi_t vifi;
{
register struct rtentry *r;
register struct uvif *v;
v = &uvifs[vifi];
for (r = routing_table; r != NULL; r = r->rt_next) {
if (r->rt_metric != UNREACHABLE &&
!VIFM_ISSET(vifi, r->rt_children)) {
VIFM_SET(vifi, r->rt_children);
r->rt_dominants [vifi] = 0;
/*XXX isn't uv_nbrmap going to be empty?*/
NBRM_CLRMASK(r->rt_subordinates, v->uv_nbrmap);
update_table_entry(r, r->rt_gateway);
}
}
}
/*
* A vif has gone down -- expire all routes that have that vif as parent,
* and update the children bitmaps in all other route entries to take into
* account the failed vif.
*/
void
delete_vif_from_routes(vifi)
register vifi_t vifi;
{
register struct rtentry *r;
for (r = routing_table; r != NULL; r = r->rt_next) {
if (r->rt_metric != UNREACHABLE) {
if (vifi == r->rt_parent) {
del_table_entry(r, 0, DEL_ALL_ROUTES);
r->rt_timer = ROUTE_EXPIRE_TIME;
r->rt_metric = UNREACHABLE;
r->rt_flags |= RTF_CHANGED;
routes_changed = TRUE;
}
else if (VIFM_ISSET(vifi, r->rt_children)) {
VIFM_CLR(vifi, r->rt_children);
NBRM_CLRMASK(r->rt_subordinates, uvifs[vifi].uv_nbrmap);
update_table_entry(r, r->rt_gateway);
}
else {
r->rt_dominants[vifi] = 0;
}
}
}
}
/*
* A new neighbor has come up. If we're flooding on the neighbor's
* vif, mark that neighbor as subordinate for all routes whose parent
* is not this vif.
*/
void
add_neighbor_to_routes(vifi, index)
register vifi_t vifi;
register int index;
{
register struct rtentry *r;
register struct uvif *v;
v = &uvifs[vifi];
if (v->uv_flags & VIFF_NOFLOOD)
return;
for (r = routing_table; r != NULL; r = r->rt_next) {
if (r->rt_metric != UNREACHABLE && r->rt_parent != vifi &&
!AVOID_TRANSIT(vifi, r)) {
NBRM_SET(index, r->rt_subordinates);
update_table_entry(r, r->rt_gateway);
}
}
}
/*
* A neighbor has failed or become unreachable. If that neighbor was
* considered a dominant or subordinate router in any route entries,
* take appropriate action. Expire all routes this neighbor advertised
* to us.
*/
void
delete_neighbor_from_routes(addr, vifi, index)
register u_int32 addr;
register vifi_t vifi;
int index;
{
register struct rtentry *r;
register struct uvif *v;
v = &uvifs[vifi];
for (r = routing_table; r != NULL; r = r->rt_next) {
if (r->rt_metric != UNREACHABLE) {
if (r->rt_parent == vifi && r->rt_gateway == addr) {
del_table_entry(r, 0, DEL_ALL_ROUTES);
r->rt_timer = ROUTE_EXPIRE_TIME;
r->rt_metric = UNREACHABLE;
r->rt_flags |= RTF_CHANGED;
routes_changed = TRUE;
} else if (r->rt_dominants[vifi] == addr) {
VIFM_SET(vifi, r->rt_children);
r->rt_dominants[vifi] = 0;
if ((uvifs[vifi].uv_flags & VIFF_NOFLOOD) ||
AVOID_TRANSIT(vifi, r))
NBRM_CLRMASK(r->rt_subordinates, uvifs[vifi].uv_nbrmap);
else
NBRM_SETMASK(r->rt_subordinates, uvifs[vifi].uv_nbrmap);
update_table_entry(r, r->rt_gateway);
} else if (NBRM_ISSET(index, r->rt_subordinates)) {
NBRM_CLR(index, r->rt_subordinates);
update_table_entry(r, r->rt_gateway);
}
}
}
}
/*
* Prepare for a sequence of ordered route updates by initializing a pointer
* to the start of the routing table. The pointer is used to remember our
* position in the routing table in order to avoid searching from the
* beginning for each update; this relies on having the route reports in
* a single message be in the same order as the route entries in the routing
* table.
*/
void
start_route_updates()
{
rtp = RT_ADDR;
}
/*
* Starting at the route entry following the one to which 'rtp' points,
* look for a route entry matching the specified origin and mask. If a
* match is found, return TRUE and leave 'rtp' pointing at the found entry.
* If no match is found, return FALSE and leave 'rtp' pointing to the route
* entry preceding the point at which the new origin should be inserted.
* This code is optimized for the normal case in which the first entry to
* be examined is the matching entry.
*/
static int
find_route(origin, mask)
register u_int32 origin, mask;
{
register struct rtentry *r;
r = rtp->rt_next;
while (r != NULL) {
if (origin == r->rt_origin && mask == r->rt_originmask) {
rtp = r;
return (TRUE);
}
if (ntohl(mask) < ntohl(r->rt_originmask) ||
(mask == r->rt_originmask &&
ntohl(origin) < ntohl(r->rt_origin))) {
rtp = r;
r = r->rt_next;
}
else break;
}
return (FALSE);
}
/*
* Create a new routing table entry for the specified origin and link it into
* the routing table. The shared variable 'rtp' is assumed to point to the
* routing entry after which the new one should be inserted. It is left
* pointing to the new entry.
*
* Only the origin, originmask, originwidth and flags fields are initialized
* in the new route entry; the caller is responsible for filling in the the
* rest.
*/
static void
create_route(origin, mask)
u_int32 origin, mask;
{
register struct rtentry *r;
if ((r = (struct rtentry *) malloc(sizeof(struct rtentry) +
(numvifs * sizeof(u_int32)))) == NULL) {
log(LOG_ERR, 0, "ran out of memory"); /* fatal */
}
r->rt_origin = origin;
r->rt_originmask = mask;
if (((char *)&mask)[3] != 0) r->rt_originwidth = 4;
else if (((char *)&mask)[2] != 0) r->rt_originwidth = 3;
else if (((char *)&mask)[1] != 0) r->rt_originwidth = 2;
else r->rt_originwidth = 1;
r->rt_flags = 0;
r->rt_dominants = (u_int32 *)(r + 1);
bzero(r->rt_dominants, numvifs * sizeof(u_int32));
r->rt_groups = NULL;
VIFM_CLRALL(r->rt_children);
NBRM_CLRALL(r->rt_subordinates);
NBRM_CLRALL(r->rt_subordadv);
r->rt_next = rtp->rt_next;
rtp->rt_next = r;
r->rt_prev = rtp;
if (r->rt_next != NULL)
(r->rt_next)->rt_prev = r;
else
rt_end = r;
rtp = r;
++nroutes;
}
/*
* Discard the routing table entry following the one to which 'prev_r' points.
*/
static void
discard_route(prev_r)
register struct rtentry *prev_r;
{
register struct rtentry *r;
r = prev_r->rt_next;
uvifs[r->rt_parent].uv_nroutes--;
/*???nbr???.al_nroutes--;*/
prev_r->rt_next = r->rt_next;
if (prev_r->rt_next != NULL)
(prev_r->rt_next)->rt_prev = prev_r;
else
rt_end = prev_r;
free((char *)r);
--nroutes;
}
/*
* Process a route report for a single origin, creating or updating the
* corresponding routing table entry if necessary. 'src' is either the
* address of a neighboring router from which the report arrived, or zero
* to indicate a change of status of one of our own interfaces.
*/
void
update_route(origin, mask, metric, src, vifi, n)
u_int32 origin, mask;
u_int metric;
u_int32 src;
vifi_t vifi;
struct listaddr *n;
{
register struct rtentry *r;
u_int adj_metric;
/*
* Compute an adjusted metric, taking into account the cost of the
* subnet or tunnel over which the report arrived, and normalizing
* all unreachable/poisoned metrics into a single value.
*/
if (src != 0 && (metric < 1 || metric >= 2*UNREACHABLE)) {
log(LOG_WARNING, 0,
"%s reports out-of-range metric %u for origin %s",
inet_fmt(src, s1), metric, inet_fmts(origin, mask, s2));
return;
}
adj_metric = metric + uvifs[vifi].uv_metric;
if (adj_metric > UNREACHABLE) adj_metric = UNREACHABLE;
/*
* Look up the reported origin in the routing table.
*/
if (!find_route(origin, mask)) {
/*
* Not found.
* Don't create a new entry if the report says it's unreachable,
* or if the reported origin and mask are invalid.
*/
if (adj_metric == UNREACHABLE) {
return;
}
if (src != 0 && !inet_valid_subnet(origin, mask)) {
log(LOG_WARNING, 0,
"%s reports an invalid origin (%s) and/or mask (%08x)",
inet_fmt(src, s1), inet_fmt(origin, s2), ntohl(mask));
return;
}
IF_DEBUG(DEBUG_RTDETAIL)
log(LOG_DEBUG, 0, "%s advertises new route %s",
inet_fmt(src, s1), inet_fmts(origin, mask, s2));
/*
* OK, create the new routing entry. 'rtp' will be left pointing
* to the new entry.
*/
create_route(origin, mask);
uvifs[vifi].uv_nroutes++;
/*n->al_nroutes++;*/
rtp->rt_metric = UNREACHABLE; /* temporary; updated below */
}
/*
* We now have a routing entry for the reported origin. Update it?
*/
r = rtp;
if (r->rt_metric == UNREACHABLE) {
/*
* The routing entry is for a formerly-unreachable or new origin.
* If the report claims reachability, update the entry to use
* the reported route.
*/
if (adj_metric == UNREACHABLE)
return;
IF_DEBUG(DEBUG_RTDETAIL)
log(LOG_DEBUG, 0, "%s advertises %s with adj_metric %d (ours was %d)",
inet_fmt(src, s1), inet_fmts(origin, mask, s2),
adj_metric, r->rt_metric);
/*
* Now "steal away" any sources that belong under this route
* by deleting any cache entries they might have created
* and allowing the kernel to re-request them.
*
* If we haven't performed final initialization yet and are
* just collecting the routing table, we can't have any
* sources so we don't perform this step.
*/
if (did_final_init)
steal_sources(rtp);
r->rt_parent = vifi;
r->rt_gateway = src;
init_children_and_leaves(r, vifi, 1);
r->rt_timer = 0;
r->rt_metric = adj_metric;
r->rt_flags |= RTF_CHANGED;
routes_changed = TRUE;
update_table_entry(r, r->rt_gateway);
}
else if (src == r->rt_gateway) {
/*
* The report has come either from the interface directly-connected
* to the origin subnet (src and r->rt_gateway both equal zero) or
* from the gateway we have chosen as the best first-hop gateway back
* towards the origin (src and r->rt_gateway not equal zero). Reset
* the route timer and, if the reported metric has changed, update
* our entry accordingly.
*/
r->rt_timer = 0;
IF_DEBUG(DEBUG_RTDETAIL)
log(LOG_DEBUG, 0, "%s (current parent) advertises %s with adj_metric %d (ours was %d)",
inet_fmt(src, s1), inet_fmts(origin, mask, s2),
adj_metric, r->rt_metric);
if (adj_metric == r->rt_metric)
return;
if (adj_metric == UNREACHABLE) {
del_table_entry(r, 0, DEL_ALL_ROUTES);
r->rt_timer = ROUTE_EXPIRE_TIME;
}
r->rt_metric = adj_metric;
r->rt_flags |= RTF_CHANGED;
routes_changed = TRUE;
}
else if (src == 0 ||
(r->rt_gateway != 0 &&
(adj_metric < r->rt_metric ||
(adj_metric == r->rt_metric &&
(ntohl(src) < ntohl(r->rt_gateway) ||
r->rt_timer >= ROUTE_SWITCH_TIME))))) {
/*
* The report is for an origin we consider reachable; the report
* comes either from one of our own interfaces or from a gateway
* other than the one we have chosen as the best first-hop gateway
* back towards the origin. If the source of the update is one of
* our own interfaces, or if the origin is not a directly-connected
* subnet and the reported metric for that origin is better than
* what our routing entry says, update the entry to use the new
* gateway and metric. We also switch gateways if the reported
* metric is the same as the one in the route entry and the gateway
* associated with the route entry has not been heard from recently,
* or if the metric is the same but the reporting gateway has a lower
* IP address than the gateway associated with the route entry.
* Did you get all that?
*/
u_int32 old_gateway;
vifi_t old_parent;
old_gateway = r->rt_gateway;
old_parent = r->rt_parent;
r->rt_gateway = src;
r->rt_parent = vifi;
IF_DEBUG(DEBUG_RTDETAIL)
log(LOG_DEBUG, 0, "%s (new parent) on vif %d advertises %s with adj_metric %d (old parent was %s on vif %d, metric %d)",
inet_fmt(src, s1), vifi, inet_fmts(origin, mask, s2),
adj_metric, inet_fmt(old_gateway, s3), old_parent,
r->rt_metric);
if (old_parent != vifi) {
init_children_and_leaves(r, vifi, 0);
uvifs[old_parent].uv_nroutes--;
uvifs[vifi].uv_nroutes++;
}
if (old_gateway != src) {
update_table_entry(r, old_gateway);
/*???old_gateway???->al_nroutes--;*/
/*n->al_nroutes++;*/
}
r->rt_timer = 0;
r->rt_metric = adj_metric;
r->rt_flags |= RTF_CHANGED;
routes_changed = TRUE;
}
else if (vifi != r->rt_parent) {
/*
* The report came from a vif other than the route's parent vif.
* Update the children info, if necessary.
*/
if (AVOID_TRANSIT(vifi, r)) {
/*
* The route's parent is a vif from which we're not supposed
* to transit onto this vif. Simply ignore the update.
*/
IF_DEBUG(DEBUG_RTDETAIL)
log(LOG_DEBUG, 0, "%s on vif %d advertises %s with metric %d (ignored due to NOTRANSIT)",
inet_fmt(src, s1), vifi, inet_fmts(origin, mask, s2),
metric);
} else if (VIFM_ISSET(vifi, r->rt_children)) {
/*
* Vif is a child vif for this route.
*/
if (metric < r->rt_metric ||
(metric == r->rt_metric &&
ntohl(src) < ntohl(uvifs[vifi].uv_lcl_addr))) {
/*
* Neighbor has lower metric to origin (or has same metric
* and lower IP address) -- it becomes the dominant router,
* and vif is no longer a child for me.
*/
VIFM_CLR(vifi, r->rt_children);
r->rt_dominants [vifi] = src;
/* XXX
* We don't necessarily want to forget about subordinateness
* so that we can become the dominant quickly if the current
* dominant fails.
*/
NBRM_CLRMASK(r->rt_subordinates, uvifs[vifi].uv_nbrmap);
update_table_entry(r, r->rt_gateway);
IF_DEBUG(DEBUG_RTDETAIL)
log(LOG_DEBUG, 0, "%s on vif %d becomes dominant for %s with metric %d",
inet_fmt(src, s1), vifi, inet_fmts(origin, mask, s2),
metric);
}
else if (metric > UNREACHABLE) { /* "poisoned reverse" */
/*
* Neighbor considers this vif to be on path to route's
* origin; record this neighbor as subordinate
*/
if (!NBRM_ISSET(n->al_index, r->rt_subordinates)) {
IF_DEBUG(DEBUG_RTDETAIL)
log(LOG_DEBUG, 0, "%s on vif %d becomes subordinate for %s with poison-reverse metric %d",
inet_fmt(src, s1), vifi, inet_fmts(origin, mask, s2),
metric - UNREACHABLE);
NBRM_SET(n->al_index, r->rt_subordinates);
update_table_entry(r, r->rt_gateway);
} else {
IF_DEBUG(DEBUG_RTDETAIL)
log(LOG_DEBUG, 0, "%s on vif %d confirms subordinateness for %s with poison-reverse metric %d",
inet_fmt(src, s1), vifi, inet_fmts(origin, mask, s2),
metric - UNREACHABLE);
}
NBRM_SET(n->al_index, r->rt_subordadv);
}
else if (NBRM_ISSET(n->al_index, r->rt_subordinates)) {
/*
* Current subordinate no longer considers this vif to be on
* path to route's origin; it is no longer a subordinate
* router.
*/
IF_DEBUG(DEBUG_RTDETAIL)
log(LOG_DEBUG, 0, "%s on vif %d is no longer a subordinate for %s with metric %d",
inet_fmt(src, s1), vifi, inet_fmts(origin, mask, s2),
metric);
NBRM_CLR(n->al_index, r->rt_subordinates);
update_table_entry(r, r->rt_gateway);
}
}
else if (src == r->rt_dominants[vifi] &&
(metric > r->rt_metric ||
(metric == r->rt_metric &&
ntohl(src) > ntohl(uvifs[vifi].uv_lcl_addr)))) {
/*
* Current dominant no longer has a lower metric to origin
* (or same metric and lower IP address); we adopt the vif
* as our own child.
*/
IF_DEBUG(DEBUG_RTDETAIL)
log(LOG_DEBUG, 0, "%s (current dominant) on vif %d is no longer dominant for %s with metric %d",
inet_fmt(src, s1), vifi, inet_fmts(origin, mask, s2),
metric);
VIFM_SET(vifi, r->rt_children);
r->rt_dominants[vifi] = 0;
if (uvifs[vifi].uv_flags & VIFF_NOFLOOD)
NBRM_CLRMASK(r->rt_subordinates, uvifs[vifi].uv_nbrmap);
else
NBRM_SETMASK(r->rt_subordinates, uvifs[vifi].uv_nbrmap);
if (metric > UNREACHABLE) {
NBRM_SET(n->al_index, r->rt_subordinates);
NBRM_SET(n->al_index, r->rt_subordadv);
}
update_table_entry(r, r->rt_gateway);
} else {
IF_DEBUG(DEBUG_RTDETAIL)
log(LOG_DEBUG, 0, "%s on vif %d advertises %s with metric %d (ignored)",
inet_fmt(src, s1), vifi, inet_fmts(origin, mask, s2),
metric);
}
}
}
/*
* On every timer interrupt, advance the timer in each routing entry.
*/
void
age_routes()
{
register struct rtentry *r;
register struct rtentry *prev_r;
extern u_long virtual_time; /* from main.c */
for (prev_r = RT_ADDR, r = routing_table;
r != NULL;
prev_r = r, r = r->rt_next) {
if ((r->rt_timer += TIMER_INTERVAL) >= ROUTE_DISCARD_TIME) {
/*
* Time to garbage-collect the route entry.
*/
del_table_entry(r, 0, DEL_ALL_ROUTES);
discard_route(prev_r);
r = prev_r;
}
else if (r->rt_timer >= ROUTE_EXPIRE_TIME &&
r->rt_metric != UNREACHABLE) {
/*
* Time to expire the route entry. If the gateway is zero,
* i.e., it is a route to a directly-connected subnet, just
* set the timer back to zero; such routes expire only when
* the interface to the subnet goes down.
*/
if (r->rt_gateway == 0) {
r->rt_timer = 0;
}
else {
del_table_entry(r, 0, DEL_ALL_ROUTES);
r->rt_metric = UNREACHABLE;
r->rt_flags |= RTF_CHANGED;
routes_changed = TRUE;
}
}
else if (virtual_time % (ROUTE_REPORT_INTERVAL * 2) == 0) {
/*
* Time out subordinateness that hasn't been reported in
* the last 2 intervals.
*/
if (!NBRM_SAME(r->rt_subordinates, r->rt_subordadv)) {
IF_DEBUG(DEBUG_ROUTE)
log(LOG_DEBUG, 0, "rt %s sub 0x%08x%08x subadv 0x%08x%08x metric %d",
RT_FMT(r, s1),
r->rt_subordinates.hi, r->rt_subordinates.lo,
r->rt_subordadv.hi, r->rt_subordadv.lo, r->rt_metric);
NBRM_MASK(r->rt_subordinates, r->rt_subordadv);
update_table_entry(r, r->rt_gateway);
}
NBRM_CLRALL(r->rt_subordadv);
}
}
}
/*
* Mark all routes as unreachable. This function is called only from
* hup() in preparation for informing all neighbors that we are going
* off the air. For consistency, we ought also to delete all reachable
* route entries from the kernel, but since we are about to exit we rely
* on the kernel to do its own cleanup -- no point in making all those
* expensive kernel calls now.
*/
void
expire_all_routes()
{
register struct rtentry *r;
for (r = routing_table; r != NULL; r = r->rt_next) {
r->rt_metric = UNREACHABLE;
r->rt_flags |= RTF_CHANGED;
routes_changed = TRUE;
}
}
/*
* Delete all the routes in the routing table.
*/
void
free_all_routes()
{
register struct rtentry *r;
r = RT_ADDR;
while (r->rt_next)
discard_route(r);
}
/*
* Process an incoming neighbor probe message.
*/
void
accept_probe(src, dst, p, datalen, level)
u_int32 src;
u_int32 dst;
char *p;
int datalen;
u_int32 level;
{
vifi_t vifi;
static struct listaddr *unknowns = NULL;
if ((vifi = find_vif(src, dst)) == NO_VIF) {
struct listaddr *a, **prev;
struct listaddr *match = NULL;
time_t now = time(0);
for (prev = &unknowns, a = *prev; a; a = *prev) {
if (a->al_addr == src)
match = a;
if (a->al_ctime + 2 * a->al_timer < now) {
/* We haven't heard from it in a long time */
*prev = a->al_next;
free(a);
} else {
prev = &a->al_next;
}
}
if (match == NULL) {
match = *prev = (struct listaddr *)malloc(sizeof(struct listaddr));
match->al_next = NULL;
match->al_addr = src;
match->al_timer = OLD_NEIGHBOR_EXPIRE_TIME;
match->al_ctime = now - match->al_timer;
}
if (match->al_ctime + match->al_timer <= now) {
log(LOG_WARNING, 0,
"ignoring probe from non-neighbor %s, check for misconfigured tunnel or routing on %s",
inet_fmt(src, s1), s1);
match->al_timer *= 2;
} else
IF_DEBUG(DEBUG_PEER)
log(LOG_DEBUG, 0,
"ignoring probe from non-neighbor %s (%d seconds until next warning)", inet_fmt(src, s1), match->al_ctime + match->al_timer - now);
return;
}
update_neighbor(vifi, src, DVMRP_PROBE, p, datalen, level);
}
struct newrt {
u_int32 mask;
u_int32 origin;
int metric;
int pad;
};
static int
compare_rts(rt1, rt2)
const void *rt1;
const void *rt2;
{
register struct newrt *r1 = (struct newrt *)rt1;
register struct newrt *r2 = (struct newrt *)rt2;
register u_int32 m1 = ntohl(r1->mask);
register u_int32 m2 = ntohl(r2->mask);
register u_int32 o1, o2;
if (m1 > m2)
return (-1);
if (m1 < m2)
return (1);
/* masks are equal */
o1 = ntohl(r1->origin);
o2 = ntohl(r2->origin);
if (o1 > o2)
return (-1);
if (o1 < o2)
return (1);
return (0);
}
void
blaster_alloc(vifi)
vifi_t vifi;
{
register struct uvif *v;
v = &uvifs[vifi];
if (v->uv_blasterbuf)
free(v->uv_blasterbuf);
v->uv_blasterlen = 64*1024;
v->uv_blasterbuf = malloc(v->uv_blasterlen);
v->uv_blastercur = v->uv_blasterend = v->uv_blasterbuf;
if (v->uv_blastertimer)
timer_clearTimer(v->uv_blastertimer);
v->uv_blastertimer = 0;
}
struct blaster_hdr {
u_int32 bh_src;
u_int32 bh_dst;
u_int32 bh_level;
int bh_datalen;
};
/*
* Queue a route report from a route-blaster.
* If the timer isn't running to process these reports,
* start it.
*/
static void
queue_blaster_report(vifi, src, dst, p, datalen, level)
vifi_t vifi;
u_int32 src, dst, level;
register char *p;
register int datalen;
{
register struct blaster_hdr *bh;
register struct uvif *v;
int bblen = sizeof(*bh) + ((datalen + 3) & ~3);
v = &uvifs[vifi];
if (v->uv_blasterend - v->uv_blasterbuf +
bblen > v->uv_blasterlen) {
int end = v->uv_blasterend - v->uv_blasterbuf;
int cur = v->uv_blastercur - v->uv_blasterbuf;
v->uv_blasterlen *= 2;
IF_DEBUG(DEBUG_IF)
log(LOG_DEBUG, 0, "increasing blasterbuf to %d bytes",
v->uv_blasterlen);
v->uv_blasterbuf = realloc(v->uv_blasterbuf,
v->uv_blasterlen);
if (v->uv_blasterbuf == NULL) {
log(LOG_WARNING, ENOMEM, "turning off blaster on vif %d", vifi);
v->uv_blasterlen = 0;
v->uv_blasterend = v->uv_blastercur = NULL;
v->uv_flags &= ~VIFF_BLASTER;
return;
}
v->uv_blasterend = v->uv_blasterbuf + end;
v->uv_blastercur = v->uv_blasterbuf + cur;
}
bh = (struct blaster_hdr *)v->uv_blasterend;
bh->bh_src = src;
bh->bh_dst = dst;
bh->bh_level = level;
bh->bh_datalen = datalen;
bcopy(p, (char *)(bh + 1), datalen);
v->uv_blasterend += bblen;
if (v->uv_blastertimer == 0) {
int *i = (int *)malloc(sizeof(int *));
if (i == NULL)
log(LOG_ERR, 0, "out of memory");
*i = vifi;
v->uv_blastertimer = timer_setTimer(5,
process_blaster_report, i);
}
}
/*
* Periodic process; process up to 5 of the routes in the route-blaster
* queue. If there are more routes remaining, reschedule myself to run
* in 1 second.
*/
static void
process_blaster_report(vifip)
void *vifip;
{
vifi_t vifi = *(int *)vifip;
register struct uvif *v;
register struct blaster_hdr *bh;
int i;
IF_DEBUG(DEBUG_ROUTE)
log(LOG_DEBUG, 0, "processing vif %d blasted routes", vifi);
v = &uvifs[vifi];
for (i = 0; i < 5; i++) {
if (v->uv_blastercur >= v->uv_blasterend)
break;
bh = (struct blaster_hdr *)v->uv_blastercur;
v->uv_blastercur += sizeof(*bh) + ((bh->bh_datalen + 3) & ~3);
accept_report(bh->bh_src, bh->bh_dst, (char *)(bh + 1),
-bh->bh_datalen, bh->bh_level);
}
if (v->uv_blastercur >= v->uv_blasterend) {
v->uv_blastercur = v->uv_blasterbuf;
v->uv_blasterend = v->uv_blasterbuf;
v->uv_blastertimer = 0;
free(vifip);
IF_DEBUG(DEBUG_ROUTE)
log(LOG_DEBUG, 0, "finish processing vif %d blaster", vifi);
} else {
IF_DEBUG(DEBUG_ROUTE)
log(LOG_DEBUG, 0, "more blasted routes to come on vif %d", vifi);
v->uv_blastertimer = timer_setTimer(1,
process_blaster_report, vifip);
}
}
/*
* Process an incoming route report message.
* If the report arrived on a vif marked as a "blaster", then just
* queue it and return; queue_blaster_report() will schedule it for
* processing later. If datalen is negative, then this is actually
* a queued report so actually process it instead of queueing it.
*/
void
accept_report(src, dst, p, datalen, level)
u_int32 src, dst, level;
register char *p;
register int datalen;
{
vifi_t vifi;
register int width, i, nrt = 0;
int metric;
u_int32 mask;
u_int32 origin;
struct newrt rt[4096];
struct listaddr *nbr;
if ((vifi = find_vif(src, dst)) == NO_VIF) {
log(LOG_INFO, 0,
"ignoring route report from non-neighbor %s", inet_fmt(src, s1));
return;
}
if (uvifs[vifi].uv_flags & VIFF_BLASTER)
if (datalen > 0) {
queue_blaster_report(vifi, src, dst, p, datalen, level);
return;
} else {
datalen = -datalen;
}
if (!(nbr = update_neighbor(vifi, src, DVMRP_REPORT, NULL, 0, level)))
return;
if (datalen > 2*4096) {
log(LOG_INFO, 0,
"ignoring oversize (%d bytes) route report from %s",
datalen, inet_fmt(src, s1));
return;
}
while (datalen > 0) { /* Loop through per-mask lists. */
if (datalen < 3) {
log(LOG_WARNING, 0,
"received truncated route report from %s",
inet_fmt(src, s1));
return;
}
((u_char *)&mask)[0] = 0xff; width = 1;
if ((((u_char *)&mask)[1] = *p++) != 0) width = 2;
if ((((u_char *)&mask)[2] = *p++) != 0) width = 3;
if ((((u_char *)&mask)[3] = *p++) != 0) width = 4;
if (!inet_valid_mask(ntohl(mask))) {
log(LOG_WARNING, 0,
"%s reports bogus netmask 0x%08x (%s)",
inet_fmt(src, s1), ntohl(mask), inet_fmt(mask, s2));
return;
}
datalen -= 3;
do { /* Loop through (origin, metric) pairs */
if (datalen < width + 1) {
log(LOG_WARNING, 0,
"received truncated route report from %s",
inet_fmt(src, s1));
return;
}
origin = 0;
for (i = 0; i < width; ++i)
((char *)&origin)[i] = *p++;
metric = *p++;
datalen -= width + 1;
rt[nrt].mask = mask;
rt[nrt].origin = origin;
rt[nrt].metric = (metric & 0x7f);
++nrt;
} while (!(metric & 0x80));
}
qsort((char*)rt, nrt, sizeof(rt[0]), compare_rts);
start_route_updates();
/*
* If the last entry is default, change mask from 0xff000000 to 0
*/
if (rt[nrt-1].origin == 0)
rt[nrt-1].mask = 0;
IF_DEBUG(DEBUG_ROUTE)
log(LOG_DEBUG, 0, "Updating %d routes from %s to %s", nrt,
inet_fmt(src, s1), inet_fmt(dst, s2));
for (i = 0; i < nrt; ++i) {
if (i != 0 && rt[i].origin == rt[i-1].origin &&
rt[i].mask == rt[i-1].mask) {
log(LOG_WARNING, 0, "%s reports duplicate route for %s",
inet_fmt(src, s1), inet_fmts(rt[i].origin, rt[i].mask, s2));
continue;
}
/* Only filter non-poisoned updates. */
if (uvifs[vifi].uv_filter && rt[i].metric < UNREACHABLE) {
struct vf_element *vfe;
int match = 0;
for (vfe = uvifs[vifi].uv_filter->vf_filter; vfe; vfe = vfe->vfe_next) {
if (vfe->vfe_flags & VFEF_EXACT) {
if ((vfe->vfe_addr == rt[i].origin) &&
(vfe->vfe_mask == rt[i].mask)) {
match = 1;
break;
}
} else {
if ((rt[i].origin & vfe->vfe_mask) == vfe->vfe_addr) {
match = 1;
break;
}
}
}
if ((uvifs[vifi].uv_filter->vf_type == VFT_ACCEPT && match == 0) ||
(uvifs[vifi].uv_filter->vf_type == VFT_DENY && match == 1)) {
IF_DEBUG(DEBUG_ROUTE)
log(LOG_DEBUG, 0, "%s skipped on vif %d because it %s %s",
inet_fmts(rt[i].origin, rt[i].mask, s1),
vifi,
match ? "matches" : "doesn't match",
match ? inet_fmts(vfe->vfe_addr, vfe->vfe_mask, s2) :
"the filter");
#if 0
rt[i].metric += vfe->vfe_addmetric;
if (rt[i].metric > UNREACHABLE)
#endif
rt[i].metric = UNREACHABLE;
}
}
update_route(rt[i].origin, rt[i].mask, rt[i].metric,
src, vifi, nbr);
}
if (routes_changed && !delay_change_reports)
report_to_all_neighbors(CHANGED_ROUTES);
}
/*
* Send a route report message to destination 'dst', via virtual interface
* 'vifi'. 'which_routes' specifies ALL_ROUTES or CHANGED_ROUTES.
*/
void
report(which_routes, vifi, dst)
int which_routes;
vifi_t vifi;
u_int32 dst;
{
register struct rtentry *r;
register int i;
r = rt_end;
while (r != RT_ADDR) {
i = report_chunk(which_routes, r, vifi, dst);
while (i-- > 0)
r = r->rt_prev;
}
}
/*
* Send a route report message to all neighboring routers.
* 'which_routes' specifies ALL_ROUTES or CHANGED_ROUTES.
*/
void
report_to_all_neighbors(which_routes)
int which_routes;
{
register vifi_t vifi;
register struct uvif *v;
register struct rtentry *r;
int routes_changed_before;
/*
* Remember the state of the global routes_changed flag before
* generating the reports, and clear the flag.
*/
routes_changed_before = routes_changed;
routes_changed = FALSE;
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
if (!NBRM_ISEMPTY(v->uv_nbrmap)) {
report(which_routes, vifi, v->uv_dst_addr);
}
}
/*
* If there were changed routes before we sent the reports AND
* if no new changes occurred while sending the reports, clear
* the change flags in the individual route entries. If changes
* did occur while sending the reports, new reports will be
* generated at the next timer interrupt.
*/
if (routes_changed_before && !routes_changed) {
for (r = routing_table; r != NULL; r = r->rt_next) {
r->rt_flags &= ~RTF_CHANGED;
}
}
/*
* Set a flag to inhibit further reports of changed routes until the
* next timer interrupt. This is to alleviate update storms.
*/
delay_change_reports = TRUE;
}
/*
* Send a route report message to destination 'dst', via virtual interface
* 'vifi'. 'which_routes' specifies ALL_ROUTES or CHANGED_ROUTES.
*/
static int
report_chunk(which_routes, start_rt, vifi, dst)
int which_routes;
register struct rtentry *start_rt;
vifi_t vifi;
u_int32 dst;
{
register struct rtentry *r;
register char *p;
register int i;
register int nrt = 0;
struct uvif *v = &uvifs[vifi];
int datalen = 0;
int width = 0;
u_int32 mask = 0;
u_int32 src;
int admetric = v->uv_admetric;
int metric;
src = v->uv_lcl_addr;
p = send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN;
for (r = start_rt; r != RT_ADDR; r = r->rt_prev) {
if (which_routes == CHANGED_ROUTES && !(r->rt_flags & RTF_CHANGED)) {
nrt++;
continue;
}
/*
* Do not poison-reverse a route for a directly-connected
* subnetwork on that subnetwork. This can cause loops when
* some router on the subnetwork is misconfigured.
*/
if (r->rt_gateway == 0 && r->rt_parent == vifi) {
nrt++;
continue;
}
if (v->uv_filter && v->uv_filter->vf_flags & VFF_BIDIR) {
struct vf_element *vfe;
int match = 0;
for (vfe = v->uv_filter->vf_filter; vfe; vfe = vfe->vfe_next) {
if (vfe->vfe_flags & VFEF_EXACT) {
if ((vfe->vfe_addr == r->rt_origin) &&
(vfe->vfe_mask == r->rt_originmask)) {
match = 1;
break;
}
} else {
if ((r->rt_origin & vfe->vfe_mask) == vfe->vfe_addr) {
match = 1;
break;
}
}
}
if ((v->uv_filter->vf_type == VFT_ACCEPT && match == 0) ||
(v->uv_filter->vf_type == VFT_DENY && match == 1)) {
IF_DEBUG(DEBUG_ROUTE)
log(LOG_DEBUG, 0, "%s not reported on vif %d because it %s %s",
RT_FMT(r, s1), vifi,
match ? "matches" : "doesn't match",
match ? inet_fmts(vfe->vfe_addr, vfe->vfe_mask, s2) :
"the filter");
nrt++;
continue;
}
}
/*
* If there is no room for this route in the current message,
* send it & return how many routes we sent.
*/
if (datalen + ((r->rt_originmask == mask) ?
(width + 1) :
(r->rt_originwidth + 4)) > MAX_DVMRP_DATA_LEN) {
*(p-1) |= 0x80;
send_on_vif(v, 0, DVMRP_REPORT, datalen);
return (nrt);
}
if (r->rt_originmask != mask || datalen == 0) {
mask = r->rt_originmask;
width = r->rt_originwidth;
if (datalen != 0) *(p-1) |= 0x80;
*p++ = ((char *)&mask)[1];
*p++ = ((char *)&mask)[2];
*p++ = ((char *)&mask)[3];
datalen += 3;
}
for (i = 0; i < width; ++i)
*p++ = ((char *)&(r->rt_origin))[i];
metric = r->rt_metric + admetric;
if (metric > UNREACHABLE)
metric = UNREACHABLE;
if (r->rt_parent != vifi && AVOID_TRANSIT(vifi, r))
metric = UNREACHABLE;
*p++ = (r->rt_parent == vifi && metric != UNREACHABLE) ?
(char)(metric + UNREACHABLE) : /* "poisoned reverse" */
(char)(metric);
++nrt;
datalen += width + 1;
}
if (datalen != 0) {
*(p-1) |= 0x80;
send_on_vif(v, 0, DVMRP_REPORT, datalen);
}
return (nrt);
}
/*
* send the next chunk of our routing table to all neighbors.
* return the length of the smallest chunk we sent out.
*/
int
report_next_chunk()
{
register vifi_t vifi;
register struct uvif *v;
register struct rtentry *sr;
register int i, n = 0, min = 20000;
static int start_rt;
if (nroutes <= 0)
return (0);
/*
* find this round's starting route.
*/
for (sr = rt_end, i = start_rt; --i >= 0; ) {
sr = sr->rt_prev;
if (sr == RT_ADDR)
sr = rt_end;
}
/*
* send one chunk of routes starting at this round's start to
* all our neighbors.
*/
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
if (!NBRM_ISEMPTY(v->uv_nbrmap)) {
n = report_chunk(ALL_ROUTES, sr, vifi, v->uv_dst_addr);
if (n < min)
min = n;
}
}
if (min == 20000)
min = 0; /* Neighborless router didn't send any routes */
n = min;
IF_DEBUG(DEBUG_ROUTE)
log(LOG_INFO, 0, "update %d starting at %d of %d",
n, (nroutes - start_rt), nroutes);
start_rt = (start_rt + n) % nroutes;
return (n);
}
/*
* Print the contents of the routing table on file 'fp'.
*/
void
dump_routes(fp)
FILE *fp;
{
register struct rtentry *r;
register vifi_t i;
fprintf(fp,
"Multicast Routing Table (%u %s)\n%s\n",
nroutes, (nroutes == 1) ? "entry" : "entries",
" Origin-Subnet From-Gateway Metric Tmr Fl In-Vif Out-Vifs");
for (r = routing_table; r != NULL; r = r->rt_next) {
fprintf(fp, " %-18s %-15s ",
inet_fmts(r->rt_origin, r->rt_originmask, s1),
(r->rt_gateway == 0) ? "" : inet_fmt(r->rt_gateway, s2));
fprintf(fp, (r->rt_metric == UNREACHABLE) ? " NR " : "%4u ",
r->rt_metric);
fprintf(fp, " %3u %c%c %3u ", r->rt_timer,
(r->rt_flags & RTF_CHANGED) ? 'C' : '.',
(r->rt_flags & RTF_HOLDDOWN) ? 'H' : '.',
r->rt_parent);
for (i = 0; i < numvifs; ++i) {
struct listaddr *n;
char l = '[';
if (VIFM_ISSET(i, r->rt_children)) {
if ((uvifs[i].uv_flags & VIFF_TUNNEL) &&
!NBRM_ISSETMASK(uvifs[i].uv_nbrmap, r->rt_subordinates))
/* Don't print out parenthood of a leaf tunnel. */
continue;
fprintf(fp, " %u", i);
if (!NBRM_ISSETMASK(uvifs[i].uv_nbrmap, r->rt_subordinates))
fprintf(fp, "*");
for (n = uvifs[i].uv_neighbors; n; n = n->al_next) {
if (NBRM_ISSET(n->al_index, r->rt_subordinates)) {
fprintf(fp, "%c%d", l, n->al_index);
l = ',';
}
}
if (l == ',')
fprintf(fp, "]");
}
}
fprintf(fp, "\n");
}
fprintf(fp, "\n");
}
struct rtentry *
determine_route(src)
u_int32 src;
{
struct rtentry *rt;
for (rt = routing_table; rt != NULL; rt = rt->rt_next) {
if (rt->rt_origin == (src & rt->rt_originmask) &&
rt->rt_metric != UNREACHABLE)
break;
}
return rt;
}
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