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2c7a97817b
freebsd/sbin/routed/table.c
Mark Murray 2c7a97817b Latest-and-greatest routed. 
Includes RIPv2 and Router Discovery.

Submitted by:	Vernon Schryver <vjs@calcite.rhyolite.com>
1999-05-02 10:51:54 +00:00

2135 lines
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/*
* Copyright (c) 1983, 1988, 1993
* The Regents of the University of California. 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgment:
* 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
* SUCH DAMAGE.
*/
#include "defs.h"
#if !defined(sgi) && !defined(__NetBSD__)
static char sccsid[] __attribute__((unused)) = "@(#)tables.c 8.1 (Berkeley) 6/5/93";
#elif defined(__NetBSD__)
__RCSID("$NetBSD$");
#endif
#ident "$Revision: 2.17 $"
static struct rt_spare *rts_better(struct rt_entry *);
static struct rt_spare rts_empty = {0,0,0,HOPCNT_INFINITY,0,0,0};
static void set_need_flash(void);
#ifdef _HAVE_SIN_LEN
static void masktrim(struct sockaddr_in *ap);
#else
static void masktrim(struct sockaddr_in_new *ap);
#endif
struct radix_node_head *rhead; /* root of the radix tree */
int need_flash = 1; /* flash update needed
* start =1 to suppress the 1st
*/
struct timeval age_timer; /* next check of old routes */
struct timeval need_kern = { /* need to update kernel table */
EPOCH+MIN_WAITTIME-1
};
int stopint;
int total_routes;
/* zap any old routes through this gateway */
naddr age_bad_gate;
/* It is desirable to "aggregate" routes, to combine differing routes of
* the same metric and next hop into a common route with a smaller netmask
* or to suppress redundant routes, routes that add no information to
* routes with smaller netmasks.
*
* A route is redundant if and only if any and all routes with smaller
* but matching netmasks and nets are the same. Since routes are
* kept sorted in the radix tree, redundant routes always come second.
*
* There are two kinds of aggregations. First, two routes of the same bit
* mask and differing only in the least significant bit of the network
* number can be combined into a single route with a coarser mask.
*
* Second, a route can be suppressed in favor of another route with a more
* coarse mask provided no incompatible routes with intermediate masks
* are present. The second kind of aggregation involves suppressing routes.
* A route must not be suppressed if an incompatible route exists with
* an intermediate mask, since the suppressed route would be covered
* by the intermediate.
*
* This code relies on the radix tree walk encountering routes
* sorted first by address, with the smallest address first.
*/
struct ag_info ag_slots[NUM_AG_SLOTS], *ag_avail, *ag_corsest, *ag_finest;
/* #define DEBUG_AG */
#ifdef DEBUG_AG
#define CHECK_AG() {int acnt = 0; struct ag_info *cag; \
for (cag = ag_avail; cag != 0; cag = cag->ag_fine) \
acnt++; \
for (cag = ag_corsest; cag != 0; cag = cag->ag_fine) \
acnt++; \
if (acnt != NUM_AG_SLOTS) { \
(void)fflush(stderr); \
abort(); \
} \
}
#else
#define CHECK_AG()
#endif
/* Output the contents of an aggregation table slot.
* This function must always be immediately followed with the deletion
* of the target slot.
*/
static void
ag_out(struct ag_info *ag,
void (*out)(struct ag_info *))
{
struct ag_info *ag_cors;
naddr bit;
/* Forget it if this route should not be output for split-horizon. */
if (ag->ag_state & AGS_SPLIT_HZ)
return;
/* If we output both the even and odd twins, then the immediate parent,
* if it is present, is redundant, unless the parent manages to
* aggregate into something coarser.
* On successive calls, this code detects the even and odd twins,
* and marks the parent.
*
* Note that the order in which the radix tree code emits routes
* ensures that the twins are seen before the parent is emitted.
*/
ag_cors = ag->ag_cors;
if (ag_cors != 0
&& ag_cors->ag_mask == ag->ag_mask<<1
&& ag_cors->ag_dst_h == (ag->ag_dst_h & ag_cors->ag_mask)) {
ag_cors->ag_state |= ((ag_cors->ag_dst_h == ag->ag_dst_h)
? AGS_REDUN0
: AGS_REDUN1);
}
/* Skip it if this route is itself redundant.
*
* It is ok to change the contents of the slot here, since it is
* always deleted next.
*/
if (ag->ag_state & AGS_REDUN0) {
if (ag->ag_state & AGS_REDUN1)
return; /* quit if fully redundant */
/* make it finer if it is half-redundant */
bit = (-ag->ag_mask) >> 1;
ag->ag_dst_h |= bit;
ag->ag_mask |= bit;
} else if (ag->ag_state & AGS_REDUN1) {
/* make it finer if it is half-redundant */
bit = (-ag->ag_mask) >> 1;
ag->ag_mask |= bit;
}
out(ag);
}
static void
ag_del(struct ag_info *ag)
{
CHECK_AG();
if (ag->ag_cors == 0)
ag_corsest = ag->ag_fine;
else
ag->ag_cors->ag_fine = ag->ag_fine;
if (ag->ag_fine == 0)
ag_finest = ag->ag_cors;
else
ag->ag_fine->ag_cors = ag->ag_cors;
ag->ag_fine = ag_avail;
ag_avail = ag;
CHECK_AG();
}
/* Flush routes waiting for aggregation.
* This must not suppress a route unless it is known that among all
* routes with coarser masks that match it, the one with the longest
* mask is appropriate. This is ensured by scanning the routes
* in lexical order, and with the most restrictive mask first
* among routes to the same destination.
*/
void
ag_flush(naddr lim_dst_h, /* flush routes to here */
naddr lim_mask, /* matching this mask */
void (*out)(struct ag_info *))
{
struct ag_info *ag, *ag_cors;
naddr dst_h;
for (ag = ag_finest;
ag != 0 && ag->ag_mask >= lim_mask;
ag = ag_cors) {
ag_cors = ag->ag_cors;
/* work on only the specified routes */
dst_h = ag->ag_dst_h;
if ((dst_h & lim_mask) != lim_dst_h)
continue;
if (!(ag->ag_state & AGS_SUPPRESS))
ag_out(ag, out);
else for ( ; ; ag_cors = ag_cors->ag_cors) {
/* Look for a route that can suppress the
* current route */
if (ag_cors == 0) {
/* failed, so output it and look for
* another route to work on
*/
ag_out(ag, out);
break;
}
if ((dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h) {
/* We found a route with a coarser mask that
* aggregates the current target.
*
* If it has a different next hop, it
* cannot replace the target, so output
* the target.
*/
if (ag->ag_gate != ag_cors->ag_gate
&& !(ag->ag_state & AGS_FINE_GATE)
&& !(ag_cors->ag_state & AGS_CORS_GATE)) {
ag_out(ag, out);
break;
}
/* If the coarse route has a good enough
* metric, it suppresses the target.
* If the suppressed target was redundant,
* then mark the suppressor redundant.
*/
if (ag_cors->ag_pref <= ag->ag_pref) {
if (ag_cors->ag_seqno > ag->ag_seqno)
ag_cors->ag_seqno = ag->ag_seqno;
if (AG_IS_REDUN(ag->ag_state)
&& ag_cors->ag_mask==ag->ag_mask<<1) {
if (ag_cors->ag_dst_h == dst_h)
ag_cors->ag_state |= AGS_REDUN0;
else
ag_cors->ag_state |= AGS_REDUN1;
}
if (ag->ag_tag != ag_cors->ag_tag)
ag_cors->ag_tag = 0;
if (ag->ag_nhop != ag_cors->ag_nhop)
ag_cors->ag_nhop = 0;
break;
}
}
}
/* That route has either been output or suppressed */
ag_cors = ag->ag_cors;
ag_del(ag);
}
CHECK_AG();
}
/* Try to aggregate a route with previous routes.
*/
void
ag_check(naddr dst,
naddr mask,
naddr gate,
naddr nhop,
char metric,
char pref,
u_int seqno,
u_short tag,
u_short state,
void (*out)(struct ag_info *)) /* output using this */
{
struct ag_info *ag, *nag, *ag_cors;
naddr xaddr;
int x;
NTOHL(dst);
/* Punt non-contiguous subnet masks.
*
* (X & -X) contains a single bit if and only if X is a power of 2.
* (X + (X & -X)) == 0 if and only if X is a power of 2.
*/
if ((mask & -mask) + mask != 0) {
struct ag_info nc_ag;
nc_ag.ag_dst_h = dst;
nc_ag.ag_mask = mask;
nc_ag.ag_gate = gate;
nc_ag.ag_nhop = nhop;
nc_ag.ag_metric = metric;
nc_ag.ag_pref = pref;
nc_ag.ag_tag = tag;
nc_ag.ag_state = state;
nc_ag.ag_seqno = seqno;
out(&nc_ag);
return;
}
/* Search for the right slot in the aggregation table.
*/
ag_cors = 0;
ag = ag_corsest;
while (ag != 0) {
if (ag->ag_mask >= mask)
break;
/* Suppress old routes (i.e. combine with compatible routes
* with coarser masks) as we look for the right slot in the
* aggregation table for the new route.
* A route to an address less than the current destination
* will not be affected by the current route or any route
* seen hereafter. That means it is safe to suppress it.
* This check keeps poor routes (e.g. with large hop counts)
* from preventing suppression of finer routes.
*/
if (ag_cors != 0
&& ag->ag_dst_h < dst
&& (ag->ag_state & AGS_SUPPRESS)
&& ag_cors->ag_pref <= ag->ag_pref
&& (ag->ag_dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h
&& (ag_cors->ag_gate == ag->ag_gate
|| (ag->ag_state & AGS_FINE_GATE)
|| (ag_cors->ag_state & AGS_CORS_GATE))) {
if (ag_cors->ag_seqno > ag->ag_seqno)
ag_cors->ag_seqno = ag->ag_seqno;
/* If the suppressed target was redundant,
* then mark the suppressor redundant.
*/
if (AG_IS_REDUN(ag->ag_state)
&& ag_cors->ag_mask==ag->ag_mask<<1) {
if (ag_cors->ag_dst_h == dst)
ag_cors->ag_state |= AGS_REDUN0;
else
ag_cors->ag_state |= AGS_REDUN1;
}
if (ag->ag_tag != ag_cors->ag_tag)
ag_cors->ag_tag = 0;
if (ag->ag_nhop != ag_cors->ag_nhop)
ag_cors->ag_nhop = 0;
ag_del(ag);
CHECK_AG();
} else {
ag_cors = ag;
}
ag = ag_cors->ag_fine;
}
/* If we find the even/odd twin of the new route, and if the
* masks and so forth are equal, we can aggregate them.
* We can probably promote one of the pair.
*
* Since the routes are encountered in lexical order,
* the new route must be odd. However, the second or later
* times around this loop, it could be the even twin promoted
* from the even/odd pair of twins of the finer route.
*/
while (ag != 0
&& ag->ag_mask == mask
&& ((ag->ag_dst_h ^ dst) & (mask<<1)) == 0) {
/* Here we know the target route and the route in the current
* slot have the same netmasks and differ by at most the
* last bit. They are either for the same destination, or
* for an even/odd pair of destinations.
*/
if (ag->ag_dst_h == dst) {
/* We have two routes to the same destination.
* Routes are encountered in lexical order, so a
* route is never promoted until the parent route is
* already present. So we know that the new route is
* a promoted (or aggregated) pair and the route
* already in the slot is the explicit route.
*
* Prefer the best route if their metrics differ,
* or the aggregated one if not, following a sort
* of longest-match rule.
*/
if (pref <= ag->ag_pref) {
ag->ag_gate = gate;
ag->ag_nhop = nhop;
ag->ag_tag = tag;
ag->ag_metric = metric;
ag->ag_pref = pref;
x = ag->ag_state;
ag->ag_state = state;
state = x;
}
/* The sequence number controls flash updating,
* and should be the smaller of the two.
*/
if (ag->ag_seqno > seqno)
ag->ag_seqno = seqno;
/* Some bits are set if they are set on either route,
* except when the route is for an interface.
*/
if (!(ag->ag_state & AGS_IF))
ag->ag_state |= (state & (AGS_AGGREGATE_EITHER
| AGS_REDUN0
| AGS_REDUN1));
return;
}
/* If one of the routes can be promoted and the other can
* be suppressed, it may be possible to combine them or
* worthwhile to promote one.
*
* Any route that can be promoted is always
* marked to be eligible to be suppressed.
*/
if (!((state & AGS_AGGREGATE)
&& (ag->ag_state & AGS_SUPPRESS))
&& !((ag->ag_state & AGS_AGGREGATE)
&& (state & AGS_SUPPRESS)))
break;
/* A pair of even/odd twin routes can be combined
* if either is redundant, or if they are via the
* same gateway and have the same metric.
*/
if (AG_IS_REDUN(ag->ag_state)
|| AG_IS_REDUN(state)
|| (ag->ag_gate == gate
&& ag->ag_pref == pref
&& (state & ag->ag_state & AGS_AGGREGATE) != 0)) {
/* We have both the even and odd pairs.
* Since the routes are encountered in order,
* the route in the slot must be the even twin.
*
* Combine and promote (aggregate) the pair of routes.
*/
if (seqno > ag->ag_seqno)
seqno = ag->ag_seqno;
if (!AG_IS_REDUN(state))
state &= ~AGS_REDUN1;
if (AG_IS_REDUN(ag->ag_state))
state |= AGS_REDUN0;
else
state &= ~AGS_REDUN0;
state |= (ag->ag_state & AGS_AGGREGATE_EITHER);
if (ag->ag_tag != tag)
tag = 0;
if (ag->ag_nhop != nhop)
nhop = 0;
/* Get rid of the even twin that was already
* in the slot.
*/
ag_del(ag);
} else if (ag->ag_pref >= pref
&& (ag->ag_state & AGS_AGGREGATE)) {
/* If we cannot combine the pair, maybe the route
* with the worse metric can be promoted.
*
* Promote the old, even twin, by giving its slot
* in the table to the new, odd twin.
*/
ag->ag_dst_h = dst;
xaddr = ag->ag_gate;
ag->ag_gate = gate;
gate = xaddr;
xaddr = ag->ag_nhop;
ag->ag_nhop = nhop;
nhop = xaddr;
x = ag->ag_tag;
ag->ag_tag = tag;
tag = x;
/* The promoted route is even-redundant only if the
* even twin was fully redundant. It is not
* odd-redundant because the odd-twin will still be
* in the table.
*/
x = ag->ag_state;
if (!AG_IS_REDUN(x))
x &= ~AGS_REDUN0;
x &= ~AGS_REDUN1;
ag->ag_state = state;
state = x;
x = ag->ag_metric;
ag->ag_metric = metric;
metric = x;
x = ag->ag_pref;
ag->ag_pref = pref;
pref = x;
/* take the newest sequence number */
if (seqno >= ag->ag_seqno)
seqno = ag->ag_seqno;
else
ag->ag_seqno = seqno;
} else {
if (!(state & AGS_AGGREGATE))
break; /* cannot promote either twin */
/* Promote the new, odd twin by shaving its
* mask and address.
* The promoted route is odd-redundant only if the
* odd twin was fully redundant. It is not
* even-redundant because the even twin is still in
* the table.
*/
if (!AG_IS_REDUN(state))
state &= ~AGS_REDUN1;
state &= ~AGS_REDUN0;
if (seqno > ag->ag_seqno)
seqno = ag->ag_seqno;
else
ag->ag_seqno = seqno;
}
mask <<= 1;
dst &= mask;
if (ag_cors == 0) {
ag = ag_corsest;
break;
}
ag = ag_cors;
ag_cors = ag->ag_cors;
}
/* When we can no longer promote and combine routes,
* flush the old route in the target slot. Also flush
* any finer routes that we know will never be aggregated by
* the new route.
*
* In case we moved toward coarser masks,
* get back where we belong
*/
if (ag != 0
&& ag->ag_mask < mask) {
ag_cors = ag;
ag = ag->ag_fine;
}
/* Empty the target slot
*/
if (ag != 0 && ag->ag_mask == mask) {
ag_flush(ag->ag_dst_h, ag->ag_mask, out);
ag = (ag_cors == 0) ? ag_corsest : ag_cors->ag_fine;
}
#ifdef DEBUG_AG
(void)fflush(stderr);
if (ag == 0 && ag_cors != ag_finest)
abort();
if (ag_cors == 0 && ag != ag_corsest)
abort();
if (ag != 0 && ag->ag_cors != ag_cors)
abort();
if (ag_cors != 0 && ag_cors->ag_fine != ag)
abort();
CHECK_AG();
#endif
/* Save the new route on the end of the table.
*/
nag = ag_avail;
ag_avail = nag->ag_fine;
nag->ag_dst_h = dst;
nag->ag_mask = mask;
nag->ag_gate = gate;
nag->ag_nhop = nhop;
nag->ag_metric = metric;
nag->ag_pref = pref;
nag->ag_tag = tag;
nag->ag_state = state;
nag->ag_seqno = seqno;
nag->ag_fine = ag;
if (ag != 0)
ag->ag_cors = nag;
else
ag_finest = nag;
nag->ag_cors = ag_cors;
if (ag_cors == 0)
ag_corsest = nag;
else
ag_cors->ag_fine = nag;
CHECK_AG();
}
static const char *
rtm_type_name(u_char type)
{
static const char *rtm_types[] = {
"RTM_ADD",
"RTM_DELETE",
"RTM_CHANGE",
"RTM_GET",
"RTM_LOSING",
"RTM_REDIRECT",
"RTM_MISS",
"RTM_LOCK",
"RTM_OLDADD",
"RTM_OLDDEL",
"RTM_RESOLVE",
"RTM_NEWADDR",
"RTM_DELADDR",
"RTM_IFINFO"
};
static char name0[10];
if (type > sizeof(rtm_types)/sizeof(rtm_types[0])
|| type == 0) {
sprintf(name0, "RTM type %#x", type);
return name0;
} else {
return rtm_types[type-1];
}
}
/* Trim a mask in a sockaddr
* Produce a length of 0 for an address of 0.
* Otherwise produce the index of the first zero byte.
*/
void
#ifdef _HAVE_SIN_LEN
masktrim(struct sockaddr_in *ap)
#else
masktrim(struct sockaddr_in_new *ap)
#endif
{
char *cp;
if (ap->sin_addr.s_addr == 0) {
ap->sin_len = 0;
return;
}
cp = (char *)(&ap->sin_addr.s_addr+1);
while (*--cp == 0)
continue;
ap->sin_len = cp - (char*)ap + 1;
}
/* Tell the kernel to add, delete or change a route
*/
static void
rtioctl(int action, /* RTM_DELETE, etc */
naddr dst,
naddr gate,
naddr mask,
int metric,
int flags)
{
struct {
struct rt_msghdr w_rtm;
struct sockaddr_in w_dst;
struct sockaddr_in w_gate;
#ifdef _HAVE_SA_LEN
struct sockaddr_in w_mask;
#else
struct sockaddr_in_new w_mask;
#endif
} w;
long cc;
# define PAT " %-10s %s metric=%d flags=%#x"
# define ARGS rtm_type_name(action), rtname(dst,mask,gate), metric, flags
again:
memset(&w, 0, sizeof(w));
w.w_rtm.rtm_msglen = sizeof(w);
w.w_rtm.rtm_version = RTM_VERSION;
w.w_rtm.rtm_type = action;
w.w_rtm.rtm_flags = flags;
w.w_rtm.rtm_seq = ++rt_sock_seqno;
w.w_rtm.rtm_addrs = RTA_DST|RTA_GATEWAY;
if (metric != 0 || action == RTM_CHANGE) {
w.w_rtm.rtm_rmx.rmx_hopcount = metric;
w.w_rtm.rtm_inits |= RTV_HOPCOUNT;
}
w.w_dst.sin_family = AF_INET;
w.w_dst.sin_addr.s_addr = dst;
w.w_gate.sin_family = AF_INET;
w.w_gate.sin_addr.s_addr = gate;
#ifdef _HAVE_SA_LEN
w.w_dst.sin_len = sizeof(w.w_dst);
w.w_gate.sin_len = sizeof(w.w_gate);
#endif
if (mask == HOST_MASK) {
w.w_rtm.rtm_flags |= RTF_HOST;
w.w_rtm.rtm_msglen -= sizeof(w.w_mask);
} else {
w.w_rtm.rtm_addrs |= RTA_NETMASK;
w.w_mask.sin_addr.s_addr = htonl(mask);
#ifdef _HAVE_SA_LEN
masktrim(&w.w_mask);
if (w.w_mask.sin_len == 0)
w.w_mask.sin_len = sizeof(long);
w.w_rtm.rtm_msglen -= (sizeof(w.w_mask) - w.w_mask.sin_len);
#endif
}
#ifndef NO_INSTALL
cc = write(rt_sock, &w, w.w_rtm.rtm_msglen);
if (cc < 0) {
if (errno == ESRCH
&& (action == RTM_CHANGE || action == RTM_DELETE)) {
trace_act("route disappeared before" PAT, ARGS);
if (action == RTM_CHANGE) {
action = RTM_ADD;
goto again;
}
return;
}
msglog("write(rt_sock)" PAT ": %s", ARGS, strerror(errno));
return;
} else if (cc != w.w_rtm.rtm_msglen) {
msglog("write(rt_sock) wrote %ld instead of %d for" PAT,
cc, w.w_rtm.rtm_msglen, ARGS);
return;
}
#endif
if (TRACEKERNEL)
trace_misc("write kernel" PAT, ARGS);
#undef PAT
#undef ARGS
}
#define KHASH_SIZE 71 /* should be prime */
#define KHASH(a,m) khash_bins[((a) ^ (m)) % KHASH_SIZE]
static struct khash {
struct khash *k_next;
naddr k_dst;
naddr k_mask;
naddr k_gate;
short k_metric;
u_short k_state;
#define KS_NEW 0x001
#define KS_DELETE 0x002 /* need to delete the route */
#define KS_ADD 0x004 /* add to the kernel */
#define KS_CHANGE 0x008 /* tell kernel to change the route */
#define KS_DEL_ADD 0x010 /* delete & add to change the kernel */
#define KS_STATIC 0x020 /* Static flag in kernel */
#define KS_GATEWAY 0x040 /* G flag in kernel */
#define KS_DYNAMIC 0x080 /* result of redirect */
#define KS_DELETED 0x100 /* already deleted from kernel */
#define KS_CHECK 0x200
time_t k_keep;
#define K_KEEP_LIM 30
time_t k_redirect_time; /* when redirected route 1st seen */
} *khash_bins[KHASH_SIZE];
static struct khash*
kern_find(naddr dst, naddr mask, struct khash ***ppk)
{
struct khash *k, **pk;
for (pk = &KHASH(dst,mask); (k = *pk) != 0; pk = &k->k_next) {
if (k->k_dst == dst && k->k_mask == mask)
break;
}
if (ppk != 0)
*ppk = pk;
return k;
}
static struct khash*
kern_add(naddr dst, naddr mask)
{
struct khash *k, **pk;
k = kern_find(dst, mask, &pk);
if (k != 0)
return k;
k = (struct khash *)rtmalloc(sizeof(*k), "kern_add");
memset(k, 0, sizeof(*k));
k->k_dst = dst;
k->k_mask = mask;
k->k_state = KS_NEW;
k->k_keep = now.tv_sec;
*pk = k;
return k;
}
/* If a kernel route has a non-zero metric, check that it is still in the
* daemon table, and not deleted by interfaces coming and going.
*/
static void
kern_check_static(struct khash *k,
struct interface *ifp)
{
struct rt_entry *rt;
struct rt_spare new;
if (k->k_metric == 0)
return;
memset(&new, 0, sizeof(new));
new.rts_ifp = ifp;
new.rts_gate = k->k_gate;
new.rts_router = (ifp != 0) ? ifp->int_addr : loopaddr;
new.rts_metric = k->k_metric;
new.rts_time = now.tv_sec;
rt = rtget(k->k_dst, k->k_mask);
if (rt != 0) {
if (!(rt->rt_state & RS_STATIC))
rtchange(rt, rt->rt_state | RS_STATIC, &new, 0);
} else {
rtadd(k->k_dst, k->k_mask, RS_STATIC, &new);
}
}
/* operate on a kernel entry
*/
static void
kern_ioctl(struct khash *k,
int action, /* RTM_DELETE, etc */
int flags)
{
switch (action) {
case RTM_DELETE:
k->k_state &= ~KS_DYNAMIC;
if (k->k_state & KS_DELETED)
return;
k->k_state |= KS_DELETED;
break;
case RTM_ADD:
k->k_state &= ~KS_DELETED;
break;
case RTM_CHANGE:
if (k->k_state & KS_DELETED) {
action = RTM_ADD;
k->k_state &= ~KS_DELETED;
}
break;
}
rtioctl(action, k->k_dst, k->k_gate, k->k_mask, k->k_metric, flags);
}
/* add a route the kernel told us
*/
static void
rtm_add(struct rt_msghdr *rtm,
struct rt_addrinfo *info,
time_t keep)
{
struct khash *k;
struct interface *ifp;
naddr mask;
if (rtm->rtm_flags & RTF_HOST) {
mask = HOST_MASK;
} else if (INFO_MASK(info) != 0) {
mask = ntohl(S_ADDR(INFO_MASK(info)));
} else {
msglog("ignore %s without mask", rtm_type_name(rtm->rtm_type));
return;
}
k = kern_add(S_ADDR(INFO_DST(info)), mask);
if (k->k_state & KS_NEW)
k->k_keep = now.tv_sec+keep;
if (INFO_GATE(info) == 0) {
trace_act("note %s without gateway",
rtm_type_name(rtm->rtm_type));
k->k_metric = HOPCNT_INFINITY;
} else if (INFO_GATE(info)->sa_family != AF_INET) {
trace_act("note %s with gateway AF=%d",
rtm_type_name(rtm->rtm_type),
INFO_GATE(info)->sa_family);
k->k_metric = HOPCNT_INFINITY;
} else {
k->k_gate = S_ADDR(INFO_GATE(info));
k->k_metric = rtm->rtm_rmx.rmx_hopcount;
if (k->k_metric < 0)
k->k_metric = 0;
else if (k->k_metric > HOPCNT_INFINITY-1)
k->k_metric = HOPCNT_INFINITY-1;
}
k->k_state &= ~(KS_DELETE | KS_ADD | KS_CHANGE | KS_DEL_ADD
| KS_DELETED | KS_GATEWAY | KS_STATIC
| KS_NEW | KS_CHECK);
if (rtm->rtm_flags & RTF_GATEWAY)
k->k_state |= KS_GATEWAY;
if (rtm->rtm_flags & RTF_STATIC)
k->k_state |= KS_STATIC;
if (0 != (rtm->rtm_flags & (RTF_DYNAMIC | RTF_MODIFIED))) {
if (INFO_AUTHOR(info) != 0
&& INFO_AUTHOR(info)->sa_family == AF_INET)
ifp = iflookup(S_ADDR(INFO_AUTHOR(info)));
else
ifp = 0;
if (supplier
&& (ifp == 0 || !(ifp->int_state & IS_REDIRECT_OK))) {
/* Routers are not supposed to listen to redirects,
* so delete it if it came via an unknown interface
* or the interface does not have special permission.
*/
k->k_state &= ~KS_DYNAMIC;
k->k_state |= KS_DELETE;
LIM_SEC(need_kern, 0);
trace_act("mark for deletion redirected %s --> %s"
" via %s",
addrname(k->k_dst, k->k_mask, 0),
naddr_ntoa(k->k_gate),
ifp ? ifp->int_name : "unknown interface");
} else {
k->k_state |= KS_DYNAMIC;
k->k_redirect_time = now.tv_sec;
trace_act("accept redirected %s --> %s via %s",
addrname(k->k_dst, k->k_mask, 0),
naddr_ntoa(k->k_gate),
ifp ? ifp->int_name : "unknown interface");
}
return;
}
/* If it is not a static route, quit until the next comparison
* between the kernel and daemon tables, when it will be deleted.
*/
if (!(k->k_state & KS_STATIC)) {
k->k_state |= KS_DELETE;
LIM_SEC(need_kern, k->k_keep);
return;
}
/* Put static routes with real metrics into the daemon table so
* they can be advertised.
*
* Find the interface toward the gateway.
*/
ifp = iflookup(k->k_gate);
if (ifp == 0)
msglog("static route %s --> %s impossibly lacks ifp",
addrname(S_ADDR(INFO_DST(info)), mask, 0),
naddr_ntoa(k->k_gate));
kern_check_static(k, ifp);
}
/* deal with packet loss
*/
static void
rtm_lose(struct rt_msghdr *rtm,
struct rt_addrinfo *info)
{
if (INFO_GATE(info) == 0
|| INFO_GATE(info)->sa_family != AF_INET) {
trace_act("ignore %s without gateway",
rtm_type_name(rtm->rtm_type));
return;
}
if (rdisc_ok)
rdisc_age(S_ADDR(INFO_GATE(info)));
age(S_ADDR(INFO_GATE(info)));
}
/* Make the gateway slot of an info structure point to something
* useful. If it is not already useful, but it specifies an interface,
* then fill in the sockaddr_in provided and point it there.
*/
static int
get_info_gate(struct sockaddr **sap,
struct sockaddr_in *sin)
{
struct sockaddr_dl *sdl = (struct sockaddr_dl *)*sap;
struct interface *ifp;
if (sdl == 0)
return 0;
if ((sdl)->sdl_family == AF_INET)
return 1;
if ((sdl)->sdl_family != AF_LINK)
return 0;
ifp = ifwithindex(sdl->sdl_index, 1);
if (ifp == 0)
return 0;
sin->sin_addr.s_addr = ifp->int_addr;
#ifdef _HAVE_SA_LEN
sin->sin_len = sizeof(*sin);
#endif
sin->sin_family = AF_INET;
*sap = (struct sockaddr*)sin;
return 1;
}
/* Clean the kernel table by copying it to the daemon image.
* Eventually the daemon will delete any extra routes.
*/
void
flush_kern(void)
{
static char *sysctl_buf;
static size_t sysctl_buf_size = 0;
size_t needed;
int mib[6];
char *next, *lim;
struct rt_msghdr *rtm;
struct sockaddr_in gate_sin;
struct rt_addrinfo info;
int i;
struct khash *k;
for (i = 0; i < KHASH_SIZE; i++) {
for (k = khash_bins[i]; k != 0; k = k->k_next) {
k->k_state |= KS_CHECK;
}
}
mib[0] = CTL_NET;
mib[1] = PF_ROUTE;
mib[2] = 0; /* protocol */
mib[3] = 0; /* wildcard address family */
mib[4] = NET_RT_DUMP;
mib[5] = 0; /* no flags */
for (;;) {
if ((needed = sysctl_buf_size) != 0) {
if (sysctl(mib, 6, sysctl_buf,&needed, 0, 0) >= 0)
break;
if (errno != ENOMEM && errno != EFAULT)
BADERR(1,"flush_kern: sysctl(RT_DUMP)");
free(sysctl_buf);
needed = 0;
}
if (sysctl(mib, 6, 0, &needed, 0, 0) < 0)
BADERR(1,"flush_kern: sysctl(RT_DUMP) estimate");
/* Kludge around the habit of some systems, such as
* BSD/OS 3.1, to not admit how many routes are in the
* kernel, or at least to be quite wrong.
*/
needed += 50*(sizeof(*rtm)+5*sizeof(struct sockaddr));
sysctl_buf = rtmalloc(sysctl_buf_size = needed,
"flush_kern sysctl(RT_DUMP)");
}
lim = sysctl_buf + needed;
for (next = sysctl_buf; next < lim; next += rtm->rtm_msglen) {
rtm = (struct rt_msghdr *)next;
if (rtm->rtm_msglen == 0) {
msglog("zero length kernel route at "
" %#lx in buffer %#lx before %#lx",
(u_long)rtm, (u_long)sysctl_buf, (u_long)lim);
break;
}
rt_xaddrs(&info,
(struct sockaddr *)(rtm+1),
(struct sockaddr *)(next + rtm->rtm_msglen),
rtm->rtm_addrs);
if (INFO_DST(&info) == 0
|| INFO_DST(&info)->sa_family != AF_INET)
continue;
/* ignore ARP table entries on systems with a merged route
* and ARP table.
*/
if (rtm->rtm_flags & RTF_LLINFO)
continue;
/* ignore multicast addresses
*/
if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info)))))
continue;
if (!get_info_gate(&INFO_GATE(&info), &gate_sin))
continue;
/* Note static routes and interface routes, and also
* preload the image of the kernel table so that
* we can later clean it, as well as avoid making
* unneeded changes. Keep the old kernel routes for a
* few seconds to allow a RIP or router-discovery
* response to be heard.
*/
rtm_add(rtm,&info,MIN_WAITTIME);
}
for (i = 0; i < KHASH_SIZE; i++) {
for (k = khash_bins[i]; k != 0; k = k->k_next) {
if (k->k_state & KS_CHECK) {
msglog("%s --> %s disappeared from kernel",
addrname(k->k_dst, k->k_mask, 0),
naddr_ntoa(k->k_gate));
del_static(k->k_dst, k->k_mask, k->k_gate, 1);
}
}
}
}
/* Listen to announcements from the kernel
*/
void
read_rt(void)
{
long cc;
struct interface *ifp;
struct sockaddr_in gate_sin;
naddr mask, gate;
union {
struct {
struct rt_msghdr rtm;
struct sockaddr addrs[RTAX_MAX];
} r;
struct if_msghdr ifm;
} m;
char str[100], *strp;
struct rt_addrinfo info;
for (;;) {
cc = read(rt_sock, &m, sizeof(m));
if (cc <= 0) {
if (cc < 0 && errno != EWOULDBLOCK)
LOGERR("read(rt_sock)");
return;
}
if (m.r.rtm.rtm_version != RTM_VERSION) {
msglog("bogus routing message version %d",
m.r.rtm.rtm_version);
continue;
}
/* Ignore our own results.
*/
if (m.r.rtm.rtm_type <= RTM_CHANGE
&& m.r.rtm.rtm_pid == mypid) {
static int complained = 0;
if (!complained) {
msglog("receiving our own change messages");
complained = 1;
}
continue;
}
if (m.r.rtm.rtm_type == RTM_IFINFO
|| m.r.rtm.rtm_type == RTM_NEWADDR
|| m.r.rtm.rtm_type == RTM_DELADDR) {
ifp = ifwithindex(m.ifm.ifm_index,
m.r.rtm.rtm_type != RTM_DELADDR);
if (ifp == 0)
trace_act("note %s with flags %#x"
" for unknown interface index #%d",
rtm_type_name(m.r.rtm.rtm_type),
m.ifm.ifm_flags,
m.ifm.ifm_index);
else
trace_act("note %s with flags %#x for %s",
rtm_type_name(m.r.rtm.rtm_type),
m.ifm.ifm_flags,
ifp->int_name);
/* After being informed of a change to an interface,
* check them all now if the check would otherwise
* be a long time from now, if the interface is
* not known, or if the interface has been turned
* off or on.
*/
if (ifinit_timer.tv_sec-now.tv_sec>=CHECK_BAD_INTERVAL
|| ifp == 0
|| ((ifp->int_if_flags ^ m.ifm.ifm_flags)
& IFF_UP) != 0)
ifinit_timer.tv_sec = now.tv_sec;
continue;
}
strcpy(str, rtm_type_name(m.r.rtm.rtm_type));
strp = &str[strlen(str)];
if (m.r.rtm.rtm_type <= RTM_CHANGE)
strp += sprintf(strp," from pid %d",m.r.rtm.rtm_pid);
rt_xaddrs(&info, m.r.addrs, &m.r.addrs[RTAX_MAX],
m.r.rtm.rtm_addrs);
if (INFO_DST(&info) == 0) {
trace_act("ignore %s without dst", str);
continue;
}
if (INFO_DST(&info)->sa_family != AF_INET) {
trace_act("ignore %s for AF %d", str,
INFO_DST(&info)->sa_family);
continue;
}
mask = ((INFO_MASK(&info) != 0)
? ntohl(S_ADDR(INFO_MASK(&info)))
: (m.r.rtm.rtm_flags & RTF_HOST)
? HOST_MASK
: std_mask(S_ADDR(INFO_DST(&info))));
strp += sprintf(strp, ": %s",
addrname(S_ADDR(INFO_DST(&info)), mask, 0));
if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) {
trace_act("ignore multicast %s", str);
continue;
}
if (m.r.rtm.rtm_flags & RTF_LLINFO) {
trace_act("ignore ARP %s", str);
continue;
}
if (get_info_gate(&INFO_GATE(&info), &gate_sin)) {
gate = S_ADDR(INFO_GATE(&info));
strp += sprintf(strp, " --> %s", naddr_ntoa(gate));
} else {
gate = 0;
}
if (INFO_AUTHOR(&info) != 0)
strp += sprintf(strp, " by authority of %s",
saddr_ntoa(INFO_AUTHOR(&info)));
switch (m.r.rtm.rtm_type) {
case RTM_ADD:
case RTM_CHANGE:
case RTM_REDIRECT:
if (m.r.rtm.rtm_errno != 0) {
trace_act("ignore %s with \"%s\" error",
str, strerror(m.r.rtm.rtm_errno));
} else {
trace_act("%s", str);
rtm_add(&m.r.rtm,&info,0);
}
break;
case RTM_DELETE:
if (m.r.rtm.rtm_errno != 0
&& m.r.rtm.rtm_errno != ESRCH) {
trace_act("ignore %s with \"%s\" error",
str, strerror(m.r.rtm.rtm_errno));
} else {
trace_act("%s", str);
del_static(S_ADDR(INFO_DST(&info)), mask,
gate, 1);
}
break;
case RTM_LOSING:
trace_act("%s", str);
rtm_lose(&m.r.rtm,&info);
break;
default:
trace_act("ignore %s", str);
break;
}
}
}
/* after aggregating, note routes that belong in the kernel
*/
static void
kern_out(struct ag_info *ag)
{
struct khash *k;
/* Do not install bad routes if they are not already present.
* This includes routes that had RS_NET_SYN for interfaces that
* recently died.
*/
if (ag->ag_metric == HOPCNT_INFINITY) {
k = kern_find(htonl(ag->ag_dst_h), ag->ag_mask, 0);
if (k == 0)
return;
} else {
k = kern_add(htonl(ag->ag_dst_h), ag->ag_mask);
}
if (k->k_state & KS_NEW) {
/* will need to add new entry to the kernel table */
k->k_state = KS_ADD;
if (ag->ag_state & AGS_GATEWAY)
k->k_state |= KS_GATEWAY;
k->k_gate = ag->ag_gate;
k->k_metric = ag->ag_metric;
return;
}
if (k->k_state & KS_STATIC)
return;
/* modify existing kernel entry if necessary */
if (k->k_gate != ag->ag_gate
|| k->k_metric != ag->ag_metric) {
/* Must delete bad interface routes etc. to change them. */
if (k->k_metric == HOPCNT_INFINITY)
k->k_state |= KS_DEL_ADD;
k->k_gate = ag->ag_gate;
k->k_metric = ag->ag_metric;
k->k_state |= KS_CHANGE;
}
/* If the daemon thinks the route should exist, forget
* about any redirections.
* If the daemon thinks the route should exist, eventually
* override manual intervention by the operator.
*/
if ((k->k_state & (KS_DYNAMIC | KS_DELETED)) != 0) {
k->k_state &= ~KS_DYNAMIC;
k->k_state |= (KS_ADD | KS_DEL_ADD);
}
if ((k->k_state & KS_GATEWAY)
&& !(ag->ag_state & AGS_GATEWAY)) {
k->k_state &= ~KS_GATEWAY;
k->k_state |= (KS_ADD | KS_DEL_ADD);
} else if (!(k->k_state & KS_GATEWAY)
&& (ag->ag_state & AGS_GATEWAY)) {
k->k_state |= KS_GATEWAY;
k->k_state |= (KS_ADD | KS_DEL_ADD);
}
/* Deleting-and-adding is necessary to change aspects of a route.
* Just delete instead of deleting and then adding a bad route.
* Otherwise, we want to keep the route in the kernel.
*/
if (k->k_metric == HOPCNT_INFINITY
&& (k->k_state & KS_DEL_ADD))
k->k_state |= KS_DELETE;
else
k->k_state &= ~KS_DELETE;
#undef RT
}
/* ARGSUSED */
static int
walk_kern(struct radix_node *rn,
struct walkarg *argp UNUSED)
{
#define RT ((struct rt_entry *)rn)
char metric, pref;
u_int ags = 0;
/* Do not install synthetic routes */
if (RT->rt_state & RS_NET_SYN)
return 0;
if (!(RT->rt_state & RS_IF)) {
/* This is an ordinary route, not for an interface.
*/
/* aggregate, ordinary good routes without regard to
* their metric
*/
pref = 1;
ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE);
/* Do not install host routes directly to hosts, to avoid
* interfering with ARP entries in the kernel table.
*/
if (RT_ISHOST(RT)
&& ntohl(RT->rt_dst) == RT->rt_gate)
return 0;
} else {
/* This is an interface route.
* Do not install routes for "external" remote interfaces.
*/
if (RT->rt_ifp != 0 && (RT->rt_ifp->int_state & IS_EXTERNAL))
return 0;
/* Interfaces should override received routes.
*/
pref = 0;
ags |= (AGS_IF | AGS_CORS_GATE);
/* If it is not an interface, or an alias for an interface,
* it must be a "gateway."
*
* If it is a "remote" interface, it is also a "gateway" to
* the kernel if is not a alias.
*/
if (RT->rt_ifp == 0
|| (RT->rt_ifp->int_state & IS_REMOTE))
ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE);
}
/* If RIP is off and IRDP is on, let the route to the discovered
* route suppress any RIP routes. Eventually the RIP routes
* will time-out and be deleted. This reaches the steady-state
* quicker.
*/
if ((RT->rt_state & RS_RDISC) && rip_sock < 0)
ags |= AGS_CORS_GATE;
metric = RT->rt_metric;
if (metric == HOPCNT_INFINITY) {
/* if the route is dead, so try hard to aggregate. */
pref = HOPCNT_INFINITY;
ags |= (AGS_FINE_GATE | AGS_SUPPRESS);
ags &= ~(AGS_IF | AGS_CORS_GATE);
}
ag_check(RT->rt_dst, RT->rt_mask, RT->rt_gate, 0,
metric,pref, 0, 0, ags, kern_out);
return 0;
#undef RT
}
/* Update the kernel table to match the daemon table.
*/
static void
fix_kern(void)
{
int i;
struct khash *k, **pk;
need_kern = age_timer;
/* Walk daemon table, updating the copy of the kernel table.
*/
(void)rn_walktree(rhead, walk_kern, 0);
ag_flush(0,0,kern_out);
for (i = 0; i < KHASH_SIZE; i++) {
for (pk = &khash_bins[i]; (k = *pk) != 0; ) {
/* Do not touch static routes */
if (k->k_state & KS_STATIC) {
kern_check_static(k,0);
pk = &k->k_next;
continue;
}
/* check hold on routes deleted by the operator */
if (k->k_keep > now.tv_sec) {
/* ensure we check when the hold is over */
LIM_SEC(need_kern, k->k_keep);
/* mark for the next cycle */
k->k_state |= KS_DELETE;
pk = &k->k_next;
continue;
}
if ((k->k_state & KS_DELETE)
&& !(k->k_state & KS_DYNAMIC)) {
kern_ioctl(k, RTM_DELETE, 0);
*pk = k->k_next;
free(k);
continue;
}
if (k->k_state & KS_DEL_ADD)
kern_ioctl(k, RTM_DELETE, 0);
if (k->k_state & KS_ADD) {
kern_ioctl(k, RTM_ADD,
((0 != (k->k_state & (KS_GATEWAY
| KS_DYNAMIC)))
? RTF_GATEWAY : 0));
} else if (k->k_state & KS_CHANGE) {
kern_ioctl(k, RTM_CHANGE,
((0 != (k->k_state & (KS_GATEWAY
| KS_DYNAMIC)))
? RTF_GATEWAY : 0));
}
k->k_state &= ~(KS_ADD|KS_CHANGE|KS_DEL_ADD);
/* Mark this route to be deleted in the next cycle.
* This deletes routes that disappear from the
* daemon table, since the normal aging code
* will clear the bit for routes that have not
* disappeared from the daemon table.
*/
k->k_state |= KS_DELETE;
pk = &k->k_next;
}
}
}
/* Delete a static route in the image of the kernel table.
*/
void
del_static(naddr dst,
naddr mask,
naddr gate,
int gone)
{
struct khash *k;
struct rt_entry *rt;
/* Just mark it in the table to be deleted next time the kernel
* table is updated.
* If it has already been deleted, mark it as such, and set its
* keep-timer so that it will not be deleted again for a while.
* This lets the operator delete a route added by the daemon
* and add a replacement.
*/
k = kern_find(dst, mask, 0);
if (k != 0 && (gate == 0 || k->k_gate == gate)) {
k->k_state &= ~(KS_STATIC | KS_DYNAMIC | KS_CHECK);
k->k_state |= KS_DELETE;
if (gone) {
k->k_state |= KS_DELETED;
k->k_keep = now.tv_sec + K_KEEP_LIM;
}
}
rt = rtget(dst, mask);
if (rt != 0 && (rt->rt_state & RS_STATIC))
rtbad(rt);
}
/* Delete all routes generated from ICMP Redirects that use a given gateway,
* as well as old redirected routes.
*/
void
del_redirects(naddr bad_gate,
time_t old)
{
int i;
struct khash *k;
for (i = 0; i < KHASH_SIZE; i++) {
for (k = khash_bins[i]; k != 0; k = k->k_next) {
if (!(k->k_state & KS_DYNAMIC)
|| (k->k_state & KS_STATIC))
continue;
if (k->k_gate != bad_gate
&& k->k_redirect_time > old
&& !supplier)
continue;
k->k_state |= KS_DELETE;
k->k_state &= ~KS_DYNAMIC;
need_kern.tv_sec = now.tv_sec;
trace_act("mark redirected %s --> %s for deletion",
addrname(k->k_dst, k->k_mask, 0),
naddr_ntoa(k->k_gate));
}
}
}
/* Start the daemon tables.
*/
extern int max_keylen;
void
rtinit(void)
{
int i;
struct ag_info *ag;
/* Initialize the radix trees */
max_keylen = sizeof(struct sockaddr_in);
rn_init();
rn_inithead((void**)&rhead, 32);
/* mark all of the slots in the table free */
ag_avail = ag_slots;
for (ag = ag_slots, i = 1; i < NUM_AG_SLOTS; i++) {
ag->ag_fine = ag+1;
ag++;
}
}
#ifdef _HAVE_SIN_LEN
static struct sockaddr_in dst_sock = {sizeof(dst_sock), AF_INET};
static struct sockaddr_in mask_sock = {sizeof(mask_sock), AF_INET};
#else
static struct sockaddr_in_new dst_sock = {_SIN_ADDR_SIZE, AF_INET};
static struct sockaddr_in_new mask_sock = {_SIN_ADDR_SIZE, AF_INET};
#endif
static void
set_need_flash(void)
{
if (!need_flash) {
need_flash = 1;
/* Do not send the flash update immediately. Wait a little
* while to hear from other routers.
*/
no_flash.tv_sec = now.tv_sec + MIN_WAITTIME;
}
}
/* Get a particular routing table entry
*/
struct rt_entry *
rtget(naddr dst, naddr mask)
{
struct rt_entry *rt;
dst_sock.sin_addr.s_addr = dst;
mask_sock.sin_addr.s_addr = mask;
masktrim(&mask_sock);
rt = (struct rt_entry *)rhead->rnh_lookup(&dst_sock,&mask_sock,rhead);
if (!rt
|| rt->rt_dst != dst
|| rt->rt_mask != mask)
return 0;
return rt;
}
/* Find a route to dst as the kernel would.
*/
struct rt_entry *
rtfind(naddr dst)
{
dst_sock.sin_addr.s_addr = dst;
return (struct rt_entry *)rhead->rnh_matchaddr(&dst_sock, rhead);
}
/* add a route to the table
*/
void
rtadd(naddr dst,
naddr mask,
u_int state, /* rt_state for the entry */
struct rt_spare *new)
{
struct rt_entry *rt;
naddr smask;
int i;
struct rt_spare *rts;
rt = (struct rt_entry *)rtmalloc(sizeof (*rt), "rtadd");
memset(rt, 0, sizeof(*rt));
for (rts = rt->rt_spares, i = NUM_SPARES; i != 0; i--, rts++)
rts->rts_metric = HOPCNT_INFINITY;
rt->rt_nodes->rn_key = (caddr_t)&rt->rt_dst_sock;
rt->rt_dst = dst;
rt->rt_dst_sock.sin_family = AF_INET;
#ifdef _HAVE_SIN_LEN
rt->rt_dst_sock.sin_len = dst_sock.sin_len;
#endif
if (mask != HOST_MASK) {
smask = std_mask(dst);
if ((smask & ~mask) == 0 && mask > smask)
state |= RS_SUBNET;
}
mask_sock.sin_addr.s_addr = mask;
masktrim(&mask_sock);
rt->rt_mask = mask;
rt->rt_state = state;
rt->rt_spares[0] = *new;
rt->rt_time = now.tv_sec;
rt->rt_poison_metric = HOPCNT_INFINITY;
rt->rt_seqno = update_seqno;
if (++total_routes == MAX_ROUTES)
msglog("have maximum (%d) routes", total_routes);
if (TRACEACTIONS)
trace_add_del("Add", rt);
need_kern.tv_sec = now.tv_sec;
set_need_flash();
if (0 == rhead->rnh_addaddr(&rt->rt_dst_sock, &mask_sock,
rhead, rt->rt_nodes)) {
msglog("rnh_addaddr() failed for %s mask=%#lx",
naddr_ntoa(dst), (u_long)mask);
}
}
/* notice a changed route
*/
void
rtchange(struct rt_entry *rt,
u_int state, /* new state bits */
struct rt_spare *new,
char *label)
{
if (rt->rt_metric != new->rts_metric) {
/* Fix the kernel immediately if it seems the route
* has gone bad, since there may be a working route that
* aggregates this route.
*/
if (new->rts_metric == HOPCNT_INFINITY) {
need_kern.tv_sec = now.tv_sec;
if (new->rts_time >= now.tv_sec - EXPIRE_TIME)
new->rts_time = now.tv_sec - EXPIRE_TIME;
}
rt->rt_seqno = update_seqno;
set_need_flash();
}
if (rt->rt_gate != new->rts_gate) {
need_kern.tv_sec = now.tv_sec;
rt->rt_seqno = update_seqno;
set_need_flash();
}
state |= (rt->rt_state & RS_SUBNET);
/* Keep various things from deciding ageless routes are stale.
*/
if (!AGE_RT(state, new->rts_ifp))
new->rts_time = now.tv_sec;
if (TRACEACTIONS)
trace_change(rt, state, new,
label ? label : "Chg ");
rt->rt_state = state;
rt->rt_spares[0] = *new;
}
/* check for a better route among the spares
*/
static struct rt_spare *
rts_better(struct rt_entry *rt)
{
struct rt_spare *rts, *rts1;
int i;
/* find the best alternative among the spares */
rts = rt->rt_spares+1;
for (i = NUM_SPARES, rts1 = rts+1; i > 2; i--, rts1++) {
if (BETTER_LINK(rt,rts1,rts))
rts = rts1;
}
return rts;
}
/* switch to a backup route
*/
void
rtswitch(struct rt_entry *rt,
struct rt_spare *rts)
{
struct rt_spare swap;
char label[10];
/* Do not change permanent routes */
if (0 != (rt->rt_state & (RS_MHOME | RS_STATIC | RS_RDISC
| RS_NET_SYN | RS_IF)))
return;
/* find the best alternative among the spares */
if (rts == 0)
rts = rts_better(rt);
/* Do not bother if it is not worthwhile.
*/
if (!BETTER_LINK(rt, rts, rt->rt_spares))
return;
swap = rt->rt_spares[0];
(void)sprintf(label, "Use #%d", (int)(rts - rt->rt_spares));
rtchange(rt, rt->rt_state & ~(RS_NET_SYN | RS_RDISC), rts, label);
if (swap.rts_metric == HOPCNT_INFINITY) {
*rts = rts_empty;
} else {
*rts = swap;
}
}
void
rtdelete(struct rt_entry *rt)
{
struct khash *k;
if (TRACEACTIONS)
trace_add_del("Del", rt);
k = kern_find(rt->rt_dst, rt->rt_mask, 0);
if (k != 0) {
k->k_state |= KS_DELETE;
need_kern.tv_sec = now.tv_sec;
}
dst_sock.sin_addr.s_addr = rt->rt_dst;
mask_sock.sin_addr.s_addr = rt->rt_mask;
masktrim(&mask_sock);
if (rt != (struct rt_entry *)rhead->rnh_deladdr(&dst_sock, &mask_sock,
rhead)) {
msglog("rnh_deladdr() failed");
} else {
free(rt);
total_routes--;
}
}
void
rts_delete(struct rt_entry *rt,
struct rt_spare *rts)
{
trace_upslot(rt, rts, &rts_empty);
*rts = rts_empty;
}
/* Get rid of a bad route, and try to switch to a replacement.
*/
void
rtbad(struct rt_entry *rt)
{
struct rt_spare new;
/* Poison the route */
new = rt->rt_spares[0];
new.rts_metric = HOPCNT_INFINITY;
rtchange(rt, rt->rt_state & ~(RS_IF | RS_LOCAL | RS_STATIC), &new, 0);
rtswitch(rt, 0);
}
/* Junk a RS_NET_SYN or RS_LOCAL route,
* unless it is needed by another interface.
*/
void
rtbad_sub(struct rt_entry *rt)
{
struct interface *ifp, *ifp1;
struct intnet *intnetp;
u_int state;
ifp1 = 0;
state = 0;
if (rt->rt_state & RS_LOCAL) {
/* Is this the route through loopback for the interface?
* If so, see if it is used by any other interfaces, such
* as a point-to-point interface with the same local address.
*/
for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
/* Retain it if another interface needs it.
*/
if (ifp->int_addr == rt->rt_ifp->int_addr) {
state |= RS_LOCAL;
ifp1 = ifp;
break;
}
}
}
if (!(state & RS_LOCAL)) {
/* Retain RIPv1 logical network route if there is another
* interface that justifies it.
*/
if (rt->rt_state & RS_NET_SYN) {
for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
if ((ifp->int_state & IS_NEED_NET_SYN)
&& rt->rt_mask == ifp->int_std_mask
&& rt->rt_dst == ifp->int_std_addr) {
state |= RS_NET_SYN;
ifp1 = ifp;
break;
}
}
}
/* or if there is an authority route that needs it. */
for (intnetp = intnets;
intnetp != 0;
intnetp = intnetp->intnet_next) {
if (intnetp->intnet_addr == rt->rt_dst
&& intnetp->intnet_mask == rt->rt_mask) {
state |= (RS_NET_SYN | RS_NET_INT);
break;
}
}
}
if (ifp1 != 0 || (state & RS_NET_SYN)) {
struct rt_spare new = rt->rt_spares[0];
new.rts_ifp = ifp1;
rtchange(rt, ((rt->rt_state & ~(RS_NET_SYN|RS_LOCAL)) | state),
&new, 0);
} else {
rtbad(rt);
}
}
/* Called while walking the table looking for sick interfaces
* or after a time change.
*/
/* ARGSUSED */
int
walk_bad(struct radix_node *rn,
struct walkarg *argp UNUSED)
{
#define RT ((struct rt_entry *)rn)
struct rt_spare *rts;
int i;
/* fix any spare routes through the interface
*/
rts = RT->rt_spares;
for (i = NUM_SPARES; i != 1; i--) {
rts++;
if (rts->rts_metric < HOPCNT_INFINITY
&& (rts->rts_ifp == 0
|| (rts->rts_ifp->int_state & IS_BROKE)))
rts_delete(RT, rts);
}
/* Deal with the main route
*/
/* finished if it has been handled before or if its interface is ok
*/
if (RT->rt_ifp == 0 || !(RT->rt_ifp->int_state & IS_BROKE))
return 0;
/* Bad routes for other than interfaces are easy.
*/
if (0 == (RT->rt_state & (RS_IF | RS_NET_SYN | RS_LOCAL))) {
rtbad(RT);
return 0;
}
rtbad_sub(RT);
return 0;
#undef RT
}
/* Check the age of an individual route.
*/
/* ARGSUSED */
static int
walk_age(struct radix_node *rn,
struct walkarg *argp UNUSED)
{
#define RT ((struct rt_entry *)rn)
struct interface *ifp;
struct rt_spare *rts;
int i;
/* age all of the spare routes, including the primary route
* currently in use
*/
rts = RT->rt_spares;
for (i = NUM_SPARES; i != 0; i--, rts++) {
ifp = rts->rts_ifp;
if (i == NUM_SPARES) {
if (!AGE_RT(RT->rt_state, ifp)) {
/* Keep various things from deciding ageless
* routes are stale
*/
rts->rts_time = now.tv_sec;
continue;
}
/* forget RIP routes after RIP has been turned off.
*/
if (rip_sock < 0) {
rtdelete(RT);
return 0;
}
}
/* age failing routes
*/
if (age_bad_gate == rts->rts_gate
&& rts->rts_time >= now_stale) {
rts->rts_time -= SUPPLY_INTERVAL;
}
/* trash the spare routes when they go bad */
if (rts->rts_metric < HOPCNT_INFINITY
&& now_garbage > rts->rts_time
&& i != NUM_SPARES)
rts_delete(RT, rts);
}
/* finished if the active route is still fresh */
if (now_stale <= RT->rt_time)
return 0;
/* try to switch to an alternative */
rtswitch(RT, 0);
/* Delete a dead route after it has been publically mourned. */
if (now_garbage > RT->rt_time) {
rtdelete(RT);
return 0;
}
/* Start poisoning a bad route before deleting it. */
if (now.tv_sec - RT->rt_time > EXPIRE_TIME) {
struct rt_spare new = RT->rt_spares[0];
new.rts_metric = HOPCNT_INFINITY;
rtchange(RT, RT->rt_state, &new, 0);
}
return 0;
}
/* Watch for dead routes and interfaces.
*/
void
age(naddr bad_gate)
{
struct interface *ifp;
int need_query = 0;
/* If not listening to RIP, there is no need to age the routes in
* the table.
*/
age_timer.tv_sec = (now.tv_sec
+ ((rip_sock < 0) ? NEVER : SUPPLY_INTERVAL));
/* Check for dead IS_REMOTE interfaces by timing their
* transmissions.
*/
for (ifp = ifnet; ifp; ifp = ifp->int_next) {
if (!(ifp->int_state & IS_REMOTE))
continue;
/* ignore unreachable remote interfaces */
if (!check_remote(ifp))
continue;
/* Restore remote interface that has become reachable
*/
if (ifp->int_state & IS_BROKE)
if_ok(ifp, "remote ");
if (ifp->int_act_time != NEVER
&& now.tv_sec - ifp->int_act_time > EXPIRE_TIME) {
msglog("remote interface %s to %s timed out after"
" %ld:%ld",
ifp->int_name,
naddr_ntoa(ifp->int_dstaddr),
(now.tv_sec - ifp->int_act_time)/60,
(now.tv_sec - ifp->int_act_time)%60);
if_sick(ifp);
}
/* If we have not heard from the other router
* recently, ask it.
*/
if (now.tv_sec >= ifp->int_query_time) {
ifp->int_query_time = NEVER;
need_query = 1;
}
}
/* Age routes. */
age_bad_gate = bad_gate;
(void)rn_walktree(rhead, walk_age, 0);
/* delete old redirected routes to keep the kernel table small
* and prevent blackholes
*/
del_redirects(bad_gate, now.tv_sec-STALE_TIME);
/* Update the kernel routing table. */
fix_kern();
/* poke reticent remote gateways */
if (need_query)
rip_query();
}
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