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freebsd/usr.sbin/routed/output.c
Garrett Wollman 892201b43f Copy SGI routed onto head.
1996-05-30 16:31:46 +00:00

749 lines
19 KiB
C
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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 acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char sccsid[] = "@(#)output.c 8.1 (Berkeley) 6/5/93";
#endif /* not lint */
#ident "$Revision: 1.1.3.1 $"
#include "defs.h"
int update_seqno;
/* walk the tree of routes with this for output
*/
struct {
struct sockaddr_in to;
naddr to_mask;
naddr to_net;
naddr to_std_mask;
naddr to_std_net;
struct interface *ifp; /* usually output interface */
struct ws_buf { /* for each buffer */
struct rip *buf;
struct netinfo *n;
struct netinfo *base;
struct netinfo *lim;
enum output_type type;
} v2, mcast;
char metric; /* adjust metrics by interface */
int npackets;
int state;
#define WS_ST_FLASH 0x01 /* send only changed routes */
#define WS_ST_RIP2_SAFE 0x02 /* send RIPv2 safe for RIPv1 */
#define WS_ST_RIP2_ALL 0x04 /* full featured RIPv2 */
#define WS_ST_AG 0x08 /* ok to aggregate subnets */
#define WS_ST_SUPER_AG 0x10 /* ok to aggregate networks */
#define WS_ST_QUERY 0x20 /* responding to a query */
#define WS_ST_TO_ON_NET 0x40 /* sending onto one of our nets */
#define WS_ST_DEFAULT 0x80 /* faking a default */
} ws;
/* A buffer for what can be heard by both RIPv1 and RIPv2 listeners */
union pkt_buf ripv2_buf;
/* Another for only RIPv2 listeners */
union pkt_buf rip_mcast_buf;
/* Send the contents of the global buffer via the non-multicast socket
*/
int /* <0 on failure */
output(enum output_type type,
struct sockaddr_in *dst, /* send to here */
struct interface *ifp,
struct rip *buf,
int size) /* this many bytes */
{
struct sockaddr_in sin;
int flags;
char *msg;
int res, serrno;
naddr tgt_mcast;
int soc;
sin = *dst;
if (sin.sin_port == 0)
sin.sin_port = htons(RIP_PORT);
#ifdef _HAVE_SIN_LEN
if (sin.sin_len == 0)
sin.sin_len = sizeof(sin);
#endif
soc = rip_sock;
flags = 0;
switch (type) {
case OUT_QUERY:
msg = "Answer Query";
if (soc < 0)
soc = ifp->int_rip_sock;
break;
case OUT_UNICAST:
msg = "Send";
if (soc < 0)
soc = ifp->int_rip_sock;
flags = MSG_DONTROUTE;
break;
case OUT_BROADCAST:
if (ifp->int_if_flags & IFF_POINTOPOINT) {
msg = "Send pt-to-pt";
} else {
msg = "Send";
}
flags = MSG_DONTROUTE;
break;
case OUT_MULTICAST:
if (ifp->int_if_flags & IFF_POINTOPOINT) {
msg = "Send pt-to-pt";
} else {
msg = "Send mcast";
if (rip_sock_mcast != ifp) {
#ifdef MCAST_PPP_BUG
/* Do not specifiy the primary interface
* explicitly if we have the multicast
* point-to-point kernel bug, since the
* kernel will do the wrong thing if the
* local address of a point-to-point link
* is the same as the address of an ordinary
* interface.
*/
if (ifp->int_addr == myaddr) {
tgt_mcast = 0;
} else
#endif
tgt_mcast = ifp->int_addr;
if (setsockopt(rip_sock,
IPPROTO_IP, IP_MULTICAST_IF,
&tgt_mcast, sizeof(tgt_mcast)))
BADERR(1,"setsockopt(rip_sock,"
"IP_MULTICAST_IF)");
rip_sock_mcast = ifp;
}
sin.sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
}
}
if (TRACEPACKETS)
trace_rip(msg, "to", &sin, ifp, buf, size);
res = sendto(soc, buf, size, flags,
(struct sockaddr *)&sin, sizeof(sin));
if (res < 0) {
serrno = errno;
msglog("sendto(%s%s%s.%d): %s",
ifp != 0 ? ifp->int_name : "",
ifp != 0 ? ", " : "",
inet_ntoa(sin.sin_addr),
ntohs(sin.sin_port),
strerror(errno));
errno = serrno;
}
return res;
}
/* install authentication if appropriate
*/
static void
set_auth(struct ws_buf *w)
{
if (ws.ifp != 0
&& ws.ifp->int_passwd[0] != '\0'
&& (ws.state & WS_ST_RIP2_SAFE)) {
w->n->n_family = RIP_AF_AUTH;
((struct netauth*)w->n)->a_type = RIP_AUTH_PW;
bcopy(ws.ifp->int_passwd, ((struct netauth*)w->n)->au.au_pw,
sizeof(((struct netauth*)w->n)->au.au_pw));
w->n++;
}
}
/* Send the buffer
*/
static void
supply_write(struct ws_buf *w)
{
/* Output multicast only if legal.
* If we would multcast and it would be illegal, then discard the
* packet.
*/
if (w != &ws.mcast
|| ((ws.state & WS_ST_RIP2_SAFE)
&& (ws.ifp == 0
|| (ws.ifp->int_if_flags & IFF_MULTICAST)))) {
if (output(w->type, &ws.to, ws.ifp, w->buf,
((char *)w->n - (char*)w->buf)) < 0
&& ws.ifp != 0)
ifbad(ws.ifp, 0);
ws.npackets++;
}
bzero(w->n = w->base, sizeof(*w->n)*NETS_LEN);
if (w->buf->rip_vers == RIPv2)
set_auth(w);
}
/* put an entry into the packet
*/
static void
supply_out(struct ag_info *ag)
{
int i;
naddr mask, v1_mask, s_mask, dst_h, ddst_h;
struct ws_buf *w;
/* Skip this route if doing a flash update and it and the routes
* it aggregates have not changed recently.
*/
if (ag->ag_seqno <= update_seqno
&& (ws.state & WS_ST_FLASH))
return;
dst_h = ag->ag_dst_h;
mask = ag->ag_mask;
v1_mask = ripv1_mask_host(htonl(dst_h),
(ws.state & WS_ST_TO_ON_NET) ? ws.ifp : 0,
0);
s_mask = std_mask(htonl(dst_h));
i = 0;
/* If we are sending RIPv2 packets that cannot (or must not) be
* heard by RIPv1 listeners, do not worry about sub- or supernets.
* Subnets (from other networks) can only be sent via multicast.
*/
if ((ws.state & WS_ST_RIP2_ALL)
|| ((ag->ag_state & AGS_RIPV2)
&& v1_mask != mask)) {
w = &ws.mcast; /* use the multicast-only buffer */
} else {
w = &ws.v2;
/* Convert supernet route into corresponding set of network
* routes for RIPv1, but leave non-contiguous netmasks
* to ag_check().
*/
if (v1_mask > mask
&& mask + (mask & -mask) == 0) {
ddst_h = v1_mask & -v1_mask;
i = (v1_mask & ~mask)/ddst_h;
if (i >= 1024) {
/* Punt if we would have to generate an
* unreasonable number of routes.
*/
#ifdef DEBUG
msglog("sending %s to %s as-is instead"
" of as %d routes",
addrname(htonl(dst_h),mask,0),
naddr_ntoa(ws.to.sin_addr.s_addr), i);
#endif
i = 0;
} else {
mask = v1_mask;
}
}
}
do {
w->n->n_family = RIP_AF_INET;
w->n->n_dst = htonl(dst_h);
w->n->n_metric = stopint ? HOPCNT_INFINITY : ag->ag_metric;
HTONL(w->n->n_metric);
if (w->buf->rip_vers == RIPv2) {
w->n->n_nhop = ag->ag_gate;
if ((ws.state & WS_ST_RIP2_ALL)
|| mask != s_mask)
w->n->n_mask = htonl(mask);
w->n->n_tag = ag->ag_tag;
}
dst_h += ddst_h;
if (++w->n >= w->lim)
supply_write(w);
} while (i-- != 0);
}
/* supply one route from the table
*/
/* ARGSUSED */
static int
walk_supply(struct radix_node *rn,
struct walkarg *w)
{
#define RT ((struct rt_entry *)rn)
u_short ags;
char metric, pref;
naddr dst, gate;
/* Do not advertise the loopback interface
* or external remote interfaces
*/
if (RT->rt_ifp != 0
&& ((RT->rt_ifp->int_if_flags & IFF_LOOPBACK)
|| (RT->rt_ifp->int_state & IS_EXTERNAL)))
return 0;
/* Do not send a route back to where it came from, except in
* response to a query. This is "split-horizon".
*
* That means not advertising back to the same network
* and so via the same interface.
*/
if (RT->rt_ifp == ws.ifp && ws.ifp != 0
&& !(ws.state & WS_ST_QUERY)
&& (ws.state & WS_ST_TO_ON_NET)
&& !(RT->rt_state & RS_IF))
return 0;
dst = RT->rt_dst;
/* If being quiet about our ability to forward, then
* do not say anything except our own host number,
* unless responding to a query.
*/
if (!supplier
&& (!mhome || myaddr != dst)
&& !(ws.state & WS_ST_QUERY))
return 0;
ags = 0;
/* do not override the fake default route */
if (dst == RIP_DEFAULT
&& (ws.state & WS_ST_DEFAULT))
return 0;
if (RT_ISHOST(RT)) {
/* We should always aggregate the host routes
* for the local end of our point-to-point links.
* If we are suppressing host routes, then do so.
*/
if ((RT->rt_state & RS_LOCAL)
|| ridhosts)
ags |= AGS_SUPPRESS;
} else if (ws.state & WS_ST_AG) {
/* Aggregate network routes, if we are allowed.
*/
ags |= AGS_SUPPRESS;
/* Generate supernets if allowed.
* If we can be heard by RIPv1 systems, we will
* later convert back to ordinary nets. This unifies
* dealing with received supernets.
*/
if ((RT->rt_state & RS_SUBNET)
|| (ws.state & WS_ST_SUPER_AG))
ags |= AGS_PROMOTE;
}
/* Never aggregate our own interfaces,
* or the host route for multi-homed servers.
*/
if (0 != (RT->rt_state & (RS_IF | RS_MHOME)))
ags &= ~(AGS_SUPPRESS | AGS_PROMOTE);
if (RT->rt_state & RS_SUBNET) {
/* Do not send authority routes into the subnet,
* or when RIP is off.
*/
if ((RT->rt_state & RS_NET_INT)
&& (on_net(dst, ws.to_net, ws.to_mask)
|| rip_sock < 0))
return 0;
/* Do not send RIPv1 advertisements of subnets to
* other networks.
*
* If possible, multicast them by RIPv2.
*/
if (!(ws.state & WS_ST_RIP2_ALL)
&& !on_net(dst, ws.to_std_net, ws.to_std_mask))
ags |= AGS_RIPV2;
} else if (RT->rt_state & RS_NET_SUB) {
/* do not send synthetic network routes if no RIPv1
* listeners might hear.
*/
if (ws.state & WS_ST_RIP2_ALL)
return 0;
/* Do not send synthetic network routes on the real subnet */
if (on_net(dst, ws.to_std_net, ws.to_std_mask))
return 0;
}
/* forget synthetic routes when RIP is off */
if (rip_sock < 0 && 0 != (RT->rt_state & RS_NET_S))
return 0;
/* Adjust outgoing metric by the cost of the link.
* Interface routes have already been adjusted.
*/
pref = metric = RT->rt_metric + ws.metric;
if (metric >= HOPCNT_INFINITY) {
metric = HOPCNT_INFINITY;
pref = ((RT->rt_hold_down > now.tv_sec)
? RT->rt_hold_metric
: metric);
}
/* Advertise the next hop if this is not a route for one
* of our interfaces and the next hop is on the same
* network as the target.
*/
if ((ws.state & WS_ST_RIP2_SAFE)
&& !(RT->rt_state & RS_IF)
&& ((ws.state & WS_ST_QUERY)
|| (on_net(RT->rt_gate, ws.ifp->int_net, ws.ifp->int_mask)
&& RT->rt_gate != ws.ifp->int_addr))) {
gate = RT->rt_gate;
} else {
gate = 0;
}
ag_check(dst, RT->rt_mask, gate, metric, pref,
RT->rt_seqno, RT->rt_tag, ags, supply_out);
return 0;
#undef RT
}
/* Supply dst with the contents of the routing tables.
* If this won't fit in one packet, chop it up into several.
*/
void
supply(struct sockaddr_in *dst,
struct interface *ifp, /* output interface */
enum output_type type,
int flash, /* 1=flash update */
int vers) /* RIP version */
{
static int init = 1;
struct rt_entry *rt;
int metric;
ws.state = 0;
ws.to = *dst;
ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
if (ifp != 0) {
ws.to_mask = ifp->int_mask;
ws.to_net = ifp->int_net;
if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask))
ws.state |= WS_ST_TO_ON_NET;
} else {
ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, 0, 0);
ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
rt = rtfind(dst->sin_addr.s_addr);
if (rt)
ifp = rt->rt_ifp;
}
ws.npackets = 0;
if (flash)
ws.state |= WS_ST_FLASH;
if (type == OUT_QUERY)
ws.state |= WS_ST_QUERY;
if ((ws.ifp = ifp) == 0) {
ws.metric = 0;
} else {
/* Adjust the advertised metric by the outgoing interface
* metric, but reduced by 1 to avoid counting this hop
* twice.
*/
ws.metric = ifp->int_metric;
if (ws.metric > 0)
ws.metric--;
}
if (init) {
init = 0;
bzero(&ripv2_buf, sizeof(ripv2_buf));
ripv2_buf.rip.rip_cmd = RIPCMD_RESPONSE;
ws.v2.buf = &ripv2_buf.rip;
ws.v2.base = &ws.v2.buf->rip_nets[0];
ws.v2.lim = ws.v2.base + NETS_LEN;
bzero(&rip_mcast_buf, sizeof(rip_mcast_buf));
rip_mcast_buf.rip.rip_cmd = RIPCMD_RESPONSE;
rip_mcast_buf.rip.rip_vers = RIPv2;
ws.mcast.buf = &rip_mcast_buf.rip;
ws.mcast.base = &ws.mcast.buf->rip_nets[0];
ws.mcast.lim = ws.mcast.base + NETS_LEN;
}
ripv2_buf.rip.rip_vers = vers;
ws.v2.type = type;
ws.v2.n = ws.v2.base;
set_auth(&ws.v2);
ws.mcast.type = (type == OUT_BROADCAST) ? OUT_MULTICAST : type;
ws.mcast.n = ws.mcast.base;
set_auth(&ws.mcast);
if (vers == RIPv2) {
ws.state |= WS_ST_RIP2_SAFE;
/* full RIPv2 only if cannot be heard by RIPv1 listeners */
if (type != OUT_BROADCAST)
ws.state |= WS_ST_RIP2_ALL;
if (!(ws.state & WS_ST_TO_ON_NET)) {
ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
} else if (ws.ifp == 0 || !(ws.ifp->int_state & IS_NO_AG)) {
ws.state |= WS_ST_AG;
if (type != OUT_BROADCAST
&& (ws.ifp == 0
|| !(ws.ifp->int_state & IS_NO_SUPER_AG)))
ws.state |= WS_ST_SUPER_AG;
}
}
/* send the routes
*/
if ((metric = ifp->int_d_metric) != 0) {
/* Fake a default route if asked */
ws.state |= WS_ST_DEFAULT;
/* Use the metric of a real default, if there is one.
*/
rt = rtget(RIP_DEFAULT, 0);
if (rt != 0
&& rt->rt_metric+ws.metric < metric)
metric = rt->rt_metric+ws.metric;
if (metric < HOPCNT_INFINITY)
ag_check(0, 0, 0, metric,metric, 0, 0, 0, supply_out);
}
(void)rn_walktree(rhead, walk_supply, 0);
ag_flush(0,0,supply_out);
/* Flush the packet buffers */
if (ws.v2.n != ws.v2.base
&& (ws.v2.n > ws.v2.base+1
|| ws.v2.n->n_family != RIP_AF_AUTH))
supply_write(&ws.v2);
if (ws.mcast.n != ws.mcast.base
&& (ws.mcast.n > ws.mcast.base+1
|| ws.mcast.n->n_family != RIP_AF_AUTH))
supply_write(&ws.mcast);
/* If we sent nothing and this is an answer to a query, send
* an empty buffer.
*/
if (ws.npackets == 0
&& (ws.state & WS_ST_QUERY))
supply_write(&ws.v2);
}
/* send all of the routing table or just do a flash update
*/
void
rip_bcast(int flash)
{
#ifdef _HAVE_SIN_LEN
static struct sockaddr_in dst = {sizeof(dst), AF_INET};
#else
static struct sockaddr_in dst = {AF_INET};
#endif
struct interface *ifp;
enum output_type type;
int vers;
struct timeval rtime;
need_flash = 0;
intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
no_flash = rtime;
timevaladd(&no_flash, &now);
if (rip_sock < 0)
return;
trace_msg("send %s and inhibit dynamic updates for %.3f sec\n",
flash ? "dynamic update" : "all routes",
rtime.tv_sec + ((float)rtime.tv_usec)/1000000.0);
for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
/* skip interfaces not doing RIP, those already queried,
* and aliases. Do try broken interfaces to see
* if they have healed.
*/
if (0 != (ifp->int_state & (IS_PASSIVE
| IS_ALIAS)))
continue;
/* skip turned off interfaces */
if (!iff_alive(ifp->int_if_flags))
continue;
/* Prefer RIPv1 announcements unless RIPv2 is on and
* RIPv2 is off.
*/
if (ifp->int_state & IS_NO_RIPV1_OUT) {
if (ifp->int_state & IS_NO_RIPV2_OUT)
continue;
vers = RIPv2;
} else {
vers = RIPv1;
}
if (ifp->int_if_flags & IFF_BROADCAST) {
/* ordinary, hardware interface */
dst.sin_addr.s_addr = ifp->int_brdaddr;
/* if RIPv1 is not turned off, then broadcast so
* that RIPv1 listeners can hear.
*/
if (!(ifp->int_state & IS_NO_RIPV1_OUT)) {
type = OUT_BROADCAST;
} else {
type = OUT_MULTICAST;
}
} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
/* point-to-point hardware interface */
dst.sin_addr.s_addr = ifp->int_dstaddr;
type = OUT_UNICAST;
} else {
/* remote interface */
dst.sin_addr.s_addr = ifp->int_addr;
type = OUT_UNICAST;
}
supply(&dst, ifp, type, flash, vers);
}
update_seqno++; /* all routes are up to date */
}
/* Ask for routes
* Do it only once to an interface, and not even after the interface
* was broken and recovered.
*/
void
rip_query(void)
{
#ifdef _HAVE_SIN_LEN
static struct sockaddr_in dst = {sizeof(dst), AF_INET};
#else
static struct sockaddr_in dst = {AF_INET};
#endif
struct interface *ifp;
struct rip buf;
enum output_type type;
if (rip_sock < 0)
return;
bzero(&buf, sizeof(buf));
for (ifp = ifnet; ifp; ifp = ifp->int_next) {
/* skip interfaces not doing RIP, those already queried,
* and aliases. Do try broken interfaces to see
* if they have healed.
*/
if (0 != (ifp->int_state & (IS_RIP_QUERIED
| IS_PASSIVE
| IS_ALIAS)))
continue;
/* skip turned off interfaces */
if (!iff_alive(ifp->int_if_flags))
continue;
/* prefer RIPv2 queries */
if (ifp->int_state & IS_NO_RIPV2_OUT) {
if (ifp->int_state & IS_NO_RIPV1_OUT)
continue;
buf.rip_vers = RIPv1;
} else {
buf.rip_vers = RIPv2;
}
buf.rip_cmd = RIPCMD_REQUEST;
buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
if (ifp->int_if_flags & IFF_BROADCAST) {
/* ordinary, hardware interface */
dst.sin_addr.s_addr = ifp->int_brdaddr;
/* if RIPv1 is not turned off, then broadcast so
* that RIPv1 listeners can hear.
*/
if (!(ifp->int_state & IS_NO_RIPV1_OUT)) {
type = OUT_BROADCAST;
} else {
type = OUT_MULTICAST;
}
} else if (ifp->int_if_flags & IFF_POINTOPOINT) {
/* point-to-point hardware interface */
dst.sin_addr.s_addr = ifp->int_dstaddr;
type = OUT_UNICAST;
} else {
/* remote interface */
dst.sin_addr.s_addr = ifp->int_addr;
type = OUT_UNICAST;
}
ifp->int_state |= IS_RIP_QUERIED;
if (output(type, &dst, ifp, &buf, sizeof(buf)) < 0)
ifbad(ifp,0);
}
}
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