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BSD 4_3_Net_1 development
[unix-history] / egp / rt_init.c
/* rt_init.c */
/* EGP User Process, ISI 23-Jun-84 */
/* rt_init(), rt_readkernel(), rt_ifinit(), rt_dumbinit(fp),
* rt_NRadvise_init()
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/mbuf.h> /* route.h */
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <stdio.h>
#include <errno.h>
#define KERNEL 1 /* to ensure all <net/route.h> compiled */
#include <net/route.h>
/* definitions from routed */
#include "trace_egp.h"
#include "if.h"
#include "rt_table.h"
/* new definitions */
#include "defs.h"
#include <nlist.h>
/* rt_init() initializes exterior and interior routing tables.
*/
extern struct rthash nethash[],
rt_interior;
rt_init()
{
register struct rthash *rh;
for (rh = nethash; rh < &nethash[ROUTEHASHSIZ]; rh++) /* interior */
rh->rt_forw = rh->rt_back = (struct rt_entry *)rh;
rt_interior.rt_forw = (struct rt_entry *)&rt_interior; /* exterior */
rt_interior.rt_back = (struct rt_entry *)&rt_interior;
}
/* rt_readkernel() initializes the EGP routing tables from the current kernel
* routing tables through /dev/kmem.
* This is necessary to ensure consistency when the EGP process is terminated
* and restarted while the supporting host continues to run. This may be done
* if configuration information needs to be changed.
*/
struct nlist nl[] = {
#define N_RTHOST 0
{ "_rthost" },
#define N_RTNET 1
{ "_rtnet"},
{ "" },
};
rt_readkernel()
{
int oldinstall;
/* Defined in <net/route.h>
*
* struct mbuf *rtnet[RTHASHSIZ];
*/
extern int install; /* if TRUE install route in kernel */
/* ..routed/table.h redefines some of the elements of
* struct rtentry defined in <net/route.h>. In order for the code from routed
* to be able to be utilized part of the kernel structure has been redefined
* with a preceding k_.
*/
struct k_rtentry {
u_long k_rt_hash; /* to speed lookups */
struct sockaddr k_rt_dst; /* key */
struct sockaddr k_rt_gateway; /* value */
short k_rt_flags; /* up/down?, host/net */
} *rt;
int i,
kmem;
struct mbuf *next,
m_buf;
nlist("/vmunix", nl);
if ((nl[N_RTHOST].n_value == 0)||(nl[N_RTNET].n_value == 0)) {
printf("rt_readkernel: rthost and rtnet not in namelist\n");
quit();
}
kmem = open("/dev/kmem", 0);
if (kmem < 0) {
p_error("rt_readkernel: /dev/kmem");
quit();
}
/* read table of net hash chains */
if (lseek(kmem, (long)nl[N_RTNET].n_value, 0) == -1
|| read(kmem, (char *)rtnet, sizeof (rtnet))
!= sizeof (rtnet)) {
printf("rt_readkernel: error reading kmem\n");
quit();
}
/* read all routing entries of each network hash chain */
TRACE_RT("rt_readkernel: Initial indirect routes read from kernel");
TRACE_RT(" (if any):\n");
for(i=0; i<RTHASHSIZ; i++) {
/* Read each route entry from net hash
* chain i and copy into EGP route
* table, the chain is
* terminated by a null pointer */
for( next=rtnet[i]; next!=NULL; next=m_buf.m_next) {
if (lseek(kmem, (long)next, 0) == -1
|| read(kmem, (char *)&m_buf,
MMINOFF + sizeof(struct k_rtentry))
!= MMINOFF + sizeof (struct k_rtentry)) {
p_error("rt_readkernel: read");
quit();
}
rt = mtod(&m_buf, struct k_rtentry *);
/* ignore direct routes */
if( !(rt->k_rt_flags & RTF_GATEWAY) ) continue;
/* ignore non-internet addresses */
if( rt->k_rt_gateway.sa_family != AF_INET ) continue;
/* add route to table of exterior
* routes, if the route is in fact an
* interior route it will be deleted
* by rt_dumbinit() */
oldinstall = install;
install = FALSE; /* don't install routes in kernel */
/* metric unknown - set largest reachable */
rt_add(EXTERIOR, &rt->k_rt_dst, &rt->k_rt_gateway,
HOPCNT_INFINITY - 1, 0);
install = oldinstall;
}
}
close(kmem);
return;
}
/* rt_ifinit() initializes the interior routing table with direct nets as
* per the interface table.
*
* External variables:
* rt_interior - start interior routes linked list
* ifnet - start interface table
* install - if FALSE don't install routes in kernel
*/
rt_ifinit()
{
register struct interface *ifp;
int oldinstall = install;
/* Add direct nets to interior route table as per interface list */
install = FALSE; /* routes for interfaces already
* installed by kernel */
TRACE_RT("rt_ifinit: interior routes for direct interfaces:\n");
for(ifp=ifnet; ifp!=NULL; ifp=ifp->int_next) {
rt_add(INTERIOR, &ifp->int_addr, &ifp->int_addr, 0,
RTS_INTERFACE);
}
install = oldinstall;
}
/* rt_dumbinit() reads the initialization file EGPINITFILE to
* initialize:
* - the interior route table with routes to known non-routing gateways on a
* shared net, these routes are static and not updated;
* - a default gateway prior to an EGP neighbor being acquired and polled;
*
* EGPINITFILE relevant format is:
* net name gateway name metric value
* defaultgateway name
*
* where name is either a symbolic name in /etc/hosts or /etc/networks or an
* internet address in dot notation and value is the distance in gateway hops
* from this gateway to the specified net.
*
* External variables:
* rt_interior - start interior routes linked list
* n_remote_nets - number remote nets in interior route table, set here
* install - if TRUE install routes in kernel
* s - socket for ioctl
* rt_default_status - default route status
*/
rt_dumbinit(fp)
FILE *fp;
{
char keyword[MAXHOSTNAMELENGTH+1];
char netname[MAXHOSTNAMELENGTH+1];
char gname[MAXHOSTNAMELENGTH+1];
struct sockaddr_in netaddr,
gateway,
defaultdst;
struct rt_entry *rt;
int metric,
c,
error = FALSE,
old_install;
bzero( (char *)&netaddr, sizeof(netaddr) );
bzero( (char *)&gateway, sizeof(gateway) );
bzero( (char *)&defaultdst, sizeof(defaultdst) );
TRACE_RT("rt_dumbinit: non-routing gateway routes (if any):\n");
rewind(fp);
while( fscanf(fp, "%s", keyword) != EOF) { /* read first word of line
and compare to key words */
if( strcmp(keyword, "net") == 0) {
if( fscanf(fp, "%s gateway %s metric %d", netname, gname,
&metric) != 3) error = TRUE;
else if( !getnetorhostname("net", netname, &netaddr)) {
printf("rt_dumbinit: invalid net name or");
printf(" address %s\n", netname);
error = TRUE;
}
else if( !getnetorhostname("host", gname, &gateway)) {
printf("rt_dumbinit: invalid gateway name or");
printf(" address %s\n", gname);
error = TRUE;
}
else { /* Initialize routings tables with
* non-routing gateway */
n_remote_nets++;
/* first delete any old route in exterior
* route table read from kernel.
*/
old_install = install;
rt = rt_ext_lookup(&netaddr);
if( rt != NULL ) {
if( equal(&rt->rt_router, &gateway))
install = FALSE; /* already in kernel*/
rt_delete(rt);
}
#ifndef notdef
/* don't install, we route through a different interface */
install = FALSE;
#endif
/* add to interior routing table */
rt_add(INTERIOR, &netaddr, &gateway, metric, RTS_PASSIVE);
install = old_install;
}
} /* end "net" entry */
else if( strcmp(keyword, "defaultgateway") == 0) {
if( fscanf(fp, "%s", gname) != 1) error = TRUE;
else if( !getnetorhostname("host", gname, &gateway)) {
printf("rt_dumbinit: invalid gateway name or");
printf(" address %s\n", gname);
error = TRUE;
}
else { /* Initialize default gateway */
/* check if a kernel entry exists for default
* route, if not add new default else change
* to new default */
defaultdst.sin_family = AF_INET;
defaultdst.sin_addr.s_addr = DEFAULTNET;
metric = HOPCNT_INFINITY - 1;
rt = rt_ext_lookup(&defaultdst);
if( rt == NULL )
rt_add(EXTERIOR, &defaultdst, &gateway, metric,
RTS_PASSIVE);
else {
rt_change(rt, &gateway, metric);
rt->rt_state |= RTS_PASSIVE;
}
rt_default_status = INSTALLED;
}
} /* end "defaultgateway" entry */
do c = fgetc(fp); while (c != '\n' && c != EOF); /* next line */
} /*end while*/
if(error) {
printf("rt_dumbinit: %s: initialization error\n", EGPINITFILE);
quit();
}
TRACE_RT("rt_dumbinit: commence EGP route updates:\n\n");
}
/* rt_NRadvise_init() reads the initialization file EGPINITFILE to
* initialize user specified nets to be advised in Network Reachability
* messages. If any such nets are specified, only those specified are advised,
* else the nets to be specified are computed in accord with normal stub
* gateway NR messages. Any such nets should be either direct nets or nets
* reached via non-routing gateways reported in EGPINITFILE, if the net
* is not one of these it is ignored.
*
* EGPINITFILE relevant format is:
* egpnetsreachable name name .... name
*
* External variables:
* rt_interior - start interior routes linked list
*/
rt_NRadvise_init(fp)
FILE *fp;
{
char keyword[MAXHOSTNAMELENGTH+1];
char netname[MAXHOSTNAMELENGTH+1];
struct sockaddr_in netaddr;
struct rt_entry *rt;
int notadvise_set = FALSE,
c,
error = FALSE,
morenets;
bzero( (char *)&netaddr, sizeof(netaddr) );
netaddr.sin_family = AF_INET;
rewind(fp);
/* read first word of line and compare to key words */
while(fscanf(fp, "%s", keyword) != EOF) {
if( strcmp(keyword, "egpnetsreachable") == 0) {
/* initially flag all interior routes as not
* to be advised in NR messages, this is only
* done for first occurrence of
* "egpnetsreachable" */
if( !notadvise_set ) {
for(rt = rt_interior.rt_forw;
rt != (struct rt_entry *)&rt_interior;
rt = rt->rt_forw)
rt->rt_state |= RTS_NOTADVISENR;
notadvise_set = TRUE;
}
/* read successive net strings into destination until end of line */
morenets = TRUE;
while ( (c = fgetc(fp)) != EOF && morenets) {
switch (c) {
case '\n':
ungetc(c, fp); /* end line read below */
case '#': /* start comment */
morenets = FALSE;
break;
case ' ':
case '\t':
break; /* next character */
default:
ungetc(c, fp);
fscanf(fp, "%s", netname);
if( !getnetorhostname( "net", netname, &netaddr)){
printf("rt_NRadvise_init: invalid net name ");
printf("or address %s\n", netname);
error = TRUE;
}
else {
/* search interior route table for net and
* set to be advised in NR messages */
for(rt = rt_interior.rt_forw;
rt != (struct rt_entry *)&rt_interior;
rt = rt->rt_forw )
if( equal(&rt->rt_dst, &netaddr)) {
rt->rt_state &= ~RTS_NOTADVISENR;
printf("advise %s, ",
inet_ntoa(((struct sockaddr_in *)
&rt->rt_dst)->sin_addr));
printf("gateway %s\n",
inet_ntoa(((struct sockaddr_in *)
&rt->rt_router)->sin_addr));
break;
}
}
} /* end switch c */
} /* end while morenets */
} /* end if "egpnetsreachable" */
do c = fgetc(fp); while (c != '\n' && c != EOF); /* next line */
} /*end while*/
if(error) {
printf("rt_NRadvise_init: %s: initialization error\n", EGPINITFILE);
quit();
}
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.