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/* @(#)src/routers/rtlib.c 1.2 24 Oct 1990 05:24:47 */
/*
* Copyright (C) 1987, 1988 Ronald S. Karr and Landon Curt Noll
*
* See the file COPYING, distributed with smail, for restriction
* and warranty information.
*/
/*
* rtlib.c:
* Support routines for smail routing drivers. Simple routers
* can depend on these routines rather than having to duplicate
* this intelligence.
*/
#include <stdio.h>
#include "defs.h"
#include "../smail.h"
#include "../addr.h"
#include "../route.h"
#include "../transport.h"
#include "../lookup.h"
#include "rtlib.h"
#ifndef DEPEND
# include "../extern.h"
# include "../debug.h"
# include "../error.h"
#endif
/*
* rtd_standard - standard function for routing to a target
* rtv_standard - standard function for verifying a target
*
* These routines calls a lookup function to route individual target
* names. This lookup routine will be called as follows:
*
* success = (*lookup)(rp, addr, fl, &rt_info, &error);
* int success; - output: success value
* struct router *rp; - input: router entry
* struct addr *addr; - input: addr to route
* int fl; - input: flags affecting operation
* struct rt_info rt_info; - output: routing information
* struct error *error; - output: routing error
* int len; - output: target match length
*
* The lookup routine should route to the target specified in the
* single stucture passed in 'addr'. If routing was successful and a
* match was found, the 'next_host', 'route' and 'len' values should
* always be set as appropriate. If routing was not successful due to
* an error other than the host not being found, error should be set
* to a structure defining the type of the error.
*
* The 'success' value should be a number from lookup.h corresponding
* to one of:
*
* DB_SUCCEED The target was matched by the router. The
* addr structure will be processed by the
* route_driver_finish() function with the
* values from the 'rt_info' structure.
*
* DB_NOMATCH The target was not matched by the router. The
* addr structure will be linked to the 'out'
* or 'retry' list without modification.
*
* DB_FAIL An unrecoverable error in routing to the
* target. This will cause the addr structure to
* be linked into the 'fail' output list, tagged
* with the 'error' structure.
*
* DB_AGAIN A temporary error in routing to the target.
* This will cause the addr structure to be
* linked into the 'defer' output list, tagged
* with the 'error' structure.
*
* FILE_NOMATCH The router considers itself optional and
* disabled. This and all subsequent unfinished
* addr structures will be linked into the 'out'
* or 'retry' list unchanged.
*
* FILE_FAIL There was an unrecoverable error in the
* router. This is treated as a configuration
* error, so the ERR_CONFERR flag is set in the
* 'error' structure. This and all subsequent
* unfinished addrs will be linked into the
* 'defer' list, tagged with the 'error'
* structure.
*
* FILE_AGAIN There was a temporary error in the router.
* This and all subsequent unfinished addrs will
* be linked into the 'defer' list, tagged with
* the 'error' structure.
*
* The 'fl' value is a bit-wise or of the following values from
* rtlib.h:
*
* RT_VERIFY Performing verification only. In this case
* we are only interested in the success value,
* not in the 'rt_info' structure. A router can
* optimize its operation accordingly. For
* example, a router need only verify that any
* match exists, it need not find the best match.
*
* The 'rt_info' structure defines the next_host, targe match length
* and, optionally, the route and transport determined by the router.
*/
void
rtd_standard(rp, in, out, defer, fail, lookup)
struct router *rp; /* router table entry */
struct addr *in; /* input addr structures */
struct addr **out; /* non-failed addr structures */
struct addr **defer; /* addrs to defer to a later time */
struct addr **fail; /* unresolvable addrs */
int (*lookup)(); /* function to actually do routing */
{
register struct addr *cur; /* current addr being processed */
struct addr *next; /* next addr to process */
struct error *error = NULL; /* error from last lookup */
char *target = NULL; /* last target that was checked */
int success; /* results of last lookup */
int file_success = 0; /* non-zero means router error */
struct rt_info rt_info; /* routing info from router */
DEBUG1(DBG_DRIVER_HI, "rtd_%s called\n", rp->driver);
for (cur = in; cur; cur = next) {
next = cur->succ;
if (cur->flags&ADDR_FINISHED) {
/* this addr has already been completed, skip it */
cur->succ = *out;
*out = cur;
continue;
}
if (file_success) {
switch (file_success) {
case FILE_NOMATCH:
cur->succ = *out;
*out = cur;
continue;
case FILE_FAIL:
case FILE_AGAIN:
cur->error = error; /* use error from last lookup */
cur->succ = *defer;
*defer = cur;
continue;
}
}
if (target == NULL || ! EQIC(target, cur->target)) {
/*
* The current target differs from the previous target, so
* look it up.
*/
rt_info.next_host = NULL;
rt_info.route = NULL;
rt_info.transport = NULL;
error = NULL;
target = cur->target;
/* no flags to pass */
success = (*lookup)(rp, cur, 0, &rt_info, &error);
}
/* Finish up routing, based on lookup response code */
switch (success) {
case DB_SUCCEED:
/* found a successful match */
route_driver_finish(rp, cur, rt_info.matchlen, rt_info.next_host,
rt_info.route, rt_info.transport);
cur->succ = *out;
*out = cur;
break;
case DB_NOMATCH:
/* No match was found. Pass the address onto the next router. */
cur->succ = *out;
*out = cur;
break;
case DB_FAIL:
/* The address should be failed, with an error of some kind. */
cur->error = error;
cur->succ = *fail;
*fail = cur;
break;
case DB_AGAIN:
/* Routing for this address should be reattempted later. */
cur->error = error;
cur->succ = *defer;
*defer = cur;
break;
case FILE_NOMATCH:
/* The file was not found, don't match any addresses. */
cur->succ = *out;
*out = cur;
file_success = FILE_NOMATCH;
break;
case FILE_FAIL:
/* Permanent router error, this is a configuration error. */
error->info |= ERR_CONFERR;
cur->error = error;
cur->succ = *defer;
*defer = cur;
file_success = FILE_FAIL;
break;
case FILE_AGAIN:
/* Temporary router database error, retry all addresses. */
cur->error = error;
cur->succ = *defer;
*defer = cur;
file_success = FILE_AGAIN;
break;
}
}
}
void
rtv_standard(rp, in, retry, okay, defer, fail, lookup)
struct router *rp; /* router entry */
struct addr *in; /* input local-form addrs */
struct addr **retry; /* output list of unmatched addrs */
struct addr **okay; /* output list of verified addrs */
struct addr **defer; /* temporariliy unverifiable addrs */
struct addr **fail; /* unverified addrs */
int (*lookup)(); /* function to actually do routing */
{
register struct addr *cur; /* current addr being processed */
struct addr *next; /* next addr to process */
struct error *error = NULL; /* error from last lookup */
char *target = NULL; /* last target that was checked */
int success; /* results of last lookup */
int file_success = 0; /* non-zero means router error */
struct rt_info rt_info; /* routing info from router */
DEBUG1(DBG_DRIVER_HI, "rtv_%s called\n", rp->driver);
for (cur = in; cur; cur = next) {
next = cur->succ;
if (file_success) {
switch (file_success) {
case FILE_NOMATCH:
cur->succ = *retry;
*retry = cur;
continue;
case FILE_FAIL:
case FILE_AGAIN:
cur->error = error; /* use error from last lookup */
cur->succ = *defer;
*defer = cur;
continue;
}
}
if (target == NULL || ! EQIC(target, cur->target)) {
/*
* The current target differs from the previous target, so
* look it up.
*/
error = NULL;
target = cur->target;
success = (*lookup)(rp, cur, RT_VERIFY, &rt_info, &error);
}
/* Finish up routing, based on lookup response code */
switch (success) {
case DB_SUCCEED:
/* Found a successful match. */
cur->succ = *okay;
*okay = cur;
break;
case DB_NOMATCH:
/* No match was found. Pass the address onto the next router. */
cur->succ = *retry;
*retry = cur;
break;
case DB_FAIL:
/* The address should be failed, with an error of some kind. */
cur->error = error;
cur->succ = *fail;
*fail = cur;
break;
case DB_AGAIN:
/* Routing for this address should be reattempted later. */
cur->error = error;
cur->succ = *defer;
*defer = cur;
break;
case FILE_NOMATCH:
/* The file was not found, don't match any addresses. */
cur->succ = *retry;
*retry = cur;
break;
case FILE_FAIL:
/* Permanent router error, this is a configuration error. */
error->info |= ERR_CONFERR;
cur->error = error;
cur->succ = *defer;
*defer = cur;
file_success = FILE_FAIL;
break;
case FILE_AGAIN:
/* Temporary router database error, retry all addresses. */
cur->error = error;
cur->succ = *defer;
*defer = cur;
file_success = FILE_AGAIN;
break;
}
}
}
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