1995-12-16 20:54:17 +00:00
|
|
|
/*
|
|
|
|
|
* Copyright (c) 1995
|
|
|
|
|
* Bill Paul <wpaul@ctr.columbia.edu>. 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 Bill Paul.
|
|
|
|
|
* 4. Neither the name of the author nor the names of any co-contributors
|
|
|
|
|
* may be used to endorse or promote products derived from this software
|
|
|
|
|
* without specific prior written permission.
|
|
|
|
|
*
|
|
|
|
|
* THIS SOFTWARE IS PROVIDED BY Bill Paul 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 Bill Paul 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.
|
|
|
|
|
*
|
1999-08-28 02:35:59 +01:00
|
|
|
* $FreeBSD$
|
1995-12-16 20:54:17 +00:00
|
|
|
*/
|
1997-10-29 07:25:05 +00:00
|
|
|
|
|
|
|
|
#include <db.h>
|
|
|
|
|
#include <limits.h>
|
1995-12-16 20:54:17 +00:00
|
|
|
#include <stdio.h>
|
|
|
|
|
#include <string.h>
|
|
|
|
|
#include <unistd.h>
|
|
|
|
|
#include <sys/cdefs.h>
|
|
|
|
|
#include <sys/types.h>
|
|
|
|
|
#include <rpc/rpc.h>
|
Big round o changes:
- yp_dblookup.c: Create non-DB specific database access functions.
Using these allows access to the underlying database functions without
needing explicit knowledge of Berkeley DB. (These are used only
when DB_CACHE is #defined. Other programs that use the non-caching
functions (yp_mkdb, ypxfr, yppush, rpc.yppasswdd) shouldn't notice
the difference.)
- yp_dnslookup: Implement async DNS lookups. We send our own DNS
requests using UDP and put the request in a queue. When the response
arrives, we use the ID in the header to find the corresponsing queue
entry and then send the response to the client. We can go about our
business and handle other YP requests in the meantime. This way, we
can deal with time consuming DNS requests without blocking and without
forking.
- yp_server.c: Convert to using new non-DB-specific database access
functions. This simplifies the code a bit and removes the need for
this module to know anything about Berkeley DB. Also convert the
ypproc_match_2_svc() function to use the async DNS lookup routines.
- yp_main.c: tweak yp_svc_run() to add the resolver socket to the
set of descriptors monitored in the select() loop. Also add a
timeout to select(); we may get stale DNS requests stuck in the
queue which we want to invalidate after a while. If the timeout
hits, we decrement the ttl on all pending DNS requests and nuke
those requests that aren't handled before ttl hits zero.
- yp_extern.h: Add prototypes for new stuff.
- yp_svc_udp.c (new file): The async resolver code needs to be able
to rummage around inside the RPC UDP transport handle in order to
work correcty. There's basically one transport handle, and each time
a request comes in, the transaction ID in the handle is changed.
This means that if we queue a DNS request, then we handle some other
unrelated requests, we will be unable to send the DNS response because
the transaction ID and remote address of the client that made the DNS
request will have been lost. What we need to do is save the client
address and transaction ID in the queue entry for the DNS request,
then put the transaction ID and address back in the transport handle
when we're ready to reply. (And then we have to undo the change so
as not to confuse any other part of the server.) The trouble is that
the transaction ID is hidden in an opaque part of the transport handle,
and only the code in the svc_udp module in the RPC library knows how
to handle it. This file contains a couple of functions that let us
read and set the transaction ID in spite of this. This is really a
dirty trick and I should be taken out and shot for even thinking about
it, but there's no other way to get this stuff to work.
- Makefile: add yp_svc_udp.c to SRCS.
1996-12-22 22:30:58 +00:00
|
|
|
#include <rpcsvc/yp.h>
|
1996-10-24 19:58:26 +01:00
|
|
|
|
1995-12-16 20:54:17 +00:00
|
|
|
#ifndef _PATH_YP
|
|
|
|
|
#define _PATH_YP "/var/yp/"
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
#ifndef _PATH_LIBEXEC
|
|
|
|
|
#define _PATH_LIBEXEC "/usr/libexec/"
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
#ifndef MAX_CHILDREN
|
|
|
|
|
#define MAX_CHILDREN 20
|
|
|
|
|
#endif
|
|
|
|
|
|
1996-10-24 19:58:26 +01:00
|
|
|
#define YP_SECURE 0x1
|
|
|
|
|
#define YP_INTERDOMAIN 0x2
|
|
|
|
|
|
1995-12-16 20:54:17 +00:00
|
|
|
/*
|
|
|
|
|
* External functions and variables.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
extern int debug;
|
1995-12-23 21:35:35 +00:00
|
|
|
extern int ypdb_debug;
|
1995-12-16 20:54:17 +00:00
|
|
|
extern int do_dns;
|
|
|
|
|
extern int children;
|
Big round o changes:
- yp_dblookup.c: Create non-DB specific database access functions.
Using these allows access to the underlying database functions without
needing explicit knowledge of Berkeley DB. (These are used only
when DB_CACHE is #defined. Other programs that use the non-caching
functions (yp_mkdb, ypxfr, yppush, rpc.yppasswdd) shouldn't notice
the difference.)
- yp_dnslookup: Implement async DNS lookups. We send our own DNS
requests using UDP and put the request in a queue. When the response
arrives, we use the ID in the header to find the corresponsing queue
entry and then send the response to the client. We can go about our
business and handle other YP requests in the meantime. This way, we
can deal with time consuming DNS requests without blocking and without
forking.
- yp_server.c: Convert to using new non-DB-specific database access
functions. This simplifies the code a bit and removes the need for
this module to know anything about Berkeley DB. Also convert the
ypproc_match_2_svc() function to use the async DNS lookup routines.
- yp_main.c: tweak yp_svc_run() to add the resolver socket to the
set of descriptors monitored in the select() loop. Also add a
timeout to select(); we may get stale DNS requests stuck in the
queue which we want to invalidate after a while. If the timeout
hits, we decrement the ttl on all pending DNS requests and nuke
those requests that aren't handled before ttl hits zero.
- yp_extern.h: Add prototypes for new stuff.
- yp_svc_udp.c (new file): The async resolver code needs to be able
to rummage around inside the RPC UDP transport handle in order to
work correcty. There's basically one transport handle, and each time
a request comes in, the transaction ID in the handle is changed.
This means that if we queue a DNS request, then we handle some other
unrelated requests, we will be unable to send the DNS response because
the transaction ID and remote address of the client that made the DNS
request will have been lost. What we need to do is save the client
address and transaction ID in the queue entry for the DNS request,
then put the transaction ID and address back in the transport handle
when we're ready to reply. (And then we have to undo the change so
as not to confuse any other part of the server.) The trouble is that
the transaction ID is hidden in an opaque part of the transport handle,
and only the code in the svc_udp module in the RPC library knows how
to handle it. This file contains a couple of functions that let us
read and set the transaction ID in spite of this. This is really a
dirty trick and I should be taken out and shot for even thinking about
it, but there's no other way to get this stuff to work.
- Makefile: add yp_svc_udp.c to SRCS.
1996-12-22 22:30:58 +00:00
|
|
|
extern int resfd;
|
1995-12-16 20:54:17 +00:00
|
|
|
extern char *progname;
|
|
|
|
|
extern char *yp_dir;
|
1999-04-29 21:24:00 +01:00
|
|
|
extern pid_t yp_pid;
|
|
|
|
|
|
Big round o changes:
- yp_dblookup.c: Create non-DB specific database access functions.
Using these allows access to the underlying database functions without
needing explicit knowledge of Berkeley DB. (These are used only
when DB_CACHE is #defined. Other programs that use the non-caching
functions (yp_mkdb, ypxfr, yppush, rpc.yppasswdd) shouldn't notice
the difference.)
- yp_dnslookup: Implement async DNS lookups. We send our own DNS
requests using UDP and put the request in a queue. When the response
arrives, we use the ID in the header to find the corresponsing queue
entry and then send the response to the client. We can go about our
business and handle other YP requests in the meantime. This way, we
can deal with time consuming DNS requests without blocking and without
forking.
- yp_server.c: Convert to using new non-DB-specific database access
functions. This simplifies the code a bit and removes the need for
this module to know anything about Berkeley DB. Also convert the
ypproc_match_2_svc() function to use the async DNS lookup routines.
- yp_main.c: tweak yp_svc_run() to add the resolver socket to the
set of descriptors monitored in the select() loop. Also add a
timeout to select(); we may get stale DNS requests stuck in the
queue which we want to invalidate after a while. If the timeout
hits, we decrement the ttl on all pending DNS requests and nuke
those requests that aren't handled before ttl hits zero.
- yp_extern.h: Add prototypes for new stuff.
- yp_svc_udp.c (new file): The async resolver code needs to be able
to rummage around inside the RPC UDP transport handle in order to
work correcty. There's basically one transport handle, and each time
a request comes in, the transaction ID in the handle is changed.
This means that if we queue a DNS request, then we handle some other
unrelated requests, we will be unable to send the DNS response because
the transaction ID and remote address of the client that made the DNS
request will have been lost. What we need to do is save the client
address and transaction ID in the queue entry for the DNS request,
then put the transaction ID and address back in the transport handle
when we're ready to reply. (And then we have to undo the change so
as not to confuse any other part of the server.) The trouble is that
the transaction ID is hidden in an opaque part of the transport handle,
and only the code in the svc_udp module in the RPC library knows how
to handle it. This file contains a couple of functions that let us
read and set the transaction ID in spite of this. This is really a
dirty trick and I should be taken out and shot for even thinking about
it, but there's no other way to get this stuff to work.
- Makefile: add yp_svc_udp.c to SRCS.
1996-12-22 22:30:58 +00:00
|
|
|
extern enum ypstat yp_errno;
|
2001-07-05 09:17:06 +01:00
|
|
|
extern void yp_error __P((const char *, ...)) __printflike(1, 2);
|
Big round o changes:
- yp_dblookup.c: Create non-DB specific database access functions.
Using these allows access to the underlying database functions without
needing explicit knowledge of Berkeley DB. (These are used only
when DB_CACHE is #defined. Other programs that use the non-caching
functions (yp_mkdb, ypxfr, yppush, rpc.yppasswdd) shouldn't notice
the difference.)
- yp_dnslookup: Implement async DNS lookups. We send our own DNS
requests using UDP and put the request in a queue. When the response
arrives, we use the ID in the header to find the corresponsing queue
entry and then send the response to the client. We can go about our
business and handle other YP requests in the meantime. This way, we
can deal with time consuming DNS requests without blocking and without
forking.
- yp_server.c: Convert to using new non-DB-specific database access
functions. This simplifies the code a bit and removes the need for
this module to know anything about Berkeley DB. Also convert the
ypproc_match_2_svc() function to use the async DNS lookup routines.
- yp_main.c: tweak yp_svc_run() to add the resolver socket to the
set of descriptors monitored in the select() loop. Also add a
timeout to select(); we may get stale DNS requests stuck in the
queue which we want to invalidate after a while. If the timeout
hits, we decrement the ttl on all pending DNS requests and nuke
those requests that aren't handled before ttl hits zero.
- yp_extern.h: Add prototypes for new stuff.
- yp_svc_udp.c (new file): The async resolver code needs to be able
to rummage around inside the RPC UDP transport handle in order to
work correcty. There's basically one transport handle, and each time
a request comes in, the transaction ID in the handle is changed.
This means that if we queue a DNS request, then we handle some other
unrelated requests, we will be unable to send the DNS response because
the transaction ID and remote address of the client that made the DNS
request will have been lost. What we need to do is save the client
address and transaction ID in the queue entry for the DNS request,
then put the transaction ID and address back in the transport handle
when we're ready to reply. (And then we have to undo the change so
as not to confuse any other part of the server.) The trouble is that
the transaction ID is hidden in an opaque part of the transport handle,
and only the code in the svc_udp module in the RPC library knows how
to handle it. This file contains a couple of functions that let us
read and set the transaction ID in spite of this. This is really a
dirty trick and I should be taken out and shot for even thinking about
it, but there's no other way to get this stuff to work.
- Makefile: add yp_svc_udp.c to SRCS.
1996-12-22 22:30:58 +00:00
|
|
|
#ifdef DB_CACHE
|
|
|
|
|
extern int yp_get_record __P(( DB *, const DBT *, DBT *, int));
|
|
|
|
|
#else
|
1995-12-16 20:54:17 +00:00
|
|
|
extern int yp_get_record __P(( const char *, const char *, const DBT *, DBT *, int));
|
Big round o changes:
- yp_dblookup.c: Create non-DB specific database access functions.
Using these allows access to the underlying database functions without
needing explicit knowledge of Berkeley DB. (These are used only
when DB_CACHE is #defined. Other programs that use the non-caching
functions (yp_mkdb, ypxfr, yppush, rpc.yppasswdd) shouldn't notice
the difference.)
- yp_dnslookup: Implement async DNS lookups. We send our own DNS
requests using UDP and put the request in a queue. When the response
arrives, we use the ID in the header to find the corresponsing queue
entry and then send the response to the client. We can go about our
business and handle other YP requests in the meantime. This way, we
can deal with time consuming DNS requests without blocking and without
forking.
- yp_server.c: Convert to using new non-DB-specific database access
functions. This simplifies the code a bit and removes the need for
this module to know anything about Berkeley DB. Also convert the
ypproc_match_2_svc() function to use the async DNS lookup routines.
- yp_main.c: tweak yp_svc_run() to add the resolver socket to the
set of descriptors monitored in the select() loop. Also add a
timeout to select(); we may get stale DNS requests stuck in the
queue which we want to invalidate after a while. If the timeout
hits, we decrement the ttl on all pending DNS requests and nuke
those requests that aren't handled before ttl hits zero.
- yp_extern.h: Add prototypes for new stuff.
- yp_svc_udp.c (new file): The async resolver code needs to be able
to rummage around inside the RPC UDP transport handle in order to
work correcty. There's basically one transport handle, and each time
a request comes in, the transaction ID in the handle is changed.
This means that if we queue a DNS request, then we handle some other
unrelated requests, we will be unable to send the DNS response because
the transaction ID and remote address of the client that made the DNS
request will have been lost. What we need to do is save the client
address and transaction ID in the queue entry for the DNS request,
then put the transaction ID and address back in the transport handle
when we're ready to reply. (And then we have to undo the change so
as not to confuse any other part of the server.) The trouble is that
the transaction ID is hidden in an opaque part of the transport handle,
and only the code in the svc_udp module in the RPC library knows how
to handle it. This file contains a couple of functions that let us
read and set the transaction ID in spite of this. This is really a
dirty trick and I should be taken out and shot for even thinking about
it, but there's no other way to get this stuff to work.
- Makefile: add yp_svc_udp.c to SRCS.
1996-12-22 22:30:58 +00:00
|
|
|
#endif
|
Performance enhancements (I hope) and new stuff:
yp_dblookup.c:
- Implement database handle caching. What this means is that instead
of opening and closing map databases for each request, we open a
database and save the handle (and, if requested, the key index)
in an array. This saves a bit of overhead on things like repeated
YPPROC_NEXT calls, such as you'd get from getpwent(). Normally,
each YPPROC_NEXT would require open()ing the database, seeking
to the location supplied by the caller (which is time consuming with
hash databases as the R_CURSOR flag doesn't work), reading the
data, close()ing the database and then shipping the data off to
the caller. The system call overhead is prohibitive, especially
with very large maps. By caching the handle to an open database,
we elimitate at least the open()/close() system calls, as well
as the associated DB setup and tear-down operations, for a large
percentage of the time. This improves performance substantially at
the cost of consuming a little more memory than before.
Note that all the caching support is surrounded by #ifdef DB_CACHE
so that this same source module can still be used by other programs
that don't need it.
- Make yp_open_db() call yp_validdomain(). Doing it here saves cycles
when caching is enabled since a hit on the map cache list by
definition means that the domain being referenced is valid.
- Also make yp_open_db() check for exhaustion of file descriptors,
just in case.
yp_server.c:
- Reorganize things a little to take advantage of the database
handle caching. Add a call to yp_flush_all() in ypproc_clear_2_svc().
- Remove calls to yp_validdomain() from some of the service procedures.
yp_validdomain() is called inside yp_open_db() now, so procedures that
call into the database package don't need to use yp_validdomain()
themselves.
- Fix a bogosity in ypproc_maplist_2_svc(): don't summarily initiallize
the result.maps pointer to NULL. This causes yp_maplist_free()
to fail and leaks memory.
- Make ypproc_master_2_svc() copy the string it gets from the database
package into a private static buffer before trying to NUL terminate it.
This is necessary with the DB handle caching: stuffing a NUL into the
data returned by DB package will goof it up internally.
yp_main.c:
- Stuff for DB handle caching: call yp_init_dbs() to clear the
handle array and add call to yp_flush_all() to the SIGHUP
signal handler.
Makefile.yp:
- Reorganize to deal with database caching. yp_mkdb(8) can now be used
to send a YPPROC_CLEAR signal to ypserv(8). Call it after each map
is created to refresh ypserv's cache.
- Add support for mail.alias map.
Contributed by Mike Murphy (mrm@sceard.com).
- Make default location for the netgroups source file be /var/yp/netgroup
instead of /etc/netgroup.
mkaliases:
- New file: script to generate mail.alias map.
Contributed by Mike Murphy (mrm@sceard.com).
Makefile:
- Install Makefile.yp as /var/yp/Makefile.dist and link it to
/var/yp/Makefile only if /var/yp/Makefile doesn't already exist.
Suggested by Peter Wemm.
- Install new mkaliases script in /usr/libexec along with mknetid.
- Use somewhat saner approach to generating rpcgen-dependent files
as suggested by Garrett Wollman.
1996-04-28 05:38:52 +01:00
|
|
|
extern int yp_first_record __P((const DB *, DBT *, DBT *, int));
|
|
|
|
|
extern int yp_next_record __P((const DB *, DBT *, DBT *, int, int));
|
1995-12-16 20:54:17 +00:00
|
|
|
extern char *yp_dnsname __P(( char * ));
|
|
|
|
|
extern char *yp_dnsaddr __P(( const char * ));
|
1996-10-24 19:58:26 +01:00
|
|
|
#ifdef DB_CACHE
|
|
|
|
|
extern int yp_access __P((const char *, const char *, const struct svc_req * ));
|
|
|
|
|
#else
|
1995-12-16 20:54:17 +00:00
|
|
|
extern int yp_access __P((const char *, const struct svc_req * ));
|
1996-10-24 19:58:26 +01:00
|
|
|
#endif
|
1995-12-16 20:54:17 +00:00
|
|
|
extern int yp_validdomain __P((const char * ));
|
|
|
|
|
extern DB *yp_open_db __P(( const char *, const char *));
|
Performance enhancements (I hope) and new stuff:
yp_dblookup.c:
- Implement database handle caching. What this means is that instead
of opening and closing map databases for each request, we open a
database and save the handle (and, if requested, the key index)
in an array. This saves a bit of overhead on things like repeated
YPPROC_NEXT calls, such as you'd get from getpwent(). Normally,
each YPPROC_NEXT would require open()ing the database, seeking
to the location supplied by the caller (which is time consuming with
hash databases as the R_CURSOR flag doesn't work), reading the
data, close()ing the database and then shipping the data off to
the caller. The system call overhead is prohibitive, especially
with very large maps. By caching the handle to an open database,
we elimitate at least the open()/close() system calls, as well
as the associated DB setup and tear-down operations, for a large
percentage of the time. This improves performance substantially at
the cost of consuming a little more memory than before.
Note that all the caching support is surrounded by #ifdef DB_CACHE
so that this same source module can still be used by other programs
that don't need it.
- Make yp_open_db() call yp_validdomain(). Doing it here saves cycles
when caching is enabled since a hit on the map cache list by
definition means that the domain being referenced is valid.
- Also make yp_open_db() check for exhaustion of file descriptors,
just in case.
yp_server.c:
- Reorganize things a little to take advantage of the database
handle caching. Add a call to yp_flush_all() in ypproc_clear_2_svc().
- Remove calls to yp_validdomain() from some of the service procedures.
yp_validdomain() is called inside yp_open_db() now, so procedures that
call into the database package don't need to use yp_validdomain()
themselves.
- Fix a bogosity in ypproc_maplist_2_svc(): don't summarily initiallize
the result.maps pointer to NULL. This causes yp_maplist_free()
to fail and leaks memory.
- Make ypproc_master_2_svc() copy the string it gets from the database
package into a private static buffer before trying to NUL terminate it.
This is necessary with the DB handle caching: stuffing a NUL into the
data returned by DB package will goof it up internally.
yp_main.c:
- Stuff for DB handle caching: call yp_init_dbs() to clear the
handle array and add call to yp_flush_all() to the SIGHUP
signal handler.
Makefile.yp:
- Reorganize to deal with database caching. yp_mkdb(8) can now be used
to send a YPPROC_CLEAR signal to ypserv(8). Call it after each map
is created to refresh ypserv's cache.
- Add support for mail.alias map.
Contributed by Mike Murphy (mrm@sceard.com).
- Make default location for the netgroups source file be /var/yp/netgroup
instead of /etc/netgroup.
mkaliases:
- New file: script to generate mail.alias map.
Contributed by Mike Murphy (mrm@sceard.com).
Makefile:
- Install Makefile.yp as /var/yp/Makefile.dist and link it to
/var/yp/Makefile only if /var/yp/Makefile doesn't already exist.
Suggested by Peter Wemm.
- Install new mkaliases script in /usr/libexec along with mknetid.
- Use somewhat saner approach to generating rpcgen-dependent files
as suggested by Garrett Wollman.
1996-04-28 05:38:52 +01:00
|
|
|
extern DB *yp_open_db_cache __P(( const char *, const char *, const char *, int ));
|
|
|
|
|
extern void yp_flush_all __P(( void ));
|
|
|
|
|
extern void yp_init_dbs __P(( void ));
|
1996-10-24 19:58:26 +01:00
|
|
|
extern int yp_testflag __P(( char *, char *, int ));
|
1996-02-24 22:01:48 +00:00
|
|
|
extern void load_securenets __P(( void ));
|
Big round o changes:
- yp_dblookup.c: Create non-DB specific database access functions.
Using these allows access to the underlying database functions without
needing explicit knowledge of Berkeley DB. (These are used only
when DB_CACHE is #defined. Other programs that use the non-caching
functions (yp_mkdb, ypxfr, yppush, rpc.yppasswdd) shouldn't notice
the difference.)
- yp_dnslookup: Implement async DNS lookups. We send our own DNS
requests using UDP and put the request in a queue. When the response
arrives, we use the ID in the header to find the corresponsing queue
entry and then send the response to the client. We can go about our
business and handle other YP requests in the meantime. This way, we
can deal with time consuming DNS requests without blocking and without
forking.
- yp_server.c: Convert to using new non-DB-specific database access
functions. This simplifies the code a bit and removes the need for
this module to know anything about Berkeley DB. Also convert the
ypproc_match_2_svc() function to use the async DNS lookup routines.
- yp_main.c: tweak yp_svc_run() to add the resolver socket to the
set of descriptors monitored in the select() loop. Also add a
timeout to select(); we may get stale DNS requests stuck in the
queue which we want to invalidate after a while. If the timeout
hits, we decrement the ttl on all pending DNS requests and nuke
those requests that aren't handled before ttl hits zero.
- yp_extern.h: Add prototypes for new stuff.
- yp_svc_udp.c (new file): The async resolver code needs to be able
to rummage around inside the RPC UDP transport handle in order to
work correcty. There's basically one transport handle, and each time
a request comes in, the transaction ID in the handle is changed.
This means that if we queue a DNS request, then we handle some other
unrelated requests, we will be unable to send the DNS response because
the transaction ID and remote address of the client that made the DNS
request will have been lost. What we need to do is save the client
address and transaction ID in the queue entry for the DNS request,
then put the transaction ID and address back in the transport handle
when we're ready to reply. (And then we have to undo the change so
as not to confuse any other part of the server.) The trouble is that
the transaction ID is hidden in an opaque part of the transport handle,
and only the code in the svc_udp module in the RPC library knows how
to handle it. This file contains a couple of functions that let us
read and set the transaction ID in spite of this. This is really a
dirty trick and I should be taken out and shot for even thinking about
it, but there's no other way to get this stuff to work.
- Makefile: add yp_svc_udp.c to SRCS.
1996-12-22 22:30:58 +00:00
|
|
|
|
|
|
|
|
#ifdef DB_CACHE
|
|
|
|
|
extern ypstat yp_select_map __P(( char *, char *, keydat *, int ));
|
|
|
|
|
extern ypstat yp_getbykey __P(( keydat *, valdat * ));
|
|
|
|
|
extern ypstat yp_firstbykey __P(( keydat *, valdat * ));
|
|
|
|
|
extern ypstat yp_nextbykey __P(( keydat *, valdat * ));
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
extern unsigned long svcudp_set_xid __P(( SVCXPRT *, unsigned long ));
|
|
|
|
|
extern unsigned long svcudp_get_xid __P(( SVCXPRT * ));
|
|
|
|
|
|
|
|
|
|
#ifndef RESOLVER_TIMEOUT
|
|
|
|
|
#define RESOLVER_TIMEOUT 3600
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
extern int yp_init_resolver __P(( void ));
|
|
|
|
|
extern void yp_run_dnsq __P(( void ));
|
|
|
|
|
extern void yp_prune_dnsq __P(( void ));
|
1996-12-25 18:10:35 +00:00
|
|
|
extern ypstat yp_async_lookup_name __P(( struct svc_req *, char * ));
|
|
|
|
|
extern ypstat yp_async_lookup_addr __P(( struct svc_req *, char * ));
|
