to be the same as -ragged in the current implementation) to
-ragged. With mdocNG, -filled displays produce the correct
output, formatted and justified to both margins.
adding (weak definitions to) stubs for some of the pthread
functions. If the threads library is linked in, the real
pthread functions will pulled in.
Use the following convention for system calls wrapped by the
threads library:
__sys_foo - actual system call
_foo - weak definition to __sys_foo
foo - weak definition to __sys_foo
Change all libc uses of system calls wrapped by the threads
library from foo to _foo. In order to define the prototypes
for _foo(), we introduce namespace.h and un-namespace.h
(suggested by bde). All files that need to reference these
system calls, should include namespace.h before any standard
includes, then include un-namespace.h after the standard
includes and before any local includes. <db.h> is an exception
and shouldn't be included in between namespace.h and
un-namespace.h namespace.h will define foo to _foo, and
un-namespace.h will undefine foo.
Try to eliminate some of the recursive calls to MT-safe
functions in libc/stdio in preparation for adding a mutex
to FILE. We have recursive mutexes, but would like to avoid
using them if possible.
Remove uneeded includes of <errno.h> from a few files.
Add $FreeBSD$ to a few files in order to pass commitprep.
Approved by: -arch
- iruserok_sa() and __ivaliduser_af() were re-organized to use
__ivaliduser_sa()
- __icheckhost() was re-written to use getaddrinfo() instead of
getipnodebyname()
- better handling of multiple destination addresses in rcmd()
These changes were basically taken from KAME and changed to fit our
rcmd.c.
Obtained from: KAME
response to return. This will stop processes waiting on DNS requests
from being woken up when a select collision occurs. This was tested
on mx1.FreeBSD.org (outgoing mail for the FreeBSD.org mailing
lists.)
Reviewed by: jlemon, peter
configure FreeBSD so that various databases such as passwd and group can be
looked up using flat files, NIS, or Hesiod.
= Hesiod has been added to libc (see hesiod(3)).
= A library routine for parsing nsswitch.conf and invoking callback
functions as specified has been added to libc (see nsdispatch(3)).
= The following C library functions have been modified to use nsdispatch:
. getgrent, getgrnam, getgrgid
. getpwent, getpwnam, getpwuid
. getusershell
. getaddrinfo
. gethostbyname, gethostbyname2, gethostbyaddr
. getnetbyname, getnetbyaddr
. getipnodebyname, getipnodebyaddr, getnodebyname, getnodebyaddr
= host.conf has been removed from src/etc. rc.network has been modified
to warn that host.conf is no longer used at boot time. In addition, if
there is a host.conf but no nsswitch.conf, the latter is created at boot
time from the former.
Obtained from: NetBSD
I changed to close to original code before merging IPv6 support.
It seems having delay before another try is useless. However, I'm
not sure that delay means. So, I leave it as-is.
PR: bin/20515
strdup()) rather than pointing it at something that's free()d
(via freeaddrinfo(res)) before the function returns.
I appreciate that this is an API change, but it's the only way
(AFAIK) of doing this without breaking existing code that uses
rcmd{,_af}().
Pointed out by: phkmalloc
management involving rcmd_af(), getaddrinfo(), freeaddrinfo(), etc.
We set *ahost to point to ai->canonname; and later free the ai-> stuff
and still leave the old pointers in *ahost to the freed data.
Perhaps the best way to deal with this is a static buffer or a static
strdup() that is freed on the next iteration or something. This gives
me headaches just thinking about this.
The new 'AJ' default for malloc() tripped this up.
- permit numeric scopeid, be more careful about buffer size
TODO: 2nd arg type should be socklen_t for RFC2553 conformance,
but due to include file dependency it is not a easy thing to do
(netdb.h does not have socklen_t)
interface addresses in a portable manner, without headache of SIOCGIFCONF
or sysctl. it is in bsdi/openbsd/netbsd already.
from kame tree (actually, mandatory for latest kame tree).
when parsing certain DNS records during a reverse address resolution. Thus
when code tries to examine the returned host name, it dereferences a null
pointer :-(
Problem noticed by: ps
getaddrinfo() accidentally returns IPv4 mapped IPv6 address instead
of native IPv4 address.
Now, getaddinfo() is scoped address ready. You can put scoped
address within /etc/hosts.
Obtained from: KAME Project.
from
all AAAA trial, then all A trial
to
try AAAA and A for each trial
TODO: more fix for the case where IPv4 mapped IPv6 addr is disabled
Reviewed by: ume
some reason. This will prevent an infinite loop if (say) a sigalarm is
being scheduled at a more frequent interval than the poll timeout.
PR: 2191, 8847, 10553
-Added more description.
-Many grammer fix.
-Fix hard sentence break.
-Many other man style fix.
Thanks for bde finding out the problem.
Thanks for sheldon for the patient and thorough review.
:-)
Submitted by: bde
Reviewed by: sheldonh
Sorry for the flapping, but no change will be done for 4.0 anymore.
Official standard will be published around April or later.
If different format would be adopted at that time, then support for
the new format will be added to the succeeding FreeBSD 4.x.
Approved by: jkh
fit in the static buffer. This fix causes it to look like there is no
data available, which is also wrong but is better than dumping core.
PR: bin/10344
Reviewed by: billf
Approved by: jkh
-Should not error return when rresvport_af() failed for one of dest
addrs resolved by getaddrinfo().
Should retry until all dest addr fail.
Approved by: jkh
(shortend format, etc)
Current KAME getaddrinfo() supports only d.d.d.d format IPv4
addr. But traditionally inet_aton() and etc support other formats.
(shortend format and octal/deciaml/hex format)
Aboud this,
-As far as the discussion on freebsd-current, many people
think traditional format should also be supported by getaddrinfo().
-X/Open spec requires getaddrinfo() also support those
traditional IPv4 format.
-RFC2553 say nothing about it.
-As the result of confirmation in ietf/ipng list, there is
no clear concensus yet, and the reply was, "RFC2553 update
and X/Open spec will be in sync"
So takeing these conditions into account, I think
getaddrinfo() should also support traditional IPv4 format.
Specified by: Marc Schneiders <marc@oldserver.demon.nl>
Approved by: jkh
KAME scoped addr format is changed recently.
before: addr@scope
now: scope%addr
Because the end of IPv6 numeric addr is tend to be truncated in
`netstat -rn ` output, so placing scope part at starting of addr
will be convenient.
Approved by: jkh
Obtained from: KAME project
Some of rcmd related function is need to be updated to
support IPv6. Some of them are already updated as standard
document. But there is also several de-facto functions and
they are not listed in standard documents.
They are,
iruserok() (used by rlogind, rshd)
ruserok() (used by kerberos, etc)
KAME package updated those functions in original way.
iruserok_af()
ruserok_af()
But recently there was discussion on IETF IPng mailing
list about how to sync those API, and it is decided,
-Those function is not standard and not documented.
-But let BSDs sync their API as de-facto.
And after some discussion, it is announced that
-add update to iruserok() as iruserok_sa()
-no ruserok() API change(it is only updated internaly)
So I sync those API before 4.0 is released.
The changes are,
-prototype changes
-ruserok() internal update (use iruserok_sa() inside)
-removal of ruserok_af()
-change iruserok_af() as static functioin, and also prefix the name with __.
-add iruserok_sa() (Just call __iruserok_af() inside)
-adding flag AI_ALL to getipnodebyaddr() called from __icheckhost().
This is necessary to support IPv4 communication via AF_INET6 socket
could be correctly authenticated via iruserok_sa()
-irusreok_af() call is replaced to iruserok_sa() call
in rlogind, and rshd.
Approved by: jkh
just use _foo() <-- foo(). In the case of a libpthread that doesn't do
call conversion (such as linuxthreads and our upcoming libpthread), this
is adequate. In the case of libc_r, we still need three names, which are
now _thread_sys_foo() <-- _foo() <-- foo().
Convert all internal libc usage of: aio_suspend(), close(), fsync(), msync(),
nanosleep(), open(), fcntl(), read(), and write() to _foo() instead of foo().
Remove all internal libc usage of: creat(), pause(), sleep(), system(),
tcdrain(), wait(), and waitpid().
Make thread cancellation fully POSIX-compliant.
Suggested by: deischen
-changed bindresvport2 to bindresvport_sa
-merged the man into bindresvport.3
All discussion between Jean-Luc Richier <Jean-Luc.Richier@imag.fr>,
Theo de Raadt <deraadt@cvs.openbsd.org>, itojun, is reflected to
this code. (Actually Theo de Raadt write the code simultaneously as the
discussion change.)
obtained from itojun.
-don't filter address families which are not supported by system at
FQDN resolving.
-don't do reverse lookup
I think I checked all lib and tools which use getaddrinfo() if
this change affect them.
Obtained from: KAME project
points. For library functions, the pattern is __sleep() <--
_libc_sleep() <-- sleep(). The arrows represent weak aliases. For
system calls, the pattern is _read() <-- _libc_read() <-- read().
(1)added error check of if_nameindex() return value at getaddrinfo().
(2)print out more detailed information when getaddrinfo() error value
is EAI_SYSTEM.(in this case system error num is kept in errno)
(1) is Discovered by: jinmei@kame.net in KAME environment.
IPv6 specific library functions addition.
(getnameinfo(), getaddrinfo(), and IPv6 transport support is not yet)
Reviewed by: freebsd-arch, cvs-committers
Obtained from: KAME project
should close all outstanding PRs on incorrect inet_aton behavior, and
since it has a decent parsing routine, doesn't allow some hysterically
working behavior.
PR: 13628
Submitted by: Adrian Chadd <adrian@FreeBSD.org>
required to be "announced" by a new bit in sa_flags to indicate the
program is aware of and has taken care of them. eg: SA_SIGINFO means
the program has used the sa_siginfo field (versus sa_handler).
sigaction, used to describe an action to be taken, is defined in the
header <signal.h> to include at least the following members:"
^^^^^^^^
A sigaction defined on stack with essentially random contents may have
just about anything underneath fields that the program doesn't know about.
It is not safe to delete the bzero.
track.
The $Id$ line is normally at the bottom of the main comment block in the
man page, separated from the rest of the manpage by an empty comment,
like so;
.\" $Id$
.\"
If the immediately preceding comment is a @(#) format ID marker than the
the $Id$ will line up underneath it with no intervening blank lines.
Otherwise, an additional blank line is inserted.
Approved by: bde
and res_* modules in a way that works for ELF. I moved the aliases
out of res_stubs.c and into the individual modules where the entry
points are defined. Weak aliases don't work in ELF unless that is
the case. (Actually, I'm surprised it worked for a.out.)
This should fix the undefined "inet_addr" and related symbols in
various applications that fail to include <arpa/inet.h> or
<resolv.h> as they are supposed to do.
One bug was relatively harmless (select's timeout had an uninitialized
tv_usec), the other I'm not so sure.. (neglected to catch select returns
less than zero). Both of these were irrelevant on kernels with poll().
chunks of res_comp.c and replacing it with chunks of bind-8.1.1's resolver
code. (There are no interface changes though)
The other parts are better bounds checking related.
isn't a prerequisite, since it isn't required for the prototypes
and isn't always needed to call the functions (the address family
might be a variable).
an unimplemented syscall returned ENOSYS, rather than EINVAL. I have run
statically linked code with this wrapper and it does appear to work fine
on 2.2-stable which doesn't have poll(). ktrace shows the poll syscall fail
once and the fallback to select() working.
if necessary. This removes the need to malloc large fd_set's for selecting
on high fd's (larger than FD_SETSIZE at libc compile time).
The syscall adaptive stuff only happens on the very first call. SIGSYS
is masked, and if the call to poll fails with ENOSYS, then we use select
for the life of the program. If poll does not fail with ENOSYS, then we
always use poll and skip the once-off signal masking gunk.
This may be overkill, but it saved my neck a few times while working on
multiple different sets of kernel sources, some with poll, some without.
Only call malloc() if the fd is too big for the compiled in fd_set size,
and don't use calloc either. This should reduce the impact of conflicts
with private malloc implementations etc. When using the fd_set on the
stack, only zero what is needed rather than all 1024 bits like FD_ZERO did.
so that all these makefiles can be used to build libc_r too.
Added .if ${LIB} == "c" tests to restrict man page builds to libc
to avoid needlessly building them with libc_r too.
Split libc Makefile into Makefile and Makefile.inc to allow the
libc_r Makefile to include Makefile.inc too.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
RELENG_2_2!
This is part#2 of the previous commit to src/lib/libc/net to contain the
potential damage.
This provides stubs so that binaries linked in 2.2 will run on 3.0
- getservent:
o put _yp_check() proto under #ifdef YP where it belongs
o local YP buffers should be YPMAXRECORD + 2 bytes long and should
be NUL terminated after copying
- gethostbynis:
o local YP buffer should be YPMAXRECORD + 2 bytes long
- getnetbynis:
o local YP buffer should be YPMAXRECORD + 2 bytes long and should
be NUL terminated after copying
- ether_addr:
o local YP buffers should be YPMAXRECORD + 2 bytes long and should
be NUL terminated after copying (in this case it's BUFSIZ + 2 bytes,
but it happens that BUFSIZ == YPMAXRECORD.
- gethostbydns:
o nuke stray 'return(NULL)' in __dns_getanswer() (harmless but looks silly)
These are 2.2 candidates. I will wait a few days to make sure these don't
break anything and then, if there are no objections, move them to the 2.2
branch.
lookup results. Without this, doing multiple host/addr lookups in a
single process yeilds strange results (the buffer is static, and
garbage may be left behind from previous lookups).
I just noticed this in 2.2-BETA. Unless somebody threatens to chop my
hands off with an axe, I'm going to move this to the 2.2-RELENG branch
shortly.
of BIND, we need to tweak some things to that gethostanswer() knows
whether or not we're dealing with an IPv4 or IPv6 address. (This'll
teach me to use a 2.1.0 system for NIS development -- but it's so nice
and stable I just can't being myself to upgrade it. :)
in lots of unrelated junk from <net/if.h> and <net/if_ether.h>. These
functions still aren't prototyped anywhere (but should be in
<net/ethernet.h>---got that, Bill?).
and he said:
The 3rd agrument is new; looks like it was part of the upgrade to
a new BIND with some IPv6 support. The third argument here should be
AF_INET. In order for it to be anything else, I'd have to add new
NIS functions to support IPv6 lookups. I don't even know what those
look like yet.
So there ya go, add AF_INET as the 3rd argument to the call.
Submitted-by: wpaul
routines from contrib/bind directly. There were too many problems,
including having to add -DUSE_OPTIONS_H to the entire libc source in
order for the contrib code to pick up it's options, and so on.
Instead, I've merged the changes, libc is now self contained again.
Here are the diffs for libc_r to get it one step closer to P1003.1c
These make most of the thread/mutex/condvar structures opaque to the
user. There are three functions which have been renamed with _np
suffixes because they are extensions to P1003.1c (I did them for JAVA,
which needs to suspend/resume threads and also start threads suspended).
I've created a new header (pthread_np.h) for the non-POSIX stuff.
The egrep tags stuff in /usr/src/lib/libc_r/Makefile that I uncommented
doesn't work. I think its best to delete it. I don't think libc_r needs
tags anyway, 'cause most of the source is in libc which does have tags.
also:
Here's the first batch of man pages for the thread functions.
The diff to /usr/src/lib/libc_r/Makefile removes some stuff that was
inherited from /usr/src/lib/libc/Makefile that should only be done with
libc.
also:
I should have sent this diff with the pthread(3) man page.
It allows people to type
make -DWANT_LIBC_R world
to get libc_r built with the rest of the world. I put this in the
pthread(3) man page. The default is still not to build libc_r.
also:
The diff attached adds a pthread(3) man page to /usr/src/share/man/man3.
The idea is that without libc_r installed, this man page will give people
enough info to know that they have to build libc_r.
set sin_len
close one ftp port bounce attack
have rresvport() use bindresvport() rather than duplicate the code,
rresvport() is a superset of bindresvport().
Obtained from: OpenBSD / Jason Downs / Theo de Raadt, minor tweaks by me.
functions are implimented as wrappers around getservent(), which means it's
up to getservent() to do all the work. The NIS support in getservent()
only allows it to scan through the services.byname map one entry at a
time until it finds the requested service name/port. This can be painfully
slow due to the overhead involved (lots and lots of successive RPCs).
To fix this, we allow getservbyname() and getservbyport() to signal
getservent() that if NIS is turned on (there's a '+' in /etc/services),
the usual yp_first()/yp_next() linear search should be abandoned and
yp_match() used instead. This causes getservent() to immediately
locate the requested entry instead of wasting time groping through the
whole map.
The downside is that this trick is accomplished by exporting a couple of
pointers from getservent.c which getservbyname.c and getservbyport.c can
preset in order to tell getservent() what to do. If all three functions
were in the same source module, then the extra cruft could be delcared
static to avoid poluting the global symbol space. Maybe they should be
combined anyway. For now I've settled on prepending lots of underscores.
privileged port within a single bind(), rather than looping through
attempts to bind over and over again over progressively lower ports.
This should speed up rlogin/rsh etc, and will probably cure some of the
strange rlogin hangs that have been reported in the past where rresvport()
managed to bind() to a port address that it shouldn't have.
man pages up to mdoc guidelines and fix some minor formatting glitches.
Also fixed a number of man pages to not abuse the .Xr macro to
display functions and path names and a lot of other junk.
broken. The translation from network number to ASCII string was not
working correctly (you would sometimes get things like 0.244.0.0 instead
of 244.0.0).
Also copied results of yp_match() to a static buffer for consistency
with gethostbynis.c.
Note: _getnetbynisaddr() chops off trailing .0's, i.e. 244.0.0 is
truncated to 244. By contrast, getnetbyht.c code (for local /etc/networks
lookups) leaves the traling .0's in place. This means that the NIS
and local file lookups will match different things when looking up the
same network number. I'm not sure which is the correct behavior. (I
think the DNS lookup code tries all combinations -- should the NIS
and local host lookup routines do that too?)
- Fix problem described in PR #1079: _gethostbynisaddr() doesn't
work. Make it accept the same arguments as all the other
gethostby*addr() functions and properly convert the supplied IP
address into a text string so that yp_match() can find it in the
hosts.byaddr map.
- Also fix potential memory leak: copy the results of yp_match() to
a static buffer and free the result (yp_match() returns dynamically
allocated memory).
ether_addr.c:
- Since I was in the neighborhood, fix ether_ntohost() and
ether_hostton() so that they don't bogusly for a free(result)
when yp_match() fails.
in the main text of various man pages.
Thanks to Warner Losh for adding an option to manck to allow
it to scan the entire man page looking for bogus xrefs, instead
of just checking the SEE ALSO section.
Also corrected a few minor formatting errors, file location and cross
references in some of the section 3 man pages.
This shuts up a lot of the output from "manck" for section 3.
both call getservent() to do most of the work, so we only need to modify
this file to take care of everybody).
Note that there is only one NIS services map (services.byname) even
though there are getservbyname() and getservbyport() library functions.
Since Bruce changed the #include <res_config.h> to #include "res_config.h"
this is no longer needed, and only makes the 'make' more verbose for
no real reason.
Note that this was done by selective patching from diffs, to not conflict
with the 4.4bsd base code.. This was *not* a trivial task.. I have been
testing this code (apart from cosmetic changes) in my libc for a while now.
Obtained from: Paul Vixie <paul@vix.com>
Fix for PR #510. The original problem was that __ivaliduser() was
failing to grant access to a machine listed in a +@netgroup specified
in /etc/hosts.equiv, even though the host being checked was most
certainly in the +@netgroup.
The /etc/hosts.equiv file in question looked like this:
localhost
+@netgroup
The reason for the failure was had to do with gethostbyaddr(). Inside
the __ivaliduser() routine, we need to do a gethostbyaddr() in order
to get back the actual name of the host we're trying to validate since
we're only passed its IP address. The hostname returned by gethostbyaddr()
is later passed as an argument to innetgr(). The problem is that
__icheckhost() later does a gethostbyname() of its own, which clobbers
the buffer returned by gethostbyaddr().
The fix is just to copy the hostname into a private buffer and use
_that_ as the 'host' argument that gets passed to innetgr().
And here I was crawling all over the innetgr() code thinking the
problem was there. *sigh*
- getnetgrent.c: address some NIS compatibility problems. We really need
to use the netgroup.byuser and netgroup.byhost maps to speed up innetgr()
when using NIS. Also, change the NIS interaction in the following way:
If /etc/netgroup does not exist or is empty (or contains only the
NIS '+' token), we now use NIS exclusively. This lets us use the
'reverse netgroup' maps and is more or less the behavior of other
platforms.
If /etc/netgroup exists and contains local netgroup data (but no '+').
we use only lthe local stuff and ignore NIS.
If /etc/netgroup exists and contains both local data and the '+',
we use the local data nd the netgroup map as a single combined
database (which, unfortunately, can be slow when the netgroup
database is large). This is what we have been doing up until now.
Head off a potential NULL pointer dereference in the old innetgr()
matching code.
Also fix the way the NIS netgroup map is incorporated into things:
adding the '+' is supposed to make it seem as though the netgroup
database is 'inserted' wherever the '+' is placed. We didn't quite
do it that way before.
(The NetBSD people apparently use a real, honest-to-gosh, netgroup.db
database that works just like the password database. This is
actually a neat idea since netgroups is the sort of thing that
can really benefit from having multi-key search capability,
particularly since reverse lookups require more than a trivial
amount of processing. Should we do something like this too?)
- netgroup.5: document all this stuff.
- rcmd.c: some sleuthing with some test programs linked with my own
version of innetgr() has revealed that SunOS always passes the NIS
domain name to innetgr() in the 'domain' argument. We might as well
do the same (if YP is defined).
- ether_addr.c: also fix the NIS interaction so that placing the
'+' token in the /etc/ethers file makes it seem like the NIS
ethers data is 'inserted' at that point. (Chances are nobody will
notice the effect of this change, which is just te way I like it. :)
the comment before checking for long lines, so there was a possibility
that the wrap-around might be used as an exploitable hostname.
Reviewed by:
Submitted by:
Obtained from:
Change strtok() to strsep(), cause memory corruption for all
programs which use strtok() too in the same time.
Fix potential NULL reference, depends of /etc/hosts.conf format
Fix the bug when service name fetched always from beginning of the line,
not from parsed token.
programs which use strtok() too in the same time.
Fix potential NULL reference, depends of /etc/hosts.conf format
Fix the bug when service name fetched always from beginning of the line,
not from parsed token.
that everyone else does: you can now use +host/-host, +user,-user and
+@netgroup/-@netgroup in /etc/hosts.equiv, /.rhosts, /etc/hosts.lpd and
~/.rhosts. Previously, __ivaliduser would only do host/user matches,
which was lame. This affects all the r-commands, lpd, and any other
program/service that uses ruserok().
An example of the usefullness of this feature would be a hosts.equiv
file that looks like this:
+@equiv-hosts
Since the netgroup database can now be accessed via NIS, this lets you
set up client machines once and then never have to worry about them
again: all hosts.equiv changes can now be done through NIS. Once I
finish with getpwent.c, we'll be able to do similar wacky things
with login authentication too. (Our password field substitution
will finally be on par with everyone else's, and I'll finally be
able to fully integrate my FreeBSD machine into my network without
having to worry about the grad students sneaking into it when I'm
not looking. :)
Danger Will Robinson! I tested this thing every which way I could, but
Murphy's Law applies! If anybody spots a potential security problem with
the way my matching algorithm works, tell me immediately! I don't want
crackers snickering and calling me names behind my back. :)
incredibly obnoxious, but also makes inverse mappings work when the local
resolver is in a cache-only configuration. (Maybe this is actually
a bug in BIND?)
While trying to figure out why rlogind wasn't working right for root,
I noticed that man wouldn't come back with a man page for iruserok, but
it would for ruserok. Checking the lib/net directory's Makefile.inc
file shows that the link to the rcmd man page just isn't getting
created.
>How-To-Repeat:
Do a 'man iruserok' and notihing will come back, where a 'man ruserok'
will.
Submitted by: Brian Moore <ziff@houdini.eecs.umich.edu>
Obtained from: NetBSD-bugs mailing list
getnet* configuration. (It's highly unlikely that you'd want to do
something different, and network lookups aren't common enough to justify
their own configuration file.)
>From: jtk@atria.com (John T. Kohl)
in rcmd:
It calls select() with a hardcoded "number of file descriptors" argument
of 32, rather than computing it based on the sockets about which it
cares.
- Now we work out the nfds arg, and do some error checking
Submitted by: Geoff.
1.1.5 support for YP, fixing a bug in 1.1.5 that prevented YP from ever
working reliably. (I'm amazed that there were no bug reports.)
IWBRNI someone could write a host.conf(5) manual page. Please look at
the code before doing so; this version is somewhat more flexible in the
format of its input.
