Apart from public and internal header files, there is a third type called
local header files, which are located next to source files in the source
directory. Currently, they have different suffixes like

  '*_lcl.h', '*_local.h', or '*_int.h'

This commit changes the different suffixes to '*_local.h' uniformly.
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9681)

Since return is inconsistent, I removed unnecessary parentheses and
unified them.
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4541)

unified them.
- return (0); -> return 0;
- return (1); -> return 1;
- return (-1); -> return -1;
Reviewed-by: NStephen Henson <steve@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4500)

Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4371)

This reverts commit a89c9a0d.
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4357)

Commit 3d8b2ec4 removed various unused functions. However now we need to
use one of them! This commit resurrects DSO_pathbyaddr(). We're not going to
resurrect the Windows version though because what we need to achieve can be
done a different way on Windows.
Reviewed-by: NTim Hudson <tjh@openssl.org>

The function strerror() is not thread safe. We should use strerror_r()
where possible, or strerror_s() on Windows.

RT#2267
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Removed the following:
    DSO_bind_var, DSO_bind_var, DSO_get_default_method,
    DSO_get_loaded_filename, DSO_get_loaded_filename, DSO_get_method,
    DSO_new_method, DSO_pathbyaddr, DSO_set_default_method, DSO_set_method,
    DSO_set_name_converter, DSO_set_name_converter
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Instead of have every DSO_METHOD_xxx in all platforms, ensure that only
one DSO_METHOD_openssl is available on all platforms.
Reviewed-by: NTim Hudson <tjh@openssl.org>

This was really easy.
Reviewed-by: NTim Hudson <tjh@openssl.org>

Then it can pass around the information where it belongs.  The
Makefile templates pick it up along with other target data, the
DSO module gets to pick up the information through
crypto/include/internal/dso_conf.h
Reviewed-by: NAndy Polyakov <appro@openssl.org>

Signed-off-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

Signed-off-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

This was done by the following
        find . -name '*.[ch]' | /tmp/pl
where /tmp/pl is the following three-line script:
        print unless $. == 1 && m@/\* .*\.[ch] \*/@;
        close ARGV if eof; # Close file to reset $.

And then some hand-editing of other files.
Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

Since we don't use the eay style any more, there's no point tryint to
tell emacs to use it.
Reviewed-by: NMatt Caswell <matt@openssl.org>

Continuing from previous commit ensure our style is consistent for malloc
return checks.
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

There are header files in crypto/ that are used by a number of crypto/
submodules.  Move those to crypto/include/internal and adapt the
affected source code and Makefiles.

The header files that got moved are:

crypto/cryptolib.h
crypto/md32_common.h
Reviewed-by: NRich Salz <rsalz@openssl.org>

Don't check for NULL before calling OPENSSL_free
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Mostly, but not completely, debugging print statements.
Some old logic kept for internal documentation reasons, perhaps.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NTim Hudson <tjh@openssl.org>

for further details.

by an address within it. Tested on Linux, Solaris, IRIX, Tru64, Darwin,
HP-UX, Win32, few BSD flavors...

(Didn't influence functionality, as on HP-UX 32bit the NULL pointer
is a 32bit 0-value and thus is identical to the required 0L.)

PR: 443

mechanism to the ENGINE framework.  This means there there are going
to be new functionality for the DSO part, and ultimately some way of
merging two file specifications together.

This commit places the merging code into the repository.  It's
currently not used anywhere, and hasn't been tested at all.  It may be
full of errors, including syntactical ones.  Those will be fixed as
promptly as possible.

system error in the error text.

or symbol name to the error stack in the event a load or bind operation
failed.

environment variable, SHLIB_PATH.  This change makes that possible.

extension .sl instead of .so.

translate library names by only adding ".so" to them without
prepending them with "lib".  Add the flag DSO_FLAG_NAME_TRANSLATION_EXT_ONLY
for that purpose.

appropriate filename translation on the host system. Apart from this point,
users should also note that there's a slight change in the API functions
too. The DSO now contains its own to-be-converted filename
("dso->filename"), and at the time the DSO loads the "dso->loaded_filename"
value is set to the translated form. As such, this also provides an impicit
way of determining if the DSO is currently loaded or not. Except, perhaps,
VMS .... :-)

The various DSO_METHODs have been updated for this mechanism except VMS
which is deliberately broken for now, Richard is going to look at how to
fit it in (the source comments in there explain "the issue").

Basically, the new callback scheme allows the filename conversion to
(a) be turned off altogether through the use of the
    DSO_FLAG_NO_NAME_TRANSLATION flag,
(b) be handled in the default way using the default DSO_METHOD's converter
(c) overriden per-DSO by setting the override callback
(d) a mix of (b) and (c) - eg. implement an override callback that;
    (i) checks if we're win32 "if(strstr(dso->meth->name, "win32"))..."
        and if so, convert "blah" into "blah32.dll" (the default is
	otherwise to make it "blah.dll").
    (ii) default to the normal behaviour - eg. we're not on win32, so
         finish with (return dso->meth->dso_name_converter(dso,NULL)).
(e) be retried a number of times by writing a new DSO_METHOD where the
    "dso_load()" handler will call the converter repeatedly. Then the
    custom converter could use state information in the DSO to suggest
    different conversions or paths each time it is invoked.

These are now processed inside DSO_ctrl() itself.

"symbols" including functions (of all prototypes( and variables. Whilst
casting any function type to another violates ANSI C (I believe), it is
a necessary evil in shared-library APIs. However, it is quite
conceivable that functions in general and data symbols could very well
be represented differently to each other on some systems, as Bodo said;

> Since the function/object distinction is a lot more likely to be
> important on real-life platforms supporting DSO *and* it can be quite
> easily done *and* it will silence compilers that don't like
> assignments from void pointers to function pointer variables, why
> not do it?

I agree. So this change splits the "dso_bind" handler in DSO_METHOD
into "dso_bind_var" and "dso_bind_func". Similarly the exported
function DSO_bind() has been split in two. I've also put together
changes for the various DSO_METHOD implementations, but so far only
DSO_dlfcn() has been tested. BTW: The prototype for dso_bind had been
a bit strange so I've taken the opportunity to change its shape (in
both variations).

Also, the README has been updated - particularly with a note about
using customised native name-translation for shared libraries (and that
you can't do it yet).

if a DSO_load(NULL,...) operation fails, it will have to call DSO_free() on
the DSO structure it created and that will filter through to this "unload"
call.

If the stack size is "< 1", then the library never actually loaded. To keep
things clean higher up, I'll treat this as a vacuous case without an error.
It makes the error stack easier to follow real world cases, and the error
this ignores was only useful for catching bugs in internal code, not
mismatched calls from applications (which should be handled in the generic
DSO layer).