/* $NetBSD: plugin.c,v 1.2 2017/01/28 21:31:49 christos Exp $ */
/*
* Copyright (c) 2006 - 2007 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* 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. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 THE INSTITUTE 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.
*/
#include "krb5_locl.h"
#ifdef HAVE_DLFCN_H
#include <dlfcn.h>
#endif
#include <dirent.h>
struct krb5_plugin {
void *symbol;
struct krb5_plugin *next;
};
struct plugin {
enum { DSO, SYMBOL } type;
union {
struct {
char *path;
void *dsohandle;
} dso;
struct {
enum krb5_plugin_type type;
char *name;
char *symbol;
} symbol;
} u;
struct plugin *next;
};
static HEIMDAL_MUTEX plugin_mutex = HEIMDAL_MUTEX_INITIALIZER;
static struct plugin *registered = NULL;
/**
* Register a plugin symbol name of specific type.
* @param context a Keberos context
* @param type type of plugin symbol
* @param name name of plugin symbol
* @param symbol a pointer to the named symbol
* @return In case of error a non zero error com_err error is returned
* and the Kerberos error string is set.
*
* @ingroup krb5_support
*/
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_plugin_register(krb5_context context,
enum krb5_plugin_type type,
const char *name,
void *symbol)
{
struct plugin *e;
HEIMDAL_MUTEX_lock(&plugin_mutex);
/* check for duplicates */
for (e = registered; e != NULL; e = e->next) {
if (e->type == SYMBOL &&
strcmp(e->u.symbol.name, name) == 0 &&
e->u.symbol.type == type && e->u.symbol.symbol == symbol) {
HEIMDAL_MUTEX_unlock(&plugin_mutex);
return 0;
}
}
e = calloc(1, sizeof(*e));
if (e == NULL) {
HEIMDAL_MUTEX_unlock(&plugin_mutex);
krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
return ENOMEM;
}
e->type = SYMBOL;
e->u.symbol.type = type;
e->u.symbol.name = strdup(name);
if (e->u.symbol.name == NULL) {
HEIMDAL_MUTEX_unlock(&plugin_mutex);
free(e);
krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
return ENOMEM;
}
e->u.symbol.symbol = symbol;
e->next = registered;
registered = e;
HEIMDAL_MUTEX_unlock(&plugin_mutex);
return 0;
}
static krb5_error_code
add_symbol(krb5_context context, struct krb5_plugin **list, void *symbol)
{
struct krb5_plugin *e;
e = calloc(1, sizeof(*e));
if (e == NULL) {
krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
return ENOMEM;
}
e->symbol = symbol;
e->next = *list;
*list = e;
return 0;
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_plugin_find(krb5_context context,
enum krb5_plugin_type type,
const char *name,
struct krb5_plugin **list)
{
struct plugin *e;
krb5_error_code ret;
*list = NULL;
HEIMDAL_MUTEX_lock(&plugin_mutex);
for (ret = 0, e = registered; e != NULL; e = e->next) {
switch(e->type) {
case DSO: {
void *sym;
if (e->u.dso.dsohandle == NULL)
continue;
sym = dlsym(e->u.dso.dsohandle, name);
if (sym)
ret = add_symbol(context, list, sym);
break;
}
case SYMBOL:
if (strcmp(e->u.symbol.name, name) == 0 && e->u.symbol.type == type)
ret = add_symbol(context, list, e->u.symbol.symbol);
break;
}
if (ret) {
_krb5_plugin_free(*list);
*list = NULL;
}
}
HEIMDAL_MUTEX_unlock(&plugin_mutex);
if (ret)
return ret;
if (*list == NULL) {
krb5_set_error_message(context, ENOENT, "Did not find a plugin for %s", name);
return ENOENT;
}
return 0;
}
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
_krb5_plugin_free(struct krb5_plugin *list)
{
struct krb5_plugin *next;
while (list) {
next = list->next;
free(list);
list = next;
}
}
/*
* module - dict of {
* ModuleName = [
* plugin = object{
* array = { ptr, ctx }
* }
* ]
* }
*/
static heim_dict_t modules;
struct plugin2 {
heim_string_t path;
void *dsohandle;
heim_dict_t names;
};
static void
plug_dealloc(void *ptr)
{
struct plugin2 *p = ptr;
heim_release(p->path);
heim_release(p->names);
if (p->dsohandle)
dlclose(p->dsohandle);
}
static char *
resolve_origin(const char *di)
{
#ifdef HAVE_DLADDR
Dl_info dl_info;
const char *dname;
char *path, *p;
#endif
if (strncmp(di, "$ORIGIN/", sizeof("$ORIGIN/") - 1) &&
strcmp(di, "$ORIGIN"))
return strdup(di);
#ifndef HAVE_DLADDR
return strdup(LIBDIR "/plugin/krb5");
#else /* !HAVE_DLADDR */
di += sizeof("$ORIGIN") - 1;
if (dladdr(_krb5_load_plugins, &dl_info) == 0)
return strdup(LIBDIR "/plugin/krb5");
dname = dl_info.dli_fname;
#ifdef _WIN32
p = strrchr(dname, '\\');
if (p == NULL)
#endif
p = strrchr(dname, '/');
if (p) {
if (asprintf(&path, "%.*s%s", (int) (p - dname), dname, di) == -1)
return NULL;
} else {
if (asprintf(&path, "%s%s", dname, di) == -1)
return NULL;
}
return path;
#endif /* !HAVE_DLADDR */
}
/**
* Load plugins (new system) for the given module @name (typically
* "krb5") from the given directory @paths.
*
* Inputs:
*
* @context A krb5_context
* @name Name of plugin module (typically "krb5")
* @paths Array of directory paths where to look
*/
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
_krb5_load_plugins(krb5_context context, const char *name, const char **paths)
{
#ifdef HAVE_DLOPEN
heim_string_t s = heim_string_create(name);
heim_dict_t module;
struct dirent *entry;
krb5_error_code ret;
const char **di;
char *dirname = NULL;
DIR *d;
#ifdef _WIN32
const char * plugin_prefix;
size_t plugin_prefix_len;
if (asprintf(&plugin_prefix, "plugin_%s_", name) == -1)
return;
plugin_prefix_len = (plugin_prefix ? strlen(plugin_prefix) : 0);
#endif
HEIMDAL_MUTEX_lock(&plugin_mutex);
if (modules == NULL) {
modules = heim_dict_create(11);
if (modules == NULL) {
HEIMDAL_MUTEX_unlock(&plugin_mutex);
return;
}
}
module = heim_dict_copy_value(modules, s);
if (module == NULL) {
module = heim_dict_create(11);
if (module == NULL) {
HEIMDAL_MUTEX_unlock(&plugin_mutex);
heim_release(s);
return;
}
heim_dict_set_value(modules, s, module);
}
heim_release(s);
for (di = paths; *di != NULL; di++) {
free(dirname);
dirname = resolve_origin(*di);
if (dirname == NULL)
continue;
d = opendir(dirname);
if (d == NULL)
continue;
rk_cloexec_dir(d);
while ((entry = readdir(d)) != NULL) {
char *n = entry->d_name;
char *path = NULL;
heim_string_t spath;
struct plugin2 *p;
/* skip . and .. */
if (n[0] == '.' && (n[1] == '\0' || (n[1] == '.' && n[2] == '\0')))
continue;
ret = 0;
#ifdef _WIN32
/*
* On Windows, plugins must be loaded from the same directory as
* heimdal.dll (typically the assembly directory) and must have
* the name form "plugin_<module>_<name>.dll".
*/
{
char *ext;
if (strnicmp(n, plugin_prefix, plugin_prefix_len))
continue;
ext = strrchr(n, '.');
if (ext == NULL || stricmp(ext, ".dll"))
continue;
ret = asprintf(&path, "%s\\%s", dirname, n);
if (ret < 0 || path == NULL)
continue;
}
#endif
#ifdef __APPLE__
{ /* support loading bundles on MacOS */
size_t len = strlen(n);
if (len > 7 && strcmp(&n[len - 7], ".bundle") == 0)
ret = asprintf(&path, "%s/%s/Contents/MacOS/%.*s", dirname, n, (int)(len - 7), n);
}
#endif
if (ret < 0 || path == NULL)
ret = asprintf(&path, "%s/%s", dirname, n);
if (ret < 0 || path == NULL)
continue;
spath = heim_string_create(n);
if (spath == NULL) {
free(path);
continue;
}
/* check if already cached */
p = heim_dict_copy_value(module, spath);
if (p == NULL) {
p = heim_alloc(sizeof(*p), "krb5-plugin", plug_dealloc);
if (p)
p->dsohandle = dlopen(path, RTLD_LOCAL|RTLD_LAZY);
if (p && p->dsohandle) {
p->path = heim_retain(spath);
p->names = heim_dict_create(11);
heim_dict_set_value(module, spath, p);
}
}
heim_release(p);
heim_release(spath);
free(path);
}
closedir(d);
}
free(dirname);
HEIMDAL_MUTEX_unlock(&plugin_mutex);
heim_release(module);
#ifdef _WIN32
if (plugin_prefix)
free(plugin_prefix);
#endif
#endif /* HAVE_DLOPEN */
}
/**
* Unload plugins (new system)
*/
KRB5_LIB_FUNCTION void KRB5_LIB_CALL
_krb5_unload_plugins(krb5_context context, const char *name)
{
HEIMDAL_MUTEX_lock(&plugin_mutex);
heim_release(modules);
modules = NULL;
HEIMDAL_MUTEX_unlock(&plugin_mutex);
}
/*
*
*/
struct common_plugin_method {
int version;
krb5_error_code (*init)(krb5_context, void **);
void (*fini)(void *);
};
struct plug {
void *dataptr;
void *ctx;
};
static void
plug_free(void *ptr)
{
struct plug *pl = ptr;
if (pl->dataptr) {
struct common_plugin_method *cpm = pl->dataptr;
cpm->fini(pl->ctx);
}
}
struct iter_ctx {
krb5_context context;
heim_string_t n;
const char *name;
int min_version;
int flags;
heim_array_t result;
krb5_error_code (KRB5_LIB_CALL *func)(krb5_context, const void *, void *, void *);
void *userctx;
krb5_error_code ret;
};
static void
search_modules(heim_object_t key, heim_object_t value, void *ctx)
{
struct iter_ctx *s = ctx;
struct plugin2 *p = value;
struct plug *pl = heim_dict_copy_value(p->names, s->n);
struct common_plugin_method *cpm;
if (pl == NULL) {
if (p->dsohandle == NULL)
return;
pl = heim_alloc(sizeof(*pl), "struct-plug", plug_free);
cpm = pl->dataptr = dlsym(p->dsohandle, s->name);
if (cpm) {
int ret;
ret = cpm->init(s->context, &pl->ctx);
if (ret)
cpm = pl->dataptr = NULL;
}
heim_dict_set_value(p->names, s->n, pl);
} else {
cpm = pl->dataptr;
}
if (cpm && cpm->version >= s->min_version)
heim_array_append_value(s->result, pl);
heim_release(pl);
}
static void
eval_results(heim_object_t value, void *ctx, int *stop)
{
struct plug *pl = value;
struct iter_ctx *s = ctx;
if (s->ret != KRB5_PLUGIN_NO_HANDLE)
return;
s->ret = s->func(s->context, pl->dataptr, pl->ctx, s->userctx);
if (s->ret != KRB5_PLUGIN_NO_HANDLE
&& !(s->flags & KRB5_PLUGIN_INVOKE_ALL))
*stop = 1;
}
/**
* Run plugins for the given @module (e.g., "krb5") and @name (e.g.,
* "kuserok"). Specifically, the @func is invoked once per-plugin with
* four arguments: the @context, the plugin symbol value (a pointer to a
* struct whose first three fields are the same as struct common_plugin_method),
* a context value produced by the plugin's init method, and @userctx.
*
* @func should unpack arguments for a plugin function and invoke it
* with arguments taken from @userctx. @func should save plugin
* outputs, if any, in @userctx.
*
* All loaded and registered plugins are invoked via @func until @func
* returns something other than KRB5_PLUGIN_NO_HANDLE. Plugins that
* have nothing to do for the given arguments should return
* KRB5_PLUGIN_NO_HANDLE.
*
* Inputs:
*
* @context A krb5_context
* @module Name of module (typically "krb5")
* @name Name of pluggable interface (e.g., "kuserok")
* @min_version Lowest acceptable plugin minor version number
* @flags Flags (none defined at this time)
* @userctx Callback data for the callback function @func
* @func A callback function, invoked once per-plugin
*
* Outputs: None, other than the return value and such outputs as are
* gathered by @func.
*/
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_plugin_run_f(krb5_context context,
const char *module,
const char *name,
int min_version,
int flags,
void *userctx,
krb5_error_code (KRB5_LIB_CALL *func)(krb5_context, const void *, void *, void *))
{
heim_string_t m = heim_string_create(module);
heim_dict_t dict;
void *plug_ctx;
struct common_plugin_method *cpm;
struct iter_ctx s;
struct krb5_plugin *registered_plugins = NULL;
struct krb5_plugin *p;
/* Get registered plugins */
(void) _krb5_plugin_find(context, SYMBOL, name, ®istered_plugins);
HEIMDAL_MUTEX_lock(&plugin_mutex);
s.context = context;
s.name = name;
s.n = heim_string_create(name);
s.flags = flags;
s.min_version = min_version;
s.result = heim_array_create();
s.func = func;
s.userctx = userctx;
s.ret = KRB5_PLUGIN_NO_HANDLE;
/* Get loaded plugins */
dict = heim_dict_copy_value(modules, m);
heim_release(m);
/* Add loaded plugins to s.result array */
if (dict)
heim_dict_iterate_f(dict, &s, search_modules);
/* We don't need to hold plugin_mutex during plugin invocation */
HEIMDAL_MUTEX_unlock(&plugin_mutex);
/* Invoke registered plugins (old system) */
for (p = registered_plugins; p; p = p->next) {
/*
* XXX This is the wrong way to handle registered plugins, as we
* call init/fini on each invocation! We do this because we
* have nowhere in the struct plugin registered list to store
* the context allocated by the plugin's init function. (But at
* least we do call init/fini!)
*
* What we should do is adapt the old plugin system to the new
* one and change how we register plugins so that we use the new
* struct plug to keep track of their context structures, that
* way we can init once, invoke many times, then fini.
*/
cpm = (struct common_plugin_method *)p->symbol;
s.ret = cpm->init(context, &plug_ctx);
if (s.ret)
continue;
s.ret = s.func(s.context, p->symbol, plug_ctx, s.userctx);
cpm->fini(plug_ctx);
if (s.ret != KRB5_PLUGIN_NO_HANDLE &&
!(flags & KRB5_PLUGIN_INVOKE_ALL))
break;
}
_krb5_plugin_free(registered_plugins);
/* Invoke loaded plugins (new system) */
if (s.ret == KRB5_PLUGIN_NO_HANDLE)
heim_array_iterate_f(s.result, &s, eval_results);
heim_release(s.result);
heim_release(s.n);
heim_release(dict);
return s.ret;
}