source: trunk/third/bonobo-activation/bonobo-activation/bonobo-activation-base-service.c @ 18563

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- */
/*
 *  bonobo-activation: A library for accessing bonobo-activation-server.
 *
 *  Copyright (C) 1999, 2000 Red Hat, Inc.
 *  Copyright (C) 2000, 2001 Eazel, Inc.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *  Author: Elliot Lee <sopwith@redhat.com>
 *
 */

/* This is part of the per-app CORBA bootstrapping - we use this to get 
   hold of a running metaserver and such */


#include <bonobo-activation/bonobo-activation-i18n.h>
#include <bonobo-activation/bonobo-activation-init.h>
#include <bonobo-activation/bonobo-activation-base-service.h>
#include <bonobo-activation/bonobo-activation-private.h>
#include <bonobo-activation/Bonobo_ActivationContext.h>
#include <bonobo-activation/bonobo-activation-client.h>

#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif
#include <string.h>
#include <limits.h>
#include <errno.h>
#include <unistd.h>
#include <time.h>
#include <stdio.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <fcntl.h>

/* If you have a strange unix, you get odd hard coded limits */
#ifndef PATH_MAX
#  define PATH_MAX 1024
#endif

static GSList *registries = NULL;

typedef struct {
        int priority;
        const BonoboActivationBaseServiceRegistry *registry;
        gpointer user_data;
} RegistryInfo;

typedef struct {
        int priority;
        BonoboActivationBaseServiceActivator activator;
} ActivatorInfo;

static gint
ri_compare (gconstpointer a, gconstpointer b)
{
        RegistryInfo *ra = (RegistryInfo *) a;
        RegistryInfo *rb = (RegistryInfo *) b;

        return (rb->priority - ra->priority);
}

void
bonobo_activation_base_service_registry_add
                      (const BonoboActivationBaseServiceRegistry *registry,
                       int                                        priority,
                       gpointer                                   user_data)
{
        RegistryInfo *new_ri;

        g_return_if_fail (registry);

        new_ri = g_new (RegistryInfo, 1);
        new_ri->priority = priority;
        new_ri->registry = registry;
        new_ri->user_data = user_data;

        registries = g_slist_insert_sorted (registries, new_ri, ri_compare);
}

CORBA_Object
bonobo_activation_base_service_check (const BonoboActivationBaseService *base_service,
                                      CORBA_Environment                 *ev)
{
        GSList *link;
        CORBA_Object retval = CORBA_OBJECT_NIL;
        int dist = INT_MAX;
        char *ior = NULL;

        for (link = registries; link; link = link->next) {
                RegistryInfo *ri;
                char *new_ior;
                int new_dist = dist;

                ri = link->data;

                if (!ri->registry->check)
                        continue;

                new_ior = ri->registry->check (ri->registry, base_service, 
                                             &new_dist, ri->user_data);
                if (new_ior && (new_dist < dist)) {
                        g_free (ior);
                        ior = new_ior;
                } else if (new_ior) {
                        g_free (new_ior);
                }
        }

        if (ior) {
                retval = CORBA_ORB_string_to_object (bonobo_activation_orb_get (), ior, ev);
                if (ev->_major != CORBA_NO_EXCEPTION)
                        retval = CORBA_OBJECT_NIL;

                g_free (ior);
        }

        return retval;
}

/*dumb marshalling hack */
static void
bonobo_activation_registration_iterate (const BonoboActivationBaseService *base_service,
                          CORBA_Object obj, CORBA_Environment *ev,
                          gulong offset, int nargs)
{
        GSList *link;
        char *ior = NULL;

        if (nargs == 4)
                ior = CORBA_ORB_object_to_string (bonobo_activation_orb_get (), obj, ev);

        for (link = registries; link; link = link->next) {
                RegistryInfo *ri;
                void (*func_ptr) ();

                ri = link->data;

                func_ptr = *(gpointer *) ((guchar *) ri->registry + offset);

                if (!func_ptr)
                        continue;

                switch (nargs) {
                case 4:
                        func_ptr (ri->registry, ior, base_service, ri->user_data);
                        break;
                case 2:
                        func_ptr (ri->registry, ri->user_data);
                        break;
                }
        }

        if (nargs == 4)
                CORBA_free (ior);
}

static int lock_count = 0;

static void
bonobo_activation_registries_lock (CORBA_Environment *ev)
{
        if (lock_count == 0)
                bonobo_activation_registration_iterate (NULL, CORBA_OBJECT_NIL, ev,
                                          G_STRUCT_OFFSET
                                          (BonoboActivationBaseServiceRegistry, lock), 2);
        lock_count++;
}

static void
bonobo_activation_registries_unlock (CORBA_Environment *ev)
{
        lock_count--;
        if (lock_count == 0)
                bonobo_activation_registration_iterate (NULL, CORBA_OBJECT_NIL, ev,
                                          G_STRUCT_OFFSET
                                          (BonoboActivationBaseServiceRegistry, unlock),
                                          2);
}

void
bonobo_activation_base_service_unset (const BonoboActivationBaseService *base_service,
                        CORBA_Object obj, CORBA_Environment *ev)
{
        bonobo_activation_registries_lock (ev);
        bonobo_activation_registration_iterate (base_service, obj, ev,
                                  G_STRUCT_OFFSET (BonoboActivationBaseServiceRegistry,
                                                   unregister), 4);
        bonobo_activation_registries_unlock (ev);
}

void
bonobo_activation_base_service_set (const BonoboActivationBaseService *base_service,
                      CORBA_Object obj, CORBA_Environment *ev)
{
        bonobo_activation_registries_lock (ev);
        bonobo_activation_registration_iterate (base_service, obj, ev,
                                  G_STRUCT_OFFSET (BonoboActivationBaseServiceRegistry,
                                                   register_new), 4);
        bonobo_activation_registries_unlock (ev);
}


const char *bonobo_activation_ac_cmd[] =
        { SERVER_LIBEXECDIR "/bonobo-activation-server", "--ac-activate", "--ior-output-fd=%d", NULL };
const char *bonobo_activation_od_cmd[] = 
        { SERVER_LIBEXECDIR "/bonobo-activation-server", "--ior-output-fd=%d", NULL };

struct SysServerInstance
{
        CORBA_Object already_running;
        char *username, *hostname;
};

struct SysServer
{
        const char *name;
        const char **cmd;
        int fd_arg;
        GSList *instances;
}
activatable_servers[] =
{
        {"IDL:Bonobo/ActivationContext:1.0", (const char **) bonobo_activation_ac_cmd,
         2, CORBA_OBJECT_NIL}, 
        { NULL}
};

#define STRMATCH(x, y) ((!x && !y) || (x && y && !strcmp(x, y)))
static CORBA_Object
existing_check (const BonoboActivationBaseService *base_service, struct SysServer *ss)
{
        GSList *link;

        for (link = ss->instances; link; link = link->next) {
                struct SysServerInstance *ssi;

                ssi = link->data;
                if (
                    (!ssi->username
                     || STRMATCH (ssi->username, base_service->username))
                    && (!ssi->hostname
                        || STRMATCH (ssi->hostname, base_service->hostname)))
                        return ssi->already_running;
        }

        return CORBA_OBJECT_NIL;
}

void
bonobo_activation_base_service_debug_shutdown (CORBA_Environment *ev)
{
        int     i;
        GSList *l, *instances;
        struct SysServerInstance *ssi;

        for (i = 0; activatable_servers[i].name; i++) {

                instances = activatable_servers[i].instances;
                activatable_servers[i].instances = NULL;

                for (l = instances; l; l = l->next) {
                        ssi = l->data;

                        CORBA_Object_release (ssi->already_running, ev);
                        g_free (ssi->username);
                        g_free (ssi->hostname);
                        g_free (ssi);
                }
                g_slist_free (instances);
        }
}

static void
bonobo_activation_existing_set (const BonoboActivationBaseService *base_service, struct SysServer *ss,
                                CORBA_Object obj, CORBA_Environment *ev)
{
        GSList *link;
        struct SysServerInstance *ssi;

        ssi = NULL;

        for (link = ss->instances; link; link = link->next) {
                ssi = link->data;
                if (
                    (!ssi->username
                     || STRMATCH (ssi->username, base_service->username))
                    && (!ssi->hostname
                        || STRMATCH (ssi->hostname, base_service->hostname))) break;
        }

        if (link == NULL) {
                ssi = g_new0 (struct SysServerInstance, 1);
                ssi->already_running = obj;
                ssi->username =
                        base_service->username ? g_strdup (base_service->username) : NULL;
                ssi->hostname =
                        base_service->hostname ? g_strdup (base_service->hostname) : NULL;
                ss->instances = g_slist_prepend (ss->instances, ssi);
        } else {
                CORBA_Object_release (ssi->already_running, ev);
                ssi->already_running = obj;
        }

        /* FIXME: all this code is unneccesarily abstract & buggy with it */
        if (!strcmp (base_service->name, "IDL:Bonobo/ActivationContext:1.0")) {
                bonobo_activation_register_client (obj, ev);
        }
}

static GSList *activator_list = NULL;

static gint
ai_compare (gconstpointer a, gconstpointer b)
{
        const ActivatorInfo *ra, *rb;

        ra = a;
        rb = b;

        return (rb->priority - ra->priority);
}

void
bonobo_activation_base_service_activator_add (BonoboActivationBaseServiceActivator activator, 
                                int priority)
{
        ActivatorInfo *new_act;

        new_act = g_new (ActivatorInfo, 1);
        new_act->priority = priority;
        new_act->activator = activator;
        activator_list =
                g_slist_insert_sorted (activator_list, new_act, ai_compare);
}

static CORBA_Object
bonobo_activation_activators_use (const BonoboActivationBaseService *base_service, const char **cmd,
                                  int fd_arg, CORBA_Environment *ev)
{
        CORBA_Object retval = CORBA_OBJECT_NIL;
        GSList *link;

        for (link = activator_list; CORBA_Object_is_nil (retval, ev) && link;
             link = link->next) {
                ActivatorInfo *actinfo;
                actinfo = link->data;

                retval = actinfo->activator (base_service, cmd, fd_arg, ev);
        }

        return retval;
}

CORBA_Object
bonobo_activation_internal_service_get_extended (
        const BonoboActivationBaseService *base_service,
        gboolean              existing_only,
        CORBA_Environment    *ev)
{
        CORBA_Object retval = CORBA_OBJECT_NIL;
        int i;
        CORBA_Environment myev, important_error_ev;
        gboolean ne;

        g_return_val_if_fail (base_service, CORBA_OBJECT_NIL);

        for (i = 0; activatable_servers[i].name; i++) {
                if (!strcmp (base_service->name, activatable_servers[i].name))
                        break;
        }

        if (!activatable_servers[i].name)
                return retval;

        CORBA_exception_init (&myev);
        CORBA_exception_init (&important_error_ev);
        
        retval = existing_check (base_service, &activatable_servers[i]);
        if (!CORBA_Object_non_existent (retval, ev))
                goto out;

        bonobo_activation_registries_lock (ev);

        retval = bonobo_activation_base_service_check (base_service, &myev);
        ne = CORBA_Object_non_existent (retval, &myev);
        if (ne && !existing_only) {
                CORBA_Object race_condition;

                CORBA_Object_release (retval, &myev);
                
                retval =
                        bonobo_activation_activators_use (base_service,
                                            activatable_servers[i].cmd,
                                            activatable_servers[i].fd_arg,
                                            &important_error_ev);

                race_condition = bonobo_activation_base_service_check (base_service, &myev);

                if (!CORBA_Object_non_existent (race_condition, &myev)) {
                        CORBA_Object_release (retval, &myev);
                        retval = race_condition;
                } else if (!CORBA_Object_is_nil (retval, &myev)) {
                        bonobo_activation_base_service_set (base_service, retval, &myev);
                        CORBA_Object_release (race_condition, &myev);
                }
        }

        bonobo_activation_registries_unlock (ev);

        if (!CORBA_Object_non_existent (retval, ev))
                bonobo_activation_existing_set (base_service, &activatable_servers[i], retval, ev);

      out:
        /* If we overwrote ev with some stupid junk, replace
         * it with the real error
         */
        if (important_error_ev._major != CORBA_NO_EXCEPTION) {
                CORBA_exception_free (ev);
                /* This transfers memory ownership */
                *ev = important_error_ev;
        }
        
        CORBA_exception_free (&myev);

        return retval;
}

CORBA_Object
bonobo_activation_service_get (const BonoboActivationBaseService *base_service)
{
        CORBA_Environment ev;
        CORBA_Object obj;
        
        CORBA_exception_init (&ev);
        
        obj = bonobo_activation_internal_service_get_extended (
                base_service, FALSE, &ev);

        CORBA_exception_free (&ev);

        return obj;
}

/*****Implementation of the IOR registration system via plain files ******/
static int lock_fd = -1;

/*
 * The linc-tmpdir might not be what we expect,
 * requires linc >= 0.5.1
 */
static const char *
get_tmpdir (void)
{
        static char *tmpdir = NULL;

        if (!tmpdir)
                tmpdir = linc_get_tmpdir ();

        if (!tmpdir) {
                g_warning ("very odd tmpdir problem");
                tmpdir = g_strdup_printf ("/tmp/orbit-%s", g_get_user_name ());
        }

        return tmpdir;
}

static char *
get_lock_fname (void)
{
        return g_strconcat (get_tmpdir (), "/bonobo-activation-register.lock", NULL);
}

static char *
get_ior_fname (void)
{
        return g_strconcat (get_tmpdir (), "/bonobo-activation-server-ior", NULL);
}

static void
wait_for_lock (void)
{
#ifdef HAVE_USLEEP
        usleep (10000);

#elif defined(HAVE_NANOSLEEP)
        struct timespec timewait;
        timewait.tv_sec = 0;
        timewait.tv_nsec = 1000000;
        nanosleep (&timewait, NULL);

#else
#warning You will have bad performance without usleep
        sleep (1);
#endif
        access ("bonobo-activation lock wait", 0);
}

static void
rloc_file_lock (const BonoboActivationBaseServiceRegistry *registry, 
                gpointer                                   user_data)
{
        char *fn;
        struct flock lock;
        int retval;
        char *err;

        fn = get_lock_fname ();

        while ((lock_fd = open (fn, O_CREAT | O_RDWR, 0700)) < 0) {

                if (errno == EEXIST)
                        wait_for_lock ();

                else {
                        g_warning ("%s locking '%s'", g_strerror (errno), fn);
                        break;
                }
        }

        fcntl (lock_fd, F_SETFD, FD_CLOEXEC);

        if (lock_fd >= 0) {
                lock.l_type = F_WRLCK;
                lock.l_whence = SEEK_SET;
                lock.l_start = 0;
                lock.l_len = 1;
                lock.l_pid = getpid ();

                while ((retval = fcntl (lock_fd, F_SETLKW, &lock)) < 0
                       && errno == EINTR) /**/;

                if (retval < 0) {
                        /* FIXME: need to report this error in a better way. */
                        err = strerror (errno);
                        g_warning ("Failed to acquire lock: %s\n.", err);
                }
        }

        g_free (fn);
}

static void
rloc_file_unlock (const BonoboActivationBaseServiceRegistry *registry, 
                  gpointer                                   user_data)
{
        struct flock lock;

        if (lock_fd >= 0) {

                lock.l_type = F_UNLCK;
                lock.l_whence = SEEK_SET;
                lock.l_start = 0;
                lock.l_len = 1;
                lock.l_pid = getpid ();

                fcntl (lock_fd, F_SETLKW, &lock);
                close (lock_fd);
                lock_fd = -1;
        }
}

static char *
rloc_file_check (const BonoboActivationBaseServiceRegistry *registry,
                 const BonoboActivationBaseService *base_service, int *ret_distance,
                 gpointer user_data)
{
        FILE *fh;
        char *fn;

        fn = get_ior_fname ();
        fh = fopen (fn, "r");
        g_free (fn);

        if (fh != NULL) {
                char iorbuf[8192];

                iorbuf[0] = '\0';
                while (fgets (iorbuf, sizeof (iorbuf), fh)
                       && strncmp (iorbuf, "IOR:", 4))
                        /**/;
                g_strstrip (iorbuf);

                fclose (fh);

                if (!strncmp (iorbuf, "IOR:", 4)) {
                        *ret_distance = 0;
                        return g_strdup (iorbuf);
                }
        }

        return NULL;
}

static void
rloc_file_register (const BonoboActivationBaseServiceRegistry *registry, const char *ior,
                    const BonoboActivationBaseService *base_service,
                    gpointer user_data)
{
        char *fn;
        FILE *fh;

        fn = get_ior_fname ();
        fh = fopen (fn, "w");

        if (fh != NULL) {
                fprintf (fh, "%s\n", ior);
                fclose (fh);
        }       

        g_free (fn);
}

static void
rloc_file_unregister (const BonoboActivationBaseServiceRegistry *registry, 
                      const char                                *ior,
                      const BonoboActivationBaseService         *base_service,
                      gpointer                                   user_data)
{
        char *fn;

        unlink ((fn = get_ior_fname ()));
        g_free (fn);
}

static const BonoboActivationBaseServiceRegistry rloc_file = {
        rloc_file_lock,
        rloc_file_unlock,
        rloc_file_check,
        rloc_file_register,
        rloc_file_unregister
};

#define STRMATCH(x, y) ((!x && !y) || (x && y && !strcmp(x, y)))

static CORBA_Object
local_re_check_fn (const Bonobo_ActivationEnvironment *environment,
                   const char                         *act_iid,
                   gpointer                            user_data,
                   CORBA_Environment                  *ev)
{
        return bonobo_activation_internal_service_get_extended (
                user_data, TRUE, ev);
}

static CORBA_Object
local_activator (const BonoboActivationBaseService *base_service,
                 const char **cmd,
                 int fd_arg, 
                 CORBA_Environment *ev)
{
        if (
            (!base_service->username
             || STRMATCH (base_service->username, g_get_user_name ()))
            && (!base_service->hostname
                || STRMATCH (base_service->hostname, bonobo_activation_hostname_get ()))) {
                return bonobo_activation_server_by_forking (
                        cmd, FALSE, fd_arg, NULL, NULL, base_service->name,
                        local_re_check_fn, (gpointer)base_service, ev);
        }

        return CORBA_OBJECT_NIL;
}

void
bonobo_activation_base_service_init (void)
{
        bonobo_activation_base_service_activator_add (local_activator, 0);

        bonobo_activation_base_service_registry_add (&rloc_file, 0, NULL);
}