[irc/rqf/shadowircd.git] / src / modules.c

/*
 *  ircd-ratbox: A slightly useful ircd.
 *  modules.c: A module loader.
 *
 *  Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
 *  Copyright (C) 1996-2002 Hybrid Development Team
 *  Copyright (C) 2002-2005 ircd-ratbox development team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 *  USA
 *
 *  $Id: modules.c 3161 2007-01-25 07:23:01Z nenolod $
 */

#include "stdinc.h"


#include "modules.h"
#include "logger.h"
#include "ircd.h"
#include "client.h"
#include "send.h"
#include "s_conf.h"
#include "s_newconf.h"
#include "numeric.h"
#include "parse.h"
#include "ircd_defs.h"
#include "match.h"
#include "s_serv.h"



/* -TimeMr14C:
 * I have moved the dl* function definitions and
 * the two functions (load_a_module / unload_a_module) to the
 * file dynlink.c 
 * And also made the necessary changes to those functions
 * to comply with shl_load and friends.
 * In this file, to keep consistency with the makefile, 
 * I added the ability to load *.sl files, too.
 * 27/02/2002
 */

#ifndef STATIC_MODULES

struct module **modlist = NULL;

static const char *core_module_table[] = {
        "m_ban",
        "m_die",
        "m_error",
        "m_join",
        "m_kick",
        "m_kill",
        "m_message",
        "m_metadata",
        "m_mode",
        "m_nick",
        "m_part",
        "m_quit",
        "m_server",
        "m_squit",
        NULL
};

#define MODS_INCREMENT 10
int num_mods = 0;
int max_mods = MODS_INCREMENT;

static rb_dlink_list mod_paths;

static int mo_modload(struct Client *, struct Client *, int, const char **);
static int mo_modlist(struct Client *, struct Client *, int, const char **);
static int mo_modreload(struct Client *, struct Client *, int, const char **);
static int mo_modunload(struct Client *, struct Client *, int, const char **);
static int mo_modrestart(struct Client *, struct Client *, int, const char **);

static int me_modload(struct Client *, struct Client *, int, const char **); 
static int me_modlist(struct Client *, struct Client *, int, const char **);
static int me_modreload(struct Client *, struct Client *, int, const char **);
static int me_modunload(struct Client *, struct Client *, int, const char **);
static int me_modrestart(struct Client *, struct Client *, int, const char **);

static int do_modload(struct Client *, const char *);
static int do_modunload(struct Client *, const char *);
static int do_modreload(struct Client *, const char *);
static int do_modlist(struct Client *, const char *);
static int do_modrestart(struct Client *); 

struct Message modload_msgtab = {
        "MODLOAD", 0, 0, 0, MFLG_SLOW,
        {mg_unreg, mg_not_oper, mg_ignore, mg_ignore, {me_modload, 2}, {mo_modload, 2}}
};

struct Message modunload_msgtab = {
        "MODUNLOAD", 0, 0, 0, MFLG_SLOW,
        {mg_unreg, mg_not_oper, mg_ignore, mg_ignore, {me_modunload, 2}, {mo_modunload, 2}}
};

struct Message modreload_msgtab = {
        "MODRELOAD", 0, 0, 0, MFLG_SLOW,
        {mg_unreg, mg_not_oper, mg_ignore, mg_ignore, {me_modreload, 2}, {mo_modreload, 2}}
};

struct Message modlist_msgtab = {
        "MODLIST", 0, 0, 0, MFLG_SLOW,
        {mg_unreg, mg_not_oper, mg_ignore, mg_ignore, {me_modlist, 0}, {mo_modlist, 0}}
};

struct Message modrestart_msgtab = {
        "MODRESTART", 0, 0, 0, MFLG_SLOW,
        {mg_unreg, mg_not_oper, mg_ignore, mg_ignore, {me_modrestart, 0}, {mo_modrestart, 0}}
};

void
modules_init(void)
{
        mod_add_cmd(&modload_msgtab);
        mod_add_cmd(&modunload_msgtab);
        mod_add_cmd(&modreload_msgtab);
        mod_add_cmd(&modlist_msgtab);
        mod_add_cmd(&modrestart_msgtab);

        /* Add the default paths we look in to the module system --nenolod */
        mod_add_path(MODPATH);
        mod_add_path(AUTOMODPATH);
}

/* mod_find_path()
 *
 * input        - path
 * output       - none
 * side effects - returns a module path from path
 */
static struct module_path *
mod_find_path(const char *path)
{
        rb_dlink_node *ptr;
        struct module_path *mpath;

        RB_DLINK_FOREACH(ptr, mod_paths.head)
        {
                mpath = ptr->data;

                if(!strcmp(path, mpath->path))
                        return mpath;
        }

        return NULL;
}

/* mod_add_path
 *
 * input        - path
 * ouput        - 
 * side effects - adds path to list
 */
void
mod_add_path(const char *path)
{
        struct module_path *pathst;

        if(mod_find_path(path))
                return;

        pathst = rb_malloc(sizeof(struct module_path));

        strcpy(pathst->path, path);
        rb_dlinkAddAlloc(pathst, &mod_paths);
}

/* mod_clear_paths()
 *
 * input        -
 * output       -
 * side effects - clear the lists of paths
 */
void
mod_clear_paths(void)
{
        rb_dlink_node *ptr, *next_ptr;

        RB_DLINK_FOREACH_SAFE(ptr, next_ptr, mod_paths.head)
        {
                rb_free(ptr->data);
                rb_free_rb_dlink_node(ptr);
        }

        mod_paths.head = mod_paths.tail = NULL;
        mod_paths.length = 0;
}

/* findmodule_byname
 *
 * input        -
 * output       -
 * side effects -
 */

int
findmodule_byname(const char *name)
{
        int i;

        for (i = 0; i < num_mods; i++)
        {
                if(!irccmp(modlist[i]->name, name))
                        return i;
        }
        return -1;
}

/* load_all_modules()
 *
 * input        -
 * output       -
 * side effects -
 */
void
load_all_modules(int warn)
{
        DIR *system_module_dir = NULL;
        struct dirent *ldirent = NULL;
        char module_fq_name[PATH_MAX + 1];
        int len;

        modules_init();

        modlist = (struct module **) rb_malloc(sizeof(struct module) * (MODS_INCREMENT));

        max_mods = MODS_INCREMENT;

        system_module_dir = opendir(AUTOMODPATH);

        if(system_module_dir == NULL)
        {
                ilog(L_MAIN, "Could not load modules from %s: %s", AUTOMODPATH, strerror(errno));
                return;
        }

        while ((ldirent = readdir(system_module_dir)) != NULL)
        {
                len = strlen(ldirent->d_name);
                if((len > 3) && !strcmp(ldirent->d_name+len-3, SHARED_SUFFIX))
                {
                        (void) rb_snprintf(module_fq_name, sizeof(module_fq_name), "%s/%s", AUTOMODPATH, ldirent->d_name);
                        (void) load_a_module(module_fq_name, warn, 0);
                }

        }
        (void) closedir(system_module_dir);
}

/* load_core_modules()
 *
 * input        -
 * output       -
 * side effects - core modules are loaded, if any fail, kill ircd
 */
void
load_core_modules(int warn)
{
        char module_name[MAXPATHLEN];
        int i;


        for (i = 0; core_module_table[i]; i++)
        {
                rb_snprintf(module_name, sizeof(module_name), "%s/%s%s", MODPATH,
                            core_module_table[i], SHARED_SUFFIX);

                if(load_a_module(module_name, warn, 1) == -1)
                {
                        ilog(L_MAIN,
                             "Error loading core module %s%s: terminating ircd",
                             core_module_table[i], SHARED_SUFFIX);
                        exit(0);
                }
        }
}

/* load_one_module()
 *
 * input        -
 * output       -
 * side effects -
 */
int
load_one_module(const char *path, int coremodule)
{
        char modpath[MAXPATHLEN];
        rb_dlink_node *pathst;
        struct module_path *mpath;

        struct stat statbuf;

        if (server_state_foreground == 1)
                inotice("loading module %s ...", path); 

        RB_DLINK_FOREACH(pathst, mod_paths.head)
        {
                mpath = pathst->data;

                rb_snprintf(modpath, sizeof(modpath), "%s/%s", mpath->path, path);
                if((strstr(modpath, "../") == NULL) && (strstr(modpath, "/..") == NULL))
                {
                        if(stat(modpath, &statbuf) == 0)
                        {
                                if(S_ISREG(statbuf.st_mode))
                                {
                                        /* Regular files only please */
                                        if(coremodule)
                                                return load_a_module(modpath, 1, 1);
                                        else
                                                return load_a_module(modpath, 1, 0);
                                }
                        }

                }
        }

        sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, "Cannot locate module %s", path);
        return -1;
}


/* load a module .. */
static int
mo_modload(struct Client *client_p, struct Client *source_p, int parc, const char **parv)
{
        if(!IsOperAdmin(source_p))
        {
                sendto_one(source_p, form_str(ERR_NOPRIVS),
                           me.name, source_p->name, "admin");
                return 0;
        }

        if(parc > 2)
        {
                sendto_match_servs(source_p, parv[2], CAP_ENCAP, NOCAPS,
                                "ENCAP %s MODLOAD %s", parv[2], parv[1]);
                if (match(parv[2], me.name) == 0)
                        return 0;
        }

        return do_modload(source_p, parv[1]);
}

static int
me_modload(struct Client *client_p, struct Client *source_p, int parc, const char **parv)
{
        if(!find_shared_conf(source_p->username, source_p->host, source_p->servptr->name, SHARED_MODULE))
        {
                sendto_one_notice(source_p, ":*** You do not have an appropriate shared block "
                                "to load modules on this server.");
                return 0;
        }

        return do_modload(source_p, parv[1]);
}

static int
do_modload(struct Client *source_p, const char *module)
{
        char *m_bn = rb_basename(module);

        if(findmodule_byname(m_bn) != -1)
        {
                sendto_one_notice(source_p, ":Module %s is already loaded", m_bn);
                rb_free(m_bn);
                return 0;
        }

        load_one_module(module, 0);

        rb_free(m_bn);

        return 0;
}


/* unload a module .. */
static int
mo_modunload(struct Client *client_p, struct Client *source_p, int parc, const char **parv)
{
        if(!IsOperAdmin(source_p))
        {
                sendto_one(source_p, form_str(ERR_NOPRIVS),
                           me.name, source_p->name, "admin");
                return 0;
        }

        if(parc > 2)
        {
                sendto_match_servs(source_p, parv[2], CAP_ENCAP, NOCAPS,
                                "ENCAP %s MODUNLOAD %s", parv[2], parv[1]);
                if (match(parv[2], me.name) == 0)
                        return 0;
        }

        return do_modunload(source_p, parv[1]);
}

static int
me_modunload(struct Client *client_p, struct Client *source_p, int parc, const char **parv)
{
        if(!find_shared_conf(source_p->username, source_p->host, source_p->servptr->name, SHARED_MODULE))
        {
                sendto_one_notice(source_p, ":*** You do not have an appropriate shared block "
                                "to load modules on this server.");
                return 0;
        }

        return do_modunload(source_p, parv[1]);
}

static int
do_modunload(struct Client *source_p, const char *module)
{
        int modindex;
        char *m_bn = rb_basename(module);

        if((modindex = findmodule_byname(m_bn)) == -1)
        {
                sendto_one_notice(source_p, ":Module %s is not loaded", m_bn);
                rb_free(m_bn);
                return 0;
        }

        if(modlist[modindex]->core == 1)
        {
                sendto_one_notice(source_p, ":Module %s is a core module and may not be unloaded", m_bn);
                rb_free(m_bn);
                return 0;
        }

        if(unload_one_module(m_bn, 1) == -1)
        {
                sendto_one_notice(source_p, ":Module %s is not loaded", m_bn);
        }

        rb_free(m_bn);
        return 0;
}

/* unload and load in one! */
static int
mo_modreload(struct Client *client_p, struct Client *source_p, int parc, const char **parv)
{
        if(!IsOperAdmin(source_p))
        {
                sendto_one(source_p, form_str(ERR_NOPRIVS),
                           me.name, source_p->name, "admin");
                return 0;
        }

        if(parc > 2)
        {
                sendto_match_servs(source_p, parv[2], CAP_ENCAP, NOCAPS,
                                "ENCAP %s MODRELOAD %s", parv[2], parv[1]);
                if (match(parv[2], me.name) == 0)
                        return 0;
        }

        return do_modreload(source_p, parv[1]);
}

static int
me_modreload(struct Client *client_p, struct Client *source_p, int parc, const char **parv)
{
        if(!find_shared_conf(source_p->username, source_p->host, source_p->servptr->name, SHARED_MODULE))
        {
                sendto_one_notice(source_p, ":*** You do not have an appropriate shared block "
                                "to load modules on this server.");
                return 0;
        }

        return do_modreload(source_p, parv[1]);
}

static int
do_modreload(struct Client *source_p, const char *module)
{
        int modindex;
        int check_core;
        char *m_bn = rb_basename(module);

        if((modindex = findmodule_byname(m_bn)) == -1)
        {
                sendto_one_notice(source_p, ":Module %s is not loaded", m_bn);
                rb_free(m_bn);
                return 0;
        }

        check_core = modlist[modindex]->core;

        if(unload_one_module(m_bn, 1) == -1)
        {
                sendto_one_notice(source_p, ":Module %s is not loaded", m_bn);
                rb_free(m_bn);
                return 0;
        }

        if((load_one_module(m_bn, check_core) == -1) && check_core)
        {
                sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
                                     "Error reloading core module: %s: terminating ircd", m_bn);
                ilog(L_MAIN, "Error loading core module %s: terminating ircd", m_bn);
                exit(0);
        }

        rb_free(m_bn);
        return 0;
}

/* list modules .. */
static int
mo_modlist(struct Client *client_p, struct Client *source_p, int parc, const char **parv)
{
        if(!IsOperAdmin(source_p))
        {
                sendto_one(source_p, form_str(ERR_NOPRIVS),
                           me.name, source_p->name, "admin");
                return 0;
        }

        if(parc > 2)
        {
                sendto_match_servs(source_p, parv[2], CAP_ENCAP, NOCAPS,
                                "ENCAP %s MODLIST %s", parv[2], parv[1]);
                if (match(parv[2], me.name) == 0)
                        return 0;
        }

        return do_modlist(source_p, parc > 1 ? parv[1] : 0);
}

static int
me_modlist(struct Client *client_p, struct Client *source_p, int parc, const char **parv)
{
        if(!find_shared_conf(source_p->username, source_p->host, source_p->servptr->name, SHARED_MODULE))
        {
                sendto_one_notice(source_p, ":*** You do not have an appropriate shared block "
                                "to load modules on this server.");
                return 0;
        }

        return do_modlist(source_p, parv[1]);
}

static int
do_modlist(struct Client *source_p, const char *pattern)
{
        int i;

        for (i = 0; i < num_mods; i++)
        {
                if(pattern)
                {
                        if(match(pattern, modlist[i]->name))
                        {
                                sendto_one(source_p, form_str(RPL_MODLIST),
                                           me.name, source_p->name,
                                           modlist[i]->name,
                                           modlist[i]->address,
                                           modlist[i]->version, modlist[i]->core ? "(core)" : "");
                        }
                }
                else
                {
                        sendto_one(source_p, form_str(RPL_MODLIST),
                                   me.name, source_p->name, modlist[i]->name,
                                   modlist[i]->address, modlist[i]->version,
                                   modlist[i]->core ? "(core)" : "");
                }
        }

        sendto_one(source_p, form_str(RPL_ENDOFMODLIST), me.name, source_p->name);
        return 0;
}

/* unload and reload all modules */
static int
mo_modrestart(struct Client *client_p, struct Client *source_p, int parc, const char **parv)
{
        if(!IsOperAdmin(source_p))
        {
                sendto_one(source_p, form_str(ERR_NOPRIVS),
                           me.name, source_p->name, "admin");
                return 0;
        }

        if(parc > 1)
        {
                sendto_match_servs(source_p, parv[1], CAP_ENCAP, NOCAPS,
                                "ENCAP %s MODRESTART", parv[1]);
                if (match(parv[1], me.name) == 0)
                        return 0;
        }

        return do_modrestart(source_p);
}

static int
me_modrestart(struct Client *client_p, struct Client *source_p, int parc, const char **parv)
{
        if(!find_shared_conf(source_p->username, source_p->host, source_p->servptr->name, SHARED_MODULE))
        {
                sendto_one_notice(source_p, ":*** You do not have an appropriate shared block "
                                "to load modules on this server.");
                return 0;
        }

        return do_modrestart(source_p);
}

static int
do_modrestart(struct Client *source_p)
{
        int modnum;

        sendto_one_notice(source_p, ":Reloading all modules");

        modnum = num_mods;
        while (num_mods)
                unload_one_module(modlist[0]->name, 0);

        load_all_modules(0);
        load_core_modules(0);
        rehash(0);

        sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
                             "Module Restart: %d modules unloaded, %d modules loaded",
                             modnum, num_mods);
        ilog(L_MAIN, "Module Restart: %d modules unloaded, %d modules loaded", modnum, num_mods);
        return 0;
}



#ifndef RTLD_NOW
#define RTLD_NOW RTLD_LAZY      /* openbsd deficiency */
#endif

#ifndef RTLD_LOCAL
#define RTLD_LOCAL 0
#endif

#ifdef CHARYBDIS_PROFILE
# ifndef RTLD_PROFILE
#  warning libdl may not support profiling, sucks. :(
#  define RTLD_PROFILE 0
# endif
#endif

static void increase_modlist(void);

#define MODS_INCREMENT 10

static char unknown_ver[] = "<unknown>";

/* This file contains the core functions to use dynamic libraries.
 * -TimeMr14C
 */


#ifdef HAVE_MACH_O_DYLD_H
/*
** jmallett's dl*(3) shims for NSModule(3) systems.
*/
#include <mach-o/dyld.h>

#ifndef HAVE_DLOPEN
#ifndef RTLD_LAZY
#define RTLD_LAZY 2185          /* built-in dl*(3) don't care */
#endif

void undefinedErrorHandler(const char *);
NSModule multipleErrorHandler(NSSymbol, NSModule, NSModule);
void linkEditErrorHandler(NSLinkEditErrors, int, const char *, const char *);
char *dlerror(void);
void *dlopen(char *, int);
int dlclose(void *);
void *dlsym(void *, char *);

static int firstLoad = TRUE;
static int myDlError;
static char *myErrorTable[] = { "Loading file as object failed\n",
        "Loading file as object succeeded\n",
        "Not a valid shared object\n",
        "Architecture of object invalid on this architecture\n",
        "Invalid or corrupt image\n",
        "Could not access object\n",
        "NSCreateObjectFileImageFromFile failed\n",
        NULL
};

void
undefinedErrorHandler(const char *symbolName)
{
        sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, "Undefined symbol: %s", symbolName);
        ilog(L_MAIN, "Undefined symbol: %s", symbolName);
        return;
}

NSModule
multipleErrorHandler(NSSymbol s, NSModule old, NSModule new)
{
        /* XXX
         ** This results in substantial leaking of memory... Should free one
         ** module, maybe?
         */
        sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
                             "Symbol `%s' found in `%s' and `%s'",
                             NSNameOfSymbol(s), NSNameOfModule(old), NSNameOfModule(new));
        ilog(L_MAIN, "Symbol `%s' found in `%s' and `%s'",
             NSNameOfSymbol(s), NSNameOfModule(old), NSNameOfModule(new));
        /* We return which module should be considered valid, I believe */
        return new;
}

void
linkEditErrorHandler(NSLinkEditErrors errorClass, int errnum,
                     const char *fileName, const char *errorString)
{
        sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
                             "Link editor error: %s for %s", errorString, fileName);
        ilog(L_MAIN, "Link editor error: %s for %s", errorString, fileName);
        return;
}

char *
dlerror(void)
{
        return myDlError == NSObjectFileImageSuccess ? NULL : myErrorTable[myDlError % 7];
}

void *
dlopen(char *filename, int unused)
{
        NSObjectFileImage myImage;
        NSModule myModule;

        if(firstLoad)
        {
                /*
                 ** If we are loading our first symbol (huzzah!) we should go ahead
                 ** and install link editor error handling!
                 */
                NSLinkEditErrorHandlers linkEditorErrorHandlers;

                linkEditorErrorHandlers.undefined = undefinedErrorHandler;
                linkEditorErrorHandlers.multiple = multipleErrorHandler;
                linkEditorErrorHandlers.linkEdit = linkEditErrorHandler;
                NSInstallLinkEditErrorHandlers(&linkEditorErrorHandlers);
                firstLoad = FALSE;
        }
        myDlError = NSCreateObjectFileImageFromFile(filename, &myImage);
        if(myDlError != NSObjectFileImageSuccess)
        {
                return NULL;
        }
        myModule = NSLinkModule(myImage, filename, NSLINKMODULE_OPTION_PRIVATE);
        return (void *) myModule;
}

int
dlclose(void *myModule)
{
        NSUnLinkModule(myModule, FALSE);
        return 0;
}

void *
dlsym(void *myModule, char *mySymbolName)
{
        NSSymbol mySymbol;

        mySymbol = NSLookupSymbolInModule((NSModule) myModule, mySymbolName);
        return NSAddressOfSymbol(mySymbol);
}
#endif
#endif


/*
 * HPUX dl compat functions
 */
#if defined(HAVE_SHL_LOAD) && !defined(HAVE_DLOPEN)
#define RTLD_LAZY BIND_DEFERRED
#define RTLD_GLOBAL DYNAMIC_PATH
#define dlopen(file,mode) (void *)shl_load((file), (mode), (long) 0)
#define dlclose(handle) shl_unload((shl_t)(handle))
#define dlsym(handle,name) hpux_dlsym(handle,name)
#define dlerror() strerror(errno)

static void *
hpux_dlsym(void *handle, char *name)
{
        void *sym_addr;
        if(!shl_findsym((shl_t *) & handle, name, TYPE_UNDEFINED, &sym_addr))
                return sym_addr;
        return NULL;
}

#endif

/* unload_one_module()
 *
 * inputs       - name of module to unload
 *              - 1 to say modules unloaded, 0 to not
 * output       - 0 if successful, -1 if error
 * side effects - module is unloaded
 */
int
unload_one_module(const char *name, int warn)
{
        int modindex;

        if((modindex = findmodule_byname(name)) == -1)
                return -1;

        /*
         ** XXX - The type system in C does not allow direct conversion between
         ** data and function pointers, but as it happens, most C compilers will
         ** safely do this, however it is a theoretical overlow to cast as we 
         ** must do here.  I have library functions to take care of this, but 
         ** despite being more "correct" for the C language, this is more 
         ** practical.  Removing the abuse of the ability to cast ANY pointer
         ** to and from an integer value here will break some compilers.
         **          -jmallett
         */
        /* Left the comment in but the code isn't here any more         -larne */
        switch (modlist[modindex]->mapi_version)
        {
        case 1:
                {
                        struct mapi_mheader_av1 *mheader = modlist[modindex]->mapi_header;
                        if(mheader->mapi_command_list)
                        {
                                struct Message **m;
                                for (m = mheader->mapi_command_list; *m; ++m)
                                        mod_del_cmd(*m);
                        }

                        /* hook events are never removed, we simply lose the
                         * ability to call them --fl
                         */
                        if(mheader->mapi_hfn_list)
                        {
                                mapi_hfn_list_av1 *m;
                                for (m = mheader->mapi_hfn_list; m->hapi_name; ++m)
                                        remove_hook(m->hapi_name, m->fn);
                        }

                        if(mheader->mapi_unregister)
                                mheader->mapi_unregister();
                        break;
                }
        default:
                sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
                                     "Unknown/unsupported MAPI version %d when unloading %s!",
                                     modlist[modindex]->mapi_version, modlist[modindex]->name);
                ilog(L_MAIN, "Unknown/unsupported MAPI version %d when unloading %s!",
                     modlist[modindex]->mapi_version, modlist[modindex]->name);
                break;
        }

        dlclose(modlist[modindex]->address);

        rb_free(modlist[modindex]->name);
        memmove(&modlist[modindex], &modlist[modindex + 1],
               sizeof(struct module) * ((num_mods - 1) - modindex));

        if(num_mods != 0)
                num_mods--;

        if(warn == 1)
        {
                ilog(L_MAIN, "Module %s unloaded", name);
                sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, "Module %s unloaded", name);
        }

        return 0;
}


/*
 * load_a_module()
 *
 * inputs       - path name of module, int to notice, int of core
 * output       - -1 if error 0 if success
 * side effects - loads a module if successful
 */
int
load_a_module(const char *path, int warn, int core)
{
        void *tmpptr = NULL;

        char *mod_basename;
        const char *ver;

        int *mapi_version;

        mod_basename = rb_basename(path);

#ifdef CHARYBDIS_PROFILE
        tmpptr = dlopen(path, RTLD_NOW | RTLD_LOCAL | RTLD_PROFILE);
#else
        tmpptr = dlopen(path, RTLD_NOW | RTLD_LOCAL);
#endif

        if(tmpptr == NULL)
        {
                const char *err = dlerror();

                sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
                                     "Error loading module %s: %s", mod_basename, err);
                ilog(L_MAIN, "Error loading module %s: %s", mod_basename, err);
                rb_free(mod_basename);
                return -1;
        }


        /*
         * _mheader is actually a struct mapi_mheader_*, but mapi_version
         * is always the first member of this structure, so we treate it
         * as a single int in order to determine the API version.
         *      -larne.
         */
        mapi_version = (int *) (uintptr_t) dlsym(tmpptr, "_mheader");
        if((mapi_version == NULL
            && (mapi_version = (int *) (uintptr_t) dlsym(tmpptr, "__mheader")) == NULL)
           || MAPI_MAGIC(*mapi_version) != MAPI_MAGIC_HDR)
        {
                sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
                                     "Data format error: module %s has no MAPI header.",
                                     mod_basename);
                ilog(L_MAIN, "Data format error: module %s has no MAPI header.", mod_basename);
                (void) dlclose(tmpptr);
                rb_free(mod_basename);
                return -1;
        }

        switch (MAPI_VERSION(*mapi_version))
        {
        case 1:
                {
                        struct mapi_mheader_av1 *mheader = (struct mapi_mheader_av1 *) mapi_version;    /* see above */
                        if(mheader->mapi_register && (mheader->mapi_register() == -1))
                        {
                                ilog(L_MAIN, "Module %s indicated failure during load.",
                                     mod_basename);
                                sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
                                                     "Module %s indicated failure during load.",
                                                     mod_basename);
                                dlclose(tmpptr);
                                rb_free(mod_basename);
                                return -1;
                        }
                        if(mheader->mapi_command_list)
                        {
                                struct Message **m;
                                for (m = mheader->mapi_command_list; *m; ++m)
                                        mod_add_cmd(*m);
                        }

                        if(mheader->mapi_hook_list)
                        {
                                mapi_hlist_av1 *m;
                                for (m = mheader->mapi_hook_list; m->hapi_name; ++m)
                                        *m->hapi_id = register_hook(m->hapi_name);
                        }

                        if(mheader->mapi_hfn_list)
                        {
                                mapi_hfn_list_av1 *m;
                                for (m = mheader->mapi_hfn_list; m->hapi_name; ++m)
                                        add_hook(m->hapi_name, m->fn);
                        }

                        ver = mheader->mapi_module_version;
                        break;
                }

        default:
                ilog(L_MAIN, "Module %s has unknown/unsupported MAPI version %d.",
                     mod_basename, MAPI_VERSION(*mapi_version));
                sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
                                     "Module %s has unknown/unsupported MAPI version %d.",
                                     mod_basename, *mapi_version);
                dlclose(tmpptr);
                rb_free(mod_basename);
                return -1;
        }

        if(ver == NULL)
                ver = unknown_ver;

        increase_modlist();

        modlist[num_mods] = rb_malloc(sizeof(struct module));
        modlist[num_mods]->address = tmpptr;
        modlist[num_mods]->version = ver;
        modlist[num_mods]->core = core;
        modlist[num_mods]->name = rb_strdup(mod_basename);
        modlist[num_mods]->mapi_header = mapi_version;
        modlist[num_mods]->mapi_version = MAPI_VERSION(*mapi_version);
        num_mods++;

        if(warn == 1)
        {
                sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
                                     "Module %s [version: %s; MAPI version: %d] loaded at 0x%lx",
                                     mod_basename, ver, MAPI_VERSION(*mapi_version),
                                     (unsigned long) tmpptr);
                ilog(L_MAIN, "Module %s [version: %s; MAPI version: %d] loaded at 0x%lx",
                     mod_basename, ver, MAPI_VERSION(*mapi_version), (unsigned long) tmpptr);
        }
        rb_free(mod_basename);
        return 0;
}

/*
 * increase_modlist
 *
 * inputs       - NONE
 * output       - NONE
 * side effects - expand the size of modlist if necessary
 */
static void
increase_modlist(void)
{
        struct module **new_modlist = NULL;

        if((num_mods + 1) < max_mods)
                return;

        new_modlist = (struct module **) rb_malloc(sizeof(struct module) *
                                                  (max_mods + MODS_INCREMENT));
        memcpy((void *) new_modlist, (void *) modlist, sizeof(struct module) * num_mods);

        rb_free(modlist);
        modlist = new_modlist;
        max_mods += MODS_INCREMENT;
}

#else /* STATIC_MODULES */

/* load_all_modules()
 *
 * input        -
 * output       -
 * side effects - all the msgtabs are added for static modules
 */
void
load_all_modules(int warn)
{
        load_static_modules();
}

#endif /* STATIC_MODULES */