serv_extensions.c

Go to the documentation of this file.

/*
 * Citadel Extension Loader
 * Originally written by Brian Costello <btx@calyx.net>
 *
 * Copyright (c) 1987-2021 by the citadel.org team
 *
 * This program is open source software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 3.
 *
 * 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.
 */
 
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/stat.h>
#include <libcitadel.h>
#include "sysdep_decls.h"
#include "modules/crypto/serv_crypto.h" /* Needed until a universal crypto startup hook is implimented for CtdlStartTLS */
#include "serv_extensions.h"
#include "ctdl_module.h"
#include "config.h"
 
 
/*
 * Structure defentitions for hook tables
 */
 
typedef struct FixedOutputHook FixedOutputHook;
struct FixedOutputHook {
    FixedOutputHook *next;
    char content_type[64];
    void (*h_function_pointer) (char *, int);
};
FixedOutputHook *FixedOutputTable = NULL;
 
 
/*
 * SessionFunctionHook extensions are used for any type of hook for which
 * the context in which it's being called (which is determined by the event
 * type) will make it obvious for the hook function to know where to look for
 * pertinent data.
 */
typedef struct SessionFunctionHook SessionFunctionHook;
struct SessionFunctionHook {
    SessionFunctionHook *next;
    int Priority;
    void (*h_function_pointer) (void);
    int eventtype;
};
SessionFunctionHook *SessionHookTable = NULL;
 
 
/*
 * UserFunctionHook extensions are used for any type of hook which implements
 * an operation on a user or username (potentially) other than the one
 * operating the current session.
 */
typedef struct UserFunctionHook UserFunctionHook;
struct UserFunctionHook {
    UserFunctionHook *next;
    void (*h_function_pointer) (struct ctdluser *usbuf);
    int eventtype;
};
UserFunctionHook *UserHookTable = NULL;
 
 
/*
 * MessageFunctionHook extensions are used for hooks which implement handlers
 * for various types of message operations (save, read, etc.)
 */
typedef struct MessageFunctionHook MessageFunctionHook;
struct MessageFunctionHook {
    MessageFunctionHook *next;
    int (*h_function_pointer) (struct CtdlMessage *msg, struct recptypes *recps);
    int eventtype;
};
MessageFunctionHook *MessageHookTable = NULL;
 
 
/*
 * DeleteFunctionHook extensions are used for hooks which get called when a
 * message is about to be deleted.
 */
typedef struct DeleteFunctionHook DeleteFunctionHook;
struct DeleteFunctionHook {
    DeleteFunctionHook *next;
    void (*h_function_pointer) (char *target_room, long msgnum);
};
DeleteFunctionHook *DeleteHookTable = NULL;
 
 
/*
 * ExpressMessageFunctionHook extensions are used for hooks which implement
 * the sending of an instant message through various channels.  Any function
 * registered should return the number of recipients to whom the message was
 * successfully transmitted.
 */
typedef struct XmsgFunctionHook XmsgFunctionHook;
struct XmsgFunctionHook {
    XmsgFunctionHook *next;
    int (*h_function_pointer) (char *, char *, char *, char *);
    int order;
};
XmsgFunctionHook *XmsgHookTable = NULL;
 
 
/*
 * RoomFunctionHook extensions are used for hooks which impliment room
 * processing functions when new messages are added.
 */
typedef struct RoomFunctionHook RoomFunctionHook;
struct RoomFunctionHook {
    RoomFunctionHook *next;
    int (*fcn_ptr) (struct ctdlroom *);
};
RoomFunctionHook *RoomHookTable = NULL;
 
 
typedef struct SearchFunctionHook SearchFunctionHook;
struct SearchFunctionHook {
    SearchFunctionHook *next;
    void (*fcn_ptr) (int *, long **, const char *);
    char *name;
};
SearchFunctionHook *SearchFunctionHookTable = NULL;
 
ServiceFunctionHook *ServiceHookTable = NULL;
 
typedef struct ProtoFunctionHook ProtoFunctionHook;
struct ProtoFunctionHook {
    void (*handler) (char *cmdbuf);
    const char *cmd;
    const char *desc;
};
 
HashList *ProtoHookList = NULL;
 
 
#define ERR_PORT (1 << 1)
 
 
static StrBuf *portlist = NULL;
static StrBuf *errormessages = NULL;
 
 
long   DetailErrorFlags;
ConstStr Empty = {HKEY("")};
char *ErrSubject = "Startup Problems";
ConstStr ErrGeneral[] = {
    {HKEY("Citadel had trouble on starting up. ")},
    {HKEY(" This means, Citadel won't be the service provider for a specific service you configured it to.\n\n"
          "If you don't want Citadel to provide these services, turn them off in WebCit via: ")},
    {HKEY("To make both ways actualy take place restart the citserver with \"sendcommand down\"\n\n"
          "The errors returned by the system were:\n")},
    {HKEY("You can recheck the above if you follow this faq item:\n"
          "http://www.citadel.org/doku.php?id=faq:mastering_your_os:net#netstat")}
};
 
ConstStr ErrPortShort = { HKEY("We couldn't bind all ports you configured to be provided by Citadel Server.\n")};
ConstStr ErrPortWhere = { HKEY("\"Admin->System Preferences->Network\".\n\nThe failed ports and sockets are: ")};
ConstStr ErrPortHint  = { HKEY("If you want Citadel to provide you with that functionality, "
                   "check the output of \"netstat -lnp\" on Linux, or \"netstat -na\" on BSD"
                   " and disable the program that binds these ports.\n")};
 
 
void LogPrintMessages(long err)
{
    StrBuf *Message;
    StrBuf *List, *DetailList;
    ConstStr *Short, *Where, *Hint; 
 
    
    Message = NewStrBufPlain(NULL, StrLength(portlist) + StrLength(errormessages));
    
    DetailErrorFlags = DetailErrorFlags & ~err;
 
    switch (err)
    {
    case ERR_PORT:
        Short = &ErrPortShort;
        Where = &ErrPortWhere;
        Hint  = &ErrPortHint;
        List  = portlist;
        DetailList = errormessages;
        break;
    default:
        Short = &Empty;
        Where = &Empty;
        Hint  = &Empty;
        List  = NULL;
        DetailList = NULL;
    }
 
    StrBufAppendBufPlain(Message, CKEY(ErrGeneral[0]), 0);
    StrBufAppendBufPlain(Message, CKEY(*Short), 0); 
    StrBufAppendBufPlain(Message, CKEY(ErrGeneral[1]), 0);
    StrBufAppendBufPlain(Message, CKEY(*Where), 0);
    StrBufAppendBuf(Message, List, 0);
    StrBufAppendBufPlain(Message, HKEY("\n\n"), 0);
    StrBufAppendBufPlain(Message, CKEY(*Hint), 0);
    StrBufAppendBufPlain(Message, HKEY("\n\n"), 0);
    StrBufAppendBufPlain(Message, CKEY(ErrGeneral[2]), 0);
    StrBufAppendBuf(Message, DetailList, 0);
    StrBufAppendBufPlain(Message, HKEY("\n\n"), 0);
    StrBufAppendBufPlain(Message, CKEY(ErrGeneral[3]), 0);
 
    syslog(LOG_ERR, "extensions: %s", ChrPtr(Message));
    syslog(LOG_ERR, "extensions: %s", ErrSubject);
    quickie_message("Citadel", NULL, NULL, AIDEROOM, ChrPtr(Message), FMT_FIXED, ErrSubject);
 
    FreeStrBuf(&Message);
    FreeStrBuf(&List);
    FreeStrBuf(&DetailList);
}
 
 
void AddPortError(char *Port, char *ErrorMessage)
{
    long len;
 
    DetailErrorFlags |= ERR_PORT;
 
    len = StrLength(errormessages);
    if (len > 0) StrBufAppendBufPlain(errormessages, HKEY("; "), 0);
    else errormessages = NewStrBuf();
    StrBufAppendBufPlain(errormessages, ErrorMessage, -1, 0);
 
 
    len = StrLength(portlist);
    if (len > 0) StrBufAppendBufPlain(portlist, HKEY(";"), 0);
    else portlist = NewStrBuf();
    StrBufAppendBufPlain(portlist, Port, -1, 0);
}
 
 
int DLoader_Exec_Cmd(char *cmdbuf)
{
    void *vP;
    ProtoFunctionHook *p;
 
    if (GetHash(ProtoHookList, cmdbuf, 4, &vP) && (vP != NULL)) {
        p = (ProtoFunctionHook*) vP;
        p->handler(&cmdbuf[5]);
        return 1;
    }
    return 0;
}
 
 
void CtdlRegisterProtoHook(void (*handler) (char *), char *cmd, char *desc)
{
    ProtoFunctionHook *p;
 
    if (ProtoHookList == NULL)
        ProtoHookList = NewHash (1, FourHash);
 
 
    p = (ProtoFunctionHook *)
        malloc(sizeof(ProtoFunctionHook));
 
    if (p == NULL) {
        fprintf(stderr, "can't malloc new ProtoFunctionHook\n");
        exit(EXIT_FAILURE);
    }
    p->handler = handler;
    p->cmd = cmd;
    p->desc = desc;
 
    Put(ProtoHookList, cmd, 4, p, NULL);
    syslog(LOG_DEBUG, "extensions: registered server command %s (%s)", cmd, desc);
}
 
 
void CtdlRegisterSessionHook(void (*fcn_ptr) (void), int EventType, int Priority)
{
    SessionFunctionHook *newfcn;
 
    newfcn = (SessionFunctionHook *)
        malloc(sizeof(SessionFunctionHook));
    newfcn->Priority = Priority;
    newfcn->h_function_pointer = fcn_ptr;
    newfcn->eventtype = EventType;
 
    SessionFunctionHook **pfcn;
    pfcn = &SessionHookTable;
    while ((*pfcn != NULL) && 
           ((*pfcn)->Priority < newfcn->Priority) &&
           ((*pfcn)->next != NULL))
        pfcn = &(*pfcn)->next;
        
    newfcn->next = *pfcn;
    *pfcn = newfcn;
    
    syslog(LOG_DEBUG, "extensions: registered a new session function (type %d Priority %d)", EventType, Priority);
}
 
 
void CtdlUnregisterSessionHook(void (*fcn_ptr) (void), int EventType)
{
    SessionFunctionHook *cur, *p, *last;
    last = NULL;
    cur = SessionHookTable;
    while  (cur != NULL) {
        if ((fcn_ptr == cur->h_function_pointer) &&
            (EventType == cur->eventtype))
        {
            syslog(LOG_DEBUG, "extensions: unregistered session function (type %d)", EventType);
            p = cur->next;
 
            free(cur);
            cur = NULL;
 
            if (last != NULL)
                last->next = p;
            else 
                SessionHookTable = p;
            cur = p;
        }
        else {
            last = cur;
            cur = cur->next;
        }
    }
}
 
 
void CtdlRegisterUserHook(void (*fcn_ptr) (ctdluser *), int EventType)
{
 
    UserFunctionHook *newfcn;
 
    newfcn = (UserFunctionHook *)
        malloc(sizeof(UserFunctionHook));
    newfcn->next = UserHookTable;
    newfcn->h_function_pointer = fcn_ptr;
    newfcn->eventtype = EventType;
    UserHookTable = newfcn;
 
    syslog(LOG_DEBUG, "extensions: registered a new user function (type %d)",
           EventType);
}
 
 
void CtdlUnregisterUserHook(void (*fcn_ptr) (struct ctdluser *), int EventType)
{
    UserFunctionHook *cur, *p, *last;
    last = NULL;
    cur = UserHookTable;
    while (cur != NULL) {
        if ((fcn_ptr == cur->h_function_pointer) &&
            (EventType == cur->eventtype))
        {
            syslog(LOG_DEBUG, "extensions: unregistered user function (type %d)", EventType);
            p = cur->next;
 
            free(cur);
            cur = NULL;
 
            if (last != NULL)
                last->next = p;
            else 
                UserHookTable = p;
            cur = p;
        }
        else {
            last = cur;
            cur = cur->next;
        }
    }
}
 
 
void CtdlRegisterMessageHook(int (*handler)(struct CtdlMessage *, struct recptypes *), int EventType)
{
 
    MessageFunctionHook *newfcn;
 
    newfcn = (MessageFunctionHook *)
        malloc(sizeof(MessageFunctionHook));
    newfcn->next = MessageHookTable;
    newfcn->h_function_pointer = handler;
    newfcn->eventtype = EventType;
    MessageHookTable = newfcn;
 
    syslog(LOG_DEBUG, "extensions: registered a new message function (type %d)", EventType);
}
 
 
void CtdlUnregisterMessageHook(int (*handler)(struct CtdlMessage *, struct recptypes *), int EventType)
{
    MessageFunctionHook *cur, *p, *last;
    last = NULL;
    cur = MessageHookTable;
    while (cur != NULL) {
        if ((handler == cur->h_function_pointer) &&
            (EventType == cur->eventtype))
        {
            syslog(LOG_DEBUG, "extensions: unregistered message function (type %d)", EventType);
            p = cur->next;
            free(cur);
            cur = NULL;
 
            if (last != NULL)
                last->next = p;
            else 
                MessageHookTable = p;
            cur = p;
        }
        else {
            last = cur;
            cur = cur->next;
        }
    }
}
 
 
void CtdlRegisterRoomHook(int (*fcn_ptr)(struct ctdlroom *))
{
    RoomFunctionHook *newfcn;
 
    newfcn = (RoomFunctionHook *)
        malloc(sizeof(RoomFunctionHook));
    newfcn->next = RoomHookTable;
    newfcn->fcn_ptr = fcn_ptr;
    RoomHookTable = newfcn;
 
    syslog(LOG_DEBUG, "extensions: registered a new room function");
}
 
 
void CtdlUnregisterRoomHook(int (*fcn_ptr)(struct ctdlroom *))
{
    RoomFunctionHook *cur, *p, *last;
    last = NULL;
    cur = RoomHookTable;
    while (cur != NULL)
    {
        if (fcn_ptr == cur->fcn_ptr) {
            syslog(LOG_DEBUG, "extensions: unregistered room function");
            p = cur->next;
 
            free(cur);
            cur = NULL;
 
            if (last != NULL)
                last->next = p;
            else 
                RoomHookTable = p;
            cur = p;
        }
        else {
            last = cur;
            cur = cur->next;
        }
    }
}
 
 
void CtdlRegisterDeleteHook(void (*handler)(char *, long) )
{
    DeleteFunctionHook *newfcn;
 
    newfcn = (DeleteFunctionHook *)
        malloc(sizeof(DeleteFunctionHook));
    newfcn->next = DeleteHookTable;
    newfcn->h_function_pointer = handler;
    DeleteHookTable = newfcn;
 
    syslog(LOG_DEBUG, "extensions: registered a new delete function");
}
 
 
void CtdlUnregisterDeleteHook(void (*handler)(char *, long) )
{
    DeleteFunctionHook *cur, *p, *last;
 
    last = NULL;
    cur = DeleteHookTable;
    while (cur != NULL) {
        if (handler == cur->h_function_pointer )
        {
            syslog(LOG_DEBUG, "extensions: unregistered delete function");
            p = cur->next;
            free(cur);
 
            if (last != NULL)
                last->next = p;
            else
                DeleteHookTable = p;
 
            cur = p;
        }
        else {
            last = cur;
            cur = cur->next;
        }
    }
}
 
 
void CtdlRegisterFixedOutputHook(char *content_type, void (*handler)(char *, int) )
{
    FixedOutputHook *newfcn;
 
    newfcn = (FixedOutputHook *)
        malloc(sizeof(FixedOutputHook));
    newfcn->next = FixedOutputTable;
    newfcn->h_function_pointer = handler;
    safestrncpy(newfcn->content_type, content_type, sizeof newfcn->content_type);
    FixedOutputTable = newfcn;
 
    syslog(LOG_DEBUG, "extensions: registered a new fixed output function for %s", newfcn->content_type);
}
 
 
void CtdlUnregisterFixedOutputHook(char *content_type)
{
    FixedOutputHook *cur, *p, *last;
 
    last = NULL;
    cur = FixedOutputTable;
    while (cur != NULL) {
        /* This will also remove duplicates if any */
        if (!strcasecmp(content_type, cur->content_type)) {
            syslog(LOG_DEBUG, "extensions: unregistered fixed output function for %s", content_type);
            p = cur->next;
            free(cur);
 
            if (last != NULL)
                last->next = p;
            else
                FixedOutputTable = p;
            
            cur = p;
        }
        else
        {
            last = cur;
            cur = cur->next;
        }
    }
}
 
 
/* returns nonzero if we found a hook and used it */
int PerformFixedOutputHooks(char *content_type, char *content, int content_length)
{
    FixedOutputHook *fcn;
 
    for (fcn = FixedOutputTable; fcn != NULL; fcn = fcn->next) {
        if (!strcasecmp(content_type, fcn->content_type)) {
            (*fcn->h_function_pointer) (content, content_length);
            return(1);
        }
    }
    return(0);
}
 
 
void CtdlRegisterXmsgHook(int (*fcn_ptr) (char *, char *, char *, char *), int order)
{
 
    XmsgFunctionHook *newfcn;
 
    newfcn = (XmsgFunctionHook *) malloc(sizeof(XmsgFunctionHook));
    newfcn->next = XmsgHookTable;
    newfcn->order = order;
    newfcn->h_function_pointer = fcn_ptr;
    XmsgHookTable = newfcn;
    syslog(LOG_DEBUG, "extensions: registered a new x-msg function (priority %d)", order);
}
 
 
void CtdlUnregisterXmsgHook(int (*fcn_ptr) (char *, char *, char *, char *), int order)
{
    XmsgFunctionHook *cur, *p, *last;
 
    last = NULL;
    cur = XmsgHookTable;
    while (cur != NULL) {
        /* This will also remove duplicates if any */
        if (fcn_ptr == cur->h_function_pointer &&
            order == cur->order) {
            syslog(LOG_DEBUG, "extensions: unregistered x-msg function (priority %d)", order);
            p = cur->next;
            free(cur);
 
            if (last != NULL) {
                last->next = p;
            }
            else {
                XmsgHookTable = p;
            }
            cur = p;
        }
        else {
            last = cur;
            cur = cur->next;
        }
    }
}
 
 
void CtdlRegisterServiceHook(int tcp_port,
                 char *sockpath,
                 void (*h_greeting_function) (void),
                 void (*h_command_function) (void),
                 void (*h_async_function) (void),
                 const char *ServiceName)
{
    ServiceFunctionHook *newfcn;
    char *message;
 
    newfcn = (ServiceFunctionHook *) malloc(sizeof(ServiceFunctionHook));
    message = (char*) malloc (SIZ + SIZ);
    
    newfcn->next = ServiceHookTable;
    newfcn->tcp_port = tcp_port;
    newfcn->sockpath = sockpath;
    newfcn->h_greeting_function = h_greeting_function;
    newfcn->h_command_function = h_command_function;
    newfcn->h_async_function = h_async_function;
    newfcn->ServiceName = ServiceName;
 
    if (sockpath != NULL) {
        newfcn->msock = ctdl_uds_server(sockpath, CtdlGetConfigInt("c_maxsessions"));
        snprintf(message, SIZ, "extensions: unix domain socket '%s': ", sockpath);
    }
    else if (tcp_port <= 0) {   /* port -1 to disable */
        syslog(LOG_INFO, "extensions: service %s has been manually disabled, skipping", ServiceName);
        free (message);
        free(newfcn);
        return;
    }
    else {
        newfcn->msock = ctdl_tcp_server(CtdlGetConfigStr("c_ip_addr"), tcp_port, CtdlGetConfigInt("c_maxsessions"));
        snprintf(message, SIZ, "extensions: TCP port %s:%d: (%s) ", 
             CtdlGetConfigStr("c_ip_addr"), tcp_port, ServiceName);
    }
 
    if (newfcn->msock > 0) {
        ServiceHookTable = newfcn;
        strcat(message, "registered.");
        syslog(LOG_INFO, "%s", message);
    }
    else {
        AddPortError(message, "failed");
        strcat(message, "FAILED.");
        syslog(LOG_ERR, "%s", message);
        free(newfcn);
    }
    free(message);
}
 
 
void CtdlUnregisterServiceHook(int tcp_port, char *sockpath,
            void (*h_greeting_function) (void),
            void (*h_command_function) (void),
            void (*h_async_function) (void)
            )
{
    ServiceFunctionHook *cur, *p, *last;
 
    last = NULL;
    cur = ServiceHookTable;
    while (cur != NULL) {
        /* This will also remove duplicates if any */
        if (h_greeting_function == cur->h_greeting_function &&
            h_command_function == cur->h_command_function &&
            h_async_function == cur->h_async_function &&
            tcp_port == cur->tcp_port && 
            !(sockpath && cur->sockpath && strcmp(sockpath, cur->sockpath)) )
        {
            if (cur->msock > 0)
                close(cur->msock);
            if (sockpath) {
                syslog(LOG_INFO, "extensions: closed UNIX domain socket %s", sockpath);
                unlink(sockpath);
            } else if (tcp_port) {
                syslog(LOG_INFO, "extensions: closed TCP port %d", tcp_port);
            } else {
                syslog(LOG_INFO, "extensions: unregistered service \"%s\"", cur->ServiceName);
            }
            p = cur->next;
            free(cur);
            if (last != NULL)
                last->next = p;
            else
                ServiceHookTable = p;
            cur = p;
        }
        else {
            last = cur;
            cur = cur->next;
        }
    }
}
 
 
void CtdlShutdownServiceHooks(void)
{
    /* sort of a duplicate of close_masters() but called earlier */
    ServiceFunctionHook *cur;
 
    cur = ServiceHookTable;
    while (cur != NULL) 
    {
        if (cur->msock != -1)
        {
            close(cur->msock);
            cur->msock = -1;
            if (cur->sockpath != NULL){
                syslog(LOG_INFO, "extensions: [%s] Closed UNIX domain socket %s", cur->ServiceName, cur->sockpath);
                unlink(cur->sockpath);
            } else {
                syslog(LOG_INFO, "extensions: [%s] closing service", cur->ServiceName);
            }
        }
        cur = cur->next;
    }
}
 
 
void CtdlRegisterSearchFuncHook(void (*fcn_ptr)(int *, long **, const char *), char *name)
{
    SearchFunctionHook *newfcn;
 
    if (!name || !fcn_ptr) {
        return;
    }
    
    newfcn = (SearchFunctionHook *)
        malloc(sizeof(SearchFunctionHook));
    newfcn->next = SearchFunctionHookTable;
    newfcn->name = name;
    newfcn->fcn_ptr = fcn_ptr;
    SearchFunctionHookTable = newfcn;
 
    syslog(LOG_DEBUG, "extensions: registered a new search function (%s)", name);
}
 
void CtdlUnregisterSearchFuncHook(void (*fcn_ptr)(int *, long **, const char *), char *name)
{
    SearchFunctionHook *cur, *p, *last;
    
    last = NULL;
    cur = SearchFunctionHookTable;
    while (cur != NULL) {
        if (fcn_ptr &&
            (cur->fcn_ptr == fcn_ptr) &&
            name && !strcmp(name, cur->name))
        {
            syslog(LOG_DEBUG, "extensions: unregistered search function(%s)", name);
            p = cur->next;
            free (cur);
            if (last != NULL)
                last->next = p;
            else
                SearchFunctionHookTable = p;
            cur = p;
        }
        else {
            last = cur;
            cur = cur->next;
        }
    }
}
 
 
void CtdlModuleDoSearch(int *num_msgs, long **search_msgs, const char *search_string, const char *func_name)
{
    SearchFunctionHook *fcn = NULL;
 
    for (fcn = SearchFunctionHookTable; fcn != NULL; fcn = fcn->next) {
        if (!func_name || !strcmp(func_name, fcn->name)) {
            (*fcn->fcn_ptr) (num_msgs, search_msgs, search_string);
            return;
        }
    }
    *num_msgs = 0;
}
 
 
void PerformSessionHooks(int EventType)
{
    SessionFunctionHook *fcn = NULL;
 
    for (fcn = SessionHookTable; fcn != NULL; fcn = fcn->next) {
        if (fcn->eventtype == EventType) {
            if (EventType == EVT_TIMER) {
                pthread_setspecific(MyConKey, NULL);    /* for every hook */
            }
            (*fcn->h_function_pointer) ();
        }
    }
}
 
void PerformUserHooks(ctdluser *usbuf, int EventType)
{
    UserFunctionHook *fcn = NULL;
 
    for (fcn = UserHookTable; fcn != NULL; fcn = fcn->next) {
        if (fcn->eventtype == EventType) {
            (*fcn->h_function_pointer) (usbuf);
        }
    }
}
 
int PerformMessageHooks(struct CtdlMessage *msg, struct recptypes *recps, int EventType)
{
    MessageFunctionHook *fcn = NULL;
    int total_retval = 0;
 
    /* Other code may elect to protect this message from server-side
     * handlers; if this is the case, don't do anything.
     */
    if (msg->cm_flags & CM_SKIP_HOOKS) {
        return(0);
    }
 
    /* Otherwise, run all the hooks appropriate to this event type.
     */
    for (fcn = MessageHookTable; fcn != NULL; fcn = fcn->next) {
        if (fcn->eventtype == EventType) {
            total_retval = total_retval + (*fcn->h_function_pointer) (msg, recps);
        }
    }
 
    /* Return the sum of the return codes from the hook functions.  If
     * this is an EVT_BEFORESAVE event, a nonzero return code will cause
     * the save operation to abort.
     */
    return total_retval;
}
 
 
int PerformRoomHooks(struct ctdlroom *target_room)
{
    RoomFunctionHook *fcn;
    int total_retval = 0;
 
    syslog(LOG_DEBUG, "extensions: performing room hooks for <%s>", target_room->QRname);
 
    for (fcn = RoomHookTable; fcn != NULL; fcn = fcn->next) {
        total_retval = total_retval + (*fcn->fcn_ptr) (target_room);
    }
 
    /* Return the sum of the return codes from the hook functions.
     */
    return total_retval;
}
 
 
void PerformDeleteHooks(char *room, long msgnum)
{
    DeleteFunctionHook *fcn;
 
    for (fcn = DeleteHookTable; fcn != NULL; fcn = fcn->next) {
        (*fcn->h_function_pointer) (room, msgnum);
    }
}
 
 
int PerformXmsgHooks(char *sender, char *sender_email, char *recp, char *msg)
{
    XmsgFunctionHook *fcn;
    int total_sent = 0;
    int p;
 
    for (p=0; p<MAX_XMSG_PRI; ++p) {
        for (fcn = XmsgHookTable; fcn != NULL; fcn = fcn->next) {
            if (fcn->order == p) {
                total_sent +=
                    (*fcn->h_function_pointer)
                        (sender, sender_email, recp, msg);
            }
        }
        /* Break out of the loop if a higher-priority function
         * successfully delivered the message.  This prevents duplicate
         * deliveries to local users simultaneously signed onto
         * remote services.
         */
        if (total_sent) break;
    }
    return total_sent;
}
 
 
/*
 * Dirty hack until we impliment a hook mechanism for this
 */
void CtdlModuleStartCryptoMsgs(char *ok_response, char *nosup_response, char *error_response)
{
#ifdef HAVE_OPENSSL
    CtdlStartTLS (ok_response, nosup_response, error_response);
#endif
}
 
 
CTDL_MODULE_INIT(modules)
{
    if (!threading) {
    }
    return "modules";
}