citadel/dynloader.c

   1 /*******************************************************
   2  *
   3  * Citadel Dynamic Loading Module
   4  * Written by Brian Costello
   5  * btx@calyx.net
   6  *
   7  * $Id$
   8  *
   9  ******************************************************/
  10
  11
  12 #include "sysdep.h"
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <dlfcn.h>
  16 #include <sys/types.h>
  17 #include <dirent.h>
  18 #include <strings.h>
  19 #include <syslog.h>
  20 #ifdef HAVE_PTHREAD_H
  21 #include <pthread.h>
  22 #endif
  23 #include <limits.h>
  24 #include <ctype.h>
  25 #include "dynloader.h"
  26 #include "citadel.h"
  27 #include "server.h"
  28 #include "sysdep_decls.h"
  29 #include "tools.h"
  30
  31 #ifndef HAVE_SNPRINTF
  32 #include <stdarg.h>
  33 #include "snprintf.h"
  34 #endif
  35
  36 struct LogFunctionHook *LogHookTable = NULL;
  37 struct CleanupFunctionHook *CleanupHookTable = NULL;
  38 struct SessionFunctionHook *SessionHookTable = NULL;
  39 struct UserFunctionHook *UserHookTable = NULL;
  40
  41 struct ProtoFunctionHook {
  42         void (*handler) (char *cmdbuf);
  43         char *cmd;
  44         char *desc;
  45         struct ProtoFunctionHook *next;
  46 } *ProtoHookList = NULL;
  47
  48 void CtdlRegisterProtoHook(void (*handler) (char *), char *cmd, char *desc)
  49 {
  50         struct ProtoFunctionHook *p = mallok(sizeof *p);
  51
  52         if (p == NULL) {
  53                 fprintf(stderr, "can't malloc new ProtoFunctionHook\n");
  54                 exit(EXIT_FAILURE);
  55         }
  56         p->handler = handler;
  57         p->cmd = cmd;
  58         p->desc = desc;
  59         p->next = ProtoHookList;
  60         ProtoHookList = p;
  61         lprintf(5, "Registered server command %s (%s)\n", cmd, desc);
  62 }
  63
  64 int DLoader_Exec_Cmd(char *cmdbuf)
  65 {
  66         struct ProtoFunctionHook *p;
  67
  68         for (p = ProtoHookList; p; p = p->next) {
  69                 if (!strncasecmp(cmdbuf, p->cmd, 4)) {
  70                         p->handler(&cmdbuf[5]);
  71                         return 1;
  72                 }
  73         }
  74         return 0;
  75 }
  76
  77 void DLoader_Init(char *pathname)
  78 {
  79         void *fcn_handle;
  80         char dl_error[256];
  81         DIR *dir;
  82         int i;
  83         struct dirent *dptr;
  84         char *(*h_init_fcn) (void);
  85         char *dl_info;
  86
  87         char pathbuf[PATH_MAX];
  88
  89         if ((dir = opendir(pathname)) == NULL) {
  90                 perror("opendir");
  91                 exit(1);
  92         }
  93         while ((dptr = readdir(dir)) != NULL) {
  94                 if (dptr->d_name[0] == '.')
  95                         continue;
  96
  97                 snprintf(pathbuf, PATH_MAX, "%s/%s", pathname, dptr->d_name);
  98 #ifdef RTLD_NOW
  99                 if (!(fcn_handle = dlopen(pathbuf, RTLD_NOW)))
 100 #else                           /* OpenBSD */
 101                 if (!(fcn_handle = dlopen(pathbuf, DL_LAZY)))
 102 #endif
 103                 {
 104                         safestrncpy(dl_error, dlerror(), sizeof dl_error);
 105                         for (i=0; i<strlen(dl_error); ++i)
 106                                 if (!isprint(dl_error[i]))
 107                                         dl_error[i]='.';
 108                         fprintf(stderr, "DLoader_Init dlopen failed: %s\n",
 109                                 dl_error);
 110                         continue;
 111                 }
 112                 h_init_fcn = (char * (*)(void))
 113 #ifndef __OpenBSD__
 114                     dlsym(fcn_handle, "Dynamic_Module_Init");
 115 #else
 116                     dlsym(fcn_handle, "_Dynamic_Module_Init");
 117 #endif
 118
 119                 if (dlerror() != NULL) {
 120                         fprintf(stderr, "DLoader_Init dlsym failed\n");
 121                         continue;
 122                 }
 123                 dl_info = h_init_fcn();
 124
 125                 lprintf(3, "Loaded module: %s\n", dl_info);
 126         }       /* While */
 127 }
 128
 129
 130
 131 void CtdlRegisterLogHook(void (*fcn_ptr) (char *), int loglevel)
 132 {
 133
 134         struct LogFunctionHook *newfcn;
 135
 136         newfcn = (struct LogFunctionHook *)
 137             mallok(sizeof(struct LogFunctionHook));
 138         newfcn->next = LogHookTable;
 139         newfcn->h_function_pointer = fcn_ptr;
 140         newfcn->loglevel = loglevel;
 141         LogHookTable = newfcn;
 142
 143         lprintf(5, "Registered a new logging function\n");
 144 }
 145
 146
 147 void CtdlRegisterCleanupHook(void (*fcn_ptr) (void))
 148 {
 149
 150         struct CleanupFunctionHook *newfcn;
 151
 152         newfcn = (struct CleanupFunctionHook *)
 153             mallok(sizeof(struct CleanupFunctionHook));
 154         newfcn->next = CleanupHookTable;
 155         newfcn->h_function_pointer = fcn_ptr;
 156         CleanupHookTable = newfcn;
 157
 158         lprintf(5, "Registered a new cleanup function\n");
 159 }
 160
 161
 162 void CtdlRegisterSessionHook(void (*fcn_ptr) (void), int EventType)
 163 {
 164
 165         struct SessionFunctionHook *newfcn;
 166
 167         newfcn = (struct SessionFunctionHook *)
 168             mallok(sizeof(struct SessionFunctionHook));
 169         newfcn->next = SessionHookTable;
 170         newfcn->h_function_pointer = fcn_ptr;
 171         newfcn->eventtype = EventType;
 172         SessionHookTable = newfcn;
 173
 174         lprintf(5, "Registered a new session function (type %d)\n",
 175                 EventType);
 176 }
 177
 178
 179 void CtdlRegisterUserHook(void (*fcn_ptr) (char *, long), int EventType)
 180 {
 181
 182         struct UserFunctionHook *newfcn;
 183
 184         newfcn = (struct UserFunctionHook *)
 185             mallok(sizeof(struct UserFunctionHook));
 186         newfcn->next = UserHookTable;
 187         newfcn->h_function_pointer = fcn_ptr;
 188         newfcn->eventtype = EventType;
 189         UserHookTable = newfcn;
 190
 191         lprintf(5, "Registered a new user function (type %d)\n",
 192                 EventType);
 193 }
 194
 195
 196 void PerformSessionHooks(int EventType)
 197 {
 198         struct SessionFunctionHook *fcn;
 199
 200         for (fcn = SessionHookTable; fcn != NULL; fcn = fcn->next) {
 201                 if (fcn->eventtype == EventType) {
 202                         (*fcn->h_function_pointer) ();
 203                 }
 204         }
 205 }
 206
 207 void PerformLogHooks(int loglevel, char *logmsg)
 208 {
 209         struct LogFunctionHook *fcn;
 210
 211         for (fcn = LogHookTable; fcn != NULL; fcn = fcn->next) {
 212                 if (fcn->loglevel >= loglevel) {
 213                         (*fcn->h_function_pointer) (logmsg);
 214                 }
 215         }
 216 }
 217
 218 void PerformUserHooks(char *username, long usernum, int EventType)
 219 {
 220         struct UserFunctionHook *fcn;
 221
 222         for (fcn = UserHookTable; fcn != NULL; fcn = fcn->next) {
 223                 if (fcn->eventtype == EventType) {
 224                         (*fcn->h_function_pointer) (username, usernum);
 225                 }
 226         }
 227 }