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 #include <limits.h>
  21 #include <ctype.h>
  22 #include "citadel.h"
  23 #include "server.h"
  24 #include "dynloader.h"
  25 #include "sysdep_decls.h"
  26 #include "msgbase.h"
  27 #include "tools.h"
  28
  29 #ifndef HAVE_SNPRINTF
  30 #include <stdarg.h>
  31 #include "snprintf.h"
  32 #endif
  33
  34 struct LogFunctionHook *LogHookTable = NULL;
  35 struct CleanupFunctionHook *CleanupHookTable = NULL;
  36 struct SessionFunctionHook *SessionHookTable = NULL;
  37 struct UserFunctionHook *UserHookTable = NULL;
  38 struct XmsgFunctionHook *XmsgHookTable = NULL;
  39 struct MessageFunctionHook *MessageHookTable = 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 (strlen(dptr->d_name) < 4)
  95                         continue;
  96                 if (strcasecmp(&dptr->d_name[strlen(dptr->d_name)-3], ".so"))
  97                         continue;
  98
  99                 snprintf(pathbuf, PATH_MAX, "%s/%s", pathname, dptr->d_name);
 100 #ifdef RTLD_NOW
 101                 if (!(fcn_handle = dlopen(pathbuf, RTLD_NOW)))
 102 #else                           /* OpenBSD */
 103                 if (!(fcn_handle = dlopen(pathbuf, DL_LAZY)))
 104 #endif
 105                 {
 106                         safestrncpy(dl_error, dlerror(), sizeof dl_error);
 107                         for (i=0; i<strlen(dl_error); ++i)
 108                                 if (!isprint(dl_error[i]))
 109                                         dl_error[i]='.';
 110                         fprintf(stderr, "DLoader_Init dlopen failed: %s\n",
 111                                 dl_error);
 112                         continue;
 113                 }
 114                 h_init_fcn = (char * (*)(void))
 115 #ifndef __OpenBSD__
 116                     dlsym(fcn_handle, "Dynamic_Module_Init");
 117 #else
 118                     dlsym(fcn_handle, "_Dynamic_Module_Init");
 119 #endif
 120
 121                 if (dlerror() != NULL) {
 122                         fprintf(stderr, "DLoader_Init dlsym failed\n");
 123                         continue;
 124                 }
 125                 dl_info = h_init_fcn();
 126
 127                 lprintf(3, "Loaded module: %s\n", dl_info);
 128         }       /* While */
 129 }
 130
 131
 132
 133 void CtdlRegisterLogHook(void (*fcn_ptr) (char *), int loglevel)
 134 {
 135
 136         struct LogFunctionHook *newfcn;
 137
 138         newfcn = (struct LogFunctionHook *)
 139             mallok(sizeof(struct LogFunctionHook));
 140         newfcn->next = LogHookTable;
 141         newfcn->h_function_pointer = fcn_ptr;
 142         newfcn->loglevel = loglevel;
 143         LogHookTable = newfcn;
 144
 145         lprintf(5, "Registered a new logging function\n");
 146 }
 147
 148
 149 void CtdlRegisterCleanupHook(void (*fcn_ptr) (void))
 150 {
 151
 152         struct CleanupFunctionHook *newfcn;
 153
 154         newfcn = (struct CleanupFunctionHook *)
 155             mallok(sizeof(struct CleanupFunctionHook));
 156         newfcn->next = CleanupHookTable;
 157         newfcn->h_function_pointer = fcn_ptr;
 158         CleanupHookTable = newfcn;
 159
 160         lprintf(5, "Registered a new cleanup function\n");
 161 }
 162
 163
 164 void CtdlRegisterSessionHook(void (*fcn_ptr) (void), int EventType)
 165 {
 166
 167         struct SessionFunctionHook *newfcn;
 168
 169         newfcn = (struct SessionFunctionHook *)
 170             mallok(sizeof(struct SessionFunctionHook));
 171         newfcn->next = SessionHookTable;
 172         newfcn->h_function_pointer = fcn_ptr;
 173         newfcn->eventtype = EventType;
 174         SessionHookTable = newfcn;
 175
 176         lprintf(5, "Registered a new session function (type %d)\n",
 177                 EventType);
 178 }
 179
 180
 181 void CtdlRegisterUserHook(void (*fcn_ptr) (char *, long), int EventType)
 182 {
 183
 184         struct UserFunctionHook *newfcn;
 185
 186         newfcn = (struct UserFunctionHook *)
 187             mallok(sizeof(struct UserFunctionHook));
 188         newfcn->next = UserHookTable;
 189         newfcn->h_function_pointer = fcn_ptr;
 190         newfcn->eventtype = EventType;
 191         UserHookTable = newfcn;
 192
 193         lprintf(5, "Registered a new user function (type %d)\n",
 194                 EventType);
 195 }
 196
 197
 198 void CtdlRegisterMessageHook(int (*handler)(struct CtdlMessage *),
 199                                 int EventType)
 200 {
 201
 202         struct MessageFunctionHook *newfcn;
 203
 204         newfcn = (struct MessageFunctionHook *)
 205             mallok(sizeof(struct MessageFunctionHook));
 206         newfcn->next = MessageHookTable;
 207         newfcn->h_function_pointer = handler;
 208         newfcn->eventtype = EventType;
 209         MessageHookTable = newfcn;
 210
 211         lprintf(5, "Registered a new message function (type %d)\n",
 212                 EventType);
 213 }
 214
 215
 216 void CtdlRegisterXmsgHook(int (*fcn_ptr) (char *, char *, char *), int order)
 217 {
 218
 219         struct XmsgFunctionHook *newfcn;
 220
 221         newfcn = (struct XmsgFunctionHook *)
 222             mallok(sizeof(struct XmsgFunctionHook));
 223         newfcn->next = XmsgHookTable;
 224         newfcn->order = order;
 225         newfcn->h_function_pointer = fcn_ptr;
 226         XmsgHookTable = newfcn;
 227         lprintf(5, "Registered a new x-msg function (priority %d)\n", order);
 228 }
 229
 230
 231 void PerformSessionHooks(int EventType)
 232 {
 233         struct SessionFunctionHook *fcn;
 234
 235         for (fcn = SessionHookTable; fcn != NULL; fcn = fcn->next) {
 236                 if (fcn->eventtype == EventType) {
 237                         (*fcn->h_function_pointer) ();
 238                 }
 239         }
 240 }
 241
 242 void PerformLogHooks(int loglevel, char *logmsg)
 243 {
 244         struct LogFunctionHook *fcn;
 245
 246         for (fcn = LogHookTable; fcn != NULL; fcn = fcn->next) {
 247                 if (fcn->loglevel >= loglevel) {
 248                         (*fcn->h_function_pointer) (logmsg);
 249                 }
 250         }
 251 }
 252
 253 void PerformUserHooks(char *username, long usernum, int EventType)
 254 {
 255         struct UserFunctionHook *fcn;
 256
 257         for (fcn = UserHookTable; fcn != NULL; fcn = fcn->next) {
 258                 if (fcn->eventtype == EventType) {
 259                         (*fcn->h_function_pointer) (username, usernum);
 260                 }
 261         }
 262 }
 263
 264 int PerformMessageHooks(struct CtdlMessage *msg, int EventType)
 265 {
 266         struct MessageFunctionHook *fcn;
 267         int total_retval = 0;
 268
 269         /* Other code may elect to protect this message from server-side
 270          * handlers; if this is the case, don't do anything.
 271          */
 272         lprintf(9, "** Event type is %d, flags are %d\n",
 273                 EventType, msg->cm_flags);
 274         if (msg->cm_flags & CM_SKIP_HOOKS) {
 275                 lprintf(9, "Skipping hooks\n");
 276                 return(0);
 277         }
 278
 279         /* Otherwise, run all the hooks appropriate to this event type.
 280          */
 281         for (fcn = MessageHookTable; fcn != NULL; fcn = fcn->next) {
 282                 if (fcn->eventtype == EventType) {
 283                         total_retval = total_retval +
 284                                 (*fcn->h_function_pointer) (msg);
 285                 }
 286         }
 287
 288         /* Return the sum of the return codes from the hook functions.  If
 289          * this is an EVT_BEFORESAVE event, a nonzero return code will cause
 290          * the save operation to abort.
 291          */
 292         return total_retval;
 293 }
 294
 295
 296
 297 int PerformXmsgHooks(char *sender, char *recp, char *msg)
 298 {
 299         struct XmsgFunctionHook *fcn;
 300         int total_sent = 0;
 301         int p;
 302
 303         for (p=0; p<MAX_XMSG_PRI; ++p) {
 304                 for (fcn = XmsgHookTable; fcn != NULL; fcn = fcn->next) {
 305                         if (fcn->order == p) {
 306                                 total_sent +=
 307                                         (*fcn->h_function_pointer)
 308                                                 (sender, recp, msg);
 309                         }
 310                 }
 311                 /* Break out of the loop if a higher-priority function
 312                  * successfully delivered the message.  This prevents duplicate
 313                  * deliveries to local users simultaneously signed onto
 314                  * remote services.
 315                  */
 316                 if (total_sent) goto DONE;
 317         }
 318 DONE:   return total_sent;
 319 }