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 struct ServiceFunctionHook *ServiceHookTable = NULL;
  41
  42 struct ProtoFunctionHook {
  43         void (*handler) (char *cmdbuf);
  44         char *cmd;
  45         char *desc;
  46         struct ProtoFunctionHook *next;
  47 } *ProtoHookList = NULL;
  48
  49 void CtdlRegisterProtoHook(void (*handler) (char *), char *cmd, char *desc)
  50 {
  51         struct ProtoFunctionHook *p = mallok(sizeof *p);
  52
  53         if (p == NULL) {
  54                 fprintf(stderr, "can't malloc new ProtoFunctionHook\n");
  55                 exit(EXIT_FAILURE);
  56         }
  57         p->handler = handler;
  58         p->cmd = cmd;
  59         p->desc = desc;
  60         p->next = ProtoHookList;
  61         ProtoHookList = p;
  62         lprintf(5, "Registered server command %s (%s)\n", cmd, desc);
  63 }
  64
  65 int DLoader_Exec_Cmd(char *cmdbuf)
  66 {
  67         struct ProtoFunctionHook *p;
  68
  69         for (p = ProtoHookList; p; p = p->next) {
  70                 if (!strncasecmp(cmdbuf, p->cmd, 4)) {
  71                         p->handler(&cmdbuf[5]);
  72                         return 1;
  73                 }
  74         }
  75         return 0;
  76 }
  77
  78 void DLoader_Init(char *pathname)
  79 {
  80         void *fcn_handle;
  81         char dl_error[256];
  82         DIR *dir;
  83         int i;
  84         struct dirent *dptr;
  85         char *(*h_init_fcn) (void);
  86         char *dl_info;
  87
  88         char pathbuf[PATH_MAX];
  89
  90         if ((dir = opendir(pathname)) == NULL) {
  91                 perror("opendir");
  92                 exit(1);
  93         }
  94         while ((dptr = readdir(dir)) != NULL) {
  95                 if (strlen(dptr->d_name) < 4)
  96                         continue;
  97                 if (strcasecmp(&dptr->d_name[strlen(dptr->d_name)-3], ".so"))
  98                         continue;
  99
 100                 snprintf(pathbuf, PATH_MAX, "%s/%s", pathname, dptr->d_name);
 101 #ifdef RTLD_NOW
 102                 if (!(fcn_handle = dlopen(pathbuf, RTLD_NOW)))
 103 #else                           /* OpenBSD */
 104                 if (!(fcn_handle = dlopen(pathbuf, DL_LAZY)))
 105 #endif
 106                 {
 107                         safestrncpy(dl_error, dlerror(), sizeof dl_error);
 108                         for (i=0; i<strlen(dl_error); ++i)
 109                                 if (!isprint(dl_error[i]))
 110                                         dl_error[i]='.';
 111                         fprintf(stderr, "DLoader_Init dlopen failed: %s\n",
 112                                 dl_error);
 113                         continue;
 114                 }
 115                 h_init_fcn = (char * (*)(void))
 116 #ifndef __OpenBSD__
 117                     dlsym(fcn_handle, "Dynamic_Module_Init");
 118 #else
 119                     dlsym(fcn_handle, "_Dynamic_Module_Init");
 120 #endif
 121
 122                 if (dlerror() != NULL) {
 123                         fprintf(stderr, "DLoader_Init dlsym failed\n");
 124                         continue;
 125                 }
 126                 dl_info = h_init_fcn();
 127
 128                 lprintf(3, "Loaded module: %s\n", dl_info);
 129         }       /* While */
 130 }
 131
 132
 133
 134 void CtdlRegisterLogHook(void (*fcn_ptr) (char *), int loglevel)
 135 {
 136
 137         struct LogFunctionHook *newfcn;
 138
 139         newfcn = (struct LogFunctionHook *)
 140             mallok(sizeof(struct LogFunctionHook));
 141         newfcn->next = LogHookTable;
 142         newfcn->h_function_pointer = fcn_ptr;
 143         newfcn->loglevel = loglevel;
 144         LogHookTable = newfcn;
 145
 146         lprintf(5, "Registered a new logging function\n");
 147 }
 148
 149
 150 void CtdlRegisterCleanupHook(void (*fcn_ptr) (void))
 151 {
 152
 153         struct CleanupFunctionHook *newfcn;
 154
 155         newfcn = (struct CleanupFunctionHook *)
 156             mallok(sizeof(struct CleanupFunctionHook));
 157         newfcn->next = CleanupHookTable;
 158         newfcn->h_function_pointer = fcn_ptr;
 159         CleanupHookTable = newfcn;
 160
 161         lprintf(5, "Registered a new cleanup function\n");
 162 }
 163
 164
 165 void CtdlRegisterSessionHook(void (*fcn_ptr) (void), int EventType)
 166 {
 167
 168         struct SessionFunctionHook *newfcn;
 169
 170         newfcn = (struct SessionFunctionHook *)
 171             mallok(sizeof(struct SessionFunctionHook));
 172         newfcn->next = SessionHookTable;
 173         newfcn->h_function_pointer = fcn_ptr;
 174         newfcn->eventtype = EventType;
 175         SessionHookTable = newfcn;
 176
 177         lprintf(5, "Registered a new session function (type %d)\n",
 178                 EventType);
 179 }
 180
 181
 182 void CtdlRegisterUserHook(void (*fcn_ptr) (char *, long), int EventType)
 183 {
 184
 185         struct UserFunctionHook *newfcn;
 186
 187         newfcn = (struct UserFunctionHook *)
 188             mallok(sizeof(struct UserFunctionHook));
 189         newfcn->next = UserHookTable;
 190         newfcn->h_function_pointer = fcn_ptr;
 191         newfcn->eventtype = EventType;
 192         UserHookTable = newfcn;
 193
 194         lprintf(5, "Registered a new user function (type %d)\n",
 195                 EventType);
 196 }
 197
 198
 199 void CtdlRegisterMessageHook(int (*handler)(struct CtdlMessage *),
 200                                 int EventType)
 201 {
 202
 203         struct MessageFunctionHook *newfcn;
 204
 205         newfcn = (struct MessageFunctionHook *)
 206             mallok(sizeof(struct MessageFunctionHook));
 207         newfcn->next = MessageHookTable;
 208         newfcn->h_function_pointer = handler;
 209         newfcn->eventtype = EventType;
 210         MessageHookTable = newfcn;
 211
 212         lprintf(5, "Registered a new message function (type %d)\n",
 213                 EventType);
 214 }
 215
 216
 217 void CtdlRegisterXmsgHook(int (*fcn_ptr) (char *, char *, char *), int order)
 218 {
 219
 220         struct XmsgFunctionHook *newfcn;
 221
 222         newfcn = (struct XmsgFunctionHook *)
 223             mallok(sizeof(struct XmsgFunctionHook));
 224         newfcn->next = XmsgHookTable;
 225         newfcn->order = order;
 226         newfcn->h_function_pointer = fcn_ptr;
 227         XmsgHookTable = newfcn;
 228         lprintf(5, "Registered a new x-msg function (priority %d)\n", order);
 229 }
 230
 231 void CtdlRegisterServiceHook(int tcp_port,
 232                         void (*h_greeting_function) (void),
 233                         void (*h_command_function) (void) )
 234 {
 235         struct ServiceFunctionHook *newfcn;
 236
 237         newfcn = (struct ServiceFunctionHook *)
 238             mallok(sizeof(struct ServiceFunctionHook));
 239         newfcn->next = ServiceHookTable;
 240         newfcn->tcp_port = tcp_port;
 241         newfcn->h_greeting_function = h_greeting_function;
 242         newfcn->h_command_function = h_command_function;
 243         newfcn->msock = (-1);
 244         ServiceHookTable = newfcn;
 245         lprintf(5, "Registered a new service (TCP port %d)\n", tcp_port);
 246 }
 247
 248
 249
 250 void PerformSessionHooks(int EventType)
 251 {
 252         struct SessionFunctionHook *fcn;
 253
 254         for (fcn = SessionHookTable; fcn != NULL; fcn = fcn->next) {
 255                 if (fcn->eventtype == EventType) {
 256                         (*fcn->h_function_pointer) ();
 257                 }
 258         }
 259 }
 260
 261 void PerformLogHooks(int loglevel, char *logmsg)
 262 {
 263         struct LogFunctionHook *fcn;
 264
 265         for (fcn = LogHookTable; fcn != NULL; fcn = fcn->next) {
 266                 if (fcn->loglevel >= loglevel) {
 267                         (*fcn->h_function_pointer) (logmsg);
 268                 }
 269         }
 270 }
 271
 272 void PerformUserHooks(char *username, long usernum, int EventType)
 273 {
 274         struct UserFunctionHook *fcn;
 275
 276         for (fcn = UserHookTable; fcn != NULL; fcn = fcn->next) {
 277                 if (fcn->eventtype == EventType) {
 278                         (*fcn->h_function_pointer) (username, usernum);
 279                 }
 280         }
 281 }
 282
 283 int PerformMessageHooks(struct CtdlMessage *msg, int EventType)
 284 {
 285         struct MessageFunctionHook *fcn;
 286         int total_retval = 0;
 287
 288         /* Other code may elect to protect this message from server-side
 289          * handlers; if this is the case, don't do anything.
 290          */
 291         lprintf(9, "** Event type is %d, flags are %d\n",
 292                 EventType, msg->cm_flags);
 293         if (msg->cm_flags & CM_SKIP_HOOKS) {
 294                 lprintf(9, "Skipping hooks\n");
 295                 return(0);
 296         }
 297
 298         /* Otherwise, run all the hooks appropriate to this event type.
 299          */
 300         for (fcn = MessageHookTable; fcn != NULL; fcn = fcn->next) {
 301                 if (fcn->eventtype == EventType) {
 302                         total_retval = total_retval +
 303                                 (*fcn->h_function_pointer) (msg);
 304                 }
 305         }
 306
 307         /* Return the sum of the return codes from the hook functions.  If
 308          * this is an EVT_BEFORESAVE event, a nonzero return code will cause
 309          * the save operation to abort.
 310          */
 311         return total_retval;
 312 }
 313
 314
 315
 316 int PerformXmsgHooks(char *sender, char *recp, char *msg)
 317 {
 318         struct XmsgFunctionHook *fcn;
 319         int total_sent = 0;
 320         int p;
 321
 322         for (p=0; p<MAX_XMSG_PRI; ++p) {
 323                 for (fcn = XmsgHookTable; fcn != NULL; fcn = fcn->next) {
 324                         if (fcn->order == p) {
 325                                 total_sent +=
 326                                         (*fcn->h_function_pointer)
 327                                                 (sender, recp, msg);
 328                         }
 329                 }
 330                 /* Break out of the loop if a higher-priority function
 331                  * successfully delivered the message.  This prevents duplicate
 332                  * deliveries to local users simultaneously signed onto
 333                  * remote services.
 334                  */
 335                 if (total_sent) goto DONE;
 336         }
 337 DONE:   return total_sent;
 338 }