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 "citadel.h"
  26 #include "server.h"
  27 #include "dynloader.h"
  28 #include "sysdep_decls.h"
  29 #include "msgbase.h"
  30 #include "tools.h"
  31
  32 #ifndef HAVE_SNPRINTF
  33 #include <stdarg.h>
  34 #include "snprintf.h"
  35 #endif
  36
  37 struct LogFunctionHook *LogHookTable = NULL;
  38 struct CleanupFunctionHook *CleanupHookTable = NULL;
  39 struct SessionFunctionHook *SessionHookTable = NULL;
  40 struct UserFunctionHook *UserHookTable = NULL;
  41 struct XmsgFunctionHook *XmsgHookTable = NULL;
  42 struct MessageFunctionHook *MessageHookTable = NULL;
  43
  44 struct ProtoFunctionHook {
  45         void (*handler) (char *cmdbuf);
  46         char *cmd;
  47         char *desc;
  48         struct ProtoFunctionHook *next;
  49 } *ProtoHookList = NULL;
  50
  51 void CtdlRegisterProtoHook(void (*handler) (char *), char *cmd, char *desc)
  52 {
  53         struct ProtoFunctionHook *p = mallok(sizeof *p);
  54
  55         if (p == NULL) {
  56                 fprintf(stderr, "can't malloc new ProtoFunctionHook\n");
  57                 exit(EXIT_FAILURE);
  58         }
  59         p->handler = handler;
  60         p->cmd = cmd;
  61         p->desc = desc;
  62         p->next = ProtoHookList;
  63         ProtoHookList = p;
  64         lprintf(5, "Registered server command %s (%s)\n", cmd, desc);
  65 }
  66
  67 int DLoader_Exec_Cmd(char *cmdbuf)
  68 {
  69         struct ProtoFunctionHook *p;
  70
  71         for (p = ProtoHookList; p; p = p->next) {
  72                 if (!strncasecmp(cmdbuf, p->cmd, 4)) {
  73                         p->handler(&cmdbuf[5]);
  74                         return 1;
  75                 }
  76         }
  77         return 0;
  78 }
  79
  80 void DLoader_Init(char *pathname)
  81 {
  82         void *fcn_handle;
  83         char dl_error[256];
  84         DIR *dir;
  85         int i;
  86         struct dirent *dptr;
  87         char *(*h_init_fcn) (void);
  88         char *dl_info;
  89
  90         char pathbuf[PATH_MAX];
  91
  92         if ((dir = opendir(pathname)) == NULL) {
  93                 perror("opendir");
  94                 exit(1);
  95         }
  96         while ((dptr = readdir(dir)) != NULL) {
  97                 if (strlen(dptr->d_name) < 4)
  98                         continue;
  99                 if (strcasecmp(&dptr->d_name[strlen(dptr->d_name)-3], ".so"))
 100                         continue;
 101
 102                 snprintf(pathbuf, PATH_MAX, "%s/%s", pathname, dptr->d_name);
 103 #ifdef RTLD_NOW
 104                 if (!(fcn_handle = dlopen(pathbuf, RTLD_NOW)))
 105 #else                           /* OpenBSD */
 106                 if (!(fcn_handle = dlopen(pathbuf, DL_LAZY)))
 107 #endif
 108                 {
 109                         safestrncpy(dl_error, dlerror(), sizeof dl_error);
 110                         for (i=0; i<strlen(dl_error); ++i)
 111                                 if (!isprint(dl_error[i]))
 112                                         dl_error[i]='.';
 113                         fprintf(stderr, "DLoader_Init dlopen failed: %s\n",
 114                                 dl_error);
 115                         continue;
 116                 }
 117                 h_init_fcn = (char * (*)(void))
 118 #ifndef __OpenBSD__
 119                     dlsym(fcn_handle, "Dynamic_Module_Init");
 120 #else
 121                     dlsym(fcn_handle, "_Dynamic_Module_Init");
 122 #endif
 123
 124                 if (dlerror() != NULL) {
 125                         fprintf(stderr, "DLoader_Init dlsym failed\n");
 126                         continue;
 127                 }
 128                 dl_info = h_init_fcn();
 129
 130                 lprintf(3, "Loaded module: %s\n", dl_info);
 131         }       /* While */
 132 }
 133
 134
 135
 136 void CtdlRegisterLogHook(void (*fcn_ptr) (char *), int loglevel)
 137 {
 138
 139         struct LogFunctionHook *newfcn;
 140
 141         newfcn = (struct LogFunctionHook *)
 142             mallok(sizeof(struct LogFunctionHook));
 143         newfcn->next = LogHookTable;
 144         newfcn->h_function_pointer = fcn_ptr;
 145         newfcn->loglevel = loglevel;
 146         LogHookTable = newfcn;
 147
 148         lprintf(5, "Registered a new logging function\n");
 149 }
 150
 151
 152 void CtdlRegisterCleanupHook(void (*fcn_ptr) (void))
 153 {
 154
 155         struct CleanupFunctionHook *newfcn;
 156
 157         newfcn = (struct CleanupFunctionHook *)
 158             mallok(sizeof(struct CleanupFunctionHook));
 159         newfcn->next = CleanupHookTable;
 160         newfcn->h_function_pointer = fcn_ptr;
 161         CleanupHookTable = newfcn;
 162
 163         lprintf(5, "Registered a new cleanup function\n");
 164 }
 165
 166
 167 void CtdlRegisterSessionHook(void (*fcn_ptr) (void), int EventType)
 168 {
 169
 170         struct SessionFunctionHook *newfcn;
 171
 172         newfcn = (struct SessionFunctionHook *)
 173             mallok(sizeof(struct SessionFunctionHook));
 174         newfcn->next = SessionHookTable;
 175         newfcn->h_function_pointer = fcn_ptr;
 176         newfcn->eventtype = EventType;
 177         SessionHookTable = newfcn;
 178
 179         lprintf(5, "Registered a new session function (type %d)\n",
 180                 EventType);
 181 }
 182
 183
 184 void CtdlRegisterUserHook(void (*fcn_ptr) (char *, long), int EventType)
 185 {
 186
 187         struct UserFunctionHook *newfcn;
 188
 189         newfcn = (struct UserFunctionHook *)
 190             mallok(sizeof(struct UserFunctionHook));
 191         newfcn->next = UserHookTable;
 192         newfcn->h_function_pointer = fcn_ptr;
 193         newfcn->eventtype = EventType;
 194         UserHookTable = newfcn;
 195
 196         lprintf(5, "Registered a new user function (type %d)\n",
 197                 EventType);
 198 }
 199
 200
 201 void CtdlRegisterMessageHook(int (*handler)(struct CtdlMessage *),
 202                                 int EventType)
 203 {
 204
 205         struct MessageFunctionHook *newfcn;
 206
 207         newfcn = (struct MessageFunctionHook *)
 208             mallok(sizeof(struct MessageFunctionHook));
 209         newfcn->next = MessageHookTable;
 210         newfcn->h_function_pointer = handler;
 211         newfcn->eventtype = EventType;
 212         MessageHookTable = newfcn;
 213
 214         lprintf(5, "Registered a new message function (type %d)\n",
 215                 EventType);
 216 }
 217
 218
 219 void CtdlRegisterXmsgHook(int (*fcn_ptr) (char *, char *, char *), int order)
 220 {
 221
 222         struct XmsgFunctionHook *newfcn;
 223
 224         newfcn = (struct XmsgFunctionHook *)
 225             mallok(sizeof(struct XmsgFunctionHook));
 226         newfcn->next = XmsgHookTable;
 227         newfcn->order = order;
 228         newfcn->h_function_pointer = fcn_ptr;
 229         XmsgHookTable = newfcn;
 230         lprintf(5, "Registered a new x-msg function (priority %d)\n", order);
 231 }
 232
 233
 234 void PerformSessionHooks(int EventType)
 235 {
 236         struct SessionFunctionHook *fcn;
 237
 238         for (fcn = SessionHookTable; fcn != NULL; fcn = fcn->next) {
 239                 if (fcn->eventtype == EventType) {
 240                         (*fcn->h_function_pointer) ();
 241                 }
 242         }
 243 }
 244
 245 void PerformLogHooks(int loglevel, char *logmsg)
 246 {
 247         struct LogFunctionHook *fcn;
 248
 249         for (fcn = LogHookTable; fcn != NULL; fcn = fcn->next) {
 250                 if (fcn->loglevel >= loglevel) {
 251                         (*fcn->h_function_pointer) (logmsg);
 252                 }
 253         }
 254 }
 255
 256 void PerformUserHooks(char *username, long usernum, int EventType)
 257 {
 258         struct UserFunctionHook *fcn;
 259
 260         for (fcn = UserHookTable; fcn != NULL; fcn = fcn->next) {
 261                 if (fcn->eventtype == EventType) {
 262                         (*fcn->h_function_pointer) (username, usernum);
 263                 }
 264         }
 265 }
 266
 267 int PerformMessageHooks(struct CtdlMessage *msg, int EventType)
 268 {
 269         struct MessageFunctionHook *fcn;
 270         int total_retval = 0;
 271
 272         /* Other code may elect to protect this message from server-side
 273          * handlers; if this is the case, don't do anything.
 274          */
 275         lprintf(9, "** Event type is %d, flags are %d\n",
 276                 EventType, msg->cm_flags);
 277         if (msg->cm_flags & CM_SKIP_HOOKS) {
 278                 lprintf(9, "Skipping hooks\n");
 279                 return(0);
 280         }
 281
 282         /* Otherwise, run all the hooks appropriate to this event type.
 283          */
 284         for (fcn = MessageHookTable; fcn != NULL; fcn = fcn->next) {
 285                 if (fcn->eventtype == EventType) {
 286                         total_retval = total_retval +
 287                                 (*fcn->h_function_pointer) (msg);
 288                 }
 289         }
 290
 291         /* Return the sum of the return codes from the hook functions.  If
 292          * this is an EVT_BEFORESAVE event, a nonzero return code will cause
 293          * the save operation to abort.
 294          */
 295         return total_retval;
 296 }
 297
 298
 299
 300 int PerformXmsgHooks(char *sender, char *recp, char *msg)
 301 {
 302         struct XmsgFunctionHook *fcn;
 303         int total_sent = 0;
 304         int p;
 305
 306         for (p=0; p<MAX_XMSG_PRI; ++p) {
 307                 for (fcn = XmsgHookTable; fcn != NULL; fcn = fcn->next) {
 308                         if (fcn->order == p) {
 309                                 total_sent +=
 310                                         (*fcn->h_function_pointer)
 311                                                 (sender, recp, msg);
 312                         }
 313                 }
 314                 /* Break out of the loop if a higher-priority function
 315                  * successfully delivered the message.  This prevents duplicate
 316                  * deliveries to local users simultaneously signed onto
 317                  * remote services.
 318                  */
 319                 if (total_sent) goto DONE;
 320         }
 321 DONE:   return total_sent;
 322 }