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 #include "config.h"
  29
  30 #ifndef HAVE_SNPRINTF
  31 #include <stdarg.h>
  32 #include "snprintf.h"
  33 #endif
  34
  35 struct LogFunctionHook *LogHookTable = NULL;
  36 struct CleanupFunctionHook *CleanupHookTable = NULL;
  37 struct SessionFunctionHook *SessionHookTable = NULL;
  38 struct UserFunctionHook *UserHookTable = NULL;
  39 struct XmsgFunctionHook *XmsgHookTable = NULL;
  40 struct MessageFunctionHook *MessageHookTable = NULL;
  41 struct ServiceFunctionHook *ServiceHookTable = NULL;
  42
  43 struct ProtoFunctionHook {
  44         void (*handler) (char *cmdbuf);
  45         char *cmd;
  46         char *desc;
  47         struct ProtoFunctionHook *next;
  48 } *ProtoHookList = NULL;
  49
  50 void CtdlRegisterProtoHook(void (*handler) (char *), char *cmd, char *desc)
  51 {
  52         struct ProtoFunctionHook *p = mallok(sizeof *p);
  53
  54         if (p == NULL) {
  55                 fprintf(stderr, "can't malloc new ProtoFunctionHook\n");
  56                 exit(EXIT_FAILURE);
  57         }
  58         p->handler = handler;
  59         p->cmd = cmd;
  60         p->desc = desc;
  61         p->next = ProtoHookList;
  62         ProtoHookList = p;
  63         lprintf(5, "Registered server command %s (%s)\n", cmd, desc);
  64 }
  65
  66 int DLoader_Exec_Cmd(char *cmdbuf)
  67 {
  68         struct ProtoFunctionHook *p;
  69
  70         for (p = ProtoHookList; p; p = p->next) {
  71                 if (!strncasecmp(cmdbuf, p->cmd, 4)) {
  72                         p->handler(&cmdbuf[5]);
  73                         return 1;
  74                 }
  75         }
  76         return 0;
  77 }
  78
  79 void DLoader_Init(char *pathname)
  80 {
  81         void *fcn_handle;
  82         char dl_error[256];
  83         DIR *dir;
  84         int i;
  85         struct dirent *dptr;
  86         char *(*h_init_fcn) (void);
  87         char *dl_info;
  88
  89         char pathbuf[PATH_MAX];
  90
  91         if ((dir = opendir(pathname)) == NULL) {
  92                 perror("opendir");
  93                 exit(1);
  94         }
  95         while ((dptr = readdir(dir)) != NULL) {
  96                 if (strlen(dptr->d_name) < 4)
  97                         continue;
  98                 if (strcasecmp(&dptr->d_name[strlen(dptr->d_name)-3], ".so"))
  99                         continue;
 100
 101                 snprintf(pathbuf, PATH_MAX, "%s/%s", pathname, dptr->d_name);
 102 #ifdef RTLD_NOW
 103                 if (!(fcn_handle = dlopen(pathbuf, RTLD_NOW)))
 104 #else                           /* OpenBSD */
 105                 if (!(fcn_handle = dlopen(pathbuf, DL_LAZY)))
 106 #endif
 107                 {
 108                         safestrncpy(dl_error, dlerror(), sizeof dl_error);
 109                         for (i=0; i<strlen(dl_error); ++i)
 110                                 if (!isprint(dl_error[i]))
 111                                         dl_error[i]='.';
 112                         fprintf(stderr, "DLoader_Init dlopen failed: %s\n",
 113                                 dl_error);
 114                         continue;
 115                 }
 116                 h_init_fcn = (char * (*)(void))
 117 #ifndef __OpenBSD__
 118                     dlsym(fcn_handle, "Dynamic_Module_Init");
 119 #else
 120                     dlsym(fcn_handle, "_Dynamic_Module_Init");
 121 #endif
 122
 123                 if (dlerror() != NULL) {
 124                         fprintf(stderr, "DLoader_Init dlsym failed\n");
 125                         continue;
 126                 }
 127                 dl_info = h_init_fcn();
 128
 129                 lprintf(3, "Loaded module: %s\n", dl_info);
 130         }       /* While */
 131 }
 132
 133
 134
 135 void CtdlRegisterLogHook(void (*fcn_ptr) (char *), int loglevel)
 136 {
 137
 138         struct LogFunctionHook *newfcn;
 139
 140         newfcn = (struct LogFunctionHook *)
 141             mallok(sizeof(struct LogFunctionHook));
 142         newfcn->next = LogHookTable;
 143         newfcn->h_function_pointer = fcn_ptr;
 144         newfcn->loglevel = loglevel;
 145         LogHookTable = newfcn;
 146
 147         lprintf(5, "Registered a new logging function\n");
 148 }
 149
 150
 151 void CtdlRegisterCleanupHook(void (*fcn_ptr) (void))
 152 {
 153
 154         struct CleanupFunctionHook *newfcn;
 155
 156         newfcn = (struct CleanupFunctionHook *)
 157             mallok(sizeof(struct CleanupFunctionHook));
 158         newfcn->next = CleanupHookTable;
 159         newfcn->h_function_pointer = fcn_ptr;
 160         CleanupHookTable = newfcn;
 161
 162         lprintf(5, "Registered a new cleanup function\n");
 163 }
 164
 165
 166 void CtdlRegisterSessionHook(void (*fcn_ptr) (void), int EventType)
 167 {
 168
 169         struct SessionFunctionHook *newfcn;
 170
 171         newfcn = (struct SessionFunctionHook *)
 172             mallok(sizeof(struct SessionFunctionHook));
 173         newfcn->next = SessionHookTable;
 174         newfcn->h_function_pointer = fcn_ptr;
 175         newfcn->eventtype = EventType;
 176         SessionHookTable = newfcn;
 177
 178         lprintf(5, "Registered a new session function (type %d)\n",
 179                 EventType);
 180 }
 181
 182
 183 void CtdlRegisterUserHook(void (*fcn_ptr) (char *, long), int EventType)
 184 {
 185
 186         struct UserFunctionHook *newfcn;
 187
 188         newfcn = (struct UserFunctionHook *)
 189             mallok(sizeof(struct UserFunctionHook));
 190         newfcn->next = UserHookTable;
 191         newfcn->h_function_pointer = fcn_ptr;
 192         newfcn->eventtype = EventType;
 193         UserHookTable = newfcn;
 194
 195         lprintf(5, "Registered a new user function (type %d)\n",
 196                 EventType);
 197 }
 198
 199
 200 void CtdlRegisterMessageHook(int (*handler)(struct CtdlMessage *),
 201                                 int EventType)
 202 {
 203
 204         struct MessageFunctionHook *newfcn;
 205
 206         newfcn = (struct MessageFunctionHook *)
 207             mallok(sizeof(struct MessageFunctionHook));
 208         newfcn->next = MessageHookTable;
 209         newfcn->h_function_pointer = handler;
 210         newfcn->eventtype = EventType;
 211         MessageHookTable = newfcn;
 212
 213         lprintf(5, "Registered a new message function (type %d)\n",
 214                 EventType);
 215 }
 216
 217
 218 void CtdlRegisterXmsgHook(int (*fcn_ptr) (char *, char *, char *), int order)
 219 {
 220
 221         struct XmsgFunctionHook *newfcn;
 222
 223         newfcn = (struct XmsgFunctionHook *)
 224             mallok(sizeof(struct XmsgFunctionHook));
 225         newfcn->next = XmsgHookTable;
 226         newfcn->order = order;
 227         newfcn->h_function_pointer = fcn_ptr;
 228         XmsgHookTable = newfcn;
 229         lprintf(5, "Registered a new x-msg function (priority %d)\n", order);
 230 }
 231
 232 void CtdlRegisterServiceHook(int tcp_port,
 233                         void (*h_greeting_function) (void),
 234                         void (*h_command_function) (void) )
 235 {
 236         struct ServiceFunctionHook *newfcn;
 237
 238         newfcn = (struct ServiceFunctionHook *)
 239             mallok(sizeof(struct ServiceFunctionHook));
 240         newfcn->next = ServiceHookTable;
 241         newfcn->tcp_port = tcp_port;
 242         newfcn->h_greeting_function = h_greeting_function;
 243         newfcn->h_command_function = h_command_function;
 244         newfcn->msock = ig_tcp_server(tcp_port, config.c_maxsessions);
 245
 246         if (newfcn->msock >= 0) {
 247                 ServiceHookTable = newfcn;
 248                 lprintf(5, "Registered a new service (TCP port %d)\n",
 249                         tcp_port);
 250         }
 251         else {
 252                 lprintf(2, "ERROR: could not bind to TCP port %d.\n",
 253                         tcp_port);
 254                 phree(newfcn);
 255         }
 256 }
 257
 258
 259
 260 void PerformSessionHooks(int EventType)
 261 {
 262         struct SessionFunctionHook *fcn;
 263
 264         for (fcn = SessionHookTable; fcn != NULL; fcn = fcn->next) {
 265                 if (fcn->eventtype == EventType) {
 266                         (*fcn->h_function_pointer) ();
 267                 }
 268         }
 269 }
 270
 271 void PerformLogHooks(int loglevel, char *logmsg)
 272 {
 273         struct LogFunctionHook *fcn;
 274
 275         for (fcn = LogHookTable; fcn != NULL; fcn = fcn->next) {
 276                 if (fcn->loglevel >= loglevel) {
 277                         (*fcn->h_function_pointer) (logmsg);
 278                 }
 279         }
 280 }
 281
 282 void PerformUserHooks(char *username, long usernum, int EventType)
 283 {
 284         struct UserFunctionHook *fcn;
 285
 286         for (fcn = UserHookTable; fcn != NULL; fcn = fcn->next) {
 287                 if (fcn->eventtype == EventType) {
 288                         (*fcn->h_function_pointer) (username, usernum);
 289                 }
 290         }
 291 }
 292
 293 int PerformMessageHooks(struct CtdlMessage *msg, int EventType)
 294 {
 295         struct MessageFunctionHook *fcn;
 296         int total_retval = 0;
 297
 298         /* Other code may elect to protect this message from server-side
 299          * handlers; if this is the case, don't do anything.
 300          */
 301         lprintf(9, "** Event type is %d, flags are %d\n",
 302                 EventType, msg->cm_flags);
 303         if (msg->cm_flags & CM_SKIP_HOOKS) {
 304                 lprintf(9, "Skipping hooks\n");
 305                 return(0);
 306         }
 307
 308         /* Otherwise, run all the hooks appropriate to this event type.
 309          */
 310         for (fcn = MessageHookTable; fcn != NULL; fcn = fcn->next) {
 311                 if (fcn->eventtype == EventType) {
 312                         total_retval = total_retval +
 313                                 (*fcn->h_function_pointer) (msg);
 314                 }
 315         }
 316
 317         /* Return the sum of the return codes from the hook functions.  If
 318          * this is an EVT_BEFORESAVE event, a nonzero return code will cause
 319          * the save operation to abort.
 320          */
 321         return total_retval;
 322 }
 323
 324
 325
 326 int PerformXmsgHooks(char *sender, char *recp, char *msg)
 327 {
 328         struct XmsgFunctionHook *fcn;
 329         int total_sent = 0;
 330         int p;
 331
 332         for (p=0; p<MAX_XMSG_PRI; ++p) {
 333                 for (fcn = XmsgHookTable; fcn != NULL; fcn = fcn->next) {
 334                         if (fcn->order == p) {
 335                                 total_sent +=
 336                                         (*fcn->h_function_pointer)
 337                                                 (sender, recp, msg);
 338                         }
 339                 }
 340                 /* Break out of the loop if a higher-priority function
 341                  * successfully delivered the message.  This prevents duplicate
 342                  * deliveries to local users simultaneously signed onto
 343                  * remote services.
 344                  */
 345                 if (total_sent) goto DONE;
 346         }
 347 DONE:   return total_sent;
 348 }