citadel/dynloader.c

   1 /*
   2  * $Id$
   3  *
   4  * Citadel Dynamic Loading Module
   5  * Written by Brian Costello <btx@calyx.net>
   6  *
   7  */
   8
   9 #include "sysdep.h"
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #ifdef HAVE_DLFCN_H
  13 #include <dlfcn.h>
  14 #endif
  15 #ifdef HAVE_DL_H
  16 #include <dl.h>
  17 #include "hpsux.h"
  18 #endif
  19 #include <sys/types.h>
  20 #include <dirent.h>
  21 #include <strings.h>
  22 #include <syslog.h>
  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 #include "config.h"
  32
  33 #ifndef HAVE_SNPRINTF
  34 #include <stdarg.h>
  35 #include "snprintf.h"
  36 #endif
  37
  38 struct LogFunctionHook *LogHookTable = NULL;
  39 struct CleanupFunctionHook *CleanupHookTable = NULL;
  40 struct SessionFunctionHook *SessionHookTable = NULL;
  41 struct UserFunctionHook *UserHookTable = NULL;
  42 struct XmsgFunctionHook *XmsgHookTable = NULL;
  43 struct MessageFunctionHook *MessageHookTable = NULL;
  44 struct ServiceFunctionHook *ServiceHookTable = NULL;
  45
  46 struct ProtoFunctionHook {
  47         void (*handler) (char *cmdbuf);
  48         char *cmd;
  49         char *desc;
  50         struct ProtoFunctionHook *next;
  51 } *ProtoHookList = NULL;
  52
  53 void CtdlRegisterProtoHook(void (*handler) (char *), char *cmd, char *desc)
  54 {
  55         struct ProtoFunctionHook *p = mallok(sizeof *p);
  56
  57         if (p == NULL) {
  58                 fprintf(stderr, "can't malloc new ProtoFunctionHook\n");
  59                 exit(EXIT_FAILURE);
  60         }
  61         p->handler = handler;
  62         p->cmd = cmd;
  63         p->desc = desc;
  64         p->next = ProtoHookList;
  65         ProtoHookList = p;
  66         lprintf(5, "Registered server command %s (%s)\n", cmd, desc);
  67 }
  68
  69 int DLoader_Exec_Cmd(char *cmdbuf)
  70 {
  71         struct ProtoFunctionHook *p;
  72
  73         for (p = ProtoHookList; p; p = p->next) {
  74                 if (!strncasecmp(cmdbuf, p->cmd, 4)) {
  75                         p->handler(&cmdbuf[5]);
  76                         return 1;
  77                 }
  78         }
  79         return 0;
  80 }
  81
  82 void DLoader_Init(char *pathname)
  83 {
  84         void *fcn_handle;
  85         char dl_error[256];
  86         DIR *dir;
  87         int i;
  88         struct dirent *dptr;
  89         char *(*h_init_fcn) (void);
  90         char *dl_info;
  91
  92         char pathbuf[PATH_MAX];
  93
  94         if ((dir = opendir(pathname)) == NULL) {
  95                 perror("opendir");
  96                 exit(1);
  97         }
  98         while ((dptr = readdir(dir)) != NULL) {
  99                 if (strlen(dptr->d_name) < 4)
 100                         continue;
 101                 if (strcasecmp(&dptr->d_name[strlen(dptr->d_name)-3], ".so"))
 102                         continue;
 103
 104                 snprintf(pathbuf, PATH_MAX, "%s/%s", pathname, dptr->d_name);
 105 #ifdef RTLD_NOW
 106                 if (!(fcn_handle = dlopen(pathbuf, RTLD_NOW)))
 107 #else                           /* OpenBSD */
 108                 if (!(fcn_handle = dlopen(pathbuf, DL_LAZY)))
 109 #endif
 110                 {
 111                         safestrncpy(dl_error, dlerror(), sizeof dl_error);
 112                         for (i=0; i<strlen(dl_error); ++i)
 113                                 if (!isprint(dl_error[i]))
 114                                         dl_error[i]='.';
 115                         fprintf(stderr, "DLoader_Init dlopen failed: %s\n",
 116                                 dl_error);
 117                         continue;
 118                 }
 119                 h_init_fcn = (char * (*)(void))
 120 #ifndef __OpenBSD__
 121                     dlsym(fcn_handle, "Dynamic_Module_Init");
 122 #else
 123                     dlsym(fcn_handle, "_Dynamic_Module_Init");
 124 #endif
 125
 126                 if (dlerror() != NULL) {
 127                         fprintf(stderr, "DLoader_Init dlsym failed\n");
 128                         continue;
 129                 }
 130                 dl_info = h_init_fcn();
 131
 132                 lprintf(3, "Loaded module: %s\n", dl_info);
 133         }       /* While */
 134 }
 135
 136
 137
 138 void CtdlRegisterLogHook(void (*fcn_ptr) (char *), int loglevel)
 139 {
 140
 141         struct LogFunctionHook *newfcn;
 142
 143         newfcn = (struct LogFunctionHook *)
 144             mallok(sizeof(struct LogFunctionHook));
 145         newfcn->next = LogHookTable;
 146         newfcn->h_function_pointer = fcn_ptr;
 147         newfcn->loglevel = loglevel;
 148         LogHookTable = newfcn;
 149
 150         lprintf(5, "Registered a new logging function\n");
 151 }
 152
 153
 154 void CtdlRegisterCleanupHook(void (*fcn_ptr) (void))
 155 {
 156
 157         struct CleanupFunctionHook *newfcn;
 158
 159         newfcn = (struct CleanupFunctionHook *)
 160             mallok(sizeof(struct CleanupFunctionHook));
 161         newfcn->next = CleanupHookTable;
 162         newfcn->h_function_pointer = fcn_ptr;
 163         CleanupHookTable = newfcn;
 164
 165         lprintf(5, "Registered a new cleanup function\n");
 166 }
 167
 168
 169 void CtdlRegisterSessionHook(void (*fcn_ptr) (void), int EventType)
 170 {
 171
 172         struct SessionFunctionHook *newfcn;
 173
 174         newfcn = (struct SessionFunctionHook *)
 175             mallok(sizeof(struct SessionFunctionHook));
 176         newfcn->next = SessionHookTable;
 177         newfcn->h_function_pointer = fcn_ptr;
 178         newfcn->eventtype = EventType;
 179         SessionHookTable = newfcn;
 180
 181         lprintf(5, "Registered a new session function (type %d)\n",
 182                 EventType);
 183 }
 184
 185
 186 void CtdlRegisterUserHook(void (*fcn_ptr) (char *, long), int EventType)
 187 {
 188
 189         struct UserFunctionHook *newfcn;
 190
 191         newfcn = (struct UserFunctionHook *)
 192             mallok(sizeof(struct UserFunctionHook));
 193         newfcn->next = UserHookTable;
 194         newfcn->h_function_pointer = fcn_ptr;
 195         newfcn->eventtype = EventType;
 196         UserHookTable = newfcn;
 197
 198         lprintf(5, "Registered a new user function (type %d)\n",
 199                 EventType);
 200 }
 201
 202
 203 void CtdlRegisterMessageHook(int (*handler)(struct CtdlMessage *),
 204                                 int EventType)
 205 {
 206
 207         struct MessageFunctionHook *newfcn;
 208
 209         newfcn = (struct MessageFunctionHook *)
 210             mallok(sizeof(struct MessageFunctionHook));
 211         newfcn->next = MessageHookTable;
 212         newfcn->h_function_pointer = handler;
 213         newfcn->eventtype = EventType;
 214         MessageHookTable = newfcn;
 215
 216         lprintf(5, "Registered a new message function (type %d)\n",
 217                 EventType);
 218 }
 219
 220
 221 void CtdlRegisterXmsgHook(int (*fcn_ptr) (char *, char *, char *), int order)
 222 {
 223
 224         struct XmsgFunctionHook *newfcn;
 225
 226         newfcn = (struct XmsgFunctionHook *)
 227             mallok(sizeof(struct XmsgFunctionHook));
 228         newfcn->next = XmsgHookTable;
 229         newfcn->order = order;
 230         newfcn->h_function_pointer = fcn_ptr;
 231         XmsgHookTable = newfcn;
 232         lprintf(5, "Registered a new x-msg function (priority %d)\n", order);
 233 }
 234
 235 void CtdlRegisterServiceHook(int tcp_port,
 236                         char *sockpath,
 237                         void (*h_greeting_function) (void),
 238                         void (*h_command_function) (void) )
 239 {
 240         struct ServiceFunctionHook *newfcn;
 241
 242         newfcn = (struct ServiceFunctionHook *)
 243             mallok(sizeof(struct ServiceFunctionHook));
 244         newfcn->next = ServiceHookTable;
 245         newfcn->tcp_port = tcp_port;
 246         newfcn->sockpath = sockpath;
 247         newfcn->h_greeting_function = h_greeting_function;
 248         newfcn->h_command_function = h_command_function;
 249
 250         if (sockpath != NULL) {
 251                 newfcn->msock = ig_uds_server(sockpath, config.c_maxsessions);
 252         }
 253         else if (tcp_port < 0) {        /* port -1 to disable */
 254                 lprintf(7, "Service has been manually disabled, skipping\n");
 255                 phree(newfcn);
 256                 return;
 257         }
 258         else {
 259                 newfcn->msock = ig_tcp_server(tcp_port, config.c_maxsessions);
 260         }
 261
 262         if (newfcn->msock >= 0) {
 263                 ServiceHookTable = newfcn;
 264                 lprintf(5, "Registered a new service (TCP port %d)\n",
 265                         tcp_port);
 266         }
 267         else {
 268                 lprintf(2, "ERROR: could not bind to TCP port %d.\n",
 269                         tcp_port);
 270                 phree(newfcn);
 271         }
 272 }
 273
 274
 275
 276 void PerformSessionHooks(int EventType)
 277 {
 278         struct SessionFunctionHook *fcn;
 279
 280         for (fcn = SessionHookTable; fcn != NULL; fcn = fcn->next) {
 281                 if (fcn->eventtype == EventType) {
 282                         (*fcn->h_function_pointer) ();
 283                 }
 284         }
 285 }
 286
 287 void PerformLogHooks(int loglevel, char *logmsg)
 288 {
 289         struct LogFunctionHook *fcn;
 290
 291         for (fcn = LogHookTable; fcn != NULL; fcn = fcn->next) {
 292                 if (fcn->loglevel >= loglevel) {
 293                         (*fcn->h_function_pointer) (logmsg);
 294                 }
 295         }
 296 }
 297
 298 void PerformUserHooks(char *username, long usernum, int EventType)
 299 {
 300         struct UserFunctionHook *fcn;
 301
 302         for (fcn = UserHookTable; fcn != NULL; fcn = fcn->next) {
 303                 if (fcn->eventtype == EventType) {
 304                         (*fcn->h_function_pointer) (username, usernum);
 305                 }
 306         }
 307 }
 308
 309 int PerformMessageHooks(struct CtdlMessage *msg, int EventType)
 310 {
 311         struct MessageFunctionHook *fcn;
 312         int total_retval = 0;
 313
 314         /* Other code may elect to protect this message from server-side
 315          * handlers; if this is the case, don't do anything.
 316          */
 317         lprintf(9, "** Event type is %d, flags are %d\n",
 318                 EventType, msg->cm_flags);
 319         if (msg->cm_flags & CM_SKIP_HOOKS) {
 320                 lprintf(9, "Skipping hooks\n");
 321                 return(0);
 322         }
 323
 324         /* Otherwise, run all the hooks appropriate to this event type.
 325          */
 326         for (fcn = MessageHookTable; fcn != NULL; fcn = fcn->next) {
 327                 if (fcn->eventtype == EventType) {
 328                         total_retval = total_retval +
 329                                 (*fcn->h_function_pointer) (msg);
 330                 }
 331         }
 332
 333         /* Return the sum of the return codes from the hook functions.  If
 334          * this is an EVT_BEFORESAVE event, a nonzero return code will cause
 335          * the save operation to abort.
 336          */
 337         return total_retval;
 338 }
 339
 340
 341
 342 int PerformXmsgHooks(char *sender, char *recp, char *msg)
 343 {
 344         struct XmsgFunctionHook *fcn;
 345         int total_sent = 0;
 346         int p;
 347
 348         for (p=0; p<MAX_XMSG_PRI; ++p) {
 349                 for (fcn = XmsgHookTable; fcn != NULL; fcn = fcn->next) {
 350                         if (fcn->order == p) {
 351                                 total_sent +=
 352                                         (*fcn->h_function_pointer)
 353                                                 (sender, recp, msg);
 354                         }
 355                 }
 356                 /* Break out of the loop if a higher-priority function
 357                  * successfully delivered the message.  This prevents duplicate
 358                  * deliveries to local users simultaneously signed onto
 359                  * remote services.
 360                  */
 361                 if (total_sent) goto DONE;
 362         }
 363 DONE:   return total_sent;
 364 }