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 #include <dlfcn.h>
  13 #include <sys/types.h>
  14 #include <dirent.h>
  15 #include <strings.h>
  16 #include <syslog.h>
  17 #include <limits.h>
  18 #include <ctype.h>
  19 #include "citadel.h"
  20 #include "server.h"
  21 #include "dynloader.h"
  22 #include "sysdep_decls.h"
  23 #include "msgbase.h"
  24 #include "tools.h"
  25 #include "config.h"
  26
  27 #ifndef HAVE_SNPRINTF
  28 #include <stdarg.h>
  29 #include "snprintf.h"
  30 #endif
  31
  32 struct LogFunctionHook *LogHookTable = NULL;
  33 struct CleanupFunctionHook *CleanupHookTable = NULL;
  34 struct SessionFunctionHook *SessionHookTable = NULL;
  35 struct UserFunctionHook *UserHookTable = NULL;
  36 struct XmsgFunctionHook *XmsgHookTable = NULL;
  37 struct MessageFunctionHook *MessageHookTable = NULL;
  38 struct ServiceFunctionHook *ServiceHookTable = NULL;
  39
  40 struct ProtoFunctionHook {
  41         void (*handler) (char *cmdbuf);
  42         char *cmd;
  43         char *desc;
  44         struct ProtoFunctionHook *next;
  45 } *ProtoHookList = NULL;
  46
  47 void CtdlRegisterProtoHook(void (*handler) (char *), char *cmd, char *desc)
  48 {
  49         struct ProtoFunctionHook *p = mallok(sizeof *p);
  50
  51         if (p == NULL) {
  52                 fprintf(stderr, "can't malloc new ProtoFunctionHook\n");
  53                 exit(EXIT_FAILURE);
  54         }
  55         p->handler = handler;
  56         p->cmd = cmd;
  57         p->desc = desc;
  58         p->next = ProtoHookList;
  59         ProtoHookList = p;
  60         lprintf(5, "Registered server command %s (%s)\n", cmd, desc);
  61 }
  62
  63 int DLoader_Exec_Cmd(char *cmdbuf)
  64 {
  65         struct ProtoFunctionHook *p;
  66
  67         for (p = ProtoHookList; p; p = p->next) {
  68                 if (!strncasecmp(cmdbuf, p->cmd, 4)) {
  69                         p->handler(&cmdbuf[5]);
  70                         return 1;
  71                 }
  72         }
  73         return 0;
  74 }
  75
  76 void DLoader_Init(char *pathname)
  77 {
  78         void *fcn_handle;
  79         char dl_error[256];
  80         DIR *dir;
  81         int i;
  82         struct dirent *dptr;
  83         char *(*h_init_fcn) (void);
  84         char *dl_info;
  85
  86         char pathbuf[PATH_MAX];
  87
  88         if ((dir = opendir(pathname)) == NULL) {
  89                 perror("opendir");
  90                 exit(1);
  91         }
  92         while ((dptr = readdir(dir)) != NULL) {
  93                 if (strlen(dptr->d_name) < 4)
  94                         continue;
  95                 if (strcasecmp(&dptr->d_name[strlen(dptr->d_name)-3], ".so"))
  96                         continue;
  97
  98                 snprintf(pathbuf, PATH_MAX, "%s/%s", pathname, dptr->d_name);
  99 #ifdef RTLD_NOW
 100                 if (!(fcn_handle = dlopen(pathbuf, RTLD_NOW)))
 101 #else                           /* OpenBSD */
 102                 if (!(fcn_handle = dlopen(pathbuf, DL_LAZY)))
 103 #endif
 104                 {
 105                         safestrncpy(dl_error, dlerror(), sizeof dl_error);
 106                         for (i=0; i<strlen(dl_error); ++i)
 107                                 if (!isprint(dl_error[i]))
 108                                         dl_error[i]='.';
 109                         fprintf(stderr, "DLoader_Init dlopen failed: %s\n",
 110                                 dl_error);
 111                         continue;
 112                 }
 113                 h_init_fcn = (char * (*)(void))
 114 #ifndef __OpenBSD__
 115                     dlsym(fcn_handle, "Dynamic_Module_Init");
 116 #else
 117                     dlsym(fcn_handle, "_Dynamic_Module_Init");
 118 #endif
 119
 120                 if (dlerror() != NULL) {
 121                         fprintf(stderr, "DLoader_Init dlsym failed\n");
 122                         continue;
 123                 }
 124                 dl_info = h_init_fcn();
 125
 126                 lprintf(3, "Loaded module: %s\n", dl_info);
 127         }       /* While */
 128 }
 129
 130
 131
 132 void CtdlRegisterLogHook(void (*fcn_ptr) (char *), int loglevel)
 133 {
 134
 135         struct LogFunctionHook *newfcn;
 136
 137         newfcn = (struct LogFunctionHook *)
 138             mallok(sizeof(struct LogFunctionHook));
 139         newfcn->next = LogHookTable;
 140         newfcn->h_function_pointer = fcn_ptr;
 141         newfcn->loglevel = loglevel;
 142         LogHookTable = newfcn;
 143
 144         lprintf(5, "Registered a new logging function\n");
 145 }
 146
 147
 148 void CtdlRegisterCleanupHook(void (*fcn_ptr) (void))
 149 {
 150
 151         struct CleanupFunctionHook *newfcn;
 152
 153         newfcn = (struct CleanupFunctionHook *)
 154             mallok(sizeof(struct CleanupFunctionHook));
 155         newfcn->next = CleanupHookTable;
 156         newfcn->h_function_pointer = fcn_ptr;
 157         CleanupHookTable = newfcn;
 158
 159         lprintf(5, "Registered a new cleanup function\n");
 160 }
 161
 162
 163 void CtdlRegisterSessionHook(void (*fcn_ptr) (void), int EventType)
 164 {
 165
 166         struct SessionFunctionHook *newfcn;
 167
 168         newfcn = (struct SessionFunctionHook *)
 169             mallok(sizeof(struct SessionFunctionHook));
 170         newfcn->next = SessionHookTable;
 171         newfcn->h_function_pointer = fcn_ptr;
 172         newfcn->eventtype = EventType;
 173         SessionHookTable = newfcn;
 174
 175         lprintf(5, "Registered a new session function (type %d)\n",
 176                 EventType);
 177 }
 178
 179
 180 void CtdlRegisterUserHook(void (*fcn_ptr) (char *, long), int EventType)
 181 {
 182
 183         struct UserFunctionHook *newfcn;
 184
 185         newfcn = (struct UserFunctionHook *)
 186             mallok(sizeof(struct UserFunctionHook));
 187         newfcn->next = UserHookTable;
 188         newfcn->h_function_pointer = fcn_ptr;
 189         newfcn->eventtype = EventType;
 190         UserHookTable = newfcn;
 191
 192         lprintf(5, "Registered a new user function (type %d)\n",
 193                 EventType);
 194 }
 195
 196
 197 void CtdlRegisterMessageHook(int (*handler)(struct CtdlMessage *),
 198                                 int EventType)
 199 {
 200
 201         struct MessageFunctionHook *newfcn;
 202
 203         newfcn = (struct MessageFunctionHook *)
 204             mallok(sizeof(struct MessageFunctionHook));
 205         newfcn->next = MessageHookTable;
 206         newfcn->h_function_pointer = handler;
 207         newfcn->eventtype = EventType;
 208         MessageHookTable = newfcn;
 209
 210         lprintf(5, "Registered a new message function (type %d)\n",
 211                 EventType);
 212 }
 213
 214
 215 void CtdlRegisterXmsgHook(int (*fcn_ptr) (char *, char *, char *), int order)
 216 {
 217
 218         struct XmsgFunctionHook *newfcn;
 219
 220         newfcn = (struct XmsgFunctionHook *)
 221             mallok(sizeof(struct XmsgFunctionHook));
 222         newfcn->next = XmsgHookTable;
 223         newfcn->order = order;
 224         newfcn->h_function_pointer = fcn_ptr;
 225         XmsgHookTable = newfcn;
 226         lprintf(5, "Registered a new x-msg function (priority %d)\n", order);
 227 }
 228
 229 void CtdlRegisterServiceHook(int tcp_port,
 230                         char *sockpath,
 231                         void (*h_greeting_function) (void),
 232                         void (*h_command_function) (void) )
 233 {
 234         struct ServiceFunctionHook *newfcn;
 235
 236         newfcn = (struct ServiceFunctionHook *)
 237             mallok(sizeof(struct ServiceFunctionHook));
 238         newfcn->next = ServiceHookTable;
 239         newfcn->tcp_port = tcp_port;
 240         newfcn->sockpath = sockpath;
 241         newfcn->h_greeting_function = h_greeting_function;
 242         newfcn->h_command_function = h_command_function;
 243
 244         if (sockpath != NULL) {
 245                 newfcn->msock = ig_uds_server(sockpath, config.c_maxsessions);
 246         }
 247         else if (tcp_port < 0) {        /* port -1 to disable */
 248                 lprintf(7, "Service has been manually disabled, skipping\n");
 249                 phree(newfcn);
 250                 return;
 251         }
 252         else {
 253                 newfcn->msock = ig_tcp_server(tcp_port, config.c_maxsessions);
 254         }
 255
 256         if (newfcn->msock >= 0) {
 257                 ServiceHookTable = newfcn;
 258                 lprintf(5, "Registered a new service (TCP port %d)\n",
 259                         tcp_port);
 260         }
 261         else {
 262                 lprintf(2, "ERROR: could not bind to TCP port %d.\n",
 263                         tcp_port);
 264                 phree(newfcn);
 265         }
 266 }
 267
 268
 269
 270 void PerformSessionHooks(int EventType)
 271 {
 272         struct SessionFunctionHook *fcn;
 273
 274         for (fcn = SessionHookTable; fcn != NULL; fcn = fcn->next) {
 275                 if (fcn->eventtype == EventType) {
 276                         (*fcn->h_function_pointer) ();
 277                 }
 278         }
 279 }
 280
 281 void PerformLogHooks(int loglevel, char *logmsg)
 282 {
 283         struct LogFunctionHook *fcn;
 284
 285         for (fcn = LogHookTable; fcn != NULL; fcn = fcn->next) {
 286                 if (fcn->loglevel >= loglevel) {
 287                         (*fcn->h_function_pointer) (logmsg);
 288                 }
 289         }
 290 }
 291
 292 void PerformUserHooks(char *username, long usernum, int EventType)
 293 {
 294         struct UserFunctionHook *fcn;
 295
 296         for (fcn = UserHookTable; fcn != NULL; fcn = fcn->next) {
 297                 if (fcn->eventtype == EventType) {
 298                         (*fcn->h_function_pointer) (username, usernum);
 299                 }
 300         }
 301 }
 302
 303 int PerformMessageHooks(struct CtdlMessage *msg, int EventType)
 304 {
 305         struct MessageFunctionHook *fcn;
 306         int total_retval = 0;
 307
 308         /* Other code may elect to protect this message from server-side
 309          * handlers; if this is the case, don't do anything.
 310          */
 311         lprintf(9, "** Event type is %d, flags are %d\n",
 312                 EventType, msg->cm_flags);
 313         if (msg->cm_flags & CM_SKIP_HOOKS) {
 314                 lprintf(9, "Skipping hooks\n");
 315                 return(0);
 316         }
 317
 318         /* Otherwise, run all the hooks appropriate to this event type.
 319          */
 320         for (fcn = MessageHookTable; fcn != NULL; fcn = fcn->next) {
 321                 if (fcn->eventtype == EventType) {
 322                         total_retval = total_retval +
 323                                 (*fcn->h_function_pointer) (msg);
 324                 }
 325         }
 326
 327         /* Return the sum of the return codes from the hook functions.  If
 328          * this is an EVT_BEFORESAVE event, a nonzero return code will cause
 329          * the save operation to abort.
 330          */
 331         return total_retval;
 332 }
 333
 334
 335
 336 int PerformXmsgHooks(char *sender, char *recp, char *msg)
 337 {
 338         struct XmsgFunctionHook *fcn;
 339         int total_sent = 0;
 340         int p;
 341
 342         for (p=0; p<MAX_XMSG_PRI; ++p) {
 343                 for (fcn = XmsgHookTable; fcn != NULL; fcn = fcn->next) {
 344                         if (fcn->order == p) {
 345                                 total_sent +=
 346                                         (*fcn->h_function_pointer)
 347                                                 (sender, recp, msg);
 348                         }
 349                 }
 350                 /* Break out of the loop if a higher-priority function
 351                  * successfully delivered the message.  This prevents duplicate
 352                  * deliveries to local users simultaneously signed onto
 353                  * remote services.
 354                  */
 355                 if (total_sent) goto DONE;
 356         }
 357 DONE:   return total_sent;
 358 }