citadel/modules/wiki/serv_wiki.c

   1 /*
   2  * $Id$
   3  *
   4  * Server-side module for Wiki rooms.  This will handle things like version control.
   5  *
   6  * Copyright (c) 2009-2009 by the citadel.org team
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 3 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software
  20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include "sysdep.h"
  24 #include <stdlib.h>
  25 #include <unistd.h>
  26 #include <stdio.h>
  27 #include <fcntl.h>
  28 #include <signal.h>
  29 #include <pwd.h>
  30 #include <errno.h>
  31 #include <ctype.h>
  32 #include <sys/types.h>
  33
  34 #if TIME_WITH_SYS_TIME
  35 # include <sys/time.h>
  36 # include <time.h>
  37 #else
  38 # if HAVE_SYS_TIME_H
  39 #  include <sys/time.h>
  40 # else
  41 #  include <time.h>
  42 # endif
  43 #endif
  44
  45 #include <sys/wait.h>
  46 #include <string.h>
  47 #include <limits.h>
  48 #include <libcitadel.h>
  49 #include "citadel.h"
  50 #include "server.h"
  51 #include "citserver.h"
  52 #include "support.h"
  53 #include "config.h"
  54 #include "control.h"
  55 #include "room_ops.h"
  56 #include "user_ops.h"
  57 #include "policy.h"
  58 #include "database.h"
  59 #include "msgbase.h"
  60 #include "euidindex.h"
  61 #include "ctdl_module.h"
  62
  63 /*
  64  * Before allowing a wiki page save to execute, we have to perform version control.
  65  * This involves fetching the old version of the page if it exists.
  66  */
  67 int wiki_upload_beforesave(struct CtdlMessage *msg) {
  68         struct CitContext *CCC = CC;
  69         long old_msgnum = (-1L);
  70         struct CtdlMessage *old_msg = NULL;
  71         long history_msgnum = (-1L);
  72         struct CtdlMessage *history_msg = NULL;
  73         char diff_old_filename[PATH_MAX];
  74         char diff_new_filename[PATH_MAX];
  75         char diff_cmd[PATH_MAX];
  76         FILE *fp;
  77         int rv;
  78         char history_page[1024];
  79         char boundary[256];
  80         char endary[260];
  81         char buf[1024];
  82         int nbytes = 0;
  83         char *diffbuf = NULL;
  84         size_t diffbuf_len = 0;
  85         char *ptr = NULL;
  86
  87         if (!CCC->logged_in) return(0); /* Only do this if logged in. */
  88
  89         /* Is this a room with a Wiki in it, don't run this hook. */
  90         if (CCC->room.QRdefaultview != VIEW_WIKI) {
  91                 return(0);
  92         }
  93
  94         /* If this isn't a MIME message, don't bother. */
  95         if (msg->cm_format_type != 4) return(0);
  96
  97         /* If there's no EUID we can't do this. */
  98         if (msg->cm_fields['E'] == NULL) return(0);
  99
 100         /* Make sure we're saving a real wiki page rather than a wiki history page.
 101          * This is important in order to avoid recursing infinitely into this hook.
 102          */
 103         if (    (strlen(msg->cm_fields['E']) >= 9)
 104                 && (!strcasecmp(&msg->cm_fields['E'][strlen(msg->cm_fields['E'])-9], "_HISTORY_"))
 105         ) {
 106                 CtdlLogPrintf(CTDL_DEBUG, "History page not being historied\n");
 107                 return(0);
 108         }
 109
 110         /* If there's no message text, obviously this is all b0rken and shouldn't happen at all */
 111         if (msg->cm_fields['M'] == NULL) return(0);
 112
 113         /* See if we can retrieve the previous version. */
 114         old_msgnum = locate_message_by_euid(msg->cm_fields['E'], &CCC->room);
 115         if (old_msgnum <= 0L) return(0);
 116         snprintf(history_page, sizeof history_page, "%s_HISTORY_", msg->cm_fields['E']);
 117
 118         old_msg = CtdlFetchMessage(old_msgnum, 1);
 119
 120         if ((old_msg != NULL) && (old_msg->cm_fields['M'] == NULL)) {   /* old version is corrupt? */
 121                 CtdlFreeMessage(old_msg);
 122                 old_msg = NULL;
 123         }
 124
 125         /* If no changes were made, don't bother saving it again */
 126         if ((old_msg != NULL) && (!strcmp(msg->cm_fields['M'], old_msg->cm_fields['M']))) {
 127                 CtdlFreeMessage(old_msg);
 128                 return(1);
 129         }
 130
 131         /*
 132          * Generate diffs
 133          */
 134         CtdlMakeTempFileName(diff_old_filename, sizeof diff_old_filename);
 135         CtdlMakeTempFileName(diff_new_filename, sizeof diff_new_filename);
 136
 137         if (old_msg != NULL) {
 138                 fp = fopen(diff_old_filename, "w");
 139                 rv = fwrite(old_msg->cm_fields['M'], strlen(old_msg->cm_fields['M']), 1, fp);
 140                 fclose(fp);
 141                 CtdlFreeMessage(old_msg);
 142         }
 143
 144         fp = fopen(diff_new_filename, "w");
 145         rv = fwrite(msg->cm_fields['M'], strlen(msg->cm_fields['M']), 1, fp);
 146         fclose(fp);
 147
 148         diffbuf_len = 0;
 149         diffbuf = NULL;
 150         snprintf(diff_cmd, sizeof diff_cmd,
 151                 "diff -u %s %s",
 152                 ((old_msg != NULL) ? diff_old_filename : "/dev/null"),
 153                 diff_new_filename
 154         );
 155         fp = popen(diff_cmd, "r");
 156         if (fp != NULL) {
 157                 do {
 158                         diffbuf = realloc(diffbuf, diffbuf_len + 1025);
 159                         nbytes = fread(&diffbuf[diffbuf_len], 1, 1024, fp);
 160                         diffbuf_len += nbytes;
 161                 } while (nbytes == 1024);
 162                 diffbuf[diffbuf_len] = 0;
 163                 pclose(fp);
 164         }
 165         CtdlLogPrintf(CTDL_DEBUG, "diff length is %d bytes\n", diffbuf_len);
 166
 167         unlink(diff_old_filename);
 168         unlink(diff_new_filename);
 169
 170         /* Determine whether this was a bogus (empty) edit */
 171         if ((diffbuf_len = 0) && (diffbuf != NULL)) {
 172                 free(diffbuf);
 173                 diffbuf = NULL;
 174         }
 175         if (diffbuf == NULL) {
 176                 return(1);              /* No changes at all?  Abandon the post entirely! */
 177         }
 178
 179         /* Now look for the existing edit history */
 180
 181         history_msgnum = locate_message_by_euid(history_page, &CCC->room);
 182         history_msg = NULL;
 183         if (history_msgnum > 0L) {
 184                 history_msg = CtdlFetchMessage(history_msgnum, 1);
 185         }
 186
 187         /* Create a new history message if necessary */
 188         if (history_msg == NULL) {
 189                 history_msg = malloc(sizeof(struct CtdlMessage));
 190                 memset(history_msg, 0, sizeof(struct CtdlMessage));
 191                 history_msg->cm_magic = CTDLMESSAGE_MAGIC;
 192                 history_msg->cm_anon_type = MES_NORMAL;
 193                 history_msg->cm_format_type = FMT_RFC822;
 194                 history_msg->cm_fields['A'] = strdup("Citadel");
 195                 history_msg->cm_fields['R'] = strdup(CCC->room.QRname);
 196                 history_msg->cm_fields['E'] = strdup(history_page);
 197                 snprintf(boundary, sizeof boundary, "Citadel--Multipart--%04x--%08lx", getpid(), time(NULL));
 198                 history_msg->cm_fields['M'] = malloc(1024);
 199                 snprintf(history_msg->cm_fields['M'], 1024,
 200                         "Content-type: multipart/mixed; boundary=\"%s\"\n\n"
 201                         "This is a Citadel wiki history encoded as multipart MIME.\n"
 202                         "--%s--\n"
 203                         ,
 204                         boundary, boundary
 205                 );
 206         }
 207
 208         /* Update the history message (regardless of whether it's new or existing) */
 209
 210         /* First, figure out the boundary string.  We do this even when we generated the
 211          * boundary string in the above code, just to be safe and consistent.
 212          */
 213         strcpy(boundary, "");
 214
 215         ptr = history_msg->cm_fields['M'];
 216         do {
 217                 ptr = memreadline(ptr, buf, sizeof buf);
 218                 if (*ptr != 0) {
 219                         striplt(buf);
 220                         if (!IsEmptyStr(buf) && (!strncasecmp(buf, "Content-type:", 13))) {
 221                                 if (
 222                                         (bmstrcasestr(buf, "multipart") != NULL)
 223                                         && (bmstrcasestr(buf, "boundary=") != NULL)
 224                                 ) {
 225                                         safestrncpy(boundary, bmstrcasestr(buf, "\""), sizeof boundary);
 226                                         char *qu;
 227                                         qu = strchr(boundary, '\"');
 228                                         if (qu) {
 229                                                 strcpy(boundary, ++qu);
 230                                         }
 231                                         qu = strchr(boundary, '\"');
 232                                         if (qu) {
 233                                                 *qu = 0;
 234                                         }
 235                                 }
 236                         }
 237                 }
 238         } while ( (IsEmptyStr(boundary)) && (*ptr != 0) );
 239
 240         if (!IsEmptyStr(boundary)) {
 241                 snprintf(endary, sizeof endary, "--%s--", boundary);
 242                 history_msg->cm_fields['M'] = realloc(history_msg->cm_fields['M'],
 243                         strlen(history_msg->cm_fields['M']) + strlen(diffbuf) + 512
 244                 );
 245                 ptr = bmstrcasestr(history_msg->cm_fields['M'], endary);
 246                 if (ptr != NULL) {
 247                         sprintf(ptr, "--%s\n"
 248                                         "Content-type: text/plain\n"
 249                                         "From: %s <%s>\n"
 250                                         "\n"
 251                                         "%s\n"
 252                                         "--%s--\n"
 253                                         ,
 254                                 boundary,
 255                                 CCC->user.fullname,
 256                                 CCC->cs_inet_email,
 257                                 diffbuf,
 258                                 boundary
 259                         );
 260                 }
 261
 262                 history_msg->cm_fields['T'] = realloc(history_msg->cm_fields['T'], 32);
 263                 snprintf(history_msg->cm_fields['T'], 32, "%ld", time(NULL));
 264
 265                 CtdlSubmitMsg(history_msg, NULL, "", 0);
 266         }
 267         else {
 268                 CtdlLogPrintf(CTDL_ALERT, "Empty boundary string in history message.  No history!\n");
 269         }
 270
 271         free(diffbuf);
 272         free(history_msg);
 273         return(0);
 274 }
 275
 276
 277 /*
 278  * Module initialization
 279  */
 280 CTDL_MODULE_INIT(wiki)
 281 {
 282         if (!threading)
 283         {
 284                 CtdlRegisterMessageHook(wiki_upload_beforesave, EVT_BEFORESAVE);
 285         }
 286
 287         /* return our Subversion id for the Log */
 288         return "$Id$";
 289 }