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 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         snprintf(history_page, sizeof history_page, "%s_HISTORY_", msg->cm_fields['E']);
 100
 101         /* Make sure we're saving a real wiki page rather than a wiki history page.
 102          * This is important in order to avoid recursing infinitely into this hook.
 103          */
 104         if (    (strlen(msg->cm_fields['E']) >= 9)
 105                 && (!strcasecmp(&msg->cm_fields['E'][strlen(msg->cm_fields['E'])-9], "_HISTORY_"))
 106         ) {
 107                 CtdlLogPrintf(CTDL_DEBUG, "History page not being historied\n");
 108                 return(0);
 109         }
 110
 111         /* If there's no message text, obviously this is all b0rken and shouldn't happen at all */
 112         if (msg->cm_fields['M'] == NULL) return(0);
 113
 114         /* See if we can retrieve the previous version. */
 115         old_msgnum = locate_message_by_euid(msg->cm_fields['E'], &CCC->room);
 116         if (old_msgnum > 0L) {
 117                 old_msg = CtdlFetchMessage(old_msgnum, 1);
 118         }
 119         else {
 120                 old_msg = NULL;
 121         }
 122
 123         if ((old_msg != NULL) && (old_msg->cm_fields['M'] == NULL)) {   /* old version is corrupt? */
 124                 CtdlFreeMessage(old_msg);
 125                 old_msg = NULL;
 126         }
 127
 128         /* If no changes were made, don't bother saving it again */
 129         if ((old_msg != NULL) && (!strcmp(msg->cm_fields['M'], old_msg->cm_fields['M']))) {
 130                 CtdlFreeMessage(old_msg);
 131                 return(1);
 132         }
 133
 134         /*
 135          * Generate diffs
 136          */
 137         CtdlMakeTempFileName(diff_old_filename, sizeof diff_old_filename);
 138         CtdlMakeTempFileName(diff_new_filename, sizeof diff_new_filename);
 139
 140         if (old_msg != NULL) {
 141                 fp = fopen(diff_old_filename, "w");
 142                 rv = fwrite(old_msg->cm_fields['M'], strlen(old_msg->cm_fields['M']), 1, fp);
 143                 fclose(fp);
 144                 CtdlFreeMessage(old_msg);
 145         }
 146
 147         fp = fopen(diff_new_filename, "w");
 148         rv = fwrite(msg->cm_fields['M'], strlen(msg->cm_fields['M']), 1, fp);
 149         fclose(fp);
 150
 151         diffbuf_len = 0;
 152         diffbuf = NULL;
 153         snprintf(diff_cmd, sizeof diff_cmd,
 154                 "diff -u %s %s",
 155                 ((old_msg != NULL) ? diff_old_filename : "/dev/null"),
 156                 diff_new_filename
 157         );
 158         fp = popen(diff_cmd, "r");
 159         if (fp != NULL) {
 160                 do {
 161                         diffbuf = realloc(diffbuf, diffbuf_len + 1025);
 162                         nbytes = fread(&diffbuf[diffbuf_len], 1, 1024, fp);
 163                         diffbuf_len += nbytes;
 164                 } while (nbytes == 1024);
 165                 diffbuf[diffbuf_len] = 0;
 166                 pclose(fp);
 167         }
 168         CtdlLogPrintf(CTDL_DEBUG, "diff length is %d bytes\n", diffbuf_len);
 169
 170         unlink(diff_old_filename);
 171         unlink(diff_new_filename);
 172
 173         /* Determine whether this was a bogus (empty) edit */
 174         if ((diffbuf_len = 0) && (diffbuf != NULL)) {
 175                 free(diffbuf);
 176                 diffbuf = NULL;
 177         }
 178         if (diffbuf == NULL) {
 179                 return(1);              /* No changes at all?  Abandon the post entirely! */
 180         }
 181
 182         /* Now look for the existing edit history */
 183
 184         history_msgnum = locate_message_by_euid(history_page, &CCC->room);
 185         history_msg = NULL;
 186         if (history_msgnum > 0L) {
 187                 history_msg = CtdlFetchMessage(history_msgnum, 1);
 188         }
 189
 190         /* Create a new history message if necessary */
 191         if (history_msg == NULL) {
 192                 history_msg = malloc(sizeof(struct CtdlMessage));
 193                 memset(history_msg, 0, sizeof(struct CtdlMessage));
 194                 history_msg->cm_magic = CTDLMESSAGE_MAGIC;
 195                 history_msg->cm_anon_type = MES_NORMAL;
 196                 history_msg->cm_format_type = FMT_RFC822;
 197                 history_msg->cm_fields['A'] = strdup("Citadel");
 198                 history_msg->cm_fields['R'] = strdup(CCC->room.QRname);
 199                 history_msg->cm_fields['E'] = strdup(history_page);
 200                 history_msg->cm_fields['U'] = strdup(history_page);
 201                 snprintf(boundary, sizeof boundary, "Citadel--Multipart--%04x--%08lx", getpid(), time(NULL));
 202                 history_msg->cm_fields['M'] = malloc(1024);
 203                 snprintf(history_msg->cm_fields['M'], 1024,
 204                         "Content-type: multipart/mixed; boundary=\"%s\"\n\n"
 205                         "This is a Citadel wiki history encoded as multipart MIME.\n"
 206                         "Each part is comprised of a diff script representing one change set.\n"
 207                         "\n"
 208                         "--%s--\n"
 209                         ,
 210                         boundary, boundary
 211                 );
 212         }
 213
 214         /* Update the history message (regardless of whether it's new or existing) */
 215
 216         /* First, figure out the boundary string.  We do this even when we generated the
 217          * boundary string in the above code, just to be safe and consistent.
 218          */
 219         strcpy(boundary, "");
 220
 221         ptr = history_msg->cm_fields['M'];
 222         do {
 223                 ptr = memreadline(ptr, buf, sizeof buf);
 224                 if (*ptr != 0) {
 225                         striplt(buf);
 226                         if (!IsEmptyStr(buf) && (!strncasecmp(buf, "Content-type:", 13))) {
 227                                 if (
 228                                         (bmstrcasestr(buf, "multipart") != NULL)
 229                                         && (bmstrcasestr(buf, "boundary=") != NULL)
 230                                 ) {
 231                                         safestrncpy(boundary, bmstrcasestr(buf, "\""), sizeof boundary);
 232                                         char *qu;
 233                                         qu = strchr(boundary, '\"');
 234                                         if (qu) {
 235                                                 strcpy(boundary, ++qu);
 236                                         }
 237                                         qu = strchr(boundary, '\"');
 238                                         if (qu) {
 239                                                 *qu = 0;
 240                                         }
 241                                 }
 242                         }
 243                 }
 244         } while ( (IsEmptyStr(boundary)) && (*ptr != 0) );
 245
 246         if (!IsEmptyStr(boundary)) {
 247                 snprintf(endary, sizeof endary, "--%s--", boundary);
 248                 history_msg->cm_fields['M'] = realloc(history_msg->cm_fields['M'],
 249                         strlen(history_msg->cm_fields['M']) + strlen(diffbuf) + 512
 250                 );
 251                 ptr = bmstrcasestr(history_msg->cm_fields['M'], endary);
 252                 if (ptr != NULL) {
 253                         sprintf(ptr, "--%s\n"
 254                                         "Content-type: text/plain\n"
 255                                         "From: %s <%s>\n"
 256                                         "\n"
 257                                         "%s\n"
 258                                         "--%s--\n"
 259                                         ,
 260                                 boundary,
 261                                 CCC->user.fullname,
 262                                 CCC->cs_inet_email,
 263                                 diffbuf,
 264                                 boundary
 265                         );
 266                 }
 267
 268                 history_msg->cm_fields['T'] = realloc(history_msg->cm_fields['T'], 32);
 269                 snprintf(history_msg->cm_fields['T'], 32, "%ld", time(NULL));
 270
 271                 CtdlSubmitMsg(history_msg, NULL, "", 0);
 272         }
 273         else {
 274                 CtdlLogPrintf(CTDL_ALERT, "Empty boundary string in history message.  No history!\n");
 275         }
 276
 277         free(diffbuf);
 278         free(history_msg);
 279         return(0);
 280 }
 281
 282
 283 /*
 284  * Module initialization
 285  */
 286 CTDL_MODULE_INIT(wiki)
 287 {
 288         if (!threading)
 289         {
 290                 CtdlRegisterMessageHook(wiki_upload_beforesave, EVT_BEFORESAVE);
 291         }
 292
 293         /* return our Subversion id for the Log */
 294         return "$Id$";
 295 }