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 / released under the GNU General Public License v3
   7  */
   8
   9 #include "sysdep.h"
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <stdio.h>
  13 #include <fcntl.h>
  14 #include <signal.h>
  15 #include <pwd.h>
  16 #include <errno.h>
  17 #include <ctype.h>
  18 #include <sys/types.h>
  19
  20 #if TIME_WITH_SYS_TIME
  21 # include <sys/time.h>
  22 # include <time.h>
  23 #else
  24 # if HAVE_SYS_TIME_H
  25 #  include <sys/time.h>
  26 # else
  27 #  include <time.h>
  28 # endif
  29 #endif
  30
  31 #include <sys/wait.h>
  32 #include <string.h>
  33 #include <limits.h>
  34 #include <libcitadel.h>
  35 #include "citadel.h"
  36 #include "server.h"
  37 #include "citserver.h"
  38 #include "support.h"
  39 #include "config.h"
  40 #include "control.h"
  41 #include "room_ops.h"
  42 #include "user_ops.h"
  43 #include "policy.h"
  44 #include "database.h"
  45 #include "msgbase.h"
  46 #include "euidindex.h"
  47 #include "ctdl_module.h"
  48
  49 /*
  50  * Before allowing a wiki page save to execute, we have to perform version control.
  51  * This involves fetching the old version of the page if it exists... FIXME finish this
  52  */
  53 int wiki_upload_beforesave(struct CtdlMessage *msg) {
  54         struct CitContext *CCC = CC;
  55         long old_msgnum = (-1L);
  56         struct CtdlMessage *old_msg = NULL;
  57         long history_msgnum = (-1L);
  58         struct CtdlMessage *history_msg = NULL;
  59         char diff_old_filename[PATH_MAX];
  60         char diff_new_filename[PATH_MAX];
  61         char diff_cmd[PATH_MAX];
  62         FILE *fp;
  63         int rv;
  64         char history_page[1024];
  65         char boundary[256];
  66         int nbytes = 0;
  67         char *diffbuf = NULL;
  68         size_t diffbuf_len = 0;
  69
  70         if (!CCC->logged_in) return(0); /* Only do this if logged in. */
  71
  72         /* Is this a room with a Wiki in it, don't run this hook. */
  73         if (CCC->room.QRdefaultview != VIEW_WIKI) {
  74                 return(0);
  75         }
  76
  77         /* If this isn't a MIME message, don't bother. */
  78         if (msg->cm_format_type != 4) return(0);
  79
  80         /* If there's no EUID we can't do this. */
  81         if (msg->cm_fields['E'] == NULL) return(0);
  82
  83         /* If there's no message text, obviously this is all b0rken and shouldn't happen at all */
  84         if (msg->cm_fields['M'] == NULL) return(0);
  85
  86         /* See if we can retrieve the previous version. */
  87         old_msgnum = locate_message_by_euid(msg->cm_fields['E'], &CCC->room);
  88         if (old_msgnum <= 0L) return(0);
  89         snprintf(history_page, sizeof history_page, "%s_HISTORY_", msg->cm_fields['E']);
  90
  91         old_msg = CtdlFetchMessage(old_msgnum, 1);
  92         if (old_msg == NULL) return(0);
  93
  94         if (old_msg->cm_fields['M'] == NULL) {          /* old version is corrupt? */
  95                 CtdlFreeMessage(old_msg);
  96                 return(0);
  97         }
  98
  99         /* If no changes were made, don't bother saving it again */
 100         if (!strcmp(msg->cm_fields['M'], old_msg->cm_fields['M'])) {
 101                 CtdlFreeMessage(old_msg);
 102                 return(1);
 103         }
 104
 105         /*
 106          * Generate diffs
 107          */
 108         CtdlMakeTempFileName(diff_old_filename, sizeof diff_old_filename);
 109         CtdlMakeTempFileName(diff_new_filename, sizeof diff_new_filename);
 110
 111         fp = fopen(diff_old_filename, "w");
 112         rv = fwrite(old_msg->cm_fields['M'], strlen(old_msg->cm_fields['M']), 1, fp);
 113         fclose(fp);
 114         CtdlFreeMessage(old_msg);
 115
 116         fp = fopen(diff_new_filename, "w");
 117         rv = fwrite(msg->cm_fields['M'], strlen(msg->cm_fields['M']), 1, fp);
 118         fclose(fp);
 119
 120         diffbuf_len = 0;
 121         diffbuf = NULL;
 122         snprintf(diff_cmd, sizeof diff_cmd, "diff -u %s %s", diff_old_filename, diff_new_filename);
 123         fp = popen(diff_cmd, "r");
 124         if (fp != NULL) {
 125                 do {
 126                         diffbuf = realloc(diffbuf, diffbuf_len + 1025);
 127                         nbytes = fread(&diffbuf[diffbuf_len], 1, 1024, fp);
 128                         diffbuf_len += nbytes;
 129                 } while (nbytes == 1024);
 130                 diffbuf[diffbuf_len] = 0;
 131                 pclose(fp);
 132         }
 133         CtdlLogPrintf(CTDL_DEBUG, "diff length is %d bytes\n", diffbuf_len);
 134
 135         unlink(diff_old_filename);
 136         unlink(diff_new_filename);
 137
 138         /* Determine whether this was a bogus (empty) edit */
 139         if ((diffbuf_len = 0) && (diffbuf != NULL)) {
 140                 free(diffbuf);
 141                 diffbuf = NULL;
 142         }
 143         if (diffbuf == NULL) {
 144                 return(1);              /* No changes at all?  Abandon the post entirely! */
 145         }
 146
 147         free(diffbuf);  /* FIXME do something with it */
 148
 149         /* Now look for the existing edit history */
 150
 151         history_msgnum = locate_message_by_euid(history_page, &CCC->room);
 152         history_msg = NULL;
 153         if (history_msgnum > 0L) {
 154                 history_msg = CtdlFetchMessage(old_msgnum, 1);
 155         }
 156
 157         /* Create a new history message if necessary */
 158         if (history_msg == NULL) {
 159                 history_msg = malloc(sizeof(struct CtdlMessage));
 160                 memset(history_msg, 0, sizeof(struct CtdlMessage));
 161                 history_msg->cm_magic = CTDLMESSAGE_MAGIC;
 162                 history_msg->cm_anon_type = MES_NORMAL;
 163                 history_msg->cm_format_type = FMT_RFC822;
 164                 history_msg->cm_fields['A'] = strdup("Citadel");
 165                 history_msg->cm_fields['R'] = strdup(CCC->room.QRname);
 166                 snprintf(boundary, sizeof boundary, "Citadel--Multipart--%04x--%08lx", getpid(), time(NULL));
 167                 history_msg->cm_fields['M'] = malloc(1024);
 168                 snprintf(history_msg->cm_fields['M'], 1024,
 169                         "Content-type: multipart/mixed; boundary=\"%s\"\n\n"
 170                         "This is a Citadel wiki history encoded as multipart MIME.\n"
 171                         "--%s--\n"
 172                         ,
 173                         boundary, boundary
 174                 );
 175         }
 176
 177         /* Update the history message (regardless of whether it's new or existing) */
 178         /* FIXME now do something with it */
 179         CtdlLogPrintf(CTDL_DEBUG, "\033[31m%s\033[0m", history_msg->cm_fields['M']);
 180
 181         /* FIXME */
 182
 183         free(history_msg);
 184         return(0);
 185 }
 186
 187
 188 /*
 189  * Module initialization
 190  */
 191 CTDL_MODULE_INIT(wiki)
 192 {
 193         if (!threading)
 194         {
 195                 CtdlRegisterMessageHook(wiki_upload_beforesave, EVT_BEFORESAVE);
 196         }
 197
 198         /* return our Subversion id for the Log */
 199         return "$Id$";
 200 }