fe318a0080e44f574801b8cf0e493eb2ba3fd824
[citadel.git] / 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... FIXME finish this
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         /* If there's no message text, obviously this is all b0rken and shouldn't happen at all */
101         if (msg->cm_fields['M'] == NULL) return(0);
102
103         /* See if we can retrieve the previous version. */
104         old_msgnum = locate_message_by_euid(msg->cm_fields['E'], &CCC->room);
105         if (old_msgnum <= 0L) return(0);
106         snprintf(history_page, sizeof history_page, "%s_HISTORY_", msg->cm_fields['E']);
107
108         old_msg = CtdlFetchMessage(old_msgnum, 1);
109         if (old_msg == NULL) return(0);
110
111         if (old_msg->cm_fields['M'] == NULL) {          /* old version is corrupt? */
112                 CtdlFreeMessage(old_msg);
113                 return(0);
114         }
115
116         /* If no changes were made, don't bother saving it again */
117         if (!strcmp(msg->cm_fields['M'], old_msg->cm_fields['M'])) {
118                 CtdlFreeMessage(old_msg);
119                 return(1);
120         }
121
122         /*
123          * Generate diffs
124          */
125         CtdlMakeTempFileName(diff_old_filename, sizeof diff_old_filename);
126         CtdlMakeTempFileName(diff_new_filename, sizeof diff_new_filename);
127
128         fp = fopen(diff_old_filename, "w");
129         rv = fwrite(old_msg->cm_fields['M'], strlen(old_msg->cm_fields['M']), 1, fp);
130         fclose(fp);
131         CtdlFreeMessage(old_msg);
132
133         fp = fopen(diff_new_filename, "w");
134         rv = fwrite(msg->cm_fields['M'], strlen(msg->cm_fields['M']), 1, fp);
135         fclose(fp);
136
137         diffbuf_len = 0;
138         diffbuf = NULL;
139         snprintf(diff_cmd, sizeof diff_cmd, "diff -u %s %s", diff_old_filename, diff_new_filename);
140         fp = popen(diff_cmd, "r");
141         if (fp != NULL) {
142                 do {
143                         diffbuf = realloc(diffbuf, diffbuf_len + 1025);
144                         nbytes = fread(&diffbuf[diffbuf_len], 1, 1024, fp);
145                         diffbuf_len += nbytes;
146                 } while (nbytes == 1024);
147                 diffbuf[diffbuf_len] = 0;
148                 pclose(fp);
149         }
150         CtdlLogPrintf(CTDL_DEBUG, "diff length is %d bytes\n", diffbuf_len);
151
152         unlink(diff_old_filename);
153         unlink(diff_new_filename);
154
155         /* Determine whether this was a bogus (empty) edit */
156         if ((diffbuf_len = 0) && (diffbuf != NULL)) {
157                 free(diffbuf);
158                 diffbuf = NULL;
159         }
160         if (diffbuf == NULL) {
161                 return(1);              /* No changes at all?  Abandon the post entirely! */
162         }
163
164         /* Now look for the existing edit history */
165
166         history_msgnum = locate_message_by_euid(history_page, &CCC->room);
167         history_msg = NULL;
168         if (history_msgnum > 0L) {
169                 history_msg = CtdlFetchMessage(old_msgnum, 1);
170         }
171
172         /* Create a new history message if necessary */
173         if (history_msg == NULL) {
174                 history_msg = malloc(sizeof(struct CtdlMessage));
175                 memset(history_msg, 0, sizeof(struct CtdlMessage));
176                 history_msg->cm_magic = CTDLMESSAGE_MAGIC;
177                 history_msg->cm_anon_type = MES_NORMAL;
178                 history_msg->cm_format_type = FMT_RFC822;
179                 history_msg->cm_fields['A'] = strdup("Citadel");
180                 history_msg->cm_fields['R'] = strdup(CCC->room.QRname);
181                 snprintf(boundary, sizeof boundary, "Citadel--Multipart--%04x--%08lx", getpid(), time(NULL));
182                 history_msg->cm_fields['M'] = malloc(1024);
183                 snprintf(history_msg->cm_fields['M'], 1024,
184                         "Content-type: multipart/mixed; boundary=\"%s\"\n\n"
185                         "This is a Citadel wiki history encoded as multipart MIME.\n"
186                         "--%s--\n"
187                         ,
188                         boundary, boundary
189                 );
190         }
191
192         /* Update the history message (regardless of whether it's new or existing) */
193
194
195         /* First, figure out the boundary string.  We do this even when we generated the
196          * boundary string in the above code, just to be safe and consistent.
197          */
198         strcpy(boundary, "");
199
200         ptr = history_msg->cm_fields['M'];
201         do {
202                 ptr = memreadline(ptr, buf, sizeof buf);
203                 if (*ptr != 0) {
204                         striplt(buf);
205                         if (!IsEmptyStr(buf) && (!strncasecmp(buf, "Content-type:", 13))) {
206                                 if (
207                                         (bmstrcasestr(buf, "multipart") != NULL)
208                                         && (bmstrcasestr(buf, "boundary=") != NULL)
209                                 ) {
210                                         safestrncpy(boundary, bmstrcasestr(buf, "\""), sizeof boundary);
211                                         char *qu;
212                                         qu = strchr(boundary, '\"');
213                                         if (qu) {
214                                                 strcpy(boundary, ++qu);
215                                         }
216                                         qu = strchr(boundary, '\"');
217                                         if (qu) {
218                                                 *qu = 0;
219                                         }
220                                 }
221                         }
222                 }
223         } while ( (IsEmptyStr(boundary)) && (*ptr != 0) );
224
225         if (!IsEmptyStr(boundary)) {
226                 snprintf(endary, sizeof endary, "--%s--", boundary);
227                 history_msg->cm_fields['M'] = realloc(history_msg->cm_fields['M'],
228                         strlen(history_msg->cm_fields['M']) + strlen(diffbuf) + 512
229                 );
230                 ptr = bmstrcasestr(history_msg->cm_fields['M'], endary);
231                 if (ptr != NULL) {
232                         sprintf(ptr, "--%s\n"
233                                         "Content-type: text/plain\n"
234                                         "From: %s <%s>\n"
235                                         "\n"
236                                         "%s\n"
237                                         "--%s--\n"
238                                         ,
239                                 boundary,
240                                 CCC->user.fullname,
241                                 CCC->cs_inet_email,
242                                 diffbuf,
243                                 boundary
244                         );
245                 }
246
247                 history_msg->cm_fields['T'] = realloc(history_msg->cm_fields['T'], 32);
248                 snprintf(history_msg->cm_fields['T'], 32, "%ld", time(NULL));
249         
250                 CtdlLogPrintf(CTDL_DEBUG, "\033[31m%s\033[0m", history_msg->cm_fields['M']);
251                 /* FIXME now do something with it */
252         }
253
254         free(diffbuf);
255         free(history_msg);
256         return(0);
257 }
258
259
260 /*
261  * Module initialization
262  */
263 CTDL_MODULE_INIT(wiki)
264 {
265         if (!threading)
266         {
267                 CtdlRegisterMessageHook(wiki_upload_beforesave, EVT_BEFORESAVE);
268         }
269
270         /* return our Subversion id for the Log */
271         return "$Id$";
272 }