Fix zlib CVE-2016-9840.
[rsync.git] / exclude.c
1 /*
2  * The filter include/exclude routines.
3  *
4  * Copyright (C) 1996-2001 Andrew Tridgell <tridge@samba.org>
5  * Copyright (C) 1996 Paul Mackerras
6  * Copyright (C) 2002 Martin Pool
7  * Copyright (C) 2003-2019 Wayne Davison
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 3 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with this program; if not, visit the http://fsf.org website.
21  */
22
23 #include "rsync.h"
24
25 extern int am_server;
26 extern int am_sender;
27 extern int eol_nulls;
28 extern int io_error;
29 extern int local_server;
30 extern int prune_empty_dirs;
31 extern int ignore_perishable;
32 extern int delete_mode;
33 extern int delete_excluded;
34 extern int cvs_exclude;
35 extern int sanitize_paths;
36 extern int protocol_version;
37 extern int module_id;
38
39 extern char curr_dir[MAXPATHLEN];
40 extern unsigned int curr_dir_len;
41 extern unsigned int module_dirlen;
42
43 filter_rule_list filter_list = { .debug_type = "" };
44 filter_rule_list cvs_filter_list = { .debug_type = " [global CVS]" };
45 filter_rule_list daemon_filter_list = { .debug_type = " [daemon]" };
46
47 int saw_xattr_filter = 0;
48
49 /* Need room enough for ":MODS " prefix plus some room to grow. */
50 #define MAX_RULE_PREFIX (16)
51
52 #define SLASH_WILD3_SUFFIX "/***"
53
54 /* The dirbuf is set by push_local_filters() to the current subdirectory
55  * relative to curr_dir that is being processed.  The path always has a
56  * trailing slash appended, and the variable dirbuf_len contains the length
57  * of this path prefix.  The path is always absolute. */
58 static char dirbuf[MAXPATHLEN+1];
59 static unsigned int dirbuf_len = 0;
60 static int dirbuf_depth;
61
62 /* This is True when we're scanning parent dirs for per-dir merge-files. */
63 static BOOL parent_dirscan = False;
64
65 /* This array contains a list of all the currently active per-dir merge
66  * files.  This makes it easier to save the appropriate values when we
67  * "push" down into each subdirectory. */
68 static filter_rule **mergelist_parents;
69 static int mergelist_cnt = 0;
70 static int mergelist_size = 0;
71
72 /* Each filter_list_struct describes a singly-linked list by keeping track
73  * of both the head and tail pointers.  The list is slightly unusual in that
74  * a parent-dir's content can be appended to the end of the local list in a
75  * special way:  the last item in the local list has its "next" pointer set
76  * to point to the inherited list, but the local list's tail pointer points
77  * at the end of the local list.  Thus, if the local list is empty, the head
78  * will be pointing at the inherited content but the tail will be NULL.  To
79  * help you visualize this, here are the possible list arrangements:
80  *
81  * Completely Empty                     Local Content Only
82  * ==================================   ====================================
83  * head -> NULL                         head -> Local1 -> Local2 -> NULL
84  * tail -> NULL                         tail -------------^
85  *
86  * Inherited Content Only               Both Local and Inherited Content
87  * ==================================   ====================================
88  * head -> Parent1 -> Parent2 -> NULL   head -> L1 -> L2 -> P1 -> P2 -> NULL
89  * tail -> NULL                         tail ---------^
90  *
91  * This means that anyone wanting to traverse the whole list to use it just
92  * needs to start at the head and use the "next" pointers until it goes
93  * NULL.  To add new local content, we insert the item after the tail item
94  * and update the tail (obviously, if "tail" was NULL, we insert it at the
95  * head).  To clear the local list, WE MUST NOT FREE THE INHERITED CONTENT
96  * because it is shared between the current list and our parent list(s).
97  * The easiest way to handle this is to simply truncate the list after the
98  * tail item and then free the local list from the head.  When inheriting
99  * the list for a new local dir, we just save off the filter_list_struct
100  * values (so we can pop back to them later) and set the tail to NULL.
101  */
102
103 static void teardown_mergelist(filter_rule *ex)
104 {
105         int j;
106
107         if (!ex->u.mergelist)
108                 return;
109
110         if (DEBUG_GTE(FILTER, 2)) {
111                 rprintf(FINFO, "[%s] deactivating mergelist #%d%s\n",
112                         who_am_i(), mergelist_cnt - 1,
113                         ex->u.mergelist->debug_type);
114         }
115
116         free(ex->u.mergelist->debug_type);
117         free(ex->u.mergelist);
118
119         for (j = 0; j < mergelist_cnt; j++) {
120                 if (mergelist_parents[j] == ex) {
121                         mergelist_parents[j] = NULL;
122                         break;
123                 }
124         }
125         while (mergelist_cnt && mergelist_parents[mergelist_cnt-1] == NULL)
126                 mergelist_cnt--;
127 }
128
129 static void free_filter(filter_rule *ex)
130 {
131         if (ex->rflags & FILTRULE_PERDIR_MERGE)
132                 teardown_mergelist(ex);
133         free(ex->pattern);
134         free(ex);
135 }
136
137 static void free_filters(filter_rule *ent)
138 {
139         while (ent) {
140                 filter_rule *next = ent->next;
141                 free_filter(ent);
142                 ent = next;
143         }
144 }
145
146 /* Build a filter structure given a filter pattern.  The value in "pat"
147  * is not null-terminated.  "rule" is either held or freed, so the
148  * caller should not free it. */
149 static void add_rule(filter_rule_list *listp, const char *pat, unsigned int pat_len,
150                      filter_rule *rule, int xflags)
151 {
152         const char *cp;
153         unsigned int pre_len, suf_len, slash_cnt = 0;
154
155         if (DEBUG_GTE(FILTER, 2)) {
156                 rprintf(FINFO, "[%s] add_rule(%s%.*s%s)%s\n",
157                         who_am_i(), get_rule_prefix(rule, pat, 0, NULL),
158                         (int)pat_len, pat,
159                         (rule->rflags & FILTRULE_DIRECTORY) ? "/" : "",
160                         listp->debug_type);
161         }
162
163         /* These flags also indicate that we're reading a list that
164          * needs to be filtered now, not post-filtered later. */
165         if (xflags & (XFLG_ANCHORED2ABS|XFLG_ABS_IF_SLASH)
166                 && (rule->rflags & FILTRULES_SIDES)
167                         == (am_sender ? FILTRULE_RECEIVER_SIDE : FILTRULE_SENDER_SIDE)) {
168                 /* This filter applies only to the other side.  Drop it. */
169                 free_filter(rule);
170                 return;
171         }
172
173         if (pat_len > 1 && pat[pat_len-1] == '/') {
174                 pat_len--;
175                 rule->rflags |= FILTRULE_DIRECTORY;
176         }
177
178         for (cp = pat; cp < pat + pat_len; cp++) {
179                 if (*cp == '/')
180                         slash_cnt++;
181         }
182
183         if (!(rule->rflags & (FILTRULE_ABS_PATH | FILTRULE_MERGE_FILE))
184          && ((xflags & (XFLG_ANCHORED2ABS|XFLG_ABS_IF_SLASH) && *pat == '/')
185           || (xflags & XFLG_ABS_IF_SLASH && slash_cnt))) {
186                 rule->rflags |= FILTRULE_ABS_PATH;
187                 if (*pat == '/')
188                         pre_len = dirbuf_len - module_dirlen - 1;
189                 else
190                         pre_len = 0;
191         } else
192                 pre_len = 0;
193
194         /* The daemon wants dir-exclude rules to get an appended "/" + "***". */
195         if (xflags & XFLG_DIR2WILD3
196          && BITS_SETnUNSET(rule->rflags, FILTRULE_DIRECTORY, FILTRULE_INCLUDE)) {
197                 rule->rflags &= ~FILTRULE_DIRECTORY;
198                 suf_len = sizeof SLASH_WILD3_SUFFIX - 1;
199         } else
200                 suf_len = 0;
201
202         if (!(rule->pattern = new_array(char, pre_len + pat_len + suf_len + 1)))
203                 out_of_memory("add_rule");
204         if (pre_len) {
205                 memcpy(rule->pattern, dirbuf + module_dirlen, pre_len);
206                 for (cp = rule->pattern; cp < rule->pattern + pre_len; cp++) {
207                         if (*cp == '/')
208                                 slash_cnt++;
209                 }
210         }
211         strlcpy(rule->pattern + pre_len, pat, pat_len + 1);
212         pat_len += pre_len;
213         if (suf_len) {
214                 memcpy(rule->pattern + pat_len, SLASH_WILD3_SUFFIX, suf_len+1);
215                 pat_len += suf_len;
216                 slash_cnt++;
217         }
218
219         if (strpbrk(rule->pattern, "*[?")) {
220                 rule->rflags |= FILTRULE_WILD;
221                 if ((cp = strstr(rule->pattern, "**")) != NULL) {
222                         rule->rflags |= FILTRULE_WILD2;
223                         /* If the pattern starts with **, note that. */
224                         if (cp == rule->pattern)
225                                 rule->rflags |= FILTRULE_WILD2_PREFIX;
226                         /* If the pattern ends with ***, note that. */
227                         if (pat_len >= 3
228                          && rule->pattern[pat_len-3] == '*'
229                          && rule->pattern[pat_len-2] == '*'
230                          && rule->pattern[pat_len-1] == '*')
231                                 rule->rflags |= FILTRULE_WILD3_SUFFIX;
232                 }
233         }
234
235         if (rule->rflags & FILTRULE_PERDIR_MERGE) {
236                 filter_rule_list *lp;
237                 unsigned int len;
238                 int i;
239
240                 if ((cp = strrchr(rule->pattern, '/')) != NULL)
241                         cp++;
242                 else
243                         cp = rule->pattern;
244
245                 /* If the local merge file was already mentioned, don't
246                  * add it again. */
247                 for (i = 0; i < mergelist_cnt; i++) {
248                         filter_rule *ex = mergelist_parents[i];
249                         const char *s;
250                         if (!ex)
251                                 continue;
252                         s = strrchr(ex->pattern, '/');
253                         if (s)
254                                 s++;
255                         else
256                                 s = ex->pattern;
257                         len = strlen(s);
258                         if (len == pat_len - (cp - rule->pattern) && memcmp(s, cp, len) == 0) {
259                                 free_filter(rule);
260                                 return;
261                         }
262                 }
263
264                 if (!(lp = new_array0(filter_rule_list, 1)))
265                         out_of_memory("add_rule");
266                 if (asprintf(&lp->debug_type, " [per-dir %s]", cp) < 0)
267                         out_of_memory("add_rule");
268                 rule->u.mergelist = lp;
269
270                 if (mergelist_cnt == mergelist_size) {
271                         mergelist_size += 5;
272                         mergelist_parents = realloc_array(mergelist_parents,
273                                                 filter_rule *,
274                                                 mergelist_size);
275                         if (!mergelist_parents)
276                                 out_of_memory("add_rule");
277                 }
278                 if (DEBUG_GTE(FILTER, 2)) {
279                         rprintf(FINFO, "[%s] activating mergelist #%d%s\n",
280                                 who_am_i(), mergelist_cnt, lp->debug_type);
281                 }
282                 mergelist_parents[mergelist_cnt++] = rule;
283         } else
284                 rule->u.slash_cnt = slash_cnt;
285
286         if (!listp->tail) {
287                 rule->next = listp->head;
288                 listp->head = listp->tail = rule;
289         } else {
290                 rule->next = listp->tail->next;
291                 listp->tail->next = rule;
292                 listp->tail = rule;
293         }
294 }
295
296 /* This frees any non-inherited items, leaving just inherited items on the list. */
297 static void pop_filter_list(filter_rule_list *listp)
298 {
299         filter_rule *inherited;
300
301         if (!listp->tail)
302                 return;
303
304         inherited = listp->tail->next;
305
306         /* Truncate any inherited items from the local list. */
307         listp->tail->next = NULL;
308         /* Now free everything that is left. */
309         free_filters(listp->head);
310
311         listp->head = inherited;
312         listp->tail = NULL;
313 }
314
315 /* This returns an expanded (absolute) filename for the merge-file name if
316  * the name has any slashes in it OR if the parent_dirscan var is True;
317  * otherwise it returns the original merge_file name.  If the len_ptr value
318  * is non-NULL the merge_file name is limited by the referenced length
319  * value and will be updated with the length of the resulting name.  We
320  * always return a name that is null terminated, even if the merge_file
321  * name was not. */
322 static char *parse_merge_name(const char *merge_file, unsigned int *len_ptr,
323                               unsigned int prefix_skip)
324 {
325         static char buf[MAXPATHLEN];
326         char *fn, tmpbuf[MAXPATHLEN];
327         unsigned int fn_len;
328
329         if (!parent_dirscan && *merge_file != '/') {
330                 /* Return the name unchanged it doesn't have any slashes. */
331                 if (len_ptr) {
332                         const char *p = merge_file + *len_ptr;
333                         while (--p > merge_file && *p != '/') {}
334                         if (p == merge_file) {
335                                 strlcpy(buf, merge_file, *len_ptr + 1);
336                                 return buf;
337                         }
338                 } else if (strchr(merge_file, '/') == NULL)
339                         return (char *)merge_file;
340         }
341
342         fn = *merge_file == '/' ? buf : tmpbuf;
343         if (sanitize_paths) {
344                 const char *r = prefix_skip ? "/" : NULL;
345                 /* null-terminate the name if it isn't already */
346                 if (len_ptr && merge_file[*len_ptr]) {
347                         char *to = fn == buf ? tmpbuf : buf;
348                         strlcpy(to, merge_file, *len_ptr + 1);
349                         merge_file = to;
350                 }
351                 if (!sanitize_path(fn, merge_file, r, dirbuf_depth, SP_DEFAULT)) {
352                         rprintf(FERROR, "merge-file name overflows: %s\n",
353                                 merge_file);
354                         return NULL;
355                 }
356                 fn_len = strlen(fn);
357         } else {
358                 strlcpy(fn, merge_file, len_ptr ? *len_ptr + 1 : MAXPATHLEN);
359                 fn_len = clean_fname(fn, CFN_COLLAPSE_DOT_DOT_DIRS);
360         }
361
362         /* If the name isn't in buf yet, it wasn't absolute. */
363         if (fn != buf) {
364                 int d_len = dirbuf_len - prefix_skip;
365                 if (d_len + fn_len >= MAXPATHLEN) {
366                         rprintf(FERROR, "merge-file name overflows: %s\n", fn);
367                         return NULL;
368                 }
369                 memcpy(buf, dirbuf + prefix_skip, d_len);
370                 memcpy(buf + d_len, fn, fn_len + 1);
371                 fn_len = clean_fname(buf, CFN_COLLAPSE_DOT_DOT_DIRS);
372         }
373
374         if (len_ptr)
375                 *len_ptr = fn_len;
376         return buf;
377 }
378
379 /* Sets the dirbuf and dirbuf_len values. */
380 void set_filter_dir(const char *dir, unsigned int dirlen)
381 {
382         unsigned int len;
383         if (*dir != '/') {
384                 memcpy(dirbuf, curr_dir, curr_dir_len);
385                 dirbuf[curr_dir_len] = '/';
386                 len = curr_dir_len + 1;
387                 if (len + dirlen >= MAXPATHLEN)
388                         dirlen = 0;
389         } else
390                 len = 0;
391         memcpy(dirbuf + len, dir, dirlen);
392         dirbuf[dirlen + len] = '\0';
393         dirbuf_len = clean_fname(dirbuf, CFN_COLLAPSE_DOT_DOT_DIRS);
394         if (dirbuf_len > 1 && dirbuf[dirbuf_len-1] == '.'
395             && dirbuf[dirbuf_len-2] == '/')
396                 dirbuf_len -= 2;
397         if (dirbuf_len != 1)
398                 dirbuf[dirbuf_len++] = '/';
399         dirbuf[dirbuf_len] = '\0';
400         if (sanitize_paths)
401                 dirbuf_depth = count_dir_elements(dirbuf + module_dirlen);
402 }
403
404 /* This routine takes a per-dir merge-file entry and finishes its setup.
405  * If the name has a path portion then we check to see if it refers to a
406  * parent directory of the first transfer dir.  If it does, we scan all the
407  * dirs from that point through the parent dir of the transfer dir looking
408  * for the per-dir merge-file in each one. */
409 static BOOL setup_merge_file(int mergelist_num, filter_rule *ex,
410                              filter_rule_list *lp)
411 {
412         char buf[MAXPATHLEN];
413         char *x, *y, *pat = ex->pattern;
414         unsigned int len;
415
416         if (!(x = parse_merge_name(pat, NULL, 0)) || *x != '/')
417                 return 0;
418
419         if (DEBUG_GTE(FILTER, 2)) {
420                 rprintf(FINFO, "[%s] performing parent_dirscan for mergelist #%d%s\n",
421                         who_am_i(), mergelist_num, lp->debug_type);
422         }
423         y = strrchr(x, '/');
424         *y = '\0';
425         ex->pattern = strdup(y+1);
426         if (!*x)
427                 x = "/";
428         if (*x == '/')
429                 strlcpy(buf, x, MAXPATHLEN);
430         else
431                 pathjoin(buf, MAXPATHLEN, dirbuf, x);
432
433         len = clean_fname(buf, CFN_COLLAPSE_DOT_DOT_DIRS);
434         if (len != 1 && len < MAXPATHLEN-1) {
435                 buf[len++] = '/';
436                 buf[len] = '\0';
437         }
438         /* This ensures that the specified dir is a parent of the transfer. */
439         for (x = buf, y = dirbuf; *x && *x == *y; x++, y++) {}
440         if (*x)
441                 y += strlen(y); /* nope -- skip the scan */
442
443         parent_dirscan = True;
444         while (*y) {
445                 char save[MAXPATHLEN];
446                 strlcpy(save, y, MAXPATHLEN);
447                 *y = '\0';
448                 dirbuf_len = y - dirbuf;
449                 strlcpy(x, ex->pattern, MAXPATHLEN - (x - buf));
450                 parse_filter_file(lp, buf, ex, XFLG_ANCHORED2ABS);
451                 if (ex->rflags & FILTRULE_NO_INHERIT) {
452                         /* Free the undesired rules to clean up any per-dir
453                          * mergelists they defined.  Otherwise pop_local_filters
454                          * may crash trying to restore nonexistent state for
455                          * those mergelists. */
456                         free_filters(lp->head);
457                         lp->head = NULL;
458                 }
459                 lp->tail = NULL;
460                 strlcpy(y, save, MAXPATHLEN);
461                 while ((*x++ = *y++) != '/') {}
462         }
463         parent_dirscan = False;
464         if (DEBUG_GTE(FILTER, 2)) {
465                 rprintf(FINFO, "[%s] completed parent_dirscan for mergelist #%d%s\n",
466                         who_am_i(), mergelist_num, lp->debug_type);
467         }
468         free(pat);
469         return 1;
470 }
471
472 struct local_filter_state {
473         int mergelist_cnt;
474         filter_rule_list mergelists[1];
475 };
476
477 /* Each time rsync changes to a new directory it call this function to
478  * handle all the per-dir merge-files.  The "dir" value is the current path
479  * relative to curr_dir (which might not be null-terminated).  We copy it
480  * into dirbuf so that we can easily append a file name on the end. */
481 void *push_local_filters(const char *dir, unsigned int dirlen)
482 {
483         struct local_filter_state *push;
484         int i;
485
486         set_filter_dir(dir, dirlen);
487         if (DEBUG_GTE(FILTER, 2)) {
488                 rprintf(FINFO, "[%s] pushing local filters for %s\n",
489                         who_am_i(), dirbuf);
490         }
491
492         if (!mergelist_cnt) {
493                 /* No old state to save and no new merge files to push. */
494                 return NULL;
495         }
496
497         push = (struct local_filter_state *)new_array(char,
498                           sizeof (struct local_filter_state)
499                         + (mergelist_cnt-1) * sizeof (filter_rule_list));
500         if (!push)
501                 out_of_memory("push_local_filters");
502
503         push->mergelist_cnt = mergelist_cnt;
504         for (i = 0; i < mergelist_cnt; i++) {
505                 filter_rule *ex = mergelist_parents[i];
506                 if (!ex)
507                         continue;
508                 memcpy(&push->mergelists[i], ex->u.mergelist, sizeof (filter_rule_list));
509         }
510
511         /* Note: parse_filter_file() might increase mergelist_cnt, so keep
512          * this loop separate from the above loop. */
513         for (i = 0; i < mergelist_cnt; i++) {
514                 filter_rule *ex = mergelist_parents[i];
515                 filter_rule_list *lp;
516                 if (!ex)
517                         continue;
518                 lp = ex->u.mergelist;
519
520                 if (DEBUG_GTE(FILTER, 2)) {
521                         rprintf(FINFO, "[%s] pushing mergelist #%d%s\n",
522                                 who_am_i(), i, lp->debug_type);
523                 }
524
525                 lp->tail = NULL; /* Switch any local rules to inherited. */
526                 if (ex->rflags & FILTRULE_NO_INHERIT)
527                         lp->head = NULL;
528
529                 if (ex->rflags & FILTRULE_FINISH_SETUP) {
530                         ex->rflags &= ~FILTRULE_FINISH_SETUP;
531                         if (setup_merge_file(i, ex, lp))
532                                 set_filter_dir(dir, dirlen);
533                 }
534
535                 if (strlcpy(dirbuf + dirbuf_len, ex->pattern,
536                     MAXPATHLEN - dirbuf_len) < MAXPATHLEN - dirbuf_len) {
537                         parse_filter_file(lp, dirbuf, ex,
538                                           XFLG_ANCHORED2ABS);
539                 } else {
540                         io_error |= IOERR_GENERAL;
541                         rprintf(FERROR,
542                             "cannot add local filter rules in long-named directory: %s\n",
543                             full_fname(dirbuf));
544                 }
545                 dirbuf[dirbuf_len] = '\0';
546         }
547
548         return (void*)push;
549 }
550
551 void pop_local_filters(void *mem)
552 {
553         struct local_filter_state *pop = (struct local_filter_state *)mem;
554         int i;
555         int old_mergelist_cnt = pop ? pop->mergelist_cnt : 0;
556
557         if (DEBUG_GTE(FILTER, 2))
558                 rprintf(FINFO, "[%s] popping local filters\n", who_am_i());
559
560         for (i = mergelist_cnt; i-- > 0; ) {
561                 filter_rule *ex = mergelist_parents[i];
562                 filter_rule_list *lp;
563                 if (!ex)
564                         continue;
565                 lp = ex->u.mergelist;
566
567                 if (DEBUG_GTE(FILTER, 2)) {
568                         rprintf(FINFO, "[%s] popping mergelist #%d%s\n",
569                                 who_am_i(), i, lp->debug_type);
570                 }
571
572                 pop_filter_list(lp);
573                 if (i >= old_mergelist_cnt && lp->head) {
574                         /* This mergelist does not exist in the state to be restored, but it
575                          * still has inherited rules.  This can sometimes happen if a per-dir
576                          * merge file calls setup_merge_file() in push_local_filters() and that
577                          * leaves some inherited rules that aren't in the pushed list state. */
578                         if (DEBUG_GTE(FILTER, 2)) {
579                                 rprintf(FINFO, "[%s] freeing parent_dirscan filters of mergelist #%d%s\n",
580                                         who_am_i(), i, ex->u.mergelist->debug_type);
581                         }
582                         pop_filter_list(lp);
583                 }
584         }
585
586         if (!pop)
587                 return; /* No state to restore. */
588
589         for (i = 0; i < old_mergelist_cnt; i++) {
590                 filter_rule *ex = mergelist_parents[i];
591                 if (!ex)
592                         continue;
593                 memcpy(ex->u.mergelist, &pop->mergelists[i], sizeof (filter_rule_list));
594         }
595
596         free(pop);
597 }
598
599 void change_local_filter_dir(const char *dname, int dlen, int dir_depth)
600 {
601         static int cur_depth = -1;
602         static void *filt_array[MAXPATHLEN/2+1];
603
604         if (!dname) {
605                 for ( ; cur_depth >= 0; cur_depth--) {
606                         if (filt_array[cur_depth]) {
607                                 pop_local_filters(filt_array[cur_depth]);
608                                 filt_array[cur_depth] = NULL;
609                         }
610                 }
611                 return;
612         }
613
614         assert(dir_depth < MAXPATHLEN/2+1);
615
616         for ( ; cur_depth >= dir_depth; cur_depth--) {
617                 if (filt_array[cur_depth]) {
618                         pop_local_filters(filt_array[cur_depth]);
619                         filt_array[cur_depth] = NULL;
620                 }
621         }
622
623         cur_depth = dir_depth;
624         filt_array[cur_depth] = push_local_filters(dname, dlen);
625 }
626
627 static int rule_matches(const char *fname, filter_rule *ex, int name_flags)
628 {
629         int slash_handling, str_cnt = 0, anchored_match = 0;
630         int ret_match = ex->rflags & FILTRULE_NEGATE ? 0 : 1;
631         char *p, *pattern = ex->pattern;
632         const char *strings[16]; /* more than enough */
633         const char *name = fname + (*fname == '/');
634
635         if (!*name)
636                 return 0;
637
638         if (!(name_flags & NAME_IS_XATTR) ^ !(ex->rflags & FILTRULE_XATTR))
639                 return 0;
640
641         if (!ex->u.slash_cnt && !(ex->rflags & FILTRULE_WILD2)) {
642                 /* If the pattern does not have any slashes AND it does
643                  * not have a "**" (which could match a slash), then we
644                  * just match the name portion of the path. */
645                 if ((p = strrchr(name,'/')) != NULL)
646                         name = p+1;
647         } else if (ex->rflags & FILTRULE_ABS_PATH && *fname != '/'
648             && curr_dir_len > module_dirlen + 1) {
649                 /* If we're matching against an absolute-path pattern,
650                  * we need to prepend our full path info. */
651                 strings[str_cnt++] = curr_dir + module_dirlen + 1;
652                 strings[str_cnt++] = "/";
653         } else if (ex->rflags & FILTRULE_WILD2_PREFIX && *fname != '/') {
654                 /* Allow "**"+"/" to match at the start of the string. */
655                 strings[str_cnt++] = "/";
656         }
657         strings[str_cnt++] = name;
658         if (name_flags & NAME_IS_DIR) {
659                 /* Allow a trailing "/"+"***" to match the directory. */
660                 if (ex->rflags & FILTRULE_WILD3_SUFFIX)
661                         strings[str_cnt++] = "/";
662         } else if (ex->rflags & FILTRULE_DIRECTORY)
663                 return !ret_match;
664         strings[str_cnt] = NULL;
665
666         if (*pattern == '/') {
667                 anchored_match = 1;
668                 pattern++;
669         }
670
671         if (!anchored_match && ex->u.slash_cnt
672             && !(ex->rflags & FILTRULE_WILD2)) {
673                 /* A non-anchored match with an infix slash and no "**"
674                  * needs to match the last slash_cnt+1 name elements. */
675                 slash_handling = ex->u.slash_cnt + 1;
676         } else if (!anchored_match && !(ex->rflags & FILTRULE_WILD2_PREFIX)
677                                    && ex->rflags & FILTRULE_WILD2) {
678                 /* A non-anchored match with an infix or trailing "**" (but not
679                  * a prefixed "**") needs to try matching after every slash. */
680                 slash_handling = -1;
681         } else {
682                 /* The pattern matches only at the start of the path or name. */
683                 slash_handling = 0;
684         }
685
686         if (ex->rflags & FILTRULE_WILD) {
687                 if (wildmatch_array(pattern, strings, slash_handling))
688                         return ret_match;
689         } else if (str_cnt > 1) {
690                 if (litmatch_array(pattern, strings, slash_handling))
691                         return ret_match;
692         } else if (anchored_match) {
693                 if (strcmp(name, pattern) == 0)
694                         return ret_match;
695         } else {
696                 int l1 = strlen(name);
697                 int l2 = strlen(pattern);
698                 if (l2 <= l1 &&
699                     strcmp(name+(l1-l2),pattern) == 0 &&
700                     (l1==l2 || name[l1-(l2+1)] == '/')) {
701                         return ret_match;
702                 }
703         }
704
705         return !ret_match;
706 }
707
708 static void report_filter_result(enum logcode code, char const *name,
709                                  filter_rule const *ent,
710                                  int name_flags, const char *type)
711 {
712         /* If a trailing slash is present to match only directories,
713          * then it is stripped out by add_rule().  So as a special
714          * case we add it back in here. */
715
716         if (DEBUG_GTE(FILTER, 1)) {
717                 static char *actions[2][2]
718                     = { {"show", "hid"}, {"risk", "protect"} };
719                 const char *w = who_am_i();
720                 const char *t = name_flags & NAME_IS_XATTR ? "xattr"
721                               : name_flags & NAME_IS_DIR ? "directory"
722                               : "file";
723                 rprintf(code, "[%s] %sing %s %s because of pattern %s%s%s\n",
724                     w, actions[*w!='s'][!(ent->rflags & FILTRULE_INCLUDE)],
725                     t, name, ent->pattern,
726                     ent->rflags & FILTRULE_DIRECTORY ? "/" : "", type);
727         }
728 }
729
730 /* This function is used to check if a file should be included/excluded
731  * from the list of files based on its name and type etc.  The value of
732  * filter_level is set to either SERVER_FILTERS or ALL_FILTERS. */
733 int name_is_excluded(const char *fname, int name_flags, int filter_level)
734 {
735         if (daemon_filter_list.head && check_filter(&daemon_filter_list, FLOG, fname, name_flags) < 0) {
736                 if (!(name_flags & NAME_IS_XATTR))
737                         errno = ENOENT;
738                 return 1;
739         }
740
741         if (filter_level != ALL_FILTERS)
742                 return 0;
743
744         if (filter_list.head && check_filter(&filter_list, FINFO, fname, name_flags) < 0)
745                 return 1;
746
747         return 0;
748 }
749
750 /* Return -1 if file "name" is defined to be excluded by the specified
751  * exclude list, 1 if it is included, and 0 if it was not matched. */
752 int check_filter(filter_rule_list *listp, enum logcode code,
753                  const char *name, int name_flags)
754 {
755         filter_rule *ent;
756
757         for (ent = listp->head; ent; ent = ent->next) {
758                 if (ignore_perishable && ent->rflags & FILTRULE_PERISHABLE)
759                         continue;
760                 if (ent->rflags & FILTRULE_PERDIR_MERGE) {
761                         int rc = check_filter(ent->u.mergelist, code, name, name_flags);
762                         if (rc)
763                                 return rc;
764                         continue;
765                 }
766                 if (ent->rflags & FILTRULE_CVS_IGNORE) {
767                         int rc = check_filter(&cvs_filter_list, code, name, name_flags);
768                         if (rc)
769                                 return rc;
770                         continue;
771                 }
772                 if (rule_matches(name, ent, name_flags)) {
773                         report_filter_result(code, name, ent, name_flags, listp->debug_type);
774                         return ent->rflags & FILTRULE_INCLUDE ? 1 : -1;
775                 }
776         }
777
778         return 0;
779 }
780
781 #define RULE_STRCMP(s,r) rule_strcmp((s), (r), sizeof (r) - 1)
782
783 static const uchar *rule_strcmp(const uchar *str, const char *rule, int rule_len)
784 {
785         if (strncmp((char*)str, rule, rule_len) != 0)
786                 return NULL;
787         if (isspace(str[rule_len]) || str[rule_len] == '_' || !str[rule_len])
788                 return str + rule_len - 1;
789         if (str[rule_len] == ',')
790                 return str + rule_len;
791         return NULL;
792 }
793
794 #define FILTRULES_FROM_CONTAINER (FILTRULE_ABS_PATH | FILTRULE_INCLUDE \
795                                 | FILTRULE_DIRECTORY | FILTRULE_NEGATE \
796                                 | FILTRULE_PERISHABLE)
797
798 /* Gets the next include/exclude rule from *rulestr_ptr and advances
799  * *rulestr_ptr to point beyond it.  Stores the pattern's start (within
800  * *rulestr_ptr) and length in *pat_ptr and *pat_len_ptr, and returns a newly
801  * allocated filter_rule containing the rest of the information.  Returns
802  * NULL if there are no more rules in the input.
803  *
804  * The template provides defaults for the new rule to inherit, and the
805  * template rflags and the xflags additionally affect parsing. */
806 static filter_rule *parse_rule_tok(const char **rulestr_ptr,
807                                    const filter_rule *template, int xflags,
808                                    const char **pat_ptr, unsigned int *pat_len_ptr)
809 {
810         const uchar *s = (const uchar *)*rulestr_ptr;
811         filter_rule *rule;
812         unsigned int len;
813
814         if (template->rflags & FILTRULE_WORD_SPLIT) {
815                 /* Skip over any initial whitespace. */
816                 while (isspace(*s))
817                         s++;
818                 /* Update to point to real start of rule. */
819                 *rulestr_ptr = (const char *)s;
820         }
821         if (!*s)
822                 return NULL;
823
824         if (!(rule = new0(filter_rule)))
825                 out_of_memory("parse_rule_tok");
826
827         /* Inherit from the template.  Don't inherit FILTRULES_SIDES; we check
828          * that later. */
829         rule->rflags = template->rflags & FILTRULES_FROM_CONTAINER;
830
831         /* Figure out what kind of a filter rule "s" is pointing at.  Note
832          * that if FILTRULE_NO_PREFIXES is set, the rule is either an include
833          * or an exclude based on the inheritance of the FILTRULE_INCLUDE
834          * flag (above).  XFLG_OLD_PREFIXES indicates a compatibility mode
835          * for old include/exclude patterns where just "+ " and "- " are
836          * allowed as optional prefixes.  */
837         if (template->rflags & FILTRULE_NO_PREFIXES) {
838                 if (*s == '!' && template->rflags & FILTRULE_CVS_IGNORE)
839                         rule->rflags |= FILTRULE_CLEAR_LIST; /* Tentative! */
840         } else if (xflags & XFLG_OLD_PREFIXES) {
841                 if (*s == '-' && s[1] == ' ') {
842                         rule->rflags &= ~FILTRULE_INCLUDE;
843                         s += 2;
844                 } else if (*s == '+' && s[1] == ' ') {
845                         rule->rflags |= FILTRULE_INCLUDE;
846                         s += 2;
847                 } else if (*s == '!')
848                         rule->rflags |= FILTRULE_CLEAR_LIST; /* Tentative! */
849         } else {
850                 char ch = 0;
851                 BOOL prefix_specifies_side = False;
852                 switch (*s) {
853                 case 'c':
854                         if ((s = RULE_STRCMP(s, "clear")) != NULL)
855                                 ch = '!';
856                         break;
857                 case 'd':
858                         if ((s = RULE_STRCMP(s, "dir-merge")) != NULL)
859                                 ch = ':';
860                         break;
861                 case 'e':
862                         if ((s = RULE_STRCMP(s, "exclude")) != NULL)
863                                 ch = '-';
864                         break;
865                 case 'h':
866                         if ((s = RULE_STRCMP(s, "hide")) != NULL)
867                                 ch = 'H';
868                         break;
869                 case 'i':
870                         if ((s = RULE_STRCMP(s, "include")) != NULL)
871                                 ch = '+';
872                         break;
873                 case 'm':
874                         if ((s = RULE_STRCMP(s, "merge")) != NULL)
875                                 ch = '.';
876                         break;
877                 case 'p':
878                         if ((s = RULE_STRCMP(s, "protect")) != NULL)
879                                 ch = 'P';
880                         break;
881                 case 'r':
882                         if ((s = RULE_STRCMP(s, "risk")) != NULL)
883                                 ch = 'R';
884                         break;
885                 case 's':
886                         if ((s = RULE_STRCMP(s, "show")) != NULL)
887                                 ch = 'S';
888                         break;
889                 default:
890                         ch = *s;
891                         if (s[1] == ',')
892                                 s++;
893                         break;
894                 }
895                 switch (ch) {
896                 case ':':
897                         rule->rflags |= FILTRULE_PERDIR_MERGE
898                                       | FILTRULE_FINISH_SETUP;
899                         /* FALL THROUGH */
900                 case '.':
901                         rule->rflags |= FILTRULE_MERGE_FILE;
902                         break;
903                 case '+':
904                         rule->rflags |= FILTRULE_INCLUDE;
905                         break;
906                 case '-':
907                         break;
908                 case 'S':
909                         rule->rflags |= FILTRULE_INCLUDE;
910                         /* FALL THROUGH */
911                 case 'H':
912                         rule->rflags |= FILTRULE_SENDER_SIDE;
913                         prefix_specifies_side = True;
914                         break;
915                 case 'R':
916                         rule->rflags |= FILTRULE_INCLUDE;
917                         /* FALL THROUGH */
918                 case 'P':
919                         rule->rflags |= FILTRULE_RECEIVER_SIDE;
920                         prefix_specifies_side = True;
921                         break;
922                 case '!':
923                         rule->rflags |= FILTRULE_CLEAR_LIST;
924                         break;
925                 default:
926                         rprintf(FERROR, "Unknown filter rule: `%s'\n", *rulestr_ptr);
927                         exit_cleanup(RERR_SYNTAX);
928                 }
929                 while (ch != '!' && *++s && *s != ' ' && *s != '_') {
930                         if (template->rflags & FILTRULE_WORD_SPLIT && isspace(*s)) {
931                                 s--;
932                                 break;
933                         }
934                         switch (*s) {
935                         default:
936                             invalid:
937                                 rprintf(FERROR,
938                                         "invalid modifier '%c' at position %d in filter rule: %s\n",
939                                         *s, (int)(s - (const uchar *)*rulestr_ptr), *rulestr_ptr);
940                                 exit_cleanup(RERR_SYNTAX);
941                         case '-':
942                                 if (!BITS_SETnUNSET(rule->rflags, FILTRULE_MERGE_FILE, FILTRULE_NO_PREFIXES))
943                                         goto invalid;
944                                 rule->rflags |= FILTRULE_NO_PREFIXES;
945                                 break;
946                         case '+':
947                                 if (!BITS_SETnUNSET(rule->rflags, FILTRULE_MERGE_FILE, FILTRULE_NO_PREFIXES))
948                                         goto invalid;
949                                 rule->rflags |= FILTRULE_NO_PREFIXES
950                                               | FILTRULE_INCLUDE;
951                                 break;
952                         case '/':
953                                 rule->rflags |= FILTRULE_ABS_PATH;
954                                 break;
955                         case '!':
956                                 /* Negation really goes with the pattern, so it
957                                  * isn't useful as a merge-file default. */
958                                 if (rule->rflags & FILTRULE_MERGE_FILE)
959                                         goto invalid;
960                                 rule->rflags |= FILTRULE_NEGATE;
961                                 break;
962                         case 'C':
963                                 if (rule->rflags & FILTRULE_NO_PREFIXES || prefix_specifies_side)
964                                         goto invalid;
965                                 rule->rflags |= FILTRULE_NO_PREFIXES
966                                               | FILTRULE_WORD_SPLIT
967                                               | FILTRULE_NO_INHERIT
968                                               | FILTRULE_CVS_IGNORE;
969                                 break;
970                         case 'e':
971                                 if (!(rule->rflags & FILTRULE_MERGE_FILE))
972                                         goto invalid;
973                                 rule->rflags |= FILTRULE_EXCLUDE_SELF;
974                                 break;
975                         case 'n':
976                                 if (!(rule->rflags & FILTRULE_MERGE_FILE))
977                                         goto invalid;
978                                 rule->rflags |= FILTRULE_NO_INHERIT;
979                                 break;
980                         case 'p':
981                                 rule->rflags |= FILTRULE_PERISHABLE;
982                                 break;
983                         case 'r':
984                                 if (prefix_specifies_side)
985                                         goto invalid;
986                                 rule->rflags |= FILTRULE_RECEIVER_SIDE;
987                                 break;
988                         case 's':
989                                 if (prefix_specifies_side)
990                                         goto invalid;
991                                 rule->rflags |= FILTRULE_SENDER_SIDE;
992                                 break;
993                         case 'w':
994                                 if (!(rule->rflags & FILTRULE_MERGE_FILE))
995                                         goto invalid;
996                                 rule->rflags |= FILTRULE_WORD_SPLIT;
997                                 break;
998                         case 'x':
999                                 rule->rflags |= FILTRULE_XATTR;
1000                                 saw_xattr_filter = 1;
1001                                 break;
1002                         }
1003                 }
1004                 if (*s)
1005                         s++;
1006         }
1007         if (template->rflags & FILTRULES_SIDES) {
1008                 if (rule->rflags & FILTRULES_SIDES) {
1009                         /* The filter and template both specify side(s).  This
1010                          * is dodgy (and won't work correctly if the template is
1011                          * a one-sided per-dir merge rule), so reject it. */
1012                         rprintf(FERROR,
1013                                 "specified-side merge file contains specified-side filter: %s\n",
1014                                 *rulestr_ptr);
1015                         exit_cleanup(RERR_SYNTAX);
1016                 }
1017                 rule->rflags |= template->rflags & FILTRULES_SIDES;
1018         }
1019
1020         if (template->rflags & FILTRULE_WORD_SPLIT) {
1021                 const uchar *cp = s;
1022                 /* Token ends at whitespace or the end of the string. */
1023                 while (!isspace(*cp) && *cp != '\0')
1024                         cp++;
1025                 len = cp - s;
1026         } else
1027                 len = strlen((char*)s);
1028
1029         if (rule->rflags & FILTRULE_CLEAR_LIST) {
1030                 if (!(rule->rflags & FILTRULE_NO_PREFIXES)
1031                  && !(xflags & XFLG_OLD_PREFIXES) && len) {
1032                         rprintf(FERROR,
1033                                 "'!' rule has trailing characters: %s\n", *rulestr_ptr);
1034                         exit_cleanup(RERR_SYNTAX);
1035                 }
1036                 if (len > 1)
1037                         rule->rflags &= ~FILTRULE_CLEAR_LIST;
1038         } else if (!len && !(rule->rflags & FILTRULE_CVS_IGNORE)) {
1039                 rprintf(FERROR, "unexpected end of filter rule: %s\n", *rulestr_ptr);
1040                 exit_cleanup(RERR_SYNTAX);
1041         }
1042
1043         /* --delete-excluded turns an un-modified include/exclude into a sender-side rule.  */
1044         if (delete_excluded
1045          && !(rule->rflags & (FILTRULES_SIDES|FILTRULE_MERGE_FILE|FILTRULE_PERDIR_MERGE)))
1046                 rule->rflags |= FILTRULE_SENDER_SIDE;
1047
1048         *pat_ptr = (const char *)s;
1049         *pat_len_ptr = len;
1050         *rulestr_ptr = *pat_ptr + len;
1051         return rule;
1052 }
1053
1054 static char default_cvsignore[] =
1055         /* These default ignored items come from the CVS manual. */
1056         "RCS SCCS CVS CVS.adm RCSLOG cvslog.* tags TAGS"
1057         " .make.state .nse_depinfo *~ #* .#* ,* _$* *$"
1058         " *.old *.bak *.BAK *.orig *.rej .del-*"
1059         " *.a *.olb *.o *.obj *.so *.exe"
1060         " *.Z *.elc *.ln core"
1061         /* The rest we added to suit ourself. */
1062         " .svn/ .git/ .hg/ .bzr/";
1063
1064 static void get_cvs_excludes(uint32 rflags)
1065 {
1066         static int initialized = 0;
1067         char *p, fname[MAXPATHLEN];
1068
1069         if (initialized)
1070                 return;
1071         initialized = 1;
1072
1073         parse_filter_str(&cvs_filter_list, default_cvsignore,
1074                          rule_template(rflags | (protocol_version >= 30 ? FILTRULE_PERISHABLE : 0)),
1075                          0);
1076
1077         p = module_id >= 0 && lp_use_chroot(module_id) ? "/" : getenv("HOME");
1078         if (p && pathjoin(fname, MAXPATHLEN, p, ".cvsignore") < MAXPATHLEN)
1079                 parse_filter_file(&cvs_filter_list, fname, rule_template(rflags), 0);
1080
1081         parse_filter_str(&cvs_filter_list, getenv("CVSIGNORE"), rule_template(rflags), 0);
1082 }
1083
1084 const filter_rule *rule_template(uint32 rflags)
1085 {
1086         static filter_rule template; /* zero-initialized */
1087         template.rflags = rflags;
1088         return &template;
1089 }
1090
1091 void parse_filter_str(filter_rule_list *listp, const char *rulestr,
1092                      const filter_rule *template, int xflags)
1093 {
1094         filter_rule *rule;
1095         const char *pat;
1096         unsigned int pat_len;
1097
1098         if (!rulestr)
1099                 return;
1100
1101         while (1) {
1102                 uint32 new_rflags;
1103
1104                 /* Remember that the returned string is NOT '\0' terminated! */
1105                 if (!(rule = parse_rule_tok(&rulestr, template, xflags, &pat, &pat_len)))
1106                         break;
1107
1108                 if (pat_len >= MAXPATHLEN) {
1109                         rprintf(FERROR, "discarding over-long filter: %.*s\n",
1110                                 (int)pat_len, pat);
1111                     free_continue:
1112                         free_filter(rule);
1113                         continue;
1114                 }
1115
1116                 new_rflags = rule->rflags;
1117                 if (new_rflags & FILTRULE_CLEAR_LIST) {
1118                         if (DEBUG_GTE(FILTER, 2)) {
1119                                 rprintf(FINFO,
1120                                         "[%s] clearing filter list%s\n",
1121                                         who_am_i(), listp->debug_type);
1122                         }
1123                         pop_filter_list(listp);
1124                         listp->head = NULL;
1125                         goto free_continue;
1126                 }
1127
1128                 if (new_rflags & FILTRULE_MERGE_FILE) {
1129                         if (!pat_len) {
1130                                 pat = ".cvsignore";
1131                                 pat_len = 10;
1132                         }
1133                         if (new_rflags & FILTRULE_EXCLUDE_SELF) {
1134                                 const char *name;
1135                                 filter_rule *excl_self;
1136
1137                                 if (!(excl_self = new0(filter_rule)))
1138                                         out_of_memory("parse_filter_str");
1139                                 /* Find the beginning of the basename and add an exclude for it. */
1140                                 for (name = pat + pat_len; name > pat && name[-1] != '/'; name--) {}
1141                                 add_rule(listp, name, (pat + pat_len) - name, excl_self, 0);
1142                                 rule->rflags &= ~FILTRULE_EXCLUDE_SELF;
1143                         }
1144                         if (new_rflags & FILTRULE_PERDIR_MERGE) {
1145                                 if (parent_dirscan) {
1146                                         const char *p;
1147                                         unsigned int len = pat_len;
1148                                         if ((p = parse_merge_name(pat, &len, module_dirlen)))
1149                                                 add_rule(listp, p, len, rule, 0);
1150                                         else
1151                                                 free_filter(rule);
1152                                         continue;
1153                                 }
1154                         } else {
1155                                 const char *p;
1156                                 unsigned int len = pat_len;
1157                                 if ((p = parse_merge_name(pat, &len, 0)))
1158                                         parse_filter_file(listp, p, rule, XFLG_FATAL_ERRORS);
1159                                 free_filter(rule);
1160                                 continue;
1161                         }
1162                 }
1163
1164                 add_rule(listp, pat, pat_len, rule, xflags);
1165
1166                 if (new_rflags & FILTRULE_CVS_IGNORE
1167                     && !(new_rflags & FILTRULE_MERGE_FILE))
1168                         get_cvs_excludes(new_rflags);
1169         }
1170 }
1171
1172 void parse_filter_file(filter_rule_list *listp, const char *fname, const filter_rule *template, int xflags)
1173 {
1174         FILE *fp;
1175         char line[BIGPATHBUFLEN];
1176         char *eob = line + sizeof line - 1;
1177         BOOL word_split = (template->rflags & FILTRULE_WORD_SPLIT) != 0;
1178
1179         if (!fname || !*fname)
1180                 return;
1181
1182         if (*fname != '-' || fname[1] || am_server) {
1183                 if (daemon_filter_list.head) {
1184                         strlcpy(line, fname, sizeof line);
1185                         clean_fname(line, CFN_COLLAPSE_DOT_DOT_DIRS);
1186                         if (check_filter(&daemon_filter_list, FLOG, line, 0) < 0)
1187                                 fp = NULL;
1188                         else
1189                                 fp = fopen(line, "rb");
1190                 } else
1191                         fp = fopen(fname, "rb");
1192         } else
1193                 fp = stdin;
1194
1195         if (DEBUG_GTE(FILTER, 2)) {
1196                 rprintf(FINFO, "[%s] parse_filter_file(%s,%x,%x)%s\n",
1197                         who_am_i(), fname, template->rflags, xflags,
1198                         fp ? "" : " [not found]");
1199         }
1200
1201         if (!fp) {
1202                 if (xflags & XFLG_FATAL_ERRORS) {
1203                         rsyserr(FERROR, errno,
1204                                 "failed to open %sclude file %s",
1205                                 template->rflags & FILTRULE_INCLUDE ? "in" : "ex",
1206                                 fname);
1207                         exit_cleanup(RERR_FILEIO);
1208                 }
1209                 return;
1210         }
1211         dirbuf[dirbuf_len] = '\0';
1212
1213         while (1) {
1214                 char *s = line;
1215                 int ch, overflow = 0;
1216                 while (1) {
1217                         if ((ch = getc(fp)) == EOF) {
1218                                 if (ferror(fp) && errno == EINTR) {
1219                                         clearerr(fp);
1220                                         continue;
1221                                 }
1222                                 break;
1223                         }
1224                         if (word_split && isspace(ch))
1225                                 break;
1226                         if (eol_nulls? !ch : (ch == '\n' || ch == '\r'))
1227                                 break;
1228                         if (s < eob)
1229                                 *s++ = ch;
1230                         else
1231                                 overflow = 1;
1232                 }
1233                 if (overflow) {
1234                         rprintf(FERROR, "discarding over-long filter: %s...\n", line);
1235                         s = line;
1236                 }
1237                 *s = '\0';
1238                 /* Skip an empty token and (when line parsing) comments. */
1239                 if (*line && (word_split || (*line != ';' && *line != '#')))
1240                         parse_filter_str(listp, line, template, xflags);
1241                 if (ch == EOF)
1242                         break;
1243         }
1244         fclose(fp);
1245 }
1246
1247 /* If the "for_xfer" flag is set, the prefix is made compatible with the
1248  * current protocol_version (if possible) or a NULL is returned (if not
1249  * possible). */
1250 char *get_rule_prefix(filter_rule *rule, const char *pat, int for_xfer,
1251                       unsigned int *plen_ptr)
1252 {
1253         static char buf[MAX_RULE_PREFIX+1];
1254         char *op = buf;
1255         int legal_len = for_xfer && protocol_version < 29 ? 1 : MAX_RULE_PREFIX-1;
1256
1257         if (rule->rflags & FILTRULE_PERDIR_MERGE) {
1258                 if (legal_len == 1)
1259                         return NULL;
1260                 *op++ = ':';
1261         } else if (rule->rflags & FILTRULE_INCLUDE)
1262                 *op++ = '+';
1263         else if (legal_len != 1
1264             || ((*pat == '-' || *pat == '+') && pat[1] == ' '))
1265                 *op++ = '-';
1266         else
1267                 legal_len = 0;
1268
1269         if (rule->rflags & FILTRULE_ABS_PATH)
1270                 *op++ = '/';
1271         if (rule->rflags & FILTRULE_NEGATE)
1272                 *op++ = '!';
1273         if (rule->rflags & FILTRULE_CVS_IGNORE)
1274                 *op++ = 'C';
1275         else {
1276                 if (rule->rflags & FILTRULE_NO_INHERIT)
1277                         *op++ = 'n';
1278                 if (rule->rflags & FILTRULE_WORD_SPLIT)
1279                         *op++ = 'w';
1280                 if (rule->rflags & FILTRULE_NO_PREFIXES) {
1281                         if (rule->rflags & FILTRULE_INCLUDE)
1282                                 *op++ = '+';
1283                         else
1284                                 *op++ = '-';
1285                 }
1286         }
1287         if (rule->rflags & FILTRULE_EXCLUDE_SELF)
1288                 *op++ = 'e';
1289         if (rule->rflags & FILTRULE_XATTR)
1290                 *op++ = 'x';
1291         if (rule->rflags & FILTRULE_SENDER_SIDE
1292             && (!for_xfer || protocol_version >= 29))
1293                 *op++ = 's';
1294         if (rule->rflags & FILTRULE_RECEIVER_SIDE
1295             && (!for_xfer || protocol_version >= 29
1296              || (delete_excluded && am_sender)))
1297                 *op++ = 'r';
1298         if (rule->rflags & FILTRULE_PERISHABLE) {
1299                 if (!for_xfer || protocol_version >= 30)
1300                         *op++ = 'p';
1301                 else if (am_sender)
1302                         return NULL;
1303         }
1304         if (op - buf > legal_len)
1305                 return NULL;
1306         if (legal_len)
1307                 *op++ = ' ';
1308         *op = '\0';
1309         if (plen_ptr)
1310                 *plen_ptr = op - buf;
1311         return buf;
1312 }
1313
1314 static void send_rules(int f_out, filter_rule_list *flp)
1315 {
1316         filter_rule *ent, *prev = NULL;
1317
1318         for (ent = flp->head; ent; ent = ent->next) {
1319                 unsigned int len, plen, dlen;
1320                 int elide = 0;
1321                 char *p;
1322
1323                 /* Note we need to check delete_excluded here in addition to
1324                  * the code in parse_rule_tok() because some rules may have
1325                  * been added before we found the --delete-excluded option.
1326                  * We must also elide any CVS merge-file rules to avoid a
1327                  * backward compatibility problem, and we elide any no-prefix
1328                  * merge files as an optimization (since they can only have
1329                  * include/exclude rules). */
1330                 if (ent->rflags & FILTRULE_SENDER_SIDE)
1331                         elide = am_sender ? 1 : -1;
1332                 if (ent->rflags & FILTRULE_RECEIVER_SIDE)
1333                         elide = elide ? 0 : am_sender ? -1 : 1;
1334                 else if (delete_excluded && !elide
1335                  && (!(ent->rflags & FILTRULE_PERDIR_MERGE)
1336                   || ent->rflags & FILTRULE_NO_PREFIXES))
1337                         elide = am_sender ? 1 : -1;
1338                 if (elide < 0) {
1339                         if (prev)
1340                                 prev->next = ent->next;
1341                         else
1342                                 flp->head = ent->next;
1343                 } else
1344                         prev = ent;
1345                 if (elide > 0)
1346                         continue;
1347                 if (ent->rflags & FILTRULE_CVS_IGNORE
1348                     && !(ent->rflags & FILTRULE_MERGE_FILE)) {
1349                         int f = am_sender || protocol_version < 29 ? f_out : -2;
1350                         send_rules(f, &cvs_filter_list);
1351                         if (f == f_out)
1352                                 continue;
1353                 }
1354                 p = get_rule_prefix(ent, ent->pattern, 1, &plen);
1355                 if (!p) {
1356                         rprintf(FERROR,
1357                                 "filter rules are too modern for remote rsync.\n");
1358                         exit_cleanup(RERR_PROTOCOL);
1359                 }
1360                 if (f_out < 0)
1361                         continue;
1362                 len = strlen(ent->pattern);
1363                 dlen = ent->rflags & FILTRULE_DIRECTORY ? 1 : 0;
1364                 if (!(plen + len + dlen))
1365                         continue;
1366                 write_int(f_out, plen + len + dlen);
1367                 if (plen)
1368                         write_buf(f_out, p, plen);
1369                 write_buf(f_out, ent->pattern, len);
1370                 if (dlen)
1371                         write_byte(f_out, '/');
1372         }
1373         flp->tail = prev;
1374 }
1375
1376 /* This is only called by the client. */
1377 void send_filter_list(int f_out)
1378 {
1379         int receiver_wants_list = prune_empty_dirs
1380             || (delete_mode && (!delete_excluded || protocol_version >= 29));
1381
1382         if (local_server || (am_sender && !receiver_wants_list))
1383                 f_out = -1;
1384         if (cvs_exclude && am_sender) {
1385                 if (protocol_version >= 29)
1386                         parse_filter_str(&filter_list, ":C", rule_template(0), 0);
1387                 parse_filter_str(&filter_list, "-C", rule_template(0), 0);
1388         }
1389
1390         send_rules(f_out, &filter_list);
1391
1392         if (f_out >= 0)
1393                 write_int(f_out, 0);
1394
1395         if (cvs_exclude) {
1396                 if (!am_sender || protocol_version < 29)
1397                         parse_filter_str(&filter_list, ":C", rule_template(0), 0);
1398                 if (!am_sender)
1399                         parse_filter_str(&filter_list, "-C", rule_template(0), 0);
1400         }
1401 }
1402
1403 /* This is only called by the server. */
1404 void recv_filter_list(int f_in)
1405 {
1406         char line[BIGPATHBUFLEN];
1407         int xflags = protocol_version >= 29 ? 0 : XFLG_OLD_PREFIXES;
1408         int receiver_wants_list = prune_empty_dirs
1409             || (delete_mode
1410              && (!delete_excluded || protocol_version >= 29));
1411         unsigned int len;
1412
1413         if (!local_server && (am_sender || receiver_wants_list)) {
1414                 while ((len = read_int(f_in)) != 0) {
1415                         if (len >= sizeof line)
1416                                 overflow_exit("recv_rules");
1417                         read_sbuf(f_in, line, len);
1418                         parse_filter_str(&filter_list, line, rule_template(0), xflags);
1419                 }
1420         }
1421
1422         if (cvs_exclude) {
1423                 if (local_server || am_sender || protocol_version < 29)
1424                         parse_filter_str(&filter_list, ":C", rule_template(0), 0);
1425                 if (local_server || am_sender)
1426                         parse_filter_str(&filter_list, "-C", rule_template(0), 0);
1427         }
1428
1429         if (local_server) /* filter out any rules that aren't for us. */
1430                 send_rules(-1, &filter_list);
1431 }