Linux needs symlink xattrs. Fixes bug 8201.
[rsync/rsync.git] / compat.c
1 /*
2  * Compatibility routines for older rsync protocol versions.
3  *
4  * Copyright (C) Andrew Tridgell 1996
5  * Copyright (C) Paul Mackerras 1996
6  * Copyright (C) 2004-2009 Wayne Davison
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 along
19  * with this program; if not, visit the http://fsf.org website.
20  */
21
22 #include "rsync.h"
23
24 int remote_protocol = 0;
25 int file_extra_cnt = 0; /* count of file-list extras that everyone gets */
26 int inc_recurse = 0;
27 int compat_flags = 0;
28 int use_safe_inc_flist = 0;
29
30 extern int am_server;
31 extern int am_sender;
32 extern int local_server;
33 extern int inplace;
34 extern int recurse;
35 extern int use_qsort;
36 extern int allow_inc_recurse;
37 extern int preallocate_files;
38 extern int append_mode;
39 extern int fuzzy_basis;
40 extern int read_batch;
41 extern int delay_updates;
42 extern int checksum_seed;
43 extern int basis_dir_cnt;
44 extern int prune_empty_dirs;
45 extern int protocol_version;
46 extern int protect_args;
47 extern int preserve_uid;
48 extern int preserve_gid;
49 extern int preserve_acls;
50 extern int preserve_xattrs;
51 extern int need_messages_from_generator;
52 extern int delete_mode, delete_before, delete_during, delete_after;
53 extern char *shell_cmd;
54 extern char *partial_dir;
55 extern char *dest_option;
56 extern char *files_from;
57 extern char *filesfrom_host;
58 extern filter_rule_list filter_list;
59 extern int need_unsorted_flist;
60 #ifdef ICONV_OPTION
61 extern iconv_t ic_send, ic_recv;
62 extern char *iconv_opt;
63 #endif
64
65 /* These index values are for the file-list's extra-attribute array. */
66 int uid_ndx, gid_ndx, acls_ndx, xattrs_ndx, unsort_ndx;
67
68 int receiver_symlink_times = 0; /* receiver can set the time on a symlink */
69 int sender_symlink_iconv = 0;   /* sender should convert symlink content */
70
71 #ifdef ICONV_OPTION
72 int filesfrom_convert = 0;
73 #endif
74
75 #define CF_INC_RECURSE   (1<<0)
76 #define CF_SYMLINK_TIMES (1<<1)
77 #define CF_SYMLINK_ICONV (1<<2)
78 #define CF_SAFE_FLIST    (1<<3)
79
80 static const char *client_info;
81
82 /* The server makes sure that if either side only supports a pre-release
83  * version of a protocol, that both sides must speak a compatible version
84  * of that protocol for it to be advertised as available. */
85 static void check_sub_protocol(void)
86 {
87         char *dot;
88         int their_protocol, their_sub;
89 #if SUBPROTOCOL_VERSION != 0
90         int our_sub = protocol_version < PROTOCOL_VERSION ? 0 : SUBPROTOCOL_VERSION;
91 #else
92         int our_sub = 0;
93 #endif
94
95         /* client_info starts with VER.SUB string if client is a pre-release. */
96         if (!(their_protocol = atoi(client_info))
97          || !(dot = strchr(client_info, '.'))
98          || !(their_sub = atoi(dot+1))) {
99 #if SUBPROTOCOL_VERSION != 0
100                 if (our_sub)
101                         protocol_version--;
102 #endif
103                 return;
104         }
105
106         if (their_protocol < protocol_version) {
107                 if (their_sub)
108                         protocol_version = their_protocol - 1;
109                 return;
110         }
111
112         if (their_protocol > protocol_version)
113                 their_sub = 0; /* 0 == final version of older protocol */
114         if (their_sub != our_sub)
115                 protocol_version--;
116 }
117
118 void set_allow_inc_recurse(void)
119 {
120         client_info = shell_cmd ? shell_cmd : "";
121
122         if (!recurse || use_qsort)
123                 allow_inc_recurse = 0;
124         else if (!am_sender
125          && (delete_before || delete_after
126           || delay_updates || prune_empty_dirs))
127                 allow_inc_recurse = 0;
128         else if (am_server && !local_server
129          && (strchr(client_info, 'i') == NULL))
130                 allow_inc_recurse = 0;
131 }
132
133 void setup_protocol(int f_out,int f_in)
134 {
135         if (am_sender)
136                 file_extra_cnt += PTR_EXTRA_CNT;
137         else
138                 file_extra_cnt++;
139         if (preserve_uid)
140                 uid_ndx = ++file_extra_cnt;
141         if (preserve_gid)
142                 gid_ndx = ++file_extra_cnt;
143         if (preserve_acls && !am_sender)
144                 acls_ndx = ++file_extra_cnt;
145         if (preserve_xattrs)
146                 xattrs_ndx = ++file_extra_cnt;
147
148         if (am_server)
149                 set_allow_inc_recurse();
150
151         if (remote_protocol == 0) {
152                 if (am_server && !local_server)
153                         check_sub_protocol();
154                 if (!read_batch)
155                         write_int(f_out, protocol_version);
156                 remote_protocol = read_int(f_in);
157                 if (protocol_version > remote_protocol)
158                         protocol_version = remote_protocol;
159         }
160         if (read_batch && remote_protocol > protocol_version) {
161                 rprintf(FERROR, "The protocol version in the batch file is too new (%d > %d).\n",
162                         remote_protocol, protocol_version);
163                 exit_cleanup(RERR_PROTOCOL);
164         }
165
166         if (DEBUG_GTE(PROTO, 1)) {
167                 rprintf(FINFO, "(%s) Protocol versions: remote=%d, negotiated=%d\n",
168                         am_server? "Server" : "Client", remote_protocol, protocol_version);
169         }
170         if (remote_protocol < MIN_PROTOCOL_VERSION
171          || remote_protocol > MAX_PROTOCOL_VERSION) {
172                 rprintf(FERROR,"protocol version mismatch -- is your shell clean?\n");
173                 rprintf(FERROR,"(see the rsync man page for an explanation)\n");
174                 exit_cleanup(RERR_PROTOCOL);
175         }
176         if (remote_protocol < OLD_PROTOCOL_VERSION) {
177                 rprintf(FINFO,"%s is very old version of rsync, upgrade recommended.\n",
178                         am_server? "Client" : "Server");
179         }
180         if (protocol_version < MIN_PROTOCOL_VERSION) {
181                 rprintf(FERROR, "--protocol must be at least %d on the %s.\n",
182                         MIN_PROTOCOL_VERSION, am_server? "Server" : "Client");
183                 exit_cleanup(RERR_PROTOCOL);
184         }
185         if (protocol_version > PROTOCOL_VERSION) {
186                 rprintf(FERROR, "--protocol must be no more than %d on the %s.\n",
187                         PROTOCOL_VERSION, am_server? "Server" : "Client");
188                 exit_cleanup(RERR_PROTOCOL);
189         }
190         if (read_batch)
191                 check_batch_flags();
192
193 #ifndef SUPPORT_PREALLOCATION
194         if (preallocate_files && !am_sender) {
195                 rprintf(FERROR, "preallocation is not supported on this %s\n",
196                         am_server ? "Server" : "Client");
197                 exit_cleanup(RERR_SYNTAX);
198         }
199 #endif
200
201         if (protocol_version < 30) {
202                 if (append_mode == 1)
203                         append_mode = 2;
204                 if (preserve_acls && !local_server) {
205                         rprintf(FERROR,
206                             "--acls requires protocol 30 or higher"
207                             " (negotiated %d).\n",
208                             protocol_version);
209                         exit_cleanup(RERR_PROTOCOL);
210                 }
211                 if (preserve_xattrs && !local_server) {
212                         rprintf(FERROR,
213                             "--xattrs requires protocol 30 or higher"
214                             " (negotiated %d).\n",
215                             protocol_version);
216                         exit_cleanup(RERR_PROTOCOL);
217                 }
218         }
219
220         if (delete_mode && !(delete_before+delete_during+delete_after)) {
221                 if (protocol_version < 30)
222                         delete_before = 1;
223                 else
224                         delete_during = 1;
225         }
226
227         if (protocol_version < 29) {
228                 if (fuzzy_basis) {
229                         rprintf(FERROR,
230                             "--fuzzy requires protocol 29 or higher"
231                             " (negotiated %d).\n",
232                             protocol_version);
233                         exit_cleanup(RERR_PROTOCOL);
234                 }
235
236                 if (basis_dir_cnt && inplace) {
237                         rprintf(FERROR,
238                             "%s with --inplace requires protocol 29 or higher"
239                             " (negotiated %d).\n",
240                             dest_option, protocol_version);
241                         exit_cleanup(RERR_PROTOCOL);
242                 }
243
244                 if (basis_dir_cnt > 1) {
245                         rprintf(FERROR,
246                             "Using more than one %s option requires protocol"
247                             " 29 or higher (negotiated %d).\n",
248                             dest_option, protocol_version);
249                         exit_cleanup(RERR_PROTOCOL);
250                 }
251
252                 if (prune_empty_dirs) {
253                         rprintf(FERROR,
254                             "--prune-empty-dirs requires protocol 29 or higher"
255                             " (negotiated %d).\n",
256                             protocol_version);
257                         exit_cleanup(RERR_PROTOCOL);
258                 }
259         } else if (protocol_version >= 30) {
260                 if (am_server) {
261                         compat_flags = allow_inc_recurse ? CF_INC_RECURSE : 0;
262 #ifdef CAN_SET_SYMLINK_TIMES
263                         compat_flags |= CF_SYMLINK_TIMES;
264 #endif
265 #ifdef ICONV_OPTION
266                         compat_flags |= CF_SYMLINK_ICONV;
267 #endif
268                         if (local_server || strchr(client_info, 'f') != NULL)
269                                 compat_flags |= CF_SAFE_FLIST;
270                         write_byte(f_out, compat_flags);
271                 } else
272                         compat_flags = read_byte(f_in);
273                 /* The inc_recurse var MUST be set to 0 or 1. */
274                 inc_recurse = compat_flags & CF_INC_RECURSE ? 1 : 0;
275                 if (am_sender) {
276                         receiver_symlink_times = am_server
277                             ? strchr(client_info, 'L') != NULL
278                             : !!(compat_flags & CF_SYMLINK_TIMES);
279                 }
280 #ifdef CAN_SET_SYMLINK_TIMES
281                 else
282                         receiver_symlink_times = 1;
283 #endif
284 #ifdef ICONV_OPTION
285                 sender_symlink_iconv = iconv_opt && (am_server
286                     ? local_server || strchr(client_info, 's') != NULL
287                     : !!(compat_flags & CF_SYMLINK_ICONV));
288 #endif
289                 if (inc_recurse && !allow_inc_recurse) {
290                         /* This should only be able to happen in a batch. */
291                         fprintf(stderr,
292                             "Incompatible options specified for inc-recursive %s.\n",
293                             read_batch ? "batch file" : "connection");
294                         exit_cleanup(RERR_SYNTAX);
295                 }
296                 use_safe_inc_flist = (compat_flags & CF_SAFE_FLIST) || protocol_version >= 31;
297                 need_messages_from_generator = 1;
298 #ifdef CAN_SET_SYMLINK_TIMES
299         } else if (!am_sender) {
300                 receiver_symlink_times = 1;
301 #endif
302         }
303
304         if (need_unsorted_flist && (!am_sender || inc_recurse))
305                 unsort_ndx = ++file_extra_cnt;
306
307         if (partial_dir && *partial_dir != '/' && (!am_server || local_server)) {
308                 int rflags = FILTRULE_NO_PREFIXES | FILTRULE_DIRECTORY;
309                 if (!am_sender || protocol_version >= 30)
310                         rflags |= FILTRULE_PERISHABLE;
311                 parse_filter_str(&filter_list, partial_dir, rule_template(rflags), 0);
312         }
313
314
315 #ifdef ICONV_OPTION
316         if (protect_args && files_from) {
317                 if (am_sender)
318                         filesfrom_convert = filesfrom_host && ic_send != (iconv_t)-1;
319                 else
320                         filesfrom_convert = !filesfrom_host && ic_recv != (iconv_t)-1;
321         }
322 #endif
323
324         if (am_server) {
325                 if (!checksum_seed)
326                         checksum_seed = time(NULL);
327                 write_int(f_out, checksum_seed);
328         } else {
329                 checksum_seed = read_int(f_in);
330         }
331 }