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) 2004-2020 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 extern int am_server;
  25 extern int am_sender;
  26 extern int local_server;
  27 extern int inplace;
  28 extern int recurse;
  29 extern int use_qsort;
  30 extern int allow_inc_recurse;
  31 extern int preallocate_files;
  32 extern int append_mode;
  33 extern int fuzzy_basis;
  34 extern int read_batch;
  35 extern int write_batch;
  36 extern int delay_updates;
  37 extern int checksum_seed;
  38 extern int basis_dir_cnt;
  39 extern int prune_empty_dirs;
  40 extern int protocol_version;
  41 extern int protect_args;
  42 extern int preserve_uid;
  43 extern int preserve_gid;
  44 extern int preserve_atimes;
  45 extern int preserve_acls;
  46 extern int preserve_xattrs;
  47 extern int xfer_flags_as_varint;
  48 extern int need_messages_from_generator;
  49 extern int delete_mode, delete_before, delete_during, delete_after;
  50 extern int xfersum_type;
  51 extern int checksum_type;
  52 extern int do_compression;
  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 char *checksum_choice;
  59 extern char *compress_choice;
  60 extern filter_rule_list filter_list;
  61 extern int need_unsorted_flist;
  62 #ifdef ICONV_OPTION
  63 extern iconv_t ic_send, ic_recv;
  64 extern char *iconv_opt;
  65 #endif
  66 extern struct name_num_obj valid_checksums;
  67
  68 int remote_protocol = 0;
  69 int file_extra_cnt = 0; /* count of file-list extras that everyone gets */
  70 int inc_recurse = 0;
  71 int compat_flags = 0;
  72 int use_safe_inc_flist = 0;
  73 int want_xattr_optim = 0;
  74 int proper_seed_order = 0;
  75 int inplace_partial = 0;
  76 int do_negotiated_strings = 0;
  77
  78 /* These index values are for the file-list's extra-attribute array. */
  79 int pathname_ndx, depth_ndx, atimes_ndx, uid_ndx, gid_ndx, acls_ndx, xattrs_ndx, unsort_ndx;
  80
  81 int receiver_symlink_times = 0; /* receiver can set the time on a symlink */
  82 int sender_symlink_iconv = 0;   /* sender should convert symlink content */
  83
  84 #ifdef ICONV_OPTION
  85 int filesfrom_convert = 0;
  86 #endif
  87
  88 #define MAX_NSTR_STRLEN 256
  89
  90 struct name_num_obj valid_compressions = {
  91         "compress", NULL, NULL, 0, 0, {
  92                 { CPRES_ZLIBX, "zlibx", NULL },
  93                 { CPRES_ZLIB, "zlib", NULL },
  94                 { CPRES_NONE, "none", NULL },
  95                 { 0, NULL, NULL }
  96         }
  97 };
  98
  99 #define CF_INC_RECURSE   (1<<0)
 100 #define CF_SYMLINK_TIMES (1<<1)
 101 #define CF_SYMLINK_ICONV (1<<2)
 102 #define CF_SAFE_FLIST    (1<<3)
 103 #define CF_AVOID_XATTR_OPTIM (1<<4)
 104 #define CF_CHKSUM_SEED_FIX (1<<5)
 105 #define CF_INPLACE_PARTIAL_DIR (1<<6)
 106 #define CF_VARINT_FLIST_FLAGS (1<<7)
 107
 108 static const char *client_info;
 109
 110 /* The server makes sure that if either side only supports a pre-release
 111  * version of a protocol, that both sides must speak a compatible version
 112  * of that protocol for it to be advertised as available. */
 113 static void check_sub_protocol(void)
 114 {
 115         char *dot;
 116         int their_protocol, their_sub;
 117 #if SUBPROTOCOL_VERSION != 0
 118         int our_sub = protocol_version < PROTOCOL_VERSION ? 0 : SUBPROTOCOL_VERSION;
 119 #else
 120         int our_sub = 0;
 121 #endif
 122
 123         /* client_info starts with VER.SUB string if client is a pre-release. */
 124         if (!(their_protocol = atoi(client_info))
 125          || !(dot = strchr(client_info, '.'))
 126          || !(their_sub = atoi(dot+1))) {
 127 #if SUBPROTOCOL_VERSION != 0
 128                 if (our_sub)
 129                         protocol_version--;
 130 #endif
 131                 return;
 132         }
 133
 134         if (their_protocol < protocol_version) {
 135                 if (their_sub)
 136                         protocol_version = their_protocol - 1;
 137                 return;
 138         }
 139
 140         if (their_protocol > protocol_version)
 141                 their_sub = 0; /* 0 == final version of older protocol */
 142         if (their_sub != our_sub)
 143                 protocol_version--;
 144 }
 145
 146 void set_allow_inc_recurse(void)
 147 {
 148         client_info = shell_cmd ? shell_cmd : "";
 149
 150         if (!recurse || use_qsort)
 151                 allow_inc_recurse = 0;
 152         else if (!am_sender
 153          && (delete_before || delete_after
 154           || delay_updates || prune_empty_dirs))
 155                 allow_inc_recurse = 0;
 156         else if (am_server && !local_server
 157          && (strchr(client_info, 'i') == NULL))
 158                 allow_inc_recurse = 0;
 159 }
 160
 161 void parse_compress_choice(int final_call)
 162 {
 163         if (valid_compressions.negotiated_name)
 164                 do_compression = valid_compressions.negotiated_num;
 165         else if (compress_choice) {
 166                 struct name_num_item *nni = get_nni_by_name(&valid_compressions, compress_choice, -1);
 167                 if (!nni) {
 168                         rprintf(FERROR, "unknown compress name: %s\n", compress_choice);
 169                         exit_cleanup(RERR_UNSUPPORTED);
 170                 }
 171                 do_compression = nni->num;
 172         } else if (do_compression)
 173                 do_compression = CPRES_ZLIB;
 174         else
 175                 do_compression = CPRES_NONE;
 176
 177         if (do_compression == CPRES_NONE)
 178                 compress_choice = NULL;
 179
 180         if (final_call && DEBUG_GTE(NSTR, am_server ? 2 : 1)) {
 181                 const char *c_s = am_server ? "Server" : "Client";
 182                 if (valid_compressions.negotiated_name)
 183                         rprintf(FINFO, "%s negotiated compress: %s\n", c_s, valid_compressions.negotiated_name);
 184                 else {
 185                         struct name_num_item *nni = get_nni_by_num(&valid_compressions, do_compression);
 186                         rprintf(FINFO, "%s compress: %s\n", c_s, nni ? nni->name : "UNKNOWN");
 187                 }
 188         }
 189 }
 190
 191 struct name_num_item *get_nni_by_name(struct name_num_obj *nno, const char *name, int len)
 192 {
 193         struct name_num_item *nni;
 194
 195         if (len < 0)
 196                 len = strlen(name);
 197
 198         for (nni = nno->list; nni->name; nni++) {
 199                 if (strncasecmp(name, nni->name, len) == 0 && nni->name[len] == '\0')
 200                         return nni;
 201         }
 202
 203         return NULL;
 204 }
 205
 206 struct name_num_item *get_nni_by_num(struct name_num_obj *nno, int num)
 207 {
 208         struct name_num_item *nni;
 209
 210         for (nni = nno->list; nni->name; nni++) {
 211                 if (num == nni->num)
 212                         return nni;
 213         }
 214
 215         return NULL;
 216 }
 217
 218 static void init_nno_saw(struct name_num_obj *nno, int val)
 219 {
 220         struct name_num_item *nni;
 221         int cnt;
 222
 223         if (!nno->saw_len) {
 224                 for (nni = nno->list; nni->name; nni++) {
 225                         if (nni->num >= nno->saw_len)
 226                                 nno->saw_len = nni->num + 1;
 227                 }
 228         }
 229
 230         if (!nno->saw) {
 231                 if (!(nno->saw = new_array0(uchar, nno->saw_len)))
 232                         out_of_memory("init_nno_saw");
 233
 234                 /* We'll take this opportunity to make sure that the main_name values are set right. */
 235                 for (cnt = 1, nni = nno->list; nni->name; nni++, cnt++) {
 236                         if (nno->saw[nni->num])
 237                                 nni->main_name = nno->list[nno->saw[nni->num]-1].name;
 238                         else
 239                                 nno->saw[nni->num] = cnt;
 240                 }
 241         }
 242
 243         memset(nno->saw, val, nno->saw_len);
 244 }
 245
 246 /* Simplify the user-provided string so that it contains valid names without any duplicates.
 247  * It also sets the "saw" flags to a 1-relative count of which name was seen first. */
 248 static int parse_nni_str(struct name_num_obj *nno, const char *from, char *tobuf, int tobuf_len)
 249 {
 250         char *to = tobuf, *tok = NULL;
 251         int cnt = 0;
 252
 253         while (1) {
 254                 if (*from == ' ' || !*from) {
 255                         if (tok) {
 256                                 struct name_num_item *nni = get_nni_by_name(nno, tok, to - tok);
 257                                 if (nni && !nno->saw[nni->num]) {
 258                                         nno->saw[nni->num] = ++cnt;
 259                                         if (nni->main_name && *nni->main_name) {
 260                                                 to = tok + strlcpy(tok, nni->main_name, tobuf_len - (tok - tobuf));
 261                                                 if (to - tobuf >= tobuf_len) {
 262                                                         to = tok - 1;
 263                                                         break;
 264                                                 }
 265                                         }
 266                                 } else
 267                                         to = tok - (tok != tobuf);
 268                                 tok = NULL;
 269                         }
 270                         if (!*from++)
 271                                 break;
 272                         continue;
 273                 }
 274                 if (!tok) {
 275                         if (to != tobuf)
 276                                 *to++ = ' ';
 277                         tok = to;
 278                 }
 279                 if (to - tobuf >= tobuf_len - 1) {
 280                         to = tok - (tok != tobuf);
 281                         break;
 282                 }
 283                 *to++ = *from++;
 284         }
 285         *to = '\0';
 286
 287         return to - tobuf;
 288 }
 289
 290 static void recv_negotiate_str(int f_in, struct name_num_obj *nno, char *tmpbuf, int len)
 291 {
 292         struct name_num_item *ret = NULL;
 293
 294         if (len < 0)
 295                 len = read_vstring(f_in, tmpbuf, MAX_NSTR_STRLEN);
 296
 297         if (DEBUG_GTE(NSTR, am_server ? 4 : 2)) {
 298                 if (am_server)
 299                         rprintf(FINFO, "Client %s list (on server): %s\n", nno->type, tmpbuf);
 300                 else
 301                         rprintf(FINFO, "Server %s list (on client): %s\n", nno->type, tmpbuf);
 302         }
 303
 304         if (len > 0) {
 305                 int best = nno->saw_len; /* We want best == 1 from the client list, so start with a big number. */
 306                 char *tok;
 307                 if (am_server)
 308                         init_nno_saw(nno, 1); /* Since we're parsing client names, anything we parse first is #1. */
 309                 for (tok = strtok(tmpbuf, " \t"); tok; tok = strtok(NULL, " \t")) {
 310                         struct name_num_item *nni = get_nni_by_name(nno, tok, -1);
 311                         if (!nni || !nno->saw[nni->num] || best <= nno->saw[nni->num])
 312                                 continue;
 313                         ret = nni;
 314                         best = nno->saw[nni->num];
 315                         if (best == 1)
 316                                 break;
 317                 }
 318                 if (ret) {
 319                         free(nno->saw);
 320                         nno->saw = NULL;
 321                         nno->negotiated_name = ret->main_name ? ret->main_name : ret->name;
 322                         nno->negotiated_num = ret->num;
 323                         return;
 324                 }
 325         }
 326
 327         if (!am_server)
 328                 rprintf(FERROR, "Failed to negotiate a common %s\n", nno->type);
 329         exit_cleanup(RERR_UNSUPPORTED);
 330 }
 331
 332 static void send_negotiate_str(int f_out, struct name_num_obj *nno, const char *env_name)
 333 {
 334         char tmpbuf[MAX_NSTR_STRLEN];
 335         struct name_num_item *nni;
 336         const char *list_str = getenv(env_name);
 337         int len, fail_if_empty = list_str && strstr(list_str, "FAIL");
 338
 339         if (!do_negotiated_strings) {
 340                 if (!am_server && fail_if_empty) {
 341                         rprintf(FERROR, "Remote rsync is too old for %s negotation\n", nno->type);
 342                         exit_cleanup(RERR_UNSUPPORTED);
 343                 }
 344                 return;
 345         }
 346
 347         init_nno_saw(nno, 0);
 348
 349         if (list_str && *list_str && (!am_server || local_server)) {
 350                 len = parse_nni_str(nno, list_str, tmpbuf, MAX_NSTR_STRLEN);
 351                 if (fail_if_empty && !len)
 352                         len = strlcpy(tmpbuf, "FAIL", MAX_NSTR_STRLEN);
 353                 list_str = tmpbuf;
 354         } else
 355                 list_str = NULL;
 356
 357         if (!list_str || !*list_str) {
 358                 int cnt = 0;
 359                 for (nni = nno->list, len = 0; nni->name; nni++) {
 360                         if (nni->main_name)
 361                                 continue;
 362                         if (len)
 363                                 tmpbuf[len++]= ' ';
 364                         len += strlcpy(tmpbuf+len, nni->name, MAX_NSTR_STRLEN - len);
 365                         if (len >= (int)MAX_NSTR_STRLEN - 1)
 366                                 exit_cleanup(RERR_UNSUPPORTED); /* IMPOSSIBLE... */
 367                         nno->saw[nni->num] = ++cnt;
 368                 }
 369         }
 370
 371         if (DEBUG_GTE(NSTR, am_server ? 4 : 2)) {
 372                 if (am_server)
 373                         rprintf(FINFO, "Server %s list (on server): %s\n", nno->type, tmpbuf);
 374                 else
 375                         rprintf(FINFO, "Client %s list (on client): %s\n", nno->type, tmpbuf);
 376         }
 377
 378         if (local_server) {
 379                 /* A local server doesn't bother to send/recv the strings, it just constructs
 380                  * and parses the same string on both sides. */
 381                 if (!read_batch)
 382                         recv_negotiate_str(-1, nno, tmpbuf, len);
 383         } else {
 384                 /* Each side sends their list of valid names to the other side and then both sides
 385                  * pick the first name in the client's list that is also in the server's list. */
 386                 write_vstring(f_out, tmpbuf, len);
 387         }
 388 }
 389
 390 static void negotiate_the_strings(int f_in, int f_out)
 391 {
 392         /* We send all the negotiation strings before we start to read them to help avoid a slow startup. */
 393
 394         if (!checksum_choice)
 395                 send_negotiate_str(f_out, &valid_checksums, "RSYNC_CHECKSUM_LIST");
 396
 397         if (do_compression && !compress_choice)
 398                 send_negotiate_str(f_out, &valid_compressions, "RSYNC_COMPRESS_LIST");
 399
 400         if (valid_checksums.saw) {
 401                 char tmpbuf[MAX_NSTR_STRLEN];
 402                 recv_negotiate_str(f_in, &valid_checksums, tmpbuf, -1);
 403         }
 404         if (valid_checksums.negotiated_name)
 405                 xfersum_type = checksum_type = valid_checksums.negotiated_num;
 406
 407         if (valid_compressions.saw) {
 408                 char tmpbuf[MAX_NSTR_STRLEN];
 409                 recv_negotiate_str(f_in, &valid_compressions, tmpbuf, -1);
 410         }
 411 #if 0
 412         if (valid_compressions.negotiated_name)
 413                 compress_type = valid_checksums.negotiated_num;
 414 #endif
 415 }
 416
 417 void setup_protocol(int f_out,int f_in)
 418 {
 419         assert(file_extra_cnt == 0);
 420         assert(EXTRA64_CNT == 2 || EXTRA64_CNT == 1);
 421
 422         /* All int64 values must be set first so that they are guaranteed to be
 423          * aligned for direct int64-pointer memory access. */
 424         if (preserve_atimes)
 425                 atimes_ndx = (file_extra_cnt += EXTRA64_CNT);
 426         if (am_sender) /* This is most likely in the in64 union as well. */
 427                 pathname_ndx = (file_extra_cnt += PTR_EXTRA_CNT);
 428         else
 429                 depth_ndx = ++file_extra_cnt;
 430         if (preserve_uid)
 431                 uid_ndx = ++file_extra_cnt;
 432         if (preserve_gid)
 433                 gid_ndx = ++file_extra_cnt;
 434         if (preserve_acls && !am_sender)
 435                 acls_ndx = ++file_extra_cnt;
 436         if (preserve_xattrs)
 437                 xattrs_ndx = ++file_extra_cnt;
 438
 439         if (am_server)
 440                 set_allow_inc_recurse();
 441
 442         if (remote_protocol == 0) {
 443                 if (am_server && !local_server)
 444                         check_sub_protocol();
 445                 if (!read_batch)
 446                         write_int(f_out, protocol_version);
 447                 remote_protocol = read_int(f_in);
 448                 if (protocol_version > remote_protocol)
 449                         protocol_version = remote_protocol;
 450         }
 451         if (read_batch && remote_protocol > protocol_version) {
 452                 rprintf(FERROR, "The protocol version in the batch file is too new (%d > %d).\n",
 453                         remote_protocol, protocol_version);
 454                 exit_cleanup(RERR_PROTOCOL);
 455         }
 456
 457         if (DEBUG_GTE(PROTO, 1)) {
 458                 rprintf(FINFO, "(%s) Protocol versions: remote=%d, negotiated=%d\n",
 459                         am_server? "Server" : "Client", remote_protocol, protocol_version);
 460         }
 461         if (remote_protocol < MIN_PROTOCOL_VERSION
 462          || remote_protocol > MAX_PROTOCOL_VERSION) {
 463                 rprintf(FERROR,"protocol version mismatch -- is your shell clean?\n");
 464                 rprintf(FERROR,"(see the rsync man page for an explanation)\n");
 465                 exit_cleanup(RERR_PROTOCOL);
 466         }
 467         if (remote_protocol < OLD_PROTOCOL_VERSION) {
 468                 rprintf(FINFO,"%s is very old version of rsync, upgrade recommended.\n",
 469                         am_server? "Client" : "Server");
 470         }
 471         if (protocol_version < MIN_PROTOCOL_VERSION) {
 472                 rprintf(FERROR, "--protocol must be at least %d on the %s.\n",
 473                         MIN_PROTOCOL_VERSION, am_server? "Server" : "Client");
 474                 exit_cleanup(RERR_PROTOCOL);
 475         }
 476         if (protocol_version > PROTOCOL_VERSION) {
 477                 rprintf(FERROR, "--protocol must be no more than %d on the %s.\n",
 478                         PROTOCOL_VERSION, am_server? "Server" : "Client");
 479                 exit_cleanup(RERR_PROTOCOL);
 480         }
 481         if (read_batch)
 482                 check_batch_flags();
 483
 484 #ifndef SUPPORT_PREALLOCATION
 485         if (preallocate_files && !am_sender) {
 486                 rprintf(FERROR, "preallocation is not supported on this %s\n",
 487                         am_server ? "Server" : "Client");
 488                 exit_cleanup(RERR_SYNTAX);
 489         }
 490 #endif
 491
 492         if (protocol_version < 30) {
 493                 if (append_mode == 1)
 494                         append_mode = 2;
 495                 if (preserve_acls && !local_server) {
 496                         rprintf(FERROR,
 497                             "--acls requires protocol 30 or higher"
 498                             " (negotiated %d).\n",
 499                             protocol_version);
 500                         exit_cleanup(RERR_PROTOCOL);
 501                 }
 502                 if (preserve_xattrs && !local_server) {
 503                         rprintf(FERROR,
 504                             "--xattrs requires protocol 30 or higher"
 505                             " (negotiated %d).\n",
 506                             protocol_version);
 507                         exit_cleanup(RERR_PROTOCOL);
 508                 }
 509         }
 510
 511         if (delete_mode && !(delete_before+delete_during+delete_after)) {
 512                 if (protocol_version < 30)
 513                         delete_before = 1;
 514                 else
 515                         delete_during = 1;
 516         }
 517
 518         if (protocol_version < 29) {
 519                 if (fuzzy_basis) {
 520                         rprintf(FERROR,
 521                             "--fuzzy requires protocol 29 or higher"
 522                             " (negotiated %d).\n",
 523                             protocol_version);
 524                         exit_cleanup(RERR_PROTOCOL);
 525                 }
 526
 527                 if (basis_dir_cnt && inplace) {
 528                         rprintf(FERROR,
 529                             "%s with --inplace requires protocol 29 or higher"
 530                             " (negotiated %d).\n",
 531                             dest_option, protocol_version);
 532                         exit_cleanup(RERR_PROTOCOL);
 533                 }
 534
 535                 if (basis_dir_cnt > 1) {
 536                         rprintf(FERROR,
 537                             "Using more than one %s option requires protocol"
 538                             " 29 or higher (negotiated %d).\n",
 539                             dest_option, protocol_version);
 540                         exit_cleanup(RERR_PROTOCOL);
 541                 }
 542
 543                 if (prune_empty_dirs) {
 544                         rprintf(FERROR,
 545                             "--prune-empty-dirs requires protocol 29 or higher"
 546                             " (negotiated %d).\n",
 547                             protocol_version);
 548                         exit_cleanup(RERR_PROTOCOL);
 549                 }
 550         } else if (protocol_version >= 30) {
 551                 if (am_server) {
 552                         compat_flags = allow_inc_recurse ? CF_INC_RECURSE : 0;
 553 #ifdef CAN_SET_SYMLINK_TIMES
 554                         compat_flags |= CF_SYMLINK_TIMES;
 555 #endif
 556 #ifdef ICONV_OPTION
 557                         compat_flags |= CF_SYMLINK_ICONV;
 558 #endif
 559                         if (local_server || strchr(client_info, 'f') != NULL)
 560                                 compat_flags |= CF_SAFE_FLIST;
 561                         if (local_server || strchr(client_info, 'x') != NULL)
 562                                 compat_flags |= CF_AVOID_XATTR_OPTIM;
 563                         if (local_server || strchr(client_info, 'C') != NULL)
 564                                 compat_flags |= CF_CHKSUM_SEED_FIX;
 565                         if (local_server || strchr(client_info, 'I') != NULL)
 566                                 compat_flags |= CF_INPLACE_PARTIAL_DIR;
 567                         if (local_server || strchr(client_info, 'v') != NULL) {
 568                                 if (!write_batch || protocol_version >= 30) {
 569                                         do_negotiated_strings = 1;
 570                                         compat_flags |= CF_VARINT_FLIST_FLAGS;
 571                                 }
 572                         }
 573                         if (strchr(client_info, 'V') != NULL) { /* Support a pre-release 'V' that got superseded */
 574                                 if (!write_batch)
 575                                         compat_flags |= CF_VARINT_FLIST_FLAGS;
 576                                 write_byte(f_out, compat_flags);
 577                         } else
 578                                 write_varint(f_out, compat_flags);
 579                 } else { /* read_varint() is compatible with the older write_byte() when the 0x80 bit isn't on. */
 580                         compat_flags = read_varint(f_in);
 581                         if  (compat_flags & CF_VARINT_FLIST_FLAGS)
 582                                 do_negotiated_strings = 1;
 583                 }
 584                 /* The inc_recurse var MUST be set to 0 or 1. */
 585                 inc_recurse = compat_flags & CF_INC_RECURSE ? 1 : 0;
 586                 want_xattr_optim = protocol_version >= 31 && !(compat_flags & CF_AVOID_XATTR_OPTIM);
 587                 proper_seed_order = compat_flags & CF_CHKSUM_SEED_FIX ? 1 : 0;
 588                 xfer_flags_as_varint = compat_flags & CF_VARINT_FLIST_FLAGS ? 1 : 0;
 589                 if (am_sender) {
 590                         receiver_symlink_times = am_server
 591                             ? strchr(client_info, 'L') != NULL
 592                             : !!(compat_flags & CF_SYMLINK_TIMES);
 593                 }
 594 #ifdef CAN_SET_SYMLINK_TIMES
 595                 else
 596                         receiver_symlink_times = 1;
 597 #endif
 598 #ifdef ICONV_OPTION
 599                 sender_symlink_iconv = iconv_opt && (am_server
 600                     ? local_server || strchr(client_info, 's') != NULL
 601                     : !!(compat_flags & CF_SYMLINK_ICONV));
 602 #endif
 603                 if (inc_recurse && !allow_inc_recurse) {
 604                         /* This should only be able to happen in a batch. */
 605                         fprintf(stderr,
 606                             "Incompatible options specified for inc-recursive %s.\n",
 607                             read_batch ? "batch file" : "connection");
 608                         exit_cleanup(RERR_SYNTAX);
 609                 }
 610                 use_safe_inc_flist = (compat_flags & CF_SAFE_FLIST) || protocol_version >= 31;
 611                 need_messages_from_generator = 1;
 612                 if (compat_flags & CF_INPLACE_PARTIAL_DIR)
 613                         inplace_partial = 1;
 614 #ifdef CAN_SET_SYMLINK_TIMES
 615         } else if (!am_sender) {
 616                 receiver_symlink_times = 1;
 617 #endif
 618         }
 619
 620         if (need_unsorted_flist && (!am_sender || inc_recurse))
 621                 unsort_ndx = ++file_extra_cnt;
 622
 623         if (partial_dir && *partial_dir != '/' && (!am_server || local_server)) {
 624                 int rflags = FILTRULE_NO_PREFIXES | FILTRULE_DIRECTORY;
 625                 if (!am_sender || protocol_version >= 30)
 626                         rflags |= FILTRULE_PERISHABLE;
 627                 parse_filter_str(&filter_list, partial_dir, rule_template(rflags), 0);
 628         }
 629
 630
 631 #ifdef ICONV_OPTION
 632         if (protect_args && files_from) {
 633                 if (am_sender)
 634                         filesfrom_convert = filesfrom_host && ic_send != (iconv_t)-1;
 635                 else
 636                         filesfrom_convert = !filesfrom_host && ic_recv != (iconv_t)-1;
 637         }
 638 #endif
 639
 640         negotiate_the_strings(f_in, f_out);
 641
 642         if (am_server) {
 643                 if (!checksum_seed)
 644                         checksum_seed = time(NULL) ^ (getpid() << 6);
 645                 write_int(f_out, checksum_seed);
 646         } else {
 647                 checksum_seed = read_int(f_in);
 648         }
 649
 650         init_flist();
 651 }
 652
 653 void maybe_write_negotiated_strings(int batch_fd)
 654 {
 655         if (valid_checksums.negotiated_name)
 656                 write_vstring(batch_fd, valid_checksums.negotiated_name, strlen(valid_checksums.negotiated_name));
 657
 658         if (valid_compressions.negotiated_name)
 659                 write_vstring(batch_fd, valid_compressions.negotiated_name, strlen(valid_compressions.negotiated_name));
 660 }