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) 2004-2022 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 #include "itypes.h"
  24 #include "ifuncs.h"
  25
  26 extern int am_server;
  27 extern int am_sender;
  28 extern int local_server;
  29 extern int inplace;
  30 extern int recurse;
  31 extern int use_qsort;
  32 extern int allow_inc_recurse;
  33 extern int preallocate_files;
  34 extern int append_mode;
  35 extern int fuzzy_basis;
  36 extern int read_batch;
  37 extern int write_batch;
  38 extern int delay_updates;
  39 extern int checksum_seed;
  40 extern int basis_dir_cnt;
  41 extern int prune_empty_dirs;
  42 extern int protocol_version;
  43 extern int protect_args;
  44 extern int preserve_uid;
  45 extern int preserve_gid;
  46 extern int preserve_atimes;
  47 extern int preserve_crtimes;
  48 extern int preserve_acls;
  49 extern int preserve_xattrs;
  50 extern int xfer_flags_as_varint;
  51 extern int need_messages_from_generator;
  52 extern int delete_mode, delete_before, delete_during, delete_after;
  53 extern int do_compression;
  54 extern int do_compression_level;
  55 extern int saw_stderr_opt;
  56 extern int msgs2stderr;
  57 extern char *shell_cmd;
  58 extern char *partial_dir;
  59 extern char *files_from;
  60 extern char *filesfrom_host;
  61 extern const char *checksum_choice;
  62 extern const char *compress_choice;
  63 extern filter_rule_list filter_list;
  64 extern int need_unsorted_flist;
  65 #ifdef ICONV_OPTION
  66 extern iconv_t ic_send, ic_recv;
  67 extern char *iconv_opt;
  68 #endif
  69 extern struct name_num_obj valid_checksums;
  70
  71 int remote_protocol = 0;
  72 int file_extra_cnt = 0; /* count of file-list extras that everyone gets */
  73 int inc_recurse = 0;
  74 int compat_flags = 0;
  75 int use_safe_inc_flist = 0;
  76 int want_xattr_optim = 0;
  77 int proper_seed_order = 0;
  78 int inplace_partial = 0;
  79 int do_negotiated_strings = 0;
  80 int xmit_id0_names = 0;
  81
  82 /* These index values are for the file-list's extra-attribute array. */
  83 int pathname_ndx, depth_ndx, atimes_ndx, crtimes_ndx, uid_ndx, gid_ndx, acls_ndx, xattrs_ndx, unsort_ndx;
  84
  85 int receiver_symlink_times = 0; /* receiver can set the time on a symlink */
  86 int sender_symlink_iconv = 0;   /* sender should convert symlink content */
  87
  88 #ifdef ICONV_OPTION
  89 int filesfrom_convert = 0;
  90 #endif
  91
  92 #define MAX_NSTR_STRLEN 256
  93
  94 struct name_num_obj valid_compressions = {
  95         "compress", NULL, NULL, 0, 0, {
  96 #ifdef SUPPORT_ZSTD
  97                 { CPRES_ZSTD, "zstd", NULL },
  98 #endif
  99 #ifdef SUPPORT_LZ4
 100                 { CPRES_LZ4, "lz4", NULL },
 101 #endif
 102                 { CPRES_ZLIBX, "zlibx", NULL },
 103                 { CPRES_ZLIB, "zlib", NULL },
 104                 { CPRES_NONE, "none", NULL },
 105                 { 0, NULL, NULL }
 106         }
 107 };
 108
 109 #define CF_INC_RECURSE   (1<<0)
 110 #define CF_SYMLINK_TIMES (1<<1)
 111 #define CF_SYMLINK_ICONV (1<<2)
 112 #define CF_SAFE_FLIST    (1<<3)
 113 #define CF_AVOID_XATTR_OPTIM (1<<4)
 114 #define CF_CHKSUM_SEED_FIX (1<<5)
 115 #define CF_INPLACE_PARTIAL_DIR (1<<6)
 116 #define CF_VARINT_FLIST_FLAGS (1<<7)
 117 #define CF_ID0_NAMES (1<<8)
 118
 119 static const char *client_info;
 120
 121 /* The server makes sure that if either side only supports a pre-release
 122  * version of a protocol, that both sides must speak a compatible version
 123  * of that protocol for it to be advertised as available. */
 124 static void check_sub_protocol(void)
 125 {
 126         char *dot;
 127         int their_protocol, their_sub;
 128 #if SUBPROTOCOL_VERSION != 0
 129         int our_sub = protocol_version < PROTOCOL_VERSION ? 0 : SUBPROTOCOL_VERSION;
 130 #else
 131         int our_sub = 0;
 132 #endif
 133
 134         /* client_info starts with VER.SUB string if client is a pre-release. */
 135         if (!(their_protocol = atoi(client_info))
 136          || !(dot = strchr(client_info, '.'))
 137          || !(their_sub = atoi(dot+1))) {
 138 #if SUBPROTOCOL_VERSION != 0
 139                 if (our_sub)
 140                         protocol_version--;
 141 #endif
 142                 return;
 143         }
 144
 145         if (their_protocol < protocol_version) {
 146                 if (their_sub)
 147                         protocol_version = their_protocol - 1;
 148                 return;
 149         }
 150
 151         if (their_protocol > protocol_version)
 152                 their_sub = 0; /* 0 == final version of older protocol */
 153         if (their_sub != our_sub)
 154                 protocol_version--;
 155 }
 156
 157 void set_allow_inc_recurse(void)
 158 {
 159         if (!local_server)
 160                 client_info = shell_cmd ? shell_cmd : "";
 161         else if (am_server) {
 162                 char buf[64];
 163                 maybe_add_e_option(buf, sizeof buf);
 164                 client_info = *buf ? strdup(buf+1) : ""; /* The +1 skips the leading "e". */
 165         }
 166
 167         if (!recurse || use_qsort)
 168                 allow_inc_recurse = 0;
 169         else if (!am_sender
 170          && (delete_before || delete_after
 171           || delay_updates || prune_empty_dirs))
 172                 allow_inc_recurse = 0;
 173         else if (am_server && strchr(client_info, 'i') == NULL)
 174                 allow_inc_recurse = 0;
 175 }
 176
 177 void parse_compress_choice(int final_call)
 178 {
 179         if (valid_compressions.negotiated_name)
 180                 do_compression = valid_compressions.negotiated_num;
 181         else if (compress_choice) {
 182                 struct name_num_item *nni = get_nni_by_name(&valid_compressions, compress_choice, -1);
 183                 if (!nni) {
 184                         rprintf(FERROR, "unknown compress name: %s\n", compress_choice);
 185                         exit_cleanup(RERR_UNSUPPORTED);
 186                 }
 187                 do_compression = nni->num;
 188                 if (am_server)
 189                         validate_choice_vs_env(NSTR_COMPRESS, do_compression, -1);
 190         } else if (do_compression)
 191                 do_compression = CPRES_ZLIB;
 192         else
 193                 do_compression = CPRES_NONE;
 194
 195         if (do_compression != CPRES_NONE && final_call)
 196                 init_compression_level(); /* There's a chance this might turn compression off! */
 197
 198         if (do_compression == CPRES_NONE)
 199                 compress_choice = NULL;
 200
 201         /* Snag the compression name for both write_batch's option output & the following debug output. */
 202         if (valid_compressions.negotiated_name)
 203                 compress_choice = valid_compressions.negotiated_name;
 204         else if (compress_choice == NULL) {
 205                 struct name_num_item *nni = get_nni_by_num(&valid_compressions, do_compression);
 206                 compress_choice = nni ? nni->name : "UNKNOWN";
 207         }
 208
 209         if (final_call && DEBUG_GTE(NSTR, am_server ? 3 : 1)
 210          && (do_compression != CPRES_NONE || do_compression_level != CLVL_NOT_SPECIFIED)) {
 211                 rprintf(FINFO, "%s%s compress: %s (level %d)\n",
 212                         am_server ? "Server" : "Client",
 213                         valid_compressions.negotiated_name ? " negotiated" : "",
 214                         compress_choice, do_compression_level);
 215         }
 216 }
 217
 218 struct name_num_item *get_nni_by_name(struct name_num_obj *nno, const char *name, int len)
 219 {
 220         struct name_num_item *nni;
 221
 222         if (len < 0)
 223                 len = strlen(name);
 224
 225         for (nni = nno->list; nni->name; nni++) {
 226                 if (strncasecmp(name, nni->name, len) == 0 && nni->name[len] == '\0')
 227                         return nni;
 228         }
 229
 230         return NULL;
 231 }
 232
 233 struct name_num_item *get_nni_by_num(struct name_num_obj *nno, int num)
 234 {
 235         struct name_num_item *nni;
 236
 237         for (nni = nno->list; nni->name; nni++) {
 238                 if (num == nni->num)
 239                         return nni;
 240         }
 241
 242         return NULL;
 243 }
 244
 245 static void init_nno_saw(struct name_num_obj *nno, int val)
 246 {
 247         struct name_num_item *nni;
 248         int cnt;
 249
 250         if (!nno->saw_len) {
 251                 for (nni = nno->list; nni->name; nni++) {
 252                         if (nni->num >= nno->saw_len)
 253                                 nno->saw_len = nni->num + 1;
 254                 }
 255         }
 256
 257         if (!nno->saw) {
 258                 nno->saw = new_array0(uchar, nno->saw_len);
 259
 260                 /* We'll take this opportunity to make sure that the main_name values are set right. */
 261                 for (cnt = 1, nni = nno->list; nni->name; nni++, cnt++) {
 262                         if (nno->saw[nni->num])
 263                                 nni->main_name = nno->list[nno->saw[nni->num]-1].name;
 264                         else
 265                                 nno->saw[nni->num] = cnt;
 266                 }
 267         }
 268
 269         memset(nno->saw, val, nno->saw_len);
 270 }
 271
 272 /* Simplify the user-provided string so that it contains valid names without any duplicates.
 273  * It also sets the "saw" flags to a 1-relative count of which name was seen first. */
 274 static int parse_nni_str(struct name_num_obj *nno, const char *from, char *tobuf, int tobuf_len)
 275 {
 276         char *to = tobuf, *tok = NULL;
 277         int saw_tok = 0, cnt = 0;
 278
 279         while (1) {
 280                 int at_space = isSpace(from);
 281                 char ch = *from++;
 282                 if (ch == '&')
 283                         ch = '\0';
 284                 if (!ch || at_space) {
 285                         if (tok) {
 286                                 struct name_num_item *nni = get_nni_by_name(nno, tok, to - tok);
 287                                 if (nni && !nno->saw[nni->num]) {
 288                                         nno->saw[nni->num] = ++cnt;
 289                                         if (nni->main_name) {
 290                                                 to = tok + strlcpy(tok, nni->main_name, tobuf_len - (tok - tobuf));
 291                                                 if (to - tobuf >= tobuf_len) {
 292                                                         to = tok - 1;
 293                                                         break;
 294                                                 }
 295                                         }
 296                                 } else
 297                                         to = tok - (tok != tobuf);
 298                                 saw_tok = 1;
 299                                 tok = NULL;
 300                         }
 301                         if (!ch)
 302                                 break;
 303                         continue;
 304                 }
 305                 if (!tok) {
 306                         if (to != tobuf)
 307                                 *to++ = ' ';
 308                         tok = to;
 309                 }
 310                 if (to - tobuf >= tobuf_len - 1) {
 311                         to = tok - (tok != tobuf);
 312                         break;
 313                 }
 314                 *to++ = ch;
 315         }
 316         *to = '\0';
 317
 318         if (saw_tok && to == tobuf)
 319                 return strlcpy(tobuf, "INVALID", MAX_NSTR_STRLEN);
 320
 321         return to - tobuf;
 322 }
 323
 324 /* This routine is always called with a tmpbuf of MAX_NSTR_STRLEN length, but the
 325  * buffer may be pre-populated with a "len" length string to use OR a len of -1
 326  * to tell us to read a string from the fd. */
 327 static void recv_negotiate_str(int f_in, struct name_num_obj *nno, char *tmpbuf, int len)
 328 {
 329         struct name_num_item *ret = NULL;
 330
 331         if (len < 0)
 332                 len = read_vstring(f_in, tmpbuf, MAX_NSTR_STRLEN);
 333
 334         if (DEBUG_GTE(NSTR, am_server ? 3 : 2)) {
 335                 if (am_server)
 336                         rprintf(FINFO, "Client %s list (on server): %s\n", nno->type, tmpbuf);
 337                 else
 338                         rprintf(FINFO, "Server %s list (on client): %s\n", nno->type, tmpbuf);
 339         }
 340
 341         if (len > 0) {
 342                 struct name_num_item *nni;
 343                 int best = nno->saw_len; /* We want best == 1 from the client list, so start with a big number. */
 344                 char *space, *tok = tmpbuf;
 345                 while (tok) {
 346                         while (*tok == ' ') tok++; /* Should be unneeded... */
 347                         if (!*tok)
 348                                 break;
 349                         if ((space = strchr(tok, ' ')) != NULL)
 350                                 *space = '\0';
 351                         nni = get_nni_by_name(nno, tok, -1);
 352                         if (space) {
 353                                 *space = ' ';
 354                                 tok = space + 1;
 355                         } else
 356                                 tok = NULL;
 357                         if (!nni || !nno->saw[nni->num] || best <= nno->saw[nni->num])
 358                                 continue;
 359                         ret = nni;
 360                         best = nno->saw[nni->num];
 361                         if (best == 1 || am_server) /* The server side stops at the first acceptable client choice */
 362                                 break;
 363                 }
 364                 if (ret) {
 365                         free(nno->saw);
 366                         nno->saw = NULL;
 367                         nno->negotiated_name = ret->main_name ? ret->main_name : ret->name;
 368                         nno->negotiated_num = ret->num;
 369                         return;
 370                 }
 371         }
 372
 373         if (!am_server || !do_negotiated_strings) {
 374                 char *cp = tmpbuf;
 375                 int j;
 376                 rprintf(FERROR, "Failed to negotiate a %s choice.\n", nno->type);
 377                 rprintf(FERROR, "%s list: %s\n", am_server ? "Client" : "Server", tmpbuf);
 378                 /* Recreate our original list from the saw values. This can't overflow our huge
 379                  * buffer because we don't have enough valid entries to get anywhere close. */
 380                 for (j = 1, *cp = '\0'; j <= nno->saw_len; j++) {
 381                         struct name_num_item *nni;
 382                         for (nni = nno->list; nni->name; nni++) {
 383                                 if (nno->saw[nni->num] == j) {
 384                                         *cp++ = ' ';
 385                                         cp += strlcpy(cp, nni->name, MAX_NSTR_STRLEN - (cp - tmpbuf));
 386                                         break;
 387                                 }
 388                         }
 389                 }
 390                 if (!*tmpbuf)
 391                         strlcpy(cp, " INVALID", MAX_NSTR_STRLEN);
 392                 rprintf(FERROR, "%s list:%s\n", am_server ? "Server" : "Client", tmpbuf);
 393         }
 394
 395         exit_cleanup(RERR_UNSUPPORTED);
 396 }
 397
 398 static const char *getenv_nstr(int ntype)
 399 {
 400         const char *env_str = getenv(ntype == NSTR_COMPRESS ? "RSYNC_COMPRESS_LIST" : "RSYNC_CHECKSUM_LIST");
 401
 402         /* When writing a batch file, we always negotiate an old-style choice. */
 403         if (write_batch)
 404                 env_str = ntype == NSTR_COMPRESS ? "zlib" : protocol_version >= 30 ? "md5" : "md4";
 405
 406         if (am_server && env_str) {
 407                 char *cp = strchr(env_str, '&');
 408                 if (cp)
 409                         env_str = cp + 1;
 410         }
 411
 412         return env_str;
 413 }
 414
 415 void validate_choice_vs_env(int ntype, int num1, int num2)
 416 {
 417         struct name_num_obj *nno = ntype == NSTR_COMPRESS ? &valid_compressions : &valid_checksums;
 418         const char *list_str = getenv_nstr(ntype);
 419         char tmpbuf[MAX_NSTR_STRLEN];
 420
 421         if (!list_str)
 422                 return;
 423
 424         while (isSpace(list_str)) list_str++;
 425
 426         if (!*list_str)
 427                 return;
 428
 429         init_nno_saw(nno, 0);
 430         parse_nni_str(nno, list_str, tmpbuf, MAX_NSTR_STRLEN);
 431
 432         if (ntype == NSTR_CHECKSUM) /* If "md4" is in the env list, all the old MD4 choices are OK too. */
 433                 nno->saw[CSUM_MD4_ARCHAIC] = nno->saw[CSUM_MD4_BUSTED] = nno->saw[CSUM_MD4_OLD] = nno->saw[CSUM_MD4];
 434
 435         if (!nno->saw[num1] || (num2 >= 0 && !nno->saw[num2])) {
 436                 rprintf(FERROR, "Your --%s-choice value (%s) was refused by the server.\n",
 437                         ntype == NSTR_COMPRESS ? "compress" : "checksum",
 438                         ntype == NSTR_COMPRESS ? compress_choice : checksum_choice);
 439                 exit_cleanup(RERR_UNSUPPORTED);
 440         }
 441
 442         free(nno->saw);
 443         nno->saw = NULL;
 444 }
 445
 446 /* The saw buffer is initialized and used to store ordinal values from 1 to N
 447  * for the order of the args in the array.  If dup_markup == '\0', duplicates
 448  * are removed otherwise the char is prefixed to the duplicate term and, if it
 449  * is an opening paren/bracket/brace, the matching closing char is suffixed.
 450  * "none" is removed on the client side unless dup_markup != '\0'. */
 451 int get_default_nno_list(struct name_num_obj *nno, char *to_buf, int to_buf_len, char dup_markup)
 452 {
 453         struct name_num_item *nni;
 454         int len = 0, cnt = 0;
 455         char delim = '\0', post_delim;
 456
 457         switch (dup_markup) {
 458         case '(': post_delim = ')'; break;
 459         case '[': post_delim = ']'; break;
 460         case '{': post_delim = '}'; break;
 461         default: post_delim = '\0'; break;
 462         }
 463
 464         init_nno_saw(nno, 0);
 465
 466         for (nni = nno->list, len = 0; nni->name; nni++) {
 467                 if (nni->main_name) {
 468                         if (!dup_markup)
 469                                 continue;
 470                         delim = dup_markup;
 471                 }
 472                 if (nni->num == 0 && !am_server && !dup_markup)
 473                         continue;
 474                 if (len)
 475                         to_buf[len++]= ' ';
 476                 if (delim) {
 477                         to_buf[len++]= delim;
 478                         delim = post_delim;
 479                 }
 480                 len += strlcpy(to_buf+len, nni->name, to_buf_len - len);
 481                 if (len >= to_buf_len - 3)
 482                         exit_cleanup(RERR_UNSUPPORTED); /* IMPOSSIBLE... */
 483                 if (delim) {
 484                         to_buf[len++]= delim;
 485                         delim = '\0';
 486                 }
 487                 nno->saw[nni->num] = ++cnt;
 488         }
 489
 490         return len;
 491 }
 492
 493 static void send_negotiate_str(int f_out, struct name_num_obj *nno, int ntype)
 494 {
 495         char tmpbuf[MAX_NSTR_STRLEN];
 496         const char *list_str = getenv_nstr(ntype);
 497         int len;
 498
 499         if (list_str && *list_str) {
 500                 init_nno_saw(nno, 0);
 501                 len = parse_nni_str(nno, list_str, tmpbuf, MAX_NSTR_STRLEN);
 502                 list_str = tmpbuf;
 503         } else
 504                 list_str = NULL;
 505
 506         if (!list_str || !*list_str)
 507                 len = get_default_nno_list(nno, tmpbuf, MAX_NSTR_STRLEN, '\0');
 508
 509         if (DEBUG_GTE(NSTR, am_server ? 3 : 2)) {
 510                 if (am_server)
 511                         rprintf(FINFO, "Server %s list (on server): %s\n", nno->type, tmpbuf);
 512                 else
 513                         rprintf(FINFO, "Client %s list (on client): %s\n", nno->type, tmpbuf);
 514         }
 515
 516         /* Each side sends their list of valid names to the other side and then both sides
 517          * pick the first name in the client's list that is also in the server's list. */
 518         if (do_negotiated_strings)
 519                 write_vstring(f_out, tmpbuf, len);
 520 }
 521
 522 static void negotiate_the_strings(int f_in, int f_out)
 523 {
 524         /* We send all the negotiation strings before we start to read them to help avoid a slow startup. */
 525
 526         if (!checksum_choice)
 527                 send_negotiate_str(f_out, &valid_checksums, NSTR_CHECKSUM);
 528
 529         if (do_compression && !compress_choice)
 530                 send_negotiate_str(f_out, &valid_compressions, NSTR_COMPRESS);
 531
 532         if (valid_checksums.saw) {
 533                 char tmpbuf[MAX_NSTR_STRLEN];
 534                 int len;
 535                 if (do_negotiated_strings)
 536                         len = -1;
 537                 else
 538                         len = strlcpy(tmpbuf, protocol_version >= 30 ? "md5" : "md4", MAX_NSTR_STRLEN);
 539                 recv_negotiate_str(f_in, &valid_checksums, tmpbuf, len);
 540         }
 541
 542         if (valid_compressions.saw) {
 543                 char tmpbuf[MAX_NSTR_STRLEN];
 544                 int len;
 545                 if (do_negotiated_strings)
 546                         len = -1;
 547                 else
 548                         len = strlcpy(tmpbuf, "zlib", MAX_NSTR_STRLEN);
 549                 recv_negotiate_str(f_in, &valid_compressions, tmpbuf, len);
 550         }
 551
 552         /* If the other side is too old to negotiate, the above steps just made sure that
 553          * the env didn't disallow the old algorithm. Mark things as non-negotiated. */
 554         if (!do_negotiated_strings)
 555                 valid_checksums.negotiated_name = valid_compressions.negotiated_name = NULL;
 556 }
 557
 558 void setup_protocol(int f_out,int f_in)
 559 {
 560         assert(file_extra_cnt == 0);
 561         assert(EXTRA64_CNT == 2 || EXTRA64_CNT == 1);
 562
 563         /* All int64 values must be set first so that they are guaranteed to be
 564          * aligned for direct int64-pointer memory access. */
 565         if (preserve_atimes)
 566                 atimes_ndx = (file_extra_cnt += EXTRA64_CNT);
 567         if (preserve_crtimes)
 568                 crtimes_ndx = (file_extra_cnt += EXTRA64_CNT);
 569         if (am_sender) /* This is most likely in the file_extras64 union as well. */
 570                 pathname_ndx = (file_extra_cnt += PTR_EXTRA_CNT);
 571         else
 572                 depth_ndx = ++file_extra_cnt;
 573         if (preserve_uid)
 574                 uid_ndx = ++file_extra_cnt;
 575         if (preserve_gid)
 576                 gid_ndx = ++file_extra_cnt;
 577         if (preserve_acls && !am_sender)
 578                 acls_ndx = ++file_extra_cnt;
 579         if (preserve_xattrs)
 580                 xattrs_ndx = ++file_extra_cnt;
 581
 582         if (am_server)
 583                 set_allow_inc_recurse();
 584
 585         if (remote_protocol == 0) {
 586                 if (am_server && !local_server)
 587                         check_sub_protocol();
 588                 if (!read_batch)
 589                         write_int(f_out, protocol_version);
 590                 remote_protocol = read_int(f_in);
 591                 if (protocol_version > remote_protocol)
 592                         protocol_version = remote_protocol;
 593         }
 594         if (read_batch && remote_protocol > protocol_version) {
 595                 rprintf(FERROR, "The protocol version in the batch file is too new (%d > %d).\n",
 596                         remote_protocol, protocol_version);
 597                 exit_cleanup(RERR_PROTOCOL);
 598         }
 599
 600         if (DEBUG_GTE(PROTO, 1)) {
 601                 rprintf(FINFO, "(%s) Protocol versions: remote=%d, negotiated=%d\n",
 602                         am_server? "Server" : "Client", remote_protocol, protocol_version);
 603         }
 604         if (remote_protocol < MIN_PROTOCOL_VERSION
 605          || remote_protocol > MAX_PROTOCOL_VERSION) {
 606                 rprintf(FERROR,"protocol version mismatch -- is your shell clean?\n");
 607                 rprintf(FERROR,"(see the rsync man page for an explanation)\n");
 608                 exit_cleanup(RERR_PROTOCOL);
 609         }
 610         if (remote_protocol < OLD_PROTOCOL_VERSION) {
 611                 rprintf(FINFO,"%s is very old version of rsync, upgrade recommended.\n",
 612                         am_server? "Client" : "Server");
 613         }
 614         if (protocol_version < MIN_PROTOCOL_VERSION) {
 615                 rprintf(FERROR, "--protocol must be at least %d on the %s.\n",
 616                         MIN_PROTOCOL_VERSION, am_server? "Server" : "Client");
 617                 exit_cleanup(RERR_PROTOCOL);
 618         }
 619         if (protocol_version > PROTOCOL_VERSION) {
 620                 rprintf(FERROR, "--protocol must be no more than %d on the %s.\n",
 621                         PROTOCOL_VERSION, am_server? "Server" : "Client");
 622                 exit_cleanup(RERR_PROTOCOL);
 623         }
 624         if (read_batch)
 625                 check_batch_flags();
 626
 627         if (!saw_stderr_opt && protocol_version <= 28 && am_server)
 628                 msgs2stderr = 0; /* The client side may not have stderr setup for us. */
 629
 630 #ifndef SUPPORT_PREALLOCATION
 631         if (preallocate_files && !am_sender) {
 632                 rprintf(FERROR, "preallocation is not supported on this %s\n",
 633                         am_server ? "Server" : "Client");
 634                 exit_cleanup(RERR_SYNTAX);
 635         }
 636 #endif
 637
 638         if (protocol_version < 30) {
 639                 if (append_mode == 1)
 640                         append_mode = 2;
 641                 if (preserve_acls && !local_server) {
 642                         rprintf(FERROR,
 643                                 "--acls requires protocol 30 or higher"
 644                                 " (negotiated %d).\n",
 645                                 protocol_version);
 646                         exit_cleanup(RERR_PROTOCOL);
 647                 }
 648                 if (preserve_xattrs && !local_server) {
 649                         rprintf(FERROR,
 650                                 "--xattrs requires protocol 30 or higher"
 651                                 " (negotiated %d).\n",
 652                                 protocol_version);
 653                         exit_cleanup(RERR_PROTOCOL);
 654                 }
 655         }
 656
 657         if (delete_mode && !(delete_before+delete_during+delete_after)) {
 658                 if (protocol_version < 30)
 659                         delete_before = 1;
 660                 else
 661                         delete_during = 1;
 662         }
 663
 664         if (protocol_version < 29) {
 665                 if (fuzzy_basis) {
 666                         rprintf(FERROR,
 667                                 "--fuzzy requires protocol 29 or higher"
 668                                 " (negotiated %d).\n",
 669                                 protocol_version);
 670                         exit_cleanup(RERR_PROTOCOL);
 671                 }
 672
 673                 if (basis_dir_cnt && inplace) {
 674                         rprintf(FERROR,
 675                                 "%s with --inplace requires protocol 29 or higher"
 676                                 " (negotiated %d).\n",
 677                                 alt_dest_opt(0), protocol_version);
 678                         exit_cleanup(RERR_PROTOCOL);
 679                 }
 680
 681                 if (basis_dir_cnt > 1) {
 682                         rprintf(FERROR,
 683                                 "Using more than one %s option requires protocol"
 684                                 " 29 or higher (negotiated %d).\n",
 685                                 alt_dest_opt(0), protocol_version);
 686                         exit_cleanup(RERR_PROTOCOL);
 687                 }
 688
 689                 if (prune_empty_dirs) {
 690                         rprintf(FERROR,
 691                                 "--prune-empty-dirs requires protocol 29 or higher"
 692                                 " (negotiated %d).\n",
 693                                 protocol_version);
 694                         exit_cleanup(RERR_PROTOCOL);
 695                 }
 696         } else if (protocol_version >= 30) {
 697                 if (am_server) {
 698                         compat_flags = allow_inc_recurse ? CF_INC_RECURSE : 0;
 699 #ifdef CAN_SET_SYMLINK_TIMES
 700                         compat_flags |= CF_SYMLINK_TIMES;
 701 #endif
 702 #ifdef ICONV_OPTION
 703                         compat_flags |= CF_SYMLINK_ICONV;
 704 #endif
 705                         if (strchr(client_info, 'f') != NULL)
 706                                 compat_flags |= CF_SAFE_FLIST;
 707                         if (strchr(client_info, 'x') != NULL)
 708                                 compat_flags |= CF_AVOID_XATTR_OPTIM;
 709                         if (strchr(client_info, 'C') != NULL)
 710                                 compat_flags |= CF_CHKSUM_SEED_FIX;
 711                         if (strchr(client_info, 'I') != NULL)
 712                                 compat_flags |= CF_INPLACE_PARTIAL_DIR;
 713                         if (strchr(client_info, 'u') != NULL)
 714                                 compat_flags |= CF_ID0_NAMES;
 715                         if (strchr(client_info, 'v') != NULL) {
 716                                 do_negotiated_strings = 1;
 717                                 compat_flags |= CF_VARINT_FLIST_FLAGS;
 718                         }
 719                         if (strchr(client_info, 'V') != NULL) { /* Support a pre-release 'V' that got superseded */
 720                                 if (!write_batch)
 721                                         compat_flags |= CF_VARINT_FLIST_FLAGS;
 722                                 write_byte(f_out, compat_flags);
 723                         } else
 724                                 write_varint(f_out, compat_flags);
 725                 } else { /* read_varint() is compatible with the older write_byte() when the 0x80 bit isn't on. */
 726                         compat_flags = read_varint(f_in);
 727                         if  (compat_flags & CF_VARINT_FLIST_FLAGS)
 728                                 do_negotiated_strings = 1;
 729                 }
 730                 /* The inc_recurse var MUST be set to 0 or 1. */
 731                 inc_recurse = compat_flags & CF_INC_RECURSE ? 1 : 0;
 732                 want_xattr_optim = protocol_version >= 31 && !(compat_flags & CF_AVOID_XATTR_OPTIM);
 733                 proper_seed_order = compat_flags & CF_CHKSUM_SEED_FIX ? 1 : 0;
 734                 xfer_flags_as_varint = compat_flags & CF_VARINT_FLIST_FLAGS ? 1 : 0;
 735                 xmit_id0_names = compat_flags & CF_ID0_NAMES ? 1 : 0;
 736                 if (!xfer_flags_as_varint && preserve_crtimes) {
 737                         fprintf(stderr, "Both rsync versions must be at least 3.2.0 for --crtimes.\n");
 738                         exit_cleanup(RERR_PROTOCOL);
 739                 }
 740                 if (am_sender) {
 741                         receiver_symlink_times = am_server
 742                             ? strchr(client_info, 'L') != NULL
 743                             : !!(compat_flags & CF_SYMLINK_TIMES);
 744                 }
 745 #ifdef CAN_SET_SYMLINK_TIMES
 746                 else
 747                         receiver_symlink_times = 1;
 748 #endif
 749 #ifdef ICONV_OPTION
 750                 sender_symlink_iconv = iconv_opt && (am_server
 751                     ? strchr(client_info, 's') != NULL
 752                     : !!(compat_flags & CF_SYMLINK_ICONV));
 753 #endif
 754                 if (inc_recurse && !allow_inc_recurse) {
 755                         /* This should only be able to happen in a batch. */
 756                         fprintf(stderr,
 757                                 "Incompatible options specified for inc-recursive %s.\n",
 758                                 read_batch ? "batch file" : "connection");
 759                         exit_cleanup(RERR_SYNTAX);
 760                 }
 761                 use_safe_inc_flist = (compat_flags & CF_SAFE_FLIST) || protocol_version >= 31;
 762                 need_messages_from_generator = 1;
 763                 if (compat_flags & CF_INPLACE_PARTIAL_DIR)
 764                         inplace_partial = 1;
 765 #ifdef CAN_SET_SYMLINK_TIMES
 766         } else if (!am_sender) {
 767                 receiver_symlink_times = 1;
 768 #endif
 769         }
 770
 771         if (read_batch)
 772                 do_negotiated_strings = 0;
 773
 774         if (need_unsorted_flist && (!am_sender || inc_recurse))
 775                 unsort_ndx = ++file_extra_cnt;
 776
 777         if (partial_dir && *partial_dir != '/' && (!am_server || local_server)) {
 778                 int rflags = FILTRULE_NO_PREFIXES | FILTRULE_DIRECTORY;
 779                 if (!am_sender || protocol_version >= 30)
 780                         rflags |= FILTRULE_PERISHABLE;
 781                 parse_filter_str(&filter_list, partial_dir, rule_template(rflags), 0);
 782         }
 783
 784
 785 #ifdef ICONV_OPTION
 786         if (protect_args && files_from) {
 787                 if (am_sender)
 788                         filesfrom_convert = filesfrom_host && ic_send != (iconv_t)-1;
 789                 else
 790                         filesfrom_convert = !filesfrom_host && ic_recv != (iconv_t)-1;
 791         }
 792 #endif
 793
 794         negotiate_the_strings(f_in, f_out);
 795
 796         if (am_server) {
 797                 if (!checksum_seed)
 798                         checksum_seed = time(NULL) ^ (getpid() << 6);
 799                 write_int(f_out, checksum_seed);
 800         } else {
 801                 checksum_seed = read_int(f_in);
 802         }
 803
 804         parse_checksum_choice(1); /* Sets checksum_type & xfersum_type */
 805         parse_compress_choice(1); /* Sets do_compression */
 806
 807         if (write_batch && !am_server)
 808                 write_batch_shell_file();
 809
 810         init_flist();
 811 }