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 #include "itypes.h"
  24
  25 extern int am_server;
  26 extern int am_sender;
  27 extern int local_server;
  28 extern int inplace;
  29 extern int recurse;
  30 extern int use_qsort;
  31 extern int allow_inc_recurse;
  32 extern int preallocate_files;
  33 extern int append_mode;
  34 extern int fuzzy_basis;
  35 extern int read_batch;
  36 extern int write_batch;
  37 extern int delay_updates;
  38 extern int checksum_seed;
  39 extern int basis_dir_cnt;
  40 extern int prune_empty_dirs;
  41 extern int protocol_version;
  42 extern int protect_args;
  43 extern int preserve_uid;
  44 extern int preserve_gid;
  45 extern int preserve_atimes;
  46 extern int preserve_crtimes;
  47 extern int preserve_acls;
  48 extern int preserve_xattrs;
  49 extern int xfer_flags_as_varint;
  50 extern int need_messages_from_generator;
  51 extern int delete_mode, delete_before, delete_during, delete_after;
  52 extern int do_compression;
  53 extern int do_compression_level;
  54 extern char *shell_cmd;
  55 extern char *partial_dir;
  56 extern char *files_from;
  57 extern char *filesfrom_host;
  58 extern const char *checksum_choice;
  59 extern const 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 int xmit_id0_names = 0;
  78
  79 /* These index values are for the file-list's extra-attribute array. */
  80 int pathname_ndx, depth_ndx, atimes_ndx, crtimes_ndx, uid_ndx, gid_ndx, acls_ndx, xattrs_ndx, unsort_ndx;
  81
  82 int receiver_symlink_times = 0; /* receiver can set the time on a symlink */
  83 int sender_symlink_iconv = 0;   /* sender should convert symlink content */
  84
  85 #ifdef ICONV_OPTION
  86 int filesfrom_convert = 0;
  87 #endif
  88
  89 #define MAX_NSTR_STRLEN 256
  90
  91 struct name_num_obj valid_compressions = {
  92         "compress", NULL, NULL, 0, 0, {
  93 #ifdef SUPPORT_ZSTD
  94                 { CPRES_ZSTD, "zstd", NULL },
  95 #endif
  96 #ifdef SUPPORT_LZ4
  97                 { CPRES_LZ4, "lz4", NULL },
  98 #endif
  99                 { CPRES_ZLIBX, "zlibx", NULL },
 100                 { CPRES_ZLIB, "zlib", NULL },
 101                 { CPRES_NONE, "none", NULL },
 102                 { 0, NULL, NULL }
 103         }
 104 };
 105
 106 #define CF_INC_RECURSE   (1<<0)
 107 #define CF_SYMLINK_TIMES (1<<1)
 108 #define CF_SYMLINK_ICONV (1<<2)
 109 #define CF_SAFE_FLIST    (1<<3)
 110 #define CF_AVOID_XATTR_OPTIM (1<<4)
 111 #define CF_CHKSUM_SEED_FIX (1<<5)
 112 #define CF_INPLACE_PARTIAL_DIR (1<<6)
 113 #define CF_VARINT_FLIST_FLAGS (1<<7)
 114 #define CF_ID0_NAMES (1<<8)
 115
 116 static const char *client_info;
 117
 118 /* The server makes sure that if either side only supports a pre-release
 119  * version of a protocol, that both sides must speak a compatible version
 120  * of that protocol for it to be advertised as available. */
 121 static void check_sub_protocol(void)
 122 {
 123         char *dot;
 124         int their_protocol, their_sub;
 125 #if SUBPROTOCOL_VERSION != 0
 126         int our_sub = protocol_version < PROTOCOL_VERSION ? 0 : SUBPROTOCOL_VERSION;
 127 #else
 128         int our_sub = 0;
 129 #endif
 130
 131         /* client_info starts with VER.SUB string if client is a pre-release. */
 132         if (!(their_protocol = atoi(client_info))
 133          || !(dot = strchr(client_info, '.'))
 134          || !(their_sub = atoi(dot+1))) {
 135 #if SUBPROTOCOL_VERSION != 0
 136                 if (our_sub)
 137                         protocol_version--;
 138 #endif
 139                 return;
 140         }
 141
 142         if (their_protocol < protocol_version) {
 143                 if (their_sub)
 144                         protocol_version = their_protocol - 1;
 145                 return;
 146         }
 147
 148         if (their_protocol > protocol_version)
 149                 their_sub = 0; /* 0 == final version of older protocol */
 150         if (their_sub != our_sub)
 151                 protocol_version--;
 152 }
 153
 154 void set_allow_inc_recurse(void)
 155 {
 156         client_info = shell_cmd ? shell_cmd : "";
 157
 158         if (!recurse || use_qsort)
 159                 allow_inc_recurse = 0;
 160         else if (!am_sender
 161          && (delete_before || delete_after
 162           || delay_updates || prune_empty_dirs))
 163                 allow_inc_recurse = 0;
 164         else if (am_server && !local_server
 165          && (strchr(client_info, 'i') == NULL))
 166                 allow_inc_recurse = 0;
 167 }
 168
 169 void parse_compress_choice(int final_call)
 170 {
 171         if (valid_compressions.negotiated_name)
 172                 do_compression = valid_compressions.negotiated_num;
 173         else if (compress_choice) {
 174                 struct name_num_item *nni = get_nni_by_name(&valid_compressions, compress_choice, -1);
 175                 if (!nni) {
 176                         rprintf(FERROR, "unknown compress name: %s\n", compress_choice);
 177                         exit_cleanup(RERR_UNSUPPORTED);
 178                 }
 179                 do_compression = nni->num;
 180                 if (am_server)
 181                         validate_choice_vs_env(NSTR_COMPRESS, do_compression, -1);
 182         } else if (do_compression)
 183                 do_compression = CPRES_ZLIB;
 184         else
 185                 do_compression = CPRES_NONE;
 186
 187         if (do_compression != CPRES_NONE && final_call)
 188                 init_compression_level(); /* There's a chance this might turn compression off! */
 189
 190         if (do_compression == CPRES_NONE)
 191                 compress_choice = NULL;
 192
 193         /* Snag the compression name for both write_batch's option output & the following debug output. */
 194         if (valid_compressions.negotiated_name)
 195                 compress_choice = valid_compressions.negotiated_name;
 196         else if (compress_choice == NULL) {
 197                 struct name_num_item *nni = get_nni_by_num(&valid_compressions, do_compression);
 198                 compress_choice = nni ? nni->name : "UNKNOWN";
 199         }
 200
 201         if (final_call && DEBUG_GTE(NSTR, am_server ? 3 : 1)
 202          && (do_compression != CPRES_NONE || do_compression_level != CLVL_NOT_SPECIFIED)) {
 203                 rprintf(FINFO, "%s%s compress: %s (level %d)\n",
 204                         am_server ? "Server" : "Client",
 205                         valid_compressions.negotiated_name ? " negotiated" : "",
 206                         compress_choice, do_compression_level);
 207         }
 208 }
 209
 210 struct name_num_item *get_nni_by_name(struct name_num_obj *nno, const char *name, int len)
 211 {
 212         struct name_num_item *nni;
 213
 214         if (len < 0)
 215                 len = strlen(name);
 216
 217         for (nni = nno->list; nni->name; nni++) {
 218                 if (strncasecmp(name, nni->name, len) == 0 && nni->name[len] == '\0')
 219                         return nni;
 220         }
 221
 222         return NULL;
 223 }
 224
 225 struct name_num_item *get_nni_by_num(struct name_num_obj *nno, int num)
 226 {
 227         struct name_num_item *nni;
 228
 229         for (nni = nno->list; nni->name; nni++) {
 230                 if (num == nni->num)
 231                         return nni;
 232         }
 233
 234         return NULL;
 235 }
 236
 237 static void init_nno_saw(struct name_num_obj *nno, int val)
 238 {
 239         struct name_num_item *nni;
 240         int cnt;
 241
 242         if (!nno->saw_len) {
 243                 for (nni = nno->list; nni->name; nni++) {
 244                         if (nni->num >= nno->saw_len)
 245                                 nno->saw_len = nni->num + 1;
 246                 }
 247         }
 248
 249         if (!nno->saw) {
 250                 nno->saw = new_array0(uchar, nno->saw_len);
 251
 252                 /* We'll take this opportunity to make sure that the main_name values are set right. */
 253                 for (cnt = 1, nni = nno->list; nni->name; nni++, cnt++) {
 254                         if (nno->saw[nni->num])
 255                                 nni->main_name = nno->list[nno->saw[nni->num]-1].name;
 256                         else
 257                                 nno->saw[nni->num] = cnt;
 258                 }
 259         }
 260
 261         memset(nno->saw, val, nno->saw_len);
 262 }
 263
 264 /* Simplify the user-provided string so that it contains valid names without any duplicates.
 265  * It also sets the "saw" flags to a 1-relative count of which name was seen first. */
 266 static int parse_nni_str(struct name_num_obj *nno, const char *from, char *tobuf, int tobuf_len)
 267 {
 268         char *to = tobuf, *tok = NULL;
 269         int saw_tok = 0, cnt = 0;
 270
 271         while (1) {
 272                 int at_space = isSpace(from);
 273                 char ch = *from++;
 274                 if (ch == '&')
 275                         ch = '\0';
 276                 if (!ch || at_space) {
 277                         if (tok) {
 278                                 struct name_num_item *nni = get_nni_by_name(nno, tok, to - tok);
 279                                 if (nni && !nno->saw[nni->num]) {
 280                                         nno->saw[nni->num] = ++cnt;
 281                                         if (nni->main_name) {
 282                                                 to = tok + strlcpy(tok, nni->main_name, tobuf_len - (tok - tobuf));
 283                                                 if (to - tobuf >= tobuf_len) {
 284                                                         to = tok - 1;
 285                                                         break;
 286                                                 }
 287                                         }
 288                                 } else
 289                                         to = tok - (tok != tobuf);
 290                                 saw_tok = 1;
 291                                 tok = NULL;
 292                         }
 293                         if (!ch)
 294                                 break;
 295                         continue;
 296                 }
 297                 if (!tok) {
 298                         if (to != tobuf)
 299                                 *to++ = ' ';
 300                         tok = to;
 301                 }
 302                 if (to - tobuf >= tobuf_len - 1) {
 303                         to = tok - (tok != tobuf);
 304                         break;
 305                 }
 306                 *to++ = ch;
 307         }
 308         *to = '\0';
 309
 310         if (saw_tok && to == tobuf)
 311                 return strlcpy(tobuf, "INVALID", MAX_NSTR_STRLEN);
 312
 313         return to - tobuf;
 314 }
 315
 316 /* This routine is always called with a tmpbuf of MAX_NSTR_STRLEN length, but the
 317  * buffer may be pre-populated with a "len" length string to use OR a len of -1
 318  * to tell us to read a string from the fd. */
 319 static void recv_negotiate_str(int f_in, struct name_num_obj *nno, char *tmpbuf, int len)
 320 {
 321         struct name_num_item *ret = NULL;
 322
 323         if (len < 0)
 324                 len = read_vstring(f_in, tmpbuf, MAX_NSTR_STRLEN);
 325
 326         if (DEBUG_GTE(NSTR, am_server ? 3 : 2)) {
 327                 if (am_server)
 328                         rprintf(FINFO, "Client %s list (on server): %s\n", nno->type, tmpbuf);
 329                 else
 330                         rprintf(FINFO, "Server %s list (on client): %s\n", nno->type, tmpbuf);
 331         }
 332
 333         if (len > 0) {
 334                 struct name_num_item *nni;
 335                 int best = nno->saw_len; /* We want best == 1 from the client list, so start with a big number. */
 336                 char *space, *tok = tmpbuf;
 337                 while (tok) {
 338                         while (*tok == ' ') tok++; /* Should be unneeded... */
 339                         if (!*tok)
 340                                 break;
 341                         if ((space = strchr(tok, ' ')) != NULL)
 342                                 *space = '\0';
 343                         nni = get_nni_by_name(nno, tok, -1);
 344                         if (space) {
 345                                 *space = ' ';
 346                                 tok = space + 1;
 347                         } else
 348                                 tok = NULL;
 349                         if (!nni || !nno->saw[nni->num] || best <= nno->saw[nni->num])
 350                                 continue;
 351                         ret = nni;
 352                         best = nno->saw[nni->num];
 353                         if (best == 1 || am_server) /* The server side stops at the first acceptable client choice */
 354                                 break;
 355                 }
 356                 if (ret) {
 357                         free(nno->saw);
 358                         nno->saw = NULL;
 359                         nno->negotiated_name = ret->main_name ? ret->main_name : ret->name;
 360                         nno->negotiated_num = ret->num;
 361                         return;
 362                 }
 363         }
 364
 365         if (!am_server || !do_negotiated_strings) {
 366                 char *cp = tmpbuf;
 367                 int j;
 368                 rprintf(FERROR, "Failed to negotiate a %s choice.\n", nno->type);
 369                 rprintf(FERROR, "%s list: %s\n", am_server ? "Client" : "Server", tmpbuf);
 370                 /* Recreate our original list from the saw values. This can't overflow our huge
 371                  * buffer because we don't have enough valid entries to get anywhere close. */
 372                 for (j = 1, *cp = '\0'; j <= nno->saw_len; j++) {
 373                         struct name_num_item *nni;
 374                         for (nni = nno->list; nni->name; nni++) {
 375                                 if (nno->saw[nni->num] == j) {
 376                                         *cp++ = ' ';
 377                                         cp += strlcpy(cp, nni->name, MAX_NSTR_STRLEN - (cp - tmpbuf));
 378                                         break;
 379                                 }
 380                         }
 381                 }
 382                 if (!*tmpbuf)
 383                         strlcpy(cp, " INVALID", MAX_NSTR_STRLEN);
 384                 rprintf(FERROR, "%s list:%s\n", am_server ? "Server" : "Client", tmpbuf);
 385         }
 386
 387         exit_cleanup(RERR_UNSUPPORTED);
 388 }
 389
 390 static const char *getenv_nstr(int ntype)
 391 {
 392         const char *env_str = getenv(ntype == NSTR_COMPRESS ? "RSYNC_COMPRESS_LIST" : "RSYNC_CHECKSUM_LIST");
 393
 394         /* When writing a batch file, we always negotiate an old-style choice. */
 395         if (write_batch)
 396                 env_str = ntype == NSTR_COMPRESS ? "zlib" : protocol_version >= 30 ? "md5" : "md4";
 397
 398         if (am_server && env_str) {
 399                 char *cp = strchr(env_str, '&');
 400                 if (cp)
 401                         env_str = cp + 1;
 402         }
 403
 404         return env_str;
 405 }
 406
 407 void validate_choice_vs_env(int ntype, int num1, int num2)
 408 {
 409         struct name_num_obj *nno = ntype == NSTR_COMPRESS ? &valid_compressions : &valid_checksums;
 410         const char *list_str = getenv_nstr(ntype);
 411         char tmpbuf[MAX_NSTR_STRLEN];
 412
 413         if (!list_str)
 414                 return;
 415
 416         while (isSpace(list_str)) list_str++;
 417
 418         if (!*list_str)
 419                 return;
 420
 421         init_nno_saw(nno, 0);
 422         parse_nni_str(nno, list_str, tmpbuf, MAX_NSTR_STRLEN);
 423
 424         if (ntype == NSTR_CHECKSUM) /* If "md4" is in the env list, all the old MD4 choices are OK too. */
 425                 nno->saw[CSUM_MD4_ARCHAIC] = nno->saw[CSUM_MD4_BUSTED] = nno->saw[CSUM_MD4_OLD] = nno->saw[CSUM_MD4];
 426
 427         if (!nno->saw[num1] || (num2 >= 0 && !nno->saw[num2])) {
 428                 rprintf(FERROR, "Your --%s-choice value (%s) was refused by the server.\n",
 429                         ntype == NSTR_COMPRESS ? "compress" : "checksum",
 430                         ntype == NSTR_COMPRESS ? compress_choice : checksum_choice);
 431                 exit_cleanup(RERR_UNSUPPORTED);
 432         }
 433
 434         free(nno->saw);
 435         nno->saw = NULL;
 436 }
 437
 438 /* The saw buffer is initialized and used to store ordinal values from 1 to N
 439  * for the order of the args in the array.  If dup_markup == '\0', duplicates
 440  * are removed otherwise the char is prefixed to the duplicate term and, if it
 441  * is an opening paren/bracket/brace, the matching closing char is suffixed.
 442  * "none" is removed on the client side unless dup_markup != '\0'. */
 443 int get_default_nno_list(struct name_num_obj *nno, char *to_buf, int to_buf_len, char dup_markup)
 444 {
 445         struct name_num_item *nni;
 446         int len = 0, cnt = 0;
 447         char delim = '\0', post_delim;
 448
 449         switch (dup_markup) {
 450         case '(': post_delim = ')'; break;
 451         case '[': post_delim = ']'; break;
 452         case '{': post_delim = '}'; break;
 453         default: post_delim = '\0'; break;
 454         }
 455
 456         init_nno_saw(nno, 0);
 457
 458         for (nni = nno->list, len = 0; nni->name; nni++) {
 459                 if (nni->main_name) {
 460                         if (!dup_markup)
 461                                 continue;
 462                         delim = dup_markup;
 463                 }
 464                 if (nni->num == 0 && !am_server && !dup_markup)
 465                         continue;
 466                 if (len)
 467                         to_buf[len++]= ' ';
 468                 if (delim) {
 469                         to_buf[len++]= delim;
 470                         delim = post_delim;
 471                 }
 472                 len += strlcpy(to_buf+len, nni->name, to_buf_len - len);
 473                 if (len >= to_buf_len - 3)
 474                         exit_cleanup(RERR_UNSUPPORTED); /* IMPOSSIBLE... */
 475                 if (delim) {
 476                         to_buf[len++]= delim;
 477                         delim = '\0';
 478                 }
 479                 nno->saw[nni->num] = ++cnt;
 480         }
 481
 482         return len;
 483 }
 484
 485 static void send_negotiate_str(int f_out, struct name_num_obj *nno, int ntype)
 486 {
 487         char tmpbuf[MAX_NSTR_STRLEN];
 488         const char *list_str = getenv_nstr(ntype);
 489         int len;
 490
 491         if (list_str && *list_str) {
 492                 init_nno_saw(nno, 0);
 493                 len = parse_nni_str(nno, list_str, tmpbuf, MAX_NSTR_STRLEN);
 494                 list_str = tmpbuf;
 495         } else
 496                 list_str = NULL;
 497
 498         if (!list_str || !*list_str)
 499                 len = get_default_nno_list(nno, tmpbuf, MAX_NSTR_STRLEN, '\0');
 500
 501         if (DEBUG_GTE(NSTR, am_server ? 3 : 2)) {
 502                 if (am_server)
 503                         rprintf(FINFO, "Server %s list (on server): %s\n", nno->type, tmpbuf);
 504                 else
 505                         rprintf(FINFO, "Client %s list (on client): %s\n", nno->type, tmpbuf);
 506         }
 507
 508         /* Each side sends their list of valid names to the other side and then both sides
 509          * pick the first name in the client's list that is also in the server's list. */
 510         if (do_negotiated_strings)
 511                 write_vstring(f_out, tmpbuf, len);
 512 }
 513
 514 static void negotiate_the_strings(int f_in, int f_out)
 515 {
 516         /* We send all the negotiation strings before we start to read them to help avoid a slow startup. */
 517
 518         if (!checksum_choice)
 519                 send_negotiate_str(f_out, &valid_checksums, NSTR_CHECKSUM);
 520
 521         if (do_compression && !compress_choice)
 522                 send_negotiate_str(f_out, &valid_compressions, NSTR_COMPRESS);
 523
 524         if (valid_checksums.saw) {
 525                 char tmpbuf[MAX_NSTR_STRLEN];
 526                 int len;
 527                 if (do_negotiated_strings)
 528                         len = -1;
 529                 else
 530                         len = strlcpy(tmpbuf, protocol_version >= 30 ? "md5" : "md4", MAX_NSTR_STRLEN);
 531                 recv_negotiate_str(f_in, &valid_checksums, tmpbuf, len);
 532         }
 533
 534         if (valid_compressions.saw) {
 535                 char tmpbuf[MAX_NSTR_STRLEN];
 536                 int len;
 537                 if (do_negotiated_strings)
 538                         len = -1;
 539                 else
 540                         len = strlcpy(tmpbuf, "zlib", MAX_NSTR_STRLEN);
 541                 recv_negotiate_str(f_in, &valid_compressions, tmpbuf, len);
 542         }
 543
 544         /* If the other side is too old to negotiate, the above steps just made sure that
 545          * the env didn't disallow the old algorithm. Mark things as non-negotiated. */
 546         if (!do_negotiated_strings)
 547                 valid_checksums.negotiated_name = valid_compressions.negotiated_name = NULL;
 548 }
 549
 550 void setup_protocol(int f_out,int f_in)
 551 {
 552         assert(file_extra_cnt == 0);
 553         assert(EXTRA64_CNT == 2 || EXTRA64_CNT == 1);
 554
 555         /* All int64 values must be set first so that they are guaranteed to be
 556          * aligned for direct int64-pointer memory access. */
 557         if (preserve_atimes)
 558                 atimes_ndx = (file_extra_cnt += EXTRA64_CNT);
 559         if (preserve_crtimes)
 560                 crtimes_ndx = (file_extra_cnt += EXTRA64_CNT);
 561         if (am_sender) /* This is most likely in the in64 union as well. */
 562                 pathname_ndx = (file_extra_cnt += PTR_EXTRA_CNT);
 563         else
 564                 depth_ndx = ++file_extra_cnt;
 565         if (preserve_uid)
 566                 uid_ndx = ++file_extra_cnt;
 567         if (preserve_gid)
 568                 gid_ndx = ++file_extra_cnt;
 569         if (preserve_acls && !am_sender)
 570                 acls_ndx = ++file_extra_cnt;
 571         if (preserve_xattrs)
 572                 xattrs_ndx = ++file_extra_cnt;
 573
 574         if (am_server)
 575                 set_allow_inc_recurse();
 576
 577         if (remote_protocol == 0) {
 578                 if (am_server && !local_server)
 579                         check_sub_protocol();
 580                 if (!read_batch)
 581                         write_int(f_out, protocol_version);
 582                 remote_protocol = read_int(f_in);
 583                 if (protocol_version > remote_protocol)
 584                         protocol_version = remote_protocol;
 585         }
 586         if (read_batch && remote_protocol > protocol_version) {
 587                 rprintf(FERROR, "The protocol version in the batch file is too new (%d > %d).\n",
 588                         remote_protocol, protocol_version);
 589                 exit_cleanup(RERR_PROTOCOL);
 590         }
 591
 592         if (DEBUG_GTE(PROTO, 1)) {
 593                 rprintf(FINFO, "(%s) Protocol versions: remote=%d, negotiated=%d\n",
 594                         am_server? "Server" : "Client", remote_protocol, protocol_version);
 595         }
 596         if (remote_protocol < MIN_PROTOCOL_VERSION
 597          || remote_protocol > MAX_PROTOCOL_VERSION) {
 598                 rprintf(FERROR,"protocol version mismatch -- is your shell clean?\n");
 599                 rprintf(FERROR,"(see the rsync man page for an explanation)\n");
 600                 exit_cleanup(RERR_PROTOCOL);
 601         }
 602         if (remote_protocol < OLD_PROTOCOL_VERSION) {
 603                 rprintf(FINFO,"%s is very old version of rsync, upgrade recommended.\n",
 604                         am_server? "Client" : "Server");
 605         }
 606         if (protocol_version < MIN_PROTOCOL_VERSION) {
 607                 rprintf(FERROR, "--protocol must be at least %d on the %s.\n",
 608                         MIN_PROTOCOL_VERSION, am_server? "Server" : "Client");
 609                 exit_cleanup(RERR_PROTOCOL);
 610         }
 611         if (protocol_version > PROTOCOL_VERSION) {
 612                 rprintf(FERROR, "--protocol must be no more than %d on the %s.\n",
 613                         PROTOCOL_VERSION, am_server? "Server" : "Client");
 614                 exit_cleanup(RERR_PROTOCOL);
 615         }
 616         if (read_batch)
 617                 check_batch_flags();
 618
 619 #ifndef SUPPORT_PREALLOCATION
 620         if (preallocate_files && !am_sender) {
 621                 rprintf(FERROR, "preallocation is not supported on this %s\n",
 622                         am_server ? "Server" : "Client");
 623                 exit_cleanup(RERR_SYNTAX);
 624         }
 625 #endif
 626
 627         if (protocol_version < 30) {
 628                 if (append_mode == 1)
 629                         append_mode = 2;
 630                 if (preserve_acls && !local_server) {
 631                         rprintf(FERROR,
 632                                 "--acls requires protocol 30 or higher"
 633                                 " (negotiated %d).\n",
 634                                 protocol_version);
 635                         exit_cleanup(RERR_PROTOCOL);
 636                 }
 637                 if (preserve_xattrs && !local_server) {
 638                         rprintf(FERROR,
 639                                 "--xattrs requires protocol 30 or higher"
 640                                 " (negotiated %d).\n",
 641                                 protocol_version);
 642                         exit_cleanup(RERR_PROTOCOL);
 643                 }
 644         }
 645
 646         if (delete_mode && !(delete_before+delete_during+delete_after)) {
 647                 if (protocol_version < 30)
 648                         delete_before = 1;
 649                 else
 650                         delete_during = 1;
 651         }
 652
 653         if (protocol_version < 29) {
 654                 if (fuzzy_basis) {
 655                         rprintf(FERROR,
 656                                 "--fuzzy requires protocol 29 or higher"
 657                                 " (negotiated %d).\n",
 658                                 protocol_version);
 659                         exit_cleanup(RERR_PROTOCOL);
 660                 }
 661
 662                 if (basis_dir_cnt && inplace) {
 663                         rprintf(FERROR,
 664                                 "%s with --inplace requires protocol 29 or higher"
 665                                 " (negotiated %d).\n",
 666                                 alt_dest_opt(0), protocol_version);
 667                         exit_cleanup(RERR_PROTOCOL);
 668                 }
 669
 670                 if (basis_dir_cnt > 1) {
 671                         rprintf(FERROR,
 672                                 "Using more than one %s option requires protocol"
 673                                 " 29 or higher (negotiated %d).\n",
 674                                 alt_dest_opt(0), protocol_version);
 675                         exit_cleanup(RERR_PROTOCOL);
 676                 }
 677
 678                 if (prune_empty_dirs) {
 679                         rprintf(FERROR,
 680                                 "--prune-empty-dirs requires protocol 29 or higher"
 681                                 " (negotiated %d).\n",
 682                                 protocol_version);
 683                         exit_cleanup(RERR_PROTOCOL);
 684                 }
 685         } else if (protocol_version >= 30) {
 686                 if (am_server) {
 687                         compat_flags = allow_inc_recurse ? CF_INC_RECURSE : 0;
 688 #ifdef CAN_SET_SYMLINK_TIMES
 689                         compat_flags |= CF_SYMLINK_TIMES;
 690 #endif
 691 #ifdef ICONV_OPTION
 692                         compat_flags |= CF_SYMLINK_ICONV;
 693 #endif
 694                         if (local_server || strchr(client_info, 'f') != NULL)
 695                                 compat_flags |= CF_SAFE_FLIST;
 696                         if (local_server || strchr(client_info, 'x') != NULL)
 697                                 compat_flags |= CF_AVOID_XATTR_OPTIM;
 698                         if (local_server || strchr(client_info, 'C') != NULL)
 699                                 compat_flags |= CF_CHKSUM_SEED_FIX;
 700                         if (local_server || strchr(client_info, 'I') != NULL)
 701                                 compat_flags |= CF_INPLACE_PARTIAL_DIR;
 702                         if (local_server || strchr(client_info, 'u') != NULL)
 703                                 compat_flags |= CF_ID0_NAMES;
 704                         if (local_server || strchr(client_info, 'v') != NULL) {
 705                                 do_negotiated_strings = 1;
 706                                 compat_flags |= CF_VARINT_FLIST_FLAGS;
 707                         }
 708                         if (strchr(client_info, 'V') != NULL) { /* Support a pre-release 'V' that got superseded */
 709                                 if (!write_batch)
 710                                         compat_flags |= CF_VARINT_FLIST_FLAGS;
 711                                 write_byte(f_out, compat_flags);
 712                         } else
 713                                 write_varint(f_out, compat_flags);
 714                 } else { /* read_varint() is compatible with the older write_byte() when the 0x80 bit isn't on. */
 715                         compat_flags = read_varint(f_in);
 716                         if  (compat_flags & CF_VARINT_FLIST_FLAGS)
 717                                 do_negotiated_strings = 1;
 718                 }
 719                 /* The inc_recurse var MUST be set to 0 or 1. */
 720                 inc_recurse = compat_flags & CF_INC_RECURSE ? 1 : 0;
 721                 want_xattr_optim = protocol_version >= 31 && !(compat_flags & CF_AVOID_XATTR_OPTIM);
 722                 proper_seed_order = compat_flags & CF_CHKSUM_SEED_FIX ? 1 : 0;
 723                 xfer_flags_as_varint = compat_flags & CF_VARINT_FLIST_FLAGS ? 1 : 0;
 724                 xmit_id0_names = compat_flags & CF_ID0_NAMES ? 1 : 0;
 725                 if (!xfer_flags_as_varint && preserve_crtimes) {
 726                         fprintf(stderr, "Both rsync versions must be at least 3.2.0 for --crtimes.\n");
 727                         exit_cleanup(RERR_PROTOCOL);
 728                 }
 729                 if (am_sender) {
 730                         receiver_symlink_times = am_server
 731                             ? strchr(client_info, 'L') != NULL
 732                             : !!(compat_flags & CF_SYMLINK_TIMES);
 733                 }
 734 #ifdef CAN_SET_SYMLINK_TIMES
 735                 else
 736                         receiver_symlink_times = 1;
 737 #endif
 738 #ifdef ICONV_OPTION
 739                 sender_symlink_iconv = iconv_opt && (am_server
 740                     ? local_server || strchr(client_info, 's') != NULL
 741                     : !!(compat_flags & CF_SYMLINK_ICONV));
 742 #endif
 743                 if (inc_recurse && !allow_inc_recurse) {
 744                         /* This should only be able to happen in a batch. */
 745                         fprintf(stderr,
 746                                 "Incompatible options specified for inc-recursive %s.\n",
 747                                 read_batch ? "batch file" : "connection");
 748                         exit_cleanup(RERR_SYNTAX);
 749                 }
 750                 use_safe_inc_flist = (compat_flags & CF_SAFE_FLIST) || protocol_version >= 31;
 751                 need_messages_from_generator = 1;
 752                 if (compat_flags & CF_INPLACE_PARTIAL_DIR)
 753                         inplace_partial = 1;
 754 #ifdef CAN_SET_SYMLINK_TIMES
 755         } else if (!am_sender) {
 756                 receiver_symlink_times = 1;
 757 #endif
 758         }
 759
 760         if (read_batch)
 761                 do_negotiated_strings = 0;
 762
 763         if (need_unsorted_flist && (!am_sender || inc_recurse))
 764                 unsort_ndx = ++file_extra_cnt;
 765
 766         if (partial_dir && *partial_dir != '/' && (!am_server || local_server)) {
 767                 int rflags = FILTRULE_NO_PREFIXES | FILTRULE_DIRECTORY;
 768                 if (!am_sender || protocol_version >= 30)
 769                         rflags |= FILTRULE_PERISHABLE;
 770                 parse_filter_str(&filter_list, partial_dir, rule_template(rflags), 0);
 771         }
 772
 773
 774 #ifdef ICONV_OPTION
 775         if (protect_args && files_from) {
 776                 if (am_sender)
 777                         filesfrom_convert = filesfrom_host && ic_send != (iconv_t)-1;
 778                 else
 779                         filesfrom_convert = !filesfrom_host && ic_recv != (iconv_t)-1;
 780         }
 781 #endif
 782
 783         negotiate_the_strings(f_in, f_out);
 784
 785         if (am_server) {
 786                 if (!checksum_seed)
 787                         checksum_seed = time(NULL) ^ (getpid() << 6);
 788                 write_int(f_out, checksum_seed);
 789         } else {
 790                 checksum_seed = read_int(f_in);
 791         }
 792
 793         parse_checksum_choice(1); /* Sets checksum_type & xfersum_type */
 794         parse_compress_choice(1); /* Sets do_compression */
 795
 796         if (write_batch && !am_server)
 797                 write_batch_shell_file();
 798
 799         init_flist();
 800 }