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_acls;
  47 extern int preserve_xattrs;
  48 extern int xfer_flags_as_varint;
  49 extern int need_messages_from_generator;
  50 extern int delete_mode, delete_before, delete_during, delete_after;
  51 extern int do_compression;
  52 extern int do_compression_level;
  53 extern char *shell_cmd;
  54 extern char *partial_dir;
  55 extern char *files_from;
  56 extern char *filesfrom_host;
  57 extern const char *checksum_choice;
  58 extern const char *compress_choice;
  59 extern filter_rule_list filter_list;
  60 extern int need_unsorted_flist;
  61 #ifdef ICONV_OPTION
  62 extern iconv_t ic_send, ic_recv;
  63 extern char *iconv_opt;
  64 #endif
  65 extern struct name_num_obj valid_checksums;
  66
  67 int remote_protocol = 0;
  68 int file_extra_cnt = 0; /* count of file-list extras that everyone gets */
  69 int inc_recurse = 0;
  70 int compat_flags = 0;
  71 int use_safe_inc_flist = 0;
  72 int want_xattr_optim = 0;
  73 int proper_seed_order = 0;
  74 int inplace_partial = 0;
  75 int do_negotiated_strings = 0;
  76
  77 /* These index values are for the file-list's extra-attribute array. */
  78 int pathname_ndx, depth_ndx, atimes_ndx, uid_ndx, gid_ndx, acls_ndx, xattrs_ndx, unsort_ndx;
  79
  80 int receiver_symlink_times = 0; /* receiver can set the time on a symlink */
  81 int sender_symlink_iconv = 0;   /* sender should convert symlink content */
  82
  83 #ifdef ICONV_OPTION
  84 int filesfrom_convert = 0;
  85 #endif
  86
  87 #define MAX_NSTR_STRLEN 256
  88
  89 struct name_num_obj valid_compressions = {
  90         "compress", NULL, NULL, 0, 0, {
  91 #ifdef SUPPORT_ZSTD
  92                 { CPRES_ZSTD, "zstd", NULL },
  93 #endif
  94 #ifdef SUPPORT_LZ4
  95                 { CPRES_LZ4, "lz4", NULL },
  96 #endif
  97                 { CPRES_ZLIBX, "zlibx", NULL },
  98                 { CPRES_ZLIB, "zlib", NULL },
  99                 { CPRES_NONE, "none", NULL },
 100                 { 0, NULL, NULL }
 101         }
 102 };
 103
 104 #define CF_INC_RECURSE   (1<<0)
 105 #define CF_SYMLINK_TIMES (1<<1)
 106 #define CF_SYMLINK_ICONV (1<<2)
 107 #define CF_SAFE_FLIST    (1<<3)
 108 #define CF_AVOID_XATTR_OPTIM (1<<4)
 109 #define CF_CHKSUM_SEED_FIX (1<<5)
 110 #define CF_INPLACE_PARTIAL_DIR (1<<6)
 111 #define CF_VARINT_FLIST_FLAGS (1<<7)
 112
 113 static const char *client_info;
 114
 115 /* The server makes sure that if either side only supports a pre-release
 116  * version of a protocol, that both sides must speak a compatible version
 117  * of that protocol for it to be advertised as available. */
 118 static void check_sub_protocol(void)
 119 {
 120         char *dot;
 121         int their_protocol, their_sub;
 122 #if SUBPROTOCOL_VERSION != 0
 123         int our_sub = protocol_version < PROTOCOL_VERSION ? 0 : SUBPROTOCOL_VERSION;
 124 #else
 125         int our_sub = 0;
 126 #endif
 127
 128         /* client_info starts with VER.SUB string if client is a pre-release. */
 129         if (!(their_protocol = atoi(client_info))
 130          || !(dot = strchr(client_info, '.'))
 131          || !(their_sub = atoi(dot+1))) {
 132 #if SUBPROTOCOL_VERSION != 0
 133                 if (our_sub)
 134                         protocol_version--;
 135 #endif
 136                 return;
 137         }
 138
 139         if (their_protocol < protocol_version) {
 140                 if (their_sub)
 141                         protocol_version = their_protocol - 1;
 142                 return;
 143         }
 144
 145         if (their_protocol > protocol_version)
 146                 their_sub = 0; /* 0 == final version of older protocol */
 147         if (their_sub != our_sub)
 148                 protocol_version--;
 149 }
 150
 151 void set_allow_inc_recurse(void)
 152 {
 153         client_info = shell_cmd ? shell_cmd : "";
 154
 155         if (!recurse || use_qsort)
 156                 allow_inc_recurse = 0;
 157         else if (!am_sender
 158          && (delete_before || delete_after
 159           || delay_updates || prune_empty_dirs))
 160                 allow_inc_recurse = 0;
 161         else if (am_server && !local_server
 162          && (strchr(client_info, 'i') == NULL))
 163                 allow_inc_recurse = 0;
 164 }
 165
 166 void parse_compress_choice(int final_call)
 167 {
 168         if (valid_compressions.negotiated_name)
 169                 do_compression = valid_compressions.negotiated_num;
 170         else if (compress_choice) {
 171                 struct name_num_item *nni = get_nni_by_name(&valid_compressions, compress_choice, -1);
 172                 if (!nni) {
 173                         rprintf(FERROR, "unknown compress name: %s\n", compress_choice);
 174                         exit_cleanup(RERR_UNSUPPORTED);
 175                 }
 176                 do_compression = nni->num;
 177                 if (am_server)
 178                         validate_choice_vs_env(NSTR_COMPRESS, do_compression, -1);
 179         } else if (do_compression)
 180                 do_compression = CPRES_ZLIB;
 181         else
 182                 do_compression = CPRES_NONE;
 183
 184         if (do_compression != CPRES_NONE && final_call)
 185                 init_compression_level(); /* There's a chance this might turn compression off! */
 186
 187         if (do_compression == CPRES_NONE)
 188                 compress_choice = NULL;
 189
 190         /* Snag the compression name for both write_batch's option output & the following debug output. */
 191         if (valid_compressions.negotiated_name)
 192                 compress_choice = valid_compressions.negotiated_name;
 193         else if (compress_choice == NULL) {
 194                 struct name_num_item *nni = get_nni_by_num(&valid_compressions, do_compression);
 195                 compress_choice = nni ? nni->name : "UNKNOWN";
 196         }
 197
 198         if (final_call && DEBUG_GTE(NSTR, am_server ? 3 : 1)
 199          && (do_compression != CPRES_NONE || do_compression_level != CLVL_NOT_SPECIFIED)) {
 200                 rprintf(FINFO, "%s%s compress: %s (level %d)\n",
 201                         am_server ? "Server" : "Client",
 202                         valid_compressions.negotiated_name ? " negotiated" : "",
 203                         compress_choice, do_compression_level);
 204         }
 205 }
 206
 207 struct name_num_item *get_nni_by_name(struct name_num_obj *nno, const char *name, int len)
 208 {
 209         struct name_num_item *nni;
 210
 211         if (len < 0)
 212                 len = strlen(name);
 213
 214         for (nni = nno->list; nni->name; nni++) {
 215                 if (strncasecmp(name, nni->name, len) == 0 && nni->name[len] == '\0')
 216                         return nni;
 217         }
 218
 219         return NULL;
 220 }
 221
 222 struct name_num_item *get_nni_by_num(struct name_num_obj *nno, int num)
 223 {
 224         struct name_num_item *nni;
 225
 226         for (nni = nno->list; nni->name; nni++) {
 227                 if (num == nni->num)
 228                         return nni;
 229         }
 230
 231         return NULL;
 232 }
 233
 234 static void init_nno_saw(struct name_num_obj *nno, int val)
 235 {
 236         struct name_num_item *nni;
 237         int cnt;
 238
 239         if (!nno->saw_len) {
 240                 for (nni = nno->list; nni->name; nni++) {
 241                         if (nni->num >= nno->saw_len)
 242                                 nno->saw_len = nni->num + 1;
 243                 }
 244         }
 245
 246         if (!nno->saw) {
 247                 nno->saw = new_array0(uchar, nno->saw_len);
 248
 249                 /* We'll take this opportunity to make sure that the main_name values are set right. */
 250                 for (cnt = 1, nni = nno->list; nni->name; nni++, cnt++) {
 251                         if (nno->saw[nni->num])
 252                                 nni->main_name = nno->list[nno->saw[nni->num]-1].name;
 253                         else
 254                                 nno->saw[nni->num] = cnt;
 255                 }
 256         }
 257
 258         memset(nno->saw, val, nno->saw_len);
 259 }
 260
 261 /* Simplify the user-provided string so that it contains valid names without any duplicates.
 262  * It also sets the "saw" flags to a 1-relative count of which name was seen first. */
 263 static int parse_nni_str(struct name_num_obj *nno, const char *from, char *tobuf, int tobuf_len)
 264 {
 265         char *to = tobuf, *tok = NULL;
 266         int saw_tok = 0, cnt = 0;
 267
 268         while (1) {
 269                 int at_space = isSpace(from);
 270                 char ch = *from++;
 271                 if (ch == '&')
 272                         ch = '\0';
 273                 if (!ch || at_space) {
 274                         if (tok) {
 275                                 struct name_num_item *nni = get_nni_by_name(nno, tok, to - tok);
 276                                 if (nni && !nno->saw[nni->num]) {
 277                                         nno->saw[nni->num] = ++cnt;
 278                                         if (nni->main_name) {
 279                                                 to = tok + strlcpy(tok, nni->main_name, tobuf_len - (tok - tobuf));
 280                                                 if (to - tobuf >= tobuf_len) {
 281                                                         to = tok - 1;
 282                                                         break;
 283                                                 }
 284                                         }
 285                                 } else
 286                                         to = tok - (tok != tobuf);
 287                                 saw_tok = 1;
 288                                 tok = NULL;
 289                         }
 290                         if (!ch)
 291                                 break;
 292                         continue;
 293                 }
 294                 if (!tok) {
 295                         if (to != tobuf)
 296                                 *to++ = ' ';
 297                         tok = to;
 298                 }
 299                 if (to - tobuf >= tobuf_len - 1) {
 300                         to = tok - (tok != tobuf);
 301                         break;
 302                 }
 303                 *to++ = ch;
 304         }
 305         *to = '\0';
 306
 307         if (saw_tok && to == tobuf)
 308                 return strlcpy(tobuf, "INVALID", MAX_NSTR_STRLEN);
 309
 310         return to - tobuf;
 311 }
 312
 313 /* This routine is always called with a tmpbuf of MAX_NSTR_STRLEN length, but the
 314  * buffer may be pre-populated with a "len" length string to use OR a len of -1
 315  * to tell us to read a string from the fd. */
 316 static void recv_negotiate_str(int f_in, struct name_num_obj *nno, char *tmpbuf, int len)
 317 {
 318         struct name_num_item *ret = NULL;
 319
 320         if (len < 0)
 321                 len = read_vstring(f_in, tmpbuf, MAX_NSTR_STRLEN);
 322
 323         if (DEBUG_GTE(NSTR, am_server ? 3 : 2)) {
 324                 if (am_server)
 325                         rprintf(FINFO, "Client %s list (on server): %s\n", nno->type, tmpbuf);
 326                 else
 327                         rprintf(FINFO, "Server %s list (on client): %s\n", nno->type, tmpbuf);
 328         }
 329
 330         if (len > 0) {
 331                 struct name_num_item *nni;
 332                 int best = nno->saw_len; /* We want best == 1 from the client list, so start with a big number. */
 333                 char *space, *tok = tmpbuf;
 334                 while (tok) {
 335                         while (*tok == ' ') tok++; /* Should be unneeded... */
 336                         if (!*tok)
 337                                 break;
 338                         if ((space = strchr(tok, ' ')) != NULL)
 339                                 *space = '\0';
 340                         nni = get_nni_by_name(nno, tok, -1);
 341                         if (space) {
 342                                 *space = ' ';
 343                                 tok = space + 1;
 344                         } else
 345                                 tok = NULL;
 346                         if (!nni || !nno->saw[nni->num] || best <= nno->saw[nni->num])
 347                                 continue;
 348                         ret = nni;
 349                         best = nno->saw[nni->num];
 350                         if (best == 1 || am_server) /* The server side stops at the first acceptable client choice */
 351                                 break;
 352                 }
 353                 if (ret) {
 354                         free(nno->saw);
 355                         nno->saw = NULL;
 356                         nno->negotiated_name = ret->main_name ? ret->main_name : ret->name;
 357                         nno->negotiated_num = ret->num;
 358                         return;
 359                 }
 360         }
 361
 362         if (!am_server || !do_negotiated_strings) {
 363                 char *cp = tmpbuf;
 364                 int j;
 365                 rprintf(FERROR, "Failed to negotiate a %s choice.\n", nno->type);
 366                 rprintf(FERROR, "%s list: %s\n", am_server ? "Client" : "Server", tmpbuf);
 367                 /* Recreate our original list from the saw values. This can't overflow our huge
 368                  * buffer because we don't have enough valid entries to get anywhere close. */
 369                 for (j = 1, *cp = '\0'; j <= nno->saw_len; j++) {
 370                         struct name_num_item *nni;
 371                         for (nni = nno->list; nni->name; nni++) {
 372                                 if (nno->saw[nni->num] == j) {
 373                                         *cp++ = ' ';
 374                                         cp += strlcpy(cp, nni->name, MAX_NSTR_STRLEN - (cp - tmpbuf));
 375                                         break;
 376                                 }
 377                         }
 378                 }
 379                 if (!*tmpbuf)
 380                         strlcpy(cp, " INVALID", MAX_NSTR_STRLEN);
 381                 rprintf(FERROR, "%s list:%s\n", am_server ? "Server" : "Client", tmpbuf);
 382         }
 383
 384         exit_cleanup(RERR_UNSUPPORTED);
 385 }
 386
 387 static const char *getenv_nstr(int ntype)
 388 {
 389         const char *env_str = getenv(ntype == NSTR_COMPRESS ? "RSYNC_COMPRESS_LIST" : "RSYNC_CHECKSUM_LIST");
 390
 391         /* When writing a batch file, we always negotiate an old-style choice. */
 392         if (write_batch)
 393                 env_str = ntype == NSTR_COMPRESS ? "zlib" : protocol_version >= 30 ? "md5" : "md4";
 394
 395         if (am_server && env_str) {
 396                 char *cp = strchr(env_str, '&');
 397                 if (cp)
 398                         env_str = cp + 1;
 399         }
 400
 401         return env_str;
 402 }
 403
 404 void validate_choice_vs_env(int ntype, int num1, int num2)
 405 {
 406         struct name_num_obj *nno = ntype == NSTR_COMPRESS ? &valid_compressions : &valid_checksums;
 407         const char *list_str = getenv_nstr(ntype);
 408         char tmpbuf[MAX_NSTR_STRLEN];
 409
 410         if (!list_str)
 411                 return;
 412
 413         while (isSpace(list_str)) list_str++;
 414
 415         if (!*list_str)
 416                 return;
 417
 418         init_nno_saw(nno, 0);
 419         parse_nni_str(nno, list_str, tmpbuf, MAX_NSTR_STRLEN);
 420
 421         if (ntype == NSTR_CHECKSUM) /* If "md4" is in the env list, all the old MD4 choices are OK too. */
 422                 nno->saw[CSUM_MD4_ARCHAIC] = nno->saw[CSUM_MD4_BUSTED] = nno->saw[CSUM_MD4_OLD] = nno->saw[CSUM_MD4];
 423
 424         if (!nno->saw[num1] || (num2 >= 0 && !nno->saw[num2])) {
 425                 rprintf(FERROR, "Your --%s-choice value (%s) was refused by the server.\n",
 426                         ntype == NSTR_COMPRESS ? "compress" : "checksum",
 427                         ntype == NSTR_COMPRESS ? compress_choice : checksum_choice);
 428                 exit_cleanup(RERR_UNSUPPORTED);
 429         }
 430
 431         free(nno->saw);
 432         nno->saw = NULL;
 433 }
 434
 435 /* The saw buffer is initialized and used to store ordinal values from 1 to N
 436  * for the order of the args in the array.  If dup_markup == '\0', duplicates
 437  * are removed otherwise the char is prefixed to the duplicate term and, if it
 438  * is an opening paren/bracket/brace, the matching closing char is suffixed.
 439  * "none" is removed on the client side unless dup_markup != '\0'. */
 440 int get_default_nno_list(struct name_num_obj *nno, char *to_buf, int to_buf_len, char dup_markup)
 441 {
 442         struct name_num_item *nni;
 443         int len = 0, cnt = 0;
 444         char delim = '\0', post_delim;
 445
 446         switch (dup_markup) {
 447         case '(': post_delim = ')'; break;
 448         case '[': post_delim = ']'; break;
 449         case '{': post_delim = '}'; break;
 450         default: post_delim = '\0'; break;
 451         }
 452
 453         init_nno_saw(nno, 0);
 454
 455         for (nni = nno->list, len = 0; nni->name; nni++) {
 456                 if (nni->main_name) {
 457                         if (!dup_markup)
 458                                 continue;
 459                         delim = dup_markup;
 460                 }
 461                 if (nni->num == 0 && !am_server && !dup_markup)
 462                         continue;
 463                 if (len)
 464                         to_buf[len++]= ' ';
 465                 if (delim) {
 466                         to_buf[len++]= delim;
 467                         delim = post_delim;
 468                 }
 469                 len += strlcpy(to_buf+len, nni->name, to_buf_len - len);
 470                 if (len >= to_buf_len - 3)
 471                         exit_cleanup(RERR_UNSUPPORTED); /* IMPOSSIBLE... */
 472                 if (delim) {
 473                         to_buf[len++]= delim;
 474                         delim = '\0';
 475                 }
 476                 nno->saw[nni->num] = ++cnt;
 477         }
 478
 479         return len;
 480 }
 481
 482 static void send_negotiate_str(int f_out, struct name_num_obj *nno, int ntype)
 483 {
 484         char tmpbuf[MAX_NSTR_STRLEN];
 485         const char *list_str = getenv_nstr(ntype);
 486         int len;
 487
 488         if (list_str && *list_str) {
 489                 init_nno_saw(nno, 0);
 490                 len = parse_nni_str(nno, list_str, tmpbuf, MAX_NSTR_STRLEN);
 491                 list_str = tmpbuf;
 492         } else
 493                 list_str = NULL;
 494
 495         if (!list_str || !*list_str)
 496                 len = get_default_nno_list(nno, tmpbuf, MAX_NSTR_STRLEN, '\0');
 497
 498         if (DEBUG_GTE(NSTR, am_server ? 3 : 2)) {
 499                 if (am_server)
 500                         rprintf(FINFO, "Server %s list (on server): %s\n", nno->type, tmpbuf);
 501                 else
 502                         rprintf(FINFO, "Client %s list (on client): %s\n", nno->type, tmpbuf);
 503         }
 504
 505         /* Each side sends their list of valid names to the other side and then both sides
 506          * pick the first name in the client's list that is also in the server's list. */
 507         if (do_negotiated_strings)
 508                 write_vstring(f_out, tmpbuf, len);
 509 }
 510
 511 static void negotiate_the_strings(int f_in, int f_out)
 512 {
 513         /* We send all the negotiation strings before we start to read them to help avoid a slow startup. */
 514
 515         if (!checksum_choice)
 516                 send_negotiate_str(f_out, &valid_checksums, NSTR_CHECKSUM);
 517
 518         if (do_compression && !compress_choice)
 519                 send_negotiate_str(f_out, &valid_compressions, NSTR_COMPRESS);
 520
 521         if (valid_checksums.saw) {
 522                 char tmpbuf[MAX_NSTR_STRLEN];
 523                 int len;
 524                 if (do_negotiated_strings)
 525                         len = -1;
 526                 else
 527                         len = strlcpy(tmpbuf, protocol_version >= 30 ? "md5" : "md4", MAX_NSTR_STRLEN);
 528                 recv_negotiate_str(f_in, &valid_checksums, tmpbuf, len);
 529         }
 530
 531         if (valid_compressions.saw) {
 532                 char tmpbuf[MAX_NSTR_STRLEN];
 533                 int len;
 534                 if (do_negotiated_strings)
 535                         len = -1;
 536                 else
 537                         len = strlcpy(tmpbuf, "zlib", MAX_NSTR_STRLEN);
 538                 recv_negotiate_str(f_in, &valid_compressions, tmpbuf, len);
 539         }
 540
 541         /* If the other side is too old to negotiate, the above steps just made sure that
 542          * the env didn't disallow the old algorithm. Mark things as non-negotiated. */
 543         if (!do_negotiated_strings)
 544                 valid_checksums.negotiated_name = valid_compressions.negotiated_name = NULL;
 545 }
 546
 547 void setup_protocol(int f_out,int f_in)
 548 {
 549         assert(file_extra_cnt == 0);
 550         assert(EXTRA64_CNT == 2 || EXTRA64_CNT == 1);
 551
 552         /* All int64 values must be set first so that they are guaranteed to be
 553          * aligned for direct int64-pointer memory access. */
 554         if (preserve_atimes)
 555                 atimes_ndx = (file_extra_cnt += EXTRA64_CNT);
 556         if (am_sender) /* This is most likely in the in64 union as well. */
 557                 pathname_ndx = (file_extra_cnt += PTR_EXTRA_CNT);
 558         else
 559                 depth_ndx = ++file_extra_cnt;
 560         if (preserve_uid)
 561                 uid_ndx = ++file_extra_cnt;
 562         if (preserve_gid)
 563                 gid_ndx = ++file_extra_cnt;
 564         if (preserve_acls && !am_sender)
 565                 acls_ndx = ++file_extra_cnt;
 566         if (preserve_xattrs)
 567                 xattrs_ndx = ++file_extra_cnt;
 568
 569         if (am_server)
 570                 set_allow_inc_recurse();
 571
 572         if (remote_protocol == 0) {
 573                 if (am_server && !local_server)
 574                         check_sub_protocol();
 575                 if (!read_batch)
 576                         write_int(f_out, protocol_version);
 577                 remote_protocol = read_int(f_in);
 578                 if (protocol_version > remote_protocol)
 579                         protocol_version = remote_protocol;
 580         }
 581         if (read_batch && remote_protocol > protocol_version) {
 582                 rprintf(FERROR, "The protocol version in the batch file is too new (%d > %d).\n",
 583                         remote_protocol, protocol_version);
 584                 exit_cleanup(RERR_PROTOCOL);
 585         }
 586
 587         if (DEBUG_GTE(PROTO, 1)) {
 588                 rprintf(FINFO, "(%s) Protocol versions: remote=%d, negotiated=%d\n",
 589                         am_server? "Server" : "Client", remote_protocol, protocol_version);
 590         }
 591         if (remote_protocol < MIN_PROTOCOL_VERSION
 592          || remote_protocol > MAX_PROTOCOL_VERSION) {
 593                 rprintf(FERROR,"protocol version mismatch -- is your shell clean?\n");
 594                 rprintf(FERROR,"(see the rsync man page for an explanation)\n");
 595                 exit_cleanup(RERR_PROTOCOL);
 596         }
 597         if (remote_protocol < OLD_PROTOCOL_VERSION) {
 598                 rprintf(FINFO,"%s is very old version of rsync, upgrade recommended.\n",
 599                         am_server? "Client" : "Server");
 600         }
 601         if (protocol_version < MIN_PROTOCOL_VERSION) {
 602                 rprintf(FERROR, "--protocol must be at least %d on the %s.\n",
 603                         MIN_PROTOCOL_VERSION, am_server? "Server" : "Client");
 604                 exit_cleanup(RERR_PROTOCOL);
 605         }
 606         if (protocol_version > PROTOCOL_VERSION) {
 607                 rprintf(FERROR, "--protocol must be no more than %d on the %s.\n",
 608                         PROTOCOL_VERSION, am_server? "Server" : "Client");
 609                 exit_cleanup(RERR_PROTOCOL);
 610         }
 611         if (read_batch)
 612                 check_batch_flags();
 613
 614 #ifndef SUPPORT_PREALLOCATION
 615         if (preallocate_files && !am_sender) {
 616                 rprintf(FERROR, "preallocation is not supported on this %s\n",
 617                         am_server ? "Server" : "Client");
 618                 exit_cleanup(RERR_SYNTAX);
 619         }
 620 #endif
 621
 622         if (protocol_version < 30) {
 623                 if (append_mode == 1)
 624                         append_mode = 2;
 625                 if (preserve_acls && !local_server) {
 626                         rprintf(FERROR,
 627                                 "--acls requires protocol 30 or higher"
 628                                 " (negotiated %d).\n",
 629                                 protocol_version);
 630                         exit_cleanup(RERR_PROTOCOL);
 631                 }
 632                 if (preserve_xattrs && !local_server) {
 633                         rprintf(FERROR,
 634                                 "--xattrs requires protocol 30 or higher"
 635                                 " (negotiated %d).\n",
 636                                 protocol_version);
 637                         exit_cleanup(RERR_PROTOCOL);
 638                 }
 639         }
 640
 641         if (delete_mode && !(delete_before+delete_during+delete_after)) {
 642                 if (protocol_version < 30)
 643                         delete_before = 1;
 644                 else
 645                         delete_during = 1;
 646         }
 647
 648         if (protocol_version < 29) {
 649                 if (fuzzy_basis) {
 650                         rprintf(FERROR,
 651                                 "--fuzzy requires protocol 29 or higher"
 652                                 " (negotiated %d).\n",
 653                                 protocol_version);
 654                         exit_cleanup(RERR_PROTOCOL);
 655                 }
 656
 657                 if (basis_dir_cnt && inplace) {
 658                         rprintf(FERROR,
 659                                 "%s with --inplace requires protocol 29 or higher"
 660                                 " (negotiated %d).\n",
 661                                 alt_dest_opt(0), protocol_version);
 662                         exit_cleanup(RERR_PROTOCOL);
 663                 }
 664
 665                 if (basis_dir_cnt > 1) {
 666                         rprintf(FERROR,
 667                                 "Using more than one %s option requires protocol"
 668                                 " 29 or higher (negotiated %d).\n",
 669                                 alt_dest_opt(0), protocol_version);
 670                         exit_cleanup(RERR_PROTOCOL);
 671                 }
 672
 673                 if (prune_empty_dirs) {
 674                         rprintf(FERROR,
 675                                 "--prune-empty-dirs requires protocol 29 or higher"
 676                                 " (negotiated %d).\n",
 677                                 protocol_version);
 678                         exit_cleanup(RERR_PROTOCOL);
 679                 }
 680         } else if (protocol_version >= 30) {
 681                 if (am_server) {
 682                         compat_flags = allow_inc_recurse ? CF_INC_RECURSE : 0;
 683 #ifdef CAN_SET_SYMLINK_TIMES
 684                         compat_flags |= CF_SYMLINK_TIMES;
 685 #endif
 686 #ifdef ICONV_OPTION
 687                         compat_flags |= CF_SYMLINK_ICONV;
 688 #endif
 689                         if (local_server || strchr(client_info, 'f') != NULL)
 690                                 compat_flags |= CF_SAFE_FLIST;
 691                         if (local_server || strchr(client_info, 'x') != NULL)
 692                                 compat_flags |= CF_AVOID_XATTR_OPTIM;
 693                         if (local_server || strchr(client_info, 'C') != NULL)
 694                                 compat_flags |= CF_CHKSUM_SEED_FIX;
 695                         if (local_server || strchr(client_info, 'I') != NULL)
 696                                 compat_flags |= CF_INPLACE_PARTIAL_DIR;
 697                         if (local_server || strchr(client_info, 'v') != NULL) {
 698                                 do_negotiated_strings = 1;
 699                                 compat_flags |= CF_VARINT_FLIST_FLAGS;
 700                         }
 701                         if (strchr(client_info, 'V') != NULL) { /* Support a pre-release 'V' that got superseded */
 702                                 if (!write_batch)
 703                                         compat_flags |= CF_VARINT_FLIST_FLAGS;
 704                                 write_byte(f_out, compat_flags);
 705                         } else
 706                                 write_varint(f_out, compat_flags);
 707                 } else { /* read_varint() is compatible with the older write_byte() when the 0x80 bit isn't on. */
 708                         compat_flags = read_varint(f_in);
 709                         if  (compat_flags & CF_VARINT_FLIST_FLAGS)
 710                                 do_negotiated_strings = 1;
 711                 }
 712                 /* The inc_recurse var MUST be set to 0 or 1. */
 713                 inc_recurse = compat_flags & CF_INC_RECURSE ? 1 : 0;
 714                 want_xattr_optim = protocol_version >= 31 && !(compat_flags & CF_AVOID_XATTR_OPTIM);
 715                 proper_seed_order = compat_flags & CF_CHKSUM_SEED_FIX ? 1 : 0;
 716                 xfer_flags_as_varint = compat_flags & CF_VARINT_FLIST_FLAGS ? 1 : 0;
 717                 if (am_sender) {
 718                         receiver_symlink_times = am_server
 719                             ? strchr(client_info, 'L') != NULL
 720                             : !!(compat_flags & CF_SYMLINK_TIMES);
 721                 }
 722 #ifdef CAN_SET_SYMLINK_TIMES
 723                 else
 724                         receiver_symlink_times = 1;
 725 #endif
 726 #ifdef ICONV_OPTION
 727                 sender_symlink_iconv = iconv_opt && (am_server
 728                     ? local_server || strchr(client_info, 's') != NULL
 729                     : !!(compat_flags & CF_SYMLINK_ICONV));
 730 #endif
 731                 if (inc_recurse && !allow_inc_recurse) {
 732                         /* This should only be able to happen in a batch. */
 733                         fprintf(stderr,
 734                                 "Incompatible options specified for inc-recursive %s.\n",
 735                                 read_batch ? "batch file" : "connection");
 736                         exit_cleanup(RERR_SYNTAX);
 737                 }
 738                 use_safe_inc_flist = (compat_flags & CF_SAFE_FLIST) || protocol_version >= 31;
 739                 need_messages_from_generator = 1;
 740                 if (compat_flags & CF_INPLACE_PARTIAL_DIR)
 741                         inplace_partial = 1;
 742 #ifdef CAN_SET_SYMLINK_TIMES
 743         } else if (!am_sender) {
 744                 receiver_symlink_times = 1;
 745 #endif
 746         }
 747
 748         if (read_batch)
 749                 do_negotiated_strings = 0;
 750
 751         if (need_unsorted_flist && (!am_sender || inc_recurse))
 752                 unsort_ndx = ++file_extra_cnt;
 753
 754         if (partial_dir && *partial_dir != '/' && (!am_server || local_server)) {
 755                 int rflags = FILTRULE_NO_PREFIXES | FILTRULE_DIRECTORY;
 756                 if (!am_sender || protocol_version >= 30)
 757                         rflags |= FILTRULE_PERISHABLE;
 758                 parse_filter_str(&filter_list, partial_dir, rule_template(rflags), 0);
 759         }
 760
 761
 762 #ifdef ICONV_OPTION
 763         if (protect_args && files_from) {
 764                 if (am_sender)
 765                         filesfrom_convert = filesfrom_host && ic_send != (iconv_t)-1;
 766                 else
 767                         filesfrom_convert = !filesfrom_host && ic_recv != (iconv_t)-1;
 768         }
 769 #endif
 770
 771         negotiate_the_strings(f_in, f_out);
 772
 773         if (am_server) {
 774                 if (!checksum_seed)
 775                         checksum_seed = time(NULL) ^ (getpid() << 6);
 776                 write_int(f_out, checksum_seed);
 777         } else {
 778                 checksum_seed = read_int(f_in);
 779         }
 780
 781         parse_checksum_choice(1); /* Sets checksum_type & xfersum_type */
 782         parse_compress_choice(1); /* Sets do_compression */
 783
 784         if (write_batch && !am_server)
 785                 write_batch_shell_file();
 786
 787         init_flist();
 788 }