io.c

   1 /*
   2  * Socket and pipe I/O utilities used in rsync.
   3  *
   4  * Copyright (C) 1996-2001 Andrew Tridgell
   5  * Copyright (C) 1996 Paul Mackerras
   6  * Copyright (C) 2001, 2002 Martin Pool <mbp@samba.org>
   7  * Copyright (C) 2003, 2004, 2005, 2006 Wayne Davison
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
  22  */
  23
  24 /* Rsync provides its own multiplexing system, which is used to send
  25  * stderr and stdout over a single socket.
  26  *
  27  * For historical reasons this is off during the start of the
  28  * connection, but it's switched on quite early using
  29  * io_start_multiplex_out() and io_start_multiplex_in(). */
  30
  31 #include "rsync.h"
  32
  33 /** If no timeout is specified then use a 60 second select timeout */
  34 #define SELECT_TIMEOUT 60
  35
  36 extern int bwlimit;
  37 extern size_t bwlimit_writemax;
  38 extern int io_timeout;
  39 extern int allowed_lull;
  40 extern int am_server;
  41 extern int am_daemon;
  42 extern int am_sender;
  43 extern int am_generator;
  44 extern int eol_nulls;
  45 extern int read_batch;
  46 extern int csum_length;
  47 extern int checksum_seed;
  48 extern int protocol_version;
  49 extern int remove_source_files;
  50 extern int preserve_hard_links;
  51 extern char *filesfrom_host;
  52 extern struct stats stats;
  53 extern struct file_list *the_file_list;
  54
  55 const char phase_unknown[] = "unknown";
  56 int ignore_timeout = 0;
  57 int batch_fd = -1;
  58 int batch_gen_fd = -1;
  59
  60 /* Ignore an EOF error if non-zero. See whine_about_eof(). */
  61 int kluge_around_eof = 0;
  62
  63 int msg_fd_in = -1;
  64 int msg_fd_out = -1;
  65 int sock_f_in = -1;
  66 int sock_f_out = -1;
  67
  68 static int io_multiplexing_out;
  69 static int io_multiplexing_in;
  70 static time_t last_io_in;
  71 static time_t last_io_out;
  72 static int no_flush;
  73
  74 static int write_batch_monitor_in = -1;
  75 static int write_batch_monitor_out = -1;
  76
  77 static int io_filesfrom_f_in = -1;
  78 static int io_filesfrom_f_out = -1;
  79 static char io_filesfrom_buf[2048];
  80 static char *io_filesfrom_bp;
  81 static char io_filesfrom_lastchar;
  82 static int io_filesfrom_buflen;
  83 static int defer_forwarding_messages = 0;
  84 static int select_timeout = SELECT_TIMEOUT;
  85 static int active_filecnt = 0;
  86 static OFF_T active_bytecnt = 0;
  87
  88 static void read_loop(int fd, char *buf, size_t len);
  89
  90 struct flist_ndx_item {
  91         struct flist_ndx_item *next;
  92         int ndx;
  93 };
  94
  95 struct flist_ndx_list {
  96         struct flist_ndx_item *head, *tail;
  97 };
  98
  99 static struct flist_ndx_list redo_list, hlink_list;
 100
 101 struct msg_list_item {
 102         struct msg_list_item *next;
 103         int len;
 104         char buf[1];
 105 };
 106
 107 struct msg_list {
 108         struct msg_list_item *head, *tail;
 109 };
 110
 111 static struct msg_list msg2genr, msg2sndr;
 112
 113 static void flist_ndx_push(struct flist_ndx_list *lp, int ndx)
 114 {
 115         struct flist_ndx_item *item;
 116
 117         if (!(item = new(struct flist_ndx_item)))
 118                 out_of_memory("flist_ndx_push");
 119         item->next = NULL;
 120         item->ndx = ndx;
 121         if (lp->tail)
 122                 lp->tail->next = item;
 123         else
 124                 lp->head = item;
 125         lp->tail = item;
 126 }
 127
 128 static int flist_ndx_pop(struct flist_ndx_list *lp)
 129 {
 130         struct flist_ndx_item *next;
 131         int ndx;
 132
 133         if (!lp->head)
 134                 return -1;
 135
 136         ndx = lp->head->ndx;
 137         next = lp->head->next;
 138         free(lp->head);
 139         lp->head = next;
 140         if (!next)
 141                 lp->tail = NULL;
 142
 143         return ndx;
 144 }
 145
 146 static void check_timeout(void)
 147 {
 148         time_t t;
 149
 150         if (!io_timeout || ignore_timeout)
 151                 return;
 152
 153         if (!last_io_in) {
 154                 last_io_in = time(NULL);
 155                 return;
 156         }
 157
 158         t = time(NULL);
 159
 160         if (t - last_io_in >= io_timeout) {
 161                 if (!am_server && !am_daemon) {
 162                         rprintf(FERROR, "io timeout after %d seconds -- exiting\n",
 163                                 (int)(t-last_io_in));
 164                 }
 165                 exit_cleanup(RERR_TIMEOUT);
 166         }
 167 }
 168
 169 /* Note the fds used for the main socket (which might really be a pipe
 170  * for a local transfer, but we can ignore that). */
 171 void io_set_sock_fds(int f_in, int f_out)
 172 {
 173         sock_f_in = f_in;
 174         sock_f_out = f_out;
 175 }
 176
 177 void set_io_timeout(int secs)
 178 {
 179         io_timeout = secs;
 180
 181         if (!io_timeout || io_timeout > SELECT_TIMEOUT)
 182                 select_timeout = SELECT_TIMEOUT;
 183         else
 184                 select_timeout = io_timeout;
 185
 186         allowed_lull = read_batch ? 0 : (io_timeout + 1) / 2;
 187 }
 188
 189 /* Setup the fd used to receive MSG_* messages.  Only needed during the
 190  * early stages of being a local sender (up through the sending of the
 191  * file list) or when we're the generator (to fetch the messages from
 192  * the receiver). */
 193 void set_msg_fd_in(int fd)
 194 {
 195         msg_fd_in = fd;
 196 }
 197
 198 /* Setup the fd used to send our MSG_* messages.  Only needed when
 199  * we're the receiver (to send our messages to the generator). */
 200 void set_msg_fd_out(int fd)
 201 {
 202         msg_fd_out = fd;
 203         set_nonblocking(msg_fd_out);
 204 }
 205
 206 /* Add a message to the pending MSG_* list. */
 207 static void msg_list_add(struct msg_list *lst, int code, const char *buf, int len)
 208 {
 209         struct msg_list_item *m;
 210         int sz = len + 4 + sizeof m[0] - 1;
 211
 212         if (!(m = (struct msg_list_item *)new_array(char, sz)))
 213                 out_of_memory("msg_list_add");
 214         m->next = NULL;
 215         m->len = len + 4;
 216         SIVAL(m->buf, 0, ((code+MPLEX_BASE)<<24) | len);
 217         memcpy(m->buf + 4, buf, len);
 218         if (lst->tail)
 219                 lst->tail->next = m;
 220         else
 221                 lst->head = m;
 222         lst->tail = m;
 223 }
 224
 225 /* Read a message from the MSG_* fd and handle it.  This is called either
 226  * during the early stages of being a local sender (up through the sending
 227  * of the file list) or when we're the generator (to fetch the messages
 228  * from the receiver). */
 229 static void read_msg_fd(void)
 230 {
 231         char buf[2048];
 232         size_t n;
 233         int fd = msg_fd_in;
 234         int tag, len;
 235
 236         /* Temporarily disable msg_fd_in.  This is needed to avoid looping back
 237          * to this routine from writefd_unbuffered(). */
 238         msg_fd_in = -1;
 239
 240         read_loop(fd, buf, 4);
 241         tag = IVAL(buf, 0);
 242
 243         len = tag & 0xFFFFFF;
 244         tag = (tag >> 24) - MPLEX_BASE;
 245
 246         switch (tag) {
 247         case MSG_DONE:
 248                 if (len != 0 || !am_generator) {
 249                         rprintf(FERROR, "invalid message %d:%d\n", tag, len);
 250                         exit_cleanup(RERR_STREAMIO);
 251                 }
 252                 flist_ndx_push(&redo_list, -1);
 253                 break;
 254         case MSG_REDO:
 255                 if (len != 4 || !am_generator) {
 256                         rprintf(FERROR, "invalid message %d:%d\n", tag, len);
 257                         exit_cleanup(RERR_STREAMIO);
 258                 }
 259                 read_loop(fd, buf, 4);
 260                 if (remove_source_files)
 261                         decrement_active_files(IVAL(buf,0));
 262                 flist_ndx_push(&redo_list, IVAL(buf,0));
 263                 break;
 264         case MSG_DELETED:
 265                 if (len >= (int)sizeof buf || !am_generator) {
 266                         rprintf(FERROR, "invalid message %d:%d\n", tag, len);
 267                         exit_cleanup(RERR_STREAMIO);
 268                 }
 269                 read_loop(fd, buf, len);
 270                 send_msg(MSG_DELETED, buf, len);
 271                 break;
 272         case MSG_SUCCESS:
 273                 if (len != 4 || !am_generator) {
 274                         rprintf(FERROR, "invalid message %d:%d\n", tag, len);
 275                         exit_cleanup(RERR_STREAMIO);
 276                 }
 277                 read_loop(fd, buf, len);
 278                 if (remove_source_files) {
 279                         decrement_active_files(IVAL(buf,0));
 280                         send_msg(MSG_SUCCESS, buf, len);
 281                 }
 282                 if (preserve_hard_links)
 283                         flist_ndx_push(&hlink_list, IVAL(buf,0));
 284                 break;
 285         case MSG_SOCKERR:
 286                 if (!am_generator) {
 287                         rprintf(FERROR, "invalid message %d:%d\n", tag, len);
 288                         exit_cleanup(RERR_STREAMIO);
 289                 }
 290                 close_multiplexing_out();
 291                 /* FALL THROUGH */
 292         case MSG_INFO:
 293         case MSG_ERROR:
 294         case MSG_LOG:
 295                 while (len) {
 296                         n = len;
 297                         if (n >= sizeof buf)
 298                                 n = sizeof buf - 1;
 299                         read_loop(fd, buf, n);
 300                         rwrite(tag, buf, n);
 301                         len -= n;
 302                 }
 303                 break;
 304         default:
 305                 rprintf(FERROR, "unknown message %d:%d [%s]\n",
 306                         tag, len, who_am_i());
 307                 exit_cleanup(RERR_STREAMIO);
 308         }
 309
 310         msg_fd_in = fd;
 311 }
 312
 313 /* This is used by the generator to limit how many file transfers can
 314  * be active at once when --remove-source-files is specified.  Without
 315  * this, sender-side deletions were mostly happening at the end. */
 316 void increment_active_files(int ndx, int itemizing, enum logcode code)
 317 {
 318         /* TODO: tune these limits? */
 319         while (active_filecnt >= (active_bytecnt >= 128*1024 ? 10 : 50)) {
 320                 if (hlink_list.head)
 321                         check_for_finished_hlinks(itemizing, code);
 322                 read_msg_fd();
 323         }
 324
 325         active_filecnt++;
 326         active_bytecnt += the_file_list->files[ndx]->length;
 327 }
 328
 329 void decrement_active_files(int ndx)
 330 {
 331         active_filecnt--;
 332         active_bytecnt -= the_file_list->files[ndx]->length;
 333 }
 334
 335 /* Try to push messages off the list onto the wire.  If we leave with more
 336  * to do, return 0.  On error, return -1.  If everything flushed, return 1.
 337  * This is only active in the receiver. */
 338 static int msg2genr_flush(int flush_it_all)
 339 {
 340         static int written = 0;
 341         struct timeval tv;
 342         fd_set fds;
 343
 344         if (msg_fd_out < 0)
 345                 return -1;
 346
 347         while (msg2genr.head) {
 348                 struct msg_list_item *m = msg2genr.head;
 349                 int n = write(msg_fd_out, m->buf + written, m->len - written);
 350                 if (n < 0) {
 351                         if (errno == EINTR)
 352                                 continue;
 353                         if (errno != EWOULDBLOCK && errno != EAGAIN)
 354                                 return -1;
 355                         if (!flush_it_all)
 356                                 return 0;
 357                         FD_ZERO(&fds);
 358                         FD_SET(msg_fd_out, &fds);
 359                         tv.tv_sec = select_timeout;
 360                         tv.tv_usec = 0;
 361                         if (!select(msg_fd_out+1, NULL, &fds, NULL, &tv))
 362                                 check_timeout();
 363                 } else if ((written += n) == m->len) {
 364                         msg2genr.head = m->next;
 365                         if (!msg2genr.head)
 366                                 msg2genr.tail = NULL;
 367                         free(m);
 368                         written = 0;
 369                 }
 370         }
 371         return 1;
 372 }
 373
 374 int send_msg(enum msgcode code, const char *buf, int len)
 375 {
 376         if (msg_fd_out < 0) {
 377                 if (!defer_forwarding_messages)
 378                         return io_multiplex_write(code, buf, len);
 379                 if (!io_multiplexing_out)
 380                         return 0;
 381                 msg_list_add(&msg2sndr, code, buf, len);
 382                 return 1;
 383         }
 384         msg_list_add(&msg2genr, code, buf, len);
 385         msg2genr_flush(NORMAL_FLUSH);
 386         return 1;
 387 }
 388
 389 int get_redo_num(int itemizing, enum logcode code)
 390 {
 391         while (1) {
 392                 if (hlink_list.head)
 393                         check_for_finished_hlinks(itemizing, code);
 394                 if (redo_list.head)
 395                         break;
 396                 read_msg_fd();
 397         }
 398
 399         return flist_ndx_pop(&redo_list);
 400 }
 401
 402 int get_hlink_num(void)
 403 {
 404         return flist_ndx_pop(&hlink_list);
 405 }
 406
 407 /**
 408  * When we're the receiver and we have a local --files-from list of names
 409  * that needs to be sent over the socket to the sender, we have to do two
 410  * things at the same time: send the sender a list of what files we're
 411  * processing and read the incoming file+info list from the sender.  We do
 412  * this by augmenting the read_timeout() function to copy this data.  It
 413  * uses the io_filesfrom_buf to read a block of data from f_in (when it is
 414  * ready, since it might be a pipe) and then blast it out f_out (when it
 415  * is ready to receive more data).
 416  */
 417 void io_set_filesfrom_fds(int f_in, int f_out)
 418 {
 419         io_filesfrom_f_in = f_in;
 420         io_filesfrom_f_out = f_out;
 421         io_filesfrom_bp = io_filesfrom_buf;
 422         io_filesfrom_lastchar = '\0';
 423         io_filesfrom_buflen = 0;
 424 }
 425
 426 /* It's almost always an error to get an EOF when we're trying to read from the
 427  * network, because the protocol is (for the most part) self-terminating.
 428  *
 429  * There is one case for the receiver when it is at the end of the transfer
 430  * (hanging around reading any keep-alive packets that might come its way): if
 431  * the sender dies before the generator's kill-signal comes through, we can end
 432  * up here needing to loop until the kill-signal arrives.  In this situation,
 433  * kluge_around_eof will be < 0.
 434  *
 435  * There is another case for older protocol versions (< 24) where the module
 436  * listing was not terminated, so we must ignore an EOF error in that case and
 437  * exit.  In this situation, kluge_around_eof will be > 0. */
 438 static void whine_about_eof(int fd)
 439 {
 440         if (kluge_around_eof && fd == sock_f_in) {
 441                 int i;
 442                 if (kluge_around_eof > 0)
 443                         exit_cleanup(0);
 444                 /* If we're still here after 10 seconds, exit with an error. */
 445                 for (i = 10*1000/20; i--; )
 446                         msleep(20);
 447         }
 448
 449         rprintf(FERROR, RSYNC_NAME ": connection unexpectedly closed "
 450                 "(%.0f bytes received so far) [%s]\n",
 451                 (double)stats.total_read, who_am_i());
 452
 453         exit_cleanup(RERR_STREAMIO);
 454 }
 455
 456 /**
 457  * Read from a socket with I/O timeout. return the number of bytes
 458  * read. If no bytes can be read then exit, never return a number <= 0.
 459  *
 460  * TODO: If the remote shell connection fails, then current versions
 461  * actually report an "unexpected EOF" error here.  Since it's a
 462  * fairly common mistake to try to use rsh when ssh is required, we
 463  * should trap that: if we fail to read any data at all, we should
 464  * give a better explanation.  We can tell whether the connection has
 465  * started by looking e.g. at whether the remote version is known yet.
 466  */
 467 static int read_timeout(int fd, char *buf, size_t len)
 468 {
 469         int n, cnt = 0;
 470
 471         io_flush(NORMAL_FLUSH);
 472
 473         while (cnt == 0) {
 474                 /* until we manage to read *something* */
 475                 fd_set r_fds, w_fds;
 476                 struct timeval tv;
 477                 int maxfd = fd;
 478                 int count;
 479
 480                 FD_ZERO(&r_fds);
 481                 FD_ZERO(&w_fds);
 482                 FD_SET(fd, &r_fds);
 483                 if (msg2genr.head) {
 484                         FD_SET(msg_fd_out, &w_fds);
 485                         if (msg_fd_out > maxfd)
 486                                 maxfd = msg_fd_out;
 487                 }
 488                 if (io_filesfrom_f_out >= 0) {
 489                         int new_fd;
 490                         if (io_filesfrom_buflen == 0) {
 491                                 if (io_filesfrom_f_in >= 0) {
 492                                         FD_SET(io_filesfrom_f_in, &r_fds);
 493                                         new_fd = io_filesfrom_f_in;
 494                                 } else {
 495                                         io_filesfrom_f_out = -1;
 496                                         new_fd = -1;
 497                                 }
 498                         } else {
 499                                 FD_SET(io_filesfrom_f_out, &w_fds);
 500                                 new_fd = io_filesfrom_f_out;
 501                         }
 502                         if (new_fd > maxfd)
 503                                 maxfd = new_fd;
 504                 }
 505
 506                 tv.tv_sec = select_timeout;
 507                 tv.tv_usec = 0;
 508
 509                 errno = 0;
 510
 511                 count = select(maxfd + 1, &r_fds, &w_fds, NULL, &tv);
 512
 513                 if (count <= 0) {
 514                         if (errno == EBADF)
 515                                 exit_cleanup(RERR_SOCKETIO);
 516                         check_timeout();
 517                         continue;
 518                 }
 519
 520                 if (msg2genr.head && FD_ISSET(msg_fd_out, &w_fds))
 521                         msg2genr_flush(NORMAL_FLUSH);
 522
 523                 if (io_filesfrom_f_out >= 0) {
 524                         if (io_filesfrom_buflen) {
 525                                 if (FD_ISSET(io_filesfrom_f_out, &w_fds)) {
 526                                         int l = write(io_filesfrom_f_out,
 527                                                       io_filesfrom_bp,
 528                                                       io_filesfrom_buflen);
 529                                         if (l > 0) {
 530                                                 if (!(io_filesfrom_buflen -= l))
 531                                                         io_filesfrom_bp = io_filesfrom_buf;
 532                                                 else
 533                                                         io_filesfrom_bp += l;
 534                                         } else {
 535                                                 /* XXX should we complain? */
 536                                                 io_filesfrom_f_out = -1;
 537                                         }
 538                                 }
 539                         } else if (io_filesfrom_f_in >= 0) {
 540                                 if (FD_ISSET(io_filesfrom_f_in, &r_fds)) {
 541                                         int l = read(io_filesfrom_f_in,
 542                                                      io_filesfrom_buf,
 543                                                      sizeof io_filesfrom_buf);
 544                                         if (l <= 0) {
 545                                                 /* Send end-of-file marker */
 546                                                 io_filesfrom_buf[0] = '\0';
 547                                                 io_filesfrom_buf[1] = '\0';
 548                                                 io_filesfrom_buflen = io_filesfrom_lastchar? 2 : 1;
 549                                                 io_filesfrom_f_in = -1;
 550                                         } else {
 551                                                 if (!eol_nulls) {
 552                                                         char *s = io_filesfrom_buf + l;
 553                                                         /* Transform CR and/or LF into '\0' */
 554                                                         while (s-- > io_filesfrom_buf) {
 555                                                                 if (*s == '\n' || *s == '\r')
 556                                                                         *s = '\0';
 557                                                         }
 558                                                 }
 559                                                 if (!io_filesfrom_lastchar) {
 560                                                         /* Last buf ended with a '\0', so don't
 561                                                          * let this buf start with one. */
 562                                                         while (l && !*io_filesfrom_bp)
 563                                                                 io_filesfrom_bp++, l--;
 564                                                 }
 565                                                 if (!l)
 566                                                         io_filesfrom_bp = io_filesfrom_buf;
 567                                                 else {
 568                                                         char *f = io_filesfrom_bp;
 569                                                         char *t = f;
 570                                                         char *eob = f + l;
 571                                                         /* Eliminate any multi-'\0' runs. */
 572                                                         while (f != eob) {
 573                                                                 if (!(*t++ = *f++)) {
 574                                                                         while (f != eob && !*f)
 575                                                                                 f++, l--;
 576                                                                 }
 577                                                         }
 578                                                         io_filesfrom_lastchar = f[-1];
 579                                                 }
 580                                                 io_filesfrom_buflen = l;
 581                                         }
 582                                 }
 583                         }
 584                 }
 585
 586                 if (!FD_ISSET(fd, &r_fds))
 587                         continue;
 588
 589                 n = read(fd, buf, len);
 590
 591                 if (n <= 0) {
 592                         if (n == 0)
 593                                 whine_about_eof(fd); /* Doesn't return. */
 594                         if (errno == EINTR || errno == EWOULDBLOCK
 595                             || errno == EAGAIN)
 596                                 continue;
 597
 598                         /* Don't write errors on a dead socket. */
 599                         if (fd == sock_f_in) {
 600                                 close_multiplexing_out();
 601                                 rsyserr(FSOCKERR, errno, "read error");
 602                         } else
 603                                 rsyserr(FERROR, errno, "read error");
 604                         exit_cleanup(RERR_STREAMIO);
 605                 }
 606
 607                 buf += n;
 608                 len -= n;
 609                 cnt += n;
 610
 611                 if (fd == sock_f_in && io_timeout)
 612                         last_io_in = time(NULL);
 613         }
 614
 615         return cnt;
 616 }
 617
 618 /**
 619  * Read a line into the "fname" buffer (which must be at least MAXPATHLEN
 620  * characters long).
 621  */
 622 int read_filesfrom_line(int fd, char *fname)
 623 {
 624         char ch, *s, *eob = fname + MAXPATHLEN - 1;
 625         int cnt;
 626         int reading_remotely = filesfrom_host != NULL;
 627         int nulls = eol_nulls || reading_remotely;
 628
 629   start:
 630         s = fname;
 631         while (1) {
 632                 cnt = read(fd, &ch, 1);
 633                 if (cnt < 0 && (errno == EWOULDBLOCK
 634                   || errno == EINTR || errno == EAGAIN)) {
 635                         struct timeval tv;
 636                         fd_set r_fds, e_fds;
 637                         FD_ZERO(&r_fds);
 638                         FD_SET(fd, &r_fds);
 639                         FD_ZERO(&e_fds);
 640                         FD_SET(fd, &e_fds);
 641                         tv.tv_sec = select_timeout;
 642                         tv.tv_usec = 0;
 643                         if (!select(fd+1, &r_fds, NULL, &e_fds, &tv))
 644                                 check_timeout();
 645                         if (FD_ISSET(fd, &e_fds)) {
 646                                 rsyserr(FINFO, errno,
 647                                         "select exception on fd %d", fd);
 648                         }
 649                         continue;
 650                 }
 651                 if (cnt != 1)
 652                         break;
 653                 if (nulls? !ch : (ch == '\r' || ch == '\n')) {
 654                         /* Skip empty lines if reading locally. */
 655                         if (!reading_remotely && s == fname)
 656                                 continue;
 657                         break;
 658                 }
 659                 if (s < eob)
 660                         *s++ = ch;
 661         }
 662         *s = '\0';
 663
 664         /* Dump comments. */
 665         if (*fname == '#' || *fname == ';')
 666                 goto start;
 667
 668         return s - fname;
 669 }
 670
 671 static char *iobuf_out;
 672 static int iobuf_out_cnt;
 673
 674 void io_start_buffering_out(void)
 675 {
 676         if (iobuf_out)
 677                 return;
 678         if (!(iobuf_out = new_array(char, IO_BUFFER_SIZE)))
 679                 out_of_memory("io_start_buffering_out");
 680         iobuf_out_cnt = 0;
 681 }
 682
 683 static char *iobuf_in;
 684 static size_t iobuf_in_siz;
 685
 686 void io_start_buffering_in(void)
 687 {
 688         if (iobuf_in)
 689                 return;
 690         iobuf_in_siz = 2 * IO_BUFFER_SIZE;
 691         if (!(iobuf_in = new_array(char, iobuf_in_siz)))
 692                 out_of_memory("io_start_buffering_in");
 693 }
 694
 695 void io_end_buffering(void)
 696 {
 697         io_flush(NORMAL_FLUSH);
 698         if (!io_multiplexing_out) {
 699                 free(iobuf_out);
 700                 iobuf_out = NULL;
 701         }
 702 }
 703
 704 void maybe_flush_socket(void)
 705 {
 706         if (iobuf_out && iobuf_out_cnt && time(NULL) - last_io_out >= 5)
 707                 io_flush(NORMAL_FLUSH);
 708 }
 709
 710 void maybe_send_keepalive(void)
 711 {
 712         if (time(NULL) - last_io_out >= allowed_lull) {
 713                 if (!iobuf_out || !iobuf_out_cnt) {
 714                         if (protocol_version < 29)
 715                                 return; /* there's nothing we can do */
 716                         write_int(sock_f_out, the_file_list->count);
 717                         write_shortint(sock_f_out, ITEM_IS_NEW);
 718                 }
 719                 if (iobuf_out)
 720                         io_flush(NORMAL_FLUSH);
 721         }
 722 }
 723
 724 /**
 725  * Continue trying to read len bytes - don't return until len has been
 726  * read.
 727  **/
 728 static void read_loop(int fd, char *buf, size_t len)
 729 {
 730         while (len) {
 731                 int n = read_timeout(fd, buf, len);
 732
 733                 buf += n;
 734                 len -= n;
 735         }
 736 }
 737
 738 /**
 739  * Read from the file descriptor handling multiplexing - return number
 740  * of bytes read.
 741  *
 742  * Never returns <= 0.
 743  */
 744 static int readfd_unbuffered(int fd, char *buf, size_t len)
 745 {
 746         static size_t remaining;
 747         static size_t iobuf_in_ndx;
 748         size_t msg_bytes;
 749         int tag, cnt = 0;
 750         char line[BIGPATHBUFLEN];
 751
 752         if (!iobuf_in || fd != sock_f_in)
 753                 return read_timeout(fd, buf, len);
 754
 755         if (!io_multiplexing_in && remaining == 0) {
 756                 remaining = read_timeout(fd, iobuf_in, iobuf_in_siz);
 757                 iobuf_in_ndx = 0;
 758         }
 759
 760         while (cnt == 0) {
 761                 if (remaining) {
 762                         len = MIN(len, remaining);
 763                         memcpy(buf, iobuf_in + iobuf_in_ndx, len);
 764                         iobuf_in_ndx += len;
 765                         remaining -= len;
 766                         cnt = len;
 767                         break;
 768                 }
 769
 770                 read_loop(fd, line, 4);
 771                 tag = IVAL(line, 0);
 772
 773                 msg_bytes = tag & 0xFFFFFF;
 774                 tag = (tag >> 24) - MPLEX_BASE;
 775
 776                 switch (tag) {
 777                 case MSG_DATA:
 778                         if (msg_bytes > iobuf_in_siz) {
 779                                 if (!(iobuf_in = realloc_array(iobuf_in, char,
 780                                                                msg_bytes)))
 781                                         out_of_memory("readfd_unbuffered");
 782                                 iobuf_in_siz = msg_bytes;
 783                         }
 784                         read_loop(fd, iobuf_in, msg_bytes);
 785                         remaining = msg_bytes;
 786                         iobuf_in_ndx = 0;
 787                         break;
 788                 case MSG_DELETED:
 789                         if (msg_bytes >= sizeof line)
 790                                 goto overflow;
 791                         read_loop(fd, line, msg_bytes);
 792                         /* A directory name was sent with the trailing null */
 793                         if (msg_bytes > 0 && !line[msg_bytes-1])
 794                                 log_delete(line, S_IFDIR);
 795                         else {
 796                                 line[msg_bytes] = '\0';
 797                                 log_delete(line, S_IFREG);
 798                         }
 799                         break;
 800                 case MSG_SUCCESS:
 801                         if (msg_bytes != 4) {
 802                                 rprintf(FERROR, "invalid multi-message %d:%ld [%s]\n",
 803                                         tag, (long)msg_bytes, who_am_i());
 804                                 exit_cleanup(RERR_STREAMIO);
 805                         }
 806                         read_loop(fd, line, msg_bytes);
 807                         successful_send(IVAL(line, 0));
 808                         break;
 809                 case MSG_INFO:
 810                 case MSG_ERROR:
 811                         if (msg_bytes >= sizeof line) {
 812                             overflow:
 813                                 rprintf(FERROR,
 814                                         "multiplexing overflow %d:%ld [%s]\n",
 815                                         tag, (long)msg_bytes, who_am_i());
 816                                 exit_cleanup(RERR_STREAMIO);
 817                         }
 818                         read_loop(fd, line, msg_bytes);
 819                         rwrite((enum logcode)tag, line, msg_bytes);
 820                         break;
 821                 default:
 822                         rprintf(FERROR, "unexpected tag %d [%s]\n",
 823                                 tag, who_am_i());
 824                         exit_cleanup(RERR_STREAMIO);
 825                 }
 826         }
 827
 828         if (remaining == 0)
 829                 io_flush(NORMAL_FLUSH);
 830
 831         return cnt;
 832 }
 833
 834 /**
 835  * Do a buffered read from @p fd.  Don't return until all @p n bytes
 836  * have been read.  If all @p n can't be read then exit with an
 837  * error.
 838  **/
 839 static void readfd(int fd, char *buffer, size_t N)
 840 {
 841         int  cnt;
 842         size_t total = 0;
 843
 844         while (total < N) {
 845                 cnt = readfd_unbuffered(fd, buffer + total, N-total);
 846                 total += cnt;
 847         }
 848
 849         if (fd == write_batch_monitor_in) {
 850                 if ((size_t)write(batch_fd, buffer, total) != total)
 851                         exit_cleanup(RERR_FILEIO);
 852         }
 853
 854         if (fd == sock_f_in)
 855                 stats.total_read += total;
 856 }
 857
 858 int read_shortint(int f)
 859 {
 860         uchar b[2];
 861         readfd(f, (char *)b, 2);
 862         return (b[1] << 8) + b[0];
 863 }
 864
 865 int32 read_int(int f)
 866 {
 867         char b[4];
 868         int32 num;
 869
 870         readfd(f,b,4);
 871         num = IVAL(b,0);
 872         if (num == (int32)0xffffffff)
 873                 return -1;
 874         return num;
 875 }
 876
 877 int64 read_longint(int f)
 878 {
 879         int64 num;
 880         char b[8];
 881         num = read_int(f);
 882
 883         if ((int32)num != (int32)0xffffffff)
 884                 return num;
 885
 886 #if SIZEOF_INT64 < 8
 887         rprintf(FERROR, "Integer overflow: attempted 64-bit offset\n");
 888         exit_cleanup(RERR_UNSUPPORTED);
 889 #else
 890         readfd(f,b,8);
 891         num = IVAL(b,0) | (((int64)IVAL(b,4))<<32);
 892 #endif
 893
 894         return num;
 895 }
 896
 897 void read_buf(int f, char *buf, size_t len)
 898 {
 899         readfd(f,buf,len);
 900 }
 901
 902 void read_sbuf(int f, char *buf, size_t len)
 903 {
 904         readfd(f, buf, len);
 905         buf[len] = '\0';
 906 }
 907
 908 uchar read_byte(int f)
 909 {
 910         uchar c;
 911         readfd(f, (char *)&c, 1);
 912         return c;
 913 }
 914
 915 int read_vstring(int f, char *buf, int bufsize)
 916 {
 917         int len = read_byte(f);
 918
 919         if (len & 0x80)
 920                 len = (len & ~0x80) * 0x100 + read_byte(f);
 921
 922         if (len >= bufsize) {
 923                 rprintf(FERROR, "over-long vstring received (%d > %d)\n",
 924                         len, bufsize - 1);
 925                 return -1;
 926         }
 927
 928         if (len)
 929                 readfd(f, buf, len);
 930         buf[len] = '\0';
 931         return len;
 932 }
 933
 934 /* Populate a sum_struct with values from the socket.  This is
 935  * called by both the sender and the receiver. */
 936 void read_sum_head(int f, struct sum_struct *sum)
 937 {
 938         sum->count = read_int(f);
 939         if (sum->count < 0) {
 940                 rprintf(FERROR, "Invalid checksum count %ld [%s]\n",
 941                         (long)sum->count, who_am_i());
 942                 exit_cleanup(RERR_PROTOCOL);
 943         }
 944         sum->blength = read_int(f);
 945         if (sum->blength < 0 || sum->blength > MAX_BLOCK_SIZE) {
 946                 rprintf(FERROR, "Invalid block length %ld [%s]\n",
 947                         (long)sum->blength, who_am_i());
 948                 exit_cleanup(RERR_PROTOCOL);
 949         }
 950         sum->s2length = protocol_version < 27 ? csum_length : (int)read_int(f);
 951         if (sum->s2length < 0 || sum->s2length > MD4_SUM_LENGTH) {
 952                 rprintf(FERROR, "Invalid checksum length %d [%s]\n",
 953                         sum->s2length, who_am_i());
 954                 exit_cleanup(RERR_PROTOCOL);
 955         }
 956         sum->remainder = read_int(f);
 957         if (sum->remainder < 0 || sum->remainder > sum->blength) {
 958                 rprintf(FERROR, "Invalid remainder length %ld [%s]\n",
 959                         (long)sum->remainder, who_am_i());
 960                 exit_cleanup(RERR_PROTOCOL);
 961         }
 962 }
 963
 964 /* Send the values from a sum_struct over the socket.  Set sum to
 965  * NULL if there are no checksums to send.  This is called by both
 966  * the generator and the sender. */
 967 void write_sum_head(int f, struct sum_struct *sum)
 968 {
 969         static struct sum_struct null_sum;
 970
 971         if (sum == NULL)
 972                 sum = &null_sum;
 973
 974         write_int(f, sum->count);
 975         write_int(f, sum->blength);
 976         if (protocol_version >= 27)
 977                 write_int(f, sum->s2length);
 978         write_int(f, sum->remainder);
 979 }
 980
 981 /**
 982  * Sleep after writing to limit I/O bandwidth usage.
 983  *
 984  * @todo Rather than sleeping after each write, it might be better to
 985  * use some kind of averaging.  The current algorithm seems to always
 986  * use a bit less bandwidth than specified, because it doesn't make up
 987  * for slow periods.  But arguably this is a feature.  In addition, we
 988  * ought to take the time used to write the data into account.
 989  *
 990  * During some phases of big transfers (file FOO is uptodate) this is
 991  * called with a small bytes_written every time.  As the kernel has to
 992  * round small waits up to guarantee that we actually wait at least the
 993  * requested number of microseconds, this can become grossly inaccurate.
 994  * We therefore keep track of the bytes we've written over time and only
 995  * sleep when the accumulated delay is at least 1 tenth of a second.
 996  **/
 997 static void sleep_for_bwlimit(int bytes_written)
 998 {
 999         static struct timeval prior_tv;
1000         static long total_written = 0;
1001         struct timeval tv, start_tv;
1002         long elapsed_usec, sleep_usec;
1003
1004 #define ONE_SEC 1000000L /* # of microseconds in a second */
1005
1006         if (!bwlimit_writemax)
1007                 return;
1008
1009         total_written += bytes_written;
1010
1011         gettimeofday(&start_tv, NULL);
1012         if (prior_tv.tv_sec) {
1013                 elapsed_usec = (start_tv.tv_sec - prior_tv.tv_sec) * ONE_SEC
1014                              + (start_tv.tv_usec - prior_tv.tv_usec);
1015                 total_written -= elapsed_usec * bwlimit / (ONE_SEC/1024);
1016                 if (total_written < 0)
1017                         total_written = 0;
1018         }
1019
1020         sleep_usec = total_written * (ONE_SEC/1024) / bwlimit;
1021         if (sleep_usec < ONE_SEC / 10) {
1022                 prior_tv = start_tv;
1023                 return;
1024         }
1025
1026         tv.tv_sec  = sleep_usec / ONE_SEC;
1027         tv.tv_usec = sleep_usec % ONE_SEC;
1028         select(0, NULL, NULL, NULL, &tv);
1029
1030         gettimeofday(&prior_tv, NULL);
1031         elapsed_usec = (prior_tv.tv_sec - start_tv.tv_sec) * ONE_SEC
1032                      + (prior_tv.tv_usec - start_tv.tv_usec);
1033         total_written = (sleep_usec - elapsed_usec) * bwlimit / (ONE_SEC/1024);
1034 }
1035
1036 /* Write len bytes to the file descriptor fd, looping as necessary to get
1037  * the job done and also (in certain circumstances) reading any data on
1038  * msg_fd_in to avoid deadlock.
1039  *
1040  * This function underlies the multiplexing system.  The body of the
1041  * application never calls this function directly. */
1042 static void writefd_unbuffered(int fd, const char *buf, size_t len)
1043 {
1044         size_t n, total = 0;
1045         fd_set w_fds, r_fds, e_fds;
1046         int maxfd, count, cnt, using_r_fds;
1047         int defer_save = defer_forwarding_messages;
1048         struct timeval tv;
1049
1050         no_flush++;
1051
1052         while (total < len) {
1053                 FD_ZERO(&w_fds);
1054                 FD_SET(fd, &w_fds);
1055                 FD_ZERO(&e_fds);
1056                 FD_SET(fd, &e_fds);
1057                 maxfd = fd;
1058
1059                 if (msg_fd_in >= 0) {
1060                         FD_ZERO(&r_fds);
1061                         FD_SET(msg_fd_in, &r_fds);
1062                         if (msg_fd_in > maxfd)
1063                                 maxfd = msg_fd_in;
1064                         using_r_fds = 1;
1065                 } else
1066                         using_r_fds = 0;
1067
1068                 tv.tv_sec = select_timeout;
1069                 tv.tv_usec = 0;
1070
1071                 errno = 0;
1072                 count = select(maxfd + 1, using_r_fds ? &r_fds : NULL,
1073                                &w_fds, &e_fds, &tv);
1074
1075                 if (count <= 0) {
1076                         if (count < 0 && errno == EBADF)
1077                                 exit_cleanup(RERR_SOCKETIO);
1078                         check_timeout();
1079                         continue;
1080                 }
1081
1082                 if (FD_ISSET(fd, &e_fds)) {
1083                         rsyserr(FINFO, errno,
1084                                 "select exception on fd %d", fd);
1085                 }
1086
1087                 if (using_r_fds && FD_ISSET(msg_fd_in, &r_fds))
1088                         read_msg_fd();
1089
1090                 if (!FD_ISSET(fd, &w_fds))
1091                         continue;
1092
1093                 n = len - total;
1094                 if (bwlimit_writemax && n > bwlimit_writemax)
1095                         n = bwlimit_writemax;
1096                 cnt = write(fd, buf + total, n);
1097
1098                 if (cnt <= 0) {
1099                         if (cnt < 0) {
1100                                 if (errno == EINTR)
1101                                         continue;
1102                                 if (errno == EWOULDBLOCK || errno == EAGAIN) {
1103                                         msleep(1);
1104                                         continue;
1105                                 }
1106                         }
1107
1108                         /* Don't try to write errors back across the stream. */
1109                         if (fd == sock_f_out)
1110                                 close_multiplexing_out();
1111                         rsyserr(FERROR, errno,
1112                                 "writefd_unbuffered failed to write %ld bytes [%s]",
1113                                 (long)len, who_am_i());
1114                         /* If the other side is sending us error messages, try
1115                          * to grab any messages they sent before they died. */
1116                         while (fd == sock_f_out && io_multiplexing_in) {
1117                                 set_io_timeout(30);
1118                                 ignore_timeout = 0;
1119                                 readfd_unbuffered(sock_f_in, io_filesfrom_buf,
1120                                                   sizeof io_filesfrom_buf);
1121                         }
1122                         exit_cleanup(RERR_STREAMIO);
1123                 }
1124
1125                 total += cnt;
1126                 defer_forwarding_messages = 1;
1127
1128                 if (fd == sock_f_out) {
1129                         if (io_timeout || am_generator)
1130                                 last_io_out = time(NULL);
1131                         sleep_for_bwlimit(cnt);
1132                 }
1133         }
1134
1135         defer_forwarding_messages = defer_save;
1136         no_flush--;
1137 }
1138
1139 static void msg2sndr_flush(void)
1140 {
1141         if (defer_forwarding_messages)
1142                 return;
1143
1144         while (msg2sndr.head && io_multiplexing_out) {
1145                 struct msg_list_item *m = msg2sndr.head;
1146                 if (!(msg2sndr.head = m->next))
1147                         msg2sndr.tail = NULL;
1148                 stats.total_written += m->len;
1149                 defer_forwarding_messages = 1;
1150                 writefd_unbuffered(sock_f_out, m->buf, m->len);
1151                 defer_forwarding_messages = 0;
1152                 free(m);
1153         }
1154 }
1155
1156 /**
1157  * Write an message to a multiplexed stream. If this fails then rsync
1158  * exits.
1159  **/
1160 static void mplex_write(enum msgcode code, const char *buf, size_t len)
1161 {
1162         char buffer[1024];
1163         size_t n = len;
1164
1165         SIVAL(buffer, 0, ((MPLEX_BASE + (int)code)<<24) + len);
1166
1167         if (n > sizeof buffer - 4)
1168                 n = 0;
1169         else
1170                 memcpy(buffer + 4, buf, n);
1171
1172         writefd_unbuffered(sock_f_out, buffer, n+4);
1173
1174         len -= n;
1175         buf += n;
1176
1177         if (len) {
1178                 defer_forwarding_messages = 1;
1179                 writefd_unbuffered(sock_f_out, buf, len);
1180                 defer_forwarding_messages = 0;
1181                 msg2sndr_flush();
1182         }
1183 }
1184
1185 void io_flush(int flush_it_all)
1186 {
1187         msg2genr_flush(flush_it_all);
1188         msg2sndr_flush();
1189
1190         if (!iobuf_out_cnt || no_flush)
1191                 return;
1192
1193         if (io_multiplexing_out)
1194                 mplex_write(MSG_DATA, iobuf_out, iobuf_out_cnt);
1195         else
1196                 writefd_unbuffered(sock_f_out, iobuf_out, iobuf_out_cnt);
1197         iobuf_out_cnt = 0;
1198 }
1199
1200 static void writefd(int fd, const char *buf, size_t len)
1201 {
1202         if (fd == msg_fd_out) {
1203                 rprintf(FERROR, "Internal error: wrong write used in receiver.\n");
1204                 exit_cleanup(RERR_PROTOCOL);
1205         }
1206
1207         if (fd == sock_f_out)
1208                 stats.total_written += len;
1209
1210         if (fd == write_batch_monitor_out) {
1211                 if ((size_t)write(batch_fd, buf, len) != len)
1212                         exit_cleanup(RERR_FILEIO);
1213         }
1214
1215         if (!iobuf_out || fd != sock_f_out) {
1216                 writefd_unbuffered(fd, buf, len);
1217                 return;
1218         }
1219
1220         while (len) {
1221                 int n = MIN((int)len, IO_BUFFER_SIZE - iobuf_out_cnt);
1222                 if (n > 0) {
1223                         memcpy(iobuf_out+iobuf_out_cnt, buf, n);
1224                         buf += n;
1225                         len -= n;
1226                         iobuf_out_cnt += n;
1227                 }
1228
1229                 if (iobuf_out_cnt == IO_BUFFER_SIZE)
1230                         io_flush(NORMAL_FLUSH);
1231         }
1232 }
1233
1234 void write_shortint(int f, int x)
1235 {
1236         uchar b[2];
1237         b[0] = x;
1238         b[1] = x >> 8;
1239         writefd(f, (char *)b, 2);
1240 }
1241
1242 void write_int(int f,int32 x)
1243 {
1244         char b[4];
1245         SIVAL(b,0,x);
1246         writefd(f,b,4);
1247 }
1248
1249 /*
1250  * Note: int64 may actually be a 32-bit type if ./configure couldn't find any
1251  * 64-bit types on this platform.
1252  */
1253 void write_longint(int f, int64 x)
1254 {
1255         char b[8];
1256
1257         if (x <= 0x7FFFFFFF) {
1258                 write_int(f, (int)x);
1259                 return;
1260         }
1261
1262 #if SIZEOF_INT64 < 8
1263         rprintf(FERROR, "Integer overflow: attempted 64-bit offset\n");
1264         exit_cleanup(RERR_UNSUPPORTED);
1265 #else
1266         write_int(f, (int32)0xFFFFFFFF);
1267         SIVAL(b,0,(x&0xFFFFFFFF));
1268         SIVAL(b,4,((x>>32)&0xFFFFFFFF));
1269
1270         writefd(f,b,8);
1271 #endif
1272 }
1273
1274 void write_buf(int f, const char *buf, size_t len)
1275 {
1276         writefd(f,buf,len);
1277 }
1278
1279 /** Write a string to the connection */
1280 void write_sbuf(int f, const char *buf)
1281 {
1282         writefd(f, buf, strlen(buf));
1283 }
1284
1285 void write_byte(int f, uchar c)
1286 {
1287         writefd(f, (char *)&c, 1);
1288 }
1289
1290 void write_vstring(int f, const char *str, int len)
1291 {
1292         uchar lenbuf[3], *lb = lenbuf;
1293
1294         if (len > 0x7F) {
1295                 if (len > 0x7FFF) {
1296                         rprintf(FERROR,
1297                                 "attempting to send over-long vstring (%d > %d)\n",
1298                                 len, 0x7FFF);
1299                         exit_cleanup(RERR_PROTOCOL);
1300                 }
1301                 *lb++ = len / 0x100 + 0x80;
1302         }
1303         *lb = len;
1304
1305         writefd(f, (char*)lenbuf, lb - lenbuf + 1);
1306         if (len)
1307                 writefd(f, str, len);
1308 }
1309
1310 /**
1311  * Read a line of up to @p maxlen characters into @p buf (not counting
1312  * the trailing null).  Strips the (required) trailing newline and all
1313  * carriage returns.
1314  *
1315  * @return 1 for success; 0 for I/O error or truncation.
1316  **/
1317 int read_line(int f, char *buf, size_t maxlen)
1318 {
1319         while (maxlen) {
1320                 buf[0] = 0;
1321                 read_buf(f, buf, 1);
1322                 if (buf[0] == 0)
1323                         return 0;
1324                 if (buf[0] == '\n')
1325                         break;
1326                 if (buf[0] != '\r') {
1327                         buf++;
1328                         maxlen--;
1329                 }
1330         }
1331         *buf = '\0';
1332         return maxlen > 0;
1333 }
1334
1335 void io_printf(int fd, const char *format, ...)
1336 {
1337         va_list ap;
1338         char buf[BIGPATHBUFLEN];
1339         int len;
1340
1341         va_start(ap, format);
1342         len = vsnprintf(buf, sizeof buf, format, ap);
1343         va_end(ap);
1344
1345         if (len < 0)
1346                 exit_cleanup(RERR_STREAMIO);
1347
1348         if (len > (int)sizeof buf) {
1349                 rprintf(FERROR, "io_printf() was too long for the buffer.\n");
1350                 exit_cleanup(RERR_STREAMIO);
1351         }
1352
1353         write_sbuf(fd, buf);
1354 }
1355
1356 /** Setup for multiplexing a MSG_* stream with the data stream. */
1357 void io_start_multiplex_out(void)
1358 {
1359         io_flush(NORMAL_FLUSH);
1360         io_start_buffering_out();
1361         io_multiplexing_out = 1;
1362 }
1363
1364 /** Setup for multiplexing a MSG_* stream with the data stream. */
1365 void io_start_multiplex_in(void)
1366 {
1367         io_flush(NORMAL_FLUSH);
1368         io_start_buffering_in();
1369         io_multiplexing_in = 1;
1370 }
1371
1372 /** Write an message to the multiplexed data stream. */
1373 int io_multiplex_write(enum msgcode code, const char *buf, size_t len)
1374 {
1375         if (!io_multiplexing_out)
1376                 return 0;
1377
1378         io_flush(NORMAL_FLUSH);
1379         stats.total_written += (len+4);
1380         mplex_write(code, buf, len);
1381         return 1;
1382 }
1383
1384 void close_multiplexing_in(void)
1385 {
1386         io_multiplexing_in = 0;
1387 }
1388
1389 /** Stop output multiplexing. */
1390 void close_multiplexing_out(void)
1391 {
1392         io_multiplexing_out = 0;
1393 }
1394
1395 void start_write_batch(int fd)
1396 {
1397         write_stream_flags(batch_fd);
1398
1399         /* Some communication has already taken place, but we don't
1400          * enable batch writing until here so that we can write a
1401          * canonical record of the communication even though the
1402          * actual communication so far depends on whether a daemon
1403          * is involved. */
1404         write_int(batch_fd, protocol_version);
1405         write_int(batch_fd, checksum_seed);
1406
1407         if (am_sender)
1408                 write_batch_monitor_out = fd;
1409         else
1410                 write_batch_monitor_in = fd;
1411 }
1412
1413 void stop_write_batch(void)
1414 {
1415         write_batch_monitor_out = -1;
1416         write_batch_monitor_in = -1;
1417 }