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) 2003-2009 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 3 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, visit the http://fsf.org website.
  21  */
  22
  23 /* Rsync provides its own multiplexing system, which is used to send
  24  * stderr and stdout over a single socket.
  25  *
  26  * For historical reasons this is off during the start of the
  27  * connection, but it's switched on quite early using
  28  * io_start_multiplex_out() and io_start_multiplex_in(). */
  29
  30 #include "rsync.h"
  31 #include "ifuncs.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 inc_recurse;
  45 extern int io_error;
  46 extern int eol_nulls;
  47 extern int flist_eof;
  48 extern int list_only;
  49 extern int read_batch;
  50 extern int csum_length;
  51 extern int protect_args;
  52 extern int checksum_seed;
  53 extern int protocol_version;
  54 extern int remove_source_files;
  55 extern int preserve_hard_links;
  56 extern struct stats stats;
  57 extern struct file_list *cur_flist;
  58 #ifdef ICONV_OPTION
  59 extern int filesfrom_convert;
  60 extern iconv_t ic_send, ic_recv;
  61 #endif
  62
  63 const char phase_unknown[] = "unknown";
  64 int ignore_timeout = 0;
  65 int batch_fd = -1;
  66 int msgdone_cnt = 0;
  67
  68 /* Ignore an EOF error if non-zero. See whine_about_eof(). */
  69 int kluge_around_eof = 0;
  70
  71 int msg_fd_in = -1;
  72 int msg_fd_out = -1;
  73 int sock_f_in = -1;
  74 int sock_f_out = -1;
  75
  76 static int iobuf_f_in = -1;
  77 static char *iobuf_in;
  78 static size_t iobuf_in_siz;
  79 static size_t iobuf_in_ndx;
  80 static size_t iobuf_in_remaining;
  81
  82 static int iobuf_f_out = -1;
  83 static char *iobuf_out;
  84 static int iobuf_out_cnt;
  85
  86 int flist_forward_from = -1;
  87
  88 static int io_multiplexing_out;
  89 static int io_multiplexing_in;
  90 static time_t last_io_in;
  91 static time_t last_io_out;
  92 static int no_flush;
  93
  94 static int write_batch_monitor_in = -1;
  95 static int write_batch_monitor_out = -1;
  96
  97 static int io_filesfrom_f_in = -1;
  98 static int io_filesfrom_f_out = -1;
  99 static xbuf ff_buf = EMPTY_XBUF;
 100 static char ff_lastchar;
 101 #ifdef ICONV_OPTION
 102 static xbuf iconv_buf = EMPTY_XBUF;
 103 #endif
 104 static int defer_forwarding_messages = 0, keep_defer_forwarding = 0;
 105 static int select_timeout = SELECT_TIMEOUT;
 106 static int active_filecnt = 0;
 107 static OFF_T active_bytecnt = 0;
 108 static int first_message = 1;
 109
 110 static char int_byte_extra[64] = {
 111         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* (00 - 3F)/4 */
 112         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* (40 - 7F)/4 */
 113         1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* (80 - BF)/4 */
 114         2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 5, 6, /* (C0 - FF)/4 */
 115 };
 116
 117 #define REMOTE_OPTION_ERROR "rsync: on remote machine: -"
 118 #define REMOTE_OPTION_ERROR2 ": unknown option"
 119
 120 enum festatus { FES_SUCCESS, FES_REDO, FES_NO_SEND };
 121
 122 static void readfd(int fd, char *buffer, size_t N);
 123 static void writefd(int fd, const char *buf, size_t len);
 124 static void writefd_unbuffered(int fd, const char *buf, size_t len);
 125 static void mplex_write(int fd, enum msgcode code, const char *buf, size_t len, int convert);
 126
 127 static flist_ndx_list redo_list, hlink_list;
 128
 129 struct msg_list_item {
 130         struct msg_list_item *next;
 131         char convert;
 132         char buf[1];
 133 };
 134
 135 struct msg_list {
 136         struct msg_list_item *head, *tail;
 137 };
 138
 139 static struct msg_list msg_queue;
 140
 141 static void got_flist_entry_status(enum festatus status, const char *buf)
 142 {
 143         int ndx = IVAL(buf, 0);
 144         struct file_list *flist = flist_for_ndx(ndx, "got_flist_entry_status");
 145
 146         if (remove_source_files) {
 147                 active_filecnt--;
 148                 active_bytecnt -= F_LENGTH(flist->files[ndx - flist->ndx_start]);
 149         }
 150
 151         if (inc_recurse)
 152                 flist->in_progress--;
 153
 154         switch (status) {
 155         case FES_SUCCESS:
 156                 if (remove_source_files)
 157                         send_msg(MSG_SUCCESS, buf, 4, 0);
 158                 if (preserve_hard_links) {
 159                         struct file_struct *file = flist->files[ndx - flist->ndx_start];
 160                         if (F_IS_HLINKED(file)) {
 161                                 flist_ndx_push(&hlink_list, ndx);
 162                                 flist->in_progress++;
 163                         }
 164                 }
 165                 break;
 166         case FES_REDO:
 167                 if (read_batch) {
 168                         if (inc_recurse)
 169                                 flist->in_progress++;
 170                         break;
 171                 }
 172                 if (inc_recurse)
 173                         flist->to_redo++;
 174                 flist_ndx_push(&redo_list, ndx);
 175                 break;
 176         case FES_NO_SEND:
 177                 break;
 178         }
 179 }
 180
 181 static void check_timeout(void)
 182 {
 183         time_t t;
 184
 185         if (!io_timeout || ignore_timeout)
 186                 return;
 187
 188         if (!last_io_in) {
 189                 last_io_in = time(NULL);
 190                 return;
 191         }
 192
 193         t = time(NULL);
 194
 195         if (t - last_io_in >= io_timeout) {
 196                 if (!am_server && !am_daemon) {
 197                         rprintf(FERROR, "io timeout after %d seconds -- exiting\n",
 198                                 (int)(t-last_io_in));
 199                 }
 200                 exit_cleanup(RERR_TIMEOUT);
 201         }
 202 }
 203
 204 /* Note the fds used for the main socket (which might really be a pipe
 205  * for a local transfer, but we can ignore that). */
 206 void io_set_sock_fds(int f_in, int f_out)
 207 {
 208         sock_f_in = f_in;
 209         sock_f_out = f_out;
 210 }
 211
 212 void set_io_timeout(int secs)
 213 {
 214         io_timeout = secs;
 215
 216         if (!io_timeout || io_timeout > SELECT_TIMEOUT)
 217                 select_timeout = SELECT_TIMEOUT;
 218         else
 219                 select_timeout = io_timeout;
 220
 221         allowed_lull = read_batch ? 0 : (io_timeout + 1) / 2;
 222 }
 223
 224 /* Setup the fd used to receive MSG_* messages.  Only needed during the
 225  * early stages of being a local sender (up through the sending of the
 226  * file list) or when we're the generator (to fetch the messages from
 227  * the receiver). */
 228 void set_msg_fd_in(int fd)
 229 {
 230         msg_fd_in = fd;
 231 }
 232
 233 /* Setup the fd used to send our MSG_* messages.  Only needed when
 234  * we're the receiver (to send our messages to the generator). */
 235 void set_msg_fd_out(int fd)
 236 {
 237         msg_fd_out = fd;
 238         set_nonblocking(msg_fd_out);
 239 }
 240
 241 /* Add a message to the pending MSG_* list. */
 242 static void msg_list_add(struct msg_list *lst, int code, const char *buf, int len, int convert)
 243 {
 244         struct msg_list_item *m;
 245         int sz = len + 4 + sizeof m[0] - 1;
 246
 247         if (!(m = (struct msg_list_item *)new_array(char, sz)))
 248                 out_of_memory("msg_list_add");
 249         m->next = NULL;
 250         m->convert = convert;
 251         SIVAL(m->buf, 0, ((code+MPLEX_BASE)<<24) | len);
 252         memcpy(m->buf + 4, buf, len);
 253         if (lst->tail)
 254                 lst->tail->next = m;
 255         else
 256                 lst->head = m;
 257         lst->tail = m;
 258 }
 259
 260 static inline int flush_a_msg(int fd)
 261 {
 262         struct msg_list_item *m = msg_queue.head;
 263         int len = IVAL(m->buf, 0) & 0xFFFFFF;
 264         int tag = *((uchar*)m->buf+3) - MPLEX_BASE;
 265
 266         if (!(msg_queue.head = m->next))
 267                 msg_queue.tail = NULL;
 268
 269         defer_forwarding_messages++;
 270         mplex_write(fd, tag, m->buf + 4, len, m->convert);
 271         defer_forwarding_messages--;
 272
 273         free(m);
 274
 275         return len;
 276 }
 277
 278 static void msg_flush(void)
 279 {
 280         if (am_generator) {
 281                 while (msg_queue.head && io_multiplexing_out)
 282                         stats.total_written += flush_a_msg(sock_f_out) + 4;
 283         } else {
 284                 while (msg_queue.head)
 285                         (void)flush_a_msg(msg_fd_out);
 286         }
 287 }
 288
 289 static void check_for_d_option_error(const char *msg)
 290 {
 291         static char rsync263_opts[] = "BCDHIKLPRSTWabceghlnopqrtuvxz";
 292         char *colon;
 293         int saw_d = 0;
 294
 295         if (*msg != 'r'
 296          || strncmp(msg, REMOTE_OPTION_ERROR, sizeof REMOTE_OPTION_ERROR - 1) != 0)
 297                 return;
 298
 299         msg += sizeof REMOTE_OPTION_ERROR - 1;
 300         if (*msg == '-' || (colon = strchr(msg, ':')) == NULL
 301          || strncmp(colon, REMOTE_OPTION_ERROR2, sizeof REMOTE_OPTION_ERROR2 - 1) != 0)
 302                 return;
 303
 304         for ( ; *msg != ':'; msg++) {
 305                 if (*msg == 'd')
 306                         saw_d = 1;
 307                 else if (*msg == 'e')
 308                         break;
 309                 else if (strchr(rsync263_opts, *msg) == NULL)
 310                         return;
 311         }
 312
 313         if (saw_d) {
 314                 rprintf(FWARNING,
 315                     "*** Try using \"--old-d\" if remote rsync is <= 2.6.3 ***\n");
 316         }
 317 }
 318
 319 /* Read a message from the MSG_* fd and handle it.  This is called either
 320  * during the early stages of being a local sender (up through the sending
 321  * of the file list) or when we're the generator (to fetch the messages
 322  * from the receiver). */
 323 static void read_msg_fd(void)
 324 {
 325         char buf[2048];
 326         size_t n;
 327         struct file_list *flist;
 328         int fd = msg_fd_in;
 329         int tag, len;
 330
 331         /* Temporarily disable msg_fd_in.  This is needed to avoid looping back
 332          * to this routine from writefd_unbuffered(). */
 333         no_flush++;
 334         msg_fd_in = -1;
 335         defer_forwarding_messages++;
 336
 337         readfd(fd, buf, 4);
 338         tag = IVAL(buf, 0);
 339
 340         len = tag & 0xFFFFFF;
 341         tag = (tag >> 24) - MPLEX_BASE;
 342
 343         switch (tag) {
 344         case MSG_DONE:
 345                 if (len < 0 || len > 1 || !am_generator) {
 346                   invalid_msg:
 347                         rprintf(FERROR, "invalid message %d:%d [%s%s]\n",
 348                                 tag, len, who_am_i(),
 349                                 inc_recurse ? "/inc" : "");
 350                         exit_cleanup(RERR_STREAMIO);
 351                 }
 352                 if (len) {
 353                         readfd(fd, buf, len);
 354                         stats.total_read = read_varlong(fd, 3);
 355                 }
 356                 msgdone_cnt++;
 357                 break;
 358         case MSG_REDO:
 359                 if (len != 4 || !am_generator)
 360                         goto invalid_msg;
 361                 readfd(fd, buf, 4);
 362                 got_flist_entry_status(FES_REDO, buf);
 363                 break;
 364         case MSG_FLIST:
 365                 if (len != 4 || !am_generator || !inc_recurse)
 366                         goto invalid_msg;
 367                 readfd(fd, buf, 4);
 368                 /* Read extra file list from receiver. */
 369                 assert(iobuf_in != NULL);
 370                 assert(iobuf_f_in == fd);
 371                 if (verbose > 3) {
 372                         rprintf(FINFO, "[%s] receiving flist for dir %d\n",
 373                                 who_am_i(), IVAL(buf,0));
 374                 }
 375                 flist = recv_file_list(fd);
 376                 flist->parent_ndx = IVAL(buf,0);
 377 #ifdef SUPPORT_HARD_LINKS
 378                 if (preserve_hard_links)
 379                         match_hard_links(flist);
 380 #endif
 381                 break;
 382         case MSG_FLIST_EOF:
 383                 if (len != 0 || !am_generator || !inc_recurse)
 384                         goto invalid_msg;
 385                 flist_eof = 1;
 386                 break;
 387         case MSG_IO_ERROR:
 388                 if (len != 4)
 389                         goto invalid_msg;
 390                 readfd(fd, buf, len);
 391                 io_error |= IVAL(buf, 0);
 392                 break;
 393         case MSG_DELETED:
 394                 if (len >= (int)sizeof buf || !am_generator)
 395                         goto invalid_msg;
 396                 readfd(fd, buf, len);
 397                 send_msg(MSG_DELETED, buf, len, 1);
 398                 break;
 399         case MSG_SUCCESS:
 400                 if (len != 4 || !am_generator)
 401                         goto invalid_msg;
 402                 readfd(fd, buf, 4);
 403                 got_flist_entry_status(FES_SUCCESS, buf);
 404                 break;
 405         case MSG_NO_SEND:
 406                 if (len != 4 || !am_generator)
 407                         goto invalid_msg;
 408                 readfd(fd, buf, 4);
 409                 got_flist_entry_status(FES_NO_SEND, buf);
 410                 break;
 411         case MSG_ERROR_SOCKET:
 412         case MSG_ERROR_UTF8:
 413         case MSG_CLIENT:
 414                 if (!am_generator)
 415                         goto invalid_msg;
 416                 if (tag == MSG_ERROR_SOCKET)
 417                         io_end_multiplex_out();
 418                 /* FALL THROUGH */
 419         case MSG_INFO:
 420         case MSG_ERROR:
 421         case MSG_ERROR_XFER:
 422         case MSG_WARNING:
 423         case MSG_LOG:
 424                 while (len) {
 425                         n = len;
 426                         if (n >= sizeof buf)
 427                                 n = sizeof buf - 1;
 428                         readfd(fd, buf, n);
 429                         rwrite((enum logcode)tag, buf, n, !am_generator);
 430                         len -= n;
 431                 }
 432                 break;
 433         default:
 434                 rprintf(FERROR, "unknown message %d:%d [%s]\n",
 435                         tag, len, who_am_i());
 436                 exit_cleanup(RERR_STREAMIO);
 437         }
 438
 439         no_flush--;
 440         msg_fd_in = fd;
 441         if (!--defer_forwarding_messages && !no_flush)
 442                 msg_flush();
 443 }
 444
 445 /* This is used by the generator to limit how many file transfers can
 446  * be active at once when --remove-source-files is specified.  Without
 447  * this, sender-side deletions were mostly happening at the end. */
 448 void increment_active_files(int ndx, int itemizing, enum logcode code)
 449 {
 450         while (1) {
 451                 /* TODO: tune these limits? */
 452                 int limit = active_bytecnt >= 128*1024 ? 10 : 50;
 453                 if (active_filecnt < limit)
 454                         break;
 455                 check_for_finished_files(itemizing, code, 0);
 456                 if (active_filecnt < limit)
 457                         break;
 458                 if (iobuf_out_cnt)
 459                         io_flush(NORMAL_FLUSH);
 460                 else
 461                         read_msg_fd();
 462         }
 463
 464         active_filecnt++;
 465         active_bytecnt += F_LENGTH(cur_flist->files[ndx - cur_flist->ndx_start]);
 466 }
 467
 468 /* Write an message to a multiplexed stream. If this fails, rsync exits. */
 469 static void mplex_write(int fd, enum msgcode code, const char *buf, size_t len, int convert)
 470 {
 471         char buffer[BIGPATHBUFLEN]; /* Oversized for use by iconv code. */
 472         size_t n = len;
 473
 474 #ifdef ICONV_OPTION
 475         /* We need to convert buf before doing anything else so that we
 476          * can include the (converted) byte length in the message header. */
 477         if (convert && ic_send != (iconv_t)-1) {
 478                 xbuf outbuf, inbuf;
 479
 480                 INIT_XBUF(outbuf, buffer + 4, 0, sizeof buffer - 4);
 481                 INIT_XBUF(inbuf, (char*)buf, len, -1);
 482
 483                 iconvbufs(ic_send, &inbuf, &outbuf,
 484                           ICB_INCLUDE_BAD | ICB_INCLUDE_INCOMPLETE);
 485                 if (inbuf.len > 0) {
 486                         rprintf(FERROR, "overflowed conversion buffer in mplex_write");
 487                         exit_cleanup(RERR_UNSUPPORTED);
 488                 }
 489
 490                 n = len = outbuf.len;
 491         } else
 492 #endif
 493         if (n > 1024 - 4) /* BIGPATHBUFLEN can handle 1024 bytes */
 494                 n = 0;    /* We'd rather do 2 writes than too much memcpy(). */
 495         else
 496                 memcpy(buffer + 4, buf, n);
 497
 498         SIVAL(buffer, 0, ((MPLEX_BASE + (int)code)<<24) + len);
 499
 500         keep_defer_forwarding++; /* defer_forwarding_messages++ on return */
 501         writefd_unbuffered(fd, buffer, n+4);
 502         keep_defer_forwarding--;
 503
 504         if (len > n)
 505                 writefd_unbuffered(fd, buf+n, len-n);
 506
 507         if (!--defer_forwarding_messages && !no_flush)
 508                 msg_flush();
 509 }
 510
 511 int send_msg(enum msgcode code, const char *buf, int len, int convert)
 512 {
 513         if (msg_fd_out < 0) {
 514                 if (!defer_forwarding_messages)
 515                         return io_multiplex_write(code, buf, len, convert);
 516                 if (!io_multiplexing_out)
 517                         return 0;
 518                 msg_list_add(&msg_queue, code, buf, len, convert);
 519                 return 1;
 520         }
 521         if (flist_forward_from >= 0)
 522                 msg_list_add(&msg_queue, code, buf, len, convert);
 523         else
 524                 mplex_write(msg_fd_out, code, buf, len, convert);
 525         return 1;
 526 }
 527
 528 void send_msg_int(enum msgcode code, int num)
 529 {
 530         char numbuf[4];
 531         SIVAL(numbuf, 0, num);
 532         send_msg(code, numbuf, 4, 0);
 533 }
 534
 535 void wait_for_receiver(void)
 536 {
 537         if (io_flush(NORMAL_FLUSH))
 538                 return;
 539         read_msg_fd();
 540 }
 541
 542 int get_redo_num(void)
 543 {
 544         return flist_ndx_pop(&redo_list);
 545 }
 546
 547 int get_hlink_num(void)
 548 {
 549         return flist_ndx_pop(&hlink_list);
 550 }
 551
 552 /**
 553  * When we're the receiver and we have a local --files-from list of names
 554  * that needs to be sent over the socket to the sender, we have to do two
 555  * things at the same time: send the sender a list of what files we're
 556  * processing and read the incoming file+info list from the sender.  We do
 557  * this by augmenting the read_timeout() function to copy this data.  It
 558  * uses ff_buf to read a block of data from f_in (when it is ready, since
 559  * it might be a pipe) and then blast it out f_out (when it is ready to
 560  * receive more data).
 561  */
 562 void io_set_filesfrom_fds(int f_in, int f_out)
 563 {
 564         io_filesfrom_f_in = f_in;
 565         io_filesfrom_f_out = f_out;
 566         alloc_xbuf(&ff_buf, 2048);
 567 #ifdef ICONV_OPTION
 568         if (protect_args)
 569                 alloc_xbuf(&iconv_buf, 1024);
 570 #endif
 571 }
 572
 573 /* It's almost always an error to get an EOF when we're trying to read from the
 574  * network, because the protocol is (for the most part) self-terminating.
 575  *
 576  * There is one case for the receiver when it is at the end of the transfer
 577  * (hanging around reading any keep-alive packets that might come its way): if
 578  * the sender dies before the generator's kill-signal comes through, we can end
 579  * up here needing to loop until the kill-signal arrives.  In this situation,
 580  * kluge_around_eof will be < 0.
 581  *
 582  * There is another case for older protocol versions (< 24) where the module
 583  * listing was not terminated, so we must ignore an EOF error in that case and
 584  * exit.  In this situation, kluge_around_eof will be > 0. */
 585 static void whine_about_eof(int fd)
 586 {
 587         if (kluge_around_eof && fd == sock_f_in) {
 588                 int i;
 589                 if (kluge_around_eof > 0)
 590                         exit_cleanup(0);
 591                 /* If we're still here after 10 seconds, exit with an error. */
 592                 for (i = 10*1000/20; i--; )
 593                         msleep(20);
 594         }
 595
 596         rprintf(FERROR, RSYNC_NAME ": connection unexpectedly closed "
 597                 "(%.0f bytes received so far) [%s]\n",
 598                 (double)stats.total_read, who_am_i());
 599
 600         exit_cleanup(RERR_STREAMIO);
 601 }
 602
 603 /**
 604  * Read from a socket with I/O timeout. return the number of bytes
 605  * read. If no bytes can be read then exit, never return a number <= 0.
 606  *
 607  * TODO: If the remote shell connection fails, then current versions
 608  * actually report an "unexpected EOF" error here.  Since it's a
 609  * fairly common mistake to try to use rsh when ssh is required, we
 610  * should trap that: if we fail to read any data at all, we should
 611  * give a better explanation.  We can tell whether the connection has
 612  * started by looking e.g. at whether the remote version is known yet.
 613  */
 614 static int read_timeout(int fd, char *buf, size_t len)
 615 {
 616         int n, cnt = 0;
 617
 618         io_flush(FULL_FLUSH);
 619
 620         while (cnt == 0) {
 621                 /* until we manage to read *something* */
 622                 fd_set r_fds, w_fds;
 623                 struct timeval tv;
 624                 int maxfd = fd;
 625                 int count;
 626
 627                 FD_ZERO(&r_fds);
 628                 FD_ZERO(&w_fds);
 629                 FD_SET(fd, &r_fds);
 630                 if (io_filesfrom_f_out >= 0) {
 631                         int new_fd;
 632                         if (ff_buf.len == 0) {
 633                                 if (io_filesfrom_f_in >= 0) {
 634                                         FD_SET(io_filesfrom_f_in, &r_fds);
 635                                         new_fd = io_filesfrom_f_in;
 636                                 } else {
 637                                         io_filesfrom_f_out = -1;
 638                                         new_fd = -1;
 639                                 }
 640                         } else {
 641                                 FD_SET(io_filesfrom_f_out, &w_fds);
 642                                 new_fd = io_filesfrom_f_out;
 643                         }
 644                         if (new_fd > maxfd)
 645                                 maxfd = new_fd;
 646                 }
 647
 648                 tv.tv_sec = select_timeout;
 649                 tv.tv_usec = 0;
 650
 651                 errno = 0;
 652
 653                 count = select(maxfd + 1, &r_fds, &w_fds, NULL, &tv);
 654
 655                 if (count <= 0) {
 656                         if (errno == EBADF) {
 657                                 defer_forwarding_messages = 0;
 658                                 exit_cleanup(RERR_SOCKETIO);
 659                         }
 660                         check_timeout();
 661                         continue;
 662                 }
 663
 664                 if (io_filesfrom_f_out >= 0) {
 665                         if (ff_buf.len) {
 666                                 if (FD_ISSET(io_filesfrom_f_out, &w_fds)) {
 667                                         int l = write(io_filesfrom_f_out,
 668                                                       ff_buf.buf + ff_buf.pos,
 669                                                       ff_buf.len);
 670                                         if (l > 0) {
 671                                                 if (!(ff_buf.len -= l))
 672                                                         ff_buf.pos = 0;
 673                                                 else
 674                                                         ff_buf.pos += l;
 675                                         } else if (errno != EINTR) {
 676                                                 /* XXX should we complain? */
 677                                                 io_filesfrom_f_out = -1;
 678                                         }
 679                                 }
 680                         } else if (io_filesfrom_f_in >= 0) {
 681                                 if (FD_ISSET(io_filesfrom_f_in, &r_fds)) {
 682 #ifdef ICONV_OPTION
 683                                         xbuf *ibuf = filesfrom_convert ? &iconv_buf : &ff_buf;
 684 #else
 685                                         xbuf *ibuf = &ff_buf;
 686 #endif
 687                                         int l = read(io_filesfrom_f_in, ibuf->buf, ibuf->size);
 688                                         if (l <= 0) {
 689                                                 if (l == 0 || errno != EINTR) {
 690                                                         /* Send end-of-file marker */
 691                                                         memcpy(ff_buf.buf, "\0\0", 2);
 692                                                         ff_buf.len = ff_lastchar? 2 : 1;
 693                                                         ff_buf.pos = 0;
 694                                                         io_filesfrom_f_in = -1;
 695                                                 }
 696                                         } else {
 697 #ifdef ICONV_OPTION
 698                                                 if (filesfrom_convert) {
 699                                                         iconv_buf.pos = 0;
 700                                                         iconv_buf.len = l;
 701                                                         iconvbufs(ic_send, &iconv_buf, &ff_buf,
 702                                                             ICB_EXPAND_OUT|ICB_INCLUDE_BAD|ICB_INCLUDE_INCOMPLETE);
 703                                                         l = ff_buf.len;
 704                                                 }
 705 #endif
 706                                                 if (!eol_nulls) {
 707                                                         char *s = ff_buf.buf + l;
 708                                                         /* Transform CR and/or LF into '\0' */
 709                                                         while (s-- > ff_buf.buf) {
 710                                                                 if (*s == '\n' || *s == '\r')
 711                                                                         *s = '\0';
 712                                                         }
 713                                                 }
 714                                                 if (!ff_lastchar) {
 715                                                         /* Last buf ended with a '\0', so don't
 716                                                          * let this buf start with one. */
 717                                                         while (l && ff_buf.buf[ff_buf.pos] == '\0')
 718                                                                 ff_buf.pos++, l--;
 719                                                 }
 720                                                 if (!l)
 721                                                         ff_buf.pos = 0;
 722                                                 else {
 723                                                         char *f = ff_buf.buf + ff_buf.pos;
 724                                                         char *t = f;
 725                                                         char *eob = f + l;
 726                                                         /* Eliminate any multi-'\0' runs. */
 727                                                         while (f != eob) {
 728                                                                 if (!(*t++ = *f++)) {
 729                                                                         while (f != eob && !*f)
 730                                                                                 f++, l--;
 731                                                                 }
 732                                                         }
 733                                                         ff_lastchar = f[-1];
 734                                                 }
 735                                                 ff_buf.len = l;
 736                                         }
 737                                 }
 738                         }
 739                 }
 740
 741                 if (!FD_ISSET(fd, &r_fds))
 742                         continue;
 743
 744                 n = read(fd, buf, len);
 745
 746                 if (n <= 0) {
 747                         if (n == 0)
 748                                 whine_about_eof(fd); /* Doesn't return. */
 749                         if (errno == EINTR || errno == EWOULDBLOCK
 750                             || errno == EAGAIN)
 751                                 continue;
 752
 753                         /* Don't write errors on a dead socket. */
 754                         if (fd == sock_f_in) {
 755                                 io_end_multiplex_out();
 756                                 rsyserr(FERROR_SOCKET, errno, "read error");
 757                         } else
 758                                 rsyserr(FERROR, errno, "read error");
 759                         exit_cleanup(RERR_STREAMIO);
 760                 }
 761
 762                 buf += n;
 763                 len -= n;
 764                 cnt += n;
 765
 766                 if (fd == sock_f_in && io_timeout)
 767                         last_io_in = time(NULL);
 768         }
 769
 770         return cnt;
 771 }
 772
 773 /* Read a line into the "buf" buffer. */
 774 int read_line(int fd, char *buf, size_t bufsiz, int flags)
 775 {
 776         char ch, *s, *eob;
 777         int cnt;
 778
 779 #ifdef ICONV_OPTION
 780         if (flags & RL_CONVERT && iconv_buf.size < bufsiz)
 781                 realloc_xbuf(&iconv_buf, bufsiz + 1024);
 782 #endif
 783
 784   start:
 785 #ifdef ICONV_OPTION
 786         s = flags & RL_CONVERT ? iconv_buf.buf : buf;
 787 #else
 788         s = buf;
 789 #endif
 790         eob = s + bufsiz - 1;
 791         while (1) {
 792                 cnt = read(fd, &ch, 1);
 793                 if (cnt < 0 && (errno == EWOULDBLOCK
 794                   || errno == EINTR || errno == EAGAIN)) {
 795                         struct timeval tv;
 796                         fd_set r_fds, e_fds;
 797                         FD_ZERO(&r_fds);
 798                         FD_SET(fd, &r_fds);
 799                         FD_ZERO(&e_fds);
 800                         FD_SET(fd, &e_fds);
 801                         tv.tv_sec = select_timeout;
 802                         tv.tv_usec = 0;
 803                         if (!select(fd+1, &r_fds, NULL, &e_fds, &tv))
 804                                 check_timeout();
 805                         /*if (FD_ISSET(fd, &e_fds))
 806                                 rprintf(FINFO, "select exception on fd %d\n", fd); */
 807                         continue;
 808                 }
 809                 if (cnt != 1)
 810                         break;
 811                 if (flags & RL_EOL_NULLS ? ch == '\0' : (ch == '\r' || ch == '\n')) {
 812                         /* Skip empty lines if dumping comments. */
 813                         if (flags & RL_DUMP_COMMENTS && s == buf)
 814                                 continue;
 815                         break;
 816                 }
 817                 if (s < eob)
 818                         *s++ = ch;
 819         }
 820         *s = '\0';
 821
 822         if (flags & RL_DUMP_COMMENTS && (*buf == '#' || *buf == ';'))
 823                 goto start;
 824
 825 #ifdef ICONV_OPTION
 826         if (flags & RL_CONVERT) {
 827                 xbuf outbuf;
 828                 INIT_XBUF(outbuf, buf, 0, bufsiz);
 829                 iconv_buf.pos = 0;
 830                 iconv_buf.len = s - iconv_buf.buf;
 831                 iconvbufs(ic_recv, &iconv_buf, &outbuf,
 832                           ICB_INCLUDE_BAD | ICB_INCLUDE_INCOMPLETE);
 833                 outbuf.buf[outbuf.len] = '\0';
 834                 return outbuf.len;
 835         }
 836 #endif
 837
 838         return s - buf;
 839 }
 840
 841 void read_args(int f_in, char *mod_name, char *buf, size_t bufsiz, int rl_nulls,
 842                char ***argv_p, int *argc_p, char **request_p)
 843 {
 844         int maxargs = MAX_ARGS;
 845         int dot_pos = 0;
 846         int argc = 0;
 847         char **argv, *p;
 848         int rl_flags = (rl_nulls ? RL_EOL_NULLS : 0);
 849
 850 #ifdef ICONV_OPTION
 851         rl_flags |= (protect_args && ic_recv != (iconv_t)-1 ? RL_CONVERT : 0);
 852 #endif
 853
 854         if (!(argv = new_array(char *, maxargs)))
 855                 out_of_memory("read_args");
 856         if (mod_name && !protect_args)
 857                 argv[argc++] = "rsyncd";
 858
 859         while (1) {
 860                 if (read_line(f_in, buf, bufsiz, rl_flags) == 0)
 861                         break;
 862
 863                 if (argc == maxargs-1) {
 864                         maxargs += MAX_ARGS;
 865                         if (!(argv = realloc_array(argv, char *, maxargs)))
 866                                 out_of_memory("read_args");
 867                 }
 868
 869                 if (dot_pos) {
 870                         if (request_p) {
 871                                 *request_p = strdup(buf);
 872                                 request_p = NULL;
 873                         }
 874                         if (mod_name)
 875                                 glob_expand_module(mod_name, buf, &argv, &argc, &maxargs);
 876                         else
 877                                 glob_expand(buf, &argv, &argc, &maxargs);
 878                 } else {
 879                         if (!(p = strdup(buf)))
 880                                 out_of_memory("read_args");
 881                         argv[argc++] = p;
 882                         if (*p == '.' && p[1] == '\0')
 883                                 dot_pos = argc;
 884                 }
 885         }
 886         argv[argc] = NULL;
 887
 888         glob_expand(NULL, NULL, NULL, NULL);
 889
 890         *argc_p = argc;
 891         *argv_p = argv;
 892 }
 893
 894 int io_start_buffering_out(int f_out)
 895 {
 896         if (iobuf_out) {
 897                 assert(f_out == iobuf_f_out);
 898                 return 0;
 899         }
 900         if (!(iobuf_out = new_array(char, IO_BUFFER_SIZE)))
 901                 out_of_memory("io_start_buffering_out");
 902         iobuf_out_cnt = 0;
 903         iobuf_f_out = f_out;
 904         return 1;
 905 }
 906
 907 int io_start_buffering_in(int f_in)
 908 {
 909         if (iobuf_in) {
 910                 assert(f_in == iobuf_f_in);
 911                 return 0;
 912         }
 913         iobuf_in_siz = 2 * IO_BUFFER_SIZE;
 914         if (!(iobuf_in = new_array(char, iobuf_in_siz)))
 915                 out_of_memory("io_start_buffering_in");
 916         iobuf_f_in = f_in;
 917         return 1;
 918 }
 919
 920 void io_end_buffering_in(void)
 921 {
 922         if (!iobuf_in)
 923                 return;
 924         free(iobuf_in);
 925         iobuf_in = NULL;
 926         iobuf_in_ndx = 0;
 927         iobuf_in_remaining = 0;
 928         iobuf_f_in = -1;
 929 }
 930
 931 void io_end_buffering_out(void)
 932 {
 933         if (!iobuf_out)
 934                 return;
 935         io_flush(FULL_FLUSH);
 936         free(iobuf_out);
 937         iobuf_out = NULL;
 938         iobuf_f_out = -1;
 939 }
 940
 941 void maybe_flush_socket(int important)
 942 {
 943         if (iobuf_out && iobuf_out_cnt
 944          && (important || time(NULL) - last_io_out >= 5))
 945                 io_flush(NORMAL_FLUSH);
 946 }
 947
 948 void maybe_send_keepalive(void)
 949 {
 950         if (time(NULL) - last_io_out >= allowed_lull) {
 951                 if (!iobuf_out || !iobuf_out_cnt) {
 952                         if (protocol_version < 29)
 953                                 return; /* there's nothing we can do */
 954                         if (protocol_version >= 30)
 955                                 send_msg(MSG_NOOP, "", 0, 0);
 956                         else {
 957                                 write_int(sock_f_out, cur_flist->used);
 958                                 write_shortint(sock_f_out, ITEM_IS_NEW);
 959                         }
 960                 }
 961                 if (iobuf_out)
 962                         io_flush(NORMAL_FLUSH);
 963         }
 964 }
 965
 966 void start_flist_forward(int f_in)
 967 {
 968         assert(iobuf_out != NULL);
 969         assert(iobuf_f_out == msg_fd_out);
 970         flist_forward_from = f_in;
 971 }
 972
 973 void stop_flist_forward()
 974 {
 975         flist_forward_from = -1;
 976         io_flush(FULL_FLUSH);
 977 }
 978
 979 /**
 980  * Continue trying to read len bytes - don't return until len has been
 981  * read.
 982  **/
 983 static void read_loop(int fd, char *buf, size_t len)
 984 {
 985         while (len) {
 986                 int n = read_timeout(fd, buf, len);
 987
 988                 buf += n;
 989                 len -= n;
 990         }
 991 }
 992
 993 /**
 994  * Read from the file descriptor handling multiplexing - return number
 995  * of bytes read.
 996  *
 997  * Never returns <= 0.
 998  */
 999 static int readfd_unbuffered(int fd, char *buf, size_t len)
1000 {
1001         size_t msg_bytes;
1002         int tag, cnt = 0;
1003         char line[BIGPATHBUFLEN];
1004
1005         if (!iobuf_in || fd != iobuf_f_in)
1006                 return read_timeout(fd, buf, len);
1007
1008         if (!io_multiplexing_in && iobuf_in_remaining == 0) {
1009                 iobuf_in_remaining = read_timeout(fd, iobuf_in, iobuf_in_siz);
1010                 iobuf_in_ndx = 0;
1011         }
1012
1013         while (cnt == 0) {
1014                 if (iobuf_in_remaining) {
1015                         len = MIN(len, iobuf_in_remaining);
1016                         memcpy(buf, iobuf_in + iobuf_in_ndx, len);
1017                         iobuf_in_ndx += len;
1018                         iobuf_in_remaining -= len;
1019                         cnt = len;
1020                         break;
1021                 }
1022
1023                 read_loop(fd, line, 4);
1024                 tag = IVAL(line, 0);
1025
1026                 msg_bytes = tag & 0xFFFFFF;
1027                 tag = (tag >> 24) - MPLEX_BASE;
1028
1029                 switch (tag) {
1030                 case MSG_DATA:
1031                         if (msg_bytes > iobuf_in_siz) {
1032                                 if (!(iobuf_in = realloc_array(iobuf_in, char,
1033                                                                msg_bytes)))
1034                                         out_of_memory("readfd_unbuffered");
1035                                 iobuf_in_siz = msg_bytes;
1036                         }
1037                         read_loop(fd, iobuf_in, msg_bytes);
1038                         iobuf_in_remaining = msg_bytes;
1039                         iobuf_in_ndx = 0;
1040                         break;
1041                 case MSG_NOOP:
1042                         if (am_sender)
1043                                 maybe_send_keepalive();
1044                         break;
1045                 case MSG_IO_ERROR:
1046                         if (msg_bytes != 4)
1047                                 goto invalid_msg;
1048                         read_loop(fd, line, msg_bytes);
1049                         send_msg_int(MSG_IO_ERROR, IVAL(line, 0));
1050                         io_error |= IVAL(line, 0);
1051                         break;
1052                 case MSG_DELETED:
1053                         if (msg_bytes >= sizeof line)
1054                                 goto overflow;
1055 #ifdef ICONV_OPTION
1056                         if (ic_recv != (iconv_t)-1) {
1057                                 xbuf outbuf, inbuf;
1058                                 char ibuf[512];
1059                                 int add_null = 0;
1060                                 int pos = 0;
1061
1062                                 INIT_CONST_XBUF(outbuf, line);
1063                                 INIT_XBUF(inbuf, ibuf, 0, -1);
1064
1065                                 while (msg_bytes) {
1066                                         inbuf.len = msg_bytes > sizeof ibuf
1067                                                   ? sizeof ibuf : msg_bytes;
1068                                         read_loop(fd, inbuf.buf, inbuf.len);
1069                                         if (!(msg_bytes -= inbuf.len)
1070                                          && !ibuf[inbuf.len-1])
1071                                                 inbuf.len--, add_null = 1;
1072                                         if (iconvbufs(ic_send, &inbuf, &outbuf,
1073                                             ICB_INCLUDE_BAD | ICB_INCLUDE_INCOMPLETE) < 0)
1074                                                 goto overflow;
1075                                         pos = -1;
1076                                 }
1077                                 if (add_null) {
1078                                         if (outbuf.len == outbuf.size)
1079                                                 goto overflow;
1080                                         outbuf.buf[outbuf.len++] = '\0';
1081                                 }
1082                                 msg_bytes = outbuf.len;
1083                         } else
1084 #endif
1085                                 read_loop(fd, line, msg_bytes);
1086                         /* A directory name was sent with the trailing null */
1087                         if (msg_bytes > 0 && !line[msg_bytes-1])
1088                                 log_delete(line, S_IFDIR);
1089                         else {
1090                                 line[msg_bytes] = '\0';
1091                                 log_delete(line, S_IFREG);
1092                         }
1093                         break;
1094                 case MSG_SUCCESS:
1095                         if (msg_bytes != 4) {
1096                           invalid_msg:
1097                                 rprintf(FERROR, "invalid multi-message %d:%ld [%s]\n",
1098                                         tag, (long)msg_bytes, who_am_i());
1099                                 exit_cleanup(RERR_STREAMIO);
1100                         }
1101                         read_loop(fd, line, msg_bytes);
1102                         successful_send(IVAL(line, 0));
1103                         break;
1104                 case MSG_NO_SEND:
1105                         if (msg_bytes != 4)
1106                                 goto invalid_msg;
1107                         read_loop(fd, line, msg_bytes);
1108                         send_msg_int(MSG_NO_SEND, IVAL(line, 0));
1109                         break;
1110                 case MSG_INFO:
1111                 case MSG_ERROR:
1112                 case MSG_ERROR_XFER:
1113                 case MSG_WARNING:
1114                         if (msg_bytes >= sizeof line) {
1115                             overflow:
1116                                 rprintf(FERROR,
1117                                         "multiplexing overflow %d:%ld [%s]\n",
1118                                         tag, (long)msg_bytes, who_am_i());
1119                                 exit_cleanup(RERR_STREAMIO);
1120                         }
1121                         read_loop(fd, line, msg_bytes);
1122                         rwrite((enum logcode)tag, line, msg_bytes, 1);
1123                         if (first_message) {
1124                                 if (list_only && !am_sender && tag == 1) {
1125                                         line[msg_bytes] = '\0';
1126                                         check_for_d_option_error(line);
1127                                 }
1128                                 first_message = 0;
1129                         }
1130                         break;
1131                 default:
1132                         rprintf(FERROR, "unexpected tag %d [%s]\n",
1133                                 tag, who_am_i());
1134                         exit_cleanup(RERR_STREAMIO);
1135                 }
1136         }
1137
1138         if (iobuf_in_remaining == 0)
1139                 io_flush(NORMAL_FLUSH);
1140
1141         return cnt;
1142 }
1143
1144 /* Do a buffered read from fd.  Don't return until all N bytes have
1145  * been read.  If all N can't be read then exit with an error. */
1146 static void readfd(int fd, char *buffer, size_t N)
1147 {
1148         int  cnt;
1149         size_t total = 0;
1150
1151         while (total < N) {
1152                 cnt = readfd_unbuffered(fd, buffer + total, N-total);
1153                 total += cnt;
1154         }
1155
1156         if (fd == write_batch_monitor_in) {
1157                 if ((size_t)write(batch_fd, buffer, total) != total)
1158                         exit_cleanup(RERR_FILEIO);
1159         }
1160
1161         if (fd == flist_forward_from)
1162                 writefd(iobuf_f_out, buffer, total);
1163
1164         if (fd == sock_f_in)
1165                 stats.total_read += total;
1166 }
1167
1168 unsigned short read_shortint(int f)
1169 {
1170         char b[2];
1171         readfd(f, b, 2);
1172         return (UVAL(b, 1) << 8) + UVAL(b, 0);
1173 }
1174
1175 int32 read_int(int f)
1176 {
1177         char b[4];
1178         int32 num;
1179
1180         readfd(f, b, 4);
1181         num = IVAL(b, 0);
1182 #if SIZEOF_INT32 > 4
1183         if (num & (int32)0x80000000)
1184                 num |= ~(int32)0xffffffff;
1185 #endif
1186         return num;
1187 }
1188
1189 int32 read_varint(int f)
1190 {
1191         union {
1192             char b[5];
1193             int32 x;
1194         } u;
1195         uchar ch;
1196         int extra;
1197
1198         u.x = 0;
1199         readfd(f, (char*)&ch, 1);
1200         extra = int_byte_extra[ch / 4];
1201         if (extra) {
1202                 uchar bit = ((uchar)1<<(8-extra));
1203                 if (extra >= (int)sizeof u.b) {
1204                         rprintf(FERROR, "Overflow in read_varint()\n");
1205                         exit_cleanup(RERR_STREAMIO);
1206                 }
1207                 readfd(f, u.b, extra);
1208                 u.b[extra] = ch & (bit-1);
1209         } else
1210                 u.b[0] = ch;
1211 #if CAREFUL_ALIGNMENT
1212         u.x = IVAL(u.b,0);
1213 #endif
1214 #if SIZEOF_INT32 > 4
1215         if (u.x & (int32)0x80000000)
1216                 u.x |= ~(int32)0xffffffff;
1217 #endif
1218         return u.x;
1219 }
1220
1221 int64 read_varlong(int f, uchar min_bytes)
1222 {
1223         union {
1224             char b[9];
1225             int64 x;
1226         } u;
1227         char b2[8];
1228         int extra;
1229
1230 #if SIZEOF_INT64 < 8
1231         memset(u.b, 0, 8);
1232 #else
1233         u.x = 0;
1234 #endif
1235         readfd(f, b2, min_bytes);
1236         memcpy(u.b, b2+1, min_bytes-1);
1237         extra = int_byte_extra[CVAL(b2, 0) / 4];
1238         if (extra) {
1239                 uchar bit = ((uchar)1<<(8-extra));
1240                 if (min_bytes + extra > (int)sizeof u.b) {
1241                         rprintf(FERROR, "Overflow in read_varlong()\n");
1242                         exit_cleanup(RERR_STREAMIO);
1243                 }
1244                 readfd(f, u.b + min_bytes - 1, extra);
1245                 u.b[min_bytes + extra - 1] = CVAL(b2, 0) & (bit-1);
1246 #if SIZEOF_INT64 < 8
1247                 if (min_bytes + extra > 5 || u.b[4] || CVAL(u.b,3) & 0x80) {
1248                         rprintf(FERROR, "Integer overflow: attempted 64-bit offset\n");
1249                         exit_cleanup(RERR_UNSUPPORTED);
1250                 }
1251 #endif
1252         } else
1253                 u.b[min_bytes + extra - 1] = CVAL(b2, 0);
1254 #if SIZEOF_INT64 < 8
1255         u.x = IVAL(u.b,0);
1256 #elif CAREFUL_ALIGNMENT
1257         u.x = IVAL(u.b,0) | (((int64)IVAL(u.b,4))<<32);
1258 #endif
1259         return u.x;
1260 }
1261
1262 int64 read_longint(int f)
1263 {
1264 #if SIZEOF_INT64 >= 8
1265         char b[9];
1266 #endif
1267         int32 num = read_int(f);
1268
1269         if (num != (int32)0xffffffff)
1270                 return num;
1271
1272 #if SIZEOF_INT64 < 8
1273         rprintf(FERROR, "Integer overflow: attempted 64-bit offset\n");
1274         exit_cleanup(RERR_UNSUPPORTED);
1275 #else
1276         readfd(f, b, 8);
1277         return IVAL(b,0) | (((int64)IVAL(b,4))<<32);
1278 #endif
1279 }
1280
1281 void read_buf(int f, char *buf, size_t len)
1282 {
1283         readfd(f,buf,len);
1284 }
1285
1286 void read_sbuf(int f, char *buf, size_t len)
1287 {
1288         readfd(f, buf, len);
1289         buf[len] = '\0';
1290 }
1291
1292 uchar read_byte(int f)
1293 {
1294         uchar c;
1295         readfd(f, (char *)&c, 1);
1296         return c;
1297 }
1298
1299 int read_vstring(int f, char *buf, int bufsize)
1300 {
1301         int len = read_byte(f);
1302
1303         if (len & 0x80)
1304                 len = (len & ~0x80) * 0x100 + read_byte(f);
1305
1306         if (len >= bufsize) {
1307                 rprintf(FERROR, "over-long vstring received (%d > %d)\n",
1308                         len, bufsize - 1);
1309                 return -1;
1310         }
1311
1312         if (len)
1313                 readfd(f, buf, len);
1314         buf[len] = '\0';
1315         return len;
1316 }
1317
1318 /* Populate a sum_struct with values from the socket.  This is
1319  * called by both the sender and the receiver. */
1320 void read_sum_head(int f, struct sum_struct *sum)
1321 {
1322         int32 max_blength = protocol_version < 30 ? OLD_MAX_BLOCK_SIZE : MAX_BLOCK_SIZE;
1323         sum->count = read_int(f);
1324         if (sum->count < 0) {
1325                 rprintf(FERROR, "Invalid checksum count %ld [%s]\n",
1326                         (long)sum->count, who_am_i());
1327                 exit_cleanup(RERR_PROTOCOL);
1328         }
1329         sum->blength = read_int(f);
1330         if (sum->blength < 0 || sum->blength > max_blength) {
1331                 rprintf(FERROR, "Invalid block length %ld [%s]\n",
1332                         (long)sum->blength, who_am_i());
1333                 exit_cleanup(RERR_PROTOCOL);
1334         }
1335         sum->s2length = protocol_version < 27 ? csum_length : (int)read_int(f);
1336         if (sum->s2length < 0 || sum->s2length > MAX_DIGEST_LEN) {
1337                 rprintf(FERROR, "Invalid checksum length %d [%s]\n",
1338                         sum->s2length, who_am_i());
1339                 exit_cleanup(RERR_PROTOCOL);
1340         }
1341         sum->remainder = read_int(f);
1342         if (sum->remainder < 0 || sum->remainder > sum->blength) {
1343                 rprintf(FERROR, "Invalid remainder length %ld [%s]\n",
1344                         (long)sum->remainder, who_am_i());
1345                 exit_cleanup(RERR_PROTOCOL);
1346         }
1347 }
1348
1349 /* Send the values from a sum_struct over the socket.  Set sum to
1350  * NULL if there are no checksums to send.  This is called by both
1351  * the generator and the sender. */
1352 void write_sum_head(int f, struct sum_struct *sum)
1353 {
1354         static struct sum_struct null_sum;
1355
1356         if (sum == NULL)
1357                 sum = &null_sum;
1358
1359         write_int(f, sum->count);
1360         write_int(f, sum->blength);
1361         if (protocol_version >= 27)
1362                 write_int(f, sum->s2length);
1363         write_int(f, sum->remainder);
1364 }
1365
1366 /**
1367  * Sleep after writing to limit I/O bandwidth usage.
1368  *
1369  * @todo Rather than sleeping after each write, it might be better to
1370  * use some kind of averaging.  The current algorithm seems to always
1371  * use a bit less bandwidth than specified, because it doesn't make up
1372  * for slow periods.  But arguably this is a feature.  In addition, we
1373  * ought to take the time used to write the data into account.
1374  *
1375  * During some phases of big transfers (file FOO is uptodate) this is
1376  * called with a small bytes_written every time.  As the kernel has to
1377  * round small waits up to guarantee that we actually wait at least the
1378  * requested number of microseconds, this can become grossly inaccurate.
1379  * We therefore keep track of the bytes we've written over time and only
1380  * sleep when the accumulated delay is at least 1 tenth of a second.
1381  **/
1382 static void sleep_for_bwlimit(int bytes_written)
1383 {
1384         static struct timeval prior_tv;
1385         static long total_written = 0;
1386         struct timeval tv, start_tv;
1387         long elapsed_usec, sleep_usec;
1388
1389 #define ONE_SEC 1000000L /* # of microseconds in a second */
1390
1391         if (!bwlimit_writemax)
1392                 return;
1393
1394         total_written += bytes_written;
1395
1396         gettimeofday(&start_tv, NULL);
1397         if (prior_tv.tv_sec) {
1398                 elapsed_usec = (start_tv.tv_sec - prior_tv.tv_sec) * ONE_SEC
1399                              + (start_tv.tv_usec - prior_tv.tv_usec);
1400                 total_written -= elapsed_usec * bwlimit / (ONE_SEC/1024);
1401                 if (total_written < 0)
1402                         total_written = 0;
1403         }
1404
1405         sleep_usec = total_written * (ONE_SEC/1024) / bwlimit;
1406         if (sleep_usec < ONE_SEC / 10) {
1407                 prior_tv = start_tv;
1408                 return;
1409         }
1410
1411         tv.tv_sec  = sleep_usec / ONE_SEC;
1412         tv.tv_usec = sleep_usec % ONE_SEC;
1413         select(0, NULL, NULL, NULL, &tv);
1414
1415         gettimeofday(&prior_tv, NULL);
1416         elapsed_usec = (prior_tv.tv_sec - start_tv.tv_sec) * ONE_SEC
1417                      + (prior_tv.tv_usec - start_tv.tv_usec);
1418         total_written = (sleep_usec - elapsed_usec) * bwlimit / (ONE_SEC/1024);
1419 }
1420
1421 static const char *what_fd_is(int fd)
1422 {
1423         static char buf[20];
1424
1425         if (fd == sock_f_out)
1426                 return "socket";
1427         else if (fd == msg_fd_out)
1428                 return "message fd";
1429         else if (fd == batch_fd)
1430                 return "batch file";
1431         else {
1432                 snprintf(buf, sizeof buf, "fd %d", fd);
1433                 return buf;
1434         }
1435 }
1436
1437 /* Write len bytes to the file descriptor fd, looping as necessary to get
1438  * the job done and also (in certain circumstances) reading any data on
1439  * msg_fd_in to avoid deadlock.
1440  *
1441  * This function underlies the multiplexing system.  The body of the
1442  * application never calls this function directly. */
1443 static void writefd_unbuffered(int fd, const char *buf, size_t len)
1444 {
1445         size_t n, total = 0;
1446         fd_set w_fds, r_fds, e_fds;
1447         int maxfd, count, cnt, using_r_fds;
1448         int defer_inc = 0;
1449         struct timeval tv;
1450
1451         if (no_flush++)
1452                 defer_forwarding_messages++, defer_inc++;
1453
1454         while (total < len) {
1455                 FD_ZERO(&w_fds);
1456                 FD_SET(fd, &w_fds);
1457                 FD_ZERO(&e_fds);
1458                 FD_SET(fd, &e_fds);
1459                 maxfd = fd;
1460
1461                 if (msg_fd_in >= 0) {
1462                         FD_ZERO(&r_fds);
1463                         FD_SET(msg_fd_in, &r_fds);
1464                         if (msg_fd_in > maxfd)
1465                                 maxfd = msg_fd_in;
1466                         using_r_fds = 1;
1467                 } else
1468                         using_r_fds = 0;
1469
1470                 tv.tv_sec = select_timeout;
1471                 tv.tv_usec = 0;
1472
1473                 errno = 0;
1474                 count = select(maxfd + 1, using_r_fds ? &r_fds : NULL,
1475                                &w_fds, &e_fds, &tv);
1476
1477                 if (count <= 0) {
1478                         if (count < 0 && errno == EBADF)
1479                                 exit_cleanup(RERR_SOCKETIO);
1480                         check_timeout();
1481                         continue;
1482                 }
1483
1484                 /*if (FD_ISSET(fd, &e_fds))
1485                         rprintf(FINFO, "select exception on fd %d\n", fd); */
1486
1487                 if (using_r_fds && FD_ISSET(msg_fd_in, &r_fds))
1488                         read_msg_fd();
1489
1490                 if (!FD_ISSET(fd, &w_fds))
1491                         continue;
1492
1493                 n = len - total;
1494                 if (bwlimit_writemax && n > bwlimit_writemax)
1495                         n = bwlimit_writemax;
1496                 cnt = write(fd, buf + total, n);
1497
1498                 if (cnt <= 0) {
1499                         if (cnt < 0) {
1500                                 if (errno == EINTR)
1501                                         continue;
1502                                 if (errno == EWOULDBLOCK || errno == EAGAIN) {
1503                                         msleep(1);
1504                                         continue;
1505                                 }
1506                         }
1507
1508                         /* Don't try to write errors back across the stream. */
1509                         if (fd == sock_f_out)
1510                                 io_end_multiplex_out();
1511                         /* Don't try to write errors down a failing msg pipe. */
1512                         if (am_server && fd == msg_fd_out)
1513                                 exit_cleanup(RERR_STREAMIO);
1514                         rsyserr(FERROR, errno,
1515                                 "writefd_unbuffered failed to write %ld bytes to %s [%s]",
1516                                 (long)len, what_fd_is(fd), who_am_i());
1517                         /* If the other side is sending us error messages, try
1518                          * to grab any messages they sent before they died. */
1519                         while (!am_server && fd == sock_f_out && io_multiplexing_in) {
1520                                 char buf[1024];
1521                                 set_io_timeout(30);
1522                                 ignore_timeout = 0;
1523                                 readfd_unbuffered(sock_f_in, buf, sizeof buf);
1524                         }
1525                         exit_cleanup(RERR_STREAMIO);
1526                 }
1527
1528                 total += cnt;
1529                 defer_forwarding_messages++, defer_inc++;
1530
1531                 if (fd == sock_f_out) {
1532                         if (io_timeout || am_generator)
1533                                 last_io_out = time(NULL);
1534                         sleep_for_bwlimit(cnt);
1535                 }
1536         }
1537
1538         no_flush--;
1539         if (keep_defer_forwarding)
1540                 defer_inc--;
1541         if (!(defer_forwarding_messages -= defer_inc) && !no_flush)
1542                 msg_flush();
1543 }
1544
1545 int io_flush(int flush_it_all)
1546 {
1547         int flushed_something = 0;
1548
1549         if (no_flush)
1550                 return 0;
1551
1552         if (iobuf_out_cnt) {
1553                 if (io_multiplexing_out)
1554                         mplex_write(sock_f_out, MSG_DATA, iobuf_out, iobuf_out_cnt, 0);
1555                 else
1556                         writefd_unbuffered(iobuf_f_out, iobuf_out, iobuf_out_cnt);
1557                 iobuf_out_cnt = 0;
1558                 flushed_something = 1;
1559         }
1560
1561         if (flush_it_all && !defer_forwarding_messages && msg_queue.head) {
1562                 msg_flush();
1563                 flushed_something = 1;
1564         }
1565
1566         return flushed_something;
1567 }
1568
1569 static void writefd(int fd, const char *buf, size_t len)
1570 {
1571         if (fd == sock_f_out)
1572                 stats.total_written += len;
1573
1574         if (fd == write_batch_monitor_out)
1575                 writefd_unbuffered(batch_fd, buf, len);
1576
1577         if (!iobuf_out || fd != iobuf_f_out) {
1578                 writefd_unbuffered(fd, buf, len);
1579                 return;
1580         }
1581
1582         while (len) {
1583                 int n = MIN((int)len, IO_BUFFER_SIZE - iobuf_out_cnt);
1584                 if (n > 0) {
1585                         memcpy(iobuf_out+iobuf_out_cnt, buf, n);
1586                         buf += n;
1587                         len -= n;
1588                         iobuf_out_cnt += n;
1589                 }
1590
1591                 if (iobuf_out_cnt == IO_BUFFER_SIZE)
1592                         io_flush(NORMAL_FLUSH);
1593         }
1594 }
1595
1596 void write_shortint(int f, unsigned short x)
1597 {
1598         char b[2];
1599         b[0] = (char)x;
1600         b[1] = (char)(x >> 8);
1601         writefd(f, b, 2);
1602 }
1603
1604 void write_int(int f, int32 x)
1605 {
1606         char b[4];
1607         SIVAL(b, 0, x);
1608         writefd(f, b, 4);
1609 }
1610
1611 void write_varint(int f, int32 x)
1612 {
1613         char b[5];
1614         uchar bit;
1615         int cnt = 4;
1616
1617         SIVAL(b, 1, x);
1618
1619         while (cnt > 1 && b[cnt] == 0)
1620                 cnt--;
1621         bit = ((uchar)1<<(7-cnt+1));
1622         if (CVAL(b, cnt) >= bit) {
1623                 cnt++;
1624                 *b = ~(bit-1);
1625         } else if (cnt > 1)
1626                 *b = b[cnt] | ~(bit*2-1);
1627         else
1628                 *b = b[cnt];
1629
1630         writefd(f, b, cnt);
1631 }
1632
1633 void write_varlong(int f, int64 x, uchar min_bytes)
1634 {
1635         char b[9];
1636         uchar bit;
1637         int cnt = 8;
1638
1639         SIVAL(b, 1, x);
1640 #if SIZEOF_INT64 >= 8
1641         SIVAL(b, 5, x >> 32);
1642 #else
1643         if (x <= 0x7FFFFFFF && x >= 0)
1644                 memset(b + 5, 0, 4);
1645         else {
1646                 rprintf(FERROR, "Integer overflow: attempted 64-bit offset\n");
1647                 exit_cleanup(RERR_UNSUPPORTED);
1648         }
1649 #endif
1650
1651         while (cnt > min_bytes && b[cnt] == 0)
1652                 cnt--;
1653         bit = ((uchar)1<<(7-cnt+min_bytes));
1654         if (CVAL(b, cnt) >= bit) {
1655                 cnt++;
1656                 *b = ~(bit-1);
1657         } else if (cnt > min_bytes)
1658                 *b = b[cnt] | ~(bit*2-1);
1659         else
1660                 *b = b[cnt];
1661
1662         writefd(f, b, cnt);
1663 }
1664
1665 /*
1666  * Note: int64 may actually be a 32-bit type if ./configure couldn't find any
1667  * 64-bit types on this platform.
1668  */
1669 void write_longint(int f, int64 x)
1670 {
1671         char b[12], * const s = b+4;
1672
1673         SIVAL(s, 0, x);
1674         if (x <= 0x7FFFFFFF && x >= 0) {
1675                 writefd(f, s, 4);
1676                 return;
1677         }
1678
1679 #if SIZEOF_INT64 < 8
1680         rprintf(FERROR, "Integer overflow: attempted 64-bit offset\n");
1681         exit_cleanup(RERR_UNSUPPORTED);
1682 #else
1683         memset(b, 0xFF, 4);
1684         SIVAL(s, 4, x >> 32);
1685         writefd(f, b, 12);
1686 #endif
1687 }
1688
1689 void write_buf(int f, const char *buf, size_t len)
1690 {
1691         writefd(f,buf,len);
1692 }
1693
1694 /** Write a string to the connection */
1695 void write_sbuf(int f, const char *buf)
1696 {
1697         writefd(f, buf, strlen(buf));
1698 }
1699
1700 void write_byte(int f, uchar c)
1701 {
1702         writefd(f, (char *)&c, 1);
1703 }
1704
1705 void write_vstring(int f, const char *str, int len)
1706 {
1707         uchar lenbuf[3], *lb = lenbuf;
1708
1709         if (len > 0x7F) {
1710                 if (len > 0x7FFF) {
1711                         rprintf(FERROR,
1712                                 "attempting to send over-long vstring (%d > %d)\n",
1713                                 len, 0x7FFF);
1714                         exit_cleanup(RERR_PROTOCOL);
1715                 }
1716                 *lb++ = len / 0x100 + 0x80;
1717         }
1718         *lb = len;
1719
1720         writefd(f, (char*)lenbuf, lb - lenbuf + 1);
1721         if (len)
1722                 writefd(f, str, len);
1723 }
1724
1725 /* Send a file-list index using a byte-reduction method. */
1726 void write_ndx(int f, int32 ndx)
1727 {
1728         static int32 prev_positive = -1, prev_negative = 1;
1729         int32 diff, cnt = 0;
1730         char b[6];
1731
1732         if (protocol_version < 30 || read_batch) {
1733                 write_int(f, ndx);
1734                 return;
1735         }
1736
1737         /* Send NDX_DONE as a single-byte 0 with no side effects.  Send
1738          * negative nums as a positive after sending a leading 0xFF. */
1739         if (ndx >= 0) {
1740                 diff = ndx - prev_positive;
1741                 prev_positive = ndx;
1742         } else if (ndx == NDX_DONE) {
1743                 *b = 0;
1744                 writefd(f, b, 1);
1745                 return;
1746         } else {
1747                 b[cnt++] = (char)0xFF;
1748                 ndx = -ndx;
1749                 diff = ndx - prev_negative;
1750                 prev_negative = ndx;
1751         }
1752
1753         /* A diff of 1 - 253 is sent as a one-byte diff; a diff of 254 - 32767
1754          * or 0 is sent as a 0xFE + a two-byte diff; otherwise we send 0xFE
1755          * & all 4 bytes of the (non-negative) num with the high-bit set. */
1756         if (diff < 0xFE && diff > 0)
1757                 b[cnt++] = (char)diff;
1758         else if (diff < 0 || diff > 0x7FFF) {
1759                 b[cnt++] = (char)0xFE;
1760                 b[cnt++] = (char)((ndx >> 24) | 0x80);
1761                 b[cnt++] = (char)ndx;
1762                 b[cnt++] = (char)(ndx >> 8);
1763                 b[cnt++] = (char)(ndx >> 16);
1764         } else {
1765                 b[cnt++] = (char)0xFE;
1766                 b[cnt++] = (char)(diff >> 8);
1767                 b[cnt++] = (char)diff;
1768         }
1769         writefd(f, b, cnt);
1770 }
1771
1772 /* Receive a file-list index using a byte-reduction method. */
1773 int32 read_ndx(int f)
1774 {
1775         static int32 prev_positive = -1, prev_negative = 1;
1776         int32 *prev_ptr, num;
1777         char b[4];
1778
1779         if (protocol_version < 30)
1780                 return read_int(f);
1781
1782         readfd(f, b, 1);
1783         if (CVAL(b, 0) == 0xFF) {
1784                 readfd(f, b, 1);
1785                 prev_ptr = &prev_negative;
1786         } else if (CVAL(b, 0) == 0)
1787                 return NDX_DONE;
1788         else
1789                 prev_ptr = &prev_positive;
1790         if (CVAL(b, 0) == 0xFE) {
1791                 readfd(f, b, 2);
1792                 if (CVAL(b, 0) & 0x80) {
1793                         b[3] = CVAL(b, 0) & ~0x80;
1794                         b[0] = b[1];
1795                         readfd(f, b+1, 2);
1796                         num = IVAL(b, 0);
1797                 } else
1798                         num = (UVAL(b,0)<<8) + UVAL(b,1) + *prev_ptr;
1799         } else
1800                 num = UVAL(b, 0) + *prev_ptr;
1801         *prev_ptr = num;
1802         if (prev_ptr == &prev_negative)
1803                 num = -num;
1804         return num;
1805 }
1806
1807 /* Read a line of up to bufsiz-1 characters into buf.  Strips
1808  * the (required) trailing newline and all carriage returns.
1809  * Returns 1 for success; 0 for I/O error or truncation. */
1810 int read_line_old(int f, char *buf, size_t bufsiz)
1811 {
1812         bufsiz--; /* leave room for the null */
1813         while (bufsiz > 0) {
1814                 buf[0] = 0;
1815                 read_buf(f, buf, 1);
1816                 if (buf[0] == 0)
1817                         return 0;
1818                 if (buf[0] == '\n')
1819                         break;
1820                 if (buf[0] != '\r') {
1821                         buf++;
1822                         bufsiz--;
1823                 }
1824         }
1825         *buf = '\0';
1826         return bufsiz > 0;
1827 }
1828
1829 void io_printf(int fd, const char *format, ...)
1830 {
1831         va_list ap;
1832         char buf[BIGPATHBUFLEN];
1833         int len;
1834
1835         va_start(ap, format);
1836         len = vsnprintf(buf, sizeof buf, format, ap);
1837         va_end(ap);
1838
1839         if (len < 0)
1840                 exit_cleanup(RERR_STREAMIO);
1841
1842         if (len > (int)sizeof buf) {
1843                 rprintf(FERROR, "io_printf() was too long for the buffer.\n");
1844                 exit_cleanup(RERR_STREAMIO);
1845         }
1846
1847         write_sbuf(fd, buf);
1848 }
1849
1850 /** Setup for multiplexing a MSG_* stream with the data stream. */
1851 void io_start_multiplex_out(void)
1852 {
1853         io_flush(NORMAL_FLUSH);
1854         io_start_buffering_out(sock_f_out);
1855         io_multiplexing_out = 1;
1856 }
1857
1858 /** Setup for multiplexing a MSG_* stream with the data stream. */
1859 void io_start_multiplex_in(void)
1860 {
1861         io_flush(NORMAL_FLUSH);
1862         io_start_buffering_in(sock_f_in);
1863         io_multiplexing_in = 1;
1864 }
1865
1866 /** Write an message to the multiplexed data stream. */
1867 int io_multiplex_write(enum msgcode code, const char *buf, size_t len, int convert)
1868 {
1869         if (!io_multiplexing_out)
1870                 return 0;
1871         io_flush(NORMAL_FLUSH);
1872         stats.total_written += (len+4);
1873         mplex_write(sock_f_out, code, buf, len, convert);
1874         return 1;
1875 }
1876
1877 void io_end_multiplex_in(void)
1878 {
1879         io_multiplexing_in = 0;
1880         io_end_buffering_in();
1881 }
1882
1883 /** Stop output multiplexing. */
1884 void io_end_multiplex_out(void)
1885 {
1886         io_multiplexing_out = 0;
1887         io_end_buffering_out();
1888 }
1889
1890 void start_write_batch(int fd)
1891 {
1892         /* Some communication has already taken place, but we don't
1893          * enable batch writing until here so that we can write a
1894          * canonical record of the communication even though the
1895          * actual communication so far depends on whether a daemon
1896          * is involved. */
1897         write_int(batch_fd, protocol_version);
1898         if (protocol_version >= 30)
1899                 write_byte(batch_fd, inc_recurse);
1900         write_int(batch_fd, checksum_seed);
1901
1902         if (am_sender)
1903                 write_batch_monitor_out = fd;
1904         else
1905                 write_batch_monitor_in = fd;
1906 }
1907
1908 void stop_write_batch(void)
1909 {
1910         write_batch_monitor_out = -1;
1911         write_batch_monitor_in = -1;
1912 }