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/** If no timeout is specified then use a 60 second select timeout */ 33#define SELECT_TIMEOUT 60 34 35extern int bwlimit; 36extern size_t bwlimit_writemax; 37extern int io_timeout; 38extern int allowed_lull; 39extern int am_server; 40extern int am_daemon; 41extern int am_sender; 42extern int am_generator; 43extern int eol_nulls; 44extern int read_batch; 45extern int csum_length; 46extern int checksum_seed; 47extern int protocol_version; 48extern int remove_source_files; 49extern int preserve_hard_links; 50extern char *filesfrom_host; 51extern struct stats stats; 52extern struct file_list *the_file_list; 53 54const char phase_unknown[] = "unknown"; 55int ignore_timeout = 0; 56int batch_fd = -1; 57int batch_gen_fd = -1; 58 59/* Ignore an EOF error if non-zero. See whine_about_eof(). */ 60int kluge_around_eof = 0; 61 62int msg_fd_in = -1; 63int msg_fd_out = -1; 64int sock_f_in = -1; 65int sock_f_out = -1; 66 67static int io_multiplexing_out; 68static int io_multiplexing_in; 69static time_t last_io_in; 70static time_t last_io_out; 71static int no_flush; 72 73static int write_batch_monitor_in = -1; 74static int write_batch_monitor_out = -1; 75 76static int io_filesfrom_f_in = -1; 77static int io_filesfrom_f_out = -1; 78static char io_filesfrom_buf[2048]; 79static char *io_filesfrom_bp; 80static char io_filesfrom_lastchar; 81static int io_filesfrom_buflen; 82static int defer_forwarding_messages = 0; 83static int select_timeout = SELECT_TIMEOUT; 84static int active_filecnt = 0; 85static OFF_T active_bytecnt = 0; 86 87static void read_loop(int fd, char *buf, size_t len); 88 89struct flist_ndx_item { 90 struct flist_ndx_item *next; 91 int ndx; 92}; 93 94struct flist_ndx_list { 95 struct flist_ndx_item *head, *tail; 96}; 97 98static struct flist_ndx_list redo_list, hlink_list; 99 100struct msg_list_item { 101 struct msg_list_item *next; 102 int len; 103 char buf[1]; 104}; 105 106struct msg_list { 107 struct msg_list_item *head, *tail; 108}; 109 110static struct msg_list msg2genr, msg2sndr; 111 112static void flist_ndx_push(struct flist_ndx_list *lp, int ndx) 113{ 114 struct flist_ndx_item *item; 115 116 if (!(item = new(struct flist_ndx_item))) 117 out_of_memory("flist_ndx_push"); 118 item->next = NULL; 119 item->ndx = ndx; 120 if (lp->tail) 121 lp->tail->next = item; 122 else 123 lp->head = item; 124 lp->tail = item; 125} 126 127static int flist_ndx_pop(struct flist_ndx_list *lp) 128{ 129 struct flist_ndx_item *next; 130 int ndx; 131 132 if (!lp->head) 133 return -1; 134 135 ndx = lp->head->ndx; 136 next = lp->head->next; 137 free(lp->head); 138 lp->head = next; 139 if (!next) 140 lp->tail = NULL; 141 142 return ndx; 143} 144 145static void check_timeout(void) 146{ 147 time_t t; 148 149 if (!io_timeout || ignore_timeout) 150 return; 151 152 if (!last_io_in) { 153 last_io_in = time(NULL); 154 return; 155 } 156 157 t = time(NULL); 158 159 if (t - last_io_in >= io_timeout) { 160 if (!am_server && !am_daemon) { 161 rprintf(FERROR, "io timeout after %d seconds -- exiting\n", 162 (int)(t-last_io_in)); 163 } 164 exit_cleanup(RERR_TIMEOUT); 165 } 166} 167 168/* Note the fds used for the main socket (which might really be a pipe 169 * for a local transfer, but we can ignore that). */ 170void io_set_sock_fds(int f_in, int f_out) 171{ 172 sock_f_in = f_in; 173 sock_f_out = f_out; 174} 175 176void set_io_timeout(int secs) 177{ 178 io_timeout = secs; 179 180 if (!io_timeout || io_timeout > SELECT_TIMEOUT) 181 select_timeout = SELECT_TIMEOUT; 182 else 183 select_timeout = io_timeout; 184 185 allowed_lull = read_batch ? 0 : (io_timeout + 1) / 2; 186} 187 188/* Setup the fd used to receive MSG_* messages. Only needed during the 189 * early stages of being a local sender (up through the sending of the 190 * file list) or when we're the generator (to fetch the messages from 191 * the receiver). */ 192void set_msg_fd_in(int fd) 193{ 194 msg_fd_in = fd; 195} 196 197/* Setup the fd used to send our MSG_* messages. Only needed when 198 * we're the receiver (to send our messages to the generator). */ 199void set_msg_fd_out(int fd) 200{ 201 msg_fd_out = fd; 202 set_nonblocking(msg_fd_out); 203} 204 205/* Add a message to the pending MSG_* list. */ 206static void msg_list_add(struct msg_list *lst, int code, char *buf, int len) 207{ 208 struct msg_list_item *m; 209 int sz = len + 4 + sizeof m[0] - 1; 210 211 if (!(m = (struct msg_list_item *)new_array(char, sz))) 212 out_of_memory("msg_list_add"); 213 m->next = NULL; 214 m->len = len + 4; 215 SIVAL(m->buf, 0, ((code+MPLEX_BASE)<<24) | len); 216 memcpy(m->buf + 4, buf, len); 217 if (lst->tail) 218 lst->tail->next = m; 219 else 220 lst->head = m; 221 lst->tail = m; 222} 223 224/* Read a message from the MSG_* fd and handle it. This is called either 225 * during the early stages of being a local sender (up through the sending 226 * of the file list) or when we're the generator (to fetch the messages 227 * from the receiver). */ 228static void read_msg_fd(void) 229{ 230 char buf[2048]; 231 size_t n; 232 int fd = msg_fd_in; 233 int tag, len; 234 235 /* Temporarily disable msg_fd_in. This is needed to avoid looping back 236 * to this routine from writefd_unbuffered(). */ 237 msg_fd_in = -1; 238 239 memset(buf, 0, 4); 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. */ 316void 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 329void 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. */ 338static 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 374int send_msg(enum msgcode code, 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 389int 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 402int 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 */ 417void 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. */ 438static 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 */ 467static 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 */ 622int 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 671static char *iobuf_out; 672static int iobuf_out_cnt; 673 674void 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 683static char *iobuf_in; 684static size_t iobuf_in_siz; 685 686void 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 695void 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 704void 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 710void 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 **/ 728static 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 */ 744static 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 **/ 839static 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 858int read_shortint(int f) 859{ 860 uchar b[2]; 861 readfd(f, (char *)b, 2); 862 return (b[1] << 8) + b[0]; 863} 864 865int32 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 877int64 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 897void read_buf(int f,char *buf,size_t len) 898{ 899 readfd(f,buf,len); 900} 901 902void read_sbuf(int f,char *buf,size_t len) 903{ 904 readfd(f, buf, len); 905 buf[len] = '\0'; 906} 907 908uchar read_byte(int f) 909{ 910 uchar c; 911 readfd(f, (char *)&c, 1); 912 return c; 913} 914 915int 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. */ 936void 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. */ 967void 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 **/ 997static 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. */ 1042static void writefd_unbuffered(int fd,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 1139static 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 **/ 1160static void mplex_write(enum msgcode code, 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 1185void 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 1200static void writefd(int fd,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 1234void 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 1242void 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 */ 1253void 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 1274void write_buf(int f,char *buf,size_t len) 1275{ 1276 writefd(f,buf,len); 1277} 1278 1279/** Write a string to the connection */ 1280void write_sbuf(int f, char *buf) 1281{ 1282 writefd(f, buf, strlen(buf)); 1283} 1284 1285void write_byte(int f, uchar c) 1286{ 1287 writefd(f, (char *)&c, 1); 1288} 1289 1290void write_vstring(int f, 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 **/ 1317int 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 1335void 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. */ 1357void 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. */ 1365void 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. */ 1373int io_multiplex_write(enum msgcode code, 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 1384void close_multiplexing_in(void) 1385{ 1386 io_multiplexing_in = 0; 1387} 1388 1389/** Stop output multiplexing. */ 1390void close_multiplexing_out(void) 1391{ 1392 io_multiplexing_out = 0; 1393} 1394 1395void 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 1413void stop_write_batch(void) 1414{ 1415 write_batch_monitor_out = -1; 1416 write_batch_monitor_in = -1; 1417} 1418