2 * Socket and pipe I/O utilities used in rsync.
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
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.
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.
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.
24 /* Rsync provides its own multiplexing system, which is used to send
25 * stderr and stdout over a single socket.
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(). */
33 /** If no timeout is specified then use a 60 second select timeout */
34 #define SELECT_TIMEOUT 60
37 extern size_t bwlimit_writemax;
38 extern int io_timeout;
39 extern int allowed_lull;
43 extern int am_generator;
45 extern int read_batch;
46 extern int csum_length;
47 extern int checksum_seed;
48 extern int protocol_version;
49 extern int remove_source_files;
50 extern int preserve_hard_links;
51 extern char *filesfrom_host;
52 extern struct stats stats;
53 extern struct file_list *the_file_list;
55 const char phase_unknown[] = "unknown";
56 int ignore_timeout = 0;
58 int batch_gen_fd = -1;
60 /* Ignore an EOF error if non-zero. See whine_about_eof(). */
61 int kluge_around_eof = 0;
68 static int io_multiplexing_out;
69 static int io_multiplexing_in;
70 static time_t last_io_in;
71 static time_t last_io_out;
74 static int write_batch_monitor_in = -1;
75 static int write_batch_monitor_out = -1;
77 static int io_filesfrom_f_in = -1;
78 static int io_filesfrom_f_out = -1;
79 static char io_filesfrom_buf[2048];
80 static char *io_filesfrom_bp;
81 static char io_filesfrom_lastchar;
82 static int io_filesfrom_buflen;
83 static int defer_forwarding_messages = 0;
84 static int select_timeout = SELECT_TIMEOUT;
85 static int active_filecnt = 0;
86 static OFF_T active_bytecnt = 0;
88 static void read_loop(int fd, char *buf, size_t len);
90 struct flist_ndx_item {
91 struct flist_ndx_item *next;
95 struct flist_ndx_list {
96 struct flist_ndx_item *head, *tail;
99 static struct flist_ndx_list redo_list, hlink_list;
101 struct msg_list_item {
102 struct msg_list_item *next;
108 struct msg_list_item *head, *tail;
111 static struct msg_list msg2genr, msg2sndr;
113 static void flist_ndx_push(struct flist_ndx_list *lp, int ndx)
115 struct flist_ndx_item *item;
117 if (!(item = new(struct flist_ndx_item)))
118 out_of_memory("flist_ndx_push");
122 lp->tail->next = item;
128 static int flist_ndx_pop(struct flist_ndx_list *lp)
130 struct flist_ndx_item *next;
137 next = lp->head->next;
146 static void check_timeout(void)
150 if (!io_timeout || ignore_timeout)
154 last_io_in = time(NULL);
160 if (t - last_io_in >= io_timeout) {
161 if (!am_server && !am_daemon) {
162 rprintf(FERROR, "io timeout after %d seconds -- exiting\n",
163 (int)(t-last_io_in));
165 exit_cleanup(RERR_TIMEOUT);
169 /* Note the fds used for the main socket (which might really be a pipe
170 * for a local transfer, but we can ignore that). */
171 void io_set_sock_fds(int f_in, int f_out)
177 void set_io_timeout(int secs)
181 if (!io_timeout || io_timeout > SELECT_TIMEOUT)
182 select_timeout = SELECT_TIMEOUT;
184 select_timeout = io_timeout;
186 allowed_lull = read_batch ? 0 : (io_timeout + 1) / 2;
189 /* Setup the fd used to receive MSG_* messages. Only needed during the
190 * early stages of being a local sender (up through the sending of the
191 * file list) or when we're the generator (to fetch the messages from
193 void set_msg_fd_in(int fd)
198 /* Setup the fd used to send our MSG_* messages. Only needed when
199 * we're the receiver (to send our messages to the generator). */
200 void set_msg_fd_out(int fd)
203 set_nonblocking(msg_fd_out);
206 /* Add a message to the pending MSG_* list. */
207 static void msg_list_add(struct msg_list *lst, int code, char *buf, int len)
209 struct msg_list_item *m;
210 int sz = len + 4 + sizeof m[0] - 1;
212 if (!(m = (struct msg_list_item *)new_array(char, sz)))
213 out_of_memory("msg_list_add");
216 SIVAL(m->buf, 0, ((code+MPLEX_BASE)<<24) | len);
217 memcpy(m->buf + 4, buf, len);
225 /* Read a message from the MSG_* fd and handle it. This is called either
226 * during the early stages of being a local sender (up through the sending
227 * of the file list) or when we're the generator (to fetch the messages
228 * from the receiver). */
229 static void read_msg_fd(void)
236 /* Temporarily disable msg_fd_in. This is needed to avoid looping back
237 * to this routine from writefd_unbuffered(). */
240 read_loop(fd, buf, 4);
243 len = tag & 0xFFFFFF;
244 tag = (tag >> 24) - MPLEX_BASE;
248 if (len != 0 || !am_generator) {
249 rprintf(FERROR, "invalid message %d:%d\n", tag, len);
250 exit_cleanup(RERR_STREAMIO);
252 flist_ndx_push(&redo_list, -1);
255 if (len != 4 || !am_generator) {
256 rprintf(FERROR, "invalid message %d:%d\n", tag, len);
257 exit_cleanup(RERR_STREAMIO);
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));
265 if (len >= (int)sizeof buf || !am_generator) {
266 rprintf(FERROR, "invalid message %d:%d\n", tag, len);
267 exit_cleanup(RERR_STREAMIO);
269 read_loop(fd, buf, len);
270 send_msg(MSG_DELETED, buf, len);
273 if (len != 4 || !am_generator) {
274 rprintf(FERROR, "invalid message %d:%d\n", tag, len);
275 exit_cleanup(RERR_STREAMIO);
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);
282 if (preserve_hard_links)
283 flist_ndx_push(&hlink_list, IVAL(buf,0));
287 rprintf(FERROR, "invalid message %d:%d\n", tag, len);
288 exit_cleanup(RERR_STREAMIO);
290 close_multiplexing_out();
299 read_loop(fd, buf, n);
305 rprintf(FERROR, "unknown message %d:%d [%s]\n",
306 tag, len, who_am_i());
307 exit_cleanup(RERR_STREAMIO);
313 /* This is used by the generator to limit how many file transfers can
314 * be active at once when --remove-source-files is specified. Without
315 * this, sender-side deletions were mostly happening at the end. */
316 void increment_active_files(int ndx, int itemizing, enum logcode code)
318 /* TODO: tune these limits? */
319 while (active_filecnt >= (active_bytecnt >= 128*1024 ? 10 : 50)) {
321 check_for_finished_hlinks(itemizing, code);
326 active_bytecnt += the_file_list->files[ndx]->length;
329 void decrement_active_files(int ndx)
332 active_bytecnt -= the_file_list->files[ndx]->length;
335 /* Try to push messages off the list onto the wire. If we leave with more
336 * to do, return 0. On error, return -1. If everything flushed, return 1.
337 * This is only active in the receiver. */
338 static int msg2genr_flush(int flush_it_all)
340 static int written = 0;
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);
353 if (errno != EWOULDBLOCK && errno != EAGAIN)
358 FD_SET(msg_fd_out, &fds);
359 tv.tv_sec = select_timeout;
361 if (!select(msg_fd_out+1, NULL, &fds, NULL, &tv))
363 } else if ((written += n) == m->len) {
364 msg2genr.head = m->next;
366 msg2genr.tail = NULL;
374 int send_msg(enum msgcode code, char *buf, int len)
376 if (msg_fd_out < 0) {
377 if (!defer_forwarding_messages)
378 return io_multiplex_write(code, buf, len);
379 if (!io_multiplexing_out)
381 msg_list_add(&msg2sndr, code, buf, len);
384 msg_list_add(&msg2genr, code, buf, len);
385 msg2genr_flush(NORMAL_FLUSH);
389 int get_redo_num(int itemizing, enum logcode code)
393 check_for_finished_hlinks(itemizing, code);
399 return flist_ndx_pop(&redo_list);
402 int get_hlink_num(void)
404 return flist_ndx_pop(&hlink_list);
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).
417 void io_set_filesfrom_fds(int f_in, int f_out)
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;
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.
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.
435 * There is another case for older protocol versions (< 24) where the module
436 * listing was not terminated, so we must ignore an EOF error in that case and
437 * exit. In this situation, kluge_around_eof will be > 0. */
438 static void whine_about_eof(int fd)
440 if (kluge_around_eof && fd == sock_f_in) {
442 if (kluge_around_eof > 0)
444 /* If we're still here after 10 seconds, exit with an error. */
445 for (i = 10*1000/20; i--; )
449 rprintf(FERROR, RSYNC_NAME ": connection unexpectedly closed "
450 "(%.0f bytes received so far) [%s]\n",
451 (double)stats.total_read, who_am_i());
453 exit_cleanup(RERR_STREAMIO);
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.
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.
467 static int read_timeout(int fd, char *buf, size_t len)
471 io_flush(NORMAL_FLUSH);
474 /* until we manage to read *something* */
484 FD_SET(msg_fd_out, &w_fds);
485 if (msg_fd_out > maxfd)
488 if (io_filesfrom_f_out >= 0) {
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;
495 io_filesfrom_f_out = -1;
499 FD_SET(io_filesfrom_f_out, &w_fds);
500 new_fd = io_filesfrom_f_out;
506 tv.tv_sec = select_timeout;
511 count = select(maxfd + 1, &r_fds, &w_fds, NULL, &tv);
515 exit_cleanup(RERR_SOCKETIO);
520 if (msg2genr.head && FD_ISSET(msg_fd_out, &w_fds))
521 msg2genr_flush(NORMAL_FLUSH);
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,
528 io_filesfrom_buflen);
530 if (!(io_filesfrom_buflen -= l))
531 io_filesfrom_bp = io_filesfrom_buf;
533 io_filesfrom_bp += l;
535 /* XXX should we complain? */
536 io_filesfrom_f_out = -1;
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,
543 sizeof io_filesfrom_buf);
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;
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')
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--;
566 io_filesfrom_bp = io_filesfrom_buf;
568 char *f = io_filesfrom_bp;
571 /* Eliminate any multi-'\0' runs. */
573 if (!(*t++ = *f++)) {
574 while (f != eob && !*f)
578 io_filesfrom_lastchar = f[-1];
580 io_filesfrom_buflen = l;
586 if (!FD_ISSET(fd, &r_fds))
589 n = read(fd, buf, len);
593 whine_about_eof(fd); /* Doesn't return. */
594 if (errno == EINTR || errno == EWOULDBLOCK
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");
603 rsyserr(FERROR, errno, "read error");
604 exit_cleanup(RERR_STREAMIO);
611 if (fd == sock_f_in && io_timeout)
612 last_io_in = time(NULL);
619 * Read a line into the "fname" buffer (which must be at least MAXPATHLEN
622 int read_filesfrom_line(int fd, char *fname)
624 char ch, *s, *eob = fname + MAXPATHLEN - 1;
626 int reading_remotely = filesfrom_host != NULL;
627 int nulls = eol_nulls || reading_remotely;
632 cnt = read(fd, &ch, 1);
633 if (cnt < 0 && (errno == EWOULDBLOCK
634 || errno == EINTR || errno == EAGAIN)) {
639 tv.tv_sec = select_timeout;
641 if (!select(fd+1, &fds, NULL, NULL, &tv))
647 if (nulls? !ch : (ch == '\r' || ch == '\n')) {
648 /* Skip empty lines if reading locally. */
649 if (!reading_remotely && s == fname)
659 if (*fname == '#' || *fname == ';')
665 static char *iobuf_out;
666 static int iobuf_out_cnt;
668 void io_start_buffering_out(void)
672 if (!(iobuf_out = new_array(char, IO_BUFFER_SIZE)))
673 out_of_memory("io_start_buffering_out");
677 static char *iobuf_in;
678 static size_t iobuf_in_siz;
680 void io_start_buffering_in(void)
684 iobuf_in_siz = 2 * IO_BUFFER_SIZE;
685 if (!(iobuf_in = new_array(char, iobuf_in_siz)))
686 out_of_memory("io_start_buffering_in");
689 void io_end_buffering(void)
691 io_flush(NORMAL_FLUSH);
692 if (!io_multiplexing_out) {
698 void maybe_flush_socket(void)
700 if (iobuf_out && iobuf_out_cnt && time(NULL) - last_io_out >= 5)
701 io_flush(NORMAL_FLUSH);
704 void maybe_send_keepalive(void)
706 if (time(NULL) - last_io_out >= allowed_lull) {
707 if (!iobuf_out || !iobuf_out_cnt) {
708 if (protocol_version < 29)
709 return; /* there's nothing we can do */
710 write_int(sock_f_out, the_file_list->count);
711 write_shortint(sock_f_out, ITEM_IS_NEW);
714 io_flush(NORMAL_FLUSH);
719 * Continue trying to read len bytes - don't return until len has been
722 static void read_loop(int fd, char *buf, size_t len)
725 int n = read_timeout(fd, buf, len);
733 * Read from the file descriptor handling multiplexing - return number
736 * Never returns <= 0.
738 static int readfd_unbuffered(int fd, char *buf, size_t len)
740 static size_t remaining;
741 static size_t iobuf_in_ndx;
744 char line[BIGPATHBUFLEN];
746 if (!iobuf_in || fd != sock_f_in)
747 return read_timeout(fd, buf, len);
749 if (!io_multiplexing_in && remaining == 0) {
750 remaining = read_timeout(fd, iobuf_in, iobuf_in_siz);
756 len = MIN(len, remaining);
757 memcpy(buf, iobuf_in + iobuf_in_ndx, len);
764 read_loop(fd, line, 4);
767 msg_bytes = tag & 0xFFFFFF;
768 tag = (tag >> 24) - MPLEX_BASE;
772 if (msg_bytes > iobuf_in_siz) {
773 if (!(iobuf_in = realloc_array(iobuf_in, char,
775 out_of_memory("readfd_unbuffered");
776 iobuf_in_siz = msg_bytes;
778 read_loop(fd, iobuf_in, msg_bytes);
779 remaining = msg_bytes;
783 if (msg_bytes >= sizeof line)
785 read_loop(fd, line, msg_bytes);
786 /* A directory name was sent with the trailing null */
787 if (msg_bytes > 0 && !line[msg_bytes-1])
788 log_delete(line, S_IFDIR);
790 line[msg_bytes] = '\0';
791 log_delete(line, S_IFREG);
795 if (msg_bytes != 4) {
796 rprintf(FERROR, "invalid multi-message %d:%ld [%s]\n",
797 tag, (long)msg_bytes, who_am_i());
798 exit_cleanup(RERR_STREAMIO);
800 read_loop(fd, line, msg_bytes);
801 successful_send(IVAL(line, 0));
805 if (msg_bytes >= sizeof line) {
808 "multiplexing overflow %d:%ld [%s]\n",
809 tag, (long)msg_bytes, who_am_i());
810 exit_cleanup(RERR_STREAMIO);
812 read_loop(fd, line, msg_bytes);
813 rwrite((enum logcode)tag, line, msg_bytes);
816 rprintf(FERROR, "unexpected tag %d [%s]\n",
818 exit_cleanup(RERR_STREAMIO);
823 io_flush(NORMAL_FLUSH);
829 * Do a buffered read from @p fd. Don't return until all @p n bytes
830 * have been read. If all @p n can't be read then exit with an
833 static void readfd(int fd, char *buffer, size_t N)
839 cnt = readfd_unbuffered(fd, buffer + total, N-total);
843 if (fd == write_batch_monitor_in) {
844 if ((size_t)write(batch_fd, buffer, total) != total)
845 exit_cleanup(RERR_FILEIO);
849 stats.total_read += total;
852 int read_shortint(int f)
855 readfd(f, (char *)b, 2);
856 return (b[1] << 8) + b[0];
859 int32 read_int(int f)
866 if (num == (int32)0xffffffff)
871 int64 read_longint(int f)
877 if ((int32)num != (int32)0xffffffff)
881 rprintf(FERROR, "Integer overflow: attempted 64-bit offset\n");
882 exit_cleanup(RERR_UNSUPPORTED);
885 num = IVAL(b,0) | (((int64)IVAL(b,4))<<32);
891 void read_buf(int f,char *buf,size_t len)
896 void read_sbuf(int f,char *buf,size_t len)
902 uchar read_byte(int f)
905 readfd(f, (char *)&c, 1);
909 int read_vstring(int f, char *buf, int bufsize)
911 int len = read_byte(f);
914 len = (len & ~0x80) * 0x100 + read_byte(f);
916 if (len >= bufsize) {
917 rprintf(FERROR, "over-long vstring received (%d > %d)\n",
928 /* Populate a sum_struct with values from the socket. This is
929 * called by both the sender and the receiver. */
930 void read_sum_head(int f, struct sum_struct *sum)
932 sum->count = read_int(f);
933 if (sum->count < 0) {
934 rprintf(FERROR, "Invalid checksum count %ld [%s]\n",
935 (long)sum->count, who_am_i());
936 exit_cleanup(RERR_PROTOCOL);
938 sum->blength = read_int(f);
939 if (sum->blength < 0 || sum->blength > MAX_BLOCK_SIZE) {
940 rprintf(FERROR, "Invalid block length %ld [%s]\n",
941 (long)sum->blength, who_am_i());
942 exit_cleanup(RERR_PROTOCOL);
944 sum->s2length = protocol_version < 27 ? csum_length : (int)read_int(f);
945 if (sum->s2length < 0 || sum->s2length > MD4_SUM_LENGTH) {
946 rprintf(FERROR, "Invalid checksum length %d [%s]\n",
947 sum->s2length, who_am_i());
948 exit_cleanup(RERR_PROTOCOL);
950 sum->remainder = read_int(f);
951 if (sum->remainder < 0 || sum->remainder > sum->blength) {
952 rprintf(FERROR, "Invalid remainder length %ld [%s]\n",
953 (long)sum->remainder, who_am_i());
954 exit_cleanup(RERR_PROTOCOL);
958 /* Send the values from a sum_struct over the socket. Set sum to
959 * NULL if there are no checksums to send. This is called by both
960 * the generator and the sender. */
961 void write_sum_head(int f, struct sum_struct *sum)
963 static struct sum_struct null_sum;
968 write_int(f, sum->count);
969 write_int(f, sum->blength);
970 if (protocol_version >= 27)
971 write_int(f, sum->s2length);
972 write_int(f, sum->remainder);
976 * Sleep after writing to limit I/O bandwidth usage.
978 * @todo Rather than sleeping after each write, it might be better to
979 * use some kind of averaging. The current algorithm seems to always
980 * use a bit less bandwidth than specified, because it doesn't make up
981 * for slow periods. But arguably this is a feature. In addition, we
982 * ought to take the time used to write the data into account.
984 * During some phases of big transfers (file FOO is uptodate) this is
985 * called with a small bytes_written every time. As the kernel has to
986 * round small waits up to guarantee that we actually wait at least the
987 * requested number of microseconds, this can become grossly inaccurate.
988 * We therefore keep track of the bytes we've written over time and only
989 * sleep when the accumulated delay is at least 1 tenth of a second.
991 static void sleep_for_bwlimit(int bytes_written)
993 static struct timeval prior_tv;
994 static long total_written = 0;
995 struct timeval tv, start_tv;
996 long elapsed_usec, sleep_usec;
998 #define ONE_SEC 1000000L /* # of microseconds in a second */
1000 if (!bwlimit_writemax)
1003 total_written += bytes_written;
1005 gettimeofday(&start_tv, NULL);
1006 if (prior_tv.tv_sec) {
1007 elapsed_usec = (start_tv.tv_sec - prior_tv.tv_sec) * ONE_SEC
1008 + (start_tv.tv_usec - prior_tv.tv_usec);
1009 total_written -= elapsed_usec * bwlimit / (ONE_SEC/1024);
1010 if (total_written < 0)
1014 sleep_usec = total_written * (ONE_SEC/1024) / bwlimit;
1015 if (sleep_usec < ONE_SEC / 10) {
1016 prior_tv = start_tv;
1020 tv.tv_sec = sleep_usec / ONE_SEC;
1021 tv.tv_usec = sleep_usec % ONE_SEC;
1022 select(0, NULL, NULL, NULL, &tv);
1024 gettimeofday(&prior_tv, NULL);
1025 elapsed_usec = (prior_tv.tv_sec - start_tv.tv_sec) * ONE_SEC
1026 + (prior_tv.tv_usec - start_tv.tv_usec);
1027 total_written = (sleep_usec - elapsed_usec) * bwlimit / (ONE_SEC/1024);
1030 /* Write len bytes to the file descriptor fd, looping as necessary to get
1031 * the job done and also (in certain circumstances) reading any data on
1032 * msg_fd_in to avoid deadlock.
1034 * This function underlies the multiplexing system. The body of the
1035 * application never calls this function directly. */
1036 static void writefd_unbuffered(int fd,char *buf,size_t len)
1038 size_t n, total = 0;
1039 fd_set w_fds, r_fds;
1040 int maxfd, count, cnt, using_r_fds;
1041 int defer_save = defer_forwarding_messages;
1046 while (total < len) {
1051 if (msg_fd_in >= 0) {
1053 FD_SET(msg_fd_in,&r_fds);
1054 if (msg_fd_in > maxfd)
1060 tv.tv_sec = select_timeout;
1064 count = select(maxfd + 1, using_r_fds ? &r_fds : NULL,
1068 if (count < 0 && errno == EBADF)
1069 exit_cleanup(RERR_SOCKETIO);
1074 if (using_r_fds && FD_ISSET(msg_fd_in, &r_fds))
1077 if (!FD_ISSET(fd, &w_fds))
1081 if (bwlimit_writemax && n > bwlimit_writemax)
1082 n = bwlimit_writemax;
1083 cnt = write(fd, buf + total, n);
1089 if (errno == EWOULDBLOCK || errno == EAGAIN) {
1095 /* Don't try to write errors back across the stream. */
1096 if (fd == sock_f_out)
1097 close_multiplexing_out();
1098 rsyserr(FERROR, errno,
1099 "writefd_unbuffered failed to write %ld bytes [%s]",
1100 (long)len, who_am_i());
1101 /* If the other side is sending us error messages, try
1102 * to grab any messages they sent before they died. */
1103 while (fd == sock_f_out && io_multiplexing_in) {
1106 readfd_unbuffered(sock_f_in, io_filesfrom_buf,
1107 sizeof io_filesfrom_buf);
1109 exit_cleanup(RERR_STREAMIO);
1113 defer_forwarding_messages = 1;
1115 if (fd == sock_f_out) {
1116 if (io_timeout || am_generator)
1117 last_io_out = time(NULL);
1118 sleep_for_bwlimit(cnt);
1122 defer_forwarding_messages = defer_save;
1126 static void msg2sndr_flush(void)
1128 if (defer_forwarding_messages)
1131 while (msg2sndr.head && io_multiplexing_out) {
1132 struct msg_list_item *m = msg2sndr.head;
1133 if (!(msg2sndr.head = m->next))
1134 msg2sndr.tail = NULL;
1135 stats.total_written += m->len;
1136 defer_forwarding_messages = 1;
1137 writefd_unbuffered(sock_f_out, m->buf, m->len);
1138 defer_forwarding_messages = 0;
1144 * Write an message to a multiplexed stream. If this fails then rsync
1147 static void mplex_write(enum msgcode code, char *buf, size_t len)
1152 SIVAL(buffer, 0, ((MPLEX_BASE + (int)code)<<24) + len);
1154 if (n > sizeof buffer - 4)
1157 memcpy(buffer + 4, buf, n);
1159 writefd_unbuffered(sock_f_out, buffer, n+4);
1165 defer_forwarding_messages = 1;
1166 writefd_unbuffered(sock_f_out, buf, len);
1167 defer_forwarding_messages = 0;
1172 void io_flush(int flush_it_all)
1174 msg2genr_flush(flush_it_all);
1177 if (!iobuf_out_cnt || no_flush)
1180 if (io_multiplexing_out)
1181 mplex_write(MSG_DATA, iobuf_out, iobuf_out_cnt);
1183 writefd_unbuffered(sock_f_out, iobuf_out, iobuf_out_cnt);
1187 static void writefd(int fd,char *buf,size_t len)
1189 if (fd == msg_fd_out) {
1190 rprintf(FERROR, "Internal error: wrong write used in receiver.\n");
1191 exit_cleanup(RERR_PROTOCOL);
1194 if (fd == sock_f_out)
1195 stats.total_written += len;
1197 if (fd == write_batch_monitor_out) {
1198 if ((size_t)write(batch_fd, buf, len) != len)
1199 exit_cleanup(RERR_FILEIO);
1202 if (!iobuf_out || fd != sock_f_out) {
1203 writefd_unbuffered(fd, buf, len);
1208 int n = MIN((int)len, IO_BUFFER_SIZE - iobuf_out_cnt);
1210 memcpy(iobuf_out+iobuf_out_cnt, buf, n);
1216 if (iobuf_out_cnt == IO_BUFFER_SIZE)
1217 io_flush(NORMAL_FLUSH);
1221 void write_shortint(int f, int x)
1226 writefd(f, (char *)b, 2);
1229 void write_int(int f,int32 x)
1237 * Note: int64 may actually be a 32-bit type if ./configure couldn't find any
1238 * 64-bit types on this platform.
1240 void write_longint(int f, int64 x)
1244 if (x <= 0x7FFFFFFF) {
1245 write_int(f, (int)x);
1249 #if SIZEOF_INT64 < 8
1250 rprintf(FERROR, "Integer overflow: attempted 64-bit offset\n");
1251 exit_cleanup(RERR_UNSUPPORTED);
1253 write_int(f, (int32)0xFFFFFFFF);
1254 SIVAL(b,0,(x&0xFFFFFFFF));
1255 SIVAL(b,4,((x>>32)&0xFFFFFFFF));
1261 void write_buf(int f,char *buf,size_t len)
1266 /** Write a string to the connection */
1267 void write_sbuf(int f, char *buf)
1269 writefd(f, buf, strlen(buf));
1272 void write_byte(int f, uchar c)
1274 writefd(f, (char *)&c, 1);
1277 void write_vstring(int f, char *str, int len)
1279 uchar lenbuf[3], *lb = lenbuf;
1284 "attempting to send over-long vstring (%d > %d)\n",
1286 exit_cleanup(RERR_PROTOCOL);
1288 *lb++ = len / 0x100 + 0x80;
1292 writefd(f, (char*)lenbuf, lb - lenbuf + 1);
1294 writefd(f, str, len);
1298 * Read a line of up to @p maxlen characters into @p buf (not counting
1299 * the trailing null). Strips the (required) trailing newline and all
1302 * @return 1 for success; 0 for I/O error or truncation.
1304 int read_line(int f, char *buf, size_t maxlen)
1308 read_buf(f, buf, 1);
1313 if (buf[0] != '\r') {
1322 void io_printf(int fd, const char *format, ...)
1325 char buf[BIGPATHBUFLEN];
1328 va_start(ap, format);
1329 len = vsnprintf(buf, sizeof buf, format, ap);
1333 exit_cleanup(RERR_STREAMIO);
1335 if (len > (int)sizeof buf) {
1336 rprintf(FERROR, "io_printf() was too long for the buffer.\n");
1337 exit_cleanup(RERR_STREAMIO);
1340 write_sbuf(fd, buf);
1343 /** Setup for multiplexing a MSG_* stream with the data stream. */
1344 void io_start_multiplex_out(void)
1346 io_flush(NORMAL_FLUSH);
1347 io_start_buffering_out();
1348 io_multiplexing_out = 1;
1351 /** Setup for multiplexing a MSG_* stream with the data stream. */
1352 void io_start_multiplex_in(void)
1354 io_flush(NORMAL_FLUSH);
1355 io_start_buffering_in();
1356 io_multiplexing_in = 1;
1359 /** Write an message to the multiplexed data stream. */
1360 int io_multiplex_write(enum msgcode code, char *buf, size_t len)
1362 if (!io_multiplexing_out)
1365 io_flush(NORMAL_FLUSH);
1366 stats.total_written += (len+4);
1367 mplex_write(code, buf, len);
1371 void close_multiplexing_in(void)
1373 io_multiplexing_in = 0;
1376 /** Stop output multiplexing. */
1377 void close_multiplexing_out(void)
1379 io_multiplexing_out = 0;
1382 void start_write_batch(int fd)
1384 write_stream_flags(batch_fd);
1386 /* Some communication has already taken place, but we don't
1387 * enable batch writing until here so that we can write a
1388 * canonical record of the communication even though the
1389 * actual communication so far depends on whether a daemon
1391 write_int(batch_fd, protocol_version);
1392 write_int(batch_fd, checksum_seed);
1395 write_batch_monitor_out = fd;
1397 write_batch_monitor_in = fd;
1400 void stop_write_batch(void)
1402 write_batch_monitor_out = -1;
1403 write_batch_monitor_in = -1;