1 /* -*- c-file-style: "linux" -*-
3 * Copyright (C) 1996-2001 by Andrew Tridgell
4 * Copyright (C) Paul Mackerras 1996
5 * Copyright (C) 2001, 2002 by Martin Pool <mbp@samba.org>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 * Socket and pipe IO utilities used in rsync.
27 * rsync provides its own multiplexing system, which is used to send
28 * stderr and stdout over a single socket. We need this because
29 * stdout normally carries the binary data stream, and stderr all our
32 * For historical reasons this is off during the start of the
33 * connection, but it's switched on quite early using
34 * io_start_multiplex_out() and io_start_multiplex_in().
39 /** If no timeout is specified then use a 60 second select timeout */
40 #define SELECT_TIMEOUT 60
42 static int io_multiplexing_out;
43 static int io_multiplexing_in;
44 static int multiplex_in_fd;
45 static int multiplex_out_fd;
46 static time_t last_io;
51 extern int io_timeout;
52 extern struct stats stats;
55 const char phase_unknown[] = "unknown";
58 * The connection might be dropped at some point; perhaps because the
59 * remote instance crashed. Just giving the offset on the stream is
60 * not very helpful. So instead we try to make io_phase_name point to
63 * For buffered/multiplexed IO these names will be somewhat
64 * approximate; perhaps for ease of support we would rather make the
65 * buffer always flush when a single application-level IO finishes.
67 * @todo Perhaps we want some simple stack functionality, but there's
68 * no need to overdo it.
70 const char *io_write_phase = phase_unknown;
71 const char *io_read_phase = phase_unknown;
73 /** Ignore EOF errors while reading a module listing if the remote
74 version is 24 or less. */
75 int kludge_around_eof = False;
78 static int io_error_fd = -1;
79 static int io_filesfrom_f_in = -1;
80 static int io_filesfrom_f_out = -1;
81 static char io_filesfrom_buf[2048];
82 static char *io_filesfrom_bp;
83 static char io_filesfrom_lastchar;
84 static int io_filesfrom_buflen;
86 static void read_loop(int fd, char *buf, size_t len);
88 static void check_timeout(void)
90 extern int am_server, am_daemon;
95 if (!io_timeout) return;
104 if (last_io && io_timeout && (t-last_io) >= io_timeout) {
105 if (!am_server && !am_daemon) {
106 rprintf(FERROR,"io timeout after %d seconds - exiting\n",
109 exit_cleanup(RERR_TIMEOUT);
113 /** Setup the fd used to propagate errors */
114 void io_set_error_fd(int fd)
119 /** Read some data from the error fd and write it to the write log code */
120 static void read_error_fd(void)
124 int fd = io_error_fd;
127 /* io_error_fd is temporarily disabled -- is this meant to
128 * prevent indefinite recursion? */
131 read_loop(fd, buf, 4);
134 len = tag & 0xFFFFFF;
140 if (n > (sizeof buf - 1))
142 read_loop(fd, buf, n);
143 rwrite((enum logcode)tag, buf, n);
151 * When we're the receiver and we have a local --files-from list of names
152 * that needs to be sent over the socket to the sender, we have to do two
153 * things at the same time: send the sender a list of what files we're
154 * processing and read the incoming file+info list from the sender. We do
155 * this by augmenting the read_timeout() function to copy this data. It
156 * uses the io_filesfrom_buf to read a block of data from f_in (when it is
157 * ready, since it might be a pipe) and then blast it out f_out (when it
158 * is ready to receive more data).
160 void io_set_filesfrom_fds(int f_in, int f_out)
162 io_filesfrom_f_in = f_in;
163 io_filesfrom_f_out = f_out;
164 io_filesfrom_bp = io_filesfrom_buf;
165 io_filesfrom_lastchar = '\0';
166 io_filesfrom_buflen = 0;
170 * It's almost always an error to get an EOF when we're trying to read
171 * from the network, because the protocol is self-terminating.
173 * However, there is one unfortunate cases where it is not, which is
174 * rsync <2.4.6 sending a list of modules on a server, since the list
175 * is terminated by closing the socket. So, for the section of the
176 * program where that is a problem (start_socket_client),
177 * kludge_around_eof is True and we just exit.
179 static void whine_about_eof(void)
181 if (kludge_around_eof)
185 "%s: connection unexpectedly closed "
186 "(%.0f bytes read so far)\n",
187 RSYNC_NAME, (double)stats.total_read);
189 exit_cleanup(RERR_STREAMIO);
194 static void die_from_readerr(int err)
196 /* this prevents us trying to write errors on a dead socket */
197 io_multiplexing_close();
199 rprintf(FERROR, "%s: read error: %s\n",
200 RSYNC_NAME, strerror(err));
201 exit_cleanup(RERR_STREAMIO);
206 * Read from a socket with IO timeout. return the number of bytes
207 * read. If no bytes can be read then exit, never return a number <= 0.
209 * TODO: If the remote shell connection fails, then current versions
210 * actually report an "unexpected EOF" error here. Since it's a
211 * fairly common mistake to try to use rsh when ssh is required, we
212 * should trap that: if we fail to read any data at all, we should
213 * give a better explanation. We can tell whether the connection has
214 * started by looking e.g. at whether the remote version is known yet.
216 static int read_timeout(int fd, char *buf, size_t len)
223 /* until we manage to read *something* */
231 if (io_error_fd != -1) {
232 FD_SET(io_error_fd, &r_fds);
233 if (io_error_fd >= fd_count) fd_count = io_error_fd+1;
235 if (io_filesfrom_f_out != -1) {
237 if (io_filesfrom_buflen == 0) {
238 if (io_filesfrom_f_in != -1) {
239 FD_SET(io_filesfrom_f_in, &r_fds);
240 new_fd = io_filesfrom_f_in;
242 io_filesfrom_f_out = -1;
247 FD_SET(io_filesfrom_f_out, &w_fds);
248 new_fd = io_filesfrom_f_out;
250 if (new_fd >= fd_count) fd_count = new_fd+1;
253 tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT;
258 count = select(fd_count, &r_fds,
259 io_filesfrom_buflen? &w_fds : NULL,
267 if (errno == EBADF) {
268 exit_cleanup(RERR_SOCKETIO);
273 if (io_error_fd != -1 && FD_ISSET(io_error_fd, &r_fds)) {
277 if (io_filesfrom_f_out != -1) {
278 if (io_filesfrom_buflen) {
279 if (FD_ISSET(io_filesfrom_f_out, &w_fds)) {
280 int l = write(io_filesfrom_f_out,
282 io_filesfrom_buflen);
284 if (!(io_filesfrom_buflen -= l))
285 io_filesfrom_bp = io_filesfrom_buf;
287 io_filesfrom_bp += l;
289 /* XXX should we complain? */
290 io_filesfrom_f_out = -1;
293 } else if (io_filesfrom_f_in != -1) {
294 if (FD_ISSET(io_filesfrom_f_in, &r_fds)) {
295 int l = read(io_filesfrom_f_in,
297 sizeof io_filesfrom_buf);
299 /* Send end-of-file marker */
300 io_filesfrom_buf[0] = '\0';
301 io_filesfrom_buf[1] = '\0';
302 io_filesfrom_buflen = io_filesfrom_lastchar? 2 : 1;
303 io_filesfrom_f_in = -1;
305 extern int eol_nulls;
307 char *s = io_filesfrom_buf + l;
308 /* Transform CR and/or LF into '\0' */
309 while (s-- > io_filesfrom_buf) {
310 if (*s == '\n' || *s == '\r')
314 if (!io_filesfrom_lastchar) {
315 /* Last buf ended with a '\0', so don't
316 * let this buf start with one. */
317 while (l && !*io_filesfrom_bp)
318 io_filesfrom_bp++, l--;
321 io_filesfrom_bp = io_filesfrom_buf;
323 char *f = io_filesfrom_bp;
326 /* Eliminate any multi-'\0' runs. */
328 if (!(*t++ = *f++)) {
329 while (f != eob && !*f)
333 io_filesfrom_lastchar = f[-1];
335 io_filesfrom_buflen = l;
341 if (!FD_ISSET(fd, &r_fds)) continue;
343 n = read(fd, buf, len);
350 last_io = time(NULL);
354 return -1; /* doesn't return */
355 } else if (n == -1) {
356 if (errno == EINTR || errno == EWOULDBLOCK ||
359 die_from_readerr(errno);
367 * Read a line into the "fname" buffer (which must be at least MAXPATHLEN
370 int read_filesfrom_line(int fd, char *fname)
372 char ch, *s, *eob = fname + MAXPATHLEN - 1;
374 extern int io_timeout;
375 extern int eol_nulls;
376 extern char *remote_filesfrom_file;
377 int reading_remotely = remote_filesfrom_file != NULL;
378 int nulls = eol_nulls || reading_remotely;
383 cnt = read(fd, &ch, 1);
384 if (cnt < 0 && (errno == EWOULDBLOCK
385 || errno == EINTR || errno == EAGAIN)) {
390 tv.tv_sec = io_timeout? io_timeout : SELECT_TIMEOUT;
392 if (!select(fd+1, &fds, NULL, NULL, &tv))
398 if (nulls? !ch : (ch == '\r' || ch == '\n')) {
399 /* Skip empty lines if reading locally. */
400 if (!reading_remotely && s == fname)
409 /* Dump comments if reading locally. */
410 if (!reading_remotely && (*fname == '#' || *fname == ';'))
418 * Continue trying to read len bytes - don't return until len has been
421 static void read_loop(int fd, char *buf, size_t len)
424 int n = read_timeout(fd, buf, len);
433 * Read from the file descriptor handling multiplexing - return number
436 * Never returns <= 0.
438 static int read_unbuffered(int fd, char *buf, size_t len)
440 static size_t remaining;
444 if (!io_multiplexing_in || fd != multiplex_in_fd)
445 return read_timeout(fd, buf, len);
449 len = MIN(len, remaining);
450 read_loop(fd, buf, len);
456 read_loop(fd, line, 4);
459 remaining = tag & 0xFFFFFF;
462 if (tag == MPLEX_BASE)
467 if (tag != FERROR && tag != FINFO) {
468 rprintf(FERROR, "unexpected tag %d\n", tag);
469 exit_cleanup(RERR_STREAMIO);
472 if (remaining > sizeof line - 1) {
473 rprintf(FERROR, "multiplexing overflow %ld\n\n",
475 exit_cleanup(RERR_STREAMIO);
478 read_loop(fd, line, remaining);
481 rprintf((enum logcode) tag, "%s", line);
491 * Do a buffered read from @p fd. Don't return until all @p n bytes
492 * have been read. If all @p n can't be read then exit with an
495 static void readfd(int fd, char *buffer, size_t N)
503 ret = read_unbuffered(fd, buffer + total, N-total);
507 stats.total_read += total;
511 int32 read_int(int f)
518 if (ret == (int32)0xffffffff) return -1;
522 int64 read_longint(int f)
528 if ((int32)ret != (int32)0xffffffff) {
533 rprintf(FERROR,"Integer overflow - attempted 64 bit offset\n");
534 exit_cleanup(RERR_UNSUPPORTED);
537 ret = IVAL(b,0) | (((int64)IVAL(b,4))<<32);
543 void read_buf(int f,char *buf,size_t len)
548 void read_sbuf(int f,char *buf,size_t len)
554 unsigned char read_byte(int f)
557 read_buf(f, (char *)&c, 1);
563 * Sleep after writing to limit I/O bandwidth usage.
565 * @todo Rather than sleeping after each write, it might be better to
566 * use some kind of averaging. The current algorithm seems to always
567 * use a bit less bandwidth than specified, because it doesn't make up
568 * for slow periods. But arguably this is a feature. In addition, we
569 * ought to take the time used to write the data into account.
571 static void sleep_for_bwlimit(int bytes_written)
578 assert(bytes_written > 0);
581 tv.tv_usec = bytes_written * 1000 / bwlimit;
582 tv.tv_sec = tv.tv_usec / 1000000;
583 tv.tv_usec = tv.tv_usec % 1000000;
585 select(0, NULL, NULL, NULL, &tv);
590 * Write len bytes to the file descriptor @p fd.
592 * This function underlies the multiplexing system. The body of the
593 * application never calls this function directly.
595 static void writefd_unbuffered(int fd,char *buf,size_t len)
606 while (total < len) {
611 if (io_error_fd != -1) {
613 FD_SET(io_error_fd,&r_fds);
614 if (io_error_fd > fd_count)
615 fd_count = io_error_fd;
618 tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT;
623 count = select(fd_count+1,
624 io_error_fd != -1?&r_fds:NULL,
633 if (errno == EBADF) {
634 exit_cleanup(RERR_SOCKETIO);
639 if (io_error_fd != -1 && FD_ISSET(io_error_fd, &r_fds)) {
643 if (FD_ISSET(fd, &w_fds)) {
645 size_t n = len-total;
646 ret = write(fd,buf+total,n);
648 if (ret == -1 && errno == EINTR) {
653 (errno == EWOULDBLOCK || errno == EAGAIN)) {
659 /* Don't try to write errors back
660 * across the stream */
661 io_multiplexing_close();
662 rprintf(FERROR, RSYNC_NAME
663 ": writefd_unbuffered failed to write %ld bytes: phase \"%s\": %s\n",
664 (long) len, io_write_phase,
666 exit_cleanup(RERR_STREAMIO);
669 sleep_for_bwlimit(ret);
674 last_io = time(NULL);
682 static char *io_buffer;
683 static int io_buffer_count;
685 void io_start_buffering(int fd)
687 if (io_buffer) return;
688 multiplex_out_fd = fd;
689 io_buffer = new_array(char, IO_BUFFER_SIZE);
690 if (!io_buffer) out_of_memory("writefd");
695 * Write an message to a multiplexed stream. If this fails then rsync
698 static void mplex_write(int fd, enum logcode code, char *buf, size_t len)
703 SIVAL(buffer, 0, ((MPLEX_BASE + (int)code)<<24) + len);
705 if (n > (sizeof buffer - 4)) {
706 n = sizeof buffer - 4;
709 memcpy(&buffer[4], buf, n);
710 writefd_unbuffered(fd, buffer, n+4);
716 writefd_unbuffered(fd, buf, len);
723 int fd = multiplex_out_fd;
727 if (!io_buffer_count || no_flush) return;
729 if (io_multiplexing_out) {
730 mplex_write(fd, FNONE, io_buffer, io_buffer_count);
732 writefd_unbuffered(fd, io_buffer, io_buffer_count);
738 void io_end_buffering(void)
741 if (!io_multiplexing_out) {
747 static void writefd(int fd,char *buf,size_t len)
749 stats.total_written += len;
753 if (!io_buffer || fd != multiplex_out_fd) {
754 writefd_unbuffered(fd, buf, len);
759 int n = MIN((int) len, IO_BUFFER_SIZE-io_buffer_count);
761 memcpy(io_buffer+io_buffer_count, buf, n);
764 io_buffer_count += n;
767 if (io_buffer_count == IO_BUFFER_SIZE) io_flush();
772 void write_int(int f,int32 x)
780 void write_int_named(int f, int32 x, const char *phase)
782 io_write_phase = phase;
784 io_write_phase = phase_unknown;
789 * Note: int64 may actually be a 32-bit type if ./configure couldn't find any
790 * 64-bit types on this platform.
792 void write_longint(int f, int64 x)
796 if (x <= 0x7FFFFFFF) {
797 write_int(f, (int)x);
802 rprintf(FERROR,"Integer overflow - attempted 64 bit offset\n");
803 exit_cleanup(RERR_UNSUPPORTED);
805 write_int(f, (int32)0xFFFFFFFF);
806 SIVAL(b,0,(x&0xFFFFFFFF));
807 SIVAL(b,4,((x>>32)&0xFFFFFFFF));
813 void write_buf(int f,char *buf,size_t len)
818 /** Write a string to the connection */
819 static void write_sbuf(int f,char *buf)
821 write_buf(f, buf, strlen(buf));
825 void write_byte(int f,unsigned char c)
827 write_buf(f,(char *)&c,1);
833 * Read a line of up to @p maxlen characters into @p buf. Does not
834 * contain a trailing newline or carriage return.
836 * @return 1 for success; 0 for io error or truncation.
838 int read_line(int f, char *buf, size_t maxlen)
845 if (buf[0] == '\n') {
849 if (buf[0] != '\r') {
863 void io_printf(int fd, const char *format, ...)
869 va_start(ap, format);
870 len = vsnprintf(buf, sizeof buf, format, ap);
873 if (len < 0) exit_cleanup(RERR_STREAMIO);
879 /** Setup for multiplexing an error stream with the data stream */
880 void io_start_multiplex_out(int fd)
882 multiplex_out_fd = fd;
884 io_start_buffering(fd);
885 io_multiplexing_out = 1;
888 /** Setup for multiplexing an error stream with the data stream */
889 void io_start_multiplex_in(int fd)
891 multiplex_in_fd = fd;
893 io_multiplexing_in = 1;
896 /** Write an message to the multiplexed error stream */
897 int io_multiplex_write(enum logcode code, char *buf, size_t len)
899 if (!io_multiplexing_out) return 0;
902 stats.total_written += (len+4);
903 mplex_write(multiplex_out_fd, code, buf, len);
907 /** Stop output multiplexing */
908 void io_multiplexing_close(void)
910 io_multiplexing_out = 0;