-/*
- Copyright (C) Andrew Tridgell 1996
+/* -*- c-file-style: "linux" -*-
+
+ Copyright (C) 1996-2001 by Andrew Tridgell
Copyright (C) Paul Mackerras 1996
+ Copyright (C) 2001, 2002 by Martin Pool <mbp@samba.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
-/*
- Utilities used in rsync
+/**
+ * @file io.c
+ *
+ * Socket and pipe IO utilities used in rsync.
+ *
+ * rsync provides its own multiplexing system, which is used to send
+ * stderr and stdout over a single socket. We need this because
+ * stdout normally carries the binary data stream, and stderr all our
+ * error messages.
+ *
+ * For historical reasons this is off during the start of the
+ * connection, but it's switched on quite early using
+ * io_start_multiplex_out() and io_start_multiplex_in().
+ **/
- tridge, June 1996
- */
#include "rsync.h"
-static int64 total_written;
-static int64 total_read;
+/* if no timeout is specified then use a 60 second select timeout */
+#define SELECT_TIMEOUT 60
static int io_multiplexing_out;
static int io_multiplexing_in;
static int multiplex_in_fd;
static int multiplex_out_fd;
static time_t last_io;
-static int eof_error=1;
+static int no_flush;
+
+extern int bwlimit;
extern int verbose;
extern int io_timeout;
+extern struct stats stats;
-int64 write_total(void)
-{
- return total_written;
-}
+/** Ignore EOF errors while reading a module listing if the remote
+ version is 24 or less. */
+int kludge_around_eof = False;
-int64 read_total(void)
-{
- return total_read;
-}
-static int buffer_f_in = -1;
+static int io_error_fd = -1;
-void setup_readbuffer(int f_in)
-{
- buffer_f_in = f_in;
-}
+static void read_loop(int fd, char *buf, size_t len);
static void check_timeout(void)
{
+ extern int am_server, am_daemon;
time_t t;
+
+ err_list_push();
if (!io_timeout) return;
t = time(NULL);
- if (last_io && io_timeout && (t-last_io)>io_timeout) {
- rprintf(FERROR,"read timeout after %d second - exiting\n",
- (int)(t-last_io));
- exit_cleanup(1);
+ if (last_io && io_timeout && (t-last_io) >= io_timeout) {
+ if (!am_server && !am_daemon) {
+ rprintf(FERROR,"io timeout after %d seconds - exiting\n",
+ (int)(t-last_io));
+ }
+ exit_cleanup(RERR_TIMEOUT);
+ }
+}
+
+/* setup the fd used to propogate errors */
+void io_set_error_fd(int fd)
+{
+ io_error_fd = fd;
+}
+
+/* read some data from the error fd and write it to the write log code */
+static void read_error_fd(void)
+{
+ char buf[200];
+ size_t n;
+ int fd = io_error_fd;
+ int tag, len;
+
+ /* io_error_fd is temporarily disabled -- is this meant to
+ * prevent indefinite recursion? */
+ io_error_fd = -1;
+
+ read_loop(fd, buf, 4);
+ tag = IVAL(buf, 0);
+
+ len = tag & 0xFFFFFF;
+ tag = tag >> 24;
+ tag -= MPLEX_BASE;
+
+ while (len) {
+ n = len;
+ if (n > (sizeof(buf)-1))
+ n = sizeof(buf)-1;
+ read_loop(fd, buf, n);
+ rwrite((enum logcode)tag, buf, n);
+ len -= n;
}
+
+ io_error_fd = fd;
}
-static char *read_buffer;
-static char *read_buffer_p;
-static int read_buffer_len;
-static int read_buffer_size;
+static void whine_about_eof (void)
+{
+ /**
+ It's almost always an error to get an EOF when we're trying
+ to read from the network, because the protocol is
+ self-terminating.
+
+ However, there is one unfortunate cases where it is not,
+ which is rsync <2.4.6 sending a list of modules on a
+ server, since the list is terminated by closing the socket.
+ So, for the section of the program where that is a problem
+ (start_socket_client), kludge_around_eof is True and we
+ just exit.
+ */
+
+ if (kludge_around_eof)
+ exit_cleanup (0);
+ else {
+ rprintf (FERROR,
+ "%s: connection unexpectedly closed "
+ "(%.0f bytes read so far)\n",
+ RSYNC_NAME, (double)stats.total_read);
+
+ exit_cleanup (RERR_STREAMIO);
+ }
+}
+
-/* read from a socket with IO timeout. return the number of
- bytes read. If no bytes can be read then exit, never return
- a number <= 0 */
-static int read_timeout(int fd, char *buf, int len)
+static void die_from_readerr (int err)
+{
+ /* this prevents us trying to write errors on a dead socket */
+ io_multiplexing_close();
+
+ rprintf(FERROR, "%s: read error: %s\n",
+ RSYNC_NAME, strerror (err));
+ exit_cleanup(RERR_STREAMIO);
+}
+
+
+/*!
+ * Read from a socket with IO timeout. return the number of bytes
+ * read. If no bytes can be read then exit, never return a number <= 0.
+ *
+ * TODO: If the remote shell connection fails, then current versions
+ * actually report an "unexpected EOF" error here. Since it's a
+ * fairly common mistake to try to use rsh when ssh is required, we
+ * should trap that: if we fail to read any data at all, we should
+ * give a better explanation. We can tell whether the connection has
+ * started by looking e.g. at whether the remote version is known yet.
+ */
+static int read_timeout (int fd, char *buf, size_t len)
{
int n, ret=0;
io_flush();
while (ret == 0) {
+ /* until we manage to read *something* */
fd_set fds;
struct timeval tv;
+ int fd_count = fd+1;
+ int count;
FD_ZERO(&fds);
FD_SET(fd, &fds);
- tv.tv_sec = io_timeout;
+ if (io_error_fd != -1) {
+ FD_SET(io_error_fd, &fds);
+ if (io_error_fd > fd) fd_count = io_error_fd+1;
+ }
+
+ tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT;
tv.tv_usec = 0;
- if (select(fd+1, &fds, NULL, NULL,
- io_timeout?&tv:NULL) != 1) {
+ errno = 0;
+
+ count = select(fd_count, &fds, NULL, NULL, &tv);
+
+ if (count == 0) {
check_timeout();
+ }
+
+ if (count <= 0) {
+ if (errno == EBADF) {
+ exit_cleanup(RERR_SOCKETIO);
+ }
continue;
}
+ if (io_error_fd != -1 && FD_ISSET(io_error_fd, &fds)) {
+ read_error_fd();
+ }
+
+ if (!FD_ISSET(fd, &fds)) continue;
+
n = read(fd, buf, len);
if (n > 0) {
if (io_timeout)
last_io = time(NULL);
continue;
+ } else if (n == 0) {
+ whine_about_eof ();
+ return -1; /* doesn't return */
+ } else if (n == -1) {
+ if (errno == EINTR || errno == EWOULDBLOCK ||
+ errno == EAGAIN)
+ continue;
+ else
+ die_from_readerr (errno);
}
-
- if (n == -1 && errno == EINTR) {
- continue;
- }
-
- if (n == 0) {
- if (eof_error) {
- rprintf(FERROR,"EOF in read_timeout\n");
- }
- exit_cleanup(1);
- }
-
- rprintf(FERROR,"read error: %s\n", strerror(errno));
- exit_cleanup(1);
}
return ret;
}
-/* continue trying to read len bytes - don't return until len
- has been read */
-static void read_loop(int fd, char *buf, int len)
+
+
+
+/*! Continue trying to read len bytes - don't return until len has
+ been read. */
+static void read_loop (int fd, char *buf, size_t len)
{
while (len) {
int n = read_timeout(fd, buf, len);
}
}
-/* read from the file descriptor handling multiplexing -
- return number of bytes read
- never return <= 0 */
-static int read_unbuffered(int fd, char *buf, int len)
+
+/**
+ * Read from the file descriptor handling multiplexing - return number
+ * of bytes read.
+ *
+ * Never returns <= 0.
+ */
+static int read_unbuffered(int fd, char *buf, size_t len)
{
- static int remaining;
- char ibuf[4];
- int tag, ret=0;
+ static size_t remaining;
+ int tag, ret = 0;
char line[1024];
- if (!io_multiplexing_in || fd != multiplex_in_fd)
+ if (!io_multiplexing_in || fd != multiplex_in_fd)
return read_timeout(fd, buf, len);
while (ret == 0) {
continue;
}
- read_loop(fd, ibuf, 4);
- tag = IVAL(ibuf, 0);
+ read_loop(fd, line, 4);
+ tag = IVAL(line, 0);
remaining = tag & 0xFFFFFF;
tag = tag >> 24;
- if (tag == MPLEX_BASE) continue;
+ if (tag == MPLEX_BASE)
+ continue;
tag -= MPLEX_BASE;
if (tag != FERROR && tag != FINFO) {
- rprintf(FERROR,"unexpected tag %d\n", tag);
- exit_cleanup(1);
+ rprintf(FERROR, "unexpected tag %d\n", tag);
+ exit_cleanup(RERR_STREAMIO);
}
- if (remaining > sizeof(line)-1) {
- rprintf(FERROR,"multiplexing overflow %d\n\n",
+ if (remaining > sizeof(line) - 1) {
+ rprintf(FERROR, "multiplexing overflow %d\n\n",
remaining);
- exit_cleanup(1);
+ exit_cleanup(RERR_STREAMIO);
}
read_loop(fd, line, remaining);
line[remaining] = 0;
- rprintf(tag,"%s", line);
+ rprintf((enum logcode) tag, "%s", line);
remaining = 0;
}
-/* This function was added to overcome a deadlock problem when using
- * ssh. It looks like we can't allow our receive queue to get full or
- * ssh will clag up. Uggh. */
-static void read_check(int f)
-{
- int n = 8192;
-
- if (f == -1) return;
-
- if (read_buffer_len == 0) {
- read_buffer_p = read_buffer;
- }
-
- if (n > MAX_READ_BUFFER/4)
- n = MAX_READ_BUFFER/4;
-
- if (read_buffer_p != read_buffer) {
- memmove(read_buffer,read_buffer_p,read_buffer_len);
- read_buffer_p = read_buffer;
- }
-
- if (n > (read_buffer_size - read_buffer_len)) {
- read_buffer_size += n;
- read_buffer = (char *)Realloc(read_buffer,read_buffer_size);
- if (!read_buffer) out_of_memory("read check");
- read_buffer_p = read_buffer;
- }
-
- n = read_unbuffered(f,read_buffer+read_buffer_len,n);
- read_buffer_len += n;
-}
-
-
/* do a buffered read from fd. don't return until all N bytes
have been read. If all N can't be read then exit with an error */
-static void readfd(int fd,char *buffer,int N)
+static void readfd (int fd, char *buffer, size_t N)
{
int ret;
- int total=0;
-
- if (read_buffer_len < N && N < 1024) {
- read_check(buffer_f_in);
- }
+ size_t total=0;
while (total < N) {
- if (read_buffer_len > 0 && buffer_f_in == fd) {
- ret = MIN(read_buffer_len,N-total);
- memcpy(buffer+total,read_buffer_p,ret);
- read_buffer_p += ret;
- read_buffer_len -= ret;
- total += ret;
- continue;
- }
-
io_flush();
- ret = read_unbuffered(fd,buffer + total,N-total);
+ ret = read_unbuffered (fd, buffer + total, N-total);
total += ret;
}
+
+ stats.total_read += total;
}
int32 read_int(int f)
{
char b[4];
+ int32 ret;
+
readfd(f,b,4);
- total_read += 4;
- return IVAL(b,0);
+ ret = IVAL(b,0);
+ if (ret == (int32)0xffffffff) return -1;
+ return ret;
}
int64 read_longint(int f)
char b[8];
ret = read_int(f);
- if ((int32)ret != (int32)0xffffffff) return ret;
+ if ((int32)ret != (int32)0xffffffff) {
+ return ret;
+ }
#ifdef NO_INT64
rprintf(FERROR,"Integer overflow - attempted 64 bit offset\n");
- exit_cleanup(1);
+ exit_cleanup(RERR_UNSUPPORTED);
#else
if (remote_version >= 16) {
readfd(f,b,8);
- total_read += 8;
ret = IVAL(b,0) | (((int64)IVAL(b,4))<<32);
}
#endif
return ret;
}
-void read_buf(int f,char *buf,int len)
+void read_buf(int f,char *buf,size_t len)
{
readfd(f,buf,len);
- total_read += len;
}
-void read_sbuf(int f,char *buf,int len)
+void read_sbuf(int f,char *buf,size_t len)
{
- read_buf(f,buf,len);
+ read_buf (f,buf,len);
buf[len] = 0;
}
unsigned char read_byte(int f)
{
unsigned char c;
- read_buf(f,(char *)&c,1);
+ read_buf (f, (char *)&c, 1);
return c;
}
-
-
-/* write len bytes to fd, possibly reading from buffer_f_in if set
- in order to unclog the pipe. don't return until all len
- bytes have been written */
-static void writefd_unbuffered(int fd,char *buf,int len)
+/* Write len bytes to fd. This underlies the multiplexing system,
+ * which is always called by application code. */
+static void writefd_unbuffered(int fd,char *buf,size_t len)
{
- int total = 0;
+ size_t total = 0;
fd_set w_fds, r_fds;
int fd_count, count;
struct timeval tv;
- int reading;
- reading = (buffer_f_in != -1 && read_buffer_len < MAX_READ_BUFFER);
+ err_list_push();
+
+ no_flush++;
while (total < len) {
FD_ZERO(&w_fds);
FD_ZERO(&r_fds);
FD_SET(fd,&w_fds);
- fd_count = fd+1;
+ fd_count = fd;
- if (reading) {
- FD_SET(buffer_f_in,&r_fds);
- if (buffer_f_in > fd)
- fd_count = buffer_f_in+1;
+ if (io_error_fd != -1) {
+ FD_SET(io_error_fd,&r_fds);
+ if (io_error_fd > fd_count)
+ fd_count = io_error_fd;
}
- tv.tv_sec = io_timeout;
+ tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT;
tv.tv_usec = 0;
- count = select(fd_count,
- reading?&r_fds:NULL,
+ errno = 0;
+
+ count = select(fd_count+1,
+ io_error_fd != -1?&r_fds:NULL,
&w_fds,NULL,
- io_timeout?&tv:NULL);
+ &tv);
- if (count <= 0) {
+ if (count == 0) {
check_timeout();
+ }
+
+ if (count <= 0) {
+ if (errno == EBADF) {
+ exit_cleanup(RERR_SOCKETIO);
+ }
continue;
}
+ if (io_error_fd != -1 && FD_ISSET(io_error_fd, &r_fds)) {
+ read_error_fd();
+ }
+
if (FD_ISSET(fd, &w_fds)) {
- int ret = write(fd,buf+total,len-total);
+ int ret;
+ size_t n = len-total;
+ ret = write(fd,buf+total,n);
if (ret == -1 && errno == EINTR) {
continue;
}
+ if (ret == -1 &&
+ (errno == EWOULDBLOCK || errno == EAGAIN)) {
+ msleep(1);
+ continue;
+ }
+
if (ret <= 0) {
- rprintf(FERROR,"erroring writing %d bytes - exiting\n", len);
- exit_cleanup(1);
+ /* Don't try to write errors back
+ * across the stream */
+ io_multiplexing_close();
+ rprintf(FERROR, RSYNC_NAME
+ ": error writing %d unbuffered bytes"
+ " - exiting: %s\n", len,
+ strerror(errno));
+ exit_cleanup(RERR_STREAMIO);
}
+ /* Sleep after writing to limit I/O bandwidth */
+ if (bwlimit)
+ {
+ tv.tv_sec = 0;
+ tv.tv_usec = ret * 1000 / bwlimit;
+ while (tv.tv_usec > 1000000)
+ {
+ tv.tv_sec++;
+ tv.tv_usec -= 1000000;
+ }
+ select(0, NULL, NULL, NULL, &tv);
+ }
+
total += ret;
+
if (io_timeout)
last_io = time(NULL);
- continue;
- }
-
- if (reading && FD_ISSET(buffer_f_in, &r_fds)) {
- read_check(buffer_f_in);
}
}
+
+ no_flush--;
}
{
if (io_buffer) return;
multiplex_out_fd = fd;
- io_buffer = (char *)malloc(IO_BUFFER_SIZE+4);
+ io_buffer = (char *)malloc(IO_BUFFER_SIZE);
if (!io_buffer) out_of_memory("writefd");
io_buffer_count = 0;
+}
+
+/* write an message to a multiplexed stream. If this fails then rsync
+ exits */
+static void mplex_write(int fd, enum logcode code, char *buf, size_t len)
+{
+ char buffer[4096];
+ size_t n = len;
+
+ SIVAL(buffer, 0, ((MPLEX_BASE + (int)code)<<24) + len);
- /* leave room for the multiplex header in case it's needed */
- io_buffer += 4;
+ if (n > (sizeof(buffer)-4)) {
+ n = sizeof(buffer)-4;
+ }
+
+ memcpy(&buffer[4], buf, n);
+ writefd_unbuffered(fd, buffer, n+4);
+
+ len -= n;
+ buf += n;
+
+ if (len) {
+ writefd_unbuffered(fd, buf, len);
+ }
}
+
void io_flush(void)
{
int fd = multiplex_out_fd;
- if (!io_buffer_count) return;
+
+ err_list_push();
+
+ if (!io_buffer_count || no_flush) return;
if (io_multiplexing_out) {
- SIVAL(io_buffer-4, 0, (MPLEX_BASE<<24) + io_buffer_count);
- writefd_unbuffered(fd, io_buffer-4, io_buffer_count+4);
+ mplex_write(fd, FNONE, io_buffer, io_buffer_count);
} else {
writefd_unbuffered(fd, io_buffer, io_buffer_count);
}
io_buffer_count = 0;
}
-void io_end_buffering(int fd)
+
+void io_end_buffering(void)
{
io_flush();
if (!io_multiplexing_out) {
- free(io_buffer-4);
+ free(io_buffer);
io_buffer = NULL;
}
}
-static void writefd(int fd,char *buf,int len)
+static void writefd(int fd,char *buf,size_t len)
{
- if (!io_buffer) {
+ stats.total_written += len;
+
+ err_list_push();
+
+ if (!io_buffer || fd != multiplex_out_fd) {
writefd_unbuffered(fd, buf, len);
return;
}
while (len) {
- int n = MIN(len, IO_BUFFER_SIZE-io_buffer_count);
+ int n = MIN((int) len, IO_BUFFER_SIZE-io_buffer_count);
if (n > 0) {
memcpy(io_buffer+io_buffer_count, buf, n);
buf += n;
char b[4];
SIVAL(b,0,x);
writefd(f,b,4);
- total_written += 4;
}
+
+/*
+ * Note: int64 may actually be a 32-bit type if ./configure couldn't find any
+ * 64-bit types on this platform.
+ */
void write_longint(int f, int64 x)
{
extern int remote_version;
return;
}
- write_int(f, -1);
+ write_int(f, (int32)0xFFFFFFFF);
SIVAL(b,0,(x&0xFFFFFFFF));
SIVAL(b,4,((x>>32)&0xFFFFFFFF));
writefd(f,b,8);
- total_written += 8;
}
-void write_buf(int f,char *buf,int len)
+void write_buf(int f,char *buf,size_t len)
{
writefd(f,buf,len);
- total_written += len;
}
/* write a string to the connection */
-void write_sbuf(int f,char *buf)
+static void write_sbuf(int f,char *buf)
{
write_buf(f, buf, strlen(buf));
}
write_buf(f,(char *)&c,1);
}
-int read_line(int f, char *buf, int maxlen)
-{
- eof_error = 0;
+
+/**
+ * Read a line of up to @p maxlen characters into @p buf. Does not
+ * contain a trailing newline or carriage return.
+ *
+ * @return 1 for success; 0 for io error or truncation.
+ **/
+int read_line(int f, char *buf, size_t maxlen)
+{
while (maxlen) {
buf[0] = 0;
read_buf(f, buf, 1);
- if (buf[0] == 0) return 0;
+ if (buf[0] == 0)
+ return 0;
if (buf[0] == '\n') {
buf[0] = 0;
break;
return 0;
}
- eof_error = 1;
-
return 1;
}
int len;
va_start(ap, format);
- len = vslprintf(buf, sizeof(buf)-1, format, ap);
+ len = vsnprintf(buf, sizeof(buf), format, ap);
va_end(ap);
- if (len < 0) exit_cleanup(1);
+ if (len < 0) exit_cleanup(RERR_STREAMIO);
write_sbuf(fd, buf);
}
{
multiplex_in_fd = fd;
io_flush();
- if (read_buffer_len) {
- fprintf(stderr,"ERROR: data in read buffer at mplx start\n");
- exit_cleanup(1);
- }
-
io_multiplexing_in = 1;
}
-/* write an message to the error stream */
-int io_multiplex_write(int f, char *buf, int len)
+/* write an message to the multiplexed error stream */
+int io_multiplex_write(enum logcode code, char *buf, size_t len)
{
if (!io_multiplexing_out) return 0;
io_flush();
-
- SIVAL(io_buffer-4, 0, ((MPLEX_BASE + f)<<24) + len);
- memcpy(io_buffer, buf, len);
-
- writefd_unbuffered(multiplex_out_fd, io_buffer-4, len+4);
+ stats.total_written += (len+4);
+ mplex_write(multiplex_out_fd, code, buf, len);
return 1;
}
-void io_close_input(int fd)
+/* stop output multiplexing */
+void io_multiplexing_close(void)
{
- buffer_f_in = -1;
+ io_multiplexing_out = 0;
}
+