-/*
- Copyright (C) Andrew Tridgell 1996
+/* -*- c-file-style: "linux" -*-
+
+ Copyright (C) 1996-2001 by Andrew Tridgell
Copyright (C) Paul Mackerras 1996
+ Copyright (C) 2001 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 int total_written = 0;
-static int total_read = 0;
+/* 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 no_flush;
+
+extern int bwlimit;
extern int verbose;
+extern int io_timeout;
+extern struct stats stats;
+
+
+/** Ignore EOF errors while reading a module listing if the remote
+ version is 24 or less. */
+int kludge_around_eof = False;
+
+
+static int io_error_fd = -1;
+
+static void read_loop(int fd, char *buf, size_t len);
-int write_total(void)
+static void check_timeout(void)
{
- return total_written;
+ extern int am_server, am_daemon;
+ time_t t;
+
+ err_list_push();
+
+ if (!io_timeout) return;
+
+ if (!last_io) {
+ last_io = time(NULL);
+ return;
+ }
+
+ t = time(NULL);
+
+ 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);
+ }
}
-int read_total(void)
+/* setup the fd used to propogate errors */
+void io_set_error_fd(int fd)
{
- return total_read;
+ 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 int buffer_f_in = -1;
-void setup_nonblocking(int f_in,int f_out)
+static void whine_about_eof (void)
{
- set_blocking(f_out,0);
- buffer_f_in = f_in;
+ /**
+ 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);
+ }
}
-static char *read_buffer = NULL;
-static char *read_buffer_p = NULL;
-static int read_buffer_len = 0;
-static int read_buffer_size = 0;
+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);
+}
-/* 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)
+/*!
+ * 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;
-
- if (read_buffer_len == 0) {
- read_buffer_p = read_buffer;
- }
-
- if ((n=num_waiting(f)) <= 0)
- return;
-
- 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;
- if (!read_buffer)
- read_buffer = (char *)malloc(read_buffer_size);
- else
- read_buffer = (char *)realloc(read_buffer,read_buffer_size);
- if (!read_buffer) out_of_memory("read check");
- read_buffer_p = read_buffer;
- }
-
- n = read(f,read_buffer+read_buffer_len,n);
- if (n > 0) {
- read_buffer_len += n;
- }
+ 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);
+ 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;
+
+ 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) {
+ buf += n;
+ len -= n;
+ ret += n;
+ 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);
+ }
+ }
+
+ return ret;
}
-static int readfd(int fd,char *buffer,int N)
+
+
+/*! 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)
{
- int ret;
- int total=0;
-
- while (total < N)
- {
- if (read_buffer_len > 0) {
- ret = MIN(read_buffer_len,N-total);
- memcpy(buffer+total,read_buffer_p,ret);
- read_buffer_p += ret;
- read_buffer_len -= ret;
- } else {
- while ((ret = read(fd,buffer + total,N - total)) == -1) {
- fd_set fds;
-
- if (errno != EAGAIN && errno != EWOULDBLOCK)
- return -1;
- FD_ZERO(&fds);
- FD_SET(fd, &fds);
- select(fd+1, &fds, NULL, NULL, NULL);
+ while (len) {
+ int n = read_timeout(fd, buf, len);
+
+ buf += n;
+ len -= n;
+ }
+}
+
+
+/**
+ * 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 size_t remaining;
+ int tag, ret = 0;
+ char line[1024];
+
+ if (!io_multiplexing_in || fd != multiplex_in_fd)
+ return read_timeout(fd, buf, len);
+
+ while (ret == 0) {
+ if (remaining) {
+ len = MIN(len, remaining);
+ read_loop(fd, buf, len);
+ remaining -= len;
+ ret = len;
+ continue;
+ }
+
+ read_loop(fd, line, 4);
+ tag = IVAL(line, 0);
+
+ remaining = tag & 0xFFFFFF;
+ tag = tag >> 24;
+
+ if (tag == MPLEX_BASE)
+ continue;
+
+ tag -= MPLEX_BASE;
+
+ if (tag != FERROR && tag != FINFO) {
+ rprintf(FERROR, "unexpected tag %d\n", tag);
+ exit_cleanup(RERR_STREAMIO);
+ }
+
+ if (remaining > sizeof(line) - 1) {
+ rprintf(FERROR, "multiplexing overflow %d\n\n",
+ remaining);
+ exit_cleanup(RERR_STREAMIO);
+ }
+
+ read_loop(fd, line, remaining);
+ line[remaining] = 0;
+
+ rprintf((enum logcode) tag, "%s", line);
+ remaining = 0;
}
- }
- if (ret <= 0)
- return total;
- total += ret;
- }
- return total;
+ return ret;
}
-int read_int(int f)
+
+/* 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, size_t N)
+{
+ int ret;
+ size_t total=0;
+
+ while (total < N) {
+ io_flush();
+
+ 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);
+ ret = IVAL(b,0);
+ if (ret == (int32)0xffffffff) return -1;
+ return ret;
+}
+
+int64 read_longint(int f)
+{
+ extern int remote_version;
+ int64 ret;
+ char b[8];
+ ret = read_int(f);
+
+ if ((int32)ret != (int32)0xffffffff) {
+ return ret;
+ }
+
+#ifdef NO_INT64
+ rprintf(FERROR,"Integer overflow - attempted 64 bit offset\n");
+ exit_cleanup(RERR_UNSUPPORTED);
+#else
+ if (remote_version >= 16) {
+ readfd(f,b,8);
+ ret = IVAL(b,0) | (((int64)IVAL(b,4))<<32);
+ }
+#endif
+
+ return ret;
+}
+
+void read_buf(int f,char *buf,size_t len)
{
- int ret;
- char b[4];
- if ((ret=readfd(f,b,4)) != 4) {
- if (verbose > 1)
- fprintf(stderr,"Error reading %d bytes : %s\n",
- 4,ret==-1?strerror(errno):"EOF");
- exit_cleanup(1);
- }
- total_read += 4;
- return IVAL(b,0);
+ readfd(f,buf,len);
}
-void read_buf(int f,char *buf,int len)
+void read_sbuf(int f,char *buf,size_t len)
{
- int ret;
- if ((ret=readfd(f,buf,len)) != len) {
- if (verbose > 1)
- fprintf(stderr,"Error reading %d bytes : %s\n",
- len,ret==-1?strerror(errno):"EOF");
- exit_cleanup(1);
- }
- total_read += len;
+ read_buf (f,buf,len);
+ buf[len] = 0;
}
unsigned char read_byte(int f)
{
- char c;
- read_buf(f,&c,1);
- return (unsigned char)c;
+ unsigned char c;
+ read_buf (f, (char *)&c, 1);
+ return c;
}
+/* 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)
+{
+ size_t total = 0;
+ fd_set w_fds, r_fds;
+ int fd_count, count;
+ struct timeval tv;
+
+ err_list_push();
+
+ no_flush++;
+
+ while (total < len) {
+ FD_ZERO(&w_fds);
+ FD_ZERO(&r_fds);
+ FD_SET(fd,&w_fds);
+ fd_count = fd;
+
+ 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?io_timeout:SELECT_TIMEOUT;
+ tv.tv_usec = 0;
+
+ errno = 0;
+
+ count = select(fd_count+1,
+ io_error_fd != -1?&r_fds:NULL,
+ &w_fds,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, &r_fds)) {
+ read_error_fd();
+ }
+
+ if (FD_ISSET(fd, &w_fds)) {
+ 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) {
+ /* Don't try to write errors back
+ * across the stream */
+ io_multiplexing_close();
+ rprintf(FERROR,
+ "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;
-static char last_byte=0;
-static int last_sparse = 0;
+ if (io_timeout)
+ last_io = time(NULL);
+ }
+ }
-int sparse_end(int f)
+ no_flush--;
+}
+
+
+static char *io_buffer;
+static int io_buffer_count;
+
+void io_start_buffering(int fd)
{
-#if SPARSE_FILES
- if (last_sparse) {
- lseek(f,-1,SEEK_CUR);
- return (write(f,&last_byte,1) == 1 ? 0 : -1);
- }
-#endif
- last_sparse = 0;
- return 0;
+ if (io_buffer) return;
+ multiplex_out_fd = fd;
+ io_buffer = (char *)malloc(IO_BUFFER_SIZE);
+ if (!io_buffer) out_of_memory("writefd");
+ io_buffer_count = 0;
}
-int write_sparse(int f,char *buf,int len)
+/* 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)
{
- int l=0;
+ char buffer[4096];
+ size_t n = len;
-#if SPARSE_FILES
- for (l=0;l<len && buf[l]==0;l++) ;
+ SIVAL(buffer, 0, ((MPLEX_BASE + (int)code)<<24) + len);
- if (l > 0)
- lseek(f,l,SEEK_CUR);
+ if (n > (sizeof(buffer)-4)) {
+ n = sizeof(buffer)-4;
+ }
- last_byte = buf[len-1];
-#endif
+ 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;
+
+ err_list_push();
+
+ if (!io_buffer_count || no_flush) return;
+
+ if (io_multiplexing_out) {
+ 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(void)
+{
+ io_flush();
+ if (!io_multiplexing_out) {
+ free(io_buffer);
+ io_buffer = NULL;
+ }
+}
+
+static void writefd(int fd,char *buf,size_t len)
+{
+ stats.total_written += len;
- if (l == len) {
- last_sparse = 1;
- return len;
- }
+ err_list_push();
- last_sparse = 0;
+ if (!io_buffer || fd != multiplex_out_fd) {
+ writefd_unbuffered(fd, buf, len);
+ return;
+ }
- return (l + write(f,buf+l,len-l));
+ while (len) {
+ int n = MIN((int) len, IO_BUFFER_SIZE-io_buffer_count);
+ if (n > 0) {
+ memcpy(io_buffer+io_buffer_count, buf, n);
+ buf += n;
+ len -= n;
+ io_buffer_count += n;
+ }
+
+ if (io_buffer_count == IO_BUFFER_SIZE) io_flush();
+ }
}
-int read_write(int fd_in,int fd_out,int size)
+
+void write_int(int f,int32 x)
{
- static char *buf=NULL;
- static int bufsize = CHUNK_SIZE;
- int total=0;
-
- if (!buf) {
- buf = (char *)malloc(bufsize);
- if (!buf) out_of_memory("read_write");
- }
-
- while (total < size) {
- int n = MIN(size-total,bufsize);
- read_buf(fd_in,buf,n);
- if (write_sparse(fd_out,buf,n) != n)
- return total;
- total += n;
- }
- return total;
+ char b[4];
+ SIVAL(b,0,x);
+ writefd(f,b,4);
}
-static int writefd(int fd,char *buf,int len)
+/*
+ * 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)
{
- int total = 0;
- fd_set fds;
- struct timeval tv;
+ extern int remote_version;
+ char b[8];
- if (buffer_f_in == -1)
- return write(fd,buf,len);
+ if (remote_version < 16 || x <= 0x7FFFFFFF) {
+ write_int(f, (int)x);
+ return;
+ }
- while (total < len) {
- int ret = write(fd,buf+total,len-total);
+ write_int(f, (int32)0xFFFFFFFF);
+ SIVAL(b,0,(x&0xFFFFFFFF));
+ SIVAL(b,4,((x>>32)&0xFFFFFFFF));
- if (ret == 0) return total;
+ writefd(f,b,8);
+}
- if (ret == -1 && !(errno == EWOULDBLOCK || errno == EAGAIN))
- return -1;
+void write_buf(int f,char *buf,size_t len)
+{
+ writefd(f,buf,len);
+}
- if (ret == -1) {
- read_check(buffer_f_in);
+/* write a string to the connection */
+static void write_sbuf(int f,char *buf)
+{
+ write_buf(f, buf, strlen(buf));
+}
- FD_ZERO(&fds);
- FD_SET(fd,&fds);
- tv.tv_sec = BLOCKING_TIMEOUT;
- tv.tv_usec = 0;
- select(fd+1,NULL,&fds,NULL,&tv);
- } else {
- total += ret;
- }
- }
- return total;
+void write_byte(int f,unsigned char c)
+{
+ write_buf(f,(char *)&c,1);
}
-void write_int(int f,int x)
+int read_line(int f, char *buf, size_t maxlen)
{
- int ret;
- char b[4];
- SIVAL(b,0,x);
- if ((ret=writefd(f,b,4)) != 4) {
- fprintf(stderr,"write_int failed : %s\n",
- ret==-1?strerror(errno):"EOF");
- exit_cleanup(1);
- }
- total_written += 4;
+ while (maxlen) {
+ buf[0] = 0;
+ read_buf(f, buf, 1);
+ if (buf[0] == 0) return 0;
+ if (buf[0] == '\n') {
+ buf[0] = 0;
+ break;
+ }
+ if (buf[0] != '\r') {
+ buf++;
+ maxlen--;
+ }
+ }
+ if (maxlen == 0) {
+ *buf = 0;
+ return 0;
+ }
+
+ return 1;
}
-void write_buf(int f,char *buf,int len)
+
+void io_printf(int fd, const char *format, ...)
{
- int ret;
- if ((ret=writefd(f,buf,len)) != len) {
- fprintf(stderr,"write_buf failed : %s\n",
- ret==-1?strerror(errno):"EOF");
- exit_cleanup(1);
- }
- total_written += len;
+ va_list ap;
+ char buf[1024];
+ int len;
+
+ va_start(ap, format);
+ len = vsnprintf(buf, sizeof(buf), format, ap);
+ va_end(ap);
+
+ if (len < 0) exit_cleanup(RERR_STREAMIO);
+
+ write_sbuf(fd, buf);
}
-void write_byte(int f,unsigned char c)
+/* setup for multiplexing an error stream with the data stream */
+void io_start_multiplex_out(int fd)
{
- write_buf(f,(char *)&c,1);
+ multiplex_out_fd = fd;
+ io_flush();
+ io_start_buffering(fd);
+ io_multiplexing_out = 1;
}
-void write_flush(int f)
+/* setup for multiplexing an error stream with the data stream */
+void io_start_multiplex_in(int fd)
{
+ multiplex_in_fd = fd;
+ io_flush();
+ io_multiplexing_in = 1;
}
+/* 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();
+ stats.total_written += (len+4);
+ mplex_write(multiplex_out_fd, code, buf, len);
+ return 1;
+}
+
+/* stop output multiplexing */
+void io_multiplexing_close(void)
+{
+ io_multiplexing_out = 0;
+}