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OS/2 Shareware BBS: 35 Internet
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rsync221.zip
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io.c
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1999-03-04
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/*
Copyright (C) Andrew Tridgell 1996
Copyright (C) Paul Mackerras 1996
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
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
Utilities used in rsync
tridge, June 1996
*/
#include "rsync.h"
/* 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;
extern int verbose;
extern int io_timeout;
extern struct stats stats;
static int buffer_f_in = -1;
void setup_readbuffer(int f_in)
{
buffer_f_in = f_in;
}
static void check_timeout(void)
{
time_t t;
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) {
rprintf(FERROR,"io timeout after %d second - exiting\n",
(int)(t-last_io));
exit_cleanup(RERR_TIMEOUT);
}
}
static char *read_buffer;
static char *read_buffer_p;
static int read_buffer_len;
static int read_buffer_size;
static int no_flush;
static int no_flush_read;
/* 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)
{
int n, ret=0;
no_flush_read++;
io_flush();
no_flush_read--;
while (ret == 0) {
fd_set fds;
struct timeval tv;
FD_ZERO(&fds);
FD_SET(fd, &fds);
tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT;
tv.tv_usec = 0;
if (select(fd+1, &fds, NULL, NULL, &tv) != 1) {
check_timeout();
continue;
}
n = read(fd, buf, len);
if (n > 0) {
buf += n;
len -= n;
ret += n;
if (io_timeout)
last_io = time(NULL);
continue;
}
if (n == -1 && errno == EINTR) {
continue;
}
if (n == -1 &&
(errno == EAGAIN || errno == EWOULDBLOCK)) {
/* this shouldn't happen, if it does then
sleep for a short time to prevent us
chewing too much CPU */
u_sleep(100);
continue;
}
if (n == 0) {
if (eof_error) {
rprintf(FERROR,"unexpected EOF in read_timeout\n");
}
exit_cleanup(RERR_STREAMIO);
}
rprintf(FERROR,"read error: %s\n", strerror(errno));
exit_cleanup(RERR_STREAMIO);
}
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)
{
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 return <= 0 */
static int read_unbuffered(int fd, char *buf, int len)
{
static int remaining;
char ibuf[4];
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, ibuf, 4);
tag = IVAL(ibuf, 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(tag,"%s", line);
remaining = 0;
}
return ret;
}
/* 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)
{
int ret;
int total=0;
if ((read_buffer_len < N) && (N < 1024)) {
read_check(buffer_f_in);
}
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;
}
no_flush_read++;
io_flush();
no_flush_read--;
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,int len)
{
readfd(f,buf,len);
}
void read_sbuf(int f,char *buf,int len)
{
read_buf(f,buf,len);
buf[len] = 0;
}
unsigned char read_byte(int f)
{
unsigned char c;
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)
{
int total = 0;
fd_set w_fds, r_fds;
int fd_count, count;
struct timeval tv;
int reading=0;
int blocked=0;
no_flush++;
while (total < len) {
FD_ZERO(&w_fds);
FD_ZERO(&r_fds);
FD_SET(fd,&w_fds);
fd_count = fd+1;
if (!no_flush_read) {
reading = (buffer_f_in != -1);
}
if (reading) {
FD_SET(buffer_f_in,&r_fds);
if (buffer_f_in > fd)
fd_count = buffer_f_in+1;
}
tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT;
tv.tv_usec = 0;
count = select(fd_count,
reading?&r_fds:NULL,
&w_fds,NULL,
&tv);
if (count <= 0) {
check_timeout();
continue;
}
if (reading && FD_ISSET(buffer_f_in, &r_fds)) {
read_check(buffer_f_in);
}
if (FD_ISSET(fd, &w_fds)) {
int n = (len-total)>>blocked;
int ret = write(fd,buf+total,n?n:1);
if (ret == -1 && errno == EINTR) {
continue;
}
if (ret == -1 &&
(errno == EAGAIN || errno == EWOULDBLOCK)) {
blocked++;
continue;
}
if (ret <= 0) {
rprintf(FERROR,"erroring writing %d bytes - exiting\n", len);
exit_cleanup(RERR_STREAMIO);
}
blocked = 0;
total += ret;
if (io_timeout)
last_io = time(NULL);
}
}
no_flush--;
}
static char *io_buffer;
static int io_buffer_count;
void io_start_buffering(int fd)
{
if (io_buffer) return;
multiplex_out_fd = fd;
io_buffer = (char *)malloc(IO_BUFFER_SIZE+4);
if (!io_buffer) out_of_memory("writefd");
io_buffer_count = 0;
/* leave room for the multiplex header in case it's needed */
io_buffer += 4;
}
void io_flush(void)
{
int fd = multiplex_out_fd;
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);
} else {
writefd_unbuffered(fd, io_buffer, io_buffer_count);
}
io_buffer_count = 0;
}
void io_end_buffering(int fd)
{
io_flush();
if (!io_multiplexing_out) {
free(io_buffer-4);
io_buffer = NULL;
}
}
static void writefd(int fd,char *buf,int len)
{
stats.total_written += len;
if (!io_buffer) {
writefd_unbuffered(fd, buf, len);
return;
}
while (len) {
int n = MIN(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();
}
}
void write_int(int f,int32 x)
{
char b[4];
SIVAL(b,0,x);
writefd(f,b,4);
}
void write_longint(int f, int64 x)
{
extern int remote_version;
char b[8];
if (remote_version < 16 || x <= 0x7FFFFFFF) {
write_int(f, (int)x);
return;
}
write_int(f, (int32)0xFFFFFFFF);
SIVAL(b,0,(x&0xFFFFFFFF));
SIVAL(b,4,((x>>32)&0xFFFFFFFF));
writefd(f,b,8);
}
void write_buf(int f,char *buf,int len)
{
writefd(f,buf,len);
}
/* write a string to the connection */
static void write_sbuf(int f,char *buf)
{
write_buf(f, buf, strlen(buf));
}
void write_byte(int f,unsigned char c)
{
write_buf(f,(char *)&c,1);
}
int read_line(int f, char *buf, int maxlen)
{
eof_error = 0;
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;
}
eof_error = 1;
return 1;
}
void io_printf(int fd, const char *format, ...)
{
va_list ap;
char buf[1024];
int len;
va_start(ap, format);
len = vslprintf(buf, sizeof(buf), format, ap);
va_end(ap);
if (len < 0) exit_cleanup(RERR_STREAMIO);
write_sbuf(fd, buf);
}
/* setup for multiplexing an error stream with the data stream */
void io_start_multiplex_out(int fd)
{
multiplex_out_fd = fd;
io_flush();
io_start_buffering(fd);
io_multiplexing_out = 1;
}
/* setup for multiplexing an error stream with the data stream */
void io_start_multiplex_in(int fd)
{
multiplex_in_fd = fd;
io_flush();
if (read_buffer_len) {
fprintf(stderr,"ERROR: data in read buffer at mplx start\n");
exit_cleanup(RERR_STREAMIO);
}
io_multiplexing_in = 1;
}
/* write an message to the error stream */
int io_multiplex_write(int f, char *buf, int len)
{
if (!io_multiplexing_out) return 0;
io_flush();
SIVAL(io_buffer-4, 0, ((MPLEX_BASE + f)<<24) + len);
memcpy(io_buffer, buf, len);
stats.total_written += (len+4);
writefd_unbuffered(multiplex_out_fd, io_buffer-4, len+4);
return 1;
}
void io_close_input(int fd)
{
buffer_f_in = -1;
}