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#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include "config.h"
#include "user_io.h"
#define BUFLEN 8192
int compression;
int paclen_in = 256;
int paclen_out = 256;
/* This is for select_loop() */
static unsigned char buf[BUFLEN];
#ifdef HAVE_ZLIB_H
#include <zlib.h>
/* Error in (de)compression happened? */
static int compression_error;
/* These are for the (de)compressor */
static unsigned char input_buffer[BUFLEN];
static unsigned char output_buffer[BUFLEN];
static z_stream incoming_stream;
static z_stream outgoing_stream;
#endif
#define min(a,b) ((a) < (b) ? (a) : (b))
void err(char *message)
{
user_write(STDOUT_FILENO, message, strlen(message));
exit(1);
}
void init_compress(void)
{
#ifdef HAVE_ZLIB_H
inflateInit(&incoming_stream);
deflateInit(&outgoing_stream, 9);
incoming_stream.next_in = input_buffer;
#else
err("*** Compression support not available!!!\r\n");
#endif
}
void end_compress(void)
{
#ifdef HAVE_ZLIB_H
inflateEnd(&incoming_stream);
deflateEnd(&outgoing_stream);
#endif
}
static int flush_output(int fd, const void *buf, size_t count)
{
const unsigned char *byte = buf;
int cnt = count;
while (cnt > 0) {
if (write(fd, byte, min(paclen_out, cnt)) < 0)
return -1;
byte += paclen_out;
cnt -= paclen_out;
}
return count;
}
int user_write(int fd, const void *buf, size_t count)
{
#ifdef HAVE_ZLIB_H
int status;
#endif
if (count == 0)
return 0;
#ifndef HAVE_ZLIB_H
return flush_output(fd, buf, count);
#else
/* Only output to stdout can be compressed */
if (fd != STDOUT_FILENO || !compression)
return flush_output(fd, buf, count);
if (compression_error) {
errno = 0;
return -1;
}
/* Input is the contents of the input buffer. */
outgoing_stream.next_in = (unsigned char *)buf;
outgoing_stream.avail_in = count;
/* Loop compressing until deflate() returns with avail_out != 0. */
do {
/* Set up fixed-size output buffer. */
outgoing_stream.next_out = output_buffer;
outgoing_stream.avail_out = BUFLEN;
/* Compress as much data into the buffer as possible. */
status = deflate(&outgoing_stream, Z_PARTIAL_FLUSH);
if (status != Z_OK) {
compression_error = status;
errno = 0;
return -1;
}
/* Now send the compressed data */
if (flush_output(fd, output_buffer, BUFLEN - outgoing_stream.avail_out) < 0)
return -1;
} while (outgoing_stream.avail_out == 0);
return count;
#endif
}
int user_read(int fd, void *buf, size_t count)
{
#ifdef HAVE_ZLIB_H
int status, len;
#endif
if (count == 0)
return 0;
#ifndef HAVE_ZLIB_H
return read(fd, buf, count);
#else
/* Only input from stdin can be compressed */
if (fd != STDIN_FILENO || !compression)
return read(fd, buf, count);
if (compression_error) {
errno = 0;
return -1;
}
incoming_stream.next_out = buf;
incoming_stream.avail_out = count;
for (;;) {
status = inflate(&incoming_stream, Z_SYNC_FLUSH);
if (count - incoming_stream.avail_out > 0)
return count - incoming_stream.avail_out;
if (status != Z_OK && status != Z_BUF_ERROR) {
compression_error = status;
errno = 0;
return -1;
}
incoming_stream.next_in = input_buffer;
incoming_stream.avail_in = 0;
len = read(fd, input_buffer, BUFLEN);
if (len <= 0)
return len;
incoming_stream.avail_in = len;
}
return 0;
#endif
}
int select_loop(int s)
{
fd_set read_fd;
int n;
if (fcntl(s, F_SETFL, O_NONBLOCK) < 0) {
close(s);
return -1;
}
if (fcntl(STDIN_FILENO, F_SETFL, O_NONBLOCK) < 0) {
close(s);
return -1;
}
/*
* Loop until one end of the connection goes away.
*/
for (;;) {
FD_ZERO(&read_fd);
FD_SET(STDIN_FILENO, &read_fd);
FD_SET(s, &read_fd);
select(s + 1, &read_fd, NULL, NULL, NULL);
if (FD_ISSET(s, &read_fd)) {
while ((n = user_read(s, buf, BUFLEN)) > 0)
user_write(STDOUT_FILENO, buf, n);
if (n == 0 || (n < 0 && errno != EAGAIN)) {
close(s);
break;
}
}
if (FD_ISSET(STDIN_FILENO, &read_fd)) {
while ((n = user_read(STDIN_FILENO, buf, BUFLEN)) > 0)
user_write(s, buf, n);
if (n == 0 || (n < 0 && errno != EAGAIN)) {
close(s);
break;
}
}
}
return 0;
}
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