osmocom
/
libtelnet
mirror of https://gerrit.osmocom.org/libtelnet
11
0
Fork 0
Code Releases Activity

save a few bytes and use only a single z_stream, because mccp2 is unidirectional

This commit is contained in:
Sean Middleditch 2009-03-15 23:39:31 -04:00
parent 08bb05f96e
commit fbe93e36bd
2 changed files with 80 additions and 72 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

147
libtelnet.c
View File

@ -48,8 +48,9 @@ static void _event(libtelnet_t *telnet, libtelnet_event_type_t type,
}
/* error generation function */
static void _error(libtelnet_t *telnet, unsigned line, const char* func,
libtelnet_error_t err, int fatal, const char *fmt, ...) {
static libtelnet_error_t _error(libtelnet_t *telnet, unsigned line,
const char* func, libtelnet_error_t err, int fatal, const char *fmt,
...) {
char buffer[512];
va_list va;
@ -63,42 +64,49 @@ static void _error(libtelnet_t *telnet, unsigned line, const char* func,
_event(telnet, fatal ? LIBTELNET_EV_ERROR : LIBTELNET_EV_WARNING, err,
0, (unsigned char *)buffer, strlen(buffer));
return err;
}
/* initialize the zlib box for a telnet box; if deflate is non-zero, it
* initializes zlib for delating (compression), otherwise for inflating
* (decompression)
* (decompression). returns LIBTELNET_EOK on success, something else on
* failure.
*/
z_stream *_init_zlib(libtelnet_t *telnet, int deflate, int err_fatal) {
z_stream *zlib;
libtelnet_error_t _init_zlib(libtelnet_t *telnet, int deflate, int err_fatal) {
z_stream *z;
int rs;
/* if compression is already enabled, fail loudly */
if (telnet->z != 0)
return _error(telnet, __LINE__, __func__, LIBTELNET_EBADVAL,
err_fatal, "cannot initialize compression twice");
/* allocate zstream box */
if ((zlib = (z_stream *)calloc(1, sizeof(z_stream)))
== 0) {
_error(telnet, __LINE__, __func__, LIBTELNET_ENOMEM, err_fatal,
if ((z= (z_stream *)calloc(1, sizeof(z_stream))) == 0)
return _error(telnet, __LINE__, __func__, LIBTELNET_ENOMEM, err_fatal,
"malloc() failed: %s", strerror(errno));
return 0;
}
/* initialize */
if (deflate) {
if ((rs = deflateInit(zlib, Z_DEFAULT_COMPRESSION)) != Z_OK) {
free(zlib);
_error(telnet, __LINE__, __func__, LIBTELNET_ECOMPRESS, err_fatal,
"deflateInit() failed: %s", zError(rs));
return 0;
if ((rs = deflateInit(z, Z_DEFAULT_COMPRESSION)) != Z_OK) {
free(z);
return _error(telnet, __LINE__, __func__, LIBTELNET_ECOMPRESS,
err_fatal, "deflateInit() failed: %s", zError(rs));
}
telnet->flags |= LIBTELNET_PFLAG_DEFLATE;
} else {
if ((rs = inflateInit(zlib)) != Z_OK) {
free(zlib);
_error(telnet, __LINE__, __func__, LIBTELNET_ECOMPRESS, err_fatal,
"inflateInit() failed: %s", zError(rs));
return 0;
if ((rs = inflateInit(z)) != Z_OK) {
free(z);
return _error(telnet, __LINE__, __func__, LIBTELNET_ECOMPRESS,
err_fatal, "inflateInit() failed: %s", zError(rs));
}
telnet->flags &= ~LIBTELNET_PFLAG_DEFLATE;
}
return zlib;
telnet->z = z;
return LIBTELNET_EOK;
}
/* initialize a telnet state tracker */
@ -120,16 +128,14 @@ void libtelnet_free(libtelnet_t *telnet) {
telnet->length = 0;
}
/* free zlib box(es) */
if (telnet->z_inflate != 0) {
inflateEnd(telnet->z_inflate);
free(telnet->z_inflate);
telnet->z_inflate = 0;
}
if (telnet->z_deflate != 0) {
deflateEnd(telnet->z_deflate);
free(telnet->z_deflate);
telnet->z_deflate = 0;
/* free zlib box */
if (telnet->z != 0) {
if (telnet->flags & LIBTELNET_PFLAG_DEFLATE)
deflateEnd(telnet->z);
else
inflateEnd(telnet->z);
free(telnet->z);
telnet->z = 0;
}
}
@ -287,10 +293,10 @@ static void _process(libtelnet_t *telnet, unsigned char *buffer,
* handling the compressed stream if it's not already.
*/
if (telnet->sb_telopt == LIBTELNET_TELOPT_COMPRESS2 &&
telnet->z_inflate == 0 &&
telnet->z == 0 &&
telnet->flags & LIBTELNET_FLAG_PROXY) {
if ((telnet->z_inflate = _init_zlib(telnet, 0, 1)) == 0)
if (_init_zlib(telnet, 0, 1) != LIBTELNET_EOK)
break;
/* notify app that compression was enabled */
@ -342,42 +348,42 @@ void libtelnet_push(libtelnet_t *telnet, unsigned char *buffer,
unsigned int size) {
#ifdef HAVE_ZLIB
/* if we have an inflate (decompression) zlib stream, use it */
if (telnet->z_inflate != 0) {
if (telnet->z != 0) {
unsigned char inflate_buffer[4096];
int rs;
/* initialize zlib state */
telnet->z_inflate->next_in = buffer;
telnet->z_inflate->avail_in = size;
telnet->z_inflate->next_out = inflate_buffer;
telnet->z_inflate->avail_out = sizeof(inflate_buffer);
telnet->z->next_in = buffer;
telnet->z->avail_in = size;
telnet->z->next_out = inflate_buffer;
telnet->z->avail_out = sizeof(inflate_buffer);
/* inflate until buffer exhausted and all output is produced */
while (telnet->z_inflate->avail_in > 0 || telnet->z_inflate->avail_out == 0) {
while (telnet->z->avail_in > 0 || telnet->z->avail_out == 0) {
/* reset output buffer */
/* decompress */
rs = inflate(telnet->z_inflate, Z_SYNC_FLUSH);
rs = inflate(telnet->z, Z_SYNC_FLUSH);
/* process the decompressed bytes on success */
if (rs == Z_OK || rs == Z_STREAM_END)
_process(telnet, inflate_buffer, sizeof(inflate_buffer) -
telnet->z_inflate->avail_out);
telnet->z->avail_out);
else
_error(telnet, __LINE__, __func__, LIBTELNET_ECOMPRESS, 1,
"inflate() failed: %s", zError(rs));
/* prepare output buffer for next run */
telnet->z_inflate->next_out = inflate_buffer;
telnet->z_inflate->avail_out = sizeof(inflate_buffer);
telnet->z->next_out = inflate_buffer;
telnet->z->avail_out = sizeof(inflate_buffer);
/* on error (or on end of stream) disable further inflation */
if (rs != Z_OK) {
_event(telnet, LIBTELNET_EV_COMPRESS, 0, 0, 0, 0);
inflateEnd(telnet->z_inflate);
free(telnet->z_inflate);
telnet->z_inflate = 0;
inflateEnd(telnet->z);
free(telnet->z);
telnet->z = 0;
break;
}
}
@ -392,34 +398,34 @@ static void _send(libtelnet_t *telnet, unsigned char *buffer,
unsigned int size) {
#ifdef HAVE_ZLIB
/* if we have a deflate (compression) zlib box, use it */
if (telnet->z_deflate != 0) {
if (telnet->z != 0) {
unsigned char deflate_buffer[1024];
int rs;
/* initialize z_deflate state */
telnet->z_deflate->next_in = buffer;
telnet->z_deflate->avail_in = size;
telnet->z_deflate->next_out = deflate_buffer;
telnet->z_deflate->avail_out = sizeof(deflate_buffer);
/* initialize z state */
telnet->z->next_in = buffer;
telnet->z->avail_in = size;
telnet->z->next_out = deflate_buffer;
telnet->z->avail_out = sizeof(deflate_buffer);
/* deflate until buffer exhausted and all output is produced */
while (telnet->z_deflate->avail_in > 0 || telnet->z_deflate->avail_out == 0) {
while (telnet->z->avail_in > 0 || telnet->z->avail_out == 0) {
/* compress */
if ((rs = deflate(telnet->z_deflate, Z_SYNC_FLUSH)) != Z_OK) {
if ((rs = deflate(telnet->z, Z_SYNC_FLUSH)) != Z_OK) {
_error(telnet, __LINE__, __func__, LIBTELNET_ECOMPRESS, 1,
"deflate() failed: %s", zError(rs));
deflateEnd(telnet->z_deflate);
free(telnet->z_deflate);
telnet->z_deflate = 0;
deflateEnd(telnet->z);
free(telnet->z);
telnet->z = 0;
break;
}
_event(telnet, LIBTELNET_EV_SEND, 0, 0, deflate_buffer,
sizeof(deflate_buffer) - telnet->z_deflate->avail_out);
sizeof(deflate_buffer) - telnet->z->avail_out);
/* prepare output buffer for next run */
telnet->z_deflate->next_out = deflate_buffer;
telnet->z_deflate->avail_out = sizeof(deflate_buffer);
telnet->z->next_out = deflate_buffer;
telnet->z->avail_out = sizeof(deflate_buffer);
}
/* COMPRESS2 is not negotiated, just send */
@ -476,10 +482,10 @@ void libtelnet_send_subnegotiation(libtelnet_t *telnet, unsigned char opt,
* make sure all further data is compressed if not already.
*/
if (telnet->flags & LIBTELNET_FLAG_PROXY &&
telnet->z_deflate == 0 &&
telnet->z == 0 &&
opt == LIBTELNET_TELOPT_COMPRESS2) {
if ((telnet->z_deflate = _init_zlib(telnet, 1, 1)) == 0)
if (_init_zlib(telnet, 1, 1) != LIBTELNET_EOK)
return;
/* notify app that compression was enabled */
@ -490,23 +496,24 @@ void libtelnet_send_subnegotiation(libtelnet_t *telnet, unsigned char opt,
void libtelnet_begin_compress2(libtelnet_t *telnet) {
#ifdef HAVE_ZLIB
z_stream *zlib;
unsigned char compress2[] = { LIBTELNET_IAC, LIBTELNET_SB,
LIBTELNET_TELOPT_COMPRESS2, LIBTELNET_IAC, LIBTELNET_SE };
/* don't do this if we've already got a compression stream */
if (telnet->z_deflate != 0) {
if (telnet->z != 0) {
_error(telnet, __LINE__, __func__, LIBTELNET_EBADVAL, 0,
"compression already enabled");
return;
}
/* attempt to create output stream first, bail if we can't */
if ((zlib = _init_zlib(telnet, 1, 0)) == 0)
if (_init_zlib(telnet, 1, 0) != LIBTELNET_EOK)
return;
/* send compression marker */
libtelnet_send_subnegotiation(telnet, LIBTELNET_TELOPT_COMPRESS2, 0, 0);
/* set our deflate stream */
telnet->z_deflate = zlib;
/* send compression marker. we send directly to the event handler
* instead of passing through _send because _send would result in
* the compress marker itself being compressed.
*/
_event(telnet, LIBTELNET_EV_SEND, 0, 0, compress2, sizeof(compress2));
#endif /* HAVE_ZLIB */
}

5
libtelnet.h
View File

@ -92,6 +92,8 @@ typedef enum libtelnet_event_type_t libtelnet_event_type_t;
/* libtelnet feature flags */
#define LIBTELNET_FLAG_PROXY (1<<0)
#define LIBTELNET_PFLAG_DEFLATE (1<<7)
/* telnet states */
enum libtelnet_state_t {
LIBTELNET_STATE_DATA = 0,
@ -152,8 +154,7 @@ struct libtelnet_t {
libtelnet_event_handler_t eh;
#ifdef HAVE_ZLIB
/* zlib (mccp2) compression */
z_stream *z_deflate;
z_stream *z_inflate;
z_stream *z;
#endif
/* sub-request buffer */
unsigned char *buffer;