libetpan - fdik
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/*
* libEtPan! -- a mail stuff library
*
* Copyright (C) 2001, 2013 - DINH Viet Hoa
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the libEtPan! project nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* Created by Ian Ragsdale on 3/8/13. */
#include "mailstream_compress.h"
#if !HAVE_ZLIB
mailstream_low * mailstream_low_compress_open(mailstream_low * ms)
{
return NULL;
}
#else
#include <stdio.h>
#include <stdlib.h>
#include <zlib.h>
#include <assert.h>
#include "mailstream_low.h"
#include "mailstream_low.h"
#include "mailstream_cancel.h"
#define CHUNK_SIZE 1024
static ssize_t mailstream_low_compress_read(mailstream_low * s, void * buf, size_t count);
static ssize_t mailstream_low_compress_write(mailstream_low * s, const void * buf, size_t count);
static int mailstream_low_compress_close(mailstream_low * s);
static int mailstream_low_compress_get_fd(mailstream_low * s);
static struct mailstream_cancel * mailstream_low_compress_get_cancel(mailstream_low * s);
static void mailstream_low_compress_free(mailstream_low * s);
static void mailstream_low_compress_cancel(mailstream_low * s);
typedef struct mailstream_compress_data
{
mailstream_low * ms;
z_stream *compress_stream;
z_stream *decompress_stream;
unsigned char input_buf[CHUNK_SIZE];
unsigned char output_buf[CHUNK_SIZE];
} compress_data;
static mailstream_low_driver local_mailstream_compress_driver = {
/* mailstream_read */ mailstream_low_compress_read,
/* mailstream_write */ mailstream_low_compress_write,
/* mailstream_close */ mailstream_low_compress_close,
/* mailstream_get_fd */ mailstream_low_compress_get_fd,
/* mailstream_free */ mailstream_low_compress_free,
/* mailstream_cancel */ mailstream_low_compress_cancel,
/* mailstream_get_cancel */ mailstream_low_compress_get_cancel,
};
mailstream_low_driver * mailstream_compress_driver = &local_mailstream_compress_driver;
mailstream_low * mailstream_low_compress_open(mailstream_low * ms)
{
mailstream_low * s;
/* stores the original mailstream */
struct mailstream_compress_data * compress_data = malloc(sizeof(* compress_data));
if (compress_data == NULL)
goto err;
/* allocate deflate state */
compress_data->compress_stream = malloc(sizeof(z_stream));
compress_data->compress_stream->zalloc = Z_NULL;
compress_data->compress_stream->zfree = Z_NULL;
compress_data->compress_stream->opaque = Z_NULL;
/* these specific settings are very important - don't change without looking at the COMPRESS RFC */
int ret = deflateInit2(compress_data->compress_stream, Z_BEST_SPEED, Z_DEFLATED, -15, 8, Z_DEFAULT_STRATEGY);
if (ret != Z_OK) {
goto free_compress_data;
}
compress_data->compress_stream->avail_in = 0;
compress_data->compress_stream->avail_out = 0;
/* allocate inflate state */
compress_data->decompress_stream = malloc(sizeof(z_stream));
compress_data->decompress_stream->zalloc = Z_NULL;
compress_data->decompress_stream->zfree = Z_NULL;
compress_data->decompress_stream->opaque = Z_NULL;
/* these specific settings are very important - don't change without looking at the COMPRESS RFC */
ret = inflateInit2(compress_data->decompress_stream, -15);
if (ret != Z_OK) {
goto free_compress_data;
}
compress_data->decompress_stream->avail_in = 0;
compress_data->decompress_stream->avail_out = 0;
compress_data->ms = ms;
s = mailstream_low_new(compress_data, mailstream_compress_driver);
if (s == NULL)
goto free_compress_data;
return s;
free_compress_data:
if (compress_data->compress_stream) {
deflateEnd(compress_data->compress_stream);
free(compress_data->compress_stream);
}
if (compress_data->decompress_stream) {
inflateEnd(compress_data->decompress_stream);
free(compress_data->decompress_stream);
}
free(compress_data);
err:
return NULL;
}
ssize_t mailstream_low_compress_read(mailstream_low * s, void * buf, size_t count) {
compress_data *data = s->data;
data->ms->timeout = s->timeout;
z_stream *strm = data->decompress_stream;
int zr;
do {
/* if there is no compressed data, read more */
if (strm->avail_in == 0) {
int read = data->ms->driver->mailstream_read(data->ms, data->input_buf, CHUNK_SIZE);
if (read <= 0) {
return read;
}
strm->avail_in = read;
strm->next_in = data->input_buf;
}
/* set the output buffer */
strm->next_out = buf;
strm->avail_out = count;
/* uncompress any waiting data */
zr = inflate(strm, Z_NO_FLUSH);
}
/*
it's possible that there was data in the stream, but not enough that zlib could figure
out what to do with it. in this case, read some more and try again.
*/
while (zr == Z_OK && strm->avail_in == 0 && strm->avail_out == count);
/* if we got an error, return -1 to close the connection */
if (zr < 0) {
return -1;
}
/* let the client know how much data was read */
return count - strm->avail_out;
}
/*
mostly copied from mailstream_ssl.c
removed their windows support - we only need iOS
*/
static int wait_write_compress(mailstream_low * s)
{
fd_set fds_read;
fd_set fds_write;
struct timeval timeout;
int r;
int fd;
int max_fd;
int cancelled;
int write_enabled;
// use the session timeout if set
if (s->timeout) {
timeout.tv_sec = s->timeout;
timeout.tv_usec = 0;
} else {
timeout = mailstream_network_delay;
}
FD_ZERO(&fds_read);
struct mailstream_cancel * cancel = mailstream_low_compress_get_cancel(s);
fd = mailstream_cancel_get_fd(cancel);
FD_SET(fd, &fds_read);
FD_ZERO(&fds_write);
FD_SET(mailstream_low_compress_get_fd(s), &fds_write);
max_fd = mailstream_low_compress_get_fd(s);
if (fd > max_fd)
max_fd = fd;
r = select(max_fd + 1, &fds_read, &fds_write, NULL, &timeout);
if (r <= 0)
return -1;
cancelled = FD_ISSET(fd, &fds_read);
write_enabled = FD_ISSET(mailstream_low_compress_get_fd(s), &fds_write);
if (cancelled) {
/* cancelled */
mailstream_cancel_ack(cancel);
return -1;
}
if (!write_enabled)
return 0;
return 1;
}
ssize_t mailstream_low_compress_write(mailstream_low * s,
const void * buf, size_t count) {
int zr, wr;
compress_data *data = s->data;
data->ms->timeout = s->timeout;
z_stream *strm = data->compress_stream;
strm->next_in = (Bytef *)buf;
/* we won't try to compress more than CHUNK_SIZE at a time so we always have enough buffer space */
int compress_len = MIN(count, CHUNK_SIZE);
strm->avail_in = compress_len;
strm->avail_out = CHUNK_SIZE;
strm->next_out = data->output_buf;
zr = deflate(strm, Z_PARTIAL_FLUSH);
assert(zr == Z_OK);
if (zr < 0) {
printf("Error deflating: %d %s", zr, strm->msg);
return -1;
}
/*
wait until we can write to the buffer - we want to avoid any situation where we can have a partial write,
because with a partial write we can't tell the caller how much uncompressed data was written
*/
wait_write_compress(s);
/* write the data to the underlying mailstream */
wr = data->ms->driver->mailstream_write(data->ms, data->output_buf, CHUNK_SIZE - strm->avail_out);
/*
if we were unable to write all the compressed data to the underlying stream, we're in a bit of trouble
we don't know how much UNcompressed data was written, so we can't let the client know how much to retry
so, we return -1 and hope that the wait_write call ensures this never happens
*/
int len = CHUNK_SIZE-strm->avail_out;
if (wr < len) {
return -1;
assert(0);
}
/* let the caller know how much data we wrote */
return compress_len - strm->avail_in;
}
int mailstream_low_compress_close(mailstream_low * s) {
compress_data *data = s->data;
return data->ms->driver->mailstream_close(data->ms);
}
int mailstream_low_compress_get_fd(mailstream_low * s) {
compress_data *data = s->data;
return data->ms->driver->mailstream_get_fd(data->ms);
}
struct mailstream_cancel * mailstream_low_compress_get_cancel(mailstream_low * s) {
compress_data *data = s->data;
return data->ms->driver->mailstream_get_cancel(data->ms);
}
void mailstream_low_compress_free(mailstream_low * s) {
compress_data *data = s->data;
data->ms->driver->mailstream_free(data->ms);
if (data->compress_stream) {
deflateEnd(data->compress_stream);
free(data->compress_stream);
}
if (data->decompress_stream) {
inflateEnd(data->decompress_stream);
free(data->decompress_stream);
}
free(data);
free(s);
}
void mailstream_low_compress_cancel(mailstream_low * s) {
compress_data *data = s->data;
data->ms->driver->mailstream_cancel(data->ms);
}
#endif