/* Copyright (c) 2013-2018 Dovecot authors, see the included COPYING file */
#include "lib.h"
#include "buffer.h"
#include "hex-binary.h"
#include "qp-decoder.h"
#include "istream-private.h"
#include "istream-qp.h"
struct qp_decoder_istream {
struct istream_private istream;
buffer_t *buf;
struct qp_decoder *qp;
};
static void i_stream_qp_decoder_close(struct iostream_private *stream,
bool close_parent)
{
struct qp_decoder_istream *bstream =
(struct qp_decoder_istream *)stream;
if (bstream->qp != NULL)
qp_decoder_deinit(&bstream->qp);
buffer_free(&bstream->buf);
if (close_parent)
i_stream_close(bstream->istream.parent);
}
static ssize_t i_stream_qp_decoder_read(struct istream_private *stream)
{
struct qp_decoder_istream *bstream =
(struct qp_decoder_istream *)stream;
const unsigned char *data;
size_t size, error_pos, max_buffer_size;
const char *error;
int ret;
max_buffer_size = i_stream_get_max_buffer_size(&stream->istream);
for (;;) {
/* remove skipped data from buffer */
if (stream->skip > 0) {
i_assert(stream->skip <= bstream->buf->used);
buffer_delete(bstream->buf, 0, stream->skip);
stream->pos -= stream->skip;
stream->skip = 0;
}
stream->buffer = bstream->buf->data;
i_assert(stream->pos <= bstream->buf->used);
if (stream->pos >= max_buffer_size) {
/* stream buffer still at maximum */
return -2;
}
/* if something is already decoded, return as much of it as
we can */
if (bstream->buf->used > 0) {
size_t new_pos, bytes;
/* only return up to max_buffer_size bytes, even when buffer
actually has more, as not to confuse the caller */
new_pos = I_MIN(bstream->buf->used, max_buffer_size);
bytes = new_pos - stream->pos;
stream->pos = new_pos;
return (ssize_t)bytes;
}
/* need to read more input */
ret = i_stream_read_more_memarea(stream->parent, &data, &size);
if (ret <= 0) {
stream->istream.stream_errno = stream->parent->stream_errno;
stream->istream.eof = stream->parent->eof;
if (ret != -1 || stream->istream.stream_errno != 0)
return ret;
/* end of quoted-printable stream. verify that the
ending is ok. */
if (qp_decoder_finish(bstream->qp, &error) == 0) {
i_assert(bstream->buf->used == 0);
return -1;
}
io_stream_set_error(&stream->iostream,
"Invalid quoted-printable input trailer: %s", error);
stream->istream.stream_errno = EPIPE;
return -1;
}
if (qp_decoder_more(bstream->qp, data, size,
&error_pos, &error) < 0) {
i_assert(error_pos < size);
io_stream_set_error(&stream->iostream,
"Invalid quoted-printable input 0x%s: %s",
binary_to_hex(data+error_pos, I_MIN(size-error_pos, 8)), error);
stream->istream.stream_errno = EINVAL;
return -1;
}
i_stream_skip(stream->parent, size);
}
}
static void
i_stream_qp_decoder_seek(struct istream_private *stream,
uoff_t v_offset, bool mark)
{
struct qp_decoder_istream *bstream =
(struct qp_decoder_istream *)stream;
const char *error;
if (v_offset < stream->istream.v_offset) {
/* seeking backwards - go back to beginning and seek
forward from there. */
stream->parent_expected_offset = stream->parent_start_offset;
stream->skip = stream->pos = 0;
stream->istream.v_offset = 0;
i_stream_seek(stream->parent, 0);
(void)qp_decoder_finish(bstream->qp, &error);
buffer_set_used_size(bstream->buf, 0);
}
i_stream_default_seek_nonseekable(stream, v_offset, mark);
}
struct istream *i_stream_create_qp_decoder(struct istream *input)
{
struct qp_decoder_istream *bstream;
bstream = i_new(struct qp_decoder_istream, 1);
bstream->istream.max_buffer_size = input->real_stream->max_buffer_size;
bstream->buf = buffer_create_dynamic(default_pool, 128);
bstream->qp = qp_decoder_init(bstream->buf);
bstream->istream.iostream.close = i_stream_qp_decoder_close;
bstream->istream.read = i_stream_qp_decoder_read;
bstream->istream.seek = i_stream_qp_decoder_seek;
bstream->istream.istream.readable_fd = FALSE;
bstream->istream.istream.blocking = input->blocking;
bstream->istream.istream.seekable = input->seekable;
return i_stream_create(&bstream->istream, input,
i_stream_get_fd(input), 0);
}