diff options
Diffstat (limited to 'src/lib-mail/istream-qp-decoder.c')
| -rw-r--r-- | src/lib-mail/istream-qp-decoder.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/lib-mail/istream-qp-decoder.c b/src/lib-mail/istream-qp-decoder.c new file mode 100644 index 0000000..7ee0580 --- /dev/null +++ b/src/lib-mail/istream-qp-decoder.c @@ -0,0 +1,140 @@ +/* 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); +} |