diff options
Diffstat (limited to '')
| -rw-r--r-- | src/lib-mail/istream-dot.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/src/lib-mail/istream-dot.c b/src/lib-mail/istream-dot.c new file mode 100644 index 0000000..9c8f3f7 --- /dev/null +++ b/src/lib-mail/istream-dot.c @@ -0,0 +1,236 @@ +/* Copyright (c) 2007-2018 Dovecot authors, see the included COPYING file */ + +#include "lib.h" +#include "istream-private.h" +#include "istream-dot.h" + +struct dot_istream { + struct istream_private istream; + + char pending[3]; /* max. \r\n */ + + /* how far in string "\r\n.\r" are we */ + unsigned int state; + /* state didn't actually start with \r */ + bool state_no_cr:1; + /* state didn't contain \n either (only at the beginnign of stream) */ + bool state_no_lf:1; + /* we've seen the "." line, keep returning EOF */ + bool dot_eof:1; + + bool send_last_lf:1; +}; + +static int i_stream_dot_read_some(struct dot_istream *dstream) +{ + struct istream_private *stream = &dstream->istream; + size_t size, avail; + ssize_t ret; + + size = i_stream_get_data_size(stream->parent); + if (size == 0) { + ret = i_stream_read_memarea(stream->parent); + if (ret <= 0) { + i_assert(ret != -2); /* 0 sized buffer can't be full */ + if (stream->parent->stream_errno != 0) { + stream->istream.stream_errno = + stream->parent->stream_errno; + } else if (ret < 0 && stream->parent->eof) { + /* we didn't see "." line */ + io_stream_set_error(&stream->iostream, + "dot-input stream ends without '.' line"); + stream->istream.stream_errno = EPIPE; + } + return ret; + } + size = i_stream_get_data_size(stream->parent); + i_assert(size != 0); + } + + if (!i_stream_try_alloc(stream, size, &avail)) + return -2; + return 1; +} + +static bool flush_pending(struct dot_istream *dstream, size_t *destp) +{ + struct istream_private *stream = &dstream->istream; + size_t dest = *destp; + unsigned int i = 0; + + for (; dstream->pending[i] != '\0' && dest < stream->buffer_size; i++) + stream->w_buffer[dest++] = dstream->pending[i]; + memmove(dstream->pending, dstream->pending + i, + sizeof(dstream->pending) - i); + *destp = dest; + return dest < stream->buffer_size; +} + +static bool flush_dot_state(struct dot_istream *dstream, size_t *destp) +{ + unsigned int i = 0; + + if (!dstream->state_no_cr) + dstream->pending[i++] = '\r'; + if (dstream->state_no_lf) + dstream->state_no_lf = FALSE; + else if (dstream->state > 1) + dstream->pending[i++] = '\n'; + dstream->pending[i] = '\0'; + + if (dstream->state != 4) + dstream->state = 0; + else { + /* \r\n.\r seen, go back to \r state */ + dstream->state = 1; + } + return flush_pending(dstream, destp); +} + +static void i_stream_dot_eof(struct dot_istream *dstream, size_t *destp) +{ + if (dstream->send_last_lf) { + dstream->state = 2; + (void)flush_dot_state(dstream, destp); + } + dstream->dot_eof = TRUE; +} + +static ssize_t +i_stream_dot_return(struct istream_private *stream, size_t dest, ssize_t ret) +{ + if (dest != stream->pos) { + i_assert(dest > stream->pos); + ret = dest - stream->pos; + stream->pos = dest; + } + return ret; +} + +static ssize_t i_stream_dot_read(struct istream_private *stream) +{ + /* @UNSAFE */ + struct dot_istream *dstream = (struct dot_istream *)stream; + const unsigned char *data; + size_t i, dest, size, avail; + ssize_t ret, ret1; + + if (dstream->pending[0] != '\0') { + if (!i_stream_try_alloc(stream, 1, &avail)) + return -2; + dest = stream->pos; + (void)flush_pending(dstream, &dest); + } else { + dest = stream->pos; + } + + if (dstream->dot_eof) { + stream->istream.eof = TRUE; + return i_stream_dot_return(stream, dest, -1); + } + + /* we have to update stream->pos before reading more data */ + ret1 = i_stream_dot_return(stream, dest, 0); + if ((ret = i_stream_dot_read_some(dstream)) <= 0) { + if (stream->istream.stream_errno != 0) + return -1; + if (ret1 != 0) + return ret1; + dest = stream->pos; + if (ret == -1 && dstream->state != 0) + (void)flush_dot_state(dstream, &dest); + return i_stream_dot_return(stream, dest, ret); + } + dest = stream->pos; + + data = i_stream_get_data(stream->parent, &size); + for (i = 0; i < size && dest < stream->buffer_size; i++) { + switch (dstream->state) { + case 0: + break; + case 1: + /* CR seen */ + if (data[i] == '\n') + dstream->state++; + else { + if (!flush_dot_state(dstream, &dest)) + goto end; + } + break; + case 2: + /* [CR]LF seen */ + if (data[i] == '.') + dstream->state++; + else { + if (!flush_dot_state(dstream, &dest)) + goto end; + } + break; + case 3: + /* [CR]LF. seen */ + if (data[i] == '\r') + dstream->state++; + else if (data[i] == '\n') { + /* EOF */ + i_stream_dot_eof(dstream, &dest); + i++; + goto end; + } else { + /* drop the initial dot */ + if (!flush_dot_state(dstream, &dest)) + goto end; + } + break; + case 4: + /* [CR]LF.CR seen */ + if (data[i] == '\n') { + /* EOF */ + i_stream_dot_eof(dstream, &dest); + i++; + goto end; + } else { + /* drop the initial dot */ + if (!flush_dot_state(dstream, &dest)) + goto end; + } + } + if (dstream->state == 0) { + if (data[i] == '\r') { + dstream->state = 1; + dstream->state_no_cr = FALSE; + } else if (data[i] == '\n') { + dstream->state = 2; + dstream->state_no_cr = TRUE; + } else { + stream->w_buffer[dest++] = data[i]; + } + } + } +end: + i_stream_skip(stream->parent, i); + + ret = i_stream_dot_return(stream, dest, 0) + ret1; + if (ret == 0) + return i_stream_dot_read(stream); + i_assert(ret > 0); + return ret; +} + +struct istream *i_stream_create_dot(struct istream *input, bool send_last_lf) +{ + struct dot_istream *dstream; + + dstream = i_new(struct dot_istream, 1); + dstream->istream.max_buffer_size = input->real_stream->max_buffer_size; + dstream->istream.read = i_stream_dot_read; + + dstream->istream.istream.readable_fd = FALSE; + dstream->istream.istream.blocking = input->blocking; + dstream->istream.istream.seekable = FALSE; + dstream->send_last_lf = send_last_lf; + dstream->state = 2; + dstream->state_no_cr = TRUE; + dstream->state_no_lf = TRUE; + return i_stream_create(&dstream->istream, input, + i_stream_get_fd(input), 0); +} |