src/lib/istream-file.c

	istream-file.c revision 03915cfec4eb1b5a65e5b6b676c8f4151bc80351
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen/* Copyright (c) 2002-2017 Dovecot authors, see the included COPYING file */
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen/* @UNSAFE: whole file */
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen#include "lib.h"
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen#include "ioloop.h"
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen#include "istream-file-private.h"
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen#include "net.h"
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen
6d2b3ce2c6ef62334985ece4f0ab8b154e0e9560Timo Sirainen#include <time.h>
c6335901c67a4c9365319190a111a2168f3b06f5Timo Sirainen#include <unistd.h>
c6335901c67a4c9365319190a111a2168f3b06f5Timo Sirainen#include <fcntl.h>
c6335901c67a4c9365319190a111a2168f3b06f5Timo Sirainen#include <sys/stat.h>
01230de017cd273de41143d88e9c18df1243ae8aTimo Sirainen
01230de017cd273de41143d88e9c18df1243ae8aTimo Sirainenvoid i_stream_file_close(struct iostream_private *stream,
047c00cd3f7f403672f81569413669238df8c15aTimo Sirainen             bool close_parent ATTR_UNUSED)
047c00cd3f7f403672f81569413669238df8c15aTimo Sirainen{
047c00cd3f7f403672f81569413669238df8c15aTimo Sirainen    struct file_istream *fstream = (struct file_istream *)stream;
047c00cd3f7f403672f81569413669238df8c15aTimo Sirainen    struct istream_private *_stream = (struct istream_private *)stream;
cf0ad1a0bddb0787f3d7b408a96d721a8b2a98a3Timo Sirainen
cf0ad1a0bddb0787f3d7b408a96d721a8b2a98a3Timo Sirainen    if (fstream->autoclose_fd && _stream->fd != -1) {
cf0ad1a0bddb0787f3d7b408a96d721a8b2a98a3Timo Sirainen        if (close(_stream->fd) < 0) {
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen            i_error("file_istream.close(%s) failed: %m",
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen                i_stream_get_name(&_stream->istream));
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen        }
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen    }
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen    _stream->fd = -1;
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen}
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainenstatic int i_stream_file_open(struct istream_private *stream)
7487ff578435377bbeefffdbfb78ca09ed1292dfTimo Sirainen{
89237470342ea6d4bbdf4cff9764037cfb3f6f45Timo Sirainen    const char *path = i_stream_get_name(&stream->istream);
89237470342ea6d4bbdf4cff9764037cfb3f6f45Timo Sirainen
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen    stream->fd = open(path, O_RDONLY);
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen    if (stream->fd == -1) {
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen        io_stream_set_error(&stream->iostream,
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen                    "open(%s) failed: %m", path);
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen        stream->istream.stream_errno = errno;
4d4d6d4745682790c20d759ba93dbea46b812c5dTimo Sirainen        return -1;
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen    }
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen    return 0;
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen}
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainenssize_t i_stream_file_read(struct istream_private *stream)
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen{
a3fe8c0c54d87822f4b4f8f0d10caac611861b2bTimo Sirainen    struct file_istream *fstream = (struct file_istream *) stream;
578ef2538ccf42e2a48234c24a8b709397101d88Timo Sirainen    uoff_t offset;
578ef2538ccf42e2a48234c24a8b709397101d88Timo Sirainen    size_t size;
578ef2538ccf42e2a48234c24a8b709397101d88Timo Sirainen    ssize_t ret;
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen    if (!i_stream_try_alloc(stream, 1, &size))
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen        return -2;
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen    if (stream->fd == -1) {
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen        if (i_stream_file_open(stream) < 0)
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen            return -1;
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen        i_assert(stream->fd != -1);
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen    }
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen    offset = stream->istream.v_offset + (stream->pos - stream->skip);
e0740628f6ca05f4bc79a9d8a90b650f4d38d4d0Timo Sirainen
e0740628f6ca05f4bc79a9d8a90b650f4d38d4d0Timo Sirainen    if (fstream->file) {
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen        ret = pread(stream->fd, stream->w_buffer + stream->pos,
3f603ef00e35fca21605afa0ad8d76e94fee2b96Timo Sirainen                size, offset);
3f603ef00e35fca21605afa0ad8d76e94fee2b96Timo Sirainen    } else if (fstream->seen_eof) {
3f603ef00e35fca21605afa0ad8d76e94fee2b96Timo Sirainen        /* don't try to read() again. EOF from keyboard (^D)
3f603ef00e35fca21605afa0ad8d76e94fee2b96Timo Sirainen           requires this to work right. */
86791365b10f45982c88e70f2eb94fd6c3fea151Timo Sirainen        ret = 0;
86791365b10f45982c88e70f2eb94fd6c3fea151Timo Sirainen    } else {
86791365b10f45982c88e70f2eb94fd6c3fea151Timo Sirainen        ret = read(stream->fd, stream->w_buffer + stream->pos,
86791365b10f45982c88e70f2eb94fd6c3fea151Timo Sirainen               size);
86791365b10f45982c88e70f2eb94fd6c3fea151Timo Sirainen    }
6fdfa4d4cf14d1d7764d7faa8258f112e39c8dbeTimo Sirainen
6fdfa4d4cf14d1d7764d7faa8258f112e39c8dbeTimo Sirainen    if (ret == 0) {
6fdfa4d4cf14d1d7764d7faa8258f112e39c8dbeTimo Sirainen        /* EOF */
6fdfa4d4cf14d1d7764d7faa8258f112e39c8dbeTimo Sirainen        stream->istream.eof = TRUE;
6fdfa4d4cf14d1d7764d7faa8258f112e39c8dbeTimo Sirainen        fstream->seen_eof = TRUE;
3f603ef00e35fca21605afa0ad8d76e94fee2b96Timo Sirainen        return -1;
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen    }
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen    if (unlikely(ret < 0)) {
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen        if ((errno == EINTR || errno == EAGAIN) &&
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen            !stream->istream.blocking) {
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen            ret = 0;
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen        } else {
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen            i_assert(errno != 0);
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen            /* if we get EBADF for a valid fd, it means something's
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen               really wrong and we'd better just crash. */
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen            i_assert(errno != EBADF);
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen            if (fstream->file) {
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen                io_stream_set_error(&stream->iostream,
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen                    "pread(size=%"PRIuSIZE_T
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen                    " offset=%"PRIuUOFF_T") failed: %m",
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen                    size, offset);
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen            } else {
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen                io_stream_set_error(&stream->iostream,
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen                    "read(size=%"PRIuSIZE_T") failed: %m",
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen                    size);
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen            }
b2d562f9c7fd13f9a16e9b3bcee904630b80b1feTimo Sirainen            stream->istream.stream_errno = errno;
b2d562f9c7fd13f9a16e9b3bcee904630b80b1feTimo Sirainen            return -1;
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen        }
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen    }
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen    if (ret > 0 && fstream->skip_left > 0) {
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen        i_assert(!fstream->file);
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen        i_assert(stream->skip == stream->pos);
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen
6c2ce1d5bf17b21e804a079eb0f973b7ab83e0d8Timo Sirainen        if (fstream->skip_left >= (size_t)ret) {
6c2ce1d5bf17b21e804a079eb0f973b7ab83e0d8Timo Sirainen            fstream->skip_left -= ret;
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen            ret = 0;
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen        } else {
d176f84ce5ca2073f4dfbafb457b9c74f6bf0d76Timo Sirainen            ret -= fstream->skip_left;
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen            stream->pos += fstream->skip_left;
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen            stream->skip += fstream->skip_left;
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen            fstream->skip_left = 0;
8d3278a82b964217d95c340ec6f82037cdc59d19Timo Sirainen        }
    }

    stream->pos += ret;
    i_assert(ret != 0 || !fstream->file);
    i_assert(ret != -1);
    return ret;
}

static void i_stream_file_seek(struct istream_private *stream, uoff_t v_offset,
                   bool mark ATTR_UNUSED)
{
    struct file_istream *fstream = (struct file_istream *) stream;

    if (!stream->istream.seekable) {
        if (v_offset < stream->istream.v_offset)
            i_panic("stream doesn't support seeking backwards");
        fstream->skip_left += v_offset - stream->istream.v_offset;
    }

    stream->istream.v_offset = v_offset;
    stream->skip = stream->pos = 0;
    fstream->seen_eof = FALSE;
}

static void i_stream_file_sync(struct istream_private *stream)
{
    if (!stream->istream.seekable) {
        /* can't do anything or data would be lost */
        return;
    }

    stream->skip = stream->pos = 0;
    stream->istream.eof = FALSE;
}

static int
i_stream_file_stat(struct istream_private *stream, bool exact ATTR_UNUSED)
{
    struct file_istream *fstream = (struct file_istream *) stream;
    const char *name = i_stream_get_name(&stream->istream);

    if (!fstream->file) {
        /* return defaults */
    } else if (stream->fd != -1) {
        if (fstat(stream->fd, &stream->statbuf) < 0) {
            stream->istream.stream_errno = errno;
            io_stream_set_error(&stream->iostream,
                "file_istream.fstat(%s) failed: %m", name);
            i_error("%s", i_stream_get_error(&stream->istream));
            return -1;
        }
    } else {
        if (stat(name, &stream->statbuf) < 0) {
            stream->istream.stream_errno = errno;
            io_stream_set_error(&stream->iostream,
                "file_istream.stat(%s) failed: %m", name);
            i_error("%s", i_stream_get_error(&stream->istream));
            return -1;
        }
    }
    return 0;
}

struct istream *
i_stream_create_file_common(struct file_istream *fstream,
                int fd, const char *path,
                size_t max_buffer_size, bool autoclose_fd)
{
    struct istream *input;
    struct stat st;
    bool is_file;

    fstream->autoclose_fd = autoclose_fd;

    fstream->istream.iostream.close = i_stream_file_close;
    fstream->istream.max_buffer_size = max_buffer_size;
    fstream->istream.read = i_stream_file_read;
    fstream->istream.seek = i_stream_file_seek;
    fstream->istream.sync = i_stream_file_sync;
    fstream->istream.stat = i_stream_file_stat;

    /* if it's a file, set the flags properly */
    if (fd == -1)
        is_file = TRUE;
    else if (fstat(fd, &st) < 0)
        is_file = FALSE;
    else if (S_ISREG(st.st_mode))
        is_file = TRUE;
    else if (!S_ISDIR(st.st_mode))
        is_file = FALSE;
    else {
        /* we're trying to open a directory.
           we're not designed for it. */
        io_stream_set_error(&fstream->istream.iostream,
            "%s is a directory, can't read it as file",
            path != NULL ? path : t_strdup_printf("<fd %d>", fd));
        fstream->istream.istream.stream_errno = EISDIR;
        is_file = FALSE;
    }
    if (is_file) {
        fstream->file = TRUE;
        fstream->istream.istream.blocking = TRUE;
        fstream->istream.istream.seekable = TRUE;
    }
    fstream->istream.istream.readable_fd = TRUE;

    input = i_stream_create(&fstream->istream, NULL, fd);
    i_stream_set_name(input, is_file ? "(file)" : "(fd)");
    return input;
}

struct istream *i_stream_create_fd(int fd, size_t max_buffer_size)
{
    struct file_istream *fstream;

    i_assert(fd != -1);

    fstream = i_new(struct file_istream, 1);
    return i_stream_create_file_common(fstream, fd, NULL,
                       max_buffer_size, FALSE);
}

struct istream *i_stream_create_fd_autoclose(int *fd, size_t max_buffer_size)
{
    struct istream *input;
    struct file_istream *fstream;

    i_assert(*fd != -1);

    fstream = i_new(struct file_istream, 1);
    input = i_stream_create_file_common(fstream, *fd, NULL,
                       max_buffer_size, TRUE);
    *fd = -1;
    return input;
}

struct istream *i_stream_create_file(const char *path, size_t max_buffer_size)
{
    struct file_istream *fstream;
    struct istream *input;

    fstream = i_new(struct file_istream, 1);
    input = i_stream_create_file_common(fstream, -1, path,
                        max_buffer_size, TRUE);
    i_stream_set_name(input, path);
    return input;
}