contrib/libarchive-2.1/libarchive/archive_read_open_fd.c

   1 /*-
   2  * Copyright (c) 2003-2007 Tim Kientzle
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "archive_platform.h"
  27 __FBSDID("$FreeBSD: src/lib/libarchive/archive_read_open_fd.c,v 1.11 2007/01/09 08:05:55 kientzle Exp $");
  28
  29 #ifdef HAVE_SYS_STAT_H
  30 #include <sys/stat.h>
  31 #endif
  32 #ifdef HAVE_ERRNO_H
  33 #include <errno.h>
  34 #endif
  35 #ifdef HAVE_STDLIB_H
  36 #include <stdlib.h>
  37 #endif
  38 #ifdef HAVE_STRING_H
  39 #include <string.h>
  40 #endif
  41 #ifdef HAVE_UNISTD_H
  42 #include <unistd.h>
  43 #endif
  44
  45 #include "archive.h"
  46
  47 struct read_fd_data {
  48         int      fd;
  49         size_t   block_size;
  50         void    *buffer;
  51 };
  52
  53 static int      file_close(struct archive *, void *);
  54 static int      file_open(struct archive *, void *);
  55 static ssize_t  file_read(struct archive *, void *, const void **buff);
  56 #if ARCHIVE_API_VERSION < 2
  57 static ssize_t  file_skip(struct archive *, void *, size_t request);
  58 #else
  59 static off_t    file_skip(struct archive *, void *, off_t request);
  60 #endif
  61
  62 int
  63 archive_read_open_fd(struct archive *a, int fd, size_t block_size)
  64 {
  65         struct read_fd_data *mine;
  66
  67         mine = (struct read_fd_data *)malloc(sizeof(*mine));
  68         if (mine == NULL) {
  69                 archive_set_error(a, ENOMEM, "No memory");
  70                 return (ARCHIVE_FATAL);
  71         }
  72         mine->block_size = block_size;
  73         mine->buffer = malloc(mine->block_size);
  74         if (mine->buffer == NULL) {
  75                 archive_set_error(a, ENOMEM, "No memory");
  76                 free(mine);
  77                 return (ARCHIVE_FATAL);
  78         }
  79         mine->fd = fd;
  80         return (archive_read_open2(a, mine, file_open, file_read, file_skip, file_close));
  81 }
  82
  83 static int
  84 file_open(struct archive *a, void *client_data)
  85 {
  86         struct read_fd_data *mine = (struct read_fd_data *)client_data;
  87         struct stat st;
  88
  89         if (fstat(mine->fd, &st) != 0) {
  90                 archive_set_error(a, errno, "Can't stat fd %d", mine->fd);
  91                 return (ARCHIVE_FATAL);
  92         }
  93
  94         if (S_ISREG(st.st_mode))
  95                 archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
  96         return (ARCHIVE_OK);
  97 }
  98
  99 static ssize_t
 100 file_read(struct archive *a, void *client_data, const void **buff)
 101 {
 102         struct read_fd_data *mine = (struct read_fd_data *)client_data;
 103         ssize_t bytes_read;
 104
 105         *buff = mine->buffer;
 106         bytes_read = read(mine->fd, mine->buffer, mine->block_size);
 107         if (bytes_read < 0) {
 108                 archive_set_error(a, errno, "Error reading fd %d", mine->fd);
 109         }
 110         return (bytes_read);
 111 }
 112
 113 #if ARCHIVE_API_VERSION < 2
 114 static ssize_t
 115 file_skip(struct archive *a, void *client_data, size_t request)
 116 #else
 117 static off_t
 118 file_skip(struct archive *a, void *client_data, off_t request)
 119 #endif
 120 {
 121         struct read_fd_data *mine = (struct read_fd_data *)client_data;
 122         off_t old_offset, new_offset;
 123
 124         /* Reduce request to the next smallest multiple of block_size */
 125         request = (request / mine->block_size) * mine->block_size;
 126         /*
 127          * Hurray for lazy evaluation: if the first lseek fails, the second
 128          * one will not be executed.
 129          */
 130         if (((old_offset = lseek(mine->fd, 0, SEEK_CUR)) < 0) ||
 131             ((new_offset = lseek(mine->fd, request, SEEK_CUR)) < 0))
 132         {
 133                 if (errno == ESPIPE)
 134                 {
 135                         /*
 136                          * Failure to lseek() can be caused by the file
 137                          * descriptor pointing to a pipe, socket or FIFO.
 138                          * Return 0 here, so the compression layer will use
 139                          * read()s instead to advance the file descriptor.
 140                          * It's slower of course, but works as well.
 141                          */
 142                         return (0);
 143                 }
 144                 /*
 145                  * There's been an error other than ESPIPE. This is most
 146                  * likely caused by a programmer error (too large request)
 147                  * or a corrupted archive file.
 148                  */
 149                 archive_set_error(a, errno, "Error seeking");
 150                 return (-1);
 151         }
 152         return (new_offset - old_offset);
 153 }
 154
 155 static int
 156 file_close(struct archive *a, void *client_data)
 157 {
 158         struct read_fd_data *mine = (struct read_fd_data *)client_data;
 159
 160         (void)a; /* UNUSED */
 161         if (mine->buffer != NULL)
 162                 free(mine->buffer);
 163         free(mine);
 164         return (ARCHIVE_OK);
 165 }