contrib/libarchive-2.1/libarchive/archive_read_open_filename.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_filename.c,v 1.18 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_FCNTL_H
  36 #include <fcntl.h>
  37 #endif
  38 #ifdef HAVE_STDLIB_H
  39 #include <stdlib.h>
  40 #endif
  41 #ifdef HAVE_STRING_H
  42 #include <string.h>
  43 #endif
  44 #ifdef HAVE_UNISTD_H
  45 #include <unistd.h>
  46 #endif
  47
  48 #include "archive.h"
  49
  50 struct read_file_data {
  51         int      fd;
  52         size_t   block_size;
  53         void    *buffer;
  54         mode_t   st_mode;  /* Mode bits for opened file. */
  55         char     filename[1]; /* Must be last! */
  56 };
  57
  58 static int      file_close(struct archive *, void *);
  59 static int      file_open(struct archive *, void *);
  60 static ssize_t  file_read(struct archive *, void *, const void **buff);
  61 #if ARCHIVE_API_VERSION < 2
  62 static ssize_t  file_skip(struct archive *, void *, size_t request);
  63 #else
  64 static off_t    file_skip(struct archive *, void *, off_t request);
  65 #endif
  66
  67 int
  68 archive_read_open_file(struct archive *a, const char *filename,
  69     size_t block_size)
  70 {
  71         return (archive_read_open_filename(a, filename, block_size));
  72 }
  73
  74 int
  75 archive_read_open_filename(struct archive *a, const char *filename,
  76     size_t block_size)
  77 {
  78         struct read_file_data *mine;
  79
  80         if (filename == NULL || filename[0] == '\0') {
  81                 mine = (struct read_file_data *)malloc(sizeof(*mine));
  82                 if (mine == NULL) {
  83                         archive_set_error(a, ENOMEM, "No memory");
  84                         return (ARCHIVE_FATAL);
  85                 }
  86                 mine->filename[0] = '\0';
  87         } else {
  88                 mine = (struct read_file_data *)malloc(sizeof(*mine) + strlen(filename));
  89                 if (mine == NULL) {
  90                         archive_set_error(a, ENOMEM, "No memory");
  91                         return (ARCHIVE_FATAL);
  92                 }
  93                 strcpy(mine->filename, filename);
  94         }
  95         mine->block_size = block_size;
  96         mine->buffer = NULL;
  97         mine->fd = -1;
  98         return (archive_read_open2(a, mine, file_open, file_read, file_skip, file_close));
  99 }
 100
 101 static int
 102 file_open(struct archive *a, void *client_data)
 103 {
 104         struct read_file_data *mine = (struct read_file_data *)client_data;
 105         struct stat st;
 106
 107         mine->buffer = malloc(mine->block_size);
 108         if (mine->buffer == NULL) {
 109                 archive_set_error(a, ENOMEM, "No memory");
 110                 return (ARCHIVE_FATAL);
 111         }
 112         if (mine->filename[0] != '\0')
 113                 mine->fd = open(mine->filename, O_RDONLY);
 114         else
 115                 mine->fd = 0; /* Fake "open" for stdin. */
 116         if (mine->fd < 0) {
 117                 archive_set_error(a, errno, "Failed to open '%s'",
 118                     mine->filename);
 119                 return (ARCHIVE_FATAL);
 120         }
 121         if (fstat(mine->fd, &st) == 0) {
 122                 /* If we're reading a file from disk, ensure that we don't
 123                    overwrite it with an extracted file. */
 124                 if (S_ISREG(st.st_mode))
 125                         archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
 126                 /* Remember mode so close can decide whether to flush. */
 127                 mine->st_mode = st.st_mode;
 128         } else {
 129                 if (mine->filename[0] == '\0')
 130                         archive_set_error(a, errno, "Can't stat stdin");
 131                 else
 132                         archive_set_error(a, errno, "Can't stat '%s'",
 133                             mine->filename);
 134                 return (ARCHIVE_FATAL);
 135         }
 136         return (0);
 137 }
 138
 139 static ssize_t
 140 file_read(struct archive *a, void *client_data, const void **buff)
 141 {
 142         struct read_file_data *mine = (struct read_file_data *)client_data;
 143         ssize_t bytes_read;
 144
 145         *buff = mine->buffer;
 146         bytes_read = read(mine->fd, mine->buffer, mine->block_size);
 147         if (bytes_read < 0) {
 148                 if (mine->filename[0] == '\0')
 149                         archive_set_error(a, errno, "Error reading stdin");
 150                 else
 151                         archive_set_error(a, errno, "Error reading '%s'",
 152                             mine->filename);
 153         }
 154         return (bytes_read);
 155 }
 156
 157 #if ARCHIVE_API_VERSION < 2
 158 static ssize_t
 159 file_skip(struct archive *a, void *client_data, size_t request)
 160 #else
 161 static off_t
 162 file_skip(struct archive *a, void *client_data, off_t request)
 163 #endif
 164 {
 165         struct read_file_data *mine = (struct read_file_data *)client_data;
 166         off_t old_offset, new_offset;
 167
 168         /* Reduce request to the next smallest multiple of block_size */
 169         request = (request / mine->block_size) * mine->block_size;
 170         /*
 171          * Hurray for lazy evaluation: if the first lseek fails, the second
 172          * one will not be executed.
 173          */
 174         if (((old_offset = lseek(mine->fd, 0, SEEK_CUR)) < 0) ||
 175             ((new_offset = lseek(mine->fd, request, SEEK_CUR)) < 0))
 176         {
 177                 if (errno == ESPIPE)
 178                 {
 179                         /*
 180                          * Failure to lseek() can be caused by the file
 181                          * descriptor pointing to a pipe, socket or FIFO.
 182                          * Return 0 here, so the compression layer will use
 183                          * read()s instead to advance the file descriptor.
 184                          * It's slower of course, but works as well.
 185                          */
 186                         return (0);
 187                 }
 188                 /*
 189                  * There's been an error other than ESPIPE. This is most
 190                  * likely caused by a programmer error (too large request)
 191                  * or a corrupted archive file.
 192                  */
 193                 if (mine->filename[0] == '\0')
 194                         /*
 195                          * Should never get here, since lseek() on stdin ought
 196                          * to return an ESPIPE error.
 197                          */
 198                         archive_set_error(a, errno, "Error seeking in stdin");
 199                 else
 200                         archive_set_error(a, errno, "Error seeking in '%s'",
 201                             mine->filename);
 202                 return (-1);
 203         }
 204         return (new_offset - old_offset);
 205 }
 206
 207 static int
 208 file_close(struct archive *a, void *client_data)
 209 {
 210         struct read_file_data *mine = (struct read_file_data *)client_data;
 211
 212         (void)a; /* UNUSED */
 213
 214         /*
 215          * Sometimes, we should flush the input before closing.
 216          *   Regular files: faster to just close without flush.
 217          *   Devices: must not flush (user might need to
 218          *      read the "next" item on a non-rewind device).
 219          *   Pipes and sockets:  must flush (otherwise, the
 220          *      program feeding the pipe or socket may complain).
 221          * Here, I flush everything except for regular files and
 222          * device nodes.
 223          */
 224         if (!S_ISREG(mine->st_mode)
 225             && !S_ISCHR(mine->st_mode)
 226             && !S_ISBLK(mine->st_mode)) {
 227                 ssize_t bytesRead;
 228                 do {
 229                         bytesRead = read(mine->fd, mine->buffer,
 230                             mine->block_size);
 231                 } while (bytesRead > 0);
 232         }
 233         /* If a named file was opened, then it needs to be closed. */
 234         if (mine->filename[0] != '\0')
 235                 close(mine->fd);
 236         if (mine->buffer != NULL)
 237                 free(mine->buffer);
 238         free(mine);
 239         return (ARCHIVE_OK);
 240 }