contrib/libarchive-2/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 1.21 2008/02/19 06:10:48 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 #ifndef O_BINARY
  51 #define O_BINARY 0
  52 #endif
  53
  54 struct read_file_data {
  55         int      fd;
  56         size_t   block_size;
  57         void    *buffer;
  58         mode_t   st_mode;  /* Mode bits for opened file. */
  59         char     can_skip; /* This file supports skipping. */
  60         char     filename[1]; /* Must be last! */
  61 };
  62
  63 static int      file_close(struct archive *, void *);
  64 static int      file_open(struct archive *, void *);
  65 static ssize_t  file_read(struct archive *, void *, const void **buff);
  66 #if ARCHIVE_API_VERSION < 2
  67 static ssize_t  file_skip(struct archive *, void *, size_t request);
  68 #else
  69 static off_t    file_skip(struct archive *, void *, off_t request);
  70 #endif
  71
  72 int
  73 archive_read_open_file(struct archive *a, const char *filename,
  74     size_t block_size)
  75 {
  76         return (archive_read_open_filename(a, filename, block_size));
  77 }
  78
  79 int
  80 archive_read_open_filename(struct archive *a, const char *filename,
  81     size_t block_size)
  82 {
  83         struct read_file_data *mine;
  84
  85         if (filename == NULL || filename[0] == '\0') {
  86                 mine = (struct read_file_data *)malloc(sizeof(*mine));
  87                 if (mine == NULL) {
  88                         archive_set_error(a, ENOMEM, "No memory");
  89                         return (ARCHIVE_FATAL);
  90                 }
  91                 mine->filename[0] = '\0';
  92         } else {
  93                 mine = (struct read_file_data *)malloc(sizeof(*mine) + strlen(filename));
  94                 if (mine == NULL) {
  95                         archive_set_error(a, ENOMEM, "No memory");
  96                         return (ARCHIVE_FATAL);
  97                 }
  98                 strcpy(mine->filename, filename);
  99         }
 100         mine->block_size = block_size;
 101         mine->buffer = NULL;
 102         mine->fd = -1;
 103         /* lseek() almost never works; disable it by default.  See below. */
 104         mine->can_skip = 0;
 105         return (archive_read_open2(a, mine, file_open, file_read, file_skip, file_close));
 106 }
 107
 108 static int
 109 file_open(struct archive *a, void *client_data)
 110 {
 111         struct read_file_data *mine = (struct read_file_data *)client_data;
 112         struct stat st;
 113
 114         mine->buffer = malloc(mine->block_size);
 115         if (mine->buffer == NULL) {
 116                 archive_set_error(a, ENOMEM, "No memory");
 117                 return (ARCHIVE_FATAL);
 118         }
 119         if (mine->filename[0] != '\0')
 120                 mine->fd = open(mine->filename, O_RDONLY | O_BINARY);
 121         else
 122                 mine->fd = 0; /* Fake "open" for stdin. */
 123         if (mine->fd < 0) {
 124                 archive_set_error(a, errno, "Failed to open '%s'",
 125                     mine->filename);
 126                 return (ARCHIVE_FATAL);
 127         }
 128         if (fstat(mine->fd, &st) == 0) {
 129                 /* If we're reading a file from disk, ensure that we don't
 130                    overwrite it with an extracted file. */
 131                 if (S_ISREG(st.st_mode)) {
 132                         archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
 133                         /*
 134                          * Enabling skip here is a performance
 135                          * optimization for anything that supports
 136                          * lseek().  On FreeBSD, only regular files
 137                          * and raw disk devices support lseek() and
 138                          * there's no portable way to determine if a
 139                          * device is a raw disk device, so we only
 140                          * enable this optimization for regular files.
 141                          */
 142                         mine->can_skip = 1;
 143                 }
 144                 /* Remember mode so close can decide whether to flush. */
 145                 mine->st_mode = st.st_mode;
 146         } else {
 147                 if (mine->filename[0] == '\0')
 148                         archive_set_error(a, errno, "Can't stat stdin");
 149                 else
 150                         archive_set_error(a, errno, "Can't stat '%s'",
 151                             mine->filename);
 152                 return (ARCHIVE_FATAL);
 153         }
 154         return (0);
 155 }
 156
 157 static ssize_t
 158 file_read(struct archive *a, void *client_data, const void **buff)
 159 {
 160         struct read_file_data *mine = (struct read_file_data *)client_data;
 161         ssize_t bytes_read;
 162
 163         *buff = mine->buffer;
 164         bytes_read = read(mine->fd, mine->buffer, mine->block_size);
 165         if (bytes_read < 0) {
 166                 if (mine->filename[0] == '\0')
 167                         archive_set_error(a, errno, "Error reading stdin");
 168                 else
 169                         archive_set_error(a, errno, "Error reading '%s'",
 170                             mine->filename);
 171         }
 172         return (bytes_read);
 173 }
 174
 175 #if ARCHIVE_API_VERSION < 2
 176 static ssize_t
 177 file_skip(struct archive *a, void *client_data, size_t request)
 178 #else
 179 static off_t
 180 file_skip(struct archive *a, void *client_data, off_t request)
 181 #endif
 182 {
 183         struct read_file_data *mine = (struct read_file_data *)client_data;
 184         off_t old_offset, new_offset;
 185
 186         if (!mine->can_skip) /* We can't skip, so ... */
 187                 return (0); /* ... skip zero bytes. */
 188
 189         /* Reduce request to the next smallest multiple of block_size */
 190         request = (request / mine->block_size) * mine->block_size;
 191         if (request == 0)
 192                 return (0);
 193
 194         /*
 195          * Hurray for lazy evaluation: if the first lseek fails, the second
 196          * one will not be executed.
 197          */
 198         if (((old_offset = lseek(mine->fd, 0, SEEK_CUR)) < 0) ||
 199             ((new_offset = lseek(mine->fd, request, SEEK_CUR)) < 0))
 200         {
 201                 /* If skip failed once, it will probably fail again. */
 202                 mine->can_skip = 0;
 203
 204                 if (errno == ESPIPE)
 205                 {
 206                         /*
 207                          * Failure to lseek() can be caused by the file
 208                          * descriptor pointing to a pipe, socket or FIFO.
 209                          * Return 0 here, so the compression layer will use
 210                          * read()s instead to advance the file descriptor.
 211                          * It's slower of course, but works as well.
 212                          */
 213                         return (0);
 214                 }
 215                 /*
 216                  * There's been an error other than ESPIPE. This is most
 217                  * likely caused by a programmer error (too large request)
 218                  * or a corrupted archive file.
 219                  */
 220                 if (mine->filename[0] == '\0')
 221                         /*
 222                          * Should never get here, since lseek() on stdin ought
 223                          * to return an ESPIPE error.
 224                          */
 225                         archive_set_error(a, errno, "Error seeking in stdin");
 226                 else
 227                         archive_set_error(a, errno, "Error seeking in '%s'",
 228                             mine->filename);
 229                 return (-1);
 230         }
 231         return (new_offset - old_offset);
 232 }
 233
 234 static int
 235 file_close(struct archive *a, void *client_data)
 236 {
 237         struct read_file_data *mine = (struct read_file_data *)client_data;
 238
 239         (void)a; /* UNUSED */
 240
 241         /*
 242          * Sometimes, we should flush the input before closing.
 243          *   Regular files: faster to just close without flush.
 244          *   Devices: must not flush (user might need to
 245          *      read the "next" item on a non-rewind device).
 246          *   Pipes and sockets:  must flush (otherwise, the
 247          *      program feeding the pipe or socket may complain).
 248          * Here, I flush everything except for regular files and
 249          * device nodes.
 250          */
 251         if (!S_ISREG(mine->st_mode)
 252             && !S_ISCHR(mine->st_mode)
 253             && !S_ISBLK(mine->st_mode)) {
 254                 ssize_t bytesRead;
 255                 do {
 256                         bytesRead = read(mine->fd, mine->buffer,
 257                             mine->block_size);
 258                 } while (bytesRead > 0);
 259         }
 260         /* If a named file was opened, then it needs to be closed. */
 261         if (mine->filename[0] != '\0')
 262                 close(mine->fd);
 263         if (mine->buffer != NULL)
 264                 free(mine->buffer);
 265         free(mine);
 266         return (ARCHIVE_OK);
 267 }