contrib/libarchive/libarchive/archive_read_support_filter_lrzip.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
  28 __FBSDID("$FreeBSD$");
  29
  30
  31 #ifdef HAVE_ERRNO_H
  32 #include <errno.h>
  33 #endif
  34 #ifdef HAVE_STDLIB_H
  35 #include <stdlib.h>
  36 #endif
  37 #ifdef HAVE_STRING_H
  38 #include <string.h>
  39 #endif
  40 #ifdef HAVE_UNISTD_H
  41 #include <unistd.h>
  42 #endif
  43
  44 #include "archive.h"
  45 #include "archive_private.h"
  46 #include "archive_read_private.h"
  47
  48 #define LRZIP_HEADER_MAGIC "LRZI"
  49 #define LRZIP_HEADER_MAGIC_LEN 4
  50
  51 static int      lrzip_bidder_bid(struct archive_read_filter_bidder *,
  52                     struct archive_read_filter *);
  53 static int      lrzip_bidder_init(struct archive_read_filter *);
  54
  55
  56 static int
  57 lrzip_reader_free(struct archive_read_filter_bidder *self)
  58 {
  59         (void)self; /* UNUSED */
  60         return (ARCHIVE_OK);
  61 }
  62
  63 int
  64 archive_read_support_filter_lrzip(struct archive *_a)
  65 {
  66         struct archive_read *a = (struct archive_read *)_a;
  67         struct archive_read_filter_bidder *reader;
  68
  69         archive_check_magic(_a, ARCHIVE_READ_MAGIC,
  70             ARCHIVE_STATE_NEW, "archive_read_support_filter_lrzip");
  71
  72         if (__archive_read_get_bidder(a, &reader) != ARCHIVE_OK)
  73                 return (ARCHIVE_FATAL);
  74
  75         reader->data = NULL;
  76         reader->name = "lrzip";
  77         reader->bid = lrzip_bidder_bid;
  78         reader->init = lrzip_bidder_init;
  79         reader->options = NULL;
  80         reader->free = lrzip_reader_free;
  81         /* This filter always uses an external program. */
  82         archive_set_error(_a, ARCHIVE_ERRNO_MISC,
  83             "Using external lrzip program for lrzip decompression");
  84         return (ARCHIVE_WARN);
  85 }
  86
  87 /*
  88  * Bidder just verifies the header and returns the number of verified bits.
  89  */
  90 static int
  91 lrzip_bidder_bid(struct archive_read_filter_bidder *self,
  92     struct archive_read_filter *filter)
  93 {
  94         const unsigned char *p;
  95         ssize_t avail, len;
  96         int i;
  97
  98         (void)self; /* UNUSED */
  99         /* Start by looking at the first six bytes of the header, which
 100          * is all fixed layout. */
 101         len = 6;
 102         p = __archive_read_filter_ahead(filter, len, &avail);
 103         if (p == NULL || avail == 0)
 104                 return (0);
 105
 106         if (memcmp(p, LRZIP_HEADER_MAGIC, LRZIP_HEADER_MAGIC_LEN))
 107                 return (0);
 108
 109         /* current major version is always 0, verify this */
 110         if (p[LRZIP_HEADER_MAGIC_LEN])
 111                 return 0;
 112         /* support only v0.6+ lrzip for sanity */
 113         i = p[LRZIP_HEADER_MAGIC_LEN + 1];
 114         if ((i < 6) || (i > 10))
 115                 return 0;
 116
 117         return (int)len;
 118 }
 119
 120 static int
 121 lrzip_bidder_init(struct archive_read_filter *self)
 122 {
 123         int r;
 124
 125         r = __archive_read_program(self, "lrzip -d -q");
 126         /* Note: We set the format here even if __archive_read_program()
 127          * above fails.  We do, after all, know what the format is
 128          * even if we weren't able to read it. */
 129         self->code = ARCHIVE_FILTER_LRZIP;
 130         self->name = "lrzip";
 131         return (r);
 132 }