lib/libarchive/test/read_open_memory.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 "test.h"
  27 __FBSDID("$FreeBSD$");
  28
  29 #include <errno.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32
  33 /*
  34  * Read an archive from a block of memory.
  35  *
  36  * This is identical to archive_read_open_memory(), except
  37  * that it goes out of its way to be a little bit unpleasant,
  38  * in order to better test the libarchive internals.
  39  */
  40
  41 struct read_memory_data {
  42         unsigned char   *buffer;
  43         unsigned char   *end;
  44         size_t   read_size;
  45         size_t copy_buff_size;
  46         char *copy_buff;
  47 };
  48
  49 static int      memory_read_close(struct archive *, void *);
  50 static int      memory_read_open(struct archive *, void *);
  51 #if ARCHIVE_VERSION_NUMBER < 2000000
  52 static ssize_t  memory_read_skip(struct archive *, void *, size_t request);
  53 #else
  54 static off_t    memory_read_skip(struct archive *, void *, off_t request);
  55 #endif
  56 static ssize_t  memory_read(struct archive *, void *, const void **buff);
  57
  58 int
  59 read_open_memory(struct archive *a, void *buff, size_t size, size_t read_size)
  60 {
  61         struct read_memory_data *mine;
  62
  63         mine = (struct read_memory_data *)malloc(sizeof(*mine));
  64         if (mine == NULL) {
  65                 archive_set_error(a, ENOMEM, "No memory");
  66                 return (ARCHIVE_FATAL);
  67         }
  68         memset(mine, 0, sizeof(*mine));
  69         mine->buffer = (unsigned char *)buff;
  70         mine->end = mine->buffer + size;
  71         mine->read_size = read_size;
  72         mine->copy_buff_size = read_size + 64;
  73         mine->copy_buff = malloc(mine->copy_buff_size);
  74         return (archive_read_open2(a, mine, memory_read_open,
  75                     memory_read, memory_read_skip, memory_read_close));
  76 }
  77
  78 /*
  79  * There's nothing to open.
  80  */
  81 static int
  82 memory_read_open(struct archive *a, void *client_data)
  83 {
  84         (void)a; /* UNUSED */
  85         (void)client_data; /* UNUSED */
  86         return (ARCHIVE_OK);
  87 }
  88
  89 /*
  90  * In order to exercise libarchive's internal read-combining logic,
  91  * we deliberately copy data for each read to a separate buffer.
  92  * That way, code that runs off the end of the provided data
  93  * will screw up.
  94  */
  95 static ssize_t
  96 memory_read(struct archive *a, void *client_data, const void **buff)
  97 {
  98         struct read_memory_data *mine = (struct read_memory_data *)client_data;
  99         size_t size;
 100
 101         (void)a; /* UNUSED */
 102         size = mine->end - mine->buffer;
 103         if (size > mine->read_size)
 104                 size = mine->read_size;
 105         memset(mine->copy_buff, 0xA5, mine->copy_buff_size);
 106         memcpy(mine->copy_buff, mine->buffer, size);
 107         *buff = mine->copy_buff;
 108
 109         mine->buffer += size;
 110         return (size);
 111 }
 112
 113 /*
 114  * How mean can a skip() routine be?  Let's try to find out.
 115  */
 116 #if ARCHIVE_VERSION_NUMBER < 2000000
 117 static ssize_t
 118 memory_read_skip(struct archive *a, void *client_data, size_t skip)
 119 #else
 120 static off_t
 121 memory_read_skip(struct archive *a, void *client_data, off_t skip)
 122 #endif
 123 {
 124         struct read_memory_data *mine = (struct read_memory_data *)client_data;
 125
 126         (void)a; /* UNUSED */
 127         /* We can't skip by more than is available. */
 128         if ((off_t)skip > (off_t)(mine->end - mine->buffer))
 129                 skip = mine->end - mine->buffer;
 130         /* Always do small skips by prime amounts. */
 131         if (skip > 71)
 132                 skip = 71;
 133         mine->buffer += skip;
 134         return (skip);
 135 }
 136
 137 /*
 138  * Close is just cleaning up our one small bit of data.
 139  */
 140 static int
 141 memory_read_close(struct archive *a, void *client_data)
 142 {
 143         struct read_memory_data *mine = (struct read_memory_data *)client_data;
 144         (void)a; /* UNUSED */
 145         free(mine->copy_buff);
 146         free(mine);
 147         return (ARCHIVE_OK);
 148 }