~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/lib/xz/xz_dec_test.c

Version: ~ [ linux-5.2 ] ~ [ linux-5.1.16 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.57 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.132 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.184 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.184 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.69 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * XZ decoder tester
  3  *
  4  * Author: Lasse Collin <lasse.collin@tukaani.org>
  5  *
  6  * This file has been put into the public domain.
  7  * You can do whatever you want with this file.
  8  */
  9 
 10 #include <linux/kernel.h>
 11 #include <linux/module.h>
 12 #include <linux/fs.h>
 13 #include <linux/uaccess.h>
 14 #include <linux/crc32.h>
 15 #include <linux/xz.h>
 16 
 17 /* Maximum supported dictionary size */
 18 #define DICT_MAX (1 << 20)
 19 
 20 /* Device name to pass to register_chrdev(). */
 21 #define DEVICE_NAME "xz_dec_test"
 22 
 23 /* Dynamically allocated device major number */
 24 static int device_major;
 25 
 26 /*
 27  * We reuse the same decoder state, and thus can decode only one
 28  * file at a time.
 29  */
 30 static bool device_is_open;
 31 
 32 /* XZ decoder state */
 33 static struct xz_dec *state;
 34 
 35 /*
 36  * Return value of xz_dec_run(). We need to avoid calling xz_dec_run() after
 37  * it has returned XZ_STREAM_END, so we make this static.
 38  */
 39 static enum xz_ret ret;
 40 
 41 /*
 42  * Input and output buffers. The input buffer is used as a temporary safe
 43  * place for the data coming from the userspace.
 44  */
 45 static uint8_t buffer_in[1024];
 46 static uint8_t buffer_out[1024];
 47 
 48 /*
 49  * Structure to pass the input and output buffers to the XZ decoder.
 50  * A few of the fields are never modified so we initialize them here.
 51  */
 52 static struct xz_buf buffers = {
 53         .in = buffer_in,
 54         .out = buffer_out,
 55         .out_size = sizeof(buffer_out)
 56 };
 57 
 58 /*
 59  * CRC32 of uncompressed data. This is used to give the user a simple way
 60  * to check that the decoder produces correct output.
 61  */
 62 static uint32_t crc;
 63 
 64 static int xz_dec_test_open(struct inode *i, struct file *f)
 65 {
 66         if (device_is_open)
 67                 return -EBUSY;
 68 
 69         device_is_open = true;
 70 
 71         xz_dec_reset(state);
 72         ret = XZ_OK;
 73         crc = 0xFFFFFFFF;
 74 
 75         buffers.in_pos = 0;
 76         buffers.in_size = 0;
 77         buffers.out_pos = 0;
 78 
 79         printk(KERN_INFO DEVICE_NAME ": opened\n");
 80         return 0;
 81 }
 82 
 83 static int xz_dec_test_release(struct inode *i, struct file *f)
 84 {
 85         device_is_open = false;
 86 
 87         if (ret == XZ_OK)
 88                 printk(KERN_INFO DEVICE_NAME ": input was truncated\n");
 89 
 90         printk(KERN_INFO DEVICE_NAME ": closed\n");
 91         return 0;
 92 }
 93 
 94 /*
 95  * Decode the data given to us from the userspace. CRC32 of the uncompressed
 96  * data is calculated and is printed at the end of successful decoding. The
 97  * uncompressed data isn't stored anywhere for further use.
 98  *
 99  * The .xz file must have exactly one Stream and no Stream Padding. The data
100  * after the first Stream is considered to be garbage.
101  */
102 static ssize_t xz_dec_test_write(struct file *file, const char __user *buf,
103                                  size_t size, loff_t *pos)
104 {
105         size_t remaining;
106 
107         if (ret != XZ_OK) {
108                 if (size > 0)
109                         printk(KERN_INFO DEVICE_NAME ": %zu bytes of "
110                                         "garbage at the end of the file\n",
111                                         size);
112 
113                 return -ENOSPC;
114         }
115 
116         printk(KERN_INFO DEVICE_NAME ": decoding %zu bytes of input\n",
117                         size);
118 
119         remaining = size;
120         while ((remaining > 0 || buffers.out_pos == buffers.out_size)
121                         && ret == XZ_OK) {
122                 if (buffers.in_pos == buffers.in_size) {
123                         buffers.in_pos = 0;
124                         buffers.in_size = min(remaining, sizeof(buffer_in));
125                         if (copy_from_user(buffer_in, buf, buffers.in_size))
126                                 return -EFAULT;
127 
128                         buf += buffers.in_size;
129                         remaining -= buffers.in_size;
130                 }
131 
132                 buffers.out_pos = 0;
133                 ret = xz_dec_run(state, &buffers);
134                 crc = crc32(crc, buffer_out, buffers.out_pos);
135         }
136 
137         switch (ret) {
138         case XZ_OK:
139                 printk(KERN_INFO DEVICE_NAME ": XZ_OK\n");
140                 return size;
141 
142         case XZ_STREAM_END:
143                 printk(KERN_INFO DEVICE_NAME ": XZ_STREAM_END, "
144                                 "CRC32 = 0x%08X\n", ~crc);
145                 return size - remaining - (buffers.in_size - buffers.in_pos);
146 
147         case XZ_MEMLIMIT_ERROR:
148                 printk(KERN_INFO DEVICE_NAME ": XZ_MEMLIMIT_ERROR\n");
149                 break;
150 
151         case XZ_FORMAT_ERROR:
152                 printk(KERN_INFO DEVICE_NAME ": XZ_FORMAT_ERROR\n");
153                 break;
154 
155         case XZ_OPTIONS_ERROR:
156                 printk(KERN_INFO DEVICE_NAME ": XZ_OPTIONS_ERROR\n");
157                 break;
158 
159         case XZ_DATA_ERROR:
160                 printk(KERN_INFO DEVICE_NAME ": XZ_DATA_ERROR\n");
161                 break;
162 
163         case XZ_BUF_ERROR:
164                 printk(KERN_INFO DEVICE_NAME ": XZ_BUF_ERROR\n");
165                 break;
166 
167         default:
168                 printk(KERN_INFO DEVICE_NAME ": Bug detected!\n");
169                 break;
170         }
171 
172         return -EIO;
173 }
174 
175 /* Allocate the XZ decoder state and register the character device. */
176 static int __init xz_dec_test_init(void)
177 {
178         static const struct file_operations fileops = {
179                 .owner = THIS_MODULE,
180                 .open = &xz_dec_test_open,
181                 .release = &xz_dec_test_release,
182                 .write = &xz_dec_test_write
183         };
184 
185         state = xz_dec_init(XZ_PREALLOC, DICT_MAX);
186         if (state == NULL)
187                 return -ENOMEM;
188 
189         device_major = register_chrdev(0, DEVICE_NAME, &fileops);
190         if (device_major < 0) {
191                 xz_dec_end(state);
192                 return device_major;
193         }
194 
195         printk(KERN_INFO DEVICE_NAME ": module loaded\n");
196         printk(KERN_INFO DEVICE_NAME ": Create a device node with "
197                         "'mknod " DEVICE_NAME " c %d 0' and write .xz files "
198                         "to it.\n", device_major);
199         return 0;
200 }
201 
202 static void __exit xz_dec_test_exit(void)
203 {
204         unregister_chrdev(device_major, DEVICE_NAME);
205         xz_dec_end(state);
206         printk(KERN_INFO DEVICE_NAME ": module unloaded\n");
207 }
208 
209 module_init(xz_dec_test_init);
210 module_exit(xz_dec_test_exit);
211 
212 MODULE_DESCRIPTION("XZ decompressor tester");
213 MODULE_VERSION("1.0");
214 MODULE_AUTHOR("Lasse Collin <lasse.collin@tukaani.org>");
215 
216 /*
217  * This code is in the public domain, but in Linux it's simplest to just
218  * say it's GPL and consider the authors as the copyright holders.
219  */
220 MODULE_LICENSE("GPL");
221 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp