lib/decompress_inflate.c

   1 #ifdef STATIC
   2 /* Pre-boot environment: included */
   3
   4 /* prevent inclusion of _LINUX_KERNEL_H in pre-boot environment: lots
   5  * errors about console_printk etc... on ARM */
   6 #define _LINUX_KERNEL_H
   7
   8 #include "zlib_inflate/inftrees.c"
   9 #include "zlib_inflate/inffast.c"
  10 #include "zlib_inflate/inflate.c"
  11
  12 #else /* STATIC */
  13 /* initramfs et al: linked */
  14
  15 #include <linux/zutil.h>
  16
  17 #include "zlib_inflate/inftrees.h"
  18 #include "zlib_inflate/inffast.h"
  19 #include "zlib_inflate/inflate.h"
  20
  21 #include "zlib_inflate/infutil.h"
  22
  23 #endif /* STATIC */
  24
  25 #include <linux/decompress/mm.h>
  26
  27 #define GZIP_IOBUF_SIZE (16*1024)
  28
  29 static int INIT nofill(void *buffer, unsigned int len)
  30 {
  31         return -1;
  32 }
  33
  34 /* Included from initramfs et al code */
  35 STATIC int INIT gunzip(unsigned char *buf, int len,
  36                        int(*fill)(void*, unsigned int),
  37                        int(*flush)(void*, unsigned int),
  38                        unsigned char *out_buf,
  39                        int *pos,
  40                        void(*error)(char *x)) {
  41         u8 *zbuf;
  42         struct z_stream_s *strm;
  43         int rc;
  44         size_t out_len;
  45
  46         rc = -1;
  47         if (flush) {
  48                 out_len = 0x8000; /* 32 K */
  49                 out_buf = malloc(out_len);
  50         } else {
  51                 out_len = ((size_t)~0) - (size_t)out_buf; /* no limit */
  52         }
  53         if (!out_buf) {
  54                 error("Out of memory while allocating output buffer");
  55                 goto gunzip_nomem1;
  56         }
  57
  58         if (buf)
  59                 zbuf = buf;
  60         else {
  61                 zbuf = malloc(GZIP_IOBUF_SIZE);
  62                 len = 0;
  63         }
  64         if (!zbuf) {
  65                 error("Out of memory while allocating input buffer");
  66                 goto gunzip_nomem2;
  67         }
  68
  69         strm = malloc(sizeof(*strm));
  70         if (strm == NULL) {
  71                 error("Out of memory while allocating z_stream");
  72                 goto gunzip_nomem3;
  73         }
  74
  75         strm->workspace = malloc(flush ? zlib_inflate_workspacesize() :
  76                                  sizeof(struct inflate_state));
  77         if (strm->workspace == NULL) {
  78                 error("Out of memory while allocating workspace");
  79                 goto gunzip_nomem4;
  80         }
  81
  82         if (!fill)
  83                 fill = nofill;
  84
  85         if (len == 0)
  86                 len = fill(zbuf, GZIP_IOBUF_SIZE);
  87
  88         /* verify the gzip header */
  89         if (len < 10 ||
  90            zbuf[0] != 0x1f || zbuf[1] != 0x8b || zbuf[2] != 0x08) {
  91                 if (pos)
  92                         *pos = 0;
  93                 error("Not a gzip file");
  94                 goto gunzip_5;
  95         }
  96
  97         /* skip over gzip header (1f,8b,08... 10 bytes total +
  98          * possible asciz filename)
  99          */
 100         strm->next_in = zbuf + 10;
 101         strm->avail_in = len - 10;
 102         /* skip over asciz filename */
 103         if (zbuf[3] & 0x8) {
 104                 do {
 105                         /*
 106                          * If the filename doesn't fit into the buffer,
 107                          * the file is very probably corrupt. Don't try
 108                          * to read more data.
 109                          */
 110                         if (strm->avail_in == 0) {
 111                                 error("header error");
 112                                 goto gunzip_5;
 113                         }
 114                         --strm->avail_in;
 115                 } while (*strm->next_in++);
 116         }
 117
 118         strm->next_out = out_buf;
 119         strm->avail_out = out_len;
 120
 121         rc = zlib_inflateInit2(strm, -MAX_WBITS);
 122
 123         if (!flush) {
 124                 WS(strm)->inflate_state.wsize = 0;
 125                 WS(strm)->inflate_state.window = NULL;
 126         }
 127
 128         while (rc == Z_OK) {
 129                 if (strm->avail_in == 0) {
 130                         /* TODO: handle case where both pos and fill are set */
 131                         len = fill(zbuf, GZIP_IOBUF_SIZE);
 132                         if (len < 0) {
 133                                 rc = -1;
 134                                 error("read error");
 135                                 break;
 136                         }
 137                         strm->next_in = zbuf;
 138                         strm->avail_in = len;
 139                 }
 140                 rc = zlib_inflate(strm, 0);
 141
 142                 /* Write any data generated */
 143                 if (flush && strm->next_out > out_buf) {
 144                         int l = strm->next_out - out_buf;
 145                         if (l != flush(out_buf, l)) {
 146                                 rc = -1;
 147                                 error("write error");
 148                                 break;
 149                         }
 150                         strm->next_out = out_buf;
 151                         strm->avail_out = out_len;
 152                 }
 153
 154                 /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */
 155                 if (rc == Z_STREAM_END) {
 156                         rc = 0;
 157                         break;
 158                 } else if (rc != Z_OK) {
 159                         error("uncompression error");
 160                         rc = -1;
 161                 }
 162         }
 163
 164         zlib_inflateEnd(strm);
 165         if (pos)
 166                 /* add + 8 to skip over trailer */
 167                 *pos = strm->next_in - zbuf+8;
 168
 169 gunzip_5:
 170         free(strm->workspace);
 171 gunzip_nomem4:
 172         free(strm);
 173 gunzip_nomem3:
 174         if (!buf)
 175                 free(zbuf);
 176 gunzip_nomem2:
 177         if (flush)
 178                 free(out_buf);
 179 gunzip_nomem1:
 180         return rc; /* returns Z_OK (0) if successful */
 181 }
 182
 183 #define decompress gunzip