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 = 0x7fffffff; /* 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         /* skip over asciz filename */
 102         if (zbuf[3] & 0x8) {
 103                 while (strm->next_in[0])
 104                         strm->next_in++;
 105                 strm->next_in++;
 106         }
 107         strm->avail_in = len - (strm->next_in - zbuf);
 108
 109         strm->next_out = out_buf;
 110         strm->avail_out = out_len;
 111
 112         rc = zlib_inflateInit2(strm, -MAX_WBITS);
 113
 114         if (!flush) {
 115                 WS(strm)->inflate_state.wsize = 0;
 116                 WS(strm)->inflate_state.window = NULL;
 117         }
 118
 119         while (rc == Z_OK) {
 120                 if (strm->avail_in == 0) {
 121                         /* TODO: handle case where both pos and fill are set */
 122                         len = fill(zbuf, GZIP_IOBUF_SIZE);
 123                         if (len < 0) {
 124                                 rc = -1;
 125                                 error("read error");
 126                                 break;
 127                         }
 128                         strm->next_in = zbuf;
 129                         strm->avail_in = len;
 130                 }
 131                 rc = zlib_inflate(strm, 0);
 132
 133                 /* Write any data generated */
 134                 if (flush && strm->next_out > out_buf) {
 135                         int l = strm->next_out - out_buf;
 136                         if (l != flush(out_buf, l)) {
 137                                 rc = -1;
 138                                 error("write error");
 139                                 break;
 140                         }
 141                         strm->next_out = out_buf;
 142                         strm->avail_out = out_len;
 143                 }
 144
 145                 /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */
 146                 if (rc == Z_STREAM_END) {
 147                         rc = 0;
 148                         break;
 149                 } else if (rc != Z_OK) {
 150                         error("uncompression error");
 151                         rc = -1;
 152                 }
 153         }
 154
 155         zlib_inflateEnd(strm);
 156         if (pos)
 157                 /* add + 8 to skip over trailer */
 158                 *pos = strm->next_in - zbuf+8;
 159
 160 gunzip_5:
 161         free(strm->workspace);
 162 gunzip_nomem4:
 163         free(strm);
 164 gunzip_nomem3:
 165         if (!buf)
 166                 free(zbuf);
 167 gunzip_nomem2:
 168         if (flush)
 169                 free(out_buf);
 170 gunzip_nomem1:
 171         return rc; /* returns Z_OK (0) if successful */
 172 }
 173
 174 #define decompress gunzip