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 INBUF_LEN (16*1024)
  28
  29 /* Included from initramfs et al code */
  30 STATIC int INIT gunzip(unsigned char *buf, int len,
  31                        int(*fill)(void*, unsigned int),
  32                        int(*flush)(void*, unsigned int),
  33                        unsigned char *out_buf,
  34                        int *pos,
  35                        void(*error_fn)(char *x)) {
  36         u8 *zbuf;
  37         struct z_stream_s *strm;
  38         int rc;
  39         size_t out_len;
  40
  41         set_error_fn(error_fn);
  42         rc = -1;
  43         if (flush) {
  44                 out_len = 0x8000; /* 32 K */
  45                 out_buf = malloc(out_len);
  46         } else {
  47                 out_len = 0x7fffffff; /* no limit */
  48         }
  49         if (!out_buf) {
  50                 error("Out of memory while allocating output buffer");
  51                 goto gunzip_nomem1;
  52         }
  53
  54         if (buf)
  55                 zbuf = buf;
  56         else {
  57                 zbuf = malloc(INBUF_LEN);
  58                 len = 0;
  59         }
  60         if (!zbuf) {
  61                 error("Out of memory while allocating input buffer");
  62                 goto gunzip_nomem2;
  63         }
  64
  65         strm = malloc(sizeof(*strm));
  66         if (strm == NULL) {
  67                 error("Out of memory while allocating z_stream");
  68                 goto gunzip_nomem3;
  69         }
  70
  71         strm->workspace = malloc(flush ? zlib_inflate_workspacesize() :
  72                                  sizeof(struct inflate_state));
  73         if (strm->workspace == NULL) {
  74                 error("Out of memory while allocating workspace");
  75                 goto gunzip_nomem4;
  76         }
  77
  78         if (len == 0)
  79                 len = fill(zbuf, INBUF_LEN);
  80
  81         /* verify the gzip header */
  82         if (len < 10 ||
  83            zbuf[0] != 0x1f || zbuf[1] != 0x8b || zbuf[2] != 0x08) {
  84                 if (pos)
  85                         *pos = 0;
  86                 error("Not a gzip file");
  87                 goto gunzip_5;
  88         }
  89
  90         /* skip over gzip header (1f,8b,08... 10 bytes total +
  91          * possible asciz filename)
  92          */
  93         strm->next_in = zbuf + 10;
  94         /* skip over asciz filename */
  95         if (zbuf[3] & 0x8) {
  96                 while (strm->next_in[0])
  97                         strm->next_in++;
  98                 strm->next_in++;
  99         }
 100         strm->avail_in = len - (strm->next_in - zbuf);
 101
 102         strm->next_out = out_buf;
 103         strm->avail_out = out_len;
 104
 105         rc = zlib_inflateInit2(strm, -MAX_WBITS);
 106
 107         if (!flush) {
 108                 WS(strm)->inflate_state.wsize = 0;
 109                 WS(strm)->inflate_state.window = NULL;
 110         }
 111
 112         while (rc == Z_OK) {
 113                 if (strm->avail_in == 0) {
 114                         /* TODO: handle case where both pos and fill are set */
 115                         len = fill(zbuf, INBUF_LEN);
 116                         if (len < 0) {
 117                                 rc = -1;
 118                                 error("read error");
 119                                 break;
 120                         }
 121                         strm->next_in = zbuf;
 122                         strm->avail_in = len;
 123                 }
 124                 rc = zlib_inflate(strm, 0);
 125
 126                 /* Write any data generated */
 127                 if (flush && strm->next_out > out_buf) {
 128                         int l = strm->next_out - out_buf;
 129                         if (l != flush(out_buf, l)) {
 130                                 rc = -1;
 131                                 error("write error");
 132                                 break;
 133                         }
 134                         strm->next_out = out_buf;
 135                         strm->avail_out = out_len;
 136                 }
 137
 138                 /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */
 139                 if (rc == Z_STREAM_END) {
 140                         rc = 0;
 141                         break;
 142                 } else if (rc != Z_OK) {
 143                         error("uncompression error");
 144                         rc = -1;
 145                 }
 146         }
 147
 148         zlib_inflateEnd(strm);
 149         if (pos)
 150                 /* add + 8 to skip over trailer */
 151                 *pos = strm->next_in - zbuf+8;
 152
 153 gunzip_5:
 154         free(strm->workspace);
 155 gunzip_nomem4:
 156         free(strm);
 157 gunzip_nomem3:
 158         if (!buf)
 159                 free(zbuf);
 160 gunzip_nomem2:
 161         if (flush)
 162                 free(out_buf);
 163 gunzip_nomem1:
 164         return rc; /* returns Z_OK (0) if successful */
 165 }
 166
 167 #define decompress gunzip