lib/decompress_inflate.c

   1 #ifdef STATIC
   2 #define PREBOOT
   3 /* Pre-boot environment: included */
   4
   5 /* prevent inclusion of _LINUX_KERNEL_H in pre-boot environment: lots
   6  * errors about console_printk etc... on ARM */
   7 #define _LINUX_KERNEL_H
   8
   9 #include "zlib_inflate/inftrees.c"
  10 #include "zlib_inflate/inffast.c"
  11 #include "zlib_inflate/inflate.c"
  12
  13 #else /* STATIC */
  14 /* initramfs et al: linked */
  15
  16 #include <linux/zutil.h>
  17
  18 #include "zlib_inflate/inftrees.h"
  19 #include "zlib_inflate/inffast.h"
  20 #include "zlib_inflate/inflate.h"
  21
  22 #include "zlib_inflate/infutil.h"
  23 #include <linux/decompress/inflate.h>
  24
  25 #endif /* STATIC */
  26
  27 #include <linux/decompress/mm.h>
  28
  29 #define GZIP_IOBUF_SIZE (16*1024)
  30
  31 static long INIT nofill(void *buffer, unsigned long len)
  32 {
  33         return -1;
  34 }
  35
  36 /* Included from initramfs et al code */
  37 STATIC int INIT __gunzip(unsigned char *buf, long len,
  38                        long (*fill)(void*, unsigned long),
  39                        long (*flush)(void*, unsigned long),
  40                        unsigned char *out_buf, long out_len,
  41                        long *pos,
  42                        void(*error)(char *x)) {
  43         u8 *zbuf;
  44         struct z_stream_s *strm;
  45         int rc;
  46
  47         rc = -1;
  48         if (flush) {
  49                 out_len = 0x8000; /* 32 K */
  50                 out_buf = malloc(out_len);
  51         } else {
  52                 if (!out_len)
  53                         out_len = ((size_t)~0) - (size_t)out_buf; /* no limit */
  54         }
  55         if (!out_buf) {
  56                 error("Out of memory while allocating output buffer");
  57                 goto gunzip_nomem1;
  58         }
  59
  60         if (buf)
  61                 zbuf = buf;
  62         else {
  63                 zbuf = malloc(GZIP_IOBUF_SIZE);
  64                 len = 0;
  65         }
  66         if (!zbuf) {
  67                 error("Out of memory while allocating input buffer");
  68                 goto gunzip_nomem2;
  69         }
  70
  71         strm = malloc(sizeof(*strm));
  72         if (strm == NULL) {
  73                 error("Out of memory while allocating z_stream");
  74                 goto gunzip_nomem3;
  75         }
  76
  77         strm->workspace = malloc(flush ? zlib_inflate_workspacesize() :
  78                                  sizeof(struct inflate_state));
  79         if (strm->workspace == NULL) {
  80                 error("Out of memory while allocating workspace");
  81                 goto gunzip_nomem4;
  82         }
  83
  84         if (!fill)
  85                 fill = nofill;
  86
  87         if (len == 0)
  88                 len = fill(zbuf, GZIP_IOBUF_SIZE);
  89
  90         /* verify the gzip header */
  91         if (len < 10 ||
  92            zbuf[0] != 0x1f || zbuf[1] != 0x8b || zbuf[2] != 0x08) {
  93                 if (pos)
  94                         *pos = 0;
  95                 error("Not a gzip file");
  96                 goto gunzip_5;
  97         }
  98
  99         /* skip over gzip header (1f,8b,08... 10 bytes total +
 100          * possible asciz filename)
 101          */
 102         strm->next_in = zbuf + 10;
 103         strm->avail_in = len - 10;
 104         /* skip over asciz filename */
 105         if (zbuf[3] & 0x8) {
 106                 do {
 107                         /*
 108                          * If the filename doesn't fit into the buffer,
 109                          * the file is very probably corrupt. Don't try
 110                          * to read more data.
 111                          */
 112                         if (strm->avail_in == 0) {
 113                                 error("header error");
 114                                 goto gunzip_5;
 115                         }
 116                         --strm->avail_in;
 117                 } while (*strm->next_in++);
 118         }
 119
 120         strm->next_out = out_buf;
 121         strm->avail_out = out_len;
 122
 123         rc = zlib_inflateInit2(strm, -MAX_WBITS);
 124
 125         if (!flush) {
 126                 WS(strm)->inflate_state.wsize = 0;
 127                 WS(strm)->inflate_state.window = NULL;
 128         }
 129
 130         while (rc == Z_OK) {
 131                 if (strm->avail_in == 0) {
 132                         /* TODO: handle case where both pos and fill are set */
 133                         len = fill(zbuf, GZIP_IOBUF_SIZE);
 134                         if (len < 0) {
 135                                 rc = -1;
 136                                 error("read error");
 137                                 break;
 138                         }
 139                         strm->next_in = zbuf;
 140                         strm->avail_in = len;
 141                 }
 142                 rc = zlib_inflate(strm, 0);
 143
 144                 /* Write any data generated */
 145                 if (flush && strm->next_out > out_buf) {
 146                         long l = strm->next_out - out_buf;
 147                         if (l != flush(out_buf, l)) {
 148                                 rc = -1;
 149                                 error("write error");
 150                                 break;
 151                         }
 152                         strm->next_out = out_buf;
 153                         strm->avail_out = out_len;
 154                 }
 155
 156                 /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */
 157                 if (rc == Z_STREAM_END) {
 158                         rc = 0;
 159                         break;
 160                 } else if (rc != Z_OK) {
 161                         error("uncompression error");
 162                         rc = -1;
 163                 }
 164         }
 165
 166         zlib_inflateEnd(strm);
 167         if (pos)
 168                 /* add + 8 to skip over trailer */
 169                 *pos = strm->next_in - zbuf+8;
 170
 171 gunzip_5:
 172         free(strm->workspace);
 173 gunzip_nomem4:
 174         free(strm);
 175 gunzip_nomem3:
 176         if (!buf)
 177                 free(zbuf);
 178 gunzip_nomem2:
 179         if (flush)
 180                 free(out_buf);
 181 gunzip_nomem1:
 182         return rc; /* returns Z_OK (0) if successful */
 183 }
 184
 185 #ifndef PREBOOT
 186 STATIC int INIT gunzip(unsigned char *buf, long len,
 187                        long (*fill)(void*, unsigned long),
 188                        long (*flush)(void*, unsigned long),
 189                        unsigned char *out_buf,
 190                        long *pos,
 191                        void (*error)(char *x))
 192 {
 193         return __gunzip(buf, len, fill, flush, out_buf, 0, pos, error);
 194 }
 195 #else
 196 STATIC int INIT __decompress(unsigned char *buf, long len,
 197                            long (*fill)(void*, unsigned long),
 198                            long (*flush)(void*, unsigned long),
 199                            unsigned char *out_buf, long out_len,
 200                            long *pos,
 201                            void (*error)(char *x))
 202 {
 203         return __gunzip(buf, len, fill, flush, out_buf, out_len, pos, error);
 204 }
 205 #endif