lib/decompress_inflate.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #ifdef STATIC
   3 #define PREBOOT
   4 /* Pre-boot environment: included */
   5
   6 /* prevent inclusion of _LINUX_KERNEL_H in pre-boot environment: lots
   7  * errors about console_printk etc... on ARM */
   8 #define _LINUX_KERNEL_H
   9
  10 #include "zlib_inflate/inftrees.c"
  11 #include "zlib_inflate/inffast.c"
  12 #include "zlib_inflate/inflate.c"
  13 #ifdef CONFIG_ZLIB_DFLTCC
  14 #include "zlib_dfltcc/dfltcc.c"
  15 #include "zlib_dfltcc/dfltcc_inflate.c"
  16 #endif
  17
  18 #else /* STATIC */
  19 /* initramfs et al: linked */
  20
  21 #include <linux/zutil.h>
  22
  23 #include "zlib_inflate/inftrees.h"
  24 #include "zlib_inflate/inffast.h"
  25 #include "zlib_inflate/inflate.h"
  26
  27 #include "zlib_inflate/infutil.h"
  28 #include <linux/decompress/inflate.h>
  29
  30 #endif /* STATIC */
  31
  32 #include <linux/decompress/mm.h>
  33
  34 #define GZIP_IOBUF_SIZE (16*1024)
  35
  36 static long INIT nofill(void *buffer, unsigned long len)
  37 {
  38         return -1;
  39 }
  40
  41 /* Included from initramfs et al code */
  42 STATIC int INIT __gunzip(unsigned char *buf, long len,
  43                        long (*fill)(void*, unsigned long),
  44                        long (*flush)(void*, unsigned long),
  45                        unsigned char *out_buf, long out_len,
  46                        long *pos,
  47                        void(*error)(char *x)) {
  48         u8 *zbuf;
  49         struct z_stream_s *strm;
  50         int rc;
  51
  52         rc = -1;
  53         if (flush) {
  54                 out_len = 0x8000; /* 32 K */
  55                 out_buf = malloc(out_len);
  56         } else {
  57                 if (!out_len)
  58                         out_len = ((size_t)~0) - (size_t)out_buf; /* no limit */
  59         }
  60         if (!out_buf) {
  61                 error("Out of memory while allocating output buffer");
  62                 goto gunzip_nomem1;
  63         }
  64
  65         if (buf)
  66                 zbuf = buf;
  67         else {
  68                 zbuf = malloc(GZIP_IOBUF_SIZE);
  69                 len = 0;
  70         }
  71         if (!zbuf) {
  72                 error("Out of memory while allocating input buffer");
  73                 goto gunzip_nomem2;
  74         }
  75
  76         strm = malloc(sizeof(*strm));
  77         if (strm == NULL) {
  78                 error("Out of memory while allocating z_stream");
  79                 goto gunzip_nomem3;
  80         }
  81
  82         strm->workspace = malloc(flush ? zlib_inflate_workspacesize() :
  83 #ifdef CONFIG_ZLIB_DFLTCC
  84         /* Always allocate the full workspace for DFLTCC */
  85                                  zlib_inflate_workspacesize());
  86 #else
  87                                  sizeof(struct inflate_state));
  88 #endif
  89         if (strm->workspace == NULL) {
  90                 error("Out of memory while allocating workspace");
  91                 goto gunzip_nomem4;
  92         }
  93
  94         if (!fill)
  95                 fill = nofill;
  96
  97         if (len == 0)
  98                 len = fill(zbuf, GZIP_IOBUF_SIZE);
  99
 100         /* verify the gzip header */
 101         if (len < 10 ||
 102            zbuf[0] != 0x1f || zbuf[1] != 0x8b || zbuf[2] != 0x08) {
 103                 if (pos)
 104                         *pos = 0;
 105                 error("Not a gzip file");
 106                 goto gunzip_5;
 107         }
 108
 109         /* skip over gzip header (1f,8b,08... 10 bytes total +
 110          * possible asciz filename)
 111          */
 112         strm->next_in = zbuf + 10;
 113         strm->avail_in = len - 10;
 114         /* skip over asciz filename */
 115         if (zbuf[3] & 0x8) {
 116                 do {
 117                         /*
 118                          * If the filename doesn't fit into the buffer,
 119                          * the file is very probably corrupt. Don't try
 120                          * to read more data.
 121                          */
 122                         if (strm->avail_in == 0) {
 123                                 error("header error");
 124                                 goto gunzip_5;
 125                         }
 126                         --strm->avail_in;
 127                 } while (*strm->next_in++);
 128         }
 129
 130         strm->next_out = out_buf;
 131         strm->avail_out = out_len;
 132
 133         rc = zlib_inflateInit2(strm, -MAX_WBITS);
 134
 135 #ifdef CONFIG_ZLIB_DFLTCC
 136         /* Always keep the window for DFLTCC */
 137 #else
 138         if (!flush) {
 139                 WS(strm)->inflate_state.wsize = 0;
 140                 WS(strm)->inflate_state.window = NULL;
 141         }
 142 #endif
 143
 144         while (rc == Z_OK) {
 145                 if (strm->avail_in == 0) {
 146                         /* TODO: handle case where both pos and fill are set */
 147                         len = fill(zbuf, GZIP_IOBUF_SIZE);
 148                         if (len < 0) {
 149                                 rc = -1;
 150                                 error("read error");
 151                                 break;
 152                         }
 153                         strm->next_in = zbuf;
 154                         strm->avail_in = len;
 155                 }
 156                 rc = zlib_inflate(strm, 0);
 157
 158                 /* Write any data generated */
 159                 if (flush && strm->next_out > out_buf) {
 160                         long l = strm->next_out - out_buf;
 161                         if (l != flush(out_buf, l)) {
 162                                 rc = -1;
 163                                 error("write error");
 164                                 break;
 165                         }
 166                         strm->next_out = out_buf;
 167                         strm->avail_out = out_len;
 168                 }
 169
 170                 /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */
 171                 if (rc == Z_STREAM_END) {
 172                         rc = 0;
 173                         break;
 174                 } else if (rc != Z_OK) {
 175                         error("uncompression error");
 176                         rc = -1;
 177                 }
 178         }
 179
 180         zlib_inflateEnd(strm);
 181         if (pos)
 182                 /* add + 8 to skip over trailer */
 183                 *pos = strm->next_in - zbuf+8;
 184
 185 gunzip_5:
 186         free(strm->workspace);
 187 gunzip_nomem4:
 188         free(strm);
 189 gunzip_nomem3:
 190         if (!buf)
 191                 free(zbuf);
 192 gunzip_nomem2:
 193         if (flush)
 194                 free(out_buf);
 195 gunzip_nomem1:
 196         return rc; /* returns Z_OK (0) if successful */
 197 }
 198
 199 #ifndef PREBOOT
 200 STATIC int INIT gunzip(unsigned char *buf, long len,
 201                        long (*fill)(void*, unsigned long),
 202                        long (*flush)(void*, unsigned long),
 203                        unsigned char *out_buf,
 204                        long *pos,
 205                        void (*error)(char *x))
 206 {
 207         return __gunzip(buf, len, fill, flush, out_buf, 0, pos, error);
 208 }
 209 #else
 210 STATIC int INIT __decompress(unsigned char *buf, long len,
 211                            long (*fill)(void*, unsigned long),
 212                            long (*flush)(void*, unsigned long),
 213                            unsigned char *out_buf, long out_len,
 214                            long *pos,
 215                            void (*error)(char *x))
 216 {
 217         return __gunzip(buf, len, fill, flush, out_buf, out_len, pos, error);
 218 }
 219 #endif