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lzop: don't support ancient versions < 0.94 (15 Oct 1997)

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0.94 came only 2 months after initial 0.90:

    0.90 (10 Aug 1997): First public release of lzop
    ...
    0.94 (15 Oct 1997): Header format change

function                                             old     new   delta
do_lzo_decompress                                    411     404      -7
f_read8                                               24       -     -24
f_read16                                              31       -     -31
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 0/1 up/down: 0/-62)             Total: -62 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-04-08 13:35:28 +02:00
parent 434f95960a
commit 3a7d16d488
1 changed files with 50 additions and 53 deletions
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103
archival/lzop.c
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@ -448,7 +448,7 @@ typedef struct header_t {
uint16_t version_needed_to_extract_be16; uint16_t version_needed_to_extract_be16;
uint8_t method; uint8_t method;
uint8_t level; uint8_t level;
uint32_t flags32; /* be32 on disk, but we keep them in native order */ uint32_t flags32; /* be32 on disk, but we keep this field in native order */
uint32_t mode_be32; uint32_t mode_be32;
uint32_t mtime_be32; uint32_t mtime_be32;
uint32_t gmtdiff_be32; uint32_t gmtdiff_be32;
@ -577,18 +577,18 @@ static void f_read(void* buf, int cnt)
xread(0, buf, cnt); xread(0, buf, cnt);
add_bytes_to_chksum(buf, cnt); add_bytes_to_chksum(buf, cnt);
} }
static int f_read8(void) //static int f_read8(void)
{ //{
uint8_t v; // uint8_t v;
f_read(&v, 1); // f_read(&v, 1);
return v; // return v;
} //}
static unsigned f_read16(void) //static unsigned f_read16(void)
{ //{
uint16_t v; // uint16_t v;
f_read(&v, 2); // f_read(&v, 2);
return ntohs(v); // return ntohs(v);
} //}
static uint32_t f_read32(void) static uint32_t f_read32(void)
{ {
uint32_t v; uint32_t v;
@ -928,66 +928,62 @@ static int read_header(header_t *h)
{ {
int l; int l;
uint32_t checksum; uint32_t checksum;
/* As it stands now, only h->flags32 is used by our caller.
* Therefore we don't store many fields in h->FIELD.
*/
unsigned h_version; unsigned h_version;
uint8_t h_method, h_level; unsigned h_version_needed_to_extract;
init_chksum(); init_chksum();
/* As it stands now, only h->flags32 is used by our caller. /* We don't support versions < 0.94, since 0.94
* Therefore we don't store many fields in h->field. * came only 2 months after 0.90:
* 0.90 (10 Aug 1997): First public release of lzop
* 0.94 (15 Oct 1997): Header format change
*/ */
h_version = f_read16();
if (h_version < 0x0900)
return 3;
/* UNUSED h->lib_version_be16 = */ f_read16();
if (h_version >= 0x0940) {
unsigned h_version_needed_to_extract = f_read16();
if (h_version_needed_to_extract > LZOP_VERSION)
return 16;
if (h_version_needed_to_extract < 0x0900) /* first lzop version */
return 3;
}
h_method = f_read8(); /* Read up to and including name length byte */
if (h_method <= 0) f_read(&h->version_be16, ((char*)&h->len_and_name[1]) - ((char*)&h->version_be16));
h_version = htons(h->version_be16);
if (h_version < 0x0940)
return 3;
h_version_needed_to_extract = htons(h->version_needed_to_extract_be16);
if (h_version_needed_to_extract > LZOP_VERSION)
return 16;
if (h_version_needed_to_extract < 0x0940)
return 3;
if (h->method <= 0)
return 14; return 14;
h_level = 0;
if (h_version >= 0x0940)
h_level = f_read8();
/* former lzo_get_method(h): */ /* former lzo_get_method(h): */
if (h_method == M_LZO1X_1) { if (h->method == M_LZO1X_1) {
if (h_level == 0) if (h->level == 0)
h_level = 3; h->level = 3;
} else if (h_method == M_LZO1X_1_15) { } else if (h->method == M_LZO1X_1_15) {
if (h_level == 0) if (h->level == 0)
h_level = 1; h->level = 1;
} else if (h_method == M_LZO1X_999) { } else if (h->method == M_LZO1X_999) {
if (h_level == 0) if (h->level == 0)
h_level = 9; h->level = 9;
} else } else
return -1; /* not a LZO method */ return -1; /* not a LZO method */
/* check compression level */ /* check compression level */
if (h_level < 1 || h_level > 9) if (h->level < 1 || h->level > 9)
return 15; return 15;
h->flags32 = f_read32(); h->flags32 = ntohl(h->flags32);
if (h->flags32 & F_H_FILTER) if (h->flags32 & F_H_FILTER)
return 16; /* filter not supported */ return 16; /* filter not supported */
/* check reserved flags */ /* check reserved flags */
if (h->flags32 & F_RESERVED) if (h->flags32 & F_RESERVED)
return -13; return -13;
/* UNUSED h->mode = */ f_read32(); l = h->len_and_name[0];
/* UNUSED h->mtime = */ f_read32();
if (h_version >= 0x0940)
/* UNUSED h->gmtdiff = */ f_read32();
l = f_read8();
/* UNUSED h->len_and_name[0] = l; */
/* UNUSED h->len_and_name[1+l] = 0; */
if (l > 0) if (l > 0)
f_read(h->len_and_name+1, l); /* UNUSED */ f_read(h->len_and_name+1, l);
/* UNUSED h->len_and_name[1+l] = 0; */
checksum = chksum_getresult(h->flags32); checksum = chksum_getresult(h->flags32);
if (f_read32() != checksum) if (f_read32() != checksum)
@ -998,12 +994,13 @@ static int read_header(header_t *h)
uint32_t extra_field_len; uint32_t extra_field_len;
uint32_t extra_field_checksum; uint32_t extra_field_checksum;
uint32_t k; uint32_t k;
char dummy;
/* note: the checksum also covers the length */ /* note: the checksum also covers the length */
init_chksum(); init_chksum();
extra_field_len = f_read32(); extra_field_len = f_read32();
for (k = 0; k < extra_field_len; k++) for (k = 0; k < extra_field_len; k++)
f_read8(); f_read(&dummy, 1);
checksum = chksum_getresult(h->flags32); checksum = chksum_getresult(h->flags32);
extra_field_checksum = f_read32(); extra_field_checksum = f_read32();
if (extra_field_checksum != checksum) if (extra_field_checksum != checksum)