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Remove 64KB string length limitation
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Dmitri Tikhonov committed Apr 30, 2019
1 parent e06228c commit 6d81ea0
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Showing 6 changed files with 324 additions and 164 deletions.
15 changes: 5 additions & 10 deletions include/lshpack.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -31,13 +31,8 @@ extern "C" {

#include <stdint.h>

/**
* Strings up to 65535 characters in length are supported.
*/
typedef uint16_t lshpack_strlen_t;

/** Maximum length is defined for convenience */
#define LSHPACK_MAX_STRLEN UINT16_MAX
#define LSHPACK_MAX_STRLEN UINT_MAX

struct lshpack_enc;
struct lshpack_dec;
Expand Down Expand Up @@ -72,8 +67,8 @@ lshpack_enc_cleanup (struct lshpack_enc *);
*/
unsigned char *
lshpack_enc_encode (struct lshpack_enc *henc, unsigned char *dst,
unsigned char *dst_end, const char *name, lshpack_strlen_t name_len,
const char *value, lshpack_strlen_t value_len, int indexed_type);
unsigned char *dst_end, const char *name, unsigned name_len,
const char *value, unsigned value_len, int indexed_type);

void
lshpack_enc_set_max_capacity (struct lshpack_enc *, unsigned);
Expand All @@ -99,8 +94,8 @@ lshpack_dec_cleanup (struct lshpack_dec *);
int
lshpack_dec_decode (struct lshpack_dec *dec,
const unsigned char **src, const unsigned char *src_end,
char *dst, char *const dst_end, lshpack_strlen_t *name_len,
lshpack_strlen_t *val_len);
char *dst, char *const dst_end, unsigned *name_len,
unsigned *val_len);

void
lshpack_dec_set_max_capacity (struct lshpack_dec *, unsigned);
Expand Down
106 changes: 64 additions & 42 deletions src/lshpack.c
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Original file line number Diff line number Diff line change
Expand Up @@ -50,8 +50,8 @@ SOFTWARE.

static const struct
{
lshpack_strlen_t name_len;
lshpack_strlen_t val_len;
unsigned name_len;
unsigned val_len;
const char *name;
const char *val;
}
Expand Down Expand Up @@ -5348,8 +5348,8 @@ struct lshpack_enc_table_entry
unsigned ete_id;
unsigned ete_nameval_hash;
unsigned ete_name_hash;
lshpack_strlen_t ete_name_len;
lshpack_strlen_t ete_val_len;
unsigned ete_name_len;
unsigned ete_val_len;
char ete_buf[0];
};

Expand Down Expand Up @@ -5441,7 +5441,7 @@ static
#endif
unsigned
lshpack_enc_get_static_nameval (uint32_t nameval_hash, const char *name,
lshpack_strlen_t name_len, const char *val, lshpack_strlen_t val_len)
unsigned name_len, const char *val, unsigned val_len)
{
unsigned i;

Expand All @@ -5466,7 +5466,7 @@ static
#endif
unsigned
lshpack_enc_get_static_name (uint32_t name_hash, const char *name,
lshpack_strlen_t name_len)
unsigned name_len)
{
unsigned i;

Expand Down Expand Up @@ -5499,8 +5499,8 @@ henc_calc_table_id (const struct lshpack_enc *enc,
static unsigned
henc_find_table_id (struct lshpack_enc *enc, uint32_t name_hash,
uint32_t nameval_hash, const char *name,
lshpack_strlen_t name_len, const char *value,
lshpack_strlen_t value_len, int *val_matched)
unsigned name_len, const char *value,
unsigned value_len, int *val_matched)
{
struct lshpack_enc_table_entry *entry;
unsigned buckno, static_table_id;
Expand Down Expand Up @@ -5549,9 +5549,12 @@ henc_find_table_id (struct lshpack_enc *enc, uint32_t name_hash,
}


static unsigned char *
henc_enc_int (unsigned char *dst, unsigned char *const end, uint32_t value,
uint8_t prefix_bits)
#if !LS_HPACK_EMIT_TEST_CODE
static
#endif
unsigned char *
lshpack_enc_enc_int (unsigned char *dst, unsigned char *const end,
uint32_t value, uint8_t prefix_bits)
{
unsigned char *const dst_orig = dst;

Expand Down Expand Up @@ -5665,7 +5668,7 @@ static
#endif
int
lshpack_enc_enc_str (unsigned char *const dst, size_t dst_len,
const unsigned char *str, lshpack_strlen_t str_len)
const unsigned char *str, unsigned str_len)
{
unsigned char size_buf[4];
unsigned char *p;
Expand Down Expand Up @@ -5718,7 +5721,7 @@ lshpack_enc_enc_str (unsigned char *const dst, size_t dst_len,
/* The guess of one-byte size was incorrect. Perform necessary
* adjustments.
*/
p = henc_enc_int(size_buf, size_buf + sizeof(size_buf), str_len, 7);
p = lshpack_enc_enc_int(size_buf, size_buf + sizeof(size_buf), str_len, 7);
if (p == size_buf)
return -1;

Expand Down Expand Up @@ -5819,8 +5822,8 @@ static
#endif
int
lshpack_enc_push_entry (struct lshpack_enc *enc, uint32_t name_hash,
uint32_t nameval_hash, const char *name, lshpack_strlen_t name_len,
const char *value, lshpack_strlen_t value_len)
uint32_t nameval_hash, const char *name, unsigned name_len,
const char *value, unsigned value_len)
{
struct lshpack_enc_table_entry *entry;
unsigned buckno;
Expand Down Expand Up @@ -5860,8 +5863,8 @@ lshpack_enc_push_entry (struct lshpack_enc *enc, uint32_t name_hash,

unsigned char *
lshpack_enc_encode (struct lshpack_enc *enc, unsigned char *dst,
unsigned char *dst_end, const char *name, lshpack_strlen_t name_len,
const char *value, lshpack_strlen_t value_len, int indexed_type)
unsigned char *dst_end, const char *name, unsigned name_len,
const char *value, unsigned value_len, int indexed_type)
{
//indexed_type: 0, Add, 1,: without, 2: never
static const char indexed_prefix_number[] = {0x40, 0x00, 0x10};
Expand Down Expand Up @@ -5889,7 +5892,7 @@ lshpack_enc_encode (struct lshpack_enc *enc, unsigned char *dst,
if (val_matched)
{
*dst = 0x80;
dst = henc_enc_int(dst, dst_end, table_id, 7);
dst = lshpack_enc_enc_int(dst, dst_end, table_id, 7);
/* No need to check return value: we pass it up as-is because
* the behavior is the same.
*/
Expand All @@ -5898,7 +5901,7 @@ lshpack_enc_encode (struct lshpack_enc *enc, unsigned char *dst,
else
{
*dst = indexed_prefix_number[indexed_type];
dst = henc_enc_int(dst, dst_end, table_id,
dst = lshpack_enc_enc_int(dst, dst_end, table_id,
((indexed_type == 0) ? 6 : 4));
if (dst == dst_org)
return dst_org;
Expand Down Expand Up @@ -5973,8 +5976,8 @@ lshpack_enc_iter_next (struct lshpack_enc *enc, void **iter,
/* Dynamic table entry: */
struct dec_table_entry
{
uint16_t dte_name_len;
uint16_t dte_val_len;
unsigned dte_name_len;
unsigned dte_val_len;
char dte_buf[0]; /* Contains both name and value */
};

Expand Down Expand Up @@ -6019,37 +6022,60 @@ lshpack_dec_cleanup (struct lshpack_dec *dec)
}


/* Maximum number of bytes required to encode a 32-bit integer */
#define LSHPACK_UINT32_ENC_SZ 6


/* Assumption: we have at least one byte to work with */
#if !LS_HPACK_EMIT_TEST_CODE
static
#endif
int
lshpack_dec_dec_int (const unsigned char **src, const unsigned char *src_end,
uint8_t prefix_bits, uint32_t *value)
lshpack_dec_dec_int (const unsigned char **src_p, const unsigned char *src_end,
unsigned prefix_bits, uint32_t *value_p)
{
uint32_t B, M;
uint8_t prefix_max = (1 << prefix_bits) - 1;
const unsigned char *const orig_src = *src_p;
const unsigned char *src;
unsigned prefix_max, M;
uint32_t val, B;

*value = (*(*src)++ & prefix_max);
src = *src_p;

if (*value < prefix_max)
prefix_max = (1 << prefix_bits) - 1;
val = *src++;
val &= prefix_max;

if (val < prefix_max)
{
*src_p = src;
*value_p = val;
return 0;
}

/* To optimize the loop for the normal case, the overflow is checked
* outside the loop. The decoder is limited to 28-bit integer values,
* which is far above limitations imposed by the APIs (16-bit integers).
*/
M = 0;
do
{
if ((*src) >= src_end)
if (src < src_end)
{
B = *src++;
val = val + ((B & 0x7f) << M);
M += 7;
}
else if (src - orig_src < LSHPACK_UINT32_ENC_SZ)
return -1;
B = *(*src)++;
*value = *value + ((B & 0x7f) << M);
M += 7;
else
return -2;
}
while (B & 0x80);

return -(M > sizeof(*value) * 8);
if (M <= 28 || (M == 35 && src[-1] <= 0xF && val - (src[-1] << 28) < val))
{
*src_p = src;
*value_p = val;
return 0;
}
else
return -2;
}


Expand Down Expand Up @@ -6209,7 +6235,7 @@ static
#endif
int
lshpack_dec_push_entry (struct lshpack_dec *dec, const char *name,
uint16_t name_len, const char *val, uint16_t val_len)
unsigned name_len, const char *val, unsigned val_len)
{
struct dec_table_entry *entry;
size_t size;
Expand Down Expand Up @@ -6237,7 +6263,7 @@ lshpack_dec_push_entry (struct lshpack_dec *dec, const char *name,
int
lshpack_dec_decode (struct lshpack_dec *dec,
const unsigned char **src, const unsigned char *src_end,
char *dst, char *const dst_end, uint16_t *name_len, uint16_t *val_len)
char *dst, char *const dst_end, unsigned *name_len, unsigned *val_len)
{
struct dec_table_entry *entry;
uint32_t index, new_capacity;
Expand Down Expand Up @@ -6355,17 +6381,13 @@ lshpack_dec_decode (struct lshpack_dec *dec,
len = hdec_dec_str((unsigned char *)name, dst_end - dst, src, src_end);
if (len < 0)
return len; //error
if (len > UINT16_MAX)
return -2;
*name_len = len;
}

len = hdec_dec_str((unsigned char *)name + *name_len,
dst_end - dst - *name_len, src, src_end);
if (len < 0)
return len; //error
if (len > UINT16_MAX)
return -2;
*val_len = len;

if (indexed_type == 0)
Expand Down
4 changes: 4 additions & 0 deletions test/CMakeLists.txt
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,3 +3,7 @@ ENABLE_TESTING()
ADD_EXECUTABLE(test_hpack test_hpack.c ../deps/xxhash/xxhash.c)
TARGET_LINK_LIBRARIES(test_hpack ls-hpack)
ADD_TEST(hpack test_hpack)

ADD_EXECUTABLE(test_int test_int.c ../deps/xxhash/xxhash.c)
TARGET_LINK_LIBRARIES(test_int ls-hpack)
ADD_TEST(int test_int)
21 changes: 13 additions & 8 deletions test/lshpack-test.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -12,20 +12,20 @@ struct enc_dyn_table_entry

unsigned
lshpack_enc_get_static_name (uint32_t name_hash, const char *name,
lshpack_strlen_t name_len);
unsigned name_len);

unsigned
lshpack_enc_get_static_nameval (uint32_t nameval_hash, const char *name,
lshpack_strlen_t name_len, const char *val, lshpack_strlen_t val_len);
unsigned name_len, const char *val, unsigned val_len);

int
lshpack_enc_push_entry (struct lshpack_enc *enc, uint32_t name_hash,
uint32_t nameval_hash, const char *name, lshpack_strlen_t name_len,
const char *value, lshpack_strlen_t value_len);
uint32_t nameval_hash, const char *name, unsigned name_len,
const char *value, unsigned value_len);

int
lshpack_enc_enc_str (unsigned char *const dst, size_t dst_len,
const unsigned char *str, lshpack_strlen_t str_len);
const unsigned char *str, unsigned str_len);

typedef void * enc_iter_t;

Expand All @@ -39,10 +39,15 @@ lshpack_enc_iter_next (struct lshpack_enc *enc, void **iter,

int
lshpack_dec_dec_int (const unsigned char **src, const unsigned char *src_end,
uint8_t prefix_bits, uint32_t *value);
unsigned prefix_bits, uint32_t *value);
int
lshpack_dec_push_entry (struct lshpack_dec *dec, const char *name,
lshpack_strlen_t name_len, const char *val,
lshpack_strlen_t val_len);
unsigned name_len, const char *val,
unsigned val_len);

unsigned char *
lshpack_enc_enc_int (unsigned char *dst, unsigned char *const end, uint32_t value,
uint8_t prefix_bits);


#endif
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