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haproxy/dev/hpack/gen-rht.c

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CONTRIB: hpack: implement a reverse huffman table generator for hpack This one was built by studying the HPACK Huffman table (RFC7541 appendix B). It creates 5 small tables (4*512 bytes, 1*64 bytes) to map one byte at a time from the input stream based on the following observations : * rht_bit31_24[256] is indexed on bits 31..24 when < 0xfe * rht_bit24_17[256] is indexed on bits 24..17 when 31..24 >= 0xfe * rht_bit15_11_fe[32] is indexed on bits 15..11 when 24..17 == 0xfe * rht_bit15_8[256] is indexed on bits 15..8 when 24..17 == 0xff * rht_bit11_4[256] is indexed on bits 11..4 when 15..8 == 0xff * when 11..4 == 0xff, 3..2 provide the following mapping : * 00 => 0x0a, 01 => 0x0d, 10 => 0x16, 11 => EOS
2017-05-19 16:14:51 +00:00
/* Reverse Huffman table generator for HPACK decoder - 2017-05-19 Willy Tarreau
*
* rht_bit31_24[256] is indexed on bits 31..24 when < 0xfe
* rht_bit24_17[256] is indexed on bits 24..17 when 31..24 >= 0xfe
* rht_bit15_11_fe[32] is indexed on bits 15..11 when 24..17 == 0xfe
* rht_bit15_8[256] is indexed on bits 15..8 when 24..17 == 0xff
* rht_bit11_4[256] is indexed on bits 11..4 when 15..8 == 0xff
* when 11..4 == 0xff, 3..2 provide the following mapping :
* 00 => 0x0a, 01 => 0x0d, 10 => 0x16, 11 => EOS
*/
BUILD: use inttypes.h instead of stdint.h I found on an (old) AIX 5.1 machine that stdint.h didn't exist while inttypes.h which is expected to include it does exist and provides the desired functionalities. As explained here, stdint being just a subset of inttypes for use in freestanding environments, it's probably always OK to switch to inttypes instead: https://pubs.opengroup.org/onlinepubs/009696799/basedefs/stdint.h.html Also it's even clearer here in the autoconf doc : https://www.gnu.org/software/autoconf/manual/autoconf-2.61/html_node/Header-Portability.html "The C99 standard says that inttypes.h includes stdint.h, so there's no need to include stdint.h separately in a standard environment. Some implementations have inttypes.h but not stdint.h (e.g., Solaris 7), but we don't know of any implementation that has stdint.h but not inttypes.h"
2019-03-29 16:26:33 +00:00
#include <inttypes.h>
CONTRIB: hpack: implement a reverse huffman table generator for hpack This one was built by studying the HPACK Huffman table (RFC7541 appendix B). It creates 5 small tables (4*512 bytes, 1*64 bytes) to map one byte at a time from the input stream based on the following observations : * rht_bit31_24[256] is indexed on bits 31..24 when < 0xfe * rht_bit24_17[256] is indexed on bits 24..17 when 31..24 >= 0xfe * rht_bit15_11_fe[32] is indexed on bits 15..11 when 24..17 == 0xfe * rht_bit15_8[256] is indexed on bits 15..8 when 24..17 == 0xff * rht_bit11_4[256] is indexed on bits 11..4 when 15..8 == 0xff * when 11..4 == 0xff, 3..2 provide the following mapping : * 00 => 0x0a, 01 => 0x0d, 10 => 0x16, 11 => EOS
2017-05-19 16:14:51 +00:00
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* from RFC7541 Appendix B */
static const struct huff {
uint32_t c; /* code point */
int b; /* bits */
} ht[257] = {
[0] = { .c = 0x00001ff8, .b = 13 },
[1] = { .c = 0x007fffd8, .b = 23 },
[2] = { .c = 0x0fffffe2, .b = 28 },
[3] = { .c = 0x0fffffe3, .b = 28 },
[4] = { .c = 0x0fffffe4, .b = 28 },
[5] = { .c = 0x0fffffe5, .b = 28 },
[6] = { .c = 0x0fffffe6, .b = 28 },
[7] = { .c = 0x0fffffe7, .b = 28 },
[8] = { .c = 0x0fffffe8, .b = 28 },
[9] = { .c = 0x00ffffea, .b = 24 },
[10] = { .c = 0x3ffffffc, .b = 30 },
[11] = { .c = 0x0fffffe9, .b = 28 },
[12] = { .c = 0x0fffffea, .b = 28 },
[13] = { .c = 0x3ffffffd, .b = 30 },
[14] = { .c = 0x0fffffeb, .b = 28 },
[15] = { .c = 0x0fffffec, .b = 28 },
[16] = { .c = 0x0fffffed, .b = 28 },
[17] = { .c = 0x0fffffee, .b = 28 },
[18] = { .c = 0x0fffffef, .b = 28 },
[19] = { .c = 0x0ffffff0, .b = 28 },
[20] = { .c = 0x0ffffff1, .b = 28 },
[21] = { .c = 0x0ffffff2, .b = 28 },
[22] = { .c = 0x3ffffffe, .b = 30 },
[23] = { .c = 0x0ffffff3, .b = 28 },
[24] = { .c = 0x0ffffff4, .b = 28 },
[25] = { .c = 0x0ffffff5, .b = 28 },
[26] = { .c = 0x0ffffff6, .b = 28 },
[27] = { .c = 0x0ffffff7, .b = 28 },
[28] = { .c = 0x0ffffff8, .b = 28 },
[29] = { .c = 0x0ffffff9, .b = 28 },
[30] = { .c = 0x0ffffffa, .b = 28 },
[31] = { .c = 0x0ffffffb, .b = 28 },
[32] = { .c = 0x00000014, .b = 6 },
[33] = { .c = 0x000003f8, .b = 10 },
[34] = { .c = 0x000003f9, .b = 10 },
[35] = { .c = 0x00000ffa, .b = 12 },
[36] = { .c = 0x00001ff9, .b = 13 },
[37] = { .c = 0x00000015, .b = 6 },
[38] = { .c = 0x000000f8, .b = 8 },
[39] = { .c = 0x000007fa, .b = 11 },
[40] = { .c = 0x000003fa, .b = 10 },
[41] = { .c = 0x000003fb, .b = 10 },
[42] = { .c = 0x000000f9, .b = 8 },
[43] = { .c = 0x000007fb, .b = 11 },
[44] = { .c = 0x000000fa, .b = 8 },
[45] = { .c = 0x00000016, .b = 6 },
[46] = { .c = 0x00000017, .b = 6 },
[47] = { .c = 0x00000018, .b = 6 },
[48] = { .c = 0x00000000, .b = 5 },
[49] = { .c = 0x00000001, .b = 5 },
[50] = { .c = 0x00000002, .b = 5 },
[51] = { .c = 0x00000019, .b = 6 },
[52] = { .c = 0x0000001a, .b = 6 },
[53] = { .c = 0x0000001b, .b = 6 },
[54] = { .c = 0x0000001c, .b = 6 },
[55] = { .c = 0x0000001d, .b = 6 },
[56] = { .c = 0x0000001e, .b = 6 },
[57] = { .c = 0x0000001f, .b = 6 },
[58] = { .c = 0x0000005c, .b = 7 },
[59] = { .c = 0x000000fb, .b = 8 },
[60] = { .c = 0x00007ffc, .b = 15 },
[61] = { .c = 0x00000020, .b = 6 },
[62] = { .c = 0x00000ffb, .b = 12 },
[63] = { .c = 0x000003fc, .b = 10 },
[64] = { .c = 0x00001ffa, .b = 13 },
[65] = { .c = 0x00000021, .b = 6 },
[66] = { .c = 0x0000005d, .b = 7 },
[67] = { .c = 0x0000005e, .b = 7 },
[68] = { .c = 0x0000005f, .b = 7 },
[69] = { .c = 0x00000060, .b = 7 },
[70] = { .c = 0x00000061, .b = 7 },
[71] = { .c = 0x00000062, .b = 7 },
[72] = { .c = 0x00000063, .b = 7 },
[73] = { .c = 0x00000064, .b = 7 },
[74] = { .c = 0x00000065, .b = 7 },
[75] = { .c = 0x00000066, .b = 7 },
[76] = { .c = 0x00000067, .b = 7 },
[77] = { .c = 0x00000068, .b = 7 },
[78] = { .c = 0x00000069, .b = 7 },
[79] = { .c = 0x0000006a, .b = 7 },
[80] = { .c = 0x0000006b, .b = 7 },
[81] = { .c = 0x0000006c, .b = 7 },
[82] = { .c = 0x0000006d, .b = 7 },
[83] = { .c = 0x0000006e, .b = 7 },
[84] = { .c = 0x0000006f, .b = 7 },
[85] = { .c = 0x00000070, .b = 7 },
[86] = { .c = 0x00000071, .b = 7 },
[87] = { .c = 0x00000072, .b = 7 },
[88] = { .c = 0x000000fc, .b = 8 },
[89] = { .c = 0x00000073, .b = 7 },
[90] = { .c = 0x000000fd, .b = 8 },
[91] = { .c = 0x00001ffb, .b = 13 },
[92] = { .c = 0x0007fff0, .b = 19 },
[93] = { .c = 0x00001ffc, .b = 13 },
[94] = { .c = 0x00003ffc, .b = 14 },
[95] = { .c = 0x00000022, .b = 6 },
[96] = { .c = 0x00007ffd, .b = 15 },
[97] = { .c = 0x00000003, .b = 5 },
[98] = { .c = 0x00000023, .b = 6 },
[99] = { .c = 0x00000004, .b = 5 },
[100] = { .c = 0x00000024, .b = 6 },
[101] = { .c = 0x00000005, .b = 5 },
[102] = { .c = 0x00000025, .b = 6 },
[103] = { .c = 0x00000026, .b = 6 },
[104] = { .c = 0x00000027, .b = 6 },
[105] = { .c = 0x00000006, .b = 5 },
[106] = { .c = 0x00000074, .b = 7 },
[107] = { .c = 0x00000075, .b = 7 },
[108] = { .c = 0x00000028, .b = 6 },
[109] = { .c = 0x00000029, .b = 6 },
[110] = { .c = 0x0000002a, .b = 6 },
[111] = { .c = 0x00000007, .b = 5 },
[112] = { .c = 0x0000002b, .b = 6 },
[113] = { .c = 0x00000076, .b = 7 },
[114] = { .c = 0x0000002c, .b = 6 },
[115] = { .c = 0x00000008, .b = 5 },
[116] = { .c = 0x00000009, .b = 5 },
[117] = { .c = 0x0000002d, .b = 6 },
[118] = { .c = 0x00000077, .b = 7 },
[119] = { .c = 0x00000078, .b = 7 },
[120] = { .c = 0x00000079, .b = 7 },
[121] = { .c = 0x0000007a, .b = 7 },
[122] = { .c = 0x0000007b, .b = 7 },
[123] = { .c = 0x00007ffe, .b = 15 },
[124] = { .c = 0x000007fc, .b = 11 },
[125] = { .c = 0x00003ffd, .b = 14 },
[126] = { .c = 0x00001ffd, .b = 13 },
[127] = { .c = 0x0ffffffc, .b = 28 },
[128] = { .c = 0x000fffe6, .b = 20 },
[129] = { .c = 0x003fffd2, .b = 22 },
[130] = { .c = 0x000fffe7, .b = 20 },
[131] = { .c = 0x000fffe8, .b = 20 },
[132] = { .c = 0x003fffd3, .b = 22 },
[133] = { .c = 0x003fffd4, .b = 22 },
[134] = { .c = 0x003fffd5, .b = 22 },
[135] = { .c = 0x007fffd9, .b = 23 },
[136] = { .c = 0x003fffd6, .b = 22 },
[137] = { .c = 0x007fffda, .b = 23 },
[138] = { .c = 0x007fffdb, .b = 23 },
[139] = { .c = 0x007fffdc, .b = 23 },
[140] = { .c = 0x007fffdd, .b = 23 },
[141] = { .c = 0x007fffde, .b = 23 },
[142] = { .c = 0x00ffffeb, .b = 24 },
[143] = { .c = 0x007fffdf, .b = 23 },
[144] = { .c = 0x00ffffec, .b = 24 },
[145] = { .c = 0x00ffffed, .b = 24 },
[146] = { .c = 0x003fffd7, .b = 22 },
[147] = { .c = 0x007fffe0, .b = 23 },
[148] = { .c = 0x00ffffee, .b = 24 },
[149] = { .c = 0x007fffe1, .b = 23 },
[150] = { .c = 0x007fffe2, .b = 23 },
[151] = { .c = 0x007fffe3, .b = 23 },
[152] = { .c = 0x007fffe4, .b = 23 },
[153] = { .c = 0x001fffdc, .b = 21 },
[154] = { .c = 0x003fffd8, .b = 22 },
[155] = { .c = 0x007fffe5, .b = 23 },
[156] = { .c = 0x003fffd9, .b = 22 },
[157] = { .c = 0x007fffe6, .b = 23 },
[158] = { .c = 0x007fffe7, .b = 23 },
[159] = { .c = 0x00ffffef, .b = 24 },
[160] = { .c = 0x003fffda, .b = 22 },
[161] = { .c = 0x001fffdd, .b = 21 },
[162] = { .c = 0x000fffe9, .b = 20 },
[163] = { .c = 0x003fffdb, .b = 22 },
[164] = { .c = 0x003fffdc, .b = 22 },
[165] = { .c = 0x007fffe8, .b = 23 },
[166] = { .c = 0x007fffe9, .b = 23 },
[167] = { .c = 0x001fffde, .b = 21 },
[168] = { .c = 0x007fffea, .b = 23 },
[169] = { .c = 0x003fffdd, .b = 22 },
[170] = { .c = 0x003fffde, .b = 22 },
[171] = { .c = 0x00fffff0, .b = 24 },
[172] = { .c = 0x001fffdf, .b = 21 },
[173] = { .c = 0x003fffdf, .b = 22 },
[174] = { .c = 0x007fffeb, .b = 23 },
[175] = { .c = 0x007fffec, .b = 23 },
[176] = { .c = 0x001fffe0, .b = 21 },
[177] = { .c = 0x001fffe1, .b = 21 },
[178] = { .c = 0x003fffe0, .b = 22 },
[179] = { .c = 0x001fffe2, .b = 21 },
[180] = { .c = 0x007fffed, .b = 23 },
[181] = { .c = 0x003fffe1, .b = 22 },
[182] = { .c = 0x007fffee, .b = 23 },
[183] = { .c = 0x007fffef, .b = 23 },
[184] = { .c = 0x000fffea, .b = 20 },
[185] = { .c = 0x003fffe2, .b = 22 },
[186] = { .c = 0x003fffe3, .b = 22 },
[187] = { .c = 0x003fffe4, .b = 22 },
[188] = { .c = 0x007ffff0, .b = 23 },
[189] = { .c = 0x003fffe5, .b = 22 },
[190] = { .c = 0x003fffe6, .b = 22 },
[191] = { .c = 0x007ffff1, .b = 23 },
[192] = { .c = 0x03ffffe0, .b = 26 },
[193] = { .c = 0x03ffffe1, .b = 26 },
[194] = { .c = 0x000fffeb, .b = 20 },
[195] = { .c = 0x0007fff1, .b = 19 },
[196] = { .c = 0x003fffe7, .b = 22 },
[197] = { .c = 0x007ffff2, .b = 23 },
[198] = { .c = 0x003fffe8, .b = 22 },
[199] = { .c = 0x01ffffec, .b = 25 },
[200] = { .c = 0x03ffffe2, .b = 26 },
[201] = { .c = 0x03ffffe3, .b = 26 },
[202] = { .c = 0x03ffffe4, .b = 26 },
[203] = { .c = 0x07ffffde, .b = 27 },
[204] = { .c = 0x07ffffdf, .b = 27 },
[205] = { .c = 0x03ffffe5, .b = 26 },
[206] = { .c = 0x00fffff1, .b = 24 },
[207] = { .c = 0x01ffffed, .b = 25 },
[208] = { .c = 0x0007fff2, .b = 19 },
[209] = { .c = 0x001fffe3, .b = 21 },
[210] = { .c = 0x03ffffe6, .b = 26 },
[211] = { .c = 0x07ffffe0, .b = 27 },
[212] = { .c = 0x07ffffe1, .b = 27 },
[213] = { .c = 0x03ffffe7, .b = 26 },
[214] = { .c = 0x07ffffe2, .b = 27 },
[215] = { .c = 0x00fffff2, .b = 24 },
[216] = { .c = 0x001fffe4, .b = 21 },
[217] = { .c = 0x001fffe5, .b = 21 },
[218] = { .c = 0x03ffffe8, .b = 26 },
[219] = { .c = 0x03ffffe9, .b = 26 },
[220] = { .c = 0x0ffffffd, .b = 28 },
[221] = { .c = 0x07ffffe3, .b = 27 },
[222] = { .c = 0x07ffffe4, .b = 27 },
[223] = { .c = 0x07ffffe5, .b = 27 },
[224] = { .c = 0x000fffec, .b = 20 },
[225] = { .c = 0x00fffff3, .b = 24 },
[226] = { .c = 0x000fffed, .b = 20 },
[227] = { .c = 0x001fffe6, .b = 21 },
[228] = { .c = 0x003fffe9, .b = 22 },
[229] = { .c = 0x001fffe7, .b = 21 },
[230] = { .c = 0x001fffe8, .b = 21 },
[231] = { .c = 0x007ffff3, .b = 23 },
[232] = { .c = 0x003fffea, .b = 22 },
[233] = { .c = 0x003fffeb, .b = 22 },
[234] = { .c = 0x01ffffee, .b = 25 },
[235] = { .c = 0x01ffffef, .b = 25 },
[236] = { .c = 0x00fffff4, .b = 24 },
[237] = { .c = 0x00fffff5, .b = 24 },
[238] = { .c = 0x03ffffea, .b = 26 },
[239] = { .c = 0x007ffff4, .b = 23 },
[240] = { .c = 0x03ffffeb, .b = 26 },
[241] = { .c = 0x07ffffe6, .b = 27 },
[242] = { .c = 0x03ffffec, .b = 26 },
[243] = { .c = 0x03ffffed, .b = 26 },
[244] = { .c = 0x07ffffe7, .b = 27 },
[245] = { .c = 0x07ffffe8, .b = 27 },
[246] = { .c = 0x07ffffe9, .b = 27 },
[247] = { .c = 0x07ffffea, .b = 27 },
[248] = { .c = 0x07ffffeb, .b = 27 },
[249] = { .c = 0x0ffffffe, .b = 28 },
[250] = { .c = 0x07ffffec, .b = 27 },
[251] = { .c = 0x07ffffed, .b = 27 },
[252] = { .c = 0x07ffffee, .b = 27 },
[253] = { .c = 0x07ffffef, .b = 27 },
[254] = { .c = 0x07fffff0, .b = 27 },
[255] = { .c = 0x03ffffee, .b = 26 },
[256] = { .c = 0x3fffffff, .b = 30 }, /* EOS */
};
int main(int argc, char **argv)
{
uint32_t c, i, j;
/* fill first byte */
printf("struct rht rht_bit31_24[256] = {\n");
for (j = 0; j < 256; j++) {
for (i = 0; i < sizeof(ht)/sizeof(ht[0]); i++) {
if (ht[i].b > 8)
continue;
c = ht[i].c << (32 - ht[i].b);
if (((c ^ (j << 24)) & -(1 << (32 - ht[i].b)) & 0xff000000) == 0) {
printf("\t[0x%02x] = { .c = 0x%02x, .l = %d },\n", j, i, ht[i].b);
break;
}
}
}
printf("};\n\n");
printf("struct rht rht_bit24_17[256] = {\n");
for (j = 0; j < 256; j++) {
for (i = 0; i < sizeof(ht)/sizeof(ht[0]); i++) {
if (ht[i].b <= 8 || ht[i].b > 16)
continue;
c = ht[i].c << (32 - ht[i].b);
if (((c ^ (j << 17)) & -(1 << (32 - ht[i].b)) & 0x01fe0000) == 0) {
printf("\t[0x%02x] = { .c = 0x%02x, .l = %d },\n", j, i, ht[i].b);
break;
}
}
}
printf("};\n\n");
printf("struct rht rht_bit15_11_fe[32] = {\n");
for (j = 0; j < 32; j++) {
for (i = 0; i < sizeof(ht)/sizeof(ht[0]); i++) {
if (ht[i].b <= 16 || ht[i].b > 21)
continue;
c = ht[i].c << (32 - ht[i].b);
if ((c & 0x00ff0000) != 0x00fe0000)
continue;
if (((c ^ (j << 11)) & -(1 << (32 - ht[i].b)) & 0x0000f800) == 0) {
printf("\t[0x%02x] = { .c = 0x%02x, .l = %d },\n", j, i, ht[i].b);
break;
}
}
}
printf("};\n\n");
printf("struct rht rht_bit15_8[256] = {\n");
for (j = 0; j < 256; j++) {
for (i = 0; i < sizeof(ht)/sizeof(ht[0]); i++) {
if (ht[i].b <= 16 || ht[i].b > 24)
continue;
c = ht[i].c << (32 - ht[i].b);
if ((c & 0x00ff0000) != 0x00ff0000)
continue;
if (((c ^ (j << 8)) & -(1 << (32 - ht[i].b)) & 0x0000ff00) == 0) {
printf("\t[0x%02x] = { .c = 0x%02x, .l = %d },\n", j, i, ht[i].b);
break;
}
}
}
printf("};\n\n");
printf("struct rht rht_bit11_4[256] = {\n");
/* fill fourth byte after 0xff 0xff 0xf6-0xff. Only 0xfffffffx are not distinguished */
for (j = 0; j < 256; j++) {
for (i = 0; i < sizeof(ht)/sizeof(ht[0]); i++) {
if (ht[i].b <= 24)
continue;
c = ht[i].c << (32 - ht[i].b);
if (((c ^ (j << 4)) & -(1 << (32 - ht[i].b)) & 0x00000ff0) == 0) {
//printf("\tj=%02x i=%02x c=%08x l=%d c/l=%08x j/l=%08x xor=%08x\n", j, i, c, ht[i].b, c & -(1 << (32 - ht[i].b)), ((j << 4) & -(1 << (32 - ht[i].b))), (c ^ (j << 4)) & -(1 << (32 - ht[i].b)));
printf("\t[0x%02x] = { .c = 0x%02x, .l = %d },\n", j, i, ht[i].b);
break;
}
}
}
printf("\t/* Note, when l==30, bits 3..2 give 00:0x0a, 01:0x0d, 10:0x16, 11:EOS */\n");
printf("};\n\n");
return 0;
}