haproxy/dev/hpack/decode.c

216 lines
5.0 KiB
C

/*
* HPACK stream decoder. Takes a series of hex codes on stdin using one line
* per HEADERS frame. Spaces, tabs, CR, '-' and ',' are silently skipped.
* e.g. :
* echo 82864188f439ce75c875fa5784 | dev/hpack/decode
*
* The DHT size may optionally be changed in argv[1].
*
* Build like this :
* gcc -I../../include -O0 -g -fno-strict-aliasing -fwrapv \
* -o decode decode.c
*/
#define HPACK_STANDALONE
#include <ctype.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <haproxy/chunk.h>
#include <haproxy/hpack-dec.h>
#define MAX_RQ_SIZE 65536
#define MAX_HDR_NUM 1000
char hex[MAX_RQ_SIZE*3+3]; // enough for "[ XX]* <CR> <LF> \0"
uint8_t buf[MAX_RQ_SIZE];
char trash_buf[MAX_RQ_SIZE];
char tmp_buf[MAX_RQ_SIZE];
THREAD_LOCAL struct buffer trash = { .area = trash_buf, .data = 0, .size = sizeof(trash_buf) };
struct buffer tmp = { .area = tmp_buf, .data = 0, .size = sizeof(tmp_buf) };
/* displays a <len> long memory block at <buf>, assuming first byte of <buf>
* has address <baseaddr>. String <pfx> may be placed as a prefix in front of
* each line. It may be NULL if unused. The output is emitted to file <out>.
*/
void debug_hexdump(FILE *out, const char *pfx, const char *buf,
unsigned int baseaddr, int len)
{
unsigned int i;
int b, j;
for (i = 0; i < (len + (baseaddr & 15)); i += 16) {
b = i - (baseaddr & 15);
fprintf(out, "%s%08x: ", pfx ? pfx : "", i + (baseaddr & ~15));
for (j = 0; j < 8; j++) {
if (b + j >= 0 && b + j < len)
fprintf(out, "%02x ", (unsigned char)buf[b + j]);
else
fprintf(out, " ");
}
if (b + j >= 0 && b + j < len)
fputc('-', out);
else
fputc(' ', out);
for (j = 8; j < 16; j++) {
if (b + j >= 0 && b + j < len)
fprintf(out, " %02x", (unsigned char)buf[b + j]);
else
fprintf(out, " ");
}
fprintf(out, " ");
for (j = 0; j < 16; j++) {
if (b + j >= 0 && b + j < len) {
if (isprint((unsigned char)buf[b + j]))
fputc((unsigned char)buf[b + j], out);
else
fputc('.', out);
}
else
fputc(' ', out);
}
fputc('\n', out);
}
}
/* enable DEBUG_HPACK to show each individual hpack code */
#define DEBUG_HPACK
#include "../src/hpack-huff.c"
#include "../src/hpack-tbl.c"
#include "../src/hpack-dec.c"
/* display the message and exit with the code */
__attribute__((noreturn)) void die(int code, const char *format, ...)
{
va_list args;
if (format) {
va_start(args, format);
vfprintf(stderr, format, args);
va_end(args);
}
exit(code);
}
/* reads <hex> and stops at the first LF, '#' or \0. Converts from hex to
* binary, ignoring spaces, tabs, CR, "-" and ','. The output is sent into
* <bin> for no more than <size> bytes. The number of bytes placed there is
* returned, or a negative value in case of parsing error.
*/
int hex2bin(const char *hex, uint8_t *bin, int size)
{
int a, b, c;
uint8_t code;
int len = 0;
a = b = -1;
for (; *hex; hex++) {
c = *hex;
if (c == ' ' || c == '\t' || c == '\r' ||
c == '-' || c == ',')
continue;
if (c == '\n' || c == '#')
break;
if (c >= '0' && c <= '9')
c -= '0';
else if (c >= 'a' && c <= 'f')
c -= 'a' - 10;
else if (c >= 'A' && c <= 'F')
c -= 'A' - 10;
else
return -1;
if (a == -1)
a = c;
else
b = c;
if (b == -1)
continue;
code = (a << 4) | b;
a = b = -1;
if (len >= size)
return -2;
bin[len] = code;
len++;
}
if (a >= 0 || b >= 0)
return -3;
return len;
}
int main(int argc, char **argv)
{
struct hpack_dht *dht;
struct http_hdr list[MAX_HDR_NUM];
struct pool_head pool;
int outlen;
int dht_size = 4096;
int len, idx;
int line;
/* first arg: dht size */
if (argc > 1) {
dht_size = atoi(argv[1]);
argv++; argc--;
}
pool.size = dht_size;
pool_head_hpack_tbl = &pool;
dht = hpack_dht_alloc();
if (!dht) {
die(1, "cannot initialize dht\n");
return 1;
}
for (line = 1; fgets(hex, sizeof(hex), stdin); line++) {
len = hex2bin(hex, buf, sizeof(buf));
if (len <= 0)
continue;
printf("###### line %d : frame len=%d #######\n", line, len);
debug_hexdump(stdout, " ", (const char *)buf, 0, len);
outlen = hpack_decode_frame(dht, buf, len, list,
sizeof(list)/sizeof(list[0]), &tmp);
if (outlen <= 0) {
printf(" HPACK decoding failed: %d\n", outlen);
continue;
}
printf("<<< Found %d headers :\n", outlen);
for (idx = 0; idx < outlen - 1; idx++) {
//printf(" \e[1;34m%s\e[0m: ",
// list[idx].n.ptr ? istpad(trash.str, list[idx].n).ptr : h2_phdr_to_str(list[idx].n.len));
//printf("\e[1;35m%s\e[0m\n", istpad(trash.str, list[idx].v).ptr);
printf(" %s: ", list[idx].n.ptr ?
istpad(trash.area, list[idx].n).ptr :
h2_phdr_to_str(list[idx].n.len));
printf("%s [n=(%p,%d) v=(%p,%d)]\n",
istpad(trash.area, list[idx].v).ptr,
list[idx].n.ptr, (int)list[idx].n.len, list[idx].v.ptr, (int)list[idx].v.len);
}
puts(">>>");
#ifdef DEBUG_HPACK
printf("<<=== DHT dump [ptr=%p]:\n", dht);
hpack_dht_dump(stdout, dht);
puts("===>>");
#endif
}
return 0;
}