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Diffstat (limited to '')
| -rw-r--r-- | dev/hpack/decode.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/dev/hpack/decode.c b/dev/hpack/decode.c new file mode 100644 index 0000000..13c95c7 --- /dev/null +++ b/dev/hpack/decode.c @@ -0,0 +1,215 @@ +/* + * 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; +} |