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unpack.c
491 lines (423 loc) · 10.4 KB
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unpack.c
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#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <zlib.h>
#include "huffman.h"
#define CHUNK 1024
struct node {
int count;
char **paths;
struct node **children;
};
static int
load_dictionary(FILE *source, char ***dictionary, int *dictionary_size,
bool stats)
{
int ret;
z_stream strm;
unsigned char in[CHUNK];
int read = 0;
// XXX keep a ref to buf for free()
unsigned char *buf = malloc(sizeof(char) * CHUNK);
/* allocate inflate state */
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
strm.avail_in = 0;
strm.next_in = Z_NULL;
ret = inflateInit(&strm);
if (ret != Z_OK) {
printf("ERROR\n");
return ret;
}
/* decompress until deflate stream ends or end of file */
do {
strm.avail_in = fread(in, 1, CHUNK, source);
if (ferror(source)) {
(void)inflateEnd(&strm);
return -1;
}
if (strm.avail_in == 0) {
printf("read entire file\n");
break;
}
strm.next_in = in;
/* run inflate() on input until output buffer not full */
do {
strm.avail_out = CHUNK;
strm.next_out = buf;
ret = inflate(&strm, Z_NO_FLUSH);
assert(ret != Z_STREAM_ERROR); /* state not clobbered */
switch (ret) {
case Z_NEED_DICT:
printf("NEED ERROR\n");
ret = Z_DATA_ERROR; /* and fall through */
case Z_DATA_ERROR:
printf("DATA ERROR\n");
case Z_MEM_ERROR:
(void)inflateEnd(&strm);
printf("MEMORY ERROR\n");
return -1;
}
read += CHUNK - strm.avail_out;
} while (strm.avail_out == 0);
// read += CHUNK;
/* done when inflate() says it's done */
} while (ret != Z_STREAM_END);
int offset_size = 64;
int *dictionary_offsets = malloc (sizeof (int) * offset_size);
*dictionary_size = 1;
int i;
int j = 0;
dictionary_offsets[j++] = 0;
for (i = 0; i < read; i++) {
if (buf[i] == '\0') {
if (i != read - 1) {
dictionary_offsets[j++] = i + 1;
(*dictionary_size)++;
if (j == offset_size) {
offset_size = offset_size * 2;
dictionary_offsets =
realloc (dictionary_offsets,
sizeof (int) *
offset_size);
}
}
}
}
*dictionary = malloc (sizeof (char *) * (*dictionary_size + 1));
for (i = 0; i < *dictionary_size; i++) {
(*dictionary)[i] = (char *) buf + dictionary_offsets[i];
}
(*dictionary_size)++;
// Add in the end of node sentinal string
char *sentinal = malloc (sizeof (char));
sentinal[0] = 0x00;
(*dictionary)[i] = sentinal;
// rewind back to unused zlib bytes
if (fseek(source, (long) strm.avail_in * -1, SEEK_CUR)) {
printf("Error seeking back in stream\n");
return -1;
}
if (stats) {
printf ("dictionary stats:\n");
printf ("\tcompressed size: %zu\n", ftell(source));
printf ("\tuncompressed size: %d\n", read);
printf ("\tentries found: %d\n", *dictionary_size);
}
inflateEnd(&strm);
return ret == Z_STREAM_END ? 0 : -1;
}
static int
load_content_sets(FILE *stream, struct node **list, int *node_count,
struct huffman_node *dictionary_tree, bool stats, bool raw)
{
unsigned char *buf = malloc (sizeof (char *) * CHUNK);
size_t read;
struct node **nodes;
int i;
unsigned char count;
fread(&count, sizeof (unsigned char), 1, stream);
uint64_t big_count;
if (count & 0x80) {
unsigned short count_bytes = count & 0x7F;
unsigned char *size_buf = malloc (sizeof (char *) *
count_bytes);
fread (size_buf, sizeof (char), count_bytes, stream);
printf ("found count: %hd\n", count_bytes);
printf ("%hd\n", (unsigned short) size_buf[0]);
printf ("%hd\n", size_buf[1]);
big_count = 0;
int offset = sizeof (uint64_t ) - count_bytes;
memcpy (((void *) &big_count) + offset, size_buf, count_bytes);
big_count = be64toh (big_count);
} else {
big_count = count;
}
if (stats) {
printf ("node stats:\n");
printf ("\tnumber of nodes: %lu\n", big_count);
} else if (raw) {
printf ("Nodes (%lu entries):\n", big_count);
}
nodes = malloc (sizeof (struct node *) * big_count);
for (i = 0; i < big_count; i++) {
nodes[i] = malloc (sizeof (struct node));
}
read = fread (buf, sizeof (char), CHUNK, stream);
unsigned char *eob = buf + read;
if (stats) {
printf("\tbytes: %zu\n", read);
}
/*
* the parent node doesn't go in the huffman tree, as nothing else
* references it.
*/
struct huffman_node *tree =
huffman_build_tree ((void **) nodes + 1,
big_count - 1);
int bits_read = 0;
for (i = 0; i < big_count; i++) {
struct node *node = nodes[i];
node->count = 0;
// XXX hard coded
node->paths = malloc (sizeof (char *) * 64);
node->children = malloc (sizeof (struct node *) * 64);
if (raw) {
printf (" Node - ");
huffman_reverse_lookup (tree, node);
printf (":\n");
}
while (true) {
if (raw) {
printf(" ");
}
char *path = (char *) huffman_lookup (dictionary_tree,
buf, &bits_read,
raw);
buf = buf + bits_read / 8;
bits_read = bits_read % 8;
if (buf >= eob) {
printf ("\nread too much: dictionary lookup\n");
return -1;
}
if (path[0] == '\0') {
if (raw) {
printf(" (<end>)\n");
}
break;
}
if (raw) {
printf (" (%s) :: ", path);
}
struct node *child =
(struct node *) huffman_lookup (tree, buf,
&bits_read,
raw);
if (raw) {
printf ("\n");
}
buf = buf + bits_read / 8;
bits_read = bits_read % 8;
if (buf >= eob) {
printf ("\nread too much: path lookup\n");
return -1;
}
node->paths[node->count] = path;
node->children[node->count] = child;
node->count++;
}
}
*list = nodes[0];
return 0;
}
struct stack {
struct stack *next;
struct stack *prev;
char *path;
};
static void
dump_content_set (struct node *content_sets, struct stack *head,
struct stack *tail)
{
int i;
struct stack stack;
stack.prev = tail;
tail->next = &stack;
for (i = 0; i < content_sets->count; i++) {
stack.path = content_sets->paths[i];
dump_content_set(content_sets->children[i], head, &stack);
}
if (content_sets->count == 0) {
struct stack *cur = head;
for (cur = head->next; cur != &stack; cur = cur->next) {
printf("/%s", cur->path);
}
printf("\n");
}
}
static void
dump_content_sets (struct node *content_sets)
{
struct stack stack;
stack.next = NULL;
stack.path = NULL;
dump_content_set (content_sets, &stack, &stack);
}
static void
count_content_set (struct node *content_sets, struct stack *head,
struct stack *tail, int *count)
{
int i;
struct stack stack;
tail->next = &stack;
for (i = 0; i < content_sets->count; i++) {
stack.path = content_sets->paths[i];
count_content_set(content_sets->children[i], head, &stack,
count);
}
if (content_sets->count == 0) {
(*count)++;
}
}
static void
count_content_sets (struct node *content_sets, int *count)
{
struct stack stack;
stack.next = NULL;
stack.path = NULL;
count_content_set (content_sets, &stack, &stack, count);
}
static void
check_content_set (struct node *content_sets, const char *path)
{
struct node *cur = content_sets;
struct stack head;
head.next = NULL;
head.path = NULL;
struct stack *stack;
stack = &head;
bool found;
while(cur != NULL) {
int i;
found = false;
if (cur->count == 0) {
found = true;
break;
}
for (i = 0; i < cur->count; i++) {
int len = strlen(cur->paths[i]);
if (cur->paths[i][0] == '$' ||
!strncmp(cur->paths[i], path, len)) {
char *slash = index(path, '/');
/*
* we've hit then end. if the content set isn't
* also at the end, it's not a match
*/
if (slash == NULL ||
strlen(slash + 1) == 0) {
if (cur->count != 0) {
found = false;
break;
}
}
path = slash + 1;
found = true;
struct stack *top =
malloc (sizeof (struct stack));
stack->next = top;
top->path = cur->paths[i];
stack = top;
cur = cur->children[i];
break;
}
}
if (!found) {
break;
}
}
if (!found) {
printf ("no match found\n");
} else {
struct stack *cur;
for (cur = head.next; cur != NULL; cur = cur->next) {
printf("/%s", cur->path);
}
printf ("\n");
}
}
static void
print_dictionary (char **dictionary, int dictionary_size,
struct huffman_node *dictionary_tree)
{
int i;
printf ("Path Dictionary (%d entries):\n", dictionary_size);
for (i = 0; i < dictionary_size - 1; i++) {
printf (" %s - ", dictionary[i]);
huffman_reverse_lookup (dictionary_tree, dictionary[i]);
printf("\n");
}
printf (" <end of node indicator> - ");
huffman_reverse_lookup (dictionary_tree, dictionary[i]);
printf ("\n");
}
int
main(int argc, char **argv) {
FILE *fp;
char **dictionary;
int dictionary_size;
struct node *content_sets;
int content_set_size;
bool stats = false;
bool raw = false;
bool dump = false;
bool check = false;
if (argc < 3) {
printf("usage: unpack [mode] [bin file]\n");
printf("mode is one of:\n");
printf("s - print stats for the binary content set blob\n");
printf("r - display the raw binary as text\n");
printf("d - dump the blob contents to stdout\n");
printf("c - check if a path is allowed by the blob\n");
printf("\n");
printf("c requires an extra argument after the bin file,\n"
"for the path to check. the path must start with "
"a '/'\n\n");
return -1;
}
switch (argv[1][0]) {
case 's':
stats = true;
break;
case 'd':
dump = true;
break;
case 'r':
raw = true;
break;
case 'c':
check = true;
if (argc != 4) {
printf("error: must specify a path "
"with check\n");
return -1;
}
break;
}
fp = fopen(argv[2], "r");
if (fp == NULL) {
printf("error: unable to open file: %s\n", argv[1]);
return -1;
}
if (load_dictionary(fp, &dictionary, &dictionary_size, stats)) {
printf("dictionary inflation failed. exiting\n");
return -1;
}
struct huffman_node *dictionary_tree =
huffman_build_tree ((void **) dictionary, dictionary_size);
if (raw) {
print_dictionary (dictionary, dictionary_size, dictionary_tree);
}
if (load_content_sets(fp, &content_sets, &content_set_size,
dictionary_tree, stats, raw)) {
printf("node list parsing failed. exiting\n");
return -1;
}
if (stats) {
int count = 0;
count_content_sets(content_sets, &count);
printf("\tcontent paths: %d\n", count);
} else if (dump) {
dump_content_sets (content_sets);
} else if (check) {
const char *path = argv[3];
if (path[0] == '/') {
path++;
}
check_content_set (content_sets, path);
}
return 0;
}