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796 lines
16 KiB
796 lines
16 KiB
#include "bencode.h"
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#include <stdio.h>
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#include <sys/uio.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <assert.h>
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#include <string.h>
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#include <ctype.h>
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#include "helpers.h"
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/* set to 0 for alloc debugging, e.g. through valgrind */
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#define BENCODE_MIN_BUFFER_PIECE_LEN 4096
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#define BENCODE_HASH_BUCKETS 31 /* prime numbers work best */
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#define BENCODE_ALLOC_ALIGN 8
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struct __bencode_buffer_piece {
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char *tail;
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size_t left;
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struct __bencode_buffer_piece *next;
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char buf[0];
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};
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struct __bencode_hash {
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struct bencode_item *buckets[BENCODE_HASH_BUCKETS];
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};
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static bencode_item_t __bencode_end_marker = {
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.type = BENCODE_END_MARKER,
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.iov = {
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{
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.iov_base = "e",
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.iov_len = 1,
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},
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},
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.iov_cnt = 1,
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.str_len = 1,
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};
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static bencode_item_t *__bencode_decode(bencode_buffer_t *buf, const char *s, const char *end);
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static void __bencode_item_init(bencode_item_t *item) {
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item->last_child = item->parent = item->child = item->sibling = NULL;
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}
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static void __bencode_container_init(bencode_item_t *cont) {
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cont->iov[0].iov_len = 1;
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cont->iov[1].iov_base = "e";
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cont->iov[1].iov_len = 1;
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cont->iov_cnt = 2;
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cont->str_len = 2;
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}
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static void __bencode_dictionary_init(bencode_item_t *dict) {
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dict->type = BENCODE_DICTIONARY;
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dict->iov[0].iov_base = "d";
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dict->value = 0;
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__bencode_container_init(dict);
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}
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static void __bencode_list_init(bencode_item_t *list) {
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list->type = BENCODE_LIST;
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list->iov[0].iov_base = "l";
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__bencode_container_init(list);
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}
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static struct __bencode_buffer_piece *__bencode_piece_new(size_t size) {
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struct __bencode_buffer_piece *ret;
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size_t alloc_size = size + sizeof(*ret) + BENCODE_ALLOC_ALIGN;
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alloc_size = MAX(alloc_size, BENCODE_MIN_BUFFER_PIECE_LEN);
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ret = BENCODE_MALLOC(alloc_size);
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if (!ret)
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return NULL;
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ret->tail = ret->buf;
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ret->left = alloc_size - sizeof(*ret) - BENCODE_ALLOC_ALIGN;
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ret->next = NULL;
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return ret;
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}
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int bencode_buffer_init(bencode_buffer_t *buf) {
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buf->pieces = __bencode_piece_new(0);
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if (!buf->pieces)
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return -1;
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buf->error = 0;
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return 0;
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}
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void *bencode_buffer_alloc(bencode_buffer_t *buf, size_t size) {
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struct __bencode_buffer_piece *piece;
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void *ret;
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size_t align_size = ((size + BENCODE_ALLOC_ALIGN - 1) / BENCODE_ALLOC_ALIGN) * BENCODE_ALLOC_ALIGN;
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if (!buf)
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return NULL;
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if (buf->error)
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return NULL;
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piece = buf->pieces;
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if (size <= piece->left)
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goto alloc;
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piece = __bencode_piece_new(size);
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if (!piece) {
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buf->error = 1;
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return NULL;
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}
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piece->next = buf->pieces;
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buf->pieces = piece;
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assert(size <= piece->left);
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alloc:
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if (piece->left >= align_size)
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piece->left -= align_size;
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else
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piece->left = 0;
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ret = piece->tail;
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piece->tail += align_size;
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return ret;
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}
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void bencode_buffer_free(bencode_buffer_t *buf) {
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struct __bencode_buffer_piece *piece, *next;
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if (!buf)
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return;
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for (piece = buf->pieces; piece; piece = next) {
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next = piece->next;
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BENCODE_FREE(piece);
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}
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}
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void bencode_buffer_merge(bencode_buffer_t *to, bencode_buffer_t *from) {
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from->pieces->next = to->pieces;
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to->pieces = from->pieces;
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from->pieces = NULL;
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}
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static bencode_item_t *__bencode_item_alloc(bencode_buffer_t *buf, size_t payload) {
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bencode_item_t *ret;
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ret = bencode_buffer_alloc(buf, sizeof(struct bencode_item) + payload);
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if (!ret)
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return NULL;
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ret->buffer = buf;
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__bencode_item_init(ret);
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return ret;
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}
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bencode_item_t *bencode_dictionary(bencode_buffer_t *buf) {
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bencode_item_t *ret;
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ret = __bencode_item_alloc(buf, 0);
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if (!ret)
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return NULL;
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__bencode_dictionary_init(ret);
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return ret;
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}
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bencode_item_t *bencode_list(bencode_buffer_t *buf) {
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bencode_item_t *ret;
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ret = __bencode_item_alloc(buf, 0);
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if (!ret)
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return NULL;
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__bencode_list_init(ret);
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return ret;
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}
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static void __bencode_container_add(bencode_item_t *parent, bencode_item_t *child) {
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if (!parent)
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return;
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if (!child)
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return;
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assert(child->parent == NULL);
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assert(child->sibling == NULL);
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child->parent = parent;
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if (parent->last_child)
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parent->last_child->sibling = child;
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parent->last_child = child;
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if (!parent->child)
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parent->child = child;
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while (parent) {
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parent->iov_cnt += child->iov_cnt;
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parent->str_len += child->str_len;
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parent = parent->parent;
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}
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}
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static bencode_item_t *__bencode_string_alloc(bencode_buffer_t *buf, const void *base,
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size_t str_len, size_t iov_len, unsigned int iov_cnt, bencode_type_t type)
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{
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bencode_item_t *ret;
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int len_len;
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assert(str_len <= 99999);
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ret = __bencode_item_alloc(buf, 7);
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if (!ret)
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return NULL;
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len_len = sprintf(ret->__buf, "%zu:", str_len);
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ret->type = type;
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ret->iov[0].iov_base = ret->__buf;
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ret->iov[0].iov_len = len_len;
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ret->iov[1].iov_base = (void *) base;
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ret->iov[1].iov_len = iov_len;
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ret->iov_cnt = iov_cnt + 1;
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ret->str_len = len_len + str_len;
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return ret;
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}
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bencode_item_t *bencode_string_len_dup(bencode_buffer_t *buf, const char *s, size_t len) {
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char *sd = bencode_buffer_alloc(buf, len);
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if (!sd)
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return NULL;
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memcpy(sd, s, len);
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return bencode_string_len(buf, sd, len);
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}
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bencode_item_t *bencode_string_len(bencode_buffer_t *buf, const char *s, size_t len) {
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return __bencode_string_alloc(buf, s, len, len, 1, BENCODE_STRING);
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}
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bencode_item_t *bencode_integer(bencode_buffer_t *buf, long long int i) {
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bencode_item_t *ret;
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int alen, rlen;
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alen = 8;
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while (1) {
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ret = __bencode_item_alloc(buf, alen + 3);
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if (!ret)
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return NULL;
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rlen = snprintf(ret->__buf, alen, "i%llde", i);
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if (rlen < alen)
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break;
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alen <<= 1;
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}
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ret->type = BENCODE_INTEGER;
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ret->iov[0].iov_base = ret->__buf;
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ret->iov[0].iov_len = rlen;
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ret->iov[1].iov_base = NULL;
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ret->iov[1].iov_len = 0;
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ret->iov_cnt = 1;
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ret->str_len = rlen;
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ret->value = i;
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return ret;
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}
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bencode_item_t *bencode_dictionary_add_len(bencode_item_t *dict, const char *key, size_t keylen, bencode_item_t *val) {
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bencode_item_t *s;
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if (!dict || !val)
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return NULL;
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assert(dict->type == BENCODE_DICTIONARY);
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s = bencode_string_len(dict->buffer, key, keylen);
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if (!s)
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return NULL;
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__bencode_container_add(dict, s);
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__bencode_container_add(dict, val);
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return val;
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}
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bencode_item_t *bencode_list_add(bencode_item_t *list, bencode_item_t *item) {
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if (!list || !item)
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return NULL;
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assert(list->type == BENCODE_LIST);
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__bencode_container_add(list, item);
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return item;
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}
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static int __bencode_iovec_cpy(struct iovec *out, const struct iovec *in, int num) {
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memcpy(out, in, num * sizeof(*out));
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return num;
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}
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static int __bencode_str_cpy(char *out, const struct iovec *in, int num) {
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char *orig = out;
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while (--num >= 0) {
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memcpy(out, in->iov_base, in->iov_len);
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out += in->iov_len;
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in++;
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}
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return out - orig;
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}
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static int __bencode_iovec_dump(struct iovec *out, bencode_item_t *item) {
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bencode_item_t *child;
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struct iovec *orig = out;
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assert(item->iov[0].iov_base != NULL);
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out += __bencode_iovec_cpy(out, &item->iov[0], 1);
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child = item->child;
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while (child) {
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out += __bencode_iovec_dump(out, child);
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child = child->sibling;
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}
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if (item->iov[1].iov_base)
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out += __bencode_iovec_cpy(out, &item->iov[1], 1);
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assert((out - orig) == item->iov_cnt);
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(void) orig;
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return item->iov_cnt;
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}
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static size_t __bencode_str_dump(char *out, bencode_item_t *item) {
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char *orig = out;
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bencode_item_t *child;
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assert(item->iov[0].iov_base != NULL);
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out += __bencode_str_cpy(out, &item->iov[0], 1);
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child = item->child;
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while (child) {
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out += __bencode_str_dump(out, child);
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child = child->sibling;
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}
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if (item->iov[1].iov_base)
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out += __bencode_str_cpy(out, &item->iov[1], 1);
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assert((out - orig) == item->str_len);
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(void) orig;
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*out = '\0';
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return item->str_len;
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}
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struct iovec *bencode_iovec(bencode_item_t *root, int *cnt, unsigned int head, unsigned int tail) {
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struct iovec *ret;
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if (!root)
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return NULL;
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assert(cnt != NULL);
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assert(root->iov_cnt > 0);
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ret = bencode_buffer_alloc(root->buffer, sizeof(*ret) * (root->iov_cnt + head + tail));
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if (!ret)
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return NULL;
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*cnt = __bencode_iovec_dump(ret + head, root);
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return ret;
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}
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char *bencode_collapse(bencode_item_t *root, size_t *len) {
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char *ret;
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size_t l;
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if (!root)
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return NULL;
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assert(root->str_len > 0);
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ret = bencode_buffer_alloc(root->buffer, root->str_len + 1);
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if (!ret)
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return NULL;
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l = __bencode_str_dump(ret, root);
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if (len)
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*len = l;
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return ret;
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}
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char *bencode_collapse_dup(bencode_item_t *root, size_t *len) {
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char *ret;
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int l;
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if (!root)
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return NULL;
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assert(root->str_len > 0);
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ret = BENCODE_MALLOC(root->str_len + 1);
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if (!ret)
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return NULL;
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l = __bencode_str_dump(ret, root);
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if (len)
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*len = l;
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return ret;
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}
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static unsigned int __bencode_hash_str_len(const unsigned char *s, int len) {
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unsigned long ul;
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unsigned int ui;
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unsigned short us;
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if (len >= sizeof(ul)) {
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memcpy(&ul, s, sizeof(ul));
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return ul % BENCODE_HASH_BUCKETS;
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}
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if (len >= sizeof(ui)) {
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memcpy(&ui, s, sizeof(ui));
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return ui % BENCODE_HASH_BUCKETS;
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}
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if (len >= sizeof(us)) {
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memcpy(&us, s, sizeof(us));
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return us % BENCODE_HASH_BUCKETS;
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}
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if (len >= sizeof(*s))
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return *s % BENCODE_HASH_BUCKETS;
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return 0;
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}
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static unsigned int __bencode_hash_str(bencode_item_t *s) {
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assert(s->type == BENCODE_STRING);
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return __bencode_hash_str_len(s->iov[1].iov_base, s->iov[1].iov_len);
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}
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static void __bencode_hash_insert(bencode_item_t *key, struct __bencode_hash *hash) {
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unsigned int bucket, i;
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i = bucket = __bencode_hash_str(key);
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while (1) {
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if (!hash->buckets[i]) {
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hash->buckets[i] = key;
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break;
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}
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i++;
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if (i >= BENCODE_HASH_BUCKETS)
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i = 0;
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if (i == bucket)
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break;
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}
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}
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static bencode_item_t *__bencode_decode_dictionary(bencode_buffer_t *buf, const char *s, const char *end) {
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bencode_item_t *ret, *key, *value;
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struct __bencode_hash *hash;
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if (*s != 'd')
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return NULL;
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s++;
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ret = __bencode_item_alloc(buf, sizeof(*hash));
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if (!ret)
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return NULL;
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__bencode_dictionary_init(ret);
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ret->value = 1;
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hash = (void *) ret->__buf;
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memset(hash, 0, sizeof(*hash));
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while (s < end) {
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key = __bencode_decode(buf, s, end);
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if (!key)
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return NULL;
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s += key->str_len;
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if (key->type == BENCODE_END_MARKER)
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break;
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if (key->type != BENCODE_STRING)
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return NULL;
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__bencode_container_add(ret, key);
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if (s >= end)
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return NULL;
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value = __bencode_decode(buf, s, end);
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if (!value)
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return NULL;
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s += value->str_len;
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if (value->type == BENCODE_END_MARKER)
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return NULL;
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__bencode_container_add(ret, value);
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__bencode_hash_insert(key, hash);
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}
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return ret;
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}
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static bencode_item_t *__bencode_decode_list(bencode_buffer_t *buf, const char *s, const char *end) {
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bencode_item_t *ret, *item;
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if (*s != 'l')
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return NULL;
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s++;
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ret = __bencode_item_alloc(buf, 0);
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if (!ret)
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return NULL;
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__bencode_list_init(ret);
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while (s < end) {
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item = __bencode_decode(buf, s, end);
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if (!item)
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return NULL;
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s += item->str_len;
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if (item->type == BENCODE_END_MARKER)
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break;
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__bencode_container_add(ret, item);
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}
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return ret;
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}
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static bencode_item_t *__bencode_decode_integer(bencode_buffer_t *buf, const char *s, const char *end) {
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long long int i;
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const char *orig = s;
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char *convend;
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bencode_item_t *ret;
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if (*s != 'i')
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return NULL;
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s++;
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if (s >= end)
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return NULL;
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if (*s == '0') {
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i = 0;
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s++;
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goto done;
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}
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i = strtoll(s, &convend, 10);
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if (convend == s)
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return NULL;
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s += (convend - s);
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done:
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if (s >= end)
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return NULL;
|
|
if (*s != 'e')
|
|
return NULL;
|
|
s++;
|
|
|
|
ret = __bencode_item_alloc(buf, 0);
|
|
if (!ret)
|
|
return NULL;
|
|
ret->type = BENCODE_INTEGER;
|
|
ret->iov[0].iov_base = (void *) orig;
|
|
ret->iov[0].iov_len = s - orig;
|
|
ret->iov[1].iov_base = NULL;
|
|
ret->iov[1].iov_len = 0;
|
|
ret->iov_cnt = 1;
|
|
ret->str_len = s - orig;
|
|
ret->value = i;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bencode_item_t *__bencode_decode_string(bencode_buffer_t *buf, const char *s, const char *end) {
|
|
unsigned long int sl;
|
|
char *convend;
|
|
const char *orig = s;
|
|
bencode_item_t *ret;
|
|
|
|
if (*s == '0') {
|
|
sl = 0;
|
|
s++;
|
|
goto colon;
|
|
}
|
|
|
|
sl = strtoul(s, &convend, 10);
|
|
if (convend == s)
|
|
return NULL;
|
|
s += (convend - s);
|
|
|
|
colon:
|
|
if (s >= end)
|
|
return NULL;
|
|
if (*s != ':')
|
|
return NULL;
|
|
s++;
|
|
|
|
if (s + sl > end)
|
|
return NULL;
|
|
|
|
ret = __bencode_item_alloc(buf, 0);
|
|
if (!ret)
|
|
return NULL;
|
|
ret->type = BENCODE_STRING;
|
|
ret->iov[0].iov_base = (void *) orig;
|
|
ret->iov[0].iov_len = s - orig;
|
|
ret->iov[1].iov_base = (void *) s;
|
|
ret->iov[1].iov_len = sl;
|
|
ret->iov_cnt = 2;
|
|
ret->str_len = s - orig + sl;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bencode_item_t *__bencode_decode(bencode_buffer_t *buf, const char *s, const char *end) {
|
|
if (s >= end)
|
|
return NULL;
|
|
|
|
switch (*s) {
|
|
case 'd':
|
|
return __bencode_decode_dictionary(buf, s, end);
|
|
case 'l':
|
|
return __bencode_decode_list(buf, s, end);
|
|
case 'i':
|
|
return __bencode_decode_integer(buf, s, end);
|
|
case 'e':
|
|
return &__bencode_end_marker;
|
|
case '0':
|
|
case '1':
|
|
case '2':
|
|
case '3':
|
|
case '4':
|
|
case '5':
|
|
case '6':
|
|
case '7':
|
|
case '8':
|
|
case '9':
|
|
return __bencode_decode_string(buf, s, end);
|
|
default:
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
bencode_item_t *bencode_decode(bencode_buffer_t *buf, const char *s, size_t len) {
|
|
assert(s != NULL);
|
|
return __bencode_decode(buf, s, s + len);
|
|
}
|
|
|
|
|
|
static int __bencode_dictionary_key_match(bencode_item_t *key, const char *keystr, size_t keylen) {
|
|
assert(key->type == BENCODE_STRING);
|
|
|
|
if (keylen != key->iov[1].iov_len)
|
|
return 0;
|
|
if (memcmp(keystr, key->iov[1].iov_base, keylen))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
bencode_item_t *bencode_dictionary_get_len(bencode_item_t *dict, const char *keystr, size_t keylen) {
|
|
bencode_item_t *key;
|
|
unsigned int bucket, i;
|
|
struct __bencode_hash *hash;
|
|
|
|
if (!dict)
|
|
return NULL;
|
|
if (dict->type != BENCODE_DICTIONARY)
|
|
return NULL;
|
|
|
|
/* try hash lookup first if possible */
|
|
if (dict->value == 1) {
|
|
hash = (void *) dict->__buf;
|
|
i = bucket = __bencode_hash_str_len((const unsigned char *) keystr, keylen);
|
|
while (1) {
|
|
key = hash->buckets[i];
|
|
if (!key)
|
|
return NULL; /* would be there, but isn't */
|
|
assert(key->sibling != NULL);
|
|
if (__bencode_dictionary_key_match(key, keystr, keylen))
|
|
return key->sibling;
|
|
i++;
|
|
if (i >= BENCODE_HASH_BUCKETS)
|
|
i = 0;
|
|
if (i == bucket)
|
|
break; /* fall back to regular lookup */
|
|
}
|
|
}
|
|
|
|
for (key = dict->child; key; key = key->sibling->sibling) {
|
|
assert(key->sibling != NULL);
|
|
if (__bencode_dictionary_key_match(key, keystr, keylen))
|
|
return key->sibling;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static ssize_t __bencode_string(const char *s, ssize_t offset, size_t len) {
|
|
size_t pos;
|
|
unsigned long sl;
|
|
char *end;
|
|
|
|
for (pos = offset; s[pos] != ':' && isdigit(s[pos]) && pos < len; ++pos);
|
|
if (pos == len)
|
|
return -1;
|
|
|
|
sl = strtoul(s + offset, &end, 10);
|
|
if (s + offset == end || end != s + pos)
|
|
return -2;
|
|
|
|
if (pos + sl > len)
|
|
return -1;
|
|
|
|
return pos + sl + 1;
|
|
}
|
|
|
|
static ssize_t __bencode_integer(const char *s, ssize_t offset, size_t len) {
|
|
size_t pos;
|
|
|
|
if (s[offset + 1] == '-') {
|
|
if (offset + 3 < len && s[offset + 2] == '0' && s[offset + 3] == 'e') {
|
|
return -2;
|
|
}
|
|
++offset;
|
|
}
|
|
|
|
if (s[offset + 1] == 'e')
|
|
return -2;
|
|
|
|
if (s[offset + 1] == '0') {
|
|
if (offset + 2 < len && s[offset + 2] == 'e')
|
|
return offset + 3;
|
|
return -2;
|
|
}
|
|
|
|
for (pos = offset + 1; s[pos] != 'e' && pos < len; ++pos) {
|
|
if (s[pos] < '0' || s[pos] > '9')
|
|
return -2;
|
|
}
|
|
|
|
if (pos == len)
|
|
return -1;
|
|
|
|
return pos + 1;
|
|
}
|
|
|
|
static ssize_t __bencode_next(const char *s, ssize_t offset, size_t len);
|
|
|
|
static ssize_t __bencode_list(const char *s, ssize_t offset, size_t len) {
|
|
for (++offset; s[offset] != 'e' && offset < len;) {
|
|
offset = __bencode_next(s, offset, len);
|
|
if (offset < 0)
|
|
return offset;
|
|
}
|
|
|
|
if (offset == len)
|
|
return -1;
|
|
|
|
return offset + 1;
|
|
}
|
|
|
|
static ssize_t __bencode_dictionary(const char *s, ssize_t offset, size_t len) {
|
|
for (++offset; s[offset] != 'e' && offset < len;) {
|
|
offset = __bencode_string(s, offset, len);
|
|
if (offset < 0)
|
|
return offset;
|
|
offset = __bencode_next(s, offset, len);
|
|
if (offset < 0)
|
|
return offset;
|
|
}
|
|
|
|
if (offset == len)
|
|
return -1;
|
|
|
|
return offset + 1;
|
|
}
|
|
|
|
static ssize_t __bencode_next(const char *s, ssize_t offset, size_t len) {
|
|
if (offset >= len)
|
|
return -1;
|
|
switch(s[offset]) {
|
|
case 'i':
|
|
return __bencode_integer(s, offset, len);
|
|
case 'l':
|
|
return __bencode_list(s, offset, len);
|
|
case 'd':
|
|
return __bencode_dictionary(s, offset, len);
|
|
case '0':
|
|
case '1':
|
|
case '2':
|
|
case '3':
|
|
case '4':
|
|
case '5':
|
|
case '6':
|
|
case '7':
|
|
case '8':
|
|
case '9':
|
|
return __bencode_string(s, offset, len);
|
|
}
|
|
return -2;
|
|
}
|
|
|
|
ssize_t bencode_valid(const char *s, size_t len) {
|
|
return __bencode_next(s, 0, len);
|
|
}
|