static bool
thex_download_handle_hashtree(struct thex_download *ctx,
const char *data, size_t size)
{
bool success = FALSE;
size_t n_nodes, n_leaves, n, start;
unsigned good_depth;
const struct tth *leaves;
struct tth tth;
if (size <= 0) {
if (GNET_PROPERTY(tigertree_debug)) {
g_debug("TTH hashtree record has no data");
}
goto finish;
}
if (size < TTH_RAW_SIZE) {
if (GNET_PROPERTY(tigertree_debug)) {
g_debug("TTH hashtree record is too small");
}
goto finish;
}
if (size % TTH_RAW_SIZE) {
if (GNET_PROPERTY(tigertree_debug)) {
g_debug("TTH hashtree has bad size");
}
goto finish;
}
memcpy(tth.data, data, TTH_RAW_SIZE);
if (!tth_eq(&tth, ctx->tth)) {
if (GNET_PROPERTY(tigertree_debug)) {
g_debug("TTH hashtree has different root hash %s",
tth_base32(&tth));
}
goto finish;
}
n_nodes = size / TTH_RAW_SIZE;
n_leaves = tt_node_count_at_depth(ctx->filesize, ctx->depth);
/* Shareaza uses a fixed depth of 9, allow one level less like others */
good_depth = tt_good_depth(ctx->filesize);
ctx->depth = MIN(ctx->depth, good_depth);
if (n_nodes < n_leaves * 2 - 1) {
ctx->depth = good_depth;
n = tt_node_count_at_depth(ctx->filesize, ctx->depth);
n = n * 2 - 1; /* All nodes, not just leaves */
while (n > n_nodes) {
n = (n + 1) / 2;
ctx->depth--;
}
if (GNET_PROPERTY(tigertree_debug)) {
g_debug("TTH calculated depth of hashtree: %u", ctx->depth);
}
n_leaves = tt_node_count_at_depth(ctx->filesize, ctx->depth);
}
if (ctx->depth < good_depth) {
if (GNET_PROPERTY(tigertree_debug)) {
g_debug("TTH tree depth (%u) is below the good depth (%u)",
ctx->depth, good_depth);
}
}
start = 0;
n = n_leaves;
while (n > 1) {
n = (n + 1) / 2;
start += n;
}
if (n_nodes < start + n_leaves) {
if (GNET_PROPERTY(tigertree_debug)) {
g_debug("TTH hashtree has too few nodes "
"(filesize=%s depth=%u nodes=%zu expected=%zu)",
filesize_to_string(ctx->filesize),
ctx->depth, n_nodes, n_leaves * 2 - 1);
}
goto finish;
}
STATIC_ASSERT(TTH_RAW_SIZE == sizeof(struct tth));
leaves = (const struct tth *) &data[start * TTH_RAW_SIZE];
tth = tt_root_hash(leaves, n_leaves);
if (!tth_eq(&tth, ctx->tth)) {
if (GNET_PROPERTY(tigertree_debug)) {
g_debug("TTH hashtree does not match root hash %s",
tth_base32(&tth));
}
goto finish;
}
ctx->leaves = g_memdup(leaves, TTH_RAW_SIZE * n_leaves);
ctx->num_leaves = n_leaves;
success = TRUE;
finish:
return success;
}
size_t
tt_good_node_count(filesize_t filesize)
{
return tt_node_count_at_depth(filesize, tt_good_depth(filesize));
}
