/* Copyright (c) 2003-2016, Arvid Norberg All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the author nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "libtorrent/kademlia/msg.hpp" #include "libtorrent/bdecode.hpp" #include "libtorrent/entry.hpp" namespace libtorrent { namespace dht { namespace dht_detail { bool verify_message(bdecode_node const& message, key_desc_t const desc[] , bdecode_node ret[], int size, char* error, int error_size) { // get a non-root bdecode_node that still // points to the root. message should not be copied bdecode_node msg = message.non_owning(); // clear the return buffer for (int i = 0; i < size; ++i) ret[i].clear(); // when parsing child nodes, this is the stack // of bdecode_nodes to return to bdecode_node stack[5]; int stack_ptr = -1; if (msg.type() != bdecode_node::dict_t) { std::snprintf(error, error_size, "not a dictionary"); return false; } ++stack_ptr; stack[stack_ptr] = msg; for (int i = 0; i < size; ++i) { key_desc_t const& k = desc[i]; // std::fprintf(stderr, "looking for %s in %s\n", k.name, print_entry(*msg).c_str()); ret[i] = msg.dict_find(k.name); // none_t means any type if (ret[i] && ret[i].type() != k.type && k.type != bdecode_node::none_t) ret[i].clear(); if (ret[i] == 0 && (k.flags & key_desc_t::optional) == 0) { // the key was not found, and it's not an optional key std::snprintf(error, error_size, "missing '%s' key", k.name); return false; } if (k.size > 0 && ret[i] && k.type == bdecode_node::string_t) { bool invalid = false; if (k.flags & key_desc_t::size_divisible) invalid = (ret[i].string_length() % k.size) != 0; else invalid = ret[i].string_length() != k.size; if (invalid) { // the string was not of the required size ret[i].clear(); if ((k.flags & key_desc_t::optional) == 0) { std::snprintf(error, error_size, "invalid value for '%s'", k.name); return false; } } } if (k.flags & key_desc_t::parse_children) { TORRENT_ASSERT(k.type == bdecode_node::dict_t); if (ret[i]) { ++stack_ptr; TORRENT_ASSERT(stack_ptr < int(sizeof(stack) / sizeof(stack[0]))); msg = ret[i]; stack[stack_ptr] = msg; } else { // skip all children while (i < size && (desc[i].flags & key_desc_t::last_child) == 0) ++i; // if this assert is hit, desc is incorrect TORRENT_ASSERT(i < size); } } else if (k.flags & key_desc_t::last_child) { TORRENT_ASSERT(stack_ptr > 0); // this can happen if the specification passed // in is unbalanced. i.e. contain more last_child // nodes than parse_children if (stack_ptr == 0) return false; --stack_ptr; msg = stack[stack_ptr]; } } return true; } } void incoming_error(entry& e, char const* msg, int error_code) { e["y"] = "e"; entry::list_type& l = e["e"].list(); l.push_back(entry(error_code)); l.push_back(entry(msg)); } } }