/* Copyright (c) 2008-2012, 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/pch.hpp" #include #include #include #include "libtorrent/config.hpp" #include "libtorrent/http_parser.hpp" #include "libtorrent/assert.hpp" #include "libtorrent/escape_string.hpp" using namespace libtorrent; namespace libtorrent { bool is_ok_status(int http_status) { return http_status == 206 // partial content || http_status == 200 // OK || (http_status >= 300 // redirect && http_status < 400); } bool is_redirect(int http_status) { return http_status >= 300 && http_status < 400; } http_parser::~http_parser() {} http_parser::http_parser(int flags) : m_recv_pos(0) , m_status_code(-1) , m_content_length(-1) , m_range_start(-1) , m_range_end(-1) , m_state(read_status) , m_recv_buffer(0, 0) , m_body_start_pos(0) , m_chunked_encoding(false) , m_finished(false) , m_cur_chunk_end(-1) , m_chunk_header_size(0) , m_partial_chunk_header(0) , m_flags(flags) {} boost::tuple http_parser::incoming( buffer::const_interval recv_buffer, bool& error) { TORRENT_ASSERT(recv_buffer.left() >= m_recv_buffer.left()); boost::tuple ret(0, 0); int start_pos = m_recv_buffer.left(); // early exit if there's nothing new in the receive buffer if (start_pos == recv_buffer.left()) return ret; m_recv_buffer = recv_buffer; if (m_state == error_state) { error = true; return ret; } char const* pos = recv_buffer.begin + m_recv_pos; restart_response: if (m_state == read_status) { TORRENT_ASSERT(!m_finished); char const* newline = std::find(pos, recv_buffer.end, '\n'); // if we don't have a full line yet, wait. if (newline == recv_buffer.end) { boost::get<1>(ret) += m_recv_buffer.left() - start_pos; return ret; } if (newline == pos) { m_state = error_state; error = true; return ret; } char const* line_end = newline; if (pos != line_end && *(line_end - 1) == '\r') --line_end; char const* line = pos; ++newline; int incoming = int(newline - pos); m_recv_pos += incoming; boost::get<1>(ret) += newline - (m_recv_buffer.begin + start_pos); pos = newline; m_protocol = read_until(line, ' ', line_end); if (m_protocol.substr(0, 5) == "HTTP/") { m_status_code = atoi(read_until(line, ' ', line_end).c_str()); m_server_message = read_until(line, '\r', line_end); } else { m_method = m_protocol; std::transform(m_method.begin(), m_method.end(), m_method.begin(), &to_lower); // the content length is assumed to be 0 for requests m_content_length = 0; m_protocol.clear(); m_path = read_until(line, ' ', line_end); m_protocol = read_until(line, ' ', line_end); m_status_code = 0; } m_state = read_header; start_pos = pos - recv_buffer.begin; } if (m_state == read_header) { TORRENT_ASSERT(!m_finished); char const* newline = std::find(pos, recv_buffer.end, '\n'); std::string line; while (newline != recv_buffer.end && m_state == read_header) { // if the LF character is preceeded by a CR // charachter, don't copy it into the line string. char const* line_end = newline; if (pos != line_end && *(line_end - 1) == '\r') --line_end; line.assign(pos, line_end); ++newline; m_recv_pos += newline - pos; pos = newline; std::string::size_type separator = line.find(':'); if (separator == std::string::npos) { if (m_status_code == 100) { // for 100 Continue, we need to read another response header // before reading the body m_state = read_status; goto restart_response; } // this means we got a blank line, // the header is finished and the body // starts. m_state = read_body; // if this is a request (not a response) // we're done once we reach the end of the headers // if (!m_method.empty()) m_finished = true; // the HTTP header should always be < 2 GB TORRENT_ASSERT(m_recv_pos < INT_MAX); m_body_start_pos = int(m_recv_pos); break; } std::string name = line.substr(0, separator); std::transform(name.begin(), name.end(), name.begin(), &to_lower); ++separator; // skip whitespace while (separator < line.size() && (line[separator] == ' ' || line[separator] == '\t')) ++separator; std::string value = line.substr(separator, std::string::npos); m_header.insert(std::make_pair(name, value)); if (name == "content-length") { m_content_length = strtoll(value.c_str(), 0, 10); } else if (name == "content-range") { bool success = true; char const* ptr = value.c_str(); // apparently some web servers do not send the "bytes" // in their content-range. Don't treat it as an error // if we can't find it, just assume the byte counters // start immediately if (string_begins_no_case("bytes ", ptr)) ptr += 6; char* end; m_range_start = strtoll(ptr, &end, 10); if (end == ptr) success = false; else if (*end != '-') success = false; else { ptr = end + 1; m_range_end = strtoll(ptr, &end, 10); if (end == ptr) success = false; } if (!success || m_range_end < m_range_start) { m_state = error_state; error = true; return ret; } // the http range is inclusive m_content_length = m_range_end - m_range_start + 1; } else if (name == "transfer-encoding") { m_chunked_encoding = string_begins_no_case("chunked", value.c_str()); } TORRENT_ASSERT(m_recv_pos <= recv_buffer.left()); newline = std::find(pos, recv_buffer.end, '\n'); } boost::get<1>(ret) += newline - (m_recv_buffer.begin + start_pos); } if (m_state == read_body) { int incoming = recv_buffer.end - pos; if (m_chunked_encoding && (m_flags & dont_parse_chunks) == 0) { if (m_cur_chunk_end == -1) m_cur_chunk_end = m_body_start_pos; while (m_cur_chunk_end <= m_recv_pos + incoming && !m_finished && incoming > 0) { size_type payload = m_cur_chunk_end - m_recv_pos; if (payload > 0) { TORRENT_ASSERT(payload < INT_MAX); m_recv_pos += payload; boost::get<0>(ret) += int(payload); incoming -= int(payload); } buffer::const_interval buf(recv_buffer.begin + m_cur_chunk_end, recv_buffer.end); size_type chunk_size; int header_size; if (parse_chunk_header(buf, &chunk_size, &header_size)) { if (chunk_size > 0) { std::pair chunk_range(m_cur_chunk_end + header_size , m_cur_chunk_end + header_size + chunk_size); m_chunked_ranges.push_back(chunk_range); } m_cur_chunk_end += header_size + chunk_size; if (chunk_size == 0) { m_finished = true; TORRENT_ASSERT(m_content_length < 0 || m_recv_pos - m_body_start_pos - m_chunk_header_size == m_content_length); } header_size -= m_partial_chunk_header; m_partial_chunk_header = 0; // fprintf(stderr, "parse_chunk_header(%d, -> %d, -> %d) -> %d\n" // " incoming = %d\n m_recv_pos = %d\n m_cur_chunk_end = %d\n" // " content-length = %d\n" // , buf.left(), int(chunk_size), header_size, 1, incoming, int(m_recv_pos) // , m_cur_chunk_end, int(m_content_length)); } else { m_partial_chunk_header += incoming; header_size = incoming; // fprintf(stderr, "parse_chunk_header(%d, -> %d, -> %d) -> %d\n" // " incoming = %d\n m_recv_pos = %d\n m_cur_chunk_end = %d\n" // " content-length = %d\n" // , buf.left(), int(chunk_size), header_size, 0, incoming, int(m_recv_pos) // , m_cur_chunk_end, int(m_content_length)); } m_chunk_header_size += header_size; m_recv_pos += header_size; boost::get<1>(ret) += header_size; incoming -= header_size; } if (incoming > 0) { m_recv_pos += incoming; boost::get<0>(ret) += incoming; incoming = 0; } } else { size_type payload_received = m_recv_pos - m_body_start_pos + incoming; if (payload_received > m_content_length && m_content_length >= 0) { TORRENT_ASSERT(m_content_length - m_recv_pos + m_body_start_pos < INT_MAX); incoming = int(m_content_length - m_recv_pos + m_body_start_pos); } TORRENT_ASSERT(incoming >= 0); m_recv_pos += incoming; boost::get<0>(ret) += incoming; } if (m_content_length >= 0 && !m_chunked_encoding && m_recv_pos - m_body_start_pos >= m_content_length) { m_finished = true; } } return ret; } bool http_parser::parse_chunk_header(buffer::const_interval buf , size_type* chunk_size, int* header_size) { char const* pos = buf.begin; // ignore one optional new-line. This is since each chunk // is terminated by a newline. we're likely to see one // before the actual header. if (pos < buf.end && pos[0] == '\r') ++pos; if (pos < buf.end && pos[0] == '\n') ++pos; if (pos == buf.end) return false; char const* newline = std::find(pos, buf.end, '\n'); if (newline == buf.end) return false; ++newline; // the chunk header is a single line, a hex length of the // chunk followed by an optional semi-colon with a comment // in case the length is 0, the stream is terminated and // there are extra tail headers, which is terminated by an // empty line // first, read the chunk length *chunk_size = strtoll(pos, 0, 16); if (*chunk_size != 0) { *header_size = newline - buf.begin; // the newline alone is two bytes TORRENT_ASSERT(newline - buf.begin > 2); return true; } // this is the terminator of the stream. Also read headers std::map tail_headers; pos = newline; newline = std::find(pos, buf.end, '\n'); std::string line; while (newline != buf.end) { // if the LF character is preceeded by a CR // charachter, don't copy it into the line string. char const* line_end = newline; if (pos != line_end && *(line_end - 1) == '\r') --line_end; line.assign(pos, line_end); ++newline; pos = newline; std::string::size_type separator = line.find(':'); if (separator == std::string::npos) { // this means we got a blank line, // the header is finished and the body // starts. *header_size = newline - buf.begin; // the newline alone is two bytes TORRENT_ASSERT(newline - buf.begin > 2); // we were successfull in parsing the headers. // add them to the headers in the parser for (std::map::const_iterator i = tail_headers.begin(); i != tail_headers.end(); ++i) m_header.insert(std::make_pair(i->first, i->second)); return true; } std::string name = line.substr(0, separator); std::transform(name.begin(), name.end(), name.begin(), &to_lower); ++separator; // skip whitespace while (separator < line.size() && (line[separator] == ' ' || line[separator] == '\t')) ++separator; std::string value = line.substr(separator, std::string::npos); tail_headers.insert(std::make_pair(name, value)); // fprintf(stderr, "tail_header: %s: %s\n", name.c_str(), value.c_str()); newline = std::find(pos, buf.end, '\n'); } return false; } buffer::const_interval http_parser::get_body() const { TORRENT_ASSERT(m_state == read_body); size_type last_byte = m_chunked_encoding && !m_chunked_ranges.empty() ? (std::min)(m_chunked_ranges.back().second, m_recv_pos) : m_content_length < 0 ? m_recv_pos : (std::min)(m_body_start_pos + m_content_length, m_recv_pos); TORRENT_ASSERT(last_byte >= m_body_start_pos); return buffer::const_interval(m_recv_buffer.begin + m_body_start_pos , m_recv_buffer.begin + last_byte); } void http_parser::reset() { m_method.clear(); m_recv_pos = 0; m_body_start_pos = 0; m_status_code = -1; m_content_length = -1; m_range_start = -1; m_range_end = -1; m_finished = false; m_state = read_status; m_recv_buffer.begin = 0; m_recv_buffer.end = 0; m_header.clear(); m_chunked_encoding = false; m_chunked_ranges.clear(); m_cur_chunk_end = -1; m_chunk_header_size = 0; m_partial_chunk_header = 0; } int http_parser::collapse_chunk_headers(char* buffer, int size) const { if (!chunked_encoding()) return size; // go through all chunks and compact them // since we're bottled, and the buffer is our after all // it's OK to mutate it char* write_ptr = (char*)buffer; // the offsets in the array are from the start of the // buffer, not start of the body, so subtract the size // of the HTTP header from them int offset = body_start(); std::vector > const& c = chunks(); for (std::vector >::const_iterator i = c.begin() , end(c.end()); i != end; ++i) { TORRENT_ASSERT(i->second - i->first < INT_MAX); TORRENT_ASSERT(i->second - offset <= size); int len = int(i->second - i->first); if (i->first - offset + len > size) len = size - int(i->first) + offset; memmove(write_ptr, buffer + i->first - offset, len); write_ptr += len; } size = write_ptr - buffer; return size; } }