/* Copyright (c) 2008, 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 #include #include #include "setup_transfer.hpp" #include "libtorrent/session.hpp" #include "libtorrent/hasher.hpp" #include "libtorrent/http_parser.hpp" #include "libtorrent/thread.hpp" #include "libtorrent/thread.hpp" #include #include #include #include "test.hpp" #include "libtorrent/assert.hpp" #include "libtorrent/alert_types.hpp" #include "libtorrent/create_torrent.hpp" #include "libtorrent/socket_io.hpp" // print_endpoint #include "libtorrent/socket_type.hpp" #include "libtorrent/instantiate_connection.hpp" #include "libtorrent/ip_filter.hpp" #ifdef TORRENT_USE_OPENSSL #include #include #endif #ifndef _WIN32 #include #include #endif #define DEBUG_WEB_SERVER 0 #define DLOG if (DEBUG_WEB_SERVER) fprintf using namespace libtorrent; namespace lt = libtorrent; static int tests_failure = 0; static std::vector failure_strings; #if defined TORRENT_WINDOWS #include #endif address rand_v4() { return address_v4((rand() << 16 | rand()) & 0xffffffff); } #if TORRENT_USE_IPV6 address rand_v6() { address_v6::bytes_type bytes; for (int i = 0; i < bytes.size(); ++i) bytes[i] = rand(); return address_v6(bytes); } #endif tcp::endpoint rand_tcp_ep() { return tcp::endpoint(rand_v4(), rand() + 1024); } udp::endpoint rand_udp_ep() { return udp::endpoint(rand_v4(), rand() + 1024); } void report_failure(char const* err, char const* file, int line) { char buf[500]; snprintf(buf, sizeof(buf), "\x1b[41m***** %s:%d \"%s\" *****\x1b[0m\n", file, line, err); fprintf(stderr, "\n%s\n", buf); failure_strings.push_back(buf); ++tests_failure; } int print_failures() { if (tests_failure == 0) fprintf(stderr, "\n\n\x1b[42;30m == %d ALL TESTS PASSED ==\x1b[0m\n\n\n", tests_failure); else fprintf(stderr, "\n\n\x1b[41m == %d TEST(S) FAILED ==\x1b[0m\n\n\n", tests_failure); return tests_failure; } std::map get_counters(libtorrent::session& s) { using namespace libtorrent; s.post_session_stats(); std::map ret; std::auto_ptr a = wait_for_alert(s, session_stats_alert::alert_type , "get_counters()"); TEST_CHECK(a.get()); if (!a.get()) return ret; session_stats_alert* sa = alert_cast(a.get()); if (!sa) return ret; static std::vector metrics = session_stats_metrics(); for (int i = 0; i < metrics.size(); ++i) ret[metrics[i].name] = sa->values[metrics[i].value_index]; return ret; } std::auto_ptr wait_for_alert(lt::session& ses, int type, char const* name) { std::auto_ptr ret; time_point end = aux::time_now() + seconds(10); while (!ret.get()) { time_point now = aux::time_now(); if (now > end) return std::auto_ptr(); ses.wait_for_alert(end - now); std::deque alerts; ses.pop_alerts(&alerts); for (std::deque::iterator i = alerts.begin() , end(alerts.end()); i != end; ++i) { fprintf(stderr, "%s: %s: [%s] %s\n", aux::time_now_string(), name , (*i)->what(), (*i)->message().c_str()); if (!ret.get() && (*i)->type() == type) { ret = std::auto_ptr(*i); } else delete *i; } } return ret; } int load_file(std::string const& filename, std::vector& v, libtorrent::error_code& ec, int limit) { ec.clear(); FILE* f = fopen(filename.c_str(), "rb"); if (f == NULL) { ec.assign(errno, boost::system::generic_category()); return -1; } int r = fseek(f, 0, SEEK_END); if (r != 0) { ec.assign(errno, boost::system::generic_category()); fclose(f); return -1; } long s = ftell(f); if (s < 0) { ec.assign(errno, boost::system::generic_category()); fclose(f); return -1; } if (s > limit) { fclose(f); return -2; } r = fseek(f, 0, SEEK_SET); if (r != 0) { ec.assign(errno, boost::system::generic_category()); fclose(f); return -1; } v.resize(s); if (s == 0) { fclose(f); return 0; } r = fread(&v[0], 1, v.size(), f); if (r < 0) { ec.assign(errno, boost::system::generic_category()); fclose(f); return -1; } fclose(f); if (r != s) return -3; return 0; } void save_file(char const* filename, char const* data, int size) { error_code ec; file out(filename, file::write_only, ec); TEST_CHECK(!ec); if (ec) { fprintf(stderr, "ERROR opening file '%s': %s\n", filename, ec.message().c_str()); return; } file::iovec_t b = { (void*)data, size_t(size) }; out.writev(0, &b, 1, ec); TEST_CHECK(!ec); if (ec) { fprintf(stderr, "ERROR writing file '%s': %s\n", filename, ec.message().c_str()); return; } } bool print_alerts(lt::session& ses, char const* name , bool allow_disconnects, bool allow_no_torrents, bool allow_failed_fastresume , bool (*predicate)(libtorrent::alert*), bool no_output) { bool ret = false; std::vector handles = ses.get_torrents(); TEST_CHECK(!handles.empty() || allow_no_torrents); torrent_handle h; if (!handles.empty()) h = handles[0]; std::deque alerts; ses.pop_alerts(&alerts); for (std::deque::iterator i = alerts.begin(); i != alerts.end(); ++i) { if (predicate && predicate(*i)) ret = true; if (peer_disconnected_alert* p = alert_cast(*i)) { fprintf(stderr, "%s: %s: [%s] (%s): %s\n", aux::time_now_string(), name, (*i)->what(), print_endpoint(p->ip).c_str(), p->message().c_str()); } else if ((*i)->message() != "block downloading" && (*i)->message() != "block finished" && (*i)->message() != "piece finished" && !no_output) { fprintf(stderr, "%s: %s: [%s] %s\n", aux::time_now_string(), name, (*i)->what(), (*i)->message().c_str()); } TEST_CHECK(alert_cast(*i) == 0 || allow_failed_fastresume); /* peer_error_alert* pea = alert_cast(*i); if (pea) { fprintf(stderr, "%s: peer error: %s\n", aux::time_now_string(), pea->error.message().c_str()); TEST_CHECK((!handles.empty() && h.status().is_seeding) || pea->error.message() == "connecting to peer" || pea->error.message() == "closing connection to ourself" || pea->error.message() == "duplicate connection" || pea->error.message() == "duplicate peer-id" || pea->error.message() == "upload to upload connection" || pea->error.message() == "stopping torrent" || (allow_disconnects && pea->error.message() == "Broken pipe") || (allow_disconnects && pea->error.message() == "Connection reset by peer") || (allow_disconnects && pea->error.message() == "no shared cipher") || (allow_disconnects && pea->error.message() == "End of file.")); } */ invalid_request_alert* ira = alert_cast(*i); if (ira) { fprintf(stderr, "peer error: %s\n", ira->message().c_str()); TEST_CHECK(false); } delete *i; } return ret; } bool listen_done = false; bool listen_alert(libtorrent::alert* a) { if (alert_cast(a) || alert_cast(a)) listen_done = true; return true; } void wait_for_listen(lt::session& ses, char const* name) { listen_done = false; alert const* a = 0; do { print_alerts(ses, name, true, true, true, &listen_alert, false); if (listen_done) break; a = ses.wait_for_alert(milliseconds(500)); } while (a); // we din't receive a listen alert! TEST_CHECK(listen_done); } bool downloading_done = false; bool downloading_alert(libtorrent::alert* a) { state_changed_alert* sc = alert_cast(a); if (sc && sc->state == torrent_status::downloading) downloading_done = true; return true; } void wait_for_downloading(lt::session& ses, char const* name) { downloading_done = false; alert const* a = 0; do { print_alerts(ses, name, true, true, true, &downloading_alert, false); if (downloading_done) break; a = ses.wait_for_alert(milliseconds(500)); } while (a); } void print_ses_rate(float time , libtorrent::torrent_status const* st1 , libtorrent::torrent_status const* st2 , libtorrent::torrent_status const* st3) { if (st1) { fprintf(stderr, "%3.1fs | %dkB/s %dkB/s %d%% %d cc:%d%s", time , int(st1->download_payload_rate / 1000) , int(st1->upload_payload_rate / 1000) , int(st1->progress * 100) , st1->num_peers , st1->connect_candidates , st1->error.empty() ? "" : (" [" + st1->error + "]").c_str()); } if (st2) fprintf(stderr, " : %3.1fs | %dkB/s %dkB/s %d%% %d cc:%d%s", time , int(st2->download_payload_rate / 1000) , int(st2->upload_payload_rate / 1000) , int(st2->progress * 100) , st2->num_peers , st2->connect_candidates , st2->error.empty() ? "" : (" [" + st2->error + "]").c_str()); if (st3) fprintf(stderr, " : %3.1fs | %dkB/s %dkB/s %d%% %d cc:%d%s", time , int(st3->download_payload_rate / 1000) , int(st3->upload_payload_rate / 1000) , int(st3->progress * 100) , st3->num_peers , st3->connect_candidates , st3->error.empty() ? "" : (" [" + st3->error + "]").c_str()); fprintf(stderr, "\n"); } void test_sleep(int milliseconds) { #if defined TORRENT_WINDOWS || defined TORRENT_CYGWIN Sleep(milliseconds); #elif defined TORRENT_BEOS snooze_until(system_time() + boost::int64_t(milliseconds) * 1000, B_SYSTEM_TIMEBASE); #else usleep(milliseconds * 1000); #endif } #ifdef _WIN32 typedef DWORD pid_type; #else typedef pid_t pid_type; #endif struct proxy_t { pid_type pid; int type; }; // maps port to proxy type static std::map running_proxies; void stop_proxy(int port) { fprintf(stderr, "stopping proxy on port %d\n", port); // don't shut down proxies until the test is // completely done. This saves a lot of time. // they're closed at the end of main() by // calling stop_all_proxies(). } // returns 0 on failure, otherwise pid pid_type async_run(char const* cmdline) { #ifdef _WIN32 char buf[2048]; snprintf(buf, sizeof(buf), "%s", cmdline); PROCESS_INFORMATION pi; STARTUPINFOA startup; memset(&startup, 0, sizeof(startup)); startup.cb = sizeof(startup); startup.hStdInput = GetStdHandle(STD_INPUT_HANDLE); startup.hStdOutput= GetStdHandle(STD_OUTPUT_HANDLE); startup.hStdError = GetStdHandle(STD_INPUT_HANDLE); int ret = CreateProcessA(NULL, buf, NULL, NULL, TRUE, CREATE_NEW_PROCESS_GROUP, NULL, NULL, &startup, &pi); if (ret == 0) { int error = GetLastError(); fprintf(stderr, "failed (%d) %s\n", error, error_code(error, system_category()).message().c_str()); return 0; } return pi.dwProcessId; #else pid_type p; char arg_storage[4096]; char* argp = arg_storage; std::vector argv; argv.push_back(argp); for (char const* in = cmdline; *in != '\0'; ++in) { if (*in != ' ') { *argp++ = *in; continue; } *argp++ = '\0'; argv.push_back(argp); } *argp = '\0'; argv.push_back(NULL); int ret = posix_spawnp(&p, argv[0], NULL, NULL, &argv[0], NULL); if (ret != 0) { fprintf(stderr, "failed (%d) %s\n", errno, strerror(errno)); return 0; } return p; #endif } void stop_process(pid_type p) { #ifdef _WIN32 HANDLE proc = OpenProcess(PROCESS_TERMINATE | SYNCHRONIZE, FALSE, p); TerminateProcess(proc, 138); CloseHandle(proc); #else printf("killing pid: %d\n", p); kill(p, SIGKILL); #endif } void stop_all_proxies() { std::map proxies = running_proxies; for (std::map::iterator i = proxies.begin() , end(proxies.end()); i != end; ++i) { stop_process(i->second.pid); running_proxies.erase(i->second.pid); } } // returns a port on success and -1 on failure int start_proxy(int proxy_type) { using namespace libtorrent; std::map :: iterator i = running_proxies.begin(); for (; i != running_proxies.end(); ++i) { if (i->second.type == proxy_type) { return i->first; } } unsigned int seed = total_microseconds(clock_type::now() - min_time()) & 0xffffffff; printf("random seed: %u\n", seed); std::srand(seed); int port = 5000 + (rand() % 55000); char const* type = ""; char const* auth = ""; char const* cmd = ""; switch (proxy_type) { case settings_pack::socks4: type = "socks4"; auth = " --allow-v4"; cmd = "python ../socks.py"; break; case settings_pack::socks5: type = "socks5"; cmd = "python ../socks.py"; break; case settings_pack::socks5_pw: type = "socks5"; auth = " --username testuser --password testpass"; cmd = "python ../socks.py"; break; case settings_pack::http: type = "http"; cmd = "python ../http.py"; break; case settings_pack::http_pw: type = "http"; auth = " --username testuser --password testpass"; cmd = "python ../http.py"; break; } char buf[512]; snprintf(buf, sizeof(buf), "%s --port %d%s", cmd, port, auth); fprintf(stderr, "%s starting proxy on port %d (%s %s)...\n", aux::time_now_string(), port, type, auth); fprintf(stderr, "%s\n", buf); pid_type r = async_run(buf); if (r == 0) exit(1); proxy_t t = { r, proxy_type }; running_proxies.insert(std::make_pair(port, t)); fprintf(stderr, "%s launched\n", aux::time_now_string()); test_sleep(500); return port; } using namespace libtorrent; template boost::shared_ptr clone_ptr(boost::shared_ptr const& ptr) { return boost::make_shared(*ptr); } unsigned char random_byte() { return std::rand() & 0xff; } void create_random_files(std::string const& path, const int file_sizes[], int num_files) { error_code ec; char* random_data = (char*)malloc(300000); for (int i = 0; i != num_files; ++i) { std::generate(random_data, random_data + 300000, random_byte); char filename[200]; snprintf(filename, sizeof(filename), "test%d", i); char dirname[200]; snprintf(dirname, sizeof(dirname), "test_dir%d", i / 5); std::string full_path = combine_path(path, dirname); error_code ec; create_directory(full_path, ec); full_path = combine_path(full_path, filename); int to_write = file_sizes[i]; file f(full_path, file::write_only, ec); if (ec) fprintf(stderr, "failed to create file \"%s\": (%d) %s\n" , full_path.c_str(), ec.value(), ec.message().c_str()); boost::int64_t offset = 0; while (to_write > 0) { int s = (std::min)(to_write, 300000); file::iovec_t b = { random_data, size_t(s)}; f.writev(offset, &b, 1, ec); if (ec) fprintf(stderr, "failed to write file \"%s\": (%d) %s\n" , full_path.c_str(), ec.value(), ec.message().c_str()); offset += s; to_write -= s; } } free(random_data); } boost::shared_ptr create_torrent(std::ostream* file, int piece_size , int num_pieces, bool add_tracker, std::string ssl_certificate) { // excercise the path when encountering invalid urls char const* invalid_tracker_url = "http:"; char const* invalid_tracker_protocol = "foo://non/existent-name.com/announce"; file_storage fs; int total_size = piece_size * num_pieces; fs.add_file("temporary", total_size); libtorrent::create_torrent t(fs, piece_size); if (add_tracker) { t.add_tracker(invalid_tracker_url); t.add_tracker(invalid_tracker_protocol); } if (!ssl_certificate.empty()) { std::vector file_buf; error_code ec; int res = load_file(ssl_certificate, file_buf, ec); if (ec || res < 0) { fprintf(stderr, "failed to load SSL certificate: %s\n", ec.message().c_str()); } else { std::string pem; std::copy(file_buf.begin(), file_buf.end(), std::back_inserter(pem)); t.set_root_cert(pem); } } std::vector piece(piece_size); for (int i = 0; i < int(piece.size()); ++i) piece[i] = (i % 26) + 'A'; // calculate the hash for all pieces int num = t.num_pieces(); sha1_hash ph = hasher(&piece[0], piece.size()).final(); for (int i = 0; i < num; ++i) t.set_hash(i, ph); if (file) { while (total_size > 0) { file->write(&piece[0], (std::min)(int(piece.size()), total_size)); total_size -= piece.size(); } } std::vector tmp; std::back_insert_iterator > out(tmp); entry tor = t.generate(); bencode(out, tor); error_code ec; return boost::make_shared( &tmp[0], tmp.size(), boost::ref(ec), 0); } boost::tuple setup_transfer(lt::session* ses1, lt::session* ses2, lt::session* ses3 , bool clear_files, bool use_metadata_transfer, bool connect_peers , std::string suffix, int piece_size , boost::shared_ptr* torrent, bool super_seeding , add_torrent_params const* p, bool stop_lsd, bool use_ssl_ports , boost::shared_ptr* torrent2) { TORRENT_ASSERT(ses1); TORRENT_ASSERT(ses2); if (stop_lsd) { settings_pack pack; pack.set_bool(settings_pack::enable_lsd, false); ses1->apply_settings(pack); ses2->apply_settings(pack); if (ses3) ses3->apply_settings(pack); } // This has the effect of applying the global // rule to all peers, regardless of if they're local or not ip_filter f; f.add_rule(address_v4::from_string("0.0.0.0") , address_v4::from_string("255.255.255.255") , 1 << lt::session::global_peer_class_id); ses1->set_peer_class_filter(f); ses2->set_peer_class_filter(f); if (ses3) ses3->set_peer_class_filter(f); settings_pack pack; pack.set_int(settings_pack::alert_mask, ~(alert::progress_notification | alert::stats_notification)); if (ses3) pack.set_bool(settings_pack::allow_multiple_connections_per_ip, true); pack.set_int(settings_pack::mixed_mode_algorithm, settings_pack::prefer_tcp); pack.set_int(settings_pack::max_failcount, 1); peer_id pid; std::generate(&pid[0], &pid[0] + 20, random_byte); pack.set_str(settings_pack::peer_fingerprint, pid.to_string()); ses1->apply_settings(pack); TORRENT_ASSERT(ses1->id() == pid); std::generate(&pid[0], &pid[0] + 20, random_byte); TORRENT_ASSERT(ses1->id() != pid); pack.set_str(settings_pack::peer_fingerprint, pid.to_string()); ses2->apply_settings(pack); TORRENT_ASSERT(ses2->id() == pid); if (ses3) { std::generate(&pid[0], &pid[0] + 20, random_byte); TORRENT_ASSERT(ses1->id() != pid); TORRENT_ASSERT(ses2->id() != pid); pack.set_str(settings_pack::peer_fingerprint, pid.to_string()); ses3->apply_settings(pack); TORRENT_ASSERT(ses3->id() == pid); } TORRENT_ASSERT(ses1->id() != ses2->id()); if (ses3) TORRENT_ASSERT(ses3->id() != ses2->id()); boost::shared_ptr t; if (torrent == 0) { error_code ec; create_directory("tmp1" + suffix, ec); std::ofstream file(combine_path("tmp1" + suffix, "temporary").c_str()); t = ::create_torrent(&file, piece_size, 9, false); file.close(); if (clear_files) { remove_all(combine_path("tmp2" + suffix, "temporary"), ec); remove_all(combine_path("tmp3" + suffix, "temporary"), ec); } char ih_hex[41]; to_hex((char const*)&t->info_hash()[0], 20, ih_hex); fprintf(stderr, "generated torrent: %s tmp1%s/temporary\n", ih_hex, suffix.c_str()); } else { t = *torrent; } // they should not use the same save dir, because the // file pool will complain if two torrents are trying to // use the same files add_torrent_params param; param.flags &= ~add_torrent_params::flag_paused; param.flags &= ~add_torrent_params::flag_auto_managed; if (p) param = *p; param.ti = clone_ptr(t); param.save_path = "tmp1" + suffix; param.flags |= add_torrent_params::flag_seed_mode; error_code ec; torrent_handle tor1 = ses1->add_torrent(param, ec); if (ec) { fprintf(stderr, "ses1.add_torrent: %s\n", ec.message().c_str()); return boost::make_tuple(torrent_handle(), torrent_handle(), torrent_handle()); } tor1.super_seeding(super_seeding); // the downloader cannot use seed_mode param.flags &= ~add_torrent_params::flag_seed_mode; TEST_CHECK(!ses1->get_torrents().empty()); torrent_handle tor2; torrent_handle tor3; if (ses3) { param.ti = clone_ptr(t); param.save_path = "tmp3" + suffix; tor3 = ses3->add_torrent(param, ec); TEST_CHECK(!ses3->get_torrents().empty()); } if (use_metadata_transfer) { param.ti.reset(); param.info_hash = t->info_hash(); } else if (torrent2) { param.ti = clone_ptr(*torrent2); } else { param.ti = clone_ptr(t); } param.save_path = "tmp2" + suffix; tor2 = ses2->add_torrent(param, ec); TEST_CHECK(!ses2->get_torrents().empty()); TORRENT_ASSERT(ses1->get_torrents().size() == 1); TORRENT_ASSERT(ses2->get_torrents().size() == 1); // test_sleep(100); if (connect_peers) { std::auto_ptr a; /* do { a = wait_for_alert(*ses2, state_changed_alert::alert_type, "ses2"); } while (static_cast(a.get())->state != torrent_status::downloading); */ // wait_for_alert(*ses1, torrent_finished_alert::alert_type, "ses1"); error_code ec; int port = 0; if (use_ssl_ports) port = ses2->ssl_listen_port(); if (port == 0) port = ses2->listen_port(); fprintf(stderr, "%s: ses1: connecting peer port: %d\n" , aux::time_now_string(), port); tor1.connect_peer(tcp::endpoint(address::from_string("127.0.0.1", ec) , port)); if (ses3) { // give the other peers some time to get an initial // set of pieces before they start sharing with each-other port = 0; int port2 = 0; if (use_ssl_ports) { port = ses2->ssl_listen_port(); port2 = ses1->ssl_listen_port(); } if (port == 0) port = ses2->listen_port(); if (port2 == 0) port2 = ses1->listen_port(); fprintf(stderr, "ses3: connecting peer port: %d\n", port); tor3.connect_peer(tcp::endpoint( address::from_string("127.0.0.1", ec), port)); fprintf(stderr, "ses3: connecting peer port: %d\n", port2); tor3.connect_peer(tcp::endpoint( address::from_string("127.0.0.1", ec) , port2)); } } return boost::make_tuple(tor1, tor2, tor3); } pid_type web_server_pid = 0; int start_web_server(bool ssl, bool chunked_encoding, bool keepalive) { unsigned int seed = total_microseconds(clock_type::now() - min_time()) & 0xffffffff; fprintf(stderr, "random seed: %u\n", seed); std::srand(seed); int port = 5000 + (rand() % 55000); char buf[200]; snprintf(buf, sizeof(buf), "python ../web_server.py %d %d %d %d" , port, chunked_encoding , ssl, keepalive); fprintf(stderr, "%s starting web_server on port %d...\n", aux::time_now_string(), port); fprintf(stderr, "%s\n", buf); pid_type r = async_run(buf); if (r == 0) exit(1); web_server_pid = r; fprintf(stderr, "%s launched\n", aux::time_now_string()); test_sleep(500); return port; } void stop_web_server() { if (web_server_pid == 0) return; fprintf(stderr, "stopping web server\n"); stop_process(web_server_pid); web_server_pid = 0; }