4 * (c) 2007 Martin Mares <mj@ucw.cz>
9 * - competition timeout & per-contestant exceptions
16 #include "lib/getopt.h"
23 #include <sys/types.h>
24 #include <sys/socket.h>
26 #include <arpa/inet.h>
27 #include <netinet/in.h>
31 /*** CONFIGURATION ***/
33 static uns port = 8888;
34 static uns dh_bits = 1024;
35 static uns max_conn = 10;
36 static uns session_timeout;
37 static byte *ca_cert_name = "?";
38 static byte *server_cert_name = "?";
39 static byte *server_key_name = "?";
40 static clist access_rules;
43 uns max_attachment_size;
46 static struct cf_section access_conf = {
47 CF_TYPE(struct access_rule),
49 CF_USER("IP", PTR_TO(struct access_rule, addrmask), &ip_addrmask_type),
50 CF_UNS("Admin", PTR_TO(struct access_rule, allow_admin)),
51 CF_UNS("PlainText", PTR_TO(struct access_rule, plain_text)),
52 CF_UNS("MaxConn", PTR_TO(struct access_rule, max_conn)),
60 clist_init(&access_rules);
64 static struct cf_section submitd_conf = {
67 CF_UNS("Port", &port),
68 CF_UNS("DHBits", &dh_bits),
69 CF_UNS("MaxConn", &max_conn),
70 CF_UNS("SessionTimeout", &session_timeout),
71 CF_UNS("MaxRequestSize", &max_request_size),
72 CF_UNS("MaxAttachSize", &max_attachment_size),
73 CF_STRING("CACert", &ca_cert_name),
74 CF_STRING("ServerCert", &server_cert_name),
75 CF_STRING("ServerKey", &server_key_name),
76 CF_LIST("Access", &access_rules, &access_conf),
77 CF_UNS("TraceTLS", &trace_tls),
78 CF_UNS("TraceCommands", &trace_commands),
85 static clist connections;
86 static uns last_conn_id;
92 clist_init(&connections);
98 struct conn *c = xmalloc_zero(sizeof(*c));
99 c->id = ++last_conn_id;
100 clist_add_tail(&connections, &c->n);
106 conn_free(struct conn *c)
113 static struct access_rule *
116 CLIST_FOR_EACH(struct access_rule *, r, access_rules)
117 if (ip_addrmask_match(&r->addrmask, ip))
126 CLIST_FOR_EACH(struct conn *, c, connections)
134 static gnutls_certificate_credentials_t cert_cred;
135 static gnutls_dh_params_t dh_params;
137 #define TLS_CHECK(name) if (err < 0) die(#name " failed: %s", gnutls_strerror(err))
144 gnutls_global_init();
145 err = gnutls_certificate_allocate_credentials(&cert_cred);
146 TLS_CHECK(gnutls_certificate_allocate_credentials);
147 err = gnutls_certificate_set_x509_trust_file(cert_cred, ca_cert_name, GNUTLS_X509_FMT_PEM);
149 die("No CA certificate found");
151 die("Unable to load X509 trust file: %s", gnutls_strerror(err));
152 err = gnutls_certificate_set_x509_key_file(cert_cred, server_cert_name, server_key_name, GNUTLS_X509_FMT_PEM);
154 die("Unable to load X509 key file: %s", gnutls_strerror(err));
156 err = gnutls_dh_params_init(&dh_params); TLS_CHECK(gnutls_dh_params_init);
157 err = gnutls_dh_params_generate2(dh_params, dh_bits); TLS_CHECK(gnutls_dh_params_generate2);
158 gnutls_certificate_set_dh_params(cert_cred, dh_params);
161 static gnutls_session_t
162 tls_new_session(int sk)
167 err = gnutls_init(&s, GNUTLS_SERVER); TLS_CHECK(gnutls_init);
168 err = gnutls_set_default_priority(s); TLS_CHECK(gnutls_set_default_priority); // FIXME
169 gnutls_credentials_set(s, GNUTLS_CRD_CERTIFICATE, cert_cred);
170 gnutls_certificate_server_set_request(s, GNUTLS_CERT_REQUEST);
171 gnutls_dh_set_prime_bits(s, dh_bits);
172 gnutls_transport_set_ptr(s, (gnutls_transport_ptr_t) sk);
177 tls_verify_cert(struct conn *c)
179 gnutls_session_t s = c->tls;
180 uns status, num_certs;
182 gnutls_x509_crt_t cert;
183 const gnutls_datum_t *certs;
185 DBG("Verifying peer certificates");
186 err = gnutls_certificate_verify_peers2(s, &status);
188 return gnutls_strerror(err);
189 DBG("Verify status: %04x", status);
190 if (status & GNUTLS_CERT_INVALID)
191 return "Certificate is invalid";
192 /* XXX: We do not handle revokation. */
193 if (gnutls_certificate_type_get(s) != GNUTLS_CRT_X509)
194 return "Certificate is not X509";
196 err = gnutls_x509_crt_init(&cert);
198 return "gnutls_x509_crt_init() failed";
199 certs = gnutls_certificate_get_peers(s, &num_certs);
201 return "No peer certificate found";
202 DBG("Got certificate list with %d peers", num_certs);
204 err = gnutls_x509_crt_import(cert, &certs[0], GNUTLS_X509_FMT_DER);
206 return "Cannot import certificate";
207 /* XXX: We do not check expiration and activation since the keys are generated for a single contest only anyway. */
210 size_t dn_len = sizeof(dn);
211 err = gnutls_x509_crt_get_dn_by_oid(cert, GNUTLS_OID_X520_COMMON_NAME, 0, 0, dn, &dn_len);
213 return "Cannot retrieve common name";
215 log(L_INFO, "Cert CN: %s", dn);
216 c->cert_name = xstrdup(dn);
218 /* Check certificate purpose */
223 size_t purp_len = sizeof(purp);
225 err = gnutls_x509_crt_get_key_purpose_oid(cert, purpi++, purp, &purp_len, &crit);
226 if (err == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
227 return "Not a client certificate";
228 TLS_CHECK(gnutls_x509_crt_get_key_purpose_oid);
230 while (strcmp(purp, GNUTLS_KP_TLS_WWW_CLIENT));
237 tls_log_params(struct conn *c)
241 gnutls_session_t s = c->tls;
242 const char *proto = gnutls_protocol_get_name(gnutls_protocol_get_version(s));
243 const char *kx = gnutls_kx_get_name(gnutls_kx_get(s));
244 const char *cert = gnutls_certificate_type_get_name(gnutls_certificate_type_get(s));
245 const char *comp = gnutls_compression_get_name(gnutls_compression_get(s));
246 const char *cipher = gnutls_cipher_get_name(gnutls_cipher_get(s));
247 const char *mac = gnutls_mac_get_name(gnutls_mac_get(s));
248 log(L_DEBUG, "TLS params: proto=%s kx=%s cert=%s comp=%s cipher=%s mac=%s",
249 proto, kx, cert, comp, cipher, mac);
252 /*** SOCKET FASTBUFS ***/
255 client_error(char *msg, ...)
259 vlog_msg(L_ERROR_R, msg, args);
264 sk_fb_refill(struct fastbuf *f)
266 struct conn *c = SKIP_BACK(struct conn, rx_fb, f);
267 int cnt = read(c->sk, f->buffer, f->bufend - f->buffer);
269 client_error("Read error: %m");
271 f->bstop = f->buffer + cnt;
276 sk_fb_spout(struct fastbuf *f)
278 struct conn *c = SKIP_BACK(struct conn, tx_fb, f);
279 int len = f->bptr - f->buffer;
282 int cnt = careful_write(c->sk, f->buffer, len);
284 client_error("Write error");
289 init_sk_fastbufs(struct conn *c)
291 struct fastbuf *rf = &c->rx_fb, *tf = &c->tx_fb;
293 rf->buffer = xmalloc(1024);
294 rf->bufend = rf->buffer + 1024;
295 rf->bptr = rf->bstop = rf->buffer;
297 rf->refill = sk_fb_refill;
299 tf->buffer = xmalloc(1024);
300 tf->bufend = tf->buffer + 1024;
301 tf->bptr = tf->bstop = tf->buffer;
303 tf->spout = sk_fb_spout;
307 tls_fb_refill(struct fastbuf *f)
309 struct conn *c = SKIP_BACK(struct conn, rx_fb, f);
311 int cnt = gnutls_record_recv(c->tls, f->buffer, f->bufend - f->buffer);
312 DBG("TLS: Received %d bytes", cnt);
314 client_error("TLS read error: %s", gnutls_strerror(cnt));
316 f->bstop = f->buffer + cnt;
321 tls_fb_spout(struct fastbuf *f)
323 struct conn *c = SKIP_BACK(struct conn, tx_fb, f);
324 int len = f->bptr - f->buffer;
327 int cnt = gnutls_record_send(c->tls, f->buffer, len);
328 DBG("TLS: Sent %d bytes", cnt);
330 client_error("TLS write error: %s", gnutls_strerror(cnt));
335 init_tls_fastbufs(struct conn *c)
337 struct fastbuf *rf = &c->rx_fb, *tf = &c->tx_fb;
339 ASSERT(rf->buffer && tf->buffer); // Already set up for the plaintext connection
340 rf->refill = tls_fb_refill;
341 tf->spout = tls_fb_spout;
344 /*** CLIENT LOOP (runs in a child process) ***/
347 sigalrm_handler(int sig UNUSED)
349 // We do not try to do any gracious shutdown to avoid races
350 client_error("Timed out");
354 client_loop(struct conn *c)
359 signal(SIGPIPE, SIG_IGN);
360 struct sigaction sa = {
361 .sa_handler = sigalrm_handler
363 if (sigaction(SIGALRM, &sa, NULL) < 0)
364 die("Cannot setup SIGALRM handler: %m");
366 if (c->rule->plain_text)
368 bputsn(&c->tx_fb, "+OK");
373 bputsn(&c->tx_fb, "+TLS");
375 c->tls = tls_new_session(c->sk);
376 int err = gnutls_handshake(c->tls);
378 client_error("TLS handshake failed: %s", gnutls_strerror(err));
380 const char *cert_err = tls_verify_cert(c);
382 client_error("TLS certificate failure: %s", cert_err);
383 init_tls_fastbufs(c);
386 alarm(session_timeout);
387 if (!process_init(c))
388 log(L_ERROR, "Protocol handshake failed");
392 alarm(session_timeout);
393 if (!process_command(c))
398 gnutls_bye(c->tls, GNUTLS_SHUT_WR);
401 gnutls_deinit(c->tls);
407 sigchld_handler(int sig UNUSED)
409 /* We do not need to do anything, just interrupt the accept syscall */
413 reap_child(pid_t pid, int status)
415 byte msg[EXIT_STATUS_MSG_SIZE];
416 if (format_exit_status(msg, status))
417 log(L_ERROR, "Child %d %s", (int)pid, msg);
419 CLIST_FOR_EACH(struct conn *, c, connections)
422 log(L_INFO, "Connection %d closed", c->id);
426 log(L_ERROR, "Cannot find connection for child process %d", (int)pid);
429 static int listen_sk;
434 listen_sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
438 if (setsockopt(listen_sk, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
439 die("setsockopt(SO_REUSEADDR): %m");
441 struct sockaddr_in sa;
442 bzero(&sa, sizeof(sa));
443 sa.sin_family = AF_INET;
444 sa.sin_addr.s_addr = INADDR_ANY;
445 sa.sin_port = htons(port);
446 if (bind(listen_sk, (struct sockaddr *) &sa, sizeof(sa)) < 0)
447 die("Cannot bind to port %d: %m", port);
448 if (listen(listen_sk, 1024) < 0)
449 die("Cannot listen on port %d: %m", port);
455 struct sockaddr_in sa;
456 int salen = sizeof(sa);
457 int sk = accept(listen_sk, (struct sockaddr *) &sa, &salen);
465 byte ipbuf[INET_ADDRSTRLEN];
466 inet_ntop(AF_INET, &sa.sin_addr, ipbuf, sizeof(ipbuf));
467 u32 addr = ntohl(sa.sin_addr.s_addr);
468 uns port = ntohs(sa.sin_port);
471 struct access_rule *rule = lookup_rule(addr);
474 err = "Unauthorized";
478 if (num_conn >= max_conn)
480 err = "Too many connections";
484 if (conn_count(addr) >= rule->max_conn)
486 err = "Too many connections from this address";
490 struct conn *c = conn_new();
491 log(L_INFO, "Connection from %s:%d (id %d, %s, %s)",
493 (rule->plain_text ? "plain-text" : "TLS"),
494 (rule->allow_admin ? "admin" : "user"));
503 err = "Server overloaded";
504 log(L_ERROR, "Fork failed: %m");
517 log(L_ERROR_R, "Connection from %s:%d rejected (%s)", ipbuf, port, err);
519 // Write an error message to the socket, but do not allow it to slow us down
520 struct linger ling = { .l_onoff=0 };
521 if (setsockopt(sk, SOL_SOCKET, SO_LINGER, &ling, sizeof(ling)) < 0)
522 log(L_ERROR, "Cannot set SO_LINGER: %m");
524 write(sk, err, strlen(err));
529 int main(int argc, char **argv)
531 setproctitle_init(argc, argv);
532 cf_def_file = "config";
533 cf_declare_section("SubmitD", &submitd_conf, 0);
536 if ((opt = cf_getopt(argc, argv, CF_SHORT_OPTS, CF_NO_LONG_OPTS, NULL)) >= 0)
537 die("This program has no options");
539 log(L_INFO, "Initializing TLS");
544 log(L_INFO, "Listening on port %d", port);
546 struct sigaction sa = {
547 .sa_handler = sigchld_handler
549 if (sigaction(SIGCHLD, &sa, NULL) < 0)
550 die("Cannot setup SIGCHLD handler: %m");
555 pid_t pid = waitpid(-1, &status, WNOHANG);
557 reap_child(pid, status);