4 * (c) 2007 Martin Mares <mj@ucw.cz>
9 * - competition timeout & per-contestant exceptions
10 * - open-data problems
17 #include "lib/getopt.h"
24 #include <sys/types.h>
25 #include <sys/socket.h>
27 #include <arpa/inet.h>
28 #include <netinet/in.h>
32 /*** CONFIGURATION ***/
34 static uns port = 8888;
35 static uns dh_bits = 1024;
36 static uns max_conn = 10;
37 static uns session_timeout;
38 static byte *ca_cert_name = "?";
39 static byte *server_cert_name = "?";
40 static byte *server_key_name = "?";
41 static clist access_rules;
44 uns max_attachment_size;
47 static struct cf_section access_conf = {
48 CF_TYPE(struct access_rule),
50 CF_USER("IP", PTR_TO(struct access_rule, addrmask), &ip_addrmask_type),
51 CF_UNS("Admin", PTR_TO(struct access_rule, allow_admin)),
52 CF_UNS("PlainText", PTR_TO(struct access_rule, plain_text)),
53 CF_UNS("MaxConn", PTR_TO(struct access_rule, max_conn)),
61 clist_init(&access_rules);
65 static struct cf_section submitd_conf = {
68 CF_UNS("Port", &port),
69 CF_UNS("DHBits", &dh_bits),
70 CF_UNS("MaxConn", &max_conn),
71 CF_UNS("SessionTimeout", &session_timeout),
72 CF_UNS("MaxRequestSize", &max_request_size),
73 CF_UNS("MaxAttachSize", &max_attachment_size),
74 CF_STRING("CACert", &ca_cert_name),
75 CF_STRING("ServerCert", &server_cert_name),
76 CF_STRING("ServerKey", &server_key_name),
77 CF_LIST("Access", &access_rules, &access_conf),
78 CF_UNS("TraceTLS", &trace_tls),
79 CF_UNS("TraceCommands", &trace_commands),
86 static clist connections;
87 static uns last_conn_id;
93 clist_init(&connections);
99 struct conn *c = xmalloc_zero(sizeof(*c));
100 c->id = ++last_conn_id;
101 clist_add_tail(&connections, &c->n);
107 conn_free(struct conn *c)
116 static struct access_rule *
119 CLIST_FOR_EACH(struct access_rule *, r, access_rules)
120 if (ip_addrmask_match(&r->addrmask, ip))
129 CLIST_FOR_EACH(struct conn *, c, connections)
137 static gnutls_certificate_credentials_t cert_cred;
138 static gnutls_dh_params_t dh_params;
140 #define TLS_CHECK(name) if (err < 0) die(#name " failed: %s", gnutls_strerror(err))
147 gnutls_global_init();
148 err = gnutls_certificate_allocate_credentials(&cert_cred);
149 TLS_CHECK(gnutls_certificate_allocate_credentials);
150 err = gnutls_certificate_set_x509_trust_file(cert_cred, ca_cert_name, GNUTLS_X509_FMT_PEM);
152 die("No CA certificate found");
154 die("Unable to load X509 trust file: %s", gnutls_strerror(err));
155 err = gnutls_certificate_set_x509_key_file(cert_cred, server_cert_name, server_key_name, GNUTLS_X509_FMT_PEM);
157 die("Unable to load X509 key file: %s", gnutls_strerror(err));
159 err = gnutls_dh_params_init(&dh_params); TLS_CHECK(gnutls_dh_params_init);
160 err = gnutls_dh_params_generate2(dh_params, dh_bits); TLS_CHECK(gnutls_dh_params_generate2);
161 gnutls_certificate_set_dh_params(cert_cred, dh_params);
164 static gnutls_session_t
165 tls_new_session(int sk)
170 err = gnutls_init(&s, GNUTLS_SERVER); TLS_CHECK(gnutls_init);
171 err = gnutls_set_default_priority(s); TLS_CHECK(gnutls_set_default_priority); // FIXME
172 gnutls_credentials_set(s, GNUTLS_CRD_CERTIFICATE, cert_cred);
173 gnutls_certificate_server_set_request(s, GNUTLS_CERT_REQUEST);
174 gnutls_dh_set_prime_bits(s, dh_bits);
175 gnutls_transport_set_ptr(s, (gnutls_transport_ptr_t) sk);
180 tls_verify_cert(struct conn *c)
182 gnutls_session_t s = c->tls;
183 uns status, num_certs;
185 gnutls_x509_crt_t cert;
186 const gnutls_datum_t *certs;
188 DBG("Verifying peer certificates");
189 err = gnutls_certificate_verify_peers2(s, &status);
191 return gnutls_strerror(err);
192 DBG("Verify status: %04x", status);
193 if (status & GNUTLS_CERT_INVALID)
194 return "Certificate is invalid";
195 /* XXX: We do not handle revokation. */
196 if (gnutls_certificate_type_get(s) != GNUTLS_CRT_X509)
197 return "Certificate is not X509";
199 err = gnutls_x509_crt_init(&cert);
201 return "gnutls_x509_crt_init() failed";
202 certs = gnutls_certificate_get_peers(s, &num_certs);
204 return "No peer certificate found";
205 DBG("Got certificate list with %d peers", num_certs);
207 err = gnutls_x509_crt_import(cert, &certs[0], GNUTLS_X509_FMT_DER);
209 return "Cannot import certificate";
210 /* XXX: We do not check expiration and activation since the keys are generated for a single contest only anyway. */
213 size_t dn_len = sizeof(dn);
214 err = gnutls_x509_crt_get_dn_by_oid(cert, GNUTLS_OID_X520_COMMON_NAME, 0, 0, dn, &dn_len);
216 return "Cannot retrieve common name";
218 log(L_INFO, "Cert CN: %s", dn);
219 c->cert_name = xstrdup(dn);
221 /* Check certificate purpose */
226 size_t purp_len = sizeof(purp);
228 err = gnutls_x509_crt_get_key_purpose_oid(cert, purpi++, purp, &purp_len, &crit);
229 if (err == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
230 return "Not a client certificate";
231 TLS_CHECK(gnutls_x509_crt_get_key_purpose_oid);
233 while (strcmp(purp, GNUTLS_KP_TLS_WWW_CLIENT));
240 tls_log_params(struct conn *c)
244 gnutls_session_t s = c->tls;
245 const char *proto = gnutls_protocol_get_name(gnutls_protocol_get_version(s));
246 const char *kx = gnutls_kx_get_name(gnutls_kx_get(s));
247 const char *cert = gnutls_certificate_type_get_name(gnutls_certificate_type_get(s));
248 const char *comp = gnutls_compression_get_name(gnutls_compression_get(s));
249 const char *cipher = gnutls_cipher_get_name(gnutls_cipher_get(s));
250 const char *mac = gnutls_mac_get_name(gnutls_mac_get(s));
251 log(L_DEBUG, "TLS params: proto=%s kx=%s cert=%s comp=%s cipher=%s mac=%s",
252 proto, kx, cert, comp, cipher, mac);
255 /*** FASTBUFS OVER SOCKETS AND TLS ***/
257 void NONRET // Fatal protocol violation
258 client_error(char *msg, ...)
262 vlog_msg(L_ERROR_R, msg, args);
267 sk_fb_refill(struct fastbuf *f)
269 struct conn *c = SKIP_BACK(struct conn, rx_fb, f);
270 int cnt = read(c->sk, f->buffer, f->bufend - f->buffer);
272 client_error("Read error: %m");
274 f->bstop = f->buffer + cnt;
279 sk_fb_spout(struct fastbuf *f)
281 struct conn *c = SKIP_BACK(struct conn, tx_fb, f);
282 int len = f->bptr - f->buffer;
285 int cnt = careful_write(c->sk, f->buffer, len);
287 client_error("Write error");
292 init_sk_fastbufs(struct conn *c)
294 struct fastbuf *rf = &c->rx_fb, *tf = &c->tx_fb;
296 rf->buffer = xmalloc(1024);
297 rf->bufend = rf->buffer + 1024;
298 rf->bptr = rf->bstop = rf->buffer;
300 rf->refill = sk_fb_refill;
302 tf->buffer = xmalloc(1024);
303 tf->bufend = tf->buffer + 1024;
304 tf->bptr = tf->bstop = tf->buffer;
306 tf->spout = sk_fb_spout;
310 tls_fb_refill(struct fastbuf *f)
312 struct conn *c = SKIP_BACK(struct conn, rx_fb, f);
314 int cnt = gnutls_record_recv(c->tls, f->buffer, f->bufend - f->buffer);
315 DBG("TLS: Received %d bytes", cnt);
317 client_error("TLS read error: %s", gnutls_strerror(cnt));
319 f->bstop = f->buffer + cnt;
324 tls_fb_spout(struct fastbuf *f)
326 struct conn *c = SKIP_BACK(struct conn, tx_fb, f);
327 int len = f->bptr - f->buffer;
330 int cnt = gnutls_record_send(c->tls, f->buffer, len);
331 DBG("TLS: Sent %d bytes", cnt);
333 client_error("TLS write error: %s", gnutls_strerror(cnt));
338 init_tls_fastbufs(struct conn *c)
340 struct fastbuf *rf = &c->rx_fb, *tf = &c->tx_fb;
342 ASSERT(rf->buffer && tf->buffer); // Already set up for the plaintext connection
343 rf->refill = tls_fb_refill;
344 tf->spout = tls_fb_spout;
347 /*** CLIENT LOOP (runs in a child process) ***/
350 sigalrm_handler(int sig UNUSED)
352 // We do not try to do any gracious shutdown to avoid races
353 client_error("Timed out");
357 client_loop(struct conn *c)
359 setproctitle("submitd: client %s", c->ip_string);
363 signal(SIGPIPE, SIG_IGN);
364 struct sigaction sa = {
365 .sa_handler = sigalrm_handler
367 if (sigaction(SIGALRM, &sa, NULL) < 0)
368 die("Cannot setup SIGALRM handler: %m");
370 if (c->rule->plain_text)
372 bputsn(&c->tx_fb, "+OK");
377 bputsn(&c->tx_fb, "+TLS");
379 c->tls = tls_new_session(c->sk);
380 int err = gnutls_handshake(c->tls);
382 client_error("TLS handshake failed: %s", gnutls_strerror(err));
384 const char *cert_err = tls_verify_cert(c);
386 client_error("TLS certificate failure: %s", cert_err);
387 init_tls_fastbufs(c);
390 alarm(session_timeout);
391 if (!process_init(c))
392 log(L_ERROR, "Protocol handshake failed");
395 setproctitle("submitd: client %s (%s)", c->ip_string, c->user);
398 alarm(session_timeout);
399 if (!process_command(c))
405 gnutls_bye(c->tls, GNUTLS_SHUT_WR);
408 gnutls_deinit(c->tls);
414 sigchld_handler(int sig UNUSED)
416 /* We do not need to do anything, just interrupt the accept syscall */
420 reap_child(pid_t pid, int status)
422 byte msg[EXIT_STATUS_MSG_SIZE];
423 if (format_exit_status(msg, status))
424 log(L_ERROR, "Child %d %s", (int)pid, msg);
426 CLIST_FOR_EACH(struct conn *, c, connections)
429 log(L_INFO, "Connection %d closed", c->id);
433 log(L_ERROR, "Cannot find connection for child process %d", (int)pid);
436 static int listen_sk;
441 listen_sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
445 if (setsockopt(listen_sk, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
446 die("setsockopt(SO_REUSEADDR): %m");
448 struct sockaddr_in sa;
449 bzero(&sa, sizeof(sa));
450 sa.sin_family = AF_INET;
451 sa.sin_addr.s_addr = INADDR_ANY;
452 sa.sin_port = htons(port);
453 if (bind(listen_sk, (struct sockaddr *) &sa, sizeof(sa)) < 0)
454 die("Cannot bind to port %d: %m", port);
455 if (listen(listen_sk, 1024) < 0)
456 die("Cannot listen on port %d: %m", port);
462 struct sockaddr_in sa;
463 int salen = sizeof(sa);
464 int sk = accept(listen_sk, (struct sockaddr *) &sa, &salen);
472 byte ipbuf[INET_ADDRSTRLEN];
473 inet_ntop(AF_INET, &sa.sin_addr, ipbuf, sizeof(ipbuf));
474 u32 addr = ntohl(sa.sin_addr.s_addr);
475 uns port = ntohs(sa.sin_port);
478 struct access_rule *rule = lookup_rule(addr);
481 err = "Unauthorized";
485 if (num_conn >= max_conn)
487 err = "Too many connections";
491 if (conn_count(addr) >= rule->max_conn)
493 err = "Too many connections from this address";
497 struct conn *c = conn_new();
498 log(L_INFO, "Connection from %s:%d (id %d, %s, %s)",
500 (rule->plain_text ? "plain-text" : "TLS"),
501 (rule->allow_admin ? "admin" : "user"));
503 c->ip_string = xstrdup(ipbuf);
511 err = "Server overloaded";
512 log(L_ERROR, "Fork failed: %m");
525 log(L_ERROR_R, "Connection from %s:%d rejected (%s)", ipbuf, port, err);
527 // Write an error message to the socket, but do not allow it to slow us down
528 struct linger ling = { .l_onoff=0 };
529 if (setsockopt(sk, SOL_SOCKET, SO_LINGER, &ling, sizeof(ling)) < 0)
530 log(L_ERROR, "Cannot set SO_LINGER: %m");
532 write(sk, err, strlen(err));
537 int main(int argc, char **argv)
539 setproctitle_init(argc, argv);
540 cf_def_file = "config";
541 cf_declare_section("SubmitD", &submitd_conf, 0);
542 cf_declare_section("Tasks", &tasks_conf, 0);
545 if ((opt = cf_getopt(argc, argv, CF_SHORT_OPTS, CF_NO_LONG_OPTS, NULL)) >= 0)
546 die("This program has no options");
548 log(L_INFO, "Initializing TLS");
553 log(L_INFO, "Listening on port %d", port);
555 struct sigaction sa = {
556 .sa_handler = sigchld_handler
558 if (sigaction(SIGCHLD, &sa, NULL) < 0)
559 die("Cannot setup SIGCHLD handler: %m");
563 setproctitle("submitd: %d connections", num_conn);
565 pid_t pid = waitpid(-1, &status, WNOHANG);
567 reap_child(pid, status);