4 * (c) 2007 Martin Mares <mj@ucw.cz>
9 * - competition timeout & per-contestant exceptions
16 #include "lib/getopt.h"
17 #include "lib/ipaccess.h"
18 #include "lib/fastbuf.h"
25 #include <sys/types.h>
26 #include <sys/socket.h>
28 #include <arpa/inet.h>
29 #include <netinet/in.h>
30 #include <gnutls/gnutls.h>
31 #include <gnutls/x509.h>
33 /*** CONFIGURATION ***/
35 static uns port = 8888;
36 static uns dh_bits = 1024;
37 static uns max_conn = 10;
38 static uns session_timeout;
39 static byte *ca_cert_name = "?";
40 static byte *server_cert_name = "?";
41 static byte *server_key_name = "?";
42 static clist access_rules;
46 struct ip_addrmask addrmask;
52 static struct cf_section access_conf = {
53 CF_TYPE(struct access_rule),
55 CF_USER("IP", PTR_TO(struct access_rule, addrmask), &ip_addrmask_type),
56 CF_UNS("Admin", PTR_TO(struct access_rule, allow_admin)),
57 CF_UNS("PlainText", PTR_TO(struct access_rule, plain_text)),
58 CF_UNS("MaxConn", PTR_TO(struct access_rule, max_conn)),
66 clist_init(&access_rules);
70 static struct cf_section submitd_conf = {
73 CF_UNS("Port", &port),
74 CF_UNS("DHBits", &dh_bits),
75 CF_UNS("MaxConn", &max_conn),
76 CF_UNS("SessionTimeout", &session_timeout),
77 CF_STRING("CACert", &ca_cert_name),
78 CF_STRING("ServerCert", &server_cert_name),
79 CF_STRING("ServerKey", &server_key_name),
80 CF_LIST("Access", &access_rules, &access_conf),
89 u32 ip; // Used by the main loop connection logic
92 struct access_rule *rule; // Rule matched by this connection
93 int sk; // Client socket
94 gnutls_session_t tls; // TLS session
95 struct fastbuf rx_fb, tx_fb; // Fastbufs for communication with the client
98 static clist connections;
99 static uns last_conn_id;
105 clist_init(&connections);
111 struct conn *c = xmalloc(sizeof(*c));
112 c->id = ++last_conn_id;
113 clist_add_tail(&connections, &c->n);
119 conn_free(struct conn *c)
126 static struct access_rule *
129 CLIST_FOR_EACH(struct access_rule *, r, access_rules)
130 if (ip_addrmask_match(&r->addrmask, ip))
139 CLIST_FOR_EACH(struct conn *, c, connections)
147 static gnutls_certificate_credentials_t cert_cred;
148 static gnutls_dh_params_t dh_params;
150 #define TLS_CHECK(name) if (err < 0) die(#name " failed: %s", gnutls_strerror(err))
157 gnutls_global_init();
158 err = gnutls_certificate_allocate_credentials(&cert_cred);
159 TLS_CHECK(gnutls_certificate_allocate_credentials);
160 err = gnutls_certificate_set_x509_trust_file(cert_cred, ca_cert_name, GNUTLS_X509_FMT_PEM);
162 die("No CA certificate found");
164 die("Unable to load X509 trust file: %s", gnutls_strerror(err));
165 err = gnutls_certificate_set_x509_key_file(cert_cred, server_cert_name, server_key_name, GNUTLS_X509_FMT_PEM);
167 die("Unable to load X509 key file: %s", gnutls_strerror(err));
169 err = gnutls_dh_params_init(&dh_params); TLS_CHECK(gnutls_dh_params_init);
170 err = gnutls_dh_params_generate2(dh_params, dh_bits); TLS_CHECK(gnutls_dh_params_generate2);
171 gnutls_certificate_set_dh_params(cert_cred, dh_params);
174 static gnutls_session_t
175 tls_new_session(int sk)
180 err = gnutls_init(&s, GNUTLS_SERVER); TLS_CHECK(gnutls_init);
181 err = gnutls_set_default_priority(s); TLS_CHECK(gnutls_set_default_priority); // FIXME
182 gnutls_credentials_set(s, GNUTLS_CRD_CERTIFICATE, cert_cred);
183 gnutls_certificate_server_set_request(s, GNUTLS_CERT_REQUEST);
184 gnutls_dh_set_prime_bits(s, dh_bits);
185 gnutls_transport_set_ptr(s, (gnutls_transport_ptr_t) sk);
190 tls_verify_cert(gnutls_session_t s)
192 uns status, num_certs;
194 gnutls_x509_crt_t cert;
195 const gnutls_datum_t *certs;
197 DBG("Verifying peer certificates");
198 err = gnutls_certificate_verify_peers2(s, &status);
200 return gnutls_strerror(err);
201 DBG("Verify status: %04x", status);
202 if (status & GNUTLS_CERT_INVALID)
203 return "Certificate is invalid";
204 /* XXX: We do not handle revokation. */
205 if (gnutls_certificate_type_get(s) != GNUTLS_CRT_X509)
206 return "Certificate is not X509";
208 err = gnutls_x509_crt_init(&cert);
210 return "gnutls_x509_crt_init() failed";
211 certs = gnutls_certificate_get_peers(s, &num_certs);
213 return "No peer certificate found";
214 DBG("Got certificate list with %d peers", num_certs);
216 err = gnutls_x509_crt_import(cert, &certs[0], GNUTLS_X509_FMT_DER);
218 return "Cannot import certificate";
219 /* XXX: We do not check expiration and activation since the keys are generated for a single contest only anyway. */
222 size_t dn_len = sizeof(dn);
223 err = gnutls_x509_crt_get_dn_by_oid(cert, GNUTLS_OID_X520_COMMON_NAME, 0, 0, dn, &dn_len);
225 return "Cannot retrieve common name";
226 log(L_INFO, "Cert CN: %s", dn);
228 /* Check certificate purpose */
233 size_t purp_len = sizeof(purp);
235 err = gnutls_x509_crt_get_key_purpose_oid(cert, purpi++, purp, &purp_len, &crit);
236 if (err == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
237 return "Not a client certificate";
238 TLS_CHECK(gnutls_x509_crt_get_key_purpose_oid);
240 while (strcmp(purp, GNUTLS_KP_TLS_WWW_CLIENT));
247 tls_log_params(gnutls_session_t s)
249 const char *proto = gnutls_protocol_get_name(gnutls_protocol_get_version(s));
250 const char *kx = gnutls_kx_get_name(gnutls_kx_get(s));
251 const char *cert = gnutls_certificate_type_get_name(gnutls_certificate_type_get(s));
252 const char *comp = gnutls_compression_get_name(gnutls_compression_get(s));
253 const char *cipher = gnutls_cipher_get_name(gnutls_cipher_get(s));
254 const char *mac = gnutls_mac_get_name(gnutls_mac_get(s));
255 log(L_DEBUG, "TLS params: proto=%s kx=%s cert=%s comp=%s cipher=%s mac=%s",
256 proto, kx, cert, comp, cipher, mac);
259 /*** SOCKET FASTBUFS ***/
262 client_error(char *msg, ...)
266 vlog_msg(L_ERROR_R, msg, args);
271 sk_fb_refill(struct fastbuf *f)
273 struct conn *c = SKIP_BACK(struct conn, rx_fb, f);
274 int cnt = read(c->sk, f->buffer, f->bufend - f->buffer);
276 client_error("Read error: %m");
278 f->bstop = f->buffer + cnt;
283 sk_fb_spout(struct fastbuf *f)
285 struct conn *c = SKIP_BACK(struct conn, tx_fb, f);
286 int len = f->bptr - f->buffer;
289 int cnt = careful_write(c->sk, f->buffer, len);
291 client_error("Write error");
296 init_sk_fastbufs(struct conn *c)
298 struct fastbuf *rf = &c->rx_fb, *tf = &c->tx_fb;
300 rf->buffer = xmalloc(1024);
301 rf->bufend = rf->buffer + 1024;
302 rf->bptr = rf->bstop = rf->buffer;
304 rf->refill = sk_fb_refill;
306 tf->buffer = xmalloc(1024);
307 tf->bufend = tf->buffer + 1024;
308 tf->bptr = tf->bstop = tf->buffer;
310 tf->spout = sk_fb_spout;
314 tls_fb_refill(struct fastbuf *f)
316 struct conn *c = SKIP_BACK(struct conn, rx_fb, f);
318 int cnt = gnutls_record_recv(c->tls, f->buffer, f->bufend - f->buffer);
319 DBG("TLS: Received %d bytes", cnt);
321 client_error("TLS read error: %s", gnutls_strerror(cnt));
323 f->bstop = f->buffer + cnt;
328 tls_fb_spout(struct fastbuf *f)
330 struct conn *c = SKIP_BACK(struct conn, tx_fb, f);
331 int len = f->bptr - f->buffer;
334 int cnt = gnutls_record_send(c->tls, f->buffer, len);
335 DBG("TLS: Sent %d bytes", cnt);
337 client_error("TLS write error: %s", gnutls_strerror(cnt));
342 init_tls_fastbufs(struct conn *c)
344 struct fastbuf *rf = &c->rx_fb, *tf = &c->tx_fb;
346 ASSERT(rf->buffer && tf->buffer); // Already set up for the plaintext connection
347 rf->refill = tls_fb_refill;
348 tf->spout = tls_fb_spout;
351 /*** CLIENT LOOP (runs in a child process) ***/
354 sigalrm_handler(int sig UNUSED)
356 // We do not try to do any gracious shutdown to avoid races
357 client_error("Timed out");
361 client_loop(struct conn *c)
366 signal(SIGPIPE, SIG_IGN);
367 struct sigaction sa = {
368 .sa_handler = sigalrm_handler
370 if (sigaction(SIGALRM, &sa, NULL) < 0)
371 die("Cannot setup SIGALRM handler: %m");
373 if (c->rule->plain_text)
375 bputsn(&c->tx_fb, "+OK");
380 bputsn(&c->tx_fb, "+TLS");
382 c->tls = tls_new_session(c->sk);
383 int err = gnutls_handshake(c->tls);
385 client_error("TLS handshake failed: %s", gnutls_strerror(err));
386 tls_log_params(c->tls);
387 const char *cert_err = tls_verify_cert(c->tls);
389 client_error("TLS certificate failure: %s", cert_err);
390 init_tls_fastbufs(c);
395 alarm(session_timeout);
397 if (!bgets(&c->rx_fb, buf, sizeof(buf)))
399 bputsn(&c->tx_fb, buf);
404 gnutls_bye(c->tls, GNUTLS_SHUT_WR);
407 gnutls_deinit(c->tls);
413 sigchld_handler(int sig UNUSED)
415 /* We do not need to do anything, just interrupt the accept syscall */
419 reap_child(pid_t pid, int status)
421 byte msg[EXIT_STATUS_MSG_SIZE];
422 if (format_exit_status(msg, status))
423 log(L_ERROR, "Child %d %s", (int)pid, msg);
425 CLIST_FOR_EACH(struct conn *, c, connections)
428 log(L_INFO, "Connection %d closed", c->id);
432 log(L_ERROR, "Cannot find connection for child process %d", (int)pid);
435 static int listen_sk;
440 listen_sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
444 if (setsockopt(listen_sk, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
445 die("setsockopt(SO_REUSEADDR): %m");
447 struct sockaddr_in sa;
448 bzero(&sa, sizeof(sa));
449 sa.sin_family = AF_INET;
450 sa.sin_addr.s_addr = INADDR_ANY;
451 sa.sin_port = htons(port);
452 if (bind(listen_sk, (struct sockaddr *) &sa, sizeof(sa)) < 0)
453 die("Cannot bind to port %d: %m", port);
454 if (listen(listen_sk, 1024) < 0)
455 die("Cannot listen on port %d: %m", port);
461 struct sockaddr_in sa;
462 int salen = sizeof(sa);
463 int sk = accept(listen_sk, (struct sockaddr *) &sa, &salen);
471 byte ipbuf[INET_ADDRSTRLEN];
472 inet_ntop(AF_INET, &sa.sin_addr, ipbuf, sizeof(ipbuf));
473 u32 addr = ntohl(sa.sin_addr.s_addr);
474 uns port = ntohs(sa.sin_port);
477 struct access_rule *rule = lookup_rule(addr);
480 err = "Unauthorized";
484 if (num_conn >= max_conn)
486 err = "Too many connections";
490 if (conn_count(addr) >= rule->max_conn)
492 err = "Too many connections from this address";
496 struct conn *c = conn_new();
497 log(L_INFO, "Connection from %s:%d (id %d, %s, %s)",
499 (rule->plain_text ? "plain-text" : "TLS"),
500 (rule->allow_admin ? "admin" : "user"));
509 err = "Server overloaded";
510 log(L_ERROR, "Fork failed: %m");
523 log(L_ERROR_R, "Connection from %s:%d rejected (%s)", ipbuf, port, err);
525 // Write an error message to the socket, but do not allow it to slow us down
526 struct linger ling = { .l_onoff=0 };
527 if (setsockopt(sk, SOL_SOCKET, SO_LINGER, &ling, sizeof(ling)) < 0)
528 log(L_ERROR, "Cannot set SO_LINGER: %m");
530 write(sk, err, strlen(err));
535 int main(int argc, char **argv)
537 setproctitle_init(argc, argv);
538 cf_def_file = "config";
539 cf_declare_section("SubmitD", &submitd_conf, 0);
542 if ((opt = cf_getopt(argc, argv, CF_SHORT_OPTS, CF_NO_LONG_OPTS, NULL)) >= 0)
543 die("This program has no options");
545 log(L_INFO, "Initializing TLS");
550 log(L_INFO, "Listening on port %d", port);
552 struct sigaction sa = {
553 .sa_handler = sigchld_handler
555 if (sigaction(SIGCHLD, &sa, NULL) < 0)
556 die("Cannot setup SIGCHLD handler: %m");
561 pid_t pid = waitpid(-1, &status, WNOHANG);
563 reap_child(pid, status);