4 * Copyright (C) 2011-2013 Simon Ruderich
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #include "connection.h"
30 /* Maximum length of a HTTP request line. Longer request lines are aborted
31 * with an error. The standard doesn't specify a maximum line length but this
32 * should be a good limit to make processing simpler. As HTTPS is used this
33 * doesn't limit long GET requests. */
34 #define MAX_REQUEST_LINE 4096
36 /* Format string used to send HTTP/1.0 error responses to the client.
38 * %s is used 4 times, first three are the error code (no %n$s!), the last is
40 #define HTTP_RESPONSE_FORMAT "HTTP/1.0 %s\r\n\
41 Content-Type: text/html; charset=US-ASCII\r\n\
43 <!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\n\
45 <head><title>%s</title></head>\n\
53 static int initialize_tls_session_client(int peer_socket,
55 gnutls_session_t *session,
56 gnutls_certificate_credentials_t *x509_cred);
57 static int initialize_tls_session_server(int peer_socket,
58 gnutls_session_t *session,
59 gnutls_certificate_credentials_t *x509_cred);
61 static int read_http_request(FILE *client_fd, char *request, size_t length);
62 static void send_bad_request(FILE *client_fd);
63 static void send_forwarding_failure(FILE *client_fd);
64 static void tls_send_invalid_cert_message(gnutls_session_t session);
66 static void transfer_data(int client, int server);
67 static int read_from_write_to(int from, int to);
68 static void transfer_data_tls(int client, int server,
69 gnutls_session_t client_session,
70 gnutls_session_t server_session);
71 static int read_from_write_to_tls(gnutls_session_t from, gnutls_session_t to,
74 static int connect_to_host(const char *hostname, const char *port);
76 static int parse_request(const char *buffer, char *host, char *port,
80 void handle_connection(int client_socket) {
82 FILE *client_fd, *server_fd;
84 char buffer[MAX_REQUEST_LINE];
85 char host[MAX_REQUEST_LINE];
88 int version_minor; /* HTTP/1.x */
91 /* client_x509_cred is used when talking to the client (acting as a TSL
92 * server), server_x509_cred is used when talking to the server (acting as
94 gnutls_certificate_credentials_t client_x509_cred, server_x509_cred;
96 gnutls_session_t client_session, server_session;
97 /* initialize_tls_session_*() called? - used for goto out */
98 int client_session_init, server_session_init;
99 /* gnutls_handshake() called? - used for goto out */
100 int client_session_started, server_session_started;
101 /* Validation failed? If yes we need to send the special "invalid"
103 int validation_failed;
105 LOG(LOG_DEBUG, "new connection");
110 client_session_init = 0;
111 server_session_init = 0;
112 client_session_started = 0;
113 server_session_started = 0;
114 validation_failed = 0;
116 client_fd = fdopen(client_socket, "a+");
117 if (client_fd == NULL) {
118 LOG_PERROR(LOG_WARNING, "fdopen(): client failed");
122 /* Read request line (CONNECT ..) and headers (they are discarded). */
123 result = read_http_request(client_fd, buffer, sizeof(buffer));
126 LOG(LOG_WARNING, "read_http_request(): client read error");
128 } else if (result == -2) {
130 LOG(LOG_WARNING, "read_http_request(): client EOF");
131 send_bad_request(client_fd);
135 if (parse_request(buffer, host, port, &version_minor) != 0) {
136 LOG(LOG_WARNING, "bad request: %s", buffer);
137 send_bad_request(client_fd);
141 LOG(LOG_DEBUG, "target: %s:%s (HTTP 1.%d)", host, port, version_minor);
143 /* Connect to proxy server or directly to server. */
144 if (global_proxy_host != NULL && global_proxy_port != NULL) {
145 LOG(LOG_DEBUG, "connecting to %s:%s", global_proxy_host,
147 server_socket = connect_to_host(global_proxy_host, global_proxy_port);
149 LOG(LOG_DEBUG, "connecting to %s:%s", host, port);
150 server_socket = connect_to_host(host, port);
153 if (server_socket == -1) {
154 LOG(LOG_WARNING, "failed to connect to server");
155 send_forwarding_failure(client_fd);
158 server_fd = fdopen(server_socket, "a+");
159 if (server_fd == NULL) {
160 LOG_PERROR(LOG_WARNING, "fdopen(): server failed");
161 send_forwarding_failure(client_fd);
165 /* Connect to proxy if requested (command line option). */
166 if (global_proxy_host != NULL && global_proxy_port != NULL) {
167 fprintf(server_fd, "CONNECT %s:%s HTTP/1.0\r\n", host, port);
168 fprintf(server_fd, "\r\n");
170 /* Read response line from proxy server. */
171 result = read_http_request(server_fd, buffer, sizeof(buffer));
174 LOG(LOG_WARNING, "read_http_request(): proxy read error");
175 send_forwarding_failure(client_fd);
177 } else if (result == -2) {
179 LOG(LOG_WARNING, "read_http_request(): proxy EOF");
180 send_forwarding_failure(client_fd);
184 /* Check response of proxy server. */
185 if (strncmp(buffer, "HTTP/1.0 200", 12)) {
186 LOG(LOG_WARNING, "bad proxy response: %s", buffer);
187 send_forwarding_failure(client_fd);
192 LOG(LOG_DEBUG, "connection to server established");
194 /* If the -u option is used and we don't know this hostname's server
195 * certificate then just pass through the connection and let the client
196 * verify the server certificate. */
197 if (global_passthrough_unknown) {
198 char path[TLSPROXY_MAX_PATH_LENGTH];
201 if (server_certificate_file(&file, host, path, sizeof(path)) == -2) {
202 /* We've established a connection, tell the client. */
203 fprintf(client_fd, "HTTP/1.0 200 Connection established\r\n");
204 fprintf(client_fd, "\r\n");
207 LOG(LOG_DEBUG, "transferring data");
209 /* Proxy data between client and server until one side is done
211 transfer_data(client_socket, server_socket);
213 LOG(LOG_DEBUG, "finished transferring data");
217 /* server_certificate_file() may have opened the file, close it. */
223 /* Initialize TLS client credentials to talk to the server. */
224 result = initialize_tls_session_server(server_socket, &server_session,
227 LOG(LOG_WARNING, "initialize_tls_session_server() failed");
228 send_forwarding_failure(client_fd);
231 server_session_init = 1;
233 LOG(LOG_DEBUG, "starting server TLS handshake");
235 /* Try to establish TLS handshake between us and server. */
236 result = gnutls_handshake(server_session);
237 if (result != GNUTLS_E_SUCCESS) {
238 LOG(LOG_WARNING, "server TLS handshake failed: %s",
239 gnutls_strerror(result));
240 send_forwarding_failure(client_fd);
243 server_session_started = 1;
245 LOG(LOG_DEBUG, "server TLS handshake finished");
247 /* Make sure the server certificate is valid and known. */
248 if (verify_tls_connection(server_session, host) != 0) {
249 LOG(LOG_ERROR, "server certificate validation failed!");
250 /* We send the error message over our TLS connection to the client,
251 * but with an invalid certificate. No data is transfered from/to the
253 validation_failed = 1;
256 /* Initialize TLS server credentials to talk to the client. */
257 result = initialize_tls_session_client(client_socket,
258 /* use a special host if the server
259 * certificate was invalid */
260 (validation_failed) ? "invalid"
265 LOG(LOG_WARNING, "initialize_tls_session_client() failed");
266 send_forwarding_failure(client_fd);
269 client_session_init = 1;
271 /* We've established a connection, tell the client. */
272 fprintf(client_fd, "HTTP/1.0 200 Connection established\r\n");
273 fprintf(client_fd, "\r\n");
276 LOG(LOG_DEBUG, "starting client TLS handshake");
278 /* Try to establish TLS handshake between client and us. */
279 result = gnutls_handshake(client_session);
280 if (result != GNUTLS_E_SUCCESS) {
281 LOG(LOG_WARNING, "client TLS handshake failed: %s",
282 gnutls_strerror(result));
283 send_forwarding_failure(client_fd);
286 client_session_started = 1;
288 LOG(LOG_DEBUG, "client TLS handshake finished");
290 /* Tell the client that the verification failed. Shouldn't be necessary as
291 * the client should terminate the connection because he received the
292 * invalid certificate but better be sure. */
293 if (validation_failed) {
294 tls_send_invalid_cert_message(client_session);
298 LOG(LOG_DEBUG, "transferring TLS data");
300 /* Proxy data between client and server until one side is done (EOF or
302 transfer_data_tls(client_socket, server_socket,
303 client_session, server_session);
305 LOG(LOG_DEBUG, "finished transferring TLS data");
308 /* Close TLS sessions if necessary. Use GNUTLS_SHUT_RDWR so the data is
309 * reliable transmitted. */
310 if (server_session_started) {
311 gnutls_bye(server_session, GNUTLS_SHUT_RDWR);
313 if (client_session_started) {
314 gnutls_bye(client_session, GNUTLS_SHUT_RDWR);
316 if (server_session_init) {
317 gnutls_deinit(server_session);
318 gnutls_certificate_free_credentials(server_x509_cred);
320 if (client_session_init) {
321 gnutls_deinit(client_session);
322 gnutls_certificate_free_cas(client_x509_cred);
323 gnutls_certificate_free_keys(client_x509_cred);
324 gnutls_certificate_free_credentials(client_x509_cred);
327 /* Close connection to server/proxy. */
328 if (server_fd != NULL) {
330 } else if (server_socket != -1) {
331 close(server_socket);
333 LOG(LOG_DEBUG, "connection to server closed");
334 /* Close connection to client. */
335 if (client_fd != NULL) {
338 close(client_socket);
340 LOG(LOG_DEBUG, "connection to client closed");
342 LOG(LOG_DEBUG, "connection finished");
346 static int initialize_tls_session_client(int peer_socket,
347 const char *hostname,
348 gnutls_session_t *session,
349 gnutls_certificate_credentials_t *x509_cred) {
351 int use_invalid_cert;
352 char path[TLSPROXY_MAX_PATH_LENGTH];
354 /* The "invalid" hostname is special. If it's used we send an invalid
355 * certificate to let the client know something is wrong. */
356 use_invalid_cert = (!strcmp(hostname, "invalid"));
358 if (proxy_certificate_path(hostname, path, sizeof(path)) != 0) {
360 "initialize_tls_session_client(): \
361 failed to get proxy certificate path");
365 result = gnutls_certificate_allocate_credentials(x509_cred);
366 if (result != GNUTLS_E_SUCCESS) {
368 "initialize_tls_session_client(): \
369 gnutls_certificate_allocate_credentials(): %s",
370 gnutls_strerror(result));
374 /* Load proxy CA file, this CA "list" is send to the client. */
375 if (!use_invalid_cert) {
376 result = gnutls_certificate_set_x509_trust_file(*x509_cred,
378 GNUTLS_X509_FMT_PEM);
381 "initialize_tls_session_client(): can't read CA file: '%s'",
383 gnutls_certificate_free_credentials(*x509_cred);
387 /* If the invalid hostname was specified do nothing, we use a self-signed
388 * certificate in this case. */
390 /* And certificate for this website and proxy's private key. */
391 if (!use_invalid_cert) {
392 result = gnutls_certificate_set_x509_key_file(*x509_cred,
393 path, PROXY_KEY_FILE,
394 GNUTLS_X509_FMT_PEM);
395 /* If the invalid hostname was specified load our special "invalid"
398 result = gnutls_certificate_set_x509_key_file(*x509_cred,
399 PROXY_INVALID_CERT_FILE,
401 GNUTLS_X509_FMT_PEM);
403 if (result != GNUTLS_E_SUCCESS) {
405 "initialize_tls_session_client(): \
406 can't read server certificate ('%s') or key file ('%s'): %s",
407 path, PROXY_KEY_FILE, gnutls_strerror(result));
408 gnutls_certificate_free_credentials(*x509_cred);
409 /* Could be a missing certificate. */
413 gnutls_certificate_set_dh_params(*x509_cred, global_tls_dh_params);
415 result = gnutls_init(session, GNUTLS_SERVER);
416 if (result != GNUTLS_E_SUCCESS) {
418 "initialize_tls_session_client(): gnutls_init(): %s",
419 gnutls_strerror(result));
420 gnutls_certificate_free_credentials(*x509_cred);
423 result = gnutls_priority_set(*session, global_tls_priority_cache);
424 if (result != GNUTLS_E_SUCCESS) {
426 "initialize_tls_session_client(): gnutls_priority_set(): %s",
427 gnutls_strerror(result));
428 gnutls_deinit(*session);
429 gnutls_certificate_free_credentials(*x509_cred);
432 result = gnutls_credentials_set(*session,
433 GNUTLS_CRD_CERTIFICATE, *x509_cred);
434 if (result != GNUTLS_E_SUCCESS) {
436 "initialize_tls_session_client(): gnutls_credentials_set(): %s",
437 gnutls_strerror(result));
438 gnutls_deinit(*session);
439 gnutls_certificate_free_credentials(*x509_cred);
443 gnutls_transport_set_ptr(*session, (gnutls_transport_ptr_t)peer_socket);
447 static int initialize_tls_session_server(int peer_socket,
448 gnutls_session_t *session,
449 gnutls_certificate_credentials_t *x509_cred) {
452 result = gnutls_certificate_allocate_credentials(x509_cred);
453 if (result != GNUTLS_E_SUCCESS) {
455 "initialize_tls_session_server(): \
456 gnutls_certificate_allocate_credentials(): %s",
457 gnutls_strerror(result));
461 result = gnutls_init(session, GNUTLS_CLIENT);
462 if (result != GNUTLS_E_SUCCESS) {
464 "initialize_tls_session_server(): gnutls_init(): %s",
465 gnutls_strerror(result));
466 gnutls_certificate_free_credentials(*x509_cred);
469 result = gnutls_priority_set(*session, global_tls_priority_cache);
470 if (result != GNUTLS_E_SUCCESS) {
472 "initialize_tls_session_server(): gnutls_priority_set(): %s",
473 gnutls_strerror(result));
474 gnutls_deinit(*session);
475 gnutls_certificate_free_credentials(*x509_cred);
478 result = gnutls_credentials_set(*session,
479 GNUTLS_CRD_CERTIFICATE, *x509_cred);
480 if (result != GNUTLS_E_SUCCESS) {
482 "initialize_tls_session_server(): gnutls_credentials_set(): %s",
483 gnutls_strerror(result));
484 gnutls_deinit(*session);
485 gnutls_certificate_free_credentials(*x509_cred);
489 gnutls_transport_set_ptr(*session, (gnutls_transport_ptr_t)peer_socket);
495 /* Read HTTP request line and headers (ignored).
497 * On success 0 is returned, -1 on client error, -2 on unexpected EOF.
499 static int read_http_request(FILE *client_fd, char *request, size_t length) {
500 char buffer[MAX_REQUEST_LINE];
502 if (fgets(request, (int)length, client_fd) == NULL) {
503 if (ferror(client_fd)) {
504 LOG_PERROR(LOG_WARNING, "read_http_request(): fgets()");
511 while (fgets(buffer, sizeof(buffer), client_fd) != NULL) {
513 if (!strcmp(buffer, "\n") || !strcmp(buffer, "\r\n")) {
517 if (ferror(client_fd)) {
518 LOG_PERROR(LOG_WARNING, "read_http_request(): fgets()");
525 static void send_bad_request(FILE *client_fd) {
526 #define RESPONSE_ERROR "400 Bad Request"
527 #define RESPONSE_MSG "Your browser sent an invalid request."
528 fprintf(client_fd, HTTP_RESPONSE_FORMAT,
529 RESPONSE_ERROR, RESPONSE_ERROR, RESPONSE_ERROR,
531 #undef RESPONSE_ERROR
534 static void send_forwarding_failure(FILE *client_fd) {
535 #define RESPONSE_ERROR "503 Forwarding failure"
536 #define RESPONSE_MSG "Failed to connect to server, check logs."
537 fprintf(client_fd, HTTP_RESPONSE_FORMAT,
538 RESPONSE_ERROR, RESPONSE_ERROR, RESPONSE_ERROR,
540 #undef RESPONSE_ERROR
543 static void tls_send_invalid_cert_message(gnutls_session_t session) {
544 #define RESPONSE_ERROR "500 Internal Server Error"
545 #define RESPONSE_MSG "Server certificate validation failed, check logs."
548 char buffer[sizeof(HTTP_RESPONSE_FORMAT) - 1 /* '\0' */
549 - 4 * 2 /* four %s */
550 + (sizeof(RESPONSE_ERROR) - 1 /* '\0' */) * 3
551 + sizeof(RESPONSE_MSG) - 1 /* '\0' */
554 result = snprintf(buffer, sizeof(buffer),
555 HTTP_RESPONSE_FORMAT,
556 RESPONSE_ERROR, RESPONSE_ERROR, RESPONSE_ERROR,
559 LOG_PERROR(LOG_ERROR,
560 "tls_send_invalid_cert_message(): snprintf failed");
562 } else if ((size_t)result >= sizeof(buffer)) {
564 "tls_send_invalid_cert_message(): snprintf buffer too short");
568 gnutls_record_send(session, buffer, sizeof(buffer) - 1);
569 /* don't send trailing '\0' */
570 #undef RESPONSE_ERROR
575 /* Transfer data between client and server sockets until one closes the
577 static void transfer_data(int client, int server) {
578 struct pollfd fds[2];
580 fds[0].events = POLLIN | POLLPRI | POLLHUP | POLLERR;
583 fds[1].events = POLLIN | POLLPRI | POLLHUP | POLLERR;
587 int result = poll(fds, 2, -1 /* no timeout */);
589 LOG_PERROR(LOG_ERROR, "transfer_data(): poll()");
593 /* Data available from client. */
594 if (fds[0].revents & POLLIN || fds[0].revents & POLLPRI) {
595 if (read_from_write_to(client, server) != 0) {
596 /* EOF (or other error) */
600 /* Data available from server. */
601 if (fds[1].revents & POLLIN || fds[1].revents & POLLPRI) {
602 if (read_from_write_to(server, client) != 0) {
603 /* EOF (or other error) */
608 /* Client closed connection. */
609 if (fds[0].revents & POLLERR || fds[0].revents & POLLHUP) {
612 /* Server closed connection. */
613 if (fds[1].revents & POLLERR || fds[1].revents & POLLHUP) {
619 /* Read available data from socket from and write it to socket to. At maximum
620 * 4096 bytes are read/written. */
621 static int read_from_write_to(int from, int to) {
623 ssize_t size_written;
626 LOG(LOG_DEBUG, "read_from_write_to(): %d -> %d", from, to);
628 size_read = read(from, buffer, sizeof(buffer));
630 LOG_PERROR(LOG_WARNING, "read_from_write_to(): read()");
634 if (size_read == 0) {
638 size_written = write(to, buffer, (size_t)size_read);
639 if (size_written < 0) {
640 LOG_PERROR(LOG_WARNING, "read_from_write_to(): write()");
643 if (size_read != size_written) {
644 LOG(LOG_ERROR, "read_from_write_to(): only written %ld of %ld bytes!",
645 (long int)size_written, (long int)size_read);
652 /* Transfer data between client and server TLS connection until one closes the
654 static void transfer_data_tls(int client, int server,
655 gnutls_session_t client_session,
656 gnutls_session_t server_session) {
659 struct pollfd fds[2];
661 fds[0].events = POLLIN | POLLPRI | POLLHUP | POLLERR;
664 fds[1].events = POLLIN | POLLPRI | POLLHUP | POLLERR;
667 /* Get maximum possible buffer size. */
668 buffer_size = gnutls_record_get_max_size(client_session);
669 if (gnutls_record_get_max_size(server_session) < buffer_size) {
670 buffer_size = gnutls_record_get_max_size(server_session);
672 LOG(LOG_DEBUG, "transfer_data_tls(): suggested buffer size: %ld",
673 (long int)buffer_size);
676 int result = poll(fds, 2, -1 /* no timeout */);
678 LOG_PERROR(LOG_ERROR, "transfer_data(): poll()");
682 /* Data available from client. */
683 if (fds[0].revents & POLLIN || fds[0].revents & POLLPRI) {
684 if (read_from_write_to_tls(client_session, server_session,
686 /* EOF (or other error) */
690 /* Data available from server. */
691 if (fds[1].revents & POLLIN || fds[1].revents & POLLPRI) {
692 if (read_from_write_to_tls(server_session, client_session,
694 /* EOF (or other error) */
699 /* Client closed connection. */
700 if (fds[0].revents & POLLERR || fds[0].revents & POLLHUP) {
703 /* Server closed connection. */
704 if (fds[1].revents & POLLERR || fds[1].revents & POLLHUP) {
710 /* Read available data from session from and write to session to. */
711 static int read_from_write_to_tls(gnutls_session_t from,
713 size_t buffer_size) {
715 ssize_t size_written;
718 if (buffer_size > sizeof(buffer)) {
719 buffer_size = sizeof(buffer);
721 LOG(LOG_DEBUG, "read_from_write_to_tls(): used buffer size: %ld",
722 (long int)buffer_size);
724 size_read = gnutls_record_recv(from, buffer, buffer_size);
726 LOG(LOG_WARNING, "read_from_write_to_tls(): gnutls_record_recv(): %s",
727 gnutls_strerror((int)size_read));
731 if (size_read == 0) {
735 size_written = gnutls_record_send(to, buffer, (size_t)size_read);
736 if (size_written < 0) {
737 LOG(LOG_WARNING, "read_from_write_to_tls(): gnutls_record_send(): %s",
738 gnutls_strerror((int)size_written));
741 if (size_read != size_written) {
742 LOG(LOG_ERROR, "read_from_write_to_tls(): only written %ld of %ld bytes!",
743 (long int)size_written, (long int)size_read);
751 static int connect_to_host(const char *hostname, const char *port) {
752 struct addrinfo gai_hints;
753 struct addrinfo *gai_result;
757 struct addrinfo *server;
759 if (hostname == NULL || port == NULL) {
763 /* Get IP of hostname server. */
764 memset(&gai_hints, 0, sizeof(gai_hints));
765 gai_hints.ai_family = AF_UNSPEC;
766 gai_hints.ai_socktype = SOCK_STREAM;
767 gai_hints.ai_protocol = 0;
768 gai_hints.ai_flags = AI_NUMERICSERV /* given port is numeric */
769 | AI_ADDRCONFIG /* supported by this computer */
770 | AI_V4MAPPED; /* support IPv4 through IPv6 */
771 gai_return = getaddrinfo(hostname, port, &gai_hints, &gai_result);
772 if (gai_return != 0) {
773 if (gai_return == EAI_SYSTEM) {
774 LOG_PERROR(LOG_WARNING, "connect_to_host(): getaddrinfo()");
776 LOG(LOG_WARNING, "connect_to_host(): getaddrinfo(): %s",
777 gai_strerror(gai_return));
782 /* Now try to connect to each server returned by getaddrinfo(), use the
783 * first successful connect. */
784 for (server = gai_result; server != NULL; server = server->ai_next) {
785 server_socket = socket(server->ai_family,
787 server->ai_protocol);
788 if (server_socket == -1) {
789 LOG_PERROR(LOG_DEBUG, "connect_to_host(): socket(), trying next");
793 if (connect(server_socket, server->ai_addr, server->ai_addrlen) != -1) {
796 LOG_PERROR(LOG_DEBUG, "connect_to_host(): connect(), trying next");
798 close(server_socket);
800 /* Make sure we free the result from getaddrinfo(). */
801 freeaddrinfo(gai_result);
803 if (server == NULL) {
804 LOG_PERROR(LOG_WARNING, "connect_to_host(): no server found, abort");
808 return server_socket;
812 /* Parse HTTP CONNECT request string and save its parameters.
814 * The following format is expected: "CONNECT host:port HTTP/1.x".
816 * request and host must have the same size! port must be at least 6 bytes
819 static int parse_request(const char *request, char *host, char *port,
820 int *version_minor) {
821 int port_unused; /* just used to verify the port is numeric */
824 /* scanf() doesn't check spaces. */
825 if (strncmp(request, "CONNECT ", 8)) {
828 /* Check request and extract data, "host:port" is not yet separated. */
829 if (sscanf(request, "CONNECT %s HTTP/1.%d", host, version_minor) != 2) {
832 /* Make sure ":port" is there. */
833 if ((position = strchr(host, ':')) == NULL) {
836 /* Make sure port is numeric. */
837 if (sscanf(position + 1, "%d", &port_unused) != 1) {
840 /* Store it in *port. */
841 strncpy(port, position + 1, 5);
843 /* And remove port from host. */