1/*
2 * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (the "License").  You may not use
5 * this file except in compliance with the License.  You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10/* socket-related functions used by s_client and s_server */
11#include <stdio.h>
12#include <stdlib.h>
13#include <string.h>
14#include <errno.h>
15#include <signal.h>
16#include <openssl/opensslconf.h>
17
18/*
19 * With IPv6, it looks like Digital has mixed up the proper order of
20 * recursive header file inclusion, resulting in the compiler complaining
21 * that u_int isn't defined, but only if _POSIX_C_SOURCE is defined, which is
22 * needed to have fileno() declared correctly...  So let's define u_int
23 */
24#if defined(OPENSSL_SYS_VMS_DECC) && !defined(__U_INT)
25# define __U_INT
26typedef unsigned int u_int;
27#endif
28
29#ifndef OPENSSL_NO_SOCK
30
31# include "apps.h"
32# include "s_apps.h"
33# include "internal/sockets.h"
34
35# include <openssl/bio.h>
36# include <openssl/err.h>
37
38/* Keep track of our peer's address for the cookie callback */
39BIO_ADDR *ourpeer = NULL;
40
41/*
42 * init_client - helper routine to set up socket communication
43 * @sock: pointer to storage of resulting socket.
44 * @host: the host name or path (for AF_UNIX) to connect to.
45 * @port: the port to connect to (ignored for AF_UNIX).
46 * @bindhost: source host or path (for AF_UNIX).
47 * @bindport: source port (ignored for AF_UNIX).
48 * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
49 *  AF_UNSPEC
50 * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
51 * @protocol: socket protocol, e.g. IPPROTO_TCP or IPPROTO_UDP (or 0 for any)
52 *
53 * This will create a socket and use it to connect to a host:port, or if
54 * family == AF_UNIX, to the path found in host.
55 *
56 * If the host has more than one address, it will try them one by one until
57 * a successful connection is established.  The resulting socket will be
58 * found in *sock on success, it will be given INVALID_SOCKET otherwise.
59 *
60 * Returns 1 on success, 0 on failure.
61 */
62int init_client(int *sock, const char *host, const char *port,
63                const char *bindhost, const char *bindport,
64                int family, int type, int protocol)
65{
66    BIO_ADDRINFO *res = NULL;
67    BIO_ADDRINFO *bindaddr = NULL;
68    const BIO_ADDRINFO *ai = NULL;
69    const BIO_ADDRINFO *bi = NULL;
70    int found = 0;
71    int ret;
72
73    if (BIO_sock_init() != 1)
74        return 0;
75
76    ret = BIO_lookup_ex(host, port, BIO_LOOKUP_CLIENT, family, type, protocol,
77                        &res);
78    if (ret == 0) {
79        ERR_print_errors(bio_err);
80        return 0;
81    }
82
83    if (bindhost != NULL || bindport != NULL) {
84        ret = BIO_lookup_ex(bindhost, bindport, BIO_LOOKUP_CLIENT,
85                            family, type, protocol, &bindaddr);
86        if (ret == 0) {
87            ERR_print_errors (bio_err);
88            goto out;
89        }
90    }
91
92    ret = 0;
93    for (ai = res; ai != NULL; ai = BIO_ADDRINFO_next(ai)) {
94        /* Admittedly, these checks are quite paranoid, we should not get
95         * anything in the BIO_ADDRINFO chain that we haven't
96         * asked for. */
97        OPENSSL_assert((family == AF_UNSPEC
98                        || family == BIO_ADDRINFO_family(ai))
99                       && (type == 0 || type == BIO_ADDRINFO_socktype(ai))
100                       && (protocol == 0
101                           || protocol == BIO_ADDRINFO_protocol(ai)));
102
103        if (bindaddr != NULL) {
104            for (bi = bindaddr; bi != NULL; bi = BIO_ADDRINFO_next(bi)) {
105                if (BIO_ADDRINFO_family(bi) == BIO_ADDRINFO_family(ai))
106                    break;
107            }
108            if (bi == NULL)
109                continue;
110            ++found;
111        }
112
113        *sock = BIO_socket(BIO_ADDRINFO_family(ai), BIO_ADDRINFO_socktype(ai),
114                           BIO_ADDRINFO_protocol(ai), 0);
115        if (*sock == INVALID_SOCKET) {
116            /* Maybe the kernel doesn't support the socket family, even if
117             * BIO_lookup() added it in the returned result...
118             */
119            continue;
120        }
121
122        if (bi != NULL) {
123            if (!BIO_bind(*sock, BIO_ADDRINFO_address(bi),
124                          BIO_SOCK_REUSEADDR)) {
125                BIO_closesocket(*sock);
126                *sock = INVALID_SOCKET;
127                break;
128            }
129        }
130
131#ifndef OPENSSL_NO_SCTP
132        if (protocol == IPPROTO_SCTP) {
133            /*
134             * For SCTP we have to set various options on the socket prior to
135             * connecting. This is done automatically by BIO_new_dgram_sctp().
136             * We don't actually need the created BIO though so we free it again
137             * immediately.
138             */
139            BIO *tmpbio = BIO_new_dgram_sctp(*sock, BIO_NOCLOSE);
140
141            if (tmpbio == NULL) {
142                ERR_print_errors(bio_err);
143                return 0;
144            }
145            BIO_free(tmpbio);
146        }
147#endif
148
149        if (!BIO_connect(*sock, BIO_ADDRINFO_address(ai),
150                         protocol == IPPROTO_TCP ? BIO_SOCK_NODELAY : 0)) {
151            BIO_closesocket(*sock);
152            *sock = INVALID_SOCKET;
153            continue;
154        }
155
156        /* Success, don't try any more addresses */
157        break;
158    }
159
160    if (*sock == INVALID_SOCKET) {
161        if (bindaddr != NULL && !found) {
162            BIO_printf(bio_err, "Can't bind %saddress for %s%s%s\n",
163                       BIO_ADDRINFO_family(res) == AF_INET6 ? "IPv6 " :
164                       BIO_ADDRINFO_family(res) == AF_INET ? "IPv4 " :
165                       BIO_ADDRINFO_family(res) == AF_UNIX ? "unix " : "",
166                       bindhost != NULL ? bindhost : "",
167                       bindport != NULL ? ":" : "",
168                       bindport != NULL ? bindport : "");
169            ERR_clear_error();
170            ret = 0;
171        }
172        ERR_print_errors(bio_err);
173    } else {
174        /* Remove any stale errors from previous connection attempts */
175        ERR_clear_error();
176        ret = 1;
177    }
178out:
179    if (bindaddr != NULL) {
180        BIO_ADDRINFO_free (bindaddr);
181    }
182    BIO_ADDRINFO_free(res);
183    return ret;
184}
185
186/*
187 * do_server - helper routine to perform a server operation
188 * @accept_sock: pointer to storage of resulting socket.
189 * @host: the host name or path (for AF_UNIX) to connect to.
190 * @port: the port to connect to (ignored for AF_UNIX).
191 * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
192 *  AF_UNSPEC
193 * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
194 * @cb: pointer to a function that receives the accepted socket and
195 *  should perform the communication with the connecting client.
196 * @context: pointer to memory that's passed verbatim to the cb function.
197 * @naccept: number of times an incoming connect should be accepted.  If -1,
198 *  unlimited number.
199 *
200 * This will create a socket and use it to listen to a host:port, or if
201 * family == AF_UNIX, to the path found in host, then start accepting
202 * incoming connections and run cb on the resulting socket.
203 *
204 * 0 on failure, something other on success.
205 */
206int do_server(int *accept_sock, const char *host, const char *port,
207              int family, int type, int protocol, do_server_cb cb,
208              unsigned char *context, int naccept, BIO *bio_s_out)
209{
210    int asock = 0;
211    int sock;
212    int i;
213    BIO_ADDRINFO *res = NULL;
214    const BIO_ADDRINFO *next;
215    int sock_family, sock_type, sock_protocol, sock_port;
216    const BIO_ADDR *sock_address;
217    int sock_options = BIO_SOCK_REUSEADDR;
218    int ret = 0;
219
220    if (BIO_sock_init() != 1)
221        return 0;
222
223    if (!BIO_lookup_ex(host, port, BIO_LOOKUP_SERVER, family, type, protocol,
224                       &res)) {
225        ERR_print_errors(bio_err);
226        return 0;
227    }
228
229    /* Admittedly, these checks are quite paranoid, we should not get
230     * anything in the BIO_ADDRINFO chain that we haven't asked for */
231    OPENSSL_assert((family == AF_UNSPEC || family == BIO_ADDRINFO_family(res))
232                   && (type == 0 || type == BIO_ADDRINFO_socktype(res))
233                   && (protocol == 0 || protocol == BIO_ADDRINFO_protocol(res)));
234
235    sock_family = BIO_ADDRINFO_family(res);
236    sock_type = BIO_ADDRINFO_socktype(res);
237    sock_protocol = BIO_ADDRINFO_protocol(res);
238    sock_address = BIO_ADDRINFO_address(res);
239    next = BIO_ADDRINFO_next(res);
240    if (sock_family == AF_INET6)
241        sock_options |= BIO_SOCK_V6_ONLY;
242    if (next != NULL
243            && BIO_ADDRINFO_socktype(next) == sock_type
244            && BIO_ADDRINFO_protocol(next) == sock_protocol) {
245        if (sock_family == AF_INET
246                && BIO_ADDRINFO_family(next) == AF_INET6) {
247            sock_family = AF_INET6;
248            sock_address = BIO_ADDRINFO_address(next);
249        } else if (sock_family == AF_INET6
250                   && BIO_ADDRINFO_family(next) == AF_INET) {
251            sock_options &= ~BIO_SOCK_V6_ONLY;
252        }
253    }
254
255    asock = BIO_socket(sock_family, sock_type, sock_protocol, 0);
256    if (asock == INVALID_SOCKET
257        || !BIO_listen(asock, sock_address, sock_options)) {
258        BIO_ADDRINFO_free(res);
259        ERR_print_errors(bio_err);
260        if (asock != INVALID_SOCKET)
261            BIO_closesocket(asock);
262        goto end;
263    }
264
265#ifndef OPENSSL_NO_SCTP
266    if (protocol == IPPROTO_SCTP) {
267        /*
268         * For SCTP we have to set various options on the socket prior to
269         * accepting. This is done automatically by BIO_new_dgram_sctp().
270         * We don't actually need the created BIO though so we free it again
271         * immediately.
272         */
273        BIO *tmpbio = BIO_new_dgram_sctp(asock, BIO_NOCLOSE);
274
275        if (tmpbio == NULL) {
276            BIO_closesocket(asock);
277            ERR_print_errors(bio_err);
278            goto end;
279        }
280        BIO_free(tmpbio);
281    }
282#endif
283
284    sock_port = BIO_ADDR_rawport(sock_address);
285
286    BIO_ADDRINFO_free(res);
287    res = NULL;
288
289    if (sock_port == 0) {
290        /* dynamically allocated port, report which one */
291        union BIO_sock_info_u info;
292        char *hostname = NULL;
293        char *service = NULL;
294        int success = 0;
295
296        if ((info.addr = BIO_ADDR_new()) != NULL
297            && BIO_sock_info(asock, BIO_SOCK_INFO_ADDRESS, &info)
298            && (hostname = BIO_ADDR_hostname_string(info.addr, 1)) != NULL
299            && (service = BIO_ADDR_service_string(info.addr, 1)) != NULL
300            && BIO_printf(bio_s_out,
301                          strchr(hostname, ':') == NULL
302                          ? /* IPv4 */ "ACCEPT %s:%s\n"
303                          : /* IPv6 */ "ACCEPT [%s]:%s\n",
304                          hostname, service) > 0)
305            success = 1;
306
307        (void)BIO_flush(bio_s_out);
308        OPENSSL_free(hostname);
309        OPENSSL_free(service);
310        BIO_ADDR_free(info.addr);
311        if (!success) {
312            BIO_closesocket(asock);
313            ERR_print_errors(bio_err);
314            goto end;
315        }
316    } else {
317        (void)BIO_printf(bio_s_out, "ACCEPT\n");
318        (void)BIO_flush(bio_s_out);
319    }
320
321    if (accept_sock != NULL)
322        *accept_sock = asock;
323    for (;;) {
324        char sink[64];
325        struct timeval timeout;
326        fd_set readfds;
327
328        if (type == SOCK_STREAM) {
329            BIO_ADDR_free(ourpeer);
330            ourpeer = BIO_ADDR_new();
331            if (ourpeer == NULL) {
332                BIO_closesocket(asock);
333                ERR_print_errors(bio_err);
334                goto end;
335            }
336            do {
337                sock = BIO_accept_ex(asock, ourpeer, 0);
338            } while (sock < 0 && BIO_sock_should_retry(sock));
339            if (sock < 0) {
340                ERR_print_errors(bio_err);
341                BIO_closesocket(asock);
342                break;
343            }
344            BIO_set_tcp_ndelay(sock, 1);
345            i = (*cb)(sock, type, protocol, context);
346
347            /*
348             * If we ended with an alert being sent, but still with data in the
349             * network buffer to be read, then calling BIO_closesocket() will
350             * result in a TCP-RST being sent. On some platforms (notably
351             * Windows) then this will result in the peer immediately abandoning
352             * the connection including any buffered alert data before it has
353             * had a chance to be read. Shutting down the sending side first,
354             * and then closing the socket sends TCP-FIN first followed by
355             * TCP-RST. This seems to allow the peer to read the alert data.
356             */
357            shutdown(sock, 1); /* SHUT_WR */
358            /*
359             * We just said we have nothing else to say, but it doesn't mean
360             * that the other side has nothing. It's even recommended to
361             * consume incoming data. [In testing context this ensures that
362             * alerts are passed on...]
363             */
364            timeout.tv_sec = 0;
365            timeout.tv_usec = 500000;  /* some extreme round-trip */
366            do {
367                FD_ZERO(&readfds);
368                openssl_fdset(sock, &readfds);
369            } while (select(sock + 1, &readfds, NULL, NULL, &timeout) > 0
370                     && readsocket(sock, sink, sizeof(sink)) > 0);
371
372            BIO_closesocket(sock);
373        } else {
374            i = (*cb)(asock, type, protocol, context);
375        }
376
377        if (naccept != -1)
378            naccept--;
379        if (i < 0 || naccept == 0) {
380            BIO_closesocket(asock);
381            ret = i;
382            break;
383        }
384    }
385 end:
386# ifdef AF_UNIX
387    if (family == AF_UNIX)
388        unlink(host);
389# endif
390    BIO_ADDR_free(ourpeer);
391    ourpeer = NULL;
392    return ret;
393}
394
395#endif  /* OPENSSL_NO_SOCK */
396