xref: /freebsd/crypto/openssl/apps/lib/s_socket.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 /*
2  * Copyright 1995-2022 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (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
26 typedef unsigned int u_int;
27 #endif
28 
29 #ifdef _WIN32
30 # include <process.h>
31 
32 /* MSVC renamed some POSIX functions to have an underscore prefix. */
33 # ifdef _MSC_VER
34 #  define getpid _getpid
35 # endif
36 #endif
37 
38 #ifndef OPENSSL_NO_SOCK
39 
40 # include "apps.h"
41 # include "s_apps.h"
42 # include "internal/sockets.h"
43 
44 # if defined(__TANDEM)
45 #  if defined(OPENSSL_TANDEM_FLOSS)
46 #   include <floss.h(floss_read)>
47 #  endif
48 # endif
49 
50 # include <openssl/bio.h>
51 # include <openssl/err.h>
52 
53 /* Keep track of our peer's address for the cookie callback */
54 BIO_ADDR *ourpeer = NULL;
55 
56 /*
57  * init_client - helper routine to set up socket communication
58  * @sock: pointer to storage of resulting socket.
59  * @host: the host name or path (for AF_UNIX) to connect to.
60  * @port: the port to connect to (ignored for AF_UNIX).
61  * @bindhost: source host or path (for AF_UNIX).
62  * @bindport: source port (ignored for AF_UNIX).
63  * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
64  *  AF_UNSPEC
65  * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
66  * @protocol: socket protocol, e.g. IPPROTO_TCP or IPPROTO_UDP (or 0 for any)
67  *
68  * This will create a socket and use it to connect to a host:port, or if
69  * family == AF_UNIX, to the path found in host.
70  *
71  * If the host has more than one address, it will try them one by one until
72  * a successful connection is established.  The resulting socket will be
73  * found in *sock on success, it will be given INVALID_SOCKET otherwise.
74  *
75  * Returns 1 on success, 0 on failure.
76  */
77 int init_client(int *sock, const char *host, const char *port,
78                 const char *bindhost, const char *bindport,
79                 int family, int type, int protocol)
80 {
81     BIO_ADDRINFO *res = NULL;
82     BIO_ADDRINFO *bindaddr = NULL;
83     const BIO_ADDRINFO *ai = NULL;
84     const BIO_ADDRINFO *bi = NULL;
85     int found = 0;
86     int ret;
87 
88     if (BIO_sock_init() != 1)
89         return 0;
90 
91     ret = BIO_lookup_ex(host, port, BIO_LOOKUP_CLIENT, family, type, protocol,
92                         &res);
93     if (ret == 0) {
94         ERR_print_errors(bio_err);
95         return 0;
96     }
97 
98     if (bindhost != NULL || bindport != NULL) {
99         ret = BIO_lookup_ex(bindhost, bindport, BIO_LOOKUP_CLIENT,
100                             family, type, protocol, &bindaddr);
101         if (ret == 0) {
102             ERR_print_errors (bio_err);
103             goto out;
104         }
105     }
106 
107     ret = 0;
108     for (ai = res; ai != NULL; ai = BIO_ADDRINFO_next(ai)) {
109         /* Admittedly, these checks are quite paranoid, we should not get
110          * anything in the BIO_ADDRINFO chain that we haven't
111          * asked for. */
112         OPENSSL_assert((family == AF_UNSPEC
113                         || family == BIO_ADDRINFO_family(ai))
114                        && (type == 0 || type == BIO_ADDRINFO_socktype(ai))
115                        && (protocol == 0
116                            || protocol == BIO_ADDRINFO_protocol(ai)));
117 
118         if (bindaddr != NULL) {
119             for (bi = bindaddr; bi != NULL; bi = BIO_ADDRINFO_next(bi)) {
120                 if (BIO_ADDRINFO_family(bi) == BIO_ADDRINFO_family(ai))
121                     break;
122             }
123             if (bi == NULL)
124                 continue;
125             ++found;
126         }
127 
128         *sock = BIO_socket(BIO_ADDRINFO_family(ai), BIO_ADDRINFO_socktype(ai),
129                            BIO_ADDRINFO_protocol(ai), 0);
130         if (*sock == INVALID_SOCKET) {
131             /* Maybe the kernel doesn't support the socket family, even if
132              * BIO_lookup() added it in the returned result...
133              */
134             continue;
135         }
136 
137         if (bi != NULL) {
138             if (!BIO_bind(*sock, BIO_ADDRINFO_address(bi),
139                           BIO_SOCK_REUSEADDR)) {
140                 BIO_closesocket(*sock);
141                 *sock = INVALID_SOCKET;
142                 break;
143             }
144         }
145 
146 #ifndef OPENSSL_NO_SCTP
147         if (protocol == IPPROTO_SCTP) {
148             /*
149              * For SCTP we have to set various options on the socket prior to
150              * connecting. This is done automatically by BIO_new_dgram_sctp().
151              * We don't actually need the created BIO though so we free it again
152              * immediately.
153              */
154             BIO *tmpbio = BIO_new_dgram_sctp(*sock, BIO_NOCLOSE);
155 
156             if (tmpbio == NULL) {
157                 ERR_print_errors(bio_err);
158                 return 0;
159             }
160             BIO_free(tmpbio);
161         }
162 #endif
163 
164         if (!BIO_connect(*sock, BIO_ADDRINFO_address(ai),
165                          BIO_ADDRINFO_protocol(ai) == IPPROTO_TCP ? BIO_SOCK_NODELAY : 0)) {
166             BIO_closesocket(*sock);
167             *sock = INVALID_SOCKET;
168             continue;
169         }
170 
171         /* Success, don't try any more addresses */
172         break;
173     }
174 
175     if (*sock == INVALID_SOCKET) {
176         if (bindaddr != NULL && !found) {
177             BIO_printf(bio_err, "Can't bind %saddress for %s%s%s\n",
178 #ifdef AF_INET6
179                        BIO_ADDRINFO_family(res) == AF_INET6 ? "IPv6 " :
180 #endif
181                        BIO_ADDRINFO_family(res) == AF_INET ? "IPv4 " :
182                        BIO_ADDRINFO_family(res) == AF_UNIX ? "unix " : "",
183                        bindhost != NULL ? bindhost : "",
184                        bindport != NULL ? ":" : "",
185                        bindport != NULL ? bindport : "");
186             ERR_clear_error();
187             ret = 0;
188         }
189         ERR_print_errors(bio_err);
190     } else {
191         /* Remove any stale errors from previous connection attempts */
192         ERR_clear_error();
193         ret = 1;
194     }
195 out:
196     if (bindaddr != NULL) {
197         BIO_ADDRINFO_free (bindaddr);
198     }
199     BIO_ADDRINFO_free(res);
200     return ret;
201 }
202 
203 int report_server_accept(BIO *out, int asock, int with_address, int with_pid)
204 {
205     int success = 1;
206 
207     if (BIO_printf(out, "ACCEPT") <= 0)
208         return 0;
209     if (with_address) {
210         union BIO_sock_info_u info;
211         char *hostname = NULL;
212         char *service = NULL;
213 
214         if ((info.addr = BIO_ADDR_new()) != NULL
215             && BIO_sock_info(asock, BIO_SOCK_INFO_ADDRESS, &info)
216             && (hostname = BIO_ADDR_hostname_string(info.addr, 1)) != NULL
217             && (service = BIO_ADDR_service_string(info.addr, 1)) != NULL) {
218             success = BIO_printf(out,
219                                  strchr(hostname, ':') == NULL
220                                  ? /* IPv4 */ " %s:%s"
221                                  : /* IPv6 */ " [%s]:%s",
222                                  hostname, service) > 0;
223         } else {
224             (void)BIO_printf(out, "unknown:error\n");
225             success = 0;
226         }
227         OPENSSL_free(hostname);
228         OPENSSL_free(service);
229         BIO_ADDR_free(info.addr);
230     }
231     if (with_pid)
232         success = success && BIO_printf(out, " PID=%d", getpid()) > 0;
233     success = success && BIO_printf(out, "\n") > 0;
234     (void)BIO_flush(out);
235 
236     return success;
237 }
238 
239 /*
240  * do_server - helper routine to perform a server operation
241  * @accept_sock: pointer to storage of resulting socket.
242  * @host: the host name or path (for AF_UNIX) to connect to.
243  * @port: the port to connect to (ignored for AF_UNIX).
244  * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
245  *  AF_UNSPEC
246  * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
247  * @cb: pointer to a function that receives the accepted socket and
248  *  should perform the communication with the connecting client.
249  * @context: pointer to memory that's passed verbatim to the cb function.
250  * @naccept: number of times an incoming connect should be accepted.  If -1,
251  *  unlimited number.
252  *
253  * This will create a socket and use it to listen to a host:port, or if
254  * family == AF_UNIX, to the path found in host, then start accepting
255  * incoming connections and run cb on the resulting socket.
256  *
257  * 0 on failure, something other on success.
258  */
259 int do_server(int *accept_sock, const char *host, const char *port,
260               int family, int type, int protocol, do_server_cb cb,
261               unsigned char *context, int naccept, BIO *bio_s_out)
262 {
263     int asock = 0;
264     int sock;
265     int i;
266     BIO_ADDRINFO *res = NULL;
267     const BIO_ADDRINFO *next;
268     int sock_family, sock_type, sock_protocol, sock_port;
269     const BIO_ADDR *sock_address;
270     int sock_family_fallback = AF_UNSPEC;
271     const BIO_ADDR *sock_address_fallback = NULL;
272     int sock_options = BIO_SOCK_REUSEADDR;
273     int ret = 0;
274 
275     if (BIO_sock_init() != 1)
276         return 0;
277 
278     if (!BIO_lookup_ex(host, port, BIO_LOOKUP_SERVER, family, type, protocol,
279                        &res)) {
280         ERR_print_errors(bio_err);
281         return 0;
282     }
283 
284     /* Admittedly, these checks are quite paranoid, we should not get
285      * anything in the BIO_ADDRINFO chain that we haven't asked for */
286     OPENSSL_assert((family == AF_UNSPEC || family == BIO_ADDRINFO_family(res))
287                    && (type == 0 || type == BIO_ADDRINFO_socktype(res))
288                    && (protocol == 0 || protocol == BIO_ADDRINFO_protocol(res)));
289 
290     sock_family = BIO_ADDRINFO_family(res);
291     sock_type = BIO_ADDRINFO_socktype(res);
292     sock_protocol = BIO_ADDRINFO_protocol(res);
293     sock_address = BIO_ADDRINFO_address(res);
294     next = BIO_ADDRINFO_next(res);
295 #ifdef AF_INET6
296     if (sock_family == AF_INET6)
297         sock_options |= BIO_SOCK_V6_ONLY;
298     if (next != NULL
299             && BIO_ADDRINFO_socktype(next) == sock_type
300             && BIO_ADDRINFO_protocol(next) == sock_protocol) {
301         if (sock_family == AF_INET
302                 && BIO_ADDRINFO_family(next) == AF_INET6) {
303             /* In case AF_INET6 is returned but not supported by the
304              * kernel, retry with the first detected address family */
305             sock_family_fallback = sock_family;
306             sock_address_fallback = sock_address;
307             sock_family = AF_INET6;
308             sock_address = BIO_ADDRINFO_address(next);
309         } else if (sock_family == AF_INET6
310                    && BIO_ADDRINFO_family(next) == AF_INET) {
311             sock_options &= ~BIO_SOCK_V6_ONLY;
312         }
313     }
314 #endif
315 
316     asock = BIO_socket(sock_family, sock_type, sock_protocol, 0);
317     if (asock == INVALID_SOCKET && sock_family_fallback != AF_UNSPEC) {
318         asock = BIO_socket(sock_family_fallback, sock_type, sock_protocol, 0);
319         sock_address = sock_address_fallback;
320     }
321     if (asock == INVALID_SOCKET
322         || !BIO_listen(asock, sock_address, sock_options)) {
323         BIO_ADDRINFO_free(res);
324         ERR_print_errors(bio_err);
325         if (asock != INVALID_SOCKET)
326             BIO_closesocket(asock);
327         goto end;
328     }
329 
330 #ifndef OPENSSL_NO_SCTP
331     if (protocol == IPPROTO_SCTP) {
332         /*
333          * For SCTP we have to set various options on the socket prior to
334          * accepting. This is done automatically by BIO_new_dgram_sctp().
335          * We don't actually need the created BIO though so we free it again
336          * immediately.
337          */
338         BIO *tmpbio = BIO_new_dgram_sctp(asock, BIO_NOCLOSE);
339 
340         if (tmpbio == NULL) {
341             BIO_closesocket(asock);
342             ERR_print_errors(bio_err);
343             goto end;
344         }
345         BIO_free(tmpbio);
346     }
347 #endif
348 
349     sock_port = BIO_ADDR_rawport(sock_address);
350 
351     BIO_ADDRINFO_free(res);
352     res = NULL;
353 
354     if (!report_server_accept(bio_s_out, asock, sock_port == 0, 0)) {
355         BIO_closesocket(asock);
356         ERR_print_errors(bio_err);
357         goto end;
358     }
359 
360     if (accept_sock != NULL)
361         *accept_sock = asock;
362     for (;;) {
363         char sink[64];
364         struct timeval timeout;
365         fd_set readfds;
366 
367         if (type == SOCK_STREAM) {
368             BIO_ADDR_free(ourpeer);
369             ourpeer = BIO_ADDR_new();
370             if (ourpeer == NULL) {
371                 BIO_closesocket(asock);
372                 ERR_print_errors(bio_err);
373                 goto end;
374             }
375             do {
376                 sock = BIO_accept_ex(asock, ourpeer, 0);
377             } while (sock < 0 && BIO_sock_should_retry(sock));
378             if (sock < 0) {
379                 ERR_print_errors(bio_err);
380                 BIO_closesocket(asock);
381                 break;
382             }
383             BIO_set_tcp_ndelay(sock, 1);
384             i = (*cb)(sock, type, protocol, context);
385 
386             /*
387              * If we ended with an alert being sent, but still with data in the
388              * network buffer to be read, then calling BIO_closesocket() will
389              * result in a TCP-RST being sent. On some platforms (notably
390              * Windows) then this will result in the peer immediately abandoning
391              * the connection including any buffered alert data before it has
392              * had a chance to be read. Shutting down the sending side first,
393              * and then closing the socket sends TCP-FIN first followed by
394              * TCP-RST. This seems to allow the peer to read the alert data.
395              */
396             shutdown(sock, 1); /* SHUT_WR */
397             /*
398              * We just said we have nothing else to say, but it doesn't mean
399              * that the other side has nothing. It's even recommended to
400              * consume incoming data. [In testing context this ensures that
401              * alerts are passed on...]
402              */
403             timeout.tv_sec = 0;
404             timeout.tv_usec = 500000;  /* some extreme round-trip */
405             do {
406                 FD_ZERO(&readfds);
407                 openssl_fdset(sock, &readfds);
408             } while (select(sock + 1, &readfds, NULL, NULL, &timeout) > 0
409                      && readsocket(sock, sink, sizeof(sink)) > 0);
410 
411             BIO_closesocket(sock);
412         } else {
413             i = (*cb)(asock, type, protocol, context);
414         }
415 
416         if (naccept != -1)
417             naccept--;
418         if (i < 0 || naccept == 0) {
419             BIO_closesocket(asock);
420             ret = i;
421             break;
422         }
423     }
424  end:
425 # ifdef AF_UNIX
426     if (family == AF_UNIX)
427         unlink(host);
428 # endif
429     BIO_ADDR_free(ourpeer);
430     ourpeer = NULL;
431     return ret;
432 }
433 
434 void do_ssl_shutdown(SSL *ssl)
435 {
436     int ret;
437 
438     do {
439         /* We only do unidirectional shutdown */
440         ret = SSL_shutdown(ssl);
441         if (ret < 0) {
442             switch (SSL_get_error(ssl, ret)) {
443             case SSL_ERROR_WANT_READ:
444             case SSL_ERROR_WANT_WRITE:
445             case SSL_ERROR_WANT_ASYNC:
446             case SSL_ERROR_WANT_ASYNC_JOB:
447                 /* We just do busy waiting. Nothing clever */
448                 continue;
449             }
450             ret = 0;
451         }
452     } while (ret < 0);
453 }
454 
455 #endif  /* OPENSSL_NO_SOCK */
456