1 /*
2  * Copyright 1995-2021 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  */
init_client(int * sock,const char * host,const char * port,const char * bindhost,const char * bindport,int family,int type,int protocol)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                          protocol == 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         char *hostname = NULL;
192 
193         hostname = BIO_ADDR_hostname_string(BIO_ADDRINFO_address(ai), 1);
194         if (hostname != NULL) {
195             BIO_printf(bio_out, "Connecting to %s\n", hostname);
196             OPENSSL_free(hostname);
197         }
198         /* Remove any stale errors from previous connection attempts */
199         ERR_clear_error();
200         ret = 1;
201     }
202 out:
203     if (bindaddr != NULL) {
204         BIO_ADDRINFO_free (bindaddr);
205     }
206     BIO_ADDRINFO_free(res);
207     return ret;
208 }
209 
report_server_accept(BIO * out,int asock,int with_address,int with_pid)210 int report_server_accept(BIO *out, int asock, int with_address, int with_pid)
211 {
212     int success = 1;
213 
214     if (BIO_printf(out, "ACCEPT") <= 0)
215         return 0;
216     if (with_address) {
217         union BIO_sock_info_u info;
218         char *hostname = NULL;
219         char *service = NULL;
220 
221         if ((info.addr = BIO_ADDR_new()) != NULL
222             && BIO_sock_info(asock, BIO_SOCK_INFO_ADDRESS, &info)
223             && (hostname = BIO_ADDR_hostname_string(info.addr, 1)) != NULL
224             && (service = BIO_ADDR_service_string(info.addr, 1)) != NULL) {
225             success = BIO_printf(out,
226                                  strchr(hostname, ':') == NULL
227                                  ? /* IPv4 */ " %s:%s"
228                                  : /* IPv6 */ " [%s]:%s",
229                                  hostname, service) > 0;
230         } else {
231             (void)BIO_printf(out, "unknown:error\n");
232             success = 0;
233         }
234         OPENSSL_free(hostname);
235         OPENSSL_free(service);
236         BIO_ADDR_free(info.addr);
237     }
238     if (with_pid)
239         success = success && BIO_printf(out, " PID=%d", getpid()) > 0;
240     success = success && BIO_printf(out, "\n") > 0;
241     (void)BIO_flush(out);
242 
243     return success;
244 }
245 
246 /*
247  * do_server - helper routine to perform a server operation
248  * @accept_sock: pointer to storage of resulting socket.
249  * @host: the host name or path (for AF_UNIX) to connect to.
250  * @port: the port to connect to (ignored for AF_UNIX).
251  * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
252  *  AF_UNSPEC
253  * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
254  * @cb: pointer to a function that receives the accepted socket and
255  *  should perform the communication with the connecting client.
256  * @context: pointer to memory that's passed verbatim to the cb function.
257  * @naccept: number of times an incoming connect should be accepted.  If -1,
258  *  unlimited number.
259  *
260  * This will create a socket and use it to listen to a host:port, or if
261  * family == AF_UNIX, to the path found in host, then start accepting
262  * incoming connections and run cb on the resulting socket.
263  *
264  * 0 on failure, something other on success.
265  */
do_server(int * accept_sock,const char * host,const char * port,int family,int type,int protocol,do_server_cb cb,unsigned char * context,int naccept,BIO * bio_s_out)266 int do_server(int *accept_sock, const char *host, const char *port,
267               int family, int type, int protocol, do_server_cb cb,
268               unsigned char *context, int naccept, BIO *bio_s_out)
269 {
270     int asock = 0;
271     int sock;
272     int i;
273     BIO_ADDRINFO *res = NULL;
274     const BIO_ADDRINFO *next;
275     int sock_family, sock_type, sock_protocol, sock_port;
276     const BIO_ADDR *sock_address;
277     int sock_family_fallback = AF_UNSPEC;
278     const BIO_ADDR *sock_address_fallback = NULL;
279     int sock_options = BIO_SOCK_REUSEADDR;
280     int ret = 0;
281 
282     if (BIO_sock_init() != 1)
283         return 0;
284 
285     if (!BIO_lookup_ex(host, port, BIO_LOOKUP_SERVER, family, type, protocol,
286                        &res)) {
287         ERR_print_errors(bio_err);
288         return 0;
289     }
290 
291     /* Admittedly, these checks are quite paranoid, we should not get
292      * anything in the BIO_ADDRINFO chain that we haven't asked for */
293     OPENSSL_assert((family == AF_UNSPEC || family == BIO_ADDRINFO_family(res))
294                    && (type == 0 || type == BIO_ADDRINFO_socktype(res))
295                    && (protocol == 0 || protocol == BIO_ADDRINFO_protocol(res)));
296 
297     sock_family = BIO_ADDRINFO_family(res);
298     sock_type = BIO_ADDRINFO_socktype(res);
299     sock_protocol = BIO_ADDRINFO_protocol(res);
300     sock_address = BIO_ADDRINFO_address(res);
301     next = BIO_ADDRINFO_next(res);
302 #ifdef AF_INET6
303     if (sock_family == AF_INET6)
304         sock_options |= BIO_SOCK_V6_ONLY;
305     if (next != NULL
306             && BIO_ADDRINFO_socktype(next) == sock_type
307             && BIO_ADDRINFO_protocol(next) == sock_protocol) {
308         if (sock_family == AF_INET
309                 && BIO_ADDRINFO_family(next) == AF_INET6) {
310             /* In case AF_INET6 is returned but not supported by the
311              * kernel, retry with the first detected address family */
312             sock_family_fallback = sock_family;
313             sock_address_fallback = sock_address;
314             sock_family = AF_INET6;
315             sock_address = BIO_ADDRINFO_address(next);
316         } else if (sock_family == AF_INET6
317                    && BIO_ADDRINFO_family(next) == AF_INET) {
318             sock_options &= ~BIO_SOCK_V6_ONLY;
319         }
320     }
321 #endif
322 
323     asock = BIO_socket(sock_family, sock_type, sock_protocol, 0);
324     if (asock == INVALID_SOCKET && sock_family_fallback != AF_UNSPEC) {
325         asock = BIO_socket(sock_family_fallback, sock_type, sock_protocol, 0);
326         sock_address = sock_address_fallback;
327     }
328     if (asock == INVALID_SOCKET
329         || !BIO_listen(asock, sock_address, sock_options)) {
330         BIO_ADDRINFO_free(res);
331         ERR_print_errors(bio_err);
332         if (asock != INVALID_SOCKET)
333             BIO_closesocket(asock);
334         goto end;
335     }
336 
337 #ifndef OPENSSL_NO_SCTP
338     if (protocol == IPPROTO_SCTP) {
339         /*
340          * For SCTP we have to set various options on the socket prior to
341          * accepting. This is done automatically by BIO_new_dgram_sctp().
342          * We don't actually need the created BIO though so we free it again
343          * immediately.
344          */
345         BIO *tmpbio = BIO_new_dgram_sctp(asock, BIO_NOCLOSE);
346 
347         if (tmpbio == NULL) {
348             BIO_closesocket(asock);
349             ERR_print_errors(bio_err);
350             goto end;
351         }
352         BIO_free(tmpbio);
353     }
354 #endif
355 
356     sock_port = BIO_ADDR_rawport(sock_address);
357 
358     BIO_ADDRINFO_free(res);
359     res = NULL;
360 
361     if (!report_server_accept(bio_s_out, asock, sock_port == 0, 0)) {
362         BIO_closesocket(asock);
363         ERR_print_errors(bio_err);
364         goto end;
365     }
366 
367     if (accept_sock != NULL)
368         *accept_sock = asock;
369     for (;;) {
370         char sink[64];
371         struct timeval timeout;
372         fd_set readfds;
373 
374         if (type == SOCK_STREAM) {
375             BIO_ADDR_free(ourpeer);
376             ourpeer = BIO_ADDR_new();
377             if (ourpeer == NULL) {
378                 BIO_closesocket(asock);
379                 ERR_print_errors(bio_err);
380                 goto end;
381             }
382             do {
383                 sock = BIO_accept_ex(asock, ourpeer, 0);
384             } while (sock < 0 && BIO_sock_should_retry(sock));
385             if (sock < 0) {
386                 ERR_print_errors(bio_err);
387                 BIO_closesocket(asock);
388                 break;
389             }
390             BIO_set_tcp_ndelay(sock, 1);
391             i = (*cb)(sock, type, protocol, context);
392 
393             /*
394              * If we ended with an alert being sent, but still with data in the
395              * network buffer to be read, then calling BIO_closesocket() will
396              * result in a TCP-RST being sent. On some platforms (notably
397              * Windows) then this will result in the peer immediately abandoning
398              * the connection including any buffered alert data before it has
399              * had a chance to be read. Shutting down the sending side first,
400              * and then closing the socket sends TCP-FIN first followed by
401              * TCP-RST. This seems to allow the peer to read the alert data.
402              */
403             shutdown(sock, 1); /* SHUT_WR */
404             /*
405              * We just said we have nothing else to say, but it doesn't mean
406              * that the other side has nothing. It's even recommended to
407              * consume incoming data. [In testing context this ensures that
408              * alerts are passed on...]
409              */
410             timeout.tv_sec = 0;
411             timeout.tv_usec = 500000;  /* some extreme round-trip */
412             do {
413                 FD_ZERO(&readfds);
414                 openssl_fdset(sock, &readfds);
415             } while (select(sock + 1, &readfds, NULL, NULL, &timeout) > 0
416                      && readsocket(sock, sink, sizeof(sink)) > 0);
417 
418             BIO_closesocket(sock);
419         } else {
420             i = (*cb)(asock, type, protocol, context);
421         }
422 
423         if (naccept != -1)
424             naccept--;
425         if (i < 0 || naccept == 0) {
426             BIO_closesocket(asock);
427             ret = i;
428             break;
429         }
430     }
431  end:
432 # ifdef AF_UNIX
433     if (family == AF_UNIX)
434         unlink(host);
435 # endif
436     BIO_ADDR_free(ourpeer);
437     ourpeer = NULL;
438     return ret;
439 }
440 
do_ssl_shutdown(SSL * ssl)441 void do_ssl_shutdown(SSL *ssl)
442 {
443     int ret;
444 
445     do {
446         /* We only do unidirectional shutdown */
447         ret = SSL_shutdown(ssl);
448         if (ret < 0) {
449             switch (SSL_get_error(ssl, ret)) {
450             case SSL_ERROR_WANT_READ:
451             case SSL_ERROR_WANT_WRITE:
452             case SSL_ERROR_WANT_ASYNC:
453             case SSL_ERROR_WANT_ASYNC_JOB:
454                 /* We just do busy waiting. Nothing clever */
455                 continue;
456             }
457             ret = 0;
458         }
459     } while (ret < 0);
460 }
461 
462 #endif  /* OPENSSL_NO_SOCK */
463