openssl/apps/s_socket.c
Matt Caswell bac6abe18d Allow an endpoint to read the alert data before closing the socket
If an alert gets sent and then we close the connection immediately with
data still in the input buffer then a TCP-RST gets sent. Some OSs
immediately abandon data in their input buffer if a TCP-RST is received -
meaning the alert data itself gets ditched. Sending a TCP-FIN before the
TCP-RST seems to avoid this.

This was causing test failures in MSYS2 builds.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Ben Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/4333)
2017-09-08 13:10:57 +01:00

263 lines
8.6 KiB
C

/*
* Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/* socket-related functions used by s_client and s_server */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <openssl/opensslconf.h>
/*
* With IPv6, it looks like Digital has mixed up the proper order of
* recursive header file inclusion, resulting in the compiler complaining
* that u_int isn't defined, but only if _POSIX_C_SOURCE is defined, which is
* needed to have fileno() declared correctly... So let's define u_int
*/
#if defined(OPENSSL_SYS_VMS_DECC) && !defined(__U_INT)
# define __U_INT
typedef unsigned int u_int;
#endif
#ifndef OPENSSL_NO_SOCK
# include "apps.h"
# include "s_apps.h"
# include "internal/sockets.h"
# include <openssl/bio.h>
# include <openssl/err.h>
/*
* init_client - helper routine to set up socket communication
* @sock: pointer to storage of resulting socket.
* @host: the host name or path (for AF_UNIX) to connect to.
* @port: the port to connect to (ignored for AF_UNIX).
* @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
* AF_UNSPEC
* @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
* @protocol: socket protocol, e.g. IPPROTO_TCP or IPPROTO_UDP (or 0 for any)
*
* This will create a socket and use it to connect to a host:port, or if
* family == AF_UNIX, to the path found in host.
*
* If the host has more than one address, it will try them one by one until
* a successful connection is established. The resulting socket will be
* found in *sock on success, it will be given INVALID_SOCKET otherwise.
*
* Returns 1 on success, 0 on failure.
*/
int init_client(int *sock, const char *host, const char *port,
int family, int type, int protocol)
{
BIO_ADDRINFO *res = NULL;
const BIO_ADDRINFO *ai = NULL;
int ret;
if (BIO_sock_init() != 1)
return 0;
ret = BIO_lookup_ex(host, port, BIO_LOOKUP_CLIENT, family, type, protocol,
&res);
if (ret == 0) {
ERR_print_errors(bio_err);
return 0;
}
ret = 0;
for (ai = res; ai != NULL; ai = BIO_ADDRINFO_next(ai)) {
/* Admittedly, these checks are quite paranoid, we should not get
* anything in the BIO_ADDRINFO chain that we haven't
* asked for. */
OPENSSL_assert((family == AF_UNSPEC
|| family == BIO_ADDRINFO_family(ai))
&& (type == 0 || type == BIO_ADDRINFO_socktype(ai))
&& (protocol == 0
|| protocol == BIO_ADDRINFO_protocol(ai)));
*sock = BIO_socket(BIO_ADDRINFO_family(ai), BIO_ADDRINFO_socktype(ai),
BIO_ADDRINFO_protocol(ai), 0);
if (*sock == INVALID_SOCKET) {
/* Maybe the kernel doesn't support the socket family, even if
* BIO_lookup() added it in the returned result...
*/
continue;
}
#ifndef OPENSSL_NO_SCTP
if (protocol == IPPROTO_SCTP) {
/*
* For SCTP we have to set various options on the socket prior to
* connecting. This is done automatically by BIO_new_dgram_sctp().
* We don't actually need the created BIO though so we free it again
* immediately.
*/
BIO *tmpbio = BIO_new_dgram_sctp(*sock, BIO_NOCLOSE);
if (tmpbio == NULL) {
ERR_print_errors(bio_err);
return 0;
}
BIO_free(tmpbio);
}
#endif
if (!BIO_connect(*sock, BIO_ADDRINFO_address(ai), 0)) {
BIO_closesocket(*sock);
*sock = INVALID_SOCKET;
continue;
}
/* Success, don't try any more addresses */
break;
}
if (*sock == INVALID_SOCKET) {
ERR_print_errors(bio_err);
} else {
/* Remove any stale errors from previous connection attempts */
ERR_clear_error();
ret = 1;
}
BIO_ADDRINFO_free(res);
return ret;
}
/*
* do_server - helper routine to perform a server operation
* @accept_sock: pointer to storage of resulting socket.
* @host: the host name or path (for AF_UNIX) to connect to.
* @port: the port to connect to (ignored for AF_UNIX).
* @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
* AF_UNSPEC
* @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
* @cb: pointer to a function that receives the accepted socket and
* should perform the communication with the connecting client.
* @context: pointer to memory that's passed verbatim to the cb function.
* @naccept: number of times an incoming connect should be accepted. If -1,
* unlimited number.
*
* This will create a socket and use it to listen to a host:port, or if
* family == AF_UNIX, to the path found in host, then start accepting
* incoming connections and run cb on the resulting socket.
*
* 0 on failure, something other on success.
*/
int 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)
{
int asock = 0;
int sock;
int i;
BIO_ADDRINFO *res = NULL;
int ret = 0;
if (BIO_sock_init() != 1)
return 0;
if (!BIO_lookup_ex(host, port, BIO_LOOKUP_SERVER, family, type, protocol,
&res)) {
ERR_print_errors(bio_err);
return 0;
}
/* Admittedly, these checks are quite paranoid, we should not get
* anything in the BIO_ADDRINFO chain that we haven't asked for */
OPENSSL_assert((family == AF_UNSPEC || family == BIO_ADDRINFO_family(res))
&& (type == 0 || type == BIO_ADDRINFO_socktype(res))
&& (protocol == 0 || protocol == BIO_ADDRINFO_protocol(res)));
asock = BIO_socket(BIO_ADDRINFO_family(res), BIO_ADDRINFO_socktype(res),
BIO_ADDRINFO_protocol(res), 0);
if (asock == INVALID_SOCKET
|| !BIO_listen(asock, BIO_ADDRINFO_address(res), BIO_SOCK_REUSEADDR)) {
BIO_ADDRINFO_free(res);
ERR_print_errors(bio_err);
if (asock != INVALID_SOCKET)
BIO_closesocket(asock);
goto end;
}
#ifndef OPENSSL_NO_SCTP
if (protocol == IPPROTO_SCTP) {
/*
* For SCTP we have to set various options on the socket prior to
* accepting. This is done automatically by BIO_new_dgram_sctp().
* We don't actually need the created BIO though so we free it again
* immediately.
*/
BIO *tmpbio = BIO_new_dgram_sctp(asock, BIO_NOCLOSE);
if (tmpbio == NULL) {
BIO_closesocket(asock);
ERR_print_errors(bio_err);
goto end;
}
BIO_free(tmpbio);
}
#endif
BIO_ADDRINFO_free(res);
res = NULL;
if (accept_sock != NULL)
*accept_sock = asock;
for (;;) {
if (type == SOCK_STREAM) {
do {
sock = BIO_accept_ex(asock, NULL, 0);
} while (sock < 0 && BIO_sock_should_retry(sock));
if (sock < 0) {
ERR_print_errors(bio_err);
BIO_closesocket(asock);
break;
}
i = (*cb)(sock, type, protocol, context);
/*
* If we ended with an alert being sent, but still with data in the
* network buffer to be read, then calling BIO_closesocket() will
* result in a TCP-RST being sent. On some platforms (notably
* Windows) then this will result in the peer immediately abandoning
* the connection including any buffered alert data before it has
* had a chance to be read. Shutting down the sending side first,
* and then closing the socket sends TCP-FIN first followed by
* TCP-RST. This seems to allow the peer to read the alert data.
*/
#ifdef _WIN32
# ifdef SD_SEND
shutdown(sock, SD_SEND);
# endif
#elif defined(SHUT_WR)
shutdown(sock, SHUT_WR);
#endif
BIO_closesocket(sock);
} else {
i = (*cb)(asock, type, protocol, context);
}
if (naccept != -1)
naccept--;
if (i < 0 || naccept == 0) {
BIO_closesocket(asock);
ret = i;
break;
}
}
end:
# ifdef AF_UNIX
if (family == AF_UNIX)
unlink(host);
# endif
return ret;
}
#endif /* OPENSSL_NO_SOCK */