openssl/crypto/bio/bss_conn.c
Richard Levitte f6483fc2db BIO_s_connect: add an error state and use it
If no connection could be made, addr_iter will eventually end up being
NULL, and if the user didn't check the returned error value, the
BIO_CONN_S_CONNECT code will be performed again and will crash.

So instead, we add a state BIO_CONN_S_CONNECT_ERROR that we enter into
when we run out of addresses to try.  That state will just simply say
"error" back, until the user does something better with the BIO, such
as free it or reset it.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10333)
2019-11-05 22:17:12 +01:00

547 lines
16 KiB
C

/*
* Copyright 1995-2018 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
*/
#include <stdio.h>
#include <errno.h>
#include "bio_local.h"
#ifndef OPENSSL_NO_SOCK
typedef struct bio_connect_st {
int state;
int connect_family;
char *param_hostname;
char *param_service;
int connect_mode;
BIO_ADDRINFO *addr_first;
const BIO_ADDRINFO *addr_iter;
/*
* int socket; this will be kept in bio->num so that it is compatible
* with the bss_sock bio
*/
/*
* called when the connection is initially made callback(BIO,state,ret);
* The callback should return 'ret'. state is for compatibility with the
* ssl info_callback
*/
BIO_info_cb *info_callback;
} BIO_CONNECT;
static int conn_write(BIO *h, const char *buf, int num);
static int conn_read(BIO *h, char *buf, int size);
static int conn_puts(BIO *h, const char *str);
static long conn_ctrl(BIO *h, int cmd, long arg1, void *arg2);
static int conn_new(BIO *h);
static int conn_free(BIO *data);
static long conn_callback_ctrl(BIO *h, int cmd, BIO_info_cb *);
static int conn_state(BIO *b, BIO_CONNECT *c);
static void conn_close_socket(BIO *data);
BIO_CONNECT *BIO_CONNECT_new(void);
void BIO_CONNECT_free(BIO_CONNECT *a);
#define BIO_CONN_S_BEFORE 1
#define BIO_CONN_S_GET_ADDR 2
#define BIO_CONN_S_CREATE_SOCKET 3
#define BIO_CONN_S_CONNECT 4
#define BIO_CONN_S_OK 5
#define BIO_CONN_S_BLOCKED_CONNECT 6
#define BIO_CONN_S_CONNECT_ERROR 7
static const BIO_METHOD methods_connectp = {
BIO_TYPE_CONNECT,
"socket connect",
/* TODO: Convert to new style write function */
bwrite_conv,
conn_write,
/* TODO: Convert to new style read function */
bread_conv,
conn_read,
conn_puts,
NULL, /* conn_gets, */
conn_ctrl,
conn_new,
conn_free,
conn_callback_ctrl,
};
static int conn_state(BIO *b, BIO_CONNECT *c)
{
int ret = -1, i;
BIO_info_cb *cb = NULL;
if (c->info_callback != NULL)
cb = c->info_callback;
for (;;) {
switch (c->state) {
case BIO_CONN_S_BEFORE:
if (c->param_hostname == NULL && c->param_service == NULL) {
BIOerr(BIO_F_CONN_STATE, BIO_R_NO_HOSTNAME_OR_SERVICE_SPECIFIED);
ERR_add_error_data(4,
"hostname=", c->param_hostname,
" service=", c->param_service);
goto exit_loop;
}
c->state = BIO_CONN_S_GET_ADDR;
break;
case BIO_CONN_S_GET_ADDR:
{
int family = AF_UNSPEC;
switch (c->connect_family) {
case BIO_FAMILY_IPV6:
if (1) { /* This is a trick we use to avoid bit rot.
* at least the "else" part will always be
* compiled.
*/
#ifdef AF_INET6
family = AF_INET6;
} else {
#endif
BIOerr(BIO_F_CONN_STATE, BIO_R_UNAVAILABLE_IP_FAMILY);
goto exit_loop;
}
break;
case BIO_FAMILY_IPV4:
family = AF_INET;
break;
case BIO_FAMILY_IPANY:
family = AF_UNSPEC;
break;
default:
BIOerr(BIO_F_CONN_STATE, BIO_R_UNSUPPORTED_IP_FAMILY);
goto exit_loop;
}
if (BIO_lookup(c->param_hostname, c->param_service,
BIO_LOOKUP_CLIENT,
family, SOCK_STREAM, &c->addr_first) == 0)
goto exit_loop;
}
if (c->addr_first == NULL) {
BIOerr(BIO_F_CONN_STATE, BIO_R_LOOKUP_RETURNED_NOTHING);
goto exit_loop;
}
c->addr_iter = c->addr_first;
c->state = BIO_CONN_S_CREATE_SOCKET;
break;
case BIO_CONN_S_CREATE_SOCKET:
ret = BIO_socket(BIO_ADDRINFO_family(c->addr_iter),
BIO_ADDRINFO_socktype(c->addr_iter),
BIO_ADDRINFO_protocol(c->addr_iter), 0);
if (ret == (int)INVALID_SOCKET) {
SYSerr(SYS_F_SOCKET, get_last_socket_error());
ERR_add_error_data(4,
"hostname=", c->param_hostname,
" service=", c->param_service);
BIOerr(BIO_F_CONN_STATE, BIO_R_UNABLE_TO_CREATE_SOCKET);
goto exit_loop;
}
b->num = ret;
c->state = BIO_CONN_S_CONNECT;
break;
case BIO_CONN_S_CONNECT:
BIO_clear_retry_flags(b);
ret = BIO_connect(b->num, BIO_ADDRINFO_address(c->addr_iter),
BIO_SOCK_KEEPALIVE | c->connect_mode);
b->retry_reason = 0;
if (ret == 0) {
if (BIO_sock_should_retry(ret)) {
BIO_set_retry_special(b);
c->state = BIO_CONN_S_BLOCKED_CONNECT;
b->retry_reason = BIO_RR_CONNECT;
ERR_clear_error();
} else if ((c->addr_iter = BIO_ADDRINFO_next(c->addr_iter))
!= NULL) {
/*
* if there are more addresses to try, do that first
*/
BIO_closesocket(b->num);
c->state = BIO_CONN_S_CREATE_SOCKET;
ERR_clear_error();
break;
} else {
SYSerr(SYS_F_CONNECT, get_last_socket_error());
ERR_add_error_data(4,
"hostname=", c->param_hostname,
" service=", c->param_service);
c->state = BIO_CONN_S_CONNECT_ERROR;
break;
}
goto exit_loop;
} else {
c->state = BIO_CONN_S_OK;
}
break;
case BIO_CONN_S_BLOCKED_CONNECT:
i = BIO_sock_error(b->num);
if (i) {
BIO_clear_retry_flags(b);
SYSerr(SYS_F_CONNECT, i);
ERR_add_error_data(4,
"hostname=", c->param_hostname,
" service=", c->param_service);
BIOerr(BIO_F_CONN_STATE, BIO_R_NBIO_CONNECT_ERROR);
ret = 0;
goto exit_loop;
} else
c->state = BIO_CONN_S_OK;
break;
case BIO_CONN_S_CONNECT_ERROR:
BIOerr(BIO_F_CONN_STATE, BIO_R_CONNECT_ERROR);
ret = 0;
goto exit_loop;
case BIO_CONN_S_OK:
ret = 1;
goto exit_loop;
default:
/* abort(); */
goto exit_loop;
}
if (cb != NULL) {
if ((ret = cb((BIO *)b, c->state, ret)) == 0)
goto end;
}
}
/* Loop does not exit */
exit_loop:
if (cb != NULL)
ret = cb((BIO *)b, c->state, ret);
end:
return ret;
}
BIO_CONNECT *BIO_CONNECT_new(void)
{
BIO_CONNECT *ret;
if ((ret = OPENSSL_zalloc(sizeof(*ret))) == NULL) {
BIOerr(BIO_F_BIO_CONNECT_NEW, ERR_R_MALLOC_FAILURE);
return NULL;
}
ret->state = BIO_CONN_S_BEFORE;
ret->connect_family = BIO_FAMILY_IPANY;
return ret;
}
void BIO_CONNECT_free(BIO_CONNECT *a)
{
if (a == NULL)
return;
OPENSSL_free(a->param_hostname);
OPENSSL_free(a->param_service);
BIO_ADDRINFO_free(a->addr_first);
OPENSSL_free(a);
}
const BIO_METHOD *BIO_s_connect(void)
{
return &methods_connectp;
}
static int conn_new(BIO *bi)
{
bi->init = 0;
bi->num = (int)INVALID_SOCKET;
bi->flags = 0;
if ((bi->ptr = (char *)BIO_CONNECT_new()) == NULL)
return 0;
else
return 1;
}
static void conn_close_socket(BIO *bio)
{
BIO_CONNECT *c;
c = (BIO_CONNECT *)bio->ptr;
if (bio->num != (int)INVALID_SOCKET) {
/* Only do a shutdown if things were established */
if (c->state == BIO_CONN_S_OK)
shutdown(bio->num, 2);
BIO_closesocket(bio->num);
bio->num = (int)INVALID_SOCKET;
}
}
static int conn_free(BIO *a)
{
BIO_CONNECT *data;
if (a == NULL)
return 0;
data = (BIO_CONNECT *)a->ptr;
if (a->shutdown) {
conn_close_socket(a);
BIO_CONNECT_free(data);
a->ptr = NULL;
a->flags = 0;
a->init = 0;
}
return 1;
}
static int conn_read(BIO *b, char *out, int outl)
{
int ret = 0;
BIO_CONNECT *data;
data = (BIO_CONNECT *)b->ptr;
if (data->state != BIO_CONN_S_OK) {
ret = conn_state(b, data);
if (ret <= 0)
return ret;
}
if (out != NULL) {
clear_socket_error();
ret = readsocket(b->num, out, outl);
BIO_clear_retry_flags(b);
if (ret <= 0) {
if (BIO_sock_should_retry(ret))
BIO_set_retry_read(b);
}
}
return ret;
}
static int conn_write(BIO *b, const char *in, int inl)
{
int ret;
BIO_CONNECT *data;
data = (BIO_CONNECT *)b->ptr;
if (data->state != BIO_CONN_S_OK) {
ret = conn_state(b, data);
if (ret <= 0)
return ret;
}
clear_socket_error();
ret = writesocket(b->num, in, inl);
BIO_clear_retry_flags(b);
if (ret <= 0) {
if (BIO_sock_should_retry(ret))
BIO_set_retry_write(b);
}
return ret;
}
static long conn_ctrl(BIO *b, int cmd, long num, void *ptr)
{
BIO *dbio;
int *ip;
const char **pptr = NULL;
long ret = 1;
BIO_CONNECT *data;
data = (BIO_CONNECT *)b->ptr;
switch (cmd) {
case BIO_CTRL_RESET:
ret = 0;
data->state = BIO_CONN_S_BEFORE;
conn_close_socket(b);
BIO_ADDRINFO_free(data->addr_first);
data->addr_first = NULL;
b->flags = 0;
break;
case BIO_C_DO_STATE_MACHINE:
/* use this one to start the connection */
if (data->state != BIO_CONN_S_OK)
ret = (long)conn_state(b, data);
else
ret = 1;
break;
case BIO_C_GET_CONNECT:
if (ptr != NULL) {
pptr = (const char **)ptr;
if (num == 0) {
*pptr = data->param_hostname;
} else if (num == 1) {
*pptr = data->param_service;
} else if (num == 2) {
*pptr = (const char *)BIO_ADDRINFO_address(data->addr_iter);
} else if (num == 3) {
switch (BIO_ADDRINFO_family(data->addr_iter)) {
# ifdef AF_INET6
case AF_INET6:
ret = BIO_FAMILY_IPV6;
break;
# endif
case AF_INET:
ret = BIO_FAMILY_IPV4;
break;
case 0:
ret = data->connect_family;
break;
default:
ret = -1;
break;
}
} else {
ret = 0;
}
} else {
ret = 0;
}
break;
case BIO_C_SET_CONNECT:
if (ptr != NULL) {
b->init = 1;
if (num == 0) {
char *hold_service = data->param_service;
/* We affect the hostname regardless. However, the input
* string might contain a host:service spec, so we must
* parse it, which might or might not affect the service
*/
OPENSSL_free(data->param_hostname);
data->param_hostname = NULL;
ret = BIO_parse_hostserv(ptr,
&data->param_hostname,
&data->param_service,
BIO_PARSE_PRIO_HOST);
if (hold_service != data->param_service)
OPENSSL_free(hold_service);
} else if (num == 1) {
OPENSSL_free(data->param_service);
data->param_service = BUF_strdup(ptr);
} else if (num == 2) {
const BIO_ADDR *addr = (const BIO_ADDR *)ptr;
if (ret) {
data->param_hostname = BIO_ADDR_hostname_string(addr, 1);
data->param_service = BIO_ADDR_service_string(addr, 1);
BIO_ADDRINFO_free(data->addr_first);
data->addr_first = NULL;
data->addr_iter = NULL;
}
} else if (num == 3) {
data->connect_family = *(int *)ptr;
} else {
ret = 0;
}
}
break;
case BIO_C_SET_NBIO:
if (num != 0)
data->connect_mode |= BIO_SOCK_NONBLOCK;
else
data->connect_mode &= ~BIO_SOCK_NONBLOCK;
break;
case BIO_C_SET_CONNECT_MODE:
data->connect_mode = (int)num;
break;
case BIO_C_GET_FD:
if (b->init) {
ip = (int *)ptr;
if (ip != NULL)
*ip = b->num;
ret = b->num;
} else
ret = -1;
break;
case BIO_CTRL_GET_CLOSE:
ret = b->shutdown;
break;
case BIO_CTRL_SET_CLOSE:
b->shutdown = (int)num;
break;
case BIO_CTRL_PENDING:
case BIO_CTRL_WPENDING:
ret = 0;
break;
case BIO_CTRL_FLUSH:
break;
case BIO_CTRL_DUP:
{
dbio = (BIO *)ptr;
if (data->param_hostname)
BIO_set_conn_hostname(dbio, data->param_hostname);
if (data->param_service)
BIO_set_conn_port(dbio, data->param_service);
BIO_set_conn_ip_family(dbio, data->connect_family);
BIO_set_conn_mode(dbio, data->connect_mode);
/*
* FIXME: the cast of the function seems unlikely to be a good
* idea
*/
(void)BIO_set_info_callback(dbio, data->info_callback);
}
break;
case BIO_CTRL_SET_CALLBACK:
ret = 0; /* use callback ctrl */
break;
case BIO_CTRL_GET_CALLBACK:
{
BIO_info_cb **fptr;
fptr = (BIO_info_cb **)ptr;
*fptr = data->info_callback;
}
break;
default:
ret = 0;
break;
}
return ret;
}
static long conn_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
{
long ret = 1;
BIO_CONNECT *data;
data = (BIO_CONNECT *)b->ptr;
switch (cmd) {
case BIO_CTRL_SET_CALLBACK:
{
data->info_callback = fp;
}
break;
default:
ret = 0;
break;
}
return ret;
}
static int conn_puts(BIO *bp, const char *str)
{
int n, ret;
n = strlen(str);
ret = conn_write(bp, str, n);
return ret;
}
BIO *BIO_new_connect(const char *str)
{
BIO *ret;
ret = BIO_new(BIO_s_connect());
if (ret == NULL)
return NULL;
if (BIO_set_conn_hostname(ret, str))
return ret;
BIO_free(ret);
return NULL;
}
#endif