1=pod 2 3=head1 NAME 4 5BIO_set_conn_address, BIO_get_conn_address, 6BIO_s_connect, BIO_new_connect, BIO_set_conn_hostname, BIO_set_conn_port, 7BIO_set_conn_ip_family, BIO_get_conn_ip_family, 8BIO_get_conn_hostname, BIO_get_conn_port, 9BIO_set_nbio, BIO_do_connect - connect BIO 10 11=head1 SYNOPSIS 12 13 #include <openssl/bio.h> 14 15 const BIO_METHOD * BIO_s_connect(void); 16 17 BIO *BIO_new_connect(char *name); 18 19 long BIO_set_conn_hostname(BIO *b, char *name); 20 long BIO_set_conn_port(BIO *b, char *port); 21 long BIO_set_conn_address(BIO *b, BIO_ADDR *addr); 22 long BIO_set_conn_ip_family(BIO *b, long family); 23 const char *BIO_get_conn_hostname(BIO *b); 24 const char *BIO_get_conn_port(BIO *b); 25 const BIO_ADDR *BIO_get_conn_address(BIO *b); 26 const long BIO_get_conn_ip_family(BIO *b); 27 28 long BIO_set_nbio(BIO *b, long n); 29 30 int BIO_do_connect(BIO *b); 31 32=head1 DESCRIPTION 33 34BIO_s_connect() returns the connect BIO method. This is a wrapper 35round the platform's TCP/IP socket connection routines. 36 37Using connect BIOs, TCP/IP connections can be made and data 38transferred using only BIO routines. In this way any platform 39specific operations are hidden by the BIO abstraction. 40 41Read and write operations on a connect BIO will perform I/O 42on the underlying connection. If no connection is established 43and the port and hostname (see below) is set up properly then 44a connection is established first. 45 46Connect BIOs support BIO_puts() but not BIO_gets(). 47 48If the close flag is set on a connect BIO then any active 49connection is shutdown and the socket closed when the BIO 50is freed. 51 52Calling BIO_reset() on a connect BIO will close any active 53connection and reset the BIO into a state where it can connect 54to the same host again. 55 56BIO_get_fd() places the underlying socket in B<c> if it is not NULL, 57it also returns the socket . If B<c> is not NULL it should be of 58type (int *). 59 60BIO_set_conn_hostname() uses the string B<name> to set the hostname. 61The hostname can be an IP address; if the address is an IPv6 one, it 62must be enclosed with brackets. The hostname can also include the 63port in the form hostname:port. 64 65BIO_set_conn_port() sets the port to B<port>. B<port> can be the 66numerical form or a string such as "http". A string will be looked 67up first using getservbyname() on the host platform but if that 68fails a standard table of port names will be used. This internal 69list is http, telnet, socks, https, ssl, ftp, and gopher. 70 71BIO_set_conn_address() sets the address and port information using 72a BIO_ADDR(3ssl). 73 74BIO_set_conn_ip_family() sets the IP family. 75 76BIO_get_conn_hostname() returns the hostname of the connect BIO or 77NULL if the BIO is initialized but no hostname is set. 78This return value is an internal pointer which should not be modified. 79 80BIO_get_conn_port() returns the port as a string. 81This return value is an internal pointer which should not be modified. 82 83BIO_get_conn_address() returns the address information as a BIO_ADDR. 84This return value is an internal pointer which should not be modified. 85 86BIO_get_conn_ip_family() returns the IP family of the connect BIO. 87 88BIO_set_nbio() sets the non blocking I/O flag to B<n>. If B<n> is 89zero then blocking I/O is set. If B<n> is 1 then non blocking I/O 90is set. Blocking I/O is the default. The call to BIO_set_nbio() 91should be made before the connection is established because 92non blocking I/O is set during the connect process. 93 94BIO_new_connect() combines BIO_new() and BIO_set_conn_hostname() into 95a single call: that is it creates a new connect BIO with B<name>. 96 97BIO_do_connect() attempts to connect the supplied BIO. It returns 1 98if the connection was established successfully. A zero or negative 99value is returned if the connection could not be established, the 100call BIO_should_retry() should be used for non blocking connect BIOs 101to determine if the call should be retried. 102 103=head1 NOTES 104 105If blocking I/O is set then a non positive return value from any 106I/O call is caused by an error condition, although a zero return 107will normally mean that the connection was closed. 108 109If the port name is supplied as part of the hostname then this will 110override any value set with BIO_set_conn_port(). This may be undesirable 111if the application does not wish to allow connection to arbitrary 112ports. This can be avoided by checking for the presence of the ':' 113character in the passed hostname and either indicating an error or 114truncating the string at that point. 115 116The values returned by BIO_get_conn_hostname(), BIO_get_conn_address(), 117and BIO_get_conn_port() are updated when a connection attempt is made. 118Before any connection attempt the values returned are those set by the 119application itself. 120 121Applications do not have to call BIO_do_connect() but may wish to do 122so to separate the connection process from other I/O processing. 123 124If non blocking I/O is set then retries will be requested as appropriate. 125 126It addition to BIO_should_read() and BIO_should_write() it is also 127possible for BIO_should_io_special() to be true during the initial 128connection process with the reason BIO_RR_CONNECT. If this is returned 129then this is an indication that a connection attempt would block, 130the application should then take appropriate action to wait until 131the underlying socket has connected and retry the call. 132 133BIO_set_conn_hostname(), BIO_set_conn_port(), BIO_get_conn_hostname(), 134BIO_set_conn_address(), BIO_get_conn_port(), BIO_get_conn_address(), 135BIO_set_conn_ip_family(), BIO_get_conn_ip_family(), 136BIO_set_nbio(), and BIO_do_connect() are macros. 137 138=head1 RETURN VALUES 139 140BIO_s_connect() returns the connect BIO method. 141 142BIO_get_fd() returns the socket or -1 if the BIO has not 143been initialized. 144 145BIO_set_conn_address(), BIO_set_conn_port(), and BIO_set_conn_ip_family() 146always return 1. 147 148BIO_set_conn_hostname() returns 1 on success and 0 on failure. 149 150BIO_get_conn_address() returns the address information or NULL if none 151was set. 152 153BIO_get_conn_hostname() returns the connected hostname or NULL if 154none was set. 155 156BIO_get_conn_ip_family() returns the address family or -1 if none was set. 157 158BIO_get_conn_port() returns a string representing the connected 159port or NULL if not set. 160 161BIO_set_nbio() always returns 1. 162 163BIO_do_connect() returns 1 if the connection was successfully 164established and 0 or -1 if the connection failed. 165 166=head1 EXAMPLES 167 168This is example connects to a webserver on the local host and attempts 169to retrieve a page and copy the result to standard output. 170 171 172 BIO *cbio, *out; 173 int len; 174 char tmpbuf[1024]; 175 176 cbio = BIO_new_connect("localhost:http"); 177 out = BIO_new_fp(stdout, BIO_NOCLOSE); 178 if (BIO_do_connect(cbio) <= 0) { 179 fprintf(stderr, "Error connecting to server\n"); 180 ERR_print_errors_fp(stderr); 181 exit(1); 182 } 183 BIO_puts(cbio, "GET / HTTP/1.0\n\n"); 184 for (;;) { 185 len = BIO_read(cbio, tmpbuf, 1024); 186 if (len <= 0) 187 break; 188 BIO_write(out, tmpbuf, len); 189 } 190 BIO_free(cbio); 191 BIO_free(out); 192 193 194=head1 SEE ALSO 195 196L<BIO_ADDR(3)> 197 198=head1 HISTORY 199 200BIO_set_conn_int_port(), BIO_get_conn_int_port(), BIO_set_conn_ip(), and BIO_get_conn_ip() 201were removed in OpenSSL 1.1.0. 202Use BIO_set_conn_address() and BIO_get_conn_address() instead. 203 204=head1 COPYRIGHT 205 206Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved. 207 208Licensed under the OpenSSL license (the "License"). You may not use 209this file except in compliance with the License. You can obtain a copy 210in the file LICENSE in the source distribution or at 211L<https://www.openssl.org/source/license.html>. 212 213=cut 214