1=pod
2
3=head1 NAME
4
5BIO_lookup_type,
6BIO_ADDRINFO, BIO_ADDRINFO_next, BIO_ADDRINFO_free,
7BIO_ADDRINFO_family, BIO_ADDRINFO_socktype, BIO_ADDRINFO_protocol,
8BIO_ADDRINFO_address,
9BIO_lookup_ex,
10BIO_lookup
11- BIO_ADDRINFO type and routines
12
13=head1 SYNOPSIS
14
15 #include <sys/types.h>
16 #include <openssl/bio.h>
17
18 typedef union bio_addrinfo_st BIO_ADDRINFO;
19
20 enum BIO_lookup_type {
21     BIO_LOOKUP_CLIENT, BIO_LOOKUP_SERVER
22 };
23
24 int BIO_lookup_ex(const char *host, const char *service, int lookup_type,
25                   int family, int socktype, int protocol, BIO_ADDRINFO **res);
26 int BIO_lookup(const char *node, const char *service,
27                enum BIO_lookup_type lookup_type,
28                int family, int socktype, BIO_ADDRINFO **res);
29
30 const BIO_ADDRINFO *BIO_ADDRINFO_next(const BIO_ADDRINFO *bai);
31 int BIO_ADDRINFO_family(const BIO_ADDRINFO *bai);
32 int BIO_ADDRINFO_socktype(const BIO_ADDRINFO *bai);
33 int BIO_ADDRINFO_protocol(const BIO_ADDRINFO *bai);
34 const BIO_ADDR *BIO_ADDRINFO_address(const BIO_ADDRINFO *bai);
35 void BIO_ADDRINFO_free(BIO_ADDRINFO *bai);
36
37=head1 DESCRIPTION
38
39The B<BIO_ADDRINFO> type is a wrapper for address information
40types provided on your platform.
41
42B<BIO_ADDRINFO> normally forms a chain of several that can be
43picked at one by one.
44
45BIO_lookup_ex() looks up a specified B<host> and B<service>, and
46uses B<lookup_type> to determine what the default address should
47be if B<host> is B<NULL>. B<family>, B<socktype> and B<protocol> are used to
48determine what protocol family, socket type and protocol should be used for
49the lookup.  B<family> can be any of AF_INET, AF_INET6, AF_UNIX and
50AF_UNSPEC. B<socktype> can be SOCK_STREAM, SOCK_DGRAM or 0. Specifying 0
51indicates that any type can be used. B<protocol> specifies a protocol such as
52IPPROTO_TCP, IPPROTO_UDP or IPPORTO_SCTP. If set to 0 than any protocol can be
53used. B<res> points at a pointer to hold the start of a B<BIO_ADDRINFO>
54chain.
55
56For the family B<AF_UNIX>, BIO_lookup_ex() will ignore the B<service>
57parameter and expects the B<node> parameter to hold the path to the
58socket file.
59
60BIO_lookup() does the same as BIO_lookup_ex() but does not provide the ability
61to select based on the protocol (any protocol may be returned).
62
63BIO_ADDRINFO_family() returns the family of the given
64B<BIO_ADDRINFO>.  The result will be one of the constants
65AF_INET, AF_INET6 and AF_UNIX.
66
67BIO_ADDRINFO_socktype() returns the socket type of the given
68B<BIO_ADDRINFO>.  The result will be one of the constants
69SOCK_STREAM and SOCK_DGRAM.
70
71BIO_ADDRINFO_protocol() returns the protocol id of the given
72B<BIO_ADDRINFO>.  The result will be one of the constants
73IPPROTO_TCP and IPPROTO_UDP.
74
75BIO_ADDRINFO_address() returns the underlying B<BIO_ADDR>
76of the given B<BIO_ADDRINFO>.
77
78BIO_ADDRINFO_next() returns the next B<BIO_ADDRINFO> in the chain
79from the given one.
80
81BIO_ADDRINFO_free() frees the chain of B<BIO_ADDRINFO> starting
82with the given one.
83
84=head1 RETURN VALUES
85
86BIO_lookup_ex() and BIO_lookup() return 1 on success and 0 when an error
87occurred, and will leave an error indication on the OpenSSL error stack in that
88case.
89
90All other functions described here return 0 or B<NULL> when the
91information they should return isn't available.
92
93=head1 NOTES
94
95The BIO_lookup_ex() implementation uses the platform provided getaddrinfo()
96function. On Linux it is known that specifying 0 for the protocol will not
97return any SCTP based addresses when calling getaddrinfo(). Therefore if an SCTP
98address is required then the B<protocol> parameter to BIO_lookup_ex() should be
99explicitly set to IPPROTO_SCTP. The same may be true on other platforms.
100
101=head1 HISTORY
102
103The BIO_lookup_ex() function was added in OpenSSL 1.1.1.
104
105=head1 COPYRIGHT
106
107Copyright 2016-2017 The OpenSSL Project Authors. All Rights Reserved.
108
109Licensed under the OpenSSL license (the "License").  You may not use
110this file except in compliance with the License.  You can obtain a copy
111in the file LICENSE in the source distribution or at
112L<https://www.openssl.org/source/license.html>.
113
114=cut
115