xref: /freebsd/crypto/openssl/doc/man3/BIO_ADDRINFO.pod (revision 7ef62cebc2f965b0f640263e179276928885e33d)
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 *host, 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<host> parameter to hold the path to the socket file.
58
59BIO_lookup() does the same as BIO_lookup_ex() but does not provide the ability
60to select based on the protocol (any protocol may be returned).
61
62BIO_ADDRINFO_family() returns the family of the given
63B<BIO_ADDRINFO>.  The result will be one of the constants
64AF_INET, AF_INET6 and AF_UNIX.
65
66BIO_ADDRINFO_socktype() returns the socket type of the given
67B<BIO_ADDRINFO>.  The result will be one of the constants
68SOCK_STREAM and SOCK_DGRAM.
69
70BIO_ADDRINFO_protocol() returns the protocol id of the given
71B<BIO_ADDRINFO>.  The result will be one of the constants
72IPPROTO_TCP and IPPROTO_UDP.
73
74BIO_ADDRINFO_address() returns the underlying B<BIO_ADDR>
75of the given B<BIO_ADDRINFO>.
76
77BIO_ADDRINFO_next() returns the next B<BIO_ADDRINFO> in the chain
78from the given one.
79
80BIO_ADDRINFO_free() frees the chain of B<BIO_ADDRINFO> starting
81with the given one.
82
83=head1 RETURN VALUES
84
85BIO_lookup_ex() and BIO_lookup() return 1 on success and 0 when an error
86occurred, and will leave an error indication on the OpenSSL error stack in that
87case.
88
89All other functions described here return 0 or B<NULL> when the
90information they should return isn't available.
91
92=head1 NOTES
93
94The BIO_lookup_ex() implementation uses the platform provided getaddrinfo()
95function. On Linux it is known that specifying 0 for the protocol will not
96return any SCTP based addresses when calling getaddrinfo(). Therefore, if an SCTP
97address is required then the B<protocol> parameter to BIO_lookup_ex() should be
98explicitly set to IPPROTO_SCTP. The same may be true on other platforms.
99
100=head1 HISTORY
101
102The BIO_lookup_ex() function was added in OpenSSL 1.1.1.
103
104=head1 COPYRIGHT
105
106Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved.
107
108Licensed under the Apache License 2.0 (the "License").  You may not use
109this file except in compliance with the License.  You can obtain a copy
110in the file LICENSE in the source distribution or at
111L<https://www.openssl.org/source/license.html>.
112
113=cut
114