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2 .\" Copyright (C) 2000, 2001, 2003 Internet Software Consortium.
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19 .\" Title: lwres_getaddrinfo
21 .\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
27 .TH "LWRES_GETADDRINFO" "3" "2007\-06\-18" "ISC" "BIND9"
28 .\" -----------------------------------------------------------------
29 .\" * Define some portability stuff
30 .\" -----------------------------------------------------------------
31 .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
32 .\" http://bugs.debian.org/507673
33 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
34 .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
37 .\" -----------------------------------------------------------------
38 .\" * set default formatting
39 .\" -----------------------------------------------------------------
40 .\" disable hyphenation
42 .\" disable justification (adjust text to left margin only)
44 .\" -----------------------------------------------------------------
45 .\" * MAIN CONTENT STARTS HERE *
46 .\" -----------------------------------------------------------------
48 lwres_getaddrinfo, lwres_freeaddrinfo \- socket address structure to host and service name
53 #include <lwres/netdb\&.h>
56 .HP \w'int\ lwres_getaddrinfo('u
57 .BI "int lwres_getaddrinfo(const\ char\ *" "hostname" ", const\ char\ *" "servname" ", const\ struct\ addrinfo\ *" "hints" ", struct\ addrinfo\ **" "res" ");"
58 .HP \w'void\ lwres_freeaddrinfo('u
59 .BI "void lwres_freeaddrinfo(struct\ addrinfo\ *" "ai" ");"
61 If the operating system does not provide a
62 \fBstruct addrinfo\fR, the following structure is used:
66 int ai_flags; /* AI_PASSIVE, AI_CANONNAME */
67 int ai_family; /* PF_xxx */
68 int ai_socktype; /* SOCK_xxx */
69 int ai_protocol; /* 0 or IPPROTO_xxx for IPv4 and IPv6 */
70 size_t ai_addrlen; /* length of ai_addr */
71 char *ai_canonname; /* canonical name for hostname */
72 struct sockaddr *ai_addr; /* binary address */
73 struct addrinfo *ai_next; /* next structure in linked list */
79 \fBlwres_getaddrinfo()\fR
80 is used to get a list of IP addresses and port numbers for host
83 \fIservname\fR\&. The function is the lightweight resolver\*(Aqs implementation of
85 as defined in RFC2133\&.
89 are pointers to null\-terminated strings or
92 is either a host name or a numeric host address string: a dotted decimal IPv4 address or an IPv6 address\&.
94 is either a decimal port number or a service name as listed in
98 is an optional pointer to a
99 \fBstruct addrinfo\fR\&. This structure can be used to provide hints concerning the type of socket that the caller supports or wishes to use\&. The caller can supply the following structure elements in
104 The protocol family that should be used\&. When
107 \fBPF_UNSPEC\fR, it means the caller will accept any protocol family supported by the operating system\&.
112 denotes the type of socket \(em
117 \(em that is wanted\&. When
119 is zero the caller will accept any socket type\&.
124 indicates which transport protocol is wanted: IPPROTO_UDP or IPPROTO_TCP\&. If
126 is zero the caller will accept any protocol\&.
133 bit is set, a successful call to
134 \fBlwres_getaddrinfo()\fR
135 will return a null\-terminated string containing the canonical name of the specified hostname in
139 structure returned\&. Setting the
141 bit indicates that the returned socket address structure is intended for used in a call to
142 \fBbind\fR(2)\&. In this case, if the hostname argument is a
144 pointer, then the IP address portion of the socket address structure will be set to
146 for an IPv4 address or
147 \fBIN6ADDR_ANY_INIT\fR
148 for an IPv6 address\&.
154 bit, the returned socket address structure will be ready for use in a call to
156 for a connection\-oriented protocol or
160 if a connectionless protocol was chosen\&. The IP address portion of the socket address structure will be set to the loopback address if
175 should be treated as a numeric string defining an IPv4 or IPv6 address and no name resolution should be attempted\&.
178 All other elements of the
179 \fBstruct addrinfo\fR
188 is treated as if the caller provided a
189 \fBstruct addrinfo\fR
190 initialized to zero with
191 \fBai_family\fRset to
194 After a successful call to
195 \fBlwres_getaddrinfo()\fR,
197 is a pointer to a linked list of one or more
200 \fBstruct addrinfo\fR
201 in this list cn be processed by following the
205 pointer is encountered\&. The three members
207 \fBai_socktype\fR, and
211 structure contain the corresponding arguments for a call to
212 \fBsocket\fR(2)\&. For each
214 structure in the list, the
216 member points to a filled\-in socket address structure of length
219 All of the information returned by
220 \fBlwres_getaddrinfo()\fR
221 is dynamically allocated: the addrinfo structures, and the socket address structures and canonical host name strings pointed to by the
222 \fBaddrinfo\fRstructures\&. Memory allocated for the dynamically allocated structures created by a successful call to
223 \fBlwres_getaddrinfo()\fR
225 \fBlwres_freeaddrinfo()\fR\&.
228 \fBstruct addrinfo\fR
230 \fBlwres_getaddrinfo()\fR\&.
233 \fBlwres_getaddrinfo()\fR
234 returns zero on success or one of the error codes listed in
235 \fBgai_strerror\fR(3)
236 if an error occurs\&. If both
241 \fBNULL\fR\fBlwres_getaddrinfo()\fR
247 \fBlwres_getaddrinfo\fR(3),
248 \fBlwres_freeaddrinfo\fR(3),
249 \fBlwres_gai_strerror\fR(3),
251 \fBgetservbyname\fR(3),
259 \fBInternet Systems Consortium, Inc\&.\fR
262 Copyright \(co 2004, 2005, 2007, 2014, 2015 Internet Systems Consortium, Inc. ("ISC")
264 Copyright \(co 2000, 2001, 2003 Internet Software Consortium.