sofia-sip/su_localinfo.h File Reference

Interface for obtaining local addresses. More...

#include <sofia-sip/su.h>

Include dependency graph for su_localinfo.h:

Go to the source code of this file.

Data Structures
struct	su_localinfo_s
	Local address info structure. More...
Defines
#define	SU_LOCALINFO_H
	Defined when <sofia-sip/su_localinfo.h> has been included.
Typedefs
typedef struct su_localinfo_s	su_localinfo_t
	Local address info structure.
Enumerations
enum	{   LI_V4MAPPED,   LI_CANONNAME,   LI_NAMEREQD,   LI_NUMERIC,   LI_DOWN,   LI_IFNAME }
	Flags for su_getlocalinfo() - li_flags. More...
enum	{   LI_SCOPE_HOST,   LI_SCOPE_LINK,   LI_SCOPE_SITE,   LI_SCOPE_GLOBAL }
	Localinfo scope - li_scope. More...
enum	{   ELI_NOADDRESS,   ELI_MEMORY,   ELI_FAMILY,   ELI_RESOLVER,   ELI_SYSTEM,   ELI_BADHINTS,   ELI_NOERROR }
	Localinfo error codes. More...
Functions
int	su_getlocalinfo (su_localinfo_t const *hints, su_localinfo_t **res)
	Request local address information.
void	su_freelocalinfo (su_localinfo_t *)
	Free local address information.
char const *	su_gli_strerror (int error)
	Describe su_localinfo errors.
su_localinfo_t *	su_copylocalinfo (su_localinfo_t const *li0)
	Copy a localinfo structure.
int	su_sockaddr_scope (su_sockaddr_t const *su, socklen_t sulen)
	Return the scope of address in the sockaddr structure.

---

Detailed Description

Interface for obtaining local addresses.

Author:

Pekka Pessi <Pekka.Pessi@nokia-email.address.hidden>

Date:

Created: Thu Aug 10 18:58:01 2000 ppessi

---

Define Documentation

#define SU_LOCALINFO_H

Defined when <sofia-sip/su_localinfo.h> has been included.

---

Typedef Documentation

typedef struct su_localinfo_s su_localinfo_t

Local address info structure.

---

Enumeration Type Documentation

anonymous enum

Flags for su_getlocalinfo() - li_flags.

Enumerator:

LI_V4MAPPED	IPv4 addresses will be mapped as IPv6.
LI_CANONNAME	Get domain name corresponding to the local address.
LI_NAMEREQD	Do not return addresses not in DNS. Implies LI_CANONNAME.
LI_NUMERIC	Instead of domain name, use numeric form.
LI_DOWN	Include interfaces even if they are down (new in 1.12.2).
LI_IFNAME	Get interface name.

anonymous enum

Localinfo scope - li_scope.

Enumerator:

LI_SCOPE_HOST	Host-local address, valid within host.
LI_SCOPE_LINK	Link-local address.
LI_SCOPE_SITE	Site-local address.
LI_SCOPE_GLOBAL	Global address.

anonymous enum

Localinfo error codes.

Enumerator:

ELI_NOADDRESS	No matching address.
ELI_MEMORY	Memory allocation error.
ELI_FAMILY	Unknown address family.
ELI_RESOLVER	Error when resolving address.
ELI_SYSTEM	System error.
ELI_BADHINTS	Invalid value for hints.
ELI_NOERROR	No error.

---

Function Documentation

void su_freelocalinfo

(

su_localinfo_t *

tbf

)

Free local address information.

Free a list of su_localinfo_t structures obtained with su_getlocalinfo() or su_copylocalinfo() along with socket addresses and strings associated with them.

See also:

su_getlocalinfo(), su_copylocalinfo(), su_localinfo_t

int su_getlocalinfo	(	su_localinfo_t const *	hints,
		su_localinfo_t **	return_localinfo
	)

Request local address information.

Gather the network interfaces and the addresses corresponding to them, check if they match to the search criteria specifed by hints and return a list of matching local address information in the return_localinfo. The local address information may include IPv4/IPv6 addresses, interface name, interface index, address scope, and domain names corresponding to the local addresses.

Parameters:

[in]	hints	specifies selection criteria
[out]	return_localinfo	return list of local addresses

Selection criteria - hints

The selection criteria hints is used to select which addresses are returned and what kind of information is included in the res list.

Selection by flags - hints->li_flags

The hints->li_flags contain flags, which can be combined with bit-wise or. The currently defined flags are as follows:

• LI_V4MAPPED: when returning IPv4 addresses, map them as IPv6 addresses. If this flag is specified, IPv4 addresses are returned even if hints->li_family is set to AF_INET6.
• LI_CANONNAME: return the domain name (DNS PTR) corresponding to the local address in li_canonname.
• LI_NAMEREQD: Do not return addresses not in DNS.
• LI_NUMERIC: instead of domain name, return the text presentation of the addresss in li_canonname.
• LI_DOWN: include interfaces and their addresses even if the interfaces are down. New in 1.12.2.
• LI_IFNAME: return the interface name in li_ifname.

Selection by address family - hints->li_family

The address family can have three values: 0, AF_INET and AF_INET6. If address family hints->li_family, both IPv4 and IPv6 addresses are returned.

Selection by interface index - hints->li_index

If the field hints->li_index is non-zero, only the addresses assigned to the interface with given index are returned. The list of interface indices and names can be obtained by the function su_if_names().

Selection by interface name - hints->li_ifname

If the field hints->li_ifname is not NULL, only the addresses assigned to the named interface are returned. The list of interface names can be obtained by the function su_if_names().

Selection by address scope - hints->li_scope

If the field hints->li_scope is nonzero, only the addresses with matching scope are returned. The different address scopes can be combined with bitwise or. They are defined as follows

• LI_SCOPE_HOST: host-local address, valid within host (::1, 127.0.0.1/8)
• LI_SCOPE_LINK: link-local address, valid within link (IP6 addresses with prefix fe80::/10, IP4 addresses in net 169.254.0.0/16).
• LI_SCOPE_SITE: site-local address, addresses valid within organization (IPv6 addresses with prefix fec::/10, private IPv4 addresses in nets 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 as defined in RFC 1918)
• LI_SCOPE_GLOBAL: global address.

For instance, setting hints->li_scope to LI_SCOPE_GLOBAL | LI_SCOPE_SITE, both the global and site-local addresses are returned.

See also:

RFC 1918, RFC 4291, su_sockaddr_scope()

Selection by domain name - hints->li_canonname

If this field is non-null, the domain name (DNS PTR) corresponding to local IP addresses should match to the name given in this field.

Returns:

Zero (ELI_NOERROR) when successful, or negative error code when failed.

Diagnostics

Use su_gli_strerror() in order to obtain a string describing the error code returned by su_getlocalinfo().

char const* su_gli_strerror

(

int

error

)

Describe su_localinfo errors.

The function su_gli_strerror() returns a string describing the error condition indicated by the code that was returned by the function su_getlocalinfo().

Parameters:

error

error code returned by su_getlocalinfo()

Returns:

A pointer to string describing the error condition.