Host Identity Protocol M. Komu
Internet-Draft Helsinki Institute for Information
Intended status: Experimental Technology
Expires: January 31, 2010 Henderson
The Boeing Company
July 30, 2009
Basic Socket Interface Extensions for Host Identity Protocol (HIP)
draft-ietf-hip-native-api-08
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Abstract
This document defines extensions to the current sockets API for the
Host Identity Protocol (HIP). The extensions focus on the use of
public-key based identifiers discovered via DNS resolution, but
define also interfaces for manual bindings between HITs and locators.
With the extensions, the application can also support more relaxed
security models where the communication can be non-HIP based,
according to local policies. The extensions in document are
experimental and provide basic tools for further experimentation with
policies.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Name Resolution Process . . . . . . . . . . . . . . . . . . . 5
3.1. Interaction with the Resolver . . . . . . . . . . . . . . 5
3.2. Interaction without a Resolver . . . . . . . . . . . . . . 6
4. API Syntax and Semantics . . . . . . . . . . . . . . . . . . . 7
4.1. Socket Family and Address Structure Extensions . . . . . . 7
4.2. Extensions to Resolver Data Structures . . . . . . . . . . 9
4.3. The Use of getsockname and getpeername Functions . . . . . 11
4.4. Selection of Source HIT Type . . . . . . . . . . . . . . . 11
4.5. Verification of Source HIT Type . . . . . . . . . . . . . 12
4.6. Explicit Handling of Locators . . . . . . . . . . . . . . 13
5. Summary of New Definitions . . . . . . . . . . . . . . . . . . 14
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
7. Security Considerations . . . . . . . . . . . . . . . . . . . 15
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 15
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15
10. Normative References . . . . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17
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1. Introduction
This document defines C-based sockets Application Programming
Interface (API) extensions for handling HIP-based identifiers
explicitly in HIP-aware applications. It is up to the applications,
or high-level programming languages or libraries, to manage the
identifiers. The extensions in this document are mainly related to
the use case in which a DNS resolution step has occurred prior to the
creation of a new socket, and assumes that the system has cached or
is otherwise able to resolve identifiers to locators (IP addresses).
The DNS extensions for HIP are described in [RFC5205]. The
extensions also cover the case in which an application may want to
explicitly provide suggested locators with the identifiers, including
supporting the opportunistic case in which the system does not know
the peer host identity.
The Host Identity Protocol (HIP) [RFC4423] proposes a new
cryptographic namespace by separating the roles of end-point
identifiers and locators by introducing a new namespace to the TCP/IP
stack. SHIM6 [I-D.ietf-shim6-proto] is another protocol based on
identity-locator split. The APIs specified in this document are
specific to HIP, but have been designed as much as possible so as not
to preclude its use with other protocols. The use of these APIs with
other protocols is, nevertheless, for further study.
The APIs in this document are based on IPv6 addresses with the ORCHID
prefix [RFC4843]. ORCHIDs are derived from Host Identifiers using a
hash and fitting the result into an IPv6 address. Such addresses are
called Host Identity Tags (HITs) and they can be distinguished from
other IPv6 addresses with the ORCHID prefix.
Applications can observe the HIP layer and its identifiers in the
networking stacks with varying degrees of visibility. [RFC5338]
discusses the lowest levels of visibility in which applications are
completely unaware of the underlying HIP layer. Such HIP-unaware
applications in some circumstances use HIP-based identifiers, such as
LSIs or HITs, instead of IPv4 or IPv6 addresses and cannot observe
the identifier-locator bindings.
This document specifies extensions to [RFC3493] to define a new
socket address family, AF_HIP. Similarly to other address families,
AF_HIP can used as an alias for PF_HIP. The extensions also describe
a new socket address structure for sockets using HITs explicitly and
describe how the socket calls in [RFC3493] are adapted or extended as
a result.
Some applications may accept incoming communications from any
identifier. Other applications may initiate outgoing communications
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without the knowledge of the peer identifier in Opportunistic Mode
(section 4.1.6 in [RFC5201]) by just relying on a peer locator. This
document describes how to address both situations using "wildcards"
as described later in this document.
There are two related API documents. Multihoming and explicit
locator-handling related APIs are defined in
[I-D.ietf-shim6-multihome-shim-api]. IPsec related policy attributes
and channel bindings APIs are defined in [I-D.ietf-btns-c-api]. Most
of the extensions defined in this document can be used independently
of the two mentioned API documents.
The identity-locator split introduced by HIP introduces some policy
related challenges with datagram oriented sockets, opportunistic
mode, and manual bindings between HITs and locators. The extensions
in this document are of an experimental nature and provide basic
tools for experimenting with policies. Policy related issues are
left for further experimentation.
To recap, the extensions in this document have three goals. The
first goal is to allow HIP-aware applications to open sockets to
other hosts based on the HITs alone, presuming that the underlying
system can resolve the HITs to addresses used for initial contact.
The second goal is that applications can explicitly initiate
communications with unknown peer identifiers. The third goal is to
illustrate how HIP-aware applications can use the SHIM API
[I-D.ietf-shim6-multihome-shim-api] to manually map locators to HITs.
2. Terminology
The terms used in this document are summarized in Table 1.
+---------+---------------------------------------------------------+
| Term | Explanation |
+---------+---------------------------------------------------------+
| HIP | Host Identity Protocol |
| HIT | Host Identity Tag, a 100-bit hash of a public key with |
| | a 28 bit prefix |
| LSI | Local Scope Identifier, a local, 32-bit descriptor for |
| | a given public key. |
| Locator | Routable IPv4 or IPv6 address used at the lower layers |
+---------+---------------------------------------------------------+
Table 1
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3. Name Resolution Process
This section provides an overview of how the API can be used. First,
the case in which a resolver is involved in name resolution is
described, and then the case in which no resolver is involved is
described.
3.1. Interaction with the Resolver
Before an application can establish network communications with the
entity named by a given FQDN or relative host name, the application
must translate the name into the corresponding identifier(s). DNS-
based hostname-to-identifier translation is illustrated in Figure 1.
The application calls the resolver in step (a) to resolve an FQDN to
HIT(s). The resolver queries the DNS in step (b) to map the FQDN to
a host identifier and locator (A and AAAA records). It should be
noticed that the FQDN may map to multiple host identifiers and
locators, and this step may involve multiple DNS transactions,
including queries for A, AAAA, HI and possibly other resource
records. The DNS server responds with a list of HIP resource records
in step (c). Optionally in step (d), the resolver caches the HIT to
locator mapping with the HIP module. The resolver converts the HIP
records to HITs and returns the HITs to the application contained in
HIP socket address structures in step (e). Depending on the
parameters for the resolver call, the resolver may return also other
socket address structures to the application. Finally, the
application receives the socket address structure(s) from the
resolver and uses them in socket calls such as connect() in step (f).
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+----------+
| |
| DNS |
| |
+----------+
^ |
b. QNAME=FQDN | | c. HIP and
| | A/AAAA
| v RR(s)
+-------------+ a. getaddrinfo(<FQDN>) +----------+
| |------------------------>| |
| Application | | Resolver |
| |<------------------------| |
+-------------+ e. <HITs> +----------+
| |
| | d. HIP and
| f. connect(<HIT>) | A/AAAA
| or any other socket call | RR(s)
v v
+----------+ +----------+
| | | |
| TCP/IP | | HIP |
| Stack | | |
+----------+ +----------+
Figure 1
In practice, the resolver functionality can be implemented in
different ways. For example, it may be implemented in existing
resolver libraries or as a HIP-aware interposing agent.
3.2. Interaction without a Resolver
The extensions in this document focus on the use of the resolver to
map host names to HITs and locators in HIP-aware applications. The
resolver may implicitly associate a HIT with the corresponding
locator(s) by communicating the HIT-to-IP mapping to the HIP daemon.
However, it is possible that an application operates directly on a
peer HIT without interacting with the resolver. In such a case, the
application may resort to the system to map the peer HIT to an IP
address. Alternatively, the application can explicitly map the HIT
to an IP address using socket options as specified in Section 4.6.
Full support for all of the extensions defined in this draft requires
a number of shim socket options [I-D.ietf-shim6-multihome-shim-api]
to be implemented by the system.
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4. API Syntax and Semantics
In this section, we describe the native HIP APIs using the syntax of
the C programming language. We limit the description to the
interfaces and data structures that are either modified or completely
new, because the native HIP APIs are otherwise identical to the
sockets API [POSIX].
4.1. Socket Family and Address Structure Extensions
The sockets API extensions define a new protocol family, PF_HIP, and
a new address family, AF_HIP. The AF_HIP and PF_HIP are aliases to
each other. These definition shall be defined as a result of
including <sys/socket.h>.
The use of the PF_HIP constant is mandatory with the socket()
function when an application uses the native HIP APIs. The
application gives the PF_HIP constant as the first argument (domain)
to the socket() function. The system returns a positive integer
representing a socket descriptor when the system supports HIP.
Otherwise, the system returns -1 and sets errno to EAFNOSUPPORT.
This is the default behavior for unsupported address families and
does not require any changes to legacy systems.
Figure 2 shows socket address structure for HIP.
#include <netinet/in.h>
typedef struct in6_addr hip_hit_t;
struct sockaddr_hip {
sa_family_t ship_family;
in_port_t ship_port;
uint32_t ship_pad;
uint64_t ship_flags;
hip_hit_t ship_hit;
uint8_t ship_reserved[16];
};
Figure 2
Figure 2 is in 4.3BSD format. The family of the socket, ship_family,
is set to AF_HIP. The port number ship_port is two octets in network
byte order and the ship_hit is 16 octets in network byte order. An
implementation may have extra member(s) in this structure.
The application usually sets the ship_hit field using the resolver.
However, the application can use three special constants to set a
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wildcard value manually into the ship_hit field. The constants are
HIP_HIT_ANY, HIP_HIT_ANY_PUB, HIP_HIT_ANY_TMP and HIP_ENDPOINT_ANY.
The first three equal to a HIT value associated with a wildcard HIT
of any type, public type, or anonymous type. The fourth constant,
HIP_ENDPOINT_ANY, denotes that the application accepts HIT, IPv4 and
IPv6-based addresses. The HIP_HIT_ANY denotes that the application
accepts any type of HIT. The anonymous identifiers refer to the use
of anonymous identifiers as specified in [RFC4423]. The system may
designate anonymous identifiers as meta data associated with a HIT
depending on whether it has been published or not. However, there is
no difference in the classes of HITs from the protocol perspective.
The application can use the HIP_HIT_ANY_* and HIP_ENDPOINT_ANY
constants to accept incoming communications to all of the HITs of the
local host. Incoming communications refers here to functions such as
bind(), recvfrom() and recvmsg(). The HIP_HIT_* constants are
similar to the sockets API constants INADDR_ANY and IN6ADDR_ANY_INIT,
but they are applicable to HITs only. After initial contact with the
peer, the application can discover the local and peer HITs using
getsockname() and getpeername() calls as described in Section 4.3.
The difference between the use of the HIP_HIT_* and HIP_ENDPOINT_ANY
constants here is that the former allows only HIP-based
communications but the latter also allows communications without HIP.
When a connection-oriented server application binds to
HIP_ENDPOINT_ANY and calls accept(), the call outputs always a
sockaddr_hip structure containing information on the connected client
with the address family set to AF_HIP. The same applies also to
datagram-oriented recvfrom() and recvmsg() calls. If the data flow
was based on HIP, the ship_hit field contains a HIT. In the case of
an IPv6 data flow without HIP, the field contains the corresponding
IPv6 address of the client. In the case of an IPv4 flow without HIP,
the fields contains the client's IPv4 address in IPv4-mapped IPv6
address format as described in section 3.7 of [RFC3493]. Section 4.5
describes how the application can verify the type of the address
returned by the socket API calls.
The application also uses the HIP_HIT_ANY constant in ship_hit field
to establish outgoing communications in Opportunistic mode [RFC5201],
i.e., when the application knows the remote peer locator but not the
HIT. Outgoing communications refers here to the use of functions
such as connect(), sendto() and sendmsg(). However, the application
should first associate the socket with at least one IP address of the
peer using SHIM_LOCLIST_PEER_PREF socket option. The use of the
HIP_HIT_ANY constant guarantees that the communications will be based
on HIP or none at all.
The use of HIP_ENDPOINT_ANY constant in the context of outgoing
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communications is left for further experimentation in the context of
opportunistic mode. It can result in a data flow with or without
HIP.
Some applications rely on system level access control, either
implicit or explicit (such as accept_filter() function found on BSD-
based systems), but such discussion is out of scope. Other
applications implement access control themselves by using the HITs.
In such a case, the application can compare two HITs contained in the
ship_hit field using memcmp() or similar function. It should be
noted that different connection attempts between the same two hosts
can result in different HITs because a host is allowed to have
multiple HITs.
4.2. Extensions to Resolver Data Structures
The HIP APIs introduce a new address family, AF_HIP, that HIP aware
applications can use to control the address type returned from
getaddrinfo() function [RFC3493]. The getaddrinfo() function uses a
data structure called addrinfo in its "hints" and "res" argument
which are described in more detail in the next section. The addrinfo
data structure is illustrated in Figure 3.
#include <netdb.h>
struct addrinfo {
int ai_flags; /* e.g. AI_CANONNAME */
int ai_family; /* e.g. AF_HIP */
int ai_socktype; /* e.g. SOCK_STREAM */
int ai_protocol; /* 0 or IPPROTO_HIP */
socklen_t ai_addrlen; /* size of *ai_addr */
struct sockaddr *ai_addr; /* sockaddr_hip */
char *ai_canonname; /* canon. name of the host */
struct addrinfo *ai_next; /* next endpoint */
int ai_eflags; /* RFC5014 extension */
};
Figure 3
An application resolving with the ai_family field set to AF_UNSPEC in
the hints argument may receive any kind of socket address structures,
including sockaddr_hip. When the application wants to receive only
HITs contained in sockaddr_hip structures, it should set the
ai_family field to AF_HIP. Otherwise, the resolver does not return
any sockaddr_hip structures. The resolver returns EAI_FAMILY when
AF_HIP is not supported.
The resolver ignores the AI_PASSIVE flag when the application sets
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the family in hints to AF_HIP.
The system may have a HIP-aware interposing DNS agent as described in
section 3.2 in [RFC5338]. In such a case, the DNS agent may,
according to local policy, return transparently LSIs or HITs in
sockaddr_in and sockaddr_in6 structures when available. A HIP-aware
application can override this local policy in two ways. First, the
application can set the family to AF_HIP in the hints argument of
getaddrinfo() when it requests only sockaddr_hip structures. Second,
the application can set AI_NO_HIT flag to prevent the resolver from
returning HITs in any kind of data structures.
When getaddrinfo() returns resolved outputs the results to res
argument, it sets the family to AF_HIP when the related structure is
sockaddr_hip.
4.2.1. Resolver Usage
A HIP-aware application creates the sockaddr_hip structures manually
or obtains them from the resolver. The explicit configuration of
locators is described in [I-D.ietf-shim6-multihome-shim-api]. This
document defines "automated" resolver extensions for getaddrinfo()
resolver [RFC3493].
#include <netdb.h>
int getaddrinfo(const char *nodename,
const char *servname,
const struct addrinfo *hints,
struct addrinfo **res)
void free_addrinfo(struct addrinfo *res)
Figure 4
As described in [RFC3493], the getaddrinfo function takes the
nodename, servname, and hints as its input arguments. It places the
result of the query into the res output argument. The return value
is zero on success, or a non-zero error value on error. The nodename
argument specifies the host name to be resolved; a NULL argument
denotes the HITs of the local host. The servname parameter declares
the port number to be set in the socket addresses in the res output
argument. Both the nodename and servname cannot be NULL at the same
time.
The input argument "hints" acts like a filter that defines the
attributes required from the resolved endpoints. A NULL hints
argument indicates that any kind of endpoints are acceptable.
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The output argument "res" is dynamically allocated by the resolver.
The application frees the res argument with the free_addrinfo
function. The res argument contains a linked list of the resolved
endpoints. The linked list contains sockaddr_hip structures only
when the input argument has the family set to AF_HIP. When the
family is zero, the list contains sockaddr_hip structures before
sockaddr_in and sockaddr_in6 structures.
The resolver can return a HIT which maps to multiple locators. The
resolver may cache the locator mappings with the HIP module. The HIP
module manages the multiple locators according to system policies of
the host. The multihoming document
[I-D.ietf-shim6-multihome-shim-api] describes how an application can
override system default policies.
It should be noted that the application can configure the HIT
explicitly without setting the locator or the resolver can fail to
resolve any locator. In this scenario, the application relies on the
system to map the HIT to an IP address. When the system fails to
provide the mapping, it returns -1 in the called sockets API function
to the application and sets errno to EADDRNOTAVAIL.
4.3. The Use of getsockname and getpeername Functions
The sockaddr_hip structure does not contain a HIT when the
application uses the HIP_HIT_ANY_* or HIP_ENDPOINT_ANY constants. In
such a case, the application can discover the local and peer HITs
using the getsockname() and getpeername() functions after the socket
is connected. The functions getsockname() and getpeername() always
output a sockaddr_hip structure when the family of the socket is
AF_HIP. The application should be prepared to handle also IPv4 and
IPv6 addresses in the ship_hit field as described in Section 4.1 in
the context of the HIP_ENDPOINT_ANY constant.
4.4. Selection of Source HIT Type
A client-side application can choose its source HIT by e.g. querying
all of the local HITs with getaddrinfo() and associating one of them
with the socket using bind(). This section describes another method
for a client-side application to affect the selection of the source
HIT type where the application does not call bind() explicitly.
Instead, the application just specifies the preferred requirements
for the source HIT type.
The Socket API for Source Address Selection [RFC5014] defines socket
options to allow applications to influence source address selection
mechanisms. In some cases, HIP-aware applications may want to
influence source HIT selection; in particular, whether an outbound
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connection should use a published or anonymous HIT. Similar to
IPV6_ADDR_PREFERENCES defined in RFC 5014, the following socket
option HIT_PREFERENCES is defined for HIP-based sockets. This socket
option can be used with setsockopt() and getsockopt() calls to set
and get the HIT selection preferences affecting a HIP-enabled socket.
The socket option value (optval) is a 32-bit unsigned integer
argument. The argument consists of a number of flags where each flag
indicates an address selection preference that modifies one of the
rules in the default HIT selection; these flags are shown in Table 2.
+---------------------------+-------------------------+
| Socket Option | Purpose |
+---------------------------+-------------------------+
| HIP_PREFER_SRC_HIT_TMP | Prefer an anonymous HIT |
| HIP_PREFER_SRC_HIT_PUBLIC | Prefer a public HIT |
+---------------------------+-------------------------+
Table 2
If the system is unable to assign the type of HIT that is requested,
at HIT selection time, the socket call (connect (), sendto(), or
sendmsg()) will fail and errno will be set to EINVAL. If the
application tries to set both of the above flags for the same socket,
this also results in the error EINVAL.
4.5. Verification of Source HIT Type
An application that uses the HIP_ENDPOINT_ANY constant may want to
check whether the actual communications was based on HIP or not.
Also, the application may want to verify whether a local HIT is
public or anonymous. The application accomplishes these using a new
function called sockaddr_is_srcaddr() which is illustrated in
Figure 5.
#include <netinet/in.h>
short sockaddr_is_srcaddr(struct sockaddr *srcaddr,
uint64_t flags);
Figure 5
The sockaddr_is_srcaddr() function operates in the same way as
inet6_is_srcaddr() function [RFC5014] which can be used to verify the
type of an address belonging to the local host. The difference is
that the sockaddr_is_srcaddr() function handles sockaddr_hip
structures in addition to sockaddr_in6, and possibly some other
socket structures in further extensions. The flags argument is also
64 bit instead of 32 bits because new function handles the same flags
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as defined in [RFC5014] in addition to two HIP-specific flags,
HIP_PREFER_SRC_HIT_TMP and HIP_PREFER_SRC_HIT_PUBLIC. With these two
flags, the application can distinguish anonymous HITs from public
HITs.
When given an AF_INET6 socket, sockaddr_is_srcaddr() behaves as
inet6_is_srcaddr() function as described in [RFC5014]. With AF_HIP
socket, the function returns 1 when the HIT contained in the socket
address structure corresponds to a valid HIT of the local host and
the HIT satisfies the given flags. The function returns -1 when the
HIT does not belong to the local host or the flags are not valid.
The function returns 0 when the preference flags are valid but the
HIT does not match the given flags.
4.6. Explicit Handling of Locators
The system resolver, or the HIP module, maps HITs to locators
implicitly. However, some applications may want to specify initial
locator mappings explicitly. In such a case, the application first
creates a socket with AF_HIP as the domain argument. Second, the
application may get or set locator information with one of the
following shim socket options as defined in the multihoming
extensions in [I-D.ietf-shim6-multihome-shim-api]. The related
socket options are summarized briefly in Table 3.
+---------------------+---------------------------------------------+
| optname | description |
+---------------------+---------------------------------------------+
| SHIM_LOC_LOCAL_PREF | Get or set the preferred locator on the |
| | local side for the context associated with |
| | the socket. |
| SHIM_LOC_PEER_PREF | Get or set the preferred locator on the |
| | remote side for the context associated with |
| | the socket. |
| SHIM_LOCLIST_LOCAL | Get or set a list of locators associated |
| | with the local EID. |
| SHIM_LOCLIST_PEER | Get or set a list of locators associated |
| | with the peer's EID. |
| SHIM_LOC_LOCAL_SEND | Set or get the default source locator of |
| | outgoing IP packets. |
| SHIM_LOC_PEER_SEND | Set or get the default destination locator |
| | of outgoing IP packets. |
+---------------------+---------------------------------------------+
Table 3
As an example of locator mappings, a connection-oriented application
creates a HIP-based socket and sets the SHIM_LOCLIST_PEER socket
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option to the socket. The HIP module uses the first address
contained in the option if multiple are provided. If the application
provides one or more addresses in the SHIM_LOCLIST_PEER setsockopt
call, the system should not connect to the host via another
destination address, in case the application intends to restrict the
range of addresses permissible as a policy choice. The application
can override the default peer locator by setting the
SHIM_LOC_PEER_PREF socket option if necessary. Finally, the
application provides a specific HIT in the ship_hit field of the
sockaddr_hip in the connect() system call. If the system cannot
reach the HIT at one of the addresses provided, the outbound socket
API functions (connect, sendmsg, etc.) return -1 and set errno to
EINVALIDLOCATOR.
Applications may also choose to associate local addresses with
sockets. The procedures specified in
[I-D.ietf-shim6-multihome-shim-api] are followed in this case.
Another use case is to use the opportunistic mode when the
destination HIT is specified as a wildcard. The application sets one
or more destination addresses using the SHIM_LOCLIST_PEER socket
option as described above and then calls connect() with the wildcard
HIT. The connect() call returns -1 and sets errno to EADDRNOTAVAIL
when the application connects to a wildcard without specifying any
destination address.
Applications using datagram-oriented sockets can use ancillary data
to control the locators. This described in detail in
[I-D.ietf-shim6-multihome-shim-api].
5. Summary of New Definitions
Table 4 summarizes the new constants and structures defined in this
document.
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+-----------------+---------------------+
| Header | Definition |
+-----------------+---------------------+
| <sys/socket.h> | AF_HIP |
| <sys/socket.h> | PF_HIP |
| <netinet/in.h> | IPPROTO_HIP |
| <netinet/hip.h> | HIP_HIT_ANY |
| <netinet/hip.h> | HIP_HIT_ANY_PUB |
| <netinet/hip.h> | HIP_HIT_ANY_TMP |
| <netinet/hip.h> | HIP_ENDPOINT_ANY |
| <netinet/hip.h> | HIP_HIT_PREFERENCES |
| <netinet/hip.h> | hip_hit_t |
| <netdb.h> | AI_NO_HIT |
| <netinet/hip.h> | sockaddr_hip |
| <netinet/hip.h> | sockaddr_is_srcaddr |
+-----------------+---------------------+
Table 4
6. IANA Considerations
No IANA considerations.
7. Security Considerations
The use of HIP_ENDPOINT_ANY can be used to accept incoming or create
outgoing data flows without HIP. The application should use the
sockaddr_is_srcaddr() function to validate the type of the connection
in order to e.g. inform the user of the lack of HIP-based security.
The use of the HIP_HIT_ANY_* constants is recommended in security-
critical applications and systems.
8. Contributors
Thanks for Jukka Ylitalo and Pekka Nikander for their original
contribution, time and effort to the native HIP APIs. Thanks for
Yoshifuji Hideaki for his contributions to this document.
9. Acknowledgements
Kristian Slavov, Julien Laganier, Jaakko Kangasharju, Mika Kousa, Jan
Melen, Andrew McGregor, Sasu Tarkoma, Lars Eggert, Joe Touch, Antti
Jarvinen, Anthony Joseph, Teemu Koponen, Jari Arkko, Ari Keranen,
Juha-Matti Tapio, Shinta Sugimoto, Philip Matthews, Joakim Koskela,
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Jeff Ahrenholz, Tobias Heer and Gonzalo Camarillo have provided
valuable ideas and feedback. Thanks also for the APPS area folks,
including Stephane Bortzmeyer, Chris Newman, Tony Finch, "der Mouse"
and Keith Moore.
10. Normative References
[I-D.ietf-btns-c-api]
Richardson, M., Williams, N., Komu, M., and S. Tarkoma,
"C-Bindings for IPsec Application Programming Interfaces",
draft-ietf-btns-c-api-04 (work in progress), March 2009.
[I-D.ietf-shim6-multihome-shim-api]
Komu, M., Bagnulo, M., Slavov, K., and S. Sugimoto,
"Socket Application Program Interface (API) for
Multihoming Shim", draft-ietf-shim6-multihome-shim-api-09
(work in progress), July 2009.
[I-D.ietf-shim6-proto]
Nordmark, E. and M. Bagnulo, "Shim6: Level 3 Multihoming
Shim Protocol for IPv6", draft-ietf-shim6-proto-12 (work
in progress), February 2009.
[POSIX] Institute of Electrical and Electronics Engineers, "IEEE
Std. 1003.1-2001 Standard for Information Technology -
Portable Operating System Interface (POSIX)", Dec 2001.
[RFC3493] Gilligan, R., Thomson, S., Bound, J., McCann, J., and W.
Stevens, "Basic Socket Interface Extensions for IPv6",
RFC 3493, February 2003.
[RFC4423] Moskowitz, R. and P. Nikander, "Host Identity Protocol
(HIP) Architecture", RFC 4423, May 2006.
[RFC4843] Nikander, P., Laganier, J., and F. Dupont, "An IPv6 Prefix
for Overlay Routable Cryptographic Hash Identifiers
(ORCHID)", RFC 4843, April 2007.
[RFC5014] Nordmark, E., Chakrabarti, S., and J. Laganier, "IPv6
Socket API for Source Address Selection", RFC 5014,
September 2007.
[RFC5201] Moskowitz, R., Nikander, P., Jokela, P., and T. Henderson,
"Host Identity Protocol", RFC 5201, April 2008.
[RFC5205] Nikander, P. and J. Laganier, "Host Identity Protocol
(HIP) Domain Name System (DNS) Extensions", RFC 5205,
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April 2008.
[RFC5338] Henderson, T., Nikander, P., and M. Komu, "Using the Host
Identity Protocol with Legacy Applications", RFC 5338,
September 2008.
Authors' Addresses
Miika Komu
Helsinki Institute for Information Technology
Metsanneidonkuja 4
Helsinki
Finland
Phone: +358503841531
Fax: +35896949768
Email: miika@iki.fi
URI: http://www.iki.fi/miika/
Thomas Henderson
The Boeing Company
P.O. Box 3707
Seattle, WA
USA
Email: thomas.r.henderson@boeing.com
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