--- 1/draft-ietf-dmm-ondemand-mobility-17.txt 2019-07-31 13:19:11.255670640 -0700 +++ 2/draft-ietf-dmm-ondemand-mobility-18.txt 2019-07-31 13:19:11.287671452 -0700 @@ -1,21 +1,21 @@ DMM Working Group A. Yegin Internet-Draft Actility Intended status: Informational D. Moses -Expires: August 26, 2019 Intel +Expires: January 31, 2020 Intel S. Jeon Sungkyunkwan University - February 22, 2019 + July 30, 2019 On Demand Mobility Management - draft-ietf-dmm-ondemand-mobility-17 + draft-ietf-dmm-ondemand-mobility-18 Abstract Applications differ with respect to whether they need session continuity and/or IP address reachability. The network providing the same type of service to any mobile host and any application running on the host yields inefficiencies, as described in [RFC7333]. This document defines a new concep of enabling applications to influence the network's mobility services (session continuity and/or IP address reachability) on a per-Socket basis, and suggests extensions to the @@ -29,21 +29,21 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on August 26, 2019. + This Internet-Draft will expire on January 31, 2020. Copyright Notice Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -55,40 +55,34 @@ Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Notational Conventions . . . . . . . . . . . . . . . . . . . 4 3. Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1. High-level Description . . . . . . . . . . . . . . . . . 4 3.2. Types of IP Addresses . . . . . . . . . . . . . . . . . . 5 3.3. Granularity of Selection . . . . . . . . . . . . . . . . 6 3.4. On Demand Nature . . . . . . . . . . . . . . . . . . . . 6 - 3.5. Conveying the Desired Address Type . . . . . . . . . . . 7 - 4. Usage example . . . . . . . . . . . . . . . . . . . . . . . . 8 - 4.1. Pseudo-code example . . . . . . . . . . . . . . . . . . . 8 - 4.2. Message Flow example . . . . . . . . . . . . . . . . . . 10 - 5. Backwards Compatibility Considerations . . . . . . . . . . . 12 - 5.1. Applications . . . . . . . . . . . . . . . . . . . . . . 12 - 5.2. IP Stack in the Mobile Host . . . . . . . . . . . . . . . 12 - 5.3. Network Infrastructure . . . . . . . . . . . . . . . . . 13 - 5.4. Merging this work with RFC5014 . . . . . . . . . . . . . 13 - 6. Summary of New Definitions . . . . . . . . . . . . . . . . . 13 - 6.1. New APIs . . . . . . . . . . . . . . . . . . . . . . . . 13 - 6.2. New Flags . . . . . . . . . . . . . . . . . . . . . . . . 14 - 7. Security Considerations . . . . . . . . . . . . . . . . . . . 15 - 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 - 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 16 - 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16 - 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 - 11.1. Normative References . . . . . . . . . . . . . . . . . . 16 - 11.2. Informative References . . . . . . . . . . . . . . . . . 17 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 + 4. Backwards Compatibility Considerations . . . . . . . . . . . 7 + 4.1. Applications . . . . . . . . . . . . . . . . . . . . . . 8 + 4.2. IP Stack in the Mobile Host . . . . . . . . . . . . . . . 8 + 4.3. Network Infrastructure . . . . . . . . . . . . . . . . . 8 + 4.4. Merging this work with RFC5014 . . . . . . . . . . . . . 8 + 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 + 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 + 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10 + 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10 + 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 + 9.1. Normative References . . . . . . . . . . . . . . . . . . 10 + 9.2. Informative References . . . . . . . . . . . . . . . . . 11 + Appendix A. Conveying the Desired Address Type . . . . . . . . . 11 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 1. Introduction In the context of Mobile IP [RFC5563][RFC6275][RFC5213][RFC5944], the following two attributes are defined for IP service provided to mobile hosts: - Session Continuity The ability to maintain an ongoing transport interaction by keeping @@ -285,29 +279,29 @@ lasting, zero or more Non-persistent and zero or more Graceful- Replacement IP addresses may be configured by the IP stack of the host. The combination may be as a result of the host policy, application demand, or a mix of the two. When an application requires a specific type of IP address and such an address is not already configured on the host, the IP stack SHALL attempt to configure one. For example, a host may not always have a Session-lasting IP address available. When an application requests one, the IP stack SHALL make an attempt to configure one by issuing a - request to the network (see Section 3.5 below for more details). If - the operation fails, the IP stack SHALL fail the associated socket - request and return an error. If successful, a Session-lasting IP - Address gets configured on the mobile host. If another socket - requests a Session-lasting IP address at a later time, the same IP - address may be served to that socket as well. When the last socket - using the same configured IP address is closed, the IP address may be - released or kept for future applications that may be launched and - require a Session-lasting IP address. + request to the network. If the operation fails, the IP stack SHALL + fail the associated socket request and return an error. If + successful, a Session-lasting IP Address gets configured on the + mobile host. If another socket requests a Session-lasting IP address + at a later time, the same IP address may be served to that socket as + well. When the last socket using the same configured IP address is + closed, the IP address may be released or kept for future + applications that may be launched and require a Session-lasting IP + address. In some cases it might be preferable for the mobile host to request a new Session-lasting IP address for a new opening of an IP socket (even though one was already assigned to the mobile host by the network and might be in use in a different, already active IP sockets). It is outside the scope of this specification to define criteria for choosing to use available addresses or choosing to request new ones. It supports both alternatives (and any combination). @@ -322,350 +316,83 @@ - The initial set of IP addresses configured on the host at boot time. - Permission to grant various types of IP addresses to a requesting application. - Determination of a default address type when an application does not make any explicit indication, whether it already supports the required API or it is just a legacy application. -3.5. Conveying the Desired Address Type - - [RFC5014] introduced the ability of applications to influence the - source address selection with the IPV6_ADDR_PREFERENCE option at the - IPPROTO_IPV6 level. This option is used with setsockopt() and - getsockopt() calls to set/get address selection preferences. - - Extending this further by adding more flags does not work when a - request for an address of a certain type results in requiring the IP - stack to wait for the network to provide the desired source IP prefix - and hence causing the setsockopt() call to block until the prefix is - allocated (or an error indication from the network is received). - - Alternatively a new socket API is defined - setsc() which allows - applications to express their desired type of session continuity - service. The new setsc() API will return an IPv6 address that is - associated with the desired session continuity service and with - status information indicating whether or not the desired service was - provided. - - An application that wishes to secure a desired service will call - setsc() with the service type definition and a place to contain the - provided IP address, and call bind() to associate that IP address - with the socket (See pseudo-code example in Section 4 below). - - When the IP stack is required to use a source IP address of a - specified type, it can use an existing address, or request a new IP - prefix (of the same type) from the network and create a new one. If - the host does not already have an IPv6 prefix of that specific type, - it MUST request one from the network. - - Using an existing address from an existing prefix is faster but might - yield a less optimal route (if a hand-off event occurred after its - configuration). On the other hand, acquiring a new IP prefix from - the network may be slower due to signaling exchange with the network. - - Applications can control the stack's operation by setting a new flag - - ON_NET flag - which directs the IP stack whether to use a - preconfigured source IP address (if exists) or to request a new IPv6 - prefix from the current serving network and configure a new IP - address. - - This new flag is added to the set of flags in the - IPV6_ADDR_PREFERENCES option at the IPPROTO_IPV6 level. It is used - in setsockopt() to set the desired behavior. - -4. Usage example - -4.1. Pseudo-code example - - The following example shows pseudo-code for creating a Stream socket - (TCP) with a Session-Lasting source IP address: - - #include - #include - - // Socket information - int s ; // socket id - - // Source information (for setsc() and bind()) - sockaddr_in6 sourceInfo // my address and port for bind() - in6_addr sourceAddress // will contain the provisioned - // source IP address - uint8_t sc_type = IPV6_REQUIRE_SESSION_LASTING_IP ; - // For requesting a Session-Lasting - // source IP address - - // Destination information (for connect()) - sockaddr_in6 serverInfo ; // server info for connect() - - // Create an IPv6 TCP socket - s = socket(AF_INET6, SOCK_STREAM, 0) ; - if (s!=0) { - // Handle socket creation error - // ... - } // if socket creation failed - else { - // Socket creation is successful - // The application cannot connect yet, since it wants to use - // a Session-Lasting source IP address It needs to request - // the Session-Lasting source IP before connecting - if (setsc(s, &sourceAddress, &sc_type)) == 0){ - // setting session continuity to Session Lasting is - // Successful. sourceAddress now contains the Session- - // Lasting source IP address - - // Bind to that source IP address - sourceInfo.sin6_family = AF_INET6 ; - sourceInfo.sin6_port = 0 // let the stack choose the port - sourceInfo.sin6_address = sourceAddress ; - // Use the source address that was - // generated by the setsc() call - if (bind(s, &sourceInfo, sizeof(sourceInfo))==0){ - // Set the desired server's information for connect() - serverInfo.sin6_family = AF_INET6 ; - serverInfo.sin6_port = SERVER_PORT_NUM ; - serverAddress.sin6_addr = SERVER_IPV6_ADDRESS ; - - // Connect to the server - if (connect(s, &serverInfo, sizeof(serverInfo))==0) { - // connect successful (3-way handshake has been - // completed with Session-Lasting source address. - - // Continue application functionality - // ... - } // if connect() is successful - else { - // connect failed - // ... - // Application code that handles connect failure and - // closes the socket - // ... - } // if connect() failed - } // if bind() successful - else { - // bind() failed - // ... - // Application code that handles bind failure and - // closes the socket - // ... - } // if bind() failed - } // if setsc() was successful and of a Session-Lasting - // source IP address was provided - else { - // application code that does not use Session-lasting IP - // address. The application may either connect without - // the desired Session-lasting service, or close the - // socket... - } // if setsc() failed - } // if socket was created successfully - - // The rest of the application's code - // ... - -4.2. Message Flow example - - The following message flow illustrates a possible interaction for - achieving On-Demand functionality. It is an example of one scenario - and should not be regarded as the only scenario or the preferred one. - - This flow describes the interaction between the following entities: - - - Applications requiring different types of On-Demand service. - - - The mobile host's IP stack. - - - The network infrastructure providing the services. - - In this example, the network infrastructure provides 2 IPv6 prefixes - upon attachment of the mobile host to the network: A Session-lasting - IPv6 prefix and a Non-persistent IPv6 prefix. Whenever the mobile - host moves to a different point-of-attachment, the network - infrastructure provides a new Non-persistent IPv6 address. - - In this example, the network infrastructure does not support Fixed IP - addresses nor Graceful-replacement IP addresses. - - Whenever an application opens an IP socket and requests a specific - IPv6 address type, the IP stack will provide one from its available - IPv6 prefixes or return an error message if the request cannot be - fulfilled. - - Message Flow: - - - The mobile device attaches to the network. - - - The Network provides two IPv6 prefixes: PREFsl1 - a Session-lasting - IPv6 prefix and PREFnp1 - a Non-persistent IPv6 prefix. - - - An application on the mobile host is launched. It opens an IP - socket and requests a Non-persistent IPv6 address. - - - The IP stack provides IPnp1 which is generated from PREFnp1. - - - Another application is launched, requesting a Non-persistent IPv6 - address. - - - The IP stack provides IPnp1 again. - - - A third application is launched. This time, it requires a Session- - lasting IPv6 address. - - - The IP stack provides IPsl1 which is generated from PREFsl1. - - - The mobile hosts moves to a new point-of-attachment. - - - The network provides a new Non-persistent IPv6 prefix - PREFnp2. - PREFnp1 is no longer valid. - - - The applications that were given IPnp1 re-establish the socket and - receive a new IPv6 address - IPnp2 which is generated from PREFnp2 - - - The application that is using IPsl1 can still use it since the - network guaranteed that PREFsl1 will be valid even after moving to a - new point-of-attachment. - - - A new application is launched, this time requiring a Graceful- - replacement IPv6 address. - - - The IP stack returns setsc() with an error since the network does - not support this service. - - - The application re-attempts to open a socket, this time requesting - a Session-lasting IPv6 address. - - - The IP stack provides IPsl1. - -5. Backwards Compatibility Considerations +4. Backwards Compatibility Considerations Backwards compatibility support is REQUIRED by the following 3 types of entities: - The Applications on the mobile host - The IP stack in the mobile host - The network infrastructure -5.1. Applications +4.1. Applications Legacy applications that do not support the On-Demand functionality will use the legacy API and will not be able to take advantage of the On-Demand Mobility feature. Applications using the new On-Demand functionality should be aware that they may be executed in legacy environments that do not support it. Such environments may include a legacy IP stack on the mobile host, legacy network infrastructure, or both. In either case, the API will return an error code and the invoking applications may just give up and use legacy calls. -5.2. IP Stack in the Mobile Host +4.2. IP Stack in the Mobile Host New IP stacks (that implement On Demand functionality) MUST continue to support all legacy operations. If an application does not use On- Demand functionality, the IP stack MUST respond in a legacy manner. If the network infrastructure supports On-Demand functionality, the IP stack SHOULD follow the application request: If the application requests a specific address type, the stack SHOULD forward this request to the network. If the application does not request an address type, the IP stack MUST NOT request an address type and leave it to the network's default behavior to choose the type of the allocated IP prefix. If an IP prefix was already allocated to the host, the IP stack uses it and may not request a new one from the network. -5.3. Network Infrastructure +4.3. Network Infrastructure The network infrastructure may or may not support the On-Demand functionality. How the IP stack on the host and the network infrastructure behave in case of a compatibility issue is outside the scope of this API specification. -5.4. Merging this work with RFC5014 +4.4. Merging this work with RFC5014 [RFC5014] defines new flags that may be used with setsockopt() to influence source IP address selection for a socket. The list of flags include: source home address, care-of address, temporary address, public address CGA (Cryptographically Created Address) and - non-CGA. When applications require session continuity service and - use setsc() and bind(), they SHOULD NOT set the flags specified in - [RFC5014]. + non-CGA. When applications require session continuity service, they + SHOULD NOT set the flags specified in [RFC5014]. However, if an application erroneously performs a combination of (1) Use setsockopt() to set a specific option (using one of the flags - specified in [RFC5014]) and (2) Selects a source IP address type - using setsc() and bind(), the IP stack will fulfill the request - specified by (2) and ignore the flags set by (1). - - If bind() was not invoked after setsc() by the application, the IP - address generated by setsc() will not be used and traffic generated - by the socket will use a source IP address that complies with the - options selected by setsockopt(). - -6. Summary of New Definitions - -6.1. New APIs - - setsc() enables applications to request a specific type of source IP - address in terms of session continuity. Its definition is: - - int setsc(int sockfd, in6_addr *sourceAddress, sc_type addressType); - - Where: - - sockfd - is the socket descriptor of the socket with which - a specific address type is associated - - sourceAddress - is a pointer to an area allocated for setsc() to - place the generated source IP address of the - desired session continuity type - - addressType - Is the desired type of session continuity service. - It is a 3-bit field containing one of the - following values: - 0 - Reserved - 1 - FIXED_IPV6_ADDRESS - 2 - SESSION_LASTING_IPV6_ADDRESS - 3 - NON_PERSISTENT_IPV6_ADDRESS - 4 - GRACEFUL_REPLACEMENT_IPV6_ADDRESS - 5-7 - Reserved - - setsc() returns the status of the operation: - - 0 - Address was successfully generated - - EAI_REQUIREDIPNOTSUPPORTED - the required service type is not - supported - - EAI_REQUIREDIPFAILED - the network could not fulfill the desired - request - - setsc() MAY block the invoking thread if it triggers the TCP/IP stack - to request a new IP prefix from the network to construct the desired - source IP address. If an IP prefix with the desired session - continuity features already exists (was previously allocated to the - mobile host) and the stack is not required to request a new one as a - result of setting the IPV6_REQUIRE_SRC_ON_NET flag (defined below), - setsc() MAY return immediately with the constructed IP address and - will not block the thread. - -6.2. New Flags - - The following flag is added to the list of flags in the - IPV6_ADDR_PREFERENCE option at the IPPROTO6 level: - - IPV6_REQUIRE_SRC_ON_NET - set IP stack address allocation behavior - - If set, the IP stack will request a new IPv6 prefix of the desired - type from the current serving network and configure a new source IP - address. If reset, the IP stack will use a preconfigured one if it - exists. If there is no preconfigured IP address of the desired type, - a new prefix will be requested and used for creating the IP address. + specified in [RFC5014]) and (2) Selects a source IP address type, the + IP stack will fulfill the request specified by (2) and ignore the + flags set by (1). -7. Security Considerations +5. Security Considerations The different service types (session continuity types and address reachability) associated with the allocated IP address types, may be associated with different costs. The cost to the operator for enabling a type of service, and the cost to applications using a selected service. A malicious application may use these to generate extra billing of a mobile subscriber, and/or impose costly services on the mobile operator. When costly services are limited, malicious applications may exhaust them, preventing other applications on the same mobile host from being able to use them. @@ -697,67 +424,67 @@ Similarly, the OS may also associated IP addresses with a lifetime. Upon receiving a request for a given type of IP address, after some time, the OS should request a new address to the network even if it already has one IP address available with the requested type. This includes any type of IP address. IP addresses of type graceful replacement or non persistent should be regularly renewed by the OS. The lifetime of an IP address may be expressed in number of seconds or in number of bytes sent through this IP address. -8. IANA Considerations +6. IANA Considerations This document has no IANA considerations. -9. Contributors +7. Contributors This document was merged with [I-D.sijeon-dmm-use-cases-api-source]. We would like to acknowledge the contribution of the following people to that document as well: Sergio Figueiredo Altran Research, France Email: sergio.figueiredo@altran.com Younghan Kim Soongsil University, Korea Email: younghak@ssu.ac.kr John Kaippallimalil Huawei, USA Email: john.kaippallimalil@huawei.com -10. Acknowledgements +8. Acknowledgements We would like to thank Wu-chi Feng, Alexandru Petrescu, Jouni Korhonen, Sri Gundavelli, Dave Dolson Lorenzo Colitti and Daniel Migault for their valuable comments and suggestions on this work. -11. References +9. References -11.1. Normative References +9.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5014] Nordmark, E., Chakrabarti, S., and J. Laganier, "IPv6 Socket API for Source Address Selection", RFC 5014, DOI 10.17487/RFC5014, September 2007, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . -11.2. Informative References +9.2. Informative References [I-D.sijeon-dmm-use-cases-api-source] Jeon, S., Figueiredo, S., Kim, Y., and J. Kaippallimalil, "Use Cases and API Extension for Source IP Address Selection", draft-sijeon-dmm-use-cases-api-source-07 (work in progress), September 2017. [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, @@ -785,21 +512,51 @@ [RFC6824] Ford, A., Raiciu, C., Handley, M., and O. Bonaventure, "TCP Extensions for Multipath Operation with Multiple Addresses", RFC 6824, DOI 10.17487/RFC6824, January 2013, . [RFC7333] Chan, H., Ed., Liu, D., Seite, P., Yokota, H., and J. Korhonen, "Requirements for Distributed Mobility Management", RFC 7333, DOI 10.17487/RFC7333, August 2014, . +Appendix A. Conveying the Desired Address Type + + Following are some suggestions of possible extensions to the Socket + API for enabling applications to convey their session continuity and + address reachability requirements. + + [RFC5014] introduced the ability of applications to influence the + source address selection with the IPV6_ADDR_PREFERENCE option at the + IPPROTO_IPV6 level. This option is used with setsockopt() and + getsockopt() calls to set/get address selection preferences. + + One alternative is to extend the defintion of the IPV6_ADDR_REFERENCE + opion with flags that express the invoker's desire. An "OnDeman" + field could contains one of the values: FIXED_IP_ADDRESS, + SESSION_LASTING_IP_ADDRESS, NON_PERSISTENT_IP_ADDRESS or + GRACEFUL_REPLACEMENT_IP_ADDRESS. + + Another alternative is to define a new Socket function used by the + invoker to convey its desire. This enables the implementation of two + behaviors of Socket functions: The existing "setsockotp()" is a + function that returns after executing, and the new "setsc()" (Set + Service Contionuity) function that may initaite a request for the + desired service, and wait until the network responds with the + allocated resources, before returning to the invoker. + + After obtaining an IP address with the desired behavior the + application can call the bind() Socket function to associate that + received IP address with the socket. + Authors' Addresses + Alper Yegin Actility Istanbul Turkey Email: alper.yegin@actility.com Danny Moses Intel Corporation Petah Tikva