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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 QUIC M. Bishop, Ed. 3 Internet-Draft Akamai 4 Intended status: Standards Track December 5, 2017 5 Expires: June 8, 2018 7 Hypertext Transfer Protocol (HTTP) over QUIC 8 draft-ietf-quic-http-08 10 Abstract 12 The QUIC transport protocol has several features that are desirable 13 in a transport for HTTP, such as stream multiplexing, per-stream flow 14 control, and low-latency connection establishment. This document 15 describes a mapping of HTTP semantics over QUIC. This document also 16 identifies HTTP/2 features that are subsumed by QUIC, and describes 17 how HTTP/2 extensions can be ported to QUIC. 19 Note to Readers 21 Discussion of this draft takes place on the QUIC working group 22 mailing list (quic@ietf.org), which is archived at 23 https://mailarchive.ietf.org/arch/search/?email_list=quic [1]. 25 Working Group information can be found at https://github.com/quicwg 26 [2]; source code and issues list for this draft can be found at 27 https://github.com/quicwg/base-drafts/labels/-http [3]. 29 Status of This Memo 31 This Internet-Draft is submitted in full conformance with the 32 provisions of BCP 78 and BCP 79. 34 Internet-Drafts are working documents of the Internet Engineering 35 Task Force (IETF). Note that other groups may also distribute 36 working documents as Internet-Drafts. The list of current Internet- 37 Drafts is at https://datatracker.ietf.org/drafts/current/. 39 Internet-Drafts are draft documents valid for a maximum of six months 40 and may be updated, replaced, or obsoleted by other documents at any 41 time. It is inappropriate to use Internet-Drafts as reference 42 material or to cite them other than as "work in progress." 44 This Internet-Draft will expire on June 8, 2018. 46 Copyright Notice 48 Copyright (c) 2017 IETF Trust and the persons identified as the 49 document authors. All rights reserved. 51 This document is subject to BCP 78 and the IETF Trust's Legal 52 Provisions Relating to IETF Documents 53 (https://trustee.ietf.org/license-info) in effect on the date of 54 publication of this document. Please review these documents 55 carefully, as they describe your rights and restrictions with respect 56 to this document. Code Components extracted from this document must 57 include Simplified BSD License text as described in Section 4.e of 58 the Trust Legal Provisions and are provided without warranty as 59 described in the Simplified BSD License. 61 Table of Contents 63 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 64 1.1. Notational Conventions . . . . . . . . . . . . . . . . . 3 65 2. QUIC Advertisement . . . . . . . . . . . . . . . . . . . . . 4 66 2.1. QUIC Version Hints . . . . . . . . . . . . . . . . . . . 4 67 3. Connection Establishment . . . . . . . . . . . . . . . . . . 5 68 3.1. Draft Version Identification . . . . . . . . . . . . . . 5 69 4. Stream Mapping and Usage . . . . . . . . . . . . . . . . . . 6 70 4.1. Control Streams . . . . . . . . . . . . . . . . . . . . . 7 71 4.2. HTTP Message Exchanges . . . . . . . . . . . . . . . . . 7 72 4.2.1. Header Compression . . . . . . . . . . . . . . . . . 8 73 4.2.2. The CONNECT Method . . . . . . . . . . . . . . . . . 8 74 4.3. Request Prioritization . . . . . . . . . . . . . . . . . 9 75 4.4. Server Push . . . . . . . . . . . . . . . . . . . . . . . 10 76 5. HTTP Framing Layer . . . . . . . . . . . . . . . . . . . . . 11 77 5.1. Frame Layout . . . . . . . . . . . . . . . . . . . . . . 11 78 5.2. Frame Definitions . . . . . . . . . . . . . . . . . . . . 12 79 5.2.1. DATA . . . . . . . . . . . . . . . . . . . . . . . . 12 80 5.2.2. HEADERS . . . . . . . . . . . . . . . . . . . . . . . 12 81 5.2.3. PRIORITY . . . . . . . . . . . . . . . . . . . . . . 12 82 5.2.4. CANCEL_PUSH . . . . . . . . . . . . . . . . . . . . . 14 83 5.2.5. SETTINGS . . . . . . . . . . . . . . . . . . . . . . 15 84 5.2.6. PUSH_PROMISE . . . . . . . . . . . . . . . . . . . . 17 85 5.2.7. GOAWAY . . . . . . . . . . . . . . . . . . . . . . . 18 86 5.2.8. MAX_PUSH_ID . . . . . . . . . . . . . . . . . . . . . 21 87 6. Connection Management . . . . . . . . . . . . . . . . . . . . 22 88 7. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 22 89 7.1. HTTP/QUIC Error Codes . . . . . . . . . . . . . . . . . . 22 90 8. Considerations for Transitioning from HTTP/2 . . . . . . . . 24 91 8.1. Streams . . . . . . . . . . . . . . . . . . . . . . . . . 24 92 8.2. HTTP Frame Types . . . . . . . . . . . . . . . . . . . . 24 93 8.3. HTTP/2 SETTINGS Parameters . . . . . . . . . . . . . . . 26 94 8.4. HTTP/2 Error Codes . . . . . . . . . . . . . . . . . . . 27 95 9. Security Considerations . . . . . . . . . . . . . . . . . . . 28 96 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28 97 10.1. Registration of HTTP/QUIC Identification String . . . . 28 98 10.2. Registration of QUIC Version Hint Alt-Svc Parameter . . 28 99 10.3. Frame Types . . . . . . . . . . . . . . . . . . . . . . 29 100 10.4. Settings Parameters . . . . . . . . . . . . . . . . . . 30 101 10.5. Error Codes . . . . . . . . . . . . . . . . . . . . . . 31 102 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 34 103 11.1. Normative References . . . . . . . . . . . . . . . . . . 34 104 11.2. Informative References . . . . . . . . . . . . . . . . . 35 105 11.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 35 106 Appendix A. Contributors . . . . . . . . . . . . . . . . . . . . 35 107 Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 35 108 B.1. Since draft-ietf-quic-http-07 . . . . . . . . . . . . . . 35 109 B.2. Since draft-ietf-quic-http-06 . . . . . . . . . . . . . . 35 110 B.3. Since draft-ietf-quic-http-05 . . . . . . . . . . . . . . 36 111 B.4. Since draft-ietf-quic-http-04 . . . . . . . . . . . . . . 36 112 B.5. Since draft-ietf-quic-http-03 . . . . . . . . . . . . . . 36 113 B.6. Since draft-ietf-quic-http-02 . . . . . . . . . . . . . . 36 114 B.7. Since draft-ietf-quic-http-01 . . . . . . . . . . . . . . 36 115 B.8. Since draft-ietf-quic-http-00 . . . . . . . . . . . . . . 37 116 B.9. Since draft-shade-quic-http2-mapping-00 . . . . . . . . . 37 117 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 37 119 1. Introduction 121 The QUIC transport protocol has several features that are desirable 122 in a transport for HTTP, such as stream multiplexing, per-stream flow 123 control, and low-latency connection establishment. This document 124 describes a mapping of HTTP semantics over QUIC, drawing heavily on 125 the existing TCP mapping, HTTP/2. Specifically, this document 126 identifies HTTP/2 features that are subsumed by QUIC, and describes 127 how the other features can be implemented atop QUIC. 129 QUIC is described in [QUIC-TRANSPORT]. For a full description of 130 HTTP/2, see [RFC7540]. 132 1.1. Notational Conventions 134 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 135 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 136 "OPTIONAL" in this document are to be interpreted as described in BCP 137 14 [RFC2119] [RFC8174] when, and only when, they appear in all 138 capitals, as shown here. 140 Field definitions are given in Augmented Backus-Naur Form (ABNF), as 141 defined in [RFC5234]. 143 This document uses the variable-length integer encoding from 144 [QUIC-TRANSPORT]. 146 Protocol elements called "frames" exist in both this document and 147 [QUIC-TRANSPORT]. Where frames from [QUIC-TRANSPORT] are referenced, 148 the frame name will be prefaced with "QUIC." For example, "QUIC 149 APPLICATION_CLOSE frames." References without this preface refer to 150 frames defined in Section 5.2. 152 2. QUIC Advertisement 154 An HTTP origin advertises the availability of an equivalent HTTP/QUIC 155 endpoint via the Alt-Svc HTTP response header or the HTTP/2 ALTSVC 156 frame ([RFC7838]), using the ALPN token defined in Section 3. 158 For example, an origin could indicate in an HTTP/1.1 or HTTP/2 159 response that HTTP/QUIC was available on UDP port 50781 at the same 160 hostname by including the following header in any response: 162 Alt-Svc: hq=":50781" 164 On receipt of an Alt-Svc header indicating HTTP/QUIC support, a 165 client MAY attempt to establish a QUIC connection to the indicated 166 host and port and, if successful, send HTTP requests using the 167 mapping described in this document. 169 Connectivity problems (e.g. firewall blocking UDP) can result in QUIC 170 connection establishment failure, in which case the client SHOULD 171 continue using the existing connection or try another alternative 172 endpoint offered by the origin. 174 Servers MAY serve HTTP/QUIC on any UDP port. Servers MUST use the 175 same port across all IP addresses that serve a single domain, and 176 SHOULD NOT change this port. 178 2.1. QUIC Version Hints 180 This document defines the "quic" parameter for Alt-Svc, which MAY be 181 used to provide version-negotiation hints to HTTP/QUIC clients. QUIC 182 versions are four-octet sequences with no additional constraints on 183 format. Syntax: 185 quic = version-number 186 version-number = 1*8HEXDIG; hex-encoded QUIC version 188 Leading zeros SHOULD be omitted for brevity. When multiple versions 189 are supported, the "quic" parameter MAY be repeated multiple times in 190 a single Alt-Svc entry. For example, if a server supported both 191 version 0x00000001 and the version rendered in ASCII as "Q034", it 192 could specify the following header: 194 Alt-Svc: hq=":49288";quic=1;quic=51303334 196 Where multiple versions are listed, the order of the values reflects 197 the server's preference (with the first value being the most 198 preferred version). Origins SHOULD list only versions which are 199 supported by the alternative, but MAY omit supported versions for any 200 reason. 202 3. Connection Establishment 204 HTTP/QUIC connections are established as described in 205 [QUIC-TRANSPORT]. During connection establishment, HTTP/QUIC support 206 is indicated by selecting the ALPN token "hq" in the crypto 207 handshake. 209 While connection-level options pertaining to the core QUIC protocol 210 are set in the initial crypto handshake, HTTP-specific settings are 211 conveyed in the SETTINGS frame. After the QUIC connection is 212 established, a SETTINGS frame (Section 5.2.5) MUST be sent by each 213 endpoint as the initial frame of their respective HTTP control stream 214 (Stream ID 2 or 3, see Section 4). The server MUST NOT send data on 215 any other stream until the client's SETTINGS frame has been received. 217 3.1. Draft Version Identification 219 *RFC Editor's Note:* Please remove this section prior to 220 publication of a final version of this document. 222 Only implementations of the final, published RFC can identify 223 themselves as "hq". Until such an RFC exists, implementations MUST 224 NOT identify themselves using this string. 226 Implementations of draft versions of the protocol MUST add the string 227 "-" and the corresponding draft number to the identifier. For 228 example, draft-ietf-quic-http-01 is identified using the string "hq- 229 01". 231 Non-compatible experiments that are based on these draft versions 232 MUST append the string "-" and an experiment name to the identifier. 233 For example, an experimental implementation based on draft-ietf-quic- 234 http-09 which reserves an extra stream for unsolicited transmission 235 of 1980s pop music might identify itself as "hq-09-rickroll". Note 236 that any label MUST conform to the "token" syntax defined in 237 Section 3.2.6 of [RFC7230]. Experimenters are encouraged to 238 coordinate their experiments on the quic@ietf.org mailing list. 240 4. Stream Mapping and Usage 242 A QUIC stream provides reliable in-order delivery of bytes, but makes 243 no guarantees about order of delivery with regard to bytes on other 244 streams. On the wire, data is framed into QUIC STREAM frames, but 245 this framing is invisible to the HTTP framing layer. A QUIC receiver 246 buffers and orders received STREAM frames, exposing the data 247 contained within as a reliable byte stream to the application. 249 QUIC reserves the first client-initiated, bidirectional stream 250 (Stream 0) for cryptographic operations. HTTP over QUIC reserves the 251 first unidirectional stream sent by either peer (Streams 2 and 3) for 252 sending and receiving HTTP control frames. This pair of 253 unidirectional streams is analogous to HTTP/2's Stream 0. The data 254 sent on these streams is critical to the HTTP connection. If either 255 control stream is closed for any reason, this MUST be treated as a 256 connection error of type QUIC_CLOSED_CRITICAL_STREAM. 258 When HTTP headers and data are sent over QUIC, the QUIC layer handles 259 most of the stream management. 261 An HTTP request/response consumes a single client-initiated, 262 bidirectional stream. A bidirectional stream ensures that the 263 response can be readily correlated with the request. This means that 264 the client's first request occurs on QUIC stream 4, with subsequent 265 requests on stream 8, 12, and so on. 267 Server push uses server-initiated, unidirectional streams. Thus, the 268 server's first push consumes stream 7 and subsequent pushes use 269 stream 11, 15, and so on. 271 These streams carry frames related to the request/response (see 272 Section 5.2). When a stream terminates cleanly, if the last frame on 273 the stream was truncated, this MUST be treated as a connection error 274 (see HTTP_MALFORMED_* in Section 7.1). Streams which terminate 275 abruptly may be reset at any point in the frame. 277 Streams SHOULD be used sequentially, with no gaps. 279 HTTP does not need to do any separate multiplexing when using QUIC - 280 data sent over a QUIC stream always maps to a particular HTTP 281 transaction. Requests and responses are considered complete when the 282 corresponding QUIC stream is closed in the appropriate direction. 284 4.1. Control Streams 286 Since most connection-level concerns will be managed by QUIC, the 287 primary use of Streams 2 and 3 will be for the SETTINGS frame when 288 the connection opens and for PRIORITY frames subsequently. 290 A pair of unidirectional streams is used rather than a single 291 bidirectional stream. This allows either peer to send data as soon 292 they are able. Depending on whether 0-RTT is enabled on the 293 connection, either client or server might be able to send stream data 294 first after the cryptographic handshake completes. 296 4.2. HTTP Message Exchanges 298 A client sends an HTTP request on a client-initiated, bidirectional 299 QUIC stream. A server sends an HTTP response on the same stream as 300 the request. 302 An HTTP message (request or response) consists of: 304 1. one header block (see Section 5.2.2) containing the message 305 headers (see [RFC7230], Section 3.2), 307 2. the payload body (see [RFC7230], Section 3.3), sent as a series 308 of DATA frames (see Section 5.2.1), 310 3. optionally, one header block containing the trailer-part, if 311 present (see [RFC7230], Section 4.1.2). 313 In addition, prior to sending the message header block indicated 314 above, a response may contain zero or more header blocks containing 315 the message headers of informational (1xx) HTTP responses (see 316 [RFC7230], Section 3.2 and [RFC7231], Section 6.2). 318 PUSH_PROMISE frames MAY be interleaved with the frames of a response 319 message indicating a pushed resource related to the response. These 320 PUSH_PROMISE frames are not part of the response, but carry the 321 headers of a separate HTTP request message. See Section 4.4 for more 322 details. 324 The "chunked" transfer encoding defined in Section 4.1 of [RFC7230] 325 MUST NOT be used. 327 Trailing header fields are carried in an additional header block 328 following the body. Such a header block is a sequence of HEADERS 329 frames with End Header Block set on the last frame. Senders MUST 330 send only one header block in the trailers section; receivers MUST 331 discard any subsequent header blocks. 333 An HTTP request/response exchange fully consumes a QUIC stream. 334 After sending a request, a client closes the stream for sending; 335 after sending a response, the server closes the stream for sending 336 and the QUIC stream is fully closed. 338 A server can send a complete response prior to the client sending an 339 entire request if the response does not depend on any portion of the 340 request that has not been sent and received. When this is true, a 341 server MAY request that the client abort transmission of a request 342 without error by triggering a QUIC STOP_SENDING with error code 343 HTTP_EARLY_RESPONSE, sending a complete response, and cleanly closing 344 its streams. Clients MUST NOT discard complete responses as a result 345 of having their request terminated abruptly, though clients can 346 always discard responses at their discretion for other reasons. 347 Servers MUST NOT abort a response in progress as a result of 348 receiving a solicited RST_STREAM. 350 4.2.1. Header Compression 352 HTTP/QUIC uses HPACK header compression as described in [RFC7541]. 353 HPACK was designed for HTTP/2 with the assumption of in-order 354 delivery such as that provided by TCP. A sequence of encoded header 355 blocks must arrive (and be decoded) at an endpoint in the same order 356 in which they were encoded. This ensures that the dynamic state at 357 the two endpoints remains in sync. 359 QUIC streams provide in-order delivery of data sent on those streams, 360 but there are no guarantees about order of delivery between streams. 361 QUIC anticipates moving to a modified version of HPACK without this 362 assumption. In the meantime, by fixing the size of the dynamic table 363 at zero, HPACK can be used in an unordered environment. 365 4.2.2. The CONNECT Method 367 The pseudo-method CONNECT ([RFC7231], Section 4.3.6) is primarily 368 used with HTTP proxies to establish a TLS session with an origin 369 server for the purposes of interacting with "https" resources. In 370 HTTP/1.x, CONNECT is used to convert an entire HTTP connection into a 371 tunnel to a remote host. In HTTP/2, the CONNECT method is used to 372 establish a tunnel over a single HTTP/2 stream to a remote host for 373 similar purposes. 375 A CONNECT request in HTTP/QUIC functions in the same manner as in 376 HTTP/2. The request MUST be formatted as described in [RFC7540], 377 Section 8.3. A CONNECT request that does not conform to these 378 restrictions is malformed. The message data stream MUST NOT be 379 closed at the end of the request. 381 A proxy that supports CONNECT establishes a TCP connection 382 ([RFC0793]) to the server identified in the ":authority" pseudo- 383 header field. Once this connection is successfully established, the 384 proxy sends a HEADERS frame containing a 2xx series status code to 385 the client, as defined in [RFC7231], Section 4.3.6. 387 All DATA frames on the request stream correspond to data sent on the 388 TCP connection. Any DATA frame sent by the client is transmitted by 389 the proxy to the TCP server; data received from the TCP server is 390 packaged into DATA frames by the proxy. Note that the size and 391 number of TCP segments is not guaranteed to map predictably to the 392 size and number of HTTP DATA or QUIC STREAM frames. 394 The TCP connection can be closed by either peer. When the client 395 ends the request stream (that is, the receive stream at the proxy 396 enters the "Data Recvd" state), the proxy will set the FIN bit on its 397 connection to the TCP server. When the proxy receives a packet with 398 the FIN bit set, it will terminate the send stream that it sends to 399 client. TCP connections which remain half-closed in a single 400 direction are not invalid, but are often handled poorly by servers, 401 so clients SHOULD NOT cause send a STREAM frame with a FIN bit for 402 connections on which they are still expecting data. 404 A TCP connection error is signaled with RST_STREAM. A proxy treats 405 any error in the TCP connection, which includes receiving a TCP 406 segment with the RST bit set, as a stream error of type 407 HTTP_CONNECT_ERROR (Section 7.1). Correspondingly, a proxy MUST send 408 a TCP segment with the RST bit set if it detects an error with the 409 stream or the QUIC connection. 411 4.3. Request Prioritization 413 HTTP/QUIC uses the priority scheme described in [RFC7540], 414 Section 5.3. In this priority scheme, a given request can be 415 designated as dependent upon another request, which expresses the 416 preference that the latter stream (the "parent" request) be allocated 417 resources before the former stream (the "dependent" request). Taken 418 together, the dependencies across all requests in a connection form a 419 dependency tree. The structure of the dependency tree changes as 420 PRIORITY frames add, remove, or change the dependency links between 421 requests. 423 HTTP/2 defines its priorities in terms of streams whereas HTTP over 424 QUIC identifies requests. The PRIORITY frame Section 5.2.3 425 identifies a request either by identifying the stream that carries a 426 request or by using a Push ID (Section 5.2.6). Other than the means 427 of identifying requests, the prioritization system is identical to 428 that in HTTP/2. 430 Only a client can send PRIORITY frames. A server MUST NOT send a 431 PRIORITY frame. 433 4.4. Server Push 435 HTTP/QUIC supports server push as described in [RFC7540]. During 436 connection establishment, the client enables server push by sending a 437 MAX_PUSH_ID frame (see Section 5.2.8). A server cannot use server 438 push until it receives a MAX_PUSH_ID frame. 440 As with server push for HTTP/2, the server initiates a server push by 441 sending a PUSH_PROMISE frame that includes request header fields 442 attributed to the request. The PUSH_PROMISE frame is sent on the 443 client-initiated, bidirectional stream that carried the request that 444 generated the push. This allows the server push to be associated 445 with a request. Ordering of a PUSH_PROMISE in relation to certain 446 parts of the response is important (see Section 8.2.1 of [RFC7540]). 448 Unlike HTTP/2, the PUSH_PROMISE does not reference a stream; when a 449 server fulfills a promise, the stream that carries the stream headers 450 references a Push ID. This allows a server to fulfill promises in 451 the order that best suits its needs. 453 The server push response is conveyed on a push stream. A push stream 454 is a server-initiated, unidirectional stream. A push stream includes 455 a header (see Figure 1) that identifies the PUSH_PROMISE that it 456 fulfills. This header consists of a Push ID, encoded as a variable- 457 length integer. The Push ID identifies a server push (see 458 Section 5.2.6). 460 0 1 2 3 461 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 462 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 463 | Push ID (i) | 464 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 466 Figure 1: Push Stream Header 468 A push stream always starts with a Push ID. A client MUST treat 469 receiving a push stream that contains a truncated variable-length 470 integer as a connection error of type HTTP_MALFORMED_PUSH. 472 A server SHOULD use Push IDs sequentially, starting at 0. A client 473 uses the MAX_PUSH_ID frame (Section 5.2.8) to limit the number of 474 pushes that a server can promise. A client MUST treat receipt of a 475 push stream with a Push ID that is greater than the maximum Push ID 476 as a connection error of type HTTP_MALFORMED_PUSH. 478 Each Push ID MUST only be used once in a push stream header. If a 479 push stream header includes a Push ID that was used in another push 480 stream header, the client MUST treat this as a connection error of 481 type HTTP_MALFORMED_PUSH. The same Push ID can be used in multiple 482 PUSH_PROMISE frames (see Section 5.2.6). 484 After the push stream header, a push contains a response 485 (Section 4.2), with response headers, a response body (if any) 486 carried by DATA frames, then trailers (if any) carried by HEADERS 487 frames. 489 If a promised server push is not needed by the client, the client 490 SHOULD send a CANCEL_PUSH frame; if the push stream is already open, 491 a QUIC STOP_SENDING frame with an appropriate error code can be used 492 instead (e.g., HTTP_PUSH_REFUSED, HTTP_PUSH_ALREADY_IN_CACHE; see 493 Section 7). This asks the server not to transfer the data and 494 indicates that it will be discarded upon receipt. 496 5. HTTP Framing Layer 498 Frames are used on each stream. This section describes HTTP framing 499 in QUIC and highlights some differences from HTTP/2 framing. For 500 more detail on differences from HTTP/2, see Section 8.2. 502 5.1. Frame Layout 504 All frames have the following format: 506 0 1 2 3 507 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 508 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 509 | Length (i) ... 510 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 511 | Type (8) | Flags (8) | Frame Payload (*) ... 512 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 514 Figure 2: HTTP/QUIC frame format 516 A frame includes the following fields: 518 Length: A variable-length integer that describes the length of the 519 Frame Payload. This length does not include the frame header. 521 Type: An 8-bit type for the frame. 523 Flags: An 8-bit field containing flags. The Type field determines 524 the semantics of flags. 526 Frame Payload: A payload, the semantics of which are determined by 527 the Type field. 529 5.2. Frame Definitions 531 5.2.1. DATA 533 DATA frames (type=0x0) convey arbitrary, variable-length sequences of 534 octets associated with an HTTP request or response payload. 536 The DATA frame defines no flags. 538 DATA frames MUST be associated with an HTTP request or response. If 539 a DATA frame is received on either control stream, the recipient MUST 540 respond with a connection error (Section 7) of type 541 HTTP_WRONG_STREAM. 543 DATA frames MUST contain a non-zero-length payload. If a DATA frame 544 is received with a payload length of zero, the recipient MUST respond 545 with a stream error (Section 7) of type HTTP_MALFORMED_DATA. 547 5.2.2. HEADERS 549 The HEADERS frame (type=0x1) is used to carry a header block, 550 compressed using HPACK Section 4.2.1. 552 No flags are defined for the HEADERS frame. 554 A HEADERS frame with any flags set MUST be treated as a connection 555 error of type HTTP_MALFORMED_HEADERS. 557 5.2.3. PRIORITY 559 The PRIORITY (type=0x02) frame specifies the sender-advised priority 560 of a stream and is substantially different in format from [RFC7540]. 561 In order to ensure that prioritization is processed in a consistent 562 order, PRIORITY frames MUST be sent on the control stream. A 563 PRIORITY frame sent on any other stream MUST be treated as a 564 HTTP_WRONG_STREAM error. 566 The format has been modified to accommodate not being sent on a 567 request stream, to allow for identification of server pushes, and the 568 larger stream ID space of QUIC. The semantics of the Stream 569 Dependency, Weight, and E flag are otherwise the same as in HTTP/2. 571 The flags defined are: 573 PUSH_PRIORITIZED (0x04): Indicates that the Prioritized Stream is a 574 server push rather than a request. 576 PUSH_DEPENDENT (0x02): Indicates a dependency on a server push. 578 E (0x01): Indicates that the stream dependency is exclusive (see 579 [RFC7540], Section 5.3). 581 0 1 2 3 582 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 583 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 584 | Prioritized Request ID (i) | 585 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 586 | Stream Dependency ID (i) | 587 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 588 | Weight (8) | 589 +-+-+-+-+-+-+-+-+ 591 Figure 3: PRIORITY frame payload 593 The PRIORITY frame payload has the following fields: 595 Prioritized Request ID: A variable-length integer that identifies a 596 request. This contains the Stream ID of a request stream when the 597 PUSH_PRIORITIZED flag is clear, or a Push ID when the 598 PUSH_PRIORITIZED flag is set. 600 Stream Dependency ID: A variable-length integer that identifies a 601 dependent request. This contains the Stream ID of a request 602 stream when the PUSH_DEPENDENT flag is clear, or a Push ID when 603 the PUSH_DEPENDENT flag is set. A request Stream ID of 0 604 indicates a dependency on the root stream. For details of 605 dependencies, see Section 4.3 and [RFC7540], Section 5.3. 607 Weight: An unsigned 8-bit integer representing a priority weight for 608 the stream (see [RFC7540], Section 5.3). Add one to the value to 609 obtain a weight between 1 and 256. 611 A PRIORITY frame identifies a request to prioritize, and a request 612 upon which that request is dependent. A Prioritized Request ID or 613 Stream Dependency ID identifies a client-initiated request using the 614 corresponding stream ID when the corresponding PUSH_PRIORITIZED or 615 PUSH_DEPENDENT flag is not set. Setting the PUSH_PRIORITIZED or 616 PUSH_DEPENDENT flag causes the Prioritized Request ID or Stream 617 Dependency ID (respectively) to identify a server push using a Push 618 ID (see Section 5.2.6 for details). 620 A PRIORITY frame MAY identify a Stream Dependency ID using a Stream 621 ID of 0; as in [RFC7540], this makes the request dependent on the 622 root of the dependency tree. 624 A PRIORITY frame MUST identify a client-initiated, bidirectional 625 stream. A server MUST treat receipt of PRIORITY frame with a Stream 626 ID of any other type as a connection error of type 627 HTTP_MALFORMED_PRIORITY. 629 Stream ID 0 cannot be reprioritized. A Prioritized Request ID that 630 identifies Stream 0 MUST be treated as a connection error of type 631 HTTP_MALFORMED_PRIORITY. 633 A PRIORITY frame that does not reference a request MUST be treated as 634 a HTTP_MALFORMED_PRIORITY error, unless it references Stream ID 0. A 635 PRIORITY that sets a PUSH_PRIORITIZED or PUSH_DEPENDENT flag, but 636 then references a non-existent Push ID MUST be treated as a 637 HTTP_MALFORMED_PRIORITY error. 639 A PRIORITY frame MUST contain only the identified fields. A PRIORITY 640 frame that contains more or fewer fields, or a PRIORITY frame that 641 includes a truncated integer encoding MUST be treated as a connection 642 error of type HTTP_MALFORMED_PRIORITY. 644 5.2.4. CANCEL_PUSH 646 The CANCEL_PUSH frame (type=0x3) is used to request cancellation of 647 server push prior to the push stream being created. The CANCEL_PUSH 648 frame identifies a server push request by Push ID (see Section 5.2.6) 649 using a variable-length integer. 651 When a server receives this frame, it aborts sending the response for 652 the identified server push. If the server has not yet started to 653 send the server push, it can use the receipt of a CANCEL_PUSH frame 654 to avoid opening a stream. If the push stream has been opened by the 655 server, the server SHOULD sent a QUIC RST_STREAM frame on those 656 streams and cease transmission of the response. 658 A server can send this frame to indicate that it won't be sending a 659 response prior to creation of a push stream. Once the push stream 660 has been created, sending CANCEL_PUSH has no effect on the state of 661 the push stream. A QUIC RST_STREAM frame SHOULD be used instead to 662 cancel transmission of the server push response. 664 A CANCEL_PUSH frame is sent on the control stream. Sending a 665 CANCEL_PUSH frame on a stream other than the control stream MUST be 666 treated as a stream error of type HTTP_WRONG_STREAM. 668 The CANCEL_PUSH frame has no defined flags. 670 The CANCEL_PUSH frame carries a Push ID encoded as a variable-length 671 integer. The Push ID identifies the server push that is being 672 cancelled (see Section 5.2.6). 674 If the client receives a CANCEL_PUSH frame, that frame might identify 675 a Push ID that has not yet been mentioned by a PUSH_PROMISE frame. 677 A server MUST treat a CANCEL_PUSH frame payload does not contain 678 exactly one variable-length integer as a connection error of type 679 HTTP_MALFORMED_CANCEL_PUSH. 681 5.2.5. SETTINGS 683 The SETTINGS frame (type=0x4) conveys configuration parameters that 684 affect how endpoints communicate, such as preferences and constraints 685 on peer behavior, and is different from [RFC7540]. Individually, a 686 SETTINGS parameter can also be referred to as a "setting". 688 SETTINGS parameters are not negotiated; they describe characteristics 689 of the sending peer, which can be used by the receiving peer. 690 However, a negotiation can be implied by the use of SETTINGS - a peer 691 uses SETTINGS to advertise a set of supported values. The recipient 692 can then choose which entries from this list are also acceptable and 693 proceed with the value it has chosen. (This choice could be 694 announced in a field of an extension frame, or in its own value in 695 SETTINGS.) 697 Different values for the same parameter can be advertised by each 698 peer. For example, a client might be willing to consume very large 699 response headers, while servers are more cautious about request size. 701 Parameters MUST NOT occur more than once. A receiver MAY treat the 702 presence of the same parameter more than once as a connection error 703 of type HTTP_MALFORMED_SETTINGS. 705 The SETTINGS frame defines no flags. 707 The payload of a SETTINGS frame consists of zero or more parameters, 708 each consisting of an unsigned 16-bit setting identifier and a 709 length-prefixed binary value. 711 0 1 2 3 712 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 713 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 714 | Identifier (16) | Length (i) ... 715 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 716 | Contents (?) ... 717 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 719 Figure 4: SETTINGS value format 721 A zero-length content indicates that the setting value is a Boolean 722 and true. False is indicated by the absence of the setting. 724 Non-zero-length values MUST be compared against the remaining length 725 of the SETTINGS frame. Any value which purports to cross the end of 726 the frame MUST cause the SETTINGS frame to be considered malformed 727 and trigger a connection error of type HTTP_MALFORMED_SETTINGS. 729 An implementation MUST ignore the contents for any SETTINGS 730 identifier it does not understand. 732 SETTINGS frames always apply to a connection, never a single stream. 733 A SETTINGS frame MUST be sent as the first frame of either control 734 stream (see Section 4) by each peer, and MUST NOT be sent 735 subsequently or on any other stream. If an endpoint receives an 736 SETTINGS frame on a different stream, the endpoint MUST respond with 737 a connection error of type HTTP_WRONG_STREAM. If an endpoint 738 receives a second SETTINGS frame, the endpoint MUST respond with a 739 connection error of type HTTP_MULTIPLE_SETTINGS. 741 The SETTINGS frame affects connection state. A badly formed or 742 incomplete SETTINGS frame MUST be treated as a connection error 743 (Section 7) of type HTTP_MALFORMED_SETTINGS. 745 5.2.5.1. Integer encoding 747 Settings which are integers use the QUIC variable-length integer 748 encoding. 750 5.2.5.2. Defined SETTINGS Parameters 752 The following settings are defined in HTTP/QUIC: 754 SETTINGS_HEADER_TABLE_SIZE (0x1): An integer with a maximum value of 755 2^30 - 1. This value MUST be zero. 757 SETTINGS_MAX_HEADER_LIST_SIZE (0x6): An integer with a maximum value 758 of 2^30 - 1 760 5.2.5.3. Usage in 0-RTT 762 When a 0-RTT QUIC connection is being used, the client's initial 763 requests will be sent before the arrival of the server's SETTINGS 764 frame. Clients SHOULD cache at least the following settings about 765 servers: 767 o SETTINGS_HEADER_TABLE_SIZE 769 o SETTINGS_MAX_HEADER_LIST_SIZE 771 Clients MUST comply with cached settings until the server's current 772 settings are received. If a client does not have cached values, it 773 SHOULD assume the following values: 775 o SETTINGS_HEADER_TABLE_SIZE: 0 octets 777 o SETTINGS_MAX_HEADER_LIST_SIZE: 16,384 octets 779 Servers MAY continue processing data from clients which exceed its 780 current configuration during the initial flight. In this case, the 781 client MUST apply the new settings immediately upon receipt. 783 If the connection is closed because these or other constraints were 784 violated during the 0-RTT flight (e.g. with 785 HTTP_HPACK_DECOMPRESSION_FAILED), clients MAY establish a new 786 connection and retry any 0-RTT requests using the settings sent by 787 the server on the closed connection. (This assumes that only 788 requests that are safe to retry are sent in 0-RTT.) If the 789 connection was closed before the SETTINGS frame was received, clients 790 SHOULD discard any cached values and use the defaults above on the 791 next connection. 793 5.2.6. PUSH_PROMISE 795 The PUSH_PROMISE frame (type=0x05) is used to carry a request header 796 set from server to client, as in HTTP/2. The PUSH_PROMISE frame 797 defines no flags. 799 0 1 2 3 800 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 801 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 802 | Push ID (i) ... 803 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 804 | Header Block (*) ... 805 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 807 Figure 5: PUSH_PROMISE frame payload 809 The payload consists of: 811 Push ID: A variable-length integer that identifies the server push 812 request. A push ID is used in push stream header (Section 4.4), 813 CANCEL_PUSH frames (Section 5.2.4), and PRIORITY frames 814 (Section 5.2.3). 816 Header Block: HPACK-compressed request headers for the promised 817 response. 819 A server MUST NOT use a Push ID that is larger than the client has 820 provided in a MAX_PUSH_ID frame (Section 5.2.8). A client MUST treat 821 receipt of a PUSH_PROMISE that contains a larger Push ID than the 822 client has advertised as a connection error of type 823 HTTP_MALFORMED_PUSH_PROMISE. 825 A server MAY use the same Push ID in multiple PUSH_PROMISE frames. 826 This allows the server to use the same server push in response to 827 multiple concurrent requests. Referencing the same server push 828 ensures that a PUSH_PROMISE can be made in relation to every response 829 in which server push might be needed without duplicating pushes. 831 A server that uses the same Push ID in multiple PUSH_PROMISE frames 832 MUST include the same header fields each time. The octets of the 833 header block MAY be different due to differing encoding, but the 834 header fields and their values MUST be identical. Note that ordering 835 of header fields is significant. A client MUST treat receipt of a 836 PUSH_PROMISE with conflicting header field values for the same Push 837 ID as a connection error of type HTTP_MALFORMED_PUSH_PROMISE. 839 Allowing duplicate references to the same Push ID is primarily to 840 reduce duplication caused by concurrent requests. A server SHOULD 841 avoid reusing a Push ID over a long period. Clients are likely to 842 consume server push responses and not retain them for reuse over 843 time. Clients that see a PUSH_PROMISE that uses a Push ID that they 844 have since consumed and discarded are forced to ignore the 845 PUSH_PROMISE. 847 5.2.7. GOAWAY 849 The GOAWAY frame (type=0x7) is used to initiate graceful shutdown of 850 a connection by a server. GOAWAY allows a server to stop accepting 851 new requests while still finishing processing of previously received 852 requests. This enables administrative actions, like server 853 maintenance. GOAWAY by itself does not close a connection. 855 The GOAWAY frame does not define any flags, and the payload is a QUIC 856 Stream ID for a client-initiated, bidirectional stream encoded as a 857 variable-length integer. 859 Clients do not need to send GOAWAY to initiate a graceful shutdown; 860 they simply stop making new requests. A server MUST treat receipt of 861 a GOAWAY frame as a connection error (Section 7) of type 862 HTTP_UNEXPECTED_GOAWAY. 864 A client MUST treat receipt of a GOAWAY frame containing a Stream ID 865 of any other type as a connection error of type 866 HTTP_MALFORMED_GOAWAY. 868 The GOAWAY frame applies to the connection, not a specific stream. 869 An endpoint MUST treat a GOAWAY frame on a stream other than the 870 control stream as a connection error (Section 7) of type 871 HTTP_WRONG_STREAM. 873 New client requests might already have been sent before the client 874 receives the server's GOAWAY frame. The GOAWAY frame contains the 875 Stream ID of the last client-initiated request that was or might be 876 processed in this connection, which enables client and server to 877 agree on which requests were accepted prior to the connection 878 shutdown. This identifier MAY be lower than the stream limit 879 identified by a QUIC MAX_STREAM_ID frame, and MAY be zero if no 880 requests were processed. Servers SHOULD NOT increase the 881 MAX_STREAM_ID limit after sending a GOAWAY frame. 883 Note: In this context, "processed" means that some data from the 884 stream was passed to some higher layer of software that might have 885 taken some action as a result. 887 Once sent, the server will refuse requests sent on streams with an 888 identifier higher than the included last Stream ID. Clients MUST NOT 889 send new requests on the connection after receiving GOAWAY, although 890 requests might already be in transit. A new connection can be 891 established for new requests. 893 If the client has sent requests on streams with a higher Stream ID 894 than indicated in the GOAWAY frame, those requests were not and will 895 not be processed. Endpoints SHOULD reset any streams above this ID 896 with the error code HTTP_REQUEST_CANCELLED. Servers MAY also reset 897 streams below the indicated ID with HTTP_REQUEST_CANCELLED if the 898 associated requests were not processed. Servers MUST NOT use the 899 HTTP_REQUEST_CANCELLED status for requests which were partially or 900 fully processed. 902 The client can treat requests cancelled by the server as though they 903 had never been sent at all, thereby allowing them to be retried later 904 on a new connection. If a stream is cancelled after receiving a 905 complete response, the client MAY ignore the cancellation and use the 906 response. However, if a stream is cancelled after receiving a 907 partial response, the response SHOULD NOT be used. Automatically 908 retrying such requests is not possible, unless this is otherwise 909 permitted (e.g., idempotent actions like GET, PUT, or DELETE). 910 Requests on Stream IDs less than or equal to the Stream ID in the 911 GOAWAY frame might have been processed; their status cannot be known 912 until they are completed successfully, reset individually, or the 913 connection terminates. 915 Servers SHOULD send a GOAWAY frame when the closing of a connection 916 is known in advance, even if the advance notice is small, so that the 917 remote peer can know whether a stream has been partially processed or 918 not. For example, if an HTTP client sends a POST at the same time 919 that a server closes a QUIC connection, the client cannot know if the 920 server started to process that POST request if the server does not 921 send a GOAWAY frame to indicate what streams it might have acted on. 923 For unexpected closures caused by error conditions, a QUIC 924 CONNECTION_CLOSE or APPLICATION_CLOSE frame MUST be used. However, a 925 GOAWAY MAY be sent first to provide additional detail to clients and 926 to allow the client to retry requests. Including the GOAWAY frame in 927 the same packet as the QUIC CONNECTION_CLOSE or APPLICATION_CLOSE 928 frame improves the chances of the frame being received by clients. 930 If a connection terminates without a GOAWAY frame, the last Stream ID 931 is effectively the highest possible Stream ID (as determined by 932 QUIC's MAX_STREAM_ID). 934 An endpoint MAY send multiple GOAWAY frames if circumstances change. 935 For instance, an endpoint that sends GOAWAY without an error code 936 during graceful shutdown could subsequently encounter an error 937 condition. The last stream identifier from the last GOAWAY frame 938 received indicates which streams could have been acted upon. A 939 server MUST NOT increase the value they send in the last Stream ID, 940 since clients might already have retried unprocessed requests on 941 another connection. 943 A client that is unable to retry requests loses all requests that are 944 in flight when the server closes the connection. A server that is 945 attempting to gracefully shut down a connection SHOULD send an 946 initial GOAWAY frame with the last Stream ID set to the current value 947 of QUIC's MAX_STREAM_ID and SHOULD NOT increase the MAX_STREAM_ID 948 thereafter. This signals to the client that a shutdown is imminent 949 and that initiating further requests is prohibited. After allowing 950 time for any in-flight requests (at least one round-trip time), the 951 server MAY send another GOAWAY frame with an updated last Stream ID. 952 This ensures that a connection can be cleanly shut down without 953 losing requests. 955 Once all requests on streams at or below the identified stream number 956 have been completed or cancelled, and all promised server push 957 responses associated with those requests have been completed or 958 cancelled, the connection can be closed using an Immediate Close (see 959 [QUIC-TRANSPORT]). An endpoint that completes a graceful shutdown 960 SHOULD use the QUIC APPLICATION_CLOSE frame with the HTTP_NO_ERROR 961 code. 963 5.2.8. MAX_PUSH_ID 965 The MAX_PUSH_ID frame (type=0xD) is used by clients to control the 966 number of server pushes that the server can initiate. This sets the 967 maximum value for a Push ID that the server can use in a PUSH_PROMISE 968 frame. Consequently, this also limits the number of push streams 969 that the server can initiate in addition to the limit set by the QUIC 970 MAX_STREAM_ID frame. 972 The MAX_PUSH_ID frame is always sent on a control stream. Receipt of 973 a MAX_PUSH_ID frame on any other stream MUST be treated as a 974 connection error of type HTTP_WRONG_STREAM. 976 A server MUST NOT send a MAX_PUSH_ID frame. A client MUST treat the 977 receipt of a MAX_PUSH_ID frame as a connection error of type 978 HTTP_MALFORMED_MAX_PUSH_ID. 980 The maximum Push ID is unset when a connection is created, meaning 981 that a server cannot push until it receives a MAX_PUSH_ID frame. A 982 client that wishes to manage the number of promised server pushes can 983 increase the maximum Push ID by sending a MAX_PUSH_ID frame as the 984 server fulfills or cancels server pushes. 986 The MAX_PUSH_ID frame has no defined flags. 988 The MAX_PUSH_ID frame carries a single variable-length integer that 989 identifies the maximum value for a Push ID that the server can use 990 (see Section 5.2.6). A MAX_PUSH_ID frame cannot reduce the maximum 991 Push ID; receipt of a MAX_PUSH_ID that contains a smaller value than 992 previously received MUST be treated as a connection error of type 993 HTTP_MALFORMED_MAX_PUSH_ID. 995 A server MUST treat a MAX_PUSH_ID frame payload that does not contain 996 a single variable-length integer as a connection error of type 997 HTTP_MALFORMED_MAX_PUSH_ID. 999 6. Connection Management 1001 QUIC connections are persistent. All of the considerations in 1002 Section 9.1 of [RFC7540] apply to the management of QUIC connections. 1004 HTTP clients are expected to use QUIC PING frames to keep connections 1005 open. Servers SHOULD NOT use PING frames to keep a connection open. 1006 A client SHOULD NOT use PING frames for this purpose unless there are 1007 responses outstanding for requests or server pushes. If the client 1008 is not expecting a response from the server, allowing an idle 1009 connection to time out (based on the idle_timeout transport 1010 parameter) is preferred over expending effort maintaining a 1011 connection that might not be needed. A gateway MAY use PING to 1012 maintain connections in anticipation of need rather than incur the 1013 latency cost of connection establishment to servers. 1015 7. Error Handling 1017 QUIC allows the application to abruptly terminate (reset) individual 1018 streams or the entire connection when an error is encountered. These 1019 are referred to as "stream errors" or "connection errors" and are 1020 described in more detail in [QUIC-TRANSPORT]. 1022 This section describes HTTP-specific error codes which can be used to 1023 express the cause of a connection or stream error. 1025 7.1. HTTP/QUIC Error Codes 1027 The following error codes are defined for use in QUIC RST_STREAM, 1028 STOP_SENDING, and CONNECTION_CLOSE frames when using HTTP/QUIC. 1030 STOPPING (0x00): This value is reserved by the transport to be used 1031 in response to QUIC STOP_SENDING frames. 1033 HTTP_NO_ERROR (0x01): No error. This is used when the connection or 1034 stream needs to be closed, but there is no error to signal. 1036 HTTP_PUSH_REFUSED (0x02): The server has attempted to push content 1037 which the client will not accept on this connection. 1039 HTTP_INTERNAL_ERROR (0x03): An internal error has occurred in the 1040 HTTP stack. 1042 HTTP_PUSH_ALREADY_IN_CACHE (0x04): The server has attempted to push 1043 content which the client has cached. 1045 HTTP_REQUEST_CANCELLED (0x05): The client no longer needs the 1046 requested data. 1048 HTTP_HPACK_DECOMPRESSION_FAILED (0x06): HPACK failed to decompress a 1049 frame and cannot continue. 1051 HTTP_CONNECT_ERROR (0x07): The connection established in response to 1052 a CONNECT request was reset or abnormally closed. 1054 HTTP_EXCESSIVE_LOAD (0x08): The endpoint detected that its peer is 1055 exhibiting a behavior that might be generating excessive load. 1057 HTTP_VERSION_FALLBACK (0x09): The requested operation cannot be 1058 served over HTTP/QUIC. The peer should retry over HTTP/2. 1060 HTTP_MALFORMED_HEADERS (0x0A): A HEADERS frame has been received 1061 with an invalid format. 1063 HTTP_MALFORMED_PRIORITY (0x0B): A PRIORITY frame has been received 1064 with an invalid format. 1066 HTTP_MALFORMED_SETTINGS (0x0C): A SETTINGS frame has been received 1067 with an invalid format. 1069 HTTP_MALFORMED_PUSH_PROMISE (0x0D): A PUSH_PROMISE frame has been 1070 received with an invalid format. 1072 HTTP_MALFORMED_DATA (0x0E): A DATA frame has been received with an 1073 invalid format. 1075 HTTP_INTERRUPTED_HEADERS (0x0F): A HEADERS frame without the End 1076 Header Block flag was followed by a frame other than HEADERS. 1078 HTTP_WRONG_STREAM (0x10): A frame was received on stream where it is 1079 not permitted. 1081 HTTP_MULTIPLE_SETTINGS (0x11): More than one SETTINGS frame was 1082 received. 1084 HTTP_MALFORMED_PUSH (0x12): A push stream header was malformed or 1085 included an invalid Push ID. 1087 HTTP_MALFORMED_MAX_PUSH_ID (0x13): A MAX_PUSH_ID frame has been 1088 received with an invalid format. 1090 HTTP_UNEXPECTED_GOAWAY (0x14): A GOAWAY frame has been received by a 1091 server. 1093 HTTP_MALFORMED_GOAWAY (0x15): A GOAWAY frame was malformed or 1094 contained an invalid Stream ID. 1096 8. Considerations for Transitioning from HTTP/2 1098 HTTP/QUIC is strongly informed by HTTP/2, and bears many 1099 similarities. This section describes the approach taken to design 1100 HTTP/QUIC, points out important differences from HTTP/2, and 1101 describes how to map HTTP/2 extensions into HTTP/QUIC. 1103 HTTP/QUIC begins from the premise that HTTP/2 code reuse is a useful 1104 feature, but not a hard requirement. HTTP/QUIC departs from HTTP/2 1105 primarily where necessary to accommodate the differences in behavior 1106 between QUIC and TCP (lack of ordering, support for streams). We 1107 intend to avoid gratuitous changes which make it difficult or 1108 impossible to build extensions with the same semantics applicable to 1109 both protocols at once. 1111 These departures are noted in this section. 1113 8.1. Streams 1115 HTTP/QUIC permits use of a larger number of streams (2^62-1) then 1116 HTTP/2. The considerations about exhaustion of stream identifier 1117 space apply, though the space is significantly larger such that it is 1118 likely that other limits in QUIC are reached first, such as the limit 1119 on the connection flow control window. 1121 8.2. HTTP Frame Types 1123 Many framing concepts from HTTP/2 can be elided away on QUIC, because 1124 the transport deals with them. Because frames are already on a 1125 stream, they can omit the stream number. Because frames do not block 1126 multiplexing (QUIC's multiplexing occurs below this layer), the 1127 support for variable-maximum-length packets can be removed. Because 1128 stream termination is handled by QUIC, an END_STREAM flag is not 1129 required. 1131 Frame payloads are largely drawn from [RFC7540]. However, QUIC 1132 includes many features (e.g. flow control) which are also present in 1133 HTTP/2. In these cases, the HTTP mapping does not re-implement them. 1134 As a result, several HTTP/2 frame types are not required in HTTP/ 1135 QUIC. Where an HTTP/2-defined frame is no longer used, the frame ID 1136 has been reserved in order to maximize portability between HTTP/2 and 1137 HTTP/QUIC implementations. However, even equivalent frames between 1138 the two mappings are not identical. 1140 Many of the differences arise from the fact that HTTP/2 provides an 1141 absolute ordering between frames across all streams, while QUIC 1142 provides this guarantee on each stream only. As a result, if a frame 1143 type makes assumptions that frames from different streams will still 1144 be received in the order sent, HTTP/QUIC will break them. 1146 For example, implicit in the HTTP/2 prioritization scheme is the 1147 notion of in-order delivery of priority changes (i.e., dependency 1148 tree mutations): since operations on the dependency tree such as 1149 reparenting a subtree are not commutative, both sender and receiver 1150 must apply them in the same order to ensure that both sides have a 1151 consistent view of the stream dependency tree. HTTP/2 specifies 1152 priority assignments in PRIORITY frames and (optionally) in HEADERS 1153 frames. To achieve in-order delivery of priority changes in HTTP/ 1154 QUIC, PRIORITY frames are sent on the control stream and the PRIORITY 1155 section is removed from the HEADERS frame. 1157 Frame type definitions in HTTP/QUIC often use the QUIC variable- 1158 length integer encoding. In particular, Stream IDs use this 1159 encoding, which allow for a larger range of possible values than the 1160 encoding used in HTTP/2. Redefinition of the encoding of extension 1161 frame types might be necessary if the encoding includes a Stream ID. 1163 Other than this issue, frame type HTTP/2 extensions are typically 1164 portable to QUIC simply by replacing Stream 0 in HTTP/2 with Stream 2 1165 or 3 in HTTP/QUIC. HTTP/QUIC extensions will not assume ordering, 1166 but would not be harmed by ordering, and would be portable to HTTP/2 1167 in the same manner. 1169 Below is a listing of how each HTTP/2 frame type is mapped: 1171 DATA (0x0): Padding is not defined in HTTP/QUIC frames. See 1172 Section 5.2.1. 1174 HEADERS (0x1): As described above, the PRIORITY region of HEADERS is 1175 not supported. A separate PRIORITY frame MUST be used. Padding 1176 is not defined in HTTP/QUIC frames. See Section 5.2.2. 1178 PRIORITY (0x2): As described above, the PRIORITY frame is sent on 1179 the control stream. See Section 5.2.3. 1181 RST_STREAM (0x3): RST_STREAM frames do not exist, since QUIC 1182 provides stream lifecycle management. The same code point is used 1183 for the CANCEL_PUSH frame (Section 5.2.4). 1185 SETTINGS (0x4): SETTINGS frames are sent only at the beginning of 1186 the connection. See Section 5.2.5 and Section 8.3. 1188 PUSH_PROMISE (0x5): The PUSH_PROMISE does not reference a stream; 1189 instead the push stream references the PUSH_PROMISE frame using a 1190 Push ID. See Section 5.2.6. 1192 PING (0x6): PING frames do not exist, since QUIC provides equivalent 1193 functionality. 1195 GOAWAY (0x7): GOAWAY is sent only from server to client and does not 1196 contain an error code. See Section 5.2.7. 1198 WINDOW_UPDATE (0x8): WINDOW_UPDATE frames do not exist, since QUIC 1199 provides flow control. 1201 CONTINUATION (0x9): CONTINUATION frames do not exist; instead, 1202 larger HEADERS/PUSH_PROMISE frames than HTTP/2 are permitted, and 1203 HEADERS frames can be used in series. 1205 Frame types defined by extensions to HTTP/2 need to be separately 1206 registered for HTTP/QUIC if still applicable. The IDs of frames 1207 defined in [RFC7540] have been reserved for simplicity. See 1208 Section 10.3. 1210 8.3. HTTP/2 SETTINGS Parameters 1212 An important difference from HTTP/2 is that settings are sent once, 1213 at the beginning of the connection, and thereafter cannot change. 1214 This eliminates many corner cases around synchronization of changes. 1216 Some transport-level options that HTTP/2 specifies via the SETTINGS 1217 frame are superseded by QUIC transport parameters in HTTP/QUIC. The 1218 HTTP-level options that are retained in HTTP/QUIC have the same value 1219 as in HTTP/2. 1221 Below is a listing of how each HTTP/2 SETTINGS parameter is mapped: 1223 SETTINGS_HEADER_TABLE_SIZE: See Section 5.2.5.2. 1225 SETTINGS_ENABLE_PUSH: This is removed in favor of the MAX_PUSH_ID 1226 which provides a more granular control over server push. 1228 SETTINGS_MAX_CONCURRENT_STREAMS: QUIC controls the largest open 1229 Stream ID as part of its flow control logic. Specifying 1230 SETTINGS_MAX_CONCURRENT_STREAMS in the SETTINGS frame is an error. 1232 SETTINGS_INITIAL_WINDOW_SIZE: QUIC requires both stream and 1233 connection flow control window sizes to be specified in the 1234 initial transport handshake. Specifying 1235 SETTINGS_INITIAL_WINDOW_SIZE in the SETTINGS frame is an error. 1237 SETTINGS_MAX_FRAME_SIZE: This setting has no equivalent in HTTP/ 1238 QUIC. Specifying it in the SETTINGS frame is an error. 1240 SETTINGS_MAX_HEADER_LIST_SIZE: See Section 5.2.5.2. 1242 Settings need to be defined separately for HTTP/2 and HTTP/QUIC. The 1243 IDs of settings defined in [RFC7540] have been reserved for 1244 simplicity. See Section 10.4. 1246 8.4. HTTP/2 Error Codes 1248 QUIC has the same concepts of "stream" and "connection" errors that 1249 HTTP/2 provides. However, because the error code space is shared 1250 between multiple components, there is no direct portability of HTTP/2 1251 error codes. 1253 The HTTP/2 error codes defined in Section 7 of [RFC7540] map to the 1254 HTTP over QUIC error codes as follows: 1256 NO_ERROR (0x0): HTTP_NO_ERROR in Section 7.1. 1258 PROTOCOL_ERROR (0x1): No single mapping. See new HTTP_MALFORMED_* 1259 error codes defined in Section 7.1. 1261 INTERNAL_ERROR (0x2): HTTP_INTERNAL_ERROR in Section 7.1. 1263 FLOW_CONTROL_ERROR (0x3): Not applicable, since QUIC handles flow 1264 control. Would provoke a QUIC_FLOW_CONTROL_RECEIVED_TOO_MUCH_DATA 1265 from the QUIC layer. 1267 SETTINGS_TIMEOUT (0x4): Not applicable, since no acknowledgement of 1268 SETTINGS is defined. 1270 STREAM_CLOSED (0x5): Not applicable, since QUIC handles stream 1271 management. Would provoke a QUIC_STREAM_DATA_AFTER_TERMINATION 1272 from the QUIC layer. 1274 FRAME_SIZE_ERROR (0x6) No single mapping. See new error codes 1275 defined in Section 7.1. 1277 REFUSED_STREAM (0x7): Not applicable, since QUIC handles stream 1278 management. Would provoke a QUIC_TOO_MANY_OPEN_STREAMS from the 1279 QUIC layer. 1281 CANCEL (0x8): HTTP_REQUEST_CANCELLED in Section 7.1. 1283 COMPRESSION_ERROR (0x9): HTTP_HPACK_DECOMPRESSION_FAILED in 1284 Section 7.1. 1286 CONNECT_ERROR (0xa): HTTP_CONNECT_ERROR in Section 7.1. 1288 ENHANCE_YOUR_CALM (0xb): HTTP_EXCESSIVE_LOAD in Section 7.1. 1290 INADEQUATE_SECURITY (0xc): Not applicable, since QUIC is assumed to 1291 provide sufficient security on all connections. 1293 HTTP_1_1_REQUIRED (0xd): HTTP_VERSION_FALLBACK in Section 7.1. 1295 Error codes need to be defined for HTTP/2 and HTTP/QUIC separately. 1296 See Section 10.5. 1298 9. Security Considerations 1300 The security considerations of HTTP over QUIC should be comparable to 1301 those of HTTP/2. 1303 The modified SETTINGS format contains nested length elements, which 1304 could pose a security risk to an uncautious implementer. A SETTINGS 1305 frame parser MUST ensure that the length of the frame exactly matches 1306 the length of the settings it contains. 1308 10. IANA Considerations 1310 10.1. Registration of HTTP/QUIC Identification String 1312 This document creates a new registration for the identification of 1313 HTTP/QUIC in the "Application Layer Protocol Negotiation (ALPN) 1314 Protocol IDs" registry established in [RFC7301]. 1316 The "hq" string identifies HTTP/QUIC: 1318 Protocol: HTTP over QUIC 1320 Identification Sequence: 0x68 0x71 ("hq") 1322 Specification: This document 1324 10.2. Registration of QUIC Version Hint Alt-Svc Parameter 1326 This document creates a new registration for version-negotiation 1327 hints in the "Hypertext Transfer Protocol (HTTP) Alt-Svc Parameter" 1328 registry established in [RFC7838]. 1330 Parameter: "quic" 1332 Specification: This document, Section 2.1 1334 10.3. Frame Types 1336 This document establishes a registry for HTTP/QUIC frame type codes. 1337 The "HTTP/QUIC Frame Type" registry manages an 8-bit space. The 1338 "HTTP/QUIC Frame Type" registry operates under either of the "IETF 1339 Review" or "IESG Approval" policies [RFC8126] for values between 0x00 1340 and 0xef, with values between 0xf0 and 0xff being reserved for 1341 Experimental Use. 1343 While this registry is separate from the "HTTP/2 Frame Type" registry 1344 defined in [RFC7540], it is preferable that the assignments parallel 1345 each other. If an entry is present in only one registry, every 1346 effort SHOULD be made to avoid assigning the corresponding value to 1347 an unrelated operation. 1349 New entries in this registry require the following information: 1351 Frame Type: A name or label for the frame type. 1353 Code: The 8-bit code assigned to the frame type. 1355 Specification: A reference to a specification that includes a 1356 description of the frame layout, its semantics, and flags that the 1357 frame type uses, including any parts of the frame that are 1358 conditionally present based on the value of flags. 1360 The entries in the following table are registered by this document. 1362 +--------------+------+---------------+ 1363 | Frame Type | Code | Specification | 1364 +--------------+------+---------------+ 1365 | DATA | 0x0 | Section 5.2.1 | 1366 | | | | 1367 | HEADERS | 0x1 | Section 5.2.2 | 1368 | | | | 1369 | PRIORITY | 0x2 | Section 5.2.3 | 1370 | | | | 1371 | CANCEL_PUSH | 0x3 | Section 5.2.4 | 1372 | | | | 1373 | SETTINGS | 0x4 | Section 5.2.5 | 1374 | | | | 1375 | PUSH_PROMISE | 0x5 | Section 5.2.6 | 1376 | | | | 1377 | Reserved | 0x6 | N/A | 1378 | | | | 1379 | GOAWAY | 0x7 | Section 5.2.7 | 1380 | | | | 1381 | Reserved | 0x8 | N/A | 1382 | | | | 1383 | Reserved | 0x9 | N/A | 1384 | | | | 1385 | MAX_PUSH_ID | 0xD | Section 5.2.8 | 1386 +--------------+------+---------------+ 1388 10.4. Settings Parameters 1390 This document establishes a registry for HTTP/QUIC settings. The 1391 "HTTP/QUIC Settings" registry manages a 16-bit space. The "HTTP/QUIC 1392 Settings" registry operates under the "Expert Review" policy 1393 [RFC8126] for values in the range from 0x0000 to 0xefff, with values 1394 between and 0xf000 and 0xffff being reserved for Experimental Use. 1395 The designated experts are the same as those for the "HTTP/2 1396 Settings" registry defined in [RFC7540]. 1398 While this registry is separate from the "HTTP/2 Settings" registry 1399 defined in [RFC7540], it is preferable that the assignments parallel 1400 each other. If an entry is present in only one registry, every 1401 effort SHOULD be made to avoid assigning the corresponding value to 1402 an unrelated operation. 1404 New registrations are advised to provide the following information: 1406 Name: A symbolic name for the setting. Specifying a setting name is 1407 optional. 1409 Code: The 16-bit code assigned to the setting. 1411 Specification: An optional reference to a specification that 1412 describes the use of the setting. 1414 The entries in the following table are registered by this document. 1416 +----------------------+------+-----------------+ 1417 | Setting Name | Code | Specification | 1418 +----------------------+------+-----------------+ 1419 | HEADER_TABLE_SIZE | 0x1 | Section 5.2.5.2 | 1420 | | | | 1421 | Reserved | 0x2 | N/A | 1422 | | | | 1423 | Reserved | 0x3 | N/A | 1424 | | | | 1425 | Reserved | 0x4 | N/A | 1426 | | | | 1427 | Reserved | 0x5 | N/A | 1428 | | | | 1429 | MAX_HEADER_LIST_SIZE | 0x6 | Section 5.2.5.2 | 1430 +----------------------+------+-----------------+ 1432 10.5. Error Codes 1434 This document establishes a registry for HTTP/QUIC error codes. The 1435 "HTTP/QUIC Error Code" registry manages a 16-bit space. The "HTTP/ 1436 QUIC Error Code" registry operates under the "Expert Review" policy 1437 [RFC8126]. 1439 Registrations for error codes are required to include a description 1440 of the error code. An expert reviewer is advised to examine new 1441 registrations for possible duplication with existing error codes. 1442 Use of existing registrations is to be encouraged, but not mandated. 1444 New registrations are advised to provide the following information: 1446 Name: A name for the error code. Specifying an error code name is 1447 optional. 1449 Code: The 16-bit error code value. 1451 Description: A brief description of the error code semantics, longer 1452 if no detailed specification is provided. 1454 Specification: An optional reference for a specification that 1455 defines the error code. 1457 The entries in the following table are registered by this document. 1459 +-----------------------------+-----+-------------+-----------------+ 1460 | Name | Cod | Description | Specification | 1461 | | e | | | 1462 +-----------------------------+-----+-------------+-----------------+ 1463 | STOPPING | 0x0 | Reserved by | [QUIC-TRANSPORT | 1464 | | 0 | QUIC | ] | 1465 | | | | | 1466 | HTTP_NO_ERROR | 0x0 | No error | Section 7.1 | 1467 | | 1 | | | 1468 | | | | | 1469 | HTTP_PUSH_REFUSED | 0x0 | Client | Section 7.1 | 1470 | | 2 | refused | | 1471 | | | pushed | | 1472 | | | content | | 1473 | | | | | 1474 | HTTP_INTERNAL_ERROR | 0x0 | Internal | Section 7.1 | 1475 | | 3 | error | | 1476 | | | | | 1477 | HTTP_PUSH_ALREADY_IN_CACHE | 0x0 | Pushed | Section 7.1 | 1478 | | 4 | content | | 1479 | | | already | | 1480 | | | cached | | 1481 | | | | | 1482 | HTTP_REQUEST_CANCELLED | 0x0 | Data no | Section 7.1 | 1483 | | 5 | longer | | 1484 | | | needed | | 1485 | | | | | 1486 | HTTP_HPACK_DECOMPRESSION_FA | 0x0 | HPACK | Section 7.1 | 1487 | ILED | 6 | cannot | | 1488 | | | continue | | 1489 | | | | | 1490 | HTTP_CONNECT_ERROR | 0x0 | TCP reset | Section 7.1 | 1491 | | 7 | or error on | | 1492 | | | CONNECT | | 1493 | | | request | | 1494 | | | | | 1495 | HTTP_EXCESSIVE_LOAD | 0x0 | Peer | Section 7.1 | 1496 | | 8 | generating | | 1497 | | | excessive | | 1498 | | | load | | 1499 | | | | | 1500 | HTTP_VERSION_FALLBACK | 0x0 | Retry over | Section 7.1 | 1501 | | 9 | HTTP/2 | | 1502 | | | | | 1503 | HTTP_MALFORMED_HEADERS | 0x0 | Invalid | Section 7.1 | 1504 | | A | HEADERS | | 1505 | | | frame | | 1506 | | | | | 1507 | HTTP_MALFORMED_PRIORITY | 0x0 | Invalid | Section 7.1 | 1508 | | B | PRIORITY | | 1509 | | | frame | | 1510 | | | | | 1511 | HTTP_MALFORMED_SETTINGS | 0x0 | Invalid | Section 7.1 | 1512 | | C | SETTINGS | | 1513 | | | frame | | 1514 | | | | | 1515 | HTTP_MALFORMED_PUSH_PROMISE | 0x0 | Invalid PUS | Section 7.1 | 1516 | | D | H_PROMISE | | 1517 | | | frame | | 1518 | | | | | 1519 | HTTP_MALFORMED_DATA | 0x0 | Invalid | Section 7.1 | 1520 | | E | DATA frame | | 1521 | | | | | 1522 | HTTP_INTERRUPTED_HEADERS | 0x0 | Incomplete | Section 7.1 | 1523 | | F | HEADERS | | 1524 | | | block | | 1525 | | | | | 1526 | HTTP_WRONG_STREAM | 0x1 | A frame was | Section 7.1 | 1527 | | 0 | sent on the | | 1528 | | | wrong | | 1529 | | | stream | | 1530 | | | | | 1531 | HTTP_MULTIPLE_SETTINGS | 0x1 | Multiple | Section 7.1 | 1532 | | 1 | SETTINGS | | 1533 | | | frames | | 1534 | | | | | 1535 | HTTP_MALFORMED_PUSH | 0x1 | Invalid | Section 7.1 | 1536 | | 2 | push stream | | 1537 | | | header | | 1538 | | | | | 1539 | HTTP_MALFORMED_MAX_PUSH_ID | 0x1 | Invalid | Section 7.1 | 1540 | | 3 | MAX_PUSH_ID | | 1541 | | | frame | | 1542 | | | | | 1543 | HTTP_UNEXPECTED_GOAWAY | 0x1 | A server | Section 7.1 | 1544 | | 4 | received | | 1545 | | | GOAWAY | | 1546 | | | | | 1547 | HTTP_MALFORMED_GOAWAY | 0x1 | Invalid | Section 7.1 | 1548 | | 5 | GOAWAY | | 1549 | | | frame | | 1550 +-----------------------------+-----+-------------+-----------------+ 1552 11. References 1554 11.1. Normative References 1556 [QUIC-TRANSPORT] 1557 Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based 1558 Multiplexed and Secure Transport", draft-ietf-quic- 1559 transport-00 (work in progress), December 2017. 1561 [RFC0793] Postel, J., "Transmission Control Protocol", STD 7, 1562 RFC 793, DOI 10.17487/RFC0793, September 1981, 1563 . 1565 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1566 Requirement Levels", BCP 14, RFC 2119, 1567 DOI 10.17487/RFC2119, March 1997, 1568 . 1570 [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax 1571 Specifications: ABNF", STD 68, RFC 5234, 1572 DOI 10.17487/RFC5234, January 2008, 1573 . 1575 [RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer 1576 Protocol (HTTP/1.1): Message Syntax and Routing", 1577 RFC 7230, DOI 10.17487/RFC7230, June 2014, 1578 . 1580 [RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer 1581 Protocol (HTTP/1.1): Semantics and Content", RFC 7231, 1582 DOI 10.17487/RFC7231, June 2014, 1583 . 1585 [RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext 1586 Transfer Protocol Version 2 (HTTP/2)", RFC 7540, 1587 DOI 10.17487/RFC7540, May 2015, 1588 . 1590 [RFC7541] Peon, R. and H. Ruellan, "HPACK: Header Compression for 1591 HTTP/2", RFC 7541, DOI 10.17487/RFC7541, May 2015, 1592 . 1594 [RFC7838] Nottingham, M., McManus, P., and J. Reschke, "HTTP 1595 Alternative Services", RFC 7838, DOI 10.17487/RFC7838, 1596 April 2016, . 1598 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 1599 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 1600 May 2017, . 1602 11.2. Informative References 1604 [RFC7301] Friedl, S., Popov, A., Langley, A., and E. Stephan, 1605 "Transport Layer Security (TLS) Application-Layer Protocol 1606 Negotiation Extension", RFC 7301, DOI 10.17487/RFC7301, 1607 July 2014, . 1609 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 1610 Writing an IANA Considerations Section in RFCs", BCP 26, 1611 RFC 8126, DOI 10.17487/RFC8126, June 2017, 1612 . 1614 11.3. URIs 1616 [1] https://mailarchive.ietf.org/arch/search/?email_list=quic 1618 [2] https://github.com/quicwg 1620 [3] https://github.com/quicwg/base-drafts/labels/-http 1622 Appendix A. Contributors 1624 The original authors of this specification were Robbie Shade and Mike 1625 Warres. 1627 A substantial portion of Mike's contribution was supported by 1628 Microsoft during his employment there. 1630 Appendix B. Change Log 1632 *RFC Editor's Note:* Please remove this section prior to 1633 publication of a final version of this document. 1635 B.1. Since draft-ietf-quic-http-07 1637 o Changes for integer encodings in QUIC (#595,#905) 1639 B.2. Since draft-ietf-quic-http-06 1641 o Track changes in QUIC error code usage (#485) 1643 B.3. Since draft-ietf-quic-http-05 1645 o Made push ID sequential, add MAX_PUSH_ID, remove 1646 SETTINGS_ENABLE_PUSH (#709) 1648 o Guidance about keep-alive and QUIC PINGs (#729) 1650 o Expanded text on GOAWAY and cancellation (#757) 1652 B.4. Since draft-ietf-quic-http-04 1654 o Cite RFC 5234 (#404) 1656 o Return to a single stream per request (#245,#557) 1658 o Use separate frame type and settings registries from HTTP/2 (#81) 1660 o SETTINGS_ENABLE_PUSH instead of SETTINGS_DISABLE_PUSH (#477) 1662 o Restored GOAWAY (#696) 1664 o Identify server push using Push ID rather than a stream ID 1665 (#702,#281) 1667 o DATA frames cannot be empty (#700) 1669 B.5. Since draft-ietf-quic-http-03 1671 None. 1673 B.6. Since draft-ietf-quic-http-02 1675 o Track changes in transport draft 1677 B.7. Since draft-ietf-quic-http-01 1679 o SETTINGS changes (#181): 1681 * SETTINGS can be sent only once at the start of a connection; no 1682 changes thereafter 1684 * SETTINGS_ACK removed 1686 * Settings can only occur in the SETTINGS frame a single time 1688 * Boolean format updated 1690 o Alt-Svc parameter changed from "v" to "quic"; format updated 1691 (#229) 1693 o Closing the connection control stream or any message control 1694 stream is a fatal error (#176) 1696 o HPACK Sequence counter can wrap (#173) 1698 o 0-RTT guidance added 1700 o Guide to differences from HTTP/2 and porting HTTP/2 extensions 1701 added (#127,#242) 1703 B.8. Since draft-ietf-quic-http-00 1705 o Changed "HTTP/2-over-QUIC" to "HTTP/QUIC" throughout (#11,#29) 1707 o Changed from using HTTP/2 framing within Stream 3 to new framing 1708 format and two-stream-per-request model (#71,#72,#73) 1710 o Adopted SETTINGS format from draft-bishop-httpbis-extended- 1711 settings-01 1713 o Reworked SETTINGS_ACK to account for indeterminate inter-stream 1714 order (#75) 1716 o Described CONNECT pseudo-method (#95) 1718 o Updated ALPN token and Alt-Svc guidance (#13,#87) 1720 o Application-layer-defined error codes (#19,#74) 1722 B.9. Since draft-shade-quic-http2-mapping-00 1724 o Adopted as base for draft-ietf-quic-http 1726 o Updated authors/editors list 1728 Author's Address 1730 Mike Bishop (editor) 1731 Akamai 1733 Email: mbishop@evequefou.be