/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2013, 2014 Tatsuhiro Tsujikawa
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef NGHTTP2_H
#define NGHTTP2_H
/* Define WIN32 when build target is Win32 API (borrowed from
libcurl) */
#if (defined(_WIN32) || defined(__WIN32__)) && !defined(WIN32)
#define WIN32
#endif
#ifdef __cplusplus
extern "C" {
#endif
#include <stdlib.h>
#if defined(_MSC_VER) && (_MSC_VER < 1800)
/* MSVC < 2013 does not have inttypes.h because it is not C99
compliant. See compiler macros and version number in
https://sourceforge.net/p/predef/wiki/Compilers/ */
#include <stdint.h>
#else /* !defined(_MSC_VER) || (_MSC_VER >= 1800) */
#include <inttypes.h>
#endif /* !defined(_MSC_VER) || (_MSC_VER >= 1800) */
#include <sys/types.h>
#include <stdarg.h>
#include <nghttp2/nghttp2ver.h>
#ifdef NGHTTP2_STATICLIB
#define NGHTTP2_EXTERN
#elif defined(WIN32)
#ifdef BUILDING_NGHTTP2
#define NGHTTP2_EXTERN __declspec(dllexport)
#else /* !BUILDING_NGHTTP2 */
#define NGHTTP2_EXTERN __declspec(dllimport)
#endif /* !BUILDING_NGHTTP2 */
#else /* !defined(WIN32) */
#ifdef BUILDING_NGHTTP2
#define NGHTTP2_EXTERN __attribute__((visibility("default")))
#else /* !BUILDING_NGHTTP2 */
#define NGHTTP2_EXTERN
#endif /* !BUILDING_NGHTTP2 */
#endif /* !defined(WIN32) */
/**
* @macro
*
* The protocol version identification string of this library
* supports. This identifier is used if HTTP/2 is used over TLS.
*/
#define NGHTTP2_PROTO_VERSION_ID "h2"
/**
* @macro
*
* The length of :macro:`NGHTTP2_PROTO_VERSION_ID`.
*/
#define NGHTTP2_PROTO_VERSION_ID_LEN 2
/**
* @macro
*
* The serialized form of ALPN protocol identifier this library
* supports. Notice that first byte is the length of following
* protocol identifier. This is the same wire format of `TLS ALPN
* extension <https://tools.ietf.org/html/rfc7301>`_. This is useful
* to process incoming ALPN tokens in wire format.
*/
#define NGHTTP2_PROTO_ALPN "\x2h2"
/**
* @macro
*
* The length of :macro:`NGHTTP2_PROTO_ALPN`.
*/
#define NGHTTP2_PROTO_ALPN_LEN (sizeof(NGHTTP2_PROTO_ALPN) - 1)
/**
* @macro
*
* The protocol version identification string of this library
* supports. This identifier is used if HTTP/2 is used over cleartext
* TCP.
*/
#define NGHTTP2_CLEARTEXT_PROTO_VERSION_ID "h2c"
/**
* @macro
*
* The length of :macro:`NGHTTP2_CLEARTEXT_PROTO_VERSION_ID`.
*/
#define NGHTTP2_CLEARTEXT_PROTO_VERSION_ID_LEN 3
struct nghttp2_session;
/**
* @struct
*
* The primary structure to hold the resources needed for a HTTP/2
* session. The details of this structure are intentionally hidden
* from the public API.
*/
typedef struct nghttp2_session nghttp2_session;
/**
* @macro
*
* The age of :type:`nghttp2_info`
*/
#define NGHTTP2_VERSION_AGE 1
/**
* @struct
*
* This struct is what `nghttp2_version()` returns. It holds
* information about the particular nghttp2 version.
*/
typedef struct {
/**
* Age of this struct. This instance of nghttp2 sets it to
* :macro:`NGHTTP2_VERSION_AGE` but a future version may bump it and
* add more struct fields at the bottom
*/
int age;
/**
* the :macro:`NGHTTP2_VERSION_NUM` number (since age ==1)
*/
int version_num;
/**
* points to the :macro:`NGHTTP2_VERSION` string (since age ==1)
*/
const char *version_str;
/**
* points to the :macro:`NGHTTP2_PROTO_VERSION_ID` string this
* instance implements (since age ==1)
*/
const char *proto_str;
/* -------- the above fields all exist when age == 1 */
} nghttp2_info;
/**
* @macro
*
* The default weight of stream dependency.
*/
#define NGHTTP2_DEFAULT_WEIGHT 16
/**
* @macro
*
* The maximum weight of stream dependency.
*/
#define NGHTTP2_MAX_WEIGHT 256
/**
* @macro
*
* The minimum weight of stream dependency.
*/
#define NGHTTP2_MIN_WEIGHT 1
/**
* @macro
*
* The maximum window size
*/
#define NGHTTP2_MAX_WINDOW_SIZE ((int32_t)((1U << 31) - 1))
/**
* @macro
*
* The initial window size for stream level flow control.
*/
#define NGHTTP2_INITIAL_WINDOW_SIZE ((1 << 16) - 1)
/**
* @macro
*
* The initial window size for connection level flow control.
*/
#define NGHTTP2_INITIAL_CONNECTION_WINDOW_SIZE ((1 << 16) - 1)
/**
* @macro
*
* The default header table size.
*/
#define NGHTTP2_DEFAULT_HEADER_TABLE_SIZE (1 << 12)
/**
* @macro
*
* The client magic string, which is the first 24 bytes byte string of
* client connection preface.
*/
#define NGHTTP2_CLIENT_MAGIC "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n"
/**
* @macro
*
* The length of :macro:`NGHTTP2_CLIENT_MAGIC`.
*/
#define NGHTTP2_CLIENT_MAGIC_LEN 24
/**
* @enum
*
* Error codes used in this library. The code range is [-999, -500],
* inclusive. The following values are defined:
*/
typedef enum {
/**
* Invalid argument passed.
*/
NGHTTP2_ERR_INVALID_ARGUMENT = -501,
/**
* Out of buffer space.
*/
NGHTTP2_ERR_BUFFER_ERROR = -502,
/**
* The specified protocol version is not supported.
*/
NGHTTP2_ERR_UNSUPPORTED_VERSION = -503,
/**
* Used as a return value from :type:`nghttp2_send_callback`,
* :type:`nghttp2_recv_callback` and
* :type:`nghttp2_send_data_callback` to indicate that the operation
* would block.
*/
NGHTTP2_ERR_WOULDBLOCK = -504,
/**
* General protocol error
*/
NGHTTP2_ERR_PROTO = -505,
/**
* The frame is invalid.
*/
NGHTTP2_ERR_INVALID_FRAME = -506,
/**
* The peer performed a shutdown on the connection.
*/
NGHTTP2_ERR_EOF = -507,
/**
* Used as a return value from
* :func:`nghttp2_data_source_read_callback` to indicate that data
* transfer is postponed. See
* :func:`nghttp2_data_source_read_callback` for details.
*/
NGHTTP2_ERR_DEFERRED = -508,
/**
* Stream ID has reached the maximum value. Therefore no stream ID
* is available.
*/
NGHTTP2_ERR_STREAM_ID_NOT_AVAILABLE = -509,
/**
* The stream is already closed; or the stream ID is invalid.
*/
NGHTTP2_ERR_STREAM_CLOSED = -510,
/**
* RST_STREAM has been added to the outbound queue. The stream is
* in closing state.
*/
NGHTTP2_ERR_STREAM_CLOSING = -511,
/**
* The transmission is not allowed for this stream (e.g., a frame
* with END_STREAM flag set has already sent).
*/
NGHTTP2_ERR_STREAM_SHUT_WR = -512,
/**
* The stream ID is invalid.
*/
NGHTTP2_ERR_INVALID_STREAM_ID = -513,
/**
* The state of the stream is not valid (e.g., DATA cannot be sent
* to the stream if response HEADERS has not been sent).
*/
NGHTTP2_ERR_INVALID_STREAM_STATE = -514,
/**
* Another DATA frame has already been deferred.
*/
NGHTTP2_ERR_DEFERRED_DATA_EXIST = -515,
/**
* Starting new stream is not allowed (e.g., GOAWAY has been sent
* and/or received).
*/
NGHTTP2_ERR_START_STREAM_NOT_ALLOWED = -516,
/**
* GOAWAY has already been sent.
*/
NGHTTP2_ERR_GOAWAY_ALREADY_SENT = -517,
/**
* The received frame contains the invalid header block (e.g., There
* are duplicate header names; or the header names are not encoded
* in US-ASCII character set and not lower cased; or the header name
* is zero-length string; or the header value contains multiple
* in-sequence NUL bytes).
*/
NGHTTP2_ERR_INVALID_HEADER_BLOCK = -518,
/**
* Indicates that the context is not suitable to perform the
* requested operation.
*/
NGHTTP2_ERR_INVALID_STATE = -519,
/**
* The user callback function failed due to the temporal error.
*/
NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE = -521,
/**
* The length of the frame is invalid, either too large or too small.
*/
NGHTTP2_ERR_FRAME_SIZE_ERROR = -522,
/**
* Header block inflate/deflate error.
*/
NGHTTP2_ERR_HEADER_COMP = -523,
/**
* Flow control error
*/
NGHTTP2_ERR_FLOW_CONTROL = -524,
/**
* Insufficient buffer size given to function.
*/
NGHTTP2_ERR_INSUFF_BUFSIZE = -525,
/**
* Callback was paused by the application
*/
NGHTTP2_ERR_PAUSE = -526,
/**
* There are too many in-flight SETTING frame and no more
* transmission of SETTINGS is allowed.
*/
NGHTTP2_ERR_TOO_MANY_INFLIGHT_SETTINGS = -527,
/**
* The server push is disabled.
*/
NGHTTP2_ERR_PUSH_DISABLED = -528,
/**
* DATA or HEADERS frame for a given stream has been already
* submitted and has not been fully processed yet. Application
* should wait for the transmission of the previously submitted
* frame before submitting another.
*/
NGHTTP2_ERR_DATA_EXIST = -529,
/**
* The current session is closing due to a connection error or
* `nghttp2_session_terminate_session()` is called.
*/
NGHTTP2_ERR_SESSION_CLOSING = -530,
/**
* Invalid HTTP header field was received and stream is going to be
* closed.
*/
NGHTTP2_ERR_HTTP_HEADER = -531,
/**
* Violation in HTTP messaging rule.
*/
NGHTTP2_ERR_HTTP_MESSAGING = -532,
/**
* Stream was refused.
*/
NGHTTP2_ERR_REFUSED_STREAM = -533,
/**
* Unexpected internal error, but recovered.
*/
NGHTTP2_ERR_INTERNAL = -534,
/**
* Indicates that a processing was canceled.
*/
NGHTTP2_ERR_CANCEL = -535,
/**
* The errors < :enum:`NGHTTP2_ERR_FATAL` mean that the library is
* under unexpected condition and processing was terminated (e.g.,
* out of memory). If application receives this error code, it must
* stop using that :type:`nghttp2_session` object and only allowed
* operation for that object is deallocate it using
* `nghttp2_session_del()`.
*/
NGHTTP2_ERR_FATAL = -900,
/**
* Out of memory. This is a fatal error.
*/
NGHTTP2_ERR_NOMEM = -901,
/**
* The user callback function failed. This is a fatal error.
*/
NGHTTP2_ERR_CALLBACK_FAILURE = -902,
/**
* Invalid client magic (see :macro:`NGHTTP2_CLIENT_MAGIC`) was
* received and further processing is not possible.
*/
NGHTTP2_ERR_BAD_CLIENT_MAGIC = -903,
/**
* Possible flooding by peer was detected in this HTTP/2 session.
* Flooding is measured by how many PING and SETTINGS frames with
* ACK flag set are queued for transmission. These frames are
* response for the peer initiated frames, and peer can cause memory
* exhaustion on server side to send these frames forever and does
* not read network.
*/
NGHTTP2_ERR_FLOODED = -904
} nghttp2_error;
/**
* @struct
*
* The object representing single contiguous buffer.
*/
typedef struct {
/**
* The pointer to the buffer.
*/
uint8_t *base;
/**
* The length of the buffer.
*/
size_t len;
} nghttp2_vec;
struct nghttp2_rcbuf;
/**
* @struct
*
* The object representing reference counted buffer. The details of
* this structure are intentionally hidden from the public API.
*/
typedef struct nghttp2_rcbuf nghttp2_rcbuf;
/**
* @function
*
* Increments the reference count of |rcbuf| by 1.
*/
NGHTTP2_EXTERN void nghttp2_rcbuf_incref(nghttp2_rcbuf *rcbuf);
/**
* @function
*
* Decrements the reference count of |rcbuf| by 1. If the reference
* count becomes zero, the object pointed by |rcbuf| will be freed.
* In this case, application must not use |rcbuf| again.
*/
NGHTTP2_EXTERN void nghttp2_rcbuf_decref(nghttp2_rcbuf *rcbuf);
/**
* @function
*
* Returns the underlying buffer managed by |rcbuf|.
*/
NGHTTP2_EXTERN nghttp2_vec nghttp2_rcbuf_get_buf(nghttp2_rcbuf *rcbuf);
/**
* @enum
*
* The flags for header field name/value pair.
*/
typedef enum {
/**
* No flag set.
*/
NGHTTP2_NV_FLAG_NONE = 0,
/**
* Indicates that this name/value pair must not be indexed ("Literal
* Header Field never Indexed" representation must be used in HPACK
* encoding). Other implementation calls this bit as "sensitive".
*/
NGHTTP2_NV_FLAG_NO_INDEX = 0x01,
/**
* This flag is set solely by application. If this flag is set, the
* library does not make a copy of header field name. This could
* improve performance.
*/
NGHTTP2_NV_FLAG_NO_COPY_NAME = 0x02,
/**
* This flag is set solely by application. If this flag is set, the
* library does not make a copy of header field value. This could
* improve performance.
*/
NGHTTP2_NV_FLAG_NO_COPY_VALUE = 0x04
} nghttp2_nv_flag;
/**
* @struct
*
* The name/value pair, which mainly used to represent header fields.
*/
typedef struct {
/**
* The |name| byte string. If this struct is presented from library
* (e.g., :type:`nghttp2_on_frame_recv_callback`), |name| is
* guaranteed to be NULL-terminated. For some callbacks
* (:type:`nghttp2_before_frame_send_callback`,
* :type:`nghttp2_on_frame_send_callback`, and
* :type:`nghttp2_on_frame_not_send_callback`), it may not be
* NULL-terminated if header field is passed from application with
* the flag :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME`). When application
* is constructing this struct, |name| is not required to be
* NULL-terminated.
*/
uint8_t *name;
/**
* The |value| byte string. If this struct is presented from
* library (e.g., :type:`nghttp2_on_frame_recv_callback`), |value|
* is guaranteed to be NULL-terminated. For some callbacks
* (:type:`nghttp2_before_frame_send_callback`,
* :type:`nghttp2_on_frame_send_callback`, and
* :type:`nghttp2_on_frame_not_send_callback`), it may not be
* NULL-terminated if header field is passed from application with
* the flag :enum:`NGHTTP2_NV_FLAG_NO_COPY_VALUE`). When
* application is constructing this struct, |value| is not required
* to be NULL-terminated.
*/
uint8_t *value;
/**
* The length of the |name|, excluding terminating NULL.
*/
size_t namelen;
/**
* The length of the |value|, excluding terminating NULL.
*/
size_t valuelen;
/**
* Bitwise OR of one or more of :type:`nghttp2_nv_flag`.
*/
uint8_t flags;
} nghttp2_nv;
/**
* @enum
*
* The frame types in HTTP/2 specification.
*/
typedef enum {
/**
* The DATA frame.
*/
NGHTTP2_DATA = 0,
/**
* The HEADERS frame.
*/
NGHTTP2_HEADERS = 0x01,
/**
* The PRIORITY frame.
*/
NGHTTP2_PRIORITY = 0x02,
/**
* The RST_STREAM frame.
*/
NGHTTP2_RST_STREAM = 0x03,
/**
* The SETTINGS frame.
*/
NGHTTP2_SETTINGS = 0x04,
/**
* The PUSH_PROMISE frame.
*/
NGHTTP2_PUSH_PROMISE = 0x05,
/**
* The PING frame.
*/
NGHTTP2_PING = 0x06,
/**
* The GOAWAY frame.
*/
NGHTTP2_GOAWAY = 0x07,
/**
* The WINDOW_UPDATE frame.
*/
NGHTTP2_WINDOW_UPDATE = 0x08,
/**
* The CONTINUATION frame. This frame type won't be passed to any
* callbacks because the library processes this frame type and its
* preceding HEADERS/PUSH_PROMISE as a single frame.
*/
NGHTTP2_CONTINUATION = 0x09,
/**
* The ALTSVC frame, which is defined in `RFC 7383
* <https://tools.ietf.org/html/rfc7838#section-4>`_.
*/
NGHTTP2_ALTSVC = 0x0a
} nghttp2_frame_type;
/**
* @enum
*
* The flags for HTTP/2 frames. This enum defines all flags for all
* frames.
*/
typedef enum {
/**
* No flag set.
*/
NGHTTP2_FLAG_NONE = 0,
/**
* The END_STREAM flag.
*/
NGHTTP2_FLAG_END_STREAM = 0x01,
/**
* The END_HEADERS flag.
*/
NGHTTP2_FLAG_END_HEADERS = 0x04,
/**
* The ACK flag.
*/
NGHTTP2_FLAG_ACK = 0x01,
/**
* The PADDED flag.
*/
NGHTTP2_FLAG_PADDED = 0x08,
/**
* The PRIORITY flag.
*/
NGHTTP2_FLAG_PRIORITY = 0x20
} nghttp2_flag;
/**
* @enum
* The SETTINGS ID.
*/
typedef enum {
/**
* SETTINGS_HEADER_TABLE_SIZE
*/
NGHTTP2_SETTINGS_HEADER_TABLE_SIZE = 0x01,
/**
* SETTINGS_ENABLE_PUSH
*/
NGHTTP2_SETTINGS_ENABLE_PUSH = 0x02,
/**
* SETTINGS_MAX_CONCURRENT_STREAMS
*/
NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS = 0x03,
/**
* SETTINGS_INITIAL_WINDOW_SIZE
*/
NGHTTP2_SETTINGS_INITIAL_WINDOW_SIZE = 0x04,
/**
* SETTINGS_MAX_FRAME_SIZE
*/
NGHTTP2_SETTINGS_MAX_FRAME_SIZE = 0x05,
/**
* SETTINGS_MAX_HEADER_LIST_SIZE
*/
NGHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE = 0x06
} nghttp2_settings_id;
/* Note: If we add SETTINGS, update the capacity of
NGHTTP2_INBOUND_NUM_IV as well */
/**
* @macro
*
* .. warning::
*
* Deprecated. The initial max concurrent streams is 0xffffffffu.
*
* Default maximum number of incoming concurrent streams. Use
* `nghttp2_submit_settings()` with
* :enum:`NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS` to change the
* maximum number of incoming concurrent streams.
*
* .. note::
*
* The maximum number of outgoing concurrent streams is 100 by
* default.
*/
#define NGHTTP2_INITIAL_MAX_CONCURRENT_STREAMS ((1U << 31) - 1)
/**
* @enum
* The status codes for the RST_STREAM and GOAWAY frames.
*/
typedef enum {
/**
* No errors.
*/
NGHTTP2_NO_ERROR = 0x00,
/**
* PROTOCOL_ERROR
*/
NGHTTP2_PROTOCOL_ERROR = 0x01,
/**
* INTERNAL_ERROR
*/
NGHTTP2_INTERNAL_ERROR = 0x02,
/**
* FLOW_CONTROL_ERROR
*/
NGHTTP2_FLOW_CONTROL_ERROR = 0x03,
/**
* SETTINGS_TIMEOUT
*/
NGHTTP2_SETTINGS_TIMEOUT = 0x04,
/**
* STREAM_CLOSED
*/
NGHTTP2_STREAM_CLOSED = 0x05,
/**
* FRAME_SIZE_ERROR
*/
NGHTTP2_FRAME_SIZE_ERROR = 0x06,
/**
* REFUSED_STREAM
*/
NGHTTP2_REFUSED_STREAM = 0x07,
/**
* CANCEL
*/
NGHTTP2_CANCEL = 0x08,
/**
* COMPRESSION_ERROR
*/
NGHTTP2_COMPRESSION_ERROR = 0x09,
/**
* CONNECT_ERROR
*/
NGHTTP2_CONNECT_ERROR = 0x0a,
/**
* ENHANCE_YOUR_CALM
*/
NGHTTP2_ENHANCE_YOUR_CALM = 0x0b,
/**
* INADEQUATE_SECURITY
*/
NGHTTP2_INADEQUATE_SECURITY = 0x0c,
/**
* HTTP_1_1_REQUIRED
*/
NGHTTP2_HTTP_1_1_REQUIRED = 0x0d
} nghttp2_error_code;
/**
* @struct
* The frame header.
*/
typedef struct {
/**
* The length field of this frame, excluding frame header.
*/
size_t length;
/**
* The stream identifier (aka, stream ID)
*/
int32_t stream_id;
/**
* The type of this frame. See `nghttp2_frame_type`.
*/
uint8_t type;
/**
* The flags.
*/
uint8_t flags;
/**
* Reserved bit in frame header. Currently, this is always set to 0
* and application should not expect something useful in here.
*/
uint8_t reserved;
} nghttp2_frame_hd;
/**
* @union
*
* This union represents the some kind of data source passed to
* :type:`nghttp2_data_source_read_callback`.
*/
typedef union {
/**
* The integer field, suitable for a file descriptor.
*/
int fd;
/**
* The pointer to an arbitrary object.
*/
void *ptr;
} nghttp2_data_source;
/**
* @enum
*
* The flags used to set in |data_flags| output parameter in
* :type:`nghttp2_data_source_read_callback`.
*/
typedef enum {
/**
* No flag set.
*/
NGHTTP2_DATA_FLAG_NONE = 0,
/**
* Indicates EOF was sensed.
*/
NGHTTP2_DATA_FLAG_EOF = 0x01,
/**
* Indicates that END_STREAM flag must not be set even if
* NGHTTP2_DATA_FLAG_EOF is set. Usually this flag is used to send
* trailer fields with `nghttp2_submit_request()` or
* `nghttp2_submit_response()`.
*/
NGHTTP2_DATA_FLAG_NO_END_STREAM = 0x02,
/**
* Indicates that application will send complete DATA frame in
* :type:`nghttp2_send_data_callback`.
*/
NGHTTP2_DATA_FLAG_NO_COPY = 0x04
} nghttp2_data_flag;
/**
* @functypedef
*
* Callback function invoked when the library wants to read data from
* the |source|. The read data is sent in the stream |stream_id|.
* The implementation of this function must read at most |length|
* bytes of data from |source| (or possibly other places) and store
* them in |buf| and return number of data stored in |buf|. If EOF is
* reached, set :enum:`NGHTTP2_DATA_FLAG_EOF` flag in |*data_flags|.
*
* Sometime it is desirable to avoid copying data into |buf| and let
* application to send data directly. To achieve this, set
* :enum:`NGHTTP2_DATA_FLAG_NO_COPY` to |*data_flags| (and possibly
* other flags, just like when we do copy), and return the number of
* bytes to send without copying data into |buf|. The library, seeing
* :enum:`NGHTTP2_DATA_FLAG_NO_COPY`, will invoke
* :type:`nghttp2_send_data_callback`. The application must send
* complete DATA frame in that callback.
*
* If this callback is set by `nghttp2_submit_request()`,
* `nghttp2_submit_response()` or `nghttp2_submit_headers()` and
* `nghttp2_submit_data()` with flag parameter
* :enum:`NGHTTP2_FLAG_END_STREAM` set, and
* :enum:`NGHTTP2_DATA_FLAG_EOF` flag is set to |*data_flags|, DATA
* frame will have END_STREAM flag set. Usually, this is expected
* behaviour and all are fine. One exception is send trailer fields.
* You cannot send trailer fields after sending frame with END_STREAM
* set. To avoid this problem, one can set
* :enum:`NGHTTP2_DATA_FLAG_NO_END_STREAM` along with
* :enum:`NGHTTP2_DATA_FLAG_EOF` to signal the library not to set
* END_STREAM in DATA frame. Then application can use
* `nghttp2_submit_trailer()` to send trailer fields.
* `nghttp2_submit_trailer()` can be called inside this callback.
*
* If the application wants to postpone DATA frames (e.g.,
* asynchronous I/O, or reading data blocks for long time), it is
* achieved by returning :enum:`NGHTTP2_ERR_DEFERRED` without reading
* any data in this invocation. The library removes DATA frame from
* the outgoing queue temporarily. To move back deferred DATA frame
* to outgoing queue, call `nghttp2_session_resume_data()`.
*
* By default, |length| is limited to 16KiB at maximum. If peer
* allows larger frames, application can enlarge transmission buffer
* size. See :type:`nghttp2_data_source_read_length_callback` for
* more details.
*
* If the application just wants to return from
* `nghttp2_session_send()` or `nghttp2_session_mem_send()` without
* sending anything, return :enum:`NGHTTP2_ERR_PAUSE`.
*
* In case of error, there are 2 choices. Returning
* :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE` will close the stream
* by issuing RST_STREAM with :enum:`NGHTTP2_INTERNAL_ERROR`. If a
* different error code is desirable, use
* `nghttp2_submit_rst_stream()` with a desired error code and then
* return :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`. Returning
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE` will signal the entire session
* failure.
*/
typedef ssize_t (*nghttp2_data_source_read_callback)(
nghttp2_session *session, int32_t stream_id, uint8_t *buf, size_t length,
uint32_t *data_flags, nghttp2_data_source *source, void *user_data);
/**
* @struct
*
* This struct represents the data source and the way to read a chunk
* of data from it.
*/
typedef struct {
/**
* The data source.
*/
nghttp2_data_source source;
/**
* The callback function to read a chunk of data from the |source|.
*/
nghttp2_data_source_read_callback read_callback;
} nghttp2_data_provider;
/**
* @struct
*
* The DATA frame. The received data is delivered via
* :type:`nghttp2_on_data_chunk_recv_callback`.
*/
typedef struct {
nghttp2_frame_hd hd;
/**
* The length of the padding in this frame. This includes PAD_HIGH
* and PAD_LOW.
*/
size_t padlen;
} nghttp2_data;
/**
* @enum
*
* The category of HEADERS, which indicates the role of the frame. In
* HTTP/2 spec, request, response, push response and other arbitrary
* headers (e.g., trailer fields) are all called just HEADERS. To
* give the application the role of incoming HEADERS frame, we define
* several categories.
*/
typedef enum {
/**
* The HEADERS frame is opening new stream, which is analogous to
* SYN_STREAM in SPDY.
*/
NGHTTP2_HCAT_REQUEST = 0,
/**
* The HEADERS frame is the first response headers, which is
* analogous to SYN_REPLY in SPDY.
*/
NGHTTP2_HCAT_RESPONSE = 1,
/**
* The HEADERS frame is the first headers sent against reserved
* stream.
*/
NGHTTP2_HCAT_PUSH_RESPONSE = 2,
/**
* The HEADERS frame which does not apply for the above categories,
* which is analogous to HEADERS in SPDY. If non-final response
* (e.g., status 1xx) is used, final response HEADERS frame will be
* categorized here.
*/
NGHTTP2_HCAT_HEADERS = 3
} nghttp2_headers_category;
/**
* @struct
*
* The structure to specify stream dependency.
*/
typedef struct {
/**
* The stream ID of the stream to depend on. Specifying 0 makes
* stream not depend any other stream.
*/
int32_t stream_id;
/**
* The weight of this dependency.
*/
int32_t weight;
/**
* nonzero means exclusive dependency
*/
uint8_t exclusive;
} nghttp2_priority_spec;
/**
* @struct
*
* The HEADERS frame. It has the following members:
*/
typedef struct {
/**
* The frame header.
*/
nghttp2_frame_hd hd;
/**
* The length of the padding in this frame. This includes PAD_HIGH
* and PAD_LOW.
*/
size_t padlen;
/**
* The priority specification
*/
nghttp2_priority_spec pri_spec;
/**
* The name/value pairs.
*/
nghttp2_nv *nva;
/**
* The number of name/value pairs in |nva|.
*/
size_t nvlen;
/**
* The category of this HEADERS frame.
*/
nghttp2_headers_category cat;
} nghttp2_headers;
/**
* @struct
*
* The PRIORITY frame. It has the following members:
*/
typedef struct {
/**
* The frame header.
*/
nghttp2_frame_hd hd;
/**
* The priority specification.
*/
nghttp2_priority_spec pri_spec;
} nghttp2_priority;
/**
* @struct
*
* The RST_STREAM frame. It has the following members:
*/
typedef struct {
/**
* The frame header.
*/
nghttp2_frame_hd hd;
/**
* The error code. See :type:`nghttp2_error_code`.
*/
uint32_t error_code;
} nghttp2_rst_stream;
/**
* @struct
*
* The SETTINGS ID/Value pair. It has the following members:
*/
typedef struct {
/**
* The SETTINGS ID. See :type:`nghttp2_settings_id`.
*/
int32_t settings_id;
/**
* The value of this entry.
*/
uint32_t value;
} nghttp2_settings_entry;
/**
* @struct
*
* The SETTINGS frame. It has the following members:
*/
typedef struct {
/**
* The frame header.
*/
nghttp2_frame_hd hd;
/**
* The number of SETTINGS ID/Value pairs in |iv|.
*/
size_t niv;
/**
* The pointer to the array of SETTINGS ID/Value pair.
*/
nghttp2_settings_entry *iv;
} nghttp2_settings;
/**
* @struct
*
* The PUSH_PROMISE frame. It has the following members:
*/
typedef struct {
/**
* The frame header.
*/
nghttp2_frame_hd hd;
/**
* The length of the padding in this frame. This includes PAD_HIGH
* and PAD_LOW.
*/
size_t padlen;
/**
* The name/value pairs.
*/
nghttp2_nv *nva;
/**
* The number of name/value pairs in |nva|.
*/
size_t nvlen;
/**
* The promised stream ID
*/
int32_t promised_stream_id;
/**
* Reserved bit. Currently this is always set to 0 and application
* should not expect something useful in here.
*/
uint8_t reserved;
} nghttp2_push_promise;
/**
* @struct
*
* The PING frame. It has the following members:
*/
typedef struct {
/**
* The frame header.
*/
nghttp2_frame_hd hd;
/**
* The opaque data
*/
uint8_t opaque_data[8];
} nghttp2_ping;
/**
* @struct
*
* The GOAWAY frame. It has the following members:
*/
typedef struct {
/**
* The frame header.
*/
nghttp2_frame_hd hd;
/**
* The last stream stream ID.
*/
int32_t last_stream_id;
/**
* The error code. See :type:`nghttp2_error_code`.
*/
uint32_t error_code;
/**
* The additional debug data
*/
uint8_t *opaque_data;
/**
* The length of |opaque_data| member.
*/
size_t opaque_data_len;
/**
* Reserved bit. Currently this is always set to 0 and application
* should not expect something useful in here.
*/
uint8_t reserved;
} nghttp2_goaway;
/**
* @struct
*
* The WINDOW_UPDATE frame. It has the following members:
*/
typedef struct {
/**
* The frame header.
*/
nghttp2_frame_hd hd;
/**
* The window size increment.
*/
int32_t window_size_increment;
/**
* Reserved bit. Currently this is always set to 0 and application
* should not expect something useful in here.
*/
uint8_t reserved;
} nghttp2_window_update;
/**
* @struct
*
* The extension frame. It has following members:
*/
typedef struct {
/**
* The frame header.
*/
nghttp2_frame_hd hd;
/**
* The pointer to extension payload. The exact pointer type is
* determined by hd.type.
*
* Currently, no extension is supported. This is a place holder for
* the future extensions.
*/
void *payload;
} nghttp2_extension;
/**
* @union
*
* This union includes all frames to pass them to various function
* calls as nghttp2_frame type. The CONTINUATION frame is omitted
* from here because the library deals with it internally.
*/
typedef union {
/**
* The frame header, which is convenient to inspect frame header.
*/
nghttp2_frame_hd hd;
/**
* The DATA frame.
*/
nghttp2_data data;
/**
* The HEADERS frame.
*/
nghttp2_headers headers;
/**
* The PRIORITY frame.
*/
nghttp2_priority priority;
/**
* The RST_STREAM frame.
*/
nghttp2_rst_stream rst_stream;
/**
* The SETTINGS frame.
*/
nghttp2_settings settings;
/**
* The PUSH_PROMISE frame.
*/
nghttp2_push_promise push_promise;
/**
* The PING frame.
*/
nghttp2_ping ping;
/**
* The GOAWAY frame.
*/
nghttp2_goaway goaway;
/**
* The WINDOW_UPDATE frame.
*/
nghttp2_window_update window_update;
/**
* The extension frame.
*/
nghttp2_extension ext;
} nghttp2_frame;
/**
* @functypedef
*
* Callback function invoked when |session| wants to send data to the
* remote peer. The implementation of this function must send at most
* |length| bytes of data stored in |data|. The |flags| is currently
* not used and always 0. It must return the number of bytes sent if
* it succeeds. If it cannot send any single byte without blocking,
* it must return :enum:`NGHTTP2_ERR_WOULDBLOCK`. For other errors,
* it must return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. The
* |user_data| pointer is the third argument passed in to the call to
* `nghttp2_session_client_new()` or `nghttp2_session_server_new()`.
*
* This callback is required if the application uses
* `nghttp2_session_send()` to send data to the remote endpoint. If
* the application uses solely `nghttp2_session_mem_send()` instead,
* this callback function is unnecessary.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_send_callback()`.
*
* .. note::
*
* The |length| may be very small. If that is the case, and
* application disables Nagle algorithm (``TCP_NODELAY``), then just
* writing |data| to the network stack leads to very small packet,
* and it is very inefficient. An application should be responsible
* to buffer up small chunks of data as necessary to avoid this
* situation.
*/
typedef ssize_t (*nghttp2_send_callback)(nghttp2_session *session,
const uint8_t *data, size_t length,
int flags, void *user_data);
/**
* @functypedef
*
* Callback function invoked when :enum:`NGHTTP2_DATA_FLAG_NO_COPY` is
* used in :type:`nghttp2_data_source_read_callback` to send complete
* DATA frame.
*
* The |frame| is a DATA frame to send. The |framehd| is the
* serialized frame header (9 bytes). The |length| is the length of
* application data to send (this does not include padding). The
* |source| is the same pointer passed to
* :type:`nghttp2_data_source_read_callback`.
*
* The application first must send frame header |framehd| of length 9
* bytes. If ``frame->data.padlen > 0``, send 1 byte of value
* ``frame->data.padlen - 1``. Then send exactly |length| bytes of
* application data. Finally, if ``frame->data.padlen > 1``, send
* ``frame->data.padlen - 1`` bytes of zero as padding.
*
* The application has to send complete DATA frame in this callback.
* If all data were written successfully, return 0.
*
* If it cannot send any data at all, just return
* :enum:`NGHTTP2_ERR_WOULDBLOCK`; the library will call this callback
* with the same parameters later (It is recommended to send complete
* DATA frame at once in this function to deal with error; if partial
* frame data has already sent, it is impossible to send another data
* in that state, and all we can do is tear down connection). When
* data is fully processed, but application wants to make
* `nghttp2_session_mem_send()` or `nghttp2_session_send()` return
* immediately without processing next frames, return
* :enum:`NGHTTP2_ERR_PAUSE`. If application decided to reset this
* stream, return :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`, then
* the library will send RST_STREAM with INTERNAL_ERROR as error code.
* The application can also return
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`, which will result in
* connection closure. Returning any other value is treated as
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE` is returned.
*/
typedef int (*nghttp2_send_data_callback)(nghttp2_session *session,
nghttp2_frame *frame,
const uint8_t *framehd, size_t length,
nghttp2_data_source *source,
void *user_data);
/**
* @functypedef
*
* Callback function invoked when |session| wants to receive data from
* the remote peer. The implementation of this function must read at
* most |length| bytes of data and store it in |buf|. The |flags| is
* currently not used and always 0. It must return the number of
* bytes written in |buf| if it succeeds. If it cannot read any
* single byte without blocking, it must return
* :enum:`NGHTTP2_ERR_WOULDBLOCK`. If it gets EOF before it reads any
* single byte, it must return :enum:`NGHTTP2_ERR_EOF`. For other
* errors, it must return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
* Returning 0 is treated as :enum:`NGHTTP2_ERR_WOULDBLOCK`. The
* |user_data| pointer is the third argument passed in to the call to
* `nghttp2_session_client_new()` or `nghttp2_session_server_new()`.
*
* This callback is required if the application uses
* `nghttp2_session_recv()` to receive data from the remote endpoint.
* If the application uses solely `nghttp2_session_mem_recv()`
* instead, this callback function is unnecessary.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_recv_callback()`.
*/
typedef ssize_t (*nghttp2_recv_callback)(nghttp2_session *session, uint8_t *buf,
size_t length, int flags,
void *user_data);
/**
* @functypedef
*
* Callback function invoked by `nghttp2_session_recv()` and
* `nghttp2_session_mem_recv()` when a frame is received. The
* |user_data| pointer is the third argument passed in to the call to
* `nghttp2_session_client_new()` or `nghttp2_session_server_new()`.
*
* If frame is HEADERS or PUSH_PROMISE, the ``nva`` and ``nvlen``
* member of their data structure are always ``NULL`` and 0
* respectively. The header name/value pairs are emitted via
* :type:`nghttp2_on_header_callback`.
*
* For HEADERS, PUSH_PROMISE and DATA frames, this callback may be
* called after stream is closed (see
* :type:`nghttp2_on_stream_close_callback`). The application should
* check that stream is still alive using its own stream management or
* :func:`nghttp2_session_get_stream_user_data()`.
*
* Only HEADERS and DATA frame can signal the end of incoming data.
* If ``frame->hd.flags & NGHTTP2_FLAG_END_STREAM`` is nonzero, the
* |frame| is the last frame from the remote peer in this stream.
*
* This callback won't be called for CONTINUATION frames.
* HEADERS/PUSH_PROMISE + CONTINUATIONs are treated as single frame.
*
* The implementation of this function must return 0 if it succeeds.
* If nonzero value is returned, it is treated as fatal error and
* `nghttp2_session_recv()` and `nghttp2_session_mem_recv()` functions
* immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_on_frame_recv_callback()`.
*/
typedef int (*nghttp2_on_frame_recv_callback)(nghttp2_session *session,
const nghttp2_frame *frame,
void *user_data);
/**
* @functypedef
*
* Callback function invoked by `nghttp2_session_recv()` and
* `nghttp2_session_mem_recv()` when an invalid non-DATA frame is
* received. The error is indicated by the |lib_error_code|, which is
* one of the values defined in :type:`nghttp2_error`. When this
* callback function is invoked, the library automatically submits
* either RST_STREAM or GOAWAY frame. The |user_data| pointer is the
* third argument passed in to the call to
* `nghttp2_session_client_new()` or `nghttp2_session_server_new()`.
*
* If frame is HEADERS or PUSH_PROMISE, the ``nva`` and ``nvlen``
* member of their data structure are always ``NULL`` and 0
* respectively.
*
* The implementation of this function must return 0 if it succeeds.
* If nonzero is returned, it is treated as fatal error and
* `nghttp2_session_recv()` and `nghttp2_session_mem_recv()` functions
* immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_on_invalid_frame_recv_callback()`.
*/
typedef int (*nghttp2_on_invalid_frame_recv_callback)(
nghttp2_session *session, const nghttp2_frame *frame, int lib_error_code,
void *user_data);
/**
* @functypedef
*
* Callback function invoked when a chunk of data in DATA frame is
* received. The |stream_id| is the stream ID this DATA frame belongs
* to. The |flags| is the flags of DATA frame which this data chunk
* is contained. ``(flags & NGHTTP2_FLAG_END_STREAM) != 0`` does not
* necessarily mean this chunk of data is the last one in the stream.
* You should use :type:`nghttp2_on_frame_recv_callback` to know all
* data frames are received. The |user_data| pointer is the third
* argument passed in to the call to `nghttp2_session_client_new()` or
* `nghttp2_session_server_new()`.
*
* If the application uses `nghttp2_session_mem_recv()`, it can return
* :enum:`NGHTTP2_ERR_PAUSE` to make `nghttp2_session_mem_recv()`
* return without processing further input bytes. The memory by
* pointed by the |data| is retained until
* `nghttp2_session_mem_recv()` or `nghttp2_session_recv()` is called.
* The application must retain the input bytes which was used to
* produce the |data| parameter, because it may refer to the memory
* region included in the input bytes.
*
* The implementation of this function must return 0 if it succeeds.
* If nonzero is returned, it is treated as fatal error, and
* `nghttp2_session_recv()` and `nghttp2_session_mem_recv()` functions
* immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_on_data_chunk_recv_callback()`.
*/
typedef int (*nghttp2_on_data_chunk_recv_callback)(nghttp2_session *session,
uint8_t flags,
int32_t stream_id,
const uint8_t *data,
size_t len, void *user_data);
/**
* @functypedef
*
* Callback function invoked just before the non-DATA frame |frame| is
* sent. The |user_data| pointer is the third argument passed in to
* the call to `nghttp2_session_client_new()` or
* `nghttp2_session_server_new()`.
*
* The implementation of this function must return 0 if it succeeds.
* It can also return :enum:`NGHTTP2_ERR_CANCEL` to cancel the
* transmission of the given frame.
*
* If there is a fatal error while executing this callback, the
* implementation should return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`,
* which makes `nghttp2_session_send()` and
* `nghttp2_session_mem_send()` functions immediately return
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*
* If the other value is returned, it is treated as if
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE` is returned. But the
* implementation should not rely on this since the library may define
* new return value to extend its capability.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_before_frame_send_callback()`.
*/
typedef int (*nghttp2_before_frame_send_callback)(nghttp2_session *session,
const nghttp2_frame *frame,
void *user_data);
/**
* @functypedef
*
* Callback function invoked after the frame |frame| is sent. The
* |user_data| pointer is the third argument passed in to the call to
* `nghttp2_session_client_new()` or `nghttp2_session_server_new()`.
*
* The implementation of this function must return 0 if it succeeds.
* If nonzero is returned, it is treated as fatal error and
* `nghttp2_session_send()` and `nghttp2_session_mem_send()` functions
* immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_on_frame_send_callback()`.
*/
typedef int (*nghttp2_on_frame_send_callback)(nghttp2_session *session,
const nghttp2_frame *frame,
void *user_data);
/**
* @functypedef
*
* Callback function invoked after the non-DATA frame |frame| is not
* sent because of the error. The error is indicated by the
* |lib_error_code|, which is one of the values defined in
* :type:`nghttp2_error`. The |user_data| pointer is the third
* argument passed in to the call to `nghttp2_session_client_new()` or
* `nghttp2_session_server_new()`.
*
* The implementation of this function must return 0 if it succeeds.
* If nonzero is returned, it is treated as fatal error and
* `nghttp2_session_send()` and `nghttp2_session_mem_send()` functions
* immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*
* `nghttp2_session_get_stream_user_data()` can be used to get
* associated data.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_on_frame_not_send_callback()`.
*/
typedef int (*nghttp2_on_frame_not_send_callback)(nghttp2_session *session,
const nghttp2_frame *frame,
int lib_error_code,
void *user_data);
/**
* @functypedef
*
* Callback function invoked when the stream |stream_id| is closed.
* The reason of closure is indicated by the |error_code|. The
* |error_code| is usually one of :enum:`nghttp2_error_code`, but that
* is not guaranteed. The stream_user_data, which was specified in
* `nghttp2_submit_request()` or `nghttp2_submit_headers()`, is still
* available in this function. The |user_data| pointer is the third
* argument passed in to the call to `nghttp2_session_client_new()` or
* `nghttp2_session_server_new()`.
*
* This function is also called for a stream in reserved state.
*
* The implementation of this function must return 0 if it succeeds.
* If nonzero is returned, it is treated as fatal error and
* `nghttp2_session_recv()`, `nghttp2_session_mem_recv()`,
* `nghttp2_session_send()`, and `nghttp2_session_mem_send()`
* functions immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_on_stream_close_callback()`.
*/
typedef int (*nghttp2_on_stream_close_callback)(nghttp2_session *session,
int32_t stream_id,
uint32_t error_code,
void *user_data);
/**
* @functypedef
*
* Callback function invoked when the reception of header block in
* HEADERS or PUSH_PROMISE is started. Each header name/value pair
* will be emitted by :type:`nghttp2_on_header_callback`.
*
* The ``frame->hd.flags`` may not have
* :enum:`NGHTTP2_FLAG_END_HEADERS` flag set, which indicates that one
* or more CONTINUATION frames are involved. But the application does
* not need to care about that because the header name/value pairs are
* emitted transparently regardless of CONTINUATION frames.
*
* The server applications probably create an object to store
* information about new stream if ``frame->hd.type ==
* NGHTTP2_HEADERS`` and ``frame->headers.cat ==
* NGHTTP2_HCAT_REQUEST``. If |session| is configured as server side,
* ``frame->headers.cat`` is either ``NGHTTP2_HCAT_REQUEST``
* containing request headers or ``NGHTTP2_HCAT_HEADERS`` containing
* trailer fields and never get PUSH_PROMISE in this callback.
*
* For the client applications, ``frame->hd.type`` is either
* ``NGHTTP2_HEADERS`` or ``NGHTTP2_PUSH_PROMISE``. In case of
* ``NGHTTP2_HEADERS``, ``frame->headers.cat ==
* NGHTTP2_HCAT_RESPONSE`` means that it is the first response
* headers, but it may be non-final response which is indicated by 1xx
* status code. In this case, there may be zero or more HEADERS frame
* with ``frame->headers.cat == NGHTTP2_HCAT_HEADERS`` which has
* non-final response code and finally client gets exactly one HEADERS
* frame with ``frame->headers.cat == NGHTTP2_HCAT_HEADERS``
* containing final response headers (non-1xx status code). The
* trailer fields also has ``frame->headers.cat ==
* NGHTTP2_HCAT_HEADERS`` which does not contain any status code.
*
* Returning :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE` will close
* the stream (promised stream if frame is PUSH_PROMISE) by issuing
* RST_STREAM with :enum:`NGHTTP2_INTERNAL_ERROR`. In this case,
* :type:`nghttp2_on_header_callback` and
* :type:`nghttp2_on_frame_recv_callback` will not be invoked. If a
* different error code is desirable, use
* `nghttp2_submit_rst_stream()` with a desired error code and then
* return :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`. Again, use
* ``frame->push_promise.promised_stream_id`` as stream_id parameter
* in `nghttp2_submit_rst_stream()` if frame is PUSH_PROMISE.
*
* The implementation of this function must return 0 if it succeeds.
* It can return :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE` to
* reset the stream (promised stream if frame is PUSH_PROMISE). For
* critical errors, it must return
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. If the other value is
* returned, it is treated as if :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`
* is returned. If :enum:`NGHTTP2_ERR_CALLBACK_FAILURE` is returned,
* `nghttp2_session_mem_recv()` function will immediately return
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_on_begin_headers_callback()`.
*/
typedef int (*nghttp2_on_begin_headers_callback)(nghttp2_session *session,
const nghttp2_frame *frame,
void *user_data);
/**
* @functypedef
*
* Callback function invoked when a header name/value pair is received
* for the |frame|. The |name| of length |namelen| is header name.
* The |value| of length |valuelen| is header value. The |flags| is
* bitwise OR of one or more of :type:`nghttp2_nv_flag`.
*
* If :enum:`NGHTTP2_NV_FLAG_NO_INDEX` is set in |flags|, the receiver
* must not index this name/value pair when forwarding it to the next
* hop. More specifically, "Literal Header Field never Indexed"
* representation must be used in HPACK encoding.
*
* When this callback is invoked, ``frame->hd.type`` is either
* :enum:`NGHTTP2_HEADERS` or :enum:`NGHTTP2_PUSH_PROMISE`. After all
* header name/value pairs are processed with this callback, and no
* error has been detected, :type:`nghttp2_on_frame_recv_callback`
* will be invoked. If there is an error in decompression,
* :type:`nghttp2_on_frame_recv_callback` for the |frame| will not be
* invoked.
*
* Both |name| and |value| are guaranteed to be NULL-terminated. The
* |namelen| and |valuelen| do not include terminal NULL. If
* `nghttp2_option_set_no_http_messaging()` is used with nonzero
* value, NULL character may be included in |name| or |value| before
* terminating NULL.
*
* Please note that unless `nghttp2_option_set_no_http_messaging()` is
* used, nghttp2 library does perform validation against the |name|
* and the |value| using `nghttp2_check_header_name()` and
* `nghttp2_check_header_value()`. In addition to this, nghttp2
* performs validation based on HTTP Messaging rule, which is briefly
* explained in :ref:`http-messaging` section.
*
* If the application uses `nghttp2_session_mem_recv()`, it can return
* :enum:`NGHTTP2_ERR_PAUSE` to make `nghttp2_session_mem_recv()`
* return without processing further input bytes. The memory pointed
* by |frame|, |name| and |value| parameters are retained until
* `nghttp2_session_mem_recv()` or `nghttp2_session_recv()` is called.
* The application must retain the input bytes which was used to
* produce these parameters, because it may refer to the memory region
* included in the input bytes.
*
* Returning :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE` will close
* the stream (promised stream if frame is PUSH_PROMISE) by issuing
* RST_STREAM with :enum:`NGHTTP2_INTERNAL_ERROR`. In this case,
* :type:`nghttp2_on_header_callback` and
* :type:`nghttp2_on_frame_recv_callback` will not be invoked. If a
* different error code is desirable, use
* `nghttp2_submit_rst_stream()` with a desired error code and then
* return :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`. Again, use
* ``frame->push_promise.promised_stream_id`` as stream_id parameter
* in `nghttp2_submit_rst_stream()` if frame is PUSH_PROMISE.
*
* The implementation of this function must return 0 if it succeeds.
* It may return :enum:`NGHTTP2_ERR_PAUSE` or
* :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`. For other critical
* failures, it must return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. If
* the other nonzero value is returned, it is treated as
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. If
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE` is returned,
* `nghttp2_session_recv()` and `nghttp2_session_mem_recv()` functions
* immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_on_header_callback()`.
*
* .. warning::
*
* Application should properly limit the total buffer size to store
* incoming header fields. Without it, peer may send large number
* of header fields or large header fields to cause out of memory in
* local endpoint. Due to how HPACK works, peer can do this
* effectively without using much memory on their own.
*/
typedef int (*nghttp2_on_header_callback)(nghttp2_session *session,
const nghttp2_frame *frame,
const uint8_t *name, size_t namelen,
const uint8_t *value, size_t valuelen,
uint8_t flags, void *user_data);
/**
* @functypedef
*
* Callback function invoked when a header name/value pair is received
* for the |frame|. The |name| is header name. The |value| is header
* value. The |flags| is bitwise OR of one or more of
* :type:`nghttp2_nv_flag`.
*
* This callback behaves like :type:`nghttp2_on_header_callback`,
* except that |name| and |value| are stored in reference counted
* buffer. If application wishes to keep these references without
* copying them, use `nghttp2_rcbuf_incref()` to increment their
* reference count. It is the application's responsibility to call
* `nghttp2_rcbuf_decref()` if they called `nghttp2_rcbuf_incref()` so
* as not to leak memory. If the |session| is created by
* `nghttp2_session_server_new3()` or `nghttp2_session_client_new3()`,
* the function to free memory is the one belongs to the mem
* parameter. As long as this free function alives, |name| and
* |value| can live after |session| was destroyed.
*/
typedef int (*nghttp2_on_header_callback2)(nghttp2_session *session,
const nghttp2_frame *frame,
nghttp2_rcbuf *name,
nghttp2_rcbuf *value, uint8_t flags,
void *user_data);
/**
* @functypedef
*
* Callback function invoked when a invalid header name/value pair is
* received for the |frame|.
*
* The parameter and behaviour are similar to
* :type:`nghttp2_on_header_callback`. The difference is that this
* callback is only invoked when a invalid header name/value pair is
* received which is silently ignored if this callback is not set.
* Only invalid regular header field are passed to this callback. In
* other words, invalid pseudo header field is not passed to this
* callback. Also header fields which includes upper cased latter are
* also treated as error without passing them to this callback.
*
* This callback is only considered if HTTP messaging validation is
* turned on (which is on by default, see
* `nghttp2_option_set_no_http_messaging()`).
*
* With this callback, application inspects the incoming invalid
* field, and it also can reset stream from this callback by returning
* :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`. By default, the
* error code is :enum:`NGHTTP2_INTERNAL_ERROR`. To change the error
* code, call `nghttp2_submit_rst_stream()` with the error code of
* choice in addition to returning
* :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`.
*/
typedef int (*nghttp2_on_invalid_header_callback)(
nghttp2_session *session, const nghttp2_frame *frame, const uint8_t *name,
size_t namelen, const uint8_t *value, size_t valuelen, uint8_t flags,
void *user_data);
/**
* @functypedef
*
* Callback function invoked when a invalid header name/value pair is
* received for the |frame|.
*
* The parameter and behaviour are similar to
* :type:`nghttp2_on_header_callback2`. The difference is that this
* callback is only invoked when a invalid header name/value pair is
* received which is silently ignored if this callback is not set.
* Only invalid regular header field are passed to this callback. In
* other words, invalid pseudo header field is not passed to this
* callback. Also header fields which includes upper cased latter are
* also treated as error without passing them to this callback.
*
* This callback is only considered if HTTP messaging validation is
* turned on (which is on by default, see
* `nghttp2_option_set_no_http_messaging()`).
*
* With this callback, application inspects the incoming invalid
* field, and it also can reset stream from this callback by returning
* :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`. By default, the
* error code is :enum:`NGHTTP2_INTERNAL_ERROR`. To change the error
* code, call `nghttp2_submit_rst_stream()` with the error code of
* choice in addition to returning
* :enum:`NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE`.
*/
typedef int (*nghttp2_on_invalid_header_callback2)(
nghttp2_session *session, const nghttp2_frame *frame, nghttp2_rcbuf *name,
nghttp2_rcbuf *value, uint8_t flags, void *user_data);
/**
* @functypedef
*
* Callback function invoked when the library asks application how
* many padding bytes are required for the transmission of the
* |frame|. The application must choose the total length of payload
* including padded bytes in range [frame->hd.length, max_payloadlen],
* inclusive. Choosing number not in this range will be treated as
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. Returning
* ``frame->hd.length`` means no padding is added. Returning
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE` will make
* `nghttp2_session_send()` and `nghttp2_session_mem_send()` functions
* immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_select_padding_callback()`.
*/
typedef ssize_t (*nghttp2_select_padding_callback)(nghttp2_session *session,
const nghttp2_frame *frame,
size_t max_payloadlen,
void *user_data);
/**
* @functypedef
*
* Callback function invoked when library wants to get max length of
* data to send data to the remote peer. The implementation of this
* function should return a value in the following range. [1,
* min(|session_remote_window_size|, |stream_remote_window_size|,
* |remote_max_frame_size|)]. If a value greater than this range is
* returned than the max allow value will be used. Returning a value
* smaller than this range is treated as
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. The |frame_type| is provided
* for future extensibility and identifies the type of frame (see
* :type:`nghttp2_frame_type`) for which to get the length for.
* Currently supported frame types are: :enum:`NGHTTP2_DATA`.
*
* This callback can be used to control the length in bytes for which
* :type:`nghttp2_data_source_read_callback` is allowed to send to the
* remote endpoint. This callback is optional. Returning
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE` will signal the entire session
* failure.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_data_source_read_length_callback()`.
*/
typedef ssize_t (*nghttp2_data_source_read_length_callback)(
nghttp2_session *session, uint8_t frame_type, int32_t stream_id,
int32_t session_remote_window_size, int32_t stream_remote_window_size,
uint32_t remote_max_frame_size, void *user_data);
/**
* @functypedef
*
* Callback function invoked when a frame header is received. The
* |hd| points to received frame header.
*
* Unlike :type:`nghttp2_on_frame_recv_callback`, this callback will
* also be called when frame header of CONTINUATION frame is received.
*
* If both :type:`nghttp2_on_begin_frame_callback` and
* :type:`nghttp2_on_begin_headers_callback` are set and HEADERS or
* PUSH_PROMISE is received, :type:`nghttp2_on_begin_frame_callback`
* will be called first.
*
* The implementation of this function must return 0 if it succeeds.
* If nonzero value is returned, it is treated as fatal error and
* `nghttp2_session_recv()` and `nghttp2_session_mem_recv()` functions
* immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*
* To set this callback to :type:`nghttp2_session_callbacks`, use
* `nghttp2_session_callbacks_set_on_begin_frame_callback()`.
*/
typedef int (*nghttp2_on_begin_frame_callback)(nghttp2_session *session,
const nghttp2_frame_hd *hd,
void *user_data);
/**
* @functypedef
*
* Callback function invoked when chunk of extension frame payload is
* received. The |hd| points to frame header. The received
* chunk is |data| of length |len|.
*
* The implementation of this function must return 0 if it succeeds.
*
* To abort processing this extension frame, return
* :enum:`NGHTTP2_ERR_CANCEL`.
*
* If fatal error occurred, application should return
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. In this case,
* `nghttp2_session_recv()` and `nghttp2_session_mem_recv()` functions
* immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. If the
* other values are returned, currently they are treated as
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*/
typedef int (*nghttp2_on_extension_chunk_recv_callback)(
nghttp2_session *session, const nghttp2_frame_hd *hd, const uint8_t *data,
size_t len, void *user_data);
/**
* @functypedef
*
* Callback function invoked when library asks the application to
* unpack extension payload from its wire format. The extension
* payload has been passed to the application using
* :type:`nghttp2_on_extension_chunk_recv_callback`. The frame header
* is already unpacked by the library and provided as |hd|.
*
* To receive extension frames, the application must tell desired
* extension frame type to the library using
* `nghttp2_option_set_user_recv_extension_type()`.
*
* The implementation of this function may store the pointer to the
* created object as a result of unpacking in |*payload|, and returns
* 0. The pointer stored in |*payload| is opaque to the library, and
* the library does not own its pointer. |*payload| is initialized as
* ``NULL``. The |*payload| is available as ``frame->ext.payload`` in
* :type:`nghttp2_on_frame_recv_callback`. Therefore if application
* can free that memory inside :type:`nghttp2_on_frame_recv_callback`
* callback. Of course, application has a liberty not ot use
* |*payload|, and do its own mechanism to process extension frames.
*
* To abort processing this extension frame, return
* :enum:`NGHTTP2_ERR_CANCEL`.
*
* If fatal error occurred, application should return
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. In this case,
* `nghttp2_session_recv()` and `nghttp2_session_mem_recv()` functions
* immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. If the
* other values are returned, currently they are treated as
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*/
typedef int (*nghttp2_unpack_extension_callback)(nghttp2_session *session,
void **payload,
const nghttp2_frame_hd *hd,
void *user_data);
/**
* @functypedef
*
* Callback function invoked when library asks the application to pack
* extension payload in its wire format. The frame header will be
* packed by library. Application must pack payload only.
* ``frame->ext.payload`` is the object passed to
* `nghttp2_submit_extension()` as payload parameter. Application
* must pack extension payload to the |buf| of its capacity |len|
* bytes. The |len| is at least 16KiB.
*
* The implementation of this function should return the number of
* bytes written into |buf| when it succeeds.
*
* To abort processing this extension frame, return
* :enum:`NGHTTP2_ERR_CANCEL`, and
* :type:`nghttp2_on_frame_not_send_callback` will be invoked.
*
* If fatal error occurred, application should return
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. In this case,
* `nghttp2_session_send()` and `nghttp2_session_mem_send()` functions
* immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. If the
* other values are returned, currently they are treated as
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. If the return value is
* strictly larger than |len|, it is treated as
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
*/
typedef ssize_t (*nghttp2_pack_extension_callback)(nghttp2_session *session,
uint8_t *buf, size_t len,
const nghttp2_frame *frame,
void *user_data);
/**
* @functypedef
*
* Callback function invoked when library provides the error message
* intended for human consumption. This callback is solely for
* debugging purpose. The |msg| is typically NULL-terminated string
* of length |len|. |len| does not include the sentinel NULL
* character.
*
* The format of error message may change between nghttp2 library
* versions. The application should not depend on the particular
* format.
*
* Normally, application should return 0 from this callback. If fatal
* error occurred while doing something in this callback, application
* should return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. In this case,
* library will return immediately with return value
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`. Currently, if nonzero value
* is returned from this callback, they are treated as
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`, but application should not
* rely on this details.
*/
typedef int (*nghttp2_error_callback)(nghttp2_session *session, const char *msg,
size_t len, void *user_data);
struct nghttp2_session_callbacks;
/**
* @struct
*
* Callback functions for :type:`nghttp2_session`. The details of
* this structure are intentionally hidden from the public API.
*/
typedef struct nghttp2_session_callbacks nghttp2_session_callbacks;
/**
* @function
*
* Initializes |*callbacks_ptr| with NULL values.
*
* The initialized object can be used when initializing multiple
* :type:`nghttp2_session` objects.
*
* When the application finished using this object, it can use
* `nghttp2_session_callbacks_del()` to free its memory.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
*/
NGHTTP2_EXTERN int
nghttp2_session_callbacks_new(nghttp2_session_callbacks **callbacks_ptr);
/**
* @function
*
* Frees any resources allocated for |callbacks|. If |callbacks| is
* ``NULL``, this function does nothing.
*/
NGHTTP2_EXTERN void
nghttp2_session_callbacks_del(nghttp2_session_callbacks *callbacks);
/**
* @function
*
* Sets callback function invoked when a session wants to send data to
* the remote peer. This callback is not necessary if the application
* uses solely `nghttp2_session_mem_send()` to serialize data to
* transmit.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_send_callback(
nghttp2_session_callbacks *cbs, nghttp2_send_callback send_callback);
/**
* @function
*
* Sets callback function invoked when the a session wants to receive
* data from the remote peer. This callback is not necessary if the
* application uses solely `nghttp2_session_mem_recv()` to process
* received data.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_recv_callback(
nghttp2_session_callbacks *cbs, nghttp2_recv_callback recv_callback);
/**
* @function
*
* Sets callback function invoked by `nghttp2_session_recv()` and
* `nghttp2_session_mem_recv()` when a frame is received.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_on_frame_recv_callback(
nghttp2_session_callbacks *cbs,
nghttp2_on_frame_recv_callback on_frame_recv_callback);
/**
* @function
*
* Sets callback function invoked by `nghttp2_session_recv()` and
* `nghttp2_session_mem_recv()` when an invalid non-DATA frame is
* received.
*/
NGHTTP2_EXTERN void
nghttp2_session_callbacks_set_on_invalid_frame_recv_callback(
nghttp2_session_callbacks *cbs,
nghttp2_on_invalid_frame_recv_callback on_invalid_frame_recv_callback);
/**
* @function
*
* Sets callback function invoked when a chunk of data in DATA frame
* is received.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_on_data_chunk_recv_callback(
nghttp2_session_callbacks *cbs,
nghttp2_on_data_chunk_recv_callback on_data_chunk_recv_callback);
/**
* @function
*
* Sets callback function invoked before a non-DATA frame is sent.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_before_frame_send_callback(
nghttp2_session_callbacks *cbs,
nghttp2_before_frame_send_callback before_frame_send_callback);
/**
* @function
*
* Sets callback function invoked after a frame is sent.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_on_frame_send_callback(
nghttp2_session_callbacks *cbs,
nghttp2_on_frame_send_callback on_frame_send_callback);
/**
* @function
*
* Sets callback function invoked when a non-DATA frame is not sent
* because of an error.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_on_frame_not_send_callback(
nghttp2_session_callbacks *cbs,
nghttp2_on_frame_not_send_callback on_frame_not_send_callback);
/**
* @function
*
* Sets callback function invoked when the stream is closed.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_on_stream_close_callback(
nghttp2_session_callbacks *cbs,
nghttp2_on_stream_close_callback on_stream_close_callback);
/**
* @function
*
* Sets callback function invoked when the reception of header block
* in HEADERS or PUSH_PROMISE is started.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_on_begin_headers_callback(
nghttp2_session_callbacks *cbs,
nghttp2_on_begin_headers_callback on_begin_headers_callback);
/**
* @function
*
* Sets callback function invoked when a header name/value pair is
* received. If both
* `nghttp2_session_callbacks_set_on_header_callback()` and
* `nghttp2_session_callbacks_set_on_header_callback2()` are used to
* set callbacks, the latter has the precedence.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_on_header_callback(
nghttp2_session_callbacks *cbs,
nghttp2_on_header_callback on_header_callback);
/**
* @function
*
* Sets callback function invoked when a header name/value pair is
* received.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_on_header_callback2(
nghttp2_session_callbacks *cbs,
nghttp2_on_header_callback2 on_header_callback2);
/**
* @function
*
* Sets callback function invoked when a invalid header name/value
* pair is received. If both
* `nghttp2_session_callbacks_set_on_invalid_header_callback()` and
* `nghttp2_session_callbacks_set_on_invalid_header_callback2()` are
* used to set callbacks, the latter takes the precedence.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_on_invalid_header_callback(
nghttp2_session_callbacks *cbs,
nghttp2_on_invalid_header_callback on_invalid_header_callback);
/**
* @function
*
* Sets callback function invoked when a invalid header name/value
* pair is received.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_on_invalid_header_callback2(
nghttp2_session_callbacks *cbs,
nghttp2_on_invalid_header_callback2 on_invalid_header_callback2);
/**
* @function
*
* Sets callback function invoked when the library asks application
* how many padding bytes are required for the transmission of the
* given frame.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_select_padding_callback(
nghttp2_session_callbacks *cbs,
nghttp2_select_padding_callback select_padding_callback);
/**
* @function
*
* Sets callback function determine the length allowed in
* :type:`nghttp2_data_source_read_callback`.
*/
NGHTTP2_EXTERN void
nghttp2_session_callbacks_set_data_source_read_length_callback(
nghttp2_session_callbacks *cbs,
nghttp2_data_source_read_length_callback data_source_read_length_callback);
/**
* @function
*
* Sets callback function invoked when a frame header is received.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_on_begin_frame_callback(
nghttp2_session_callbacks *cbs,
nghttp2_on_begin_frame_callback on_begin_frame_callback);
/**
* @function
*
* Sets callback function invoked when
* :enum:`NGHTTP2_DATA_FLAG_NO_COPY` is used in
* :type:`nghttp2_data_source_read_callback` to avoid data copy.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_send_data_callback(
nghttp2_session_callbacks *cbs,
nghttp2_send_data_callback send_data_callback);
/**
* @function
*
* Sets callback function invoked when the library asks the
* application to pack extension frame payload in wire format.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_pack_extension_callback(
nghttp2_session_callbacks *cbs,
nghttp2_pack_extension_callback pack_extension_callback);
/**
* @function
*
* Sets callback function invoked when the library asks the
* application to unpack extension frame payload from wire format.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_unpack_extension_callback(
nghttp2_session_callbacks *cbs,
nghttp2_unpack_extension_callback unpack_extension_callback);
/**
* @function
*
* Sets callback function invoked when chunk of extension frame
* payload is received.
*/
NGHTTP2_EXTERN void
nghttp2_session_callbacks_set_on_extension_chunk_recv_callback(
nghttp2_session_callbacks *cbs,
nghttp2_on_extension_chunk_recv_callback on_extension_chunk_recv_callback);
/**
* @function
*
* Sets callback function invoked when library tells error message to
* the application.
*/
NGHTTP2_EXTERN void nghttp2_session_callbacks_set_error_callback(
nghttp2_session_callbacks *cbs, nghttp2_error_callback error_callback);
/**
* @functypedef
*
* Custom memory allocator to replace malloc(). The |mem_user_data|
* is the mem_user_data member of :type:`nghttp2_mem` structure.
*/
typedef void *(*nghttp2_malloc)(size_t size, void *mem_user_data);
/**
* @functypedef
*
* Custom memory allocator to replace free(). The |mem_user_data| is
* the mem_user_data member of :type:`nghttp2_mem` structure.
*/
typedef void (*nghttp2_free)(void *ptr, void *mem_user_data);
/**
* @functypedef
*
* Custom memory allocator to replace calloc(). The |mem_user_data|
* is the mem_user_data member of :type:`nghttp2_mem` structure.
*/
typedef void *(*nghttp2_calloc)(size_t nmemb, size_t size, void *mem_user_data);
/**
* @functypedef
*
* Custom memory allocator to replace realloc(). The |mem_user_data|
* is the mem_user_data member of :type:`nghttp2_mem` structure.
*/
typedef void *(*nghttp2_realloc)(void *ptr, size_t size, void *mem_user_data);
/**
* @struct
*
* Custom memory allocator functions and user defined pointer. The
* |mem_user_data| member is passed to each allocator function. This
* can be used, for example, to achieve per-session memory pool.
*
* In the following example code, ``my_malloc``, ``my_free``,
* ``my_calloc`` and ``my_realloc`` are the replacement of the
* standard allocators ``malloc``, ``free``, ``calloc`` and
* ``realloc`` respectively::
*
* void *my_malloc_cb(size_t size, void *mem_user_data) {
* return my_malloc(size);
* }
*
* void my_free_cb(void *ptr, void *mem_user_data) { my_free(ptr); }
*
* void *my_calloc_cb(size_t nmemb, size_t size, void *mem_user_data) {
* return my_calloc(nmemb, size);
* }
*
* void *my_realloc_cb(void *ptr, size_t size, void *mem_user_data) {
* return my_realloc(ptr, size);
* }
*
* void session_new() {
* nghttp2_session *session;
* nghttp2_session_callbacks *callbacks;
* nghttp2_mem mem = {NULL, my_malloc_cb, my_free_cb, my_calloc_cb,
* my_realloc_cb};
*
* ...
*
* nghttp2_session_client_new3(&session, callbacks, NULL, NULL, &mem);
*
* ...
* }
*/
typedef struct {
/**
* An arbitrary user supplied data. This is passed to each
* allocator function.
*/
void *mem_user_data;
/**
* Custom allocator function to replace malloc().
*/
nghttp2_malloc malloc;
/**
* Custom allocator function to replace free().
*/
nghttp2_free free;
/**
* Custom allocator function to replace calloc().
*/
nghttp2_calloc calloc;
/**
* Custom allocator function to replace realloc().
*/
nghttp2_realloc realloc;
} nghttp2_mem;
struct nghttp2_option;
/**
* @struct
*
* Configuration options for :type:`nghttp2_session`. The details of
* this structure are intentionally hidden from the public API.
*/
typedef struct nghttp2_option nghttp2_option;
/**
* @function
*
* Initializes |*option_ptr| with default values.
*
* When the application finished using this object, it can use
* `nghttp2_option_del()` to free its memory.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
*/
NGHTTP2_EXTERN int nghttp2_option_new(nghttp2_option **option_ptr);
/**
* @function
*
* Frees any resources allocated for |option|. If |option| is
* ``NULL``, this function does nothing.
*/
NGHTTP2_EXTERN void nghttp2_option_del(nghttp2_option *option);
/**
* @function
*
* This option prevents the library from sending WINDOW_UPDATE for a
* connection automatically. If this option is set to nonzero, the
* library won't send WINDOW_UPDATE for DATA until application calls
* `nghttp2_session_consume()` to indicate the consumed amount of
* data. Don't use `nghttp2_submit_window_update()` for this purpose.
* By default, this option is set to zero.
*/
NGHTTP2_EXTERN void
nghttp2_option_set_no_auto_window_update(nghttp2_option *option, int val);
/**
* @function
*
* This option sets the SETTINGS_MAX_CONCURRENT_STREAMS value of
* remote endpoint as if it is received in SETTINGS frame. Without
* specifying this option, before the local endpoint receives
* SETTINGS_MAX_CONCURRENT_STREAMS in SETTINGS frame from remote
* endpoint, SETTINGS_MAX_CONCURRENT_STREAMS is unlimited. This may
* cause problem if local endpoint submits lots of requests initially
* and sending them at once to the remote peer may lead to the
* rejection of some requests. Specifying this option to the sensible
* value, say 100, may avoid this kind of issue. This value will be
* overwritten if the local endpoint receives
* SETTINGS_MAX_CONCURRENT_STREAMS from the remote endpoint.
*/
NGHTTP2_EXTERN void
nghttp2_option_set_peer_max_concurrent_streams(nghttp2_option *option,
uint32_t val);
/**
* @function
*
* By default, nghttp2 library, if configured as server, requires
* first 24 bytes of client magic byte string (MAGIC). In most cases,
* this will simplify the implementation of server. But sometimes
* server may want to detect the application protocol based on first
* few bytes on clear text communication.
*
* If this option is used with nonzero |val|, nghttp2 library does not
* handle MAGIC. It still checks following SETTINGS frame. This
* means that applications should deal with MAGIC by themselves.
*
* If this option is not used or used with zero value, if MAGIC does
* not match :macro:`NGHTTP2_CLIENT_MAGIC`, `nghttp2_session_recv()`
* and `nghttp2_session_mem_recv()` will return error
* :enum:`NGHTTP2_ERR_BAD_CLIENT_MAGIC`, which is fatal error.
*/
NGHTTP2_EXTERN void
nghttp2_option_set_no_recv_client_magic(nghttp2_option *option, int val);
/**
* @function
*
* By default, nghttp2 library enforces subset of HTTP Messaging rules
* described in `HTTP/2 specification, section 8
* <https://tools.ietf.org/html/rfc7540#section-8>`_. See
* :ref:`http-messaging` section for details. For those applications
* who use nghttp2 library as non-HTTP use, give nonzero to |val| to
* disable this enforcement.
*/
NGHTTP2_EXTERN void nghttp2_option_set_no_http_messaging(nghttp2_option *option,
int val);
/**
* @function
*
* RFC 7540 does not enforce any limit on the number of incoming
* reserved streams (in RFC 7540 terms, streams in reserved (remote)
* state). This only affects client side, since only server can push
* streams. Malicious server can push arbitrary number of streams,
* and make client's memory exhausted. This option can set the
* maximum number of such incoming streams to avoid possible memory
* exhaustion. If this option is set, and pushed streams are
* automatically closed on reception, without calling user provided
* callback, if they exceed the given limit. The default value is
* 200. If session is configured as server side, this option has no
* effect. Server can control the number of streams to push.
*/
NGHTTP2_EXTERN void
nghttp2_option_set_max_reserved_remote_streams(nghttp2_option *option,
uint32_t val);
/**
* @function
*
* Sets extension frame type the application is willing to handle with
* user defined callbacks (see
* :type:`nghttp2_on_extension_chunk_recv_callback` and
* :type:`nghttp2_unpack_extension_callback`). The |type| is
* extension frame type, and must be strictly greater than 0x9.
* Otherwise, this function does nothing. The application can call
* this function multiple times to set more than one frame type to
* receive. The application does not have to call this function if it
* just sends extension frames.
*/
NGHTTP2_EXTERN void
nghttp2_option_set_user_recv_extension_type(nghttp2_option *option,
uint8_t type);
/**
* @function
*
* Sets extension frame type the application is willing to receive
* using builtin handler. The |type| is the extension frame type to
* receive, and must be strictly greater than 0x9. Otherwise, this
* function does nothing. The application can call this function
* multiple times to set more than one frame type to receive. The
* application does not have to call this function if it just sends
* extension frames.
*
* If same frame type is passed to both
* `nghttp2_option_set_builtin_recv_extension_type()` and
* `nghttp2_option_set_user_recv_extension_type()`, the latter takes
* precedence.
*/
NGHTTP2_EXTERN void
nghttp2_option_set_builtin_recv_extension_type(nghttp2_option *option,
uint8_t type);
/**
* @function
*
* This option prevents the library from sending PING frame with ACK
* flag set automatically when PING frame without ACK flag set is
* received. If this option is set to nonzero, the library won't send
* PING frame with ACK flag set in the response for incoming PING
* frame. The application can send PING frame with ACK flag set using
* `nghttp2_submit_ping()` with :enum:`NGHTTP2_FLAG_ACK` as flags
* parameter.
*/
NGHTTP2_EXTERN void nghttp2_option_set_no_auto_ping_ack(nghttp2_option *option,
int val);
/**
* @function
*
* This option sets the maximum length of header block (a set of
* header fields per one HEADERS frame) to send. The length of a
* given set of header fields is calculated using
* `nghttp2_hd_deflate_bound()`. The default value is 64KiB. If
* application attempts to send header fields larger than this limit,
* the transmission of the frame fails with error code
* :enum:`NGHTTP2_ERR_FRAME_SIZE_ERROR`.
*/
NGHTTP2_EXTERN void
nghttp2_option_set_max_send_header_block_length(nghttp2_option *option,
size_t val);
/**
* @function
*
* This option sets the maximum dynamic table size for deflating
* header fields. The default value is 4KiB. In HTTP/2, receiver of
* deflated header block can specify maximum dynamic table size. The
* actual maximum size is the minimum of the size receiver specified
* and this option value.
*/
NGHTTP2_EXTERN void
nghttp2_option_set_max_deflate_dynamic_table_size(nghttp2_option *option,
size_t val);
/**
* @function
*
* This option prevents the library from retaining closed streams to
* maintain the priority tree. If this option is set to nonzero,
* applications can discard closed stream completely to save memory.
*/
NGHTTP2_EXTERN void nghttp2_option_set_no_closed_streams(nghttp2_option *option,
int val);
/**
* @function
*
* Initializes |*session_ptr| for client use. The all members of
* |callbacks| are copied to |*session_ptr|. Therefore |*session_ptr|
* does not store |callbacks|. The |user_data| is an arbitrary user
* supplied data, which will be passed to the callback functions.
*
* The :type:`nghttp2_send_callback` must be specified. If the
* application code uses `nghttp2_session_recv()`, the
* :type:`nghttp2_recv_callback` must be specified. The other members
* of |callbacks| can be ``NULL``.
*
* If this function fails, |*session_ptr| is left untouched.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
*/
NGHTTP2_EXTERN int
nghttp2_session_client_new(nghttp2_session **session_ptr,
const nghttp2_session_callbacks *callbacks,
void *user_data);
/**
* @function
*
* Initializes |*session_ptr| for server use. The all members of
* |callbacks| are copied to |*session_ptr|. Therefore |*session_ptr|
* does not store |callbacks|. The |user_data| is an arbitrary user
* supplied data, which will be passed to the callback functions.
*
* The :type:`nghttp2_send_callback` must be specified. If the
* application code uses `nghttp2_session_recv()`, the
* :type:`nghttp2_recv_callback` must be specified. The other members
* of |callbacks| can be ``NULL``.
*
* If this function fails, |*session_ptr| is left untouched.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
*/
NGHTTP2_EXTERN int
nghttp2_session_server_new(nghttp2_session **session_ptr,
const nghttp2_session_callbacks *callbacks,
void *user_data);
/**
* @function
*
* Like `nghttp2_session_client_new()`, but with additional options
* specified in the |option|.
*
* The |option| can be ``NULL`` and the call is equivalent to
* `nghttp2_session_client_new()`.
*
* This function does not take ownership |option|. The application is
* responsible for freeing |option| if it finishes using the object.
*
* The library code does not refer to |option| after this function
* returns.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
*/
NGHTTP2_EXTERN int
nghttp2_session_client_new2(nghttp2_session **session_ptr,
const nghttp2_session_callbacks *callbacks,
void *user_data, const nghttp2_option *option);
/**
* @function
*
* Like `nghttp2_session_server_new()`, but with additional options
* specified in the |option|.
*
* The |option| can be ``NULL`` and the call is equivalent to
* `nghttp2_session_server_new()`.
*
* This function does not take ownership |option|. The application is
* responsible for freeing |option| if it finishes using the object.
*
* The library code does not refer to |option| after this function
* returns.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
*/
NGHTTP2_EXTERN int
nghttp2_session_server_new2(nghttp2_session **session_ptr,
const nghttp2_session_callbacks *callbacks,
void *user_data, const nghttp2_option *option);
/**
* @function
*
* Like `nghttp2_session_client_new2()`, but with additional custom
* memory allocator specified in the |mem|.
*
* The |mem| can be ``NULL`` and the call is equivalent to
* `nghttp2_session_client_new2()`.
*
* This function does not take ownership |mem|. The application is
* responsible for freeing |mem|.
*
* The library code does not refer to |mem| pointer after this
* function returns, so the application can safely free it.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
*/
NGHTTP2_EXTERN int nghttp2_session_client_new3(
nghttp2_session **session_ptr, const nghttp2_session_callbacks *callbacks,
void *user_data, const nghttp2_option *option, nghttp2_mem *mem);
/**
* @function
*
* Like `nghttp2_session_server_new2()`, but with additional custom
* memory allocator specified in the |mem|.
*
* The |mem| can be ``NULL`` and the call is equivalent to
* `nghttp2_session_server_new2()`.
*
* This function does not take ownership |mem|. The application is
* responsible for freeing |mem|.
*
* The library code does not refer to |mem| pointer after this
* function returns, so the application can safely free it.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
*/
NGHTTP2_EXTERN int nghttp2_session_server_new3(
nghttp2_session **session_ptr, const nghttp2_session_callbacks *callbacks,
void *user_data, const nghttp2_option *option, nghttp2_mem *mem);
/**
* @function
*
* Frees any resources allocated for |session|. If |session| is
* ``NULL``, this function does nothing.
*/
NGHTTP2_EXTERN void nghttp2_session_del(nghttp2_session *session);
/**
* @function
*
* Sends pending frames to the remote peer.
*
* This function retrieves the highest prioritized frame from the
* outbound queue and sends it to the remote peer. It does this as
* many as possible until the user callback
* :type:`nghttp2_send_callback` returns
* :enum:`NGHTTP2_ERR_WOULDBLOCK` or the outbound queue becomes empty.
* This function calls several callback functions which are passed
* when initializing the |session|. Here is the simple time chart
* which tells when each callback is invoked:
*
* 1. Get the next frame to send from outbound queue.
*
* 2. Prepare transmission of the frame.
*
* 3. If the control frame cannot be sent because some preconditions
* are not met (e.g., request HEADERS cannot be sent after GOAWAY),
* :type:`nghttp2_on_frame_not_send_callback` is invoked. Abort
* the following steps.
*
* 4. If the frame is HEADERS, PUSH_PROMISE or DATA,
* :type:`nghttp2_select_padding_callback` is invoked.
*
* 5. If the frame is request HEADERS, the stream is opened here.
*
* 6. :type:`nghttp2_before_frame_send_callback` is invoked.
*
* 7. If :enum:`NGHTTP2_ERR_CANCEL` is returned from
* :type:`nghttp2_before_frame_send_callback`, the current frame
* transmission is canceled, and
* :type:`nghttp2_on_frame_not_send_callback` is invoked. Abort
* the following steps.
*
* 8. :type:`nghttp2_send_callback` is invoked one or more times to
* send the frame.
*
* 9. :type:`nghttp2_on_frame_send_callback` is invoked.
*
* 10. If the transmission of the frame triggers closure of the
* stream, the stream is closed and
* :type:`nghttp2_on_stream_close_callback` is invoked.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`
* The callback function failed.
*/
NGHTTP2_EXTERN int nghttp2_session_send(nghttp2_session *session);
/**
* @function
*
* Returns the serialized data to send.
*
* This function behaves like `nghttp2_session_send()` except that it
* does not use :type:`nghttp2_send_callback` to transmit data.
* Instead, it assigns the pointer to the serialized data to the
* |*data_ptr| and returns its length. The other callbacks are called
* in the same way as they are in `nghttp2_session_send()`.
*
* If no data is available to send, this function returns 0.
*
* This function may not return all serialized data in one invocation.
* To get all data, call this function repeatedly until it returns 0
* or one of negative error codes.
*
* The assigned |*data_ptr| is valid until the next call of
* `nghttp2_session_mem_send()` or `nghttp2_session_send()`.
*
* The caller must send all data before sending the next chunk of
* data.
*
* This function returns the length of the data pointed by the
* |*data_ptr| if it succeeds, or one of the following negative error
* codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
*
* .. note::
*
* This function may produce very small byte string. If that is the
* case, and application disables Nagle algorithm (``TCP_NODELAY``),
* then writing this small chunk leads to very small packet, and it
* is very inefficient. An application should be responsible to
* buffer up small chunks of data as necessary to avoid this
* situation.
*/
NGHTTP2_EXTERN ssize_t nghttp2_session_mem_send(nghttp2_session *session,
const uint8_t **data_ptr);
/**
* @function
*
* Receives frames from the remote peer.
*
* This function receives as many frames as possible until the user
* callback :type:`nghttp2_recv_callback` returns
* :enum:`NGHTTP2_ERR_WOULDBLOCK`. This function calls several
* callback functions which are passed when initializing the
* |session|. Here is the simple time chart which tells when each
* callback is invoked:
*
* 1. :type:`nghttp2_recv_callback` is invoked one or more times to
* receive frame header.
*
* 2. When frame header is received,
* :type:`nghttp2_on_begin_frame_callback` is invoked.
*
* 3. If the frame is DATA frame:
*
* 1. :type:`nghttp2_recv_callback` is invoked to receive DATA
* payload. For each chunk of data,
* :type:`nghttp2_on_data_chunk_recv_callback` is invoked.
*
* 2. If one DATA frame is completely received,
* :type:`nghttp2_on_frame_recv_callback` is invoked. If the
* reception of the frame triggers the closure of the stream,
* :type:`nghttp2_on_stream_close_callback` is invoked.
*
* 4. If the frame is the control frame:
*
* 1. :type:`nghttp2_recv_callback` is invoked one or more times to
* receive whole frame.
*
* 2. If the received frame is valid, then following actions are
* taken. If the frame is either HEADERS or PUSH_PROMISE,
* :type:`nghttp2_on_begin_headers_callback` is invoked. Then
* :type:`nghttp2_on_header_callback` is invoked for each header
* name/value pair. For invalid header field,
* :type:`nghttp2_on_invalid_header_callback` is called. After
* all name/value pairs are emitted successfully,
* :type:`nghttp2_on_frame_recv_callback` is invoked. For other
* frames, :type:`nghttp2_on_frame_recv_callback` is invoked.
* If the reception of the frame triggers the closure of the
* stream, :type:`nghttp2_on_stream_close_callback` is invoked.
*
* 3. If the received frame is unpacked but is interpreted as
* invalid, :type:`nghttp2_on_invalid_frame_recv_callback` is
* invoked.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_EOF`
* The remote peer did shutdown on the connection.
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`
* The callback function failed.
* :enum:`NGHTTP2_ERR_BAD_CLIENT_MAGIC`
* Invalid client magic was detected. This error only returns
* when |session| was configured as server and
* `nghttp2_option_set_no_recv_client_magic()` is not used with
* nonzero value.
* :enum:`NGHTTP2_ERR_FLOODED`
* Flooding was detected in this HTTP/2 session, and it must be
* closed. This is most likely caused by misbehaviour of peer.
*/
NGHTTP2_EXTERN int nghttp2_session_recv(nghttp2_session *session);
/**
* @function
*
* Processes data |in| as an input from the remote endpoint. The
* |inlen| indicates the number of bytes in the |in|.
*
* This function behaves like `nghttp2_session_recv()` except that it
* does not use :type:`nghttp2_recv_callback` to receive data; the
* |in| is the only data for the invocation of this function. If all
* bytes are processed, this function returns. The other callbacks
* are called in the same way as they are in `nghttp2_session_recv()`.
*
* In the current implementation, this function always tries to
* processes all input data unless either an error occurs or
* :enum:`NGHTTP2_ERR_PAUSE` is returned from
* :type:`nghttp2_on_header_callback` or
* :type:`nghttp2_on_data_chunk_recv_callback`. If
* :enum:`NGHTTP2_ERR_PAUSE` is used, the return value includes the
* number of bytes which was used to produce the data or frame for the
* callback.
*
* This function returns the number of processed bytes, or one of the
* following negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`
* The callback function failed.
* :enum:`NGHTTP2_ERR_BAD_CLIENT_MAGIC`
* Invalid client magic was detected. This error only returns
* when |session| was configured as server and
* `nghttp2_option_set_no_recv_client_magic()` is not used with
* nonzero value.
* :enum:`NGHTTP2_ERR_FLOODED`
* Flooding was detected in this HTTP/2 session, and it must be
* closed. This is most likely caused by misbehaviour of peer.
*/
NGHTTP2_EXTERN ssize_t nghttp2_session_mem_recv(nghttp2_session *session,
const uint8_t *in,
size_t inlen);
/**
* @function
*
* Puts back previously deferred DATA frame in the stream |stream_id|
* to the outbound queue.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* The stream does not exist; or no deferred data exist.
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
*/
NGHTTP2_EXTERN int nghttp2_session_resume_data(nghttp2_session *session,
int32_t stream_id);
/**
* @function
*
* Returns nonzero value if |session| wants to receive data from the
* remote peer.
*
* If both `nghttp2_session_want_read()` and
* `nghttp2_session_want_write()` return 0, the application should
* drop the connection.
*/
NGHTTP2_EXTERN int nghttp2_session_want_read(nghttp2_session *session);
/**
* @function
*
* Returns nonzero value if |session| wants to send data to the remote
* peer.
*
* If both `nghttp2_session_want_read()` and
* `nghttp2_session_want_write()` return 0, the application should
* drop the connection.
*/
NGHTTP2_EXTERN int nghttp2_session_want_write(nghttp2_session *session);
/**
* @function
*
* Returns stream_user_data for the stream |stream_id|. The
* stream_user_data is provided by `nghttp2_submit_request()`,
* `nghttp2_submit_headers()` or
* `nghttp2_session_set_stream_user_data()`. Unless it is set using
* `nghttp2_session_set_stream_user_data()`, if the stream is
* initiated by the remote endpoint, stream_user_data is always
* ``NULL``. If the stream does not exist, this function returns
* ``NULL``.
*/
NGHTTP2_EXTERN void *
nghttp2_session_get_stream_user_data(nghttp2_session *session,
int32_t stream_id);
/**
* @function
*
* Sets the |stream_user_data| to the stream denoted by the
* |stream_id|. If a stream user data is already set to the stream,
* it is replaced with the |stream_user_data|. It is valid to specify
* ``NULL`` in the |stream_user_data|, which nullifies the associated
* data pointer.
*
* It is valid to set the |stream_user_data| to the stream reserved by
* PUSH_PROMISE frame.
*
* This function returns 0 if it succeeds, or one of following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* The stream does not exist
*/
NGHTTP2_EXTERN int
nghttp2_session_set_stream_user_data(nghttp2_session *session,
int32_t stream_id, void *stream_user_data);
/**
* @function
*
* Returns the number of frames in the outbound queue. This does not
* include the deferred DATA frames.
*/
NGHTTP2_EXTERN size_t
nghttp2_session_get_outbound_queue_size(nghttp2_session *session);
/**
* @function
*
* Returns the number of DATA payload in bytes received without
* WINDOW_UPDATE transmission for the stream |stream_id|. The local
* (receive) window size can be adjusted by
* `nghttp2_submit_window_update()`. This function takes into account
* that and returns effective data length. In particular, if the
* local window size is reduced by submitting negative
* window_size_increment with `nghttp2_submit_window_update()`, this
* function returns the number of bytes less than actually received.
*
* This function returns -1 if it fails.
*/
NGHTTP2_EXTERN int32_t nghttp2_session_get_stream_effective_recv_data_length(
nghttp2_session *session, int32_t stream_id);
/**
* @function
*
* Returns the local (receive) window size for the stream |stream_id|.
* The local window size can be adjusted by
* `nghttp2_submit_window_update()`. This function takes into account
* that and returns effective window size.
*
* This function does not take into account the amount of received
* data from the remote endpoint. Use
* `nghttp2_session_get_stream_local_window_size()` to know the amount
* of data the remote endpoint can send without receiving stream level
* WINDOW_UPDATE frame. Note that each stream is still subject to the
* connection level flow control.
*
* This function returns -1 if it fails.
*/
NGHTTP2_EXTERN int32_t nghttp2_session_get_stream_effective_local_window_size(
nghttp2_session *session, int32_t stream_id);
/**
* @function
*
* Returns the amount of flow-controlled payload (e.g., DATA) that the
* remote endpoint can send without receiving stream level
* WINDOW_UPDATE frame. It is also subject to the connection level
* flow control. So the actual amount of data to send is
* min(`nghttp2_session_get_stream_local_window_size()`,
* `nghttp2_session_get_local_window_size()`).
*
* This function returns -1 if it fails.
*/
NGHTTP2_EXTERN int32_t nghttp2_session_get_stream_local_window_size(
nghttp2_session *session, int32_t stream_id);
/**
* @function
*
* Returns the number of DATA payload in bytes received without
* WINDOW_UPDATE transmission for a connection. The local (receive)
* window size can be adjusted by `nghttp2_submit_window_update()`.
* This function takes into account that and returns effective data
* length. In particular, if the local window size is reduced by
* submitting negative window_size_increment with
* `nghttp2_submit_window_update()`, this function returns the number
* of bytes less than actually received.
*
* This function returns -1 if it fails.
*/
NGHTTP2_EXTERN int32_t
nghttp2_session_get_effective_recv_data_length(nghttp2_session *session);
/**
* @function
*
* Returns the local (receive) window size for a connection. The
* local window size can be adjusted by
* `nghttp2_submit_window_update()`. This function takes into account
* that and returns effective window size.
*
* This function does not take into account the amount of received
* data from the remote endpoint. Use
* `nghttp2_session_get_local_window_size()` to know the amount of
* data the remote endpoint can send without receiving
* connection-level WINDOW_UPDATE frame. Note that each stream is
* still subject to the stream level flow control.
*
* This function returns -1 if it fails.
*/
NGHTTP2_EXTERN int32_t
nghttp2_session_get_effective_local_window_size(nghttp2_session *session);
/**
* @function
*
* Returns the amount of flow-controlled payload (e.g., DATA) that the
* remote endpoint can send without receiving connection level
* WINDOW_UPDATE frame. Note that each stream is still subject to the
* stream level flow control (see
* `nghttp2_session_get_stream_local_window_size()`).
*
* This function returns -1 if it fails.
*/
NGHTTP2_EXTERN int32_t
nghttp2_session_get_local_window_size(nghttp2_session *session);
/**
* @function
*
* Returns the remote window size for a given stream |stream_id|.
*
* This is the amount of flow-controlled payload (e.g., DATA) that the
* local endpoint can send without stream level WINDOW_UPDATE. There
* is also connection level flow control, so the effective size of
* payload that the local endpoint can actually send is
* min(`nghttp2_session_get_stream_remote_window_size()`,
* `nghttp2_session_get_remote_window_size()`).
*
* This function returns -1 if it fails.
*/
NGHTTP2_EXTERN int32_t nghttp2_session_get_stream_remote_window_size(
nghttp2_session *session, int32_t stream_id);
/**
* @function
*
* Returns the remote window size for a connection.
*
* This function always succeeds.
*/
NGHTTP2_EXTERN int32_t
nghttp2_session_get_remote_window_size(nghttp2_session *session);
/**
* @function
*
* Returns 1 if local peer half closed the given stream |stream_id|.
* Returns 0 if it did not. Returns -1 if no such stream exists.
*/
NGHTTP2_EXTERN int
nghttp2_session_get_stream_local_close(nghttp2_session *session,
int32_t stream_id);
/**
* @function
*
* Returns 1 if remote peer half closed the given stream |stream_id|.
* Returns 0 if it did not. Returns -1 if no such stream exists.
*/
NGHTTP2_EXTERN int
nghttp2_session_get_stream_remote_close(nghttp2_session *session,
int32_t stream_id);
/**
* @function
*
* Returns the current dynamic table size of HPACK inflater, including
* the overhead 32 bytes per entry described in RFC 7541.
*/
NGHTTP2_EXTERN size_t
nghttp2_session_get_hd_inflate_dynamic_table_size(nghttp2_session *session);
/**
* @function
*
* Returns the current dynamic table size of HPACK deflater including
* the overhead 32 bytes per entry described in RFC 7541.
*/
NGHTTP2_EXTERN size_t
nghttp2_session_get_hd_deflate_dynamic_table_size(nghttp2_session *session);
/**
* @function
*
* Signals the session so that the connection should be terminated.
*
* The last stream ID is the minimum value between the stream ID of a
* stream for which :type:`nghttp2_on_frame_recv_callback` was called
* most recently and the last stream ID we have sent to the peer
* previously.
*
* The |error_code| is the error code of this GOAWAY frame. The
* pre-defined error code is one of :enum:`nghttp2_error_code`.
*
* After the transmission, both `nghttp2_session_want_read()` and
* `nghttp2_session_want_write()` return 0.
*
* This function should be called when the connection should be
* terminated after sending GOAWAY. If the remaining streams should
* be processed after GOAWAY, use `nghttp2_submit_goaway()` instead.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
*/
NGHTTP2_EXTERN int nghttp2_session_terminate_session(nghttp2_session *session,
uint32_t error_code);
/**
* @function
*
* Signals the session so that the connection should be terminated.
*
* This function behaves like `nghttp2_session_terminate_session()`,
* but the last stream ID can be specified by the application for fine
* grained control of stream. The HTTP/2 specification does not allow
* last_stream_id to be increased. So the actual value sent as
* last_stream_id is the minimum value between the given
* |last_stream_id| and the last_stream_id we have previously sent to
* the peer.
*
* The |last_stream_id| is peer's stream ID or 0. So if |session| is
* initialized as client, |last_stream_id| must be even or 0. If
* |session| is initialized as server, |last_stream_id| must be odd or
* 0.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* The |last_stream_id| is invalid.
*/
NGHTTP2_EXTERN int nghttp2_session_terminate_session2(nghttp2_session *session,
int32_t last_stream_id,
uint32_t error_code);
/**
* @function
*
* Signals to the client that the server started graceful shutdown
* procedure.
*
* This function is only usable for server. If this function is
* called with client side session, this function returns
* :enum:`NGHTTP2_ERR_INVALID_STATE`.
*
* To gracefully shutdown HTTP/2 session, server should call this
* function to send GOAWAY with last_stream_id (1u << 31) - 1. And
* after some delay (e.g., 1 RTT), send another GOAWAY with the stream
* ID that the server has some processing using
* `nghttp2_submit_goaway()`. See also
* `nghttp2_session_get_last_proc_stream_id()`.
*
* Unlike `nghttp2_submit_goaway()`, this function just sends GOAWAY
* and does nothing more. This is a mere indication to the client
* that session shutdown is imminent. The application should call
* `nghttp2_submit_goaway()` with appropriate last_stream_id after
* this call.
*
* If one or more GOAWAY frame have been already sent by either
* `nghttp2_submit_goaway()` or `nghttp2_session_terminate_session()`,
* this function has no effect.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_INVALID_STATE`
* The |session| is initialized as client.
*/
NGHTTP2_EXTERN int nghttp2_submit_shutdown_notice(nghttp2_session *session);
/**
* @function
*
* Returns the value of SETTINGS |id| notified by a remote endpoint.
* The |id| must be one of values defined in
* :enum:`nghttp2_settings_id`.
*/
NGHTTP2_EXTERN uint32_t nghttp2_session_get_remote_settings(
nghttp2_session *session, nghttp2_settings_id id);
/**
* @function
*
* Returns the value of SETTINGS |id| of local endpoint acknowledged
* by the remote endpoint. The |id| must be one of the values defined
* in :enum:`nghttp2_settings_id`.
*/
NGHTTP2_EXTERN uint32_t nghttp2_session_get_local_settings(
nghttp2_session *session, nghttp2_settings_id id);
/**
* @function
*
* Tells the |session| that next stream ID is |next_stream_id|. The
* |next_stream_id| must be equal or greater than the value returned
* by `nghttp2_session_get_next_stream_id()`.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* The |next_stream_id| is strictly less than the value
* `nghttp2_session_get_next_stream_id()` returns; or
* |next_stream_id| is invalid (e.g., even integer for client, or
* odd integer for server).
*/
NGHTTP2_EXTERN int nghttp2_session_set_next_stream_id(nghttp2_session *session,
int32_t next_stream_id);
/**
* @function
*
* Returns the next outgoing stream ID. Notice that return type is
* uint32_t. If we run out of stream ID for this session, this
* function returns 1 << 31.
*/
NGHTTP2_EXTERN uint32_t
nghttp2_session_get_next_stream_id(nghttp2_session *session);
/**
* @function
*
* Tells the |session| that |size| bytes for a stream denoted by
* |stream_id| were consumed by application and are ready to
* WINDOW_UPDATE. The consumed bytes are counted towards both
* connection and stream level WINDOW_UPDATE (see
* `nghttp2_session_consume_connection()` and
* `nghttp2_session_consume_stream()` to update consumption
* independently). This function is intended to be used without
* automatic window update (see
* `nghttp2_option_set_no_auto_window_update()`).
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* The |stream_id| is 0.
* :enum:`NGHTTP2_ERR_INVALID_STATE`
* Automatic WINDOW_UPDATE is not disabled.
*/
NGHTTP2_EXTERN int nghttp2_session_consume(nghttp2_session *session,
int32_t stream_id, size_t size);
/**
* @function
*
* Like `nghttp2_session_consume()`, but this only tells library that
* |size| bytes were consumed only for connection level. Note that
* HTTP/2 maintains connection and stream level flow control windows
* independently.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_INVALID_STATE`
* Automatic WINDOW_UPDATE is not disabled.
*/
NGHTTP2_EXTERN int nghttp2_session_consume_connection(nghttp2_session *session,
size_t size);
/**
* @function
*
* Like `nghttp2_session_consume()`, but this only tells library that
* |size| bytes were consumed only for stream denoted by |stream_id|.
* Note that HTTP/2 maintains connection and stream level flow control
* windows independently.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* The |stream_id| is 0.
* :enum:`NGHTTP2_ERR_INVALID_STATE`
* Automatic WINDOW_UPDATE is not disabled.
*/
NGHTTP2_EXTERN int nghttp2_session_consume_stream(nghttp2_session *session,
int32_t stream_id,
size_t size);
/**
* @function
*
* Changes priority of existing stream denoted by |stream_id|. The
* new priority specification is |pri_spec|.
*
* The priority is changed silently and instantly, and no PRIORITY
* frame will be sent to notify the peer of this change. This
* function may be useful for server to change the priority of pushed
* stream.
*
* If |session| is initialized as server, and ``pri_spec->stream_id``
* points to the idle stream, the idle stream is created if it does
* not exist. The created idle stream will depend on root stream
* (stream 0) with weight 16.
*
* Otherwise, if stream denoted by ``pri_spec->stream_id`` is not
* found, we use default priority instead of given |pri_spec|. That
* is make stream depend on root stream with weight 16.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* Attempted to depend on itself; or no stream exist for the given
* |stream_id|; or |stream_id| is 0
*/
NGHTTP2_EXTERN int
nghttp2_session_change_stream_priority(nghttp2_session *session,
int32_t stream_id,
const nghttp2_priority_spec *pri_spec);
/**
* @function
*
* Creates idle stream with the given |stream_id|, and priority
* |pri_spec|.
*
* The stream creation is done without sending PRIORITY frame, which
* means that peer does not know about the existence of this idle
* stream in the local endpoint.
*
* RFC 7540 does not disallow the use of creation of idle stream with
* odd or even stream ID regardless of client or server. So this
* function can create odd or even stream ID regardless of client or
* server. But probably it is a bit safer to use the stream ID the
* local endpoint can initiate (in other words, use odd stream ID for
* client, and even stream ID for server), to avoid potential
* collision from peer's instruction. Also we can use
* `nghttp2_session_set_next_stream_id()` to avoid to open created
* idle streams accidentally if we follow this recommendation.
*
* If |session| is initialized as server, and ``pri_spec->stream_id``
* points to the idle stream, the idle stream is created if it does
* not exist. The created idle stream will depend on root stream
* (stream 0) with weight 16.
*
* Otherwise, if stream denoted by ``pri_spec->stream_id`` is not
* found, we use default priority instead of given |pri_spec|. That
* is make stream depend on root stream with weight 16.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* Attempted to depend on itself; or stream denoted by |stream_id|
* already exists; or |stream_id| cannot be used to create idle
* stream (in other words, local endpoint has already opened
* stream ID greater than or equal to the given stream ID; or
* |stream_id| is 0
*/
NGHTTP2_EXTERN int
nghttp2_session_create_idle_stream(nghttp2_session *session, int32_t stream_id,
const nghttp2_priority_spec *pri_spec);
/**
* @function
*
* Performs post-process of HTTP Upgrade request. This function can
* be called from both client and server, but the behavior is very
* different in each other.
*
* .. warning::
*
* This function is deprecated in favor of
* `nghttp2_session_upgrade2()`, because this function lacks the
* parameter to tell the library the request method used in the
* original HTTP request. This information is required for client
* to validate actual response body length against content-length
* header field (see `nghttp2_option_set_no_http_messaging()`). If
* HEAD is used in request, the length of response body must be 0
* regardless of value included in content-length header field.
*
* If called from client side, the |settings_payload| must be the
* value sent in ``HTTP2-Settings`` header field and must be decoded
* by base64url decoder. The |settings_payloadlen| is the length of
* |settings_payload|. The |settings_payload| is unpacked and its
* setting values will be submitted using `nghttp2_submit_settings()`.
* This means that the client application code does not need to submit
* SETTINGS by itself. The stream with stream ID=1 is opened and the
* |stream_user_data| is used for its stream_user_data. The opened
* stream becomes half-closed (local) state.
*
* If called from server side, the |settings_payload| must be the
* value received in ``HTTP2-Settings`` header field and must be
* decoded by base64url decoder. The |settings_payloadlen| is the
* length of |settings_payload|. It is treated as if the SETTINGS
* frame with that payload is received. Thus, callback functions for
* the reception of SETTINGS frame will be invoked. The stream with
* stream ID=1 is opened. The |stream_user_data| is ignored. The
* opened stream becomes half-closed (remote).
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* The |settings_payload| is badly formed.
* :enum:`NGHTTP2_ERR_PROTO`
* The stream ID 1 is already used or closed; or is not available.
*/
NGHTTP2_EXTERN int nghttp2_session_upgrade(nghttp2_session *session,
const uint8_t *settings_payload,
size_t settings_payloadlen,
void *stream_user_data);
/**
* @function
*
* Performs post-process of HTTP Upgrade request. This function can
* be called from both client and server, but the behavior is very
* different in each other.
*
* If called from client side, the |settings_payload| must be the
* value sent in ``HTTP2-Settings`` header field and must be decoded
* by base64url decoder. The |settings_payloadlen| is the length of
* |settings_payload|. The |settings_payload| is unpacked and its
* setting values will be submitted using `nghttp2_submit_settings()`.
* This means that the client application code does not need to submit
* SETTINGS by itself. The stream with stream ID=1 is opened and the
* |stream_user_data| is used for its stream_user_data. The opened
* stream becomes half-closed (local) state.
*
* If called from server side, the |settings_payload| must be the
* value received in ``HTTP2-Settings`` header field and must be
* decoded by base64url decoder. The |settings_payloadlen| is the
* length of |settings_payload|. It is treated as if the SETTINGS
* frame with that payload is received. Thus, callback functions for
* the reception of SETTINGS frame will be invoked. The stream with
* stream ID=1 is opened. The |stream_user_data| is ignored. The
* opened stream becomes half-closed (remote).
*
* If the request method is HEAD, pass nonzero value to
* |head_request|. Otherwise, pass 0.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* The |settings_payload| is badly formed.
* :enum:`NGHTTP2_ERR_PROTO`
* The stream ID 1 is already used or closed; or is not available.
*/
NGHTTP2_EXTERN int nghttp2_session_upgrade2(nghttp2_session *session,
const uint8_t *settings_payload,
size_t settings_payloadlen,
int head_request,
void *stream_user_data);
/**
* @function
*
* Serializes the SETTINGS values |iv| in the |buf|. The size of the
* |buf| is specified by |buflen|. The number of entries in the |iv|
* array is given by |niv|. The required space in |buf| for the |niv|
* entries is ``6*niv`` bytes and if the given buffer is too small, an
* error is returned. This function is used mainly for creating a
* SETTINGS payload to be sent with the ``HTTP2-Settings`` header
* field in an HTTP Upgrade request. The data written in |buf| is NOT
* base64url encoded and the application is responsible for encoding.
*
* This function returns the number of bytes written in |buf|, or one
* of the following negative error codes:
*
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* The |iv| contains duplicate settings ID or invalid value.
*
* :enum:`NGHTTP2_ERR_INSUFF_BUFSIZE`
* The provided |buflen| size is too small to hold the output.
*/
NGHTTP2_EXTERN ssize_t nghttp2_pack_settings_payload(
uint8_t *buf, size_t buflen, const nghttp2_settings_entry *iv, size_t niv);
/**
* @function
*
* Returns string describing the |lib_error_code|. The
* |lib_error_code| must be one of the :enum:`nghttp2_error`.
*/
NGHTTP2_EXTERN const char *nghttp2_strerror(int lib_error_code);
/**
* @function
*
* Returns string representation of HTTP/2 error code |error_code|
* (e.g., ``PROTOCOL_ERROR`` is returned if ``error_code ==
* NGHTTP2_PROTOCOL_ERROR``). If string representation is unknown for
* given |error_code|, this function returns string ``unknown``.
*/
NGHTTP2_EXTERN const char *nghttp2_http2_strerror(uint32_t error_code);
/**
* @function
*
* Initializes |pri_spec| with the |stream_id| of the stream to depend
* on with |weight| and its exclusive flag. If |exclusive| is
* nonzero, exclusive flag is set.
*
* The |weight| must be in [:enum:`NGHTTP2_MIN_WEIGHT`,
* :enum:`NGHTTP2_MAX_WEIGHT`], inclusive.
*/
NGHTTP2_EXTERN void nghttp2_priority_spec_init(nghttp2_priority_spec *pri_spec,
int32_t stream_id,
int32_t weight, int exclusive);
/**
* @function
*
* Initializes |pri_spec| with the default values. The default values
* are: stream_id = 0, weight = :macro:`NGHTTP2_DEFAULT_WEIGHT` and
* exclusive = 0.
*/
NGHTTP2_EXTERN void
nghttp2_priority_spec_default_init(nghttp2_priority_spec *pri_spec);
/**
* @function
*
* Returns nonzero if the |pri_spec| is filled with default values.
*/
NGHTTP2_EXTERN int
nghttp2_priority_spec_check_default(const nghttp2_priority_spec *pri_spec);
/**
* @function
*
* Submits HEADERS frame and optionally one or more DATA frames.
*
* The |pri_spec| is priority specification of this request. ``NULL``
* means the default priority (see
* `nghttp2_priority_spec_default_init()`). To specify the priority,
* use `nghttp2_priority_spec_init()`. If |pri_spec| is not ``NULL``,
* this function will copy its data members.
*
* The ``pri_spec->weight`` must be in [:enum:`NGHTTP2_MIN_WEIGHT`,
* :enum:`NGHTTP2_MAX_WEIGHT`], inclusive. If ``pri_spec->weight`` is
* strictly less than :enum:`NGHTTP2_MIN_WEIGHT`, it becomes
* :enum:`NGHTTP2_MIN_WEIGHT`. If it is strictly greater than
* :enum:`NGHTTP2_MAX_WEIGHT`, it becomes :enum:`NGHTTP2_MAX_WEIGHT`.
*
* The |nva| is an array of name/value pair :type:`nghttp2_nv` with
* |nvlen| elements. The application is responsible to include
* required pseudo-header fields (header field whose name starts with
* ":") in |nva| and must place pseudo-headers before regular header
* fields.
*
* This function creates copies of all name/value pairs in |nva|. It
* also lower-cases all names in |nva|. The order of elements in
* |nva| is preserved. For header fields with
* :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME` and
* :enum:`NGHTTP2_NV_FLAG_NO_COPY_VALUE` are set, header field name
* and value are not copied respectively. With
* :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME`, application is responsible to
* pass header field name in lowercase. The application should
* maintain the references to them until
* :type:`nghttp2_on_frame_send_callback` or
* :type:`nghttp2_on_frame_not_send_callback` is called.
*
* HTTP/2 specification has requirement about header fields in the
* request HEADERS. See the specification for more details.
*
* If |data_prd| is not ``NULL``, it provides data which will be sent
* in subsequent DATA frames. In this case, a method that allows
* request message bodies
* (https://tools.ietf.org/html/rfc7231#section-4) must be specified
* with ``:method`` key in |nva| (e.g. ``POST``). This function does
* not take ownership of the |data_prd|. The function copies the
* members of the |data_prd|. If |data_prd| is ``NULL``, HEADERS have
* END_STREAM set. The |stream_user_data| is data associated to the
* stream opened by this request and can be an arbitrary pointer,
* which can be retrieved later by
* `nghttp2_session_get_stream_user_data()`.
*
* This function returns assigned stream ID if it succeeds, or one of
* the following negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_STREAM_ID_NOT_AVAILABLE`
* No stream ID is available because maximum stream ID was
* reached.
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* Trying to depend on itself (new stream ID equals
* ``pri_spec->stream_id``).
* :enum:`NGHTTP2_ERR_PROTO`
* The |session| is server session.
*
* .. warning::
*
* This function returns assigned stream ID if it succeeds. But
* that stream is not opened yet. The application must not submit
* frame to that stream ID before
* :type:`nghttp2_before_frame_send_callback` is called for this
* frame.
*
*/
NGHTTP2_EXTERN int32_t nghttp2_submit_request(
nghttp2_session *session, const nghttp2_priority_spec *pri_spec,
const nghttp2_nv *nva, size_t nvlen, const nghttp2_data_provider *data_prd,
void *stream_user_data);
/**
* @function
*
* Submits response HEADERS frame and optionally one or more DATA
* frames against the stream |stream_id|.
*
* The |nva| is an array of name/value pair :type:`nghttp2_nv` with
* |nvlen| elements. The application is responsible to include
* required pseudo-header fields (header field whose name starts with
* ":") in |nva| and must place pseudo-headers before regular header
* fields.
*
* This function creates copies of all name/value pairs in |nva|. It
* also lower-cases all names in |nva|. The order of elements in
* |nva| is preserved. For header fields with
* :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME` and
* :enum:`NGHTTP2_NV_FLAG_NO_COPY_VALUE` are set, header field name
* and value are not copied respectively. With
* :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME`, application is responsible to
* pass header field name in lowercase. The application should
* maintain the references to them until
* :type:`nghttp2_on_frame_send_callback` or
* :type:`nghttp2_on_frame_not_send_callback` is called.
*
* HTTP/2 specification has requirement about header fields in the
* response HEADERS. See the specification for more details.
*
* If |data_prd| is not ``NULL``, it provides data which will be sent
* in subsequent DATA frames. This function does not take ownership
* of the |data_prd|. The function copies the members of the
* |data_prd|. If |data_prd| is ``NULL``, HEADERS will have
* END_STREAM flag set.
*
* This method can be used as normal HTTP response and push response.
* When pushing a resource using this function, the |session| must be
* configured using `nghttp2_session_server_new()` or its variants and
* the target stream denoted by the |stream_id| must be reserved using
* `nghttp2_submit_push_promise()`.
*
* To send non-final response headers (e.g., HTTP status 101), don't
* use this function because this function half-closes the outbound
* stream. Instead, use `nghttp2_submit_headers()` for this purpose.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* The |stream_id| is 0.
* :enum:`NGHTTP2_ERR_DATA_EXIST`
* DATA or HEADERS has been already submitted and not fully
* processed yet. Normally, this does not happen, but when
* application wrongly calls `nghttp2_submit_response()` twice,
* this may happen.
* :enum:`NGHTTP2_ERR_PROTO`
* The |session| is client session.
*
* .. warning::
*
* Calling this function twice for the same stream ID may lead to
* program crash. It is generally considered to a programming error
* to commit response twice.
*/
NGHTTP2_EXTERN int
nghttp2_submit_response(nghttp2_session *session, int32_t stream_id,
const nghttp2_nv *nva, size_t nvlen,
const nghttp2_data_provider *data_prd);
/**
* @function
*
* Submits trailer fields HEADERS against the stream |stream_id|.
*
* The |nva| is an array of name/value pair :type:`nghttp2_nv` with
* |nvlen| elements. The application is responsible not to include
* pseudo-header fields (header field whose name starts with ":") in
* |nva|.
*
* This function creates copies of all name/value pairs in |nva|. It
* also lower-cases all names in |nva|. The order of elements in
* |nva| is preserved. For header fields with
* :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME` and
* :enum:`NGHTTP2_NV_FLAG_NO_COPY_VALUE` are set, header field name
* and value are not copied respectively. With
* :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME`, application is responsible to
* pass header field name in lowercase. The application should
* maintain the references to them until
* :type:`nghttp2_on_frame_send_callback` or
* :type:`nghttp2_on_frame_not_send_callback` is called.
*
* For server, trailer fields must follow response HEADERS or response
* DATA without END_STREAM flat set. The library does not enforce
* this requirement, and applications should do this for themselves.
* If `nghttp2_submit_trailer()` is called before any response HEADERS
* submission (usually by `nghttp2_submit_response()`), the content of
* |nva| will be sent as response headers, which will result in error.
*
* This function has the same effect with `nghttp2_submit_headers()`,
* with flags = :enum:`NGHTTP2_FLAG_END_STREAM` and both pri_spec and
* stream_user_data to NULL.
*
* To submit trailer fields after `nghttp2_submit_response()` is
* called, the application has to specify
* :type:`nghttp2_data_provider` to `nghttp2_submit_response()`.
* Inside of :type:`nghttp2_data_source_read_callback`, when setting
* :enum:`NGHTTP2_DATA_FLAG_EOF`, also set
* :enum:`NGHTTP2_DATA_FLAG_NO_END_STREAM`. After that, the
* application can send trailer fields using
* `nghttp2_submit_trailer()`. `nghttp2_submit_trailer()` can be used
* inside :type:`nghttp2_data_source_read_callback`.
*
* This function returns 0 if it succeeds and |stream_id| is -1.
* Otherwise, this function returns 0 if it succeeds, or one of the
* following negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* The |stream_id| is 0.
*/
NGHTTP2_EXTERN int nghttp2_submit_trailer(nghttp2_session *session,
int32_t stream_id,
const nghttp2_nv *nva, size_t nvlen);
/**
* @function
*
* Submits HEADERS frame. The |flags| is bitwise OR of the
* following values:
*
* * :enum:`NGHTTP2_FLAG_END_STREAM`
*
* If |flags| includes :enum:`NGHTTP2_FLAG_END_STREAM`, this frame has
* END_STREAM flag set.
*
* The library handles the CONTINUATION frame internally and it
* correctly sets END_HEADERS to the last sequence of the PUSH_PROMISE
* or CONTINUATION frame.
*
* If the |stream_id| is -1, this frame is assumed as request (i.e.,
* request HEADERS frame which opens new stream). In this case, the
* assigned stream ID will be returned. Otherwise, specify stream ID
* in |stream_id|.
*
* The |pri_spec| is priority specification of this request. ``NULL``
* means the default priority (see
* `nghttp2_priority_spec_default_init()`). To specify the priority,
* use `nghttp2_priority_spec_init()`. If |pri_spec| is not ``NULL``,
* this function will copy its data members.
*
* The ``pri_spec->weight`` must be in [:enum:`NGHTTP2_MIN_WEIGHT`,
* :enum:`NGHTTP2_MAX_WEIGHT`], inclusive. If ``pri_spec->weight`` is
* strictly less than :enum:`NGHTTP2_MIN_WEIGHT`, it becomes
* :enum:`NGHTTP2_MIN_WEIGHT`. If it is strictly greater than
* :enum:`NGHTTP2_MAX_WEIGHT`, it becomes :enum:`NGHTTP2_MAX_WEIGHT`.
*
* The |nva| is an array of name/value pair :type:`nghttp2_nv` with
* |nvlen| elements. The application is responsible to include
* required pseudo-header fields (header field whose name starts with
* ":") in |nva| and must place pseudo-headers before regular header
* fields.
*
* This function creates copies of all name/value pairs in |nva|. It
* also lower-cases all names in |nva|. The order of elements in
* |nva| is preserved. For header fields with
* :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME` and
* :enum:`NGHTTP2_NV_FLAG_NO_COPY_VALUE` are set, header field name
* and value are not copied respectively. With
* :enum:`NGHTTP2_NV_FLAG_NO_COPY_NAME`, application is responsible to
* pass header field name in lowercase. The application should
* maintain the references to them until
* :type:`nghttp2_on_frame_send_callback` or
* :type:`nghttp2_on_frame_not_send_callback` is called.
*
* The |stream_user_data| is a pointer to an arbitrary data which is
* associated to the stream this frame will open. Therefore it is
* only used if this frame opens streams, in other words, it changes
* stream state from idle or reserved to open.
*
* This function is low-level in a sense that the application code can
* specify flags directly. For usual HTTP request,
* `nghttp2_submit_request()` is useful. Likewise, for HTTP response,
* prefer `nghttp2_submit_response()`.
*
* This function returns newly assigned stream ID if it succeeds and
* |stream_id| is -1. Otherwise, this function returns 0 if it
* succeeds, or one of the following negative error codes:
*
* :enum:`NGHTTP2_ERR_NOMEM`
* Out of memory.
* :enum:`NGHTTP2_ERR_STREAM_ID_NOT_AVAILABLE`
* No stream ID is available because maximum stream ID was
* reached.
* :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
* The |stream_id| is 0; or trying to depend on itself (stream ID
* equals ``pri_spec->stream_id``).
* :enum:`NGHTTP2_ERR_DATA_EXIST`
* DATA or HEADERS has been already submitted and not fully
* processed yet. This happens if stream denoted by |stream_id|
* is in reserved state.
* :enum:`NGHTTP2_ERR_PROTO`
* The |stream_id| is -1, and |session| is server session.
*
* .. warning::
*
* This function returns assigned stream ID if it succeeds and
* |stream_id| is -1. But that stream is not opened yet. The
* application must not submit frame to that stream ID before
* :type:`nghttp2_before_frame_send_callback` is called for this
* frame.
*
*/
NGHTTP2_EXTERN int32_t nghttp2_submit_headers(
nghttp2_session *session, uint8_t flags, int32_t stream_id,
const nghttp2_priority_spec *pri_spec, const nghttp2_nv *nva, size_t nvlen,
void *stream_user_data);
/**
* @function
*
* Submits one or more DATA frames to the stream |stream_id|. The
* data to be sent are provided by |data_prd|. If |flags| contains
* :enum:`NGHTTP2_FLAG_END_STREAM`, the last DATA frame has END_STREAM
* flag set.