/*
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_EVENT_QUIC_WIRE_H_INCLUDED_
#define _NGX_EVENT_QUIC_WIRE_H_INCLUDED_


#include <ngx_event_openssl.h>


#define ngx_quic_long_pkt(flags)  ((flags) & 0x80)            /* 17.2   */
#define ngx_quic_short_pkt(flags) (((flags) & 0x80) == 0)     /* 17.3   */

/* Long packet types */
#define NGX_QUIC_PKT_INITIAL                             0xC0 /* 17.2.2 */
#define NGX_QUIC_PKT_ZRTT                                0xD0 /* 17.2.3 */
#define NGX_QUIC_PKT_HANDSHAKE                           0xE0 /* 17.2.4 */
#define NGX_QUIC_PKT_RETRY                               0xF0 /* 17.2.5 */

#define ngx_quic_pkt_in(flags)     (((flags) & 0xF0) == NGX_QUIC_PKT_INITIAL)
#define ngx_quic_pkt_zrtt(flags)   (((flags) & 0xF0) == NGX_QUIC_PKT_ZRTT)
#define ngx_quic_pkt_hs(flags)     (((flags) & 0xF0) == NGX_QUIC_PKT_HANDSHAKE)
#define ngx_quic_pkt_retry(flags)  (((flags) & 0xF0) == NGX_QUIC_PKT_RETRY)

/* 12.4.  Frames and Frame Types */
#define NGX_QUIC_FT_PADDING                              0x00
#define NGX_QUIC_FT_PING                                 0x01
#define NGX_QUIC_FT_ACK                                  0x02
#define NGX_QUIC_FT_ACK_ECN                              0x03
#define NGX_QUIC_FT_RESET_STREAM                         0x04
#define NGX_QUIC_FT_STOP_SENDING                         0x05
#define NGX_QUIC_FT_CRYPTO                               0x06
#define NGX_QUIC_FT_NEW_TOKEN                            0x07
#define NGX_QUIC_FT_STREAM0                              0x08
#define NGX_QUIC_FT_STREAM1                              0x09
#define NGX_QUIC_FT_STREAM2                              0x0A
#define NGX_QUIC_FT_STREAM3                              0x0B
#define NGX_QUIC_FT_STREAM4                              0x0C
#define NGX_QUIC_FT_STREAM5                              0x0D
#define NGX_QUIC_FT_STREAM6                              0x0E
#define NGX_QUIC_FT_STREAM7                              0x0F
#define NGX_QUIC_FT_MAX_DATA                             0x10
#define NGX_QUIC_FT_MAX_STREAM_DATA                      0x11
#define NGX_QUIC_FT_MAX_STREAMS                          0x12
#define NGX_QUIC_FT_MAX_STREAMS2                         0x13
#define NGX_QUIC_FT_DATA_BLOCKED                         0x14
#define NGX_QUIC_FT_STREAM_DATA_BLOCKED                  0x15
#define NGX_QUIC_FT_STREAMS_BLOCKED                      0x16
#define NGX_QUIC_FT_STREAMS_BLOCKED2                     0x17
#define NGX_QUIC_FT_NEW_CONNECTION_ID                    0x18
#define NGX_QUIC_FT_RETIRE_CONNECTION_ID                 0x19
#define NGX_QUIC_FT_PATH_CHALLENGE                       0x1A
#define NGX_QUIC_FT_PATH_RESPONSE                        0x1B
#define NGX_QUIC_FT_CONNECTION_CLOSE                     0x1C
#define NGX_QUIC_FT_CONNECTION_CLOSE2                    0x1D
#define NGX_QUIC_FT_HANDSHAKE_DONE                       0x1E

/* 22.4.  QUIC Transport Error Codes Registry */
#define NGX_QUIC_ERR_NO_ERROR                            0x00
#define NGX_QUIC_ERR_INTERNAL_ERROR                      0x01
#define NGX_QUIC_ERR_SERVER_BUSY                         0x02
#define NGX_QUIC_ERR_FLOW_CONTROL_ERROR                  0x03
#define NGX_QUIC_ERR_STREAM_LIMIT_ERROR                  0x04
#define NGX_QUIC_ERR_STREAM_STATE_ERROR                  0x05
#define NGX_QUIC_ERR_FINAL_SIZE_ERROR                    0x06
#define NGX_QUIC_ERR_FRAME_ENCODING_ERROR                0x07
#define NGX_QUIC_ERR_TRANSPORT_PARAMETER_ERROR           0x08
#define NGX_QUIC_ERR_CONNECTION_ID_LIMIT_ERROR           0x09
#define NGX_QUIC_ERR_PROTOCOL_VIOLATION                  0x0A
#define NGX_QUIC_ERR_INVALID_TOKEN                       0x0B
/* 0xC is not defined */
#define NGX_QUIC_ERR_CRYPTO_BUFFER_EXCEEDED              0x0D
/* 0xE is not defined */
#define NGX_QUIC_ERR_CRYPTO_ERROR                        0x10

#define NGX_QUIC_ERR_LAST  NGX_QUIC_ERR_CRYPTO_ERROR

/* Transport parameters */
#define NGX_QUIC_TP_ORIGINAL_CONNECTION_ID               0x00
#define NGX_QUIC_TP_MAX_IDLE_TIMEOUT                     0x01
#define NGX_QUIC_TP_STATELESS_RESET_TOKEN                0x02
#define NGX_QUIC_TP_MAX_PACKET_SIZE                      0x03
#define NGX_QUIC_TP_INITIAL_MAX_DATA                     0x04
#define NGX_QUIC_TP_INITIAL_MAX_STREAM_DATA_BIDI_LOCAL   0x05
#define NGX_QUIC_TP_INITIAL_MAX_STREAM_DATA_BIDI_REMOTE  0x06
#define NGX_QUIC_TP_INITIAL_MAX_STREAM_DATA_UNI          0x07
#define NGX_QUIC_TP_INITIAL_MAX_STREAMS_BIDI             0x08
#define NGX_QUIC_TP_INITIAL_MAX_STREAMS_UNI              0x09
#define NGX_QUIC_TP_ACK_DELAY_EXPONENT                   0x0A
#define NGX_QUIC_TP_MAX_ACK_DELAY                        0x0B
#define NGX_QUIC_TP_DISABLE_ACTIVE_MIGRATION             0x0C
#define NGX_QUIC_TP_PREFERRED_ADDRESS                    0x0D
#define NGX_QUIC_TP_ACTIVE_CONNECTION_ID_LIMIT           0x0E


typedef struct {
    ngx_uint_t                                  pn;
    uint64_t                                    largest;
    uint64_t                                    delay;
    uint64_t                                    range_count;
    uint64_t                                    first_range;
    uint64_t                                    ranges[20];
    /* TODO: ecn counts */
} ngx_quic_ack_frame_t;


typedef struct {
    uint64_t                                    offset;
    uint64_t                                    len;
    u_char                                     *data;
} ngx_quic_crypto_frame_t;


typedef struct {
    uint64_t                                    seqnum;
    uint64_t                                    retire;
    uint8_t                                     len;
    u_char                                      cid[20];
    u_char                                      srt[16];
} ngx_quic_new_conn_id_frame_t;


typedef struct {
    uint8_t                                     type;
    uint64_t                                    stream_id;
    uint64_t                                    offset;
    uint64_t                                    length;
    unsigned                                    off:1;
    unsigned                                    len:1;
    unsigned                                    fin:1;
    u_char                                     *data;
} ngx_quic_stream_frame_t;


typedef struct {
    uint64_t                                    max_data;
} ngx_quic_max_data_frame_t;


typedef struct {
    uint64_t                                    error_code;
    uint64_t                                    frame_type;
    ngx_str_t                                   reason;
} ngx_quic_close_frame_t;


typedef struct {
    uint64_t                                    id;
    uint64_t                                    error_code;
    uint64_t                                    final_size;
} ngx_quic_reset_stream_frame_t;


typedef struct {
    uint64_t                                    id;
    uint64_t                                    error_code;
} ngx_quic_stop_sending_frame_t;


typedef struct {
    uint64_t                                    limit;
    ngx_uint_t                                  bidi;  /* unsigned: bidi:1 */
} ngx_quic_streams_blocked_frame_t;


typedef struct {
    uint64_t                                    limit;
    ngx_uint_t                                  bidi;  /* unsigned: bidi:1 */
} ngx_quic_max_streams_frame_t;


typedef struct {
    uint64_t                                    id;
    uint64_t                                    limit;
} ngx_quic_max_stream_data_frame_t;


typedef struct {
    uint64_t                                    limit;
} ngx_quic_data_blocked_frame_t;


typedef struct {
    uint64_t                                    id;
    uint64_t                                    limit;
} ngx_quic_stream_data_blocked_frame_t;


typedef struct {
    uint64_t                                    sequence_number;
} ngx_quic_retire_cid_frame_t;


typedef struct {
    u_char                                      data[8];
} ngx_quic_path_challenge_frame_t;


typedef struct ngx_quic_frame_s                 ngx_quic_frame_t;

struct ngx_quic_frame_s {
    ngx_uint_t                                  type;
    enum ssl_encryption_level_t                 level;
    ngx_quic_frame_t                           *next;
    union {
        ngx_quic_ack_frame_t                    ack;
        ngx_quic_crypto_frame_t                 crypto;
        ngx_quic_new_conn_id_frame_t            ncid;
        ngx_quic_stream_frame_t                 stream;
        ngx_quic_max_data_frame_t               max_data;
        ngx_quic_close_frame_t                  close;
        ngx_quic_reset_stream_frame_t           reset_stream;
        ngx_quic_stop_sending_frame_t           stop_sending;
        ngx_quic_streams_blocked_frame_t        streams_blocked;
        ngx_quic_max_streams_frame_t            max_streams;
        ngx_quic_max_stream_data_frame_t        max_stream_data;
        ngx_quic_data_blocked_frame_t           data_blocked;
        ngx_quic_stream_data_blocked_frame_t    stream_data_blocked;
        ngx_quic_retire_cid_frame_t             retire_cid;
        ngx_quic_path_challenge_frame_t         path_challenge;
        ngx_quic_path_challenge_frame_t         path_response;
    } u;
    u_char                                      info[128]; // for debug
};


typedef struct {
    ngx_log_t                                  *log;

    struct ngx_quic_secret_s                   *secret;
    ngx_uint_t                                  type;
    ngx_uint_t                                 *number;
    uint8_t                                     flags;
    uint32_t                                    version;
    ngx_str_t                                   token;
    enum ssl_encryption_level_t                 level;

    /* filled in by parser */
    ngx_buf_t                                  *raw;   /* udp datagram */

    u_char                                     *data;  /* quic packet */
    size_t                                      len;

    /* cleartext fields */
    ngx_str_t                                   dcid;
    ngx_str_t                                   scid;
    uint64_t                                    pn;
    ngx_str_t                                   payload;  /* decrypted */
} ngx_quic_header_t;


u_char *ngx_quic_error_text(uint64_t error_code);

ngx_int_t ngx_quic_parse_long_header(ngx_quic_header_t *pkt);
size_t ngx_quic_create_long_header(ngx_quic_header_t *pkt, ngx_str_t *out,
    size_t pkt_len, u_char **pnp);

ngx_int_t ngx_quic_parse_short_header(ngx_quic_header_t *pkt,
    ngx_str_t *dcid);
ngx_int_t ngx_quic_parse_initial_header(ngx_quic_header_t *pkt);
ngx_int_t ngx_quic_parse_handshake_header(ngx_quic_header_t *pkt);

ssize_t ngx_quic_parse_frame(ngx_quic_header_t *pkt, u_char *start, u_char *end,
    ngx_quic_frame_t *frame);
ssize_t ngx_quic_create_frame(u_char *p, u_char *end, ngx_quic_frame_t *f);

ngx_int_t ngx_quic_parse_transport_params(u_char *p, u_char *end,
    ngx_quic_tp_t *tp, ngx_log_t *log);
ssize_t ngx_quic_create_transport_params(u_char *p, u_char *end,
    ngx_quic_tp_t *tp);

#endif /* _NGX_EVENT_QUIC_WIRE_H_INCLUDED_ */