lsquic_trans_params.h revision 692a9102 
1/* Copyright (c) 2017 - 2020 LiteSpeed Technologies Inc.  See LICENSE. */
2/*
3 * lsquic_trans_params.h -- Transport parameters types and functions.
4 */
5
6#ifndef LSQUIC_TRANS_PARAMS_H
7#define LSQUIC_TRANS_PARAMS_H 1
8
9/* Transport parameters are grouped by the type of their values: numeric,
10 * empty, and custom.
11 *
12 * The enum values are arbitrary.  The literal transport parameter ID
13 * *values* (e.g. 0x1057 for loss bits) are not exposed by the API.
14 */
15enum transport_param_id
16{
17    /*
18     * Numeric transport parameters that have default values:
19     */
20    TPI_MAX_IDLE_TIMEOUT,
21    TPI_MAX_UDP_PAYLOAD_SIZE,
22    TPI_INIT_MAX_DATA,
23    TPI_INIT_MAX_STREAM_DATA_BIDI_LOCAL,
24    TPI_INIT_MAX_STREAM_DATA_BIDI_REMOTE,
25    TPI_INIT_MAX_STREAM_DATA_UNI,
26    TPI_INIT_MAX_STREAMS_BIDI,
27    TPI_INIT_MAX_STREAMS_UNI,
28    TPI_ACK_DELAY_EXPONENT,
29    TPI_MAX_ACK_DELAY,
30    TPI_ACTIVE_CONNECTION_ID_LIMIT,         MAX_NUM_WITH_DEF_TPI = TPI_ACTIVE_CONNECTION_ID_LIMIT,
31
32    /*
33     * Numeric transport parameters without default values:
34     */
35    TPI_MIN_ACK_DELAY,
36    TPI_LOSS_BITS,                          MAX_NUMERIC_TPI = TPI_LOSS_BITS,
37
38    /*
39     * Empty transport parameters:
40     */
41    TPI_TIMESTAMPS,
42    TPI_GREASE_QUIC_BIT,
43    TPI_DISABLE_ACTIVE_MIGRATION,           MAX_EMPTY_TPI = TPI_DISABLE_ACTIVE_MIGRATION,
44
45    /*
46     * Custom handlers:
47     */
48    TPI_PREFERRED_ADDRESS,
49        /* CIDs must be in a contiguous range for tp_cids array to work */
50#define FIRST_TP_CID TPI_ORIGINAL_DEST_CID
51    TPI_ORIGINAL_DEST_CID,
52    TPI_INITIAL_SOURCE_CID,
53#define LAST_TP_CID TPI_RETRY_SOURCE_CID
54    TPI_RETRY_SOURCE_CID,
55#if LSQUIC_TEST_QUANTUM_READINESS
56    /* https://github.com/quicwg/base-drafts/wiki/Quantum-Readiness-test */
57#define QUANTUM_READY_SZ 1200
58    TPI_QUANTUM_READINESS,
59#endif
60    TPI_STATELESS_RESET_TOKEN,              LAST_TPI = TPI_STATELESS_RESET_TOKEN
61};
62
63#define TP_CID_IDX(tpi_) ((tpi_) - FIRST_TP_CID)
64
65
66struct transport_params
67{
68    /* Which transport parameters values are set: */
69    unsigned                tp_set;
70
71    /* Which transport parameters were present (set by the decoder): */
72    unsigned                tp_decoded;
73
74    uint64_t                tp_numerics[MAX_NUMERIC_TPI + 1];
75
76#define tp_init_max_stream_data_bidi_local  tp_numerics[TPI_INIT_MAX_STREAM_DATA_BIDI_LOCAL]
77#define tp_init_max_stream_data_bidi_remote tp_numerics[TPI_INIT_MAX_STREAM_DATA_BIDI_REMOTE]
78#define tp_init_max_stream_data_uni         tp_numerics[TPI_INIT_MAX_STREAM_DATA_UNI]
79#define tp_init_max_data                    tp_numerics[TPI_INIT_MAX_DATA]
80#define tp_max_idle_timeout                 tp_numerics[TPI_MAX_IDLE_TIMEOUT]
81#define tp_init_max_streams_bidi            tp_numerics[TPI_INIT_MAX_STREAMS_BIDI]
82#define tp_init_max_streams_uni             tp_numerics[TPI_INIT_MAX_STREAMS_UNI]
83#define tp_max_udp_payload_size             tp_numerics[TPI_MAX_UDP_PAYLOAD_SIZE]
84#define tp_ack_delay_exponent               tp_numerics[TPI_ACK_DELAY_EXPONENT]
85#define tp_max_ack_delay                    tp_numerics[TPI_MAX_ACK_DELAY]
86#define tp_active_connection_id_limit       tp_numerics[TPI_ACTIVE_CONNECTION_ID_LIMIT]
87#define tp_loss_bits                        tp_numerics[TPI_LOSS_BITS]
88
89    uint8_t     tp_stateless_reset_token[IQUIC_SRESET_TOKEN_SZ];
90    struct {
91        uint8_t         ipv4_addr[4];
92        uint16_t        ipv4_port;
93        uint8_t         ipv6_addr[16];
94        uint16_t        ipv6_port;
95        lsquic_cid_t    cid;
96        uint8_t         srst[IQUIC_SRESET_TOKEN_SZ];
97    }           tp_preferred_address;
98    lsquic_cid_t    tp_cids[3];
99#define tp_original_dest_cid tp_cids[TP_CID_IDX(TPI_ORIGINAL_DEST_CID)]
100#define tp_initial_source_cid tp_cids[TP_CID_IDX(TPI_INITIAL_SOURCE_CID)]
101#define tp_retry_source_cid tp_cids[TP_CID_IDX(TPI_RETRY_SOURCE_CID)]
102};
103
104#define MAX_TP_STR_SZ ((LAST_TPI + 1) *                                     \
105    (34 /* longest entry in tt2str */ + 2 /* semicolon */ + 2 /* colon */)  \
106  + INET_ADDRSTRLEN + INET6_ADDRSTRLEN + 5 /* Port */ * 2                   \
107  + MAX_CID_LEN * 2 * 4 /* there are four CIDs */                           \
108  + 11 * (MAX_NUMERIC_TPI + 1)                                              \
109  + IQUIC_SRESET_TOKEN_SZ * 2 * 2 /* there are two reset tokens */)
110
111#define TP_DEF_MAX_UDP_PAYLOAD_SIZE 65527
112#define TP_DEF_ACK_DELAY_EXP 3
113#define TP_DEF_INIT_MAX_STREAMS_UNI 0
114#define TP_DEF_INIT_MAX_STREAMS_BIDI 0
115#define TP_DEF_INIT_MAX_DATA 0
116#define TP_DEF_DISABLE_ACTIVE_MIGRATION 0
117#define TP_DEF_INIT_MAX_STREAM_DATA_BIDI_LOCAL 0
118#define TP_DEF_INIT_MAX_STREAM_DATA_BIDI_REMOTE 0
119#define TP_DEF_INIT_MAX_STREAM_DATA_UNI 0
120#define TP_DEF_MAX_IDLE_TIMEOUT 0
121#define TP_DEF_MAX_ACK_DELAY 25
122#define TP_DEF_ACTIVE_CONNECTION_ID_LIMIT 2
123
124/* [draft-ietf-quic-transport-18], Section 18.1 */
125#define TP_MAX_MAX_ACK_DELAY ((1u << 14) - 1)
126
127#define TP_DEFAULT_VALUES                                                             \
128    .tp_set = ((1 << (MAX_NUM_WITH_DEF_TPI + 1)) - 1),                                \
129    .tp_active_connection_id_limit        =  TP_DEF_ACTIVE_CONNECTION_ID_LIMIT,       \
130    .tp_max_idle_timeout                  =  TP_DEF_MAX_IDLE_TIMEOUT,                 \
131    .tp_max_ack_delay                     =  TP_DEF_MAX_ACK_DELAY,                    \
132    .tp_max_udp_payload_size              =  TP_DEF_MAX_UDP_PAYLOAD_SIZE,             \
133    .tp_ack_delay_exponent                =  TP_DEF_ACK_DELAY_EXP,                    \
134    .tp_init_max_streams_bidi             =  TP_DEF_INIT_MAX_STREAMS_BIDI,            \
135    .tp_init_max_streams_uni              =  TP_DEF_INIT_MAX_STREAMS_UNI,             \
136    .tp_init_max_data                     =  TP_DEF_INIT_MAX_DATA,                    \
137    .tp_init_max_stream_data_bidi_local   =  TP_DEF_INIT_MAX_STREAM_DATA_BIDI_LOCAL,  \
138    .tp_init_max_stream_data_bidi_remote  =  TP_DEF_INIT_MAX_STREAM_DATA_BIDI_REMOTE, \
139    .tp_init_max_stream_data_uni          =  TP_DEF_INIT_MAX_STREAM_DATA_UNI
140
141#define TP_INITIALIZER() (struct transport_params) { TP_DEFAULT_VALUES }
142
143int
144lsquic_tp_encode (const struct transport_params *, int is_server,
145                  unsigned char *const buf, size_t bufsz);
146
147int
148lsquic_tp_decode (const unsigned char *const buf, size_t bufsz,
149    /* This argument specifies whose transport parameters we are parsing.  If
150     * true, we are parsing parameters sent by the server; if false, we are
151     * parsing parameteres sent by the client.
152     */
153                  int is_server,
154                  struct transport_params *);
155
156void
157lsquic_tp_to_str (const struct transport_params *params, char *buf, size_t sz);
158
159int
160lsquic_tp_encode_27 (const struct transport_params *, int is_server,
161                  unsigned char *const buf, size_t bufsz);
162
163int
164lsquic_tp_decode_27 (const unsigned char *const buf, size_t bufsz,
165                  int is_server,
166                  struct transport_params *);
167
168void
169lsquic_tp_to_str_27 (const struct transport_params *params, char *buf, size_t sz);
170
171int
172lsquic_tp_has_pref_ipv4 (const struct transport_params *);
173
174int
175lsquic_tp_has_pref_ipv6 (const struct transport_params *);
176
177extern const char * const lsquic_tpi2str[LAST_TPI + 1];
178
179#endif
180