lsquic_parse.h revision 9626cfc2 
1/* Copyright (c) 2017 - 2018 LiteSpeed Technologies Inc.  See LICENSE. */
2#ifndef LSQUIC_PARSE_H
3#define LSQUIC_PARSE_H 1
4
5#include <stdint.h>
6
7#include "lsquic_packet_common.h"
8
9struct lsquic_packet_in;
10struct lsquic_packet_out;
11struct packin_parse_state;
12struct stream_frame;
13enum packet_out_flags;
14
15#define LSQUIC_PARSE_ACK_TIMESTAMPS 0
16
17typedef struct ack_info
18{
19    unsigned    n_timestamps;   /* 0 to 255 */
20    unsigned    n_ranges;       /* This is at least 1 */
21                                /* Largest acked is ack_info.ranges[0].high */
22    lsquic_time_t   lack_delta;
23    struct lsquic_packno_range ranges[256];
24#if LSQUIC_PARSE_ACK_TIMESTAMPS
25    struct {
26        /* Currently we just read these timestamps in (assuming it is
27         * compiled in, of course), but do not do anything with them.
28         * When we do, the representation of these fields should be
29         * switched to whatever is most appropriate/efficient.
30         */
31        unsigned char   packet_delta;
32        uint64_t        delta_usec;
33    }           timestamps[255];
34#endif
35} ack_info_t;
36
37struct short_ack_info
38{
39    unsigned                    sai_n_timestamps;
40    lsquic_time_t               sai_lack_delta;
41    struct lsquic_packno_range  sai_range;
42};
43
44#define largest_acked(acki) (+(acki)->ranges[0].high)
45
46#define smallest_acked(acki) (+(acki)->ranges[(acki)->n_ranges - 1].low)
47
48/* gaf_: generate ACK frame */
49struct lsquic_packno_range;
50typedef const struct lsquic_packno_range *
51    (*gaf_rechist_first_f)          (void *rechist);
52typedef const struct lsquic_packno_range *
53    (*gaf_rechist_next_f)           (void *rechist);
54typedef lsquic_time_t
55    (*gaf_rechist_largest_recv_f)   (void *rechist);
56
57/* gsf_: generate stream frame */
58typedef size_t (*gsf_read_f) (void *stream, void *buf, size_t len, int *fin);
59
60/* This structure contains functions that parse and generate packets and
61 * frames in version-specific manner.  To begin with, there is difference
62 * between GQUIC's little-endian (Q038 and lower) and big-endian formats
63 * (Q039 and higher).  Q044 uses different format for packet headers.
64 */
65struct parse_funcs
66{
67    /* Return buf length */
68    int
69    (*pf_gen_reg_pkt_header) (const struct lsquic_conn *,
70                const struct lsquic_packet_out *, unsigned char *, size_t);
71    void
72    (*pf_parse_packet_in_finish) (struct lsquic_packet_in *packet_in,
73                                                struct packin_parse_state *);
74    enum QUIC_FRAME_TYPE
75    (*pf_parse_frame_type) (unsigned char);
76    /* Return used buffer length */
77    int
78    (*pf_gen_stream_frame) (unsigned char *buf, size_t bufsz,
79                            uint32_t stream_id, uint64_t offset,
80                            int fin, size_t size, gsf_read_f, void *stream);
81    int
82    (*pf_parse_stream_frame) (const unsigned char *buf, size_t rem_packet_sz,
83                                                    struct stream_frame *);
84    int
85    (*pf_parse_ack_frame) (const unsigned char *buf, size_t buf_len,
86                                                    ack_info_t *ack_info);
87    int
88    (*pf_gen_ack_frame) (unsigned char *outbuf, size_t outbuf_sz,
89                gaf_rechist_first_f, gaf_rechist_next_f,
90                gaf_rechist_largest_recv_f, void *rechist, lsquic_time_t now,
91                int *has_missing, lsquic_packno_t *largest_received);
92    int
93    (*pf_gen_stop_waiting_frame) (unsigned char *buf, size_t buf_len,
94                    lsquic_packno_t cur_packno, enum lsquic_packno_bits,
95                    lsquic_packno_t least_unacked_packno);
96    int
97    (*pf_parse_stop_waiting_frame) (const unsigned char *buf, size_t buf_len,
98                     lsquic_packno_t cur_packno, enum lsquic_packno_bits,
99                     lsquic_packno_t *least_unacked);
100    int
101    (*pf_skip_stop_waiting_frame) (size_t buf_len, enum lsquic_packno_bits);
102    int
103    (*pf_gen_window_update_frame) (unsigned char *buf, int buf_len,
104                                    uint32_t stream_id, uint64_t offset);
105    int
106    (*pf_parse_window_update_frame) (const unsigned char *buf, size_t buf_len,
107                                      uint32_t *stream_id, uint64_t *offset);
108    int
109    (*pf_gen_blocked_frame) (unsigned char *buf, size_t buf_len,
110                                                        uint32_t stream_id);
111    int
112    (*pf_parse_blocked_frame) (const unsigned char *buf, size_t buf_len,
113                                                        uint32_t *stream_id);
114    int
115    (*pf_gen_rst_frame) (unsigned char *buf, size_t buf_len, uint32_t stream_id,
116                          uint64_t offset, uint32_t error_code);
117    int
118    (*pf_parse_rst_frame) (const unsigned char *buf, size_t buf_len,
119                uint32_t *stream_id, uint64_t *offset, uint32_t *error_code);
120    int
121    (*pf_gen_connect_close_frame) (unsigned char *buf, int buf_len,
122                uint32_t error_code, const char *reason, int reason_len);
123    int
124    (*pf_parse_connect_close_frame) (const unsigned char *buf, size_t buf_len,
125                uint32_t *error_code, uint16_t *reason_length,
126                uint8_t *reason_offset);
127    int
128    (*pf_gen_goaway_frame) (unsigned char *buf, size_t buf_len,
129                uint32_t error_code, uint32_t last_good_stream_id,
130                const char *reason, size_t reason_len);
131    int
132    (*pf_parse_goaway_frame) (const unsigned char *buf, size_t buf_len,
133                uint32_t *error_code, uint32_t *last_good_stream_id,
134                uint16_t *reason_length, const char **reason);
135    int
136    (*pf_gen_ping_frame) (unsigned char *buf, int buf_len);
137#ifndef NDEBUG
138    /* These float reading and writing functions assume `mem' has at least
139     * 2 bytes.
140     */
141    void
142    (*pf_write_float_time16) (lsquic_time_t time_us, void *mem);
143    uint64_t
144    (*pf_read_float_time16) (const void *mem);
145#endif
146    size_t
147    (*pf_calc_stream_frame_header_sz) (uint32_t stream_id, uint64_t offset);
148    void
149    (*pf_turn_on_fin) (unsigned char *);
150
151    size_t
152    (*pf_packout_size) (const struct lsquic_conn *,
153                                            const struct lsquic_packet_out *);
154
155    size_t
156    (*pf_packout_header_size) (const struct lsquic_conn *,
157                                            enum packet_out_flags);
158};
159
160extern const struct parse_funcs lsquic_parse_funcs_gquic_le;
161/* Q039 and later are big-endian: */
162extern const struct parse_funcs lsquic_parse_funcs_gquic_Q039;
163extern const struct parse_funcs lsquic_parse_funcs_gquic_Q044;
164
165#define select_pf_by_ver(ver) (                                         \
166    ((1 << (ver)) & (1 << LSQVER_035))                                  \
167        ? &lsquic_parse_funcs_gquic_le                                  \
168        : (ver) < LSQVER_044                                            \
169        ? &lsquic_parse_funcs_gquic_Q039                                \
170        : &lsquic_parse_funcs_gquic_Q044)
171
172int
173lsquic_gquic_parse_packet_in_begin (struct lsquic_packet_in *, size_t length,
174                                int is_server, struct packin_parse_state *);
175
176int
177lsquic_iquic_parse_packet_in_long_begin (struct lsquic_packet_in *,
178            size_t length, int is_server, struct packin_parse_state *state);
179
180int
181lsquic_iquic_parse_packet_in_short_begin (struct lsquic_packet_in *,
182            size_t length, int is_server, struct packin_parse_state *state);
183
184enum QUIC_FRAME_TYPE
185parse_frame_type_gquic_Q035_thru_Q039 (unsigned char first_byte);
186
187size_t
188calc_stream_frame_header_sz_gquic (uint32_t stream_id, uint64_t offset);
189
190size_t
191lsquic_gquic_packout_size (const struct lsquic_conn *,
192                                            const struct lsquic_packet_out *);
193
194size_t
195lsquic_gquic_packout_header_size (const struct lsquic_conn *conn,
196                                                enum packet_out_flags flags);
197
198size_t
199lsquic_gquic_po_header_sz (enum packet_out_flags flags);
200
201/* This maps two bits as follows:
202 *  00  ->  1
203 *  01  ->  2
204 *  10  ->  4
205 *  11  ->  6
206 *
207 * Assumes that only two low bits are set.
208 */
209#define twobit_to_1246(bits) ((bits) * 2 + !(bits))
210
211/* This maps two bits as follows:
212 *  00  ->  1
213 *  01  ->  2
214 *  10  ->  4
215 *  11  ->  8
216 *
217 * Assumes that only two low bits are set.
218 */
219#define twobit_to_1248(bits) (1 << (bits))
220
221char *
222acki2str (const struct ack_info *acki, size_t *sz);
223
224void
225lsquic_turn_on_fin_Q035_thru_Q039 (unsigned char *);
226
227#endif
228