lsquic_parse.h revision 49f1f4f6 
1/* Copyright (c) 2017 - 2020 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#include "lsquic_packet_gquic.h"
9
10struct lsquic_conn;
11struct lsquic_packet_in;
12struct lsquic_packet_out;
13struct packin_parse_state;
14struct stream_frame;
15struct lsquic_cid;
16enum packet_out_flags;
17enum lsquic_version;
18enum stream_dir;
19
20
21struct ack_info
22{
23    enum packnum_space pns;
24    enum {
25        AI_ECN        = 1 << 0, /* ecn_counts[1,2,3] contain ECN counts */
26        AI_TRUNCATED  = 1 << 1, /* There were more ranges to parse, but we
27                                 * ran out of elements in `ranges'.
28                                 */
29    }               flags;
30    unsigned    n_ranges;       /* This is at least 1 */
31                                /* Largest acked is ack_info.ranges[0].high */
32    lsquic_time_t   lack_delta;
33    uint64_t        ecn_counts[4];
34    struct lsquic_packno_range ranges[256];
35};
36
37#define largest_acked(acki) (+(acki)->ranges[0].high)
38
39#define smallest_acked(acki) (+(acki)->ranges[(acki)->n_ranges - 1].low)
40
41/* Chrome may send an empty ACK frame when it closes a connection.
42 * We do not know why it occurs -- perhaps a bug in Chrome.
43 */
44/* This macro cannot be used in IETF QUIC as zero is a valid packet number.
45 * Hopefully the Chrome bug will have been fixed by then.
46 */
47#define empty_ack_frame(acki) (largest_acked(acki) == 0)
48
49/* gaf_: generate ACK frame */
50struct lsquic_packno_range;
51typedef const struct lsquic_packno_range *
52    (*gaf_rechist_first_f)          (void *rechist);
53typedef const struct lsquic_packno_range *
54    (*gaf_rechist_next_f)           (void *rechist);
55typedef lsquic_time_t
56    (*gaf_rechist_largest_recv_f)   (void *rechist);
57
58/* gsf_: generate stream frame */
59typedef size_t (*gsf_read_f) (void *stream, void *buf, size_t len, int *fin);
60
61/* This structure contains functions that parse and generate packets and
62 * frames in version-specific manner.  To begin with, there is difference
63 * between GQUIC's little-endian (Q038 and lower) and big-endian formats
64 * (Q039 and higher).  Q046 and higher uses different format for packet headers.
65 */
66struct parse_funcs
67{
68    /* Return buf length */
69    int
70    (*pf_gen_reg_pkt_header) (const struct lsquic_conn *,
71                const struct lsquic_packet_out *, unsigned char *, size_t,
72                /* In Q050 and IETF QUIC, these are set: */
73                unsigned *packno_off, unsigned *packno_len);
74    void
75    (*pf_parse_packet_in_finish) (struct lsquic_packet_in *packet_in,
76                                                struct packin_parse_state *);
77    enum quic_frame_type
78    (*pf_parse_frame_type) (const unsigned char *, size_t);
79    /* Return used buffer length or a negative value if there was not enough
80     * room to write the stream frame.  In the latter case, the negative of
81     * the negative return value is the number of bytes required.  The
82     * exception is -1, which is a generic error code, as we always need
83     * more than 1 byte to write a STREAM frame.
84     */
85    /* pf_gen_stream_frame and pf_gen_crypto_frame must be adjacent so that
86     * they can be cast to an array.
87     */
88    int
89    (*pf_gen_stream_frame) (unsigned char *buf, size_t bufsz,
90                            lsquic_stream_id_t stream_id, uint64_t offset,
91                            int fin, size_t size, gsf_read_f, void *stream);
92    /* The two "UNUSED" parameters are here so that it matches
93     * pf_gen_stream_frame.
94     */
95    int
96    (*pf_gen_crypto_frame) (unsigned char *buf, size_t bufsz,
97                            lsquic_stream_id_t UNUSED_1, uint64_t offset,
98                            int UNUSED_2, size_t size, gsf_read_f, void *stream);
99    /* pf_parse_stream_frame and pf_parse_crypto_frame must be adjacent so that
100     * they can be cast to an array.
101     */
102    int
103    (*pf_parse_stream_frame) (const unsigned char *buf, size_t rem_packet_sz,
104                                                    struct stream_frame *);
105    int
106    (*pf_parse_crypto_frame) (const unsigned char *buf, size_t rem_packet_sz,
107                                                    struct stream_frame *);
108    int
109    (*pf_parse_ack_frame) (const unsigned char *buf, size_t buf_len,
110                                    struct ack_info *ack_info, uint8_t exp);
111    int
112    (*pf_gen_ack_frame) (unsigned char *outbuf, size_t outbuf_sz,
113                gaf_rechist_first_f, gaf_rechist_next_f,
114                gaf_rechist_largest_recv_f, void *rechist, lsquic_time_t now,
115                int *has_missing, lsquic_packno_t *largest_received,
116                const uint64_t *ecn_counts);
117    int
118    (*pf_gen_stop_waiting_frame) (unsigned char *buf, size_t buf_len,
119                    lsquic_packno_t cur_packno, enum packno_bits,
120                    lsquic_packno_t least_unacked_packno);
121    int
122    (*pf_parse_stop_waiting_frame) (const unsigned char *buf, size_t buf_len,
123                     lsquic_packno_t cur_packno, enum packno_bits,
124                     lsquic_packno_t *least_unacked);
125    int
126    (*pf_skip_stop_waiting_frame) (size_t buf_len, enum packno_bits);
127    int
128    (*pf_gen_window_update_frame) (unsigned char *buf, int buf_len,
129                                lsquic_stream_id_t stream_id, uint64_t offset);
130    int
131    (*pf_parse_window_update_frame) (const unsigned char *buf, size_t buf_len,
132                              lsquic_stream_id_t *stream_id, uint64_t *offset);
133    /* The third argument for pf_gen_blocked_frame() and pf_parse_blocked_frame()
134     * is Stream ID for GQUIC and offset for IETF QUIC.  Since both of these are
135     * uint64_t, we'll use the same function pointer.  Just have to be a little
136     * careful here.
137     */
138    int
139    (*pf_gen_blocked_frame) (unsigned char *buf, size_t buf_len,
140                                                lsquic_stream_id_t stream_id);
141    int
142    (*pf_parse_blocked_frame) (const unsigned char *buf, size_t buf_len,
143        /* TODO: rename third argument when dropping GQUIC */
144                                                lsquic_stream_id_t *stream_id);
145    unsigned
146    (*pf_blocked_frame_size) (uint64_t);
147    unsigned
148    (*pf_rst_frame_size) (lsquic_stream_id_t stream_id, uint64_t final_size,
149                                                        uint64_t error_code);
150    int
151    (*pf_gen_rst_frame) (unsigned char *buf, size_t buf_len,
152        lsquic_stream_id_t stream_id, uint64_t offset, uint64_t error_code);
153    int
154    (*pf_parse_rst_frame) (const unsigned char *buf, size_t buf_len,
155        lsquic_stream_id_t *stream_id, uint64_t *offset, uint64_t *error_code);
156    int
157    (*pf_parse_stop_sending_frame) (const unsigned char *buf, size_t buf_len,
158        lsquic_stream_id_t *stream_id, uint64_t *error_code);
159    unsigned
160    (*pf_stop_sending_frame_size) (lsquic_stream_id_t, uint64_t);
161    int
162    (*pf_gen_stop_sending_frame) (unsigned char *buf, size_t buf_len,
163                                    lsquic_stream_id_t, uint64_t error_code);
164    size_t
165    (*pf_connect_close_frame_size) (int app_error, unsigned error_code,
166                                unsigned frame_type, size_t reason_len);
167    int
168    (*pf_gen_connect_close_frame) (unsigned char *buf, size_t buf_len,
169        int app_error, unsigned error_code, const char *reason, int reason_len);
170    int
171    (*pf_parse_connect_close_frame) (const unsigned char *buf, size_t buf_len,
172                int *app_error, uint64_t *error_code, uint16_t *reason_length,
173                uint8_t *reason_offset);
174    int
175    (*pf_gen_goaway_frame) (unsigned char *buf, size_t buf_len,
176                uint32_t error_code, lsquic_stream_id_t last_good_stream_id,
177                const char *reason, size_t reason_len);
178    int
179    (*pf_parse_goaway_frame) (const unsigned char *buf, size_t buf_len,
180                uint32_t *error_code, lsquic_stream_id_t *last_good_stream_id,
181                uint16_t *reason_length, const char **reason);
182    int
183    (*pf_gen_ping_frame) (unsigned char *buf, int buf_len);
184    int
185    (*pf_parse_path_chal_frame) (const unsigned char *buf, size_t,
186                                                            uint64_t *chal);
187    int
188    (*pf_parse_path_resp_frame) (const unsigned char *buf, size_t,
189                                                            uint64_t *resp);
190#ifndef NDEBUG
191    /* These float reading and writing functions assume `mem' has at least
192     * 2 bytes.
193     */
194    void
195    (*pf_write_float_time16) (lsquic_time_t time_us, void *mem);
196    uint64_t
197    (*pf_read_float_time16) (const void *mem);
198#endif
199    ssize_t
200    (*pf_generate_simple_prst) (const lsquic_cid_t *cid,
201                                                    unsigned char *, size_t);
202    size_t
203    (*pf_calc_stream_frame_header_sz) (lsquic_stream_id_t stream_id,
204                                            uint64_t offset, unsigned data_sz);
205    size_t
206    (*pf_calc_crypto_frame_header_sz) (uint64_t offset, unsigned data_sz);
207    void
208    (*pf_turn_on_fin) (unsigned char *);
209
210    size_t
211    (*pf_packout_size) (const struct lsquic_conn *,
212                                            const struct lsquic_packet_out *);
213
214    /* This returns the high estimate of the header size.  Note that it
215     * cannot account for the size of the token in the IETF QUIC Initial
216     * packets as it does not know it.
217     */
218    size_t
219    (*pf_packout_max_header_size) (const struct lsquic_conn *,
220                                    enum packet_out_flags, size_t dcid_len);
221
222    enum packno_bits
223    (*pf_calc_packno_bits) (lsquic_packno_t packno,
224                        lsquic_packno_t least_unacked, uint64_t n_in_flight);
225    unsigned
226    (*pf_packno_bits2len) (enum packno_bits);
227
228    int
229    (*pf_parse_max_data) (const unsigned char *, size_t, uint64_t *);
230    int
231    (*pf_gen_max_data_frame) (unsigned char *, size_t, uint64_t);
232    unsigned
233    (*pf_max_data_frame_size) (uint64_t);
234    /*
235     * Returns number of bytes parsed on success or negative value on error:
236     *  -1  Out of input buffer
237     *  -2  Invalid CID length value
238     */
239    int
240    (*pf_parse_new_conn_id) (const unsigned char *, size_t, uint64_t *,
241                        uint64_t *, lsquic_cid_t *, const unsigned char **);
242    unsigned
243    (*pf_stream_blocked_frame_size) (lsquic_stream_id_t, uint64_t);
244    int
245    (*pf_gen_stream_blocked_frame) (unsigned char *buf, size_t,
246                                                lsquic_stream_id_t, uint64_t);
247    int
248    (*pf_parse_stream_blocked_frame) (const unsigned char *buf, size_t,
249                                            lsquic_stream_id_t *, uint64_t *);
250    unsigned
251    (*pf_max_stream_data_frame_size) (lsquic_stream_id_t, uint64_t);
252    int
253    (*pf_gen_max_stream_data_frame) (unsigned char *buf, size_t,
254                                                lsquic_stream_id_t, uint64_t);
255    int
256    (*pf_parse_max_stream_data_frame) (const unsigned char *buf, size_t,
257                                            lsquic_stream_id_t *, uint64_t *);
258    int
259    (*pf_parse_new_token_frame) (const unsigned char *buf, size_t,
260                            const unsigned char **token, size_t *token_size);
261    size_t
262    (*pf_new_connection_id_frame_size) (unsigned seqno, unsigned cid_len);
263    int
264    (*pf_gen_new_connection_id_frame) (unsigned char *buf, size_t,
265                unsigned seqno, const struct lsquic_cid *,
266                const unsigned char *token, size_t);
267    size_t
268    (*pf_retire_cid_frame_size) (uint64_t);
269    int
270    (*pf_gen_retire_cid_frame) (unsigned char *buf, size_t, uint64_t);
271    int
272    (*pf_parse_retire_cid_frame) (const unsigned char *buf, size_t, uint64_t *);
273    size_t
274    (*pf_new_token_frame_size) (size_t);
275    int
276    (*pf_gen_new_token_frame) (unsigned char *buf, size_t,
277                                        const unsigned char *token, size_t);
278    int
279    (*pf_gen_streams_blocked_frame) (unsigned char *buf, size_t buf_len,
280                                        enum stream_dir, uint64_t);
281    int
282    (*pf_parse_streams_blocked_frame) (const unsigned char *buf, size_t buf_len,
283                                        enum stream_dir *, uint64_t *);
284    unsigned
285    (*pf_streams_blocked_frame_size) (uint64_t);
286    int
287    (*pf_gen_max_streams_frame) (unsigned char *buf, size_t buf_len,
288                                        enum stream_dir, uint64_t);
289    int
290    (*pf_parse_max_streams_frame) (const unsigned char *buf, size_t buf_len,
291                                        enum stream_dir *, uint64_t *);
292    unsigned
293    (*pf_max_streams_frame_size) (uint64_t);
294    unsigned
295    (*pf_path_chal_frame_size) (void);
296    int
297    (*pf_gen_path_chal_frame) (unsigned char *, size_t, uint64_t chal);
298    unsigned
299    (*pf_path_resp_frame_size) (void);
300    int
301    (*pf_gen_path_resp_frame) (unsigned char *, size_t, uint64_t resp);
302    int
303    (*pf_gen_handshake_done_frame) (unsigned char *buf, size_t buf_len);
304    int
305    (*pf_parse_handshake_done_frame) (const unsigned char *buf, size_t buf_len);
306    unsigned
307    (*pf_handshake_done_frame_size) (void);
308    int
309    (*pf_gen_ack_frequency_frame) (unsigned char *buf, size_t buf_len,
310        uint64_t seqno, uint64_t pack_tol, uint64_t upd_mad, int ignore);
311    int
312    (*pf_parse_ack_frequency_frame) (const unsigned char *buf, size_t buf_len,
313        uint64_t *seqno, uint64_t *pack_tol, uint64_t *upd_mad, int *ignore);
314    unsigned
315    (*pf_ack_frequency_frame_size) (uint64_t seqno, uint64_t pack_tol,
316        uint64_t upd_mad /* Don't need to pass `ignore' */);
317    int
318    (*pf_gen_timestamp_frame) (unsigned char *buf, size_t buf_len, uint64_t);
319    int
320    (*pf_parse_timestamp_frame) (const unsigned char *buf, size_t, uint64_t *);
321};
322
323
324extern const struct parse_funcs lsquic_parse_funcs_gquic_Q043;
325extern const struct parse_funcs lsquic_parse_funcs_gquic_Q046;
326extern const struct parse_funcs lsquic_parse_funcs_gquic_Q050;
327extern const struct parse_funcs lsquic_parse_funcs_ietf_v1;
328
329#define select_pf_by_ver(ver) (                                             \
330    (1 << (ver)) & (1 << LSQVER_043)                     ?                  \
331                                         &lsquic_parse_funcs_gquic_Q043 :   \
332    (1 << (ver)) & (1 << LSQVER_046)                            ?           \
333                                         &lsquic_parse_funcs_gquic_Q046 :   \
334    (1 << (ver)) & ((1 << LSQVER_050)|LSQUIC_EXPERIMENTAL_Q098) ?           \
335                                         &lsquic_parse_funcs_gquic_Q050 :   \
336    &lsquic_parse_funcs_ietf_v1)
337
338/* This function is gQUIC-version independent */
339int
340lsquic_gquic_parse_packet_in_begin (struct lsquic_packet_in *, size_t length,
341                int is_server, unsigned cid_len, struct packin_parse_state *);
342
343int
344lsquic_Q046_parse_packet_in_short_begin (struct lsquic_packet_in *, size_t length,
345                int is_server, unsigned, struct packin_parse_state *);
346
347int
348lsquic_Q046_parse_packet_in_long_begin (struct lsquic_packet_in *, size_t length,
349                int is_server, unsigned, struct packin_parse_state *);
350
351int
352lsquic_Q050_parse_packet_in_long_begin (struct lsquic_packet_in *, size_t length,
353                int is_server, unsigned, struct packin_parse_state *);
354
355enum quic_frame_type
356lsquic_parse_frame_type_gquic_Q035_thru_Q046 (const unsigned char *, size_t);
357
358extern const enum quic_frame_type lsquic_iquic_byte2type[0x40];
359
360size_t
361lsquic_calc_stream_frame_header_sz_gquic (lsquic_stream_id_t stream_id,
362                                                    uint64_t offset, unsigned);
363
364size_t
365lsquic_gquic_packout_size (const struct lsquic_conn *,
366                                            const struct lsquic_packet_out *);
367
368size_t
369lsquic_gquic_packout_header_size (const struct lsquic_conn *conn,
370                                enum packet_out_flags flags, size_t unused);
371
372size_t
373lsquic_gquic_po_header_sz (enum packet_out_flags flags);
374
375size_t
376lsquic_gquic_packout_size (const struct lsquic_conn *,
377                                            const struct lsquic_packet_out *);
378
379size_t
380lsquic_gquic_po_header_sz (enum packet_out_flags flags);
381
382/* This maps two bits as follows:
383 *  00  ->  1
384 *  01  ->  2
385 *  10  ->  4
386 *  11  ->  6
387 *
388 * Assumes that only two low bits are set.
389 */
390#define twobit_to_1246(bits) ((bits) * 2 + !(bits))
391
392/* This maps two bits as follows:
393 *  00  ->  1
394 *  01  ->  2
395 *  10  ->  4
396 *  11  ->  8
397 *
398 * Assumes that only two low bits are set.
399 */
400#define twobit_to_1248(bits) (1 << (bits))
401
402#define ECN_COUNTS_STR  " ECT(0): 01234567879012345678790;" \
403                        " ECT(1): 01234567879012345678790;" \
404                        " CE: 01234567879012345678790"
405#define RANGES_TRUNCATED_STR " ranges truncated! "
406
407#define MAX_ACKI_STR_SZ (256 * (3 /* [-] */ + 20 /* ~0ULL */ * 2) \
408                    + sizeof(ECN_COUNTS_STR) + sizeof(RANGES_TRUNCATED_STR))
409
410void
411lsquic_acki2str (const struct ack_info *acki, char *, size_t);
412
413void
414lsquic_turn_on_fin_Q035_thru_Q046 (unsigned char *);
415
416enum packno_bits
417lsquic_gquic_calc_packno_bits (lsquic_packno_t packno,
418                        lsquic_packno_t least_unacked, uint64_t n_in_flight);
419
420unsigned
421lsquic_gquic_packno_bits2len (enum packno_bits);
422
423int
424lsquic_merge_acks (struct ack_info *dst, const struct ack_info *src);
425
426#endif
427