lsquic_parse.h revision b8fa6195 
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    void
73    (*pf_parse_packet_in_finish) (struct lsquic_packet_in *packet_in,
74                                                struct packin_parse_state *);
75    enum quic_frame_type
76    (*pf_parse_frame_type) (const unsigned char *, size_t);
77    /* Return used buffer length or a negative value if there was not enough
78     * room to write the stream frame.  In the latter case, the negative of
79     * the negative return value is the number of bytes required.  The
80     * exception is -1, which is a generic error code, as we always need
81     * more than 1 byte to write a STREAM frame.
82     */
83    /* pf_gen_stream_frame and pf_gen_crypto_frame must be adjacent so that
84     * they can be cast to an array.
85     */
86    int
87    (*pf_gen_stream_frame) (unsigned char *buf, size_t bufsz,
88                            lsquic_stream_id_t stream_id, uint64_t offset,
89                            int fin, size_t size, gsf_read_f, void *stream);
90    /* The two "UNUSED" parameters are here so that it matches
91     * pf_gen_stream_frame.
92     */
93    int
94    (*pf_gen_crypto_frame) (unsigned char *buf, size_t bufsz,
95                            lsquic_stream_id_t UNUSED_1, uint64_t offset,
96                            int UNUSED_2, size_t size, gsf_read_f, void *stream);
97    /* pf_parse_stream_frame and pf_parse_crypto_frame must be adjacent so that
98     * they can be cast to an array.
99     */
100    int
101    (*pf_parse_stream_frame) (const unsigned char *buf, size_t rem_packet_sz,
102                                                    struct stream_frame *);
103    int
104    (*pf_parse_crypto_frame) (const unsigned char *buf, size_t rem_packet_sz,
105                                                    struct stream_frame *);
106    int
107    (*pf_parse_ack_frame) (const unsigned char *buf, size_t buf_len,
108                                    struct ack_info *ack_info, uint8_t exp);
109    int
110    (*pf_gen_ack_frame) (unsigned char *outbuf, size_t outbuf_sz,
111                gaf_rechist_first_f, gaf_rechist_next_f,
112                gaf_rechist_largest_recv_f, void *rechist, lsquic_time_t now,
113                int *has_missing, lsquic_packno_t *largest_received,
114                const uint64_t *ecn_counts);
115    int
116    (*pf_gen_stop_waiting_frame) (unsigned char *buf, size_t buf_len,
117                    lsquic_packno_t cur_packno, enum packno_bits,
118                    lsquic_packno_t least_unacked_packno);
119    int
120    (*pf_parse_stop_waiting_frame) (const unsigned char *buf, size_t buf_len,
121                     lsquic_packno_t cur_packno, enum packno_bits,
122                     lsquic_packno_t *least_unacked);
123    int
124    (*pf_skip_stop_waiting_frame) (size_t buf_len, enum packno_bits);
125    int
126    (*pf_gen_window_update_frame) (unsigned char *buf, int buf_len,
127                                lsquic_stream_id_t stream_id, uint64_t offset);
128    int
129    (*pf_parse_window_update_frame) (const unsigned char *buf, size_t buf_len,
130                              lsquic_stream_id_t *stream_id, uint64_t *offset);
131    /* The third argument for pf_gen_blocked_frame() and pf_parse_blocked_frame()
132     * is Stream ID for GQUIC and offset for IETF QUIC.  Since both of these are
133     * uint64_t, we'll use the same function pointer.  Just have to be a little
134     * careful here.
135     */
136    int
137    (*pf_gen_blocked_frame) (unsigned char *buf, size_t buf_len,
138                                                lsquic_stream_id_t stream_id);
139    int
140    (*pf_parse_blocked_frame) (const unsigned char *buf, size_t buf_len,
141        /* TODO: rename third argument when dropping GQUIC */
142                                                lsquic_stream_id_t *stream_id);
143    unsigned
144    (*pf_blocked_frame_size) (uint64_t);
145    unsigned
146    (*pf_rst_frame_size) (lsquic_stream_id_t stream_id, uint64_t final_size,
147                                                        uint64_t error_code);
148    int
149    (*pf_gen_rst_frame) (unsigned char *buf, size_t buf_len,
150        lsquic_stream_id_t stream_id, uint64_t offset, uint64_t error_code);
151    int
152    (*pf_parse_rst_frame) (const unsigned char *buf, size_t buf_len,
153        lsquic_stream_id_t *stream_id, uint64_t *offset, uint64_t *error_code);
154    int
155    (*pf_parse_stop_sending_frame) (const unsigned char *buf, size_t buf_len,
156        lsquic_stream_id_t *stream_id, uint64_t *error_code);
157    unsigned
158    (*pf_stop_sending_frame_size) (lsquic_stream_id_t, uint64_t);
159    int
160    (*pf_gen_stop_sending_frame) (unsigned char *buf, size_t buf_len,
161                                    lsquic_stream_id_t, uint64_t error_code);
162    size_t
163    (*pf_connect_close_frame_size) (int app_error, unsigned error_code,
164                                unsigned frame_type, size_t reason_len);
165    int
166    (*pf_gen_connect_close_frame) (unsigned char *buf, size_t buf_len,
167        int app_error, unsigned error_code, const char *reason, int reason_len);
168    int
169    (*pf_parse_connect_close_frame) (const unsigned char *buf, size_t buf_len,
170                int *app_error, uint64_t *error_code, uint16_t *reason_length,
171                uint8_t *reason_offset);
172    int
173    (*pf_gen_goaway_frame) (unsigned char *buf, size_t buf_len,
174                uint32_t error_code, lsquic_stream_id_t last_good_stream_id,
175                const char *reason, size_t reason_len);
176    int
177    (*pf_parse_goaway_frame) (const unsigned char *buf, size_t buf_len,
178                uint32_t *error_code, lsquic_stream_id_t *last_good_stream_id,
179                uint16_t *reason_length, const char **reason);
180    int
181    (*pf_gen_ping_frame) (unsigned char *buf, int buf_len);
182    int
183    (*pf_parse_path_chal_frame) (const unsigned char *buf, size_t,
184                                                            uint64_t *chal);
185    int
186    (*pf_parse_path_resp_frame) (const unsigned char *buf, size_t,
187                                                            uint64_t *resp);
188#ifndef NDEBUG
189    /* These float reading and writing functions assume `mem' has at least
190     * 2 bytes.
191     */
192    void
193    (*pf_write_float_time16) (lsquic_time_t time_us, void *mem);
194    uint64_t
195    (*pf_read_float_time16) (const void *mem);
196#endif
197    ssize_t
198    (*pf_generate_simple_prst) (const lsquic_cid_t *cid,
199                                                    unsigned char *, size_t);
200    size_t
201    (*pf_calc_stream_frame_header_sz) (lsquic_stream_id_t stream_id,
202                                            uint64_t offset, unsigned data_sz);
203    size_t
204    (*pf_calc_crypto_frame_header_sz) (uint64_t offset, unsigned data_sz);
205    void
206    (*pf_turn_on_fin) (unsigned char *);
207
208    size_t
209    (*pf_packout_size) (const struct lsquic_conn *,
210                                            const struct lsquic_packet_out *);
211
212    /* This returns the high estimate of the header size.  Note that it
213     * cannot account for the size of the token in the IETF QUIC Initial
214     * packets as it does not know it.
215     */
216    size_t
217    (*pf_packout_max_header_size) (const struct lsquic_conn *,
218                                    enum packet_out_flags, size_t dcid_len);
219
220    enum packno_bits
221    (*pf_calc_packno_bits) (lsquic_packno_t packno,
222                        lsquic_packno_t least_unacked, uint64_t n_in_flight);
223    unsigned
224    (*pf_packno_bits2len) (enum packno_bits);
225
226    /* Used by IETF QUIC and gQUIC >= Q050 */
227    void
228    (*pf_packno_info) (const struct lsquic_conn *,
229        const struct lsquic_packet_out *, unsigned *packno_off,
230        unsigned *packno_len);
231    int
232    (*pf_parse_max_data) (const unsigned char *, size_t, uint64_t *);
233    int
234    (*pf_gen_max_data_frame) (unsigned char *, size_t, uint64_t);
235    unsigned
236    (*pf_max_data_frame_size) (uint64_t);
237    /*
238     * Returns number of bytes parsed on success or negative value on error:
239     *  -1  Out of input buffer
240     *  -2  Invalid CID length value
241     */
242    int
243    (*pf_parse_new_conn_id) (const unsigned char *, size_t, uint64_t *,
244                        uint64_t *, lsquic_cid_t *, const unsigned char **);
245    unsigned
246    (*pf_stream_blocked_frame_size) (lsquic_stream_id_t, uint64_t);
247    int
248    (*pf_gen_stream_blocked_frame) (unsigned char *buf, size_t,
249                                                lsquic_stream_id_t, uint64_t);
250    int
251    (*pf_parse_stream_blocked_frame) (const unsigned char *buf, size_t,
252                                            lsquic_stream_id_t *, uint64_t *);
253    unsigned
254    (*pf_max_stream_data_frame_size) (lsquic_stream_id_t, uint64_t);
255    int
256    (*pf_gen_max_stream_data_frame) (unsigned char *buf, size_t,
257                                                lsquic_stream_id_t, uint64_t);
258    int
259    (*pf_parse_max_stream_data_frame) (const unsigned char *buf, size_t,
260                                            lsquic_stream_id_t *, uint64_t *);
261    int
262    (*pf_parse_new_token_frame) (const unsigned char *buf, size_t,
263                            const unsigned char **token, size_t *token_size);
264    size_t
265    (*pf_new_connection_id_frame_size) (unsigned seqno, unsigned cid_len);
266    int
267    (*pf_gen_new_connection_id_frame) (unsigned char *buf, size_t,
268                unsigned seqno, const struct lsquic_cid *,
269                const unsigned char *token, size_t);
270    size_t
271    (*pf_retire_cid_frame_size) (uint64_t);
272    int
273    (*pf_gen_retire_cid_frame) (unsigned char *buf, size_t, uint64_t);
274    int
275    (*pf_parse_retire_cid_frame) (const unsigned char *buf, size_t, uint64_t *);
276    size_t
277    (*pf_new_token_frame_size) (size_t);
278    int
279    (*pf_gen_new_token_frame) (unsigned char *buf, size_t,
280                                        const unsigned char *token, size_t);
281    int
282    (*pf_gen_streams_blocked_frame) (unsigned char *buf, size_t buf_len,
283                                        enum stream_dir, uint64_t);
284    int
285    (*pf_parse_streams_blocked_frame) (const unsigned char *buf, size_t buf_len,
286                                        enum stream_dir *, uint64_t *);
287    unsigned
288    (*pf_streams_blocked_frame_size) (uint64_t);
289    int
290    (*pf_gen_max_streams_frame) (unsigned char *buf, size_t buf_len,
291                                        enum stream_dir, uint64_t);
292    int
293    (*pf_parse_max_streams_frame) (const unsigned char *buf, size_t buf_len,
294                                        enum stream_dir *, uint64_t *);
295    unsigned
296    (*pf_max_streams_frame_size) (uint64_t);
297    unsigned
298    (*pf_path_chal_frame_size) (void);
299    int
300    (*pf_gen_path_chal_frame) (unsigned char *, size_t, uint64_t chal);
301    unsigned
302    (*pf_path_resp_frame_size) (void);
303    int
304    (*pf_gen_path_resp_frame) (unsigned char *, size_t, uint64_t resp);
305    int
306    (*pf_gen_handshake_done_frame) (unsigned char *buf, size_t buf_len);
307    int
308    (*pf_parse_handshake_done_frame) (const unsigned char *buf, size_t buf_len);
309    unsigned
310    (*pf_handshake_done_frame_size) (void);
311    int
312    (*pf_gen_ack_frequency_frame) (unsigned char *buf, size_t buf_len,
313        uint64_t seqno, uint64_t pack_tol, uint64_t upd_mad);
314    int
315    (*pf_parse_ack_frequency_frame) (const unsigned char *buf, size_t buf_len,
316        uint64_t *seqno, uint64_t *pack_tol, uint64_t *upd_mad);
317    unsigned
318    (*pf_ack_frequency_frame_size) (uint64_t seqno, uint64_t pack_tol,
319        uint64_t upd_mad);
320    int
321    (*pf_gen_timestamp_frame) (unsigned char *buf, size_t buf_len, uint64_t);
322    int
323    (*pf_parse_timestamp_frame) (const unsigned char *buf, size_t, uint64_t *);
324};
325
326
327extern const struct parse_funcs lsquic_parse_funcs_gquic_Q043;
328extern const struct parse_funcs lsquic_parse_funcs_gquic_Q046;
329extern const struct parse_funcs lsquic_parse_funcs_gquic_Q050;
330extern const struct parse_funcs lsquic_parse_funcs_ietf_v1;
331
332#define select_pf_by_ver(ver) (                                             \
333    (1 << (ver)) & (1 << LSQVER_043)                     ?                  \
334                                         &lsquic_parse_funcs_gquic_Q043 :   \
335    (1 << (ver)) & (1 << LSQVER_046)                            ?           \
336                                         &lsquic_parse_funcs_gquic_Q046 :   \
337    (1 << (ver)) & ((1 << LSQVER_050)|LSQUIC_EXPERIMENTAL_Q098) ?           \
338                                         &lsquic_parse_funcs_gquic_Q050 :   \
339    &lsquic_parse_funcs_ietf_v1)
340
341/* This function is gQUIC-version independent */
342int
343lsquic_gquic_parse_packet_in_begin (struct lsquic_packet_in *, size_t length,
344                int is_server, unsigned cid_len, struct packin_parse_state *);
345
346int
347lsquic_Q046_parse_packet_in_short_begin (struct lsquic_packet_in *, size_t length,
348                int is_server, unsigned, struct packin_parse_state *);
349
350int
351lsquic_Q046_parse_packet_in_long_begin (struct lsquic_packet_in *, size_t length,
352                int is_server, unsigned, struct packin_parse_state *);
353
354int
355lsquic_Q050_parse_packet_in_long_begin (struct lsquic_packet_in *, size_t length,
356                int is_server, unsigned, struct packin_parse_state *);
357
358enum quic_frame_type
359lsquic_parse_frame_type_gquic_Q035_thru_Q046 (const unsigned char *, size_t);
360
361extern const enum quic_frame_type lsquic_iquic_byte2type[0x40];
362
363size_t
364lsquic_calc_stream_frame_header_sz_gquic (lsquic_stream_id_t stream_id,
365                                                    uint64_t offset, unsigned);
366
367size_t
368lsquic_gquic_packout_size (const struct lsquic_conn *,
369                                            const struct lsquic_packet_out *);
370
371size_t
372lsquic_gquic_packout_header_size (const struct lsquic_conn *conn,
373                                enum packet_out_flags flags, size_t unused);
374
375size_t
376lsquic_gquic_po_header_sz (enum packet_out_flags flags);
377
378size_t
379lsquic_gquic_packout_size (const struct lsquic_conn *,
380                                            const struct lsquic_packet_out *);
381
382size_t
383lsquic_gquic_po_header_sz (enum packet_out_flags flags);
384
385/* This maps two bits as follows:
386 *  00  ->  1
387 *  01  ->  2
388 *  10  ->  4
389 *  11  ->  6
390 *
391 * Assumes that only two low bits are set.
392 */
393#define twobit_to_1246(bits) ((bits) * 2 + !(bits))
394
395/* This maps two bits as follows:
396 *  00  ->  1
397 *  01  ->  2
398 *  10  ->  4
399 *  11  ->  8
400 *
401 * Assumes that only two low bits are set.
402 */
403#define twobit_to_1248(bits) (1 << (bits))
404
405#define ECN_COUNTS_STR  " ECT(0): 01234567879012345678790;" \
406                        " ECT(1): 01234567879012345678790;" \
407                        " CE: 01234567879012345678790"
408#define RANGES_TRUNCATED_STR " ranges truncated! "
409
410#define MAX_ACKI_STR_SZ (256 * (3 /* [-] */ + 20 /* ~0ULL */ * 2) \
411                    + sizeof(ECN_COUNTS_STR) + sizeof(RANGES_TRUNCATED_STR))
412
413void
414lsquic_acki2str (const struct ack_info *acki, char *, size_t);
415
416void
417lsquic_turn_on_fin_Q035_thru_Q046 (unsigned char *);
418
419enum packno_bits
420lsquic_gquic_calc_packno_bits (lsquic_packno_t packno,
421                        lsquic_packno_t least_unacked, uint64_t n_in_flight);
422
423unsigned
424lsquic_gquic_packno_bits2len (enum packno_bits);
425
426int
427lsquic_merge_acks (struct ack_info *dst, const struct ack_info *src);
428
429#endif
430