lsquic_parse.h revision feca77f5 
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/* gcf_: generate CRYPTO frame */
62typedef size_t (*gcf_read_f) (void *stream, void *buf, size_t len);
63
64/* This structure contains functions that parse and generate packets and
65 * frames in version-specific manner.  To begin with, there is difference
66 * between GQUIC's little-endian (Q038 and lower) and big-endian formats
67 * (Q039 and higher).  Q046 and higher uses different format for packet headers.
68 */
69struct parse_funcs
70{
71    /* Return buf length */
72    int
73    (*pf_gen_reg_pkt_header) (const struct lsquic_conn *,
74                const struct lsquic_packet_out *, unsigned char *, size_t);
75    void
76    (*pf_parse_packet_in_finish) (struct lsquic_packet_in *packet_in,
77                                                struct packin_parse_state *);
78    enum quic_frame_type
79    (*pf_parse_frame_type) (const unsigned char *, size_t);
80    /* Return used buffer length or a negative value if there was not enough
81     * room to write the stream frame.  In the latter case, the negative of
82     * the negative return value is the number of bytes required.  The
83     * exception is -1, which is a generic error code, as we always need
84     * more than 1 byte to write a STREAM frame.
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    int
91    (*pf_parse_stream_frame) (const unsigned char *buf, size_t rem_packet_sz,
92                                                    struct stream_frame *);
93    int
94    (*pf_parse_crypto_frame) (const unsigned char *buf, size_t rem_packet_sz,
95                                                    struct stream_frame *);
96    int
97    (*pf_gen_crypto_frame) (unsigned char *buf, size_t bufsz, uint64_t offset,
98                            size_t size, gcf_read_f, void *stream);
99    int
100    (*pf_parse_ack_frame) (const unsigned char *buf, size_t buf_len,
101                                    struct ack_info *ack_info, uint8_t exp);
102    int
103    (*pf_gen_ack_frame) (unsigned char *outbuf, size_t outbuf_sz,
104                gaf_rechist_first_f, gaf_rechist_next_f,
105                gaf_rechist_largest_recv_f, void *rechist, lsquic_time_t now,
106                int *has_missing, lsquic_packno_t *largest_received,
107                const uint64_t *ecn_counts);
108    int
109    (*pf_gen_stop_waiting_frame) (unsigned char *buf, size_t buf_len,
110                    lsquic_packno_t cur_packno, enum packno_bits,
111                    lsquic_packno_t least_unacked_packno);
112    int
113    (*pf_parse_stop_waiting_frame) (const unsigned char *buf, size_t buf_len,
114                     lsquic_packno_t cur_packno, enum packno_bits,
115                     lsquic_packno_t *least_unacked);
116    int
117    (*pf_skip_stop_waiting_frame) (size_t buf_len, enum packno_bits);
118    int
119    (*pf_gen_window_update_frame) (unsigned char *buf, int buf_len,
120                                lsquic_stream_id_t stream_id, uint64_t offset);
121    int
122    (*pf_parse_window_update_frame) (const unsigned char *buf, size_t buf_len,
123                              lsquic_stream_id_t *stream_id, uint64_t *offset);
124    /* The third argument for pf_gen_blocked_frame() and pf_parse_blocked_frame()
125     * is Stream ID for GQUIC and offset for IETF QUIC.  Since both of these are
126     * uint64_t, we'll use the same function pointer.  Just have to be a little
127     * careful here.
128     */
129    int
130    (*pf_gen_blocked_frame) (unsigned char *buf, size_t buf_len,
131                                                lsquic_stream_id_t stream_id);
132    int
133    (*pf_parse_blocked_frame) (const unsigned char *buf, size_t buf_len,
134        /* TODO: rename third argument when dropping GQUIC */
135                                                lsquic_stream_id_t *stream_id);
136    unsigned
137    (*pf_blocked_frame_size) (uint64_t);
138    unsigned
139    (*pf_rst_frame_size) (lsquic_stream_id_t stream_id, uint64_t final_size,
140                                                        uint64_t error_code);
141    int
142    (*pf_gen_rst_frame) (unsigned char *buf, size_t buf_len,
143        lsquic_stream_id_t stream_id, uint64_t offset, uint64_t error_code);
144    int
145    (*pf_parse_rst_frame) (const unsigned char *buf, size_t buf_len,
146        lsquic_stream_id_t *stream_id, uint64_t *offset, uint64_t *error_code);
147    int
148    (*pf_parse_stop_sending_frame) (const unsigned char *buf, size_t buf_len,
149        lsquic_stream_id_t *stream_id, uint64_t *error_code);
150    unsigned
151    (*pf_stop_sending_frame_size) (lsquic_stream_id_t, uint64_t);
152    int
153    (*pf_gen_stop_sending_frame) (unsigned char *buf, size_t buf_len,
154                                    lsquic_stream_id_t, uint64_t error_code);
155    size_t
156    (*pf_connect_close_frame_size) (int app_error, unsigned error_code,
157                                unsigned frame_type, size_t reason_len);
158    int
159    (*pf_gen_connect_close_frame) (unsigned char *buf, size_t buf_len,
160        int app_error, unsigned error_code, const char *reason, int reason_len);
161    int
162    (*pf_parse_connect_close_frame) (const unsigned char *buf, size_t buf_len,
163                int *app_error, uint64_t *error_code, uint16_t *reason_length,
164                uint8_t *reason_offset);
165    int
166    (*pf_gen_goaway_frame) (unsigned char *buf, size_t buf_len,
167                uint32_t error_code, lsquic_stream_id_t last_good_stream_id,
168                const char *reason, size_t reason_len);
169    int
170    (*pf_parse_goaway_frame) (const unsigned char *buf, size_t buf_len,
171                uint32_t *error_code, lsquic_stream_id_t *last_good_stream_id,
172                uint16_t *reason_length, const char **reason);
173    int
174    (*pf_gen_ping_frame) (unsigned char *buf, int buf_len);
175    int
176    (*pf_parse_path_chal_frame) (const unsigned char *buf, size_t,
177                                                            uint64_t *chal);
178    int
179    (*pf_parse_path_resp_frame) (const unsigned char *buf, size_t,
180                                                            uint64_t *resp);
181#ifndef NDEBUG
182    /* These float reading and writing functions assume `mem' has at least
183     * 2 bytes.
184     */
185    void
186    (*pf_write_float_time16) (lsquic_time_t time_us, void *mem);
187    uint64_t
188    (*pf_read_float_time16) (const void *mem);
189#endif
190    ssize_t
191    (*pf_generate_simple_prst) (const lsquic_cid_t *cid,
192                                                    unsigned char *, size_t);
193    size_t
194    (*pf_calc_stream_frame_header_sz) (lsquic_stream_id_t stream_id,
195                                            uint64_t offset, unsigned data_sz);
196    size_t
197    (*pf_calc_crypto_frame_header_sz) (uint64_t offset, unsigned data_sz);
198    void
199    (*pf_turn_on_fin) (unsigned char *);
200
201    size_t
202    (*pf_packout_size) (const struct lsquic_conn *,
203                                            const struct lsquic_packet_out *);
204
205    /* This returns the high estimate of the header size.  Note that it
206     * cannot account for the size of the token in the IETF QUIC Initial
207     * packets as it does not know it.
208     */
209    size_t
210    (*pf_packout_max_header_size) (const struct lsquic_conn *,
211                                    enum packet_out_flags, size_t dcid_len);
212
213    enum packno_bits
214    (*pf_calc_packno_bits) (lsquic_packno_t packno,
215                        lsquic_packno_t least_unacked, uint64_t n_in_flight);
216    unsigned
217    (*pf_packno_bits2len) (enum packno_bits);
218
219    /* Used by IETF QUIC and gQUIC >= Q050 */
220    void
221    (*pf_packno_info) (const struct lsquic_conn *,
222        const struct lsquic_packet_out *, unsigned *packno_off,
223        unsigned *packno_len);
224    int
225    (*pf_parse_max_data) (const unsigned char *, size_t, uint64_t *);
226    int
227    (*pf_gen_max_data_frame) (unsigned char *, size_t, uint64_t);
228    unsigned
229    (*pf_max_data_frame_size) (uint64_t);
230    /*
231     * Returns number of bytes parsed on success or negative value on error:
232     *  -1  Out of input buffer
233     *  -2  Invalid CID length value
234     */
235    int
236    (*pf_parse_new_conn_id) (const unsigned char *, size_t, uint64_t *,
237                        uint64_t *, lsquic_cid_t *, const unsigned char **);
238    unsigned
239    (*pf_stream_blocked_frame_size) (lsquic_stream_id_t, uint64_t);
240    int
241    (*pf_gen_stream_blocked_frame) (unsigned char *buf, size_t,
242                                                lsquic_stream_id_t, uint64_t);
243    int
244    (*pf_parse_stream_blocked_frame) (const unsigned char *buf, size_t,
245                                            lsquic_stream_id_t *, uint64_t *);
246    unsigned
247    (*pf_max_stream_data_frame_size) (lsquic_stream_id_t, uint64_t);
248    int
249    (*pf_gen_max_stream_data_frame) (unsigned char *buf, size_t,
250                                                lsquic_stream_id_t, uint64_t);
251    int
252    (*pf_parse_max_stream_data_frame) (const unsigned char *buf, size_t,
253                                            lsquic_stream_id_t *, uint64_t *);
254    int
255    (*pf_parse_new_token_frame) (const unsigned char *buf, size_t,
256                            const unsigned char **token, size_t *token_size);
257    size_t
258    (*pf_new_connection_id_frame_size) (unsigned seqno, unsigned cid_len);
259    int
260    (*pf_gen_new_connection_id_frame) (unsigned char *buf, size_t,
261                unsigned seqno, const struct lsquic_cid *,
262                const unsigned char *token, size_t);
263    size_t
264    (*pf_retire_cid_frame_size) (uint64_t);
265    int
266    (*pf_gen_retire_cid_frame) (unsigned char *buf, size_t, uint64_t);
267    int
268    (*pf_parse_retire_cid_frame) (const unsigned char *buf, size_t, uint64_t *);
269    size_t
270    (*pf_new_token_frame_size) (size_t);
271    int
272    (*pf_gen_new_token_frame) (unsigned char *buf, size_t,
273                                        const unsigned char *token, size_t);
274    int
275    (*pf_gen_streams_blocked_frame) (unsigned char *buf, size_t buf_len,
276                                        enum stream_dir, uint64_t);
277    int
278    (*pf_parse_streams_blocked_frame) (const unsigned char *buf, size_t buf_len,
279                                        enum stream_dir *, uint64_t *);
280    unsigned
281    (*pf_streams_blocked_frame_size) (uint64_t);
282    int
283    (*pf_gen_max_streams_frame) (unsigned char *buf, size_t buf_len,
284                                        enum stream_dir, uint64_t);
285    int
286    (*pf_parse_max_streams_frame) (const unsigned char *buf, size_t buf_len,
287                                        enum stream_dir *, uint64_t *);
288    unsigned
289    (*pf_max_streams_frame_size) (uint64_t);
290    unsigned
291    (*pf_path_chal_frame_size) (void);
292    int
293    (*pf_gen_path_chal_frame) (unsigned char *, size_t, uint64_t chal);
294    unsigned
295    (*pf_path_resp_frame_size) (void);
296    int
297    (*pf_gen_path_resp_frame) (unsigned char *, size_t, uint64_t resp);
298    int
299    (*pf_gen_handshake_done_frame) (unsigned char *buf, size_t buf_len);
300    int
301    (*pf_parse_handshake_done_frame) (const unsigned char *buf, size_t buf_len);
302    unsigned
303    (*pf_handshake_done_frame_size) (void);
304    int
305    (*pf_gen_ack_frequency_frame) (unsigned char *buf, size_t buf_len,
306        uint64_t seqno, uint64_t pack_tol, uint64_t upd_mad);
307    int
308    (*pf_parse_ack_frequency_frame) (const unsigned char *buf, size_t buf_len,
309        uint64_t *seqno, uint64_t *pack_tol, uint64_t *upd_mad);
310    unsigned
311    (*pf_ack_frequency_frame_size) (uint64_t seqno, uint64_t pack_tol,
312        uint64_t upd_mad);
313};
314
315
316extern const struct parse_funcs lsquic_parse_funcs_gquic_Q043;
317extern const struct parse_funcs lsquic_parse_funcs_gquic_Q046;
318extern const struct parse_funcs lsquic_parse_funcs_gquic_Q050;
319extern const struct parse_funcs lsquic_parse_funcs_ietf_id24;
320extern const struct parse_funcs lsquic_parse_funcs_ietf_v1;
321
322#define select_pf_by_ver(ver) (                                             \
323    (1 << (ver)) & (1 << LSQVER_043)                     ?                  \
324                                         &lsquic_parse_funcs_gquic_Q043 :   \
325    (1 << (ver)) & (1 << LSQVER_046)                            ?           \
326                                         &lsquic_parse_funcs_gquic_Q046 :   \
327    (1 << (ver)) & ((1 << LSQVER_050)|LSQUIC_EXPERIMENTAL_Q098) ?           \
328                                         &lsquic_parse_funcs_gquic_Q050 :   \
329    (1 << (ver)) & (1 << LSQVER_ID24)                           ?           \
330                                         &lsquic_parse_funcs_ietf_id24 :    \
331    &lsquic_parse_funcs_ietf_v1)
332
333/* This function is gQUIC-version independent */
334int
335lsquic_gquic_parse_packet_in_begin (struct lsquic_packet_in *, size_t length,
336                int is_server, unsigned cid_len, struct packin_parse_state *);
337
338int
339lsquic_Q046_parse_packet_in_short_begin (struct lsquic_packet_in *, size_t length,
340                int is_server, unsigned, struct packin_parse_state *);
341
342int
343lsquic_Q046_parse_packet_in_long_begin (struct lsquic_packet_in *, size_t length,
344                int is_server, unsigned, struct packin_parse_state *);
345
346int
347lsquic_Q050_parse_packet_in_long_begin (struct lsquic_packet_in *, size_t length,
348                int is_server, unsigned, struct packin_parse_state *);
349
350enum quic_frame_type
351lsquic_parse_frame_type_gquic_Q035_thru_Q046 (const unsigned char *, size_t);
352
353extern const enum quic_frame_type lsquic_iquic_byte2type[0x40];
354
355size_t
356calc_stream_frame_header_sz_gquic (lsquic_stream_id_t stream_id,
357                                                    uint64_t offset, unsigned);
358
359size_t
360lsquic_gquic_packout_size (const struct lsquic_conn *,
361                                            const struct lsquic_packet_out *);
362
363size_t
364lsquic_gquic_packout_header_size (const struct lsquic_conn *conn,
365                                enum packet_out_flags flags, size_t unused);
366
367size_t
368lsquic_gquic_po_header_sz (enum packet_out_flags flags);
369
370size_t
371lsquic_gquic_packout_size (const struct lsquic_conn *,
372                                            const struct lsquic_packet_out *);
373
374size_t
375lsquic_gquic_po_header_sz (enum packet_out_flags flags);
376
377/* This maps two bits as follows:
378 *  00  ->  1
379 *  01  ->  2
380 *  10  ->  4
381 *  11  ->  6
382 *
383 * Assumes that only two low bits are set.
384 */
385#define twobit_to_1246(bits) ((bits) * 2 + !(bits))
386
387/* This maps two bits as follows:
388 *  00  ->  1
389 *  01  ->  2
390 *  10  ->  4
391 *  11  ->  8
392 *
393 * Assumes that only two low bits are set.
394 */
395#define twobit_to_1248(bits) (1 << (bits))
396
397#define ECN_COUNTS_STR  " ECT(0): 01234567879012345678790;" \
398                        " ECT(1): 01234567879012345678790;" \
399                        " CE: 01234567879012345678790"
400#define RANGES_TRUNCATED_STR " ranges truncated! "
401
402#define MAX_ACKI_STR_SZ (256 * (3 /* [-] */ + 20 /* ~0ULL */ * 2) \
403                    + sizeof(ECN_COUNTS_STR) + sizeof(RANGES_TRUNCATED_STR))
404
405void
406lsquic_acki2str (const struct ack_info *acki, char *, size_t);
407
408void
409lsquic_turn_on_fin_Q035_thru_Q046 (unsigned char *);
410
411enum packno_bits
412lsquic_gquic_calc_packno_bits (lsquic_packno_t packno,
413                        lsquic_packno_t least_unacked, uint64_t n_in_flight);
414
415unsigned
416lsquic_gquic_packno_bits2len (enum packno_bits);
417
418int
419lsquic_merge_acks (struct ack_info *dst, const struct ack_info *src);
420
421#endif
422