lsquic_parse.h revision 7a8b2ece 
1/* Copyright (c) 2017 - 2019 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#define LSQUIC_PARSE_ACK_TIMESTAMPS 0
21
22struct ack_info
23{
24    enum packnum_space pns;
25    enum {
26        AI_ECN        = 1 << 0, /* ecn_counts[1,2,3] contain ECN counts */
27        AI_TRUNCATED  = 1 << 1, /* There were more ranges to parse, but we
28                                 * ran out of elements in `ranges'.
29                                 */
30    }               flags;
31    unsigned    n_timestamps;   /* 0 to 255 */
32    unsigned    n_ranges;       /* This is at least 1 */
33                                /* Largest acked is ack_info.ranges[0].high */
34    lsquic_time_t   lack_delta;
35    uint64_t        ecn_counts[4];
36    struct lsquic_packno_range ranges[256];
37#if LSQUIC_PARSE_ACK_TIMESTAMPS
38    struct {
39        /* Currently we just read these timestamps in (assuming it is
40         * compiled in, of course), but do not do anything with them.
41         * When we do, the representation of these fields should be
42         * switched to whatever is most appropriate/efficient.
43         */
44        unsigned char   packet_delta;
45        uint64_t        delta_usec;
46    }           timestamps[255];
47#endif
48};
49
50
51struct short_ack_info
52{
53    unsigned                    sai_n_timestamps;
54    lsquic_time_t               sai_lack_delta;
55    struct lsquic_packno_range  sai_range;
56};
57
58#define largest_acked(acki) (+(acki)->ranges[0].high)
59
60#define smallest_acked(acki) (+(acki)->ranges[(acki)->n_ranges - 1].low)
61
62/* Chrome may send an empty ACK frame when it closes a connection.
63 * We do not know why it occurs -- perhaps a bug in Chrome.
64 */
65/* This macro cannot be used in IETF QUIC as zero is a valid packet number.
66 * Hopefully the Chrome bug will have been fixed by then.
67 */
68#define empty_ack_frame(acki) (largest_acked(acki) == 0)
69
70/* gaf_: generate ACK frame */
71struct lsquic_packno_range;
72typedef const struct lsquic_packno_range *
73    (*gaf_rechist_first_f)          (void *rechist);
74typedef const struct lsquic_packno_range *
75    (*gaf_rechist_next_f)           (void *rechist);
76typedef lsquic_time_t
77    (*gaf_rechist_largest_recv_f)   (void *rechist);
78
79/* gsf_: generate stream frame */
80typedef size_t (*gsf_read_f) (void *stream, void *buf, size_t len, int *fin);
81
82/* gcf_: generate CRYPTO frame */
83typedef size_t (*gcf_read_f) (void *stream, void *buf, size_t len);
84
85/* This structure contains functions that parse and generate packets and
86 * frames in version-specific manner.  To begin with, there is difference
87 * between GQUIC's little-endian (Q038 and lower) and big-endian formats
88 * (Q039 and higher).  Q046 and higher uses different format for packet headers.
89 */
90struct parse_funcs
91{
92    /* Return buf length */
93    int
94    (*pf_gen_reg_pkt_header) (const struct lsquic_conn *,
95                const struct lsquic_packet_out *, unsigned char *, size_t);
96    void
97    (*pf_parse_packet_in_finish) (struct lsquic_packet_in *packet_in,
98                                                struct packin_parse_state *);
99    enum quic_frame_type
100    (*pf_parse_frame_type) (unsigned char);
101    /* Return used buffer length or a negative value if there was not enough
102     * room to write the stream frame.  In the latter case, the negative of
103     * the negative return value is the number of bytes required.  The
104     * exception is -1, which is a generic error code, as we always need
105     * more than 1 byte to write a STREAM frame.
106     */
107    int
108    (*pf_gen_stream_frame) (unsigned char *buf, size_t bufsz,
109                            lsquic_stream_id_t stream_id, uint64_t offset,
110                            int fin, size_t size, gsf_read_f, void *stream);
111    int
112    (*pf_parse_stream_frame) (const unsigned char *buf, size_t rem_packet_sz,
113                                                    struct stream_frame *);
114    int
115    (*pf_parse_crypto_frame) (const unsigned char *buf, size_t rem_packet_sz,
116                                                    struct stream_frame *);
117    int
118    (*pf_gen_crypto_frame) (unsigned char *buf, size_t bufsz, uint64_t offset,
119                            size_t size, gcf_read_f, void *stream);
120    int
121    (*pf_parse_ack_frame) (const unsigned char *buf, size_t buf_len,
122                                    struct ack_info *ack_info, uint8_t exp);
123    int
124    (*pf_gen_ack_frame) (unsigned char *outbuf, size_t outbuf_sz,
125                gaf_rechist_first_f, gaf_rechist_next_f,
126                gaf_rechist_largest_recv_f, void *rechist, lsquic_time_t now,
127                int *has_missing, lsquic_packno_t *largest_received,
128                const uint64_t *ecn_counts);
129    int
130    (*pf_gen_stop_waiting_frame) (unsigned char *buf, size_t buf_len,
131                    lsquic_packno_t cur_packno, enum packno_bits,
132                    lsquic_packno_t least_unacked_packno);
133    int
134    (*pf_parse_stop_waiting_frame) (const unsigned char *buf, size_t buf_len,
135                     lsquic_packno_t cur_packno, enum packno_bits,
136                     lsquic_packno_t *least_unacked);
137    int
138    (*pf_skip_stop_waiting_frame) (size_t buf_len, enum packno_bits);
139    int
140    (*pf_gen_window_update_frame) (unsigned char *buf, int buf_len,
141                                lsquic_stream_id_t stream_id, uint64_t offset);
142    int
143    (*pf_parse_window_update_frame) (const unsigned char *buf, size_t buf_len,
144                              lsquic_stream_id_t *stream_id, uint64_t *offset);
145    /* The third argument for pf_gen_blocked_frame() and pf_parse_blocked_frame()
146     * is Stream ID for GQUIC and offset for IETF QUIC.  Since both of these are
147     * uint64_t, we'll use the same function pointer.  Just have to be a little
148     * careful here.
149     */
150    int
151    (*pf_gen_blocked_frame) (unsigned char *buf, size_t buf_len,
152                                                lsquic_stream_id_t stream_id);
153    int
154    (*pf_parse_blocked_frame) (const unsigned char *buf, size_t buf_len,
155        /* TODO: rename third argument when dropping GQUIC */
156                                                lsquic_stream_id_t *stream_id);
157    unsigned
158    (*pf_blocked_frame_size) (uint64_t);
159    unsigned
160    (*pf_rst_frame_size) (lsquic_stream_id_t stream_id, uint64_t final_size,
161                                                        uint64_t error_code);
162    int
163    (*pf_gen_rst_frame) (unsigned char *buf, size_t buf_len,
164        lsquic_stream_id_t stream_id, uint64_t offset, uint64_t error_code);
165    int
166    (*pf_parse_rst_frame) (const unsigned char *buf, size_t buf_len,
167        lsquic_stream_id_t *stream_id, uint64_t *offset, uint64_t *error_code);
168    int
169    (*pf_parse_stop_sending_frame) (const unsigned char *buf, size_t buf_len,
170        lsquic_stream_id_t *stream_id, uint64_t *error_code);
171    unsigned
172    (*pf_stop_sending_frame_size) (lsquic_stream_id_t, uint64_t);
173    int
174    (*pf_gen_stop_sending_frame) (unsigned char *buf, size_t buf_len,
175                                    lsquic_stream_id_t, uint64_t error_code);
176    int
177    (*pf_gen_connect_close_frame) (unsigned char *buf, size_t buf_len,
178        int app_error, unsigned error_code, const char *reason, int reason_len);
179    int
180    (*pf_parse_connect_close_frame) (const unsigned char *buf, size_t buf_len,
181                int *app_error, uint64_t *error_code, uint16_t *reason_length,
182                uint8_t *reason_offset);
183    int
184    (*pf_gen_goaway_frame) (unsigned char *buf, size_t buf_len,
185                uint32_t error_code, lsquic_stream_id_t last_good_stream_id,
186                const char *reason, size_t reason_len);
187    int
188    (*pf_parse_goaway_frame) (const unsigned char *buf, size_t buf_len,
189                uint32_t *error_code, lsquic_stream_id_t *last_good_stream_id,
190                uint16_t *reason_length, const char **reason);
191    int
192    (*pf_gen_ping_frame) (unsigned char *buf, int buf_len);
193    int
194    (*pf_parse_path_chal_frame) (const unsigned char *buf, size_t,
195                                                            uint64_t *chal);
196    int
197    (*pf_parse_path_resp_frame) (const unsigned char *buf, size_t,
198                                                            uint64_t *resp);
199#ifndef NDEBUG
200    /* These float reading and writing functions assume `mem' has at least
201     * 2 bytes.
202     */
203    void
204    (*pf_write_float_time16) (lsquic_time_t time_us, void *mem);
205    uint64_t
206    (*pf_read_float_time16) (const void *mem);
207#endif
208    ssize_t
209    (*pf_generate_simple_prst) (const lsquic_cid_t *cid,
210                                                    unsigned char *, size_t);
211    size_t
212    (*pf_calc_stream_frame_header_sz) (lsquic_stream_id_t stream_id,
213                                            uint64_t offset, unsigned data_sz);
214    size_t
215    (*pf_calc_crypto_frame_header_sz) (uint64_t offset, unsigned data_sz);
216    void
217    (*pf_turn_on_fin) (unsigned char *);
218
219    size_t
220    (*pf_packout_size) (const struct lsquic_conn *,
221                                            const struct lsquic_packet_out *);
222
223    /* This returns the high estimate of the header size.  Note that it
224     * cannot account for the size of the token in the IETF QUIC Initial
225     * packets as it does not know it.
226     */
227    size_t
228    (*pf_packout_max_header_size) (const struct lsquic_conn *,
229                                    enum packet_out_flags, size_t dcid_len);
230
231    enum packno_bits
232    (*pf_calc_packno_bits) (lsquic_packno_t packno,
233                        lsquic_packno_t least_unacked, uint64_t n_in_flight);
234    unsigned
235    (*pf_packno_bits2len) (enum packno_bits);
236
237    /* Used by IETF QUIC and gQUIC >= Q050 */
238    void
239    (*pf_packno_info) (const struct lsquic_conn *,
240        const struct lsquic_packet_out *, unsigned *packno_off,
241        unsigned *packno_len);
242    int
243    (*pf_parse_max_data) (const unsigned char *, size_t, uint64_t *);
244    int
245    (*pf_gen_max_data_frame) (unsigned char *, size_t, uint64_t);
246    unsigned
247    (*pf_max_data_frame_size) (uint64_t);
248    /*
249     * Returns number of bytes parsed on success or negative value on error:
250     *  -1  Out of input buffer
251     *  -2  Invalid CID length value
252     */
253    int
254    (*pf_parse_new_conn_id) (const unsigned char *, size_t, uint64_t *,
255                        uint64_t *, lsquic_cid_t *, const unsigned char **);
256    unsigned
257    (*pf_stream_blocked_frame_size) (lsquic_stream_id_t, uint64_t);
258    int
259    (*pf_gen_stream_blocked_frame) (unsigned char *buf, size_t,
260                                                lsquic_stream_id_t, uint64_t);
261    int
262    (*pf_parse_stream_blocked_frame) (const unsigned char *buf, size_t,
263                                            lsquic_stream_id_t *, uint64_t *);
264    unsigned
265    (*pf_max_stream_data_frame_size) (lsquic_stream_id_t, uint64_t);
266    int
267    (*pf_gen_max_stream_data_frame) (unsigned char *buf, size_t,
268                                                lsquic_stream_id_t, uint64_t);
269    int
270    (*pf_parse_max_stream_data_frame) (const unsigned char *buf, size_t,
271                                            lsquic_stream_id_t *, uint64_t *);
272    int
273    (*pf_parse_new_token_frame) (const unsigned char *buf, size_t,
274                            const unsigned char **token, size_t *token_size);
275    size_t
276    (*pf_new_connection_id_frame_size) (unsigned seqno, unsigned cid_len);
277    int
278    (*pf_gen_new_connection_id_frame) (unsigned char *buf, size_t,
279                unsigned seqno, const struct lsquic_cid *,
280                const unsigned char *token, size_t);
281    size_t
282    (*pf_retire_cid_frame_size) (uint64_t);
283    int
284    (*pf_gen_retire_cid_frame) (unsigned char *buf, size_t, uint64_t);
285    int
286    (*pf_parse_retire_cid_frame) (const unsigned char *buf, size_t, uint64_t *);
287    size_t
288    (*pf_new_token_frame_size) (size_t);
289    int
290    (*pf_gen_new_token_frame) (unsigned char *buf, size_t,
291                                        const unsigned char *token, size_t);
292    int
293    (*pf_gen_streams_blocked_frame) (unsigned char *buf, size_t buf_len,
294                                        enum stream_dir, uint64_t);
295    int
296    (*pf_parse_streams_blocked_frame) (const unsigned char *buf, size_t buf_len,
297                                        enum stream_dir *, uint64_t *);
298    unsigned
299    (*pf_streams_blocked_frame_size) (uint64_t);
300    int
301    (*pf_gen_max_streams_frame) (unsigned char *buf, size_t buf_len,
302                                        enum stream_dir, uint64_t);
303    int
304    (*pf_parse_max_streams_frame) (const unsigned char *buf, size_t buf_len,
305                                        enum stream_dir *, uint64_t *);
306    unsigned
307    (*pf_max_streams_frame_size) (uint64_t);
308    unsigned
309    (*pf_path_chal_frame_size) (void);
310    int
311    (*pf_gen_path_chal_frame) (unsigned char *, size_t, uint64_t chal);
312    unsigned
313    (*pf_path_resp_frame_size) (void);
314    int
315    (*pf_gen_path_resp_frame) (unsigned char *, size_t, uint64_t resp);
316};
317
318
319extern const struct parse_funcs lsquic_parse_funcs_gquic_Q039;
320extern const struct parse_funcs lsquic_parse_funcs_gquic_Q046;
321extern const struct parse_funcs lsquic_parse_funcs_gquic_Q050;
322extern const struct parse_funcs lsquic_parse_funcs_ietf_v1;
323
324#define select_pf_by_ver(ver) (                                             \
325    (1 << (ver)) & ((1 << LSQVER_039)|(1 << LSQVER_043)) ?                  \
326                                         &lsquic_parse_funcs_gquic_Q039 :   \
327    (1 << (ver)) & (1 << LSQVER_046)                            ?           \
328                                         &lsquic_parse_funcs_gquic_Q046 :   \
329    (1 << (ver)) & ((1 << LSQVER_050)|LSQUIC_EXPERIMENTAL_Q098) ?           \
330                                         &lsquic_parse_funcs_gquic_Q050 :   \
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 (unsigned char first_byte);
352
353extern const enum quic_frame_type lsquic_iquic_byte2type[0x100];
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
397char *
398acki2str (const struct ack_info *acki, size_t *sz);
399
400void
401lsquic_turn_on_fin_Q035_thru_Q046 (unsigned char *);
402
403enum packno_bits
404lsquic_gquic_calc_packno_bits (lsquic_packno_t packno,
405                        lsquic_packno_t least_unacked, uint64_t n_in_flight);
406
407unsigned
408lsquic_gquic_packno_bits2len (enum packno_bits);
409
410#endif
411