lsquic_conn.h revision fbc6cc04 
1/* Copyright (c) 2017 - 2020 LiteSpeed Technologies Inc.  See LICENSE. */
2/*
3 * lsquic_conn.h -- Connection interface
4 *
5 * There are two types of connections: full (lsquic_full_conn.h) and mini
6 * (lsquic_mini_conn.h).  The function pointers and struct in this header
7 * file provide a unified interface engine.c can use to interact with
8 * either of the connection types.  For this to work, struct lsquic_conn
9 * must be the first element of struct full_conn and struct mini_conn.
10 */
11#ifndef LSQUIC_CONN_H
12#define LSQUIC_CONN_H
13
14#include <sys/queue.h>
15#ifndef WIN32
16#include <sys/socket.h>
17#include <netinet/in.h>
18#else
19#include <ws2ipdef.h>
20#endif
21
22struct lsquic_conn;
23struct lsquic_engine_public;
24struct lsquic_packet_out;
25struct lsquic_packet_in;
26struct sockaddr;
27struct parse_funcs;
28struct attq_elem;
29#if LSQUIC_CONN_STATS
30struct conn_stats;
31#endif
32
33enum lsquic_conn_flags {
34    LSCONN_TICKED         = (1 << 0),
35    LSCONN_HAS_OUTGOING   = (1 << 1),
36    LSCONN_HASHED         = (1 << 2),
37    LSCONN_MINI           = (1 << 3),   /* This is a mini connection */
38    LSCONN_IMMED_CLOSE    = (1 << 4),
39    LSCONN_UNUSED_5       = (1 << 5),
40    LSCONN_HANDSHAKE_DONE = (1 << 6),
41    LSCONN_CLOSING        = (1 << 7),
42    LSCONN_PEER_GOING_AWAY= (1 << 8),
43    LSCONN_TCID0          = (1 << 9),
44    LSCONN_VER_SET        = (1 <<10),   /* cn_version is set */
45    LSCONN_EVANESCENT     = (1 <<11),   /* evanescent connection */
46    LSCONN_TICKABLE       = (1 <<12),   /* Connection is in the Tickable Queue */
47    LSCONN_COI_ACTIVE     = (1 <<13),
48    LSCONN_COI_INACTIVE   = (1 <<14),
49    LSCONN_SEND_BLOCKED   = (1 <<15),   /* Send connection blocked frame */
50    LSCONN_PROMOTED       = (1 <<16),   /* Promoted.  Only set if LSCONN_MINI is set */
51    LSCONN_NEVER_TICKABLE = (1 <<17),   /* Do not put onto the Tickable Queue */
52    LSCONN_UNUSED_18      = (1 <<18),
53    LSCONN_ATTQ           = (1 <<19),
54    LSCONN_SKIP_ON_PROC   = (1 <<20),
55    LSCONN_UNUSED_21      = (1 <<21),
56    LSCONN_SERVER         = (1 <<22),
57    LSCONN_IETF           = (1 <<23),
58    LSCONN_RETRY_CONN     = (1 <<24),   /* This is a retry connection */
59};
60
61/* A connection may have things to send and be closed at the same time.
62 */
63enum tick_st {
64    TICK_SEND    = (1 << 0),
65    TICK_CLOSE   = (1 << 1),
66    TICK_PROMOTE = (1 << 2), /* Promote mini connection to full connection */
67};
68
69#define TICK_QUIET 0
70
71struct network_path
72{
73    union {
74        unsigned char           buf[sizeof(struct sockaddr_in6)];
75        struct sockaddr         sockaddr;
76    }               np_local_addr_u;
77#define np_local_addr np_local_addr_u.buf
78    unsigned char   np_peer_addr[sizeof(struct sockaddr_in6)];
79    void           *np_peer_ctx;
80    lsquic_cid_t    np_dcid;
81    unsigned short  np_pack_size;
82    unsigned char   np_path_id;
83};
84
85#define NP_LOCAL_SA(path_) (&(path_)->np_local_addr_u.sockaddr)
86#define NP_PEER_SA(path_) ((struct sockaddr *) (path_)->np_peer_addr)
87#define NP_IS_IPv6(path_) (AF_INET6 == NP_LOCAL_SA(path_)->sa_family)
88
89struct ack_state
90{
91    uint32_t    arr[6];
92};
93
94struct to_coal
95{
96    const struct lsquic_packet_out  *prev_packet;
97    size_t                           prev_sz_sum;
98};
99
100struct conn_iface
101{
102    enum tick_st
103    (*ci_tick) (struct lsquic_conn *, lsquic_time_t now);
104
105    void
106    (*ci_packet_in) (struct lsquic_conn *, struct lsquic_packet_in *);
107
108    /* Note: all packets "checked out" by calling this method should be
109     * returned back to the connection via ci_packet_sent() or
110     * ci_packet_not_sent() calls before the connection is ticked next.
111     * The connection, in turn, should not perform any extra processing
112     * (especially schedule more packets) during any of these method
113     * calls.  This is because the checked out packets are not accounted
114     * for by the congestion controller.
115     */
116    struct lsquic_packet_out *
117    (*ci_next_packet_to_send) (struct lsquic_conn *, const struct to_coal *);
118
119    void
120    (*ci_packet_sent) (struct lsquic_conn *, struct lsquic_packet_out *);
121
122    void
123    (*ci_packet_not_sent) (struct lsquic_conn *, struct lsquic_packet_out *);
124
125    void
126    (*ci_packet_too_large) (struct lsquic_conn *, struct lsquic_packet_out *);
127
128    void
129    (*ci_hsk_done) (struct lsquic_conn *, enum lsquic_hsk_status);
130
131    void
132    (*ci_destroy) (struct lsquic_conn *);
133
134    int
135    (*ci_is_tickable) (struct lsquic_conn *);
136
137    lsquic_time_t
138    (*ci_next_tick_time) (struct lsquic_conn *, unsigned *why);
139
140    int
141    (*ci_can_write_ack) (struct lsquic_conn *);
142
143    /* No return status: best effort */
144    void
145    (*ci_write_ack) (struct lsquic_conn *, struct lsquic_packet_out *);
146
147#if LSQUIC_CONN_STATS
148    const struct conn_stats *
149    (*ci_get_stats) (struct lsquic_conn *);
150#endif
151
152    void
153    (*ci_client_call_on_new) (struct lsquic_conn *);
154
155    enum LSQUIC_CONN_STATUS
156    (*ci_status) (struct lsquic_conn *, char *errbuf, size_t bufsz);
157
158    unsigned
159    (*ci_n_avail_streams) (const struct lsquic_conn *);
160
161    unsigned
162    (*ci_n_pending_streams) (const struct lsquic_conn *);
163
164    unsigned
165    (*ci_cancel_pending_streams) (struct lsquic_conn *, unsigned n);
166
167    void
168    (*ci_going_away) (struct lsquic_conn *);
169
170    int
171    (*ci_is_push_enabled) (struct lsquic_conn *);
172
173    /* Optional: only used by gQUIC frames reader */
174    /* If stream is already closed, NULL is returned */
175    struct lsquic_stream *
176    (*ci_get_stream_by_id) (struct lsquic_conn *, lsquic_stream_id_t stream_id);
177
178    struct lsquic_engine *
179    (*ci_get_engine) (struct lsquic_conn *);
180
181    void
182    (*ci_make_stream) (struct lsquic_conn *);
183
184    void
185    (*ci_abort) (struct lsquic_conn *);
186
187    void
188    (*ci_retire_cid) (struct lsquic_conn *);
189
190    void
191    (*ci_close) (struct lsquic_conn *);
192
193    void
194    (*ci_stateless_reset) (struct lsquic_conn *);
195
196    int
197    (*ci_crypto_keysize) (const struct lsquic_conn *);
198
199    int
200    (*ci_crypto_alg_keysize) (const struct lsquic_conn *);
201
202    enum lsquic_crypto_ver
203    (*ci_crypto_ver) (const struct lsquic_conn *);
204
205    const char *
206    (*ci_crypto_cipher) (const struct lsquic_conn *);
207
208    int
209    (*ci_push_stream) (struct lsquic_conn *, void *hset, struct lsquic_stream *,
210        const struct lsquic_http_headers *headers);
211
212    /* Use this to abort the connection when unlikely errors occur */
213    void
214    (*ci_internal_error) (struct lsquic_conn *, const char *format, ...)
215#if __GNUC__
216            __attribute__((format(printf, 2, 3)))
217#endif
218    ;
219
220    /* Abort connection with error */
221    void
222    (*ci_abort_error) (struct lsquic_conn *, int is_app, unsigned error_code,
223                                                        const char *format, ...)
224#if __GNUC__
225            __attribute__((format(printf, 4, 5)))
226#endif
227    ;
228
229    void
230    (*ci_tls_alert) (struct lsquic_conn *, uint8_t);
231
232    /* Returns 0 if connection is to be deleted immediately */
233    lsquic_time_t
234    (*ci_drain_time) (const struct lsquic_conn *);
235
236    /* Returns true if it's time to report the connection's CIDs' liveness */
237    int
238    (*ci_report_live) (struct lsquic_conn *, lsquic_time_t now);
239
240    /* If `local_sa' is NULL, return default path */
241    struct network_path *
242    (*ci_get_path) (struct lsquic_conn *, const struct sockaddr *local_sa);
243
244    unsigned char
245    (*ci_record_addrs) (struct lsquic_conn *, void *peer_ctx,
246        const struct sockaddr *local_sa, const struct sockaddr *peer_sa);
247
248    const lsquic_cid_t *
249    (*ci_get_log_cid) (const struct lsquic_conn *);
250
251    /* Optional method.  Only used by the IETF client code. */
252    void
253    (*ci_drop_crypto_streams) (struct lsquic_conn *);
254
255    /* Optional method.  Only used by IETF connections */
256    void
257    (*ci_count_garbage) (struct lsquic_conn *, size_t);
258
259    /* Optional method.  Must be implemented if connection sends MTU probes */
260    void
261    (*ci_mtu_probe_acked) (struct lsquic_conn *,
262                                            const struct lsquic_packet_out *);
263
264    /* Optional method.  It is called when RTO occurs. */
265    void
266    (*ci_retx_timeout) (struct lsquic_conn *);
267
268    void
269    (*ci_ack_snapshot) (struct lsquic_conn *, struct ack_state *);
270
271    void
272    (*ci_ack_rollback) (struct lsquic_conn *, struct ack_state *);
273
274    /* Optional method. */
275    int
276    (*ci_want_datagram_write) (struct lsquic_conn *, int);
277
278    /* Optional method */
279    int
280    (*ci_set_min_datagram_size) (struct lsquic_conn *, size_t);
281
282    /* Optional method */
283    size_t
284    (*ci_get_min_datagram_size) (struct lsquic_conn *);
285};
286
287#define LSCONN_CCE_BITS 3
288#define LSCONN_MAX_CCES (1 << LSCONN_CCE_BITS)
289
290struct conn_cid_elem
291{
292    struct lsquic_hash_elem     cce_hash_el;    /* Must be first element */
293    lsquic_cid_t                cce_cid;
294    union {
295        unsigned            seqno;
296        unsigned short      port;
297    }                           cce_u;
298#define cce_seqno cce_u.seqno
299#define cce_port cce_u.port
300    enum conn_cce_flags {
301        CCE_USED        = 1 << 0,       /* Connection ID has been used */
302        CCE_SEQNO       = 1 << 1,       /* cce_seqno is set (CIDs in Initial
303                                         * packets have no sequence number).
304                                         */
305        CCE_REG         = 1 << 2,       /* CID has been registered */
306        CCE_PORT        = 1 << 3,       /* It's not a CID element at all:
307                                         * cce_port is the hash value.
308                                         */
309    }                           cce_flags;
310};
311
312struct lsquic_conn
313{
314    void                        *cn_enc_session;
315    const struct enc_session_funcs_common
316                                *cn_esf_c;
317    union {
318        const struct enc_session_funcs_gquic   *g;
319        const struct enc_session_funcs_iquic   *i;
320    }                            cn_esf;
321#define cn_cid cn_cces[0].cce_cid
322    STAILQ_ENTRY(lsquic_conn)    cn_next_closed_conn;
323    /* This and cn_next_closed_conn could be made into a union, as new full
324     * connections are never closed.
325     */
326    STAILQ_ENTRY(lsquic_conn)    cn_next_new_full;
327    TAILQ_ENTRY(lsquic_conn)     cn_next_ticked;
328    TAILQ_ENTRY(lsquic_conn)     cn_next_out;
329    TAILQ_ENTRY(lsquic_conn)     cn_next_pr;
330    const struct conn_iface     *cn_if;
331    const struct parse_funcs    *cn_pf;
332    struct attq_elem            *cn_attq_elem;
333    lsquic_time_t                cn_last_sent;
334    lsquic_time_t                cn_last_ticked;
335    struct conn_cid_elem        *cn_cces;   /* At least one is available */
336    lsquic_conn_ctx_t           *cn_conn_ctx;
337    enum lsquic_conn_flags       cn_flags;
338    enum lsquic_version          cn_version:8;
339    unsigned char                cn_cces_mask;  /* Those that are set */
340    unsigned char                cn_n_cces; /* Number of CCEs in cn_cces */
341    unsigned char                cn_cur_cce_idx;
342#if LSQUIC_TEST
343    struct conn_cid_elem         cn_cces_buf[8];
344#define LSCONN_INITIALIZER_CID(lsconn_, cid_) { \
345                .cn_cces = (lsconn_).cn_cces_buf, \
346                .cn_cces_buf[0].cce_seqno = 0, \
347                .cn_cces_buf[0].cce_flags = CCE_SEQNO, \
348                .cn_cces_buf[0].cce_cid = (cid_), \
349                .cn_n_cces = 8, .cn_cces_mask = 1, }
350#define LSCONN_INITIALIZER_CIDLEN(lsconn_, len_) { \
351                .cn_cces = (lsconn_).cn_cces_buf, \
352                .cn_cces_buf[0].cce_seqno = 0, \
353                .cn_cces_buf[0].cce_flags = CCE_SEQNO, \
354                .cn_cces_buf[0].cce_cid = { .len = len_ }, \
355                .cn_n_cces = 8, .cn_cces_mask = 1, }
356#define LSCONN_INITIALIZE(lsconn_) do { \
357            (lsconn_)->cn_cces = (lsconn_)->cn_cces_buf; \
358            (lsconn_)->cn_n_cces = 8; (lsconn_)->cn_cces_mask = 1; } while (0)
359#endif
360};
361
362#define END_OF_CCES(conn) ((conn)->cn_cces + (conn)->cn_n_cces)
363
364#define CN_SCID(conn) (&(conn)->cn_cces[(conn)->cn_cur_cce_idx].cce_cid)
365
366unsigned char
367lsquic_conn_record_sockaddr (lsquic_conn_t *lconn, void *peer_ctx,
368            const struct sockaddr *local_sa, const struct sockaddr *peer_sa);
369
370int
371lsquic_conn_decrypt_packet (lsquic_conn_t *lconn,
372                    struct lsquic_engine_public *, struct lsquic_packet_in *);
373
374int
375lsquic_conn_copy_and_release_pi_data (const lsquic_conn_t *conn,
376                    struct lsquic_engine_public *, struct lsquic_packet_in *);
377
378void
379lsquic_generate_cid (lsquic_cid_t *cid, size_t len);
380
381void
382lsquic_generate_cid_gquic (lsquic_cid_t *cid);
383
384void
385lsquic_generate_scid (struct lsquic_conn *lconn, lsquic_cid_t *scid,
386                                                                unsigned len);
387
388void
389lsquic_conn_retire_cid (lsquic_conn_t *lconn);
390
391#define lsquic_conn_adv_time(c) ((c)->cn_attq_elem->ae_adv_time)
392
393#if LSQUIC_CONN_STATS
394struct conn_stats {
395    /* All counters are of the same type, unsigned long, because we cast the
396     * struct to an array to update the aggregate.
397     */
398    unsigned long           n_ticks;            /* How many time connection was ticked */
399    struct {
400        unsigned long       stream_data_sz;     /* Sum of all STREAM frames payload */
401        unsigned long       stream_frames;      /* Number of STREAM frames */
402        unsigned long       packets,            /* Incoming packets */
403                            undec_packets,      /* Undecryptable packets */
404                            dup_packets,        /* Duplicate packets */
405                            err_packets;        /* Error packets(?) */
406        unsigned long       n_acks,
407                            n_acks_proc,
408                            n_acks_merged;
409        unsigned long       bytes;              /* Overall bytes in */
410        unsigned long       headers_uncomp;     /* Sum of uncompressed header bytes */
411        unsigned long       headers_comp;       /* Sum of compressed header bytes */
412    }                   in;
413    struct {
414        unsigned long       stream_data_sz;
415        unsigned long       stream_frames;
416        unsigned long       acks;
417        unsigned long       packets;            /* Number of sent packets */
418        unsigned long       acked_via_loss;     /* Number of packets acked via loss record */
419        unsigned long       retx_packets;       /* Number of retransmitted packets */
420        unsigned long       bytes;              /* Overall bytes out */
421        unsigned long       headers_uncomp;     /* Sum of uncompressed header bytes */
422        unsigned long       headers_comp;       /* Sum of compressed header bytes */
423    }                   out;
424};
425#endif
426
427#endif
428