lsquic_conn.h revision b8fa6195 
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 conn_iface
90{
91    enum tick_st
92    (*ci_tick) (struct lsquic_conn *, lsquic_time_t now);
93
94    void
95    (*ci_packet_in) (struct lsquic_conn *, struct lsquic_packet_in *);
96
97    /* Note: all packets "checked out" by calling this method should be
98     * returned back to the connection via ci_packet_sent() or
99     * ci_packet_not_sent() calls before the connection is ticked next.
100     * The connection, in turn, should not perform any extra processing
101     * (especially schedule more packets) during any of these method
102     * calls.  This is because the checked out packets are not accounted
103     * for by the congestion controller.
104     */
105    struct lsquic_packet_out *
106    (*ci_next_packet_to_send) (struct lsquic_conn *, size_t);
107
108    void
109    (*ci_packet_sent) (struct lsquic_conn *, struct lsquic_packet_out *);
110
111    void
112    (*ci_packet_not_sent) (struct lsquic_conn *, struct lsquic_packet_out *);
113
114    void
115    (*ci_packet_too_large) (struct lsquic_conn *, struct lsquic_packet_out *);
116
117    void
118    (*ci_hsk_done) (struct lsquic_conn *, enum lsquic_hsk_status);
119
120    void
121    (*ci_destroy) (struct lsquic_conn *);
122
123    int
124    (*ci_is_tickable) (struct lsquic_conn *);
125
126    lsquic_time_t
127    (*ci_next_tick_time) (struct lsquic_conn *, unsigned *why);
128
129    int
130    (*ci_can_write_ack) (struct lsquic_conn *);
131
132    /* No return status: best effort */
133    void
134    (*ci_write_ack) (struct lsquic_conn *, struct lsquic_packet_out *);
135
136#if LSQUIC_CONN_STATS
137    const struct conn_stats *
138    (*ci_get_stats) (struct lsquic_conn *);
139#endif
140
141    void
142    (*ci_client_call_on_new) (struct lsquic_conn *);
143
144    enum LSQUIC_CONN_STATUS
145    (*ci_status) (struct lsquic_conn *, char *errbuf, size_t bufsz);
146
147    unsigned
148    (*ci_n_avail_streams) (const struct lsquic_conn *);
149
150    unsigned
151    (*ci_n_pending_streams) (const struct lsquic_conn *);
152
153    unsigned
154    (*ci_cancel_pending_streams) (struct lsquic_conn *, unsigned n);
155
156    void
157    (*ci_going_away) (struct lsquic_conn *);
158
159    int
160    (*ci_is_push_enabled) (struct lsquic_conn *);
161
162    /* Optional: only used by gQUIC frames reader */
163    /* If stream is already closed, NULL is returned */
164    struct lsquic_stream *
165    (*ci_get_stream_by_id) (struct lsquic_conn *, lsquic_stream_id_t stream_id);
166
167    struct lsquic_engine *
168    (*ci_get_engine) (struct lsquic_conn *);
169
170    struct lsquic_conn_ctx *
171    (*ci_get_ctx) (const struct lsquic_conn *);
172
173    void
174    (*ci_set_ctx) (struct lsquic_conn *, struct lsquic_conn_ctx *);
175
176    void
177    (*ci_make_stream) (struct lsquic_conn *);
178
179    void
180    (*ci_abort) (struct lsquic_conn *);
181
182    void
183    (*ci_retire_cid) (struct lsquic_conn *);
184
185    void
186    (*ci_close) (struct lsquic_conn *);
187
188    void
189    (*ci_stateless_reset) (struct lsquic_conn *);
190
191    int
192    (*ci_crypto_keysize) (const struct lsquic_conn *);
193
194    int
195    (*ci_crypto_alg_keysize) (const struct lsquic_conn *);
196
197    enum lsquic_crypto_ver
198    (*ci_crypto_ver) (const struct lsquic_conn *);
199
200    const char *
201    (*ci_crypto_cipher) (const struct lsquic_conn *);
202
203    int
204    (*ci_push_stream) (struct lsquic_conn *, void *hset, struct lsquic_stream *,
205        const struct lsquic_http_headers *headers);
206
207    /* Use this to abort the connection when unlikely errors occur */
208    void
209    (*ci_internal_error) (struct lsquic_conn *, const char *format, ...)
210#if __GNUC__
211            __attribute__((format(printf, 2, 3)))
212#endif
213    ;
214
215    /* Abort connection with error */
216    void
217    (*ci_abort_error) (struct lsquic_conn *, int is_app, unsigned error_code,
218                                                        const char *format, ...)
219#if __GNUC__
220            __attribute__((format(printf, 4, 5)))
221#endif
222    ;
223
224    void
225    (*ci_tls_alert) (struct lsquic_conn *, uint8_t);
226
227    /* Returns 0 if connection is to be deleted immediately */
228    lsquic_time_t
229    (*ci_drain_time) (const struct lsquic_conn *);
230
231    /* Returns true if it's time to report the connection's CIDs' liveness */
232    int
233    (*ci_report_live) (struct lsquic_conn *, lsquic_time_t now);
234
235    /* If `local_sa' is NULL, return default path */
236    struct network_path *
237    (*ci_get_path) (struct lsquic_conn *, const struct sockaddr *local_sa);
238
239    unsigned char
240    (*ci_record_addrs) (struct lsquic_conn *, void *peer_ctx,
241        const struct sockaddr *local_sa, const struct sockaddr *peer_sa);
242
243    const lsquic_cid_t *
244    (*ci_get_log_cid) (const struct lsquic_conn *);
245
246    /* Optional method.  Only used by the IETF client code. */
247    void
248    (*ci_drop_crypto_streams) (struct lsquic_conn *);
249
250    /* Optional method.  Only used by IETF connections */
251    void
252    (*ci_count_garbage) (struct lsquic_conn *, size_t);
253
254    /* Optional method.  Must be implemented if connection sends MTU probes */
255    void
256    (*ci_mtu_probe_acked) (struct lsquic_conn *,
257                                            const struct lsquic_packet_out *);
258
259    /* Optional method.  It is called when RTO occurs. */
260    void
261    (*ci_retx_timeout) (struct lsquic_conn *);
262};
263
264#define LSCONN_CCE_BITS 3
265#define LSCONN_MAX_CCES (1 << LSCONN_CCE_BITS)
266
267struct conn_cid_elem
268{
269    struct lsquic_hash_elem     cce_hash_el;    /* Must be first element */
270    lsquic_cid_t                cce_cid;
271    union {
272        unsigned            seqno;
273        unsigned short      port;
274    }                           cce_u;
275#define cce_seqno cce_u.seqno
276#define cce_port cce_u.port
277    enum conn_cce_flags {
278        CCE_USED        = 1 << 0,       /* Connection ID has been used */
279        CCE_SEQNO       = 1 << 1,       /* cce_seqno is set (CIDs in Initial
280                                         * packets have no sequence number).
281                                         */
282        CCE_REG         = 1 << 2,       /* CID has been registered */
283        CCE_PORT        = 1 << 3,       /* It's not a CID element at all:
284                                         * cce_port is the hash value.
285                                         */
286    }                           cce_flags;
287};
288
289struct lsquic_conn
290{
291    void                        *cn_enc_session;
292    const struct enc_session_funcs_common
293                                *cn_esf_c;
294    union {
295        const struct enc_session_funcs_gquic   *g;
296        const struct enc_session_funcs_iquic   *i;
297    }                            cn_esf;
298#define cn_cid cn_cces[0].cce_cid
299    STAILQ_ENTRY(lsquic_conn)    cn_next_closed_conn;
300    /* This and cn_next_closed_conn could be made into a union, as new full
301     * connections are never closed.
302     */
303    STAILQ_ENTRY(lsquic_conn)    cn_next_new_full;
304    TAILQ_ENTRY(lsquic_conn)     cn_next_ticked;
305    TAILQ_ENTRY(lsquic_conn)     cn_next_out;
306    TAILQ_ENTRY(lsquic_conn)     cn_next_pr;
307    const struct conn_iface     *cn_if;
308    const struct parse_funcs    *cn_pf;
309    struct attq_elem            *cn_attq_elem;
310    lsquic_time_t                cn_last_sent;
311    lsquic_time_t                cn_last_ticked;
312    struct conn_cid_elem        *cn_cces;   /* At least one is available */
313    enum lsquic_conn_flags       cn_flags;
314    enum lsquic_version          cn_version:8;
315    unsigned char                cn_cces_mask;  /* Those that are set */
316    unsigned char                cn_n_cces; /* Number of CCEs in cn_cces */
317    unsigned char                cn_cur_cce_idx;
318#if LSQUIC_TEST
319    struct conn_cid_elem         cn_cces_buf[8];
320#define LSCONN_INITIALIZER_CID(lsconn_, cid_) { \
321                .cn_cces = (lsconn_).cn_cces_buf, \
322                .cn_cces_buf[0].cce_seqno = 0, \
323                .cn_cces_buf[0].cce_flags = CCE_SEQNO, \
324                .cn_cces_buf[0].cce_cid = (cid_), \
325                .cn_n_cces = 8, .cn_cces_mask = 1, }
326#define LSCONN_INITIALIZER_CIDLEN(lsconn_, len_) { \
327                .cn_cces = (lsconn_).cn_cces_buf, \
328                .cn_cces_buf[0].cce_seqno = 0, \
329                .cn_cces_buf[0].cce_flags = CCE_SEQNO, \
330                .cn_cces_buf[0].cce_cid = { .len = len_ }, \
331                .cn_n_cces = 8, .cn_cces_mask = 1, }
332#define LSCONN_INITIALIZE(lsconn_) do { \
333            (lsconn_)->cn_cces = (lsconn_)->cn_cces_buf; \
334            (lsconn_)->cn_n_cces = 8; (lsconn_)->cn_cces_mask = 1; } while (0)
335#endif
336};
337
338#define END_OF_CCES(conn) ((conn)->cn_cces + (conn)->cn_n_cces)
339
340#define CN_SCID(conn) (&(conn)->cn_cces[(conn)->cn_cur_cce_idx].cce_cid)
341
342unsigned char
343lsquic_conn_record_sockaddr (lsquic_conn_t *lconn, void *peer_ctx,
344            const struct sockaddr *local_sa, const struct sockaddr *peer_sa);
345
346int
347lsquic_conn_decrypt_packet (lsquic_conn_t *lconn,
348                    struct lsquic_engine_public *, struct lsquic_packet_in *);
349
350int
351lsquic_conn_copy_and_release_pi_data (const lsquic_conn_t *conn,
352                    struct lsquic_engine_public *, struct lsquic_packet_in *);
353
354void
355lsquic_generate_cid (lsquic_cid_t *cid, size_t len);
356
357void
358lsquic_generate_cid_gquic (lsquic_cid_t *cid);
359
360void
361lsquic_conn_retire_cid (lsquic_conn_t *lconn);
362
363#define lsquic_conn_adv_time(c) ((c)->cn_attq_elem->ae_adv_time)
364
365#if LSQUIC_CONN_STATS
366struct conn_stats {
367    /* All counters are of the same type, unsigned long, because we cast the
368     * struct to an array to update the aggregate.
369     */
370    unsigned long           n_ticks;            /* How many time connection was ticked */
371    struct {
372        unsigned long       stream_data_sz;     /* Sum of all STREAM frames payload */
373        unsigned long       stream_frames;      /* Number of STREAM frames */
374        unsigned long       packets,            /* Incoming packets */
375                            undec_packets,      /* Undecryptable packets */
376                            dup_packets,        /* Duplicate packets */
377                            err_packets;        /* Error packets(?) */
378        unsigned long       n_acks,
379                            n_acks_proc,
380                            n_acks_merged;
381        unsigned long       bytes;              /* Overall bytes in */
382        unsigned long       headers_uncomp;     /* Sum of uncompressed header bytes */
383        unsigned long       headers_comp;       /* Sum of compressed header bytes */
384    }                   in;
385    struct {
386        unsigned long       stream_data_sz;
387        unsigned long       stream_frames;
388        unsigned long       acks;
389        unsigned long       packets;            /* Number of sent packets */
390        unsigned long       acked_via_loss;     /* Number of packets acked via loss record */
391        unsigned long       retx_packets;       /* Number of retransmitted packets */
392        unsigned long       bytes;              /* Overall bytes out */
393        unsigned long       headers_uncomp;     /* Sum of uncompressed header bytes */
394        unsigned long       headers_comp;       /* Sum of compressed header bytes */
395    }                   out;
396};
397#endif
398
399#endif
400