litespeed-quic/src/liblsquic/lsquic_packet_out.h

163 lines
6.5 KiB
C

/* Copyright (c) 2017 LiteSpeed Technologies Inc. See LICENSE. */
/*
* lsquic_packet_out.h -- Structure and routines dealing with packet_out
*/
#ifndef LSQUIC_PACKET_OUT_H
#define LSQUIC_PACKET_OUT_H 1
#include <sys/queue.h>
struct malo;
struct lsquic_engine_public;
struct lsquic_mm;
struct lsquic_stream;
struct parse_funcs;
/* Each stream_rec is associated with one packet_out. packet_out can have
* zero or more stream_rec structures. stream_rec keeps a pointer to a stream
* that has STREAM or RST_STREAM frames inside packet_out. `sr_frame_types'
* is a bitmask that records which of these two frames are in the packet.
* If this value is zero, `sr_stream' and `sr_off' values are not valid.
* `sr_off' indicates where inside packet_out->po_data STREAM frame begins.
*
* We need this information for two reasons:
* 1. A stream is not destroyed until all of its STREAM and RST_STREAM
* frames are acknowledged. This is to make sure that we do not exceed
* maximum allowed number of streams.
* 2. When a packet is resubmitted, STREAM frames for a stream that has
* been reset are not to be resubmitted.
*/
struct stream_rec {
struct lsquic_stream *sr_stream;
unsigned short sr_off;
short sr_frame_types;
};
#define srec_taken(srec) ((srec)->sr_frame_types)
struct stream_rec_arr {
STAILQ_ENTRY(stream_rec_arr) next_stream_rec_arr;
struct stream_rec srecs[
( 64 /* Efficient size for malo allocator */
- sizeof(SLIST_ENTRY(stream_rec)) /* next_stream_rec */
) / sizeof(struct stream_rec)
];
};
typedef struct lsquic_packet_out
{
/* `po_next' is used for packets_out, unacked_packets and expired_packets
* lists.
*/
TAILQ_ENTRY(lsquic_packet_out)
po_next;
lsquic_time_t po_sent; /* Time sent */
lsquic_packno_t po_packno;
/* A lot of packets contain data belonging to only one stream. Thus,
* `srec' is used first. If this is not enough, any number of
* stream_rec_arr structures can be allocated to handle more stream
* records.
*/
struct stream_rec po_srec;
STAILQ_HEAD(, stream_rec_arr)
po_srec_arrs;
/* If PO_ENCRYPTED is set, this points to the buffer that holds encrypted
* data.
*/
unsigned char *po_enc_data;
lsquic_ver_tag_t po_ver_tag; /* Set if PO_VERSION is set */
short po_frame_types; /* Bitmask of QUIC_FRAME_* */
unsigned short po_data_sz; /* Number of usable bytes in data */
unsigned short po_enc_data_sz; /* Number of usable bytes in data */
unsigned short po_regen_sz; /* Number of bytes at the beginning
* of data containing bytes that are
* not to be retransmitted, e.g. ACK
* frames.
*/
unsigned short po_n_alloc; /* Total number of bytes allocated in po_data */
enum packet_out_flags {
PO_HELLO = (1 << 1), /* Packet contains SHLO or CHLO data */
PO_ENCRYPTED= (1 << 3), /* po_enc_data has encrypted data */
PO_WRITEABLE= (1 << 4), /* Packet is writeable */
#define POBIT_SHIFT 5
PO_BITS_0 = (1 << 5), /* PO_BITS_0 and PO_BITS_1 encode the */
PO_BITS_1 = (1 << 6), /* packet number length. See macros below. */
PO_NONCE = (1 << 7), /* Use value in `po_nonce' to generate header */
PO_VERSION = (1 << 8), /* Use value in `po_ver_tag' to generate header */
PO_CONN_ID = (1 << 9), /* Include connection ID in public header */
PO_REPACKNO = (1 <<10), /* Regenerate packet number */
PO_NOENCRYPT= (1 <<11), /* Do not encrypt data in po_data */
PO_VERNEG = (1 <<12), /* Version negotiation packet. */
} po_flags:16;
unsigned char *po_nonce; /* Use to generate header if PO_NONCE is set */
unsigned char *po_data;
} lsquic_packet_out_t;
/* The size of lsquic_packet_out_t could be further reduced:
*
* po_ver_tag could be encoded as a few bits representing enum lsquic_version
* in po_flags. The cost is a bit of complexity. This will save us four bytes.
*/
#define lsquic_packet_out_avail(p) ((unsigned short) \
((p)->po_n_alloc - (p)->po_data_sz))
#define lsquic_packet_out_packno_bits(p) (((p)->po_flags >> POBIT_SHIFT) & 0x3)
/* XXX This will need to be made into a method for Q041 */
#define lsquic_po_header_length(po_flags) ( \
1 /* Type */ \
+ (!!((po_flags) & PO_CONN_ID) << 3) /* Connection ID */ \
+ (!!((po_flags) & PO_VERSION) << 2) /* Version */ \
+ (!!((po_flags) & PO_NONCE) << 5) /* Nonce */ \
+ packno_bits2len(((po_flags) >> POBIT_SHIFT) & 0x3) /* Packet number */ \
)
#define lsquic_packet_out_verneg(p) \
(((p)->po_flags & (PO_NOENCRYPT|PO_VERNEG)) == (PO_NOENCRYPT|PO_VERNEG))
#define lsquic_packet_out_pubres(p) \
(((p)->po_flags & (PO_NOENCRYPT|PO_VERNEG)) == PO_NOENCRYPT )
struct packet_out_srec_iter {
lsquic_packet_out_t *packet_out;
struct stream_rec_arr *cur_srec_arr;
unsigned srec_idx;
int past_srec;
};
struct stream_rec *
posi_first (struct packet_out_srec_iter *posi, lsquic_packet_out_t *);
struct stream_rec *
posi_next (struct packet_out_srec_iter *posi);
lsquic_packet_out_t *
lsquic_packet_out_new (struct lsquic_mm *, struct malo *, int use_cid,
unsigned short size, enum lsquic_packno_bits,
const lsquic_ver_tag_t *, const unsigned char *nonce);
void
lsquic_packet_out_destroy (lsquic_packet_out_t *,
struct lsquic_engine_public *);
int
lsquic_packet_out_add_stream (lsquic_packet_out_t *packet_out,
struct lsquic_mm *mm,
struct lsquic_stream *new_stream,
enum QUIC_FRAME_TYPE,
unsigned short off);
void
lsquic_packet_out_elide_reset_stream_frames (lsquic_packet_out_t *,
const struct parse_funcs *, uint32_t);
void
lsquic_packet_out_chop_regen (lsquic_packet_out_t *);
#endif