/* 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 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, values of the other struct members are not valid. * `sr_off' indicates where inside packet_out->po_data STREAM frame begins * and `sr_len' is its length. These values are not kept for RST_STREAM * frames. * * We need this information for three 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. * 3. A buffered packet may have to be split before it is scheduled (this * occurs if we guessed incorrectly the number of bytes required to * encode the packet number and the actual number would make packet * larger than the max). * */ struct stream_rec { struct lsquic_stream *sr_stream; unsigned short sr_off, sr_len; short sr_frame_types; }; #define srec_taken(srec) ((srec)->sr_frame_types) struct stream_rec_arr { TAILQ_ENTRY(stream_rec_arr) next_stream_rec_arr; struct stream_rec srecs[ ( 64 /* Efficient size for malo allocator */ - sizeof(TAILQ_ENTRY(stream_rec)) /* next_stream_rec_arr */ ) / sizeof(struct stream_rec) ]; }; TAILQ_HEAD(stream_rec_arr_tailq, stream_rec_arr); 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, * `one' is used first. If this is not enough, any number of * stream_rec_arr structures can be allocated to handle more stream * records. */ union { struct stream_rec one; struct stream_rec_arr_tailq arr; } po_srecs; /* 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_SREC_ARR = (1 << 4), #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 impl_idx; }; 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, unsigned short len); void lsquic_packet_out_elide_reset_stream_frames (lsquic_packet_out_t *, uint32_t); int lsquic_packet_out_split_in_two (struct lsquic_mm *, lsquic_packet_out_t *, lsquic_packet_out_t *, const struct parse_funcs *, unsigned excess_bytes); void lsquic_packet_out_chop_regen (lsquic_packet_out_t *); int lsquic_packet_out_has_frame (struct lsquic_packet_out *, const struct lsquic_stream *, enum QUIC_FRAME_TYPE); int lsquic_packet_out_has_hsk_frames (struct lsquic_packet_out *); void lsquic_packet_out_ack_streams (struct lsquic_packet_out *); void lsquic_packet_out_zero_pad (struct lsquic_packet_out *); size_t lsquic_packet_out_mem_used (const struct lsquic_packet_out *); int lsquic_packet_out_turn_on_fin (struct lsquic_packet_out *, const struct parse_funcs *, const struct lsquic_stream *); #endif