/* Copyright (c) 2017 - 2019 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_conn; 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_type' * specifies the type of the frame; if this value is zero, values of the * other struct members are not valid. `sr_off' indicates where inside * packet_out->po_data the frame begins and `sr_len' is its length. * * 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; enum quic_frame_type sr_frame_type:16; }; #define srec_taken(srec) ((srec)->sr_frame_type) 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; 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_STREAM_END = (1 <<13), /* STREAM frame reaches the end of the packet: no * further writes are allowed. */ PO_SCHED = (1 <<14), /* On scheduled queue */ PO_SENT_SZ = (1 <<15), PO_LONGHEAD = (1 <<16), PO_GQUIC = (1 <<17), /* Used for logging */ #define POLEV_SHIFT 18 PO_BITS_2 = (1 <<18), /* PO_BITS_2 and PO_BITS_3 encode the */ PO_BITS_3 = (1 <<19), /* crypto level. Used for logging. */ #define POIPv6_SHIFT 20 PO_IPv6 = (1 <<20), /* Set if pmi_allocate was passed is_ipv6=1, * otherwise unset. */ PO_LIMITED = (1 <<21), /* Used to credit sc_next_limit if needed. */ } po_flags; enum quic_ft_bit po_frame_types:16; /* 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_sent_sz; /* If PO_SENT_SZ is set, real size of sent buffer. */ 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 header_type po_header_type:8; unsigned char *po_data; lsquic_packno_t po_ack2ed; /* If packet has ACK frame, value of * largest acked in it. */ /* 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 */ unsigned char *po_nonce; /* Use to generate header if PO_NONCE is set */ } 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) #define lsquic_packet_out_set_packno_bits(p, b) do { \ (p)->po_flags &= ~(0x3 << POBIT_SHIFT); \ (p)->po_flags |= ((b) & 0x3) << POBIT_SHIFT; \ } while (0) #define lsquic_packet_out_ipv6(p) ((int)(((p)->po_flags >> POIPv6_SHIFT) & 1)) #define lsquic_packet_out_set_ipv6(p, b) do { \ (p)->po_flags &= ~(1 << POIPv6_SHIFT); \ (p)->po_flags |= ((b) & 1) << POIPv6_SHIFT; \ } while (0) #define lsquic_po_header_length(lconn, po_flags) ( \ lconn->cn_pf->pf_packout_header_size(lconn, po_flags)) #define lsquic_packet_out_total_sz(lconn, p) (\ lconn->cn_pf->pf_packout_size(lconn, p)) #if __GNUC__ #if LSQUIC_EXTRA_CHECKS #define lsquic_packet_out_sent_sz(lconn, p) ( \ __builtin_expect(((p)->po_flags & PO_SENT_SZ), 1) ? \ (assert((p)->po_sent_sz == lsquic_packet_out_total_sz(lconn, p)), \ (p)->po_sent_sz) : lsquic_packet_out_total_sz(lconn, p)) # else #define lsquic_packet_out_sent_sz(lconn, p) ( \ __builtin_expect(((p)->po_flags & PO_SENT_SZ), 1) ? \ (p)->po_sent_sz : lsquic_packet_out_total_sz(lconn, p)) #endif #else # define lsquic_packet_out_sent_sz(lconn, p) ( \ (p)->po_flags & PO_SENT_SZ ? \ (p)->po_sent_sz : lsquic_packet_out_total_sz(lconn, p)) #endif #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 ) #define lsquic_packet_out_set_enc_level(p, level) do { \ (p)->po_flags &= ~(3 << POLEV_SHIFT); \ (p)->po_flags |= level << POLEV_SHIFT; \ } while (0) #define lsquic_packet_out_enc_level(p) (((p)->po_flags >> POLEV_SHIFT) & 3) 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, const struct lsquic_conn *, 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 *, void *peer_ctx); 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); unsigned 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 *); 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