/* Copyright (c) 2017 - 2022 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 network_path; struct parse_funcs; struct bwp_state; /* Each frame_rec is associated with one packet_out. packet_out can have * zero or more frame_rec structures. frame_rec keeps a pointer to a stream * that has STREAM, CRYPTO, or RST_STREAM frames inside packet_out. * `fe_frame_type' specifies the type of the frame; if this value is zero * (this happens when a frame is elided), values of the other struct members * are not valid. `fe_off' indicates where inside packet_out->po_data the * frame begins and `fe_len' is its length. * * We need this information for four 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). * 4. A lost or scheduled packet may need to be resized (down) when path * changes or MTU is reduced due to an RTO. * * In IETF, all frames are recorded. In gQUIC, only STREAM, RST_STREAM, * ACK, and STOP_WAITING are recorded. The latter two are done so that * ACK-deleting code in send controller (see po_regen_sz) is the same for * both QUIC versions. */ struct frame_rec { union { struct lsquic_stream *stream; uintptr_t data; } fe_u; #define fe_stream fe_u.stream unsigned short fe_off, fe_len; enum quic_frame_type fe_frame_type; }; #define frec_taken(frec) ((frec)->fe_frame_type) struct frame_rec_arr { TAILQ_ENTRY(frame_rec_arr) next_stream_rec_arr; struct frame_rec frecs[ ( 64 /* Efficient size for malo allocator */ - sizeof(TAILQ_ENTRY(frame_rec)) /* next_stream_rec_arr */ ) / sizeof(struct frame_rec) ]; }; TAILQ_HEAD(frame_rec_arr_tailq, frame_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; lsquic_packno_t po_ack2ed; /* If packet has ACK frame, value of * largest acked in it. */ struct lsquic_packet_out *po_loss_chain; /* Circular linked list */ enum quic_ft_bit po_frame_types; /* Bitmask of QUIC_FRAME_* */ enum packet_out_flags { /* TODO XXX Phase out PO_MINI in favor of a more specialized flag: * we only need an indicator that a packet contains STREAM frames * but no associated frecs. This type of packets in only created * by GQUIC mini conn. */ PO_MINI = (1 << 0), /* Allocated by mini connection */ PO_HELLO = (1 << 1), /* Packet contains SHLO or CHLO data */ PO_SENT = (1 << 2), /* Packet has been sent (mini only) */ PO_ENCRYPTED= (1 << 3), /* po_enc_data has encrypted data */ PO_FREC_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_ACKED_LOSS_CHAIN = (1<<17), #define POIPv6_SHIFT 20 PO_IPv6 = (1 <<20), /* Set if pmi_allocate was passed is_ipv6=1, * otherwise unset. */ PO_MTU_PROBE= (1 <<21), /* Special loss and ACK rules apply */ #define POPNS_SHIFT 22 PO_PNS_HSK = (1 <<22), /* PNS bits contain the value of the */ PO_PNS_APP = (1 <<23), /* packet number space. */ PO_RETRY = (1 <<24), /* Retry packet */ PO_RETX = (1 <<25), /* Retransmitted packet: don't append to it */ PO_POISON = (1 <<26), /* Used to detect opt-ACK attack */ PO_LOSS_REC = (1 <<27), /* This structure is a loss record */ /* Only one of PO_SCHED, PO_UNACKED, or PO_LOST can be set. If pressed * for room in the enum, we can switch to using two bits to represent * this information. */ PO_UNACKED = (1 <<28), /* On unacked queue */ PO_LOST = (1 <<29), /* On lost queue */ #define POSPIN_SHIFT 30 PO_SPIN_BIT = (1 <<30), /* Value of the spin bit */ } po_flags; 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. */ /* TODO Revisit po_regen_sz once gQUIC is dropped. Now that all frames * are recorded, we have more flexibility where to place ACK frames; they * no longer really have to be at the beginning of the packet, since we * can locate them. */ 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 */ unsigned short po_token_len; enum header_type po_header_type:8; unsigned char po_dcid_len; /* If PO_ENCRYPTED is set */ enum { POL_GQUIC = 1 << 0, /* Used for logging */ #define POLEV_SHIFT 1 POL_ELBIT_0 = 1 << 1, /* EL bits encode the crypto level. */ POL_ELBIT_1 = 1 << 2, #define POKP_SHIFT 3 POL_KEY_PHASE= 1 << 3, #define POECN_SHIFT 4 POL_ECNBIT_0 = 1 << 4, POL_ECNBIT_1 = 1 << 5, POL_LOG_QL_BITS = 1 << 6, POL_SQUARE_BIT = 1 << 7, POL_LOSS_BIT = 1 << 8, #ifndef NDEBUG POL_HEADER_PROT = 1 << 9, /* Header protection applied */ #endif POL_LIMITED = 1 << 10, /* Used to credit sc_next_limit if needed. */ POL_FACKED = 1 << 11, /* Lost due to FACK check */ } po_lflags:16; unsigned char *po_data; /* A lot of packets contain only one frame. Thus, `one' is used first. * If this is not enough, any number of frame_rec_arr structures can be * allocated to handle more frame records. */ union { struct frame_rec one; struct frame_rec_arr_tailq arr; } po_frecs; /* 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 short po_retx_cnt; unsigned short po_padding_sz; unsigned char *po_nonce; /* Use to generate header if PO_NONCE is set */ const struct network_path *po_path; #define po_token po_nonce struct bwp_state *po_bwp_state; } lsquic_packet_out_t; /* This is to make sure these bit names are not used, they are only for * convenience in gdb output. */ #define PO_PNS_HSK #define PO_PNS_APP /* 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_packet_out_spin_bit(p) (((p)->po_flags & PO_SPIN_BIT) > 0) #define lsquic_packet_out_square_bit(p) (((p)->po_lflags & POL_SQUARE_BIT) > 0) #define lsquic_packet_out_loss_bit(p) (((p)->po_lflags & POL_LOSS_BIT) > 0) #define lsquic_packet_out_set_spin_bit(p, b) do { \ (p)->po_flags &= ~PO_SPIN_BIT; \ (p)->po_flags |= ((b) & 1) << POSPIN_SHIFT; \ } while (0) #define lsquic_po_header_length(lconn, po_flags, dcid_len, header_type) ( \ lconn->cn_pf->pf_packout_max_header_size(lconn, po_flags, dcid_len, \ header_type)) \ #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_flags & PO_HELLO /* Avoid client DCID change */) \ || (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_RETRY)) == (PO_NOENCRYPT|PO_VERNEG)) #define lsquic_packet_out_pubres(p) \ (((p)->po_flags & (PO_NOENCRYPT|PO_VERNEG|PO_RETRY)) == PO_NOENCRYPT ) #define lsquic_packet_out_retry(p) \ (((p)->po_flags & (PO_NOENCRYPT|PO_VERNEG|PO_RETRY)) == (PO_NOENCRYPT|PO_RETRY) ) #define lsquic_packet_out_set_enc_level(p, level) do { \ (p)->po_lflags &= ~(3 << POLEV_SHIFT); \ (p)->po_lflags |= level << POLEV_SHIFT; \ } while (0) #define lsquic_packet_out_enc_level(p) (((p)->po_lflags >> POLEV_SHIFT) & 3) #define lsquic_packet_out_set_kp(p, kp) do { \ (p)->po_lflags &= ~(1 << POKP_SHIFT); \ (p)->po_lflags |= kp << POKP_SHIFT; \ } while (0) #define lsquic_packet_out_kp(p) (((p)->po_lflags >> POKP_SHIFT) & 1) #define lsquic_packet_out_set_pns(p, pns) do { \ (p)->po_flags &= ~(3 << POPNS_SHIFT); \ (p)->po_flags |= pns << POPNS_SHIFT; \ } while (0) #define lsquic_packet_out_pns(p) (((p)->po_flags >> POPNS_SHIFT) & 3) #define lsquic_packet_out_set_ecn(p, ecn) do { \ (p)->po_lflags &= ~(3 << POECN_SHIFT); \ (p)->po_lflags |= ecn << POECN_SHIFT; \ } while (0) #define lsquic_packet_out_ecn(p) (((p)->po_lflags >> POECN_SHIFT) & 3) struct packet_out_frec_iter { lsquic_packet_out_t *packet_out; struct frame_rec_arr *cur_frec_arr; unsigned frec_idx; int impl_idx; }; struct frame_rec * lsquic_pofi_first (struct packet_out_frec_iter *pofi, lsquic_packet_out_t *); struct frame_rec * lsquic_pofi_next (struct packet_out_frec_iter *pofi); lsquic_packet_out_t * lsquic_packet_out_new (struct lsquic_mm *, struct malo *, int use_cid, const struct lsquic_conn *, enum packno_bits, const lsquic_ver_tag_t *, const unsigned char *nonce, const struct network_path *, enum header_type); void lsquic_packet_out_destroy (lsquic_packet_out_t *, struct lsquic_engine_public *, void *peer_ctx); int lsquic_packet_out_add_frame (struct lsquic_packet_out *, struct lsquic_mm *, uintptr_t data, enum quic_frame_type, unsigned short off, unsigned short len); 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 *, lsquic_stream_id_t); 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 *); int lsquic_packet_out_equal_dcids (const struct lsquic_packet_out *, const struct lsquic_packet_out *); void lsquic_packet_out_pad_over (struct lsquic_packet_out *packet_out, enum quic_ft_bit frame_types); #endif