diff options
Diffstat (limited to 'include/net/tcp.h')
| -rw-r--r-- | include/net/tcp.h | 524 |
1 files changed, 524 insertions, 0 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h new file mode 100644 index 00000000000..6f4d58a1234 --- /dev/null +++ b/include/net/tcp.h @@ -0,0 +1,524 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * TCP Support with SACK for file transfer. + * + * Copyright 2017 Duncan Hare, All rights reserved. + */ + +#define TCP_ACTIVITY 127 /* Number of packets received */ + /* before console progress mark */ +/** + * struct ip_tcp_hdr - IP and TCP header + * @ip_hl_v: header length and version + * @ip_tos: type of service + * @ip_len: total length + * @ip_id: identification + * @ip_off: fragment offset field + * @ip_ttl: time to live + * @ip_p: protocol + * @ip_sum: checksum + * @ip_src: Source IP address + * @ip_dst: Destination IP address + * @tcp_src: TCP source port + * @tcp_dst: TCP destination port + * @tcp_seq: TCP sequence number + * @tcp_ack: TCP Acknowledgment number + * @tcp_hlen: 4 bits TCP header Length/4, 4 bits reserved, 2 more bits reserved + * @tcp_flag: flags of TCP + * @tcp_win: TCP windows size + * @tcp_xsum: Checksum + * @tcp_ugr: Pointer to urgent data + */ +struct ip_tcp_hdr { + u8 ip_hl_v; + u8 ip_tos; + u16 ip_len; + u16 ip_id; + u16 ip_off; + u8 ip_ttl; + u8 ip_p; + u16 ip_sum; + struct in_addr ip_src; + struct in_addr ip_dst; + u16 tcp_src; + u16 tcp_dst; + u32 tcp_seq; + u32 tcp_ack; + u8 tcp_hlen; + u8 tcp_flags; + u16 tcp_win; + u16 tcp_xsum; + u16 tcp_ugr; +} __packed; + +#define IP_TCP_HDR_SIZE (sizeof(struct ip_tcp_hdr)) +#define TCP_HDR_SIZE (IP_TCP_HDR_SIZE - IP_HDR_SIZE) + +#define TCP_DATA 0x00 /* Data Packet - internal use only */ +#define TCP_FIN 0x01 /* Finish flag */ +#define TCP_SYN 0x02 /* Synch (start) flag */ +#define TCP_RST 0x04 /* reset flag */ +#define TCP_PUSH 0x08 /* Push - Notify app */ +#define TCP_ACK 0x10 /* Acknowledgment of data received */ +#define TCP_URG 0x20 /* Urgent */ +#define TCP_ECE 0x40 /* Congestion control */ +#define TCP_CWR 0x80 /* Congestion Control */ + +/* + * TCP header options, Seq, MSS, and SACK + */ + +#define TCP_SACK 32 /* Number of packets analyzed */ + /* on leading edge of stream */ + +#define TCP_O_END 0x00 /* End of option list */ +#define TCP_1_NOP 0x01 /* Single padding NOP */ +#define TCP_O_NOP 0x01010101 /* NOPs pad to 32 bit boundary */ +#define TCP_O_MSS 0x02 /* MSS Size option */ +#define TCP_O_SCL 0x03 /* Window Scale option */ +#define TCP_P_SACK 0x04 /* SACK permitted */ +#define TCP_V_SACK 0x05 /* SACK values */ +#define TCP_O_TS 0x08 /* Timestamp option */ +#define TCP_OPT_LEN_2 0x02 +#define TCP_OPT_LEN_3 0x03 +#define TCP_OPT_LEN_4 0x04 +#define TCP_OPT_LEN_6 0x06 +#define TCP_OPT_LEN_8 0x08 +#define TCP_OPT_LEN_A 0x0a /* Timestamp Length */ +#define TCP_MSS 1460 /* Max segment size */ +#define TCP_SCALE 0x01 /* Scale */ + +/** + * struct tcp_mss - TCP option structure for MSS (Max segment size) + * @kind: Field ID + * @len: Field length + * @mss: Segment size value + */ +struct tcp_mss { + u8 kind; + u8 len; + u16 mss; +} __packed; + +/** + * struct tcp_scale - TCP option structure for Windows scale + * @kind: Field ID + * @len: Field length + * @scale: windows shift value used for networks with many hops. + * Typically 4 or more hops + */ +struct tcp_scale { + u8 kind; + u8 len; + u8 scale; +} __packed; + +/** + * struct tcp_sack_p - TCP option structure for SACK permitted + * @kind: Field ID + * @len: Field length + */ +struct tcp_sack_p { + u8 kind; + u8 len; +} __packed; + +/** + * struct sack_edges - structure for SACK edges + * @l: Left edge of stream + * @r: right edge of stream + */ +struct sack_edges { + u32 l; + u32 r; +} __packed; + +#define TCP_SACK_SIZE (sizeof(struct sack_edges)) + +/* + * A TCP stream has holes when packets are missing or disordered. + * A hill is the inverse of a hole, and is data received. + * TCP received hills (a sequence of data), and inferrs Holes + * from the "hills" or packets received. + */ + +#define TCP_SACK_HILLS 4 + +/** + * struct tcp_sack_v - TCP option structure for SACK + * @kind: Field ID + * @len: Field length + * @hill: L & R window edges + */ +struct tcp_sack_v { + u8 kind; + u8 len; + struct sack_edges hill[TCP_SACK_HILLS]; +} __packed; + +/** + * struct tcp_t_opt - TCP option structure for time stamps + * @kind: Field ID + * @len: Field length + * @t_snd: Sender timestamp + * @t_rcv: Receiver timestamp + */ +struct tcp_t_opt { + u8 kind; + u8 len; + u32 t_snd; + u32 t_rcv; +} __packed; + +#define TCP_TSOPT_SIZE (sizeof(struct tcp_t_opt)) + +/* + * ip tcp structure with options + */ + +/** + * struct ip_tcp_hdr_o - IP + TCP header + TCP options + * @hdr: IP + TCP header + * @mss: TCP MSS Option + * @scale: TCP Windows Scale Option + * @sack_p: TCP Sack-Permitted Option + * @t_opt: TCP Timestamp Option + * @end: end of options + */ +struct ip_tcp_hdr_o { + struct ip_tcp_hdr hdr; + struct tcp_mss mss; + struct tcp_scale scale; + struct tcp_sack_p sack_p; + struct tcp_t_opt t_opt; + u8 end; +} __packed; + +#define IP_TCP_O_SIZE (sizeof(struct ip_tcp_hdr_o)) + +/** + * struct ip_tcp_hdr_s - IP + TCP header + TCP options + * @hdr: IP + TCP header + * @t_opt: TCP Timestamp Option + * @sack_v: TCP SACK Option + * @end: end of options + */ +struct ip_tcp_hdr_s { + struct ip_tcp_hdr hdr; + struct tcp_t_opt t_opt; + struct tcp_sack_v sack_v; + u8 end; +} __packed; + +#define IP_TCP_SACK_SIZE (sizeof(struct ip_tcp_hdr_s)) + +/* + * TCP pseudo header definitions + */ +#define PSEUDO_PAD_SIZE 8 + +/** + * struct pseudo_hdr - Pseudo Header + * @padding: pseudo hdr size = ip_tcp hdr size + * @p_src: Source IP address + * @p_dst: Destination IP address + * @rsvd: reserved + * @p: protocol + * @len: length of header + */ +struct pseudo_hdr { + u8 padding[PSEUDO_PAD_SIZE]; + struct in_addr p_src; + struct in_addr p_dst; + u8 rsvd; + u8 p; + u16 len; +} __packed; + +#define PSEUDO_HDR_SIZE ((sizeof(struct pseudo_hdr)) - PSEUDO_PAD_SIZE) + +/** + * union tcp_build_pkt - union for building TCP/IP packet. + * @ph: pseudo header + * @ip: IP and TCP header plus TCP options + * @sack: IP and TCP header plus SACK options + * @raw: buffer + * + * Build Pseudo header in packed buffer + * first, calculate TCP checksum, then build IP header in packed buffer. + * + */ +union tcp_build_pkt { + struct pseudo_hdr ph; + struct ip_tcp_hdr_o ip; + struct ip_tcp_hdr_s sack; + uchar raw[1600]; +} __packed; + +/** + * enum tcp_state - TCP State machine states for connection + * @TCP_CLOSED: Need to send SYN to connect + * @TCP_SYN_SENT: Trying to connect, waiting for SYN ACK + * @TCP_SYN_RECEIVED: Initial SYN received, waiting for ACK + * @TCP_ESTABLISHED: both server & client have a connection + * @TCP_CLOSE_WAIT: Rec FIN, passed to app for FIN, ACK rsp + * @TCP_CLOSING: Rec FIN, sent FIN, ACK waiting for ACK + * @TCP_FIN_WAIT_1: Sent FIN waiting for response + * @TCP_FIN_WAIT_2: Rec ACK from FIN sent, waiting for FIN + * @TCP_LAST_ACK: Waiting for ACK of the connection termination + */ +enum tcp_state { + TCP_CLOSED, + TCP_SYN_SENT, + TCP_SYN_RECEIVED, + TCP_ESTABLISHED, + TCP_CLOSE_WAIT, + TCP_CLOSING, + TCP_FIN_WAIT_1, + TCP_FIN_WAIT_2, + TCP_LAST_ACK, +}; + +/** + * enum tcp_status - TCP stream status for connection + * @TCP_ERR_OK: no rx/tx errors + * @TCP_ERR_TOUT: rx/tx timeout happened + * @TCP_ERR_RST: connection was reset + * @TCP_ERR_IO: input/output error + */ +enum tcp_status { + TCP_ERR_OK = 0, + TCP_ERR_TOUT, + TCP_ERR_RST, + TCP_ERR_IO +}; + +/** + * struct tcp_stream - TCP data stream structure + * @rhost: Remote host, network byte order + * @rport: Remote port, host byte order + * @lport: Local port, host byte order + * + * @priv: User private data (not used by tcp module) + * + * @max_retry_count: Maximum retransmit attempts (default 3) + * @initial_timeout: Timeout from initial TX to reTX (default 2 sec) + * @rx_inactiv_timeout: Maximum time from last rx till connection drop + * (default 30 sec) + * + * @on_closed: User callback, called just before destroying TCP stream + * @on_established: User callback, called when TCP stream enters + * TCP_ESTABLISHED state + * @on_rcv_nxt_update: User callback, called when all data in the segment + * [0..rx_bytes - 1] was received + * @on_snd_una_update: User callback, called when all data in the segment + * [0..tx_bytes - 1] were transferred and acknowledged + * @rx: User callback, called on receive of segment + * [rx_offs..rx_offs+len-1]. If NULL -- all incoming data + * will be ignored. User SHOULD store the segment and + * return the number of accepted bytes or negative value + * on error. + * WARNING: Previous segmengs may not be received yet + * @tx: User callback, called on transmit/retransmit of segment + * [tx_offs..tx_offs+maxlen-1]. If NULL -- no data will + * be transmitted. User SHOULD fill provided buffer and + * return the number of bytes in the buffer or negative + * value on error. + * WARNING: do not use tcp_stream_close() from this + * callback (it will break stream). Better use + * on_snd_una_update() callback for such purposes. + * + * @time_last_rx: Arrival time of last valid incoming package (ticks) + * @time_start: Timeout start time (ticks) + * @time_delta: Timeout duration (ticks) + * @time_handler Timeout handler for a stream + * + * @state: TCP connection state + * @status: TCP stream status (OK or ERR) + * @rx_packets: total number of received packets + * @tx_packets: total number of transmitted packets + * + * @fin_rx: Non-zero if TCP_FIN was received + * @fin_rx_seq: TCP sequence of rx FIN bit + * @fin_tx: Non-zero if TCP_FIN was sent (or planned to send) + * @fin_tx_seq: TCP sequence of tx FIN bit + * + * @iss: Initial send sequence number + * @snd_una: Send unacknowledged + * @snd_nxt: Send next + * @snd_wnd: Send window (in bytes) + * @snd_wl1: Segment sequence number used for last window update + * @snd_wl2: Segment acknowledgment number used for last window update + * + * @irs: Initial receive sequence number + * @rcv_nxt: Receive next + * @rcv_wnd: Receive window (in bytes) + * + * @loc_timestamp: Local timestamp + * @rmt_timestamp: Remote timestamp + * + * @rmt_win_scale: Remote window scale factor + * + * @lost: Used for SACK + * + * @retry_cnt: Number of retry attempts remaining. Only SYN, FIN + * or DATA segments are tried to retransmit. + * @retry_timeout: Current retry timeout (ms) + * @retry_action: TCP flags used for sending + * @retry_seq_num: TCP sequence for retransmit + * retry_tx_len: Number of data to transmit + * @retry_tx_offs: Position in the TX stream + */ +struct tcp_stream { + struct in_addr rhost; + u16 rport; + u16 lport; + + void *priv; + + int max_retry_count; + int initial_timeout; + int rx_inactiv_timeout; + + void (*on_closed)(struct tcp_stream *tcp); + void (*on_established)(struct tcp_stream *tcp); + void (*on_rcv_nxt_update)(struct tcp_stream *tcp, u32 rx_bytes); + void (*on_snd_una_update)(struct tcp_stream *tcp, u32 tx_bytes); + int (*rx)(struct tcp_stream *tcp, u32 rx_offs, void *buf, int len); + int (*tx)(struct tcp_stream *tcp, u32 tx_offs, void *buf, int maxlen); + + ulong time_last_rx; + ulong time_start; + ulong time_delta; + void (*time_handler)(struct tcp_stream *tcp); + + enum tcp_state state; + enum tcp_status status; + u32 rx_packets; + u32 tx_packets; + + int fin_rx; + u32 fin_rx_seq; + + int fin_tx; + u32 fin_tx_seq; + + u32 iss; + u32 snd_una; + u32 snd_nxt; + u32 snd_wnd; + u32 snd_wl1; + u32 snd_wl2; + + u32 irs; + u32 rcv_nxt; + u32 rcv_wnd; + + /* TCP option timestamp */ + u32 loc_timestamp; + u32 rmt_timestamp; + + /* TCP window scale */ + u8 rmt_win_scale; + + /* TCP sliding window control used to request re-TX */ + struct tcp_sack_v lost; + + /* used for data retransmission */ + int retry_cnt; + int retry_timeout; + u8 retry_action; + u32 retry_seq_num; + u32 retry_tx_len; + u32 retry_tx_offs; +}; + +void tcp_init(void); + +/* + * This function sets user callback called on TCP stream creation. + * Callback should: + * + Check TCP stream endpoint and make connection verdict + * - return non-zero value to accept connection + * - return zero to drop connection + * + Setup TCP stream callbacks like: on_closed(), on_established(), + * n_rcv_nxt_update(), on_snd_una_update(), rx() and tx(). + * + Setup other stream related data + * + * WARNING: User MUST setup TCP stream on_create handler. Without it + * no connection (including outgoung) will be created. + */ +void tcp_stream_set_on_create_handler(int (*on_create)(struct tcp_stream *)); + +/* + * tcp_stream_get -- Get or create TCP stream + * @is_new: if non-zero and no stream found, then create a new one + * @rhost: Remote host, network byte order + * @rport: Remote port, host byte order + * @lport: Local port, host byte order + * + * Returns: TCP stream structure or NULL (if not found/created) + */ +struct tcp_stream *tcp_stream_get(int is_new, struct in_addr rhost, + u16 rport, u16 lport); + +/* + * tcp_stream_connect -- Create new TCP stream for remote connection. + * @rhost: Remote host, network byte order + * @rport: Remote port, host byte order + * + * Returns: TCP new stream structure or NULL (if not created). + * Random local port will be used. + */ +struct tcp_stream *tcp_stream_connect(struct in_addr rhost, u16 rport); + +/* + * tcp_stream_put -- Return stream to a TCP subsystem. Subsystem will + * check stream and destroy it (if stream was already + * closed). Otherwize no stream change will happen. + * @tcp: TCP stream to put + */ +void tcp_stream_put(struct tcp_stream *tcp); + +/* + * tcp_stream_restart_rx_timer -- Restart RX inactivity timer. Usually there + * is no needs to call this function. Timer + * will be restarted on receiving of any valid + * tcp packet belonging to a stream. + * + * This function may be used to prevent connection + * break in the following case: + * - u-boot is busy with very long data processing + * - remote side waits for u-boot reply + * + * @tcp: TCP stream to put + */ +void tcp_stream_restart_rx_timer(struct tcp_stream *tcp); + +enum tcp_state tcp_stream_get_state(struct tcp_stream *tcp); +enum tcp_status tcp_stream_get_status(struct tcp_stream *tcp); + +/* + * tcp_stream_rx_offs(), + * tcp_stream_tx_offs() -- Returns offset of first unacknowledged byte + * in receive/transmit stream correspondingly. + * The result is NOT affected by sin/fin flags. + * @tcp: TCP stream + */ +u32 tcp_stream_rx_offs(struct tcp_stream *tcp); +u32 tcp_stream_tx_offs(struct tcp_stream *tcp); + +/* reset tcp stream */ +void tcp_stream_reset(struct tcp_stream *tcp); +/* force TCP stream closing, do NOT use from tcp->tx callback */ +void tcp_stream_close(struct tcp_stream *tcp); + +void tcp_streams_poll(void); + +int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int payload_len, + u8 action, u32 tcp_seq_num, u32 tcp_ack_num); + +void rxhand_tcp_f(union tcp_build_pkt *b, unsigned int len); + +u16 tcp_set_pseudo_header(uchar *pkt, struct in_addr src, struct in_addr dest, + int tcp_len, int pkt_len); |