diff options
Diffstat (limited to 'include/net/tcp.h')
| -rw-r--r-- | include/net/tcp.h | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h new file mode 100644 index 00000000000..c29d4ce24a7 --- /dev/null +++ b/include/net/tcp.h @@ -0,0 +1,305 @@ +/* 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 + */ +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 +}; + +enum tcp_state tcp_get_tcp_state(void); +void tcp_set_tcp_state(enum tcp_state new_state); +int tcp_set_tcp_header(uchar *pkt, int dport, int sport, int payload_len, + u8 action, u32 tcp_seq_num, u32 tcp_ack_num); + +/** + * rxhand_tcp() - An incoming packet handler. + * @pkt: pointer to the application packet + * @dport: destination TCP port + * @sip: source IP address + * @sport: source TCP port + * @tcp_seq_num: TCP sequential number + * @tcp_ack_num: TCP acknowledgment number + * @action: TCP action (SYN, ACK, FIN, etc) + * @len: packet length + */ +typedef void rxhand_tcp(uchar *pkt, u16 dport, + struct in_addr sip, u16 sport, + u32 tcp_seq_num, u32 tcp_ack_num, + u8 action, unsigned int len); +void tcp_set_tcp_handler(rxhand_tcp *f); + +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); |