diff options
Diffstat (limited to 'include/linux/tcp.h')
| -rw-r--r-- | include/linux/tcp.h | 505 |
1 files changed, 505 insertions, 0 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h new file mode 100644 index 00000000..b6c62d29 --- /dev/null +++ b/include/linux/tcp.h @@ -0,0 +1,505 @@ +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Definitions for the TCP protocol. + * + * Version: @(#)tcp.h 1.0.2 04/28/93 + * + * Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#ifndef _LINUX_TCP_H +#define _LINUX_TCP_H + +#include <linux/types.h> +#include <asm/byteorder.h> +#include <linux/socket.h> + +struct tcphdr { + __be16 source; + __be16 dest; + __be32 seq; + __be32 ack_seq; +#if defined(__LITTLE_ENDIAN_BITFIELD) + __u16 res1:4, + doff:4, + fin:1, + syn:1, + rst:1, + psh:1, + ack:1, + urg:1, + ece:1, + cwr:1; +#elif defined(__BIG_ENDIAN_BITFIELD) + __u16 doff:4, + res1:4, + cwr:1, + ece:1, + urg:1, + ack:1, + psh:1, + rst:1, + syn:1, + fin:1; +#else +#error "Adjust your <asm/byteorder.h> defines" +#endif + __be16 window; + __sum16 check; + __be16 urg_ptr; +}; + +/* + * The union cast uses a gcc extension to avoid aliasing problems + * (union is compatible to any of its members) + * This means this part of the code is -fstrict-aliasing safe now. + */ +union tcp_word_hdr { + struct tcphdr hdr; + __be32 words[5]; +}; + +#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3]) + +enum { + TCP_FLAG_CWR = __cpu_to_be32(0x00800000), + TCP_FLAG_ECE = __cpu_to_be32(0x00400000), + TCP_FLAG_URG = __cpu_to_be32(0x00200000), + TCP_FLAG_ACK = __cpu_to_be32(0x00100000), + TCP_FLAG_PSH = __cpu_to_be32(0x00080000), + TCP_FLAG_RST = __cpu_to_be32(0x00040000), + TCP_FLAG_SYN = __cpu_to_be32(0x00020000), + TCP_FLAG_FIN = __cpu_to_be32(0x00010000), + TCP_RESERVED_BITS = __cpu_to_be32(0x0F000000), + TCP_DATA_OFFSET = __cpu_to_be32(0xF0000000) +}; + +/* + * TCP general constants + */ +#define TCP_MSS_DEFAULT 536U /* IPv4 (RFC1122, RFC2581) */ +#define TCP_MSS_DESIRED 1220U /* IPv6 (tunneled), EDNS0 (RFC3226) */ + +/* TCP socket options */ +#define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */ +#define TCP_MAXSEG 2 /* Limit MSS */ +#define TCP_CORK 3 /* Never send partially complete segments */ +#define TCP_KEEPIDLE 4 /* Start keeplives after this period */ +#define TCP_KEEPINTVL 5 /* Interval between keepalives */ +#define TCP_KEEPCNT 6 /* Number of keepalives before death */ +#define TCP_SYNCNT 7 /* Number of SYN retransmits */ +#define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */ +#define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */ +#define TCP_WINDOW_CLAMP 10 /* Bound advertised window */ +#define TCP_INFO 11 /* Information about this connection. */ +#define TCP_QUICKACK 12 /* Block/reenable quick acks */ +#define TCP_CONGESTION 13 /* Congestion control algorithm */ +#define TCP_MD5SIG 14 /* TCP MD5 Signature (RFC2385) */ +#define TCP_COOKIE_TRANSACTIONS 15 /* TCP Cookie Transactions */ +#define TCP_THIN_LINEAR_TIMEOUTS 16 /* Use linear timeouts for thin streams*/ +#define TCP_THIN_DUPACK 17 /* Fast retrans. after 1 dupack */ +#define TCP_USER_TIMEOUT 18 /* How long for loss retry before timeout */ + +/* for TCP_INFO socket option */ +#define TCPI_OPT_TIMESTAMPS 1 +#define TCPI_OPT_SACK 2 +#define TCPI_OPT_WSCALE 4 +#define TCPI_OPT_ECN 8 /* ECN was negociated at TCP session init */ +#define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */ + +enum tcp_ca_state { + TCP_CA_Open = 0, +#define TCPF_CA_Open (1<<TCP_CA_Open) + TCP_CA_Disorder = 1, +#define TCPF_CA_Disorder (1<<TCP_CA_Disorder) + TCP_CA_CWR = 2, +#define TCPF_CA_CWR (1<<TCP_CA_CWR) + TCP_CA_Recovery = 3, +#define TCPF_CA_Recovery (1<<TCP_CA_Recovery) + TCP_CA_Loss = 4 +#define TCPF_CA_Loss (1<<TCP_CA_Loss) +}; + +struct tcp_info { + __u8 tcpi_state; + __u8 tcpi_ca_state; + __u8 tcpi_retransmits; + __u8 tcpi_probes; + __u8 tcpi_backoff; + __u8 tcpi_options; + __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4; + + __u32 tcpi_rto; + __u32 tcpi_ato; + __u32 tcpi_snd_mss; + __u32 tcpi_rcv_mss; + + __u32 tcpi_unacked; + __u32 tcpi_sacked; + __u32 tcpi_lost; + __u32 tcpi_retrans; + __u32 tcpi_fackets; + + /* Times. */ + __u32 tcpi_last_data_sent; + __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */ + __u32 tcpi_last_data_recv; + __u32 tcpi_last_ack_recv; + + /* Metrics. */ + __u32 tcpi_pmtu; + __u32 tcpi_rcv_ssthresh; + __u32 tcpi_rtt; + __u32 tcpi_rttvar; + __u32 tcpi_snd_ssthresh; + __u32 tcpi_snd_cwnd; + __u32 tcpi_advmss; + __u32 tcpi_reordering; + + __u32 tcpi_rcv_rtt; + __u32 tcpi_rcv_space; + + __u32 tcpi_total_retrans; +}; + +/* for TCP_MD5SIG socket option */ +#define TCP_MD5SIG_MAXKEYLEN 80 + +struct tcp_md5sig { + struct __kernel_sockaddr_storage tcpm_addr; /* address associated */ + __u16 __tcpm_pad1; /* zero */ + __u16 tcpm_keylen; /* key length */ + __u32 __tcpm_pad2; /* zero */ + __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */ +}; + +/* for TCP_COOKIE_TRANSACTIONS (TCPCT) socket option */ +#define TCP_COOKIE_MIN 8 /* 64-bits */ +#define TCP_COOKIE_MAX 16 /* 128-bits */ +#define TCP_COOKIE_PAIR_SIZE (2*TCP_COOKIE_MAX) + +/* Flags for both getsockopt and setsockopt */ +#define TCP_COOKIE_IN_ALWAYS (1 << 0) /* Discard SYN without cookie */ +#define TCP_COOKIE_OUT_NEVER (1 << 1) /* Prohibit outgoing cookies, + * supercedes everything. */ + +/* Flags for getsockopt */ +#define TCP_S_DATA_IN (1 << 2) /* Was data received? */ +#define TCP_S_DATA_OUT (1 << 3) /* Was data sent? */ + +/* TCP_COOKIE_TRANSACTIONS data */ +struct tcp_cookie_transactions { + __u16 tcpct_flags; /* see above */ + __u8 __tcpct_pad1; /* zero */ + __u8 tcpct_cookie_desired; /* bytes */ + __u16 tcpct_s_data_desired; /* bytes of variable data */ + __u16 tcpct_used; /* bytes in value */ + __u8 tcpct_value[TCP_MSS_DEFAULT]; +}; + +#ifdef __KERNEL__ + +#include <linux/skbuff.h> +#include <linux/dmaengine.h> +#include <net/sock.h> +#include <net/inet_connection_sock.h> +#include <net/inet_timewait_sock.h> + +static inline struct tcphdr *tcp_hdr(const struct sk_buff *skb) +{ + return (struct tcphdr *)skb_transport_header(skb); +} + +static inline unsigned int tcp_hdrlen(const struct sk_buff *skb) +{ + return tcp_hdr(skb)->doff * 4; +} + +static inline unsigned int tcp_optlen(const struct sk_buff *skb) +{ + return (tcp_hdr(skb)->doff - 5) * 4; +} + +/* This defines a selective acknowledgement block. */ +struct tcp_sack_block_wire { + __be32 start_seq; + __be32 end_seq; +}; + +struct tcp_sack_block { + u32 start_seq; + u32 end_seq; +}; + +/*These are used to set the sack_ok field in struct tcp_options_received */ +#define TCP_SACK_SEEN (1 << 0) /*1 = peer is SACK capable, */ +#define TCP_FACK_ENABLED (1 << 1) /*1 = FACK is enabled locally*/ +#define TCP_DSACK_SEEN (1 << 2) /*1 = DSACK was received from peer*/ + +struct tcp_options_received { +/* PAWS/RTTM data */ + long ts_recent_stamp;/* Time we stored ts_recent (for aging) */ + u32 ts_recent; /* Time stamp to echo next */ + u32 rcv_tsval; /* Time stamp value */ + u32 rcv_tsecr; /* Time stamp echo reply */ + u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */ + tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */ + dsack : 1, /* D-SACK is scheduled */ + wscale_ok : 1, /* Wscale seen on SYN packet */ + sack_ok : 4, /* SACK seen on SYN packet */ + snd_wscale : 4, /* Window scaling received from sender */ + rcv_wscale : 4; /* Window scaling to send to receiver */ + u8 cookie_plus:6, /* bytes in authenticator/cookie option */ + cookie_out_never:1, + cookie_in_always:1; + u8 num_sacks; /* Number of SACK blocks */ + u16 user_mss; /* mss requested by user in ioctl */ + u16 mss_clamp; /* Maximal mss, negotiated at connection setup */ +}; + +static inline void tcp_clear_options(struct tcp_options_received *rx_opt) +{ + rx_opt->tstamp_ok = rx_opt->sack_ok = 0; + rx_opt->wscale_ok = rx_opt->snd_wscale = 0; + rx_opt->cookie_plus = 0; +} + +/* This is the max number of SACKS that we'll generate and process. It's safe + * to increase this, although since: + * size = TCPOLEN_SACK_BASE_ALIGNED (4) + n * TCPOLEN_SACK_PERBLOCK (8) + * only four options will fit in a standard TCP header */ +#define TCP_NUM_SACKS 4 + +struct tcp_cookie_values; +struct tcp_request_sock_ops; + +struct tcp_request_sock { + struct inet_request_sock req; +#ifdef CONFIG_TCP_MD5SIG + /* Only used by TCP MD5 Signature so far. */ + const struct tcp_request_sock_ops *af_specific; +#endif + u32 rcv_isn; + u32 snt_isn; + u32 snt_synack; /* synack sent time */ +}; + +static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req) +{ + return (struct tcp_request_sock *)req; +} + +struct tcp_sock { + /* inet_connection_sock has to be the first member of tcp_sock */ + struct inet_connection_sock inet_conn; + u16 tcp_header_len; /* Bytes of tcp header to send */ + u16 xmit_size_goal_segs; /* Goal for segmenting output packets */ + +/* + * Header prediction flags + * 0x5?10 << 16 + snd_wnd in net byte order + */ + __be32 pred_flags; + +/* + * RFC793 variables by their proper names. This means you can + * read the code and the spec side by side (and laugh ...) + * See RFC793 and RFC1122. The RFC writes these in capitals. + */ + u32 rcv_nxt; /* What we want to receive next */ + u32 copied_seq; /* Head of yet unread data */ + u32 rcv_wup; /* rcv_nxt on last window update sent */ + u32 snd_nxt; /* Next sequence we send */ + + u32 snd_una; /* First byte we want an ack for */ + u32 snd_sml; /* Last byte of the most recently transmitted small packet */ + u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */ + u32 lsndtime; /* timestamp of last sent data packet (for restart window) */ + + /* Data for direct copy to user */ + struct { + struct sk_buff_head prequeue; + struct task_struct *task; + struct iovec *iov; + int memory; + int len; +#ifdef CONFIG_NET_DMA + /* members for async copy */ + struct dma_chan *dma_chan; + int wakeup; + struct dma_pinned_list *pinned_list; + dma_cookie_t dma_cookie; +#endif + } ucopy; + + u32 snd_wl1; /* Sequence for window update */ + u32 snd_wnd; /* The window we expect to receive */ + u32 max_window; /* Maximal window ever seen from peer */ + u32 mss_cache; /* Cached effective mss, not including SACKS */ + + u32 window_clamp; /* Maximal window to advertise */ + u32 rcv_ssthresh; /* Current window clamp */ + + u32 frto_highmark; /* snd_nxt when RTO occurred */ + u16 advmss; /* Advertised MSS */ + u8 frto_counter; /* Number of new acks after RTO */ + u8 nonagle : 4,/* Disable Nagle algorithm? */ + thin_lto : 1,/* Use linear timeouts for thin streams */ + thin_dupack : 1,/* Fast retransmit on first dupack */ + unused : 2; + +/* RTT measurement */ + u32 srtt; /* smoothed round trip time << 3 */ + u32 mdev; /* medium deviation */ + u32 mdev_max; /* maximal mdev for the last rtt period */ + u32 rttvar; /* smoothed mdev_max */ + u32 rtt_seq; /* sequence number to update rttvar */ + + u32 packets_out; /* Packets which are "in flight" */ + u32 retrans_out; /* Retransmitted packets out */ + + u16 urg_data; /* Saved octet of OOB data and control flags */ + u8 ecn_flags; /* ECN status bits. */ + u8 reordering; /* Packet reordering metric. */ + u32 snd_up; /* Urgent pointer */ + + u8 keepalive_probes; /* num of allowed keep alive probes */ +/* + * Options received (usually on last packet, some only on SYN packets). + */ + struct tcp_options_received rx_opt; + +/* + * Slow start and congestion control (see also Nagle, and Karn & Partridge) + */ + u32 snd_ssthresh; /* Slow start size threshold */ + u32 snd_cwnd; /* Sending congestion window */ + u32 snd_cwnd_cnt; /* Linear increase counter */ + u32 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */ + u32 snd_cwnd_used; + u32 snd_cwnd_stamp; + u32 prior_cwnd; /* Congestion window at start of Recovery. */ + u32 prr_delivered; /* Number of newly delivered packets to + * receiver in Recovery. */ + u32 prr_out; /* Total number of pkts sent during Recovery. */ + + u32 rcv_wnd; /* Current receiver window */ + u32 write_seq; /* Tail(+1) of data held in tcp send buffer */ + u32 pushed_seq; /* Last pushed seq, required to talk to windows */ + u32 lost_out; /* Lost packets */ + u32 sacked_out; /* SACK'd packets */ + u32 fackets_out; /* FACK'd packets */ + u32 tso_deferred; + u32 bytes_acked; /* Appropriate Byte Counting - RFC3465 */ + + /* from STCP, retrans queue hinting */ + struct sk_buff* lost_skb_hint; + struct sk_buff *scoreboard_skb_hint; + struct sk_buff *retransmit_skb_hint; + + struct sk_buff_head out_of_order_queue; /* Out of order segments go here */ + + /* SACKs data, these 2 need to be together (see tcp_build_and_update_options) */ + struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */ + struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/ + + struct tcp_sack_block recv_sack_cache[4]; + + struct sk_buff *highest_sack; /* skb just after the highest + * skb with SACKed bit set + * (validity guaranteed only if + * sacked_out > 0) + */ + + int lost_cnt_hint; + u32 retransmit_high; /* L-bits may be on up to this seqno */ + + u32 lost_retrans_low; /* Sent seq after any rxmit (lowest) */ + + u32 prior_ssthresh; /* ssthresh saved at recovery start */ + u32 high_seq; /* snd_nxt at onset of congestion */ + + u32 retrans_stamp; /* Timestamp of the last retransmit, + * also used in SYN-SENT to remember stamp of + * the first SYN. */ + u32 undo_marker; /* tracking retrans started here. */ + int undo_retrans; /* number of undoable retransmissions. */ + u32 total_retrans; /* Total retransmits for entire connection */ + + u32 urg_seq; /* Seq of received urgent pointer */ + unsigned int keepalive_time; /* time before keep alive takes place */ + unsigned int keepalive_intvl; /* time interval between keep alive probes */ + + int linger2; + +/* Receiver side RTT estimation */ + struct { + u32 rtt; + u32 seq; + u32 time; + } rcv_rtt_est; + +/* Receiver queue space */ + struct { + int space; + u32 seq; + u32 time; + } rcvq_space; + +/* TCP-specific MTU probe information. */ + struct { + u32 probe_seq_start; + u32 probe_seq_end; + } mtu_probe; + +#ifdef CONFIG_TCP_MD5SIG +/* TCP AF-Specific parts; only used by MD5 Signature support so far */ + const struct tcp_sock_af_ops *af_specific; + +/* TCP MD5 Signature Option information */ + struct tcp_md5sig_info __rcu *md5sig_info; +#endif + + /* When the cookie options are generated and exchanged, then this + * object holds a reference to them (cookie_values->kref). Also + * contains related tcp_cookie_transactions fields. + */ + struct tcp_cookie_values *cookie_values; +}; + +static inline struct tcp_sock *tcp_sk(const struct sock *sk) +{ + return (struct tcp_sock *)sk; +} + +struct tcp_timewait_sock { + struct inet_timewait_sock tw_sk; + u32 tw_rcv_nxt; + u32 tw_snd_nxt; + u32 tw_rcv_wnd; + u32 tw_ts_recent; + long tw_ts_recent_stamp; +#ifdef CONFIG_TCP_MD5SIG + struct tcp_md5sig_key *tw_md5_key; +#endif + /* Few sockets in timewait have cookies; in that case, then this + * object holds a reference to them (tw_cookie_values->kref). + */ + struct tcp_cookie_values *tw_cookie_values; +}; + +static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk) +{ + return (struct tcp_timewait_sock *)sk; +} + +#endif /* __KERNEL__ */ + +#endif /* _LINUX_TCP_H */ |