X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=qemu%2Froms%2Fipxe%2Fsrc%2Finclude%2Fipxe%2Ftcp.h;fp=qemu%2Froms%2Fipxe%2Fsrc%2Finclude%2Fipxe%2Ftcp.h;h=9baa6391cd621b4e3b84fd4f89b641aea29d7e71;hb=e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb;hp=0000000000000000000000000000000000000000;hpb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;p=kvmfornfv.git diff --git a/qemu/roms/ipxe/src/include/ipxe/tcp.h b/qemu/roms/ipxe/src/include/ipxe/tcp.h new file mode 100644 index 000000000..9baa6391c --- /dev/null +++ b/qemu/roms/ipxe/src/include/ipxe/tcp.h @@ -0,0 +1,381 @@ +#ifndef _IPXE_TCP_H +#define _IPXE_TCP_H + +/** @file + * + * TCP protocol + * + * This file defines the iPXE TCP API. + * + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include + +/** + * A TCP header + */ +struct tcp_header { + uint16_t src; /* Source port */ + uint16_t dest; /* Destination port */ + uint32_t seq; /* Sequence number */ + uint32_t ack; /* Acknowledgement number */ + uint8_t hlen; /* Header length (4), Reserved (4) */ + uint8_t flags; /* Reserved (2), Flags (6) */ + uint16_t win; /* Advertised window */ + uint16_t csum; /* Checksum */ + uint16_t urg; /* Urgent pointer */ +}; + +/** @defgroup tcpopts TCP options + * @{ + */ + +/** End of TCP options list */ +#define TCP_OPTION_END 0 + +/** TCP option pad */ +#define TCP_OPTION_NOP 1 + +/** Generic TCP option */ +struct tcp_option { + uint8_t kind; + uint8_t length; +} __attribute__ (( packed )); + +/** TCP MSS option */ +struct tcp_mss_option { + uint8_t kind; + uint8_t length; + uint16_t mss; +} __attribute__ (( packed )); + +/** Code for the TCP MSS option */ +#define TCP_OPTION_MSS 2 + +/** TCP window scale option */ +struct tcp_window_scale_option { + uint8_t kind; + uint8_t length; + uint8_t scale; +} __attribute__ (( packed )); + +/** Padded TCP window scale option (used for sending) */ +struct tcp_window_scale_padded_option { + uint8_t nop; + struct tcp_window_scale_option wsopt; +} __attribute (( packed )); + +/** Code for the TCP window scale option */ +#define TCP_OPTION_WS 3 + +/** Advertised TCP window scale + * + * Using a scale factor of 2**9 provides for a maximum window of 32MB, + * which is sufficient to allow Gigabit-speed transfers with a 200ms + * RTT. The minimum advertised window is 512 bytes, which is still + * less than a single packet. + */ +#define TCP_RX_WINDOW_SCALE 9 + +/** TCP timestamp option */ +struct tcp_timestamp_option { + uint8_t kind; + uint8_t length; + uint32_t tsval; + uint32_t tsecr; +} __attribute__ (( packed )); + +/** Padded TCP timestamp option (used for sending) */ +struct tcp_timestamp_padded_option { + uint8_t nop[2]; + struct tcp_timestamp_option tsopt; +} __attribute__ (( packed )); + +/** Code for the TCP timestamp option */ +#define TCP_OPTION_TS 8 + +/** Parsed TCP options */ +struct tcp_options { + /** MSS option, if present */ + const struct tcp_mss_option *mssopt; + /** Window scale option, if present */ + const struct tcp_window_scale_option *wsopt; + /** Timestamp option, if present */ + const struct tcp_timestamp_option *tsopt; +}; + +/** @} */ + +/* + * TCP flags + */ +#define TCP_CWR 0x80 +#define TCP_ECE 0x40 +#define TCP_URG 0x20 +#define TCP_ACK 0x10 +#define TCP_PSH 0x08 +#define TCP_RST 0x04 +#define TCP_SYN 0x02 +#define TCP_FIN 0x01 + +/** +* @defgroup tcpstates TCP states +* +* The TCP state is defined by a combination of the flags that have +* been sent to the peer, the flags that have been acknowledged by the +* peer, and the flags that have been received from the peer. +* +* @{ +*/ + +/** TCP flags that have been sent in outgoing packets */ +#define TCP_STATE_SENT(flags) ( (flags) << 0 ) +#define TCP_FLAGS_SENT(state) ( ( (state) >> 0 ) & 0xff ) + +/** TCP flags that have been acknowledged by the peer + * + * Note that this applies only to SYN and FIN. + */ +#define TCP_STATE_ACKED(flags) ( (flags) << 8 ) +#define TCP_FLAGS_ACKED(state) ( ( (state) >> 8 ) & 0xff ) + +/** TCP flags that have been received from the peer + * + * Note that this applies only to SYN and FIN, and that once SYN has + * been received, we should always be sending ACK. + */ +#define TCP_STATE_RCVD(flags) ( (flags) << 16 ) +#define TCP_FLAGS_RCVD(state) ( ( (state) >> 16 ) & 0xff ) + +/** TCP flags that are currently being sent in outgoing packets */ +#define TCP_FLAGS_SENDING(state) \ + ( TCP_FLAGS_SENT ( state ) & ~TCP_FLAGS_ACKED ( state ) ) + +/** CLOSED + * + * The connection has not yet been used for anything. + */ +#define TCP_CLOSED TCP_RST + +/** LISTEN + * + * Not currently used as a state; we have no support for listening + * connections. Given a unique value to avoid compiler warnings. + */ +#define TCP_LISTEN 0 + +/** SYN_SENT + * + * SYN has been sent, nothing has yet been received or acknowledged. + */ +#define TCP_SYN_SENT ( TCP_STATE_SENT ( TCP_SYN ) ) + +/** SYN_RCVD + * + * SYN has been sent but not acknowledged, SYN has been received. + */ +#define TCP_SYN_RCVD ( TCP_STATE_SENT ( TCP_SYN | TCP_ACK ) | \ + TCP_STATE_RCVD ( TCP_SYN ) ) + +/** ESTABLISHED + * + * SYN has been sent and acknowledged, SYN has been received. + */ +#define TCP_ESTABLISHED ( TCP_STATE_SENT ( TCP_SYN | TCP_ACK ) | \ + TCP_STATE_ACKED ( TCP_SYN ) | \ + TCP_STATE_RCVD ( TCP_SYN ) ) + +/** FIN_WAIT_1 + * + * SYN has been sent and acknowledged, SYN has been received, FIN has + * been sent but not acknowledged, FIN has not been received. + * + * RFC 793 shows that we can enter FIN_WAIT_1 without have had SYN + * acknowledged, i.e. if the application closes the connection after + * sending and receiving SYN, but before having had SYN acknowledged. + * However, we have to *pretend* that SYN has been acknowledged + * anyway, otherwise we end up sending SYN and FIN in the same + * sequence number slot. Therefore, when we transition from SYN_RCVD + * to FIN_WAIT_1, we have to remember to set TCP_STATE_ACKED(TCP_SYN) + * and increment our sequence number. + */ +#define TCP_FIN_WAIT_1 ( TCP_STATE_SENT ( TCP_SYN | TCP_ACK | TCP_FIN ) | \ + TCP_STATE_ACKED ( TCP_SYN ) | \ + TCP_STATE_RCVD ( TCP_SYN ) ) + +/** FIN_WAIT_2 + * + * SYN has been sent and acknowledged, SYN has been received, FIN has + * been sent and acknowledged, FIN ha not been received. + */ +#define TCP_FIN_WAIT_2 ( TCP_STATE_SENT ( TCP_SYN | TCP_ACK | TCP_FIN ) | \ + TCP_STATE_ACKED ( TCP_SYN | TCP_FIN ) | \ + TCP_STATE_RCVD ( TCP_SYN ) ) + +/** CLOSING / LAST_ACK + * + * SYN has been sent and acknowledged, SYN has been received, FIN has + * been sent but not acknowledged, FIN has been received. + * + * This state actually encompasses both CLOSING and LAST_ACK; they are + * identical with the definition of state that we use. I don't + * *believe* that they need to be distinguished. + */ +#define TCP_CLOSING_OR_LAST_ACK \ + ( TCP_STATE_SENT ( TCP_SYN | TCP_ACK | TCP_FIN ) | \ + TCP_STATE_ACKED ( TCP_SYN ) | \ + TCP_STATE_RCVD ( TCP_SYN | TCP_FIN ) ) + +/** TIME_WAIT + * + * SYN has been sent and acknowledged, SYN has been received, FIN has + * been sent and acknowledged, FIN has been received. + */ +#define TCP_TIME_WAIT ( TCP_STATE_SENT ( TCP_SYN | TCP_ACK | TCP_FIN ) | \ + TCP_STATE_ACKED ( TCP_SYN | TCP_FIN ) | \ + TCP_STATE_RCVD ( TCP_SYN | TCP_FIN ) ) + +/** CLOSE_WAIT + * + * SYN has been sent and acknowledged, SYN has been received, FIN has + * been received. + */ +#define TCP_CLOSE_WAIT ( TCP_STATE_SENT ( TCP_SYN | TCP_ACK ) | \ + TCP_STATE_ACKED ( TCP_SYN ) | \ + TCP_STATE_RCVD ( TCP_SYN | TCP_FIN ) ) + +/** Can send data in current state + * + * We can send data if and only if we have had our SYN acked and we + * have not yet sent our FIN. + */ +#define TCP_CAN_SEND_DATA(state) \ + ( ( (state) & ( TCP_STATE_ACKED ( TCP_SYN ) | \ + TCP_STATE_SENT ( TCP_FIN ) ) ) \ + == TCP_STATE_ACKED ( TCP_SYN ) ) + +/** Have ever been fully established + * + * We have been fully established if we have both received a SYN and + * had our own SYN acked. + */ +#define TCP_HAS_BEEN_ESTABLISHED(state) \ + ( ( (state) & ( TCP_STATE_ACKED ( TCP_SYN ) | \ + TCP_STATE_RCVD ( TCP_SYN ) ) ) \ + == ( TCP_STATE_ACKED ( TCP_SYN ) | TCP_STATE_RCVD ( TCP_SYN ) ) ) + +/** Have closed gracefully + * + * We have closed gracefully if we have both received a FIN and had + * our own FIN acked. + */ +#define TCP_CLOSED_GRACEFULLY(state) \ + ( ( (state) & ( TCP_STATE_ACKED ( TCP_FIN ) | \ + TCP_STATE_RCVD ( TCP_FIN ) ) ) \ + == ( TCP_STATE_ACKED ( TCP_FIN ) | TCP_STATE_RCVD ( TCP_FIN ) ) ) + +/** @} */ + +/** Mask for TCP header length field */ +#define TCP_MASK_HLEN 0xf0 + +/** Smallest port number on which a TCP connection can listen */ +#define TCP_MIN_PORT 1 + +/** + * Maxmimum advertised TCP window size + * + * The maximum bandwidth on any link is limited by + * + * max_bandwidth * round_trip_time = tcp_window + * + * Some rough expectations for achievable bandwidths over various + * links are: + * + * a) Gigabit LAN: expected bandwidth 125MB/s, typical RTT 0.5ms, + * minimum required window 64kB + * + * b) Home Internet connection: expected bandwidth 10MB/s, typical + * RTT 25ms, minimum required window 256kB + * + * c) WAN: expected bandwidth 2MB/s, typical RTT 100ms, minimum + * required window 200kB. + * + * The maximum possible value for the TCP window size is 1GB (using + * the maximum window scale of 2**14). However, it is advisable to + * keep the window size as small as possible (without limiting + * bandwidth), since in the event of a lost packet the window size + * represents the maximum amount that will need to be retransmitted. + * + * We therefore choose a maximum window size of 256kB. + */ +#define TCP_MAX_WINDOW_SIZE ( 256 * 1024 ) + +/** + * Path MTU + * + * IPv6 requires all data link layers to support a datagram size of + * 1280 bytes. We choose to use this as our maximum transmitted + * datagram size, on the assumption that any practical link layer we + * encounter will allow this size. This is a very conservative + * assumption in practice, but the impact of making such a + * conservative assumption is insignificant since the amount of data + * that we transmit (rather than receive) is negligible. + * + * We allow space within this 1280 bytes for an IPv6 header, a TCP + * header, and a (padded) TCP timestamp option. + */ +#define TCP_PATH_MTU \ + ( 1280 - 40 /* IPv6 */ - 20 /* TCP */ - 12 /* TCP timestamp */ ) + +/** TCP maximum segment lifetime + * + * Currently set to 2 minutes, as per RFC 793. + */ +#define TCP_MSL ( 2 * 60 * TICKS_PER_SEC ) + +/** + * TCP maximum header length + * + */ +#define TCP_MAX_HEADER_LEN \ + ( MAX_LL_NET_HEADER_LEN + \ + sizeof ( struct tcp_header ) + \ + sizeof ( struct tcp_mss_option ) + \ + sizeof ( struct tcp_window_scale_padded_option ) + \ + sizeof ( struct tcp_timestamp_padded_option ) ) + +/** + * Compare TCP sequence numbers + * + * @v seq1 Sequence number 1 + * @v seq2 Sequence number 2 + * @ret diff Sequence difference + * + * Analogous to memcmp(), returns an integer less than, equal to, or + * greater than zero if @c seq1 is found, respectively, to be before, + * equal to, or after @c seq2. + */ +static inline __attribute__ (( always_inline )) int32_t +tcp_cmp ( uint32_t seq1, uint32_t seq2 ) { + return ( ( int32_t ) ( seq1 - seq2 ) ); +} + +/** + * Check if TCP sequence number lies within window + * + * @v seq Sequence number + * @v start Start of window + * @v len Length of window + * @ret in_window Sequence number is within window + */ +static inline int tcp_in_window ( uint32_t seq, uint32_t start, + uint32_t len ) { + return ( ( seq - start ) < len ); +} + +extern struct tcpip_protocol tcp_protocol __tcpip_protocol; + +#endif /* _IPXE_TCP_H */