tools/include/uapi/linux/tcp.h

Source file repositories/reference/linux-study-clean/tools/include/uapi/linux/tcp.h

File Facts

System
Linux kernel
Corpus path
tools/include/uapi/linux/tcp.h
Extension
.h
Size
11790 bytes
Lines
358
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

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 = __constant_cpu_to_be32(0x00800000),
	TCP_FLAG_ECE = __constant_cpu_to_be32(0x00400000),
	TCP_FLAG_URG = __constant_cpu_to_be32(0x00200000),
	TCP_FLAG_ACK = __constant_cpu_to_be32(0x00100000),
	TCP_FLAG_PSH = __constant_cpu_to_be32(0x00080000),
	TCP_FLAG_RST = __constant_cpu_to_be32(0x00040000),
	TCP_FLAG_SYN = __constant_cpu_to_be32(0x00020000),
	TCP_FLAG_FIN = __constant_cpu_to_be32(0x00010000),
	TCP_RESERVED_BITS = __constant_cpu_to_be32(0x0F000000),
	TCP_DATA_OFFSET = __constant_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_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 */
#define TCP_REPAIR		19	/* TCP sock is under repair right now */
#define TCP_REPAIR_QUEUE	20
#define TCP_QUEUE_SEQ		21
#define TCP_REPAIR_OPTIONS	22
#define TCP_FASTOPEN		23	/* Enable FastOpen on listeners */
#define TCP_TIMESTAMP		24

Annotation

Implementation Notes