• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Fundamental constants relating to TCP Protocol
4  *
5  * Copyright (C) 1999-2019, Broadcom.
6  *
7  *      Unless you and Broadcom execute a separate written software license
8  * agreement governing use of this software, this software is licensed to you
9  * under the terms of the GNU General Public License version 2 (the "GPL"),
10  * available at http://www.broadcom.com/licenses/GPLv2.php, with the
11  * following added to such license:
12  *
13  *      As a special exception, the copyright holders of this software give you
14  * permission to link this software with independent modules, and to copy and
15  * distribute the resulting executable under terms of your choice, provided that
16  * you also meet, for each linked independent module, the terms and conditions of
17  * the license of that module.  An independent module is a module which is not
18  * derived from this software.  The special exception does not apply to any
19  * modifications of the software.
20  *
21  *      Notwithstanding the above, under no circumstances may you combine this
22  * software in any way with any other Broadcom software provided under a license
23  * other than the GPL, without Broadcom's express prior written consent.
24  *
25  *
26  * <<Broadcom-WL-IPTag/Open:>>
27  *
28  * $Id: bcmtcp.h 700076 2017-05-17 14:42:22Z $
29  */
30 
31 #ifndef _bcmtcp_h_
32 #define _bcmtcp_h_
33 
34 #ifndef _TYPEDEFS_H_
35 #include <typedefs.h>
36 #endif // endif
37 
38 /* This marks the start of a packed structure section. */
39 #include <packed_section_start.h>
40 
41 #define TCP_SRC_PORT_OFFSET	0	/* TCP source port offset */
42 #define TCP_DEST_PORT_OFFSET	2	/* TCP dest port offset */
43 #define TCP_SEQ_NUM_OFFSET	4	/* TCP sequence number offset */
44 #define TCP_ACK_NUM_OFFSET	8	/* TCP acknowledgement number offset */
45 #define TCP_HLEN_OFFSET		12	/* HLEN and reserved bits offset */
46 #define TCP_FLAGS_OFFSET	13	/* FLAGS and reserved bits offset */
47 #define TCP_CHKSUM_OFFSET	16	/* TCP body checksum offset */
48 
49 #define TCP_PORT_LEN		2	/* TCP port field length */
50 
51 /* 8bit TCP flag field */
52 #define TCP_FLAG_URG            0x20
53 #define TCP_FLAG_ACK            0x10
54 #define TCP_FLAG_PSH            0x08
55 #define TCP_FLAG_RST            0x04
56 #define TCP_FLAG_SYN            0x02
57 #define TCP_FLAG_FIN            0x01
58 
59 #define TCP_HLEN_MASK           0xf000
60 #define TCP_HLEN_SHIFT          12
61 
62 /* These fields are stored in network order */
63 BWL_PRE_PACKED_STRUCT struct bcmtcp_hdr
64 {
65 	uint16	src_port;	/* Source Port Address */
66 	uint16	dst_port;	/* Destination Port Address */
67 	uint32	seq_num;	/* TCP Sequence Number */
68 	uint32	ack_num;	/* TCP Sequence Number */
69 	uint16	hdrlen_rsvd_flags;	/* Header length, reserved bits and flags */
70 	uint16	tcpwin;		/* TCP window */
71 	uint16	chksum;		/* Segment checksum with pseudoheader */
72 	uint16	urg_ptr;	/* Points to seq-num of byte following urg data */
73 } BWL_POST_PACKED_STRUCT;
74 
75 #define TCP_MIN_HEADER_LEN 20
76 
77 #define TCP_HDRLEN_MASK 0xf0
78 #define TCP_HDRLEN_SHIFT 4
79 #define TCP_HDRLEN(hdrlen) (((hdrlen) & TCP_HDRLEN_MASK) >> TCP_HDRLEN_SHIFT)
80 
81 #define TCP_FLAGS_MASK  0x1f
82 #define TCP_FLAGS(hdrlen) ((hdrlen) & TCP_FLAGS_MASK)
83 
84 /* This marks the end of a packed structure section. */
85 #include <packed_section_end.h>
86 
87 /* To address round up by 32bit. */
88 #define IS_TCPSEQ_GE(a, b) ((a - b) < NBITVAL(31))		/* a >= b */
89 #define IS_TCPSEQ_LE(a, b) ((b - a) < NBITVAL(31))		/* a =< b */
90 #define IS_TCPSEQ_GT(a, b) !IS_TCPSEQ_LE(a, b)		/* a > b */
91 #define IS_TCPSEQ_LT(a, b) !IS_TCPSEQ_GE(a, b)		/* a < b */
92 
93 #endif	/* #ifndef _bcmtcp_h_ */
94