1 /* 2 * Fundamental constants relating to TCP Protocol 3 * 4 * Copyright (C) 2020, Broadcom. 5 * 6 * Unless you and Broadcom execute a separate written software license 7 * agreement governing use of this software, this software is licensed to you 8 * under the terms of the GNU General Public License version 2 (the "GPL"), 9 * available at http://www.broadcom.com/licenses/GPLv2.php, with the 10 * following added to such license: 11 * 12 * As a special exception, the copyright holders of this software give you 13 * permission to link this software with independent modules, and to copy and 14 * distribute the resulting executable under terms of your choice, provided that 15 * you also meet, for each linked independent module, the terms and conditions of 16 * the license of that module. An independent module is a module which is not 17 * derived from this software. The special exception does not apply to any 18 * modifications of the software. 19 * 20 * 21 * <<Broadcom-WL-IPTag/Dual:>> 22 */ 23 24 #ifndef _bcmtcp_h_ 25 #define _bcmtcp_h_ 26 27 #ifndef _TYPEDEFS_H_ 28 #include <typedefs.h> 29 #endif 30 31 /* This marks the start of a packed structure section. */ 32 #include <packed_section_start.h> 33 34 #define TCP_SRC_PORT_OFFSET 0 /* TCP source port offset */ 35 #define TCP_DEST_PORT_OFFSET 2 /* TCP dest port offset */ 36 #define TCP_SEQ_NUM_OFFSET 4 /* TCP sequence number offset */ 37 #define TCP_ACK_NUM_OFFSET 8 /* TCP acknowledgement number offset */ 38 #define TCP_HLEN_OFFSET 12 /* HLEN and reserved bits offset */ 39 #define TCP_FLAGS_OFFSET 13 /* FLAGS and reserved bits offset */ 40 #define TCP_CHKSUM_OFFSET 16 /* TCP body checksum offset */ 41 42 #define TCP_PORT_LEN 2 /* TCP port field length */ 43 44 /* 8bit TCP flag field */ 45 #define TCP_FLAG_URG 0x20 46 #define TCP_FLAG_ACK 0x10 47 #define TCP_FLAG_PSH 0x08 48 #define TCP_FLAG_RST 0x04 49 #define TCP_FLAG_SYN 0x02 50 #define TCP_FLAG_FIN 0x01 51 52 #define TCP_HLEN_MASK 0xf000 53 #define TCP_HLEN_SHIFT 12 54 55 /* These fields are stored in network order */ 56 BWL_PRE_PACKED_STRUCT struct bcmtcp_hdr 57 { 58 uint16 src_port; /* Source Port Address */ 59 uint16 dst_port; /* Destination Port Address */ 60 uint32 seq_num; /* TCP Sequence Number */ 61 uint32 ack_num; /* TCP Sequence Number */ 62 uint16 hdrlen_rsvd_flags; /* Header length, reserved bits and flags */ 63 uint16 tcpwin; /* TCP window */ 64 uint16 chksum; /* Segment checksum with pseudoheader */ 65 uint16 urg_ptr; /* Points to seq-num of byte following urg data */ 66 } BWL_POST_PACKED_STRUCT; 67 68 #define TCP_MIN_HEADER_LEN 20 69 70 #define TCP_HDRLEN_MASK 0xf0 71 #define TCP_HDRLEN_SHIFT 4 72 #define TCP_HDRLEN(hdrlen) (((hdrlen) & TCP_HDRLEN_MASK) >> TCP_HDRLEN_SHIFT) 73 74 #define TCP_FLAGS_MASK 0x1f 75 #define TCP_FLAGS(hdrlen) ((hdrlen) & TCP_FLAGS_MASK) 76 77 /* This marks the end of a packed structure section. */ 78 #include <packed_section_end.h> 79 80 /* To address round up by 32bit. */ 81 #define IS_TCPSEQ_GE(a, b) ((a - b) < NBITVAL(31)) /* a >= b */ 82 #define IS_TCPSEQ_LE(a, b) ((b - a) < NBITVAL(31)) /* a =< b */ 83 #define IS_TCPSEQ_GT(a, b) !IS_TCPSEQ_LE(a, b) /* a > b */ 84 #define IS_TCPSEQ_LT(a, b) !IS_TCPSEQ_GE(a, b) /* a < b */ 85 86 #endif /* #ifndef _bcmtcp_h_ */ 87