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/*
* Copyright (c) 2015 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* ip4/tcp_packet.h: TCP packet format (see RFC 793)
*
* Copyright (c) 2008 Eliot Dresselhaus
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef included_tcp_packet_h
#define included_tcp_packet_h
/* TCP flags bit 0 first. */
#define foreach_tcp_flag \
_ (FIN) \
_ (SYN) \
_ (RST) \
_ (PSH) \
_ (ACK) \
_ (URG) \
_ (ECE) \
_ (CWR)
enum {
#define _(f) TCP_FLAG_BIT_##f,
foreach_tcp_flag
#undef _
TCP_N_FLAG_BITS,
#define _(f) TCP_FLAG_##f = 1 << TCP_FLAG_BIT_##f,
foreach_tcp_flag
#undef _
};
typedef struct {
/* Source and destination port. */
union {
struct {
u16 src, dst;
};
u32 src_and_dst;
} ports;
/* Sequence and acknowledgment number. */
u32 seq_number, ack_number;
/* Size of TCP header in 32-bit units plus 4 reserved bits. */
u8 tcp_header_u32s_and_reserved;
/* see foreach_tcp_flag for enumation of tcp flags. */
u8 flags;
/* Current window advertised by sender.
This is the number of bytes sender is willing to receive
right now. */
u16 window;
/* Checksum of TCP pseudo header and data. */
u16 checksum;
u16 urgent_pointer;
} tcp_header_t;
always_inline int
tcp_header_bytes (tcp_header_t * t)
{ return (t->tcp_header_u32s_and_reserved >> 4) * sizeof (u32); }
/* TCP options. */
typedef enum tcp_option_type {
TCP_OPTION_END = 0,
TCP_OPTION_NOP = 1,
TCP_OPTION_MSS = 2,
TCP_OPTION_WINDOW_SCALE = 3,
TCP_OPTION_SACK_PERMITTED = 4,
TCP_OPTION_SACK_BLOCK = 5,
TCP_OPTION_TIME_STAMP = 8,
} tcp_option_type_t;
/* All except NOP and END have 1 byte length field. */
typedef struct {
tcp_option_type_t type : 8;
/* Length of this option in bytes. */
u8 length;
} tcp_option_with_length_t;
#endif /* included_tcp_packet_h */
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