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Diffstat (limited to 'lib/src/protocol/tcp.h')
| -rw-r--r-- | lib/src/protocol/tcp.h | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/lib/src/protocol/tcp.h b/lib/src/protocol/tcp.h new file mode 100644 index 000000000..e563372d0 --- /dev/null +++ b/lib/src/protocol/tcp.h @@ -0,0 +1,165 @@ +/* + * Copyright (c) 2021-2022 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. + */ + +#ifndef HICN_PROTOCOL_TCP_H +#define HICN_PROTOCOL_TCP_H + +#include <hicn/base.h> +#include <hicn/common.h> +#include <hicn/name.h> + +/* + * The length of the TCP header struct must be 20 bytes. + */ +#define EXPECTED_TCP_HDRLEN 20 + +/* + * NOTE: bitfields are problematic for portability reasons. There are provided + * here for reference and documentation purposes, we might just provide a macro + * to disable and use it instead of __BYTE_ORDER__. + */ +typedef struct +{ + u16 sport; + u16 dport; + union + { + u32 seq; + hicn_name_suffix_t name_suffix; + }; + union + { + u32 seq_ack; + struct + { + hicn_path_label_t pathlabel; + u8 pad[3]; + }; + }; + + union + { + struct + { + u8 data_offset_and_reserved; + u8 flags; + }; +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + struct + { + u16 reserved : 4; + u16 doff : 4; + u16 fin : 1; + u16 syn : 1; + u16 rst : 1; + u16 psh : 1; + u16 ack : 1; + u16 urg : 1; + u16 ece : 1; + u16 cwr : 1; + }; + struct + { /* __ denotes unchanged bitfields */ + u16 timescale : 4; + u16 __doff : 4; + u16 __fin : 1; + u16 __syn : 1; + u16 __rst : 1; + u16 sig : 1; + u16 __ack : 1; + u16 man : 1; + u16 id : 1; + u16 __cwr : 1; + }; +#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ + struct + { + u16 doff : 4; + u16 reserved : 4; + u16 cwr : 1; + u16 ece : 1; + u16 urg : 1; + u16 ack : 1; + u16 psh : 1; + u16 rst : 1; + u16 syn : 1; + u16 fin : 1; + }; + struct + { + u16 __doff : 4; + u16 timescale : 4; + u16 __cwr : 1; + u16 id : 1 u16 man : 1; + u16 __ack : 1; + u16 sig : 1; + u16 __rst : 1; + u16 __syn : 1; + u16 __fin : 1; + }; +#endif + }; + union + { + u16 window; + u16 ldr; + }; + u16 csum; + union + { + u16 urg_ptr; + u16 lifetime; + }; +} _tcp_header_t; + +#define TCP_HDRLEN sizeof (_tcp_header_t) +static_assert (EXPECTED_TCP_HDRLEN == TCP_HDRLEN, + "Size of TCP struct does not match its expected size."); + +/* TCP flags bit 0 first. */ +#define foreach_tcp_flag \ + _ (FIN) /**< No more data from sender. */ \ + _ (SYN) /**< Synchronize sequence numbers. */ \ + _ (RST) /**< Reset the connection. */ \ + _ (PSH) /**< Push function. */ \ + _ (ACK) /**< Ack field significant. */ \ + _ (URG) /**< Urgent pointer field significant. */ \ + _ (ECE) /**< ECN-echo. Receiver got CE packet */ \ + _ (CWR) /**< Sender reduced congestion window */ + +enum +{ +#define _(f) HICN_TCP_FLAG_BIT_##f, + foreach_tcp_flag +#undef _ + HICN_TCP_N_FLAG_BITS, +}; + +enum +{ +#define _(f) HICN_TCP_FLAG_##f = 1 << HICN_TCP_FLAG_BIT_##f, + foreach_tcp_flag +#undef _ +}; + +#endif /* HICN_PROTOCOL_TCP_H */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |