1/**
2 * @file
3 * IPv4 protocol definitions
4 */
5
6/*
7 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without modification,
11 * are permitted provided that the following conditions are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright notice,
14 *    this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright notice,
16 *    this list of conditions and the following disclaimer in the documentation
17 *    and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
24 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
26 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
29 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
30 * OF SUCH DAMAGE.
31 *
32 * This file is part of the lwIP TCP/IP stack.
33 *
34 * Author: Adam Dunkels <adam@sics.se>
35 *
36 */
37#ifndef LWIP_HDR_PROT_IP4_H
38#define LWIP_HDR_PROT_IP4_H
39
40#include "lwip/arch.h"
41#include "lwip/ip4_addr.h"
42
43#ifdef __cplusplus
44extern "C" {
45#endif
46
47/** This is the packed version of ip4_addr_t,
48    used in network headers that are itself packed */
49#ifdef PACK_STRUCT_USE_INCLUDES
50#  include "arch/bpstruct.h"
51#endif
52PACK_STRUCT_BEGIN
53struct ip4_addr_packed {
54  PACK_STRUCT_FIELD(u32_t addr);
55} PACK_STRUCT_STRUCT;
56PACK_STRUCT_END
57#ifdef PACK_STRUCT_USE_INCLUDES
58#  include "arch/epstruct.h"
59#endif
60
61typedef struct ip4_addr_packed ip4_addr_p_t;
62
63/* Size of the IPv4 header. Same as 'sizeof(struct ip_hdr)'. */
64#define IP_HLEN 20
65
66#ifdef PACK_STRUCT_USE_INCLUDES
67#  include "arch/bpstruct.h"
68#endif
69PACK_STRUCT_BEGIN
70/* The IPv4 header */
71struct ip_hdr {
72  /* version / header length */
73  PACK_STRUCT_FLD_8(u8_t _v_hl);
74  /* type of service */
75  PACK_STRUCT_FLD_8(u8_t _tos);
76  /* total length */
77  PACK_STRUCT_FIELD(u16_t _len);
78  /* identification */
79  PACK_STRUCT_FIELD(u16_t _id);
80  /* fragment offset field */
81  PACK_STRUCT_FIELD(u16_t _offset);
82#define IP_RF 0x8000U        /* reserved fragment flag */
83#define IP_DF 0x4000U        /* don't fragment flag */
84#define IP_MF 0x2000U        /* more fragments flag */
85#define IP_OFFMASK 0x1fffU   /* mask for fragmenting bits */
86  /* time to live */
87  PACK_STRUCT_FLD_8(u8_t _ttl);
88  /* protocol*/
89  PACK_STRUCT_FLD_8(u8_t _proto);
90  /* checksum */
91  PACK_STRUCT_FIELD(u16_t _chksum);
92  /* source and destination IP addresses */
93  PACK_STRUCT_FLD_S(ip4_addr_p_t src);
94  PACK_STRUCT_FLD_S(ip4_addr_p_t dest);
95} PACK_STRUCT_STRUCT;
96PACK_STRUCT_END
97#ifdef PACK_STRUCT_USE_INCLUDES
98#  include "arch/epstruct.h"
99#endif
100
101/* Macros to get struct ip_hdr fields: */
102#define IPH_V(hdr)  ((hdr)->_v_hl >> 4)
103#define IPH_HL(hdr) ((hdr)->_v_hl & 0x0f)
104#define IPH_TOS(hdr) ((hdr)->_tos)
105#define IPH_LEN(hdr) ((hdr)->_len)
106#define IPH_ID(hdr) ((hdr)->_id)
107#define IPH_OFFSET(hdr) ((hdr)->_offset)
108#define IPH_TTL(hdr) ((hdr)->_ttl)
109#define IPH_PROTO(hdr) ((hdr)->_proto)
110#define IPH_CHKSUM(hdr) ((hdr)->_chksum)
111
112/* Macros to set struct ip_hdr fields: */
113#define IPH_VHL_SET(hdr, v, hl) (hdr)->_v_hl = (u8_t)((((v) << 4) | (hl)))
114#define IPH_TOS_SET(hdr, tos) (hdr)->_tos = (tos)
115#define IPH_LEN_SET(hdr, len) (hdr)->_len = (len)
116#define IPH_ID_SET(hdr, id) (hdr)->_id = (id)
117#define IPH_OFFSET_SET(hdr, off) (hdr)->_offset = (off)
118#define IPH_TTL_SET(hdr, ttl) (hdr)->_ttl = (u8_t)(ttl)
119#define IPH_PROTO_SET(hdr, proto) (hdr)->_proto = (u8_t)(proto)
120#define IPH_CHKSUM_SET(hdr, chksum) (hdr)->_chksum = (chksum)
121
122
123#ifdef __cplusplus
124}
125#endif
126
127#endif /* LWIP_HDR_PROT_IP4_H */
128