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ip6_frag.h
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1 /**
2  * @file
3  *
4  * IPv6 fragmentation and reassembly.
5  */
6 
7 /*
8  * Copyright (c) 2010 Inico Technologies Ltd.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without modification,
12  * are permitted provided that the following conditions are met:
13  *
14  * 1. Redistributions of source code must retain the above copyright notice,
15  * this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright notice,
17  * this list of conditions and the following disclaimer in the documentation
18  * and/or other materials provided with the distribution.
19  * 3. The name of the author may not be used to endorse or promote products
20  * derived from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
25  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
27  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
30  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
31  * OF SUCH DAMAGE.
32  *
33  * This file is part of the lwIP TCP/IP stack.
34  *
35  * Author: Ivan Delamer <delamer@inicotech.com>
36  *
37  *
38  * Please coordinate changes and requests with Ivan Delamer
39  * <delamer@inicotech.com>
40  */
41 #ifndef LWIP_HDR_IP6_FRAG_H
42 #define LWIP_HDR_IP6_FRAG_H
43 
44 #include "lwip/opt.h"
45 #include "lwip/pbuf.h"
46 #include "lwip/ip6_addr.h"
47 #include "lwip/ip6.h"
48 #include "lwip/netif.h"
49 
50 #ifdef __cplusplus
51 extern "C" {
52 #endif
53 
54 
55 #if LWIP_IPV6 && LWIP_IPV6_REASS /* don't build if not configured for use in lwipopts.h */
56 
57 /** The IPv6 reassembly timer interval in milliseconds. */
58 #define IP6_REASS_TMR_INTERVAL 1000
59 
60 /** IP6_FRAG_COPYHEADER==1: for platforms where sizeof(void*) > 4, "struct
61  * ip6_reass_helper" is too large to be stored in the IPv6 fragment header, and
62  * will bleed into the header before it, which may be the IPv6 header or an
63  * extension header. This means that for each first fragment packet, we need to
64  * 1) make a copy of some IPv6 header fields (src+dest) that we need later on,
65  * just in case we do overwrite part of the IPv6 header, and 2) make a copy of
66  * the header data that we overwrote, so that we can restore it before either
67  * completing reassembly or sending an ICMPv6 reply. The last part is true even
68  * if this setting is disabled, but if it is enabled, we need to save a bit
69  * more data (up to the size of a pointer) because we overwrite more. */
70 #ifndef IPV6_FRAG_COPYHEADER
71 #define IPV6_FRAG_COPYHEADER 0
72 #endif
73 
74 /* With IPV6_FRAG_COPYHEADER==1, a helper structure may (or, depending on the
75  * presence of extensions, may not) overwrite part of the IP header. Therefore,
76  * we copy the fields that we need from the IP header for as long as the helper
77  * structure may still be in place. This is easier than temporarily restoring
78  * those fields in the IP header each time we need to perform checks on them. */
79 #if IPV6_FRAG_COPYHEADER
80 #define IPV6_FRAG_SRC(ipr) ((ipr)->src)
81 #define IPV6_FRAG_DEST(ipr) ((ipr)->dest)
82 #else /* IPV6_FRAG_COPYHEADER */
83 #define IPV6_FRAG_SRC(ipr) ((ipr)->iphdr->src)
84 #define IPV6_FRAG_DEST(ipr) ((ipr)->iphdr->dest)
85 #endif /* IPV6_FRAG_COPYHEADER */
86 
87 /** IPv6 reassembly helper struct.
88  * This is exported because memp needs to know the size.
89  */
90 struct ip6_reassdata {
91  struct ip6_reassdata *next;
92  struct pbuf *p;
93  struct ip6_hdr *iphdr; /* pointer to the first (original) IPv6 header */
94 #if IPV6_FRAG_COPYHEADER
95  ip6_addr_p_t src; /* copy of the source address in the IP header */
96  ip6_addr_p_t dest; /* copy of the destination address in the IP header */
97  /* This buffer (for the part of the original header that we overwrite) will
98  * be slightly oversized, but we cannot compute the exact size from here. */
99  u8_t orig_hdr[sizeof(struct ip6_frag_hdr) + sizeof(void*)];
100 #else /* IPV6_FRAG_COPYHEADER */
101  /* In this case we still need the buffer, for sending ICMPv6 replies. */
102  u8_t orig_hdr[sizeof(struct ip6_frag_hdr)];
103 #endif /* IPV6_FRAG_COPYHEADER */
104  u32_t identification;
105  u16_t datagram_len;
106  u8_t nexth;
107  u8_t timer;
108 #if LWIP_IPV6_SCOPES
109  u8_t src_zone; /* zone of original packet's source address */
110  u8_t dest_zone; /* zone of original packet's destination address */
111 #endif /* LWIP_IPV6_SCOPES */
112 };
113 
114 #define ip6_reass_init() /* Compatibility define */
115 void ip6_reass_tmr(void);
116 struct pbuf *ip6_reass(struct pbuf *p);
117 
118 #endif /* LWIP_IPV6 && LWIP_IPV6_REASS */
119 
120 #if LWIP_IPV6 && LWIP_IPV6_FRAG /* don't build if not configured for use in lwipopts.h */
121 
122 #ifndef LWIP_PBUF_CUSTOM_REF_DEFINED
123 #define LWIP_PBUF_CUSTOM_REF_DEFINED
124 /** A custom pbuf that holds a reference to another pbuf, which is freed
125  * when this custom pbuf is freed. This is used to create a custom PBUF_REF
126  * that points into the original pbuf. */
127 struct pbuf_custom_ref {
128  /** 'base class' */
129  struct pbuf_custom pc;
130  /** pointer to the original pbuf that is referenced */
131  struct pbuf *original;
132 };
133 #endif /* LWIP_PBUF_CUSTOM_REF_DEFINED */
134 
135 err_t ip6_frag(struct pbuf *p, struct netif *netif, const ip6_addr_t *dest);
136 
137 #endif /* LWIP_IPV6 && LWIP_IPV6_FRAG */
138 
139 
140 #ifdef __cplusplus
141 }
142 #endif
143 
144 #endif /* LWIP_HDR_IP6_FRAG_H */
ip6.h
IPv6 layer.
opt.h
lwIP Options Configuration
ip6_addr.h
IPv6 addresses.
netif.h
netif API (to be used from TCPIP thread)
pbuf
Main packet buffer struct.
Definition: ppp_service_if.h:136
netif
Generic data structure used for all lwIP network interfaces.
Definition: ppp_service_if.h:157
ip6_frag_hdr
Definition: prot/ip6.h:211
pbuf.h
pbuf API
nsapi_addr
IP address structure for passing IP addresses by value.
Definition: nsapi_types.h:237
ip6_hdr
The IPv6 header.
Definition: prot/ip6.h:80
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