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#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/icmp6.h>
The proto parameter to the socket(2) call to create an ICMPv6 socket may be obtained from getprotobyname(3). ICMPv6 sockets are connectionless, and are normally used with the sendto(2) and recvfrom(2) calls, though the connect(2) call may also be used to fix the destination for future packets (in which case read(2) or recv(2) and write(2) or send(2) system calls may be used).
Outgoing packets automatically have an IPv6 header prepended to them (based on the destination address). Incoming packets on the socket are received with the IPv6 header and any extension headers removed.
Num | Abbrev. | Description |
1 | unreach | Destination unreachable |
2 | toobig | Packet too big |
3 | timex | Time exceeded |
4 | paramprob | Invalid IPv6 header |
128 | echoreq | Echo service request |
129 | echorep | Echo service reply |
130 | groupqry | Group membership query |
130 | listqry | Multicast listener query |
131 | grouprep | Group membership report |
131 | listenrep | Multicast listener report |
132 | groupterm | Group membership termination |
132 | listendone | Multicast listener done |
133 | routersol | Router solicitation |
134 | routeradv | Router advertisement |
135 | neighbrsol | Neighbor solicitation |
136 | neighbradv | Neighbor advertisement |
137 | redir | Shorter route exists |
138 | routrrenum | Route renumbering |
139 | fqdnreq | FQDN query |
139 | niqry | Node information query |
139 | wrureq | Who-are-you request |
140 | fqdnrep | FQDN reply |
140 | nirep | Node information reply |
140 | wrurep | Who-are-you reply |
200 | mtraceresp | mtrace response |
201 | mtrace | mtrace messages |
The following codes are defined:
Num | Abbrev. | Type | Description |
0 | noroute-unr | unreach | No route to destination |
1 | admin-unr | unreach | Administratively prohibited |
2 | beyond-unr | unreach | Beyond scope of source address |
2 | notnbr-unr | unreach | Not a neighbor (obsolete) |
3 | addr-unr | unreach | Address unreachable |
4 | port-unr | unreach | Port unreachable |
0 | transit | timex | Time exceeded in transit |
1 | reassemb | timex | Time exceeded in reassembly |
0 | badhead | paramprob | Erroneous header field |
1 | nxthdr | paramprob | Unrecognized next header |
2 | redir | Unrecognized option | |
0 | redironlink | redir | Redirection to on-link node |
1 | redirrouter | redir | Redirection to better router |
struct icmp6_hdr { uint8_t icmp6_type; /* type field */ uint8_t icmp6_code; /* code field */ uint16_t icmp6_cksum; /* checksum field */ union { uint32_t icmp6_un_data32[1]; /* type-specific */ uint16_t icmp6_un_data16[2]; /* type-specific */ uint8_t icmp6_un_data8[4]; /* type-specific */ } icmp6_dataun; } __packed;#define icmp6_data32 icmp6_dataun.icmp6_un_data32 #define icmp6_data16 icmp6_dataun.icmp6_un_data16 #define icmp6_data8 icmp6_dataun.icmp6_un_data8 #define icmp6_pptr icmp6_data32[0] /* parameter prob */ #define icmp6_mtu icmp6_data32[0] /* packet too big */ #define icmp6_id icmp6_data16[0] /* echo request/reply */ #define icmp6_seq icmp6_data16[1] /* echo request/reply */ #define icmp6_maxdelay icmp6_data16[0] /* mcast group membership*/
icmp6_type describes the type of the message. Suitable values are defined in < netinet/icmp6.h>. icmp6_code describes the sub-type of the message and depends on icmp6_type. icmp6_cksum contains the checksum for the message and is filled in by the kernel on outgoing messages. The other fields are used for type-specific purposes.
The icmp6_filter structure may be used to refine the input message set according to the ICMPv6 type. By default, all messages types are allowed on newly created raw ICMPv6 sockets. The following macros may be used to refine the input set:
void ICMP6_FILTER_SETPASSALL(struct icmp6_filter *filterp) | |
Allow all incoming messages. filterp is modified to allow all message types. | |
void ICMP6_FILTER_SETBLOCKALL(struct icmp6_filter *filterp) | |
Ignore all incoming messages. filterp is modified to ignore all message types. | |
void ICMP6_FILTER_SETPASS(int type, struct icmp6_filter *filterp) Allow ICMPv6 messages with the given type. filterp is modified to allow such messages. | |
void ICMP6_FILTER_SETBLOCK"(int type, struct icmp6_filter *filterp) Ignore ICMPv6 messages with the given type. filterp is modified to ignore such messages. | |
int ICMP6_FILTER_WILLPASS"(int type, const struct icmp6_filter *filterp) Determine if the given filter will allow an ICMPv6 message of the given type. | |
int ICMP6_FILTER_WILLBLOCK"(int type, const struct icmp6_filter *filterp) Determine if the given filter will ignore an ICMPv6 message of the given type. | |
The getsockopt(2) and setsockopt(2) calls may be used to obtain and install the filter on ICMPv6 sockets at option level IPPROTO_ICMPV6 and name ICMP6_FILTER with a pointer to the icmp6_filter structure as the option value.
RFC 2292, Advanced Sockets API for IPv6, February 1998.
, ,RFC 2463, Internet Control Message Protocol (ICMPv6) for the Internet, December 1998.
, ,ICMP6 (4) | November 7, 2012 |
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