The IPv6 getipnodebyaddr() function call improves upon the IPv4 gethostbyaddr() by adding an error number parameter.
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 | NOTE: Starting with the HP-UX 11i v2 release, the getipnodebyaddr() function is entering OBSOLESCENCE, and will be
OBSOLETED in a future HP-UX release. Therefore, it is recommended
the getaddrinfo() function be used instead. |
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Header
Files |
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#include <sys/socket.h>#include <netdb.h> |
Syntax |
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name_ptr =getipnodebyaddr(const void *src, size_t len,int af, int *error_num); |
Parameters |
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*src: A pointer to the structure containing the IP address
searched.
len: The length of the IP address: four octets for AF_INET or sixteen octets for AF_INET6.
af: Address family AF_INET or AF_INET6.
*error_num: *error_num is a pointer to the integer containing an error code,
if any.
name_ptr: A pointer to the struct hostent returned by the function, containing the host name.
Data Structures |
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struct hostent {
char *h_name; /* Canonical name of host name such as grace.hp.com*/
char **h_alias; /* Pointer to an array of pointers to alias names */
int h_addrtype; /* AF_INET (for IPv4 addresses)AF_INET6 (for IPv6)*/
int h_length; /* 4 octets (IPv6) or 16 octets (IPv6) */
char **h_addr_list[0]; /* Pointer to an array of pointers to IPv4 */
} /* addresses or IPv6 addresses */ |
How getipnodebyaddr()
processes IPv4-compatible IPv6 addresses |
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If af is AF_INET6, len equals 16, and the IPv6 address is an IPv4-mapped
or an IPv4-compatible IPv6 address, then:
skip
the first 12 bytes of the IPv6 address.
set af to AF_INET.
set len to 4.
If af is AF_INET, lookup the name for the given IPv4 address; that
is, query for a PTR record in the in-addr.arpa domain.
If af is AF_INET6, lookup the name for the given IPv6 address;
that is, query for a PTR record in the ip6.int domain.
A successful function call copies *src and af into the returned hostent name_ptr structure. An unsuccessful function returns a nonzero error_num.
