"Socket::GetAddrInfo::Emul" − Pure Perl emulation of "getaddrinfo" and "getnameinfo" using IPv4−only legacy resolvers
"Socket::GetAddrInfo" attempts to provide the "getaddrinfo" and "getnameinfo" functions by some XS code that calls the real functions in libc. If for some reason this cannot be done; either there is no C compiler, or libc does not provide these functions, then they will be emulated using the legacy resolvers "gethostbyname", etc... These emulations are not a complete replacement of the real functions, because they only support IPv4 (the "AF_INET" socket family). In this case, the following restrictions will apply.
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If the "family" hint is supplied, it must be "AF_INET". Any other value will result in an error thrown by "croak". | ||
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The only supported "flags" hint values are "AI_PASSIVE", "AI_CANONNAME", "AI_NUMERICSERV" and "AI_NUMERICHOST". |
The flags "AI_V4MAPPED" and "AI_ALL" are recognised but ignored, as they do not apply to "AF_INET" lookups. Since this function only returns "AF_INET" addresses, it does not need to probe the system for configured addresses in other families, so the "AI_ADDRCONFIG" flag is also ignored.
Note that "AI_NUMERICSERV" is an extension not defined by RFC 2553, but is provided by most OSes. It is possible (though unlikely) that even the native XS implementation does not recognise this constant.
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If the sockaddr family of $addr is anything other than "AF_INET", an error will be thrown with "croak". | ||
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The only supported $flags values are "NI_NUMERICHOST", "NI_NUMERICSERV", "NI_NOFQDN", "NI_NAMEREQD" and "NI_DGRAM". |
This pure-perl emulation provides the IDN constants such as "AI_IDN" and "NI_IDN", but the "getaddrinfo" and "getnameinfo" functions will croak if passed these flags. This should allow a program to probe for their support, and fall back to some other behaviour instead.
Paul Evans <[email protected]>