.TH net 3erl "kernel 8.5.4.2" "Ericsson AB" "Erlang Module Definition"
.SH NAME
net \- Network interface.
.SH DESCRIPTION
.LP
This module provides an API for the network interface\&.
.SH DATA TYPES
.nf

\fBaddress_info()\fR\& = 
.br
    #{family := socket:domain(),
.br
      socktype := socket:type(),
.br
      protocol := socket:protocol(),
.br
      address := socket:sockaddr()}
.br
.fi
.nf

\fBifaddrs()\fR\& = 
.br
    #{name := string(),
.br
      flags := ifaddrs_flags(),
.br
      addr => socket:sockaddr(),
.br
      netmask => socket:sockaddr(),
.br
      broadaddr => socket:sockaddr(),
.br
      dstaddr => socket:sockaddr()}
.br
.fi
.RS
.LP
This type defines all addresses (and flags) associated with the interface\&.
.LP

.RS -4
.B
Note:
.RE
Not all fields of this map has to be present\&. The flags field can be used to test for some of the fields\&. For example \fIbroadaddr\fR\& will only be present if the \fIbroadcast\fR\& flag is present in flags\&.

.RE

.nf

\fBifaddrs_flag()\fR\& = 
.br
    up | broadcast | debug | loopback | pointopoint | notrailers |
.br
    running | noarp | promisc | master | slave | multicast |
.br
    portsel | automedia | dynamic
.br
.fi
.nf

\fBifaddrs_flags()\fR\& = [ifaddrs_flag()]
.br
.fi
.nf

\fBifaddrs_filter()\fR\& = 
.br
    all | default | inet | inet6 | packet |
.br
    ifaddrs_filter_map() |
.br
    ifaddrs_filter_fun()
.br
.fi
.RS
.RS 2
.TP 2
.B
all:
All interfaces
.TP 2
.B
default:
Interfaces with address family \fIinet\fR\&\fIand\fR\&\fIinet6\fR\&
.TP 2
.B
inet | inet6 | packet:
Interfaces with \fIonly\fR\& the specified address family
.RE
.RE

.nf

\fBifaddrs_filter_map()\fR\& = 
.br
    #{family := default | inet | inet6 | packet | all,
.br
      flags := any | [ifaddrs_flag()]}
.br
.fi
.RS
.LP
The \fIfamily\fR\& field can only have the (above) specified values (and not all the values of socket:domain())\&.
.LP
The use of the \fIflags\fR\& field is that any flag provided must exist for the interface\&.
.LP
For example, if \fIfamily\fR\& is set to \fIinet\fR\& and \fIflags\fR\& to \fI[broadcast, multicast]\fR\& only interfaces with address family \fIinet\fR\& and the flags \fIbroadcast\fR\& and \fImulticast\fR\& will be listed\&.
.RE

.nf

\fBifaddrs_filter_fun()\fR\& = fun((ifaddrs()) -> boolean())
.br
.fi
.RS
.LP
For each \fIifaddrs\fR\& entry, return either \fItrue\fR\& to keep the entry or \fIfalse\fR\& to discard the entry\&.
.LP
For example, to get an interface list which only contains non-\fIloopback\fR\& \fIinet\fR\& interfaces:
.LP
.nf

	net:getifaddrs(fun(#{addr  := #{family := inet},
	                     flags := Flags}) ->
			       not lists:member(loopback, Flags);
			  (_) ->
			       false
		       end).
	
.fi
.RE

.nf

\fBname_info()\fR\& = #{host := string(), service := string()}
.br
.fi
.nf

\fBname_info_flags()\fR\& = [name_info_flag() | name_info_flag_ext()]
.br
.fi
.nf

\fBname_info_flag()\fR\& = 
.br
    namereqd | dgram | nofqdn | numerichost | numericserv
.br
.fi
.nf

\fBname_info_flag_ext()\fR\& = idn
.br
.fi
.nf

\fBnetwork_interface_name()\fR\& = string()
.br
.fi
.nf

\fBnetwork_interface_index()\fR\& = integer() >= 0
.br
.fi
.SH EXPORTS
.LP
.nf

.B
gethostname() -> {ok, HostName} | {error, Reason}
.br
.fi
.br
.RS
.LP
Types:

.RS 3
HostName = string()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Returns the name of the current host\&.
.RE

.LP
.nf

.B
getnameinfo(SockAddr) -> {ok, Info} | {error, Reason}
.br
.fi
.br
.nf

.B
getnameinfo(SockAddr, Flags) -> {ok, Info} | {error, Reason}
.br
.fi
.br
.RS
.LP
Types:

.RS 3
SockAddr = socket:sockaddr()
.br
Flags = name_info_flags() | undefined
.br
Info = name_info()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Address-to-name translation in a protocol-independant manner\&.
.LP
This function is the inverse of \fIgetaddrinfo\fR\&\&. It converts a socket address to a corresponding host and service\&.
.RE

.LP
.nf

.B
getaddrinfo(Host) -> {ok, Info} | {error, Reason}
.br
.fi
.br
.nf

.B
getaddrinfo(Host, Service :: undefined) ->
.B
               {ok, Info} | {error, Reason}
.br
.fi
.br
.nf

.B
getaddrinfo(Host :: undefined, Service) ->
.B
               {ok, Info} | {error, Reason}
.br
.fi
.br
.nf

.B
getaddrinfo(Host, Service) -> {ok, Info} | {error, Reason}
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Host = Service = string()
.br
Info = [address_info()]
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Network address and service translation\&.
.LP
This function is the inverse of \fIgetnameinfo\fR\&\&. It converts host and service to a corresponding socket address\&.
.LP
One of the \fIHost\fR\& and \fIService\fR\& may be \fIundefined\fR\& but \fInot\fR\& both\&.
.RE

.LP
.nf

.B
getifaddrs() -> {ok, IfAddrs} | {error, Reason}
.br
.fi
.br
.nf

.B
getifaddrs(Filter) -> {ok, IfAddrs} | {error, Reason}
.br
.fi
.br
.nf

.B
getifaddrs(Namespace) -> {ok, IfAddrs} | {error, Reason}
.br
.fi
.br
.nf

.B
getifaddrs(Filter, Namespace) -> {ok, IfAddrs} | {error, Reason}
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Filter = ifaddrs_filter()
.br
Namespace = file:filename_all()
.br
IfAddrs = [ifaddrs()]
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Get interface addresses\&.
.LP
This function is used to get the machines interface addresses, possibly filtered according to \fIFilter\fR\&\&.
.LP
By default, a filter with the content: \fI#{family => default, flags => any}\fR\& is used\&. This will return all interfaces with addresses in the \fIinet\fR\& and \fIinet6\fR\& families\&.
.RE

.LP
.nf

.B
if_name2index(Name) -> {ok, Idx} | {error, Reason}
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Name = network_interface_name()
.br
Idx = network_interface_index()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Mappings between network interface names and indexes\&.
.RE

.LP
.nf

.B
if_index2name(Idx) -> {ok, Name} | {error, Reason}
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Idx = network_interface_index()
.br
Name = network_interface_name()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Mappings between network interface index and names\&.
.RE

.LP
.nf

.B
if_names() -> {ok, Names} | {error, Reason}
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Names = [{Idx, If}]
.br
Idx = network_interface_index()
.br
If = network_interface_name()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Get network interface names and indexes\&.
.RE