IF_TCP(4P) Protocols IF_TCP(4P)

NAME

if_tcp, if - general properties of Internet Protocol network
interfaces

DESCRIPTION

A network interface is a device for sending and receiving packets on
a network. It is usually a hardware device, although it can be
implemented in software. Network interfaces used by the Internet
Protocol (IPv4 or IPv6) must be STREAMS devices conforming to the
Data Link Provider Interface (DLPI). See dlpi(4P).

APPLICATION PROGRAMMING INTERFACE

An interface becomes available to IP when it is opened and the IP
module is pushed onto the stream with the I_PUSH ioctl(2) command.
(See streamio(4I)). The SIOCSLIFNAME ioctl(2) is issued to specify
the name of the interface and to indicate whether it is IPv4 or IPv6.
This may be initiated by the kernel at boot time or by a user program
after the system is running. Each interface must be assigned an IP
address with the SIOCSLIFADDR ioctl() before it can be used. On
interfaces where the network-to-link layer address mapping is static,
only the network number is taken from the ioctl() request; the
remainder is found in a hardware specific manner. On interfaces which
provide dynamic network-to-link layer address mapping facilities (for
example, Ethernets using arp(4P)), the entire address specified in
the ioctl() is used. A routing table entry for destinations on the
network of the interface is installed automatically when an
interface's address is set.


You cannot create IPMP IP interfaces using the procedure described
above. Instead, use ifconfig(8).

IOCTLS

The following ioctl() calls may be used to manipulate IP network
interfaces. Unless specified otherwise, the request takes an lifreq
structure as its parameter. This structure has the form:

struct lifreq {
#define LIFNAMSIZ 32
char lifr_name[LIFNAMSIZ]; /* if name, e.g. "le1" */
union {
int lifru_addrlen; /* for subnet/token etc */
uint_t lifru_ppa; /* SIOCSLIFNAME */
} lifr_lifru1;
union {
struct sockaddr_storage lifru_addr;
struct sockaddr_storage lifru_dstaddr;
struct sockaddr_storage lifru_broadaddr;
struct sockaddr_storage lifru_token; /* With lifr_addrlen */
struct sockaddr_storage lifru_subnet; /* With lifr_addrlen */
int lifru_index; /* interface index */
uint64_t lifru_flags; /* SIOC?LIFFLAGS */
int lifru_metric;
uint_t lifru_mtu;
int lif_muxid[2]; /* mux id's for arp & ip */
struct lif_nd_req lifru_nd_req; /* SIOCLIF*ND */
struct lif_ifinfo_req lifru_ifinfo_req;
zoneid_t lifru_zone; /* SIOC[GS]LIFZONE */
} lifr_lifru;

#define lifr_addrlen lifr_lifru1.lifru_addrlen
#define lifr_ppa lifr_lifru1.lifru_ppa /* Driver's ppa */
#define lifr_addr lifr_lifru.lifru_addr /* address */
#define lifr_dstaddr lifr_lifru.lifru_dstaddr
#define lifr_broadaddr lifr_lifru.lifru_broadaddr /* broadcast addr. */
#define lifr_token lifr_lifru.lifru_token /* address token */
#define lifr_subnet lifr_lifru.lifru_subnet /* subnet prefix */
#define lifr_index lifr_lifru.lifru_index /* interface index */
#define lifr_flags lifr_lifru.lifru_flags /* flags */
#define lifr_metric lifr_lifru.lifru_metric /* metric */
#define lifr_mtu lifr_lifru.lifru_mtu /* mtu */
#define lifr_ip_muxid lifr_lifru.lif_muxid[0]
#define lifr_arp_muxid lifr_lifru.lif_muxid[1]
#define lifr_nd lifr_lifru.lifru_nd_req /* SIOCLIF*ND */
#define lifr_ifinfo lifr_lifru.lifru_ifinfo_req /* SIOC[GS]LIFLNKINFO */
#define lifr_zone lifr_lifru.lifru_zone /* SIOC[GS]LIFZONE */
};


SIOCSLIFADDR
Set interface address.


SIOCGLIFADDR
Get interface address.


SIOCSLIFDSTADDR
Set point to point address for interface.


SIOCGLIFDSTADDR
Get point to point address for interface.


SIOCSLIFFLAGS
Set interface flags field. If the interface is
marked down, any processes currently routing
packets through the interface are notified.


SIOCGLIFFLAGS
Get interface flags.


SIOCGLIFCONF
Get interface configuration list. This request
takes a lifconf structure (see below) as a value-
result parameter. The lifc_family field can be
set to AF_UNSPEC to retrieve both AF_INET and
AF_INET6 interfaces. The lifc_len field should be
set to the size of the buffer pointed to by
lifc_buf.

The lifc_flags field should usually be set to
zero, but callers that need low-level knowledge of
the underlying IP interfaces that comprise an
IPMP group can set it to LIFC_UNDER_IPMP to
request that those interfaces be included in the
result. Upon success, lifc_len contains the
length, in bytes, of the array of lifreq
structures pointed to by lifc_req. For each
lifreq structure, the lifr_name and lifr_addr
fields are valid.


SIOCGLIFNUM
Get number of interfaces. This request returns an
integer which is the number of interface
descriptions (struct lifreq) returned by the
SIOCGLIFCONF ioctl (in other words, indicates how
large lifc_len must be).

This request takes a struct lifnum (see below)
as a value-result parameter. The lifn_family field
can be set to AF_UNSPEC to count both AF_INET and
AF_INET6 interfaces. The lifn_flags field should
usually be set to zero, but callers that need low-
level knowledge of the underlying IP interfaces
that comprise an IPMP group can set it to
LIFC_UNDER_IPMP to request that those interfaces
be included in the count.


SIOCSLIFMTU
Set the maximum transmission unit (MTU) size for
interface. Place the request in the lifru_mtu
field. The MTU can not exceed the physical MTU
limitation (which is reported in the DLPI
DL_INFO_ACK message).


SIOCGLIFMTU
Get the maximum transmission unit size for
interface.


SIOCSLIFMETRIC
Set the metric associated with the interface. The
metric is used by routing daemons such as
in.routed(8).


SIOCGLIFMETRIC
Get the metric associated with the interface.


SIOCGLIFMUXID
Get the ip and arp muxid associated with the
interface.


SIOCSLIFMUXID
Set the ip and arp muxid associated with the
interface.


SIOCGLIFINDEX
Get the interface index associated with the
interface.


SIOCSLIFINDEX
Set the interface index associated with the
interface.


SIOCGLIFZONE
Get the zone associated with the interface.


SIOCSLIFZONE
Set the zone associated with the interface. Only
applies for zones that use the shared-IP instance.


SIOCLIFADDIF
Add a new logical interface on a physical
interface using an unused logical interface
number.


SIOCLIFREMOVEIF
Remove a logical interface by specifying its IP
address or logical interface name.


SIOCSLIFTOKEN
Set the address token used to form IPv6 link-local
addresses and for stateless address
autoconfiguration.


SIOCGLIFTOKEN
Get the address token used to form IPv6 link-local
addresses and for stateless address
autoconfiguration.


SIOCSLIFSUBNET
Set the subnet prefix associated with the
interface.


SIOCGLIFSUBNET
Get the subnet prefix associated with the
interface.


SIOCSLIFLNKINFO
Set link specific parameters for the interface.


SIOCGLIFLNKINFO
Get link specific parameters for the interface.


SIOCLIFDELND
Delete a neighbor cache entry for IPv6.


SIOCLIFGETND
Get a neighbor cache entry for IPv6.


SIOCLIFSETND
Set a neighbor cache entry for IPv6.


SIOCSLIFUSESRC
Set the interface from which to choose a source
address. The lifr_index field has the interface
index corresponding to the interface whose address
is to be used as the source address for packets
going out on the interface whose name is provided
by lifr_name. If the lifr_index field is set to
zero, the previous setting is cleared. See
ifconfig(8) for examples of the usesrc option.


SIOCGLIFUSESRC
Get the interface index of the interface whose
address is used as the source address for packets
going out on the interface provided by lifr_name
field. The value is retrieved in the lifr_index
field. See ifconfig(8) for examples of the usesrc
option.


SIOCGLIFSRCOF
Get the interface configuration list for
interfaces that use an address hosted on the
interface provided by the lifs_ifindex field in
the lifsrcof struct (see below), as a source
address. The application sets lifs_maxlen to the
size (in bytes) of the buffer it has allocated for
the data. On return, the kernel sets lifs_len to
the actual size required. Note, the application
could set lifs_maxlen to zero to query the kernel
of the required buffer size instead of estimating
a buffer size. The application tests lifs_len <=
lifs_maxlen -- if that's true, the buffer was big
enough and the application has an accurate list.
If it is false, it needs to allocate a bigger
buffer and try again, and lifs_len provides a hint
of how big to make the next trial. See ifconfig(8)
for examples of the usesrc option.


SIOCTONLINK
Test if the address is directly reachable, for
example, that it can be reached without going
through a router. This request takes an
sioc_addrreq structure (see below) as a value-
result parameter. The sa_addr field should be set
to the address to test. The sa_res field will
contain a non-zero value if the address is onlink.


SIOCTMYADDR
Test if the address is assigned to this node. This
request takes an sioc_addrreq structure (see
below) as a value-result parameter. The sa_addr
field should be set to the address to test. The
sa_res field will contain a non-zero value if the
address is assigned to this node.


SIOCTMYSITE
Test if the address is part of the same site as
this node. This request takes an sioc_addrreq
structure (see below) as a value-result parameter.
The sa_addr field should be set to the address to
test. The sa_res field will contain a non-zero
value if the address is in the same site.


The structure used by SIOCGLIFCONF has the form:

struct lifconf {
sa_family_t lifc_family;
int lifc_flags; /* request specific
/* interfaces */
int lifc_len; /* size of assoc. buffer */
union {
caddr_t lifcu_buf;
struct lifreq *lifcu_req;
} lifc_lifcu;

#define lifc_buf lifc_lifcu.lifcu_buf /* buffer address */
#define lifc_req lifc_lifcu.lifcu_req /* array of structs returned */
};


The structure used by SIOCGLIFNUM has the form:

struct lifnum {
sa_family_t lifn_family;
int lifn_flags; /* req. specf. interfaces */
int lifn_count; /* Result */
};


The structure used by SIOCTONLINK, SIOCTMYADDR and SIOCTMYSITE has
the form:

struct sioc_addrreq {
struct sockaddr_storage sa_addr; /* Address to test */
int sa_res; /* Result - 0/1 */
};


The structure used by SIOCGLIFSRCOF has the form:

struct lifsrcof {
uint_t lifs_ifindex; /* addr on this interface */
/* used as the src addr */
size_t lifs_maxlen; /* size of buffer: input */
size_t lifs_len; /* size of buffer: output */
union {
caddr_t lifsu_buf;
struct lifreq *lifsu_req;
} lifs_lifsu;
#define lifs_buf lifs_lifsu.lifsu_buf /* buffer addr. */
#define lifs_req lifs_lifsu.lifsu_req /* array returned */
};


The following ioctl() calls are maintained for compatibility but only
apply to IPv4 network interfaces, since the data structures are too
small to hold an IPv6 address. Unless specified otherwise, the
request takes an ifreq structure as its parameter. This structure has
the form:

struct ifreq {
#define IFNAMSIZ 16
char ifr_name[IFNAMSIZ]; /* interface name - e.g. "hme0" */
union {
struct sockaddr ifru_addr;
struct sockaddr ifru_dstaddr;
struct sockaddr ifru_broadaddr;
short ifru_flags;
int ifru_metric;
int if_muxid[2]; /* mux id's for arp and ip */
int ifru_index; /* interface index */
} ifr_ifru;

#define ifr_addr ifr_ifru.ifru_addr /* address */
#define ifr_dstaddr ifr_ifru.ifru_dstaddr /* other end of p-to-p link */
#define ifr_broadaddr ifr_ifru.ifru_broadaddr /* broadcast address */
#define ifr_flags ifr_ifru.ifru_flags /* flags */
#define ifr_index ifr_ifru.ifru_index /* interface index */
#define ifr_metric ifr_ifru.ifru_metric /* metric */
};


SIOCSIFADDR
Set interface address.


SIOCGIFADDR
Get interface address.


SIOCSIFDSTADDR
Set point to point address for interface.


SIOCGIFDSTADDR
Get point to point address for interface.


SIOCSIFFLAGS
Set interface flags field. If the interface is
marked down, any processes currently routing
packets through the interface are notified.


SIOCGIFFLAGS
Get interface flags.


SIOCGIFCONF
Get interface configuration list. This request
takes an ifconf structure (see below) as a value-
result parameter. The ifc_len field should be set
to the size of the buffer pointed to by ifc_buf.
Upon success, ifc_len will contain the length, in
bytes, of the array of ifreq structures pointed to
by ifc_req. For each ifreq structure, the ifr_name
and ifr_addr fields are valid. Though IPMP IP
interfaces are included in the array, underlying IP
interfaces that comprise those IPMP groups are not.


SIOCGIFNUM
Get number of interfaces. This request returns an
integer which is the number of interface
descriptions (struct ifreq) returned by the
SIOCGIFCONF ioctl (in other words, indicates how
large ifc_len must be). Though IPMP IP interfaces
are included in the array, underlying IP
interfaces that comprise those IPMP groups are not.


SIOCSIFMTU
Set the maximum transmission unit (MTU) size for
interface. Place the request in the ifr_metric
field. The MTU has to be smaller than physical MTU
limitation (which is reported in the DLPI
DL_INFO_ACK message).


SIOCGIFMTU
Get the maximum transmission unit size for
interface. Upon success, the request is placed in
the ifr_metric field.


SIOCSIFMETRIC
Set the metric associated with the interface. The
metric is used by routine daemons such as
in.routed(8).


SIOCGIFMETRIC
Get the metric associated with the interface.


SIOCGIFMUXID
Get the ip and arp muxid associated with the
interface.


SIOCSIFMUXID
Set the ip and arp muxid associated with the
interface.


SIOCGIFINDEX
Get the interface index associated with the
interface.


SIOCSIFINDEX
Set the interface index associated with the
interface.


The ifconf structure has the form:

struct ifconf {
int ifc_len; /* size of assoc. buffer */
union {
caddr_t ifcu_buf;
struct ifreq *ifcu_req;
} ifc_ifcu;

#define ifc_buf ifc_ifcu.ifcu_buf /* buffer address */
#define ifc_req ifc_ifcu.ifcu_req /* array of structs returned */
};


IFF_ Flags
You can use the ifconfig(8) command to display the IFF_ flags listed
below (with the leading IFF_ prefix removed). See the ifconfig(8)
manpage for a definition of each flag.

#define IFF_UP 0x0000000001 /* Address is up */
#define IFF_BROADCAST 0x0000000002 /* Broadcast address valid */
#define IFF_DEBUG 0x0000000004 /* Turn on debugging */
#define IFF_LOOPBACK 0x0000000008 /* Loopback net */

#define IFF_POINTOPOINT 0x0000000010 /* Interface is p-to-p */
#define IFF_NOTRAILERS 0x0000000020 /* Avoid use of trailers */
#define IFF_RUNNING 0x0000000040 /* Resources allocated */
#define IFF_NOARP 0x0000000080 /* No address res. protocol */

#define IFF_PROMISC 0x0000000100 /* Receive all packets */
#define IFF_ALLMULTI 0x0000000200 /* Receive all multicast pkts */
#define IFF_INTELLIGENT 0x0000000400 /* Protocol code on board */
#define IFF_MULTICAST 0x0000000800 /* Supports multicast */

#define IFF_MULTI_BCAST 0x0000001000 /* Multicast using broadcst. add. */
#define IFF_UNNUMBERED 0x0000002000 /* Non-unique address */
#define IFF_DHCPRUNNING 0x0000004000 /* DHCP controls interface */
#define IFF_PRIVATE 0x0000008000 /* Do not advertise */

#define IFF_NOXMIT 0x0000010000 /* Do not transmit pkts */
#define IFF_NOLOCAL 0x0000020000 /* No address - just on-link subnet */
#define IFF_DEPRECATED 0x0000040000 /* Address is deprecated */
#define IFF_ADDRCONF 0x0000080000 /* Addr. from stateless addrconf */

#define IFF_ROUTER 0x0000100000 /* Router on interface */
#define IFF_NONUD 0x0000200000 /* No NUD on interface */
#define IFF_ANYCAST 0x0000400000 /* Anycast address */
#define IFF_NORTEXCH 0x0000800000 /* Don't xchange rout. info */

#define IFF_IPV4 0x0001000000 /* IPv4 interface */
#define IFF_IPV6 0x0002000000 /* IPv6 interface */
#define IFF_NOFAILOVER 0x0008000000 /* in.mpathd test address */
#define IFF_FAILED 0x0010000000 /* Interface has failed */

#define IFF_STANDBY 0x0020000000 /* Interface is a hot-spare */
#define IFF_INACTIVE 0x0040000000 /* Functioning but not used */
#define IFF_OFFLINE 0x0080000000 /* Interface is offline */
#define IFF_XRESOLV 0x0100000000 /* IPv6 external resolver */

#define IFF_COS_ENABLED 0x0200000000 /* If CoS marking is supported */
#define IFF_PREFERRED 0x0400000000 /* Prefer as source address */
#define IFF_TEMPORARY 0x0800000000 /* RFC3041 */
#define IFF_FIXEDMTU 0x1000000000 /* MTU set with SIOCSLIFMTU */

#define IFF_VIRTUAL 0x2000000000 /* Cannot send/receive pkts */
#define IFF_DUPLICATE 0x4000000000 /* Local address in use */
#define IFF_IPMP 0x8000000000 /* IPMP IP interface */

ERRORS

EPERM
Calling process has insufficient privileges.


ENXIO
The lifr_name member of the lifreq structure contains
an invalid value.

For SIOCGLIFSRCOF, the lifs_ifindex member of the
lifsrcof structure contains an invalid value.

For SIOCSLIFUSESRC, this error is returned if the
lifr_index is set to an invalid value.


EBADADDR
Wrong address family or malformed address.


EINVAL
For SIOCSLIFMTU, this error is returned when the
requested MTU size is invalid. This error indicates the
MTU size is greater than the MTU size supported by the
DLPI provider or less than 68 (for IPv4) or less than
1280 (for IPv6).

For SIOCSLIFUSESRC, this error is returned if either the
lifr_index or lifr_name identify interfaces that are
already part of an existing IPMP group.


EEXIST
For SIOCLIFADDIF, this error is returned if the lifr_name
member in the lifreq structure corresponds to an
interface that already has the PPA specified by lifr_ppa
plumbed.

SEE ALSO

ioctl(2), sockaddr(3SOCKET), streamio(4I), arp(4P), dlpi(4P), ip(4P),
ip6(4P), ndp(4P), ifconfig(8), in.routed(8)

September 2, 2015 IF_TCP(4P)