BSD 4_4 release

[unix-history] / usr / src / share / man / man4 / netintro.4

diff --git a/usr/src/share/man/man4/netintro.4 b/usr/src/share/man/man4/netintro.4
index 4915df0..ee01dd3 100644 (file)
--- a/usr/src/share/man/man4/netintro.4
+++ b/usr/src/share/man/man4/netintro.4
@@ -1,48 +1,59 @@
-.\" Copyright (c) 1983 Regents of the University of California.
-.\" All rights reserved.  The Berkeley software License Agreement
-.\" specifies the terms and conditions for redistribution.
+.\" Copyright (c) 1983, 1990, 1991, 1993
+.\"    The Regents of the University of California.  All rights reserved.

 .\"
 .\"

-.\"    @(#)netintro.4  6.5 (Berkeley) %G%
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"    This product includes software developed by the University of
+.\"    California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.

 .\"
 .\"

-.TH NETINTRO 4 ""
-.UC 5
-.SH NAME
-networking \- introduction to networking facilities
-.SH SYNOPSIS
-.nf
-.ft B
-#include <sys/socket.h>
-#include <net/route.h>
-#include <net/if.h>
-.fi R
-.fi
-.SH DESCRIPTION
-.de _d
-.if t .ta .6i 2.1i 2.6i
-.\" 2.94 went to 2.6, 3.64 to 3.30
-.if n .ta .84i 2.6i 3.30i
-..
-.de _f
-.if t .ta .5i 1.25i 2.5i
-.\" 3.5i went to 3.8i
-.if n .ta .7i 1.75i 3.8i
-..
-This section briefly describes the networking facilities
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"     @(#)netintro.4 8.1 (Berkeley) 7/19/93
+.\"
+.Dd July 19, 1993
+.Dt NETINTRO 4
+.Os BSD 4.2
+.Sh NAME
+.Nm networking
+.Nd introduction to networking facilities
+.Sh SYNOPSIS
+.Fd #include <sys/socket.h>
+.Fd #include <net/route.h>
+.Fd #include <net/if.h>
+.Sh DESCRIPTION
+This section is a general introduction to the networking facilities

 available in the system.
 Documentation in this part of section
 4 is broken up into three areas:
 available in the system.
 Documentation in this part of section
 4 is broken up into three areas:

-.I "protocol families
+.Em protocol families

 (domains),
 (domains),

-.IR protocols ,
+.Em protocols ,

 and
 and

-.IR "network interfaces" .
-Entries describing a protocol family are marked ``4F,''
-while entries describing protocol use are marked ``4P.''
-Hardware support for network interfaces are found
-among the standard ``4'' entries.
-.PP
+.Em network interfaces .
+.Pp

 All network protocols are associated with a specific
 All network protocols are associated with a specific

-.IR "protocol family" .
+.Em protocol family .

 A protocol family provides basic services to the protocol
 implementation to allow it to function within a specific
 network environment.  These services may include 
 A protocol family provides basic services to the protocol
 implementation to allow it to function within a specific
 network environment.  These services may include 


@@ -51,14 +62,13 @@ basic transport.  A protocol family may support multiple
 methods of addressing, though the current protocol implementations
 do not.  A protocol family is normally comprised of a number
 of protocols, one per
 methods of addressing, though the current protocol implementations
 do not.  A protocol family is normally comprised of a number
 of protocols, one per

-.IR socket (2)
+.Xr socket 2

 type.  It is not required that a protocol family support
 all socket types.  A protocol family may contain multiple
 protocols supporting the same socket abstraction. 
 type.  It is not required that a protocol family support
 all socket types.  A protocol family may contain multiple
 protocols supporting the same socket abstraction. 

-.PP
-A protocol supports one of the socket abstractions detailed
-in
-.IR socket (2).
+.Pp
+A protocol supports one of the socket abstractions detailed in
+.Xr socket 2 .

 A specific protocol may be accessed either by creating a
 socket of the appropriate type and protocol family, or
 by requesting the protocol explicitly when creating a socket.
 A specific protocol may be accessed either by creating a
 socket of the appropriate type and protocol family, or
 by requesting the protocol explicitly when creating a socket.


@@ -70,10 +80,10 @@ protocol specific.  All protocols are expected to support
 the basic model for their particular socket type, but may,
 in addition, provide non-standard facilities or extensions
 to a mechanism.  For example, a protocol supporting the
 the basic model for their particular socket type, but may,
 in addition, provide non-standard facilities or extensions
 to a mechanism.  For example, a protocol supporting the

-SOCK_STREAM
+.Dv SOCK_STREAM

 abstraction may allow more than one byte of out-of-band
 data to be transmitted per out-of-band message.
 abstraction may allow more than one byte of out-of-band
 data to be transmitted per out-of-band message.

-.PP
+.Pp

 A network interface is similar to a device interface.
 Network interfaces comprise the lowest layer of the
 networking subsystem, interacting with the actual transport
 A network interface is similar to a device interface.
 Network interfaces comprise the lowest layer of the
 networking subsystem, interacting with the actual transport


@@ -83,234 +93,236 @@ The SYNOPSIS section of each network interface
 entry gives a sample specification
 of the related drivers for use in providing
 a system description to the
 entry gives a sample specification
 of the related drivers for use in providing
 a system description to the

-.IR config (8)
+.Xr config 8

 program.
 The DIAGNOSTICS section lists messages which may appear on the console
 and/or in the system error log,
 program.
 The DIAGNOSTICS section lists messages which may appear on the console
 and/or in the system error log,

-.I /usr/adm/messages
+.Pa /var/log/messages

 (see
 (see

-.IR syslogd (8)),
+.Xr syslogd 8 ) ,

 due to errors in device operation.
 due to errors in device operation.

-.SH PROTOCOLS
-The system currently supports the DARPA Internet
-protocols and the Xerox Network Systems(tm) protocols.
-Raw socket interfaces are provided to the IP protocol
-layer of the DARPA Internet, to the IMP link layer (1822), and to
-the IDP protocol of Xerox NS.
+.Sh PROTOCOLS
+The system currently supports the
+Internet
+protocols, the Xerox Network Systems(tm) protocols,
+and some of the
+.Tn ISO OSI
+protocols.
+Raw socket interfaces are provided to the
+.Tn IP
+protocol
+layer of the
+Internet, and to the
+.Tn IDP
+protocol of Xerox
+.Tn NS .

 Consult the appropriate manual pages in this section for more
 information regarding the support for each protocol family.
 Consult the appropriate manual pages in this section for more
 information regarding the support for each protocol family.

-.SH ADDRESSING
+.Sh ADDRESSING

 Associated with each protocol family is an address
 Associated with each protocol family is an address

-format.  The following address formats are used by the system (and additional
-formats are defined for possible future implementation):
-.sp 1
-.nf
-._d
-#define        AF_UNIX 1       /* local to host (pipes, portals) */
-#define        AF_INET 2       /* internetwork: UDP, TCP, etc. */
-#define        AF_IMPLINK      3       /* arpanet imp addresses */
-#define        AF_PUP  4       /* pup protocols: e.g. BSP */
-#define        AF_NS   6       /* Xerox NS protocols */
-#define        AF_HYLINK       15      /* NSC Hyperchannel */
-.fi
-.SH ROUTING
-The network facilities provided limited packet routing.
-A simple set of data structures comprise a ``routing table''
-used in selecting the appropriate network interface when
-transmitting packets.  This table contains a single entry for
-each route to a specific network or host.  A user process,
-the routing daemon, maintains this data base with the aid
-of two socket-specific 
-.IR ioctl (2)
-commands, SIOCADDRT and SIOCDELRT.  The commands allow
-the addition and deletion of a single routing
-table entry, respectively.  Routing table manipulations may
-only be carried out by super-user.
-.PP
-A routing table entry has the following form, as defined
-in
-.RI < net/route.h >;
-.sp 1
-._f
-.nf
-struct rtentry {
-       u_long  rt_hash;
-       struct  sockaddr rt_dst;
-       struct  sockaddr rt_gateway;
-       short   rt_flags;
-       short   rt_refcnt;
-       u_long  rt_use;
-       struct  ifnet *rt_ifp;
+format.  All network address adhere to a general structure,
+called a sockaddr, described below. However, each protocol
+imposes finer and more specific structure, generally renaming
+the variant, which is discussed in the protocol family manual
+page alluded to above.
+.Bd -literal -offset indent
+    struct sockaddr {
+       u_char  sa_len;
+       u_char  sa_family;
+       char    sa_data[14];

 };
 };

-.sp 1
-.fi
-with
-.I rt_flags
-defined from,
-.sp 1
-.nf
-._d
-#define        RTF_UP  0x1             /* route usable */
-#define        RTF_GATEWAY     0x2             /* destination is a gateway */
-#define        RTF_HOST        0x4             /* host entry (net otherwise) */
-#define        RTF_DYNAMIC     0x10            /* created dynamically (by redirect) */
-.fi
-.PP
-Routing table entries come in three flavors: for a specific
-host, for all hosts on a specific network, for any destination
-not matched by entries of the first two types (a wildcard route). 
-When the system is booted and addresses are assigned
-to the network interfaces, each protocol family
-installs a routing table entry for each interface when it is ready for traffic.
-Normally the protocol specifies the route
-through each interface as a ``direct'' connection to the destination host
-or network.  If the route is direct, the transport layer of
-a protocol family usually requests the packet be sent to the
-same host specified in the packet.  Otherwise, the interface
-is requested to address the packet to the gateway listed in the routing entry
-(i.e. the packet is forwarded).
-.PP
-Routing table entries installed by a user process may not specify
-the hash, reference count, use, or interface fields; these are filled
-in by the routing routines.  If
-a route is in use when it is deleted
-.RI ( rt_refcnt
-is non-zero),
-the routing entry will be marked down and removed from the routing table,
-but the resources associated with it will not
-be reclaimed until all references to it are released. 
-The routing code returns EEXIST if
-requested to duplicate an existing entry, ESRCH if
-requested to delete a non-existent entry,
-or ENOBUFS if insufficient resources were available
-to install a new route.
-User processes read the routing tables through the
-.I /dev/kmem 
-device.
-The
-.I rt_use
-field contains the number of packets sent along the route.
-.PP
-When routing a packet,
-the kernel will first attempt to find a route to the destination host.
-Failing that, a search is made for a route to the network of the destination.
-Finally, any route to a default (``wildcard'') gateway is chosen.
-If multiple routes are present in the table,
-the first route found will be used.
-If no entry is found, the destination is declared to be unreachable.
-.PP
-A wildcard routing entry is specified with a zero
-destination address value.  Wildcard routes are used
-only when the system fails to find a route to the
-destination host and network.  The combination of wildcard
-routes and routing redirects can provide an economical
-mechanism for routing traffic.
-.SH INTERFACES
+.Ed
+.Pp
+The field
+.Ar sa_len
+contains the total length of the of the structure,
+which may exceed 16 bytes.
+The following address values for
+.Ar sa_family
+are known to the system
+(and additional formats are defined for possible future implementation):
+.Bd -literal
+#define    AF_UNIX      1    /* local to host (pipes, portals) */
+#define    AF_INET      2    /* internetwork: UDP, TCP, etc. */
+#define    AF_NS        6    /* Xerox NS protocols */
+#define    AF_CCITT     10   /* CCITT protocols, X.25 etc */
+#define    AF_HYLINK    15   /* NSC Hyperchannel */
+#define    AF_ISO       18   /* ISO protocols */
+.Ed
+.Sh ROUTING
+.Tn UNIX
+provides some packet routing facilities.
+The kernel maintains a routing information database, which
+is used in selecting the appropriate network interface when
+transmitting packets.
+.Pp
+A user process (or possibly multiple co-operating processes)
+maintains this database by sending messages over a special kind
+of socket.
+This supplants fixed size
+.Xr ioctl 2
+used in earlier releases.
+.Pp
+This facility is described in
+.Xr route 4 .
+.Sh INTERFACES

 Each network interface in a system corresponds to a
 path through which messages may be sent and received.  A network
 interface usually has a hardware device associated with it, though
 certain interfaces such as the loopback interface,
 Each network interface in a system corresponds to a
 path through which messages may be sent and received.  A network
 interface usually has a hardware device associated with it, though
 certain interfaces such as the loopback interface,

-.IR lo (4),
+.Xr lo 4 ,

 do not.
 do not.

-.PP
+.Pp

 The following 
 The following 

-.I ioctl
+.Xr ioctl

 calls may be used to manipulate network interfaces.
 The
 calls may be used to manipulate network interfaces.
 The

-.I ioctl
-is made on a socket (typically of type SOCK_DGRAM)
+.Xr ioctl
+is made on a socket (typically of type
+.Dv SOCK_DGRAM )

 in the desired domain.
 in the desired domain.

-Unless specified otherwise, the request takes an
-.I ifrequest
+Most of the requests supported in earlier releases 
+take an
+.Ar ifreq

 structure as its parameter.  This structure has the form
 structure as its parameter.  This structure has the form

-.PP
-.nf
-.DT
+.Bd -literal

 struct ifreq {
 struct ifreq {

-#define        IFNAMSIZ        16
-       char    ifr_name[IFNAMSIZE];            /* if name, e.g. "en0" */
-       union {
-               struct  sockaddr ifru_addr;
-               struct  sockaddr ifru_dstaddr;
-               struct  sockaddr ifru_broadaddr;
-               short   ifru_flags;
-               int     ifru_metric;
-               caddr_t ifru_data;
-       } 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_metric      ifr_ifru.ifru_metric    /* metric */
-#define        ifr_data        ifr_ifru.ifru_data      /* for use by interface */
+#define    IFNAMSIZ    16
+    char    ifr_name[IFNAMSIZE];        /* if name, e.g. "en0" */
+    union {
+        struct    sockaddr ifru_addr;
+        struct    sockaddr ifru_dstaddr;
+        struct    sockaddr ifru_broadaddr;
+        short     ifru_flags;
+        int       ifru_metric;
+        caddr_t   ifru_data;
+    } 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_metric    ifr_ifru.ifru_metric  /* metric */
+#define ifr_data      ifr_ifru.ifru_data    /* for use by interface */

 };
 };

-.fi
-.TP
-SIOCSIFADDR
+.Ed
+.Pp
+Calls which are now deprecated are:
+.Bl -tag -width SIOCGIFBRDADDR
+.It Dv SIOCSIFADDR

 Set interface address for protocol family.  Following the address
 assignment, the ``initialization'' routine for
 the interface is called.
 Set interface address for protocol family.  Following the address
 assignment, the ``initialization'' routine for
 the interface is called.

-.TP
-SIOCGIFADDR
-Get interface address for protocol family.
-.TP
-SIOCSIFDSTADDR
+.It Dv SIOCSIFDSTADDR

 Set point to point address for protocol family and interface.
 Set point to point address for protocol family and interface.

-.TP
-SIOCGIFDSTADDR
-Get point to point address for protocol family and interface.
-.TP
-SIOCSIFBRDADDR
+.It Dv SIOCSIFBRDADDR

 Set broadcast address for protocol family and interface.
 Set broadcast address for protocol family and interface.

-.TP
-SIOCGIFBRDADDR
+.El
+.Pp
+.Xr Ioctl
+requests to obtain addresses and requests both to set and
+retreive other data are still fully supported
+and use the
+.Ar ifreq
+structure:
+.Bl -tag -width SIOCGIFBRDADDR
+.It Dv SIOCGIFADDR
+Get interface address for protocol family.
+.It Dv SIOCGIFDSTADDR
+Get point to point address for protocol family and interface.
+.It Dv SIOCGIFBRDADDR

 Get broadcast address for protocol family and interface.
 Get broadcast address for protocol family and interface.

-.TP
-SIOCSIFFLAGS
+.It Dv SIOCSIFFLAGS

 Set interface flags field.  If the interface is marked down,
 any processes currently routing packets through the interface
 are notified;
 some interfaces may be reset so that incoming packets are no longer received.
 When marked up again, the interface is reinitialized.
 Set interface flags field.  If the interface is marked down,
 any processes currently routing packets through the interface
 are notified;
 some interfaces may be reset so that incoming packets are no longer received.
 When marked up again, the interface is reinitialized.

-.TP
-SIOCGIFFLAGS
+.It Dv SIOCGIFFLAGS

 Get interface flags.
 Get interface flags.

-.TP
-SIOCSIFMETRIC
+.It Dv SIOCSIFMETRIC

 Set interface routing metric.
 The metric is used only by user-level routers.
 Set interface routing metric.
 The metric is used only by user-level routers.

-.TP
-SIOCGIFMETRIC
+.It Dv SIOCGIFMETRIC

 Get interface metric.
 Get interface metric.

-.TP
-SIOCGIFCONF
+.El
+.Pp
+There are two requests that make use of a new structure:
+.Bl -tag -width SIOCGIFBRDADDR
+.It Dv SIOCAIFADDR
+An interface may have more than one address associated with it
+in some protocols.  This request provides a means to
+add additional addresses (or modify characteristics of the
+primary address if the default address for the address family
+is specified).  Rather than making separate calls to
+set destination or broadcast addresses, or network masks
+(now an integral feature of multiple protocols)
+a separate structure is used to specify all three facets simultaneously
+(see below).
+One would use a slightly tailored version of this struct specific
+to each family (replacing each sockaddr by one
+of the family-specific type).
+Where the sockaddr itself is larger than the
+default size, one needs to modify the
+.Xr ioctl
+identifier itself to include the total size, as described in
+.Xr ioctl .
+.It Dv SIOCDIFADDR
+This requests deletes the specified address from the list
+associated with an interface.  It also uses the
+.Ar if_aliasreq
+structure to allow for the possibility of protocols allowing
+multiple masks or destination addresses, and also adopts the
+convention that specification of the default address means
+to delete the first address for the interface belonging to
+the address family in which the original socket was opened.
+.It Dv SIOCGIFCONF

 Get interface configuration list.  This request takes an
 Get interface configuration list.  This request takes an

-.I ifconf
+.Ar ifconf

 structure (see below) as a value-result parameter.  The 
 structure (see below) as a value-result parameter.  The 

-.I ifc_len
+.Ar ifc_len

 field should be initially set to the size of the buffer
 pointed to by 
 field should be initially set to the size of the buffer
 pointed to by 

-.IR ifc_buf .
+.Ar ifc_buf .

 On return it will contain the length, in bytes, of the
 configuration list.
 On return it will contain the length, in bytes, of the
 configuration list.

-.PP
-.nf
-.DT
+.El
+.Bd -literal

 /*
 /*

- * Structure used in SIOCGIFCONF request.
- * Used to retrieve interface configuration
- * for machine (useful for programs which
- * must know all networks accessible).
- */
-struct ifconf {
-       int     ifc_len;                /* size of associated 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 structures returned */
+* Structure used in SIOCAIFCONF request.
+*/
+struct ifaliasreq {
+        char    ifra_name[IFNAMSIZ];   /* if name, e.g. "en0" */
+        struct  sockaddr        ifra_addr;
+        struct  sockaddr        ifra_broadaddr;
+        struct  sockaddr        ifra_mask;

 };
 };

-.fi
-.SH SEE ALSO
-socket(2), ioctl(2), intro(4), config(8), routed(8C)
+.Ed
+.Pp
+.Bd -literal
+/*
+* Structure used in SIOCGIFCONF request.
+* Used to retrieve interface configuration
+* for machine (useful for programs which
+* must know all networks accessible).
+*/
+struct ifconf {
+    int   ifc_len;             /* size of associated 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 structures returned */
+};
+.Ed
+.Sh SEE ALSO
+.Xr socket 2 ,
+.Xr ioctl 2 ,
+.Xr intro 4 ,
+.Xr config 8 ,
+.Xr routed 8
+.Sh HISTORY
+The
+.Nm netintro
+manual appeared in
+.Bx 4.3 tahoe .