ip.7: Added kernel version numbers for IP_* socket options

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man7/ip.7

@@ -6,7 +6,7 @@
 .\" and in case of nontrivial modification author and date
 .\" of the modification is added to the header.
 .\" $Id: ip.7,v 1.19 2000/12/20 18:10:31 ak Exp $
-.TH IP  7 2008-11-21 "Linux" "Linux Programmer's Manual"
+.TH IP  7 2008-11-24 "Linux" "Linux Programmer's Manual"
 .SH NAME
 ip \- Linux IPv4 protocol implementation
 .SH SYNOPSIS
@@ -31,7 +31,7 @@ contains a level 2 multicasting implementation conforming to RFC\ 1112.
 It also contains an IP router including a packet filter.
 .\" FIXME has someone verified that 2.1 is really 1812 compliant?
 .PP
-The programming interface is BSD sockets compatible.
+The programming interface is BSD-sockets compatible.
 For more information on sockets, see
 .BR socket (7).
 .PP
@@ -154,6 +154,7 @@ or set using the
 .BR inet_makeaddr (3)
 library functions or directly with the name resolver (see
 .BR gethostbyname (3)).
+
 IPv4 addresses are divided into unicast, broadcast
 and multicast addresses.
 Unicast addresses specify a single interface of a host,
@@ -199,7 +200,7 @@ A boolean integer flag is zero when it is false, otherwise true.
 .\" FIXME Document IP_FREEBIND
 .\"
 .TP
-.B IP_ADD_MEMBERSHIP
+.B IP_ADD_MEMBERSHIP " (since Linux 1.2)"
 Join a multicast group.
 Argument is an
 .I ip_mreqn
@@ -248,7 +249,7 @@ Only valid as a
 .BR setsockopt (2).
 .\"
 .TP
-.B IP_DROP_MEMBERSHIP
+.BR IP_DROP_MEMBERSHIP " (since Linux 1.2)"
 Leave a multicast group.
 Argument is an
 .I ip_mreqn
@@ -257,7 +258,7 @@ or
 structure similar to
 .BR IP_ADD_MEMBERSHIP .
 .TP
-.B IP_HDRINCL
+.BR IP_HDRINCL " (since Linux 2.0)"
 If enabled,
 the user supplies an IP header in front of the user data.
 Only valid for
@@ -273,14 +274,16 @@ and
 .B IP_TOS
 are ignored.
 .TP
-.B IP_MTU
+.BR IP_MTU " (since Linux 2.2)"
+.\" Precisely: 2.1.124
 Retrieve the current known path MTU of the current socket.
 Only valid when the socket has been connected.
 Returns an integer.
 Only valid as a
 .BR getsockopt (2).
 .TP
-.B IP_MTU_DISCOVER
+.BR IP_MTU_DISCOVER " (since Linux 2.2)"
+.\" Precisely: 2.1.124
 Sets or receives the Path MTU Discovery setting for a socket.
 When enabled, Linux will perform Path MTU Discovery
 as defined in RFC\ 1191
@@ -356,7 +359,7 @@ This is also particularly useful for diagnostic tools such as
 that wish to deliberately send probe packets larger than
 the observed Path MTU.
 .TP
-.B IP_MULTICAST_IF
+.BR IP_MULTICAST_IF " (since Linux 1.2)"
 Set the local device for a multicast socket.
 Argument is an
 .I ip_mreqn
@@ -369,11 +372,11 @@ When an invalid socket option is passed,
 .B ENOPROTOOPT
 is returned.
 .TP
-.B IP_MULTICAST_LOOP
+.BR IP_MULTICAST_LOOP " (since Linux 1.2)"
 Sets or reads a boolean integer argument that determines whether
 sent multicast packets should be looped back to the local sockets.
 .TP
-.B IP_MULTICAST_TTL
+.BR IP_MULTICAST_TTL " (since Linux 1.2)"
 Set or read the time-to-live value of outgoing multicast packets for this
 socket.
 It is very important for multicast packets to set the smallest TTL possible.
@@ -381,7 +384,8 @@ The default is 1 which means that multicast packets don't leave the local
 network unless the user program explicitly requests it.
 Argument is an integer.
 .TP
-.B IP_OPTIONS
+.BR IP_OPTIONS " (since Linux 2.0)"
+.\" Precisely: 1.3.30
 Sets or get the IP options to be sent with every packet from this socket.
 The arguments are a pointer to a memory buffer containing the options
 and the option length.
@@ -409,7 +413,8 @@ with
 .B IP_OPTIONS
 puts the current IP options used for sending into the supplied buffer.
 .TP
-.B IP_PKTINFO
+.BR IP_PKTINFO " (since Linux 2.2)"
+.\" Precisely: 2.1.68
 Pass an
 .B IP_PKTINFO
 ancillary message that contains a
@@ -459,7 +464,8 @@ index overwrites
 .I ipi_spec_dst
 for the routing table lookup.
 .TP
-.BR IP_RECVERR " (defined in \fI<linux/errqueue.h>\fP)"
+.BR IP_RECVERR " (defined in \fI<linux/errqueue.h>\fP; since Linux 2.2)"
+.\" Precisely: 2.1.15
 Enable extended reliable error message passing.
 When enabled on a datagram socket, all
 generated errors will be queued in a per-socket error queue.
@@ -596,7 +602,8 @@ It sets or retrieves an integer boolean flag.
 .B IP_RECVERR
 defaults to off.
 .TP
-.B IP_RECVOPTS
+.BR IP_RECVOPTS " (since Linux 2.2)"
+.\" Precisely: 2.1.15
 Pass all incoming IP options to the user in a
 .B IP_OPTIONS
 control message.
@@ -606,7 +613,8 @@ Not supported for
 .B SOCK_STREAM
 sockets.
 .TP
-.B IP_RECVTOS
+.BR IP_RECVTOS " (since Linux 2.2)"
+.\" Precisely: 2.1.68
 If enabled the
 .B IP_TOS
 ancillary message is passed with incoming packets.
@@ -614,7 +622,8 @@ It contains a byte which specifies the Type of Service/Precedence
 field of the packet header.
 Expects a boolean integer flag.
 .TP
-.B IP_RECVTTL
+.BR IP_RECVTTL " (since Linux 2.2)"
+.\" Precisely: 2.1.68
 When this flag is set, pass a
 .B IP_TTL
 control message with the time to live
@@ -623,13 +632,15 @@ Not supported for
 .B SOCK_STREAM
 sockets.
 .TP
-.B IP_RETOPTS
+.BR IP_RETOPTS " (since Linux 2.2)"
+.\" Precisely: 2.1.15
 Identical to
 .BR IP_RECVOPTS ,
 but returns raw unprocessed options with timestamp and route record
 options not filled in for this hop.
 .TP
-.B IP_ROUTER_ALERT
+.BR IP_ROUTER_ALERT " (since Linux 2.2)"
+.\" Precisely: 2.1.68
 Pass all to-be forwarded packets with the
 IP Router Alert option set to this socket.
 Only valid for raw sockets.
@@ -640,7 +651,7 @@ Socket binding is ignored,
 such packets are only filtered by protocol.
 Expects an integer flag.
 .TP
-.B IP_TOS
+.BR IP_TOS " (since Linux 1.0)"
 Set or receive the Type-Of-Service (TOS) field that is sent
 with every IP packet originating from this socket.
 It is used to prioritize packets on the network.
@@ -669,7 +680,7 @@ The priority can also be set in a protocol independent way by the
 socket option (see
 .BR socket (7)).
 .TP
-.B IP_TTL
+.BR IP_TTL " (since Linux 1.0)"
 Set or retrieve the current time-to-live field that is used in every packet
 sent from this socket.
 .SS /proc interfaces
@@ -736,7 +747,7 @@ This is useful for dialup interface with changing IP addresses.
 .TP
 .IR ip_forward " (Boolean; default: disabled; since Linux 1.2)"
 Enable IP forwarding with a boolean flag.
-IP forwarding can be also set on a per interface basis.
+IP forwarding can be also set on a per-interface basis.
 .\"
 .TP
 .IR ip_local_port_range " (since Linux 2.2)"
@@ -911,8 +922,7 @@ and
 .B IP_RECVERR
 and
 .B IP_ROUTER_ALERT
-are new options in Linux 2.2.
-They are also all Linux-specific and should not be used in
+are Linux-specific and should not be used in
 programs intended to be portable.
 .PP
 .\" FIXME