From: Alejandro Colomar <alx@kernel.org>
Date: Sun, 23 Nov 2025 23:03:08 +0000 (+0100)
Subject: man/man2const/{IPPROTO_IP,IP_MTU}.2const: Split IP_MTU from IPPROTO_IP(2const)
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4fc3d6888a2d97c3d1bbfcacfb36c8ce53ad3dd9;p=thirdparty%2Fman-pages.git

man/man2const/{IPPROTO_IP,IP_MTU}.2const: Split IP_MTU from IPPROTO_IP(2const)

Signed-off-by: Alejandro Colomar <alx@kernel.org>
---

diff --git a/man/man2const/IPPROTO_IP.2const b/man/man2const/IPPROTO_IP.2const
index ec299334f..b8fe34f76 100644
--- a/man/man2const/IPPROTO_IP.2const
+++ b/man/man2const/IPPROTO_IP.2const
@@ -87,16 +87,8 @@ fail with the error
 .BR IP_LOCAL_PORT_RANGE (2const)
 .TQ
 .BR IP_MSFILTER (2const)
-.TP
-.BR IP_MTU " (since Linux 2.2)"
-.\" Precisely: since Linux 2.1.124
-Retrieve the current known path MTU of the current socket.
-Returns an integer.
-.IP
-.B IP_MTU
-is valid only for
-.BR getsockopt (2)
-and can be employed only when the socket has been connected.
+.TQ
+.BR IP_MTU (2const)
 .TP
 .BR IP_MTU_DISCOVER " (since Linux 2.2)"
 .\" Precisely: since Linux 2.1.124
@@ -142,7 +134,7 @@ the path MTU per destination host.
 When it is connected to a specific peer with
 .BR connect (2),
 the currently known path MTU can be retrieved conveniently using the
-.B IP_MTU
+.BR IP_MTU (2const)
 socket option (e.g., after an
 .B EMSGSIZE
 error occurred).
@@ -168,7 +160,7 @@ path MTU, connect a datagram socket to the destination address using
 and retrieve the MTU by calling
 .BR getsockopt (2)
 with the
-.B IP_MTU
+.BR IP_MTU (2const)
 option.
 .IP
 It is possible to implement RFC 4821 MTU probing with
@@ -714,7 +706,6 @@ See
 See
 .BR ip (7).
 .SH NOTES
-.BR IP_MTU ,
 .BR IP_MTU_DISCOVER ,
 .BR IP_RECVORIGDSTADDR ,
 .BR IP_PASSSEC ,
diff --git a/man/man2const/IP_MTU.2const b/man/man2const/IP_MTU.2const
new file mode 100644
index 000000000..a444fa4bb
--- /dev/null
+++ b/man/man2const/IP_MTU.2const
@@ -0,0 +1,44 @@
+.\" Copyright, the authors of the Linux man-pages project
+.\"
+.\" SPDX-License-Identifier: Linux-man-pages-copyleft
+.\"
+.TH IP_MTU 2const (date) "Linux man-pages (unreleased)"
+.SH NAME
+IP_MTU
+\-
+path maximum transmission unit size
+.SH LIBRARY
+Standard C library
+.RI ( libc ,\~ \-lc )
+.SH SYNOPSIS
+.nf
+.BR "#include <netinet/in.h>" "  /* Definition of " IP* " constants */"
+.B #include <sys/socket.h>
+.P
+.BI int\~getsockopt(int\~ sockfd ,\~IPPROTO_IP,\~IP_MTU,
+.BI "               int\~*" val ,\~sizeof(int));
+.fi
+.SH DESCRIPTION
+.TP
+.BR IP_MTU " (since Linux 2.2)"
+.\" Precisely: since Linux 2.1.124
+Retrieve the current known path MTU of the current socket.
+Returns an integer.
+.IP
+.B IP_MTU
+is valid only for
+.BR getsockopt (2)
+and can be employed only when the socket has been connected.
+.SH ERRORS
+See
+.BR IPPROTO_IP (2const).
+See
+.BR getsockopt (2).
+See
+.BR ip (7).
+.SH STANDARDS
+Linux.
+.SH SEE ALSO
+.BR IPPROTO_IP (2const),
+.BR getsockopt (2),
+.BR ip (7)