git: a02915589dff - stable/14 - traceroute.8: improve the documentation of -P

The branch stable/14 has been updated by ivy:

URL: https://cgit.FreeBSD.org/src/commit/?id=a02915589dffa4b2eb93a686e430b35f7cbb10cc

commit a02915589dffa4b2eb93a686e430b35f7cbb10cc
Author:     Lexi Winter <ivy@FreeBSD.org>
AuthorDate: 2025-05-14 16:05:02 +0000
Commit:     Lexi Winter <ivy@FreeBSD.org>
CommitDate: 2025-05-21 06:29:17 +0000

    traceroute.8: improve the documentation of -P
    
    1. -P didn't say what the argument is supposed to be; in the case of
       udplite(4), "-Pudp-lite" is not valid, one must use "-Pudplite".
    2. be more explicit about what sort of packets we generate, particularly
       for -Psctp and -Pgre.
    
    Reviewed by:    imp, tuexen, des
    Approved by:    des (mentor)
    Pull Request:   https://github.com/freebsd/freebsd-src/pull/1657
    
    (cherry picked from commit 0829839fd0cd6046fbb5c0b6c6432b5ffe0d91e8)
---
 usr.sbin/traceroute/traceroute.8 | 64 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 63 insertions(+), 1 deletion(-)

diff --git a/usr.sbin/traceroute/traceroute.8 b/usr.sbin/traceroute/traceroute.8
index 21427ef6e97c..6b46ec05a1c9 100644
--- a/usr.sbin/traceroute/traceroute.8
+++ b/usr.sbin/traceroute/traceroute.8
@@ -16,7 +16,7 @@
 .\"	$Id: traceroute.8,v 1.19 2000/09/21 08:44:19 leres Exp $
 .\"	$FreeBSD$
 .\"
-.Dd October 25, 2023
+.Dd May 14, 2025
 .Dt TRACEROUTE 8
 .Os
 .Sh NAME
@@ -148,6 +148,68 @@ at the destination host (so an ICMP PORT_UNREACHABLE message will
 be returned to terminate the route tracing).  If something is
 listening on a port in the default range, this option can be used
 to pick an unused port range.
+.It Fl P Ar proto
+Use packets of specified IP protocol when sending probes.
+The
+.Ar proto
+argument may be one of the following:
+.Bl -tag -width Ar udplite
+.It Ar udp
+Use
+.Xr udp 4
+packets.
+This is the default.
+.It Ar icmp
+Use
+.Xr icmp 4
+.Dq echo request
+packets.
+.It Ar udplite
+Use
+.Xr udplite 4
+packets.
+.It Ar tcp
+Use
+.Xr tcp 4
+.Dq SYN
+packets.
+This will cause a successful traceroute to end with no response (i.e., a
+.Dq *
+response) since
+.Nm
+does not know how to detect the RST or SYN+ACK response from the
+destination host.
+.It Ar sctp
+Use
+.Xr sctp 4
+packets.
+The
+.Ar packetlen
+argument must be a multiple of 4.
+SCTP probes will be constructed as SCTP
+.Dq INIT
+chunks, unless the packet length is too small, in which case the probes
+will be SCTP
+.Dq SHUTDOWN-ACK
+chunks followed by zero or one
+.Dq PAD
+chunks.
+.It Ar gre
+Use
+.Xr gre 4
+packets.
+The GRE packets will be constructed as if they contain a PPTP
+(Point-to-Point Tunneling Protocol) payload.
+.El
+.Pp
+Other protocols may also be specified, either by number or by name (see
+.Xr protocols 5 ) ,
+though
+.Nm
+does not implement any special knowledge of their packet formats.
+This option is useful for determining which router along a path may be blocking
+packets based on IP protocol number.
+But see BUGS below.
 .It Fl q Ar nprobes
 Set the number of probes per hop (default is 3,
 unless