.\" Copyright (c) 2015 Mark Johnston .\" All rights reserved. .\" .\" 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. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. .\" .\" $FreeBSD: releng/12.2/share/man/man4/dtrace_udp.4 337018 2018-07-31 22:56:03Z tuexen $ .\" .Dd August 1, 2018 .Dt DTRACE_UDP 4 .Os .Sh NAME .Nm dtrace_udp .Nd a DTrace provider for tracing events related to the UDP protocol .Sh SYNOPSIS .Fn udp:::receive "pktinfo_t *" "csinfo_t *" "ipinfo_t *" "udpsinfo_t *" \ "udpinfo_t *" .Fn udp:::send "pktinfo_t *" "csinfo_t *" "ipinfo_t *" "udpsinfo_t *" \ "udpinfo_t *" .Sh DESCRIPTION The DTrace .Nm udp provider allows users to trace events in the .Xr udp 4 protocol implementation. The .Fn udp:::send probe fires whenever the kernel prepares to transmit a UDP packet, and the .Fn udp:::receive probe fires whenever the kernel receives a UDP packet, unless the UDP header is incomplete, the destination port is 0, the length field is invalid, or the checksum is wrong. The arguments to these probes can be used to obtain detailed information about the IP and UDP headers of the corresponding packet. .Sh ARGUMENTS The .Vt pktinfo_t argument is currently unimplemented and is included for compatibility with other implementations of this provider. Its fields are: .Bl -tag -width "uintptr_t pkt_addr" -offset indent .It Vt uintptr_t pkt_addr Always set to 0. .El .Pp The .Vt csinfo_t argument is currently unimplemented and is included for compatibility with other implementations of this provider. Its fields are: .Bl -tag -width "uintptr_t cs_addr" -offset indent .It Vt uintptr_t cs_addr Always set to 0. .It Vt uint64_t cs_cid A pointer to the .Vt struct inpcb for this packet, or .Dv NULL . .It Vt pid_t cs_pid Always set to 0. .El .Pp The .Vt ipinfo_t argument contains IP fields common to both IPv4 and IPv6 packets. Its fields are: .Bl -tag -width "uint32_t ip_plength" -offset indent .It Vt uint8_t ip_ver IP version of the packet, 4 for IPv4 packets and 6 for IPv6 packets. .It Vt uint32_t ip_plength IP payload size. This does not include the size of the IP header or IPv6 option headers. .It Vt string ip_saddr IP source address. .It Vt string ip_daddr IP destination address. .El .Pp The .Vt udpsinfo_t argument contains the state of the UDP connection associated with the packet. Its fields are: .Bl -tag -width "uintptr_t udps_addr" -offset indent .It Vt uintptr_t udps_addr Pointer to the .Vt struct inpcb containing the IP state for the associated socket. .It Vt uint16_t udps_lport Local UDP port. .It Vt uint16_t udps_rport Remote UDP port. .It Vt string udps_laddr Local IPv4 or IPv6 address. .It Vt string udps_raddr Remote IPv4 or IPv6 address. .El .Pp The .Vt udpinfo_t argument is the raw UDP header of the packet, with all fields in host order. Its fields are: .Bl -tag -width "struct udphdr *udp_hdr" -offset indent .It Vt uint16_t udp_sport Source UDP port. .It Vt uint16_t udp_dport Destination UDP port. .It Vt uint16_t udp_length Length of the UDP header and payload, in bytes. .It Vt uint16_t udp_checksum A checksum of the UDP header and payload, or 0 if no checksum was calculated. .It Vt struct udphdr *udp_hdr A pointer to the raw UDP header. .El .Sh FILES .Bl -tag -width "/usr/lib/dtrace/udp.d" -compact .It Pa /usr/lib/dtrace/udp.d DTrace type and translator definitions for the .Nm udp provider. .El .Sh EXAMPLES The following script counts transmitted packets by destination port. .Bd -literal -offset indent udp:::send { @num[args[4]->udp_dport] = count(); } .Ed .Pp This script will print some details of each UDP packet as it is sent or received by the kernel: .Bd -literal -offset indent #pragma D option quiet #pragma D option switchrate=10Hz dtrace:::BEGIN { printf(" %10s %36s %-36s %6s\\n", "DELTA(us)", "SOURCE", "DEST", "BYTES"); last = timestamp; } udp:::send { this->elapsed = (timestamp - last) / 1000; self->dest = strjoin(strjoin(args[2]->ip_daddr, ":"), lltostr(args[4]->udp_dport)); printf(" %10d %30s:%-5d -> %-36s %6d\\n", this->elapsed, args[2]->ip_saddr, args[4]->udp_sport, self->dest, args[4]->udp_length); last = timestamp; } udp:::receive { this->elapsed = (timestamp - last) / 1000; self->dest = strjoin(strjoin(args[2]->ip_saddr, ":"), lltostr(args[4]->udp_sport)); printf(" %10d %30s:%-5d <- %-36s %6d\\n", this->elapsed, args[2]->ip_daddr, args[4]->udp_dport, self->dest, args[4]->udp_length); last = timestamp; } .Ed .Sh COMPATIBILITY This provider is compatible with the .Nm udp provider in Solaris. .Sh SEE ALSO .Xr dtrace 1 , .Xr dtrace_ip 4 , .Xr dtrace_sctp 4 , .Xr dtrace_tcp 4 , .Xr dtrace_udplite 4 , .Xr udp 4 , .Xr SDT 9 .Sh HISTORY The .Nm udp provider first appeared in .Fx 10.0. .Sh AUTHORS This manual page was written by .An Mark Johnston Aq Mt markj@FreeBSD.org .