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DTRACE_UDP(4)		 BSD Kernel Interfaces Manual		 DTRACE_UDP(4)

NAME
     dtrace_udp	-- a DTrace provider for tracing events	related	to the UDP
     protocol

SYNOPSIS
     udp:::receive(pktinfo_t *,	csinfo_t *, ipinfo_t *,	udpsinfo_t *,
	 udpinfo_t *);

     udp:::send(pktinfo_t *, csinfo_t *, ipinfo_t *, udpsinfo_t	*,
	 udpinfo_t *);

DESCRIPTION
     The DTrace	udp provider allows users to trace events in the udp(4)	proto-
     col implementation.  The udp:::send() probe fires whenever	the kernel
     prepares to transmit a UDP	packet,	and the	udp:::receive()	probe fires
     whenever the kernel receives a UDP	packet,	unless the UDP header is in-
     complete, 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.

ARGUMENTS
     The pktinfo_t argument is currently unimplemented and is included for
     compatibility with	other implementations of this provider.	 Its fields
     are:

	   uintptr_t pkt_addr  Always set to 0.

     The csinfo_t argument is currently	unimplemented and is included for com-
     patibility	with other implementations of this provider.  Its fields are:

	   uintptr_t cs_addr  Always set to 0.

	   uint64_t cs_cid    A	pointer	to the struct inpcb for	this packet,
			      or NULL.

	   pid_t cs_pid	      Always set to 0.

     The ipinfo_t argument contains IP fields common to	both IPv4 and IPv6
     packets.  Its fields are:

	   uint8_t ip_ver	IP version of the packet, 4 for	IPv4 packets
				and 6 for IPv6 packets.

	   uint32_t ip_plength	IP payload size.  This does not	include	the
				size of	the IP header or IPv6 option headers.

	   string ip_saddr	IP source address.

	   string ip_daddr	IP destination address.

     The udpsinfo_t argument contains the state	of the UDP connection associ-
     ated with the packet.  Its	fields are:

	   uintptr_t udps_addr	Pointer	to the struct inpcb containing the IP
				state for the associated socket.

	   uint16_t udps_lport	Local UDP port.

	   uint16_t udps_rport	Remote UDP port.

	   string udps_laddr	Local IPv4 or IPv6 address.

	   string udps_raddr	Remote IPv4 or IPv6 address.

     The udpinfo_t argument is the raw UDP header of the packet, with all
     fields in host order.  Its	fields are:

	   uint16_t udp_sport	   Source UDP port.

	   uint16_t udp_dport	   Destination UDP port.

	   uint16_t udp_length	   Length of the UDP header and	payload, in
				   bytes.

	   uint16_t udp_checksum   A checksum of the UDP header	and payload,
				   or 0	if no checksum was calculated.

	   struct udphdr *udp_hdr  A pointer to	the raw	UDP header.

FILES
     /usr/lib/dtrace/udp.d  DTrace type	and translator definitions for the udp
			    provider.

EXAMPLES
     The following script counts transmitted packets by	destination port.

	   udp:::send
	   {
		   @num[args[4]->udp_dport] = count();
	   }

     This script will print some details of each UDP packet as it is sent or
     received by the kernel:

	   #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;
	   }

COMPATIBILITY
     This provider is compatible with the udp provider in Solaris.

SEE ALSO
     dtrace(1),	dtrace_ip(4), dtrace_sctp(4), dtrace_tcp(4),
     dtrace_udplite(4),	udp(4),	SDT(9)

HISTORY
     The udp provider first appeared in	FreeBSD	10.0.

AUTHORS
     This manual page was written by Mark Johnston <markj@FreeBSD.org>.

BSD				August 1, 2018				   BSD
NAME | SYNOPSIS | DESCRIPTION | ARGUMENTS | FILES | EXAMPLES | COMPATIBILITY | SEE ALSO | HISTORY | AUTHORS

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