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DTRACE_UDPLITE(4) FreeBSD Kernel Interfaces Manual DTRACE_UDPLITE(4)
NAME
dtrace_udplite - a DTrace provider for tracing events related to the UDP-
Lite protocol
SYNOPSIS
udplite:::receive(pktinfo_t *, csinfo_t *, ipinfo_t *, udplitesinfo_t *,
udpliteinfo_t *);
udplite:::send(pktinfo_t *, csinfo_t *, ipinfo_t *, udplitesinfo_t *,
udpliteinfo_t *);
DESCRIPTION
The DTrace udplite provider allows users to trace events in the
udplite(4) protocol implementation. The udplite:::send() probe fires
whenever the kernel prepares to transmit a UDP-Lite packet, and the
udplite:::receive() probe fires whenever the kernel receives a UDP-Lite
packet, unless the UDP-Lite 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-Lite 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
compatibility 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 udplitesinfo_t argument contains the state of the UDP-Lite connection
associated with the packet. Its fields are:
uintptr_t udplites_addr Pointer to the struct inpcb containing the
IP state for the associated socket.
string udplites_raddr Remote IPv4 or IPv6 address.
The udpliteinfo_t argument is the raw UDP-Lite header of the packet, with
all fields in host order. Its fields are:
uint16_t udplite_sport Source UDP-Lite port.
uint16_t udplite_dport Destination UDP-Lite port.
uint16_t udplite_coverage Checksum coverage of the UDP-Lite
header, in bytes, or 0 for full
coverage.
uint16_t udplite_checksum A checksum of the UDP-Lite header
and payload, or 0 if no checksum
was calculated.
struct udplitehdr *udplite_hdr A pointer to the raw UDP-Lite
header.
FILES
/usr/lib/dtrace/udplite.d DTrace type and translator definitions for the
udplite provider.
EXAMPLES
The following script counts transmitted packets by destination port.
udplite:::send
{
@num[args[4]->udplite_dport] = count();
}
This script will print some details of each UDP-Lite 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", "COV");
last = timestamp;
}
udplite:::send
{
this->elapsed = (timestamp - last) / 1000;
self->dest = strjoin(strjoin(args[2]->ip_daddr, ":"),
lltostr(args[4]->udplite_dport));
printf(" %10d %30s:%-5d -> %-36s %6d\n", this->elapsed,
args[2]->ip_saddr, args[4]->udplite_sport,
self->dest, args[4]->udplite_coverage);
last = timestamp;
}
udplite:::receive
{
this->elapsed = (timestamp - last) / 1000;
SEE ALSO
dtrace(1), dtrace_ip(4), dtrace_sctp(4), dtrace_tcp(4), dtrace_udp(4),
udplite(4), SDT(9)
HISTORY
The udplite provider first appeared in FreeBSD 12.0.
AUTHORS
This manual page was written by Mark Johnston <markj@FreeBSD.org> and
Michael Tuexen <tuexen@FreeBSD.org>.
FreeBSD 14.0-RELEASE-p6 August 1, 2018 FreeBSD 14.0-RELEASE-p6