dtrace_udplite — a DTrace provider for tracing events related to the UDP-Lite protocol
Contents
Arguments
The pktinfo_t argument is currently unimplemented and is included for compatibility with other
implementations of this provider. Its fields are:
uintptr_tpkt_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_tcs_addr Always set to 0.
uint64_tcs_cid A pointer to the structinpcb for this packet, or NULL.
pid_tcs_pid Always set to 0.
The ipinfo_t argument contains IP fields common to both IPv4 and IPv6 packets. Its fields are:
uint8_tip_ver IP version of the packet, 4 for IPv4 packets and 6 for IPv6 packets.
uint32_tip_plength IP payload size. This does not include the size of the IP header or IPv6
option headers.
stringip_saddr IP source address.
stringip_daddr IP destination address.
The udplitesinfo_t argument contains the state of the UDP-Lite connection associated with the packet.
Its fields are:
uintptr_tudplites_addr Pointer to the structinpcb containing the IP state for the associated
socket.
uint16_tudplites_lport Local UDP-Lite port.
uint16_tudplites_rport Remote UDP-Lite port.
stringudplites_laddr Local IPv4 or IPv6 address.
stringudplites_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_tudplite_sport Source UDP-Lite port.
uint16_tudplite_dport Destination UDP-Lite port.
uint16_tudplite_coverage Checksum coverage of the UDP-Lite header, in bytes, or 0 for full
coverage.
uint16_tudplite_checksum A checksum of the UDP-Lite header and payload, or 0 if no checksum
was calculated.
structudplitehdr*udplite_hdr A pointer to the raw UDP-Lite header.
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.
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;
self->dest = strjoin(strjoin(args[2]->ip_saddr, ":"),
lltostr(args[4]->udplite_sport));
printf(" %10d %30s:%-5d <- %-36s %6d\n", this->elapsed,
args[2]->ip_daddr, args[4]->udplite_dport,
self->dest, args[4]->udplite_coverage);
last = timestamp;
}
Files
/usr/lib/dtrace/udplite.d DTrace type and translator definitions for the udplite provider.
History
The udplite provider first appeared in FreeBSD 12.0.
Name
dtrace_udplite — a DTrace provider for tracing events related to the UDP-Lite protocol
See Also
dtrace(1), dtrace_ip(4), dtrace_sctp(4), dtrace_tcp(4), dtrace_udp(4), udplite(4), SDT(9)
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*);
