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.

           uint16_t udplites_lport  Local UDP-Lite port.

           uint16_t udplites_rport  Remote UDP-Lite port.

           string udplites_laddr    Local IPv4 or IPv6 address.

           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;
                   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;
           }

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 13.1-RELEASE-p6         August 1, 2018         FreeBSD 13.1-RELEASE-p6