1.\" Copyright (c) 2015 Mark Johnston <markj@FreeBSD.org> 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd September 14, 2015 28.Dt DTRACE_IP 4 29.Os 30.Sh NAME 31.Nm dtrace_ip 32.Nd a DTrace provider for tracing events related to the IPv4 and IPv6 protocols 33.Sh SYNOPSIS 34.Fn ip:::receive "pktinfo_t *" "csinfo_t *" "ipinfo_t *" "ifinfo_t *" \ 35 "ipv4info_t *" "ipv6info_t *" 36.Fn ip:::send "pktinfo_t *" "csinfo_t *" "ipinfo_t *" "ifinfo_t *" \ 37 "ipv4info_t *" "ipv6info_t *" 38.Sh DESCRIPTION 39The DTrace 40.Nm ip 41provider allows users to trace events in the 42.Xr ip 4 43and 44.Xr ip6 4 45protocol implementations. 46The 47.Fn ip:::send 48probe fires whenever the kernel prepares to transmit an IP packet, and the 49.Fn ip:::receive 50probe fires whenever the kernel receives an IP packet. 51The arguments to these probes can be used to obtain detailed information about 52the IP headers of the corresponding packet, as well as the network interface on 53which the packet was sent or received. 54Unlike the 55.Xr dtrace_tcp 4 56and 57.Xr dtrace_udp 4 58providers, 59.Nm ip 60provider probes are triggered by forwarded packets. 61That is, the probes will fire on packets that are not destined to the local 62host. 63.Sh ARGUMENTS 64The 65.Vt pktinfo_t 66argument is currently unimplemented and is included for compatibility with other 67implementations of this provider. 68Its fields are: 69.Bl -tag -width "uintptr_t pkt_addr" -offset indent 70.It Vt uintptr_t pkt_addr 71Always set to 0. 72.El 73.Pp 74The 75.Vt csinfo_t 76argument is currently unimplemented and is included for compatibility with other 77implementations of this provider. 78Its fields are: 79.Bl -tag -width "uintptr_t cs_addr" -offset indent 80.It Vt uintptr_t cs_addr 81Always set to 0. 82.It Vt uint64_t cs_cid 83A pointer to the 84.Vt struct inpcb 85for this packet, or 86.Dv NULL . 87.It Vt pid_t cs_pid 88Always set to 0. 89.El 90.Pp 91The 92.Vt ipinfo_t 93argument contains IP fields common to both IPv4 and IPv6 packets. 94Its fields are: 95.Bl -tag -width "uint32_t ip_plength" -offset indent 96.It Vt uint8_t ip_ver 97IP version of the packet, 4 for IPv4 packets and 6 for IPv6 packets. 98.It Vt uint32_t ip_plength 99IP payload size. 100This does not include the size of the IP header or IPv6 option headers. 101.It Vt string ip_saddr 102IP source address. 103.It Vt string ip_daddr 104IP destination address. 105.El 106.Pp 107The 108.Vt ifinfo_t 109argument describes the outgoing and incoming interfaces for the packet in the 110.Fn ip:::send 111and 112.Fn ip:::receive 113probes respectively. 114Its fields are: 115.Bl -tag -width "uintptr_t if_addr" -offset indent 116.It Vt string if_name 117The interface name. 118.It Vt int8_t if_local 119A boolean value indicating whether or not the interface is a loopback interface. 120.It Vt uintptr_t if_addr 121A pointer to the 122.Vt struct ifnet 123which describes the interface. 124See the 125.Xr ifnet 9 126manual page. 127.El 128.Pp 129The 130.Vt ipv4info_t 131argument contains the fields of the IP header for IPv4 packets. 132This argument is 133.Dv NULL 134for IPv6 packets. 135DTrace scripts should use the 136.Fn ip_ver 137field in the 138.Vt ipinfo_t 139argument to determine whether to use this argument. 140Its fields are: 141.Bl -tag -width "uint16_t ipv4_checksum" -offset indent 142.It Vt uint8_t ipv4_ver 143IP version. 144This will always be 4 for IPv4 packets. 145.It Vt uint8_t ipv4_ihl 146The IP header length, including options, in 32-bit words. 147.It Vt uint8_t ipv4_tos 148IP type of service field. 149.It Vt uint16_t ipv4_length 150The total packet length, including the header, in bytes. 151.It Vt uint16_t ipv4_ident 152Identification field. 153.It Vt uint8_t ipv4_flags 154The IP flags. 155.It Vt uint16_t ipv4_offset 156The fragment offset of the packet. 157.It Vt uint8_t ipv4_ttl 158Time to live field. 159.It Vt uint8_t ipv4_protocol 160Next-level protocol ID. 161.It Vt string ipv4_protostr 162A string containing the name of the encapsulated protocol. 163The protocol strings are defined in the 164.Va protocol 165array in 166.Pa /usr/lib/dtrace/ip.d 167.It Vt uint16_t ipv4_checksum 168The IP checksum. 169.It Vt ipaddr_t ipv4_src 170IPv4 source address. 171.It Vt ipaddr_t ipv4_dst 172IPv4 destination address. 173.It Vt string ipv4_saddr 174A string representation of the source address. 175.It Vt string ipv4_daddr 176A string representation of the destination address. 177.It Vt ipha_t *ipv4_hdr 178A pointer to the raw IPv4 header. 179.El 180.Pp 181The 182.Vt ipv6info_t 183argument contains the fields of the IP header for IPv6 packets. 184Its fields are not set for IPv4 packets; as with the 185.Vt ipv4info_t 186argument, the 187.Fn ip_ver 188field should be used to determine whether this argument is valid. 189Its fields are: 190.Bl -tag -width "uint16_t ipv4_checksum" -offset indent 191.It Vt uint8_t ipv6_ver 192IP version. 193This will always be 6 for IPv6 packets. 194.It Vt uint8_t ipv6_tclass 195The traffic class, used to set the differentiated services codepoint and 196extended congestion notification flags. 197.It Vt uint32_t ipv6_flow 198The flow label of the packet. 199.It Vt uint16_t ipv6_plen 200The IP payload size, including extension headers, in bytes. 201.It Vt uint8_t ipv6_nexthdr 202An identifier for the type of the next header. 203.It Vt string ipv6_nextstr 204A string representation of the type of the next header. 205.It Vt uint8_t ipv6_hlim 206The hop limit. 207.It Vt ip6_addr_t *ipv6_src 208IPv6 source address. 209.It Vt ip6_addr_t *ipv6_dst 210IPv6 destination address. 211.It Vt string ipv6_saddr 212A string representation of the source address. 213.It Vt string ipv6_daddr 214A string representation of the destination address. 215.It Vt struct ip6_hdr *ipv6_hdr 216A pointer to the raw IPv6 header. 217.El 218.Sh FILES 219.Bl -tag -width "/usr/lib/dtrace/ip.d" -compact 220.It Pa /usr/lib/dtrace/ip.d 221DTrace type and translator definitions for the 222.Nm ip 223provider. 224.El 225.Sh EXAMPLES 226The following script counts received packets by remote host address. 227.Bd -literal -offset indent 228ip:::receive 229{ 230 @num[args[2]->ip_saddr] = count(); 231} 232.Ed 233.Pp 234This script will print some details of each IP packet as it is sent or received 235by the kernel: 236.Bd -literal -offset indent 237#pragma D option quiet 238#pragma D option switchrate=10Hz 239 240dtrace:::BEGIN 241{ 242 printf(" %10s %30s %-30s %8s %6s\\n", "DELTA(us)", "SOURCE", 243 "DEST", "INT", "BYTES"); 244 last = timestamp; 245} 246 247ip:::send 248{ 249 this->elapsed = (timestamp - last) / 1000; 250 printf(" %10d %30s -> %-30s %8s %6d\\n", this->elapsed, 251 args[2]->ip_saddr, args[2]->ip_daddr, args[3]->if_name, 252 args[2]->ip_plength); 253 last = timestamp; 254} 255 256ip:::receive 257{ 258 this->elapsed = (timestamp - last) / 1000; 259 printf(" %10d %30s <- %-30s %8s %6d\\n", this->elapsed, 260 args[2]->ip_daddr, args[2]->ip_saddr, args[3]->if_name, 261 args[2]->ip_plength); 262 last = timestamp; 263} 264.Ed 265.Sh COMPATIBILITY 266This provider is compatible with the 267.Nm ip 268providers found in Solaris and Darwin. 269.Sh SEE ALSO 270.Xr dtrace 1 , 271.Xr dtrace_tcp 4 , 272.Xr dtrace_udp 4 , 273.Xr ip 4 , 274.Xr ip6 4 , 275.Xr ifnet 9 , 276.Xr SDT 9 277.Sh HISTORY 278The 279.Nm ip 280provider first appeared in 281.Fx 28210.0. 283.Sh AUTHORS 284This manual page was written by 285.An Mark Johnston Aq Mt markj@FreeBSD.org . 286