/* $NetBSD: pcap-common.c,v 1.7 2019/10/01 16:02:12 christos Exp $ */ /* * Copyright (c) 1993, 1994, 1995, 1996, 1997 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that: (1) source code distributions * retain the above copyright notice and this paragraph in its entirety, (2) * distributions including binary code include the above copyright notice and * this paragraph in its entirety in the documentation or other materials * provided with the distribution, and (3) all advertising materials mentioning * features or use of this software display the following acknowledgement: * ``This product includes software developed by the University of California, * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of * the University nor the names of its contributors may be used to endorse * or promote products derived from this software without specific prior * written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. * * pcap-common.c - common code for pcap and pcapng files */ #include __RCSID("$NetBSD: pcap-common.c,v 1.7 2019/10/01 16:02:12 christos Exp $"); #ifdef HAVE_CONFIG_H #include #endif #include #include "pcap-int.h" #include "extract.h" #include "pcap/sll.h" #include "pcap/usb.h" #include "pcap/nflog.h" #include "pcap/can_socketcan.h" #include "pcap-common.h" /* * We don't write DLT_* values to capture files, because they're not the * same on all platforms. * * Unfortunately, the various flavors of BSD have not always used the same * numerical values for the same data types, and various patches to * libpcap for non-BSD OSes have added their own DLT_* codes for link * layer encapsulation types seen on those OSes, and those codes have had, * in some cases, values that were also used, on other platforms, for other * link layer encapsulation types. * * This means that capture files of a type whose numerical DLT_* code * means different things on different BSDs, or with different versions * of libpcap, can't always be read on systems other than those like * the one running on the machine on which the capture was made. * * Instead, we define here a set of LINKTYPE_* codes, and map DLT_* codes * to LINKTYPE_* codes when writing a savefile header, and map LINKTYPE_* * codes to DLT_* codes when reading a savefile header. * * For those DLT_* codes that have, as far as we know, the same values on * all platforms (DLT_NULL through DLT_FDDI), we define LINKTYPE_xxx as * DLT_xxx; that way, captures of those types can still be read by * versions of libpcap that map LINKTYPE_* values to DLT_* values, and * captures of those types written by versions of libpcap that map DLT_ * values to LINKTYPE_ values can still be read by older versions * of libpcap. * * The other LINKTYPE_* codes are given values starting at 100, in the * hopes that no DLT_* code will be given one of those values. * * In order to ensure that a given LINKTYPE_* code's value will refer to * the same encapsulation type on all platforms, you should not allocate * a new LINKTYPE_* value without consulting * "tcpdump-workers@lists.tcpdump.org". The tcpdump developers will * allocate a value for you, and will not subsequently allocate it to * anybody else; that value will be added to the "pcap.h" in the * tcpdump.org Git repository, so that a future libpcap release will * include it. * * You should, if possible, also contribute patches to libpcap and tcpdump * to handle the new encapsulation type, so that they can also be checked * into the tcpdump.org Git repository and so that they will appear in * future libpcap and tcpdump releases. * * Do *NOT* assume that any values after the largest value in this file * are available; you might not have the most up-to-date version of this * file, and new values after that one might have been assigned. Also, * do *NOT* use any values below 100 - those might already have been * taken by one (or more!) organizations. * * Any platform that defines additional DLT_* codes should: * * request a LINKTYPE_* code and value from tcpdump.org, * as per the above; * * add, in their version of libpcap, an entry to map * those DLT_* codes to the corresponding LINKTYPE_* * code; * * redefine, in their "net/bpf.h", any DLT_* values * that collide with the values used by their additional * DLT_* codes, to remove those collisions (but without * making them collide with any of the LINKTYPE_* * values equal to 50 or above; they should also avoid * defining DLT_* values that collide with those * LINKTYPE_* values, either). */ #define LINKTYPE_NULL DLT_NULL #define LINKTYPE_ETHERNET DLT_EN10MB /* also for 100Mb and up */ #define LINKTYPE_EXP_ETHERNET DLT_EN3MB /* 3Mb experimental Ethernet */ #define LINKTYPE_AX25 DLT_AX25 #define LINKTYPE_PRONET DLT_PRONET #define LINKTYPE_CHAOS DLT_CHAOS #define LINKTYPE_IEEE802_5 DLT_IEEE802 /* DLT_IEEE802 is used for 802.5 Token Ring */ #define LINKTYPE_ARCNET_BSD DLT_ARCNET /* BSD-style headers */ #define LINKTYPE_SLIP DLT_SLIP #define LINKTYPE_PPP DLT_PPP #define LINKTYPE_FDDI DLT_FDDI /* * LINKTYPE_PPP is for use when there might, or might not, be an RFC 1662 * PPP in HDLC-like framing header (with 0xff 0x03 before the PPP protocol * field) at the beginning of the packet. * * This is for use when there is always such a header; the address field * might be 0xff, for regular PPP, or it might be an address field for Cisco * point-to-point with HDLC framing as per section 4.3.1 of RFC 1547 ("Cisco * HDLC"). This is, for example, what you get with NetBSD's DLT_PPP_SERIAL. * * We give it the same value as NetBSD's DLT_PPP_SERIAL, in the hopes that * nobody else will choose a DLT_ value of 50, and so that DLT_PPP_SERIAL * captures will be written out with a link type that NetBSD's tcpdump * can read. */ #define LINKTYPE_PPP_HDLC 50 /* PPP in HDLC-like framing */ #define LINKTYPE_PPP_ETHER 51 /* NetBSD PPP-over-Ethernet */ #define LINKTYPE_SYMANTEC_FIREWALL 99 /* Symantec Enterprise Firewall */ /* * These correspond to DLT_s that have different values on different * platforms; we map between these values in capture files and * the DLT_ values as returned by pcap_datalink() and passed to * pcap_open_dead(). */ #define LINKTYPE_ATM_RFC1483 100 /* LLC/SNAP-encapsulated ATM */ #define LINKTYPE_RAW 101 /* raw IP */ #define LINKTYPE_SLIP_BSDOS 102 /* BSD/OS SLIP BPF header */ #define LINKTYPE_PPP_BSDOS 103 /* BSD/OS PPP BPF header */ /* * Values starting with 104 are used for newly-assigned link-layer * header type values; for those link-layer header types, the DLT_ * value returned by pcap_datalink() and passed to pcap_open_dead(), * and the LINKTYPE_ value that appears in capture files, are the * same. * * LINKTYPE_MATCHING_MIN is the lowest such value; LINKTYPE_MATCHING_MAX * is the highest such value. */ #define LINKTYPE_MATCHING_MIN 104 /* lowest value in the "matching" range */ #define LINKTYPE_C_HDLC 104 /* Cisco HDLC */ #define LINKTYPE_IEEE802_11 105 /* IEEE 802.11 (wireless) */ #define LINKTYPE_ATM_CLIP 106 /* Linux Classical IP over ATM */ #define LINKTYPE_FRELAY 107 /* Frame Relay */ #define LINKTYPE_LOOP 108 /* OpenBSD loopback */ #define LINKTYPE_ENC 109 /* OpenBSD IPSEC enc */ /* * These three types are reserved for future use. */ #define LINKTYPE_LANE8023 110 /* ATM LANE + 802.3 */ #define LINKTYPE_HIPPI 111 /* NetBSD HIPPI */ #define LINKTYPE_HDLC 112 /* NetBSD HDLC framing */ #define LINKTYPE_LINUX_SLL 113 /* Linux cooked socket capture */ #define LINKTYPE_LTALK 114 /* Apple LocalTalk hardware */ #define LINKTYPE_ECONET 115 /* Acorn Econet */ /* * Reserved for use with OpenBSD ipfilter. */ #define LINKTYPE_IPFILTER 116 #define LINKTYPE_PFLOG 117 /* OpenBSD DLT_PFLOG */ #define LINKTYPE_CISCO_IOS 118 /* For Cisco-internal use */ #define LINKTYPE_IEEE802_11_PRISM 119 /* 802.11 plus Prism II monitor mode radio metadata header */ #define LINKTYPE_IEEE802_11_AIRONET 120 /* 802.11 plus FreeBSD Aironet driver radio metadata header */ /* * Reserved for Siemens HiPath HDLC. */ #define LINKTYPE_HHDLC 121 #define LINKTYPE_IP_OVER_FC 122 /* RFC 2625 IP-over-Fibre Channel */ #define LINKTYPE_SUNATM 123 /* Solaris+SunATM */ /* * Reserved as per request from Kent Dahlgren * for private use. */ #define LINKTYPE_RIO 124 /* RapidIO */ #define LINKTYPE_PCI_EXP 125 /* PCI Express */ #define LINKTYPE_AURORA 126 /* Xilinx Aurora link layer */ #define LINKTYPE_IEEE802_11_RADIOTAP 127 /* 802.11 plus radiotap radio metadata header */ /* * Reserved for the TZSP encapsulation, as per request from * Chris Waters * TZSP is a generic encapsulation for any other link type, * which includes a means to include meta-information * with the packet, e.g. signal strength and channel * for 802.11 packets. */ #define LINKTYPE_TZSP 128 /* Tazmen Sniffer Protocol */ #define LINKTYPE_ARCNET_LINUX 129 /* Linux-style headers */ /* * Juniper-private data link types, as per request from * Hannes Gredler . The corresponding * DLT_s are used for passing on chassis-internal * metainformation such as QOS profiles, etc.. */ #define LINKTYPE_JUNIPER_MLPPP 130 #define LINKTYPE_JUNIPER_MLFR 131 #define LINKTYPE_JUNIPER_ES 132 #define LINKTYPE_JUNIPER_GGSN 133 #define LINKTYPE_JUNIPER_MFR 134 #define LINKTYPE_JUNIPER_ATM2 135 #define LINKTYPE_JUNIPER_SERVICES 136 #define LINKTYPE_JUNIPER_ATM1 137 #define LINKTYPE_APPLE_IP_OVER_IEEE1394 138 /* Apple IP-over-IEEE 1394 cooked header */ #define LINKTYPE_MTP2_WITH_PHDR 139 #define LINKTYPE_MTP2 140 #define LINKTYPE_MTP3 141 #define LINKTYPE_SCCP 142 #define LINKTYPE_DOCSIS 143 /* DOCSIS MAC frames */ #define LINKTYPE_LINUX_IRDA 144 /* Linux-IrDA */ /* * Reserved for IBM SP switch and IBM Next Federation switch. */ #define LINKTYPE_IBM_SP 145 #define LINKTYPE_IBM_SN 146 /* * Reserved for private use. If you have some link-layer header type * that you want to use within your organization, with the capture files * using that link-layer header type not ever be sent outside your * organization, you can use these values. * * No libpcap release will use these for any purpose, nor will any * tcpdump release use them, either. * * Do *NOT* use these in capture files that you expect anybody not using * your private versions of capture-file-reading tools to read; in * particular, do *NOT* use them in products, otherwise you may find that * people won't be able to use tcpdump, or snort, or Ethereal, or... to * read capture files from your firewall/intrusion detection/traffic * monitoring/etc. appliance, or whatever product uses that LINKTYPE_ value, * and you may also find that the developers of those applications will * not accept patches to let them read those files. * * Also, do not use them if somebody might send you a capture using them * for *their* private type and tools using them for *your* private type * would have to read them. * * Instead, in those cases, ask "tcpdump-workers@lists.tcpdump.org" for a * new DLT_ and LINKTYPE_ value, as per the comment in pcap/bpf.h, and use * the type you're given. */ #define LINKTYPE_USER0 147 #define LINKTYPE_USER1 148 #define LINKTYPE_USER2 149 #define LINKTYPE_USER3 150 #define LINKTYPE_USER4 151 #define LINKTYPE_USER5 152 #define LINKTYPE_USER6 153 #define LINKTYPE_USER7 154 #define LINKTYPE_USER8 155 #define LINKTYPE_USER9 156 #define LINKTYPE_USER10 157 #define LINKTYPE_USER11 158 #define LINKTYPE_USER12 159 #define LINKTYPE_USER13 160 #define LINKTYPE_USER14 161 #define LINKTYPE_USER15 162 /* * For future use with 802.11 captures - defined by AbsoluteValue * Systems to store a number of bits of link-layer information * including radio information: * * http://www.shaftnet.org/~pizza/software/capturefrm.txt */ #define LINKTYPE_IEEE802_11_AVS 163 /* 802.11 plus AVS radio metadata header */ /* * Juniper-private data link type, as per request from * Hannes Gredler . The corresponding * DLT_s are used for passing on chassis-internal * metainformation such as QOS profiles, etc.. */ #define LINKTYPE_JUNIPER_MONITOR 164 /* * BACnet MS/TP frames. */ #define LINKTYPE_BACNET_MS_TP 165 /* * Another PPP variant as per request from Karsten Keil . * * This is used in some OSes to allow a kernel socket filter to distinguish * between incoming and outgoing packets, on a socket intended to * supply pppd with outgoing packets so it can do dial-on-demand and * hangup-on-lack-of-demand; incoming packets are filtered out so they * don't cause pppd to hold the connection up (you don't want random * input packets such as port scans, packets from old lost connections, * etc. to force the connection to stay up). * * The first byte of the PPP header (0xff03) is modified to accomodate * the direction - 0x00 = IN, 0x01 = OUT. */ #define LINKTYPE_PPP_PPPD 166 /* * Juniper-private data link type, as per request from * Hannes Gredler . The DLT_s are used * for passing on chassis-internal metainformation such as * QOS profiles, cookies, etc.. */ #define LINKTYPE_JUNIPER_PPPOE 167 #define LINKTYPE_JUNIPER_PPPOE_ATM 168 #define LINKTYPE_GPRS_LLC 169 /* GPRS LLC */ #define LINKTYPE_GPF_T 170 /* GPF-T (ITU-T G.7041/Y.1303) */ #define LINKTYPE_GPF_F 171 /* GPF-F (ITU-T G.7041/Y.1303) */ /* * Requested by Oolan Zimmer for use in Gcom's T1/E1 line * monitoring equipment. */ #define LINKTYPE_GCOM_T1E1 172 #define LINKTYPE_GCOM_SERIAL 173 /* * Juniper-private data link type, as per request from * Hannes Gredler . The DLT_ is used * for internal communication to Physical Interface Cards (PIC) */ #define LINKTYPE_JUNIPER_PIC_PEER 174 /* * Link types requested by Gregor Maier of Endace * Measurement Systems. They add an ERF header (see * http://www.endace.com/support/EndaceRecordFormat.pdf) in front of * the link-layer header. */ #define LINKTYPE_ERF_ETH 175 /* Ethernet */ #define LINKTYPE_ERF_POS 176 /* Packet-over-SONET */ /* * Requested by Daniele Orlandi for raw LAPD * for vISDN (http://www.orlandi.com/visdn/). Its link-layer header * includes additional information before the LAPD header, so it's * not necessarily a generic LAPD header. */ #define LINKTYPE_LINUX_LAPD 177 /* * Juniper-private data link type, as per request from * Hannes Gredler . * The Link Types are used for prepending meta-information * like interface index, interface name * before standard Ethernet, PPP, Frelay & C-HDLC Frames */ #define LINKTYPE_JUNIPER_ETHER 178 #define LINKTYPE_JUNIPER_PPP 179 #define LINKTYPE_JUNIPER_FRELAY 180 #define LINKTYPE_JUNIPER_CHDLC 181 /* * Multi Link Frame Relay (FRF.16) */ #define LINKTYPE_MFR 182 /* * Juniper-private data link type, as per request from * Hannes Gredler . * The DLT_ is used for internal communication with a * voice Adapter Card (PIC) */ #define LINKTYPE_JUNIPER_VP 183 /* * Arinc 429 frames. * DLT_ requested by Gianluca Varenni . * Every frame contains a 32bit A429 label. * More documentation on Arinc 429 can be found at * http://www.condoreng.com/support/downloads/tutorials/ARINCTutorial.pdf */ #define LINKTYPE_A429 184 /* * Arinc 653 Interpartition Communication messages. * DLT_ requested by Gianluca Varenni . * Please refer to the A653-1 standard for more information. */ #define LINKTYPE_A653_ICM 185 /* * This used to be "USB packets, beginning with a USB setup header; * requested by Paolo Abeni ." * * However, that header didn't work all that well - it left out some * useful information - and was abandoned in favor of the DLT_USB_LINUX * header. * * This is now used by FreeBSD for its BPF taps for USB; that has its * own headers. So it is written, so it is done. */ #define LINKTYPE_USB_FREEBSD 186 /* * Bluetooth HCI UART transport layer (part H:4); requested by * Paolo Abeni. */ #define LINKTYPE_BLUETOOTH_HCI_H4 187 /* * IEEE 802.16 MAC Common Part Sublayer; requested by Maria Cruz * . */ #define LINKTYPE_IEEE802_16_MAC_CPS 188 /* * USB packets, beginning with a Linux USB header; requested by * Paolo Abeni . */ #define LINKTYPE_USB_LINUX 189 /* * Controller Area Network (CAN) v. 2.0B packets. * DLT_ requested by Gianluca Varenni . * Used to dump CAN packets coming from a CAN Vector board. * More documentation on the CAN v2.0B frames can be found at * http://www.can-cia.org/downloads/?269 */ #define LINKTYPE_CAN20B 190 /* * IEEE 802.15.4, with address fields padded, as is done by Linux * drivers; requested by Juergen Schimmer. */ #define LINKTYPE_IEEE802_15_4_LINUX 191 /* * Per Packet Information encapsulated packets. * LINKTYPE_ requested by Gianluca Varenni . */ #define LINKTYPE_PPI 192 /* * Header for 802.16 MAC Common Part Sublayer plus a radiotap radio header; * requested by Charles Clancy. */ #define LINKTYPE_IEEE802_16_MAC_CPS_RADIO 193 /* * Juniper-private data link type, as per request from * Hannes Gredler . * The DLT_ is used for internal communication with a * integrated service module (ISM). */ #define LINKTYPE_JUNIPER_ISM 194 /* * IEEE 802.15.4, exactly as it appears in the spec (no padding, no * nothing), and with the FCS at the end of the frame; requested by * Mikko Saarnivala . * * This should only be used if the FCS is present at the end of the * frame; if the frame has no FCS, DLT_IEEE802_15_4_NOFCS should be * used. */ #define LINKTYPE_IEEE802_15_4_WITHFCS 195 /* * Various link-layer types, with a pseudo-header, for SITA * (http://www.sita.aero/); requested by Fulko Hew (fulko.hew@gmail.com). */ #define LINKTYPE_SITA 196 /* * Various link-layer types, with a pseudo-header, for Endace DAG cards; * encapsulates Endace ERF records. Requested by Stephen Donnelly * . */ #define LINKTYPE_ERF 197 /* * Special header prepended to Ethernet packets when capturing from a * u10 Networks board. Requested by Phil Mulholland * . */ #define LINKTYPE_RAIF1 198 /* * IPMB packet for IPMI, beginning with a 2-byte header, followed by * the I2C slave address, followed by the netFn and LUN, etc.. * Requested by Chanthy Toeung . * * XXX - its DLT_ value used to be called DLT_IPMB, back when we got the * impression from the email thread requesting it that the packet * had no extra 2-byte header. We've renamed it; if anybody used * DLT_IPMB and assumed no 2-byte header, this will cause the compile * to fail, at which point we'll have to figure out what to do about * the two header types using the same DLT_/LINKTYPE_ value. If that * doesn't happen, we'll assume nobody used it and that the redefinition * is safe. */ #define LINKTYPE_IPMB_KONTRON 199 /* * Juniper-private data link type, as per request from * Hannes Gredler . * The DLT_ is used for capturing data on a secure tunnel interface. */ #define LINKTYPE_JUNIPER_ST 200 /* * Bluetooth HCI UART transport layer (part H:4), with pseudo-header * that includes direction information; requested by Paolo Abeni. */ #define LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR 201 /* * AX.25 packet with a 1-byte KISS header; see * * http://www.ax25.net/kiss.htm * * as per Richard Stearn . */ #define LINKTYPE_AX25_KISS 202 /* * LAPD packets from an ISDN channel, starting with the address field, * with no pseudo-header. * Requested by Varuna De Silva . */ #define LINKTYPE_LAPD 203 /* * PPP, with a one-byte direction pseudo-header prepended - zero means * "received by this host", non-zero (any non-zero value) means "sent by * this host" - as per Will Barker . */ #define LINKTYPE_PPP_WITH_DIR 204 /* Don't confuse with LINKTYPE_PPP_PPPD */ /* * Cisco HDLC, with a one-byte direction pseudo-header prepended - zero * means "received by this host", non-zero (any non-zero value) means * "sent by this host" - as per Will Barker . */ #define LINKTYPE_C_HDLC_WITH_DIR 205 /* Cisco HDLC */ /* * Frame Relay, with a one-byte direction pseudo-header prepended - zero * means "received by this host" (DCE -> DTE), non-zero (any non-zero * value) means "sent by this host" (DTE -> DCE) - as per Will Barker * . */ #define LINKTYPE_FRELAY_WITH_DIR 206 /* Frame Relay */ /* * LAPB, with a one-byte direction pseudo-header prepended - zero means * "received by this host" (DCE -> DTE), non-zero (any non-zero value) * means "sent by this host" (DTE -> DCE)- as per Will Barker * . */ #define LINKTYPE_LAPB_WITH_DIR 207 /* LAPB */ /* * 208 is reserved for an as-yet-unspecified proprietary link-layer * type, as requested by Will Barker. */ /* * IPMB with a Linux-specific pseudo-header; as requested by Alexey Neyman * . */ #define LINKTYPE_IPMB_LINUX 209 /* * FlexRay automotive bus - http://www.flexray.com/ - as requested * by Hannes Kaelber . */ #define LINKTYPE_FLEXRAY 210 /* * Media Oriented Systems Transport (MOST) bus for multimedia * transport - http://www.mostcooperation.com/ - as requested * by Hannes Kaelber . */ #define LINKTYPE_MOST 211 /* * Local Interconnect Network (LIN) bus for vehicle networks - * http://www.lin-subbus.org/ - as requested by Hannes Kaelber * . */ #define LINKTYPE_LIN 212 /* * X2E-private data link type used for serial line capture, * as requested by Hannes Kaelber . */ #define LINKTYPE_X2E_SERIAL 213 /* * X2E-private data link type used for the Xoraya data logger * family, as requested by Hannes Kaelber . */ #define LINKTYPE_X2E_XORAYA 214 /* * IEEE 802.15.4, exactly as it appears in the spec (no padding, no * nothing), but with the PHY-level data for non-ASK PHYs (4 octets * of 0 as preamble, one octet of SFD, one octet of frame length+ * reserved bit, and then the MAC-layer data, starting with the * frame control field). * * Requested by Max Filippov . */ #define LINKTYPE_IEEE802_15_4_NONASK_PHY 215 /* * David Gibson requested this for * captures from the Linux kernel /dev/input/eventN devices. This * is used to communicate keystrokes and mouse movements from the * Linux kernel to display systems, such as Xorg. */ #define LINKTYPE_LINUX_EVDEV 216 /* * GSM Um and Abis interfaces, preceded by a "gsmtap" header. * * Requested by Harald Welte . */ #define LINKTYPE_GSMTAP_UM 217 #define LINKTYPE_GSMTAP_ABIS 218 /* * MPLS, with an MPLS label as the link-layer header. * Requested by Michele Marchetto on behalf * of OpenBSD. */ #define LINKTYPE_MPLS 219 /* * USB packets, beginning with a Linux USB header, with the USB header * padded to 64 bytes; required for memory-mapped access. */ #define LINKTYPE_USB_LINUX_MMAPPED 220 /* * DECT packets, with a pseudo-header; requested by * Matthias Wenzel . */ #define LINKTYPE_DECT 221 /* * From: "Lidwa, Eric (GSFC-582.0)[SGT INC]" * Date: Mon, 11 May 2009 11:18:30 -0500 * * DLT_AOS. We need it for AOS Space Data Link Protocol. * I have already written dissectors for but need an OK from * legal before I can submit a patch. * */ #define LINKTYPE_AOS 222 /* * Wireless HART (Highway Addressable Remote Transducer) * From the HART Communication Foundation * IES/PAS 62591 * * Requested by Sam Roberts . */ #define LINKTYPE_WIHART 223 /* * Fibre Channel FC-2 frames, beginning with a Frame_Header. * Requested by Kahou Lei . */ #define LINKTYPE_FC_2 224 /* * Fibre Channel FC-2 frames, beginning with an encoding of the * SOF, and ending with an encoding of the EOF. * * The encodings represent the frame delimiters as 4-byte sequences * representing the corresponding ordered sets, with K28.5 * represented as 0xBC, and the D symbols as the corresponding * byte values; for example, SOFi2, which is K28.5 - D21.5 - D1.2 - D21.2, * is represented as 0xBC 0xB5 0x55 0x55. * * Requested by Kahou Lei . */ #define LINKTYPE_FC_2_WITH_FRAME_DELIMS 225 /* * Solaris ipnet pseudo-header; requested by Darren Reed . * * The pseudo-header starts with a one-byte version number; for version 2, * the pseudo-header is: * * struct dl_ipnetinfo { * uint8_t dli_version; * uint8_t dli_family; * uint16_t dli_htype; * uint32_t dli_pktlen; * uint32_t dli_ifindex; * uint32_t dli_grifindex; * uint32_t dli_zsrc; * uint32_t dli_zdst; * }; * * dli_version is 2 for the current version of the pseudo-header. * * dli_family is a Solaris address family value, so it's 2 for IPv4 * and 26 for IPv6. * * dli_htype is a "hook type" - 0 for incoming packets, 1 for outgoing * packets, and 2 for packets arriving from another zone on the same * machine. * * dli_pktlen is the length of the packet data following the pseudo-header * (so the captured length minus dli_pktlen is the length of the * pseudo-header, assuming the entire pseudo-header was captured). * * dli_ifindex is the interface index of the interface on which the * packet arrived. * * dli_grifindex is the group interface index number (for IPMP interfaces). * * dli_zsrc is the zone identifier for the source of the packet. * * dli_zdst is the zone identifier for the destination of the packet. * * A zone number of 0 is the global zone; a zone number of 0xffffffff * means that the packet arrived from another host on the network, not * from another zone on the same machine. * * An IPv4 or IPv6 datagram follows the pseudo-header; dli_family indicates * which of those it is. */ #define LINKTYPE_IPNET 226 /* * CAN (Controller Area Network) frames, with a pseudo-header as supplied * by Linux SocketCAN, and with multi-byte numerical fields in that header * in big-endian byte order. * * See Documentation/networking/can.txt in the Linux source. * * Requested by Felix Obenhuber . */ #define LINKTYPE_CAN_SOCKETCAN 227 /* * Raw IPv4/IPv6; different from DLT_RAW in that the DLT_ value specifies * whether it's v4 or v6. Requested by Darren Reed . */ #define LINKTYPE_IPV4 228 #define LINKTYPE_IPV6 229 /* * IEEE 802.15.4, exactly as it appears in the spec (no padding, no * nothing), and with no FCS at the end of the frame; requested by * Jon Smirl . */ #define LINKTYPE_IEEE802_15_4_NOFCS 230 /* * Raw D-Bus: * * http://www.freedesktop.org/wiki/Software/dbus * * messages: * * http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-messages * * starting with the endianness flag, followed by the message type, etc., * but without the authentication handshake before the message sequence: * * http://dbus.freedesktop.org/doc/dbus-specification.html#auth-protocol * * Requested by Martin Vidner . */ #define LINKTYPE_DBUS 231 /* * Juniper-private data link type, as per request from * Hannes Gredler . */ #define LINKTYPE_JUNIPER_VS 232 #define LINKTYPE_JUNIPER_SRX_E2E 233 #define LINKTYPE_JUNIPER_FIBRECHANNEL 234 /* * DVB-CI (DVB Common Interface for communication between a PC Card * module and a DVB receiver). See * * http://www.kaiser.cx/pcap-dvbci.html * * for the specification. * * Requested by Martin Kaiser . */ #define LINKTYPE_DVB_CI 235 /* * Variant of 3GPP TS 27.010 multiplexing protocol. Requested * by Hans-Christoph Schemmel . */ #define LINKTYPE_MUX27010 236 /* * STANAG 5066 D_PDUs. Requested by M. Baris Demiray * . */ #define LINKTYPE_STANAG_5066_D_PDU 237 /* * Juniper-private data link type, as per request from * Hannes Gredler . */ #define LINKTYPE_JUNIPER_ATM_CEMIC 238 /* * NetFilter LOG messages * (payload of netlink NFNL_SUBSYS_ULOG/NFULNL_MSG_PACKET packets) * * Requested by Jakub Zawadzki */ #define LINKTYPE_NFLOG 239 /* * Hilscher Gesellschaft fuer Systemautomation mbH link-layer type * for Ethernet packets with a 4-byte pseudo-header and always * with the payload including the FCS, as supplied by their * netANALYZER hardware and software. * * Requested by Holger P. Frommer */ #define LINKTYPE_NETANALYZER 240 /* * Hilscher Gesellschaft fuer Systemautomation mbH link-layer type * for Ethernet packets with a 4-byte pseudo-header and FCS and * 1 byte of SFD, as supplied by their netANALYZER hardware and * software. * * Requested by Holger P. Frommer */ #define LINKTYPE_NETANALYZER_TRANSPARENT 241 /* * IP-over-InfiniBand, as specified by RFC 4391. * * Requested by Petr Sumbera . */ #define LINKTYPE_IPOIB 242 /* * MPEG-2 transport stream (ISO 13818-1/ITU-T H.222.0). * * Requested by Guy Martin . */ #define LINKTYPE_MPEG_2_TS 243 /* * ng4T GmbH's UMTS Iub/Iur-over-ATM and Iub/Iur-over-IP format as * used by their ng40 protocol tester. * * Requested by Jens Grimmer . */ #define LINKTYPE_NG40 244 /* * Pseudo-header giving adapter number and flags, followed by an NFC * (Near-Field Communications) Logical Link Control Protocol (LLCP) PDU, * as specified by NFC Forum Logical Link Control Protocol Technical * Specification LLCP 1.1. * * Requested by Mike Wakerly . */ #define LINKTYPE_NFC_LLCP 245 /* * pfsync output; DLT_PFSYNC is 18, which collides with DLT_CIP in * SuSE 6.3, on OpenBSD, NetBSD, DragonFly BSD, and macOS, and * is 121, which collides with DLT_HHDLC, in FreeBSD. We pick a * shiny new link-layer header type value that doesn't collide with * anything, in the hopes that future pfsync savefiles, if any, * won't require special hacks to distinguish from other savefiles. * */ #define LINKTYPE_PFSYNC 246 /* * Raw InfiniBand packets, starting with the Local Routing Header. * * Requested by Oren Kladnitsky . */ #define LINKTYPE_INFINIBAND 247 /* * SCTP, with no lower-level protocols (i.e., no IPv4 or IPv6). * * Requested by Michael Tuexen . */ #define LINKTYPE_SCTP 248 /* * USB packets, beginning with a USBPcap header. * * Requested by Tomasz Mon */ #define LINKTYPE_USBPCAP 249 /* * Schweitzer Engineering Laboratories "RTAC" product serial-line * packets. * * Requested by Chris Bontje . */ #define DLT_RTAC_SERIAL 250 /* * Bluetooth Low Energy air interface link-layer packets. * * Requested by Mike Kershaw . */ #define LINKTYPE_BLUETOOTH_LE_LL 251 /* * Link-layer header type for upper-protocol layer PDU saves from wireshark. * * the actual contents are determined by two TAGs stored with each * packet: * EXP_PDU_TAG_LINKTYPE the link type (LINKTYPE_ value) of the * original packet. * * EXP_PDU_TAG_PROTO_NAME the name of the wireshark dissector * that can make sense of the data stored. */ #define LINKTYPE_WIRESHARK_UPPER_PDU 252 /* * Link-layer header type for the netlink protocol (nlmon devices). */ #define LINKTYPE_NETLINK 253 /* * Bluetooth Linux Monitor headers for the BlueZ stack. */ #define LINKTYPE_BLUETOOTH_LINUX_MONITOR 254 /* * Bluetooth Basic Rate/Enhanced Data Rate baseband packets, as * captured by Ubertooth. */ #define LINKTYPE_BLUETOOTH_BREDR_BB 255 /* * Bluetooth Low Energy link layer packets, as captured by Ubertooth. */ #define LINKTYPE_BLUETOOTH_LE_LL_WITH_PHDR 256 /* * PROFIBUS data link layer. */ #define LINKTYPE_PROFIBUS_DL 257 /* * Apple's DLT_PKTAP headers. * * Sadly, the folks at Apple either had no clue that the DLT_USERn values * are for internal use within an organization and partners only, and * didn't know that the right way to get a link-layer header type is to * ask tcpdump.org for one, or knew and didn't care, so they just * used DLT_USER2, which causes problems for everything except for * their version of tcpdump. * * So I'll just give them one; hopefully this will show up in a * libpcap release in time for them to get this into 10.10 Big Sur * or whatever Mavericks' successor is called. LINKTYPE_PKTAP * will be 258 *even on macOS*; that is *intentional*, so that * PKTAP files look the same on *all* OSes (different OSes can have * different numerical values for a given DLT_, but *MUST NOT* have * different values for what goes in a file, as files can be moved * between OSes!). */ #define LINKTYPE_PKTAP 258 /* * Ethernet packets preceded by a header giving the last 6 octets * of the preamble specified by 802.3-2012 Clause 65, section * 65.1.3.2 "Transmit". */ #define LINKTYPE_EPON 259 /* * IPMI trace packets, as specified by Table 3-20 "Trace Data Block Format" * in the PICMG HPM.2 specification. */ #define LINKTYPE_IPMI_HPM_2 260 /* * per Joshua Wright , formats for Zwave captures. */ #define LINKTYPE_ZWAVE_R1_R2 261 #define LINKTYPE_ZWAVE_R3 262 /* * per Steve Karg , formats for Wattstopper * Digital Lighting Management room bus serial protocol captures. */ #define LINKTYPE_WATTSTOPPER_DLM 263 /* * ISO 14443 contactless smart card messages. */ #define LINKTYPE_ISO_14443 264 /* * Radio data system (RDS) groups. IEC 62106. * Per Jonathan Brucker . */ #define LINKTYPE_RDS 265 /* * USB packets, beginning with a Darwin (macOS, etc.) header. */ #define LINKTYPE_USB_DARWIN 266 /* * OpenBSD DLT_OPENFLOW. */ #define LINKTYPE_OPENFLOW 267 /* * SDLC frames containing SNA PDUs. */ #define LINKTYPE_SDLC 268 /* * per "Selvig, Bjorn" used for * TI protocol sniffer. */ #define LINKTYPE_TI_LLN_SNIFFER 269 /* * per: Erik de Jong for * https://github.com/eriknl/LoRaTap/releases/tag/v0.1 */ #define LINKTYPE_LORATAP 270 /* * per: Stefanha at gmail.com for * http://lists.sandelman.ca/pipermail/tcpdump-workers/2017-May/000772.html * and: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/uapi/linux/vsockmon.h * for: http://qemu-project.org/Features/VirtioVsock */ #define LINKTYPE_VSOCK 271 /* * Nordic Semiconductor Bluetooth LE sniffer. */ #define LINKTYPE_NORDIC_BLE 272 /* * Excentis DOCSIS 3.1 RF sniffer (XRA-31) * per: bruno.verstuyft at excentis.com * http://www.xra31.com/xra-header */ #define LINKTYPE_DOCSIS31_XRA31 273 /* * mPackets, as specified by IEEE 802.3br Figure 99-4, starting * with the preamble and always ending with a CRC field. */ #define LINKTYPE_ETHERNET_MPACKET 274 /* * DisplayPort AUX channel monitoring data as specified by VESA * DisplayPort(DP) Standard preceeded by a pseudo-header. * per dirk.eibach at gdsys.cc */ #define LINKTYPE_DISPLAYPORT_AUX 275 /* * Linux cooked sockets v2. */ #define LINKTYPE_LINUX_SLL2 276 #define LINKTYPE_MATCHING_MAX 276 /* highest value in the "matching" range */ /* * The DLT_ and LINKTYPE_ values in the "matching" range should be the * same, so DLT_MATCHING_MAX and LINKTYPE_MATCHING_MAX should be the * same. */ #if LINKTYPE_MATCHING_MAX != DLT_MATCHING_MAX #error The LINKTYPE_ matching range does not match the DLT_ matching range #endif static struct linktype_map { int dlt; int linktype; } map[] = { /* * These DLT_* codes have LINKTYPE_* codes with values identical * to the values of the corresponding DLT_* code. */ { DLT_NULL, LINKTYPE_NULL }, { DLT_EN10MB, LINKTYPE_ETHERNET }, { DLT_EN3MB, LINKTYPE_EXP_ETHERNET }, { DLT_AX25, LINKTYPE_AX25 }, { DLT_PRONET, LINKTYPE_PRONET }, { DLT_CHAOS, LINKTYPE_CHAOS }, { DLT_IEEE802, LINKTYPE_IEEE802_5 }, { DLT_ARCNET, LINKTYPE_ARCNET_BSD }, { DLT_SLIP, LINKTYPE_SLIP }, { DLT_PPP, LINKTYPE_PPP }, { DLT_FDDI, LINKTYPE_FDDI }, { DLT_SYMANTEC_FIREWALL, LINKTYPE_SYMANTEC_FIREWALL }, /* * These DLT_* codes have different values on different * platforms; we map them to LINKTYPE_* codes that * have values that should never be equal to any DLT_* * code. */ #ifdef DLT_FR /* BSD/OS Frame Relay */ { DLT_FR, LINKTYPE_FRELAY }, #endif { DLT_ATM_RFC1483, LINKTYPE_ATM_RFC1483 }, { DLT_RAW, LINKTYPE_RAW }, { DLT_SLIP_BSDOS, LINKTYPE_SLIP_BSDOS }, { DLT_PPP_BSDOS, LINKTYPE_PPP_BSDOS }, /* BSD/OS Cisco HDLC */ { DLT_C_HDLC, LINKTYPE_C_HDLC }, /* * These DLT_* codes are not on all platforms, but, so far, * there don't appear to be any platforms that define * other codes with those values; we map them to * different LINKTYPE_* values anyway, just in case. */ /* Linux ATM Classical IP */ { DLT_ATM_CLIP, LINKTYPE_ATM_CLIP }, /* NetBSD sync/async serial PPP (or Cisco HDLC) */ { DLT_PPP_SERIAL, LINKTYPE_PPP_HDLC }, /* NetBSD PPP over Ethernet */ { DLT_PPP_ETHER, LINKTYPE_PPP_ETHER }, /* * All LINKTYPE_ values between LINKTYPE_MATCHING_MIN * and LINKTYPE_MATCHING_MAX are mapped to identical * DLT_ values. */ { -1, -1 } }; int dlt_to_linktype(int dlt) { int i; /* * DLTs that, on some platforms, have values in the matching range * but that *don't* have the same value as the corresponding * LINKTYPE because, for some reason, not all OSes have the * same value for that DLT (note that the DLT's value might be * outside the matching range on some of those OSes). */ if (dlt == DLT_PFSYNC) return (LINKTYPE_PFSYNC); if (dlt == DLT_PKTAP) return (LINKTYPE_PKTAP); /* * For all other values in the matching range, the DLT * value is the same as the LINKTYPE value. */ if (dlt >= DLT_MATCHING_MIN && dlt <= DLT_MATCHING_MAX) return (dlt); /* * Map the values outside that range. */ for (i = 0; map[i].dlt != -1; i++) { if (map[i].dlt == dlt) return (map[i].linktype); } /* * If we don't have a mapping for this DLT, return an * error; that means that this is a value with no corresponding * LINKTYPE, and we need to assign one. */ return (-1); } int linktype_to_dlt(int linktype) { int i; /* * LINKTYPEs in the matching range that *don't* * have the same value as the corresponding DLTs * because, for some reason, not all OSes have the * same value for that DLT. */ if (linktype == LINKTYPE_PFSYNC) return (DLT_PFSYNC); if (linktype == LINKTYPE_PKTAP) return (DLT_PKTAP); /* * For all other values in the matching range, the LINKTYPE * value is the same as the DLT value. */ if (linktype >= LINKTYPE_MATCHING_MIN && linktype <= LINKTYPE_MATCHING_MAX) return (linktype); /* * Map the values outside that range. */ for (i = 0; map[i].linktype != -1; i++) { if (map[i].linktype == linktype) return (map[i].dlt); } /* * If we don't have an entry for this LINKTYPE, return * the link type value; it may be a DLT from an older * version of libpcap. */ return linktype; } /* * Return the maximum snapshot length for a given DLT_ value. * * For most link-layer types, we use MAXIMUM_SNAPLEN. * * For DLT_DBUS, the maximum is 128MiB, as per * * https://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-messages * * For DLT_USBPCAP, the maximum is 1MiB, as per * * https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=15985 */ u_int max_snaplen_for_dlt(int dlt) { switch (dlt) { case DLT_DBUS: return 128*1024*1024; case DLT_USBPCAP: return 1024*1024; default: return MAXIMUM_SNAPLEN; } } /* * DLT_LINUX_SLL packets with a protocol type of LINUX_SLL_P_CAN or * LINUX_SLL_P_CANFD have SocketCAN headers in front of the payload, * with the CAN ID being in host byte order. * * When reading a DLT_LINUX_SLL capture file, we need to check for those * packets and convert the CAN ID from the byte order of the host that * wrote the file to this host's byte order. */ static void swap_linux_sll_header(const struct pcap_pkthdr *hdr, u_char *buf) { u_int caplen = hdr->caplen; u_int length = hdr->len; struct sll_header *shdr = (struct sll_header *)buf; uint16_t protocol; pcap_can_socketcan_hdr *chdr; if (caplen < (u_int) sizeof(struct sll_header) || length < (u_int) sizeof(struct sll_header)) { /* Not enough data to have the protocol field */ return; } protocol = EXTRACT_16BITS(&shdr->sll_protocol); if (protocol != LINUX_SLL_P_CAN && protocol != LINUX_SLL_P_CANFD) return; /* * SocketCAN packet; fix up the packet's header. */ chdr = (pcap_can_socketcan_hdr *)(buf + sizeof(struct sll_header)); if (caplen < (u_int) sizeof(struct sll_header) + sizeof(chdr->can_id) || length < (u_int) sizeof(struct sll_header) + sizeof(chdr->can_id)) { /* Not enough data to have the CAN ID */ return; } chdr->can_id = SWAPLONG(chdr->can_id); } /* * The DLT_USB_LINUX and DLT_USB_LINUX_MMAPPED headers are in host * byte order when capturing (it's supplied directly from a * memory-mapped buffer shared by the kernel). * * When reading a DLT_USB_LINUX or DLT_USB_LINUX_MMAPPED capture file, * we need to convert it from the byte order of the host that wrote * the file to this host's byte order. */ static void swap_linux_usb_header(const struct pcap_pkthdr *hdr, u_char *buf, int header_len_64_bytes) { pcap_usb_header_mmapped *uhdr = (pcap_usb_header_mmapped *)buf; bpf_u_int32 offset = 0; /* * "offset" is the offset *past* the field we're swapping; * we skip the field *before* checking to make sure * the captured data length includes the entire field. */ /* * The URB id is a totally opaque value; do we really need to * convert it to the reading host's byte order??? */ offset += 8; /* skip past id */ if (hdr->caplen < offset) return; uhdr->id = SWAPLL(uhdr->id); offset += 4; /* skip past various 1-byte fields */ offset += 2; /* skip past bus_id */ if (hdr->caplen < offset) return; uhdr->bus_id = SWAPSHORT(uhdr->bus_id); offset += 2; /* skip past various 1-byte fields */ offset += 8; /* skip past ts_sec */ if (hdr->caplen < offset) return; uhdr->ts_sec = SWAPLL(uhdr->ts_sec); offset += 4; /* skip past ts_usec */ if (hdr->caplen < offset) return; uhdr->ts_usec = SWAPLONG(uhdr->ts_usec); offset += 4; /* skip past status */ if (hdr->caplen < offset) return; uhdr->status = SWAPLONG(uhdr->status); offset += 4; /* skip past urb_len */ if (hdr->caplen < offset) return; uhdr->urb_len = SWAPLONG(uhdr->urb_len); offset += 4; /* skip past data_len */ if (hdr->caplen < offset) return; uhdr->data_len = SWAPLONG(uhdr->data_len); if (uhdr->transfer_type == URB_ISOCHRONOUS) { offset += 4; /* skip past s.iso.error_count */ if (hdr->caplen < offset) return; uhdr->s.iso.error_count = SWAPLONG(uhdr->s.iso.error_count); offset += 4; /* skip past s.iso.numdesc */ if (hdr->caplen < offset) return; uhdr->s.iso.numdesc = SWAPLONG(uhdr->s.iso.numdesc); } else offset += 8; /* skip USB setup header */ /* * With the old header, there are no isochronous descriptors * after the header. * * With the new header, the actual number of descriptors in * the header is not s.iso.numdesc, it's ndesc - only the * first N descriptors, for some value of N, are put into * the header, and ndesc is set to the actual number copied. * In addition, if s.iso.numdesc is negative, no descriptors * are captured, and ndesc is set to 0. */ if (header_len_64_bytes) { /* * This is either the "version 1" header, with * 16 bytes of additional fields at the end, or * a "version 0" header from a memory-mapped * capture, with 16 bytes of zeroed-out padding * at the end. Byte swap them as if this were * a "version 1" header. */ offset += 4; /* skip past interval */ if (hdr->caplen < offset) return; uhdr->interval = SWAPLONG(uhdr->interval); offset += 4; /* skip past start_frame */ if (hdr->caplen < offset) return; uhdr->start_frame = SWAPLONG(uhdr->start_frame); offset += 4; /* skip past xfer_flags */ if (hdr->caplen < offset) return; uhdr->xfer_flags = SWAPLONG(uhdr->xfer_flags); offset += 4; /* skip past ndesc */ if (hdr->caplen < offset) return; uhdr->ndesc = SWAPLONG(uhdr->ndesc); if (uhdr->transfer_type == URB_ISOCHRONOUS) { /* swap the values in struct linux_usb_isodesc */ usb_isodesc *pisodesc; uint32_t i; pisodesc = (usb_isodesc *)(void *)(buf+offset); for (i = 0; i < uhdr->ndesc; i++) { offset += 4; /* skip past status */ if (hdr->caplen < offset) return; pisodesc->status = SWAPLONG(pisodesc->status); offset += 4; /* skip past offset */ if (hdr->caplen < offset) return; pisodesc->offset = SWAPLONG(pisodesc->offset); offset += 4; /* skip past len */ if (hdr->caplen < offset) return; pisodesc->len = SWAPLONG(pisodesc->len); offset += 4; /* skip past padding */ pisodesc++; } } } } /* * The DLT_NFLOG "packets" have a mixture of big-endian and host-byte-order * data. They begin with a fixed-length header with big-endian fields, * followed by a set of TLVs, where the type and length are in host * byte order but the values are either big-endian or are a raw byte * sequence that's the same regardless of the host's byte order. * * When reading a DLT_NFLOG capture file, we need to convert the type * and length values from the byte order of the host that wrote the * file to the byte order of this host. */ static void swap_nflog_header(const struct pcap_pkthdr *hdr, u_char *buf) { u_char *p = buf; nflog_hdr_t *nfhdr = (nflog_hdr_t *)buf; nflog_tlv_t *tlv; u_int caplen = hdr->caplen; u_int length = hdr->len; uint16_t size; if (caplen < (u_int) sizeof(nflog_hdr_t) || length < (u_int) sizeof(nflog_hdr_t)) { /* Not enough data to have any TLVs. */ return; } if (nfhdr->nflog_version != 0) { /* Unknown NFLOG version */ return; } length -= sizeof(nflog_hdr_t); caplen -= sizeof(nflog_hdr_t); p += sizeof(nflog_hdr_t); while (caplen >= sizeof(nflog_tlv_t)) { tlv = (nflog_tlv_t *) p; /* Swap the type and length. */ tlv->tlv_type = SWAPSHORT(tlv->tlv_type); tlv->tlv_length = SWAPSHORT(tlv->tlv_length); /* Get the length of the TLV. */ size = tlv->tlv_length; if (size % 4 != 0) size += 4 - size % 4; /* Is the TLV's length less than the minimum? */ if (size < sizeof(nflog_tlv_t)) { /* Yes. Give up now. */ return; } /* Do we have enough data for the full TLV? */ if (caplen < size || length < size) { /* No. */ return; } /* Skip over the TLV. */ length -= size; caplen -= size; p += size; } } void swap_pseudo_headers(int linktype, struct pcap_pkthdr *hdr, u_char *data) { /* * Convert pseudo-headers from the byte order of * the host on which the file was saved to our * byte order, as necessary. */ switch (linktype) { case DLT_LINUX_SLL: swap_linux_sll_header(hdr, data); break; case DLT_USB_LINUX: swap_linux_usb_header(hdr, data, 0); break; case DLT_USB_LINUX_MMAPPED: swap_linux_usb_header(hdr, data, 1); break; case DLT_NFLOG: swap_nflog_header(hdr, data); break; } }