#include #ifdef __rtems__ #include #include "rtems-bsd-tcpdump-namespace.h" #endif /* __rtems__ */ /* * Copyright (c) 1988, 1989, 1990, 1991, 1992, 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. */ /* \summary: Linux cooked sockets capture printer */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include "netdissect.h" #include "addrtoname.h" #include "ethertype.h" #include "extract.h" #include "ether.h" /* * For captures on Linux cooked sockets, we construct a fake header * that includes: * * a 2-byte "packet type" which is one of: * * LINUX_SLL_HOST packet was sent to us * LINUX_SLL_BROADCAST packet was broadcast * LINUX_SLL_MULTICAST packet was multicast * LINUX_SLL_OTHERHOST packet was sent to somebody else * LINUX_SLL_OUTGOING packet was sent *by* us; * * a 2-byte Ethernet protocol field; * * a 2-byte link-layer type; * * a 2-byte link-layer address length; * * an 8-byte source link-layer address, whose actual length is * specified by the previous value. * * All fields except for the link-layer address are in network byte order. * * DO NOT change the layout of this structure, or change any of the * LINUX_SLL_ values below. If you must change the link-layer header * for a "cooked" Linux capture, introduce a new DLT_ type (ask * "tcpdump-workers@lists.tcpdump.org" for one, so that you don't give it * a value that collides with a value already being used), and use the * new header in captures of that type, so that programs that can * handle DLT_LINUX_SLL captures will continue to handle them correctly * without any change, and so that capture files with different headers * can be told apart and programs that read them can dissect the * packets in them. * * This structure, and the #defines below, must be the same in the * libpcap and tcpdump versions of "sll.h". */ /* * A DLT_LINUX_SLL fake link-layer header. */ #define SLL_HDR_LEN 16 /* total header length */ #define SLL_ADDRLEN 8 /* length of address field */ struct sll_header { uint16_t sll_pkttype; /* packet type */ uint16_t sll_hatype; /* link-layer address type */ uint16_t sll_halen; /* link-layer address length */ uint8_t sll_addr[SLL_ADDRLEN]; /* link-layer address */ uint16_t sll_protocol; /* protocol */ }; /* * The LINUX_SLL_ values for "sll_pkttype"; these correspond to the * PACKET_ values on Linux, but are defined here so that they're * available even on systems other than Linux, and so that they * don't change even if the PACKET_ values change. */ #define LINUX_SLL_HOST 0 #define LINUX_SLL_BROADCAST 1 #define LINUX_SLL_MULTICAST 2 #define LINUX_SLL_OTHERHOST 3 #define LINUX_SLL_OUTGOING 4 /* * The LINUX_SLL_ values for "sll_protocol"; these correspond to the * ETH_P_ values on Linux, but are defined here so that they're * available even on systems other than Linux. We assume, for now, * that the ETH_P_ values won't change in Linux; if they do, then: * * if we don't translate them in "pcap-linux.c", capture files * won't necessarily be readable if captured on a system that * defines ETH_P_ values that don't match these values; * * if we do translate them in "pcap-linux.c", that makes life * unpleasant for the BPF code generator, as the values you test * for in the kernel aren't the values that you test for when * reading a capture file, so the fixup code run on BPF programs * handed to the kernel ends up having to do more work. * * Add other values here as necessary, for handling packet types that * might show up on non-Ethernet, non-802.x networks. (Not all the ones * in the Linux "if_ether.h" will, I suspect, actually show up in * captures.) */ #define LINUX_SLL_P_802_3 0x0001 /* Novell 802.3 frames without 802.2 LLC header */ #define LINUX_SLL_P_802_2 0x0004 /* 802.2 frames (not D/I/X Ethernet) */ static const struct tok sll_pkttype_values[] = { { LINUX_SLL_HOST, "In" }, { LINUX_SLL_BROADCAST, "B" }, { LINUX_SLL_MULTICAST, "M" }, { LINUX_SLL_OTHERHOST, "P" }, { LINUX_SLL_OUTGOING, "Out" }, { 0, NULL} }; static inline void sll_print(netdissect_options *ndo, register const struct sll_header *sllp, u_int length) { u_short ether_type; ND_PRINT((ndo, "%3s ",tok2str(sll_pkttype_values,"?",EXTRACT_16BITS(&sllp->sll_pkttype)))); /* * XXX - check the link-layer address type value? * For now, we just assume 6 means Ethernet. * XXX - print others as strings of hex? */ if (EXTRACT_16BITS(&sllp->sll_halen) == 6) ND_PRINT((ndo, "%s ", etheraddr_string(ndo, sllp->sll_addr))); if (!ndo->ndo_qflag) { ether_type = EXTRACT_16BITS(&sllp->sll_protocol); if (ether_type <= ETHERMTU) { /* * Not an Ethernet type; what type is it? */ switch (ether_type) { case LINUX_SLL_P_802_3: /* * Ethernet_802.3 IPX frame. */ ND_PRINT((ndo, "802.3")); break; case LINUX_SLL_P_802_2: /* * 802.2. */ ND_PRINT((ndo, "802.2")); break; default: /* * What is it? */ ND_PRINT((ndo, "ethertype Unknown (0x%04x)", ether_type)); break; } } else { ND_PRINT((ndo, "ethertype %s (0x%04x)", tok2str(ethertype_values, "Unknown", ether_type), ether_type)); } ND_PRINT((ndo, ", length %u: ", length)); } } /* * This is the top level routine of the printer. 'p' points to the * Linux "cooked capture" header of the packet, 'h->ts' is the timestamp, * 'h->len' is the length of the packet off the wire, and 'h->caplen' * is the number of bytes actually captured. */ u_int sll_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) { u_int caplen = h->caplen; u_int length = h->len; register const struct sll_header *sllp; u_short ether_type; int llc_hdrlen; u_int hdrlen; if (caplen < SLL_HDR_LEN) { /* * XXX - this "can't happen" because "pcap-linux.c" always * adds this many bytes of header to every packet in a * cooked socket capture. */ ND_PRINT((ndo, "[|sll]")); return (caplen); } sllp = (const struct sll_header *)p; if (ndo->ndo_eflag) sll_print(ndo, sllp, length); /* * Go past the cooked-mode header. */ length -= SLL_HDR_LEN; caplen -= SLL_HDR_LEN; p += SLL_HDR_LEN; hdrlen = SLL_HDR_LEN; ether_type = EXTRACT_16BITS(&sllp->sll_protocol); recurse: /* * Is it (gag) an 802.3 encapsulation, or some non-Ethernet * packet type? */ if (ether_type <= ETHERMTU) { /* * Yes - what type is it? */ switch (ether_type) { case LINUX_SLL_P_802_3: /* * Ethernet_802.3 IPX frame. */ ipx_print(ndo, p, length); break; case LINUX_SLL_P_802_2: /* * 802.2. * Try to print the LLC-layer header & higher layers. */ llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL); if (llc_hdrlen < 0) goto unknown; /* unknown LLC type */ hdrlen += llc_hdrlen; break; default: /*FALLTHROUGH*/ unknown: /* packet type not known, print raw packet */ if (!ndo->ndo_suppress_default_print) ND_DEFAULTPRINT(p, caplen); break; } } else if (ether_type == ETHERTYPE_8021Q) { /* * Print VLAN information, and then go back and process * the enclosed type field. */ if (caplen < 4) { ND_PRINT((ndo, "[|vlan]")); return (hdrlen + caplen); } if (length < 4) { ND_PRINT((ndo, "[|vlan]")); return (hdrlen + length); } if (ndo->ndo_eflag) { uint16_t tag = EXTRACT_16BITS(p); ND_PRINT((ndo, "%s, ", ieee8021q_tci_string(tag))); } ether_type = EXTRACT_16BITS(p + 2); if (ether_type <= ETHERMTU) ether_type = LINUX_SLL_P_802_2; if (!ndo->ndo_qflag) { ND_PRINT((ndo, "ethertype %s, ", tok2str(ethertype_values, "Unknown", ether_type))); } p += 4; length -= 4; caplen -= 4; hdrlen += 4; goto recurse; } else { if (ethertype_print(ndo, ether_type, p, length, caplen, NULL, NULL) == 0) { /* ether_type not known, print raw packet */ if (!ndo->ndo_eflag) sll_print(ndo, sllp, length + SLL_HDR_LEN); if (!ndo->ndo_suppress_default_print) ND_DEFAULTPRINT(p, caplen); } } return (hdrlen); } #ifdef __rtems__ #include "rtems-bsd-tcpdump-print-sll-data.h" #endif /* __rtems__ */