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Diffstat (limited to 'print-pktap.c')
| -rw-r--r-- | print-pktap.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/print-pktap.c b/print-pktap.c new file mode 100644 index 0000000..05ce5f9 --- /dev/null +++ b/print-pktap.c @@ -0,0 +1,177 @@ +/* + * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000 + * 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: Apple's DLT_PKTAP printer */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include "netdissect-stdinc.h" + +#define ND_LONGJMP_FROM_TCHECK +#include "netdissect.h" +#include "extract.h" + +#ifdef DLT_PKTAP + +/* + * XXX - these are little-endian in the captures I've seen, but Apple + * no longer make any big-endian machines (Macs use x86, iOS machines + * use ARM and run it little-endian), so that might be by definition + * or they might be host-endian. + * + * If a big-endian PKTAP file ever shows up, and it comes from a + * big-endian machine, presumably these are host-endian, and we need + * to just fetch the fields directly in tcpdump but byte-swap them + * to host byte order in libpcap. + */ +typedef struct pktap_header { + nd_uint32_t pkt_len; /* length of pktap header */ + nd_uint32_t pkt_rectype; /* type of record */ + nd_uint32_t pkt_dlt; /* DLT type of this packet */ + char pkt_ifname[24]; /* interface name */ + nd_uint32_t pkt_flags; + nd_uint32_t pkt_pfamily; /* "protocol family" */ + nd_uint32_t pkt_llhdrlen; /* link-layer header length? */ + nd_uint32_t pkt_lltrlrlen; /* link-layer trailer length? */ + nd_uint32_t pkt_pid; /* process ID */ + char pkt_cmdname[20]; /* command name */ + nd_uint32_t pkt_svc_class; /* "service class" */ + nd_uint16_t pkt_iftype; /* "interface type" */ + nd_uint16_t pkt_ifunit; /* unit number of interface? */ + nd_uint32_t pkt_epid; /* "effective process ID" */ + char pkt_ecmdname[20]; /* "effective command name" */ +} pktap_header_t; + +/* + * Record types. + */ +#define PKT_REC_NONE 0 /* nothing follows the header */ +#define PKT_REC_PACKET 1 /* a packet follows the header */ + +static void +pktap_header_print(netdissect_options *ndo, const u_char *bp, u_int length) +{ + const pktap_header_t *hdr; + uint32_t dlt, hdrlen; + const char *dltname; + + hdr = (const pktap_header_t *)bp; + + dlt = GET_LE_U_4(hdr->pkt_dlt); + hdrlen = GET_LE_U_4(hdr->pkt_len); + dltname = pcap_datalink_val_to_name(dlt); + if (!ndo->ndo_qflag) { + ND_PRINT("DLT %s (%u) len %u", + (dltname != NULL ? dltname : "UNKNOWN"), dlt, hdrlen); + } else { + ND_PRINT("%s", (dltname != NULL ? dltname : "UNKNOWN")); + } + + ND_PRINT(", length %u: ", length); +} + +/* + * This is the top level routine of the printer. 'p' points + * to the ether 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. + */ +void +pktap_if_print(netdissect_options *ndo, + const struct pcap_pkthdr *h, const u_char *p) +{ + uint32_t dlt, hdrlen, rectype; + u_int caplen = h->caplen; + u_int length = h->len; + if_printer printer; + const pktap_header_t *hdr; + struct pcap_pkthdr nhdr; + + ndo->ndo_protocol = "pktap"; + if (length < sizeof(pktap_header_t)) { + ND_PRINT(" (packet too short, %u < %zu)", + length, sizeof(pktap_header_t)); + goto invalid; + } + hdr = (const pktap_header_t *)p; + dlt = GET_LE_U_4(hdr->pkt_dlt); + hdrlen = GET_LE_U_4(hdr->pkt_len); + if (hdrlen < sizeof(pktap_header_t)) { + /* + * Claimed header length < structure length. + * XXX - does this just mean some fields aren't + * being supplied, or is it truly an error (i.e., + * is the length supplied so that the header can + * be expanded in the future)? + */ + ND_PRINT(" (pkt_len too small, %u < %zu)", + hdrlen, sizeof(pktap_header_t)); + goto invalid; + } + if (hdrlen > length) { + ND_PRINT(" (pkt_len too big, %u > %u)", + hdrlen, length); + goto invalid; + } + ND_TCHECK_LEN(p, hdrlen); + + if (ndo->ndo_eflag) + pktap_header_print(ndo, p, length); + + length -= hdrlen; + caplen -= hdrlen; + p += hdrlen; + + rectype = GET_LE_U_4(hdr->pkt_rectype); + switch (rectype) { + + case PKT_REC_NONE: + ND_PRINT("no data"); + break; + + case PKT_REC_PACKET: + printer = lookup_printer(dlt); + if (printer != NULL) { + nhdr = *h; + nhdr.caplen = caplen; + nhdr.len = length; + printer(ndo, &nhdr, p); + hdrlen += ndo->ndo_ll_hdr_len; + } else { + if (!ndo->ndo_eflag) + pktap_header_print(ndo, (const u_char *)hdr, + length + hdrlen); + + if (!ndo->ndo_suppress_default_print) + ND_DEFAULTPRINT(p, caplen); + } + break; + } + + ndo->ndo_ll_hdr_len += hdrlen; + return; + +invalid: + nd_print_invalid(ndo); +} +#endif /* DLT_PKTAP */ |