Add support for Apple's DLT_PKTAP.

1 files changed, 167 insertions, 0 deletions

diff --git a/print-pktap.c b/print-pktap.c
new file mode 100644
index 00000000..009a663f
--- /dev/null
+++ b/print-pktap.c
@@ -0,0 +1,167 @@
+/*
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <tcpdump-stdinc.h>
+
+#include "interface.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 {
+	uint32_t	pkt_len;	/* length of pktap header */
+	uint32_t	pkt_rectype;	/* type of record */
+	uint32_t	pkt_dlt;	/* DLT type of this packet */
+	char		pkt_ifname[24];	/* interface name */
+	uint32_t	pkt_flags;
+	uint32_t	pkt_pfamily;	/* "protocol family" */
+	uint32_t	pkt_llhdrlen;	/* link-layer header length? */
+	uint32_t	pkt_lltrlrlen;	/* link-layer trailer length? */
+	uint32_t	pkt_pid;	/* process ID */
+	char		pkt_cmdname[20]; /* command name */
+	uint32_t	pkt_svc_class;	/* "service class" */
+	uint16_t	pkt_iftype;	/* "interface type" */
+	uint16_t	pkt_ifunit;	/* unit number of interface? */
+	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 inline void
+pktap_header_print(struct netdissect_options *ndo, const u_char *bp, u_int length)
+{
+	const pktap_header_t *hdr;
+	uint32_t dlt, hdrlen;
+
+	hdr = (const pktap_header_t *)bp;
+
+	dlt = EXTRACT_LE_32BITS(&hdr->pkt_dlt);
+	hdrlen = EXTRACT_LE_32BITS(&hdr->pkt_len);
+	if (!ndo->ndo_qflag) {
+		ND_PRINT((ndo,", DLT %s (%d) len %d",
+			  pcap_datalink_val_to_name(dlt), dlt, hdrlen));
+        } else {
+		ND_PRINT((ndo,", %s", pcap_datalink_val_to_name(dlt)));
+        }
+
+	ND_PRINT((ndo, ", 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.
+ */
+u_int
+pktap_if_print(struct 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_ndo_printer ndo_printer;
+        if_printer printer;
+	pktap_header_t *hdr;
+
+	if (caplen < sizeof(pktap_header_t) || length < sizeof(pktap_header_t)) {
+		ND_PRINT((ndo, "[|pktap]"));
+		return (0);
+	}
+	hdr = (pktap_header_t *)p;
+	dlt = EXTRACT_LE_32BITS(&hdr->pkt_dlt);
+	hdrlen = EXTRACT_LE_32BITS(&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((ndo, "[|pktap]"));
+		return (0);
+	}
+	if (caplen < hdrlen || length < hdrlen) {
+		ND_PRINT((ndo, "[|pktap]"));
+		return (hdrlen);
+	}
+
+	if (ndo->ndo_eflag)
+		pktap_header_print(ndo, p, length);
+
+	length -= hdrlen;
+	caplen -= hdrlen;
+	p += hdrlen;
+
+	rectype = EXTRACT_LE_32BITS(&hdr->pkt_rectype);
+	switch (rectype) {
+
+	case PKT_REC_NONE:
+		ND_PRINT((ndo, "no data"));
+
+	case PKT_REC_PACKET:
+		if ((printer = lookup_printer(dlt)) != NULL) {
+			printer(h, p);
+		} else if ((ndo_printer = lookup_ndo_printer(dlt)) != NULL) {
+			ndo_printer(ndo, h, p);
+		} else {
+			if (!ndo->ndo_eflag)
+				pktap_header_print(ndo, (u_char *)hdr,
+						length + hdrlen);
+
+			if (!ndo->ndo_suppress_default_print)
+				ND_DEFAULTPRINT(p, caplen);
+		}
+		break;
+	}
+
+	return (hdrlen);
+}
+
+/*
+ * Local Variables:
+ * c-style: whitesmith
+ * c-basic-offset: 8
+ * End:
+ */
+
+#endif /* DLT_PKTAP */