static void
show_dlts_and_exit(const char *device, pcap_t *pd)
{
int n_dlts;
int *dlts = 0;
const char *dlt_name;
n_dlts = pcap_list_datalinks(pd, &dlts);
if (n_dlts < 0)
error("%s", pcap_geterr(pd));
else if (n_dlts == 0 || !dlts)
error("No data link types.");
/*
* If the interface is known to support monitor mode, indicate
* whether these are the data link types available when not in
* monitor mode, if -I wasn't specified, or when in monitor mode,
* when -I was specified (the link-layer types available in
* monitor mode might be different from the ones available when
* not in monitor mode).
*/
if (supports_monitor_mode)
(void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
device,
Iflag ? "when in monitor mode" : "when not in monitor mode");
else
(void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
device);
while (--n_dlts >= 0) {
dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
if (dlt_name != NULL) {
(void) fprintf(stderr, " %s (%s)", dlt_name,
pcap_datalink_val_to_description(dlts[n_dlts]));
/*
* OK, does tcpdump handle that type?
*/
if (lookup_printer(dlts[n_dlts]) == NULL
&& lookup_ndo_printer(dlts[n_dlts]) == NULL)
(void) fprintf(stderr, " (printing not supported)");
putchar('\n');
} else {
(void) fprintf(stderr, " DLT %d (printing not supported)\n",
dlts[n_dlts]);
}
}
free(dlts);
exit(0);
}
/*
* 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"));
break;
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);
}
