/*
* For DLT_PRISM_HEADER; like DLT_IEEE802_11, but with an extra header,
* containing information such as radio information, which we
* currently ignore.
*
* If, however, the packet begins with WLANCAP_MAGIC_COOKIE_V1 or
* WLANCAP_MAGIC_COOKIE_V2, it's really DLT_IEEE802_11_RADIO_AVS
* (currently, on Linux, there's no ARPHRD_ type for
* DLT_IEEE802_11_RADIO_AVS, as there is a ARPHRD_IEEE80211_PRISM
* for DLT_PRISM_HEADER, so ARPHRD_IEEE80211_PRISM is used for
* the AVS header, and the first 4 bytes of the header are used to
* indicate whether it's a Prism header or an AVS header).
*/
u_int
prism_if_print(const struct pcap_pkthdr *h, const u_char *p)
{
u_int caplen = h->caplen;
u_int length = h->len;
u_int32_t msgcode;
if (caplen < 4) {
printf("[|802.11]");
return caplen;
}
msgcode = EXTRACT_32BITS(p);
if (msgcode == WLANCAP_MAGIC_COOKIE_V1 ||
msgcode == WLANCAP_MAGIC_COOKIE_V2)
return ieee802_11_avs_radio_print(p, length, caplen);
if (caplen < PRISM_HDR_LEN) {
printf("[|802.11]");
return caplen;
}
return PRISM_HDR_LEN + ieee802_11_print(p + PRISM_HDR_LEN,
length - PRISM_HDR_LEN, caplen - PRISM_HDR_LEN, 0, 0);
}
static u_int
ieee802_11_avs_radio_print(const u_char *p, u_int length, u_int caplen)
{
u_int32_t caphdr_len;
if (caplen < 8) {
printf("[|802.11]");
return caplen;
}
caphdr_len = EXTRACT_32BITS(p + 4);
if (caphdr_len < 8) {
/*
* Yow! The capture header length is claimed not
* to be large enough to include even the version
* cookie or capture header length!
*/
printf("[|802.11]");
return caplen;
}
if (caplen < caphdr_len) {
printf("[|802.11]");
return caplen;
}
return caphdr_len + ieee802_11_print(p + caphdr_len,
length - caphdr_len, caplen - caphdr_len, 0, 0);
}
static u_int ieee802_11_radio_print(struct smartconfig *sc, const u_char * p, u_int length, u_int caplen)
{
#define BIT(n) (1U << n)
#define IS_EXTENDED(__p) \
(EXTRACT_LE_32BITS(__p) & BIT(IEEE80211_RADIOTAP_EXT)) != 0
struct cpack_state cpacker;
const struct ieee80211_radiotap_header *hdr;
uint32_t presentflags;
const uint32_t *presentp;
u_int len;
uint16_t channel = 0;
uint8_t flags;
if (caplen < sizeof(*hdr)) {
return caplen;
}
hdr = (const struct ieee80211_radiotap_header *)p;
len = EXTRACT_LE_16BITS(&hdr->it_len);
if (caplen < len) {
return caplen;
}
cpack_init(&cpacker, (const uint8_t *)hdr, len); /* align against header start */
cpack_advance(&cpacker, sizeof(*hdr)); /* includes the 1st bitmap */
flags = 0;
presentp = &hdr->it_present;
presentflags = EXTRACT_LE_32BITS(presentp);
print_in_radiotap_namespace(sc, &cpacker, &flags, presentflags, 0, &channel);
return len + ieee802_11_print(sc, p + len, length - len, caplen - len, channel);
}
u_int
ieee802_11_if_print(const struct pcap_pkthdr *h, const u_char *p)
{
return ieee802_11_print(p, h->len, h->caplen, 0);
}
static u_int
ieee802_11_radio_print(const u_char *p, u_int length, u_int caplen)
{
#define BITNO_32(x) (((x) >> 16) ? 16 + BITNO_16((x) >> 16) : BITNO_16((x)))
#define BITNO_16(x) (((x) >> 8) ? 8 + BITNO_8((x) >> 8) : BITNO_8((x)))
#define BITNO_8(x) (((x) >> 4) ? 4 + BITNO_4((x) >> 4) : BITNO_4((x)))
#define BITNO_4(x) (((x) >> 2) ? 2 + BITNO_2((x) >> 2) : BITNO_2((x)))
#define BITNO_2(x) (((x) & 2) ? 1 : 0)
#define BIT(n) (1 << n)
#define IS_EXTENDED(__p) \
(EXTRACT_LE_32BITS(__p) & BIT(IEEE80211_RADIOTAP_EXT)) != 0
struct cpack_state cpacker;
struct ieee80211_radiotap_header *hdr;
u_int32_t present, next_present;
u_int32_t *presentp, *last_presentp;
enum ieee80211_radiotap_type bit;
int bit0;
const u_char *iter;
u_int len;
int pad;
if (caplen < sizeof(*hdr)) {
printf("[|802.11]");
return caplen;
}
hdr = (struct ieee80211_radiotap_header *)p;
len = EXTRACT_LE_16BITS(&hdr->it_len);
if (caplen < len) {
printf("[|802.11]");
return caplen;
}
for (last_presentp = &hdr->it_present;
IS_EXTENDED(last_presentp) &&
(u_char*)(last_presentp + 1) <= p + len;
last_presentp++);
/* are there more bitmap extensions than bytes in header? */
if (IS_EXTENDED(last_presentp)) {
printf("[|802.11]");
return caplen;
}
iter = (u_char*)(last_presentp + 1);
if (cpack_init(&cpacker, (u_int8_t*)iter, len - (iter - p)) != 0) {
/* XXX */
printf("[|802.11]");
return caplen;
}
/* Assume no Atheros padding between 802.11 header and body */
pad = 0;
for (bit0 = 0, presentp = &hdr->it_present; presentp <= last_presentp;
presentp++, bit0 += 32) {
for (present = EXTRACT_LE_32BITS(presentp); present;
present = next_present) {
/* clear the least significant bit that is set */
next_present = present & (present - 1);
/* extract the least significant bit that is set */
bit = (enum ieee80211_radiotap_type)
(bit0 + BITNO_32(present ^ next_present));
if (print_radiotap_field(&cpacker, bit, &pad) != 0)
goto out;
}
}
out:
return len + ieee802_11_print(p + len, length - len, caplen - len, pad);
#undef BITNO_32
#undef BITNO_16
#undef BITNO_8
#undef BITNO_4
#undef BITNO_2
#undef BIT
}
