/*
* Function to decode the layer 2 header in the packet.
* You need to fill out:
* - ctx->l2len
* - ctx->srcaddr
* - ctx->dstaddr
* - ctx->proto
* - ctx->decoded_extra
* Returns: TCPEDIT_ERROR | TCPEDIT_OK | TCPEDIT_WARN
*/
int
dlt_ieee80211_decode(tcpeditdlt_t *ctx, const u_char *packet, const int pktlen)
{
assert(ctx);
assert(packet);
assert(pktlen >= dlt_ieee80211_l2len(ctx, packet, pktlen));
dbgx(3, "Decoding 802.11 packet " COUNTER_SPEC, ctx->tcpedit->runtime.packetnum);
if (! ieee80211_is_data(ctx, packet, pktlen)) {
tcpedit_seterr(ctx->tcpedit, "Packet " COUNTER_SPEC " is not a normal 802.11 data frame",
ctx->tcpedit->runtime.packetnum);
return TCPEDIT_SOFT_ERROR;
}
if (ieee80211_is_encrypted(ctx, packet, pktlen)) {
tcpedit_seterr(ctx->tcpedit, "Packet " COUNTER_SPEC " is encrypted. Unable to decode frame.",
ctx->tcpedit->runtime.packetnum);
return TCPEDIT_SOFT_ERROR;
}
ctx->l2len = dlt_ieee80211_l2len(ctx, packet, pktlen);
memcpy(&(ctx->srcaddr), ieee80211_get_src((ieee80211_hdr_t *)packet), ETHER_ADDR_LEN);
memcpy(&(ctx->dstaddr), ieee80211_get_dst((ieee80211_hdr_t *)packet), ETHER_ADDR_LEN);
ctx->proto = dlt_ieee80211_proto(ctx, packet, pktlen);
return TCPEDIT_OK; /* success */
}
/*
* Function returns the Layer 3 protocol type of the given packet, or TCPEDIT_ERROR on error
* Make sure you return this in host byte order since all the comparisions will be
* against the ETHERTYPE_* values which are oddly in host byte order.
*/
int
dlt_radiotap_proto(tcpeditdlt_t *ctx, const u_char *packet, const int pktlen)
{
int radiolen;
u_char *data;
assert(ctx);
assert(packet);
assert(pktlen > (int)sizeof(radiotap_hdr_t));
radiolen = dlt_radiotap_l2len(ctx, packet, pktlen);
data = dlt_radiotap_get_80211(ctx, packet, pktlen, radiolen);
return dlt_ieee80211_proto(ctx, data, pktlen - radiolen);
}