Skip to content

F1: Honour HT-MCS in send_packet (gated by DEVOURER_TX_HT_MCS) #88

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
josephnef merged 1 commit into from
Jun 7, 2026
+18 −0
Merged

F1: Honour HT-MCS in send_packet (gated by DEVOURER_TX_HT_MCS) #88

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 18 additions & 0 deletions src/RtlJaguarDevice.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -71,6 +71,7 @@ bool RtlJaguarDevice::send_packet(const uint8_t *packet, size_t length) {
break;

case IEEE80211_RADIOTAP_MCS: {
u8 mcs_known = iterator.this_arg[0];
u8 mcs_flags = iterator.this_arg[1];

uint8_t mcs_bw_field = mcs_flags & IEEE80211_RADIOTAP_MCS_BW_MASK;
Expand All @@ -87,6 +88,23 @@ bool RtlJaguarDevice::send_packet(const uint8_t *packet, size_t length) {
} else {
sgi = 0;
}

/* DEVOURER_TX_HT_MCS=1: honour the HT MCS index from radiotap byte 2
* and set fixed_rate accordingly. Without this knob the historic
* behaviour kicks in — fixed_rate stays at the MGN_1M default and the
* chip transmits 1 Mbps CCK regardless of the HT-MCS field (see PR
* #80's README: "send_packet only wires fixed_rate from the radiotap
* RATE/VHT fields — never the HT MCS index"). Gated because flipping
* this unconditionally would silently change the regression matrix's
* rate sweeps and the precoder PoC's locked-in 6 Mbps OFDM carrier. */
static const bool ht_mcs_enabled =
std::getenv("DEVOURER_TX_HT_MCS") != nullptr;
if (ht_mcs_enabled && (mcs_known & IEEE80211_RADIOTAP_MCS_HAVE_MCS)) {
uint8_t mcs_index = iterator.this_arg[2];
if (mcs_index <= 31) {
fixed_rate = MGN_MCS0 + mcs_index;
}
}
} break;

case IEEE80211_RADIOTAP_VHT: {
Expand Down
Loading