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OpenRGB/Controllers/LogitechController/LogitechHIDPP20Controller/LogitechHIDPP20Controller_Linux.cpp

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16 KiB
C++

/*---------------------------------------------------------*\
| LogitechHIDPP20Controller_Linux.cpp |
| |
| Linux-specific path-migration and device-name lookup |
| for the unified Logitech HID++ 2.0 controller. |
| |
| Uses sysfs (/sys/class/hidraw) to find the same |
| physical device on a new hidraw path after a USB <-> |
| wireless transition, and to read Centurion sub-device |
| friendly names from HID_NAME uevent fields. |
| |
| This file is part of the OpenRGB project |
| SPDX-License-Identifier: GPL-2.0-or-later |
\*---------------------------------------------------------*/
#include <cstring>
#include <cctype>
#include <cstdio>
#include <chrono>
#include <vector>
#include <string>
#include <fstream>
#include <dirent.h>
#include "LogitechHIDPP20Controller.h"
#include "LogManager.h"
#define LOG_TAG log_tag.c_str()
std::string LogitechHIDPP20Controller::GetCenturionSubDeviceName(const std::string& path)
{
/*--------------------------------------------------------*\
| Centurion sub-device friendly name comes from sysfs |
| HID_NAME=, same field Solaar reads. The `path` arg is a |
| hidraw dev path like /dev/hidraw5; extract the hidrawN |
| basename and read /sys/class/hidraw/<basename>/device/ |
| uevent. |
\*--------------------------------------------------------*/
std::string sysfs_name;
size_t pos = path.rfind("hidraw");
if(pos == std::string::npos)
{
return sysfs_name;
}
std::string uevent_path = "/sys/class/hidraw/" + path.substr(pos) + "/device/uevent";
FILE* f = fopen(uevent_path.c_str(), "r");
if(!f)
{
return sysfs_name;
}
char line[256];
while(fgets(line, sizeof(line), f))
{
if(strncmp(line, "HID_NAME=", 9) == 0)
{
sysfs_name = line + 9;
while(!sysfs_name.empty() && (sysfs_name.back() == '\n' || sysfs_name.back() == '\r'))
{
sysfs_name.pop_back();
}
break;
}
}
fclose(f);
return sysfs_name;
}
bool LogitechHIDPP20Controller::ScanForDevice(bool force)
{
/*---------------------------------------------------------*\
| Scan sysfs for a hidraw with matching unitId. Called by |
| the power thread either periodically (normal reactive |
| mode — only when device_online==false, USB/wireless |
| transition or physical unplug) or on demand from the |
| reader thread after a HID++1.0 Device Connection |
| notification arrives (force=true, bypasses the online |
| gate). Finds the device on its new connection path. |
| |
| Reactive-only: we never migrate while the current path |
| still works. On devices like the G502 X PLUS that expose |
| both a USB-direct hidraw AND a wireless-via-dongle hidraw |
| simultaneously (when paired to the receiver and plugged |
| in at the same time), eager migration would bounce us off |
| a working path onto one the firmware has actively muted, |
| breaking control. The device signals which path is |
| active by returning errors/going silent on the inactive |
| path — our reader thread picks that up as a hid_read |
| failure and flips device_online=false, at which point the |
| power thread calls this function to pick the new path. |
| |
| Linux implementation: walks /sys/class/hidraw and matches |
| on HID_UNIQ. The Windows counterpart (same class method, |
| different .cpp file) uses hid_enumerate + serial_number. |
| |
| Match criteria: |
| - device_online == false (caller should already ensure) |
| - HID_UNIQ matches our unitId |
| - Logitech VID (046D) |
| - HID++ interface (usage_page 0xFF00, usage 2) |
| - Different from our current path (device moved) |
\*---------------------------------------------------------*/
if(caps.unit_id.empty() || caps.unit_id == "00000000")
{
return false;
}
/*---------------------------------------------------------*\
| Online guard: never migrate off a working path unless |
| the caller explicitly forces a re-check. The normal |
| periodic scan path stays gated on device_online==false |
| so it's a no-op when everything is healthy. |
| |
| The reader thread bypasses this guard (force=true) after |
| seeing a HID++1.0 Device Connection Status notification |
| from the Lightspeed receiver, which fires BEFORE the |
| firmware fully switches its data flow from wireless to |
| USB. At that moment device_online is still true (the |
| current path hasn't failed yet), but we want the scan to |
| run so we can migrate to the new path proactively. |
\*---------------------------------------------------------*/
if(!force && device_online.load())
{
return false;
}
/*---------------------------------------------------------*\
| Normalize our unitId to lowercase hex without dashes for |
| comparison. Sysfs HID_UNIQ varies between drivers: |
| - Lightspeed virtual: "0d-12-5d-47" (dashes) |
| - USB direct: "0D125D47" (no dashes) |
| We strip dashes and lowercase both sides for matching. |
\*---------------------------------------------------------*/
std::string target_norm;
for(char c : caps.unit_id)
{
if(c != '-')
{
target_norm += (char)tolower(c);
}
}
/*---------------------------------------------------------*\
| Read our current PID from sysfs. Only migrate to paths |
| with a DIFFERENT PID — same PID means same receiver, |
| just a different pairing slot (e.g., stale pairing). |
\*---------------------------------------------------------*/
unsigned int current_pid = 0;
{
std::string cur_hidraw = location.substr(location.rfind('/') + 1);
std::string cur_uevent = "/sys/class/hidraw/" + cur_hidraw + "/device/uevent";
std::ifstream cur_file(cur_uevent);
std::string line;
while(std::getline(cur_file, line))
{
if(line.compare(0, 7, "HID_ID=") == 0)
{
size_t lc = line.rfind(':');
if(lc != std::string::npos)
{
sscanf(line.c_str() + lc + 1, "%x", &current_pid);
}
break;
}
}
}
/*----------------------------------------------------------*\
| Collect ALL sysfs hidraws with matching unit_id + Logitech |
| VID + different PID. With multiple Lightspeed dongles in |
| the system, several hidraws can share the same HID_UNIQ: |
| one is the live virt-slot on the connected dongle, others |
| are stale virt-slots on dongles where our device is not |
| actually present. We have to probe each one to find out |
| which slot is real — sysfs alone can't tell them apart. |
\*----------------------------------------------------------*/
struct Candidate
{
std::string dev_path;
unsigned int pid;
};
std::vector<Candidate> candidates;
DIR* dir = opendir("/sys/class/hidraw");
if(!dir)
{
return false;
}
struct dirent* entry;
while((entry = readdir(dir)) != nullptr)
{
if(strncmp(entry->d_name, "hidraw", 6) != 0)
{
continue;
}
std::string uevent_path = "/sys/class/hidraw/" +
std::string(entry->d_name) + "/device/uevent";
std::ifstream uevent(uevent_path);
if(!uevent.is_open())
{
continue;
}
std::string line;
std::string hid_uniq;
std::string hid_id;
while(std::getline(uevent, line))
{
if(line.compare(0, 9, "HID_UNIQ=") == 0)
{
hid_uniq = line.substr(9);
}
else if(line.compare(0, 7, "HID_ID=") == 0)
{
hid_id = line.substr(7);
}
}
std::string uniq_norm;
for(char c : hid_uniq)
{
if(c != '-')
{
uniq_norm += (char)tolower(c);
}
}
if(uniq_norm != target_norm)
{
continue;
}
if(hid_id.find("0000046D") == std::string::npos &&
hid_id.find("0000046d") == std::string::npos)
{
continue;
}
std::string dev_path = "/dev/" + std::string(entry->d_name);
if(dev_path == location)
{
continue;
}
size_t last_colon = hid_id.rfind(':');
if(last_colon == std::string::npos)
{
continue;
}
unsigned int pid = 0;
sscanf(hid_id.c_str() + last_colon + 1, "%x", &pid);
if(pid == current_pid)
{
continue;
}
candidates.push_back({dev_path, pid});
}
closedir(dir);
if(candidates.empty())
{
return false;
}
/*----------------------------------------------------------*\
| Probe each candidate before committing. Two-dongle systems |
| can expose multiple sysfs hidraws with the same HID_UNIQ: |
| one is the live slot, others are stale pairings that |
| respond with short-format UNKNOWN_DEVICE errors. Issue a |
| cheap IRoot GetFeature (feat 0x0001) to distinguish them. |
| A live slot returns a long-form response with feat_idx=0 |
| and feat_byte matching the sub-index we asked for. A stale |
| slot returns r[10 xx 8F 00 00 08 ...] (short error, code |
| 0x08 UNKNOWN_DEVICE). We accept the first candidate that |
| passes; the overall pending_path_check retry loop will |
| naturally re-probe all candidates on subsequent scans if |
| none pass on the current pass (e.g., mid-transition). |
\*----------------------------------------------------------*/
std::string found_path;
hid_device* found_dev = nullptr;
for(size_t c = 0; c < candidates.size(); c++)
{
const Candidate& cand = candidates[c];
LOG_DEBUG("%s Scan: migration candidate at %s (pid=0x%04X, current=%s pid=0x%04X)",
LOG_TAG, cand.dev_path.c_str(), cand.pid,
location.c_str(), current_pid);
/*-----------------------------------------------------*\
| Multi-dongle caveat: hid_enumerate returns entries |
| for ALL dongles with this PID (046D:4099 Lightspeed |
| can appear several times in a single machine). Match |
| strictly on the sysfs candidate's dev_path so each |
| candidate resolves to its OWN dongle's HID++ |
| interface — not the first match we stumble across. |
\*-----------------------------------------------------*/
hid_device_info* devs = hid_enumerate(0x046D, (uint16_t)cand.pid);
std::string hidpp20_path;
for(hid_device_info* d = devs; d != nullptr; d = d->next)
{
LOG_TRACE("%s Scan: enumerate PID=0x%04X path=%s page=0x%04X usage=%d",
LOG_TAG, cand.pid, d->path, d->usage_page, d->usage);
if(std::string(d->path) == cand.dev_path &&
d->usage_page == 0xFF00 && d->usage == 2 &&
std::string(d->path) != location)
{
hidpp20_path = d->path;
break;
}
}
hid_free_enumeration(devs);
if(hidpp20_path.empty())
{
LOG_DEBUG("%s Scan: %s no matching LogitechHID++ interface in enum",
LOG_TAG, cand.dev_path.c_str());
continue;
}
hid_device* test_dev = hid_open_path(hidpp20_path.c_str());
if(!test_dev)
{
LOG_DEBUG("%s Scan: %s failed to open", LOG_TAG, hidpp20_path.c_str());
continue;
}
/*------------------------------------------------------*\
| Probe: HID++2.0 IRoot GetFeature for feat 0x0001 |
| (IFeatureSet). Wire: w[10 FF 0000 000100] |
| - report_id 0x10 (short) |
| - device_index 0xFF |
| - feat_idx 0x00 (IRoot) |
| - address 0x00 (func 0 GetFeature, sw_id 0) |
| - payload 00 01 00 (feat_id 0x0001) |
| |
| A live device returns r[11 xx 00 0X ...] — long form, |
| feat_idx 0x00, the address byte we sent back, and the |
| feature index in the payload. |
| A stale slot returns r[10 xx 8F 00 00 08 ...] — short |
| error form. Reject anything that starts with 0x10. |
\*------------------------------------------------------*/
uint8_t probe[7] = {0x10, 0xFF, 0x00, 0x00, 0x00, 0x01, 0x00};
uint8_t reply[20] = {};
int write_rc = hid_write(test_dev, probe, sizeof(probe));
bool probe_ok = false;
if(write_rc >= 0)
{
/*-----------------------------------------------------*\
| Drain up to ~100ms, looking for a long-form response |
| matching our probe. Skip stray reports from unrelated |
| firmware events that might be queued on the hidraw. |
\*-----------------------------------------------------*/
std::chrono::steady_clock::time_point deadline = std::chrono::steady_clock::now() +
std::chrono::milliseconds(100);
while(std::chrono::steady_clock::now() < deadline)
{
int read_rc = hid_read_timeout(test_dev, reply, sizeof(reply), 50);
if(read_rc <= 0)
{
continue;
}
if(reply[0] == 0x11 && reply[2] == 0x00 && reply[3] == 0x00)
{
probe_ok = true;
break;
}
if(reply[0] == 0x10 && reply[2] == 0x8F)
{
LOG_DEBUG("%s Scan: %s probe rejected — err=0x%02X (stale slot)",
LOG_TAG, hidpp20_path.c_str(), reply[5]);
break;
}
}
}
if(!probe_ok)
{
hid_close(test_dev);
continue;
}
LOG_DEBUG("%s Scan: %s probe accepted (feat_idx=0x%02X)",
LOG_TAG, hidpp20_path.c_str(), reply[4]);
found_path = hidpp20_path;
found_dev = test_dev;
break;
}
if(!found_dev)
{
return false;
}
LOG_INFO("%s Device migrated: %s -> %s", LOG_TAG, location.c_str(), found_path.c_str());
SwapHIDHandle(found_dev, found_path);
return true;
}