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fix(hyprland-ipc): harden fd lifecycle and listener loop

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Hyprland IPC had fd lifecycle risks on failure/shutdown paths and used a
spin-sleep listener model.

I initialized fd state defensively, tightened connect/close/shutdown handling,
moved to blocking read with newline framing, and added RAII-style fd cleanup in
socket1 reply paths.

Signed-off-by: Austin Horstman <khaneliman12@gmail.com>
This commit is contained in:
Austin Horstman
2026-02-09 13:48:28 -06:00
parent fd086d0f33
commit d0363313b8
2 changed files with 101 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
include/modules/hyprland/backend.hpp
View File

@@ -1,5 +1,6 @@
#pragma once
#include <atomic>
#include <filesystem>
#include <list>
#include <mutex>
@@ -43,10 +44,11 @@ class IPC {
std::thread ipcThread_;
std::mutex callbackMutex_;
std::mutex socketMutex_;
util::JsonParser parser_;
std::list<std::pair<std::string, EventHandler*>> callbacks_;
int socketfd_; // the hyprland socket file descriptor
pid_t socketOwnerPid_;
bool running_ = true; // the ipcThread will stop running when this is false
int socketfd_ = -1; // the hyprland socket file descriptor
pid_t socketOwnerPid_ = -1;
std::atomic<bool> running_ = true; // the ipcThread will stop running when this is false
};
}; // namespace waybar::modules::hyprland

111
src/modules/hyprland/backend.cpp
View File

@@ -9,11 +9,35 @@
#include <sys/un.h>
#include <unistd.h>
#include <array>
#include <cerrno>
#include <cstring>
#include <filesystem>
#include <string>
namespace waybar::modules::hyprland {
namespace {
class ScopedFd {
public:
explicit ScopedFd(int fd) : fd_(fd) {}
~ScopedFd() {
if (fd_ != -1) {
close(fd_);
}
}
// ScopedFd is non-copyable
ScopedFd(const ScopedFd&) = delete;
ScopedFd& operator=(const ScopedFd&) = delete;
int get() const { return fd_; }
private:
int fd_;
};
} // namespace
std::filesystem::path IPC::socketFolder_;
std::filesystem::path IPC::getSocketFolder(const char* instanceSig) {
@@ -45,8 +69,8 @@ std::filesystem::path IPC::getSocketFolder(const char* instanceSig) {
IPC::IPC() {
// will start IPC and relay events to parseIPC
ipcThread_ = std::thread([this]() { socketListener(); });
socketOwnerPid_ = getpid();
ipcThread_ = std::thread([this]() { socketListener(); });
}
IPC::~IPC() {
@@ -54,20 +78,21 @@ IPC::~IPC() {
// failed exec()) exits.
if (getpid() != socketOwnerPid_) return;
running_ = false;
running_.store(false, std::memory_order_relaxed);
spdlog::info("Hyprland IPC stopping...");
{
std::lock_guard<std::mutex> lock(socketMutex_);
if (socketfd_ != -1) {
spdlog::trace("Shutting down socket");
if (shutdown(socketfd_, SHUT_RDWR) == -1) {
if (shutdown(socketfd_, SHUT_RDWR) == -1 && errno != ENOTCONN) {
spdlog::error("Hyprland IPC: Couldn't shutdown socket");
}
spdlog::trace("Closing socket");
if (close(socketfd_) == -1) {
spdlog::error("Hyprland IPC: Couldn't close socket");
}
}
if (ipcThread_.joinable()) {
ipcThread_.join();
}
}
IPC& IPC::inst() {
static IPC ipc;
@@ -86,9 +111,9 @@ void IPC::socketListener() {
spdlog::info("Hyprland IPC starting");
struct sockaddr_un addr;
socketfd_ = socket(AF_UNIX, SOCK_STREAM, 0);
const int socketfd = socket(AF_UNIX, SOCK_STREAM, 0);
if (socketfd_ == -1) {
if (socketfd == -1) {
spdlog::error("Hyprland IPC: socketfd failed");
return;
}
@@ -102,27 +127,48 @@ void IPC::socketListener() {
int l = sizeof(struct sockaddr_un);
if (connect(socketfd_, (struct sockaddr*)&addr, l) == -1) {
spdlog::error("Hyprland IPC: Unable to connect?");
if (connect(socketfd, (struct sockaddr*)&addr, l) == -1) {
spdlog::error("Hyprland IPC: Unable to connect? {}", std::strerror(errno));
close(socketfd);
return;
}
auto* file = fdopen(socketfd_, "r");
if (file == nullptr) {
spdlog::error("Hyprland IPC: Couldn't open file descriptor");
return;
{
std::lock_guard<std::mutex> lock(socketMutex_);
socketfd_ = socketfd;
}
while (running_) {
std::string pending;
while (running_.load(std::memory_order_relaxed)) {
std::array<char, 1024> buffer; // Hyprland socket2 events are max 1024 bytes
const ssize_t bytes_read = read(socketfd, buffer.data(), buffer.size());
auto* receivedCharPtr = fgets(buffer.data(), buffer.size(), file);
if (bytes_read == 0) {
if (running_.load(std::memory_order_relaxed)) {
spdlog::warn("Hyprland IPC: Socket closed by peer");
}
break;
}
if (receivedCharPtr == nullptr) {
std::this_thread::sleep_for(std::chrono::milliseconds(1));
if (bytes_read < 0) {
if (errno == EINTR) {
continue;
}
if (!running_.load(std::memory_order_relaxed)) {
break;
}
spdlog::error("Hyprland IPC: read failed: {}", std::strerror(errno));
break;
}
std::string messageReceived(buffer.data());
messageReceived = messageReceived.substr(0, messageReceived.find_first_of('\n'));
pending.append(buffer.data(), static_cast<std::size_t>(bytes_read));
for (auto newline_pos = pending.find('\n'); newline_pos != std::string::npos;
newline_pos = pending.find('\n')) {
std::string messageReceived = pending.substr(0, newline_pos);
pending.erase(0, newline_pos + 1);
if (messageReceived.empty()) {
continue;
}
spdlog::debug("hyprland IPC received {}", messageReceived);
try {
@@ -132,8 +178,16 @@ void IPC::socketListener() {
} catch (...) {
throw;
}
std::this_thread::sleep_for(std::chrono::milliseconds(1));
}
}
{
std::lock_guard<std::mutex> lock(socketMutex_);
if (socketfd_ != -1) {
if (close(socketfd_) == -1) {
spdlog::error("Hyprland IPC: Couldn't close socket");
}
socketfd_ = -1;
}
}
spdlog::debug("Hyprland IPC stopped");
}
@@ -178,9 +232,9 @@ void IPC::unregisterForIPC(EventHandler* ev_handler) {
std::string IPC::getSocket1Reply(const std::string& rq) {
// basically hyprctl
const auto serverSocket = socket(AF_UNIX, SOCK_STREAM, 0);
ScopedFd serverSocket(socket(AF_UNIX, SOCK_STREAM, 0));
if (serverSocket < 0) {
if (serverSocket.get() < 0) {
throw std::runtime_error("Hyprland IPC: Couldn't open a socket (1)");
}
@@ -203,12 +257,13 @@ std::string IPC::getSocket1Reply(const std::string& rq) {
throw std::runtime_error("Hyprland IPC: Couldn't copy socket path (6)");
}
if (connect(serverSocket, reinterpret_cast<sockaddr*>(&serverAddress), sizeof(serverAddress)) <
if (connect(serverSocket.get(), reinterpret_cast<sockaddr*>(&serverAddress),
sizeof(serverAddress)) <
0) {
throw std::runtime_error("Hyprland IPC: Couldn't connect to " + socketPath + ". (3)");
}
auto sizeWritten = write(serverSocket, rq.c_str(), rq.length());
auto sizeWritten = write(serverSocket.get(), rq.c_str(), rq.length());
if (sizeWritten < 0) {
spdlog::error("Hyprland IPC: Couldn't write (4)");
@@ -219,17 +274,15 @@ std::string IPC::getSocket1Reply(const std::string& rq) {
std::string response;
do {
sizeWritten = read(serverSocket, buffer.data(), 8192);
sizeWritten = read(serverSocket.get(), buffer.data(), 8192);
if (sizeWritten < 0) {
spdlog::error("Hyprland IPC: Couldn't read (5)");
close(serverSocket);
return "";
}
response.append(buffer.data(), sizeWritten);
} while (sizeWritten > 0);
close(serverSocket);
return response;
}