polybar-dwm/src/polybar-msg.cpp
patrick96 291a4844bc fix(ipc): Crash when sending to multiple instances
In polybar-msg, the connection handle was captured as a reference to a
shared_ptr, but the shared_ptr went out of scope right after.

This probably always caused UB, but was only noticeable for two or more
instances.
2022-10-23 14:19:26 +02:00

295 lines
8.1 KiB
C++

#include <fcntl.h>
#include <unistd.h>
#include <algorithm>
#include <cassert>
#include <cstdlib>
#include <cstring>
#include <deque>
#include "common.hpp"
#include "components/eventloop.hpp"
#include "ipc/decoder.hpp"
#include "ipc/encoder.hpp"
#include "ipc/msg.hpp"
#include "ipc/util.hpp"
#include "modules/ipc.hpp"
#include "utils/actions.hpp"
#include "utils/file.hpp"
using namespace std;
using namespace polybar;
using namespace eventloop;
static const char* exec = nullptr;
static constexpr auto USAGE = "<command=(action|cmd)> <payload> [...]";
static constexpr auto USAGE_HOOK = "hook <module-name> <hook-index>";
void display(const string& msg) {
fprintf(stdout, "%s\n", msg.c_str());
}
void error(const string& msg) {
throw std::runtime_error(msg);
}
void uv_error(int status, int pid, const string& msg) {
fprintf(stderr, "%s: %s (PID: %d)\n", msg.c_str(), uv_strerror(status), pid);
}
void usage(FILE* f, const string& parameters) {
fprintf(f, "Usage: %s [-p pid] %s\n", exec, parameters.c_str());
}
void remove_socket(const string& handle) {
if (unlink(handle.c_str()) == -1) {
error("Could not remove stale ipc channel: "s + strerror(errno));
} else {
display("Removed stale ipc channel: " + handle);
}
}
bool validate_type(const string& type) {
return (type == "action" || type == "cmd" || type == "hook");
}
static vector<string> get_sockets() {
auto sockets = file_util::glob(ipc::get_glob_socket_path());
auto new_end = std::remove_if(sockets.begin(), sockets.end(), [](const auto& path) {
int pid = ipc::get_pid_from_socket(path);
if (pid <= 0) {
return true;
}
if (!file_util::exists("/proc/" + to_string(pid))) {
remove_socket(path);
return true;
}
return false;
});
sockets.erase(new_end, sockets.end());
return sockets;
}
static void on_write(PipeHandle& conn, ipc::decoder& dec, int pid) {
conn.read_start(
[&](const auto& e) {
try {
if (!dec.closed()) {
dec.on_read(reinterpret_cast<const uint8_t*>(e.data), e.len);
}
} catch (const ipc::decoder::error& e) {
conn.close();
}
},
[&]() { conn.close(); },
[&, pid](const auto& e) {
conn.close();
uv_error(e.status, pid, "There was an error while reading polybar's response");
});
}
static void on_connection(PipeHandle& conn, ipc::decoder& dec, int pid, const ipc::type_t type, const string& payload) {
const auto data = ipc::encode(type, payload);
conn.write(
data, [&, pid]() { on_write(conn, dec, pid); },
[&, pid](const auto& e) {
conn.close();
uv_error(e.status, pid, "There was an error while sending the IPC message.");
});
}
static std::pair<ipc::type_t, string> parse_message(deque<string> args) {
// Validate args
const string ipc_type{args.front()};
args.pop_front();
string ipc_payload{args.front()};
args.pop_front();
if (!validate_type(ipc_type)) {
error("\"" + ipc_type + "\" is not a valid message type.");
}
ipc::type_t type = ipc::TYPE_ERR;
/*
* Check hook specific args
*
* The hook type is deprecated. Its contents are translated into a hook action.
*/
if (ipc_type == "hook") {
if (args.size() != 1) {
usage(stderr, USAGE_HOOK);
throw std::runtime_error("Mismatched number of arguments for hook, expected 1, got "s + to_string(args.size()));
} else {
if (ipc_payload.find("module/") == 0) {
ipc_payload.erase(0, strlen("module/"));
}
// Hook commands use 1-indexed hooks but actions use 0-indexed ones
int hook_index = std::stoi(args.front()) - 1;
args.pop_front();
type = to_integral(ipc::v0::ipc_type::ACTION);
ipc_payload =
actions_util::get_action_string(ipc_payload, polybar::modules::ipc_module::EVENT_HOOK, to_string(hook_index));
fprintf(stderr,
"Warning: Using IPC hook commands is deprecated, use the hook action on the ipc module: %s %s \"%s\"\n", exec,
"action", ipc_payload.c_str());
}
}
if (ipc_type == "action") {
type = to_integral(ipc::v0::ipc_type::ACTION);
/**
* Alternatively polybar-msg action <module name> <action> <data>
* is also accepted
*/
if (!args.empty()) {
string name = ipc_payload;
string action = args.front();
args.pop_front();
string data{};
if (!args.empty()) {
data = args.front();
args.pop_front();
}
ipc_payload = actions_util::get_action_string(name, action, data);
}
}
if (ipc_type == "cmd") {
type = to_integral(ipc::v0::ipc_type::CMD);
}
if (!args.empty()) {
error("Too many arguments");
}
assert(type != ipc::TYPE_ERR);
return {type, ipc_payload};
}
int run(int argc, char** argv) {
deque<string> args{argv + 1, argv + argc};
string socket_path;
auto help_pos = find_if(args.begin(), args.end(), [](const string& a) { return a == "-h" || a == "--help"; });
if (help_pos != args.end()) {
usage(stdout, USAGE);
return EXIT_SUCCESS;
}
/* If -p <pid> is passed, check if the process is running and that
* a valid channel socket is available
*/
if (args.size() >= 2 && args[0].compare(0, 2, "-p") == 0) {
auto& pid_string = args[1];
socket_path = ipc::get_socket_path(pid_string);
if (!file_util::exists("/proc/" + pid_string)) {
error("No process with pid " + pid_string);
} else if (!file_util::exists(socket_path)) {
error("No channel available for pid " + pid_string);
}
args.pop_front();
args.pop_front();
}
// If no pid was given, search for all open sockets.
auto sockets = socket_path.empty() ? get_sockets() : vector<string>{socket_path};
// Get availble channel sockets
if (sockets.empty()) {
error("No active ipc channels");
}
if (args.size() < 2) {
usage(stderr, USAGE);
return EXIT_FAILURE;
}
string payload;
ipc::type_t type;
std::tie(type, payload) = parse_message(args);
string type_str = type == to_integral(ipc::v0::ipc_type::ACTION) ? "action" : "command";
bool success = true;
loop loop;
logger null_logger{loglevel::NONE};
/*
* Store all decoders in vector so that they're alive for the whole eventloop.
*/
vector<ipc::decoder> decoders;
for (auto&& channel : sockets) {
int pid = ipc::get_pid_from_socket(channel);
assert(pid > 0);
decoders.emplace_back(
null_logger, [pid, channel, &payload, &type_str, &success](uint8_t, ipc::type_t type, const auto& response) {
switch (type) {
case ipc::TYPE_OK:
printf("Successfully wrote %s '%s' to PID %d\n", type_str.c_str(), payload.c_str(), pid);
break;
case ipc::TYPE_ERR: {
string err_str{response.begin(), response.end()};
fprintf(stderr, "%s: Failed to write %s '%s' to PID %d (reason: %s)\n", exec, type_str.c_str(),
payload.c_str(), pid, err_str.c_str());
success = false;
break;
}
default:
fprintf(stderr, "%s: Got back unrecognized message type %d from PID %d\n", exec, type, pid);
success = false;
break;
}
});
/*
* Index to decoder is captured because reference can be invalidated due to the vector being modified.
*/
auto idx = decoders.size() - 1;
auto conn = loop.handle<PipeHandle>();
conn->connect(
channel,
[&handle = *conn, &decoders, pid, type, payload, channel, idx]() {
on_connection(handle, decoders[idx], pid, type, payload);
},
[&](const auto& e) {
fprintf(stderr, "%s: Failed to connect to '%s' (err: '%s')\n", exec, channel.c_str(), uv_strerror(e.status));
success = false;
});
}
try {
loop.run();
} catch (const exception& e) {
throw std::runtime_error("Uncaught exception in eventloop: "s + e.what());
}
return success ? EXIT_SUCCESS : EXIT_FAILURE;
}
int main(int argc, char** argv) {
exec = argv[0];
try {
return run(argc, argv);
} catch (const std::exception& e) {
fprintf(stderr, "%s: %s\n", exec, e.what());
return EXIT_FAILURE;
}
}