kcsbridge: Add alternative daemon
This removes the unused signal handling logic and ensures that the main
event loop only drives timeouts from the management channel, and
transitions back to reading when needed.
Change-Id: I01a70de8b301b5ba0b417922fd6a6555433e18b7
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/subprojects/kcsbridge/src/main.cpp b/subprojects/kcsbridge/src/main.cpp
new file mode 100644
index 0000000..8a7114b
--- /dev/null
+++ b/subprojects/kcsbridge/src/main.cpp
@@ -0,0 +1,206 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "args.hpp"
+#include "dbus.hpp"
+
+#include <fmt/format.h>
+#include <linux/ipmi_bmc.h>
+#include <systemd/sd-daemon.h>
+
+#include <sdbusplus/bus.hpp>
+#include <sdbusplus/exception.hpp>
+#include <sdbusplus/server/interface.hpp>
+#include <sdbusplus/vtable.hpp>
+#include <sdeventplus/event.hpp>
+#include <sdeventplus/source/io.hpp>
+#include <sdeventplus/source/signal.hpp>
+#include <stdplus/fd/create.hpp>
+#include <stdplus/fd/ops.hpp>
+#include <stdplus/signal.hpp>
+
+#include <array>
+#include <map>
+#include <stdexcept>
+#include <tuple>
+#include <utility>
+#include <variant>
+
+namespace kcsbridge
+{
+
+using sdbusplus::bus::bus;
+using sdbusplus::message::message;
+using sdeventplus::source::IO;
+using sdeventplus::source::Signal;
+using stdplus::fd::OpenAccess;
+using stdplus::fd::OpenFlag;
+using stdplus::fd::OpenFlags;
+
+void setAttention(message& m, stdplus::Fd& kcs)
+{
+ stdplus::fd::ioctl(kcs, IPMI_BMC_IOCTL_SET_SMS_ATN, nullptr);
+ m.new_method_return().method_return();
+}
+
+void clearAttention(message& m, stdplus::Fd& kcs)
+{
+ stdplus::fd::ioctl(kcs, IPMI_BMC_IOCTL_CLEAR_SMS_ATN, nullptr);
+ m.new_method_return().method_return();
+}
+
+void forceAbort(message& m, stdplus::Fd& kcs)
+{
+ stdplus::fd::ioctl(kcs, IPMI_BMC_IOCTL_FORCE_ABORT, nullptr);
+ m.new_method_return().method_return();
+}
+
+template <typename Data>
+constexpr sdbusplus::vtable::vtable_t dbusMethods[] = {
+ sdbusplus::vtable::start(),
+ sdbusplus::vtable::method("setAttention", "", "",
+ methodRsp<setAttention, Data>),
+ sdbusplus::vtable::method("clearAttention", "", "",
+ methodRsp<clearAttention, Data>),
+ sdbusplus::vtable::method("forceAbort", "", "",
+ methodRsp<forceAbort, Data>),
+ sdbusplus::vtable::end(),
+};
+
+void write(stdplus::Fd& kcs, message&& m)
+{
+ std::array<uint8_t, 1024> buffer;
+ stdplus::span<uint8_t> out(buffer.begin(), 3);
+ try
+ {
+ if (m.is_method_error())
+ {
+ // Extra copy to workaround lack of `const sd_bus_error` constructor
+ auto error = *m.get_error();
+ throw sdbusplus::exception::SdBusError(&error, "ipmid response");
+ }
+ std::tuple<uint8_t, uint8_t, uint8_t, uint8_t, std::vector<uint8_t>>
+ ret;
+ m.read(ret);
+ const auto& [netfn, lun, cmd, cc, data] = ret;
+ // Based on the IPMI KCS spec Figure 9-2
+ // netfn needs to be changed to odd in KCS responses
+ buffer[0] = (netfn | 1) << 2;
+ buffer[0] |= lun;
+ buffer[1] = cmd;
+ buffer[2] = cc;
+ memcpy(&buffer[3], data.data(), data.size());
+ out = stdplus::span<uint8_t>(buffer.begin(), data.size() + 3);
+ }
+ catch (const std::exception& e)
+ {
+ fmt::print(stderr, "IPMI response failure: {}\n", e.what());
+ buffer[0] |= 1 << 2;
+ buffer[2] = 0xff;
+ }
+ stdplus::fd::writeExact(kcs, out);
+}
+
+void read(stdplus::Fd& kcs, bus& bus, ManagedSdBusSlot& slot)
+{
+ std::array<uint8_t, 1024> buffer;
+ auto in = stdplus::fd::read(kcs, buffer);
+ if (in.empty())
+ {
+ return;
+ }
+ if (slot)
+ {
+ fmt::print(stderr, "Canceling outstanding request\n");
+ slot.reset();
+ }
+ if (in.size() < 2)
+ {
+ fmt::print(stderr, "Read too small, ignoring\n");
+ return;
+ }
+ auto m = bus.new_method_call("xyz.openbmc_project.Ipmi.Host",
+ "/xyz/openbmc_project/Ipmi",
+ "xyz.openbmc_project.Ipmi.Server", "execute");
+ std::map<std::string, std::variant<int>> options;
+ // Based on the IPMI KCS spec Figure 9-1
+ uint8_t netfn = in[0] >> 2, lun = in[0] & 3, cmd = in[1];
+ m.append(netfn, lun, cmd, in.subspan(2), options);
+ slot = busCallAsync(std::move(m), [&](message&& m) {
+ slot.reset();
+ write(kcs, std::move(m));
+ });
+}
+
+int execute(const char* channel)
+{
+ // Set up our DBus and event loop
+ auto event = sdeventplus::Event::get_default();
+ auto bus = sdbusplus::bus::new_default();
+ bus.attach_event(event.get(), SD_EVENT_PRIORITY_NORMAL);
+
+ // Configure basic signal handling
+ auto exit_handler = [&](Signal&, const struct signalfd_siginfo*) {
+ fmt::print(stderr, "Interrupted, Exiting\n");
+ event.exit(0);
+ };
+ stdplus::signal::block(SIGINT);
+ Signal sig_int(event, SIGINT, exit_handler);
+ stdplus::signal::block(SIGTERM);
+ Signal sig_term(event, SIGTERM, exit_handler);
+
+ // Open an FD for the KCS channel
+ stdplus::ManagedFd kcs = stdplus::fd::open(
+ fmt::format("/dev/{}", channel),
+ OpenFlags(OpenAccess::ReadWrite).set(OpenFlag::NonBlock));
+ ManagedSdBusSlot slot(std::nullopt);
+
+ // Add a reader to the bus for handling inbound IPMI
+ IO ioSource(event, kcs.get(), EPOLLIN | EPOLLET,
+ [&](IO&, int, uint32_t) { read(kcs, bus, slot); });
+
+ // Allow processes to affect the state machine
+ std::optional<sdbusplus::server::interface::interface> intf;
+ {
+ std::string dbusChannel = channel;
+ std::replace(dbusChannel.begin(), dbusChannel.end(), '-', '_');
+ auto obj = "/xyz/openbmc_project/Ipmi/Channel/" + dbusChannel;
+ auto srv = "com.google.gbmc." + dbusChannel;
+ intf.emplace(bus, obj.c_str(), "xyz.openbmc_project.Ipmi.Channel.SMS",
+ dbusMethods<stdplus::Fd>,
+ reinterpret_cast<stdplus::Fd*>(&kcs));
+ bus.request_name(srv.c_str());
+ }
+
+ sd_notify(0, "READY=1");
+ return event.loop();
+}
+
+} // namespace kcsbridge
+
+int main(int argc, char* argv[])
+{
+ try
+ {
+ kcsbridge::Args args(argc, argv);
+ return kcsbridge::execute(args.channel);
+ }
+ catch (const std::exception& e)
+ {
+ fmt::print(stderr, "FAILED: {}\n", e.what());
+ return 1;
+ }
+}