fru/fru_device.cpp

#include "fru_device.hpp"

#include "fru_utils.hpp"

#include <errno.h>
#include <fcntl.h>
#include <linux/i2c.h>
#include <linux/limits.h>
#include <sys/ioctl.h>
#include <unistd.h>

#include <sdbusplus/bus.hpp>
#include <sdbusplus/exception.hpp>

#include <cstdint>
#include <iostream>
#include <string>
#include <vector>

extern "C"
{
#include <i2c/smbus.h>
#include <linux/i2c-dev.h>
}

static constexpr const char* FRUDeviceService = "xyz.openbmc_project.FruDevice";
static constexpr const char* FRUDeviceObjPath =
    "/xyz/openbmc_project/FruDevice";
static constexpr const char* FRUDeviceManagerInterface =
    "xyz.openbmc_project.FruDeviceManager";
struct FileDesc
{
    explicit FileDesc(int fd) : _desc(fd)
    {}

    explicit operator int() const
    {
        return _desc;
    }

    bool operator==(const FileDesc& other) const
    {
        return _desc == other._desc;
    }
    bool operator!=(const FileDesc& other) const
    {
        return _desc != other._desc;
    }
    bool operator==(std::nullptr_t) const
    {
        return _desc == -1;
    }
    bool operator!=(std::nullptr_t) const
    {
        return _desc != -1;
    }

    ~FileDesc()
    {
        if (_desc != -1)
        {
            close(_desc);
        }
    }

    int _desc;
};

// Code reference from
// https://kernel.googlesource.com/pub/scm/utils/i2c-tools/i2c-tools/+/v3.1.2/tools/i2cdetect.c
bool FRUDevice::isValidDevice() const
{
    uint64_t funcs;

    std::string i2cBus = "/dev/i2c-" + std::to_string(bus);

    // Make sure file is closed before any exit path.
    FileDesc file(open(i2cBus.c_str(), O_RDWR | O_CLOEXEC));
    if (static_cast<int>(file) < 0)
    {
        return false;
    }

    if (ioctl(static_cast<int>(file), I2C_FUNCS, &funcs) < 0)
    {
        std::cerr << "Error: Could not get the I2C adapter functionality "
                     "matrix: "
                  << strerror(errno) << '\n';
        return false;
    }
    if (!(funcs & I2C_FUNC_SMBUS_READ_BYTE))
    {
        std::cerr << "Error: Can't use SMBus Read Byte command on this bus"
                  << '\n';
        return false;
    }

    if (ioctl(static_cast<int>(file), I2C_SLAVE, addr) < 0)
    {
        // Valid device if true
        return errno == EBUSY;
    }

    if (i2c_smbus_read_byte(static_cast<int>(file)) < 0)
    {
        return false;
    }

    return true;
}

std::vector<uint8_t> FRUDevice::getFRUContents() const
{
    uint8_t retry = 0;
    std::vector<uint8_t> rawFRU;

    auto systemBus = sdbusplus::bus::new_bus();

    auto method =
        systemBus.new_method_call(FRUDeviceService, FRUDeviceObjPath,
                                  FRUDeviceManagerInterface, "GetRawFru");
    method.append(static_cast<uint16_t>(bus));
    method.append(static_cast<uint8_t>(addr));

    do
    {
        try
        {
            sdbusplus::message_t reply = systemBus.call(method);
            reply.read(rawFRU);
            break;
        }
        catch (const sdbusplus::exception_t& e)
        {
            std::cerr << "GetRawFru call failed on Bus: " << bus
                      << " at address: " << addr << "retrying after 1 second."
                      << e.what() << '\n';
        }
        sleep(1);
    } while (retry++ < 10);

    if (rawFRU.empty())
    {
        std::cerr << "FRU device manager does have this FRU detected. Bus: "
                  << bus << "Address: " << addr << '\n';
    }

    return rawFRU;
}