15 files changed, 1064 insertions, 0 deletions
diff --git a/src/Makefile.am b/src/Makefile.am
new file mode 100644
index 0000000..38a8564
--- /dev/null
+++ b/src/Makefile.am
@@ -0,0 +1,21 @@
+nobase_include_HEADERS =
+pkgconfig_DATA = ipmiblob.pc
+lib_LTLIBRARIES = libipmiblob.la
+libipmiblob_la_SOURCES =
+libipmiblob_la_LIBADD = $(COMMON_LIBS)
+
+# Don't install the crc header.
+libipmiblob_la_SOURCES += ipmiblob/crc.cpp
+
+nobase_include_HEADERS += ipmiblob/blob_interface.hpp
+nobase_include_HEADERS += ipmiblob/blob_handler.hpp
+libipmiblob_la_SOURCES += ipmiblob/blob_handler.cpp
+
+nobase_include_HEADERS += ipmiblob/ipmi_interface.hpp
+nobase_include_HEADERS += ipmiblob/ipmi_handler.hpp
+libipmiblob_la_SOURCES += ipmiblob/ipmi_handler.cpp
+
+nobase_include_HEADERS += ipmiblob/internal/sys.hpp
+libipmiblob_la_SOURCES += ipmiblob/internal/sys.cpp
+
+nobase_include_HEADERS += ipmiblob/test/ipmi_interface_mock.hpp
diff --git a/src/ipmiblob.pc.in b/src/ipmiblob.pc.in
new file mode 100644
index 0000000..2b8dd0f
--- /dev/null
+++ b/src/ipmiblob.pc.in
@@ -0,0 +1,10 @@
+prefix=@prefix@
+exec_prefix=@prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: ipmiblob
+Description: C++ library for talking to BLOB handlers over IPMI
+Version: @VERSION@
+Cflags: -I${includedir}
+Libs: -L${libdir} -lipmiblob
diff --git a/src/ipmiblob/blob_errors.hpp b/src/ipmiblob/blob_errors.hpp
new file mode 100644
index 0000000..45f0e46
--- /dev/null
+++ b/src/ipmiblob/blob_errors.hpp
@@ -0,0 +1,23 @@
+#pragma once
+
+#include <exception>
+#include <string>
+
+namespace host_tool
+{
+
+class BlobException : public std::exception
+{
+  public:
+    explicit BlobException(const std::string& message) : message(message){};
+
+    virtual const char* what() const noexcept override
+    {
+        return message.c_str();
+    }
+
+  private:
+    std::string message;
+};
+
+} // namespace host_tool
diff --git a/src/ipmiblob/blob_handler.cpp b/src/ipmiblob/blob_handler.cpp
new file mode 100644
index 0000000..5be0b2d
--- /dev/null
+++ b/src/ipmiblob/blob_handler.cpp
@@ -0,0 +1,315 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * 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 "blob_handler.hpp"
+
+#include "blob_errors.hpp"
+#include "crc.hpp"
+#include "ipmi_errors.hpp"
+
+#include <array>
+#include <cstring>
+
+namespace host_tool
+{
+
+namespace
+{
+const std::array<std::uint8_t, 3> ipmiPhosphorOen = {0xcf, 0xc2, 0x00};
+}
+
+std::vector<std::uint8_t>
+    BlobHandler::sendIpmiPayload(BlobOEMCommands command,
+                                 const std::vector<std::uint8_t>& payload)
+{
+    std::vector<std::uint8_t> request, reply, bytes;
+
+    std::copy(ipmiPhosphorOen.begin(), ipmiPhosphorOen.end(),
+              std::back_inserter(request));
+    request.push_back(command);
+
+    if (payload.size() > 0)
+    {
+        /* Grow the vector to hold the bytes. */
+        request.reserve(request.size() + sizeof(std::uint16_t));
+
+        /* CRC required. */
+        std::uint16_t crc = generateCrc(payload);
+        auto src = reinterpret_cast<const std::uint8_t*>(&crc);
+
+        std::copy(src, src + sizeof(crc), std::back_inserter(request));
+
+        /* Copy the payload. */
+        std::copy(payload.begin(), payload.end(), std::back_inserter(request));
+    }
+
+    try
+    {
+        reply = ipmi->sendPacket(request);
+    }
+    catch (const IpmiException& e)
+    {
+        throw BlobException(e.what());
+    }
+
+    /* IPMI_CC was OK, and it returned no bytes, so let's be happy with that for
+     * now.
+     */
+    if (reply.size() == 0)
+    {
+        return reply;
+    }
+
+    /* This cannot be a response because it's smaller than the smallest
+     * response.
+     */
+    if (reply.size() < ipmiPhosphorOen.size())
+    {
+        throw BlobException("Invalid response length");
+    }
+
+    /* Verify the OEN. */
+    if (std::memcmp(ipmiPhosphorOen.data(), reply.data(),
+                    ipmiPhosphorOen.size()) != 0)
+    {
+        throw BlobException("Invalid OEN received");
+    }
+
+    /* In this case there was no data, as there was no CRC. */
+    std::size_t headerSize = ipmiPhosphorOen.size() + sizeof(std::uint16_t);
+    if (reply.size() < headerSize)
+    {
+        return {};
+    }
+
+    /* Validate CRC. */
+    std::uint16_t crc;
+    auto ptr = reinterpret_cast<std::uint8_t*>(&crc);
+    std::memcpy(ptr, &reply[ipmiPhosphorOen.size()], sizeof(crc));
+
+    for (const auto& byte : reply)
+    {
+        std::fprintf(stderr, "0x%02x ", byte);
+    }
+    std::fprintf(stderr, "\n");
+
+    bytes.insert(bytes.begin(), reply.begin() + headerSize, reply.end());
+
+    auto computed = generateCrc(bytes);
+    if (crc != computed)
+    {
+        std::fprintf(stderr, "Invalid CRC, received: 0x%x, computed: 0x%x\n",
+                     crc, computed);
+        throw BlobException("Invalid CRC on received data.");
+    }
+
+    return bytes;
+}
+
+int BlobHandler::getBlobCount()
+{
+    std::uint32_t count;
+    try
+    {
+        auto resp = sendIpmiPayload(BlobOEMCommands::bmcBlobGetCount, {});
+        if (resp.size() != sizeof(count))
+        {
+            return 0;
+        }
+
+        /* LE to LE (need to make this portable as some point. */
+        std::memcpy(&count, resp.data(), sizeof(count));
+    }
+    catch (const BlobException& b)
+    {
+        return 0;
+    }
+
+    std::fprintf(stderr, "BLOB Count: %d\n", count);
+    return count;
+}
+
+std::string BlobHandler::enumerateBlob(std::uint32_t index)
+{
+    std::vector<std::uint8_t> payload;
+    auto data = reinterpret_cast<const std::uint8_t*>(&index);
+
+    std::copy(data, data + sizeof(std::uint32_t), std::back_inserter(payload));
+
+    try
+    {
+        auto resp = sendIpmiPayload(BlobOEMCommands::bmcBlobEnumerate, payload);
+        return (resp.size() > 0) ? std::string(&resp[0], &resp[resp.size() - 1])
+                                 : "";
+    }
+    catch (const BlobException& b)
+    {
+        return "";
+    }
+}
+
+void BlobHandler::writeGeneric(BlobOEMCommands command, std::uint16_t session,
+                               std::uint32_t offset,
+                               const std::vector<std::uint8_t>& bytes)
+{
+    std::vector<std::uint8_t> payload;
+
+    payload.reserve(sizeof(std::uint16_t) + sizeof(std::uint32_t) +
+                    bytes.size());
+
+    auto data = reinterpret_cast<const std::uint8_t*>(&session);
+    std::copy(data, data + sizeof(std::uint16_t), std::back_inserter(payload));
+
+    data = reinterpret_cast<const std::uint8_t*>(&offset);
+    std::copy(data, data + sizeof(std::uint32_t), std::back_inserter(payload));
+
+    std::copy(bytes.begin(), bytes.end(), std::back_inserter(payload));
+
+    auto resp = sendIpmiPayload(command, payload);
+}
+
+void BlobHandler::writeMeta(std::uint16_t session, std::uint32_t offset,
+                            const std::vector<std::uint8_t>& bytes)
+{
+    return writeGeneric(BlobOEMCommands::bmcBlobWriteMeta, session, offset,
+                        bytes);
+}
+
+void BlobHandler::writeBytes(std::uint16_t session, std::uint32_t offset,
+                             const std::vector<std::uint8_t>& bytes)
+{
+    return writeGeneric(BlobOEMCommands::bmcBlobWrite, session, offset, bytes);
+}
+
+std::vector<std::string> BlobHandler::getBlobList()
+{
+    std::vector<std::string> list;
+    int blobCount = getBlobCount();
+
+    for (int i = 0; i < blobCount; i++)
+    {
+        auto name = enumerateBlob(i);
+        /* Currently ignore failures. */
+        if (!name.empty())
+        {
+            list.push_back(name);
+        }
+    }
+
+    return list;
+}
+
+StatResponse BlobHandler::getStat(const std::string& id)
+{
+    StatResponse meta;
+    std::vector<std::uint8_t> name, resp;
+
+    std::copy(id.begin(), id.end(), std::back_inserter(name));
+    name.push_back(0x00); /* need to add nul-terminator. */
+
+    try
+    {
+        resp = sendIpmiPayload(BlobOEMCommands::bmcBlobStat, name);
+    }
+    catch (const BlobException& b)
+    {
+        throw;
+    }
+
+    std::memcpy(&meta.blob_state, &resp[0], sizeof(meta.blob_state));
+    std::memcpy(&meta.size, &resp[sizeof(meta.blob_state)], sizeof(meta.size));
+    int offset = sizeof(meta.blob_state) + sizeof(meta.size);
+    std::uint8_t len = resp[offset];
+    if (len > 0)
+    {
+        std::copy(&resp[offset + 1], &resp[resp.size()],
+                  std::back_inserter(meta.metadata));
+    }
+
+    return meta;
+}
+
+std::uint16_t BlobHandler::openBlob(const std::string& id,
+                                    std::uint16_t handlerFlags)
+{
+    std::uint16_t session;
+    std::vector<std::uint8_t> request, resp;
+    auto addrFlags = reinterpret_cast<const std::uint8_t*>(&handlerFlags);
+
+    std::copy(addrFlags, addrFlags + sizeof(handlerFlags),
+              std::back_inserter(request));
+    std::copy(id.begin(), id.end(), std::back_inserter(request));
+    request.push_back(0x00); /* need to add nul-terminator. */
+
+    try
+    {
+        resp = sendIpmiPayload(BlobOEMCommands::bmcBlobOpen, request);
+    }
+    catch (const BlobException& b)
+    {
+        throw;
+    }
+
+    if (resp.size() != sizeof(session))
+    {
+        throw BlobException("Did not receive session.");
+    }
+
+    std::memcpy(&session, resp.data(), sizeof(session));
+    return session;
+}
+
+void BlobHandler::closeBlob(std::uint16_t session)
+{
+    std::vector<std::uint8_t> request;
+    auto addrSession = reinterpret_cast<const std::uint8_t*>(&session);
+    std::copy(addrSession, addrSession + sizeof(session),
+              std::back_inserter(request));
+
+    try
+    {
+        sendIpmiPayload(BlobOEMCommands::bmcBlobClose, request);
+    }
+    catch (const BlobException& b)
+    {
+        std::fprintf(stderr, "Received failure on close: %s\n", b.what());
+    }
+
+    return;
+}
+
+std::vector<std::uint8_t> BlobHandler::readBytes(std::uint16_t session,
+                                                 std::uint32_t offset,
+                                                 std::uint32_t length)
+{
+    std::vector<std::uint8_t> payload;
+
+    payload.reserve(sizeof(std::uint16_t) + sizeof(std::uint32_t) +
+                    sizeof(std::uint32_t));
+
+    auto data = reinterpret_cast<const std::uint8_t*>(&session);
+    std::copy(data, data + sizeof(std::uint16_t), std::back_inserter(payload));
+
+    data = reinterpret_cast<const std::uint8_t*>(&offset);
+    std::copy(data, data + sizeof(std::uint32_t), std::back_inserter(payload));
+
+    data = reinterpret_cast<const std::uint8_t*>(&length);
+    std::copy(data, data + sizeof(std::uint32_t), std::back_inserter(payload));
+
+    return sendIpmiPayload(BlobOEMCommands::bmcBlobRead, payload);
+}
+
+} // namespace host_tool
diff --git a/src/ipmiblob/blob_handler.hpp b/src/ipmiblob/blob_handler.hpp
new file mode 100644
index 0000000..cbac9d4
--- /dev/null
+++ b/src/ipmiblob/blob_handler.hpp
@@ -0,0 +1,108 @@
+#pragma once
+
+#include "blob_interface.hpp"
+#include "ipmi_interface.hpp"
+
+namespace host_tool
+{
+
+class BlobHandler : public BlobInterface
+{
+  public:
+    enum BlobOEMCommands
+    {
+        bmcBlobGetCount = 0,
+        bmcBlobEnumerate = 1,
+        bmcBlobOpen = 2,
+        bmcBlobRead = 3,
+        bmcBlobWrite = 4,
+        bmcBlobCommit = 5,
+        bmcBlobClose = 6,
+        bmcBlobDelete = 7,
+        bmcBlobStat = 8,
+        bmcBlobSessionStat = 9,
+        bmcBlobWriteMeta = 10,
+    };
+
+    explicit BlobHandler(IpmiInterface* ipmi) : ipmi(ipmi){};
+
+    /**
+     * Retrieve the blob count.
+     *
+     * @return the number of blob_ids found (0 on failure).
+     */
+    int getBlobCount();
+
+    /**
+     * Given an index into the list of blobs, return the name.
+     *
+     * @param[in] index - the index into the list of blob ids.
+     * @return the name as a string or empty on failure.
+     */
+    std::string enumerateBlob(std::uint32_t index);
+
+    /**
+     * @throws BlobException.
+     */
+    void writeMeta(std::uint16_t session, std::uint32_t offset,
+                   const std::vector<std::uint8_t>& bytes) override;
+
+    /**
+     * @throw BlobException.
+     */
+    void writeBytes(std::uint16_t session, std::uint32_t offset,
+                    const std::vector<std::uint8_t>& bytes) override;
+
+    std::vector<std::string> getBlobList() override;
+
+    /**
+     * @throws BlobException.
+     */
+    StatResponse getStat(const std::string& id) override;
+
+    /**
+     * @throws BlobException.
+     */
+    std::uint16_t openBlob(const std::string& id,
+                           std::uint16_t handlerFlags) override;
+
+    void closeBlob(std::uint16_t session) override;
+
+    /**
+     * @throws BlobException.
+     */
+    std::vector<std::uint8_t> readBytes(std::uint16_t session,
+                                        std::uint32_t offset,
+                                        std::uint32_t length) override;
+
+  private:
+    /**
+     * Send the contents of the payload to IPMI, this method handles wrapping
+     * with the OEN, subcommand and CRC.
+     *
+     * @param[in] command - the blob command.
+     * @param[in] payload - the payload bytes.
+     * @return the bytes returned from the ipmi interface.
+     * @throws BlobException.
+     */
+    std::vector<std::uint8_t>
+        sendIpmiPayload(BlobOEMCommands command,
+                        const std::vector<std::uint8_t>& payload);
+
+    /**
+     * Generic blob byte writer.
+     *
+     * @param[in] command - the command associated with this write.
+     * @param[in] session - the session id.
+     * @param[in] offset - the offset for the metadata to write.
+     * @param[in] bytes - the bytes to send.
+     * @throws BlobException on failure.
+     */
+    void writeGeneric(BlobOEMCommands command, std::uint16_t session,
+                      std::uint32_t offset,
+                      const std::vector<std::uint8_t>& bytes);
+
+    IpmiInterface* ipmi;
+};
+
+} // namespace host_tool
diff --git a/src/ipmiblob/blob_interface.hpp b/src/ipmiblob/blob_interface.hpp
new file mode 100644
index 0000000..f85be59
--- /dev/null
+++ b/src/ipmiblob/blob_interface.hpp
@@ -0,0 +1,91 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace host_tool
+{
+
+struct StatResponse
+{
+    std::uint16_t blob_state;
+    std::uint32_t size;
+    std::vector<std::uint8_t> metadata;
+};
+
+class BlobInterface
+{
+  public:
+    virtual ~BlobInterface() = default;
+
+    /**
+     * Write metadata to a blob.
+     *
+     * @param[in] session - the session id.
+     * @param[in] offset - the offset for the metadata to write.
+     * @param[in] bytes - the bytes to send.
+     * @throws BlobException on failure.
+     */
+    virtual void writeMeta(std::uint16_t session, std::uint32_t offset,
+                           const std::vector<std::uint8_t>& bytes) = 0;
+
+    /**
+     * Write bytes to a blob.
+     *
+     * @param[in] session - the session id.
+     * @param[in] offset - the offset to which to write the bytes.
+     * @param[in] bytes - the bytes to send.
+     * @throws BlobException on failure.
+     */
+    virtual void writeBytes(std::uint16_t session, std::uint32_t offset,
+                            const std::vector<std::uint8_t>& bytes) = 0;
+
+    /**
+     * Get a list of the blob_ids provided by the BMC.
+     *
+     * @return list of strings, each representing a blob_id returned.
+     */
+    virtual std::vector<std::string> getBlobList() = 0;
+
+    /**
+     * Get the stat() on the blob_id.
+     *
+     * @param[in] id - the blob_id.
+     * @return metadata structure.
+     */
+    virtual StatResponse getStat(const std::string& id) = 0;
+
+    /**
+     * Attempt to open the file using the specific data interface flag.
+     *
+     * @param[in] blob - the blob_id to open.
+     * @param[in] handlerFlags - the data interface flag, if relevant.
+     * @return the session id on success.
+     * @throws BlobException on failure.
+     */
+    virtual std::uint16_t openBlob(const std::string& id,
+                                   std::uint16_t handlerFlags) = 0;
+
+    /**
+     * Attempt to close the open session.
+     *
+     * @param[in] session - the session to close.
+     */
+    virtual void closeBlob(std::uint16_t session) = 0;
+
+    /**
+     * Read bytes from a blob.
+     *
+     * @param[in] session - the session id.
+     * @param[in] offset - the offset to which to write the bytes.
+     * @param[in] length - the number of bytes to read.
+     * @return the bytes read
+     * @throws BlobException on failure.
+     */
+    virtual std::vector<std::uint8_t> readBytes(std::uint16_t session,
+                                                std::uint32_t offset,
+                                                std::uint32_t length) = 0;
+};
+
+} // namespace host_tool
diff --git a/src/ipmiblob/crc.cpp b/src/ipmiblob/crc.cpp
new file mode 100644
index 0000000..d6f59ef
--- /dev/null
+++ b/src/ipmiblob/crc.cpp
@@ -0,0 +1,44 @@
+#include "crc.hpp"
+
+namespace host_tool
+{
+
+/*
+ * This implementation tracks the specification given at
+ * http://srecord.sourceforge.net/crc16-ccitt.html
+ * Code copied from internal portable sources.
+ */
+std::uint16_t generateCrc(const std::vector<std::uint8_t>& data)
+{
+    const std::uint16_t kPoly = 0x1021;
+    const std::uint16_t kLeftBit = 0x8000;
+    const int kExtraRounds = 2;
+    const std::uint8_t* bytes = data.data();
+    std::uint16_t crc = 0xFFFF;
+    std::size_t i;
+    std::size_t j;
+    std::size_t size = data.size();
+
+    for (i = 0; i < size + kExtraRounds; ++i)
+    {
+        for (j = 0; j < 8; ++j)
+        {
+            bool xor_flag = (crc & kLeftBit) ? 1 : 0;
+            crc <<= 1;
+            // If this isn't an extra round and the current byte's j'th bit from
+            // the left is set, increment the CRC.
+            if (i < size && (bytes[i] & (1 << (7 - j))))
+            {
+                crc++;
+            }
+            if (xor_flag)
+            {
+                crc ^= kPoly;
+            }
+        }
+    }
+
+    return crc;
+}
+
+} // namespace host_tool
diff --git a/src/ipmiblob/crc.hpp b/src/ipmiblob/crc.hpp
new file mode 100644
index 0000000..c335ed2
--- /dev/null
+++ b/src/ipmiblob/crc.hpp
@@ -0,0 +1,20 @@
+#pragma once
+
+#include <cstdint>
+#include <vector>
+
+namespace host_tool
+{
+
+/**
+ * Generate the CRC for a payload (really any bytes).
+ *
+ * This is meant to only be called on the payload and not the CRC or the OEM
+ * header, etc.
+ *
+ * @param[in] data - the bytes against to run the CRC
+ * @return the CRC value
+ */
+std::uint16_t generateCrc(const std::vector<std::uint8_t>& data);
+
+} // namespace host_tool
diff --git a/src/ipmiblob/internal/sys.cpp b/src/ipmiblob/internal/sys.cpp
new file mode 100644
index 0000000..46c6642
--- /dev/null
+++ b/src/ipmiblob/internal/sys.cpp
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * 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 "sys.hpp"
+
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+namespace internal
+{
+
+int SysImpl::open(const char* pathname, int flags) const
+{
+    return ::open(pathname, flags);
+}
+
+int SysImpl::read(int fd, void* buf, std::size_t count) const
+{
+    return static_cast<int>(::read(fd, buf, count));
+}
+
+int SysImpl::close(int fd) const
+{
+    return ::close(fd);
+}
+
+void* SysImpl::mmap(void* addr, std::size_t length, int prot, int flags, int fd,
+                    off_t offset) const
+{
+    return ::mmap(addr, length, prot, flags, fd, offset);
+}
+
+int SysImpl::munmap(void* addr, std::size_t length) const
+{
+    return ::munmap(addr, length);
+}
+
+int SysImpl::getpagesize() const
+{
+    return ::getpagesize();
+}
+
+int SysImpl::ioctl(int fd, unsigned long request, void* param) const
+{
+    return ::ioctl(fd, request, param);
+}
+
+int SysImpl::poll(struct pollfd* fds, nfds_t nfds, int timeout) const
+{
+    return ::poll(fds, nfds, timeout);
+}
+
+SysImpl sys_impl;
+
+} // namespace internal
diff --git a/src/ipmiblob/internal/sys.hpp b/src/ipmiblob/internal/sys.hpp
new file mode 100644
index 0000000..2975b8c
--- /dev/null
+++ b/src/ipmiblob/internal/sys.hpp
@@ -0,0 +1,61 @@
+#pragma once
+
+/* NOTE: IIRC, wak@ is working on exposing some of this in stdplus, so we can
+ * transition when that's ready.
+ *
+ * Copied some from gpioplus to enable unit-testing of lpc nuvoton and later
+ * other pieces.
+ */
+
+#include <poll.h>
+#include <sys/mman.h>
+
+#include <cinttypes>
+#include <cstddef>
+
+namespace internal
+{
+
+/**
+ * @class Sys
+ * @brief Overridable direct syscall interface
+ */
+class Sys
+{
+  public:
+    virtual ~Sys() = default;
+
+    virtual int open(const char* pathname, int flags) const = 0;
+    virtual int read(int fd, void* buf, std::size_t count) const = 0;
+    virtual int close(int fd) const = 0;
+    virtual void* mmap(void* addr, std::size_t length, int prot, int flags,
+                       int fd, off_t offset) const = 0;
+    virtual int munmap(void* addr, std::size_t length) const = 0;
+    virtual int getpagesize() const = 0;
+    virtual int ioctl(int fd, unsigned long request, void* param) const = 0;
+    virtual int poll(struct pollfd* fds, nfds_t nfds, int timeout) const = 0;
+};
+
+/**
+ * @class SysImpl
+ * @brief syscall concrete implementation
+ * @details Passes through all calls to the normal linux syscalls
+ */
+class SysImpl : public Sys
+{
+  public:
+    int open(const char* pathname, int flags) const override;
+    int read(int fd, void* buf, std::size_t count) const override;
+    int close(int fd) const override;
+    void* mmap(void* addr, std::size_t length, int prot, int flags, int fd,
+               off_t offset) const override;
+    int munmap(void* addr, std::size_t length) const override;
+    int getpagesize() const override;
+    int ioctl(int fd, unsigned long request, void* param) const override;
+    int poll(struct pollfd* fds, nfds_t nfds, int timeout) const override;
+};
+
+/** @brief Default instantiation of sys */
+extern SysImpl sys_impl;
+
+} // namespace internal
diff --git a/src/ipmiblob/ipmi_errors.hpp b/src/ipmiblob/ipmi_errors.hpp
new file mode 100644
index 0000000..9f1a9f9
--- /dev/null
+++ b/src/ipmiblob/ipmi_errors.hpp
@@ -0,0 +1,47 @@
+#pragma once
+
+#include <exception>
+#include <map>
+#include <sstream>
+#include <string>
+
+namespace host_tool
+{
+
+class IpmiException : public std::exception
+{
+  public:
+    const std::map<int, std::string> commonFailures = {
+        {0xc0, "busy"},
+        {0xc1, "invalid"},
+        {0xc3, "timeout"},
+    };
+
+    explicit IpmiException(int cc)
+    {
+        std::ostringstream smessage;
+
+        auto search = commonFailures.find(cc);
+        if (search != commonFailures.end())
+        {
+            smessage << "Received IPMI_CC: " << search->second;
+        }
+        else
+        {
+            smessage << "Received IPMI_CC: " << cc;
+        }
+
+        message = smessage.str();
+    }
+    explicit IpmiException(const std::string& message) : message(message){};
+
+    virtual const char* what() const noexcept override
+    {
+        return message.c_str();
+    }
+
+  private:
+    std::string message;
+};
+
+} // namespace host_tool
diff --git a/src/ipmiblob/ipmi_handler.cpp b/src/ipmiblob/ipmi_handler.cpp
new file mode 100644
index 0000000..9278338
--- /dev/null
+++ b/src/ipmiblob/ipmi_handler.cpp
@@ -0,0 +1,165 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * 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 "ipmi_handler.hpp"
+
+#include "ipmi_errors.hpp"
+
+#include <fcntl.h>
+#include <linux/ipmi.h>
+#include <linux/ipmi_msgdefs.h>
+#include <sys/ioctl.h>
+
+#include <array>
+#include <cstdint>
+#include <cstring>
+#include <sstream>
+#include <string>
+#include <vector>
+
+namespace host_tool
+{
+
+void IpmiHandler::open()
+{
+    const int device = 0;
+    const std::vector<std::string> formats = {"/dev/ipmi", "/dev/ipmi/",
+                                              "/dev/ipmidev/"};
+
+    for (const auto& format : formats)
+    {
+        std::ostringstream path;
+        path << format << device;
+
+        fd = sys->open(path.str().c_str(), O_RDWR);
+        if (fd < 0)
+        {
+            continue;
+        }
+        break;
+    }
+
+    if (fd < 0)
+    {
+        throw IpmiException("Unable to open any ipmi devices");
+    }
+}
+
+std::vector<std::uint8_t>
+    IpmiHandler::sendPacket(std::vector<std::uint8_t>& data)
+{
+    if (fd < 0)
+    {
+        open();
+    }
+
+    constexpr int ipmiOEMNetFn = 46;
+    constexpr int ipmiOEMLun = 0;
+    /* /openbmc/phosphor-host-ipmid/blob/master/host-ipmid/oemopenbmc.hpp */
+    constexpr int ipmiOEMBlobCmd = 128;
+    constexpr int fifteenMs = 15 * 1000;
+    constexpr int ipmiReadTimeout = fifteenMs;
+    constexpr int ipmiResponseBufferLen = IPMI_MAX_MSG_LENGTH;
+    constexpr int ipmiOk = 0;
+
+    /* We have a handle to the IPMI device. */
+    std::array<std::uint8_t, ipmiResponseBufferLen> responseBuffer;
+
+    /* Build address. */
+    struct ipmi_system_interface_addr systemAddress;
+    systemAddress.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
+    systemAddress.channel = IPMI_BMC_CHANNEL;
+    systemAddress.lun = ipmiOEMLun;
+
+    /* Build request. */
+    struct ipmi_req request;
+    std::memset(&request, 0, sizeof(request));
+    request.addr = reinterpret_cast<unsigned char*>(&systemAddress);
+    request.addr_len = sizeof(systemAddress);
+    request.msgid = sequence++;
+    request.msg.data = reinterpret_cast<unsigned char*>(data.data());
+    request.msg.data_len = data.size();
+    request.msg.netfn = ipmiOEMNetFn;
+    request.msg.cmd = ipmiOEMBlobCmd;
+
+    struct ipmi_recv reply;
+    reply.addr = reinterpret_cast<unsigned char*>(&systemAddress);
+    reply.addr_len = sizeof(systemAddress);
+    reply.msg.data = reinterpret_cast<unsigned char*>(responseBuffer.data());
+    reply.msg.data_len = responseBuffer.size();
+
+    /* Try to send request. */
+    int rc = sys->ioctl(fd, IPMICTL_SEND_COMMAND, &request);
+    if (rc < 0)
+    {
+        throw IpmiException("Unable to send IPMI request.");
+    }
+
+    /* Could use sdeventplus, but for only one type of event is it worth it? */
+    struct pollfd pfd;
+    pfd.fd = fd;
+    pfd.events = POLLIN;
+
+    do
+    {
+        rc = sys->poll(&pfd, 1, ipmiReadTimeout);
+        if (rc < 0)
+        {
+            if (errno == EINTR)
+            {
+                continue;
+            }
+            throw IpmiException("Error occurred.");
+        }
+        else if (rc == 0)
+        {
+            throw IpmiException("Timeout waiting for reply.");
+        }
+
+        /* Yay, happy case! */
+        rc = sys->ioctl(fd, IPMICTL_RECEIVE_MSG_TRUNC, &reply);
+        if (rc < 0)
+        {
+            throw IpmiException("Unable to read reply.");
+        }
+
+        if (request.msgid != reply.msgid)
+        {
+            std::fprintf(stderr, "Received wrong message, trying again.\n");
+        }
+    } while (request.msgid != reply.msgid);
+
+    if (responseBuffer[0] != ipmiOk)
+    {
+        throw IpmiException(static_cast<int>(responseBuffer[0]));
+    }
+
+    std::vector<std::uint8_t> returning;
+    auto dataLen = reply.msg.data_len - 1;
+
+    returning.insert(returning.begin(), responseBuffer.begin() + 1,
+                     responseBuffer.begin() + dataLen + 1);
+
+    for (const auto& byte : returning)
+    {
+        std::fprintf(stderr, "0x%02x ", byte);
+    }
+    std::fprintf(stderr, "\n");
+
+    return returning;
+}
+
+} // namespace host_tool
diff --git a/src/ipmiblob/ipmi_handler.hpp b/src/ipmiblob/ipmi_handler.hpp
new file mode 100644
index 0000000..1c91bff
--- /dev/null
+++ b/src/ipmiblob/ipmi_handler.hpp
@@ -0,0 +1,46 @@
+#pragma once
+
+#include "internal/sys.hpp"
+#include "ipmi_interface.hpp"
+
+#include <vector>
+
+namespace host_tool
+{
+
+class IpmiHandler : public IpmiInterface
+{
+  public:
+    explicit IpmiHandler(const internal::Sys* sys = &internal::sys_impl) :
+        sys(sys){};
+
+    ~IpmiHandler() = default;
+    IpmiHandler(const IpmiHandler&) = delete;
+    IpmiHandler& operator=(const IpmiHandler&) = delete;
+    IpmiHandler(IpmiHandler&&) = default;
+    IpmiHandler& operator=(IpmiHandler&&) = default;
+
+    /**
+     * Attempt to open the device node.
+     *
+     * @throws IpmiException on failure.
+     */
+    void open();
+
+    /**
+     * @throws IpmiException on failure.
+     */
+    std::vector<std::uint8_t>
+        sendPacket(std::vector<std::uint8_t>& data) override;
+
+  private:
+    const internal::Sys* sys;
+    /** TODO: Use a smart file descriptor when it's ready.  Until then only
+     * allow moving this object.
+     */
+    int fd = -1;
+    /* The last IPMI sequence number we used. */
+    int sequence = 0;
+};
+
+} // namespace host_tool
diff --git a/src/ipmiblob/ipmi_interface.hpp b/src/ipmiblob/ipmi_interface.hpp
new file mode 100644
index 0000000..6bad7db
--- /dev/null
+++ b/src/ipmiblob/ipmi_interface.hpp
@@ -0,0 +1,25 @@
+#pragma once
+
+#include <cstdint>
+#include <vector>
+
+namespace host_tool
+{
+
+class IpmiInterface
+{
+  public:
+    virtual ~IpmiInterface() = default;
+
+    /**
+     * Send an IPMI packet to the BMC.
+     *
+     * @param[in] data - a vector of the IPMI packet contents.
+     * @return the bytes returned.
+     * @throws IpmiException on failure.
+     */
+    virtual std::vector<std::uint8_t>
+        sendPacket(std::vector<std::uint8_t>& data) = 0;
+};
+
+} // namespace host_tool
diff --git a/src/ipmiblob/test/ipmi_interface_mock.hpp b/src/ipmiblob/test/ipmi_interface_mock.hpp
new file mode 100644
index 0000000..c3e187e
--- /dev/null
+++ b/src/ipmiblob/test/ipmi_interface_mock.hpp
@@ -0,0 +1,18 @@
+#pragma once
+
+#include <ipmiblob/ipmi_interface.hpp>
+
+#include <gmock/gmock.h>
+
+namespace host_tool
+{
+
+class IpmiInterfaceMock : public IpmiInterface
+{
+  public:
+    virtual ~IpmiInterfaceMock() = default;
+    MOCK_METHOD1(sendPacket,
+                 std::vector<std::uint8_t>(std::vector<std::uint8_t>&));
+};
+
+} // namespace host_tool