diff --git a/tools/test/Makefile.am b/tools/test/Makefile.am
index c05654b..1fe35a0 100644
--- a/tools/test/Makefile.am
+++ b/tools/test/Makefile.am
@@ -18,6 +18,7 @@
 check_PROGRAMS = \
 	tools_bt_unittest \
 	tools_lpc_unittest \
+	tools_net_unittest \
 	tools_updater_unittest \
 	tools_helper_unittest
 
@@ -29,6 +30,9 @@
 tools_lpc_unittest_SOURCES = tools_lpc_unittest.cpp
 tools_lpc_unittest_LDADD = $(top_builddir)/tools/libupdater.la
 
+tools_net_unittest_SOURCES = tools_net_unittest.cpp
+tools_net_unittest_LDADD = $(top_builddir)/tools/libupdater.la
+
 tools_updater_unittest_SOURCES = tools_updater_unittest.cpp
 tools_updater_unittest_LDADD = $(top_builddir)/tools/libupdater.la
 
diff --git a/tools/test/tools_net_unittest.cpp b/tools/test/tools_net_unittest.cpp
new file mode 100644
index 0000000..51556ff
--- /dev/null
+++ b/tools/test/tools_net_unittest.cpp
@@ -0,0 +1,230 @@
+#include "data.hpp"
+#include "internal_sys_mock.hpp"
+#include "net.hpp"
+#include "progress_mock.hpp"
+
+#include <cstring>
+#include <ipmiblob/test/blob_interface_mock.hpp>
+
+#include <gtest/gtest.h>
+
+namespace host_tool
+{
+namespace
+{
+
+using namespace std::literals;
+
+using ::testing::_;
+using ::testing::AllOf;
+using ::testing::ContainerEq;
+using ::testing::Field;
+using ::testing::Gt;
+using ::testing::InSequence;
+using ::testing::NotNull;
+using ::testing::Pointee;
+using ::testing::Return;
+using ::testing::SetArgPointee;
+using ::testing::SetErrnoAndReturn;
+using ::testing::StrEq;
+
+class NetHandleTest : public ::testing::Test
+{
+  protected:
+    NetHandleTest() : handler(&blobMock, &progMock, host, port, &sysMock)
+    {
+        sa.sin6_family = AF_INET6;
+        sa.sin6_port = htons(622);
+        sa.sin6_flowinfo = 0;
+        sa.sin6_addr = in6addr_loopback; // ::1
+        sa.sin6_scope_id = 0;
+
+        addr.ai_family = AF_INET6;
+        addr.ai_socktype = SOCK_STREAM;
+        addr.ai_addr = reinterpret_cast<struct sockaddr*>(&sa);
+        addr.ai_addrlen = sizeof(sa);
+        addr.ai_protocol = 0;
+        addr.ai_next = nullptr;
+    }
+
+    void expectOpenFile()
+    {
+        EXPECT_CALL(sysMock, open(StrEq(filePath.c_str()), _))
+            .WillOnce(Return(inFd));
+        EXPECT_CALL(sysMock, close(inFd)).WillOnce(Return(0));
+        EXPECT_CALL(sysMock, getSize(StrEq(filePath.c_str())))
+            .WillOnce(Return(fakeFileSize));
+
+        EXPECT_CALL(progMock, start(fakeFileSize));
+    }
+
+    void expectAddrInfo()
+    {
+        EXPECT_CALL(
+            sysMock,
+            getaddrinfo(StrEq(host), StrEq(port),
+                        AllOf(Field(&addrinfo::ai_flags, AI_NUMERICHOST),
+                              Field(&addrinfo::ai_family, AF_INET),
+                              Field(&addrinfo::ai_socktype, SOCK_STREAM)),
+                        NotNull()))
+            .WillOnce(DoAll(SetArgPointee<3>(&addr), Return(0)));
+        EXPECT_CALL(sysMock, freeaddrinfo(&addr));
+    }
+
+    void expectConnection()
+    {
+        EXPECT_CALL(sysMock, socket(AF_INET6, SOCK_STREAM, 0))
+            .WillOnce(Return(connFd));
+        EXPECT_CALL(sysMock, close(connFd)).WillOnce(Return(0));
+        EXPECT_CALL(sysMock,
+                    connect(connFd, reinterpret_cast<struct sockaddr*>(&sa),
+                            sizeof(sa)))
+            .WillOnce(Return(0));
+    }
+
+    internal::InternalSysMock sysMock;
+    ipmiblob::BlobInterfaceMock blobMock;
+    ProgressMock progMock;
+
+    const std::string host = "::1"s;
+    const std::string port = "622"s;
+
+    struct sockaddr_in6 sa;
+    struct addrinfo addr;
+
+    static constexpr std::uint16_t session = 0xbeef;
+    const std::string filePath = "/asdf"s;
+    static constexpr int inFd = 5;
+    static constexpr int connFd = 7;
+    static constexpr size_t fakeFileSize = 128;
+    static constexpr size_t chunkSize = 16;
+
+    NetDataHandler handler;
+};
+
+TEST_F(NetHandleTest, openFileFail)
+{
+    EXPECT_CALL(sysMock, open(StrEq(filePath.c_str()), _))
+        .WillOnce(SetErrnoAndReturn(EACCES, -1));
+
+    EXPECT_FALSE(handler.sendContents(filePath, session));
+}
+
+TEST_F(NetHandleTest, getSizeFail)
+{
+    EXPECT_CALL(sysMock, open(StrEq(filePath.c_str()), _))
+        .WillOnce(Return(inFd));
+    EXPECT_CALL(sysMock, close(inFd)).WillOnce(Return(0));
+    EXPECT_CALL(sysMock, getSize(StrEq(filePath.c_str()))).WillOnce(Return(0));
+
+    EXPECT_FALSE(handler.sendContents(filePath, session));
+}
+
+TEST_F(NetHandleTest, getaddrinfoFail)
+{
+    expectOpenFile();
+
+    EXPECT_CALL(sysMock,
+                getaddrinfo(StrEq(host), StrEq(port),
+                            AllOf(Field(&addrinfo::ai_flags, AI_NUMERICHOST),
+                                  Field(&addrinfo::ai_family, AF_INET),
+                                  Field(&addrinfo::ai_socktype, SOCK_STREAM)),
+                            NotNull()))
+        .WillOnce(Return(EAI_ADDRFAMILY));
+
+    EXPECT_FALSE(handler.sendContents(filePath, session));
+}
+
+TEST_F(NetHandleTest, connectFail)
+{
+    expectOpenFile();
+    expectAddrInfo();
+
+    EXPECT_CALL(sysMock, socket(AF_INET6, SOCK_STREAM, 0))
+        .WillOnce(Return(connFd));
+    EXPECT_CALL(sysMock, close(connFd)).WillOnce(Return(0));
+    EXPECT_CALL(
+        sysMock,
+        connect(connFd, reinterpret_cast<struct sockaddr*>(&sa), sizeof(sa)))
+        .WillOnce(SetErrnoAndReturn(ECONNREFUSED, -1));
+
+    EXPECT_FALSE(handler.sendContents(filePath, session));
+}
+
+TEST_F(NetHandleTest, sendfileFail)
+{
+    expectOpenFile();
+    expectAddrInfo();
+    expectConnection();
+
+    EXPECT_CALL(sysMock, sendfile(connFd, inFd, Pointee(0), _))
+        .WillOnce(SetErrnoAndReturn(ETIMEDOUT, -1));
+
+    EXPECT_FALSE(handler.sendContents(filePath, session));
+}
+
+TEST_F(NetHandleTest, successOneChunk)
+{
+    expectOpenFile();
+    expectAddrInfo();
+    expectConnection();
+
+    {
+        InSequence seq;
+
+        EXPECT_CALL(sysMock,
+                    sendfile(connFd, inFd, Pointee(0), Gt(fakeFileSize)))
+            .WillOnce(
+                DoAll(SetArgPointee<2>(fakeFileSize), Return(fakeFileSize)));
+        EXPECT_CALL(sysMock, sendfile(connFd, inFd, Pointee(fakeFileSize),
+                                      Gt(fakeFileSize)))
+            .WillOnce(Return(0));
+    }
+
+    struct ipmi_flash::ExtChunkHdr chunk;
+    chunk.length = fakeFileSize;
+    std::vector<std::uint8_t> chunkBytes(sizeof(chunk));
+    std::memcpy(chunkBytes.data(), &chunk, sizeof(chunk));
+    EXPECT_CALL(blobMock, writeBytes(session, 0, ContainerEq(chunkBytes)));
+
+    EXPECT_CALL(progMock, updateProgress(fakeFileSize));
+
+    EXPECT_TRUE(handler.sendContents(filePath, session));
+}
+
+TEST_F(NetHandleTest, successMultiChunk)
+{
+    expectOpenFile();
+    expectAddrInfo();
+    expectConnection();
+
+    struct ipmi_flash::ExtChunkHdr chunk;
+    chunk.length = chunkSize;
+    std::vector<std::uint8_t> chunkBytes(sizeof(chunk));
+    std::memcpy(chunkBytes.data(), &chunk, sizeof(chunk));
+
+    {
+        InSequence seq;
+
+        for (std::uint32_t offset = 0; offset < fakeFileSize;
+             offset += chunkSize)
+        {
+            EXPECT_CALL(sysMock,
+                        sendfile(connFd, inFd, Pointee(offset), Gt(chunkSize)))
+                .WillOnce(DoAll(SetArgPointee<2>(offset + chunkSize),
+                                Return(chunkSize)));
+
+            EXPECT_CALL(blobMock,
+                        writeBytes(session, offset, ContainerEq(chunkBytes)));
+            EXPECT_CALL(progMock, updateProgress(chunkSize));
+        }
+        EXPECT_CALL(sysMock, sendfile(connFd, inFd, Pointee(fakeFileSize),
+                                      Gt(chunkSize)))
+            .WillOnce(Return(0));
+    }
+
+    EXPECT_TRUE(handler.sendContents(filePath, session));
+}
+
+} // namespace
+} // namespace host_tool