Xdp adjust head part1 (#522)

xdp_adjust_head : Part 1

include/ebpf_nethooks.h

@@ -36,6 +36,27 @@ typedef enum _xdp_action
 typedef xdp_action_t
 xdp_hook_t(xdp_md_t* context);
 
+// XDP helper functions.
+#define XDP_EXT_HELPER_FN_BASE 0xFFFF
+
+#ifndef __doxygen
+#define EBPF_HELPER(return_type, name, args) typedef return_type(*name##_t) args
+#endif
+
+/**
+ * @brief Adjust XDP context data pointer.
+ *
+ * @param[in] ctx XDP context.
+ * @param[in] delta Number of bytes to move the data pointer by.
+ *
+ * @retval 0 The operation was successful.
+ * @retval <0 A failure occured.
+ */
+EBPF_HELPER(int, bpf_xdp_adjust_head, (xdp_md_t * ctx, int delta));
+#ifndef __doxygen
+#define bpf_xdp_adjust_head ((bpf_xdp_adjust_head_t)XDP_EXT_HELPER_FN_BASE + 1)
+#endif
+
 // BIND hook
 
 typedef enum _bind_operation

libs/platform/unit/platform_unit_test.cpp

@@ -21,6 +21,7 @@
 #include "ebpf_xdp_program_data.h"
 #include "ebpf_state.h"
 #include "encode_program_info.h"
+#include "net_ebpf_ext_program_info.h"
 
 class _test_helper
 {
@@ -418,7 +419,9 @@ TEST_CASE("program_type_info_stored", "[platform]")
         ebpf_program_info_decode(
             &xdp_program_info, _ebpf_encoded_xdp_program_info_data, sizeof(_ebpf_encoded_xdp_program_info_data)) ==
         EBPF_SUCCESS);
-    REQUIRE(xdp_program_info->count_of_helpers == ebpf_core_helper_functions_count);
+    REQUIRE(
+        xdp_program_info->count_of_helpers ==
+        ebpf_core_helper_functions_count + EBPF_COUNT_OF(_xdp_ebpf_extension_helper_function_prototype));
     REQUIRE(strcmp(xdp_program_info->program_type_descriptor.name, "xdp") == 0);
     ebpf_free(xdp_program_info);
 

libs/platform/user/ebpf_extension_user.c

@@ -47,8 +47,6 @@ ebpf_extension_load(
     ebpf_extension_provider_t** hash_table_find_result = NULL;
     ebpf_extension_client_t* local_extension_client = NULL;
 
-    UNREFERENCED_PARAMETER(extension_changed);
-
     state = ebpf_lock_lock(&_ebpf_provider_table_lock);
 
     if (provider_binding_context == NULL) {
@@ -113,6 +111,10 @@ ebpf_extension_load(
     if (provider_dispatch_table != NULL)
         *provider_dispatch_table = local_extension_provider->provider_dispatch_table;
 
+    // Invoke extension changed on client.
+    if ((extension_changed != NULL) && (provider_data != NULL))
+        extension_changed(extension_client_context, provider_binding_context, *provider_data);
+
 Done:
     if (local_extension_provider && local_extension_client) {
         ebpf_hash_table_delete(

netebpfext/net_ebpf_ext.h

@@ -37,6 +37,8 @@ Environment:
 #include "ebpf_program_types.h"
 #include "ebpf_windows.h"
 
+#include "net_ebpf_ext_program_info.h"
+
 #define NET_EBPF_EXTENSION_NPI_PROVIDER_VERSION 0
 
 //

netebpfext/net_ebpf_ext_program_info.h

@@ -0,0 +1,26 @@
+// Copyright (c) Microsoft Corporation
+// SPDX-License-Identifier: MIT
+
+#include "ebpf_program_types.h"
+#include "ebpf_platform.h"
+#include "ebpf_nethooks.h"
+
+#define XDP_EXT_HELPER_FUNCTION_START EBPF_MAX_GENERAL_HELPER_FUNCTION
+
+// XDP Extension Helper function prototype descriptors.
+static ebpf_helper_function_prototype_t _xdp_ebpf_extension_helper_function_prototype[] = {
+    {XDP_EXT_HELPER_FUNCTION_START + 1,
+     "bpf_xdp_adjust_head",
+     EBPF_RETURN_TYPE_INTEGER,
+     {EBPF_ARGUMENT_TYPE_PTR_TO_CTX, EBPF_ARGUMENT_TYPE_ANYTHING}}};
+
+// XDP Extension program information.
+static ebpf_context_descriptor_t _ebpf_xdp_context_descriptor = {
+    sizeof(xdp_md_t),
+    EBPF_OFFSET_OF(xdp_md_t, data),
+    EBPF_OFFSET_OF(xdp_md_t, data_end),
+    EBPF_OFFSET_OF(xdp_md_t, data_meta)};
+static ebpf_program_info_t _ebpf_xdp_program_info = {
+    {"xdp", &_ebpf_xdp_context_descriptor, {0}},
+    EBPF_COUNT_OF(_xdp_ebpf_extension_helper_function_prototype),
+    _xdp_ebpf_extension_helper_function_prototype};

netebpfext/net_ebpf_ext_xdp.c

@@ -21,14 +21,20 @@ HANDLE _net_ebpf_ext_l2_injection_handle = NULL;
 static ebpf_ext_attach_hook_provider_registration_t* _ebpf_xdp_hook_provider_registration = NULL;
 static ebpf_extension_provider_t* _ebpf_xdp_program_info_provider = NULL;
 
-static ebpf_context_descriptor_t _ebpf_xdp_context_descriptor = {
-    sizeof(xdp_md_t),
-    EBPF_OFFSET_OF(xdp_md_t, data),
-    EBPF_OFFSET_OF(xdp_md_t, data_end),
-    EBPF_OFFSET_OF(xdp_md_t, data_meta)};
-static ebpf_program_info_t _ebpf_xdp_program_info = {{"xdp", &_ebpf_xdp_context_descriptor, {0}}, 0, NULL};
+static int
+_net_ebpf_xdp_adjust_head(xdp_md_t* ctx, int delta)
+{
+    UNREFERENCED_PARAMETER(ctx);
+    UNREFERENCED_PARAMETER(delta);
+    return -1;
+}
 
-static ebpf_program_data_t _ebpf_xdp_program_data = {&_ebpf_xdp_program_info, NULL};
+static const void* _ebpf_xdp_helper_functions[] = {(void*)&_net_ebpf_xdp_adjust_head};
+
+static ebpf_helper_function_addresses_t _ebpf_xdp_helper_function_address_table = {
+    EBPF_COUNT_OF(_ebpf_xdp_helper_functions), (uint64_t*)_ebpf_xdp_helper_functions};
+
+static ebpf_program_data_t _ebpf_xdp_program_data = {&_ebpf_xdp_program_info, &_ebpf_xdp_helper_function_address_table};
 
 static ebpf_extension_data_t _ebpf_xdp_program_info_provider_data = {
     NET_EBPF_EXTENSION_NPI_PROVIDER_VERSION, sizeof(_ebpf_xdp_program_data), &_ebpf_xdp_program_data};

netebpfext/netebpfext.vcxproj

@@ -138,6 +138,7 @@
     <ClInclude Include="net_ebpf_ext.h" />
     <ClInclude Include="net_ebpf_ext_bind.h" />
     <ClInclude Include="net_ebpf_ext_xdp.h" />
+    <ClInclude Include="net_ebpf_ext_program_info.h" />
     <ClInclude Include="ebpf_ext_attach_provider.h" />
     <ClInclude Include="resource.h" />
   </ItemGroup>

netebpfext/netebpfext.vcxproj.filters

@@ -52,6 +52,9 @@
     <ClInclude Include="net_ebpf_ext_xdp.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="net_ebpf_ext_program_info.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
     <ClInclude Include="resource.h">
       <Filter>Header Files</Filter>
     </ClInclude>

tests/end_to_end/end_to_end.cpp

@@ -118,6 +118,12 @@ typedef class _udp_packet
         return _packet.size();
     }
 
+    std::vector<uint8_t>&
+    packet()
+    {
+        return _packet;
+    }
+
     static const ebpf::UDP_HEADER*
     _get_udp_header(_In_ const uint8_t* packet_buffer, ADDRESS_FAMILY address_family)
     {
@@ -1026,7 +1032,60 @@ _xdp_reflect_packet_test(ebpf_execution_type_t execution_type, ADDRESS_FAMILY ad
     }
 }
 
-TEST_CASE("xdp-reflect-v4-jit", "[xdp_tests]") { _xdp_reflect_packet_test(EBPF_EXECUTION_INTERPRET, AF_INET); }
-TEST_CASE("xdp-reflect-v6-jit", "[xdp_tests]") { _xdp_reflect_packet_test(EBPF_EXECUTION_INTERPRET, AF_INET6); }
+static void
+_xdp_encap_reflect_packet_test(ebpf_execution_type_t execution_type, ADDRESS_FAMILY address_family)
+{
+    _test_helper_end_to_end test_helper;
+    single_instance_hook_t hook(EBPF_PROGRAM_TYPE_XDP, EBPF_ATTACH_TYPE_XDP);
+    program_info_provider_t xdp_program_info(EBPF_PROGRAM_TYPE_XDP);
+    program_load_attach_helper_t program_helper(
+        SAMPLE_PATH "reflect_packet.o", EBPF_PROGRAM_TYPE_XDP, "encap_reflect_packet", execution_type, hook);
+
+    // Dummy UDP datagram with fake IP and MAC addresses.
+    udp_packet_t packet(address_family);
+    packet.set_destination_port(ntohs(REFLECTION_TEST_PORT));
+
+    // Dummy context (not used by the eBPF program).
+    xdp_md_helper_t ctx(packet.packet());
+    uint8_t* ip_header = packet.packet().data() + sizeof(ebpf::ETHERNET_HEADER);
+    std::vector<uint8_t> original_ip_datagram(ip_header, packet.packet().data() + packet.packet().size());
+
+    int hook_result;
+    REQUIRE(hook.fire(&ctx, &hook_result) == EBPF_SUCCESS);
+    REQUIRE(hook_result == 3);
+
+    ebpf::ETHERNET_HEADER* ethernet_header = reinterpret_cast<ebpf::ETHERNET_HEADER*>(ctx.data);
+    REQUIRE(memcmp(ethernet_header->Destination, _test_source_mac.data(), sizeof(ethernet_header->Destination)) == 0);
+    REQUIRE(memcmp(ethernet_header->Source, _test_destination_mac.data(), sizeof(ethernet_header->Source)) == 0);
+
+    if (address_family == AF_INET) {
+        ebpf::IPV4_HEADER* ipv4 = reinterpret_cast<ebpf::IPV4_HEADER*>(ethernet_header + 1);
+        REQUIRE(ipv4->SourceAddress == _test_destination_ipv4.s_addr);
+        REQUIRE(ipv4->DestinationAddress == _test_source_ipv4.s_addr);
+        REQUIRE(ipv4->Protocol == IPPROTO_IPV4);
+        uint8_t* inner_ip_header = (uint8_t*)(ipv4 + 1);
+        REQUIRE(memcmp(inner_ip_header, original_ip_datagram.data(), original_ip_datagram.size()) == 0);
+    } else {
+        ebpf::IPV6_HEADER* ipv6 = reinterpret_cast<ebpf::IPV6_HEADER*>(ethernet_header + 1);
+        REQUIRE(memcmp(ipv6->SourceAddress, &_test_destination_ipv6, sizeof(ebpf::ipv6_address_t)) == 0);
+        REQUIRE(memcmp(ipv6->DestinationAddress, &_test_source_ipv6, sizeof(ebpf::ipv6_address_t)) == 0);
+        REQUIRE(ipv6->NextHeader == IPPROTO_IPV6);
+        uint8_t* inner_ip_header = (uint8_t*)(ipv6 + 1);
+        REQUIRE(memcmp(inner_ip_header, original_ip_datagram.data(), original_ip_datagram.size()) == 0);
+    }
+}
+
+TEST_CASE("xdp-reflect-v4-jit", "[xdp_tests]") { _xdp_reflect_packet_test(EBPF_EXECUTION_JIT, AF_INET); }
+TEST_CASE("xdp-reflect-v6-jit", "[xdp_tests]") { _xdp_reflect_packet_test(EBPF_EXECUTION_JIT, AF_INET6); }
 TEST_CASE("xdp-reflect-v4-interpret", "[xdp_tests]") { _xdp_reflect_packet_test(EBPF_EXECUTION_INTERPRET, AF_INET); }
-TEST_CASE("xdp-reflect-v6-interpret", "[xdp_tests]") { _xdp_reflect_packet_test(EBPF_EXECUTION_INTERPRET, AF_INET6); }
+TEST_CASE("xdp-reflect-v6-interpret", "[xdp_tests]") { _xdp_reflect_packet_test(EBPF_EXECUTION_INTERPRET, AF_INET6); }
+TEST_CASE("xdp-encap-reflect-v4-jit", "[xdp_tests]") { _xdp_encap_reflect_packet_test(EBPF_EXECUTION_JIT, AF_INET); }
+TEST_CASE("xdp-encap-reflect-v6-jit", "[xdp_tests]") { _xdp_encap_reflect_packet_test(EBPF_EXECUTION_JIT, AF_INET6); }
+TEST_CASE("xdp-encap-reflect-v4-interpret", "[xdp_tests]")
+{
+    _xdp_encap_reflect_packet_test(EBPF_EXECUTION_INTERPRET, AF_INET);
+}
+TEST_CASE("xdp-encap-reflect-v6-interpret", "[xdp_tests]")
+{
+    _xdp_encap_reflect_packet_test(EBPF_EXECUTION_INTERPRET, AF_INET6);
+}

tests/end_to_end/helpers.h

@@ -8,6 +8,7 @@
 #include "ebpf_nethooks.h"
 #include "ebpf_platform.h"
 #include "ebpf_program_types.h"
+#include "net_ebpf_ext_program_info.h"
 #include "sample_ext_program_info.h"
 
 typedef struct _ebpf_free_memory
@@ -172,14 +173,64 @@ typedef class _single_instance_hook : public _hook_helper
 
 #define TEST_NET_EBPF_EXTENSION_NPI_PROVIDER_VERSION 0
 
-static ebpf_context_descriptor_t _ebpf_xdp_context_descriptor = {
-    sizeof(xdp_md_t),
-    EBPF_OFFSET_OF(xdp_md_t, data),
-    EBPF_OFFSET_OF(xdp_md_t, data_end),
-    EBPF_OFFSET_OF(xdp_md_t, data_meta)};
-static ebpf_program_info_t _ebpf_xdp_program_info = {{"xdp", &_ebpf_xdp_context_descriptor, {0}}, 0, NULL};
+typedef class xdp_md_helper : public xdp_md_t
+{
+  public:
+    xdp_md_helper(std::vector<uint8_t>& packet)
+        : xdp_md_t{packet.data(), packet.data() + packet.size()}, _packet(&packet), _begin(0), _end(packet.size()){};
+    int
+    adjust_head(int delta)
+    {
+        int return_value = 0;
+        if (delta == 0)
+            // Nothing changes.
+            goto Done;
 
-static ebpf_program_data_t _ebpf_xdp_program_data = {&_ebpf_xdp_program_info, NULL};
+        if (delta > 0) {
+            if (_begin + delta > _end) {
+                return_value = -1;
+                goto Done;
+            }
+            _begin += delta;
+        } else {
+            int abs_delta = -delta;
+            if (_begin >= abs_delta)
+                _begin -= abs_delta;
+            else {
+                size_t additional_space_needed = abs_delta - _begin;
+                // Prepend _packet with additional_space_needed count of 0.
+                _packet->insert(_packet->begin(), additional_space_needed, 0);
+                _begin = 0;
+                _end += additional_space_needed;
+            }
+            // Adjust xdp_md data pointers.
+            data = _packet->data();
+            data_end = _packet->data() + _packet->size();
+        }
+    Done:
+        return return_value;
+    }
+
+  private:
+    std::vector<uint8_t>* _packet;
+    size_t _begin;
+    size_t _end;
+} xdp_md_helper_t;
+
+static int
+_test_xdp_adjust_head(xdp_md_t* ctx, int delta)
+{
+    ((xdp_md_helper_t*)ctx)->adjust_head(delta);
+    return 0;
+}
+
+static const void* _test_ebpf_xdp_helper_functions[] = {(void*)&_test_xdp_adjust_head};
+
+static ebpf_helper_function_addresses_t _test_ebpf_xdp_helper_function_address_table = {
+    EBPF_COUNT_OF(_test_ebpf_xdp_helper_functions), (uint64_t*)_test_ebpf_xdp_helper_functions};
+
+static ebpf_program_data_t _ebpf_xdp_program_data = {
+    &_ebpf_xdp_program_info, &_test_ebpf_xdp_helper_function_address_table};
 
 static ebpf_extension_data_t _ebpf_xdp_program_info_provider_data = {
     TEST_NET_EBPF_EXTENSION_NPI_PROVIDER_VERSION, sizeof(_ebpf_xdp_program_data), &_ebpf_xdp_program_data};

tests/end_to_end/mock.cpp

@@ -72,6 +72,9 @@ clean_up_rpc_binding() { return RPC_S_OK; }
 ebpf_result_t
 ebpf_rpc_load_program(ebpf_program_load_info* info, const char** logs, uint32_t* logs_size)
 {
+    // Set the handle of program being verified in thread-local storage.
+    set_program_under_verification(info->program_handle);
+
     // Short circuit rpc call to service lib.
     ebpf_result_t result = ebpf_verify_and_load_program(
         &info->program_type,

tests/libs/util/test_util.vcxproj

@@ -130,7 +130,7 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <AdditionalIncludeDirectories>$(SolutionDir)libs\api_common;$(SolutionDir)libs\execution_context;$(SolutionDir)include;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\sample\ext\inc;$(OutDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(SolutionDir)libs\api_common;$(SolutionDir)libs\execution_context;$(SolutionDir)include;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\sample\ext\inc;$(SolutionDir)\netebpfext;$(OutDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <TreatWarningAsError>true</TreatWarningAsError>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
@@ -149,7 +149,7 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <AdditionalIncludeDirectories>$(SolutionDir)libs\api_common;$(SolutionDir)libs\execution_context;$(SolutionDir)include;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\sample\ext\inc;$(OutDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(SolutionDir)libs\api_common;$(SolutionDir)libs\execution_context;$(SolutionDir)include;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\sample\ext\inc;$(SolutionDir)\netebpfext;$(OutDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <TreatWarningAsError>true</TreatWarningAsError>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>

tests/performance/performance.vcxproj

@@ -125,7 +125,7 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <AdditionalIncludeDirectories>$(SolutionDir)libs\api_common;$(SolutionDir)include;$(SolutionDir)libs\api;$(SolutionDir)libs\ebpfnetsh;$(SolutionDir)tests\libs\util;$(SolutionDir)tests\libs\common;$(OutDir);$(SolutionDir)external\ebpf-verifier\src;$(SolutionDir)libs\service;$(SolutionDir)rpc_interface;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)libs\execution_context;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\sample\ext\inc;$(SolutionDir)external\ubpf\vm;$(SolutionDir)external\ubpf\vm\inc;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(SolutionDir)libs\api_common;$(SolutionDir)include;$(SolutionDir)libs\api;$(SolutionDir)libs\ebpfnetsh;$(SolutionDir)tests\libs\util;$(SolutionDir)tests\libs\common;$(OutDir);$(SolutionDir)external\ebpf-verifier\src;$(SolutionDir)libs\service;$(SolutionDir)rpc_interface;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)libs\execution_context;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\sample\ext\inc;$(SolutionDir)\netebpfext;$(SolutionDir)external\ubpf\vm;$(SolutionDir)external\ubpf\vm\inc;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <TreatWarningAsError>true</TreatWarningAsError>
       <LanguageStandard>stdcpp17</LanguageStandard>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
@@ -144,7 +144,7 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <AdditionalIncludeDirectories>$(SolutionDir)libs\api_common;$(SolutionDir)include;$(SolutionDir)libs\api;$(SolutionDir)libs\ebpfnetsh;$(SolutionDir)tests\libs\util;$(SolutionDir)tests\libs\common;$(OutDir);$(SolutionDir)external\ebpf-verifier\src;$(SolutionDir)libs\service;$(SolutionDir)rpc_interface;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)libs\execution_context;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\sample\ext\inc;$(SolutionDir)external\ubpf\vm;$(SolutionDir)external\ubpf\vm\inc;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(SolutionDir)libs\api_common;$(SolutionDir)include;$(SolutionDir)libs\api;$(SolutionDir)libs\ebpfnetsh;$(SolutionDir)tests\libs\util;$(SolutionDir)tests\libs\common;$(OutDir);$(SolutionDir)external\ebpf-verifier\src;$(SolutionDir)libs\service;$(SolutionDir)rpc_interface;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)libs\execution_context;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\sample\ext\inc;;$(SolutionDir)\netebpfext;$(SolutionDir)external\ubpf\vm;$(SolutionDir)external\ubpf\vm\inc;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <TreatWarningAsError>true</TreatWarningAsError>
       <LanguageStandard>stdcpp17</LanguageStandard>
     </ClCompile>

tests/sample/ebpf.h

@@ -17,6 +17,8 @@ ntohs(uint16_t us)
     return us << 8 | us >> 8;
 }
 
+#define htons(x) ntohs(x)
+
 typedef uint8_t mac_address_t[6];
 
 #define ETHERNET_TYPE_IPV4 0x0800
@@ -34,6 +36,8 @@ typedef struct _ETHERNET_HEADER
 } ETHERNET_HEADER, *PETHERNET_HEADER;
 
 #define IPPROTO_UDP 17
+#define IPPROTO_IPV4 4
+#define IPPROTO_IPV6 41
 
 typedef struct _IPV4_HEADER
 {

tests/sample/ext/app/sample_ext_app.vcxproj

@@ -125,7 +125,7 @@
       <ConformanceMode>true</ConformanceMode>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
-      <AdditionalIncludeDirectories>$(SolutionDir)include;$(SolutionDir)libs\api;$(SolutionDir)libs\execution_context;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)external\ebpf-verifier\src;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\libs\util;$(SolutionDir)tests\libs\common;$(SolutionDir)tests\sample;$(SolutionDir)tests\sample\ext\inc;$(OutDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(SolutionDir)include;$(SolutionDir)libs\api;$(SolutionDir)libs\execution_context;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)external\ebpf-verifier\src;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\libs\util;$(SolutionDir)tests\libs\common;$(SolutionDir)tests\sample;$(SolutionDir)tests\sample\ext\inc;$(SolutionDir)\netebpfext;$(OutDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <LanguageStandard>stdcpplatest</LanguageStandard>
       <TreatWarningAsError>true</TreatWarningAsError>
     </ClCompile>
@@ -142,7 +142,7 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <AdditionalIncludeDirectories>$(SolutionDir)include;$(SolutionDir)libs\api;$(SolutionDir)libs\execution_context;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)external\ebpf-verifier\src;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\libs\util;$(SolutionDir)tests\libs\common;$(SolutionDir)tests\sample;$(SolutionDir)tests\sample\ext\inc;$(OutDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(SolutionDir)include;$(SolutionDir)libs\api;$(SolutionDir)libs\execution_context;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)external\ebpf-verifier\src;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\libs\util;$(SolutionDir)tests\libs\common;$(SolutionDir)tests\sample;$(SolutionDir)tests\sample\ext\inc;$(SolutionDir)\netebpfext;$(OutDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <LanguageStandard>stdcpplatest</LanguageStandard>
       <TreatWarningAsError>true</TreatWarningAsError>
       <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>

tests/sample/reflect_packet.c

@@ -5,20 +5,13 @@
 #include "ebpf.h"
 #include "xdp_tests_common.h"
 
-void
-copy_mac_address(mac_address_t destination, mac_address_t source)
-{
-    for (int i = 0; i < sizeof(mac_address_t); i++)
-        destination[i] = source[i];
-}
-
 void
 swap_mac_addresses(ETHERNET_HEADER* ethernet_header)
 {
     mac_address_t mac = {0};
-    copy_mac_address(mac, ethernet_header->Destination);
-    copy_mac_address(ethernet_header->Destination, ethernet_header->Source);
-    copy_mac_address(ethernet_header->Source, mac);
+    memcpy(mac, ethernet_header->Destination, sizeof(mac_address_t));
+    memcpy(ethernet_header->Destination, ethernet_header->Source, sizeof(mac_address_t));
+    memcpy(ethernet_header->Source, mac, sizeof(mac_address_t));
 }
 
 void
@@ -29,20 +22,13 @@ swap_ipv4_addresses(IPV4_HEADER* ipv4_header)
     ipv4_header->SourceAddress = address;
 }
 
-void
-copy_ipv6_address(ipv6_address_t destination, ipv6_address_t source)
-{
-    for (int i = 0; i < sizeof(ipv6_address_t); i++)
-        destination[i] = source[i];
-}
-
 void
 swap_ipv6_addresses(IPV6_HEADER* ipv6_header)
 {
     ipv6_address_t address = {0};
-    copy_ipv6_address(address, ipv6_header->DestinationAddress);
-    copy_ipv6_address(ipv6_header->DestinationAddress, ipv6_header->SourceAddress);
-    copy_ipv6_address(ipv6_header->SourceAddress, address);
+    memcpy(address, ipv6_header->DestinationAddress, sizeof(ipv6_address_t));
+    memcpy(ipv6_header->DestinationAddress, ipv6_header->SourceAddress, sizeof(ipv6_address_t));
+    memcpy(ipv6_header->SourceAddress, address, sizeof(ipv6_address_t));
 }
 
 //
@@ -50,7 +36,7 @@ swap_ipv6_addresses(IPV6_HEADER* ipv6_header)
 // by swapping the MAC and IP addresses. The program will only work for packets where UDP is the next header
 // for IP header. For instance this will not work for AH packets.
 //
-SEC("xdp")
+SEC("xdp/reflect")
 int
 reflect_packet(xdp_md_t* ctx)
 {
@@ -100,6 +86,166 @@ reflect_packet(xdp_md_t* ctx)
         }
     }
 
+Done:
+    return rc;
+}
+
+int
+encapsulate_ipv4_reflect_packet(xdp_md_t* ctx)
+{
+    int rc = XDP_DROP;
+
+    // Adjust XDP context to allocate space for outer IPv4 header.
+    if (bpf_xdp_adjust_head(ctx, -sizeof(IPV4_HEADER)) < 0)
+        goto Done;
+
+    // The new ethernet header will be at the beginning of the expanded buffer.
+    char* next_header = (char*)ctx->data;
+    if ((char*)next_header + sizeof(ETHERNET_HEADER) > (char*)ctx->data_end)
+        goto Done;
+    ETHERNET_HEADER* new_ethernet_header = (ETHERNET_HEADER*)next_header;
+
+    // The old ethernet header is at an offset sizeof(IPV4_HEADER) from the start of the XDP buffer.
+    next_header = (char*)ctx->data;
+    if ((char*)next_header + sizeof(IPV4_HEADER) > (char*)ctx->data_end)
+        goto Done;
+    next_header = (char*)ctx->data + sizeof(IPV4_HEADER);
+    ETHERNET_HEADER* old_ethernet_header = (ETHERNET_HEADER*)next_header;
+
+    // The outer IPv4 header will be after the new ethernet header.
+    next_header = (char*)(new_ethernet_header + 1);
+    if ((char*)next_header + sizeof(IPV4_HEADER) > (char*)ctx->data_end)
+        goto Done;
+    IPV4_HEADER* outer_ipv4_header = (IPV4_HEADER*)next_header;
+
+    // The inner IPv4 header will be after the old ethernet header.
+    next_header = (char*)(old_ethernet_header + 1);
+    if ((char*)next_header + sizeof(IPV4_HEADER) > (char*)ctx->data_end)
+        goto Done;
+    IPV4_HEADER* inner_ipv4_header = (IPV4_HEADER*)next_header;
+
+    // Copy over the old ethernet header to the new one.
+    memcpy(new_ethernet_header, old_ethernet_header, sizeof(ETHERNET_HEADER));
+    // Swap the MAC addresses.
+    swap_mac_addresses(new_ethernet_header);
+
+    // Copy over the inner IP header to the encap IP header.
+    memcpy(outer_ipv4_header, inner_ipv4_header, sizeof(IPV4_HEADER));
+    // Swap the IP addresses.
+    swap_ipv4_addresses(outer_ipv4_header);
+    // Adjust header fields.
+    outer_ipv4_header->Protocol = IPPROTO_IPV4;
+    outer_ipv4_header->HeaderLength = sizeof(IPV4_HEADER) / sizeof(uint32_t);
+    outer_ipv4_header->TotalLength = htons((ntohs(inner_ipv4_header->TotalLength) + sizeof(IPV4_HEADER)));
+    outer_ipv4_header->HeaderChecksum = 0;
+
+    rc = XDP_TX;
+
+Done:
+    return rc;
+}
+
+int
+encapsulate_ipv6_reflect_packet(xdp_md_t* ctx)
+{
+    int rc = XDP_DROP;
+
+    // Adjust XDP context to allocate space for outer IPv6 header.
+    if (bpf_xdp_adjust_head(ctx, -sizeof(IPV6_HEADER)) < 0)
+        goto Done;
+
+    // The new ethernet header will be at the beginning of the expanded buffer.
+    char* next_header = (char*)ctx->data;
+    if ((char*)next_header + sizeof(ETHERNET_HEADER) > (char*)ctx->data_end)
+        goto Done;
+    ETHERNET_HEADER* new_ethernet_header = (ETHERNET_HEADER*)next_header;
+
+    // The old ethernet header is at an offset sizeof(IPV6_HEADER) from the start of the XDP buffer.
+    next_header = (char*)ctx->data;
+    if ((char*)next_header + sizeof(IPV6_HEADER) > (char*)ctx->data_end)
+        goto Done;
+    next_header = (char*)ctx->data + sizeof(IPV6_HEADER);
+    ETHERNET_HEADER* old_ethernet_header = (ETHERNET_HEADER*)next_header;
+
+    // The outer IPv6 header will be after the new ethernet header.
+    next_header = (char*)(new_ethernet_header + 1);
+    if ((char*)next_header + sizeof(IPV6_HEADER) > (char*)ctx->data_end)
+        goto Done;
+    IPV6_HEADER* outer_ipv6_header = (IPV6_HEADER*)next_header;
+
+    // The inner IPv6 header will be after the old ethernet header.
+    next_header = (char*)(old_ethernet_header + 1);
+    if ((char*)next_header + sizeof(IPV6_HEADER) > (char*)ctx->data_end)
+        goto Done;
+    IPV6_HEADER* inner_ipv6_header = (IPV6_HEADER*)next_header;
+
+    // Copy over the old ethernet header to the new one.
+    memcpy(new_ethernet_header, old_ethernet_header, sizeof(ETHERNET_HEADER));
+    // Swap the MAC addresses.
+    swap_mac_addresses(new_ethernet_header);
+
+    // Copy over the inner IP header to the encap IP header.
+    memcpy(outer_ipv6_header, inner_ipv6_header, sizeof(IPV6_HEADER));
+    // Swap the IP addresses.
+    swap_ipv6_addresses(outer_ipv6_header);
+    // Adjust header fields.
+    outer_ipv6_header->NextHeader = IPPROTO_IPV6;
+    outer_ipv6_header->PayloadLength = htons((ntohs(inner_ipv6_header->PayloadLength) + sizeof(IPV6_HEADER)));
+
+    rc = XDP_TX;
+
+Done:
+    return rc;
+}
+
+//
+// Same as the reflect_packet function, except the reflected packet is encapsulated in a new IP header.
+// The addresses on the outer IP header are the reverse of those on the inner IP header.
+// This program uses the bpf_xdp_adjust_head helper function.
+// (This program can only perform v4 in v4 and v6 in v6 encapsulation.)
+//
+SEC("xdp/encap_reflect")
+int
+encap_reflect_packet(xdp_md_t* ctx)
+{
+    int rc = XDP_PASS;
+
+    ETHERNET_HEADER* ethernet_header = NULL;
+    char* next_header = (char*)ctx->data;
+    if ((char*)next_header + sizeof(ETHERNET_HEADER) > (char*)ctx->data_end)
+        goto Done;
+    ethernet_header = (ETHERNET_HEADER*)next_header;
+    next_header = (char*)(ethernet_header + 1);
+    if (ethernet_header->Type == ntohs(ETHERNET_TYPE_IPV4)) {
+        if ((char*)next_header + sizeof(IPV4_HEADER) > (char*)ctx->data_end)
+            goto Done;
+        // IPv4.
+        IPV4_HEADER* ipv4_header = (IPV4_HEADER*)next_header;
+        next_header = (char*)ipv4_header + sizeof(uint32_t) * ipv4_header->HeaderLength;
+        if (ipv4_header->Protocol == IPPROTO_UDP) {
+            if ((char*)next_header + sizeof(UDP_HEADER) > (char*)ctx->data_end)
+                goto Done;
+            // UDP.
+            UDP_HEADER* udp_header = (UDP_HEADER*)next_header;
+            if (udp_header->destPort == ntohs(REFLECTION_TEST_PORT))
+                rc = encapsulate_ipv4_reflect_packet(ctx);
+        }
+    } else if (ethernet_header->Type == ntohs(ETHERNET_TYPE_IPV6)) {
+        if ((char*)next_header + sizeof(IPV6_HEADER) > (char*)ctx->data_end)
+            goto Done;
+        // IPv6.
+        IPV6_HEADER* ipv6_header = (IPV6_HEADER*)next_header;
+        next_header = (char*)(ipv6_header + 1);
+        if (ipv6_header->NextHeader == IPPROTO_UDP) {
+            if ((char*)next_header + sizeof(UDP_HEADER) > (char*)ctx->data_end)
+                goto Done;
+            // UDP.
+            UDP_HEADER* udp_header = (UDP_HEADER*)next_header;
+            if (udp_header->destPort == ntohs(REFLECTION_TEST_PORT))
+                rc = encapsulate_ipv6_reflect_packet(ctx);
+        }
+    }
+
 Done:
     return rc;
 }

tests/unit/test.vcxproj

@@ -126,7 +126,7 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <AdditionalIncludeDirectories>$(SolutionDir)libs\api_common;$(SolutionDir)include;$(SolutionDir)libs\api;$(SolutionDir)libs\ebpfnetsh;$(SolutionDir)tests\libs\util;$(SolutionDir)tests\libs\common;$(OutDir);$(SolutionDir)external\ebpf-verifier\src;$(SolutionDir)libs\service;$(SolutionDir)rpc_interface;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)libs\execution_context;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\sample;$(SolutionDir)tests\sample\ext\inc;$(SolutionDir)\tests\xdp;$(SolutionDir)tools\encode_program_info;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(SolutionDir)libs\api_common;$(SolutionDir)include;$(SolutionDir)libs\api;$(SolutionDir)libs\ebpfnetsh;$(SolutionDir)tests\libs\util;$(SolutionDir)tests\libs\common;$(OutDir);$(SolutionDir)external\ebpf-verifier\src;$(SolutionDir)libs\service;$(SolutionDir)rpc_interface;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)libs\execution_context;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\sample;$(SolutionDir)tests\sample\ext\inc;$(SolutionDir)\netebpfext;$(SolutionDir)\tests\xdp;$(SolutionDir)tools\encode_program_info;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <TreatWarningAsError>true</TreatWarningAsError>
       <LanguageStandard>stdcpp17</LanguageStandard>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
@@ -146,7 +146,7 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <AdditionalIncludeDirectories>$(SolutionDir)libs\api_common;$(SolutionDir)include;$(SolutionDir)libs\api;$(SolutionDir)libs\ebpfnetsh;$(SolutionDir)tests\libs\util;$(SolutionDir)tests\libs\common;$(OutDir);$(SolutionDir)external\ebpf-verifier\src;$(SolutionDir)libs\service;$(SolutionDir)rpc_interface;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)libs\execution_context;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\sample;$(SolutionDir)tests\sample\ext\inc;$(SolutionDir)\tests\xdp;$(SolutionDir)tools\encode_program_info;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(SolutionDir)libs\api_common;$(SolutionDir)include;$(SolutionDir)libs\api;$(SolutionDir)libs\ebpfnetsh;$(SolutionDir)tests\libs\util;$(SolutionDir)tests\libs\common;$(OutDir);$(SolutionDir)external\ebpf-verifier\src;$(SolutionDir)libs\service;$(SolutionDir)rpc_interface;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)libs\execution_context;$(SolutionDir)tests\end_to_end;$(SolutionDir)tests\sample;$(SolutionDir)tests\sample\ext\inc;$(SolutionDir)\netebpfext;$(SolutionDir)\tests\xdp;$(SolutionDir)tools\encode_program_info;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <TreatWarningAsError>true</TreatWarningAsError>
       <LanguageStandard>stdcpp17</LanguageStandard>
     </ClCompile>

tools/encode_program_info/encode_program_info.cpp

@@ -1,10 +1,12 @@
 // Copyright (c) Microsoft Corporation
 // SPDX-License-Identifier: MIT
-
 #include <stdio.h>
+#include <vector>
+
 #include "ebpf_api.h"
 #include "ebpf_nethooks.h"
 #include "encode_program_info.h"
+#include "net_ebpf_ext_program_info.h"
 
 static ebpf_result_t
 _emit_program_info_file(const char* file_name, const char* symbol_name, uint8_t* buffer, unsigned long buffer_size)
@@ -72,8 +74,16 @@ _encode_xdp()
         EBPF_OFFSET_OF(xdp_md_t, data_meta)};
     ebpf_program_type_descriptor_t xdp_program_type = {"xdp", &xdp_context_descriptor, EBPF_PROGRAM_TYPE_XDP};
     ebpf_program_info_t xdp_program_info = {xdp_program_type, 0, NULL};
-    xdp_program_info.count_of_helpers = ebpf_core_helper_functions_count;
-    xdp_program_info.helper_prototype = ebpf_core_helper_function_prototype;
+    xdp_program_info.count_of_helpers =
+        ebpf_core_helper_functions_count + EBPF_COUNT_OF(_xdp_ebpf_extension_helper_function_prototype);
+    std::vector<ebpf_helper_function_prototype_t> _helper_function_prototypes;
+    _helper_function_prototypes.assign(
+        ebpf_core_helper_function_prototype, ebpf_core_helper_function_prototype + ebpf_core_helper_functions_count);
+    _helper_function_prototypes.insert(
+        _helper_function_prototypes.end(),
+        _xdp_ebpf_extension_helper_function_prototype,
+        _xdp_ebpf_extension_helper_function_prototype + EBPF_COUNT_OF(_xdp_ebpf_extension_helper_function_prototype));
+    xdp_program_info.helper_prototype = _helper_function_prototypes.data();
     return_value = ebpf_program_info_encode(&xdp_program_info, &buffer, &buffer_size);
     if (return_value != EBPF_SUCCESS)
         goto Done;

tools/encode_program_info/encode_program_info.vcxproj

@@ -126,7 +126,7 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <AdditionalIncludeDirectories>$(SolutionDir)include;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)libs\api</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(SolutionDir)include;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)libs\api;$(SolutionDir)\netebpfext</AdditionalIncludeDirectories>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
     </ClCompile>
     <Link>
@@ -153,7 +153,7 @@ $(OutputPath)encode_program_info.exe</Command>
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
-      <AdditionalIncludeDirectories>$(SolutionDir)include;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)libs\api</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(SolutionDir)include;$(SolutionDir)libs\platform;$(SolutionDir)libs\platform\user;$(SolutionDir)libs\api;$(SolutionDir)\netebpfext</AdditionalIncludeDirectories>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>