Add netsh command to show maps (#476)

Signed-off-by: Dave Thaler <dthaler@microsoft.com>

Co-authored-by: saxena-anurag <43585259+saxena-anurag@users.noreply.github.com>

libs/ebpfnetsh/ebpfnetsh.vcxproj

@@ -164,10 +164,12 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClCompile Include="elf.cpp" />
+    <ClCompile Include="maps.cpp" />
     <ClCompile Include="programs.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="elf.h" />
+    <ClInclude Include="maps.h" />
     <ClInclude Include="programs.h" />
     <ClInclude Include="tokens.h" />
   </ItemGroup>

libs/ebpfnetsh/ebpfnetsh.vcxproj.filters

@@ -25,6 +25,9 @@
     <ClCompile Include="programs.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="maps.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="elf.h">
@@ -36,5 +39,8 @@
     <ClInclude Include="tokens.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="maps.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
-</Project>
+</Project>

libs/ebpfnetsh/maps.cpp

@@ -0,0 +1,82 @@
+// Copyright (c) Microsoft Corporation
+// SPDX-License-Identifier: MIT
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+#include <iostream>
+#include <iomanip>
+#include <netsh.h>
+#include <string>
+#include <vector>
+#include "ebpf_api.h"
+#include "ebpf_windows.h"
+#include "maps.h"
+#include "tokens.h"
+
+static std::string _map_type_names[] = {
+    "Other", "Hash", "Array", "Program array", "Per-CPU hash table", "Per-CPU array", "Hash of maps", "Array of maps"};
+
+static std::string
+_get_map_type_name(ebpf_map_type_t type)
+{
+    int index = (type >= _countof(_map_type_names)) ? 0 : type;
+    return _map_type_names[index];
+}
+
+DWORD
+handle_ebpf_show_maps(
+    LPCWSTR machine, LPWSTR* argv, DWORD current_index, DWORD argc, DWORD flags, LPCVOID data, BOOL* done)
+{
+    ebpf_result_t result;
+
+    UNREFERENCED_PARAMETER(machine);
+    UNREFERENCED_PARAMETER(flags);
+    UNREFERENCED_PARAMETER(data);
+    UNREFERENCED_PARAMETER(done);
+
+    std::cout << "\n";
+    std::cout << "                     Key  Value      Max  Inner\n";
+    std::cout << "          Map Type  Size   Size  Entries  Index\n";
+    std::cout << "==================  ====  =====  =======  =====\n";
+
+    fd_t map_fd = ebpf_fd_invalid;
+    for (;;) {
+        fd_t next_map_fd;
+        result = ebpf_get_next_map(map_fd, &next_map_fd);
+        if (result != EBPF_SUCCESS) {
+            break;
+        }
+
+        if (map_fd != ebpf_fd_invalid) {
+            ebpf_close_fd(map_fd);
+        }
+        map_fd = next_map_fd;
+
+        if (map_fd == ebpf_fd_invalid) {
+            break;
+        }
+
+        ebpf_map_definition_in_file_t map_definition;
+        result = ebpf_map_query_definition(
+            map_fd,
+            &map_definition.size,
+            (uint32_t*)&map_definition.type,
+            &map_definition.key_size,
+            &map_definition.value_size,
+            &map_definition.max_entries,
+            &map_definition.inner_map_idx);
+        if (result != EBPF_SUCCESS) {
+            break;
+        }
+
+        std::cout << std::setw(18) << std::right << _get_map_type_name(map_definition.type) << std::setw(6)
+                  << std::right << map_definition.key_size << std::setw(7) << std::right << map_definition.value_size
+                  << std::setw(9) << std::right << map_definition.max_entries << std::setw(7) << std::right
+                  << map_definition.inner_map_idx << "\n";
+    }
+    if (map_fd != ebpf_fd_invalid) {
+        ebpf_close_fd(map_fd);
+    }
+    return result;
+}

libs/ebpfnetsh/maps.h

@@ -0,0 +1,14 @@
+// Copyright (c) Microsoft Corporation
+// SPDX-License-Identifier: MIT
+#pragma once
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    FN_HANDLE_CMD handle_ebpf_show_maps;
+
+#ifdef __cplusplus
+}
+#endif

tests/end_to_end/netsh_test.cpp

@@ -3,9 +3,15 @@
 
 #include <windows.h>
 #include <netsh.h> // Must be included after windows.h
+#include "bpf.h"
 #include "capture_helper.hpp"
 #include "catch_wrapper.hpp"
 #include "elf.h"
+#pragma warning(push)
+#pragma warning(disable : 4200)
+#include "libbpf.h"
+#pragma warning(pop)
+#include "maps.h"
 #include "programs.h"
 #include "test_helper.hpp"
 
@@ -65,8 +71,6 @@ static std::string
 _run_netsh_command(
     _In_ FN_HANDLE_CMD* command, _In_opt_z_ const wchar_t* arg1, _In_opt_z_ const wchar_t* arg2, _Out_ int* result)
 {
-    _test_helper_end_to_end test_helper;
-
     capture_helper_t capture;
     errno_t error = capture.begin_capture();
     if (error != NO_ERROR) {
@@ -193,6 +197,8 @@ TEST_CASE("show verification bpf.o", "[netsh][verification]")
 
 TEST_CASE("show verification droppacket.o", "[netsh][verification]")
 {
+    _test_helper_libbpf test_helper;
+
     int result;
     std::string output = _run_netsh_command(handle_ebpf_show_verification, L"droppacket.o", L"xdp", &result);
     REQUIRE(result == NO_ERROR);
@@ -206,6 +212,8 @@ TEST_CASE("show verification droppacket.o", "[netsh][verification]")
 
 TEST_CASE("show verification droppacket_unsafe.o", "[netsh][verification]")
 {
+    _test_helper_libbpf test_helper;
+
     int result;
     std::string output = _run_netsh_command(handle_ebpf_show_verification, L"droppacket_unsafe.o", L"xdp", &result);
     REQUIRE(result == ERROR_SUPPRESS_OUTPUT);
@@ -225,13 +233,52 @@ TEST_CASE("show verification droppacket_unsafe.o", "[netsh][verification]")
 
 TEST_CASE("show programs", "[netsh][programs]")
 {
-    int result;
+    _test_helper_libbpf test_helper;
+
+    // Load a program to show.
+    struct bpf_object* object;
+    int program_fd;
+    int result = bpf_prog_load("tail_call.o", BPF_PROG_TYPE_XDP, &object, &program_fd);
+    REQUIRE(result == 0);
+    REQUIRE(object != nullptr);
+    REQUIRE(program_fd != -1);
+
     std::string output = _run_netsh_command(handle_ebpf_show_programs, nullptr, nullptr, &result);
     REQUIRE(result == NO_ERROR);
 
-    // Since we mocked the ioctl, there should be no programs shown.
     REQUIRE(
         output == "\n"
                   "           File Name          Section  Requested Execution Type\n"
-                  "====================  ===============  ========================\n");
+                  "====================  ===============  ========================\n"
+                  "         tail_call.o         xdp_prog                       JIT\n"
+                  "         tail_call.o       xdp_prog/0                       JIT\n");
+
+    bpf_object__close(object);
+}
+
+TEST_CASE("show maps", "[netsh][maps]")
+{
+    _test_helper_end_to_end test_helper;
+
+    // Create maps to show.
+    int outer_map_fd = bpf_create_map(BPF_MAP_TYPE_HASH_OF_MAPS, sizeof(__u32), sizeof(__u32), 2, 0);
+    REQUIRE(outer_map_fd > 0);
+
+    int inner_map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, sizeof(__u32), sizeof(__u32), 1, 0);
+    REQUIRE(inner_map_fd > 0);
+
+    int result;
+    std::string output = _run_netsh_command(handle_ebpf_show_maps, nullptr, nullptr, &result);
+    REQUIRE(result == NO_ERROR);
+
+    REQUIRE(
+        output == "\n"
+                  "                     Key  Value      Max  Inner\n"
+                  "          Map Type  Size   Size  Entries  Index\n"
+                  "==================  ====  =====  =======  =====\n"
+                  "      Hash of maps     4      4        2      0\n"
+                  "             Array     4      4        1      0\n");
+
+    ebpf_close_fd(inner_map_fd); // TODO(issue #287): change to _close(inner_map_fd);
+    ebpf_close_fd(outer_map_fd); // TODO(issue #287): change to _close(outer_map_fd);
 }

tools/netsh/ebpfnetsh.rc

@@ -211,6 +211,14 @@ BEGIN
 \nRemarks: Shows the verifier results of the specified eBPF program.\
 \n"
 
+    HLP_EBPF_SHOW_MAPS  "Shows eBPF maps.\n"
+    HLP_EBPF_SHOW_MAPS_EX "\
+\nUsage: %1!s!\
+\n\
+\nRemarks: Shows all loaded maps.\
+\n"
+
+
 END
 
 #endif    // English (United States) resources

tools/netsh/resource.h

@@ -16,6 +16,8 @@
 #define HLP_EBPF_SHOW_SECTIONS_EX 112
 #define HLP_EBPF_SHOW_VERIFICATION 113
 #define HLP_EBPF_SHOW_VERIFICATION_EX 114
+#define HLP_EBPF_SHOW_MAPS 115
+#define HLP_EBPF_SHOW_MAPS_EX 116
 
 // Next default values for new objects
 //