nat: 1:1 policy NAT

A NAT sub-plugin doing statically configured match/rewrite on IP4 input or output.
It's stateless (no connection tracking).
Currently it supports rewriting of SA, DA and TCP/UDP ports.
It should be simple to add new rewrites if required.

API:
pnat_binding_add, pnat_binding_del, pnat_bindings_get, pnat_interfaces_get

CLI:
set pnat translation interface <name> match <5-tuple> rewrite <5-tuple> {in|out} [del]
show pnat translations
show pnat interfaces

Trying a new C based unit testing scheme. Where the graph node is tested
in isolation. See pnat/pnat_test.c.
Also added new cmake targets to generate coverage directly.
E.g.:
make test_pnat-ccov-report

File '/vpp/sdnat/src/plugins/nat/pnat/pnat.c':
Name                               Regions    Miss   Cover     Lines    Miss   Cover
------------------------------------------------------------------------------------
pnat_interface_by_sw_if_index           39       8  79.49%        13       0 100.00%
pnat_instructions_from_mask              9       0 100.00%        13       0 100.00%
pnat_binding_add                        64       8  87.50%        31       2  93.55%
pnat_flow_lookup                         4       4   0.00%        10      10   0.00%
pnat_binding_attach                    104      75  27.88%        33       6  81.82%
pnat_binding_detach                     30       5  83.33%        23       2  91.30%
pnat_binding_del                        97      33  65.98%        17       3  82.35%
pnat.c:pnat_calc_key_from_5tuple         9       1  88.89%        14       1  92.86%
pnat.c:pnat_interface_check_mask        10       2  80.00%        11       2  81.82%
pnat.c:pnat_enable                       5       0 100.00%        11       0 100.00%
pnat.c:pnat_enable_interface           107      26  75.70%        60      15  75.00%
pnat.c:pnat_disable_interface           91      30  67.03%        32       7  78.12%
pnat.c:pnat_disable                      7       2  71.43%        13       7  46.15%
------------------------------------------------------------------------------------
TOTAL                                  576     194  66.32%       281      55  80.43%

File '/vpp/sdnat/src/plugins/nat/pnat/pnat_node.h':
Name                               Regions    Miss   Cover     Lines    Miss   Cover
------------------------------------------------------------------------------------
pnat_test.c:pnat_node_inline            67      11  83.58%       115       1  99.13%
pnat_test.c:pnat_calc_key                9       2  77.78%        14       2  85.71%
pnat_test.c:pnat_rewrite_ip4            55      11  80.00%        60      12  80.00%
pnat_test.c:format_pnat_trace            1       1   0.00%        12      12   0.00%
pnat_node.c:pnat_node_inline            63      63   0.00%       115     115   0.00%
pnat_node.c:pnat_calc_key                9       9   0.00%        14      14   0.00%
pnat_node.c:pnat_rewrite_ip4            55      55   0.00%        60      60   0.00%
pnat_node.c:format_pnat_trace            5       5   0.00%        12      12   0.00%
------------------------------------------------------------------------------------
TOTAL                                  264     157  40.53%       402     228  43.28%

Type: feature
Change-Id: I9c897f833603054a8303e7369ebff6512517c9e0
Signed-off-by: Ole Troan <ot@cisco.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/src/plugins/nat/CMakeLists.txt b/src/plugins/nat/CMakeLists.txt
index 83c148f9658..d3f3eac3c05 100644
--- a/src/plugins/nat/CMakeLists.txt
+++ b/src/plugins/nat/CMakeLists.txt
@@ -139,3 +139,59 @@ add_vpp_plugin(nat64
 
   LINK_LIBRARIES nat
 )
+
+add_vpp_plugin(pnat
+  SOURCES
+  pnat/pnat.c
+  pnat/pnat_cli.c
+  pnat/pnat_api.c
+  pnat/pnat_node.c
+
+  API_FILES
+  pnat/pnat.api
+)
+
+# Unit tests
+add_vpp_executable(test_pnat
+  SOURCES
+  pnat/pnat_test.c
+  pnat/pnat_node.c
+  pnat/pnat.c
+  ../../vnet/ip/ip_checksum.c
+  LINK_LIBRARIES vppinfra vlib
+  NO_INSTALL
+)
+
+if("${CMAKE_VERSION}" VERSION_GREATER_EQUAL "3.13" AND "${CMAKE_C_COMPILER_ID}" MATCHES "(Apple)?[Cc]lang")
+  set(TARGET_NAME test_pnat)
+  set(COV_SOURCES ${CMAKE_SOURCE_DIR}/plugins/nat/pnat/pnat.c ${CMAKE_SOURCE_DIR}/plugins/nat/pnat/pnat_node.h ${CMAKE_SOURCE_DIR}/plugins/nat/pnat/pnat_node.c)
+
+  message("Building with llvm Code Coverage Tools ${TARGET_NAME}")
+  target_compile_options(${TARGET_NAME} PRIVATE -fprofile-instr-generate -fcoverage-mapping)
+  target_link_options(${TARGET_NAME} PRIVATE -fprofile-instr-generate -fcoverage-mapping)
+  target_compile_options(${TARGET_NAME} PRIVATE -fsanitize=address)
+  target_link_options(${TARGET_NAME} PRIVATE -fsanitize=address)
+
+  # llvm-cov
+  add_custom_target(${TARGET_NAME}-ccov-preprocessing
+    COMMAND LLVM_PROFILE_FILE=${TARGET_NAME}.profraw $<TARGET_FILE:${TARGET_NAME}>
+    COMMAND llvm-profdata merge -sparse ${TARGET_NAME}.profraw -o ${TARGET_NAME}.profdata
+    DEPENDS ${TARGET_NAME})
+
+  add_custom_target(${TARGET_NAME}-ccov-show
+    COMMAND llvm-cov show $<TARGET_FILE:${TARGET_NAME}> -instr-profile=${TARGET_NAME}.profdata -show-line-counts-or-regions ${COV_SOURCES}
+    DEPENDS ${TARGET_NAME}-ccov-preprocessing)
+
+  add_custom_target(${TARGET_NAME}-ccov-report
+    COMMAND llvm-cov report -show-functions $<TARGET_FILE:${TARGET_NAME}> -instr-profile=${TARGET_NAME}.profdata ${COV_SOURCES}
+    DEPENDS ${TARGET_NAME}-ccov-preprocessing)
+
+  add_custom_target(${TARGET_NAME}-ccov
+    COMMAND llvm-cov show $<TARGET_FILE:${TARGET_NAME}> -instr-profile=${TARGET_NAME}.profdata -show-line-counts-or-regions -output-dir=${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${TARGET_NAME}-llvm-cov -format="html" ${COV_SOURCES}
+    DEPENDS ${TARGET_NAME}-ccov-preprocessing)
+
+  add_custom_command(TARGET ${TARGET_NAME}-ccov POST_BUILD
+    COMMAND ;
+    COMMENT "Open ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${TARGET_NAME}-llvm-cov/index.html in your browser to view the coverage report."
+)
+endif()